AC losses in Sn-doped Bi1.6Pb0.4Sr2(Ca1-xSnx)2Cu3Oδ superconductors

Measurements of complex AC susceptibility χ = χ + χ as a function of temperature have been carried out on Sn-doped Bi1.6Pb0.4Sr2(Ca1-xSnx)2Cu3Oδ superconductor samples prepared via the conventional solid state reaction method. All the samples exhibit perfect diamagnetism below 109 K. The χ (T) curves display two-step features, indicating the presence of mixed phases and therefore weakening of the grains' coupling. The amount of shielded volume in Sn-free samples is greater than that in Sn-doped samples. The intrinsic peak due to the small AC losses within the grain was not observed in the χ (T) curves for all samples. However, the coupling peak, TP, for Sn-free samples at an applied field of 1.0 Oe was observed at 89 K and shifted to a lower temperature ranging from 59 K to 64.2 K in Sn-doped samples. The amounts of hysteresis losses above the TP in all doped samples were smaller than that of the Sn-free sample. Therefore, the effect of Sn doping suppressed the inter-granular critical current, Jcm, and the presence of weak links that coupled the superconducting grains

Analysis of daytime and nighttime ground level ozone concentrations using boosted regression tree technique

This paper investigated the use of boosted regression trees (BRTs) to draw an inference about daytime and nighttime ozone formation in a coastal environment. Hourly ground-level ozone data for a full calendar year in 2010 were obtained from the Kemaman (CA 002) air quality monitoring station. A BRT model was developed using hourly ozone data as a response variable and nitric oxide (NO), Nitrogen Dioxide (NO2) and Nitrogen Dioxide (NOx) and meteorological parameters as explanatory variables. The ozone BRT algorithm model was constructed from multiple regression models, and the ‘best iteration’ of BRT model was performed by optimizing prediction performance. Sensitivity testing of the BRT model was conducted to determine the best parameters and good explanatory variables. Using the number of trees between 2,500-3,500, learning rate of 0.01, and interaction depth of 5 were found to be the best setting for developing the ozone boosting model. The performance of the O3 boosting models were assessed, and the fraction of predictions within two factor (FAC2), coefficient of determination (R²) and the index of agreement (IOA) of the model developed for day andnighttime are 0.93, 0.69 and 0.73 for daytime and 0.79, 0.55 and 0.69 for nighttime respectively. Results showed that the model developed was within the acceptable range and could be used to understand ozone formation and identify potential sources of ozone for estimating O3 concentrations during daytime and nighttime Results indicated that the wind speed, wind direction, relative humidity, and temperature were the most dominant variables in terms of influencing ozone formation. Finally, empirical evidence of the production of a high ozone level by wind blowing from coastal areas towards the interior region, especially from industrial areas, was obtained

Cahaya Enterprise : Lamp Installment Services / Ahmad Akmal Azman ...[et al.]

Our product are use to control light by using light dependent resistant (LOR) and timer. The LDR will operate when the light intensity is low. While, the timer is set by the user themselves whenever they want the lamp to light up. Our product and service are suitable for houses, factory and office

Thermal, dynamic mechanical analysis and mechanical properties of polybutylene terephthalate/polyethylene terephthalate blends

Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and mechanical tests were conducted to characterize the properties of polybutylene terephthalate/polyethylene terephthalate (PBT/PET) blends. PBT and PET were blended at different PBT/PET ratios (80/20, 60/40, 40/60, 20/80) via twin screw extruder prior to injection molding. DSC characterization showed a single glass transition temperature for all PBT/PET blends indicating that the miscibility occurred in the amorphous region. From DMA results, loss modulus and tan δ also showed a single peak for all PBT/PET blends, confirming the DSC results. At room temperature, PBT/PET 20/80 has the highest storage modulus followed by PBT/PET 80/20 blend. PET has higher tensile strength, flexural strength, Young’s and flexural modulus than PBT but lower in elongation at break and impact strength. PBT/PET 80/20 blend has the highest tensile strength, flexural strength, elongation at break, and impact strength compared to other PBT/PET blends. PBT/PET 80/20 blend can be suggested as an optimum formulation with balanced mechanical properties in terms of stiffness and toughness

Innovative invention skills and individual competency model for vocational education

Invention is a process of developing creative minds, innovative and inventive in preparing the workforce informed, and competent in facing the challenges of rapid technological development today. Knowledge and individual competency are needed to produce a new design of a product. Knowledge and skills are the components related to invention process that could be identified easily. Therefore, this study aimed to determine the level of student’s knowledge and preferences in invention process, student’s skills in selecting the process knowledge, and to identify the relationship between the student’s knowledge and the preferences process that they chose. 528 students from vocational colleges were involved in this study. The set of questionnaires based on Renwick model and iceberg competency model was used to measure the variables needed. The results showed the level of student’s knowledge in invention process was high and the students also preferred the idea of development when they chose the invention process. This study also concluded that there was a significant relationship between knowledge and student’s preferences in invention process. In conclusion, the application of skills and knowledge in invention process will be applied in students’ competency and it is capable of developing new ideas to create innovative and creative products

