Optical properties of diamond like carbon films prepared by DC-PECVD

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

Analysis of human bradykinin receptor gene and endothelial nitric oxide synthase gene polymorphisms in end-stage renal disease among Malaysians

The aim of this study was to determine the association of the c.894G>T; p.Glu298Asp polymorphism and the variable number tandem repeat (VNTR) polymorphism of the endothelial nitric oxide synthase (eNOS) gene and c.181C>T polymorphism of the bradykinin type 2 receptor gene (B2R) in Malaysian end-stage renal disease (ESRD) subjects. A total of 150 ESRD patients were recruited from the National Kidney Foundation’s (NKF)dialysis centers in Malaysia and compared with 150 normal healthy individuals. Genomic DNA was extracted from buccal cells of all the subjects. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was carried out to amplify the products and the restricted fragments were separated by agarose gel electrophoresis. Statistical analyses were carried out using software where a level of p T, 4b/a) and eNOS gene (c.894G>T) polymorphisms were not statistically significant (p >0.05) when compared to the control subjects. The B2R and eNOS gene polymorphisms may not be considered as genetic susceptibility markers for Malaysian ESRD subjects

Electrospun nanofiber-coated membrane: a review

The nanofibre development offers various useful applications in many ways including energy and environmental application. Polymeric nanofibre fabricated by electrospinning has been seen as innovative membrane materials for water remediation owing to the high surface area, interconnected porous structure, and light weight. This paper reviews the exciting functionality of nanofibre involving the development of smart heterogeneous approaches in membrane material. These heterogeneous materials allow the water molecules to spontaneously penetrate from one side to another, while blocking penetration in reverse direction due to hydrophilic-hydrophobic differences. Composite membrane containing different features arrangements of nanofibres have been utilised for their ability for water applications especially in membrane distillation

Development of Hybrid Artificial Neural Network for Quantifying Energy Saving using Measurement and Verification

This paper presents a Hybrid Artificial Neural Network (HANN) for chiller system Measurement and Verification (M&V) model development. In this work, hybridization of Evolutionary Programming (EP) and Artificial Neural Network (ANN) are considered in modeling the baseline electrical energy consumption for a chiller system hence quantifying saving. EP with coefficient of correlation (R) objective function is used in optimizing the neural network training process and selecting the optimal values of ANN initial weights and biases. Three inputs that are affecting energy use of the chiller system are selected; 1) operating time, 2) refrigerant tonnage and 3) differential temperature. The output is hourly energy use of building air-conditioning system. The HANN model is simulated with 16 different structures and the results reveal that all HANN structures produce higher prediction performance with R is above 0.977. The best structure with the highest value of R is selected as the baseline model hence is used to determine the saving. The avoided energy calculated from this model is 132944.59 kWh that contributes to 1.38% of saving percentage

Generic skills requirements (KSA model) towards future mechanical engineers using discriminant analysis

Generic Skills is a basic requirement that engineers need to master in all areas of Engineering. This study was conducted throughout the peninsular Malaysia involving small, medium and heavy industries using the KSA Model. The objectives of this study are studying the level of requirement of Generic Skills that need to be mastered in order to become a competitive Mechanical Engineer and identifying the most dominant Generic Skills required by the industry/employer towards the future of the Mechanical Engineer. The set of questionnaires distributed to respondents was analyzed using software XLSTAT2014 software to obtain Descriptive Statistics and Discriminant Analysis (DA) as required to achieve the objective of the study. This study will guide all future engineers, especially in the field of Mechanical Engineering in Malaysia to penetrate the job market according to the current market needs.Keywords: generic skills; KSA model; mechanical engineers; discriminant analysi

Optimal risk computation on precious metal’s assets diversification

Optimization is the selection of a best element with regards to certain criterion from set of available alternatives. This paper investigates the effects of assets in optimizing risk using diversification strategy and also examines gold quality of hedging and safe haven. The reduction strength of assets is estimated. Hence, it is observed that gold exhibits highest risk reduction strength. Also it is noticed that gold acts as hedge and safe haven for investors during economic recession

Impact of stabilization environment and heating rates on P84 co-polyimide/nanocrystaline cellulose carbon membrane for hydrogen enrichment

These past few decades, the separation of various gas mixtures problems in order to obtain high purity gases can be overcome by the introduction of membrane-based technology. This current research was focusing on the development of tubular carbon membranes (TCMs) from polymeric precursors for the separation of hydrogen and nitrogen. The fabrication of TCMs involved the dip coating technique and was using P84 co-polyimide as the main precursor by blending of nanocrystaline cellulose (NCC) as an additive. It was believed a slight adjustment on time, temperature, or environment of the carbonization protocol for the commercially available PI/NCC membranes can alter the final properties of the carbons produced. The modifications on the carbonization parameters such as stabilization conditions and heating rates during fabrication of PI/NCC-based carbon membranes could also affect their gas separation performance. A large variety of TCMs for gas separation have been developed by simple carbonization of a PI/NCC deposited on a ceramic tubular support. Herein, in this study, the effect of different heating rates (1, 3, 5, and 7 °C/min) and stabilization environment (Argon, Nitrogen, and Helium) were investigated for all resultant TCMs. As a result, it was observed that stabilization under Argon environment with heating rate of 3 °C/min produced carbon membranes with the best H2/N2 separation and the highest selectivity of 434.68 ± 1.39, respectively

