Search results for: Mardhiana Binti Ismail

Authors: Syed Ali Taqi, Muhammad Ismail

Abstract:

A comparative study of estimators of population means in two phase sampling in the presence of non-response when Unknown population means of the auxiliary variable(s) and incomplete information of study variable y as well as of auxiliary variable(s) is made. Three real data sets of University students, hospital and unemployment are used for comparison of all the available techniques in two phase sampling in the presence of non-response with the newly generalized ratio estimators.

Keywords: two-phase sampling, ratio estimator, product estimator, generalized estimators

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Authors: Muhammad Heikal Ismail, Law Chung Lim, Hii Ching Lik

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In maintaining food quality and shelf life, drying is employed in food industry as the most reliable perseverance technique. In this way, heat pump drying and hot air drying of fresh rice noodles was deduced to freeze drying in achieving quality attributes of oil content Scanning Electron Microscope (SEM) images, texture, and colour. Soxthlet analysis shows freeze dried noodles contain more than 10 times oil content, distinct pores of SEM images, higher hardness by more than three times, and wider colour changes by average more than two times to both methods to explain the less transparency physical outlook of freeze dried samples.

Keywords: freeze drying, heat pump drying, noodles, Soxthlet

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Authors: Mehdi Saeidmanesh, Razali Ismail

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Recently, Graphene Nanoribbon Field Effect Transistors (GNR FETs) attract a great deal of attention due to their better performance in comparison with conventional devices. In this paper, channel length Modulation (CLM) effect on the electrical characteristics of GNR FETs is analytically studied and modeled. To this end, the special distribution of the electric potential along the channel and current-voltage characteristic of the device is modeled. The obtained results of analytical model are compared to the experimental data of published works. As a result, it is observable that considering the effect of CLM, the current-voltage response of GNR FET is more realistic.

Keywords: graphene nanoribbon, field effect transistors, short channel effects, channel length modulation

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Authors: Dia I. Abu-Al-Nadi, M. J. Mismar, T. H. Ismail

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A technique for estimating the direction-of-arrival (DOA) of unknown number of source signals is presented using the eigen-approach. The eigenvector corresponding to the minimum eigenvalue of the autocorrelation matrix yields the minimum output power of the array. Also, the array polynomial with this eigenvector possesses roots on the unit circle. Therefore, the pseudo-spectrum is found by perturbing the phases of the roots one by one and calculating the corresponding array output power. The results indicate that the DOAs and the number of source signals are estimated accurately in the presence of a wide range of input noise levels.

Keywords: array signal processing, direction-of-arrival, antenna arrays, Eigenvalues, Eigenvectors, Lagrange multiplier

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Authors: M. Y. Ismail, M. Inam

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This paper presents equivalent circuit modeling of active planar reflectors which can be used for the detailed analysis and characterization of reflector performance in terms of lumped components. Equivalent circuit representation has been proposed for PIN diodes and liquid crystal based active planar reflectors designed within X-band frequency range. A very close agreement has been demonstrated between equivalent circuit results, 3D EM simulated results as well as measured scattering parameter results. In the case of measured results, a maximum discrepancy of 1.05dB was observed in the reflection loss performance, which can be attributed to the losses occurred during measurement process.

Keywords: Equivalent circuit modelling, planar reflectors, reflectarray antenna, PIN diode, liquid crystal

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Authors: Keng Keh Lim, Zaleha Ismail, Yudariah Mohammad Yusof

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This paper aims to find out how students using convergent and divergent thinking in creative problem solving to solve mathematical problems creatively. Eight engineering undergraduates in a local university took part in this study. They were divided into two groups. They solved the mathematical problems with the use of creative problem solving skills. Their solutions were collected and analyzed to reveal all the processes of problem solving, namely: problem definition, ideas generation, ideas evaluation, ideas judgment, and solution implementation. The result showed that the students were able to solve the mathematical problem with the use of creative problem solving skills.

