Hydrophobic silica thin films by sol-gel processing and spin coating technique at low temperature

Hydrophobic silica thin films were prepared by sol-gel processing and self-assembly by chemical vapor reaction with Trimethylchlorosilane (TMCS) at low temperature. The sols were divided into Sol A with ethanol, Polyethylene glycol (PEG) and water (H2O) while Sol B were contain precursor of silica Tetraethylorthosilicate (TEOS) hydrolyze with ethanol which was stirred for 15 minutes. HCl was added into the mixture and stirred for another 10 minutes. After deposition on 1 x 1 cm corning glass using spin coating technique (two-step timer), the films were heated at 60˚C for 10 minutes and finally annealed at 150°C for 1 hour. The films were characterized by using Rudolph/Auto EL Ellipsometer, Shimadzu Spectrophotometer, Perkin Elmer Fourier Transform Infrared (FTIR) and Atomic Force Microscope (AFM). The results showed that the films thickness and refractive index were in the range of 105.2 to 112.4 nm and 1.35 to 1.38, respectively. The films were transmitted 70-80% of light (in visible range) with various bondings of C-H, Si-O-Si, Si-C and Si-OH. Surface roughness of the films was increased from 30.6 nm (silica thin film) to 140.5 nm (hydrophobic silica thin films) after modification have been done on the films by using TMCS (heated at 40˚C). It was found that the water contact angles increased when time of reaction increased from 109° to 124

SIGNAL PROCESSING FOR RAMAN SPECTRA FOR DISEASE DETECTION

Raman Spectroscopy enables in-depth study into the molecular structure of solid, liquid and gasses from its scattering spectrum. As such, the spectrum could offer a biochemical fingerprint to identify unknown molecules. Surface Enhanced Raman Spectroscopy (SERS) amplifies the weak Raman signal by 10+3 to 10+7 times, revolutionary making the method appealing to the research community. SERS has been proven useful for disease detection from a medium such as a cell, serum, urine, plasma, saliva, tears. The spectra displayed are noisy and complicated by the presence of other molecules, besides the targeted one. Moreover, the difference between the infected and controlled samples is far too minute for detection by the naked human eyes. Hence, signal processing techniques are found crucial to single out fingerprint of the target molecule from biological spectra. Our work here examines signal processing techniques attempted on SERS spectra for disease detection, such as Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), Artificial Neural Network (ANN), Support Vector Machine (SVM) and Logistic Regression Analysis (LRA). It is found that PCA-LDA is the most popular (45%), ensued by PCA-ANN (33%) and SVM (22%). PCA-SVM yields the highest in accuracy (99.9%), followed by PCA-ANN (98%) and LRA (97%). PCA-LDA and SVM score the highest in both sensitivity-specificity.Keywords: Raman Spectra, Surface Enhanced Raman Spectroscopy (SERS), Neural Network (NN), Support Vector Machine (SVM), Logistic Regression Analysis (LRA), Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA)

Effect of Vaned Diffuser on the Performance of Small Turbocharger

This work presents an experimental investigation of performance of small turbocharger compressor with vaned diffuser. The aim of the study is to investigate the effect of number vaned diffuser on peak pressure ratio in turbocharger. The study was carried out using cold-flow turbocharger test rig driven by compressed air with the impeller rotational speed from 40,000 to 70,000 rpm. Tests were conducted with 6, 8 and 10 number of vanes while maintaining the vane blades angle of 6°, turning angle of 30° and blade length of 21.8 mm. The vanes as a flow deflector were designed as a thin flat plate of 1 mm thickness. All the results were compared with original vaneless diffuser of the compressor. The results found that the proposed design of 6 and 8 vanes shifted the peak pressure ratio toward low mass flow rate region. It was observed that modification from conventional vaneless diffuser compressor to the one equipped with vaned diffuser has significant improvement on the overall pressure ratio of the turbocharger

Entrepreneurship challenges: A case study among single mother entrepreneurs in northern region

Entrepreneurship is not a foreign concept for women. Today, the number of women who enter the entrepreneurial field has been shown to increase tremendously. For example, McKay (2001) reported that in 1999 almost half of the small businesses in the United States were owned by women. In the meantime Shafizad, Coetzer, & Alan (2016) stated that women play a major role in the growth of small businesses in Australia. In addition, the UK Government also estimated that nearly a quarter and a third of business firms in the country were owned by women (Brierley, 2014). Meanwhile, Orhan and Scott (2001) reported that 26% of total entrepreneurs in France were women. Meanwhile closer to home, the ex-Minister of Women, Family, and Community Development, Datuk Seri Rohani Abdul Karim, had stated that in Malaysia, 19.7% of Small and Medium-sized Enterprises (SMEs) are owned by women. From that percentage, about 91.7% are involved in the service sector, followed by 6.9% in the manufacturing sector, and the rest are in other sectors (Jaafar & Sazili, 2017). However, it was reported that there are at least 1.9% single mothers who have their own business enterprises in Malaysia

Experimental Investigation Of Performance And Emissions Of A Stratified Charge CNG Direct Injection Engine With Turbocharger

This paper presents the results from 1.6 litre, 4 cylinders stratified charge compressed natural gas (CNG) direct injection engine with boosting device. A turbocharger with compressor trim of 40 was used to increase engine output. The engine was tested at wide open throttle (WOT) and speed ranging from 1000 to 5000 rpm. Engine performance and emissions data were recorded under steady state condition. Results show turbocharged CNG engine produced an average of 26% increment in brake power and 24% additional maximum brake torque as compared with natural aspirated (NA) CNG engine. Turbocharged CNG engine improved brake specific fuel consumption (BSFC) and yielded higher fuel conversion efficiency (FCE). Relatively turbocharged CNG engine showed lower emission of hydrocarbon (HC) and carbon monoxide (CO) throughout tested engine speed. Conversely, the carbon dioxide (CO2) and nitrogen oxide (NOx) emission produced were slightly higher compared with NA CNG engine

Effect of vaned diffuser on the performance of small turbocharger / Hilmi Amiruddin...[et al.]