Usability evaluation of encyclopedia websites

Usability is an important aspect that every website should focus more. It tells us how well and success website will function with real users. Many people often think usability tests are expensive and time-consuming. It can be a cost-effective and time saver with usability testing instead of spending more time fixing an unusable website. This study evaluates the usability of encyclopedia websites by using automated usability testing tools and questionnaire methods. The questionnaire was developed based on a standard form called Website Analysis and Measurement Inventory (WAMMI) that identified 20 common usability questions divided into five categories. Each category deals with one aspect of usability. Simultaneously, the automated usability testing tools used in this study were Pingdom and GT Metrix to calculate and analyse the website performance of selected encyclopedia websites based on website components including page load time, media size and overall web performance grades. This study could help web designer, developer, and practitioners design better and more user-friendly encyclopedia websites

Improvement of foundation student performance in biology through intensive station based learning approach

A growing revolution is underway in teaching introductory science to foundation studies. Recent educational research explains that traditional teaching approaches in large classes often fail to reach many students. To address this problem, we conducted an intensive station rotation-based workshop called “Bio Made Easy” for a group of students who obtained F grade in the first Biology assessment, N = 120. The workshop was designed to improve students’ understanding of selected Biology topics by providing simple examples, analogy, and explanation of the concept using various active and interactive approaches. The goal was to change the students’ perception of biology and deliver the content within a short period of time. The students were divided into small groups and required to complete all stations conducted by different instructors. For each station, students were directed to perform activities that required them to actively participate, interact, and discuss among the group members. A comparison was made between their performance during the first test and the second test of the semester. From F grade in the first test, about 88.3% of the students accomplished higher performance grades in the test 2 assessment. This reflects an encouraging sign that active-learning practice and direct engagement of students in the station rotation-based learning approach improve student performance in biology subject and serve as one of the strategies to motivate students for better grades

Deciphering Learning Motivation in Open Distance Learning towards Sustainable Medical Education

Open distance learning has become a new norm in medical education since the COVID-19 pandemic. The abrupt shift from conventional medical education to fully virtual learning deserves a reflection on how it affected the learning motivation among medical students. Hence, this study aimed to investigate the effect of open distance learning on their learning motivation during this pandemic period, with suggestions to improve through reflections and recommendations. This qualitative study involved 152 medical students undertaking the Doctor of Medicine program in Universiti Kebangsaan Malaysia, Malaysia, during the COVID-19 pandemic. All data were collected through a validated questionnaire. We found that medical students portrayed intrinsic motivation—mainly self-motivation, self-discipline, and self-adaptation—in open distance learning during the pandemic period. Feedback from medical students also showed that they advocated a better internet connection, innovative teaching, and learning, as well as new appropriate assessment methods and strengthening of the learning management system for a sustainable open distance learning outcome. Hence, medical educators should be creative in making use of open distance learning as an attractive complementary platform in medical education to ensure life-long learning

Deciphering Learning Motivation in Open Distance Learning towards Sustainable Medical Education

Open distance learning has become a new norm in medical education since the COVID-19 pandemic. The abrupt shift from conventional medical education to fully virtual learning deserves a reflection on how it affected the learning motivation among medical students. Hence, this study aimed to investigate the effect of open distance learning on their learning motivation during this pandemic period, with suggestions to improve through reflections and recommendations. This qualitative study involved 152 medical students undertaking the Doctor of Medicine program in Universiti Kebangsaan Malaysia, Malaysia, during the COVID-19 pandemic. All data were collected through a validated questionnaire. We found that medical students portrayed intrinsic motivation—mainly self-motivation, self-discipline, and self-adaptation—in open distance learning during the pandemic period. Feedback from medical students also showed that they advocated a better internet connection, innovative teaching, and learning, as well as new appropriate assessment methods and strengthening of the learning management system for a sustainable open distance learning outcome. Hence, medical educators should be creative in making use of open distance learning as an attractive complementary platform in medical education to ensure life-long learning

Mechanical and thermal properties of dolomite filled polycarbonate/acrylonitrile butadiene styrene composites

Polycarbonate (PC)/acrylonitrile butadiene styrene (ABS) composites usefulness is majorly due to its good mechanical properties and low cost to performance ratio. The purpose of adding fillers into polymers is to further lower the cost and improve the mechanical properties of the composites. The objective of this study is to investigate the effects of dolomite content on the mechanical properties of PC/ABS blend and to determine the optimum formulation for the PC/ABS/dolomite composites. Dolomite content in the PC/ABS/dolomite composites was varied ranging from 0 to 15 wt.%. The composite samples were then tested for mechanical, thermal and flame retardancy properties. The study concluded that 5 wt.% dolomite content was the the optimum filler content for PC/ABS/dolomite composites