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Aljouf

University Science and

Engineering

Journal

Peer-reviewed International Journal

Vol. 2June 2015

AUSEJ ISSN: 1658-6670

Aljouf University Science and Engineering Journal (AUSEJ): 2015; 2(1)

All rights are reserved. No part of this publication may be reproduced, stored in a retrieval

system or transmitted in any form or by any means, electronic, mechanical, photocopying,

recording or otherwise, without prior permission of editors

IN THE NAME OF ALLAH, THE MOST GRACIOUS, THE MOST MERCIFULIN THE NAME OF ALLAH, THE MOST GRACIOUS, THE MOST MERCIFULIN THE NAME OF ALLAH, THE MOST GRACIOUS, THE MOST MERCIFUL

Aljouf University Science and Engineering Journal 2015

ii

Dear professional colleagues, researchers and fellow students:

We are very pleased to introduce the first issue of Aljouf University Science and Engineering Journal (AUSEJ). AUSEJ was established under the generous patronage and leadership of his esteem Prof. Ismail M. Al-Beshry, the Rector of Aljouf University, Aljouf, Sakaka, KSA. Its maturity is an outcome of the consistent support of high-performing authors, a supportive and professional dedicated reviewers, many vigorous and conscientious editorial boards and collective input from the editorial board members. Various researchers who are active in the above field have been

enrolled for providing the necessary impetus for the new journal. We are quite hopeful and shall be grateful to the service that these eminent scientists shall provide to the growth of AUSEJ. We are certain that the renowned scientists and academicians both from the industry and academic institutions all over the world will be enriched by sharing their research experiences through AUSEJ. We are happy to invite you to submit your valuable research works in Aljouf

scientific journals. We strongly believe that our journal will help to develop your own professional career.

Thanks

Editors


iii

Editorial Board

General Supervisor

Najm M. AL-HosainyVice Rector of Aljouf University for Graduate Studies and Scientific ResearchAljouf University, Sakaka, Saudi Arabia

Editor-in-Chief

Alwassil, Abdulaziz Ibrahim; Professor Dept. of Chemistry; College of Science; King Saud UniversityOffice No.: 2A 106 Tel. +966-114675978PO Box 2455, Riyadh 11451, Saudi ArabiaE-mail: [email protected]

Associate Editor-In-Chief

AbdElazim M. Mebed; Associate Prof. Computational Solid State Physics.Faculty of Science, Assiut University, Physics Department, Assiut 71516, Egypt.Current Address:Aljouf University, Physics Department, Faculty of Science , Sakaka 2014, Saudi Arabia.E-mail: [email protected]

EditorsMansour M Alsulaiman; Associate Professor, Computer EngineeringCollege of Computer & Information Sciences (CCIS)King Saud University (KSU)P.O. Box 51178, CCIS, KSU, RIYADH 11543.

Prof.Saleh A. Rabeh; Professor, Aquatic MicrobiologyNational Institute of Oceanography and Fisheries (NIOF)Inland waters and Aquaculture Branch, Egypt.Current Address:Department of Biology, Faculty of Science, Aljouf UniversityAljouf,Sakaka, Saudi Arabia

A. A. Nayl; Associate Professor of Chemistry,Egyptian Atomic Energy Authority, Cairo, Egypt.Current address: Chemistry Department, Faculty of Science, Aljouf University, Sakaka, Saudi Arabia.

Ould Ahmed Mahmoud Sid Ahmed; Associate ProfessorFunctional Analysis and Operator TheoryMathematics Department. Faculty of Science. Aljouf UniversitySakaka 2014 – Aljouf, Saudi Arabia.

Idrees Solaiman Ali Al-kofahi; Associate Professor, Microelectronics EngineeringElectrical Engineering Dept., College of Engineering, Aljouf University, Saudi Arabia.


iv

Advisory Board

Henri Jean Dumont; ProfessorDepartment of Biology, Ghent University, B-9000 Ghent (Belgium)E mail: [email protected]

Institute of Hydrobiology, Jinan University, 510632 Guangzhou, China.

Mahmoud M. Sakr; ProfessorPresident of Academy of Scientific Research & Technology (ASRT)Biotechnology Project Officer, STDF, Egypt101 Kasr Al-Eini, Cairo, Egypt.E-mail: [email protected], [email protected]

Focus and Scope

With its vision to promote science and scientific knowledge to everybody, Aljouf Science andEngineering Journal (ASEJ) is an international peer-reviewed journal owned by Aljouf Universitywith a focused aim of promoting and publishing original high quality research papers dealing withbasic and engineering science. ASEJ publishes rigorous and original contributions in the Sciencedisciplines of

Physics Engineering, All Fields Applied BiologyChemistry Mathematics & Statistics PhysiologyBiochemistry Computer Science Plant BiologyBiological Sciences Genomics Population BiologyBiophysics Geology Food & Food TechnologyPetroleum & Gas Environment RoboticsCell Biology Solid State Technology Signal TransductionParasitological Science Communication & IT Space ScienceDevelopmental Biology Microbiology EnergyGenetics Zoology Textile Industry & FabricsConstruction Nanotechnology Toxicology

The papers published in Aljouf Science and Engineering Journal (ASEJ) should present novelresults and have either theoretical significance or practical utility or both. They may be presentedin the form of full articles, short communications or state-of-the-art reviews.

All contributions will be rigorously reviewed to ensure both scientific quality and technicalrelevance. Revisions of manuscripts may thus be required.

Manuscripts must be submitted in the English language and authors must ensure that the articlehas not been published or submitted for publication elsewhere in any format, and that there are noethical concerns with the contents or data collection. The authors warrant that the informationsubmitted is not redundant and respects general guidelines of ethics in publishing. All papers areevaluated by at least two international referees, who are known scholars in their fields.


v

Objectives

The main objective of ASEJ is to provide an international forum for academics, researchers,industry leaders, and policy makers to investigate and exchange novel ideas and disseminateknowledge and information covering the broad range of natural science and industrial activities. Inaddition, it aims to establish an effective channel of communication between policy makers,government agencies, academic and research institutions and persons concerned with basicscience and its applications. It also aims to promote and coordinate developments in the fields ofnatural science, engineering science and other related fields. The international dimension isemphasized in order to overcome cultural and national barriers and to meet the needs ofaccelerating ecological and technological advances in all industries and the global society andeconomy.

Open Access Policy

This journal provides immediate open access to its content on the principle that making researchfreely available to the public supports a greater global exchange of knowledge.

All published manuscripts will be available on the Journals website http://vrgs.ju.edu.sa/#. Westrongly believe that our journal will help to develop your own professional career. You cancommunicate with us at any time, throughout the publishing process.

EDITORIAL OFFICE & COMMUNICATION

Aljouf University Science and Engineering Journal

(AUSEJ) Aljouf University, Sakaka, 2014, Aljouf,

Saudi Arabia Email: [email protected]


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TABLE OF CONTENTS

GUIDE FOR AUTHOR i

GENERALIZED f-PROJECTION ALGORITHM FOR A SPLIT SET- VALUED MIXED VARIATIONAL INEQUALITY PROBLEM... Naeem Ahmad

1

MEASUREMENT OF RN-222 AND ESTIMATE ANNUAL EFFECTIVE DOSE EXPOSURE IN GROUNDWATER FROM AL JOUF PROVINCE, KINGDOM OF SAUDI ARABIA... Adel G E Abbady et al

10

EFFECT OF CALCIUM PHOSPHATE SURFACE LAYER ON DRUG BINDING AND RELEASE FROM BIOACTIVE GLASS: ATR-FTIR AND SEM-EDX STUDIES... Karima Ahmed et al

18

EFFICIENCY OF GPAF SYSTEM ON EXPANSIVE SOIL AT TABUK CITY,SAUDI ARABIA... Osama M. Ibrahim et al

27

AUSEJGUIDE FOR AUTHOR

Aljouf University Science and Engineering Journal (AUSEJ): 2015; 2: i - vii i

GUIDE FOR AUTHOR

TYPES OF CONTRIBUTIONS

Original research papers and occasional reviews,

short communications, letters, letters to the

editor and news items. Please ensure that you

indicate clearly the appropriate article type when

making your submission.

BEFORE YOU BEGIN

Ethical guidelines

Confidentiality

All material submitted to Science Journal of

Aljouf University (SJJU), accordingly to Aljouf

university Science, Engineering Journal

(AUSEJ) remains confidential, and the Editor

operates a peer review system in which the

identity of the referees is protected.

Duplicate publication

Duplicate publication is the publication of the

same paper or substantially similar papers in

more than one journal. Authors must explain in

the submission letter any prior publication of the

same or a substantially similar paper, and should

explain any circumstances that might lead the

Editor or reviewers to believe that the paper may

have been published elsewhere (for example,

when the title of a submitted paper is the same as

or similar to the title of a previously published

article).

If work that makes up more than 10% of the

manuscript submitted to AUSEJ has been

published elsewhere, please provide a copy of

the published article in order that the Editor can

make a judgment on the amount of overlap

without delay. If a member of the editorial board

learns that work under consideration has

previously been published in whole or in part,

the Editor may return the paper without review,

reject the paper, announce the duplication

publicly in an editorial and/or contact the

authors’ employers.

Submission of manuscripts to more than one

journal

Authors may not send the same manuscript to

more than one journal concurrently. If this

occurs, the Editor may return the paper without

review, reject the paper, contact the Editor of the

other journal(s) in question and/or contact the

authors’ employers.

Plagiarism and scientific misconduct

Plagiarism is the use of others’ published and

unpublished ideas or words (or other intellectual

property) without due reference or permission

and/or their presentation as new and original

points. Plagiarism is serious scientific

misconduct and will be dealt with accordingly.

All papers submitted to the journal is cheched

with iThenticate program for plagiarism. We

define plagiarism as a case in which a paper

reproduces another work with at least 15%

similarity and without citation.

If evidence of plagiarism is found before or after

acceptance or after publication of the paper, the

author will be offered a chance to defend his/her

paper. If the arguments are found to be

unsatisfactory, the manuscript will be retracted

and authors found to have been guilty of

plagiarism will no longer have papers accepted

for publication by AUSEJ.

iThenticate compares submitted documents to

extensive data repositories to create a


Aljouf University Science and Engineering Journal (AUSEJ): 2015; 2: i - vii ii

comprehensive Similarity Report, which

highlights and provides links to any significant

text matches, helping to ensure that you are

submitting an original and well-attributed

document.

Data auditing

The journal reserves the right to view original

figures and data and may make periodic requests

to see these.

Conflict of interest

All authors are requested to disclose any actual

or potential conflict of interest including any

financial, personal or other relationships with

other people or organizations within three years

of beginning the submitted work that could

inappropriately influence, or be perceived to

influence, their work.

Submission declaration

Submission of an article implies that the work

described has not been published previously

(except in the form of an abstract or as part of a

published lecture or academic thesis or as an

electronic preprint, that it is not under

consideration for publication elsewhere, that its

publication is approved by all authors and tacitly

or explicitly by the responsible authorities where

the work was carried out, and that, if accepted, it

will not be published elsewhere including

electronically in the same form, in English or in

any other language, without the written consent

of the copyright-holder.

Changes in authorship

Requests to add or remove an author, or to

rearrange the author names, must be sent to the

Journal Manager from the corresponding author

of the accepted manuscript before the accepted

manuscript is published and must include: (a)

the reason for the addition, removal, or

rearrangement of the authors, names and (b)

written confirmation (e-mail, fax, letter) from all

authors that they agree with the addition,

removal or rearrangement. In the case of

addition or removal of authors, this includes

confirmation from the author being added or

removed. Requests that are not sent by the

corresponding author will be forwarded by the

Journal Manager to the corresponding author,

who must follow the procedure as described

above. Note that: (1) Journal Managers will

inform the Journal Editors of any such requests

and (2) publication of the accepted manuscript is

suspended until authorship has been agreed.

Copyright

Upon acceptance of an article, authors will be

asked to complete a 'Journal Publishing

Agreement' An e-mail will be sent to the

corresponding author confirming receipt of the

manuscript together with a 'Journal Publishing

Agreement'.

Subscribers may reproduce tables of contents or

prepare lists of articles, including abstracts for

internal circulation within their institutions.

Permission of the Publisher is required for resale

or distribution outside the institution and for all

other derivative works, including compilations

and translations.

If excerpts from other copyrighted works are

included, the author(s) must obtain written

permission from the copyright owners and credit

the source(s) in the article.

Retained author rights

As an author you (or your employer or

institution) have the right to use your articles for

a wide range of scholarly purposes.

Role of the funding source

You are requested to identify who provided

financial support for the conduct of the research

and/or preparation of the article and to briefly

describe the role of the sponsor(s), if any, in

study design; in the collection, analysis and

interpretation of data; in the writing of the

report; and in the decision to submit the article


Aljouf University Science and Engineering Journal (AUSEJ): 2015; 2: i - vii iii

for publication. If the funding source(s) had no

such involvement then this should be stated

Subscription

Articles are made available to subscribers as

well as developing countries and patient groups

Language (usage and editing services)

Please write your text in good English

(American or British usage is accepted, but not a

mixture of these). If the English language is

used, extra abstract in Arabic should be

provided.

