Moisture absorption and diffusivity of epoxy filled layered-structure nanocomposite

This paper studies moisture absorption and diffusivity of epoxy reinforced layered structure nanocomposites and its effect on fracture toughness. Two different types of layered fillers employed in the study were clay and graphene platelets, in which both surface layers were unmodified and modified by characterized by swelling analysis and fracture toughness measurement. The outcomes surfactant. The nanocomposites were showed that the moisture absorption and diffusivity decreased with the addition of layered fillers. It was found that the modified graphene platelets and clay outperformed the unmodified layers and neat epoxy in terms of reduction of moisture absorption and diffusivity. The modified graphene platelets reduced the moisture uptake and diffusivity about 30% and 33%, respectively compare to neat epoxy, thus indicates its outstanding performance in barrier applications. However, once the nanocomposites were swelling in the water for 5 days, it is noticed that the fracture toughness of nanocomposites were reduced significantly about 35% in average. Nevertheless, the modified graphene platelets still display the better performance compare to the other samples although there was reduction of fracture toughness

Overview effect of biodiesel storage on properties and characteristics

Abstract. Biofuels based on vegetable oils offer the advantage being a sustainable and environmen-tally attractive alternative to conventional petroleum based fuel. The key issue in using vegetable oil-based fuels is oxidation stability, stoichiometric point, bio-fuel composition, antioxidants on the degradation and much oxygen with comparing to diesel gas oil. This provides a critical review of current understanding of main factor in storage method which affecting the biodiesel properties and characteristics. In the quest for fulfill the industry specifications standard; the fuel should be stored in a clean, dry and dark environment. Water and sediment contamination are basically housekeep-ing issues for biodiesel. Degradation by oxidation yields products that may compromise fuel proper-ties, impair fuel quality and engine performance. The effect of storage method on the fuel properties and burning process in biodiesel fuel combustion will strongly affects the exhaust emissions

SERUM URIC ACID CONCENTRATION AND URINARY EXCRETION OF URIC ACID IN SUDANESE PATIENTS WITH GOUT

Objectives: To assess the relationship between serum uric acid concentration and urinary excretion of uric acid in patients with gout. Materials and Methods: Fifty three Sudanese patients with gout were included in this study; thirty three of them were gouty subjects not under treatment, twenty subjects were under treatment. Twenty normal subjects were used as control. The biochemical parameters included in this study were: serum uric acid, urine uric acid. Urine volume, pH, specific gravity, and urine crystals were also determined. Results: Serum uric acid concentration in gouty subjects not under treatment was significantly higher (p<0.01) as compared to control group. While serum uric acid concentration in gouty subjects under treatment was not significantly higher than the control group, the difference between means was statistically significant between gouty subjects not under treatment and control group. No significant differences were found for urine uric acid excretion. There was a weak positive correlation between serum uric acid concentration and urinary excretion of uric acid in gouty groups; however control group gave a weak negative sign. The risk factors, which were considered, were obesity (over weight), ethnic origin, and age. The difference between means for body weight and height was significantly higher (P<0.05) in gouty subjects compared with control group, and the difference between means for urine volume, urine specific gravity, and urine crystalls showed no significant effect on the three groups, while urine pH showed significant mean difference between these groups. Conclusion: The determination of serum uric is of good diagnostic value, whereas estimation of urine uric acid is of little diagnostic value. Urine crystals can be used only for screening for the investigation of urine uric acid crystals

A multilevel association model for IT employees' life stress and job satisfaction: An Information Technology (IT) industry case study

The aim of this research was to investigate the association among IT employees’ life stress and job satisfaction in information technology (IT) firms. Data on 250 IT employees’ in 30 working groups was obtained from 10 Information Technology (IT) Chinese firms from Beijing, and analyzed using hierarchical linear modeling (HLM). Results found momentous association among life stress of IT employees’ and their job satisfaction at an individual-level and group-level in IT firms. Furthermore, life stress in Beijing at group-level moderates the association among job satisfaction and IT employees’ life stress at an individual-level. Finally, limitations and implications of the present study are also discussed

Effect of storage temperature and storage duration on biodiesel properties and characteristics

