http://www.mjfas.utm.my/index.php/mjfas/issue/feedMalaysian Journal of Fundamental and Applied Sciences2017-09-11T10:33:04+08:00Prof. Dr. Hadi Nurhadi@ibnusina.utm.myOpen Journal Systems<p style="margin-top: 0; margin-bottom: 0;" align="right"> </p><p style="margin-top: 0; margin-bottom: 0;" align="right"><img src="/files/journals/1/promote.gif" alt="" border="0" /></p><p style="margin-top: 0; margin-bottom: 0;"><iframe name="ifrm1" src="http://hadinur.com/slidemjfas/slide.html" frameborder="0" scrolling="no" width="100%" height="271"></iframe></p><p style="margin-top: 0; margin-bottom: 0;"> </p><table style="margin-top: 0; margin-bottom: 0;" width="100%" border="0"><tbody><tr><td width="230"><p style="margin-top: 0; margin-bottom: 0;"><a href="http://ip-science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=EX&ISSN=2289-5981" target="_blank"><img src="/files/journals/1/esci.gif" alt="" width="150" height="150" border="0" /></a></p></td><td width="801"><p style="margin-top: 0; margin-bottom: 0;" align="left"><span>Journal abbreviation: </span><strong>Mal. J. Fund. Appl. Sci.</strong></p><p style="margin-top: 0; margin-bottom: 0;" align="left"><strong></strong><strong>ISSN: 2289-5981. e-ISSN: 2289-599X.</strong></p></td></tr></tbody></table><p style="margin-top: 0; margin-bottom: 0;" align="justify"><span style="font-size: 10px;"><strong><br /> </strong></span></p><p style="margin-top: 0; margin-bottom: 0;" align="justify">The Malaysian Journal of Fundamental and Applied Sciences (MJFAS) (formely known as Journal of Fundamental Sciences, ISSN: 1823-626X) is a refereed research journal published by Penerbit UTM Press, Universiti Teknologi Malaysia. The aims and scope of the journal encompasses research articles, original research reports, reviews, short communications and scientific commentaries from fundamental principles to practical applications in the broad field of mathematics, physics, chemistry and biology. All manuscript submissions must be made through the journal's online manuscript system at <a href="/index.php/mjfas/about/submissions#onlineSubmissions"> Online Submissions</a>. This journal is indexed by <a href="http://ip-science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=EX&ISSN=2289-5981" target="_blank">ISI Web of Science</a><span style="margin-top: 0; margin-bottom: 0;">, </span><a href="http://www.mycite.my/" target="_blank">MyCite</a>, <a href="http://my-ais.org/" target="_blank">MyAis</a>, and <a href="http://scholar.google.com" target="_blank">Google Scholar</a>.</p><p style="margin-top: 0; margin-bottom: 0;" align="justify"> </p><p style="margin-top: 0; margin-bottom: 0;" align="justify">The <span>Malaysian Journal of Fundamental and Applied Sciences (MJFAS)</span> is now entering its twelfth year and it is now the official journal of the <strong><a href="http://imresearchconsortium.ning.com/" target="_blank">Indonesia-Malaysia Research Consortium</a></strong> (I'M Research Consortium). The consortium's aims are to foster the development of the field through a crossdisciplinary approach and to reach consensus in areas of common interest in fundamental and applied sciences field. By making The <span>Malaysian Journal of Fundamental and Applied Sciences</span> the official journal of the I'M Research Consortium, we hope to provide a forum to bring together society members and to publish peer-reviewed consensus documents that emerge from the activities of the consortium.<strong><br /></strong><strong><br /></strong></p><div id="mc_embed_signup"><form id="mc-embedded-subscribe-form" class="validate" action="//utm.us8.list-manage.com/subscribe/post?u=7752c8c8944df4c47c528d7f3&id=434f3356f7" method="post" name="mc-embedded-subscribe-form" target="_blank"><p><input id="mc-embedded-subscribe" class="button" type="submit" name="subscribe" value="Subscribe" /> <label for="mce-EMAIL">to <strong>MJFAS Newsletter</strong></label> <input id="mce-EMAIL" class="email" type="email" name="EMAIL" value="email address" /> <!-- real people should not fill this in and expect good things - do not remove this or risk form bot signups--></p><div style="position: absolute; left: -5000px; z-index: 1;"><input tabindex="-1" type="text" name="b_7752c8c8944df4c47c528d7f3_434f3356f7" value="" /></div></form></div><p style="margin-top: 0; margin-bottom: 0;"><strong><br /></strong></p><h3 align="left">The Publishing Process of MJFAS and its Requirements<strong><br /></strong></h3><p style="margin-top: 0; margin-bottom: 0;" align="justify">Below are the new requirements and other guidelines related to publication as well as communicating your results. <br /><br /></p><p style="margin-top: 0; margin-bottom: 0;" align="justify">[Click image to enlarge]<strong><br /></strong><strong><br /></strong></p><p style="margin-top: 0; margin-bottom: 0;" align="left"><a href="/files/journals/1/flow_big.png" target="_blank"><img src="/files/journals/1/flow.gif" alt="" border="0" /></a><strong><br /></strong><strong><br /></strong></p><p align="justify">Before