bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoluminescence Studies on Lithium- Calcium Borophosphate Glasses doped with Transition Metal Ions
Authors: Poh Sum Wong , Ming Hua Wan , Tien Yew Eeu , Hussin Rosli , Ibrahim Zuhairi
Published: October 2017

The mixed alkali borophosphate 25Li2CO3:25Ca2O3:30B2O3:20P2O5 glasses doped with 1 mol% of different transition metal ions were prepared and studied using photoluminescence techniques. The transition metal ions used included chromium, manganese and iron. Chromium doped glass exhibits a violet emission band at ̴ 316 nm and this band has been assigned to the transition of z6Dᵒ1/2 → a4P5/2. While manganese doped glass show a violet emission band at ̴ 408 nm which is assigned to z7Pᵒ4 → a5D4 and a red emission band at ̴ 632 nm which is assigned to the transition of z5Pᵒ3 → a5G6. Lastly, for the iron doped glass shows many emission bands along the visible range.
Optical properties of Diamond like Carbon films prepared by DC-PECVD
Authors: Tshomo S. , Mohsin A.K. , Ismail B. , Hussin R. , Md.Yusuf M.n. , Wan Shamsuri W.N. , Deraman K. , Hussein S. Sholehah
Published: October 2017

Diamond-like carbon (DLC) thin films were deposited at different substrate temperatures using methane and hydrogen gas in DC-PECVD at 2x10-1Torr. From the light transmission using UV-VIS spectroscopy it was found that the optical transition had changed from allowed indirect transition to allowed direct transition as the substrate temperature increased. The Optical gap increased with temperature, highest of 3.034 eV was observed at 573 K, beyond which it dropped. Colour of the film changed from light brownish to a colourless transparent film in the higher temperature. The Urbach energy decreased from 1.25 eV to 0.75 eV with increasing substrate temperature till 573 K and a slight increase after it. This trend is attributed to change in sp3/sp2 ratio or change in structure. The cluster size decreases with temperature, resulting in larger band gap and the structure more ordered. Similar pattern is also witnessed in the emission spectrum of the photoluminescence.
Polyaniline-Supported Palladium(II)-Schiff Base Complex as Efficient Catalyst for Mizoroki-Heck Cross-Coupling Reaction
Authors: Che Soh Siti Kamilah , Shamsuddin Mustaffa
Published: October 2017

Mizoroki-Heck cross-coupling reaction of 4-bromoacetophenone with methyl acrylate were investigated as a model system of heterogeneous reaction in order to evaluate the performance of polyaniline supported N,N’-bis(3,5-di-tert-butylsalicylidene)propane-1,3-diaminepalladium(II) complex as catalyst. The reactions were carried out in both N,N-dimethylacetamide (DMAc) and water-DMAc mixed solvent. The performances of the catalyst in both media are comparable, giving more than 90 % conversion after 24 hours of reaction with 100 % selectivity and high isolated product yields of cinnamic esters were obtained. The used of mixed solvent gave more advantages such as less organic solvent was required and an enhanced recyclability in which the supported catalyst could be reusable at least four times without noticeable decrease in the product conversion. The properties of the catalyst was characterized by various techniques such as FTIR spectroscopy, TG-DTA, AAS, BET surface area, XRD and FESEM.
Qualitative and quantitative biological studies of three chemotypes of basil essential oils grown in Malaysia against E.coli, S.aureus and P. aeruginosa
Authors: Ismail Zuriah , Hamid Nour Azhari , Elhussein Salah
Published: October 2017

Different accessions of basil introduced to Malaysia as seeds and cultivated at University Malaysia Pahang (UMP) farm and their essential oils extracted by steam distillation. Three chemotypes of these essential oils with estragole, linalool and methyl cinnamate as dominant compounds were evaluated against three facultative anaerobic bacteria obtained from the National Pharmaceutical Control Bureau, Ministry of Health Malaysia: namely, Escherichia coli, Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive) by qualitative and quantitative method. Different concentration ranged from 10 μL/mL to 1000 μL/mL of basil essential oil solutions prepared and tested against bacterial strain using agar well diffusion and quantitative methods. Minimum inhibitory concentration (MIC) was performed using broth microdilution plate. Eight different concentrations of serial two-fold dilutions ranged between 250 μL/mL and 1.95 μL/mL performed using Magellan software of Tecan Infinite Series M200 Pro microplate reader. In the result of agar well diffusion test, the zone of inhibition increased as the concentration of essential oil increased. The MIC was 7.81 μL/mL for all chemotype of the oils against E.coli and S.aureus while 15.63 μL/mL for P.aeruginosa of linalool-rich chemotype and 31.25 μL/mL for estragole and methyl cinnamate-rich chemotypes. The results obtained in this study were considered encouraging the potential of basil essential oil for medicinal uses as antibiotics and hygienic purposes as antibacterial products.
Red Wood (Pterocarpus Indicus Wild) and Bread Fruit (Artocarpus Communis ) Bark Sap as Attractant of Stingless Bee (Trigona Spp)
Authors: Marisa Hanifa , Salni Salni
Published: October 2017

An investigation about the power of redwood bark sap to invite stingless bee arrival had been done at Biology campus area, The University of Sriwijaya, Indralaya, South Sumatera, Indonesia; during Nopember 2010. Redwood breadfruit bark have been hurt for outcoming the red sap, and duration time for stingless bee arrival be measured then. Meanly, in 17 minutes, stingless bee had came for red sap; and in 5 minutes for breadfruit. Chemical test of redwood sap after soluted in methanol and put on gelsilicon chromatography with ethil-acetate and methanol (1:1), and sprayed by sulphic acid indicate that the compounds is terpenid (tannin) for red wood sap, and tannin and alcaloid for bread fruit sap.
Effects of Modifier Polarity on Extraction of Limonene from Citrus Sinensis L. Osbeck Using Supercritical Carbon Dioxide
Authors: Ibrahim Azreen , Sarbatly Rosalam
Published: October 2017

