A Study of the Problems Related to the Testing of Smoke Emission From Diesel Powered Vehicles in Malaysia

This study was carried out to examine the smoke emission level from diesel powered vehicles plying Malaysian roads and the problems related to the enforcement of the Motor Vehicles (Smoke and Gas Emission) Rules 1977. The results show that approximately 35% of the lorries examined had excessive smoke emission compared to 33% for taxis, 16% for buses and mini buses, and 13% for cars. Further examination£on of the data did not show any relationship between the degree of smoke emission and parameters such as age and maintainance of the vehicle, or duration since the last mandatory inspect£on by the RTD. A study of the past records of enforcement carnage out by the DOE showed that an average of only 52. 7% of the planned exercises were actually carnage out during 1979 to 1983. This was due to various reasons including manpower and budget problems, equipment, transportation, and weather. The selection of suitable sites for curb-side enforcement is nearly always hampered by the need to select locations which would not cause severe traffic problems and hence did not necessarily match the traffic flow. The main problem faced by the RTD is the lack of space to carry out inspection of the motor vehicles. The results also give a strong indication that some drivers of diesel vehicle may adopt underhand tactics such as tempenng with the engine parts or adding volatile additives into the fuel tanks to achieve short term reductions for smoke emission during the RTD tests

Determinants of Living Arrangements, Health Status and Abuse among Elderly Women: A Study of Rural Naogaon District, Bangladesh

In this study, the socio-economic backdrops, living arrangements, health status and abuse of the women aged 60 years and older in the rural Naogaon district of Bangladesh are examined. The data were collected from seven villages by using probability proportional to size (PPS) sampling and the results show that an overwhelming majority of the elderly women in the age group 60-69 years who are widowed, illiterate, have no education and income, economically dependent, living with married children, unhealthy, suffer from arthritis related illness and are taking treatment from village doctors. Furthermore, the study shows that, nearly 35 percent elderly women are abused, mostly mentally abused due to poverty. Logistic regression analysis reveals the determinants of living arrangements, health status and abuse of the elderly women. The findings of the study should get due attention to provide secured later life of the elder especially female elderly in Bangladesh and developing nation as well

Sulfonamides determination in chicken meat products from Malaysia

Sulfonamides (SAs), synthetic antibiotics, are commonly used by veterinarians in chicken for therapeutic, prophylactic or as growth promoter and halt the growth of bacteria in animal production. Four common SAs, Sulfadiazine (SDZ), Sulfamethazine (SMZ), Sulfamethoxazole (SMX) and Sulfaquinoxaline (SQX), were determined in chicken breast and liver samples using reverse phase HPLC using UV detector at 266nm. The concentration of SAs detected in samples from 11 states in Peninsular Malaysia ranged from 0.006-0.062 µg/g in breast meat samples and 0.08-0.193 µg/g in liver samples. Except for sample from Johor, concentration of SAs in all the samples were lower than MRLs established by Malaysia (0.1 µg/g). Exposure of sulfonamides in Malaysian consumers ranged from 0.002-0.088 µg/kg body wt. /day. The highest value of sulfonamides exposure was found in Johor with an estimated daily intake (EDA) of Sulfamethoxazole (SMX) in Johor

Electrical-field activated sintering and forming of micro-components

As the demand for miniature products has increased significantly, so also has the need for these products to be produced in a rapid, flexible and cost efficient manner. The application of electroplasticity shows significant potential to produce the components by using powder materials. Nevertheless, previous research has shown that there are still significant challenges to be met in order to achieve increased relative densification of product samples and simplification of the processes. The process concept in this study comprises the combination of electrical-field activated sintering and forming processes. Therefore, the aims of the research were to develop the process concept for the manufacture of micro-components and to design the die sets along with other tooling for machine setup to enable the forming of micro-components from powder materials. A comprehensive literature review on micro-manufacturing, size effects, powder metallurgy and the electroplasticity process has been conducted. The development of the die sets for the process has been described, followed by a series of experiments. The FE thermal-electrical analysis was also carried out to study the heating flows of the die sets development during the process. In this research, titanium (Ti) and titanium tin alloy (90Ti10Sn) have been selected for the main powder materials tested for both vacuum and open-air process environment by using a Gleeble® 3800 testing system and Projection Welding machine respectively. Meanwhile, for the additional experiment, copper (Cu) has been selected to be tested in the open-air process environment by using a Projection Welding machine with die sets prepared by the Micro-FAST project. Based on the data collected, this efficient process has the potential to produce components with a high relative density of around 98%. Changes of the particles concerning deformation and breaking are crucial in the course of achieving the densification which differs from a conventional sintering process

