Preparation And Characterization Of Silicone Rubber Composites Filled Waste Mineral Fillers For High Voltage Insulation Application

Silicone rubber (SiR) based composites has increased demand in high voltage (HV) insulator application, due to their exceptional advantages over the existing conventional ceramic based insulator. SiR based insulator has compromised light-weight, superb breakage resistance, improved seismic performance and more flexible and manufacturable, than ceramic insulator. Hence, this research was conducted to prepare and characterize the performance of SiR based composites filled with mineral fillers, that derived from waste resources of silica (SiO2) from waste glass, calcium carbonate (CaCO3) from waste cockle shell and wollastonite (CaSiO3) from combination of both. Simplified calcination heat treatment between SiO2 and CaCO3 (at percentage ratio of 51.70% : 48.30%), has successfully derived synthetic mineral CaSiO3, as confirmed by x-ray diffraction at 37.5°of 2Ɵ peak. Later, SiR filled mineral filler was compounded by internal mixer with addition of dicumyl peroxide (DCP) as vulcanization agent, aux-heat stabilizer as colorant and mineral filler. Vulcanization via hot compression molding was performed before continuing into prolonged post-cured for complete conditioning. Two main independent variables has been tested in this research, which are the effects of mineral filler types and the effects of mineral filler loadings (at 5.00, 10.00, 20.00, 30.00 and 40.00wt.%), towards the resulted electrical, physical, mechanical and morphological performances of SiR filled composites. For electrical testing, an inclined plane test (IPT), surface resistivity and relative permittivity tests were conducted. Fracture surface observation via scanning electron microscope (SEM) was performed to relate the behavior of resulted mechanical strength of produced SiR based composites.It was interestingly found that, addition of mineral fillers caused an improvement in tensile strength about 70%, which exhibited by SiR/CaSiO3 at 5.00wt.% filler added. In terms of IPT test, SiR/CaSiO3 had maximally passed the tracking failure limit (4 out of 5 samples < 2.50cm) as compared than the other SiR composites. In addition, SiR/CaSiO3 at 40wt.% exhibits highest value of surface resistivity and relative permittivity. Not only that, it also possessed maximal hardness value which indicating complete peroxide curing, at before and after HV exposure. While stable water absorption was also obtained by SiR/CaSiO3 sample. In overall, SiR based composites provide absolute significant improvement as compared than unfilled especially for SiR/CaSiO3 composites, which has dominated the best properties almost for entire performed tests. These findings, was underlined the potential of CaSiO3 over the other mineral fillers, to established improved filler-matrix interaction, due to their needle-like structure and protrusion condition and its extraordinary insulation effects, which benefited for electrical insulation and strength performances of SiR based composites for outstanding and reliable HV application

DC Inline Plane Test Of Silicone Rubber Samples With Different Filler For High-Voltage Insulation

This paper is about preparation of silicone rubber (SiR) samples with different filler for high-voltage insulation purpose. The fillers used were silica from waste glass, calcium carbonate from cockle shell, silica/calcium carbonate and wollastonite. All the fillers were crushed into powder and undergo internal mixer and hot press as a material preparation. It was expected that the combination of filler with silicone rubber would give better result when experiencing ageing process. The direct current (DC) inclined plane test was used to investigate the tracking and erosion on silicone rubber composites. The tracking length was observed between the top and bottom electrode. Comparison would then be made between the silicone rubbers with different fillers based on the result obtained from the experimen

Construction court in Malaysia: a legal analysis / Farisha Husna Mat Darus...[et al.]