Limonene constitutes 98% of the essential oil obtained from orange peel. Besides being used as fragrances and flavours in the food, perfume and cosmetic industries, limonene is also a good degreasing agent. Supercritical carbon dioxide is an excellent solvent for non-polar compound like limonene but poor solvent for polar compound like α-terpineol. Common practice in supercritical fluid extraction is to change the polarity of supercritical carbon dioxide by employing polar modifiers to increase its solvating power towards polar analytes. Base on this, in the attempt to extract more limonene in orange essential oil, less polar modifiers were added instead. In this study, effects of adding modifiers with different polarity on extraction of aroma compounds (limonene, linalool and α-terpineol) from Citrus Sinensis L. Osbeck or sweet orange peel were investigated. Supercritical extraction was carried out at defined pressure and temperature for duration of 45 minutes. Concentration of aroma compounds extracted was analysed using GC-MS. The optimum conditions for extraction were observed at 318K and 12MPa. The concentrations of limonene increased significantly by the addition of methanol and slightly with n-heptane. It was also found that n-heptane is effective on supercritical CO2 extractions of linalool and α-terpineol.
Ranking Fuzzy Numbers by Centroid Method
Authors: Azman Fateen Najwa , Abdullah Lazim
Published: October 2017

Ranking fuzzy numbers are one of the important tools in decision process. There are many methods that have been proposed by a number of researchers but most of the methods are nondiscriminating and counterintuitive. Thus, proposing a new method for ranking fuzzy numbers are very prominent. The main objective of this paper is to get better ranking results to rank generalized fuzzy numbers than existing method. This paper reviews the centroid method in ranking fuzzy numbers by several researchers. A new calculation of centroid method will be proposed in this paper. At the end of the paper, a numerical calculation and a comparison of centroid method between the proposed method and other researchers’ method will be showed to check on its consistency.
Fractional Reaction-Diffusion Equations for Modelling Complex Biological Patterns
Authors: Ku Akil Ku Azlina , V Muniandy Sithi , Lim Einly
Published: October 2017

We consider a system of nonlinear time-fractional reaction-diffusion equations (TFRDE) on a finite spatial domain x ∈ [0, L], and time t ∈ [0, T]. The system of standard reaction-diffusion equations with Neumann boundary conditions are generalized by replacing the first-order time derivatives with Caputo time-fractional derivatives of order α ∈ (0, 1). We solve the TFRDE numerically using Grünwald-Letnikov derivative approximation for time-fractional derivative and centred difference approximation for spatial derivative. We discuss the numerical results and propose the applications of TFRDE for the modelling of complex patterns in biological systems.
Sticker Systems Over Monoids
Authors: Mohd Sebry N.A. , Hamzah N. Z. A. , Sarmin N.H. , Fong W.H. , Turaev S.
Published: October 2017

Molecular computing has gained many interests among researchers since Head introduced the first theoretical model for DNA based computation using the splicing operation in 1987. Another model for DNA computing was proposed by using the sticker operation which Adlemanused in his successful experiment for the computation of Hamiltonian paths in a graph: a double stranded DNA sequence is composed by prolonging to the left and to the right a sequence of (single or double) symbols by using given single stranded strings or even more complex dominoes with sticky ends, gluing these ends together with the sticky ends of the current sequence according to a complementarity relation. According to this sticker operation, a language generative mechanism, called a sticker system, can be defined: a set of (incomplete) double-stranded sequences (axioms) and a set of pairs of single or double-stranded complementary sequences are given. The initial sequences are prolonged to the left and to the right by using sequences from the latter set, respectively. The iterations of these prolongations produce “computations” of possibly arbitrary length. These processes stop when a complete double stranded sequence is obtained. Sticker systems will generate only regular languages without restrictions. Additional restrictions can be imposed on the matching pairs of strands to obtain more powerful languages. Several types of sticker systems are shown to have the same power as regular grammars; one type is found to represent all linear languages whereas another one is proved to be able to represent any recursively enumerable language. The main aim of this research is to introduce and study sticker systems over monoids in which with each sticker operation, an element of a monoid is associated and a complete double stranded sequence is considered to be valid if the computation of the associated elements of the monoid produces the neutral element. Moreover, the sticker system over monoids is defined in this study.
Understanding the Shift of Correlation Structure in Major Currency Exchange Rate
Authors: Yusoff Nur Syahidah , Abdurachman Djauhari Maman
Published: October 2017

In this paper, we study the high dimensional correlation structure of financial market. Correlation structure can be considered as a complex system that relates each variable to the others in terms of correlation. To analyze such complex system, minimum spanning tree is constructed to simplify the network. A case study will be presented and a conclusion will be highlighted.
Characterization of Si nanowires synthesized using metal-assisted wet-chemical etching
Authors: S. M. Ashour Eman , Sulaiman M.Y. , Amin N. , Ibrahim Z.
Published: October 2017