Keywords: convergent thinking, divergent thinking, creative problem solving, creativity

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Authors: Şirin Küçük, Ayşe Kök, İsmail Şahin

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Mobile devices are very popular and useful tools for assisting people in daily life. With the advancement of mobile technologies, the issue of mobile learning has been widely investigated in education. Many researches consider that it is important to integrate pedagogical and technical strengths of mobile technology into learning environments. For this reason, the purpose of this research is to examine the effect of mobile technology use in education with meta-analysis method. Meta-analysis is a statistical technique which combines the findings of independent studies in a specific subject. In this respect, the articles will be examined by searching the databases for researches which are conducted between 2005 and 2014. It is expected that the results of this research will contribute to future research related to mobile technology use in education.

Keywords: mobile learning, meta-analysis, mobile technology, education

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Authors: Noor Aliza Binti Ahmad, Azra Munirah Mat Daud, Sabariah Musa, Mohamad Azhar MK

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Flooding is a common natural disaster in Malaysia triggered by heavy rainfall. Urbanization that increases the construction of paved areas, subsequently raise surface runoff and reduce time of concentration. It increases flood magnitude and so that leads to greater flood problems as what has happened at Universiti Tun Hussein Onn Malaysia (UTHM) area in December 2006 and earlier 2007. Tasik Kemajuan and Tasik Inovasi were constructed as recreation ponds and have also functioned as flood ponds. Unfortunately, the flood problem still occurs persistently. Thus, the effectiveness of Tasik Kemajuan and Tasik Inovasi in reducing the flood problems need to be investigated and the causes of flood events at UTHM Campus need to be evaluated. The results from this study show that the conditions of Tasik Kemajuan and Tasik Inovasi are effective in reducing the flood water levels. It also can be concluded that increasing water level in both lakes in UTHM Campus are significantly influenced by presence of the grass and rubbish. During dry condition, the flow rates with three different days are 59.38m3/s, 60.71m3/s and 59.08m3/s and while for wet condition in two different days are 89.59 m3/s and 86.61m3/s. In conclusion, this system should be improved to prevent future flooding either widened or reduced drainage floor, and also perform maintenance on the plants that live around the lake.

Keywords: drainage system, flood detention, lakes, storm water

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Authors: Ofosuhene O. Apenteng, Noor Azina Ismail

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Recently tourism is a major foreign exchange earner in the World. In this paper, we propose the mathematical model to study the impact of tourists on the spread of HIV incidences using compartmental differential equation models. Simulation studies of reproduction number are used to demonstrate new insights on the spread of HIV disease. The periodogram analysis of a time series was used to determine the speed at which the disease is spread. The results indicate that with the persistent flow of tourism into a country, the disease status has increased the epidemic rate. The result suggests that the government must put more control on illegal prostitution, unprotected sexual activity as well as to emphasis on prevention policies that include the safe sexual activity through the campaign by the tourism board.

Keywords: HIV/AIDS, mathematical transmission modeling, tourists, stability, simulation

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Authors: Eftah Bte. Moh Hj Abdullah, Abd Aziz Bin Abd Shukor, Norazilawati Binti Abdullah, Rahimah Adam, Othman Bin Lebar

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The competency and integrity required for better understanding and practice of School-based Assessment (PBS) comes not only from the process, but also in providing the support or ‘scaffolding’ for teachers to recognize the student as a learner, improve their self-assessment skills, understanding of the daily teaching plan and its constructive alignment of the curriculum, pedagogy and assessment. The cultivation of integrity in PBS among the teachers is geared towards encouraging them to become committed and dedicated in implementing assessments in a serious, efficient manner, thus moving away from the usual teacher-focused approach to the student-focused approach. The teachers show their integrity via their professional commitment, responsibility and actions. The module based on the cultivation of integrity in PBS among Malaysian teachers aims to broaden the guidance support for teachers (embedded in the training), which consists of various domains to enable better evaluation of complex assessment tasks and the construction of suitable instrument for measuring the relevant cognitive, affective and psychomotor domains to describe the students’ achievement. The instrument for integrity cultivation in PBS has been developed and validated for measuring the effectiveness of the module constructed. This module is targeted towards assisting the staff in the Education Ministry, especially the principal trainers, teachers, headmasters and education officers to acquire effective intervention for improving the PBS assessors’ integrity and competency.

