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

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

Unsteady Magnetohydrodynamic Flow of Jeffrey Fluid through a Porous Oscillating Rectangular Duct

This chapter presents some new exact solutions corresponding to unsteady magnetohydrodynamic (MHD) flow of Jeffrey fluid in a long porous rectangular duct oscillating parallel to its length. The exact solutions are established by means of the double finite Fourier sine transform (DFFST) and discrete Laplace transform (LT). The series solution of velocity field, associated shear stress and volume flow rate in terms of Fox H-functions, satisfying all imposed initial and boundary conditions, have been obtained. Also, the obtained results are analyzed graphically through various pertinent parameter

Causes of Relapse into Illiteracy of Adult Female Neo-Literates: An Evaluation

The present study was designed to explore the factors that responsible for the relapse into basic literacy skills of adult neo-literates. This qualitative study utilized strategies, including: a survey, interviews, focused group discussions, artifacts, and observations. Random and criterion sampling techniques were applied. The data was analyzed by sorting, coding, and categorizing the views of the respondents. The study explored these three problems areas: the implementation of a literacy program, addressing the needs and aspirations of adult female neo-literates and the teachers’ delivery of the courses. The results of this inquiry identified key factors tied to the three problem areas: the teachers were inadequately trained and failed to observe the basic standards of courtesy and respect for the learners. The courses ran at inappropriate times, were too short and used inadequate accommodation. While not excessively difficult, the materials used were not related to the real needs of the learners who wished, in the main, for literacy skills in relation to income generating activities. There was a need for increased opportunities to practise the skills taught and follow up courses were required

Anxiety and Attitude Of Secondary School Students Towards Foreign Language Learning

AbstractMultiple methodologies are being used for teaching and learning of foreign language. In countries where English is taught as a foreign language, learners suffer various levels of being anxious and develop a specific attitude towards English. The paper examined foreign language anxiety of 10th grade students and their attitude towards foreign language learning. Sample of the study was 360 male and 360 female students of 10th grade students of public sector secondary schools from six districts of the Punjab Province of Pakistan. Statistical Package for Social Sciences (SPSS) was used for data analysis. Level of anxiety and level of attitude were determined through percentage. t-test was used to find out difference between boys and girls of 10th grade. Relationship of anxiety with attitude of the students was determined though Pearson product moment coefficient. Results showed significant differences between boys and girls in foreign language anxiety and attitude towards foreign language learning. There was significant negative correlation between foreign language anxiety and students’ attitude towards foreign language learning. Girls showed less anxiety in English language class and had more positive attitude towards English. Similarly, rural students had high anxiety in English and had less positive attitude towards English. It was suggested that training might be given to English language teachers on modern pedagogical patterns. English language Curriculum might be redesigned keeping the context of the learners in mind

Hazard identification, risk assessment and risk control: a study at construction site

Occupational Safety and Health Act (OSHA) is an Act to make further provisions for securing the safety, health and welfare of persons at work, for protecting others against risks to safety or health in connection with the activities of persons at work, to establish the National Council for Occupational Safety and Health, and for matters connected therewith. This study focuses on infrastructure construction in Pagoh Education Hub. In present days, despite of knowledge in OSHA act, workers often proceed the work without considering any safety precaution or act at workplace as stated in OSHA Act. Due to ignorance of workers and employee on OSHA Act, workers are exposed to danger and hazard at their workplace causing them minor or worst fatal injury. The data collection was carried out through site investigation using Preliminary Hazard Analysis (PHA), HIRARC form and interview session with several workers in the constructio. The main objective of this study is to support the idea to coordinate and redefined the practice of occupational safety and health as workers discipline at their workplace based on existing potential hazard. This study was conducted to identify the hazard that occur at the workplace and analyse the safety precaution taken by the workers and employer to avoid accidents. As a result, this study listed several suggestions to improve the practice of occupational safety and health among workers in the workplace

From clay to graphene for polymer nanocomposites-a survey

The development of aerospace and automotive in- dustries requests lightweight, high-performance materials, and polymer nanocomposites are ideal candidates in this case, which is shown by the increasingly more publications in this research field over the past two decades. However, the perfor- mance of nanocomposite not only depend on the properties of their individual constituents, but on their morphology and surface characteristics of fillers as well. Selections of nanofillers geometries, e.g. particulate, fibrous or layered have a tremendous influence on the properties of nanocomposites and their processing methods. In this paper, we review the chronological works performed in the field of polymer nano- composites, in particular epoxy nanocomposites reinforced with layered fillers, such as clay and graphene. Surprisingly layered fillers are commercially available and more cost- effective than nanoparticles and carbon nanofibres, and these make them to the most extensively studied fillers that can be geared toward future applications, particularly in large-scale polymer nanocomposite production

Discussion of the technology and research in fuel injectors common rail system

Common rail is one of the most important components in a diesel and gasoline direct injection system. It features a high-pressure (100 bar) fuel rail feeding solenoid valves, as opposed to a low-pressure fuel pump feeding unit injectors. Third-generation common rail diesels now feature piezoelectric injectors for increased precision, with fuel pressures up to 2,500 bar. The purpose of this review paper is to investigate the technology and research in fuel injectors common rail system. This review paper focuses on component of common rail injection system, pioneer of common rail injection, characteristics of common rail injection system, method to reduce smoke and NOx emission simultaneously and impact of common rail injection system. Based on our research, it can be concluded that common rail injection gives many benefit such as good for the engine performance, safe to use, and for to reduce the emission of the vehicle. Fuel injection common rail system is the modern technology that must be developed. Nowadays, our earth is polluting by vehicle output such as smoke. If the common rail system is developed, it can reduce the pollution and keep our atmosphere clean and safe