Submission

To submit your paper, please send

your manuscripts by e-mail to the

Editor ([email protected]). You must

submit the manuscript in a single

electronic file. The manuscript should be

edited using Microsoft (MS) Word (2003 up to

2010, with .doc or .docx extension)

Referees

Please submit, with the manuscript, the

names, addresses and e-mail addresses of three

potential referees. Note that the Editor retains

the only one who has the right to decide

whether or not the suggested reviewers are

used.

PREPARATION

Use of word processing software

Manuscripts must be in an electronic format that

meets the following specifications:

Do not submit a manuscript file as a PDF

file. Remove line numbering.

The manuscript file—with tables and

figures placed at the end of the file, each on

a separate page—should be in Microsoft

Word (2003 up to 2010, with .doc or .docx

extension).

Do not use the Microsoft Word “Styles and

Formatting” or “Track Changes” features in

the file.

Tables should be in MS Word (.doc or

.docx), one table to a page using hard page

breaks.

Figures (graphics of any kind) should be

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images, one figure to a page using hard

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Equations may be created and inserted as

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ARTICLE STRUCTURE

Manuscript Page setup

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Font (typeface): Times New Roman, no

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Numbering: Insert page numbers at upper

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Text: Single-spaced.

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FIRST-LEVEL SUBHEAD

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mailto:[email protected]


Aljouf University Science and Engineering Journal (AUSEJ): 2015; 2: i - vii iv

Fourth-Level Subhead (initial capitals,

boldface, on same line as text, with extra letter

space between the subhead and text)

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• Bulleted and numbered lists: Indent first line

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Table Titles and Figure Captions:

TABLE 5 Effects of All Factors

(Insert title above the table; “Table” is all

capitals; title is initial capitals; all types are

boldfaced;

Extra space, but no punctuation after number;

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FIGURE 3 Example of results.

(Insert caption below the figure; “Figure” is all

capitals; caption is sentence case; all type is

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Body of the manuscript

Introduction

State the objectives of the work and provide an

adequate background, avoiding a detailed

literature survey or a summary of the results.

Materials and methods

Provide sufficient detail to allow the work to be

reproduced. Methods already published should

be indicated by a reference: only relevant

modifications should be described.

Theory/calculation

A Theory section should extend, not repeat, the

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Results

Results should be clear and concise.

Discussion

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Results and Discussion section is often

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Conclusions

The main conclusions of the study may be

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Discussion or Results and Discussion section.

Appendices

If there is more than one appendix, they should

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equations in appendices should be given separate

numbering: Eq. (A.1), Eq. (A.2), etc.; in a

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Essential title page information

• Title. Concise and informative. Titles are

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Avoid

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postal address of each affiliation, including the


Aljouf University Science and Engineering Journal (AUSEJ): 2015; 2: i - vii v

country name, and, if available, the e-mail

address of each author.

• Corresponding author. Clearly indicate who

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must be retained as the main, affiliation address.

Superscript Arabic numerals are used for such

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Abstract

A concise and factual abstract is required. The

abstract should state briefly the purpose of the

research, the principal results and major

conclusions. An abstract is often presented

separately from the article, so it must be able to

stand alone. For this reason, References should

be avoided, but if essential, then cite the

author(s) and year(s). Also, non-standard or

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mention in the abstract itself.

Keywords

Immediately after the abstract, provide a

maximum of 6 keywords, using American

spelling and

avoiding general and plural terms and multiple

concepts (avoid, for example, 'and', 'of'). Be

sparing with abbreviations: only abbreviations

firmly established in the field may be eligible.

These keywords will be used for indexing

purposes.

Abbreviations

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of the article. Such abbreviations that are

unavoidable in the abstract must be defined at

their first mention there, as well as in the

footnote. Ensure consistency of abbreviations

throughout the article.

Acknowledgements

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at the end of the article before the references and

do not, therefore, include them on the title page,

as a footnote to the title or otherwise. List here

those individuals who provided help during the

research (e.g., providing language help, writing

assistance or proof reading the article, etc.).

Nomenclature and units

Follow internationally accepted rules and

conventions: use the international system of

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conveniently denoted by exp. Number

consecutively any equations that have to be

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Footnotes

Footnotes should be used sparingly. Number

them consecutively throughout the article, using

superscript Arabic numbers. Many word

processors build footnotes into the text, and this

feature may be used. Should this not be the case,

indicate the position of footnotes in the text and

present the footnotes themselves separately at


Aljouf University Science and Engineering Journal (AUSEJ): 2015; 2: i - vii vi

the end of the article. Do not include footnotes in

the Reference list.

Table footnotes

Indicate each footnote in a table with a

superscript lowercase letter.

Tables

Number tables consecutively in accordance with

their appearance in the text. Place footnotes to

tables below the table body and indicate them

with superscript lowercase letters. Avoid vertical

rules. Be sparing in the use of tables and ensure

that the data presented in tables do not duplicate

results described elsewhere in the article.

References

Citation in text

Please ensure that every reference cited in the

text is also present in the reference list (and vice

versa). Any references cited in the abstract must

be given in full. Unpublished results and

personal communications are not recommended

in the reference list, but may be mentioned in the

text. If these references are included in the

reference list they should follow the standard

reference style of the journal and should include

a substitution of the publication date with either

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communication'. Citation of a reference as 'in

press' implies that the item has been accepted for

publication.

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As a minimum, the full URL should be given

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References in a special issue

Please ensure that the words 'this issue' are

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Reference style

Text: Indicate references by number(s) in square

brackets in line with the text. The actual authors

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must always be given. Example: '..... as

demonstrated [3,6]. Barnaby and Jones [8]

obtained a different result ....'

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appear in the text.

Examples:

Reference to a journal publication:

[1] J. van der Geer, J.A.J. Hanraads, R.A.

Lupton, The art of writing a scientific article, J.

Sci. Commun. 163 (2010) 51–59.

Reference to a book:

[2] W. Strunk Jr., E.B. White, The Elements of

Style, fourth ed., Longman, New York, 2000.

Reference to a chapter in an edited book:

[3] G.R. Mettam, L.B. Adams, How to prepare

an electronic version of your article, In: B.S.

Jones, R.Z. Smith (Eds.), Introduction to the

Electronic Age, E-Publishing Inc., New York,

2009, pp. 281–304.

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to the List of title word abbreviations

http://www.sciencemag.org/site/feature/contribin

fo/prep/res/journal_abbrevs.xhtml

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The following list will be useful during the final

checking of an article prior to sending it to the

journal for review. Please consult this Guide for

Authors for further details of any item.

Ensure that the following items are present:

One author has been designated as the

corresponding author with contact details:

• E-mail address

http://www.sciencemag.org/site/feature/contribinfo/prep/res/journal_abbrevs.xhtml

http://www.sciencemag.org/site/feature/contribinfo/prep/res/journal_abbrevs.xhtml


Aljouf University Science and Engineering Journal (AUSEJ): 2015; 2: i - vii vii

• Full postal address

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• Keywords

Further considerations

• Manuscript has been 'spell-checked' and

'grammar-checked'

• References are in the correct format for this

journal

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are cited in the text, and vice versa

• Permission has been obtained for use of

copyrighted material from other sources

(including the Web)

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Proofs

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do not have an e-mail address then paper proofs

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please list your corrections quoting line number.

If, for any reason, this is not possible, then mark

the corrections and any other comments on a

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the pages and e-mail, or by post. Please use this

proof only for checking the typesetting, editing,

completeness and correctness of the text, tables

and figures. Significant changes to the article as

accepted for publication will only be considered

at this stage with permission from the Editor.

We will do everything possible to get your

article published quickly and accurately – please

let us have all your corrections within 48 hours.

It is important to ensure that all corrections are

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check carefully before replying, as inclusion of

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provided with a PDF file of the article via email

(the PDF file is a watermarked version of the

published article and includes a cover sheet with

the journal cover image and a disclaimer

outlining the terms and conditions of use). For

an extra charge, paper offprints can be ordered

via the offprint order form which is sent once the

article is accepted for publication. Both

corresponding and co-authors may order

offprints at any time via e-mail

([email protected])

AUTHOR INQUIRIES

For inquiries relating to the submission of

articles (including electronic submission) please

visit this journal's homepage. Contact details for

questions arising after acceptance of an article,

especially those relating to proofs, will be

provided by the publisher.

DISCLAIMER

Aljouf university Science and Engineering

Journal shall not take any responsibility for the

contents of articles published in the journal and

all such responsibility shall lie with the author/s.

The opinions expressed in the articles are solely

of the author/s and AUSEJ may not agree with

such opinions in part or in full.

Offprint

mailto:[email protected]

Aljouf University Science and Engineering Journal 2015; 2(1): 01-09Published online July 2015 (http://vrgs.ju.edu.sa/ #)ISSN: 1658-6670

Department of Mathematics, College of Sciences, Al Jouf University, Sakakah, KINGDOM OF SAUDI ARABIA

Email address: [email protected], [email protected]

Abstract: In this paper, we introduce a split set-valued variational inequality problem which is a natural extension of split variational inequality problem and variational inequality problems in Hilbert spaces. Using generalized f -projection method, we propose an iterative algorithm for the split

set-valued mixed variational inequality problem and discuss some its special cases. Further, we dis-cuss the convergence criteria of the iterative algorithm. The result presented in this paper generalized unify the previously known many results for the split-variational and variational inequality problems.

Keywords: Generalized f -projection operator; mixed variational inequality; split set-valued mixed variational inequality; iterative algorithm; convergence analysis.

1. Introduction

Throughout the paper unless otherwise stated,

for each {1,2}i ∈ , let iH be a real Hilbert

space with inner product ·,· i⟨ ⟩ and norm

i⋅� � ; iC be a nonempty, closed and convex

subset of iH .

The variational inequality problem (in short,

VIP) is to find 1 1x C∈ such that

1 1 1 1 1 1, ( ), 0 (1.1) F x y x y C⟨ − ⟩ ≥ ∀ ∈where 1 1 1:F C H→ be a nonlinear map-

ping. Variational inequality theory introduced by Stampachia [26] and Fichera [10] in depen-dently in easily sixties in potential theory and mechanics, respectively, constitutes a signifi-cant extension of variational principles. It has been shown that the variational inequality theorem provided the natural, descent, unified and efficient framework for a general treat-

ment of a wide class of unrelated linear and nonlinear problem arising in elasticity, eco-nomics, transportations, optimization, control theory and engineering sciences, see for in-stance [16]. An important and useful genera-lized of the variational inequality problem is called mixed variational inequality problem (in short MVIP) of finding 1 1x C∈ such that

1 1 1 1 1 1 1 1 1 1 1, ( ), ( ) ( ) 0 (1.2)F x y x f y f x y C⟨ − ⟩ + − ≥ ∀ ∈where 1 1: { }f C → ∪ +∞ℝ be a nonli-

near mapping.

MVIP was originally considered by Lescarret [19] and Browder [3] in connection with its numerous applications. Konnov and Volots-

kaya [17] considered rather broad classes of general economic equilibrium problems and oligopolistic equilibrium problems which can be formulated as MVIPs. It is well known that projection method and its

variants have represented an important tool for solving variational inequalities. Recently, Wu and

GENERALIZED f -PROJECTION ALGORITHM FOR A SPLIT

SET-VALUED MIXED VARIATIONAL INEQUALITY PROBLEM Naeem Ahmad

2 Naeem Ahmad.: GENERALIZED f -PROJECTION ALGORITHM

Huang [25] introduced a new generalized f -projection operator in a Banach space,

which was a useful tool solving MVIPs. They extended the definition of the generalized pro-jection operators introduced by Alber [1,2] and proved some properties of the generalized f -projection operator. Fan, Liu and Li [9]

presented some basic results for the genera-lized f -projection operator, and discussed

the existence of solutions and approximation of the solutions for generalized variational in-equalities in noncompact subsets of Banach spaces by using iterative schemes. Li, Zou and Huang [22] proved some stability results for the generalized f -projection operators with

perturbations of constant sets in Banach spac-es.

Very recently, Li and Li [21] proved the exis tence of solution and discussed the conver-gence of iterative sequences generated by ge-neralized f-projection algorithm for a new system of set-valued mixed variational inequa-lity problem. On the other hand, Censor et al. [7] introduced and studied the following split variational in-equality problem (in short, SpVIP). For each

{1,2}i ∈ , let :i i iF H H→ be a nonli-

near mapping and 1 2:A H H→ be a

bounded linear operator with its adjoint op-

erator *A Then SpVIP is to: Find *1 1x C∈

such that

* *1 1 1 1 1 1, ( ), 0, ( 1.3a)F x x x x C⟨ − ⟩ ≥ ∀ ∈

and such that * *2 1 2x Ax C= ∈ solves

* *2 2 2 2 2 2, ( ), 0, (1.3b)F x x x x C⟨ − ⟩ ≥ ∀ ∈

SpVIP ( )1.3a 1.3b− amount to saying:

find a solution of variational inequality prob-

lem VIP( )1.3a , the image of which under a

given bounded linear operator is a solution of

VIP ( )1.3b . It is worth mentioning that is

quite general and permits split minimization between two spaces so the image of a mini-mizer of a given function, under a bounded linear operator, is a minimizer of another func-

tion. SpVIP ( )1.3a 1.3b− is an important

generalization of VIP( )1.1 . It also includes as

special case, the split zero problem and split feasibility problem which has already been studied and used in practice as a model in in-tensity-modulated radiation therapy treatment planning, see [5,6,8]. For the further related work, we refer to see Moudafi [24], Byrne et

al. [4], Kazmi and Rizvi [13-15] and Kazmi [11-12]. In this paper, we introduce the following im-portant generalization of SpVIP

( )1.3a 1.3b− .