A synthesis of vertical silicon nanowire array through metal-assisted chemical etching of highly doped p-type silicon wafers (100) in a solution of hydrofluoric acid and silver nitrate has been proposed. . The influences of the growth parameters such as solution concentration, etching time have been investigated. In addition, we consider other common parameters like wafer resistivity and temperature, which rely on the silicon nanowires formation. The results indicate that the silicon nanowires retain the single crystalline structure and crystallographic orientation of the starting silicon wafer. Furthermore, They provide excellent antireflection property with a low reflection loss of 3% for incident light within the wavelength range of 200–900 nm. Such nanowire arrays may have potential applications as antireflection surface for silicon solar cells
Hydrothermally Synthesized Cadmium Selenide Quantum Dot for Solar Cell Application
Authors: Ahamefula Ubani Charles , Sulaiman Mohamad Yusof , Ibarahim Zahari , Ibarahim Noor baaya , Othman Muhammad Yusof
Published: October 2017

Hydrothermal synthesis autoclave reactor offers simple, safer and environmentally friendlier process for the preparation of valuable nanoparticles. In this study, cadmium selenide (CdSe) quantum dot (QD) were successfully synthesized via one-step hydrothermal synthetic route at 195 oC. The reactant mixtures used for the synthesis was added into Teflon and comprises 15 mg of selenium (Se) powder, 15 mg of cadmium oxide (CdO), 20 ml of octadecene (OTD), 10 ml of oleic acid (OA) and 1 ml of trioctylphosphine (TOP). The synthesis lasted for 3 hours 20 minutes. The synthesized CdSe QDs were characterized using optical absorption spectroscopy, fluorescence spectroscopy (PL), scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray analysis (EDAX). The broad absorption peak of the sample depicted the suitability of the sample for photovoltaic application while the fluorescence peaks was assigned to band edge emission to shallow and deep trap states. AFM and SEM microstructure images revealed the surface morphology and the crystal orientation of CdSe QD while the QD size and particles distribution were obtained using TEM and FESEM. The EDX were used to obtain the compositional ratio of the materials in the synthesized CdSe QD sample. The formation mechanisms were discussed on the basis of the experimental results and the quantum dots were found to be stable for about three months.
Fabrication and characterization of ferrites (Mg and Mn) based on FTIR, XRD, SEM and TEM
Authors: Ing Hua Tang , Sundari Rita
Published: October 2017

This study has encountered with the fabrication of ferrites (Mg and Mn) using citric acid as anionic surfactant in sol-gel method followed by calcinations at varied temperatures (300, 600, 800°C) for 2h, respectively. The fabricated ferrites have been characterized by FTIR (Fourier Transform Infrared Spectroscopy), XRD (X-Ray Diffraction), SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope). The FTIR spectrum for MnFeO3 shows that some functional groups already removed under 300°C calcination due to several oxidation numbers possessed by Mn leading to more flexibility. The XRD diffractograms for both MgFe2O4 and MnFeO3 show that the transition phase from amorphous to crystalline structure occurred in the temperature range of 300-600°C. The SEM mappings based on the Fe distribution for both MgFe2O4 and MnFeO3 show that more Fe distributed over the ferrites surface at 600 and 800°C, while the SEM mappings for both ferrites (Mg and Mn) show less Fe distribution at 300°C calcination, thus, it indicates more repulsion force bearing by higher amounts of Fe atoms at higher thermal agitation due to volume expansion. The TEM spectra proved that both ferrites existed as crystals after calcined at 600°C. The fabricated ferrites have remarkable electrical properties useful for the manufacture of semiconducting materials.
Statistical Discrimination of Blue Ballpoint Pen Inks by Infrared (IR) Spectroscopy
Authors: Abdul Halim Mohamed Izzharif , Abdul Aziz Nur Syafinaz , Saim Norashikin , Osman Rozita , Jasmani Halila
Published: October 2017

Statistical chemometric method was used in discriminating 24 blue ballpoint pen inks from six different brands (Pilot, Carera, Stabilo, Faber-Castle, G-soft and Papermate) available in Malaysian market. Discrimination method was developed based on the combination of infrared spectra (IR) and chemometric technique which comprise of principal component analysis (PCA) and Agglomerative Hierarchical Clustering (AHC). The chemometric software used was XLSTAT 2011. The spectral region 4000–400 cm-1 was used to ‘fingerprint’ each ink from the 24 samples. PCA was used to detect any outliers whereas AHC was used to separate the ballpoint pen inks into their own class. This study showed that acceptable statistical discrimination (70.92% correct classification of the ballpoint pen dataset) between these 24 samples. FTIR-PCA and FTIR-AHC were successfully discriminate three different brands which were Carera, Pilot and g-soft. While, the other three brands, Papermate, Fabercastle and Stabilo could not be discriminated perfectly. The results of this study indicate that Transmission FTIR Spectroscopy coupled with chemometrics is useful discriminating tool for forensic studies involving inks.
Synthesis and characterization of mixed nickel thiosemicarbazone complexes
Authors: Bashir Shawish Hana , Maah Mohd Jamil , Abdul Halim Siti Nadia
Published: October 2017

Three nickel thiosemicarbazone mixed ligands complexes have been synthesized. Complexes with the formula [NiL(PPh3)]Cl, [Ni2L2(Phen)],[Ni2L2(Bpy)] (where L= 2,3,4-trihydroxybenzaldehydethiosemicarbazone, PPh3=Triphenylphosphine, Phen=1,10-phenanthroline, Bpy= 2,2 –Bipyridine)have been characterized by IR spectroscopy, as well as elemental analysis. The structure of [NiL (PPh3)]Cl has been determined by X-raycrystallography. The crystal structure of this complex shows that the Schiff base ligand functions as an N,O,S chelating anion to the phosphine –coordinated nickel(II) atom, which exists as a distorted square – planar geometry.
Nickel(II)-salen Schiff Base Complex as Anion Receptor
Authors: Endud Salasiah , Wen Yee Wong
Published: October 2017