The reasoning behind this research is to study the effectiveness and efficiency of the Malaysian Construction Court, which is a new specialist court in the Malaysian legal landscape. As the Construction Court is still in its infancy, this research is carried out in order to provide information on the Construction Court, where previously no information has been made available. Besides that, the research is also carried out in order to see if it is necessary to establish a Construction Court, and if the Construction Court has been effective. A qualitative approach is taken in doing the research. Interviews with the Construction Court judges and the General Manager of Business Division of the Construction Industrial Development Board had been conducted in order to gain relevant information. As the construction industry is increasingly developing, this research may be beneficial to those in the construction industry, and also to those with an interest in construction law. The focus of the research is on the effectiveness and efficiency of the Construction Court in order to determine whether the establishment of the Construction Court is necessary and warranted. An examination of the construction industry in Malaysia prior to the establishment of the Construction Court is made, whereby it was found that the construction industry had faced certain disadvantages which slowed its progression. The disadvantages include the lengthy time take to resolve disputes, inadequate relief, and the insufficiency of dispute resolution provided by civil courts and arbitration. This gave rise to the establishment of the Construction Court, which was the product of like-minded parties including the construction industry and the judiciary. The collaboration occurred in a bit to address the issues that are faced by the construction industry, which may affect adversely the Malaysian economy. Many cases have been filed at the Construction Court since its inception, which can be interpreted^ that there is a demand for a specialist Construction Court. According to the Construction Industry Development Board, out of the 205 cases filed in the Construction Court, 124 cases were disposed by June 2014, meaning that 60.5% of cases were disposed in the period of fifteen months. Based on the number of cases disposed, it can be said that the Construction Court is effective

Investigation with gifted students in learning physics concept based on cognitive structure

Physics concept is an understanding of natural occurrence. Physics is one of the natural science subjects that involves the study of matter and motion through space and time, along with related concepts. The concepts of physics explained everything involving the environment and human relation that happened in our daily life. Physics is one of the toughest subjects. Many students have difficulty to understand the subject properly. The factor of difficulty in learning physics concept come from many aspects, which is subject matter, materials for learning, the environment in class, and teaching style. Therefore, this study aims at investigating the main factor affecting the understanding of student performance in physics subject. This study has been done by given question paper that is designed based on taxonomy bloom. The question paper consists of 10 questions divided into three stages of taxonomy bloom, which are C1 (remembering), C2 (understanding), and C3 (applying). The test has been conducted among 17 years old students in Kolej PERMATA Insan. The result of the test has been analyzed. Based on the test that has been held, the results showed that most students did not reach the minimum mark of for the three stages in taxonomy bloom mainly stage C3 questions that apply the physics concept in daily life. The results from the test showed that physic is a tough subject to be learned

Erratum to: Methods for evaluating medical tests and biomarkers

[This corrects the article DOI: 10.1186/s41512-016-0001-y.]

Evidence synthesis to inform model-based cost-effectiveness evaluations of diagnostic tests: a methodological systematic review of health technology assessments

Background: Evaluations of diagnostic tests are challenging because of the indirect nature of their impact on patient outcomes. Model-based health economic evaluations of tests allow different types of evidence from various sources to be incorporated and enable cost-effectiveness estimates to be made beyond the duration of available study data. To parameterize a health-economic model fully, all the ways a test impacts on patient health must be quantified, including but not limited to diagnostic test accuracy. Methods: We assessed all UK NIHR HTA reports published May 2009-July 2015. Reports were included if they evaluated a diagnostic test, included a model-based health economic evaluation and included a systematic review and meta-analysis of test accuracy. From each eligible report we extracted information on the following topics: 1) what evidence aside from test accuracy was searched for and synthesised, 2) which methods were used to synthesise test accuracy evidence and how did the results inform the economic model, 3) how/whether threshold effects were explored, 4) how the potential dependency between multiple tests in a pathway was accounted for, and 5) for evaluations of tests targeted at the primary care setting, how evidence from differing healthcare settings was incorporated. Results: The bivariate or HSROC model was implemented in 20/22 reports that met all inclusion criteria. Test accuracy data for health economic modelling was obtained from meta-analyses completely in four reports, partially in fourteen reports and not at all in four reports. Only 2/7 reports that used a quantitative test gave clear threshold recommendations. All 22 reports explored the effect of uncertainty in accuracy parameters but most of those that used multiple tests did not allow for dependence between test results. 7/22 tests were potentially suitable for primary care but the majority found limited evidence on test accuracy in primary care settings. Conclusions: The uptake of appropriate meta-analysis methods for synthesising evidence on diagnostic test accuracy in UK NIHR HTAs has improved in recent years. Future research should focus on other evidence requirements for cost-effectiveness assessment, threshold effects for quantitative tests and the impact of multiple diagnostic tests