For each {1,2}i ∈ , let 1C be a nonempty,

closed and convex subset of iH ; let

:i i i iT H H H× → be a nonlinear mapping;

let 1 1: 2 iHF H → be a set-valued mapping

and 2 2 2:F H H→ be a nonlinear mapping;

let : { }i if C → ∪ +∞R be a proper, con-

vex and lower semicontinuous functional. Then we consider the problem:

Find *1 1x C∈ , * *

1 1 1( )u F x∈ such that

* * * *1 1 1 1 1 1 1 1 1 1 1( , ), ( ) ( ) 0, , (1.4a)T x u x x f x f x x C⟨ − ⟩ + − ≥ ∀ ∈

and such that * *2 1 2x Ax C= ∈ solves

* * * *2 2 2 2 2 2 2 2 2 2 2 2( , ( )), ( ) ( ) . 0, (1.4b)T x F x x x f x f x x C⟨ − ⟩ + − ≥ ∀ ∈

where 1 2:A H H→ is a bounded linear

operator. We call it the split set-valued mixed

variational inequality problem (in short SpSMVIP)

Aljouf University Science and Engineering Journal 2015; 2(1): 01-09 3

If , the (SpSMVIP) ( )1.4a 1.4b−reduces to split set-valued variational inequ-

ality problem(SpSVIP):

Find *1 1x C∈ , * *

1 1 1( )u F x∈ such that

* * *1 1 1 1 1 1 1, (( , ), 1.5a, )0T x u x x x C⟨ − ⟩ ≥ ∀ ∈

and such that * *2 1 2x Ax C= ∈ solve

* * *2 2 2 2 2 2 2 2. ( , ( )) (1.5 ), b0, T x F x x x x C⟨ − ⟩ ≥ ∀ ∈

which appears to be new. Using generalized f -projection method, we

propose an iterative algorithm for solving

(SpSMVIP) ( )1.4a 1.4b− and discuss

some its special cases. Further, we discuss the convergence criteria of the iterative algorithm. The results presented in this paper generalize, unify and improve the previously known many results for the split-variational and variational inequality problems.

2. PreliminariesThe property of generalizedf -projection op-

erator plays an important role in solving the (SpSMVIP). First we recall the concept of the generalized f -projector operator, together

with its properties. Let

1 1: { }G H C× → ∪ +∞R be a functional

defined as follows

2 21 1 1 1 1( , ) 2 , 2 ( ), (2.1)G x x x fξ ξ ξ ρ ξ= − ⟨ ⟩ + +‖ ‖ ‖ ‖

where 1 1, C x Hξ ∈ ∈ and 1ρ is a positive

number. Definition 2.1[27]. Let 1C be a nonempty closed and convex

subset of Hilbert space 1H .

Let 1 1: { }f C → ∪ +∞ℝ be a proper con-

vex and lower semicontinuous functional. We

say that 1 1 1

1

,1: 2f C

CP Hρ → is a gener-

lized 1f -projection operator if

1 1

11

,1 1 1 1{ : ( , ) inf ( , )}, .f

C CP x u C G x u G x x Hρ

ξξ

∈= ∈ = ∈

Lemma 2.1[9,27].Let 1C be a nonempty closed and convex

subset of Hilbert space 1H .

Let 1 1: { }f C → ∪ +∞ℝ be a proper con-

vex and lower semicontinuous functional. Then the following statements hold:

(i) 1 1

1

,fCP ρ

is a single-valued mapping with

nonempty values;

(ii) 1 1

1

,*1 1 1, f

Cx H x P xρ∀ ∈ = if and only if

* * *1 1 1 1 1 1 1 1 1 1 1 1 1, ( ) ( ) 0, ;x x y x f y f x y Cρ ρ⟨ − − ⟩ + − ≥ ∀ ∈

(iii) 1 1

1

,fCP ρ

continuous.

Lemma 2.2[20].Let 1C be a nonempty closed and convex

subset of Hilbert space 1H . Let1 1: { }f C → ∪ +∞ℝ be a proper convex

and lower semicontinuous functional. Then


1 1 1 1

1 1

, ,1 1 1 1 1 1 1 1 1 , , .f f

C CP x P y x y x y Hρ ρ− ≤ − ∀ ∈‖ ‖ ‖ ‖

Definition 2.2 [20]. Let 1C and 1D be closed convex subsets

in 1H . The Hausdorff distance 1( , )⋅ ⋅H be-

tween 1C and 1D is defined as follows:

1 11 1

1 1 1 1 1( , ) max supinf , supinf .y D x Cx C y D

C D x y x y∈ ∈∈ ∈

= − −

H ‖ ‖ ‖ ‖

Definition 2.3 [22]. Let 1 1 1 1:T H H H× → be a mapping. 1T

is said to be

γ -Lipschitz continuous with respect to

the first argument, if there exists a constant 0γ > such that

1 1 1 1 1( , ) ( , ) , , , .T x z T y z x y x y z Hγ− ≤ − ∀ ∈‖ ‖ ‖ ‖

µ -strongly monotone with respect to thefirst argument, if there exists a constant

0µ > such that

21 1 1 1 1( , ) ( , ), , , .,T x z T y z x y x y x y z Hµ⟨ − − ⟩ ≥ − ∀ ∈‖ ‖

Definition 2.4 [22]. Let 1 1: 2 iHF H → be a set-valued

mapping. 1F is said to be

ξ - 1H -Lipschitz continuous, if there exists a

constant 0ξ ≥ such that

1 1 1 1 1( ( ), ( )) , , . F x F y x y x y Hξ≤ − ∀ ∈‖ ‖H

3. Iterative AlgorithmsFrom Lemma 2.1, we can easily prove that following technical lemma:

Lemma 3.1 (SpSMVIP) ( )1.4a 1.4b− is

equivalent to find * * *1 2 1 2 1 1 1( , ) , ( )x x C C u F x∈ × ∈

with * *2 1x Ax= such that

1 1

1

,* * *1 1 1 1 1 1( , )( )f

Cx P x T x uρ ρ= −

( )2 2

2

,* * * *2 2 2 2 2 2 2( , ( )) 3.1( ). f

Cx P x T x F xρ ρ= −

where 1 2, 0ρ ρ > .

From any 01 1x C∈ we choose

0 01 1 1( )u F x∈ . By Nadler [25], for any

11 1x C∈ and 1 0>ε , there exists1 11 1 1( )u F x∈ such that

( )0 1 0 11 1 1 1 1 1 1 1 (1 ) ( ), 2( 3.)( ). u u F x F x− ≤ +‖ ‖ ε H


Based on Lemma 3.1 and ( )3.2 , we can

construct the following iterative algorithm for

solving SpSMVIP ( )1.4a 1.4b− . Let

{ } (0,1)nα ⊆ be a sequence such that

1

n

n

α∞

=

= +∞∑ , and let 1 2, ,ρ ρ γ are para-

meters with positive valued. Let

1 1 1: ( )F H C H→ be a set-valued mapping,

where 1C( )H is the collection of all non-

empty compact subsets of 1H .

Iterative algorithm 3.1. Given any 0 0 01 1 1 1 1, ( )x C u F x∈ ∈ , compute the iterative

sequences 1 1{ },{ },{ },{ }n n n nx y z u defined

by the iterative schemes:

( )1 1

1

,1 1 1 1 1 3.3a( , )( ) fn n n n

Cy P x T x uρ ρ= −

( )2 2

2

,2 2 2( , ( )) 3.3b( ) fn n n

C nz P Ay T Ay F Ayρ ρ= −

( )1 *1 1(1 ) ( ) 3.3c[ ]n n n n n n nx x y A z Ayα α γ+ = − + + −

for all 1 20,1,2,............., , , 0n ρ ρ γ= > .

If =0, i= 1, 2, if then Iterative algorithm

3.1 reduces to the following iterative algorithm

for solving (SpSVIP)( )1.5a 1.5b− .

Iterative algorithm 3.2. Given any

0 0 01 1 1 1 1, ( )x C u F x∈ ∈ , compute the iterative

sequences 1 1{ },{ },{ },{ }n n n nx y z u defined

by the iterative schemes:

1 1 1 1 1 1( , )( )n n n nCy P x T x uρ= −

2 2 2 2( , ( ))( )n n nC nz P Ay T Ay F Ayρ= −

1 *1 1(1 ) ( )[ ]n n n n n n nx x y A z Ayα α γ+ = − + + −

1 1 1 11 1 1 1 1 1 1 1 1 1( ) : ( ), ( )( )n n n n n nu F x u u F x F x+ + + +∈ − ≤‖ ‖ H

for all for all

1 20,1,2,.........., , , 0n ρ ρ γ= > , where

iCP is the metric projection on iC .

4. Main Result.Now, we study the convergence of the se-

quences generated by Iterative algorithm 3.1

for (SpSMVIP) ( )1.4a 1.4b− .

Theorem 4.1. For each {1,2}i ∈ , let iC be

a nonempty, closed and convex subset of iHand : { }i if C → ∪ +∞R be a proper

convex and lower semicontinuous mappings.

Let :i i i iT H H H× → be iµ -strongly

monotone and ir -Lipschitz continuous with

respect to the first variable, and iτ -Lipschitz

continuous with respect to the second variable.

Let 1 1 1: ( )F H C H→ be 1ξ - 1H -Lipschitz

continuous, where 1C( )H denotes the col-

lection of all nonempty compact subsets of

1H . Let 2 2 2:F H H→ be 2ξ -Lipschitz

continuous mapping. Let 1 2:A H H→ be a

bounded linear operator with respect its adjoint


operator *A . Suppose * *

1 1 2( , , )x u x is a so-

lution of (SpSMVIP) ( )1.4a 1.4b− , then

the sequences 1 1{ },{ },{ },{ }n n n nx y u z , gen-

erated by Iterative algorithm 3.1 converge

strongly respectively to * * 11 2 1 1( , , , )x x u Ax

provided that the constants iρ and γ satis-

fy the following conditions:

2 2 2 21 1 1 11 1

1 2 2 2 21 1 1 1

( ) ( )(1 )| | d r dd

r r

µ α αµ αρα α

− − − −− ≤

− −2 2

1 1 1 1 ( )(1 ) d r dµ α α≥ + − −

1 1 2

2, 1, 0,( )r d

Aα γ> < ∈

‖ ‖

2 22 2 2 2 2 2 2 2 2 : 1 2 0, 0rθ ρ µ ρ ρ τ ξ ρ= − + + > >

( )11 1 1 2 . : , : (1 2 ) 1 4.dα τ ξ θ −= = +

Proof: Since * * *

1 2 1 2 1 1 1( , ) , ( )x x C C u F x∈ × ∈ with * *2 1x Ax= is a solution of (SpSMVIP)

( )1.3a 1.3b− , then it satisfies

( )1 1

1

,* * * *1 1 1 1 1 1 ( , ) 4.2a( )f

Cx P x T x uρ ρ= −

( )2 2

2

,* * * *1 1 2 2 1 2 1( , ( )) 4.2b( )f

CAx P Ax T Ax F Axρ ρ= −

for 1 2, 0.ρ ρ >From Iterative algorithm 3.1( )3.3a , and

( )4.2a , we have

1 1 1 1

1 1

, ,* * * *1 1 1 1 1 1 1 1 1 1 1 1 1 ( , ) ( , )( ) ( )f fn n n n

C Cy x P x T x u P x T x uρ ρρ ρ− = − − −‖ ‖ ‖ ‖

* *1 1 1 1 1 1 1 1 1 1 ( , ) ( , )( )n n n nx x T x u T x uρ≤ − − −‖ ‖

* * *1 1 1 1 1 1 1 1 1 1 ( , ) ( , )( )n n nx x T x u T x uρ≤ − − −‖ ‖

( )* *1 1 1 1 1 1 1 1( , ) ( , ) 4.3( )n nT x u T x uρ+ −‖ ‖

Now, since 1T is 1µ -strongly monotone and

1r -Lipschitz continuous with respect to the

first variable, and 1τ -Lipschitz continuous

with respect to the second variable, and 1F is

1ξ - 1H -Lipschitz continuous, then we have

* * * 21 1 1 1 1 1 1 1 1 1( ( , ) ( , ))n n nx x T x u T x uρ− − −‖ ‖

* 2 *1 1 1 1 1 1 1 1 1 1 1 2 ( ( , ) ( , )n n n nx x T x u T x uρ= − − ⟨ − ⟩‖ ‖

2 * 21 1 1 1 1 1 1 1( ( , ) ( , ))n n nT x u T x uρ+ −‖ ‖


* 2 * 2 2 2 * 21 1 1 1 1 1 1 1 1 1 1 1 1 2n n nx x x x r x xρ µ ρ≤ − − − + −‖ ‖ ‖ ‖ ‖ ‖