Keywords: school-based assessment, assessment competency integrity cultivation, professional commitment, module

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Authors: Abd Aziz Bin Abd Shukor, Eftah Binti Moh Hj Abdullah

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This case study aims to identify teachers’ perception as regards integrity in School-Ba sed Assessment (PBS) practice. This descriptive study involved 9 teachers from 4 secondary schools in 3 districts in the state of Perak. The respondents had undergone an integrity in PBS Practice interview using a focused group discussion method. The overall findings showed that the teachers believed that integrity in PBS practice could be achieved by adjusting the teaching methods align with learning objectives and the students’ characteristics. Many teachers, parents and student did not understand the best practice of PBS. This would affect the integrity in PBS practice. Teachers did not emphasis the principles and ethics. Their integrity as an innovative public servant may also be affected with the frequently changing assessment system, lack of training and no prior action research. The analysis of findings showed that the teachers viewed that organizational integrity involving the integrity of PBS was difficult to be implemented based on the expectations determined by Malaysia Ministry of Education (KPM). A few elements which assisted in the achievement of PBS integrity were the training, students’ understanding, the parents’ understanding of PBS, environment (involving human resources such as support and appreciation and non-human resources such as technology infrastructure readiness and media). The implications of this study show that teachers, as the PBS implementers, have a strong influence on the integrity of PBS. However, the transformation of behavior involving PBS integrity among teachers requires the stabilisation of support and infrastructure in order to enable the teachers to implement PBS in an ethical manner.

Keywords: assessment integrity, integrity, perception, school-based assessment

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Authors: Funda Kul, İsmail Gür

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Pension scheme providers have to price mortality risk by accurate mortality forecasting method. There are many mortality-forecasting methods constructed and used in literature. The Lee-Carter model is the first model to consider stochastic improvement trends in life expectancy. It is still precisely used. Mortality forecasting is done by mortality index in the Lee-Carter model. It is assumed that mortality index fits ARIMA time series model. In this paper, we propose and use dynamic normal inverse gaussian distribution to modeling mortality indes in the Lee-Carter model. Using population mortality data for Italy, France, and Turkey, the model is forecasting capability is investigated, and a comparative analysis with other models is ensured by some well-known benchmarking criterions.

Keywords: mortality, forecasting, lee-carter model, normal inverse gaussian distribution

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Authors: M. Hijazi, A. Zeki, A. Ismail

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An enormous amount of valuable human knowledge is preserved in documents. The rapid growth in the number of machine-readable documents for public or private access requires the use of automatic text classification. Text classification can be defined as assigning or structuring documents into a defined set of classes known in advance. Arabic text classification methods have emerged as a natural result of the existence of a massive amount of varied textual information written in the Arabic language on the web. This paper presents a review on the published researches of Arabic Text Classification using classical data representation, Bag of words (BoW), and using conceptual data representation based on semantic resources such as Arabic WordNet and Wikipedia.

Keywords: Arabic text classification, Arabic WordNet, bag of words, conceptual representation, semantic relations

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Authors: Ismail Aksoy, Haci Bodur, Nihan Altintaş

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This paper introduces a boost converter with a new active snubber cell. In this circuit, all of the semiconductor components in the converter softly turns on and turns off with the help of the active snubber cell. Compared to the other converters, the proposed converter has advantages of size, number of components and cost. The main feature of proposed converter is that the extra voltage stresses do not occur on the main switches and main diodes. Also, the current stress on the main switch is acceptable level. Moreover, the proposed converter can operates under light load conditions and wide input line voltage. In this study, the operating principle of the proposed converter is presented and its operation is verified with the Proteus simulation software for a 1 kW and 100 kHz model.

