Zulfaqar JDSET

Journal of Defence Science, Engineering & Technology

NONPARAMETRIC ROBUST ESTIMATOR FOR SLOPE PARAMETER IN LINEAR STRUCTURAL RELATIONSHIP MODEL

Amel Saad Alshargawi, Abdul Ghapor Hussin, Ummul Fahri binti Abd Rauf

 

Abstract

In this study, the slope parameter of linear structural relationship model is determined by using the proposed robust nonparametric method based on trimmed mean. This method is an upgrade to the nonparametric method that was introduced by Al-Nasser et al. (2005) by employing trimmed mean for all likely paired slopes rather than median slopes. Simulation study and real data were used to compare the proposed method’s performance versus the traditional maximum likelihood method. In the simulation study, based on both methods’ mean square error, it was inferred that the MLE method break down due to the presence of outliers even though its elaborate was not affected when there was no outlier in the data set. Based on the real life examples, it can be concluded that the performance of our proposed method was better in determining the slope parameter and thus provides a good alternative to MLE method when outliers are present.

 

 

LOW COST AND ROOM TEMPERATURE METHANE DETECTION USING MULTI WALLED-CARBON NANOTUBES FUNCTIONALIZED WITH OCTADECANOL

Nurjahirah Janudin, Norli Abdullah, Faizah Md Yasin, Mohd Hanif Yaacob, Muhammad Zamharir Ahmad, Luqman Chuah Abdullah, Raja Nor Izawati Raja Othman, Noor Aisyah Ahmad Syah, Shafreeza Sobri, Noor Azilah Mohd Kasim

 

Abstract

Multi walled-carbon nanotubes (CNT) functionalized with ester was used for detecting methane, CH4 gas at room temperature. Quartz substrate with interdigitated prepatterned gold electrodes was employed as transducers and drop casting method was used to deposit the CNT samples. The electrical properties of the functionalized CNT samples in the presence of CH4 gas were studied and the changes of resistance were recorded using digital multimeter. Concentration of CH4 gas was varied from 0.125 % to 1.0 %. The resistance variation of functionalized CNT increased with the concentration of tested gas. Sensor response of functionalized CNT was improved more than 10 % as compared to pristine CNT. CNT-Ester gives the higher sensitivity due to the presence of ester functional group which act as active site to react with CH4 gas. The fast response of functionalized CNT towards CH4 gas suggested that the functional group enhanced the rate of gas adsorption on sensing layer.

 

 

CARBON NANOTUBES-BASED GAS SENSOR IN DETECTION OF METHANE GAS AT ROOM TEMPERATURE

Nurjahirah Janudin, Norli Abdullah, Faizah Md Yasin, Mohd Hanif Yaacob, Muhammad Zamharir Ahmad, Luqman Chuah Abdullah, Raja Nor Izawati Raja Othman, Noor Aisyah Ahmad Syah, Shafreeza Sobri, Noor Azilah Mohd Kasim

 

Abstract

Room temperature carbon nanotubes (CNT)-based gas sensor was utilised in detection of methane, CH4 gas. The CNT was functionalized with amide group via Fischer esterification process and labelled as CNT-Amide. Silicon dioxide, SiO2 substrate with interdigitated prepatterned gold electrodes were employed as transducers and drop casting technique was used to deposit the multi walled-CNT samples. The electrical properties of the functionalized CNT samples in the exposure of CH4 gas are studied by recorded the changes of resistance using digital multimeter. Concentration of CH4 gas was varied from 1250 ppm to 10 000 ppm. The changes of electrical resistance of CNT-Amide increases with the concentration of tested gas. Sensor response of functionalized CNT are improved more than 10% as compared to pristine CNT. The sensitivity of CNT-Amide also better than CNT-Carboxyl due to the presence of nitrogen element in amide functional group which chemically active to react with CH4 gas. Additionally, fast response of CNT-Amide towards CH4 gas suggested that the functional group enhanced the rate of gas adsorption on sensing layer.

 

 

A SHORT REVIEW OF POLYLACTIC ACID BLENDS PROPERTIES FOR IMPROVEMENT AND INNOVATION

Mohd Junaedy Osman, Wan Md Zin Wan Yunus, Nabiilah Faris

 

Abstract

Advanced technology in petrochemical-based polymer has brought many benefits to mankind. However, the use of nonbiodegradable plastics materials for disposable application such as food packaging and house whole appliances are significantly disturbing and damaging the earth ecosystem. Polylactic acid (PLA) is a biodegradable plastic that is brittle. Because of this nature, PLA has a limitation in its usage. The common way to improve the toughness of PLA is via adding plasticizer. This review will provide brief account on recent developments in the synthesis of lactic acid (monomer of PLA) through biological route, PLA synthesis, unique material properties of PLA and modification of those by making copolymers and composites PLA absorption and degradation.

 

 

SYNTHESIS OF EPOXIDIZED FATTY HYDRAZIDES FROM PALM OLEIN: A PRELIMINARY STUDY

Zakiah Jamingan, Wan Md Zin Wan Yunus, Norli Abdullah, Ong Keat Khim

 

Abstract

Epoxidized fatty hydrazides (EFHs) which have amine, amide and epoxide functional groups in their molecules are a versatile starting material for synthesizing of many industrially important compounds. In this report we describe the results of our preliminary study of synthesizing these compounds using a chemical reaction of epoxidized palm olein (EPO) and hydrazine monohydrate. The products were characterized by using Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) technique and CHN elemental analyser. The optimum reaction conditions for the hydrazide preparation were investigated by studying effect of each important reaction parameters on the product yields. The study shows that the optimum conditions to produce EFHs were using EPO to hydrazine monohydrate (mol ratio of 1 to 12), n-hexane as the solvent and at the temperature of 69 ̊C.