( )2 2 * 21 1 1 1 1 1 1(1 2 ) , 4.4nr x xρ µ ρ= − + −‖ ‖

and

* *1 1 1 1 1 1 1 1 1 1 1( , ) ( , ) n n nT x u T x u u uτ− ≤ −‖ ‖ ‖ ‖

*1 1 1 1 1 1 ( ( ), ( ))nH F x F xτ≤

( )*1 1 1 1 1 4.5nx xτ ξ≤ −‖ ‖

It follows from ( ) ( ) ( )4.3 , 4.4 , 4.5 that

( )* 2 2 * *1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 (1 2 ) , 4.6[ ]n n ny x r x x x xρ µ ρ ρ τ ξ θ− ≤ − + + − = −‖ ‖ ‖ ‖ ‖ ‖

where2 2

1 1 1 1 1 1 1 1 : (1 2 )[ ].rθ ρ µ ρ ρ τ ξ= − + +Next, from Iterative algorithm 3.1( )3.3c , we

have

1 * *1 1 1 1 1 1 (1 )n n nx x x xα+ − ≤ − −‖ ‖ ‖ ‖

( )* * * * *1 1 1 1 1( ) 4.8([ ] n n n ny x A Ay Ax A z Axα γ γ+ − − − + −‖ ‖ ‖ ‖)

Now by the definition of adjoint operator *A .

and from the assumption that *A is a

bounded linear operator and using the fact that

* A A= ‖ ‖ ‖ ‖ , we have

* * * 21 1 1( )n ny x A Ay Axγ− − −‖ ‖

* 2 * * * 2 * * 21 1 1 1 1 1 1 2 , ( ) ( )n n n ny x y x A Ay Ax A Ay Axγ γ= − − ⟨ − − ⟩ + −‖ ‖ ‖ ‖

* 2 * 2 *1 1 1 2 1 1 (2 ) n n ny x A Ay Ax y xγ γ≤ − − − − −‖ ‖ ‖ ‖ ‖ ‖ ‖ ‖

( )*1 1 , 9.4ny x≤ −‖ ‖

because 2

20,( )

Aγ ∈

‖ ‖.

Further using( )4.7 , we estimate

* * * * * *1 1 1 2 1 2( ) n n nA z Ax A z Ax A z Ax− ≤ − ≤ − ‖ ‖ ‖ ‖ ‖ ‖ ‖ ‖ ‖ ‖

*2 1 1 nA y xθ≤ − ‖ ‖ ‖ ‖

( )* *2 1 2 . 4.10nA Ay Axθ≤ − ‖ ‖ ‖ ‖

From ( ) ( ) ( )4.6 , 4.8 , 4.9 and ( )4.10 , we have

( )1 * *1 1 1 1 1 1 [1 ( 4.111 )]n n nx x x xα θ+ − ≤ − − −‖ ‖ ‖ ‖


where 21 2(1 )Aθ θ γ θ= + ‖ ‖ . Hence, after iteration, we obtain

1 *1 1 1nx x+ − ≤‖ ‖ ( )0

1 11

*1 . [1 ( 4.1 ) 1] 2j

n

j

x xα θ=

− − −∏ ‖ ‖

Since 2 2Aγ <‖ ‖ hence the maximum

value of 22(1 )Aγ θ+ ‖ ‖ is 2(1 2 )θ+ .

Further, (0,1)θ ∈ if and only if

( )11 2(1 2 ) : . 4.13dθ θ −< + =

We also observe that (0,1)d ∈ , since

2 0θ > . The inequality ( )4.13 holds from

condition ( )4.1 Since1

n

n

α∞

=

= +∞∑ and

0 1θ< < , it implies in the light of [23] that

1

[1 (1 )l ] .0imn

x

j

j

α θ→∞

=

− − =∏ Thus it fol-

lows from ( )4.12 that 1{ }nx converges

strongly to *1x as n → ∞ .

Since A is bounded linear operator on Hil-bert spaces, it is continuous. Further since

1 20 1, 0 1θ θ< < < < , it follows from

( ) ( ) ( )4.5 , 4.6 , 4.7that

*1 1 1 1( )nu u F x→ ∈ ,

*1

ny x→ ,*1

nAy Ax→ , and *1

nz Ax→ as

n → ∞ .This completes the proof. The following results

for (SpSVIP) ( )1.5a 1.5b− is an imme-

diately consequence of Theorem 4.1

Corollary 4.1. For each {1,2}i ∈ , let iC be

a nonempty, closed and convex subset of iH .

Let :i i i iT H H H× → be iµ -strongly

monotone and ir -Lipschitz continuous with

respect to the first variable, and iτ -Lipschitz

continuous with respect to the second variable.

Let 1 1 1: ( )F H C H→ be 1ξ - 1H -Lipschitz

continuous, where 1C( )H denotes the col-

lection of all nonempty compact subsets of 1H .

Let 2 2 2:F H H→ be 2ξ -Lipschitz conti-

nuous mapping. Let 1 2:A H H→ be a

bounded linear operator with respect its adjoint

operator *A . Suppose * *

1 1 2( , , )x u x is a so-

lution of (SpSMVIP) ( )1.5 1.5a b− , then

the sequences 1 1{ },{ },{ },{ }n n n nx y u z , gen-

erated by Iterative algorithm 3.2 converge

strongly respectively to * * 11 2 1 1( , , , )x x u Ax

provided that the constants iρ and γ satisfy

the conditions (4.1).

References


Aljouf University Science and Engineering Journal 2015; 2(1): 10-17Published online June 2015 (http://vrgs.ju.edu.sa/ #)ISSN: 1658-6670

MEASUREMENT OF RN-222 AND ESTIMATE ANNUALEFFECTIVE DOSE EXPOSURE IN GROUNDWATER FROMAL JOUF PROVINCE, KINGDOM OF SAUDI ARABIA

1,4and MA Elosealy1,4, A M Mebed1,3, Mohammed D Alenezy1,2Adel G E Abbady

1Physics Department, Faculty of Science, Aljouf University, Aljouf, Skaka, KSA2Physics Department, Faculty of science, South Valley University, Qena, Egypt3Physics Department, Faculty of Education, Al Dammam University, Al Dammam, KSA4Physics Department, Faculty of science, Assuit, EgyptCorresponding Author:Adel G. E. Abbady

Email address:

[email protected]

Radon concentrations are measured in thirty groundwater samples from Al Jouf province Us-ing RAD7. It is found that the measured radon contents ranges from 0.23 Bq L-1to 10.36 Bq L-1 withmean value of 2.6± 0.64 Bq L-1, except one site shows value of 13 Bq L-1. The measured values ofradon concentration are found to be well in the range within the EPAs maximum contaminant level of11.1 Bq L-1. The annual effective doses resulting from Rn-222 in groundwater from Al Jouf provincewere significantly lower than the UNSCEAR standards that is 1 mSv y-1. The measured concentrationfor the ground water in this study suggest that the area far away of being dangerous for people live inas per as radon concentration is concerned.

Keywords: Groundwater- Radon - Annual effective dose -Al Jouf

1. INTRODUCTION

Radioactive isotopes in nature occur both in thelithosphere and in the atmosphere. In the lithosphere,the most important radioactive series are the U-238and Th-232 series. The decay products from the firstmembers of these seriesare leached out of the rocksto be dissolved in the groundwater in different de-grees. Radon, in the gaseous radioactive state is amember of the uranium series. It is easily dissolve inwater and is enriched in relation to other members ofthe series. Hence, the radioactivity of groundwater ismainly contributed by radon. Naturally occurring222-Rn, belonging to the 238-U decay-series, is aninert gas and thus found at a highly enriched level ingroundwater and underground spaces. The inhala-tion or ingestion of radon may cause cancers in hu-man organs particularly in the lungs because the

radon and its series produce alpha and beta particles.Thus, it is essential to assess radon in water and airto reduce potential exposure to it [1] .In ten years, agreat interest arose towards the natural radioactivityin water [2,3,4]. Activity concentrations of theRn-222 was measured in samples of drinkingwater from the Sothern Greater Poland using liquidscintillation technique. The determined valuesranged from 0.42 to 10.52 Bq L-1 with the geometricmean value of 1.92 Bq L-1. The calculated averageannual effective doses from using water and inhala-tion of radionuclide escaping from water were 1.15and 11.8 µSvy-1, respectively. Wen, T.,[5] measured222-Rn in groundwater and surface seawater duringa full tidal period, estimated 222-Rn activity alongthe coast of Xiangshan, Zhejiang, China. 222-Rn

Aljouf University Science and Engineering Journal 2015; 2(1): 10-1711

activity in Xiangshan coast was in range of 2.4 ×

104 - 1.7×105 Bq/m3 with an average of 9.6×104

Bq/m3 for groundwater; 0.2 × 102 - 2.8 × 102

Bq/m3 with an average of 1.1 × 102 Bq/m3 for

surface seawater. Ravikumar, P. [6] studied the dis-tribution of radon in ground and surface water sam-ples in Sankey Tank and Mallathahalli Lake areas,the mean radon activity in surface water was 7.24

± 1.48 and 11.43 ± 1.11 Bq L-1, respectively.

The mean radon activities in groundwater ranged

from 11.6±1.7 to 381.2±2.0 Bq L-1 and 1.50 ±

0.83 to 18.9±1.59 Bq L-1, respectively. Correa [7]

analyzed concentration activity of 222-Rn activityconcentration in well water. About 70% of watersamples from monitored wells presented 222-Rnconcentration values above the limit of 11.1 Bq L-1

recommended by the United States EnvironmentalProtection Agency USEPA. Different samples ofwater have been collected from Islamabad the capi-tal of Pakistan and Murree[8].It was observed thatthe average values of radon concentrations in water

samples were 88.63±4.23 kBq.m-3 and 4.38±0.44

kBq.m-3, respectively. Also,radon concentration ingroundwater samples at different areas of the dis-tricts of SriGanganagar, Hanumangarh Sikar andChuru in northern Rajasthan is estimated [9].Theyfound that the radon concentrations in the ground-

water ranged from 0.5±0.3 Bq L-1 (Chimanpura) to

85.7±4.9 Bq L-1 (Khandela) with a mean value of

9.03±1.03 Bq L-1. The proposed safe value by(USEPA) of Radon concentration in water is 11 BqL-1 [10].In Saudi Arabia, studies on natural radioactivitycontents in the environments are dispersed in lastfew years. Shabana et al [11], measured twenty ninegroundwater samples, collected from Wadi Nu'manwells, Mecca Province, Saudi Arabia. 222-Rn con-centrations is found to be ranged from 10-100 Bq L-1

with an average value of 40 Bq L-1. 222-Rn levels in171 waters well located in and around Riyad cityis evaluated by Aleissa et al [12] using an ultra-lowlevel liquid scintillation spectrometer equipped with

an / discrimination device. The measured 222-Rn

concentrations of shallow wells ranged from 0.72±

0.08 to 7.21±0.58 Bq L-1 (mean 2.74±0.24 Bq L-1),

whereas those of deep wells ranged from 0.34 ±

0.05 to 3.52±0.30 Bq L-1 (mean1.01±0.10 Bq L-1)respectively. Alabdulaaly [13] measured radon levelsin eight water supply municipalities of the CentralRegion of Saudi Arabia. The radon level in well

water was in the range of 0.89- 35.44 Bq L-1 with anoverall weighted geometric mean value of 8.80 BqL-1. The contents of 222-Rn has been assessed inunderground water samples collected fromAl-Mukarramah area west of Saudi Arabia, Kadi [14]to lie in the range 0.6-3.9 Bq L-1. Alabdulaaly[15]assayed radon levels in a water distribution networkof the capital city of Saudi Arabia, Riyadh. All sam-ples have shown low radon levels with an averageconcentration of 0.2 Bq L-1 and range values of0.1-1.0 Bq L-1. Rn-222 in the groundwater suppliesof the capital city of Saudi Arabia (Riyadh)have low

radon levels with average concentrations of 2.99 ±

0.29 and 3.44 ± 0.35 Bq L-1 for the deep and

shallow well waters, respectively[16]

2. Location of the study area

Al Jouf province is formed of three governorateswhich are Skaka, the capital, Dowmat Algandal, and

Alqurayat and located between 42.37 longitude and

32.29 latitude in the northwestern part of SaudiArabia. Figure 1 shows location map of Al Joufprovince in Saudi Arabia. The study is performed ofthe Nafud Basin in the northern part of the kingdom.The Nafud Basin has been separated on tec-tono-sedimentary considerations into three distincthydro geological provinces namely Tabuk Basin inthe west, Al-Sirhan Basin in the middle and WadianBasin Margin in the east [17] [18].