Keywords: active snubber cell, boost converter, zero current switching, zero voltage switching

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Authors: Naim Suleyman Ting, Yakup Sahin, Ismail Aksoy

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This paper presents a zero voltage transition-zero current transition (ZVT-ZCT)-PWM DC-DC boost converter with direct power transfer. In this converter, the main switch turns on with ZVT and turns off with ZCT. The auxiliary switch turns on and off with zero current switching (ZCS). The main diode turns on with ZVS and turns off with ZCS. Besides, the additional current or voltage stress does not occur on the main device. The converter has features as simple structure, fast dynamic response and easy control. Also, the proposed converter has direct power transfer feature as well as excellent soft switching techniques. In this study, the operating principle of the converter is presented and its operation is verified for 1 kW and 100 kHz model.

Keywords: direct power transfer, boost converter, zero-voltage transition, zero-current transition

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Authors: Mucip Tapan, Ali Ozvan, Ismail Akkaya

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This study investigated how the concrete confinement strength and axial load carrying capacity of reinforced concrete columns are affected by corrosion damage to the stirrups. A total of small-scale 12 test specimens were cast for evaluating the effect of stirrup corrosion on confinement strength of concrete. The results of this study show that the stirrup corrosion alone dramatically decreases the axial load carrying capacity of corroded reinforced concrete columns. Recommendations were presented for improved inspection practices which will allow estimating concrete confinement strength of corrosion-damaged reinforced concrete bridge columns.

Keywords: bridge, column, concrete, corrosion, inspection, stirrup reinforcement

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Authors: Nurul Amziah Md Yunus, Izhal Abdul Halin, Nasri Sulaiman, Noor Faezah Ismail, Nik Hasniza Nik Aman

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Nanotechnology has become the world attention in various applications including the solar cells devices due to the uniqueness and benefits of achieving low cost and better performances of devices. Recently, thin film solar cells such as cadmium telluride (CdTe), copper-indium-gallium-diSelenide (CIGS), copper-zinc-tin-sulphide (CZTS), and dye-sensitized solar cells (DSSC) enhanced by nanotechnology have attracted much attention. Thus, a compilation of nanotechnology devices giving the progress in the solar cells has been presented. It is much related to nanoparticles or nanocrystallines, carbon nanotubes, and nanowires or nanorods structures.

Keywords: nanotechnology, nanocrystalline, nanowires, carbon nanotubes, nanorods, thin film solar cells

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Authors: İsmail Çeli̇k, Gülgün Ayhan-Kılcıgi̇l, Arzu Onay-Beşi̇kçi̇

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In this study, some 2-(2-phenyl/substitutedphenyl)- lH-benzo[d]'imidazol-l-yl)-N'-(alkylthiosemicarbazide were designed and prepared. Firstly, 2-phenyl/ suhstitutedphenyl-lH-Benzo[d]imidazole was prepared via oxidative condensation of o-phenylenediamine, benzaldehyde and sodium metabisulfite. Treatment of the benzimidazole compound with ethyl chloroacetate in KOH/DMSO gave the ester compound ethyl 2-(2-substitutedphenyl)-1H-benzo[d]imidazol-l-yl)acetate. Hydrazine hydrate and the ester in ethanol were refluxed for 4 h to give 2-(2-phenyl/substitutedphenyl)-1H-benzo[d]imidazol-l-yl)acetohydrazide. Thiosemicarbazides were obtained by condensing acyl hydrazide with the alkylisothiocyanate in ethanol. Following the structure elucidation, benzimidazole compounds were tested for their EGFR kinase inhibitory activities by using ADP-GloTM Kinase Assay.

