Wax Lipids from Leaf Surfaces of Some Common plants of Malaysia

Epicuticular wax lipids from leaves of some common plant species found in the Klang Valley, Malaysia were extracted into dichloromethane for analysis. Extracts were separated into hydrocarbon, carboxylic acid, ketone and alcohol fractions. The fractions after derivatization were then subjected to gas chromatographic (GC) and gas chromatography-mass spectrometric (GC-M5) analyses. The wax yield was highest for Mestta ferrea while the lowest yield was obtained from Eugenia gran dis. In most species studied the m~or n-alkane was found to be hentriacontane (C31 ), followed by tritriacontane (C,,) and nonacosane (C",) , respectively. The n-alkanes exhibit a saw-tooth pattern which is characteristic of a biogenic origin. A strong even-to-odd carbon number predominance is observed for both the n-alkanoic acids and 1)alkanols. Only traces of mainly B-sitosterol were detected in some of the species. The triterpenoids and triterpenes were mostly found in the wax of Mesua ferrea with «- and p-boswellic acids as the major components and minor amounts of «- and p-amyrin. Other biomarkers identified were «and p-amyrones, friedelin, friedelanol, friedelane, olean-12-ene, taraxerene, squalene, dihydronyctanthic acid, dihydroroburic acid and dihydrocanaric acid. This study has shown that the distribution of n-alkanes is a function of the ambient temperature

An innovative assembly to maintain isoflurane anaesthesia for dental procedure in rats

An innovative assembly to maintain isoflurane anaesthesia in rats is described. This assembly was used successfully in laboratory rats for dental procedures that may last as long as sixty minutes. Repeated exposures to isoflurane anaesthesia, of up to eight times within a 30-day study period in healthy laboratory rats did not result in any observable adverse-effects

Demonstration of Palm Vein Pattern Biometric Recognition by Machine Learning

This paper aims to demonstrate the extraction of palm vein pattern features by local binary pattern (LBP) and its different recognition rate by two types of classification methods. The first classification method is by K-nearest neighbour (KNN) while the second method is support vector machine (SVM). Whilst SVM is optimized for direct classification between two classes, the KNN is best for multi-class classification. Based on the biometric recognition framework shared in this paper, both techniques shared comparable performance in terms of the recognition rate. The difference in the recognition rate can only be seen if the LBP features extracted for the classification are different. In general, higher recognition rate can be achieved for palm vein pattern biometric system if all LBP bins are used for the classification, compared to if only selected features are used for the purpose. Best recognition rate that can be achieved by the three datasets demonstrated in this paper are 60%, 70% and 100% respectively for the CASIA, PolyU and self-dataset

The generation revenue and demand payment assessment for pool based market model in Malaysia electricity supply industry

The objective of this paper is to address the economic benefits in term of generation revenue and demand payment for the pool based market model in Malaysia electricity supply industry (MESI). In pool market model, there are issues on the benefit of the generators such as too high system marginal price (SMP) during peak demand and no revenue during low demand. Therefore, conceptual study for two bus test system in MESI involving four generators around Peninsular Malaysia is conducted to perform the economic analysis in term of generation revenue and demand assessment considering existing single buyer model and pool based market model, i.e., pool model, spot market model and the proposed model, in order to identify which market model is superior. As a result, the proposed model managed to decrease the demand payment as it is proportional to generation revenue, even though the generation revenue is at intermediate value and succeed to increase the low and medium generator’s revenue

Mechanical performance of roselle/sugar palm fiber hybrid reinforced polyurethane composites

The effect of sugar palm fiber (SPF) loading was studied relative to the mechanical properties of roselle (RF)/SPF/thermoplastic polyurethane (TPU) hybrid composites. RF/SPF/TPU hybrid composites were fabricated at different weight ratios (100:0, 75:25, 50:50, 25:75, and 0:100) by melt mixing and hot compression. The mechanical (tensile, flexural, and impact test) and morphological properties of tensile fractured samples were examined using a universal testing machine, impact machine, and scanning electron microscope. It was found that the hybridization of RF/SPF increased its impact strength corresponding to the increases in the SPF content of the composites. The tensile and flexural properties of the hybrid composites decreased due to poor interfacial bonding between the fiber and matrix. Scanning electron micrographs of the tensile fractured surface of the RF/SPF hybrid composites revealed fiber pullouts and poor adhesion bonding. In conclusion, the hybridization of SPF with RF/TPU composites enhanced its impact strength while decreasing the tensile and flexural strength

Effects of high power converter on power line carrier signal

Power line carrier (PLC) systems are used in transmission of signals for teleprotection, teletripping, telecontrol and speech communication. The signal to noise ratio (SNR) of the PLC is based on the noise level at the input of the carrier's receiver. The interference due to large power converter will be superimposed on the background noise at lower level. It has reduced the SNR to an unacceptable value. This paper deals with analysis of high frequency (HF) harmonics (higher than 20 kHz) produced from the converters, and the methods used to reduce the noise imposed on the PLC communication signal. The experimental and simulation results have been obtained for both processes