Fig 1 .Location map of Al Jouf province in Saudi Arabia

3. Experimental Technique

30 samples from Al Jouf province were selected forinvestigation. To ensure sample quality; the wells

12Adel G E Abbady et al.: MEASUREMENT OF RN-222 AND ESTIMATE ……….

were purged through pumping for 10 min. The watersamples were collected in 250 mL special glass bot-tles designed for measuring radon activity in-water.That enable the minimum radon loss by degassingwithout any air contact as reported in [19] and [20].

3.1 Radon measurement instrumentRAD7

Radon-in-air monitor RAD7 using RAD H2O tech-nique with closed loop aeration concept is utilizedfor measuring the ground water samples [21]and[20]. It employs closed loop concept. RAD7consisting of three components, (1) radon monitor (2)the water vial with aerator, and (3) the tube of des-iccant, supported by the retort stand above asmarked in figure 2. A hemisphere with a silicon sol-id state detector is located in the interior of RAD7instrument. Figure 3 [22] shows a representation ofthe measurement chamber with the detector.Through the filter the sample air is sucked in by thepump and reaches the detector chamber. The posi-tively ionized polonium-218 particles are accelerat-ed towards the detector using a high voltage of 2000to 2500V between the detector and the hemisphere.On the surface of the detector the short lived 218Podecays and the α radiation with a characteristic en-ergy is emitted to the detector. The detector producesa signal with 50 per cent probability to be intensifiedelectronically and transformed into a digital signal.The microprocessor stores the energy level of thesignal and produces the spectrum Figure 4. Figure 5explain RAD7 measuring equipment for the deter-mination of radon water gas concentration..

3.2 Work principle of RAD7

A hemisphere with volume 0.7 liter representsthe internal cell of RAD7, as shown in Fig. 3. Thereis a silicon alpha detector is implanted at the centerof the hemisphere. The inside conductor is chargeddue to the high voltage power circuit to a potentialof 2000–2500 V, relative to the detector to create anelectric field throughout the volume of the cell. Thedecay of the radon and thoron daughters when theydeposited on the surface of the detector, they emitalpha particles of characteristic energy directly intothe solid-state detector. After the RAD7’s micropro-cessor picks up the signal and stores it according tothe energy of the particle, it accumulate many sig-nals forming the spectrum. The sniff mode should beused when following the rapid changes in radonconcentration to achieves rapid responses to thechange in radon levels by focusing on 3 min 218Po

alpha peak. RAD7 draws air from the environmentusing the internal pump. The air will then return tothe environment [23]. Accordingly, the radon con-centration in the internal cell of RAD7 is determinedby the following differential equation:

dC(t) / dt = −λ C(t) , (1)

dCPo(t) / dt= λPoC(t) – λPoCPo(t), (2)

Where C (t) is the radon concentration in theinternal cell of RAD7, λ is the decay constant ofradon, Cpo (t) is 218Po concentration, and λpo is 218Podecay constant and equals to0.0037 s−1.

After a certain time of pumping equation (2)can be rewritten as,

dCPo(t) dt = λPoC0 − λPoCPo(t). (3)

When the radon concentration in internal cellof RAD7 equals to that of the environment C0.

The initial condition is CPo(0) = 0 (4)

The solution of Eq. (4) is CPo(t) = C0(1-e− λot) (5)

If the time is much longer than the half-life of218Po, Eq. (5) can be rewritten as [24].

CPo(t) = C0. (6)

Radon concentration can be obtained from Eq. (6).

The radon monitor (RAD7) uses a high electricfield above a silicon semi-conductor detected atground potential to attract the positively chargedpolonium daughters, 218Po (t1/2 = 3.1 min; alpha en-ergy = 6.00 MeV) and 214Po (t1/2 = 164 µs; alphaenergy = 7.67 MeV), which are counted as a meas-ure of 222-Rn concentration in air. The time elapsedfor the sample collection and analysis corrected us-ing the equation

C = C0 e-λt (7)

where C0 initial concentration (to be calculate)after the decay correction, C is the measured con-centration, and t is the time elapsed since collection(days), λ = (0.693)/ (t1/2) =0.181, t1/2= 3.83 days

3.3 Calculation the annual effective dose

Radon gas represents the largest contributor to thecollective exposition to natural radiation of the pop-ulation in the world [25 and 26].The inhalation ofshort-lived decay products of radon accounts onaverage about 50% of the effective equivalent doseon the human being [27]. One can evaluate the an-nual effective dose to an individual, due to intake ofradon from drinking water, using the relation-


ship[28].DW = CW CRWDCW (8)where Dw is the annual effective dose (Sv y-1) dueto ingestion of radio-nuclides from the consumptionof water, CRw annual intake of drinking water (L y1),Cw concentration of 222-Rn in the ingested drinkingwater (Bq L-1), Dcw is the ingested dose conversionfactor for 222-Rn (Sv Bq-1) [29,30]. A dose conver-sion factor of 5 x 10-9 Sv Bq-1 is suggested by theUnited Nations Scientific Committee on the Effectsof Atomic Radiation has been used [31]to calculatethe effective dose considering that an adult (Age >18year ) takes, on average, 1029 L water annually [32].Following ingestion of 222-Rn dissolved in drinkingwater, annual effective doses (μSv y-1) and effectivedoses per liter (nSv L-1) were calculated

Fig 2. Aerating a 250 mL water sample.

Fig 3. Measurement chamber of the RAD7.

Fig 4. RAD7 alpha spectrum- 218Po (window A) and 214Po(window C).

Fig 5. RAD H2O Schematic. The components, as shown,automatically perform everything required to determinethe radon concentration in the water.

4. Results and Discussion

The number of samples collected from Sakaka andDomat Al Gandal are shown in table (1) along withthe overall results of their analysis. The range ofradon varied from 0.23 to 13.01Bq L-1 with averagevalue of 2.6Bq L-1 for Al Jouf province. The averagevalue was lower than the USA average of 7-25.4 BqL-1 [33,34, 35].The distribution pattern of Radonconcentration in groundwater from Al Jouf and otherareas, Saudi Arabia has been presented in Figure(6).The region with high radon value of 13 Bq L-1,which is located in Albohyrat, farm C, 10km north-ern Domat Al Gandal city. The reason for this high


Table 1. Radon concentration and their annual effectivedose exposure in groundwater from Al Jouf, Saudi Arabia.

Table 2. Range of radon concentrations in various types ofwater worldwide

value is under investigation in cooperation with thegeological scientist. The obtained results are far lesscompared to radon results obtained by [36, 37, and38].The results represent the levels of radon in wellwater before any kind of treatment. In treatmentplants, they perform processes, which include aera-tion and cooling, that reduces the levels of radonreaches the consumers to minimum level in therange of 78.7 - 96.5%.[13]. In Riyadh, the removalof radon in the six water treatment plants was in therange of 74- 96% [35].The radon concentrationsfound in this work are presented together with com-parable measurements from the rest of the world inTables 2.

Fig.(6) Radon concentration in groundwater from Al Joufand other areas, Saudi Arabia.

Fig. (7) Annual effective dose exposure in groundwaterfrom Al Jouf and other areas, Saudi Arabia.

It is noticed in current study that the annual effectivedose-rates (AED) were varying with increase in ra-don concentration. The calculated AED were rang-ing from 0.78 to 60 with mean value 14.3 μSv y-1

(Table 1). It is evident that; the total annual effec-tive doses resulting from radon in groundwater fromAl Jouf are significantly lower than the recom-mended limit 1 mSv y-1 for the public [39,40]. An-nual effective dose exposure in groundwater from AlJouf and other areas, Saudi Arabia are shown in fig-ure (7).The spatial variations in radon concentration couldbe a function of the geological structure of the area,

0.00

5.00

10.00

15.00

Avar

ega

Rad

on c

once

ntra

tion

(Bq/

l)

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

Ava

rega

Ann

ual e

ffect

ive

dose

exp

osur

e(μ

Sv/

y)


differences in the climate, soil type,geo-hydrological processes that occurs in the areaand depth of the water source. High radon concen-trations in groundwater and soil are observed abovestructural planes like fault, fracture, fold, and linea-ments. Various studies conducted in different ter-rains on the concentration of radon in groundwaterindicates a direct relation between the presence ofuranium and thorium in the parent rock and radonenrichment in groundwater. The present value arebelow this recommended value in comparison withthe allowed maximum contamination level for radonconcentration in water (which is 11.1 Bq L-1), pro-posed by the USEPA. Moreover, the measured val-ues of radon concentration were below these limitsof the European Commission Recommendations onthe protection of the public against exposure to ra-don in drinking water supplies, which is 100 Bq L-1

for public water supplies.

5. Conclusion

30 groundwater samples collected from differentareas in Sakaka and Domat Al Gandal were analyzedfor radon content. The results obtained show that,the concentration of radon in well water are belowthe maximum contamination level recommendedfrom the U.S. Environmental Protection Agency, thatis 11Bq L-1. The total radon concentrations for allsamples ranging from 0.4 Bq L-1 as minimum con-tamination levels up to 17.8 Bq L-1 as a maximumcontamination level to pose no serious health risks.Moreover, the drinking water has lower value due toaeration and cooling. It is evident that the total an-nual effective doses resulting from radon ingroundwater from Al Jouf were significantly lowerthan the recommended limit for the public. The ra-don concentrations in Al Jouf area are found to belower than concentrations measured in the rest of theworld. The spatial variations in radon concentrationcould be a function of the geological structure of thearea, differences in the climate and geo-hydrologicalprocesses.

6. Acknowledgements

This project was funded by the Deanship of Scien-tific Research (DSR), Aljouf University, under grantNo.(183/34).The authors, therefore, acknowledgewith thanks DSR technical and financial support.

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Aljouf University Science and Engineering Journal 2015; 2(1): 18-26Published online June 2015 (http://vrgs.ju.edu.sa/ #)ISSN: 1658-6670

EFFECT OF CALCIUM PHOSPHATE SURFACE LAYER ONDRUG BINDING AND RELEASE FROM BIOACTIVE GLASS:

ATR-FTIR AND SEM-EDX STUDIESKarima Ahmed1, Ahmed El-Ghannam2

1Department of Physics, Aljouf University, Aljouf, Kingdom of Saudi Arabia2Department of Mechanical Engineering and Engineering Science, DCH 177, The University of North Carolinaat Charlotte, 9201 University City Blvd., Charlotte, NC 28223, USACorresponding Author:Karima Ahmed Aly Ahmed

Email address:

[email protected]

Treatment of infected large bone defects requires the use of a bioactive drug delivery system that can eradicate bacteria and promote bone formation. 45S5 bioactive glass (BG) has excellent bioac-tivity, osteogenic and angiogenic effects; however, it has limited control over drug binding and release. The present study evaluates the role of the surface carbonate hydroxyapatite (HCA) on antibiotic bind-ing to and release kinetics from BG. The loading capacity of nafcillin sodium to surface modified BG (mBG) was (15.445±2.98 mg/g) which is significantly higher than that of unmodified BG (9.52±1.4 mg/g) (p<0.05). Release kinetics studies revealed 71.55±4.09% burst drug release from BG which was significantly higher (p<0.01) than the 40.25±3.76% released from mBG at 0-6 h. Thereafter, both samples showed comparable cumulative release rate of 0.588±0.07 µ g/ml/h and 0.766±0.08 µ g/ml/h from BG and mBG respectively. At the end of 35 days, drug retention on mBG was (44%) which was significantly higher than that retained on BG (2.7%). ATR-FTIR analysis suggested that the slow rate of release of nafcillin from mBG is attributed to the chemisorption of the drug molecules to the PO4

-3

and CO3-2 available on the hydroxyapatite surface layer. On the other hand, there were no measurable

changes in the ATR-FTIR bond energy of the functional groups of BG after drug loading suggesting physisorption. The results of the study demonstrate the ability of the calcium phosphate functional groups to control drug binding and release from biomaterials. .

Keywords: Bioactive glass, Drug delivery, Nafcillin Sodium, Surface modification

1. INTRODUCTION

Many biomaterials have been employed as antibi-otic carriers to provide sustained drug release locallyto treat infected wound. These include polymethyl-methacrylate (PMMA) beads, polylactic acid compo-sites, calcium phosphates, plaster of Paris and bioac-tive glasses [1-5]. Standard melt derived 45S5 bioac-tive glass is widely applied as bone graft material forsmall bone defects, bioactive coatings for orthopedicimplants [6] and as filler particles in biopolymer com-posites [7,8]. It has excellent bioactivity, biocompati-bility, osteogenic and angiogenic effects [9-11]. How-ever, 45S5 bioactive glass has limited control over

drug binding and release due to the limited surfacearea and weak interfacial bond with drug molecules[12].

