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Understanding Plasma Dynamics of Argentina Nano Focus Machine Using the Lee Code
No full textArgentina Nano Focus Machine is a small plasma focus machine used as an intense neutron source.
To understand the working of its plasma dynamics, the Lee model code is used. The results obtained
from the Lee code agree reasonably well with the experimental data in terms of the peak current,
radial start time and the pinch duration. Additionally, this code also produces information such as
the optimum neutron yield (6.2x104), maximum ion beam energy (1.2 J) and the dependence of these
yields and various speeds on operating pressure. The resultant data is reliable and all the input that
is required is just one experimental current waveform together with the actual machine and
operating parameter
Forecasting Using K-means Clustering and RNN Methods with PCA Feature Selection
No full textArtificial Neural Networks is a computing system that is inspired by how the nervous system works in humans and continues to grow rapidly until now. Just like the nervous system in humans, artificial neural networks work through the process of studying existing data to formulate new data outputs. An artificial neural network using the Recurrent Neural Network (RNN) method is one of the popular models used today, especially in forecasting cases. In simple terms, the forecasting flow using the RNN method begins by dividing the test data and training data, the forward calculation process, the backward calculation process, the optimization calculation, and the evaluation calculation of the forecasting model. The main obstacle of the RNN method is the presence of a vanishing gradient which can cause poor forecasting results. In this study, the authors propose a Principal Component Analysis (PCA) dimension reduction method to obtain the most influential variables and become inputs for the prediction model that is built to minimize existing errors. The author also uses the K-means clustering method to divide the data with similar trend variations. To increase the clustering effect, the researcher used similarity calculation based on Euclidean distance. So that in an effort to build optimal prediction results, first time series data with the most influential variables will be selected using the PCA method. Furthermore, the data are grouped using the K-means method and will be included in the prediction model that is built. In the RNN prediction model, the data will be trained using the Backpropagation Through Time (BPTT) method and the optimization method used is Stochastic Gradient Descent (SGD). Forecasting with the RNN method with PCA produces an accuracy of 93%, while forecasting using the RNN method without PCA produces an accuracy of 82%. The experimental results show that the RNN method with PCA achieves higher predictive accuracy and flexibility than RNN without PCA
Design of DC Electric Screw Jack Telescopic Push Rod Operated Scissor Lift
No full textThe scissor lift is widely used in industries as a lifting system to lift up load vertically. The scissor mechanism or pantograph with linked, folding supports in a criss-cross “X” pattern mostly powered by hydraulic system are used to achieve the upward motion.
The power system employed on the scissor lift usually is a hydraulic system which installed at the lowest set of supports to elongate the crossing pattern and moving the platform on top of the scissor lift vertically. The primary components of the hydraulic system consist of reservoir, filters, pump, control valves, pressure relief valve and hydraulic cylinder. Hydraulic systems are more complex and expensive and subject to leakage.
In this study the solid model and assembly of the part has been developed by the Autodesk Inventor software. The finite element analysis of the system will also be investigated with the same software i.e. stress, deflection, and safety factor values of system elements should be obtained. The formulation of the equation to determine the effective load of scissor lift and general equation of force required to lift up the load versus the angle of inclination of scissor’s link have been derived. A large thrust DC electric screw jack telescopic push rod or electric actuator which is high precision, longer service life, cheaper and easy to be installed will be selected to replace the hydraulic system. As a result of the analyses, a prototype is fabricated with the system designed that should safely be used during loading and unloading operations
An investigation of Aerodynamic Improvement on Truck’s Forebody
No full textAn overview of aerodynamics of heavy-duty vehicles is the main focus of this paper. To be more specific, drag reduction systems, implementation of which can noticeably decrease fuel consumption of a truck, thus improving its efficiency. To do that, several different deflector designs were created. To evaluate them, multiple simulations of the flow field acting on a truck were made with Computational Fluid Dynamics (CFD) techniques. The simulations are based on steady-state formula, and their purpose is to evaluate aerodynamic properties of trucks. All the important characteristics and aerodynamic variables were determined by using TRIZ method. The resulting data clearly showed that curtain deflector designs can decrease drag coefficient and fuel consumption by as much as 0.02 and 0.83 liters respectively. It was proven that the solid basis can be established for future aerodynamic enhancements and their numerical and experimental evaluations
Study of Green Energy Production in INTI’s 3 kJ Plasma Focus Device
No full textGreen and sustainable energy production has recently become a topic of great interest due to limited natural resources such as oil and gas, the increasing political turmoil and environmental concerns over temperature increase due to greenhouse effect. In INTI, a basic study of the creation of green energy or plasma energy was carried out. Plasma can be understood as the highest energy state of matter. When matter is heated to a high enough temperature, it is ionized into positive and negative charged particles with potential of energy production. To study such energy production, INTI’s 3 kJ Mather- type plasma focus machine is charged to 13.5 kV and discharged into 3 Torr deuterium gas. This machine produces a current sheet that travels at extremely high speeds which will heat and compress (pinch) the plasma above the anode to produce extremely high temperature. This pinch undergoes instabilities and breaks up releasing intense electromagnetic radiation (including fusion energy). To make fusion energy more reliable and commercially viable, continuous fusion reaction is needed and plasma should be sustained over a long period of time. The leading candidate for a fusion reactor is a different plasma machine call a tokamak, but the plasma focus is emerging as a more compact contender
Relationships between Coping Styles, Emotional Distress, and Fear of COVID-19 among Workers in the Oil and Gas Industry in Malaysia during the COVID-19 Pandemic
No full textThe COVID-19 pandemic has had serious impacts on psychological health globally. However, very little is currently known regarding the link between fear of COVID-19 with psychological health and various coping styles, especially among oil and gas workers. This study aims to assess the prevalence of depression and anxiety among oil and gas workers, and subsequently examine the role of sociodemographic and occupational variables, various coping styles, and emotional distress in contributing to fear of COVID-19. A total of 299 oil and gas workers participated in this study. The DASS-21, Brief COPE, and Fear of COVID-19 (FCV-19) were used to assess the research variables. The descriptive analyses of DASS-21 indicated a prevalence of 26.8%, 33.5%, and 17.1% for depression, anxiety, and stress, respectively, among oil and gas workers. The results also indicated that all types of coping styles (problem-oriented, emotion-oriented, and dysfunctional-oriented) were significant predictors of fear of COVID-19. Sociodemographic and occupational variables and emotional distress variables were not significant predictors of fear of COVID-19. The study suggests how crucial it is for occupational mental health surveillance and prompt intervention for oil and gas workers
E-SERVICE QUALITY ATTRIBUTES THAT INFLUENCES ONLINE PURCHASE INTENTION OF HARD LUXURIES AMONG GENERATION Y CONSUMERS IN MALAYSIA: THE MEDIATING ROLE OF E-SATISFACTION.