Micromechanical Studies of 4n Gold Wire for Fine Pitch Wirebonding

This study focuses towards typical micromechanical properties such as strength, yield point, Young’s Modulus, strain, shapes of fracture end and element analysis, atomic percentage of Ca of 4N gold (Au) wire using microstructures and composition observation, micro-tensile test and depth sensing indentation technique. A series of micro-tensile test were performed with different strain rate values of 10˚-10-4 min-1 on to a 25.4 μm diameter plain gold wire. The nanoindentation with 20 mN maximum load was indented on a near fracture end of a gold wire specimen, for which this test was carried out after the micro-tensile test. The stress-strain curves were used to characterize the 4N purity gold wire. The shapes of fracture end of gold wire after micro tensile test were carried out using Scanning Electron Microscopic (SEM). The finding showed that the mechanical properties of ultra-fine gold wire was in the proportional relationship with the increment of the strain rate value. It is suggested that micromechanical behaviour gave the effect for the wirebonding process in order to characterize the wire loop control and strengthen the wire loop to avoid the wire sweep

Theoretical investigations of β-tricalcium

Beta-tri-calcium phosphate (β-TCP) materials have gained a great deal of research considerations in biomaterial area due to their excellent biocompatibility and identical chemical compositions to the natural teeth and bones. Therefore, the β-TCP compound can be used as coatings, cement and composites as well as biocompatible ceramics for medical and dental applications. Electronic and optical properties for β-TCP compound have been investigated using density functional theory (DFT). For the calculations, we used full potential linear augmented plane wave method (FPLAPW), within three types of approximations along with local density approximations (LDA), generalized gradient approximations (GGA) and Modified Becke-Johnson (mBJ) to get the effect of the exchange and correlation in our calculations to get an accurate results. The computed band gap values for (β-TCP) compound using LDA, GGA, and mBJ-GGA approximations are 5.5 eV, 5.9 eV and 6.8 eV respectively. This is also predicted that the chemical bonding in this compound is a kind of combination of covalent and ionic character that is in a line with the experimental findings. The optical parameter, static dielectric constant ε1(0) reaches the values of 3.23681 (eV) at 0 GPa for the β-TCP compound. The obtained results are of vital nature for rising the quality of the electronic and optical properties of this material, and provide more evidence to fabricate novel Beta-Tri-calcium phosphate biomaterials for medical and dental applications

Cu2+ Montmorillonite K10 Clay Catalyst as a Green Catalyst for Production of Stearic Acid Methyl Ester: Optimization Using Response Surface Methodology (RSM)

Clay catalyst has received much attention to replace the homogeneous catalysts in the esterification reaction to produce fatty acid methyl ester as the source of biodiesel as it is low cost, easily available, as well as environmental friendly. However, the use of unmodified clay, in particular montmorillonite K10 (MMT K10), for the esterification of fatty acids showed that the acid conversion was less than 60% and this is not preferable to the production of biodiesel. In this study, synthesis of stearic acid methyl ester using Cu2+-MMT K10 (Cu-MMT K10) was successfully optimized via response surface methodo-logy (RSM) based on 3-variable of Box-Behnken design (BB). The parameters were; reaction time (5-180 minutes), reaction temperature (80-120 oC) and concentration of Cu2+ in MMT K10 (0.25-1 M). The use of RSM in optimizing the conversion of stearic acid was successfully developed as the actual experimental conversion of stearic acid was found similar to the actual values under the optimum conditions. The model equation predicted that the following conditions would generate the maximum conversion of stearic acid (87.05 %reaction time of 62 minutes, a reaction temperature of 80 oC and catalyst used is 1.0 M Cu-MMT K10. This finding can be considered as green catalytic process as it worked at moderate reaction temperature using low cost clay catalyst with a short reaction time.

Adaptive memory-based single distribution resampling for particle filter

The restrictions that are related to using single distribution resampling for some specific computing devices’ memory gives developers several difficulties as a result of the increased effort and time needed for the development of a particle filter. Thus, one needs a new sequential resampling algorithm that is flexible enough to allow it to be used with various computing devices. Therefore, this paper formulated a new single distribution resampling called the adaptive memory size-based single distribution resampling (AMSSDR). This resampling method integrates traditional variation resampling and traditional resampling in one architecture. The algorithm changes the resampling algorithm using the memory in a computing device. This helps the developer formulate a particle filter without over considering the computing devices’ memory utilisation during the development of different particle filters. At the start of the operational process, it uses the AMSSDR selector to choose an appropriate resampling algorithm (for example, rounding copy resampling or systematic resampling), based on the current computing devices’ physical memory. If one chooses systematic resampling, the resampling will sample every particle for every cycle. On the other hand, if it chooses the rounding copy resampling, the resampling will sample more than one of each cycle’s particle. This illustrates that the method (AMSSDR) being proposed is capable of switching resampling algorithms based on various physical memory requirements. The aim of the authors is to extend this research in the future by applying their proposed method in various emerging applications such as real-time locator systems or medical applications