The Schiff base salen was incorporated to nickel(II) ion to afford nickel(II) diethylamino-substituted salen complex. The diethylamino-substituted salen l salen complex were characterized by Fourier Transform Infrared Spectroscopy (FTIR), diffuse reflectance ultravisible spectroscopy (DR UV-Vis) and 1H (1H-NMR). The binding affinity of the nickel(II) diethylamino-substituted salen complex towards specific anion in dichloromethane was investigated by us
Review on Fuzzy Difference Equation
Authors: Darus Mukminah , Wahab Abd Fatah
Published: October 2017

Fuzzy difference equation has been introduced by Kandel and Byatt in 1978. This topic has been growing rapidly for many years. Fuzzy difference forms is suitable for uncertainty or vagueness problems such as mathematical modelling, finance or else and it also applied in engineering, economics, science and etc. In this paper, we review the application of fuzzy difference equations that has been used before. We also give some ideas to relate from this type-1 fuzzy difference equation to type-2 fuzzy. The using of type-2 fuzzy is for more uncertainties and it is really suitable for problems in finance.
Sufficient conditions for new integral transformation
Authors: Mohammed Aabed , Darus Maslina
Published: October 2017

By using the integral transformation for meromorphic functions, an integral transformation on the class Aof analytic functions in the unit disk is defined. Some sufficient conditions for this transformation to be in the some known subclasses are derived. Furthermore, new function on the class of meromorphic functions in the punctured open unit disk is introduced. Finally, starlikeness conditions for this function are pointed out.
Partial Sums For Class Of Analytic Functions Defined By Integral Operator
Authors: Mustafa Nagat. M. , Darus Maslina
Published: October 2017

In the present paper, we study the class of analytic functions involving generalized integral operator, which is defined by means of a general Hurwitz Lerch Zeta function denoted by ,()sbfzαℑwith negative coefficients. The aim of the paper is to obtain the coefficient estimates and also partial sums of its sequence ,()
Solving a Mixed Boundary Value Problem via an Integral Equation with Generalized Neumann Kernel on Unbounded Multiply Connected Region
Authors: Alhatemi S.A.A. , Murid A.H.M. , Nasser M.M.S.
Published: October 2017

In this paper, we solve the mixed boundary value problem on unbounded multiply connected region by using the method of boundary integral equation. Our approach in this paper is to reformulate the mixed boundary value problem into the form of Riemann-Hilbert problem. The Riemann-Hilbert problem is then solved using a uniquely solvable Fredholm integral equation on the boundary of the region. The kernel of this integral equation is the generalized Neumann kernel. As an examination of the proposed method, some numerical examples for some different test regions are presented.
Graph Dynamics of Fuzzy Autocatalytic Set of Fuzzy Graph Type-3 of a Clinical Waste Incineration Process
Authors: Abu Bakar Sumarni , Ahmad Tahir , Baharun Sabariah
Published: October 2017

Fuzzy Autocatalytic Set of Fuzzy Graph Type-3 (FACS) has been successfully implemented in modeling clinical waste incineration process. Six important variables identified in the process are represented as nodes and the catalytic relationships are represented by fuzzy edges in the graph. However, in this paper, graph dynamics of FACS is further investigated using left Perron vector of its transition matrix of fuzzy graph of FACS. This paper will highlight two important variables in the incineration process with regards to the actual process.
Numerical Method for Inverse Laplace Transform with Haar Wavelet Operational Matrix
Authors: Mt Aznam Suazlan , Hussin Amran
Published: October 2017

Wavelets have been applied successfully in signal and image processing. Many attempts have been made in mathematics to use orthogonal wavelet function as numerical computational tool. In this work, an orthogonal wavelet function namely Haar wavelet function is considered. We present a numerical method for inversion of Laplace transform using the method of Haar wavelet operational matrix for integration. We proved the method for the cases of the irrational transfer function using the extension of Riemenn-Liouville fractional integral. The proposed method extends the work of J.L.Wu et al. (2001) to cover the whole of time domain. Moreover, this work gives an alternative way to find the solution for inversion of Laplace transform in a faster way. The use of numerical Haar operational matrix method is much simpler than the conventional contour integration method and it can be easily coded. Additionally, few benefits come from its great features such as faster computation and attractiveness. Numerical results demonstrate good performance of the method in term of accuracy and competitiveness compare to analytical solution. Examples on solving differential equation by Laplace transform method are also given.
Leaching of Pb2+ and Te4+ in Yb3+ doped lead tellurite glasses in aqueous solution
Authors: Hamzah Khaidzir , Mohd Yassin M. Abdullah Izat , Sahar Md. Rahim , Ghoshal Sib Krishna
Published: October 2017

A series of Yb doped lead oxychloride tellurite glasses with composition of (80-x)TeO2-10PbO-10PbCl2-xYb2O3 were prepared using conventional melt quenching technique. These glasses were then immersed in distilled water (pH 4 and pH 9) for 10 days. The quantitative analysis of Pb2+ and Te4+ were made using induced coupled plasma-mass spectrometer (ICP-MS). The results showed that Te4+ and Pb2+ were highly leached in acidic solution or at lower pH compared to alkaline solution and the addition of Yb3+ in the glass system had reduced or maintained the leaching of Te4+ and Pb2+ from the glasses.
The investigation of Neutron Scattering In Spin Waves Theory of Ferromagnetic Crystals
Authors: Farzaneh Azadeh , Abdi Mohammad Reza , Ebrahim Saraee Khadije Rezaee
Published: October 2017