No full textMany department stores, jewellery and watch specialist stores closed due to the COVID-19 pandemic in 2020 and 2021. To sustain the revenue of these businesses many of these stores turn to e-commence. Research Problem: As Generation Y consumers’ in Malaysia represent a greater potential for these businesses, there was a lack of understanding of their online buying behaviour for Hard Jewellery especially during the early days of COVID19 pandemic. Research Objectives: (1)To study the relationship between the attributes for e-service quality and customer satisfaction of hard luxury online stores among Generation Y consumers; (2) To identify the relationship between customer e-satisfaction and online purchase intention of hard luxuries among Generation Y consumers and (3) To examine the mediating effect of customer e-satisfaction between attributes of e-service quality and the online purchase intention of hard luxuries among Generation Y consumers. The study was conducted on Generation Y customers consist of male and female Malaysians between 25 and 40 years old who had visited, purchased or used the services provided by hard luxury goods retailers online at least once; a pilot study was conducted prior the actual survey to test the validity and reliability of the research instrument; a convenient sample of 200 respondents was collected via a Google Form online questionnaire, where the link was shared on Facebook, WhatsApp and email, and MS Excel was used to sort the primary data. The data analysis was conducted with the help of Structural Equation Modeling (SEM) with partial least squares (PLS) analysis using the SmartPLS 3.0 software and SmartPLS was used to generate T-statistics for significance testing of both the inner and outer model. Result Outcomes: The study established that Website design, Customer Service and Fulfillment had an effect on customer e-satisfaction which had an effect on online purchase intention during the pandemic but security/privacy does not have a significant and positive effect on customer e-satisfaction and does not affect online purchase intention. Henceforth, customer e-satisfaction does not mediate the relationship between security/privacy and online purchase intention in the study
Effects of Property Construction Cost Increase during Covid-19 Pandemic
No full textThe development of the property sector can significantly influence socio-economic growth and infrastructure development as an essential part of the construction industry. But the sudden COVID-19 pandemic has had severe, and far-reaching effects felt all over the world. Controls on movement, slower circulation of human and material resources and blockades on entry and exit have affected almost all sectors, including the construction industry. For property construction, the increase in costs is a vital issue. The increase in costs due to the pandemic has held back development, and it is essential to minimise the rise in costs. The point of cost increase needs to be explored in terms of its effects on property construction. As this study is more closely related to property construction, an online questionnaire was distributed to property developers, contractors and quantity surveyors in Kuala Lumpur and Selangor to obtain their views. The primary data collected was analysed using statistical tools such as the one sample T-test. The study results indicated that the most significant effect on property construction due to the increased costs of the COVID-19 pandemic was due to funding shortages and financial distress, followed by the credit crisis and more conflict
Photosynthetic Microbes as Bioindicator for Nanoparticles in Aquatic Environment: A Review
No full textThe intensive usage of nanoparticles such as Ag, ZnO, and TiO2 in industries inevitably leads to environmental pollution, especially in the water ecosystem. The bio-uptake and accumulation of nanoparticles in aquatic environments can lead to dire consequences to the flora and fauna, thereby affecting the whole food chain. Photosynthetic microorganisms such as microalgae and cyanobacteria are found abundantly in the natural environment which may be affected by the presence of nanoparticles in the environment, due to their high sensitivity to the presence of pollutants. The present review highlighted the photosynthetic responses after exposure of microalgae and cyanobacteria to these nanoparticles. The different parameters studied on the photosynthetic responses are algal growth, chlorophyll fluorescence emission, algal biomass, primary metabolic content (carbohydrates, lipids, and protein), and the microscopic examination of algae after exposure were summarized and discussed. The effective concentration of microalgae and cyanobacteria was also further investigated in determining the algae with the highest sensitivity as the best potential bioindicator for nanoparticle toxicity in an aquatic environment
Review on the challenges of hybrid propulsion system in marine transport system
No full textHybrid propulsion systems have become more widely available as electrical systems and power supply equipment have become more integrated into maritime transportation over the past few decades. These benefits include improved compliance with international regulations, enhanced flexibility and reliability and decreased operating and maintenance costs. A key component in improving the performance of marine vessels' hybrid propulsion systems is the Battery Energy Storage System (BESS). The optimal sizing and operation must be ensured in order to fully use the installation of BESS onboard ships. This is one of the challenges associated with applying BESS in hybrid propulsion systems. This study presents a comprehensive overview of the challenges in implementing BESS to the hybrid propulsion systems found on modern commercial ships. Additionally, various technologies and the advantages of the BESS are covered. This paper concludes by addressing the future development of BESS control and performance to tackle increasingly challenging issues in the maritime transport hybrid propulsion system