Preliminary study for optimization of enzymatic hydrolysis of waste cellulosic materials

Lignocellulose is a generic term describing the main constituents in most plants, namely cellulose, hemicelluloses, and lignin. Cellulose is a glucose polysaccharide, hemicelluloses are polysaccharides with a backbone of different hexoses (glucose, mannose, galactose) and pentoses (xylan, arabinose), and lignin is a complex network of different phenyl propane units. The cellulosic materials are potential sources of ethanol. Steps of this process are saccharification of cellulose to reduce sugars, under enzymes action and to reduce sugars fermentation by yeast to obtain ethanol.The aim of this study is to examine the influence of substrateconcentration, temperature and pH upon enzymatic saccharification ofwaste cellulosic materials, based on office paper, newspaper andcardboard, in ratio of 1:1:1 (w/w) and reducing sugar accumulationdynamics in optimised conditions. The study has established optimalparameters: the ratio of enzyme:substrate as 0.5 EU/g substrate,temperature 48°C, pH 4.8 and addition of surfactant Tween 80 inproportion of 0.3 %, reported to the total volume of liquid. The reducing sugar yield was 35 mg reducing sugars/ g dry weight cellulosic waste

Cogging torque reduction of 6s-4p spoke-type IPMSM using a new combination of rotor design

Cogging torque is one of the vital issues in permanent magnet motors (PMM). Reducing cogging torque, which may cause vibration and acoustic noises, has become an increasingly critical issue in PMM. Low cogging torque significantly reduces acoustic noises and vibration, and enhances the positioning control of the motor for electric vehicle drive application. Therefore, this thesis exemplifies the significance of various rotor-PM configurations of three-phase 6S-4P Spoke-type (IPMSM). Initially, conventional cogging torque reduction techniques of skewing (Sk), notching (Not), radial pole pairing (Pop), and axial pole pairing (App) were analysed. Then, a new combination such as skewing with pole pairing (SkPop), skewing with pole axial pairing (SkApp), notching with pole pairing (NotPop), and notching with pole axial pairing (NotApp) were proposed and compared. The validity of the proposed designed techniques has been confirmed by 3-D Finite Element Analysis (FEA) executed in commercial JMAG designer version 14.1, under open circuit and short circuit conditions. Simulation results showed that the conventional techniques have reduced the cogging torque of 6S-4P Spoke-type IPMSM by 70.59%, 21.57%, 32.35%, and 48.04% for Sk, Not, Pop, and App respectively from the original value of 1.01Nm. The new proposed combination techniques reduce the cogging torque by 71.86%, 63.55%, 30.93%, and 51.55% for SkPop, SkApp, NotPop, and NotApp simultaneously. In addition, the cogging torque in 6S-4P Spoke-type IPMSM has been successfully reduced and the best technique is NotPop with 30.93% of cogging torque reduction, as well as the highest torque and power capabilities of 7.643 Nm and 959.03 W respectively. Finally, design analysis to improve NotPop performance has been done in this thesis. As a result, a new 6S4P Spoke-type IPMSM with low cogging torque and 19.05% torque improvement has been successfully designed

Properties of insulation board made from rice husk and waste paper / Ahmad Ariffuddin Bahrim

The properties of insulation board made from rice husk and waste paper was observed and studied. The dependent variable used in this study was the rice husk to paper ratio. The ratio used was 80:20, 60:40 and 40:60. The objectives of this study were to investigate the bending and thermal insulation properties of insulation board made from different ratio of rice husk and waste paper and the optimum ratio for insulation material. In this study, no adhesive was used and the rice husk used was unscreened and untreated instead the rice husk was bonded by paper fibers. In addition, the tests used were only bending test (MOR and MOE) and thermal conductivity test. The result obtained shows that higher ratio of paper gives higher bending strength. The ratio also affected thermal conductivity as the board with 80:20 ratios has the lowest thermal conductivity value which shows the best thermal resistance compare to the board with 60:40 and 40:60 ratios

Optimization of biosynthesis conditions and catalitic behavior evaluation of cellulase-free xylanase produced by a new Streptomyces sp. strain

Cellulase-free xylanase by Streptomyces sp.P12-137 was obtained bycultivation on the wheat bran as the sole carbon source. The effect of carbon and nitrogen sources and a ratio of them on the cellulase-free xylanase production was investigated. The new isolate Streptomyces sp. strain was able to grow in submerged system and to produce an increased level of xylanase. Wheat bran induced xylanase biosynthesis yield at a high level (9.27 UA/ml). For economical reasons cultivation was achieved on a cheap fermentative medium represented by agro-industrial wastes. The optima of the pH and temperature of the crude xylanase activity were 5.5 and 70°C,respectively

A study in the admissibility of digital evidence in the Malaysian courts / Md. Shazli Munip Abdul Malek…[et al.]

This research was done to fulfil one of the requirements of the Bachelor of Legal Studies program. The research examines the issue of admissibility of digital evidence in Malaysian courts. The issue of authenticity of evidence is not new; however the nature of digital evidence makes it easier for it to be manipulated, altered and tempered. Thus, it is important to determine whether the current laws in Malaysia are sufficient to safeguard evidence in digital forms from being tempered. Two critical issues were discussed in this research. The first issue was whether digital evidence can be considered as evidence in Malaysian courts. The second issue was whether digital forms of evidence are admissible as documentary evidence. To shed some light on the issues concerned, the research had focused on the definition of evidence under the Malaysian Evidence Act and the rules governing the admissibility of documentary evidence. To understand the issue of admissibility of documentary evidence reference were made to Malaysian authors. The research has also examines the position taken by other common law countries such as the United States, Australia, United Kingdom and India on the issue. After examining the problems surrounding admissibility of digital evidence, some recommendations were suggested at the end of this research