the paper moves into production and is published <strong>(Step 9)</strong>, the author(s) needs to register as member of I'M Research Consortium <strong>(Step 8)</strong> through the following website:</p><p align="justify"><a href="http://imresearchconsortium.ning.com/main/authorization/signUp" target="_blank"><strong>http://imresearchconsortium.ning.com/main/authorization/signUp</strong></a></p><p align="justify">The MJFAS is an Open Access journal. Publishing an article in the MJFAS requires article processing charges that will be billed to the submitting author following the acceptance of an article for publication. Apart from these article processing charges, there are no submission charges, page charges, or color charges. The fee to be paid following the acceptance of an article. The fee is <strong>300 Malaysian Ringgit</strong>. Article processing charges will be used for operating expenses of the journal such as allowance to reviewers, layout editors and proofreaders.<strong><br /></strong><strong><br /></strong>For a detailed guidelines for submission of an article please refer to <a href="/index.php/mjfas/about/submissions#onlineSubmissions">Online Submission</a>. Please follow these guidelines to prepare and upload your article.</p><h3>Editor's Message</h3><p align="justify">Dear Colleagues,</p><p align="justify"><img style="border-width: 3; border-color: white; border-style: solid;" src="/files/journals/1/hadi.png" alt="" width="200" height="200" align="left" border="0" hspace="16" vspace="8" />As the Editor-in-Chief of the Malaysian Journal of Fundamental and Applied Sciences, I am writing to invite you to submit your most important research to the Journal. We envision the Journal as the best place to publish all of the levels of research in fundamental and applied sciences from all over the world, especially from researchers in Malaysia dan Indonesia.</p><p align="justify">Working with our knowledgeable and international Editorial Board members and I can assure you of a rapid, robust and fair peer-review process. As the Malaysian Journal of Fundamental and Applied Sciences is now indexed by <a href="http://ip-science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=EX&ISSN=2289-5981" target="_blank">Thomson Reuters Web of Science</a>, we are especially aiming to reduce time to decision. We also have begun to work towards raising the Journal’s impact factor.</p><p align="justify">For the coming submissions, the MJFAS will start implementing the "Your Paper, Your Way" initiative. In this way, authors can focus on the scientific quality of the paper. Journal-specific formatting such as reference style is no longer needed.</p><p align="justify">Thank you in advance for your valuable contributions to the Malaysian Journal of Fundamental and Applied Sciences.</p><p>Sincerely,<strong><br /></strong></p><p><img src="/files/journals/1/sign.gif" alt="" border="0" /></p><p style="margin-top: 0; margin-bottom: 0;"><strong>Prof. Dr. Hadi Nur </strong>(<a href="/index.php/mjfas/pages/view/hadi">short bio</a>)</p><p style="margin-top: 0; margin-bottom: 0;">Editor-in-chief</p><p style="margin-top: 0; margin-bottom: 0;">e-mail: <a href="mailto:hadi@ibnusina.utm.my" target="_blank">hadi@ibnusina.utm.my</a></p><p style="margin-top: 0; margin-bottom: 0;">website: <a href="http://hadinur.com" target="_blank">http://hadinur.com</a></p>http://www.mjfas.utm.my/index.php/mjfas/article/view/571Autocovariance and autocorrelation structures of the generalised autoregressive moving average (GARMA(1,3;δ,1)) model2017-09-11T10:33:04+08:00Suguneswary Ellappansugunes@gmail.comNorhashidah Awangshidah@usm.edu.myThulasyammal Ramiah Pillaihulasyammal.ramiahpillai@taylors.edu.myGeneralized ARMA (GARMA) model is a new class of model that has been introduced to reveal some unknown features of certain time series data. The objective of this paper is to derive the autocovariance and autocorrelation structure of GARMA(1,3;δ,1) model in order to study the behaviour of the model. It is shown that the results of this model can be reduced to the autocovariance and autocorrelation of the standard ARMA model as well as a special case. Numerical examples are used to illustrate the behaviour of the autocovariance and autocorrelation at different δ values to show the various structures that the model can represent2017-06-19T16:24:25+08:00Copyright (c) 2017 Suguneswary Ellappan, Norashidah Awang, Thulasyammal Ramiah Pillaihttp://www.mjfas.utm.my/index.php/mjfas/article/view/556On the generalized conjugacy class graph of some dihedral groups2017-09-11T10:33:04+08:00Nurhidayah Zaidedayahzaid@yahoo.comNor Haniza Sarminnhs@utm.myHamisan Rahmathamisan@utm.my<p>A graph is a mathematical structure which consists of vertices and edges that is used to model relations between object. In this research, the generalized conjugacy class graph is constructed for some dihedral groups to show the relation between orbits and their cardinalities. In order to construct the graph, the probability that an element of the dihedral groups fixes a set must first be obtained. The set under this study is the set of all pairs of commuting elements in the form of (<em>a</em>,<em>b</em>) where <em>a</em> and <em>b</em> are elements of the dihedral groups and the lowest common multiple of the order of the elements is two. The orbits of the set are then computed using conjugation action. Based on the results obtained, the generalized conjugacy class graph is constructed and some graph properties are also found.