 

 

 

THE WELL-BABY CLINIC AND PILLARS OF PREVENTIVE CHILD CARE

Prameela Kannan Kutty, Deborah Shobana Das

 

Abstract

This article targets all who are committed to the care of young children. Commencing with the clinical history and physical examination, the fundamentals of preventive child health offered in a well-baby clinic are highlighted. In this important clinic, the monitoring of core health components such as nutrition, growth, development and vaccination as pillars of preventive health services augments the health status of both a community and a nation. It is here that much needed information on infant nutrition in the first eighteen months of life, exclusive breastfeeding and complementary feeding, early growth and development, together with the provision of immunisation, is delivered. Health care provision is further strengthened by integrating knowledge with progressive dynamics of health services in line with the government’s health objectives such that communities are empowered with crucial information on preventive health. Significance to local scenarios, pertinent to parents and of importance to preventive health, with community relevance, is touched upon. In this way, it may be opportune to attempt innovative parental counsel on contextually related issues linked to the everyday care of children, whenever necessary. Of interest and given the focus of this journal, specific health concerns apropos to a military scenario, may well be further deliberated on and developed.

 

 

UTILIZATION OF NANO-DEEP EVANESCENT FIELD FOR PARTICLES OPTOPHORESIS

Khor Kang Nan, Mohamad Halim Abd Wahid, Nor Azura Malini Ahmad Hambali, Vithyacharan Retnasamy, Mukhzeer Mohamad Shahimin

 

Abstract

Separation and sorting of microparticles have set foot in critical diagnostics, advanced chemical and biomedical assessment. By utilizing specific characteristics for sorting, various techniques have been developed and optimized. Evanescent field optical trapping of microparticles is one of the emerging technologies to sort and separate in a non-mechanical and non-destructively several particles simultaneously. This paper describes the studies carried out, both theoretically and experimentally, to optimize the propulsion of polymer particles on copper ion-exchanged channel waveguides, to ultimately allow for the trapping and separation of mammalian adipose tissue derived stem cells (AT-SCs) according to their size and refractive index. The propulsion of polymer particles was observed to increase with the supplied input power and with laser polarization at transverse electric (TE) mode. The propulsion of particles was demonstrated to peak on a 4μm channel width of a 1μm thick copper ion-exchanged waveguide. The work carried out provides the optimal optical and waveguide parameters to be exploited for trapping and sorting AT-SCs on copper ion-exchanged waveguides.

 

 

SOLID METAL OXIDE CATALYSTS: SYNTHESIS AND CHARACTERISATION

Mardhiahtul Iftiah Ariffin, Norli Abdullah, Noor Azilah Kasim, Siti Hasnawati Jamal, Noor Aisyah Ahmad Shah

 

Abstract

Metal oxide particles have been studied by many researchers as potential catalysts for the production of biofuel. However, better understanding of catalysts preparation and characterisation are essential. A series of solid metal oxide catalysts were synthesised by chemical precipitation method using metal salt precursor such as magnesium nitrate hexahydrate, (Mg(NO3)2.6H2O), copper (II) nitrate tryhidrate (Cu(NO3)2.3H2O) and nickel nitrate hexahydrate, (Ni(NO3)2.6H2O ). The synthesised catalysts before and after calcination were further characterised using Thermal Gravity Analysis (TGA), Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), N2 physisorption and Scanning Electron Microscope (SEM) analysis. Higher catalytic activity and higher production of biofuel may benefits from this higher surface area metal oxide catalysts synthesis by precipitation method in this work.

 

 

THE AERODYNAMICS STUDY OF SKYSCRAPERS IN KUALA LUMPUR: THE EFFECT ON OCCUPANTS AND PEDESTRIANS COMFORT

Nur ‘Izzati Mohmad Ismail, Mohd Rashdan Saad, Muhammad Taufiq Jumahadi, Azam Che Idris, Mohd Rosdzimin Abdul Rahman, Suriyadi Sujipto

 

Abstract

Skyscrapers have been constructed all over the world because of the social demand for more iconic building, including excellent aerodynamic performance and architectural aesthetic reasons. However, the increasing high-rise buildings in densely built-up cities created low velocity air flow caused by the phenomena of flow separation at pedestrian level and also exerts drag force on the building walls that may affect the occupants’ and pedestrians’ comfort. Therefore, the objective of this study is to investigate the drag force and pedestrian level wind condition of 15 skyscrapers in Kuala Lumpur of various designs and shapes by using Solidworks Flow Simulation. The effect of the height of surrounding buildings were also investigated. From the results, the bamboo shape of the Telekom tower shows the lowest drag coefficient by 0.1056 compared to others and the ratio of surrounding building height to skyscraper of 0.83 shows the smallest drag.

 

 

MONITORING STUDENTS PERFORMANCE USING SELF ORGANIZING MAP TREND CLUSTERING

Puteri Nor Ellyza Nohuddin, Zuraini Zainol, Aliimran Nordin

 

Abstract

The analysis of relation between student performance and other variables in education setting is often useful in identifying influential factors on performance. Consequently, the need for adopting an effective tool to process these big data has risen. The analysis of big data will transform passive data into useful information. Data mining is referred to an analytic process designed that discovers data patterns and relationships between datasets. In this study, clustering is used to cluster student grade datasets to generate trend line clusters. The aim of the study is to assist lecturers and academic advisors to recognize the progress of their students.

 

 

 

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