Several researchers have incorporated antibioticsinto sol-gel bioactive glasses and investigated theirability to bind and release drug in a controlled fashionto treat bone infection [13-15]. A ceramic–glass ma-trix loaded with vancomycin showed a maximum rateof drug release after 3 days at which the concentrationof the released drug exceeded the range of therapeuticdose into the potentially toxic concentration range[15]. As diffusion-dependent sustained release stage,


the concentration of the drug dropped rapidly to be-come suboptimal and its therapeutic benefit was lost[15,16]. Han et al. loaded meso–macroporous bioac-tive glass with Ibuprofen and reported the rapid drugrelease of 40% within 0.5 h and 75% at 24 h [17]. Tri-als to control drug binding and release kinetics in-cluded change in glass composition [18,19], creationof BG composites [20], binding the drug to a stabiliz-ing agent before loading [21] or changing the drugloading technique into the material [22,23].Domingues et al. tried to increase the release durationof tetracycline from sol-gel bioactive glass by using acomplex of tetracycline and β-cyclodextrin, at 1:1molar ratio [21]. However, this approach compro-mised the potency of tetracycline and resulted in ahigh drug retention with total release of 22–25% af-ter 80 days. Nandi et al. impregnated cefuroxime ax-etil in bioactive glass composite by simple vacuuminfiltration and reported an initial high rate of releasefor three days after which it dropped significantly andstopped after 6 days [24]. The high drug release ratein the first 3 days was correlated to the macropores ofthe struts and the lower drug release rate at day 3-6was attributed to subsurface micropores formed as aresult of heterogeneous nucleation of Ca–P phasesafter the initial glass surface dissolution.

Trials to reduce the high rate of drug release frombioactive glass included coating with natural biode-gradable polymer [19,25]. Coating porous bioactiveglass with 0.5–1% chitosan decreased the burst re-lease and the overall release rate. However, chitosancoated bioactive glass was mildly cytotoxic withmoderate wound healing potential [19].

Soaking mesoporous bioactive glass samples indrug solution allows for the entrapment of the biolog-ical molecules inside pores with or without chemicalbonding. Comparison between melt-derived and sol-gel bioglass showed that the later material has overtwofold higher drug-uptake capacity than that of theformer scaffold [18]. The slow gentamicin releaserate from mesoporous BG was explained by the slowdiffusion through the mesoporous channels that con-nect the drug by hydrogen bond. The hydrogen bondcan be accomplished by the interaction of hydroxyland amino groups of the drug molecules with the Si–OH groups and P-OH groups present on the bioactiveglass surface [26]. In addition, drug molecules canjust be physically adsorbed on the surface [27]. Noneof the above studies have addressed the goal of ad-dressing the effect of the interfacial bond betweendrug molecules and the biomaterial carrier on bindingand release kinetics. The objective of the presentstudy is the synthesis and characterization of nafcil-lin-BG hybrid and analysis of the effect of glass sur-face modification on drug binding and release kinet-ics.

2. MATERIALS AND METHODS

2.1 Surface treatment of bioactive glass

Bioactive glass (Sylc®) with particle size 25-120µm was obtained from Denfotex Research Ltd., UK.The BG particles (7 g) were immersed in 3 L simu-lated body fluid (SBF) at 37oC. The pH of the SBFwas adjusted to 6 in order to minimize the alterationof the solution pH due to accumulation of the degra-dation products of the BG. After 1 week, the BG par-ticles were collected and dried at 37oC for 48h.

2.2 Drug loading

Nafcillin sodium (Sigma Aldrich, USA) solutions ofconcentration (10 mg/ml) was prepared in DI water.One milliliter of the nafcillin solution was separatelymicropipetted on 0.2 g control unmodified (BG) andmBG particles in 60 ml sterilized polystyrene con-tainers and incubated at 37oC for 1 hour. The drugconcentration in the solution was measured beforeand after immersion using a UV-Vis spectrophotom-eter (BOECO S-20, Germany) at 325 nm. The BG-antibiotic constructs (BG-N and mBG-N) were driedat 37oC overnight. All samples were performed infive replicates (n =5). The antibiotic uptake by thegranules was calculated as the difference in solutionantibiotic concentration before and after particles im-mersion. The efficiency of drug loading was calcu-lated as the percentage of adsorbed drug from the in-itial amount (10 mg) in the immersion solution

2.3 Determination of Release Kinetics

The BG-N and mBG-N particles in five replicates(n =5) were separately immersed in 15 ml of a drug-free SBF at slightly acidic pH = 6, at 37oC. The acidicpH was selected to mimic the pH of the infectedwounds. To determine the concentration of nafcillinreleased from the samples into the SBF, 50% of theSBF volume was withdrawn and replaced by anotherfresh SBF after 1, 3, 6, 24 h, then after 2, 3, 6, 9, 12,15, 21 and 35 days. The concentration of the releasednafcillin in the collected samples was calculated usinga calibration curve of known drug concentrations inthe range 7.8 - 250 µg/ml.

2.4 Material Characterization

2.4.1 Attenuated Total Reflectance Fourier Transf- orm Infrared Spectroscopy (ATR-FTIR)

ATR-FTIR analysis were performed for BG and mBGparticles before and after drug loading as well as dur-ing drug release employing (ATR-FTIR 6100 Jasco,Japan) spectrometer in the wave number range 400-4000 cm-1

20 Karima Ahmed et al.: EFFECT OF CALCIUM PHOSPHATE SURFACE LAYER ON DRUG.....................

2.4.2 Scanning Electron Microscopy-Energy disper-sive X-ray analysis

The surface morphology of the BG and mBGbefore and after drug binding and release was charac-terized using scanning electron microscope-energydispersive X-ray analysis (SEM; QUNTA FEG 250and EDAX; AMETEK OCTANE PRO, USA). Thesamples were coated with gold before analysis.

2.5 Statistical analysis

Five (n = 5) replicates were used for drug loading andrelease kinetics. Statistical analysis was performedusing T-test. The level of significance was set atP<0.05.

3. RESULTS

3.1 Drug loading on bioactive glass particles

mBG adsorbed significantly higher amount of nafcil-

lin (15.445±2.98 mg/g) compared to BG (9.52±1.4mg/g) (p < 0.05) (Fig. 1). The efficiency of nafcillin

loading onto mBG and BG particles was 30.89±6%

and 19.04±2.8% respectively (Fig. 1).

Fig 1. The amount (mg) and the efficiency (%) of nafcillinadsorbed on control BG and mBG particles.

3.4 ATR-FTIR surface chemistry analysis

Measurements of drug concentration (Fig. 2) showedsignificant increase in the rate of nafcillin releasefrom BG compared to mBG. During the burst release

stage (0-6 h), BG released 71.55±4.09 % of the

loaded drug while mBG released 40.25±3.76% (Fig.

2). After 6 h, BG and mBG showed first-order releasekinetics with an average cumulative release rate of

0.588±0.07 µg/ml/h and 0.766±0.08 µg/ml/h re-spectively (p<0.1) (Fig. 3). At the end of 35 days, BG

and mBG released 97.34±7.6% and 56.04±5.5% ofthe original loaded drug respectively.

Fig 2. Percent of nafcillin released from control BG andmBG into SBF.

Fig 3. Cumulative concentration of nafcillin released fromcontrol BG and mBG.

3.3 pH Changes

The SBF incubated with BG and mBG slightly in-creased up to 8.56 and 8.36 after 28 days respectively(Fig. 4).

Fig 4. pH measurements during drug release.

3.4 ATR-FTIR surface chemistry analysis

3.4.1 BG and mBG

ATR-FTIR analysis of control BG (Fig. 5) showed thecharacteristic peaks of amorphous 45S5 bioactiveglass including; bands at 1020, 914 and 760 cm-1

which are attributed to Si-O and Si-O-Si stretchingvibration, and symmetric stretching vibration, sv, re-spectively [28]. The peak at 464 cm-1 is attributed tothe Si-O-Si bending vibration [29]. Other studies


have reported similar FTIR bands for amorphous bi-oactive silicate glasses [28-32].

Fig 5. ATR-FTIR spectra of BG and mBG before drug load-ing

ATR-FTIR Spectrum of mBG (Fig. 5) showed three main bands attributed to PO4 group: 1022 cm-1 as-signed to P-O stretching vibration and the two bands at 603 cm-1 and 563 cm-1 are assigned to P-O bending vibration [33,34]. The shoulder at ~1240 cm-1 is cor-responding to P=O [28]. Moreover, new ATR-FTIR bands at 1425 cm-1 and at 877 cm-1 corresponding to the asymmetric stretching, av, and the symmetric bending, sv, of the CO3

-2 (C-O) appeared together with a free water band at 1631 cm-1 [28]. The new bands appeared in the spectrum of modified BG are consistent with the formation of a carbonate hydrox-yapatite (HCA) layer on the material surface in ac-cordance with the literature [33-36]. In conjunction with the deposition of mineralized HCA layer, signif-icant modifications in the two ATR-FTIR bands char-acteristic of the Si-O-Si bond was observed where the band at 914 cm-1 disappeared and that at 464 cm-1 was shifted to a lower wave number 457 cm-1.

3.4.2 BG and mBG after drug loading

ATR-FTIR spectrum for nafcillin sodium is shown inFigure 6. The bands in the range 1350-1550 cm-1 arecorresponding to N-H amide II of nafcillin [28]. Thebands at 1463, 1515, and 1598 cm-1 are due to C-Hbending, C=C, and amino group C=N stretching re-spectively [28,37]. After nafcillin loading, manychanges in the absorption bands (broadening, split-ting, or shifting) were observed in the ATR-FTIRspectra of control BG and mBG spectra (Figs.7, 8).

After drug loading, ATR-FTIR analysis of mBG-N(Fig. 7) showed an increase in the area under thev(PO4

-3) band accompanied by a shift in the peakmaximum from 1022 cm-1 to 1035 cm-1. The shift toa higher wavenumber of the ATR-FTIR band corre-sponding to P−O stretch vibration indicates an in-crease in the bond energy. In addition, the ATR-FTIR

Fig 6. ATR-FTIR spectra of nafcillin sodium

Fig 7. ATR-FTIR spectra of mBG before and after drugloading

Fig 8. ATR-FTIR spectra of control BG before and afterdrug loading

bands at 563 and 603 cm-1corresponding to P−Obending vibration of PO4

-3 tetrahedra in crystallineHCA layer [36] disappeared after drug loading. In ad-dition, the intensity of the bands at 846 and 1420cm-1

assigned for the C−O symmetric bending and asym-metric stretching decreased. Changes in the silicatebands after drug adsorption included shift in the sili-cate band from 457 to 466 cm-1 and the appearance ofa band at 925 cm-1 corresponding to Si-O group.Bands corresponding to N-H amide II of nafcillinwere appeared in the range 1350-1550 cm-1 [28]. Thechanges in the ATR-FTIR spectra of mBG after drugloading support the important role played by the P-Oand C-O functional groups on binding the drug mol-ecules to the material surface in drug binding.

Comparing ATR-FTIR spectra of control BG before


and after drug loading is shown in Figure 8. The fig-ure shows a decrease in silicate peaks at 756, 877 and914 cm-1 with increased intensity in orthophosphateband stretching vibration, v, at 1022 cm-1. After drugloading, an increase in the area under v(PO4

-3) bandwas measured. Pronounced bands characteristic forthe adsorbed nafcillin including the N-H amid II, C-H bending, C=C, and amino group C=N stretching vi-bration [28,37]. These changes in the ATR-FTIRspectra of control BG after drug loading indicate thebinding of drug to the material surface.

After 24 h immersion, mBG shows peaks at 563 and798 cm-1 which are due to P-O bending vibration, andP-O-P stretching respectively (Fig. 9). Characteristicbands of v(PO4

-3) are shown at 1031 and 1033 cm-1 incontrol BG and mBG spectra respectively. The Si-Ostretching mode band at 925 cm-1dimensionedstrongly in mBG spectra but still well appeared incontrol BG after 24 h.

Fig 9. ATR-FTIR spectra of control BG and mBG after 24h drug release

Figures 10 and 11 demonstrate the ATR-FTIR spectra for control BG-N and mBG-N during drug release, respectively. As the drug release duration increases, the orthophosphate bands at 560 and 600 cm-1and the CO3

-2 band at 871 cm-1 are demonstrated and be-come more pronounced in the spectra of BG and mBG.

Fig 10. ATR-FTIR spectra of control BG before and afterdrug loading and during drug release

Fig 11. ATR-FTIR spectra of mBG before and after drugloading and during drug release

3.5 Morphology and surface chemistry analysis

SEM analysis showed the deposition of aheavy HCA layer on the surface of mBG. EDX anal-ysis for BG and mBG is shown in Figure 12. The av-erage Na/Si atomic ratios were 0.87 and 1.43 on thesurface of mBG and control BG respectively. Thestructure of the hydroxyapatite layer was confirmedby the FTIR analysis (Fig. 5).

Fig 12. EDX of control BG (left) and mBG (right) beforedrug loading

Fig 13. SEM and EDX of a) BG and b) mBG after 7 daysimmersion during drug release

After 7 days of immersion in SBF, SEM-EDXanalysis of control BG showed the formation of a sur-face HCA layer (Fig. 13a) and a thickening of theHCA layer on the surface of mBG (Fig. 13b). In con-junction with the increased deposition of the HCAlayer, EDX showed a decreased Si concentration onthe surface and the average Ca/P atomic ratios were1.79 and 1.53 on the surface of mBG and control BGrespectively.


After 35 days, no silica bands appeared inEDX for both control BG and mBG. The averageatomic Ca/P ratio increased to 2.21 and 1.55 on thesurfaces of mBG and control BG respectively.