</p><p> </p>2017-06-19T16:24:25+08:00Copyright (c) 2017 Nurhidayah Zaid, Nor Haniza Sarmin, Hamisan Rahmathttp://www.mjfas.utm.my/index.php/mjfas/article/view/540Global convergence analysis of a new hybrid conjugate gradient method for unconstrained optimization problems2017-09-11T10:33:04+08:00Ibrahim Abdullahiiabdullahi94@gmail.comRohanin Ahmadrohanin@utm.myIn this paper, we propose a new hybrid conjugate gradient method for unconstrained optimization problems. The proposed method comprises of beta (DY), beta (WHY), beta (RAMI) and beta (New). The beta (New) was constructed purposely for this proposed hybrid method.The method possesses sufficient descent property irrespective of the line search. Under Strong Wolfe-Powell line search, we proved that the method is globally convergent. Numerical experimentation shows the effectiveness and robustness of the proposed method when compare with some hybrid as well as some modified conjugate gradient methods.2017-09-11T10:30:49+08:00Copyright (c) 2017 Ibrahim Abdullahi, Rohanin Ahmadhttp://www.mjfas.utm.my/index.php/mjfas/article/view/532Porosity effect on unsteady MHD free convection flow of Jeffrey fluid past an oscillating vertical plate with ramped wall temperature2017-09-11T10:33:04+08:00Nor Athirah Mohd Zinnorathirah24@gmail.comAhmad Qushairi Mohamadahmadqushairi91@yahoo.comIlyas Khanilyaskhanqau@yahoo.comSharidan Shafiesharidan@utm.my<p>The unsteady magnetohydrodynamic (MHD) free convection flow of Jeffrey fluid embedded in porous medium past an oscillating vertical plate generated by thermal radiation with ramped wall temperature is investigated. The incompressible fluid is taken electrically conducting under the action of transverse magnetic field towards the flow. Constitutive relation of Jeffrey fluid is employed to model the governing equations in terms of partial differential equations with some physical conditions. The transformed dimensionless governing equations are solved analytically using Laplace transform technique. The impact of various pertinent parameters namely material parameter of Jeffrey fluid , dimensionless parameter of Jeffrey fluid , phase angle , Hartmann number , permeability parameter , Grashof number , Prandtl number , radiation parameter and dimensionless time on velocity and temperature distributions are presented graphically and discussed in details. It is observed that, the permeability parameter tend to retard the fluid velocity for ramped wall temperature but enhance the velocity for an isothermal plate. Besides that, this study shows, the amplitude of velocity and temperature fields for ramped wall temperature are always lower than isothermal plate. A comparison with the existing published work is also provided to confirm the validity of the present results and an excellent agreement are found. </p>2017-06-19T16:24:25+08:00Copyright (c) 2017 Nor Athirah Mohd Zin, ahmad Qushairi Mohamad, Ilyas Khan, Sharidan Shafiehttp://www.mjfas.utm.my/index.php/mjfas/article/view/606Heat and mass transfer of steady magnetohydrodynamics mixed convection of dusty fluid flow with chemical reaction past an exponentially stretching sheet2017-09-11T10:33:04+08:00Siti Nur Haseela Izanisnhaseela_izani@yahoo.comAnati Alianati@utm.my<p>An analysis has been carried out to study a problem of the chemical reaction effects on magnetohydrodynamics (MHD) mixed convective boundary layer flow with a fluid-particle suspension due to an exponentially stretching sheet. The effects of magnetic field and mass transfer are taken into account for the first time in the dusty fluid over the exponentially stretching sheet. The governing partial nonlinear differential equations corresponding to the momentum, energy and concentration are converted into a system of ordinary differential equations by using similarity transformations. The relevant dimensionless equations are then solved numerically using Runge-Kutta-Fehlberg fourth fifth order method (RKF45) with the help of Maple symbolic software. The influence of physical parameters on the velocity, temperature and concentration distributions for both phases were discussed numerically and presented in details through plotted graphs and tables. Also, the numerical values of skin friction coefficient, Nusselt and Sherwood number of the governing parameters are analyzed and discussed in details. The outcomes show that the reaction parameter affects the fluid flow whereas the magnetic field retards the fluid flow. A comparative study of the present results with the previous study provides an excellent agreement.