An argument for developing waste-to-energy technologies in Saudi Arabia

Municipal Solid Waste (MSW) management is a chronic environmental problem in most of the developing countries, including the Kingdom of Saudi Arabia (KSA). The concept of Waste-to-Energy (WTE) is known as one of the several technologies capable of benefiting a society, which desires to reduce fossil-fuel addiction. Currently, there is no WTE facility existing in the KSA. The MSW is collected and disposed in landfills untreated. A substantial increase in the population by 3.4 %/y over the last 35 y coupled with urbanization and raised living standards have resulted in high generation rate of MSW. In 2014, about 15.3 Mt of MSW was generated in KSA. The food and plastic waste are the two main waste streams, which covers 70 % of the total MSW. The waste is highly organic (up to 72 %) in nature and food waste covers 50.6 % of it. An estimated electricity potential of 2.99 TWh can be generated annually, if all of the food waste is utilized in anaerobic digestion (AD) facilities. Similarly, 1.03 and 1.55 TWh electricity can be produced annually if all of the plastics and other mixed waste are processed in the pyrolysis and refuse derived fuel (RDF) technologies respectively. The aim of this paper is to review the prospective WTE technologies in Saudi Arabia. However, the real selection of the conversion technologies will be done in conjunction with the fieldwork on waste characterization and laboratory examination of selected technologies and further socio-economic and environmental evaluations

Animal fiber characterization and fiber loading effect on mechanical behaviors of sheep wool fiber reinforced polyester composites

© 2020 Taylor & Francis. This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Natural Fibers on 06/12/2020, available online: https://doi.org/10.1080/15440478.2020.1848743.This study presents animal fiber characterization and the influence of various fiber loadings on mechanical properties of sheep hair fiber-reinforced polymer (SHFRP) composites. The sheep hair fibers (SHF) characterization was carried out using X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM) and non-contact surface roughness machine. The functional group and chemical bond were analyzed using FTIR techniques. The crystallinity index and thermal stability of the SHF were characterized, using XRD and TGA techniques, respectively. The composites were fabricated using a compression molding technique and a varying weight percentage of 20, 30 and 40 fiber. The composite plates were cut into test samples according to ASTM standard methods for their mechanical (tensile, flexural and impact) behaviors to be extensively analyzed. The surface morphology of the fractured samples was examined with aid of an SEM. From the results obtained, it was evident that the SHFRP composite recorded a significantly increased tensile strength property when fiber loading was increased from 20 to 40 wt%. The optimum 40 wt% SHFRP composite sample recorded better flexural and impact strength, when compared with other counterparts. This was attributed to a better fiber-matrix interfacial adhesion, as established fromSEM micrographs.Peer reviewedFinal Accepted Versio

Effect of chemical treatment on physico-chemical properties of a novel extracted cellulosic Cryptostegia grandiflora fiber

© 2023 The Author(s). Published by IOP Publishing Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/The increasing global need to achieve sustainability in product development demands the use of biodegradable materials from renewable resources in many engineering applications. Accordingly, various natural fibers were explored as suitable reinforcement in polymer matrixes due to their low density and biodegradability. Hence, in this present work, a novel fiber reinforcement was extracted from the stem of the Cryptostegia grandiflora (CG) plant through a retting process and manual intervention. The extracted Cryptostegia grandiflora fibers(CGFs)were chemically treated using NaOH and silane. Various properties like crystal structure, chemical composition, surface morphology, and thermal degradation were studied using x-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR) Scanning electron Microscopy (SEM) and Thermogravimetric analysis (TGA). The increasing cellulose content and the removal of hemicellulose after the chemical treatment indicate the potential for this CGfiber as a better reinforcement element in polymers. The increasing trend of tensile strength was observed for the CGfiber in the following order: silane > NaOH > untreated conditions. Two-stage thermal degradation was observed in all the cases where the maximum thermal degradation was found at the silane-treated CGfibers. Based on their performance, the chemically treated CGfibres can be made into composites and used for structural applications.Peer reviewe