Inelastic neutron scattering, probing the temporal spin-spin correlation at the different microscopic scale, is a powerful technique to study the magnetic behaviour of ferromagnetic crystals. In addition, high penetration power of neutron in samples has made it as a useful way for spin-spin interaction in neutron scattering. Changes in the magnetic cross section in term of different energy transfer and temperatures are calculated for nickel and iron as transition metals in Heisenberg model versus spin wave theory by considering atomic form factor. Finally, the effect of magnetic structure and behaviour of crystal in measuring cross-section shows that increasing temperature results in the Cross-section increase Also, the existence of propagating spin waves below Tc is compared in Ni and Fe in different momentum transfers. The relation of spin wave energy with temperature dependence of nickel has created different behaviour in the changes of cross section rather than iron.
Controlled Pore Diameter in Porous Anodic Aluminium Oxide Templates for Nanotube/Nanowire Fabrication
Authors: Subari Noor Fariza , Sakrani Samsudi , Raja Ibrahim Raja Kamarulzaman
Published: October 2017

A porous anodic aluminium oxide (AAO) templates were fabricated on aluminium by electrodeposition method using a two-step anodization process. The AAO templates were anodized in 0.3 M oxalic acid solution by applying a constant voltage of 40V, which was afterward treated with chemical etching process in a mixed solution of 6% phosphoric acid and 1.8% chromic acid, respectively. The temperature was kept constant in 15oC during the anodization process and the anodization time were done between 20 to 60 min. All the samples were characterized using by scanning electron microscopy (SEM) to study the surface morphology of AAO templates. It was found that the pore diameters of AAO templates can be controlled by changing the anodizing time. The influence of the electropolishing were also discussed. Highly uniform self-ordered AAO template were effectively formed from these polished foils via an anodizing process.
TCLUST: Trimming Approach of Robust Clustering Method
Authors: Md. Jedi Muhamad Alias , Adnan Robiah
Published: October 2017

TCLUST is a method in statistical clustering technique which is based on modification of trimmed k-means clustering algorithm. It is called “crisp” clustering approach because the observation is can be eliminated or assigned to a group. TCLUST strengthen the group assignment by putting constraint to the cluster scatter matrix. The emphasis in this paper is to restrict on the eigenvalues, λ of the scatter matrix. The idea of imposing constraints is to maximize the log-likelihood function of spurious-outlier model. A review of different robust clustering approach is presented as a comparison to TCLUST methods. This paper will discuss the nature of TCLUST algorithm and how to determine the number of cluster or group properly and measure the strength of group assignment. At the end of this paper, R-package on TCLUST implement the types of scatter restriction, making the algorithm to be more flexible for choosing the number of clusters and the trimming proportion.
In Silico Protein Folding Simulation of Amyloid A4 Peptide
Authors: Mohamed Tap Fatahiya , Ahmad Khairudin Nurul Bahiyah
Published: October 2017

The objective of this study is to investigate the folding pathways of Amyloid A4 peptide (PDB ID: 1AML). The structure and trajectories of this protein has been studied using Molecular Dynamics (MD) simulation. The simulation was run at 300K for 50nsec. The model at 2nsec was aligned to the Nuclear Magnetic Resonance (NMR) structure with the RMSD value of 7.85Å for the overall structure. It was found that the 3_10_helix started to form (ILE32 GLY33 LEU34 MET35) at 4nsec until 7nsec.
FTIR Spectroscopy Characterization of Si-C bonding in SiC Thin Film prepared at Room Temperature by Conventional 13.56MHz RF PECVD
Authors: Omar Muhammad Firdaus , Ismail Abd.Khamim , Sumpono Imam , Alim Emilly Albert , Nawi Mohd Nazri , Rahim Mukri Mohd ‘Azizir , Othaman Zulkafli , Sakrani Samsudi
Published: October 2017

SiC thin film has been synthesized by using conventional 13.56MHz radio frequency plasma enhanced chemical vapour deposition (PECVD). The mixture of silane (SiH4) and methane (CH4) were used as precursor gases while hydrogen as carrier gas. The SiH4/CH4 ratio and the substrate temperature have been varied in order to examine the reaction of the active species which can produce the Si-C bonding in the deposited film. FTIR spectroscopy was used to analyse the type of bonding and particularly to confirm the existence of Si-C bonding by comparing the spectrums obtained from deposited thin film samples and standard reference sample of bulk SiC single crystal wafer. The existence of Si-C bonding was confirmed and it was slightly shifted from the bulk SiC wafer at around 722cm-1 and 817cm-1.
Characterization of Alum Sludge for Reuse and Disposal
Authors: Awab Hanim , Paramalinggam P.T. Thanalechumi , Mohd Yusoff Abdull Rahim
Published: October 2017

The properties of spent drinking water treatment sludge (WTS) were investigated to determine its physical and chemical properties. WTS was obtained from the Semanggar Water Treatment Plant, Kota Tinggi, Johore, Malaysia. Bulk density, particle density, porosity, surface area, particle size, moisture content, ash content, chemical composition, leachability of heavy metals, pH and the total organic carbon (TOC) were determined. Surface and other physicochemical properties were also studied using the scanning electron microscope (SEM), field emission scanning electron microscope (FESEM), X-ray diffractometer (XRD), TGA, FTIR, BET single point surface area analyzer, and TOC analyzer. Results showed that the particle size, bulk density and particle density of WTS were 2-5 μm, 0.831 ± 0.061 g/cm3 and 2.66 ± 0.029 g/cm3, respectively. The porosity was 68-69% with surface of 38.92 m2/g and ash content of 67%, reflecting the high TOC of 1440.37±14.71. The sludge contained 29% moisture and showed a pH value of 4.28 in solution. Analysis of acid digest indicated a high content of Al and Fe. The WTS were shown to leach very low levels of selected heavy metals.
Factors Affecting Performance in Cooperative Terengganu By Using Logistic Regression
Authors: Safiar Nor Bazilah , Ahmad Sabri , Yacob Jusoh
Published: October 2017