</p>2017-06-19T16:24:25+08:00Copyright (c) 2017 Siti Nur Haseela Izani, Anati Alihttp://www.mjfas.utm.my/index.php/mjfas/article/view/603Analysis and comparison of numerical algorithms for finding the GCD of certain types of polynomials in the Chebyshev basis2017-09-11T10:33:04+08:00Siti Nor Asiah Isasnasiahisa@gmail.comNor'aini Arisnoraini@utm.myAhmad Zharif Salami Mohd Tahasalami.osc@gmail.com<p>This research investigates on the numerical methods for computing the greatest common divisors (GCD) of two polynomials in the orthogonal basis without having to convert to the power series form. Previous implementations were conducted using the Gauss Elimination with partial pivoting (GEPP) and QR Householder algorithms, respectively. This work proceeds to seek for a better approximate solution by comparing the results of the implementations with the QR with column pivoting (QRCP) algorithm. The results reveal that QRCP is as competent as the GEPP algorithm, up to a certain degree, giving a reasonably good approximate solution. It is also found that normalizing the columns of the associated coefficient matrix slightly reduces the condition number of the matrix but has no significant effect on the GCD solutions when applying the GEPP and QR Householder algorithms. However equilibration of the columns by computing its ∞-norm is capable to improve the solution when QRCP is applied. Comparing the three algorithms on some test problems, QR Householder outperforms the rest and is able to give a good approximate solution in the worst case condition when the smallest element of the matrix is 1, the entries ranging up to 15 digits integers.</p>2017-06-19T16:24:25+08:00Copyright (c) 2017 Siti Nor Asiah Isa, Nor'aini Aris, Ahmad Zharif Salami Mohd Tahahttp://www.mjfas.utm.my/index.php/mjfas/article/view/602On the dominating number, independent number and the regularity of the relative co-prime graph of a group2017-09-11T10:33:04+08:00Norarida Abd Rhaniarida.ar@gmail.comNor Muhainiah Mohd Alinormuhainiah@utm.myNor Haniza Sarminnhs@utm.myAhmad Erfanianerfanian@um.ac.ir<p>Let <em>H</em> be a subgroup of a finite group <em>G</em>. The co-prime graph of a group is defined as a graph whose vertices are elements of <em>G</em> and two distinct vertices<em> </em>are adjacent if and only if the greatest common divisor of order of <em>x</em> and <em>y</em> is equal to one. This concept has been extended to the relative co-prime graph of a group with respect to a subgroup <em>H</em>, which is defined as a graph whose vertices are elements of <em>G</em> and two distinct vertices <em>x</em> and <em>y</em> are joined by an edge if and only if their orders are co-prime and any of <em>x</em> or <em>y</em> is in <em>H</em>. Some properties of graph such as the dominating number, degree of a dominating set of order one and independent number are obtained. Lastly, the regularity of the relative co-prime graph of a group is found.</p>2017-06-19T16:24:25+08:00Copyright (c) 2017 Norarida Abd Rhani, Nor Muhainiah Mohd Ali, Nor Haniza` Sarmin, Ahmad Erfanianhttp://www.mjfas.utm.my/index.php/mjfas/article/view/641Multiscale boundary element method for Poisson’s equation2017-09-11T10:33:04+08:00Nor Afifah Hanim Zulkeflinorafifahhanim.z@gmail.comSu Hoe Yeaks.h.yeak@utm.myMunira Ismailmuniraismail@utm.myThis paper applied the multiscale boundary element method for the numerical solution of the Poisson equation. The multiscale technique coupling with boundary element method will be used to solve the problem of Poisson equation efficiently and faster. Numerical example is given to illustrate the efficiency of the propose method. The solution of proposed method will be compared with boundary element method and the former method show less iteration in computation.2017-06-19T16:24:25+08:00Copyright (c) 2017 Nor Afifah Hanim Zulkefli, Su Hoe Yeak, Munira Ismailhttp://www.mjfas.utm.my/index.php/mjfas/article/view/640The adjacency matrix of the conjugate graph of metacyclic 2-groups2017-09-11T10:33:04+08:00Nur Idayu Alimonnuridayualimon@yahoo.comNor Haniza Sarminnhs@utm.myAmira Fadina Ahmad Fadzilnuridayualimon@yahoo.comLet <em>G</em> be a metacyclic 2-group and g<em>amma(conj,G)</em> is the conjugate graph of <em>G</em>. The vertices of<em> gamma(conj,G)</em> are non-central elements in which two vertices are adjacent if they are conjugate. The adjacency matrix of <em>gamma(conj,G)</em> is a matrix <em>A=[a(i,j)]</em> consisting 0'<em>s</em> and 1'<em>s</em> in which the entry <em>a(i,j)</em> is 1 if there is an edge between<em> i</em>th and <em>j</em>th vertices and 0 otherwise. In this paper, the adjacency matrix of a conjugate graph of metacyclic 2-groups is presented.2017-06-19T16:24:25+08:00Copyright (c) 2017 Nur Idayu Alimonhttp://www.mjfas.utm.my/index.php/mjfas/article/view/655Microstructure and superconducting properties of Ag-substituted YBa2-xAgxCu3O7- δ ceramics prepared by sol-gel