Keywords: benzimidazole, EGFR kinase inhibitor, synthesis, thiosemicarbazide

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Authors: Abdallah Ghoul, Bachir Ouamri, Ismail Khalil Bousserhane

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In this paper, we have developed a sliding mode controller for PUMA 600 manipulator robot, to control the remote robot a teleoperation system was developed. This system includes two sites, local and remote. The sliding mode controller is installed at the remote site. The client asks for a position through an interface and receives the real positions after running of the task by the remote robot. Both sites are interconnected via the Internet. In order to verify the effectiveness of the sliding mode controller, that is compared with a classic PID controller. The developed approach is tested on a virtual robot. The results confirmed the high performance of this approach.

Keywords: internet, manipulator robot, PID controller, remote control, sliding mode, teleoperation

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Authors: A. M. Sultana, Norhirdawati Binti Mhd Zahir, Norzalan Hadi Yaacob

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Recently in Malaysia, women's participation in teaching profession has increased. The increasing trend of women’s participation in the teaching profession poses challenges in families, especially in the developing countries like Malaysia. One of these challenges, concerns in balancing their role between family and job responsibility that faced by many women teachers. The purpose of this study is to discover how women teachers' impact on family happiness and the challenges faced by them in balancing their role between family and job responsibility. The findings presented in this study are based on survey research in a secondary school Dato’ Bijaya Setia in the district of Gugusan Manjoi which is located in Kedah, Malaysia. The study found that employment of women in economic activity has several beneficial impacts of improving the economic condition of the family. The results also revealed that in low income earning families, both husbands and wives’ employment contribute to the family income that less likely to experience of family poverty. The study also showed despite women's teachers’ significant role towards the overall development of the family, the majority of women teachers encountered a number of difficulties in balancing their role between family and job responsibility especially when they need to work more than the normal working time. Therefore, it is common for the majority of women suffering from psychological stress when they are unable to complete the task at a fixed time. The present study also suggests implication of family friendly policy and its appropriate practice to support the women teachers who are significantly contributing to family, community and the country.

Keywords: emotional exhaustion, family friendly policy, work family conflict, women teacher

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Authors: İsmail İnce, Mustafa Fener

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Natural stones used as building materials are exposed to various direct or indirect atmospheric effects depending on the climatic and seasonal conditions. Stones deteriorate partially or fully as a result of these effects. Freezing and thawing (F-T) process is the most important interaction. Nevşehir is located in the Central Anatolia region in Turkey and it has a typical continental climate with cold, snowy winters and hot, dry summers. Effects of freeze-thaw processes were widely observed on the building stones used in the region. Pyroclastic rocks, which are named as Nevşehir stone in the region, have been used in most of these buildings. The purpose of this study is to investigate the variations in engineering and textural properties of Nevşehir stone during different F-T cycles.

Keywords: Nevşehir stone, freeze-thaw, engineering properties, textural properties

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Authors: Ismail Seçer

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The purpose of this study is to analyze the predictive effect of anxiety sensitivity on obsessive compulsive symptoms. The sample of the study consists of 542 students selected with appropriate sampling method from the secondary and high schools in Erzurum city center. Obsessive Compulsive Inventory and Anxiety Sensitivity Index were used in the study to collect data. The data obtained through the study was analyzed with structural equation modeling. As a result of the study, it was determined that there is a significant relationship between obsessive Compulsive Disorder (OCD) and anxiety sensitivity. Anxiety sensitivity has direct and indirect meaningful effects on the latent variable of OCD in the sub-dimensions of doubting-checking, obsessing, hoarding, washing, ordering, and mental neutralizing, and also anxiety sensitivity is a significant predictor of obsessive compulsive symptoms.