4. Discussion

Quantitative analyses of drug binding demonstrated that mBG adsorbed significantly higher amount of nafcillin (15.445 ± 2.98 mg/g) compared to control BG (9.52 ±1.4 mg/g) (p<0.05) (Fig. 1). The in-creased amount of drug loading on mBG is attributed to the physicochemical characteristics of the car-bonate hydroxyapatite surface layer. Previous studies have correlated the efficiency of incorporation of an-tibiotics into carbonated hydroxyapatite to the num-ber of carboxylic groups present in the drug mole-cules [38]. Antibiotics containing higher number of carboxylic groups have a better interaction with cal-cium of the bioceramic. Because of the chemical binding, the release rate of acidic antibiotics from the calcium phosphate coating was slow [38]. In our study, ATR-FTIR analysis (Fig. 7) showed an in-crease in the area under the P-O band together with a shift in the peak maximum from 1022 cm-1 to a higher wave number (1035 cm-1) after nafcillin binding. The increase in the P-O bond energy in ATR-FTIR of mBG is attributed to the involvement of the P-OH and P-O-Ca-O-P in binding the nafcillin molecules by chemisorption. The bond between nafcillin functional groups (HO-, and -COO-) and the glass positively charged groups (Ca++) enhances the P-O bond and increases its energy. The bond between positively charged functional groups on the drug molecules (e.g. NH3+) and the P-OH of the HCA layer is also respon-sible for the increase in the bond energy recorded for the P-O bond after drug loading. These hydroxyl groups are negatively charged and become potential bridging agents to sodium nafcillin. In a similar fash-ion, the NH3+ of nafcillin is expected to bond the drug molecule to the C-O groups of the HCA layer. Indeed, (Fig. 7) showed a decrease in the intensity of the C-O bands at 846 and 1420 cm-1 after drug loading. In addition, the HCA layer on bioactive glass surface is highly porous with nanometers to a few microns pore size [39-41]. The high porosity and surface roughness of the HCA layer increase the surface area available for drug binding. The limited adsorption of the nafcillin onto control BG compared to mBG is at-tributed to the relatively smaller surface area and to the higher dissolution rate of the surface of the former material.

Nafcillin binding to control BG was evidenced bythe presence of the nafcillin bands at 1402, 1463,1515, and 1598 cm-1 corresponding to N-H amid II,C-H bending, C=C, and amino group C=N stretchingrespectively. It could be argued that the higher inten-sity of the ATR-FTIR bands of nafcillin adsorbed ontocontrol BG, compared to mBG, is indicative of the

higher quantity of drug adsorbed on the former mate-rial. This is not true, UV-Vis quantitative analysismeasured a significantly higher quantity of nafcillinadsorbed onto mBG compared to control BG.Therefore, the difference in the band intensity couldbe attributed to the surface roughness and porosity ofthe HCA layer as well as to the difference in the con-formation of the adsorbed nafcillin molecules on thesurface of the two materials. This is particularly truein view of the difference in the nature of adsorptionon BG and mBG. For control BG, ATR-FTIR analysisshowed that drug binding was not associated with anyshift in the v Si-O-Si or the P-O bands (Fig. 8) indi-cating physisorption.

The dynamic of the bioactivity reactions naturallytaking place on the BG surface in physiological solu-tion is associated with multiple switches in the surfacecharge of the material [42]. The release of Na+ ionsleaves behind a glass surface rich in negativelycharges hydroxyl ions which increases the zeta poten-tial in the negative direction. Furthermore, the in-crease in the solution pH after Na ions release in-creases the number of hydroxyl ions around the glassparticles. The repulsion between the hydroxylated BGsurface and negatively charged drug functionalgroups would make it harder for the nafcillin to ad-sorb and accumulate onto the surface of the controlBG samples. For the same reasons, control BG re-leased 71.55±4.09 % of the loaded drug in the burstrelease stage (0-6 h). Moreover, EDX analysis (Fig.12) showed a significantly higher average Na/Siatomic ratio on the surface of control BG (Na/Si =1.43) compared to that (Na/Si = 0.87) on the surfaceof mBG. The high Na content motivates high surfacedissolution and hence more drug elution in the burstrelease stage. On the other hand, the surface of mBGis covered by a rough HCA layer which is known toform on the top of a silica rich layer [43-45]. The dualsilica-rich and the HCA layers serve as barrier againstthe dissolution of the mBG and hence stabilize the ad-sorbed drug layer and facilitated relatively low 40.25±3.76% burst release from mBG.

After 6 h, the rate of drug release from control BGslows down and becomes similar to that of drug re-leased from mBG after 72 h. The decrease in the drugrelease rate from control BG is attributed to the for-mation of a HCA layer on the material surface as con-firmed by ATR-FTIR and SEM-EDX (Figs.10, 13a).As the immersion period in SBF increased, the rate ofdrug release from both BG and mBG were similar in-dicating that the HCA layer formation is the dominat-ing factor controlling the release kinetics from bothcarriers. Data in the literature have associated the de-crease in the drug release rate from BG to the deposi-tion of calcium phosphate phase [46]. Moreover, itwas noted that CaO content in bioactive glass compo-sition influences the release kinetics because of thechelation between the drug and the calcium species[47].


The initial low pH of the physiological solutionused in the present study is relevant to a range of clin-ical conditions including bacterial infections [48], in-flammation [48] and oral cavity after consumption ofacidic beverages [49]. However, pH measurementsshowed that during drug release the dissolution prod-ucts of BG caused a slight pH rise (Fig. 4) which in-dicates that the use of BG as antibiotic carrier can alsocounteract the pH drop during bacterial infections[50]. The increase alkalinity of the solution have beenshown to disfavor protein interaction with mesopo-rous and dense hydroxyapatite particles due to the in-creased negativity of the zeta potential [51-53]. In ourstudy, the increase in medium pH facilitated nafcillinrelease from both materials, however since mediumincubated with BG had higher pH, the release rate wasfaster especially in the time period before the for-mation of the HCA layer. It should be noted that theeffect of dissolution products of BG on raising the pHof the tissue fluid [54,55] may be eased by the fluidturn-over and the acidic products produced by cells.Results of our study as well as others in the literature[56-58] demonstrated the enhancement effect of thelow pH on the deposition of the bioactive hydroxyap-atite layer on the glass surface. Therefore, the low pHcaused by bacterial infection is unlikely to inhibit ap-atite formation [57].

5. Conclusion

While BG surface dissolution is an essential stepthat results in a Si-rich surface that nucleates the dep-osition of the HA layer necessary for bone bonding,the high surface mobility does not support drug bind-ing and long term controlled release. The pre-deposi-tion of the HCA layer before drug loading created asurface that enhanced drug loading and long termcontrolled release. However, the concentration of thereleased drug in the sustained release stage was belowthe minimum inhibitory concentration. The slow rateof release of nafcillin from mBG and the high drugretention are attributed to the chemisorption nature ofthe interfacial bond. Results of the study indicate thepossibility of engineering drug binding and release ki-netics by calcium phosphate coating on the bio-material carriers.

6. Acknowledgements

This work was financially supported by Aljouf Uni-versity, Kingdom of Saudi Arabia, project number222/34.

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Published online June 2015 (http://vrgs.ju.edu.sa/ #)ISSN: 1658-6670

1. INTRODUCTION

Expansive soils are considered a natural hazard forpavements and light structures at many countries aroundthe world. These soils undergo significant change involume (swell and shrinkage) due to changes inmoisture content. This swell-shrink behavior ofexpansive soils causes distress in the structures that arefounded on this kind of soils. Understanding theexpansive mechanism and the factors affecting theswelling behavior was studied extensively [1,2,3,4,5].The swelling of soils is due to the presence ofexpanding clay minerals, such as smectite, that absorbwater, the more content of this clay causes higher soilswell potential and the more water it can absorb.Expansive soils cover a vast area of the Kingdom ofSaudi Arabia (KSA) estimated to be about 800,000 km2

as found in [6]. Figure 1 shows the distribution ofexpansive soils in the Kingdom of Saudi Arabia.According to Ruwaih [6], the expansive soils in SaudiArabia can be identified as clayey shale formations,clay, and calcareous clayey soils. Clayey shaleformations are encountered in cities Al Ghatt, Tymaa,Tabuk, and Tabarjal. Clayey soils are located in a

Madina, and calcareous clayey soils prevail in theeastern region of the Saudi Arabia.

Fig 1. Distribution of expansive soil in KSA.

EFFICIENCY OF GPAF SYSTEM ON EXPANSIVE SOIL ATTABUK CITY, SAUDI ARABIA.

Osama M. Ibrahim1, Tamer Y. Elkady2,3 and Mohamed I. Amer4

1Geotechnical Engineer, Faculty of Engineering, Cairo University, Giza, Egypt.2Department of Civil Engineering, College of Engineering, King Saud University, Riyadh, SA.3SMFRL, Faculty of Engineering, Cairo University, Giza, Egypt.4Professor, SMFRL, Faculty of Engineering, Cairo University, Giza, Egypt.

Corresponding authorOsama M. Ibrahim

E-mail address:[email protected]

Expansive soils cause many problems and cracks in most structures and roads, which are constructed on it. Theresearch is aimed at studying the efficiency of granular pile anchor foundation (GPAF) system in reducing heave ofslab on-grade constructed on expansive soils in the city of Tabuk, Saudi Arabia. Initially, the geotechnical propertiesand swelling characteristics of Tabuk shale were determined. In the field, two full scale reinforced concrete slab ongrade with and without granular anchor piles were constructed on top of the expansive shale. The field models wereconstructed to evaluate the efficiency of the (GPA-Foundation system), Monitoring the performance of two slabsafter wetting indicated that the GPAF system caused a 57% reduction in upward movement due expansive shaleheave. Furthermore, a numerical model is analyzed using the finite element package PLAXIS software showed agood agreement with field measurements.

Keywords: Expansive soil, slab, granular pile anchor, heave, finite element.



1. INTRODUCTION














1. INTRODUCTION












and Engineering Journal 2015; 2(1): 27-33

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Different techniques are used to mitigate expansive soilseffects on the constructions. These techniques involveuse of stiffened foundations, expansive soil replacement[7], Chemical stabilization using cement, lime, and flyash [8,9], and soil reinforcement using soil anchoring[10], micro piles [11], stone columns [12] and granularpile anchor [13]. The suitability of a mitigationtechnique depends varies from area to another as itinvolves many parameters.

Granular pile anchor foundation system (GPAF) is aninnovative foundation technique used in mitigatingheave of expansive clay and improving theirengineering behavior. It is a modification of theconventional granular pile. Granular piles are a well-known ground improvement technique used forreducing the settlement and increasing load-carryingcapacity of soft clay beds [12]. In a granular pile anchor,the foundation is anchored at the bottom of the granularpile to an anchored steel plate with the help of a mildsteel rod. This renders the granular pile to be tensionresistant and enables it to offer resistance to the upliftforce exerted on the foundation by the swelling soil.Figure 2 shows a typical schematic representation of thefundamental concept of a granular pile anchorfoundation (GPAF) system and the various forces actingon the foundation. The uplift force acting on the base ofthe foundation in the vertical direction is due to theswelling pressure of the expansive soil. This uplift forceis resisted by the weight of the granular pile acting inthe downward direction. The friction mobilized alongthe pile-soil interface also resists the upward movementof the foundation. This friction is generated mainlybecause of the anchor in the system. The upwardresistance is further augmented by the lateral swellingpressure, which confines the granular pile anchorradially, increases the friction along the pile soilinterface, and prevents it from being uplifted [14].

An experimental laboratory testing program usinggranular pile anchor conducted by [15] showed that theheave response is non-linear behavior and increasescontinuously with time until reach the equilibrium.Furthermore, they reported that the heave of GPAFsystem decreases with installation of granular pileanchor in expansive soil and decreases more byincreasing pile depth and/or pile diameter. Similarresults were obtained for research conducted by[13,16,17,18].

In this study, the efficiency of GPAF system in heavereduction of field slab on-grade model constructed onexpansive soil in City of Tabuk, Saudi Arabia wasinvestigated in this paper.

Fig 2. Concept of granular pile anchor foundation system

2. DESCRIPTION OF FIELD WORK

Work strategy includes soil investigation of testing area,determination of the geotechnical soil properties atlaboratory, and construction of field models.

2.1. Site Selection and Subsurface Stratigraphy

The site at which the proposed field test was constructedis located within bounds of the University of Tabuk –Ladies Campus in the Masif District, northwest ofTabuk. An approximate location of the site was shownin Figure 3. This site was selected due to structuraldamages observed in campus building attributed toexpansive shale.

Fig 3. Testing area location at girls university, Tabuk – SaudiArabia.

Footing

Granularpile-anchor

Anchor rod

Anchorplate

Resisting forcein the downwarddirection due to

the friction

Upward force on thefooting due to

swelling

Aljouf University SciencPublished online June 2015 (http://ISSN: 1658-6670











Footing

Granularpile-anchor

Anchor rod

Anchorplate


the friction


swelling













Footing

Granularpile-anchor

Anchor rod

Anchorplate


the friction


swelling



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Prior to test construction of field model, a borehole wasdrilled at testing test location to depth of 8.0m. Thesubsurface layers encountered at the site are illustratedin Figure 4. Additional four boreholes drilled at thetesting location to depths ranging from 15m to 20mconfirmed the presence of shale formation that extendedto the maximum drilled depths. Visual observations ofsamples obtained from boreholes classified as laminatedweathered shale. Summary of geotechnicalcharacteristics is provided in table 1.