method2017-09-11T10:33:04+08:00Fariesha Farha Ramlifarie466@perak.uitm.edu.myNorazidah Abd Wahabfarie466@perak.uitm.edu.myAzhan Hashimfarie466@perak.uitm.edu.my<p>Superconductor YBa<sub>2-x</sub>Ag<sub>x</sub>Cu<sub>3</sub>O<sub>7- δ</sub> in a bulk form has been developed through modified sol-gel processing. The preparation involved dissolving metal organic precursor in a mixture of propanoic acid and propylamine which then undergo for annealing at 900 °C for 5 hours and sintering at 950 °C for 5 hours. The bulk samples were characterized using X-ray diffractogram (XRD), resistivity measurement technique and Scanning Electron Microscope (SEM). The highest <em>T<sub>C</sub></em> value was found at 84 K for x=0.05. The value decrease as the Ag concentration increase. The highest <em>J<sub>C</sub></em> value measured for x =0.05 were 5.977 A/cm<sup>2</sup> at 50 K and 4.748 A/cm<sup>2</sup> a 60 K. 123 phase remains as orthorhombic for all samples. SEM micrograph showed the clear grains for the pure samples and it became not visible as the Ag concentration increase. </p>2017-06-19T16:24:24+08:00Copyright (c) 2017 Fariesha Farha Ramlihttp://www.mjfas.utm.my/index.php/mjfas/article/view/530Quantile regression for analysing PM10 concentrations in Petaling Jaya2017-09-11T10:33:04+08:00Kar Yong Ngkaryong92@yahoo.comNorhashidah Awangshidah@usm.myParticulate matter with diameter less than 10µm (PM<sub>10</sub>) data usually exhibit different variations as they include normal days and pollution days. This paper applied quantile regression (QR) technique to inspect the changing relationship between predictor variables and PM<sub>10</sub> concentrations at Petaling Jaya monitoring station in the year 2014 over different PM<sub>10</sub> distributions. For comparative purpose, multiple linear regression (MLR) using ordinary least squares (OLS) estimation approach was also performed. The QR analysis results showed that the interrelationship between predictor variables and PM<sub>10</sub> was not consistent across the PM<sub>10</sub> quantile distributions and hence, proved discordancy with MLR estimates. The lagged PM<sub>10</sub> concentration was the only important factor throughout the quantile distributions of PM<sub>10</sub>. It was found that the effects of lagged PM<sub>10</sub>, temperature, carbon monoxide (CO) increased from low to high quantile distributions, while the effects of lagged humidity, east-west wind component, wind speed and nitrogen monoxide (NO) showed the otherwise patterns. The lagged NO associated significantly with PM<sub>10</sub> at low quantiles, whereas the lagged temperature and CO associated significantly at high quantiles only. Lagged humidity, east-west wind component and wind speed correlated significantly and negatively with PM<sub>10</sub> at low and middle quantiles. Ozone (O<sub>3</sub>), however, had effect of changing nature from positive association at low PM<sub>10</sub> distributions to negative association at high levels. Thus, QR is helpful to provide a more complete description of predictor variable effects on PM<sub>10</sub> at different distributions, and may assist in PM<sub>10</sub> management especially during haze periods.2017-06-19T16:24:25+08:00Copyright (c) 2017 Kar Yong Ng, Norhashidah Awanghttp://www.mjfas.utm.my/index.php/mjfas/article/view/536Generated paths of an autocatalytic set of a secondary system of a pressurized water reactor2017-09-11T10:33:04+08:00Zainab Mahamudzainab.mahamud@yahoo.comTahir Ahmadtahir@ibnusina.utm.my<p>A graph is used to model pairwise relation between objects. In this paper, it is used to model secondary system of pressurized water reactor. The process is presented as a dynamic graph by integrating the concept of Autocatalytic Set (ACS). The graph is then transformed into an omega algebra whereby all the possible paths of the process are determined. Seven variables are identified to represent the nodes with twenty one links to indicate catalytic relations among these nodes. A programming code of C++ is developed for the identification of these 317 links.</p>2017-06-19T16:24:26+08:00Copyright (c) 2017 zainab mahamudhttp://www.mjfas.utm.my/index.php/mjfas/article/view/544Slant tube characterization for the implementation of k0 - standardization in Nigerian reseach reactor-12017-09-11T10:33:04+08:00Umar Aliyu Abubakarauabubakarphysics@gmail.comJonah A Sundayjonah@abu.edu.ngUmar Sadiqsadiqumarx@yahoo.co.ukKhaidzir Hamzahkhaidzir@utm.my<p>The result for large sample irradiation are continuously piping into the Center for Energy Research and Training (CERT), Ahmadu Bello University, Zaria. Therefore, characterization of the irradiation channels that can accommodate large samples become a challenge. In the first series of trial for large samples irradiation through slant tube of NIRR-1 which is a miniature research reactor is necessary in order to compare with some standard values reported by the arena of researchers including nuclear regulatory bodies. The thermal to epithermal flux