This work presents an experimental investigation of performance of small turbocharger compressor with vaned diffuser. The aim of the study is to investigate the effect of number vaned diffuser on peak pressure ratio in turbocharger. The study was carried out using cold-flow turbocharger test rig driven by compressed air with the impeller rotational speed from 40,000 to 70,000 rpm. Tests were conducted with 6, 8 and 10 number of vanes while maintaining the vane blades angle of 6°, turning angle of 30° and blade length of 21.8 mm. The vanes as a flow deflector were designed as a thin flat plate of 1 mm thickness. All the results were compared with original vaneless diffuser of the compressor. The results found that the proposed design of 6 and 8 vanes shifted the peak pressure ratio toward low mass flow rate region. It was observed that modification from conventional vaneless diffuser compressor to the one equipped with vaned diffuser has significant improvement on the overall pressure ratio of the turbocharger

Usability Evaluation of Online Digital Manuscript Interface

Manuscripts are among the special collections of most libraries. The collection of manuscripts of the International Islamic University Malaysia (IIUM) library can be retrieved from the Digital Manuscript interface of the IIUM Library website. User evaluation of the interface is much needed to enable library administration know users’ experience while interacting with the interface. This study attempts to evaluate the effectiveness, efficiency and user satisfaction with the IIUM Digital Manuscript interface among the library users, based on the usability metrics established by the American National Standards Institute (ANSI). Questionnaires were administered to gather information about users’ background and their satisfaction with the use of the interface. In addition, each respondent was given eight tasks that have been specifically designed to measure their ability to navigate within the digital manuscript interface of the library. Findings indicate that despite some of the shortcomings observed with the interface design, respondents were able to complete the tasks assigned, though at different completion duration. They were also satisfied with the overall design of the interface. Comments and recommendations given by the respondents were as well reported

Social and communication skills in english through virtual or simulated environment

Virtual world or environment such as MOO (MUD- Multi-User Domain,Object Oriented) is one of the predominantly text-based synchronous Computer Mediated Communication (CMC) tools. Since early 1990s, MOO has generated much interest among second language researchers. However, to date, not many studies have focused on the impact of using MOO on face-to-face communication skills. For the purpose of this research, in UTM, a full-fledged virtual university called UniTekMOO, was developed and regularly updated to benefit the students in their English communication skills and specific areas of study. With the construction of the virtual campus of UnitekMOO, this study began investigating on the effects of MOO on learners’ communication skills and on their attitudes towards English language learning. Data were gathered through participant observation (done virtually), classroom observation, questionnaire and online interview. Content and conversational analysis were also done on the MOO chatlogs. Through interviews and questionnaires, learners believed that their interaction experiences within the MOO had improved their communication skills. In particular, more than half of the students felt that their interactions within the MOO environment have i) boosted their interest in learning English, ii) helped improve their spelling, and iii) increased their confidence in face-to-face interactions in English. We would recommend that the UnitekMOO be made available to students to practice using the target language as activities to complement their regular English proficiency classes

Physical and structural properties of Nd : YAG crystal growth by czocharalski method

Neodymium doped Yttrium Aluminium Garnet, Nd:YAG crystal with nominal dopant concentration of 1.4 at. % was successfully grown by Czochralski technique equipped with an Automatic Diameter Control – Crystal Growth System (ADC-CGS). Correlation between dopant concentrations with the length of crystal boule in relation with physical and structural properties was studied. It was found that the crystal was partially transparent with some visible macroscopic defects such as cracks, gas pores, and inclusion. Its physical appearance is strongly affected by heat zone design. From EDX analysis, it was found that the doping concentration of Nd3+ ion increased as the crystal boule became longer than its initial pulling point. From the top to the bottom of Nd:YAG crystal boule, the concentration of Nd3+ changed from 0.13 at. % to 0.65 at. %. The density of the samples was determined by Archimedes method which showed an increasing trend of density with the crystal length which was found to be in the range of 4.5344±0.0153 gcm-3 to 4.5628±0.0114 gcm-3. It was also discovered that Vickers hardness increased with increasing dopant concentration which was from 1590 Hv to 1776 Hv. Raman spectrum was obtained in the range of 100 cm-1 – 1000 cm-1. From the spectra, the intensity was found to vary and shifting occured in the band due to the Nd3+ dopant concentration. Meanwhile, the IR spectra shows absorption occurring around 2000 cm-1 to 4500 cm-1. Absorption tends to be greater with increasing dopant concentration. Furthermore, the effect of melts level to the growth process has also been studied and it is suggested that the crucible should be lifted up according to the level of the melts drop during growing process to maintain the temperature gradient of the hot zone