Co-operative is a direct translation from the Latin word "Co-operation" which means "working together". Cooperative as an organization comprising a group of people to carry out economic and social activities for the benefit of its members. A society registered under the Societies Act 1993 with the aim of improving the economic interests of its members through activities carried out based on the principles of cooperatives. but there are a few cooperatives in Terengganu not run smoothly and become loss. The main objective of this study was to determine whether there is relationship between independent variable such as the number of cooperative members legally registered, the assets owned by each cooperative, amount of capital or shared used by each society involved in the initial engagement, ,the function of cooperative, turnover and the seat of cooperative in the state of Terengganu on the dependent variable which is earnings cooperative. The secondary data for the years 2010 were obtained from Department of Cooperatives Commission of Malaysia (SKM) Terengganu branch .Data were analyzed by using the “Logistic Regression”. At the end of the study, can determine which factors having the influence to performance (profit and loss), examine the association between variables (members, assets ,capital shares ,region, function and turnover),and construct the logistic model.
Profile analysis of daily electricity workloads in Malaysia
Authors: Zolkepley Zunna’aim , Djauhari Maman Abdurachman
Published: October 2017

We learn from literature review that research on statistical modelling of Malaysia daily electricity workload has received very much attention. However, to our knowledge, profile analysis of daily electricity workload had received far less attention. Profile analysis will provide us with daily time series model which is very important in order to understand the statistical model for annual situation. This paper deal with profile analysis and its advantage.
Measurement of natural radioactivity level in surface sediment in southern Kuala Selangor coastal area
Authors: Hamzah Zaini , Abdul Karim Umi Kalsum , Saat Ahmad
Published: October 2017

Kuala Selangor is located in Sungai Selangor estuary in the west coast of Peninsular Malaysia. Kuala Selangor coastal area is susceptible to pollution load as a lot of industrial and human activities are located in the west coast of Peninsular Malaysia and along Sungai Selangor. Surface sediment was taken from 14 points at two locations in southern Kuala Selangor that are in ‘Pantai Remis’ and ‘Pantai Jeram’. This study focused on radioactivity level of naturally occurring radionuclide (mainly 226Ra, 228Ra and 40K) in surface sediment using gamma-ray spectrometry with a high-purity germanium (HPGe) detector. For 40K, the presence of this was measured directly via its 1460 keV energy peak. For 226Ra (of the 238U) and 228Ra (of the 232Th) the γ-ray lines 609.3 keV (214Bi) and 911.1 keV (228Ac) were used. The concentration of 226Ra, 228Ra and 40K in samples obtained from Pantai Remis coastal area ranged between 42.9±1.4-60.0±1.6 (mean 47.6±1.5) Bq/kg, 61.9±2.8-79.3±2.9 (mean 69.5±2.7) Bq/kg and 324.5±10.6-455.8±13.2 (mean 422.2±12.2) Bq/kg, respectively. Meanwhile, the concentration of 226Ra, 228Ra and 40K in samples obtained from Pantai Jeram coastal area ranged between 45.1±1.6-50.4±1.5 (mean 47.2±1.6) Bq/kg, 62.5±2.8-75.9±3.0 (mean 69.2±2.9) Bq/kg and 338.7±10.7-490.6±14.0 (mean 428.2±12.4) Bq/kg, respectively. The mean external hazard index due to these radionuclides is 0.484 for ‘Pantai Remis’ and ‘Pantai Jeram’ (less than unity). Thus, it is expected that no radiation hazard attributed to the radiation from the study radionuclides will be experience by people in the areas.
Combining simulation to nonlinear fitting for the determination of rate constants of elementary reactions by using Excel spreadsheets
Authors: M. Tighezza Ammar , M. Aldhayan Daifallah , A. Aldawsari Nouir
Published: October 2017

A common problem in chemistry is to determine parameters (constants) in an equation used to represent experimental data. Examples are fitting a set of data to a model equation (straight line or curve) to obtain unknown parameters. In chemical kinetics, a set of data is usually a number of concentrations versus time, but the model equation is not well defined! Instead of a well defined model equation we have a set of coupled ODE’s (ordinary differential equations) which represent rate equations for reactants and products. The analytical integration of these ODE’s is rarely possible. The numerical integration is the alternative. In this work are combined the simulation of chemical reactions, by using numerical integration, and nonlinear regression (curve fitting) by using “Solver add-in” of Microsoft Excel to find rate constants of elementary reactions from experimental data. This method is illustrated on three complex mechanisms. The simulation of chemical reactions in Excel spreadsheets is illustrated with/without VBA programming. The automation (automatic obtaining of rate equations from mechanism: no need of chemical kinetics knowledge from the end user!) of mechanism simulation is demonstrated on many example.
Synthesis of Cationic Porphyrins as Potential Gene Transfection Carriers
Authors: Siaw Fui Kiew , Zulkifli Razauden Mohamed , Bakar Mohd Bakri
Published: October 2017