ratio (f), epithermal neutron flux distribution parameters (α) were determined using two slant tube channels of NIRR-1. The adopted methodology here is bared and cadmium covered monitor foils method. The vertical dipstick higher purity germanium detector (HPGE) was calibrated and used for the calculation. The f and α values were calculated as 111.8 and -0.04977 respectively. The good agreement between the certified and experimental values of the shaping factors was achieved. </p>2017-06-19T16:24:26+08:00Copyright (c) 2017 Jonah A Sunday, Umar Sadiq, Khaidzir Hamzahhttp://www.mjfas.utm.my/index.php/mjfas/article/view/557On the conjugate graphs of finite p-groups2017-09-11T10:33:04+08:00Athirah Zulkarnainathirah.zulkarnain91@gmail.comNor Haniza Sarminnhs@utm.myAlia Husna Mohd Noormylife_syafia@yahoo.com<p>Graphs can be related to groups by looking at its vertices and edges. The vertices are comprised of the elements or sets from the groups and the edges are the properties and conditions for the graph. Recently, research on graphs of groups have attracted many authors. A conjugate graph of a group is defined as; its vertex set is the set of non-central classes of <em>G</em>, and two distinct vertices <em>A</em> and <em>B</em> are connected by an edge if and only if they are conjugate. In this research, the conjugacy class of some finite <em>p</em>-groups are first found. Then, the conjugate graph are determined.<strong></strong></p>2017-06-19T16:24:26+08:00Copyright (c) 2017 Athirah Zulkarnain, Nor Haniza Sarmin, Alia Husna Mohd Noorhttp://www.mjfas.utm.my/index.php/mjfas/article/view/563Mini-review: Recent updates on the mathematical modelling of radiation-induced bystander effects2017-09-11T10:33:04+08:00Muhamad Hanis Nasirmhanis33@live.utm.myFuaada Mohd Siamfuaada@utm.my<p>Radiotherapy treatment uses ionizing radiation (IR) in order to kill cancer cells. However, the IR exerted its effects outside the radiation field and causes cell death in healthy cells. This effect namely as radiation-induced bystander effects (RIBE) phenomenon. The scope of the overview of the RIBE phenomenon discussed in this paper includes the RIBE mechanism, danger signaling process, deoxyribonucleic acid (DNA) double-strand breaks (DSBs) damage and the damage repair. This paper extended with the discussion of several mathematical models used to describe the RIBE phenomenon. The discussions towards the mathematical models include the models of signals concentration, the models of bystander effects and the survival fraction model. Mathematical modelling and computer simulation are powerful tools used to understand the biological phenomenon of RIBE. The suitable mathematical model of repair and mis-repair DNA DSBs damage has been briefly reviewed in view of the relevance of this model towards RIBE phenomenon. The outcome of this paper suggested a recommendation for future research on the suitable mathematical model and simulation analysis in describing the complexity of RIBE phenomenon.</p>2017-06-19T16:24:26+08:00Copyright (c) 2017 Muhamad Hanis Nasir, Fuaada Mohd Siamhttp://www.mjfas.utm.my/index.php/mjfas/article/view/564The application of fuzzy logistic equations in population growth with parameter estimation via minimization2017-09-11T10:33:04+08:00Nor Atirah Izzah Zulkeflinoratirahizzah@gmail.comSu Hoe Yeaks.h.yeak@utm.myNormah Maannormahmaan@utm.my<p>This paper presents a numerical solution for the first order fuzzy logistic equations by extended Runge-Kutta fourth order method with estimated parameters. The parameters are estimated by minimization technique using conjugate gradient approach. Then, the fuzzy logistic model with the estimated parameters is used to fit the population growth in Malaysia. Numerical example is given to show the efficiency of the proposed model.</p><p> </p><p><strong><em>Keywords</em></strong><strong>:</strong> Fuzzy logistic equations, Population growth, Parameter estimation, Minimization technique</p>2017-06-19T16:24:26+08:00Copyright (c) 2017 Nor Atirah Izzah Zulkefli, Su Hoe Yeak, Normah Maanhttp://www.mjfas.utm.my/index.php/mjfas/article/view/565Modelling of macrophage interactions by partial differential equations2017-09-11T10:33:04+08:00Mohd Rashid Admonrashid_2411@yahoo.com.myNormah Maannormahmaan@utm.my<p>The recruitment of macrophages at the tumor sites is the earliest immune response takes place during tumor progression. In breast cancer, experimental studies reveals that the tumor cells are capable of taking advantage on the plasticity of macrophages. Tumor cells respond to epidermal growth factor, EGF that released by macrophages while macrophages respond to colony stimulating factor 1, CSF-1 that released by tumor cells. This chains continues and results a paracrine signalling loop. Consequently, tumor cells and macrophages will aggregate and invade to other tissues or organ. Tumor cells also receive their own signals, adding a new feature of interaction called autocrine signalling loop. By considering in vitro