A Tribological Analysis of PAO-Based Hybrid SiO2-TiO2 Nanolubricants

Friction and wear are caused by contact between sliding surfaces over time. It is possible to reduce friction in a compressor by improving its lubrication. The nanoparticle lubrication will aid in reducing wear and friction of the piston mechanism of the compressor. This work aims to analyse the tribology properties of performance of the system employing Polyalphaolefin (PAO)-based hybrid nanolubricants. A two-step method was used to disperse SiO2 and TiO2 nanoparticles in the PAO lubricant at volume concentrations of 0.01% and 0.05% using a two-step method. Then, hybrid nanolubricants are observed visually, and their coefficient of friction (COF) is evaluated using a four-ball tribometer. The SiO2-TiO2/PAO hybrid nanolubricants were found to have a higher than 80% sedimentation ratio up to 180 hours and to be visually stable for up to 30 days. The 0.01% SiO2-TiO2/PAO has a lower COF than the base PAO 68 oil. The 0.05%, however, does not show the expected reduction. The COF ratio for volume concentrations of 0.01% and 0.05% is 0.97 and 1.01, respectively. The highest COF reduction of nanolubricants was attained up to 2.53% at 0.01% volume concentration. Therefore, 0.01% SiO2-TiO2/PAO is the ideal condition for use and is recommended for further investigations

Increasing T-method accuracy through application of robust M-estimatior

Mahalanobis Taguchi System is an analytical tool involving classification, clustering as well as prediction techniques. T-Method which is part of it is a multivariate analysis technique designed mainly for prediction and optimization purposes. The good things about T-Method is that prediction is always possible even with limited sample size. In applying T-Method, the analyst is advised to clearly understand the trend and states of the data population since this method is good in dealing with limited sample size data but for higher samples or extremely high samples data it might have more things to ponder. T-Method is not being mentioned robust to the effect of outliers within it, so dealing with high sample data will put the prediction accuracy at risk. By incorporating outliers in overall data analysis, it may contribute to a non-normality state beside the entire classical methods breakdown. Considering the risk towards lower prediction accuracy, it is important to consider the risk of lower accuracy for the individual estimates so that the overall prediction accuracy will be increased. Dealing with that intention, there exist several robust parameters estimates such as M-estimator, that able to give good results even with the data contain or may not contain outliers in it. Generalized inverse regression estimator (GIR) also been used in this research as well as Ordinary Lease Square Method (OLS) as part of comparison study. Embedding these methods into T-Method individual estimates conditionally helps in enhancing the accuracy of the T-Method while analyzing the robustness of T-method itself. However, from the 3 main case studies been used within this analysis, it shows that T-Method contributed to a better and acceptable performance with error percentages range 2.5% ~ 22.8% between all cases compared to other methods. M-estimator is proved to be sensitive with data consist of leverage point in x-axis as well as data with limited sample size. Referring to these 3 case studies only, it can be concluded that robust M-estimator is not feasible to be applied into T-Method as of now. Further enhance analysis is needed to encounter issues such as Airfoil noise case study data which T -method contributed to highest error% prediction. Hence further analysis need to be done for better result review

A Strategies of Success Virtual Mobility for Technical Students

Student mobility program have risen to the top of local universities' worldwide priorities. In addition to giving university students the chance to learn about different cultures, this programme helps expose them to various study strategies. Mobility programmes should adopt a new strategy in the age of Revolution Industry 4.0 and use technology as the vehicle for implementation. This study aims to determine whether virtual mobility programmes are appropriate for implementation, the level of students' knowledge regarding virtual mobility implementation, the reasons why students joined virtual mobility programmes, and the kinds of media that students anticipated using when participating in virtual mobility. Quantitative method was used with survey questionnaire to collect the data. A total of 304 students of Malaysian Technical Higher Institution were involved as a sample in this study also descriptive and inferential analysis were employed to this study. The findings showed that virtual mobility can be seen as an alternative for conventional mobility and it still has an impact on students’ soft skills. Besides, the data showed that the level of students’ knowledge towards the implementation of virtual mobility is moderate and majority of the respondents decided to join the virtual mobility program because they could develop their information technology skills. Meanwhile, most of the respondents expected to use internet as a main medium to join the virtual mobility program