Porphyrins are found having strong but reversible interaction with nucleic acid and thus can be used as complementary to other non-viral vectors in gene transfection delivery. Amphiphilic porphyrins with combination of hydrophobic and hydrophilic substituents along the peripheral of porphyrin macrocycle were synthesized with an attempt to facilitate the membrane penetration as well as better accumulation on the targeted cells. Besides, their fluorescent properties can be used as marker to identify their localization in the intracellular domain. Adler-Longo condensation method was employed to synthesize basic cationic porphyrins and novel asymmetrical amphiphilic cationic porphyrins. All compounds were characterized using 1H-NMR, 13C-NMR, Ultraviolet (UV) and Infrared (IR) spectroscopy.
Solid Phase Micro Tip Extraction Coupled With High Performance Liquid Chromatography for Diclofenac Sodium Analysis in Urine Sample
Authors: Hermawan Dadan , Hui Ling Law , Wan Ibrahim Wan Aini , Sanagi Mohd Marsin
Published: October 2017

A solid phase micro tip extraction (SPMTE) has been developed as sample preparation technique for the analysis of diclofenac sodium, a non-steroidal anti-inflammatory drug (NSAID) in human urine sample. The analysis was performed by high performance liquid chromatography (HPLC) system using methanol:water (60:40, v/v) as mobile phase, flow rate of 1.0 mL/min under UV detection wavelength at 282 nm. Extraction conditions such as desorption solvent and extraction time were optimized in this study. The optimized SPMTE coupled with the HPLC method was successfully applied for the determination of diclofenac sodium in urine samples. The best recovery of diclofenac sodium in urine samples is 74.80% with RSD of 3.56% (n=3). The proposed method provides simple and rapid analysis of diclofenac sodium in urine sample.
Parikh Matrices and Istrail Morphism
Authors: Subramanian K.G. , Isawasan Pradeep , Venkat Ibrahim
Published: October 2017

A word
Effect of iridium loading on the formation of protonic acid sites over Ir/Pt-HZSM5
Authors: Triwahyono S. , Setiabudi H.D. , Jalil A.A. , Timmiati S.N. , Annuar N.H.R. , Fatah N.A.A. , Sazegar M.R. , Teh L.P.
Published: October 2017

The Ir/Pt-HZSM5 with different iridium loading (0.3-1.0 wt%) was prepared by impregnation of iridium on Pt-HZSM5. The acidic properties of Ir/Pt-HZSM5 were studied by FTIR spectroscopy, while the activity of the catalysts was tested for n-pentane isomerization in a microcatalytic pulse reactor.The IR results of adsorbed 2,6-lutidine showed that all catalysts possessed strong Brönsted and Lewis acid sites in the outgassing at 473 K and below.When Ir/Pt-HZSM5 was heated in hydrogen, protonic acid sites were formed with concomitant decrease of Lewis acid sites. An increase in iridiumloading continuously decreased the Lewis and Brönsted acid sites and inhibited the formation of protonic acid sites induced by hydrogen. The formationof protonic acid sites induced by hydrogen was also confirmed by the formation of electron detected by ESR spectroscopy. Additionally for n-pentaneisomerization, an increase in iridium loading decreased the yield of isopentane due to the inhibition in the formation of protonic acid sites via hydrogenspillover phenomenon.
Copper-, Lead- and Mercury-Induced Changes in Maximum Quantum Yield, Chlorophyll A Content and Relative Growth of Three Malaysian Green Macroalgae
Authors: Ahamad Zakeri Hazlina , Abu Bakar Luqman
Published: October 2017

In this study, we reported on the responses of three Malaysian green algae, Caulerpa racemosa, Caulerpa lentillifera and Ulva reticulata against three heavy metals, copper (Cu), lead (Pb) and mercury (Hg). Responses were determined as maximum quantum yield (Fv/Fm) for photosynthetic quantum efficiency, chlorophyll (chl) a content and relative growth measured as changes in fresh weight. The algae were exposed for 8h in two concentrations of metals, which were 1 mg/L and 2 mg/L. In general, all algae were severely affected by the presence of Hg compared to the other two metals. Fv/Fm of the algae was significantly reduced to the lowest of 18% in 1 mg/L Hg as observed in C. racemosa while the lowest for Cu and Pb was 29% and 41%, respectively, also observed in similar algal species. All algae showed an undetected value of Fv/Fm when concentration of Hg was increased to 2 mg/L. An increase in Fv/Fm was observed for C. lentillifera in 1 mg/L of Cu and Pb but the value showed a reduction when the concentration of both metals was increased to 2 mg/L. Among the algae, Fv/Fm of C. racemosa was severely affected by the presence of all metals particularly at 2 mg/L where it showed undetected value. An increase in the content of chl a was observed in C. racemosa and C. lentillifera for each metals at both concentrations while a decrease in the content was observed in U. reticulata. Algal relative growth was negatively affected by the presence of metals with Hg showed the strongest effect. However, some algae showed a positive effect of Pb on their growth.
MHD Mixed Convection Flow of Viscoelastic Fluid Embedded in Porous Medium
Authors: Kasim A.R.M. , Mohammad N.F. , Aurangzaib Aurangzaib , Shafie S.
Published: October 2017

An analysis has been carried out to investigate the effect of magnetic field presence on the mixed convection boundary layer flow of viscoelastic fluid over a horizontal circular cylinder in a porous medium. The governing non-similar partial differential equations are transformed into dimensionless forms and then solved numerically using the Keller-box method. Some important parameters have been discussed in this study which include the Prandtl number (Pr), magnetic parameter (M), viscoelastic parameter (K), porosity parameter (γ) and the mixed convection parameters (λ). The results show the values of the velocity decrease when the value of viscoelastic parameter increase and the reverse trend were observe for temperature profile. Numerical results of local skin friction as well as local Nusselt number are also presented in tabular form.
Methanation Reaction over Samarium Oxide Based Catalysts
Authors: Wan Abu Bakar Wan Azelee , Jamal Mat Rosid Salmiah , Ali Rusmidah
Published: October 2017