interactions, a system of partial differential equations that incorporate the saturating functions for secretion terms was developed. This functions describes the production of chemical signals saturates with increasing cell density. Stability analysis are then performed to investigate the conditions for aggregation. For a given average of cells density, the homogeneous steady state is non-trivial and the concentration of CSF-1 and EGF are produced in the saturated production. Stability results show that regions for instability are reduced, compared to previous model which assumes the production rates are linear with increasing cell density. Besides, the inclusion of autocrine signalling loop increase the occurrence of aggregation. Decreasing the production rates and chemotaxis sensitivity, together with increasing the decay rates are required to impede the aggregation from initiated. This results should provide valuable clinical suggestions in guiding medical experts during drug designs.</p>2017-06-19T16:24:26+08:00Copyright (c) 2017 Mohd Rashid, Normah Maanhttp://www.mjfas.utm.my/index.php/mjfas/article/view/595Effects of surfactants on antibacterial drugs – A brief review2017-09-11T10:33:04+08:00Mohd Amir Asyraf Mohd Hamzahmohdamirasyraf_edu@yahoo.comClaira Arul Aruldassclairaarul@gmail.comWan Azlina Ahmadazlina@kimia.fs.utm.mySiti Aminah Setusitiaminahsetu@kimia.fs.utm.my<p>More than half of the reported new discovered/invented drugs are ones with poor solubility, absorption or both. These are the crucial issues that can affect the bioavailability of the drugs. Therefore, improving solubility of poor-soluble drugs is absolutely important. One of the methods to solubilize them in biological fluids is using surfactants. Surfactants are an amphiphilic organic compound containing hydrophilic and lipophilic parts that allow it to reduce the surface tension between two opposite polar phases. Several popular methods used to determine critical micelle concentration which includes surface tension, conductivity and UV-vis spectroscopy. These surfactants plays number of roles in antibacterial compound synthesis include size reduction agent, stabilizer, solubilizer and drug-carrier. This review will also critically discuss on the roles of surfactants in antibacterial compound synthesis/production and its effect on the antibacterial activity of the drugs. </p>2017-06-19T16:24:26+08:00Copyright (c) 2017 Mohd Amir Asyraf Mohd Hamzah, Claira Arul Aruldass, Wan Azlina Ahmad, Siti Aminah Setuhttp://www.mjfas.utm.my/index.php/mjfas/article/view/636Pyrolysis of torrefied oil palm wastes for better biochar2017-09-11T10:33:04+08:00Aminu Safana Aliyubasalihe2@gmail.comNurhayati Abdullahinurhaya@usm.myFauziah Sulaimanfauziahsulaiman@usm.my<p>The objective of this research work is to investigate the effect of torrefaction on the pyrolysis product. Biomass materials such as empty fruit bunch (EFB), mesocarp fibre (MF) and palm shell (PKS) were torrefied and pyrolyzed. The experiment conditions were set to be respectively at 220 <sup>o</sup> C of temperature, 10 <sup>o</sup> C/min of heating rate and 30 minutes holding time for torrefaction and at 650 <sup>o</sup>C of temperature, 20 <sup>o </sup>C/min heating rate and 2 hours holding time for pyrolysis. Nitrogen flow rate of 2L/min was maintained for both experiments. The torrefied biomass contains high carbon content and low oxygen content than the raw biomass. Also, the biochar derived from torrefied biomass have high fixed carbon content than the biochar derived from untorrefied biomass. The maximum higher heating value (HHV) of about 31.2 MJkg<sup>-1</sup> is obtained in the biochar derived from the torrefied shell. Though, all the biomass materials used in this research have exhibited a positive outcome after being torrefied and pyrolyzed. It is clear from scanning electron microscopy (SEM) images that the biochar (b) and (d) derived from torrefied biomass could be better in the application of soil amendment and water retention due to a large number of uniform holes. Therefore, it can be concluded that pyrolysis of torrefied biomass improved the quality of biochar than the biochar obtained from untorrefied biomass.</p>2017-06-19T16:24:24+08:00Copyright (c) 2017 Aminu Safana Aliyu, Nurhayati Abdullahi, Fauziah Sulaimanhttp://www.mjfas.utm.my/index.php/mjfas/article/view/639The Laplacian energy of conjugacy class graph of some dihedral groups2017-09-11T10:33:04+08:00Rabiha Birkia Mahmoudrabihabirkia@gmail.comNor Haniza Sarminnhs@utm.myAhmad Erfanianerfanian@um.ac.irAmira Fadina Ahmad Fadzilamirafadinaahmadfadzil@yahoo.com<p>Let <em>G </em>be a dihedral group and Gamma its conjugacy class graph. The Laplacian energy of the graph, LE(Gamma) is defined as the sum of the absolute values of the difference between the Laplacian eigenvalues and the ratio of twice the edges number divided by the number of vertices. In this research, the Laplacian matrices of the conjugacy class graph of some dihedral groups and its eigenvalues are first computed. Then, the Laplacian energy of this graph is determined.