The Ultimate Ballistic Drift Velocity in Carbon Nanotubes

The carriers in a carbon nanotube (CNT), like in any quasi-1-dimensional (Q1D) nanostructure, have analog energy spectrum only in the quasifree direction; while the other two Cartesian directions are quantum-confined leading to a digital (quantized) energy spectrum. We report the salient features of the mobility and saturation velocity controlling the charge transport in a semiconducting single-walled CNT (SWCNT) channel. The ultimate drift velocity in SWCNT due to the high-electric-field streaming is based on the asymmetrical distribution function that converts randomness in zero-field to a stream-lined one in a very high electric field. Specifically, we show that a higher mobility in an SWCNT does not necessarily lead to a higher saturation velocity that is limited by the mean intrinsic velocity depending upon the band parameters. The intrinsic velocity is found to be appropriate thermal velocity in the nondegenerate regime, increasing with the temperature, but independent of carrier concentration. However, this intrinsic velocity is the Fermi velocity that is independent of temperature, but depends strongly on carrier concentration. The velocity that saturates in a high electric field can be lower than the intrinsic velocity due to onset of a quantum emission. In an SWCNT, the mobility may also become ballistic if the length of the channel is comparable or less than the mean free path.Peer Reviewe

Ply-stacking effects on mechanical properties of Kevlar-29/banana woven mats reinforced epoxy hybrid composites

© The Author(s) 2022. This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, https://creativecommons.org/licenses/by-nc/4.0/Development of new hybrid laminated composites of Kevlar-29 (K-29)/banana fiber (Musa acuminata) mats to meet future demand for fiber reinforced polymer (FRP) composites has been investigated. The different ply-stacking sequenced Kevlar (K)/natural (N) banana reinforced epoxy polymeric hybrid composite samples were designated as KN1, KN2, KN3, KN4, KN5 and KN6, in addition to NN7 and KK8 for single or non-hybrid FRP (control) composite samples. The ply-stacking effects on mechanical properties of all the laminated composite were investigated. The maximum tensile, flexural, impact and interlaminar shear strengths (ILSS) were obtained with sample KN4, because of the stacking of its Kevlar and natural banana mats, which was K2/N4/K2 of 8 layers and different from other stacking sequences. The percentage improvements on tensile strength of sample KN4 when compared with other hybrid composite samples KN1, KN2, KN3, KN5 and KN6 were 6.3, 4.4, 3.6, 13.1 and 11.3%, respectively. While, same optimum sample KN4 recorded highest flexural strength among hybrid samples with percentage improvements of 122.19, 70.97, 31.03 and 83.68% when compared with other hybrid samples KN2, KN3, KN5 and KN6, respectively. Similar trend of results was obtained for their tensile and flexural moduli. But, both hybrid composite samples KN3 and KN4 recorded higher impact strengths of 3.0 and 2.8 J, respectively, when compared with other hybrid counterparts. The tensile and flexural strengths of sample KN4 were 147.48 and 223.69 MPa, respectively. The tensile properties of various theoretical model were compared with experimental values.Peer reviewe

Experimental investigation and statistical analysis of additively manufactured onyx-carbon fiber reinforced composites

This is the peer reviewed version of the following article published in final form at https://doi.org/10.1002/app.50338. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Availability of additive manufacturing (AM) has influenced the scientific community to improve on production and versatility of the components created with several associated technologies. Adding multiple substances through superimposing levels is considered as a part of three-dimensional (3D) printing innovations to produce required products. These technologies are experiencing an increase in development nowadays. It requires frequently adding substance and has capacity to fabricate extremely complex geometrical shapes. However, the fundamental issues with this advancement include alteration of capacity to create special products with usefulness and properties at an economically viable price. In this study, significant procedural parameters: layer designs/ patterns (hexagonal, rectangular and triangular) and infill densities (30, 40 and 50%) were considered to investigate into their effects on mechanical behaviors of fused deposition modeling (FDM) or 3D-printed onyx-carbon fiber reinforced composite specimens, using a high-end 3D printing machine. Mechanical (tensile and impact) properties of the printed specimens were conclusively analyzed. From the results obtained, it was observed that better qualities were achieved with an increased infill density, and rectangular-shaped design exhibited an optimum or maximum tensile strength and energy absorption rate, when compared with other counterparts. The measurable relapse conditions were viably evolved to anticipate the real mechanical qualities with an accuracy of 96.4%. In comparison with other patterns, this was more closely predicted in the rectangular design, using regression models. The modeled linear regression helps to define the association of two dependent variables linked with properties of the dissimilar composite material natures. The models can further predict response of the quantities before and also guide practical applications.Peer reviewedFinal Accepted Versio