Keywords: obsession, compulsion, structural equation, anxiety sensitivity

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Authors: Fahanim Abdul Rashid, Muhammad Azzam Ismail

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Part and parcel of building green homes (GHs) with favorable thermal comfort (TC) is to design and build with reduced carbon footprint (CF) from embodied energy in the building envelope and reduced operational CF overall. Together, the environmental impact of GHs can be reduced significantly. Nevertheless, there is still a need to identify the base CF value for Malaysian GHs and this can be done by assessing existing ones which can then be compared to conventional and vernacular houses which are built differently with different building materials. This paper underlines the research design and introduces the case studies. For now, the operational CF of the case studies is beyond the scope of this study. Findings from this research could identify the best building material and construction technique combination to build GHs depending on the available skills, financial constraints and the condition of the immediate environment.

Keywords: embodied carbon footprint, Malaysian green homes

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Authors: Amiraa Ali Mansor, Haslinda Abdullah, Angela Chan Nguk Fong, Norhaida Hanim Binti Ahmad Tajudin, Asnarulkhadi Abu Samah

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Obesity has risen sharply over the past three decades, posing a grave public health concern globally. In Malaysia, it has also emerged as a significant health threat. While the second Sustainable Development Goal, "Zero Hunger", aims to ensure equitable access to nutritious food for all, a key challenge lies in addressing food insecurity. Food insecurity not only pertains to the quantity but also the quality of food, with both dimensions playing a pivotal role in health outcomes. To date, much of the research on food security has focused on household levels. There remains a research gap concerning university students, a population transitioning to independence from parental support and grappling with limited resources. This study seeks to bridge this gap by extending the Food Security Theory to incorporate the psychological dimension of self-esteem. Using a quantitative approach, data was collected from 452 public university students in Malaysia through a cross-sectional research design and a multi-stage cluster sampling technique. The anticipated findings will provide novel insights by linking food security with self-esteem. Such insights have implications for healthcare policy and the framing of preventive strategies against obesity. It is hoped that this research will not only contribute to the academic discourse on Food Security Theory but also serve as a foundation for refining national health policies and programs aimed at fostering a healthier lifestyle.

Keywords: obesity, food security, body image, self-esteem

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Authors: Mohsen Khaledian, Razali Ismail, Mehdi Saeidmanesh, Mahdiar Hosseinghadiry

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A semi-analytical model for impact ionization coefficient of graphene nanoribbon (GNR) is presented. The model is derived by calculating probability of electrons reaching ionization threshold energy Et and the distance traveled by electron gaining Et. In addition, ionization threshold energy is semi-analytically modeled for GNR. We justify our assumptions using analytic modeling and comparison with simulation results. Gaussian simulator together with analytical modeling is used in order to calculate ionization threshold energy and Kinetic Monte Carlo is employed to calculate ionization coefficient and verify the analytical results. Finally, the profile of ionization is presented using the proposed models and simulation and the results are compared with that of silicon.

Keywords: nanostructures, electronic transport, semiconductor modeling, systems engineering

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Authors: T. M. Ismail, M. A. El-Salam

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A mathematical model study was carried out to investigate gasification of biomass fuels using high-temperature air and steam as a gasifying agent using high-temperature air up to 1000°C. In this study, a 2D computational fluid dynamics model was developed to study the gasification process in an updraft gasifier, considering drying, pyrolysis, combustion, and gasification reactions. The gas and solid phases were resolved using a Euler−Euler multiphase approach, with exchange terms for the momentum, mass, and energy. The standard k−ε turbulence model was used in the gas phase, and the particle phase was modeled using the kinetic theory of granular flow. The results show that the present model giving a promising way in its capability and sensitivity for the parameter effects that influence the gasification process.