Biodiesel based on vegetable oils offer the advantage being a sustainable and environmentally attractive alternative to conventional petroleum based fuel. Biodiesel is produced from any fat or oil such as soybean oil, through a refinery process called transesterification. The key issue in using vegetable oil-based fuels is oxidation stability, stoichiometric point, bio-fuel composition, antioxidants on the degradation and much oxygen with comparing to diesel gas oil. Biodiesel can be used as a pure fuel or blended with petroleum in any percentage but the standard storage and handling procedures used for biodiesel are the main issue due to the biodiesel fuel specifications. In the quest for fulfill the industry specifications standard; the fuel should be stored in a clean, dry and dark environment. In this research, three different storage temperature were study which are; low (0 – 5 °C), ambient, and high (40 – 50 °C). The key parameters that are required to store biodiesel are discussed, and the recent research advances are noted. Five types of biodiesel after storage all the samples for 2016 hours were tested plus with two product of combustion. Images analysis for combustion process was used to image appearances analysis. Under 2016 hours of storage duration, the effect of degradation was happen although the effect is not significance because the changes are still in acceptable ranges

Study of vibration absorbers using epoxy reinforced natural fibers

It is well known fact that vibrations contribute to excessive wear, fatigue failure and other premature failure of machine components. Thus, various methods have been applied to control these vibrations. One of the commonly used is vibration absorber. The aim of this paper is to explore the potential of epoxy reinforced natural fibers as an alternative material for vibration absorber. Both mechanical properties and dynamic characteristic of the composites are investigated through tensile test and transmissibility test, respectively. Two types of natural fibers were selected for the study; coconut coir and pineapple leaf. The results show that the tensile modulus of composites increases with the increase of fiber content, although the strength was found decreases. This reduction indicates an ineffective stress transfer between the fiber and matrix. From the tensile test result, 20 vol% of pineapple leaf fiber was found to be the optimum fraction, in which afterward was employed for fabrication vibration absorber. Meanwhile, from the transmissibility test, it was noticed that when base excitation increases, the resonance peak and attenuation frequency were changed to the lower value. The fixed-fixed end beam with attached composite vibration absorbers showed that the resonance amplitude of the beam decreased significantly. More absorbers attached on the beam produce better result in attenuating the global structural vibration

Evolution engine technology in exhaust gas recirculation for heavy-duty diesel engine

In this present year, engineers have been researching and inventing to get the optimum of less emission in every vehicle for a better environmental friendly. Diesel engines are known reusing of the exhaust gas in order to reduce the exhaust emissions such as NOx that contribute high factors in the pollution. In this paper, we have conducted a study that EGR instalment in the vehicle can be good as it helps to prevent highly amount of toxic gas formation, which NOx level can be lowered. But applying the EGR it can lead to more cooling and more space which will affect in terms of the costing. Throughout the research, fuelling in the engine affects the EGR producing less emission. Other than that, it contributes to the less of performance efficiency when vehicle load is less

Occupational safety and health practice: a study at quarry site by using hirarc form

Occupational Safety and Health Act (OSHA) is a discipline with wide scope involving many specialized fields. In other words, occupational health and safety comprises of aspects in terms of social, mental and physical. This study focuses on the occupational safety and health act ABC Quarry Site located in Kedah. Nowadays, the workers lack of safety and health practice from their companies based on the observations being done one site during this project’s site visit. It is very important for the employers to manage occupational safety and health at the workplace because of the lack of management control often leads to the existence of causes of accidents and allows for unsafe practices among the workers. The data collection was carried out through site investigation and HIRARC form and interview with the person in charge during the site visit. The objective of this study is to promote the occupational environment adaptable to the employer and employees at the workplace based on the existing potential hazard. This report was conducted to identify the hazard on the construction site and to analyse the occupational safety and health in the workplace. This study suggests recommendations for improving occupational safety and health act in the construction site. Effective job safety and health training will help to reduce worker injuries and illnesses

Firms’ environmental performance: voluntary actions and managerial attitudes

This study considers Malaysian palm oil mills’ Environmental Performance from two aspects: voluntary actions and firm’s internal factors effects. Having a good understanding of the factors affecting the environmental performance of firm helps policy-makers develop more effective environmental policies. In fact, analyzing the factors helps the firm evaluate and improve the results of their voluntary actions. Environmental performance, in this study, is specified as a function of voluntary actions, managerial attitudes, and some control variables. Our findings show that voluntary actions have the highest contribution to a firm’s environmental performance among others. Managerial attitudes toward improving environmental performance also have a significant effect on the firm’s environmental performance. However, age and size seem to have negative effects. Our results reveal that public owned firms are more polluting than their privately owned counterparts