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

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

Carbonization cbn550 effect on tensile properties of composite for marine structure application

The composites have gained commercial success, where strength, stiffness, durability and light weight are required as well as retardant capacity. Improvement has been made such new series of resin such as vinyl ester and epoxy type[1, 2]. However 95% of pleasure vessels and boats under 60 feet today are still made with polyester resin. The main consideration for most composite builders is cost, with performance and more importantly value for money often being a secondary consideration. Therefore, this study investigate the tensile - mechanical effects of mixing carbon black CBN550 with wax and non-wax type resin and manufactured according to fiber orientation of [0°] and [90°]. The 10% CBN550 exhibit highest reading for stress under [90°] fiber orientation and the lowest reading when arranged at [0°] fiber orientation. The preliminary study on CBN550 flammability has indicated the suitability for this study to pursue in. The structural composites samples of 1000 mm by 1000 mm prepared which consist of 10 of composite mats layer in combination of CSM 450 g/m2 and Woven Roving 600 g/m2. The carbon black (CB) volume fraction range from/with 0% to 20% volume fractions. Optical observation revealed the most suitable fraction of CBN550 in wax polyester resin is at 10% and non-wax polyester resin is also at 10%. The fire resistance behaviour of this CBN550 - CSM 450 g/m2 - Woven Roving 600 g/m2 composite (polyester wax) and polyester non wax was investigated previously as per[3]. This results are in line with the finding of the maximum load where the highest reading was recorded by the 10%CBN550 specimen. This study showed that the introduction of carbon black into the resin mixture helps reinforce the matrix materials. The results suggested that CBN550 mixture should attend to next level of experiment investigation such as oxygen content, TG value, microstructure and other mechanical destructive test. The CBN550 could be a suitable candidate for fire retardance application in marine composite structure

The effect of N550 carbon black in polyester resin for fire-retardant application in marine composite

This paper presents the experimental investigation on the influence of N550 carbon black (CBN550) series in polyester resin (wax and non -wax type). The CBN550 was added into polyester resin at different weight percentages with a curing agent. The investigation is mainlyto study the effect on fire retardance application in marine composite structure. The fire-resistant structural composites samples of 1000 mm by 1000 mm prepared which consist of 10 of composite mats layer in combination of CSM 450 g/m2 and Woven Roving 600 g/m2. The carbon black (CB) volume fraction range from/with 0% to 20% volume fractions. Optical observation revealed the most suitable fraction of CBN550 in wax polyester resin is at 10% and non-wax polyester resin is also at 10%. The fire resistance behavior of this CBN550 - CSM 450 g/m2 - Woven Roving 600 g/m2 composite (polyester wax) and polyester non wax was investigated by Fire Test Procedure Code-Resolution A.653 [1]. Though smaller filler size escalates the rheological behavior and values outstandingly at initial reading compare to large particles but it slow down the curing processdue to its small particle size, large surface area and high dispersion rate. Experimental data showed the retardance level has been increased up to 56.66% in non-wax type polyester resin (10%/CBN550) and 30.14% in wax polyester resin (10%/CBN550). The improvement in fire resistance points are due to the presence of CBN550 which acts as a positive additive in both polyester resin wax and non-wax. Filling CBN550 in polyester resin also reduces the cost of theend products.The preliminary results suggested that CBN550should attend to next level of experiment investigation such as oxygen content, TG value, microstructure as well as mechanical destructive test. The CBN550 could be a suitable candidate for fire retardance application in marine composite structure.In conclusion, crystallinity of polyester resin increases with additional of CB particles

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.

Dosimetric Assessment of Routine X-Ray Examination at Selected Health Clinics in Perak Using Commercialized Optically-Stimulated Luminescence Dosimeter (OSLD)

This study aims to compare entrance surface dose (ESD) values measured with nanoDot Al2O3:C optically-stimulated luminescence dosimeter (OSLD) and guidance level set under the second national dose survey which utilized old-version LiF:Mg,Ti thermoluminescence dosimeter (TLD). In this study, we conducted a dosimetric assessment for posteroanterior chest X-ray (PA-CXR) examinations performed at various community clinics in Perak, Malaysia. These clinics were selected as they were excluded from the first and second national dose survey conducted in Malaysia in 1993-1995 and 2005-2009, respectively. The ESD is obtained by mounting the OSLD on the surface of polymethyl methacrylate (PMMA) slabs. The PMMA slabs were then exposed to X-ray based on the current practice of respective clinics. The results show that the 3rd quartile of ESDs ranged from 0.180 mGy to 0.229 mGy which is less than the recommended guidance level of the second national dose survey by 77 %. ESD measured using OSLD was found to be lower than the guidance values recommended from the second national dose survey. The finding showed a good competency of the radiographer to optimize radiological practice specifically in routine X-ray examination

Gravitational aeration tower filter system to increase the dissolved oxygen amount for iron removal in groundwater

This paper discusses the Gravitational Aeration Tower Filter System (GATS) aims to increase the amount of Dissolved Oxygen (DO) for iron removal in groundwater. The groundwater is mainly used in remote areas. The presence of a large volume of iron contained in the groundwater will subject to water contamination besides limiting the lifespan of existing water filter to filter the contaminants. Pre-treatment systems i.e., aeration techniques are often used to reduce the amount of iron contained in the groundwater. One of the aeration techniques i.e., the GATS is proposed and designed for this work. The GATS is tested to assess its effectiveness in increasing the DO and in the removal of iron in the water. The study area is located in Kampung Majid Ibrahim, Simpang Renggam. The initial value of the iron in the tubewell ranged from 1.4 mg/L to 2.3 mg/L, which exceeded the standard limit of 0.3 mg/L. Using AQUAREAD AP2000 and Hanna High Iron Checker, data collection is carried out in-situ testing. The flow rate is set at 5.5 L/min through the GATS, with varying air parameters. The results of the GATS test demonstrate the DO percentage increases up to 90.50 % and the percentage of iron removal is up to 10.24% with an airflow of 1.0 L/min

Kinetic Model and Simulation Analysis for Propane Dehydrogenation in an Industrial Moving Bed Reactor

A kinetic model for propane dehydrogenation in an industrial moving bed reactor is developed based on the reported reaction scheme. The kinetic parameters and activity constant are fine tuned with several sets of balanced plant data. Plant data at different operating conditions is applied to validate the model and the results show a good agreement between the model predictions and plant observations in terms of the amount of main product, propylene produced. The simulation analysis of key variables such as inlet temperature of each reactor (T ) and hydrogen to total hydrocarbon ratio (H2/THC) affecting process performance is performed to identify the operating condition to maximize the production of propylene. Within the range of operating conditions applied in the present studies, the operating condition to maximize the propylene production at the same weighted average inlet temperature (WAIT) is ΔT = -2, ΔT inrx1 = +1, ΔT inrx2 inrx = +1 , ΔT inrx4 inrx3 = +2 and ΔH2/THC= -0.02. Under this condition, the surplus propylene produced is 7.07 tons/day as compared with base case

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