Malaysia produces an acidic crude natural gas which contains 23% of CO2 and <1% of H2S. Thu their presence will corrode the carbon steel gas pipeline system, thus resulting decreasing quality and price of natural gas as well as pollute the environment. Instead, using catalysts for the CO2 methanation have been extensively studied and high potentiality towards converting CO2 gas to methane. The potential of samarium has been widely explored for their ability as a dopant catalyst for CO2 methanation from researchers for metal oxide in CO2 methanation. However, the potential of samarium as a based catalyst in CO2 methanation have not been explored yet. Therefore, in this study the supported samarium oxide doped transition metals catalysts was prepared by wetness impregnation method for carbon dioxide methanation reaction by using trimetallic oxide catalyst because of the lower performance of conversion of CO2 in monometallic oxide and bimetallic oxide catalysts. The catalytic activity of prepared catalysts was tested using in-house built micro reactor coupled with Fourier Transform Infrared (FTIR) toward CO2/H2 methanation. Then, the catalysts were optimized by different calcination temperatures and different based oxide loadings. The potential catalysts of Ru/Mn/Sm (5:35:60)/Al2O3 calcined at 1000 °C and 1100 oC gave > 95 % of CO2 conversion at 300 oC reaction temperature and yielded about 93.46 % of CH4 at reaction temperature of 400 °C. XRD analysis showed the potential catalysts are an amorphous phase, while FESEM analysis illustrated the surface of the catalysts were covered with small and dispersed spherical particles. EDX analysis revealed that there were 0.3 % reduction of Ru in the Ru/Mn/Sm (5:35:60)/Al2O3 ofused catalysts compared to fresh catalysts. Meanwhile NA analysis showed that Ru/Mn/Sm (5:35:60)/Al2O3 catalystattained surface area of 47.38 m2/g.
Permutation Groups in Automata Diagrams
Authors: Yee Siang Gan , Wan Heng Fong , Sarmin Nor Haniza , Turaev Sherzod
Published: October 2017

Automata act as classical models for recognition devices. From the previous researches, the classical models of automata have been used to scan strings and to determine the types of languages a string belongs to. In the study of automata and group theory, it has been found that the properties of a group can be recognized by the automata using the automata diagrams. There are two types of automata used to study the properties of a group, namely modified finite automata and modified Watson-Crick finite automata. Thus, in this paper, automata diagrams are constructed to recognize permutation groups using the data given by the Cayley table. Thus, the properties of permutation group are analyzed using the automaton diagram that has been constructed. Moreover, some theorems for the properties of permutation group in term of automata are also given in this paper.
Liquid Membrane Formulation for Removal of Kraft Lignin from Simulated Liquid Waste Solution
Authors: Othman Norasikin , Zing Yi Ooi , Harruddin Norlisa
Published: October 2017

Extraction of lignin from pulping wastewater as an external biofuel and in specialty chemicals will additionally benefit the chemical and automobile industries. Though lignin is nontoxic, it imparts brownish black colouration to the water bodies can cause environmental problems. Emulsion liquid membrane (ELM) technology is proposed to extract and recover the kraft lignin (KL) compound from the aqueous waste solution. This study investigated on development of a liquid membrane formulation for lignin removal from aqueous waste solution. Several parameters such as types and concentration of carrier, types of diluents and types of stripping agentswere studied. The results showed that the most favorable liquid membrane formulation is using Aliquat 336 as extractant, kerosene as diluents and sodium bicarbonate (NaHCO3) as stripping agent which is almost 93% of lignin was extracted.
Conductivity and Dielectric Behaviour Studies of LiCF3SO3 Dissociation in L-Chitosan/PMMA-Based Polymer Electrolytes
Authors: Khiar A.S.A , Mat Radzi S. , Abd Razak N.
Published: October 2017

Lauroyl-chitosan/poly(methylmethacrylate)-lithium trifluorosulfonate (LiCF3SO3) polymer electrolytes has been prepared by the solution casting method. Ionic conductivity analysis was conducted over a wide range of frequency between 50 Hz-1 MHz using impedance spectroscopy to evaluate the dielectric properties and conductivity of the sample. Sample with 30 wt% of LiCF3SO3 showed the highest conductivity of 7.59 ± 3.64 x 10-4 Scm-1 at room temperature. Complex permittivity for real (εr), imaginary (εi) and electrical modulus for real (Mr) and imaginary (Mi) part was determined and plotted. The relaxation time, τ for these samples was determined and the plot shows that τ decreases with conductivity of the complexes.
Network Quality of Service Assessment Implementation Using a Microcontroller Board
Authors: Dogman Aboagela , Saatchi Reza , Al-Khayatt Samir
Published: October 2017

Network Quality of Service (QoS) assessment plays an important role in managing network resources and ensuring that various applications receive an appropriate prioritisation or sufficient resources. Therefore, developing a portable hand-held device that accurately assesses QoS for different applications is very valuable. In this study, a QoS monitoring system was designed and evaluated. The QoS assessment was based on regression modelling that was implemented on the MCB2300 KEIL ARM microcontroller board. The system analysed the QoS requirements (delay, jitter andpacket loss ratio) of multimedia applications to determine their overall QoS. The QoS assessment results were compared with other assessment methods (e.g. Fuzzy Inference System and Neural Network based QoS monitoring). The study indicated the effectiveness of the developed system in monitoring multimedia QoS accurately.