Erratum to: Methods for evaluating medical tests and biomarkers

[This corrects the article DOI: 10.1186/s41512-016-0001-y.]

Preliminary study on microplastics in surface water of Sarawak river

Degradation of plastics in the environment produce small fragments which the size is usually less than 5 mm, known as microplastics. This study was designed to investigate the abundance of the microplastics in Sarawak River including their morphological features, chemical characterisation and surface texture. Overall, there are 138 particles found. The identification of microplastics was conducted based on the physical characterisation (type, colour, size) and chemical characterisation (ATR FTIR analysis) for a functional group of polymers. Fragment type, white colour and size of 4 mm microplastics were most dominant in the area. Polypropylene was the most abundant chemical compound found. The result was analysed by One-way Analysis Variance (ANOVA), there was a significant difference of total microplastics between all the stations. It is recommended to conduct this research in future for baseline information on microplastic issue in Malaysia

Association between sleep patterns and academic performance

Most university students have experienced sleepiness during class hours. They are more likely to face problems with learning and focusing on class and it may affect their academic performance. Hence, the aim of this study is to find out the relationship between sleep patterns and academic performance among semester five Science Mathematics undergraduates of UiTM Kelantan branch. Fifty students were chosen randomly as the respondents. This study employed descriptive analysis and chi-square test of independence was used to explore the association between sleep pattern and academic performance. It was found that the respondents indicate to have different sleep patterns either in respects of wake time, bedtime or daytime nap and sleep duration. The study found that the patterns of sleep and wakefulness varies widely between respondent, and it was influenced by many causes which are phone, caffeinated drinks and health problem. The findings also found that the respondents' academic performance, as measured by CGPA was significantly affected by their sleep patterns. It can be concluded that majority of the students managed to have a good sleep duration in which the total of sleep duration is related to their wake time, bedtime and daytime nap. In terms of recommendations, students who are having poor sleep patterns should manage their wake time, bedtime and daytime nap properly if they want to have a better sleep duration, students should avoid from using mobile phone at least 1 hour before bedtime and students should improve their sleep patterns to increase their academic performance

C5–C7 linear alkane hydroisomerization over MoO3–ZrO2 and Pt/MoO3–ZrO2 catalysts

The catalytic activity of MoO3–ZrO2 and Pt/MoO3–ZrO2 has been assessed based on the C5–C7 linear alkane hydroisomerization in a microcatalytic pulse reactor at 323–623 K. The introduction of Pt altered the crystallinity and acidity of MoO3–ZrO2. The catalytic activity of Pt/MoO3–ZrO2 was inferior than that of MoO3–ZrO2, although the Pt/MoO3–ZrO2 performed higher hydrogen uptake capacity. IR and ESR studies confirmed the heating of MoO3–ZrO2 in the presence of hydrogen formed active protonic acid sites and electrons which led to change in the Mo oxidation state. Similar phenomenon was observed for Pt/MoO3–ZrO2 at ⩽323 K. Contrarily, heating of Pt/MoO3–ZrO2 in the presence of hydrogen at higher temperature did not form protonic acid sites but intensified Lewis acidic sites. It is suggested that Pt facilitates in the interaction of spiltover hydrogen atom and MoO3 to form MoO2 or Mo2O5 over ZrO2 support which may be intensified the Lewis acidic sites