</p>2017-06-19T16:24:26+08:00Copyright (c) 2017 RABIHA BIRKIA MAHMOUD, Nor Haniza Sarmin, Ahmad Erfanian, Amira Fadina Ahmad Fadzilhttp://www.mjfas.utm.my/index.php/mjfas/article/view/643Effect of gravity modulation on mixed convection flow of second grade fluid with different shapes of nanoparticles2017-09-11T10:33:04+08:00Noraihan Afiqah Rawinafiqah38@gmail.comMohd Rijal Iliasrijal_rs@hotmail.comZaiton Mat Isazaitonmi@utm.mySharidan Shafiesharidan@utm.my<p>The problem of unsteady mixed convection flow of second grade fluid over an inclined stretching plate under the influence of different shapes of nanoparticles is studied in this paper. The influence of gravity modulation is also considered. Carboxymethyl cellulose solution (CMC) is chosen as the non-Newtonian base fluid. Based on Tiwari-Das nanofluid model, the governing partial differential equations are transformed into a system of ordinary differential equations and solved numerically using an implicit finite difference scheme. The effect of different shapes and volume fraction of solid nanoparticles on the enhancement of convective heat transfer of second grade nanofluid associated with the effect amplitude of modulation, frequency of oscillation, and material parameter is discussed in details. The results indicated that, the needle-shaped nanoparticles give the highest enhancement on the heat transfer of second grade nanofluid compared to sphere and disk-shaped nanoparticles.</p>2017-06-19T16:24:26+08:00Copyright (c) 2017 Noraihan Afiqah Rawi, Mohd Rijal Ilias, Zaiton Mat Isa, Sharidan Shafiehttp://www.mjfas.utm.my/index.php/mjfas/article/view/652Direct synthesis of ZSM-5 from kaolin and the influence of organic template2017-09-11T10:33:04+08:00Didik Prasetyokodidik.prasetyoko@gmail.comRustam Rustamrsangarwal@yahoo.comRatna Ediatirediati@chem.its.ac.idBerty Septiyanaberty.septiyana@gmail.comYusuf Muhammad Zeinyusufmuhammadzein@gmail.comHasliza BahrujiBahrujiH@cardiff.ac.ukImroatul Qoniahqoniah07@gmail.comHartati Hartatihartatidodit@gmail.comHadi Nurhadi@kimia.fs.utm.my<p>We investigated the transformation of kaolin to ZSM-5 using hydrothermal synthesis method and the influence of organic template as a structure-directing agent. The formation of ZSM-5 from kaolin occurred via dissolution of kaolin to form amorphous silica. Zeolite-like analcime produced when the hydrothermal treatment was extended to 18 h. We found synergistic effect of using a mixture of TPAOH and TPABr organic template to enhance kaolin dissolution, initiate ZSM-5 formation and inhibit the transformation of ZSM-5 to analcime.</p>2017-06-19T16:24:25+08:00Copyright (c) 2017 Didik Prasetyoko, Rustam Rustam, Ratna Ediati, Berty Septiyana, Yusuf Muhammad Zein, Hasliza Bahruji, Imroatul Qoniah, Hartati Hartati, Hadi Nurhttp://www.mjfas.utm.my/index.php/mjfas/article/view/617Role of Na+ ion removal on the photocatalytic properties of hydrothermally-prepared nanotubes TiO22017-09-11T10:33:04+08:00Naimat Abimbola Eleburuikenaeleburuike@gmail.comWan Azelee Wan Abu Bakarwazelee@kimia.fs.utm.myRusmidah Alirusmidah@kimia.fs.utm.my<p>Nanostructured TiO<sub>2</sub> enjoys wide patronage for the remediation of water sources that have been contaminated with organic pollutants due to its excellent photocatalytic properties. This study investigated the role of removal of Na<sup>+</sup> ions from hydrothermally-prepared TiO<sub>2</sub> nanotubes (TNTs) by washing with dilute hydrochloric acid. The photocatalytic activity of TNTs was tested on the degradation of modelled paraquat dichloride-contaminated water. It was found that the amount of residual Na<sup>+</sup> ions after acid washing greatly influenced the photocatalytic properties of TNTs. The Na<sup>+</sup> ions had significant effect on the crystal structure of TNTs and the crystal structure varied with the annealing temperature. Hence, the effect of the residual Na<sup>+</sup> ions was observed at different annealing temperatures of 500, 700 and 800 °C. It was discovered that TNTs containing negligible Na<sup>+</sup> ions demonstrated high photocatalytic activity at 500 °C annealing temperature because it consisted of active crystalline anatase species at this temperature. On the other hand, TNTs with high Na<sup>+</sup> ion content showed poor performance at 500 °C due to the presence of amorphous sodium titanate species which could result in rapid electron-hole pair recombination. So, it showed highest photocatalytic activity at 800 °C when the crystallinity had increased. Generally, it can be concluded that TNTs with negligible Na<sup>+</sup> ion content demonstrated excellent photocatalytic activity by achieving 77.1% degradation of paraquat dichloride compared to those with high Na<sup>+</sup> ion content which achieved 61.1% degradation of paraquat dichloride within 5 h.</p>2017-06-19T16:24:26+08:00Copyright (c) 2017 Naimat Abimbola Eleburuike, Wan Azelee Wan Abu Bakar, Rusmidah Ali