Fig 4. Sub-surface layers log

Table 1. Physical properties of natural soil

Property Value

Dry density (gm/cm3) 1.7

Specific gravity 2.76

Natural water content (%) 3.1

Liquid limit (LL) % 55.7

Plastic limit (PL) % 25.2

Plasticity index (PI ) % 30.5

Shrinkage limit (SL) % 19.6

Degree of saturation (S) % 14.0

Sand content % 6.7

Silt content % 52.3

Clay content % 41.0

Clay activity(A) 0.74

Swelling pressure (kN/m2) 120

Free swell % 97

USCS : Unified Soil

Classification

CH

2.2 Concrete Slab Construction

The field work involved constructing two full-scalereinforced concrete slabs on top of the expansive shalelayer encountered at the test site (i.e., foundation level isapproximately 3.5 m below ground surface). One slabrepresenting a regular footing, while the other slabsimulates the GPAF system with four granular pileanchors at a spacing of 1.0 m center-to-center as shownin Figure 5. The granular pile anchors had dimensionsof 2.0 m depth and 0.2 m in diameter. Constructionsequence of granular pile anchors involved hole drillingusing a machine driven auger and compressed air,placement of steel anchor, and compaction of granularmaterial (1:1aggregate of maximum size 20 mm tosand). The steel anchor comprised of a steel bar with asteel plate welded to one of its ends. The anchor wasextended above foundation level to ensure anchorage toconcrete slab foundation as shown in Figure 6.

Fig 5. Schematic drawing for slab supported by GPA-foundation





Property Value









Sand content % 6.7

Silt content % 52.3

Clay content % 41.0



Free swell % 97

USCS : Unified Soil

Classification

CH



slab supported by GPA-ion






Property Value









Sand content % 6.7

Silt content % 52.3

Clay content % 41.0



Free swell % 97

USCS : Unified Soil

Classification

CH



Fig 5. Schematic drawing ffound

Fig 5. Schematic drawing foor r slab supported by GPA-foundaat tion

29Osama M. Ibrahim et al.: EFFICIENCY OF GPAF SYSTEM ON EXPANSIVE SOIL.....................


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Fig 6. Installation of GPA

Finally, reinforced concrete slabs with plan dimensions2.0 m x 2.0 m and thickness of 0.40 m were casted inplace as shown in Figure 7, using ready-mix normalweight concrete with a target compressive strength of25 MPa after 28 days. A sand trench of 0.3 m width and0.4m depth was dug around the slab as shown in Figure5 to facilitate the infiltration of water into the expansivesoil underneath the slabs.

Fig 7. Slab on-grade model

The testing area and sand trench was submerged withwater continuously three times weekly. As waterinfiltrates beneath the slab, soil experienced swellingand swelling pressure underneath the slabs increased.The upward movement of slabs was monitored bysurveying instruments. At end of field testing period,one borehole was drilled using compressed air toinvestigate the depth of infiltrated water underneath theslab which was measured to be 0.9 m. This correspondsto a volumetric strain in saturated shale layer of 14%.

3. NUMERICAL ANALYSIS

PLAXIS 2D-Version 8.2 finite element program wasused in numerical modeling of the GPAF system. In thismodel, the active zone of the expansive soil is thewetted depth which was observed to be 0.9 m. A

verification model was constructed to simulateobservations in the field. As the volumetric strainthrough the wetted shale layer is not uniform alonglayer depth, and for simplicity, the wetted subsurfacelayer beneath the slab in the model was divided into twolayers have thicknesses of 0.5 m, and 0.4 m,respectively. The geometry section of model for finiteelement modeling is shown in figure 8.

Fig 8. Schematic drawing for slab supported by GPAF

Figure 9 shows the model of described problem. Thesoil parts are modeled using 15-node triangular element.The slab and anchor plate are modeled using plateelement, while the anchor rod is modeled using node-to-node element. The shale material under the slab andgranular pile material were modeled using Mohr-Coulomb (MC) model, assumed to behave in thedrained manner. Steel is used as a material for anchorplate, anchor rod and slab on-grade, and assumed aslinear elastic model. Summary of materials and modelsparameters used in the analysis are listed in Tables 2and 3. In plaxis 2D analysis in this research, theequivalent pile thickness assumed same value of pilediameter. The swelling action in the wetted zone of theshale is modeled by applying a positive volumetricstrain of 14% and 7% to the expansive clay layers 1 and























2 respectively, these volumetric strain values wereassumed to achieve a numerical model verifying theupward movement occurred in the field model. In fact,the rate at which expansive clay would normally swelldepends on the location from the source of moisture andmagnitude of overburden pressure. However, forsimplicity, in the analyses presented herein, thevolumetric strain was applied uniformly across the fullthickness of the expansive soil layers.

Fig 9. Descriptive Sketch of Geometry model

Tables 2. All materials and models with set of parameters arelisted in

GPLayer 3Layers1 & 2

Layer no.

MCMaterial modelDrainedType of material behavior

18.017.016.0Soil dry unit weight, γ dry

(kN/m3)

20.019.018.0Soil saturated unit weight,γsat. (kN/m3)

1.00.010.01

Horizontal permeability,Kx(m/day)

1.00.010.01Vertical permeability,Ky(m/day)

15000010000034000Young’s modulus, E ref(kN/m2)

0.20.40.4Poisson’s ratio, ν51010Cohesion, c ref

401818Friction angle, φo

Table 3. Material properties of plate and anchor elements

Anchorrod

Anchorplate

Slab on-grade

Parameter

ElasticElasticElasticMaterial behavior

2.24 x 1041.5 x 1053.7 x 107Normal stiffness,EA (kN/m)

------------0.81.07 x 105Flexural rigidity,EI (kN.m2/m)

------------0.0080.19Equivalentthickness, D (m)

------------0.10.1Poisson’s ratio, ν

4. RESULTS AND DISCUSSIONS

4.1. Effect of GPAF on upward movement ofslabs

By supplying water to the testing area, shale swellingpressure resulted in increase in uplift displacement ofslabs. After test period, the displacement of slab on-grade foundation was 125 mm, while the displacementof the GPAF system was 54 mm. This corresponds to a57% efficiency in reducing the upward movement dueto the use of GPAF system in. Figure 10 shows theuplift displacement occurred for the tested slabs.

Fig 10. Displacement measurements of slab on-grade modelsduring test period

4.2. Finite Element Modeling of Slab On-gradeUsing GPAF

The field model for the GPAF system showed a verticaldisplacement of was 54 mm while the upliftdisplacement deduced from plaxis model for the slabhas value almost as the field model which was 51.3 mm.Therefore, there is a good agreement between field

0

20

40

60

80

100

120

140

0 10 20 30 40 50 60 70 80

Upl

ift

mov

emen

t (m

m)

Time (day)

slab on-gradeplaced onnatural soilSlabsupported byGPAF

31Osama M. Ibrahim et al.: EFFICIENCY OF GPAF SYSTEM ON EXPANSIVE SOIL.........................


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observation data and finite element analysis. The modeldeformed shape due to swelling effect is illustrated inFigure 11.

Fig 11. Deformed model shape

Series of Plaxis models were constructed to investigatethe efficiency of GPA in mitigate the swelling effect.The studied parameters was GPA depth and diameter.Using GPA with diameter of 20 cm and lengths varyingbetween 1.5 m and 3.0 m, reduces the upwardmovement of slab from 63.3 mm to 43.4 mm, whileusing 30 cm diameter of GPA for same depths reducesthe slab on-grade displacement from 53.6 mm to 35.7mm. The heave below slab reduced by increasing piledepth inside non-swelling soil. The efficiency of the(GPA-Foundation System) in arresting the heaveinduced by expansive soil layer is shown in figure 12.

lacement

5. Conclusions

Field testing and numerical modeling were conducted tostudy the performance of the GPAF in expansive soil atfield. This study focuses on studying the efficiency ofGPAF system in minimizing heave of slabs founded onexpansive clay. The main conclusions that can bederived from this study are summarized as follows:

1. Installation of granular pile anchors in expansive soilreduces the amount of heave effectively.

2. The efficiency of GPAF system in heave reductioncan be developed when granular pile anchorsembedded in expansive soil layer and extend to non-expansive clay layer at sufficient depth.

3. At field model, the GPAF system reduced theupward slab displacement caused due to the swellingeffect by 57%.

4. Heave reduction in GPAF system can be attributedto the frictional resistance mobilized along the pile-soil interface, the effect of anchorage which rendersthe granular pile to be tension resistant and enables itto resist the uplift force exerted on the foundation. Inaddition, the upward resistance augmented by thelateral swelling pressure, which confines the GPAradially, increasing the friction along the pile soilinterface, and increase the uplift resistance.

5. Installation of GPAF system in expansive soilaccelerate the rate of heave, as the higherpermeability of the granular material allows a quickpervasion and absorption of water and the path ofradial inflow of water becomes shorter resultingquick moisture changes.

References

[1] A. Casagrande, Classification and Identification ofSoils. Transactions of ASCE, 113 (1948) 901-931.

[2] F.H. CHEN, Foundations on Expansive Soils. Devel.in geotechnical engineering, Elsevier, Amsterdam.(1975) 12.

[3] W.G. Holtz, and H.J. Gibbs, Engineering propertiesof expansive soils. Transactions of ASCE, 121(1956) 641-679.

[4] D.E. Slater, Potential Expansive Soils in ArabianPeninsula. Transactions of ASCE, 109 (1983) 746-774.

[5] A. Sridharan, and K. Prakash, Classificationprocedures of expansive soils. Proceedings of





Fig 12. Effect of GPA depth on slab diFig 12. Effect of GPA depth on slab disspplacement

5. Conclusions







References






3.0Pile depth (m

Pile diametercm






Fig 12. Effect of GPA depth on slab displacement

5. Conclusions







References







Institution of Civil Engineers, GeotechnicalEngineering, 143 (2000) 235-240.

[6] I.A. Ruwaih, Experiences with Expansive Soils inSaudi Arabia. Proceedings of the Sixth InternationalConference on Expansive Soils, New Delhi, India,(1987) 317–322.

[7] B. Satyanarayana, Behavior of expansive soil treatedor cushioned with sand. Proceedings of 2nd NationalConference on Expansive soils, Texas, (1969) 308-316.

[8] B.M. Das, Principles of Foundation Engineering.Fifth Edition, Tomson Books, California, USA,(2004).

[9] B.R. Phani Kumar, and R.S. Sharma, Effect of FlyAsh on Engineering Properties of Expansive Soils, JGeotechnical and Geo-environmental Eng. 130(2004) 764–767.

[10] D.A. Greenwood, Mechanical Improvement ofSoils Below Ground Surface. Proc GroundEngineering Conference, Inst. of Civil Engrs.,London, (1970) 9-20.

[11] O.K. Nusier, A.S. Alawneh and B.M. Abdullatit,Small scale micropiles to control heave on expansivesoils. Ground Improvement Journal, ASCE, (2009)II 27-35

[12] J.M. Hughes, and N.J. Withers, Reinforcing ofSoft Cohesive Soils with Stone Columns. GroundEng., 17 (1974) 42-49.

[13] P.H. Krishna, V.R. Murty, and J.A. Vakula. FiledStudy on Reduction of Flooring Panels Resting onExpansive Soils Using Granular Anchor Piles andCushions, Int. J. Eng. and Sci. (IJES), 2 (2013) 111-115.

[14] A.D. Muawia, and A.M. Al-Shamrani, SwellingCharacteristics of Saudi Tayma Shale andConsequential Impact on Light Structures. J CivilEng. . Archit., 8 (2014) 613-623.

[15] F.I. Saad, N.A. Ala, and I.A. Ahmad, HeaveBehavior of Granular Pile Anchor-Foundation(GPA-Foundation) System in Expansive Soil, J CivilEng. and Urbanism, 4 (2014) 213-222.

[16] M.A. Ismail, and M. Shahin, Finite ElementAnalysis of Granular Pile Anchors as A FoundationOption for Reactive Soils. International Conferenceon Advances in Geotechnical Engineering, Perth,Australia (2011).

[17] B.R. Phani Kumar, R.S. Sharma, R.A. Srirama, andM.R. Madhav, Granular Pile - Anchor Foundation

(GPAF) System for Improving the EngineeringBehavior of Expansive Clay Beds, (ASTM)Geotechnical Testing Journal, 27, (3) (2004) 279 –287.

[18] B.R. Phani Kumar, R.A. Srirama, and K. Suresh,Field Behavior of granular pile – anchors inexpansive Soils. Ground Improvement, Proceedingof the Institution of Civil Engineers 161(G14)(2008) 199-206.

33Osama M. Ibrahim et al.: EFFICIENCY OF GPAF SYSTEM ON EXPANSIVE SOIL...................

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