Keywords: computational fluid dynamics, gasification, biomass fuel, fixed bed gasifier

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Authors: Salima Tabti, Amel Djedouani., Djouhra Aggoun, Ismail Warad

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The reaction of copper (II) with 4-hydroxy-3-[(2E)-3-(1H-indol-3-yl)prop-2-enoyl]-6-methyl-2H-pyran-2-one (HL) lead to a new complexe: Cu(L)₂(DMF)₂. The crystal structure of the Cu(L)₂(DMF)₂ complex have been determined by X-ray diffraction methods. The Cu(II) lying on an inversion centre is coordinated to six oxygen atoms forming an octahedral elongated. Additionally, the electrochemical behavior of the metal complexe was investigated by cyclic voltammetry at a glassy carbon electrode (GC) in CH₃CN solution, showing the quasi-reversible redox process ascribed to the reduction of the MII/MI couple. The X-ray single crystal structure data of the complex was matched excellently with the optimized monomer structure of the desired compound; Hirschfeld surface analysis supported the packed crystal lattice 3D network intermolecular forces.

Keywords: chalcones, cyclic voltametry, X-ray, Hirschfeld surface

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Authors: Muhammad A. Ado, Intan S. Ismail, Hasanah M. Ghazali, Faridah Abas

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In this study, we have investigated the phytochemical constituents of soluble fractions of dichloromethane (DCM) of methanolic leaves extract of the Callicarpa maingayi. The phytochemicals investigation has resulted in the isolation of three triterpenoids (euscaphic acid (1), arjunic acid (2), and ursolic acid (3)) together with two flavones apigenin (4) and acacetin (5)), two phytosterols (stigmasterol 3-O-β-glycopyranoside (6) and sitosterol 3-O-β-glycopyranoside (7)), and one fatty acid (n-hexacosanoic acid (8)). Six (6) compounds isolated from this species were isolated for the first time (1, 2, 3, 4, 5, and 8). Their structures were elucidated and identified by spectral methods of one and two-dimensional NMR techniques, gas chromatography-mass spectrometry, and comparison with the previously reported literature. The biological activity of three compounds (1-3) was carried out on acetylcholinesterase inhibition activity. Compound (3) was found to displayed good inhibition against AChE with an IC₅₀ value of 21.5 ± 0.022 μM.

Keywords: acetylcholinesterase, Callicarpa maingayi, euscaphic acid, ursolic acid

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Authors: Haitham S. Hamza, Mohamed Maher, Shourok Alaa, Aya Khattab, Hadeal Ismail, Kamilia Hosny

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Radio Frequency Identification (RFID) has become a key technology in the margining concept of Internet of Things (IoT). Naturally, business applications would require the deployment of various RFID systems that are developed by different vendors and use various data formats. This heterogeneity poses a real challenge in developing large-scale IoT systems with RFID as integration is becoming very complex and challenging. Semantic integration is a key approach to deal with this challenge. To do so, ontology for RFID systems need to be developed in order to annotated semantically RFID systems, and hence, facilitate their integration. Accordingly, in this paper, we propose ontology for RFID systems. The proposed ontology can be used to semantically enrich RFID systems, and hence, improve their usage and reasoning. The usage of the proposed ontology is explained through a simple scenario in the health care domain.

Keywords: RFID, semantic technology, ontology, sparql query language, heterogeneity

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Authors: Ridvan Yamanoglu, Erdinc Efendi, Ismail Daoud

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In this study, Ti-5Al-2.5Fe alloy was prepared by powder metallurgy. The elemental titanium, aluminum, and iron powders were mechanically alloyed for 10 h in a vacuum atmosphere. A stainless steel jar and stainless steel balls were used for mechanical alloying. The alloyed powders were then sintered by vacuum hot pressing at 950 °C for a soaking time of 30 minutes. Pure titanium was also sintered at the same conditions for comparison of mechanical properties and microstructural behavior. The samples were investigated by scanning electron microscopy, XRD analysis, and optical microscopy. Results showed that, after mechanical alloying, a homogeneous distribution of the elements was obtained, and desired a-b structure was determined. Ti-5Al-2.5Fe alloy was successfully produced, and the alloy showed enhanced mechanical properties compared to the commercial pure titanium.

Keywords: Ti5Al-2.5Fe, mechanical alloying, hot pressing, sintering

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