83 research outputs found

    The schur multiplier of pairs of nonabelian groups of order p4

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    Let (G,N) be a pair of groups where G is any group and N is a normal subgroup of G, then the Schur multiplier of pairs of groups is a functorial abelian group. The notion of the Schur multiplier of pairs of groups is an extension from the Schur multiplier of a group G. In this research, the Schur multiplier of pairs of finite nonabelian groups of order p4, where p is an odd prime, is determined

    Patterned membrane in an energy-efficient tilted panel filtration system for fouling control in activated sludge filtration

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    A membrane bioreactor enhances the overall biological performance of a conventional activated sludge system for wastewater treatment by producing high-quality effluent suitable for reuse. However, membrane fouling hinders the widespread application of membrane bioreactors by reducing the hydraulic performance, shortening membrane lifespan, and increasing the operational costs for membrane fouling management. This study assesses the combined effect of membrane surface corrugation and a tilted panel in enhancing the impact of air bubbling for membrane fouling control in activated sludge filtration, applicable for membrane bioreactors. The filterability performance of such a system was further tested under variable parameters: Filtration cycle, aeration rate, and intermittent aeration. Results show that a combination of surface corrugation and panel tilting enhances the impact of aeration and leads to 87% permeance increment. The results of the parametric study shows that the highest permeance was achieved under short filtration-relaxation cycle of 5 min, high aeration rate of 1.5 L/min, and short switching period of 2.5 min, to yield the permeances of 465 ± 18, 447 ± 2, and 369 ± 9 L/(m2h bar), respectively. The high permeances lead to higher operational flux that helps to lower the membrane area as well as energy consumption. Initial estimation of the fully aerated system yields the energy input of 0.152 kWh/m3, much lower than data from the full-scale references of <0.4 kWh/m3. Further energy savings and a lower system footprint can still be achieved by applying the two-sided panel with a switching system, which will be addressed in the future

    Consumers' perception of automatic emergency braking (AEB): Theoretical model and construct development

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    Due to remarkable developments, various automated driving systems, known as Advanced Driver Assistance Systems (ADAS), have been implemented, and the entire range of human driver activity in modern vehicles is undergoing changes. However, whether or not the consumers will accept and satisfy the emerging technologies, especially Automatic Emergency Braking (AEB), remains a big question. Therefore, it is vital to understand how vehicle consumers or potential consumers decide to use or not to use, and what they expect or perceive of AEB. This work intends to review the published works on AEB to understand the current market of the technology. In order to investigate the user's perception, a developed theoretical model is planned to be adopted. The review was conducted by searching from Google Scholar and the ScienceDirect database through Universiti Malaysia Pahang online databases. The knowledge and understanding of the current AEB market and theoretical model will help researchers plan the next steps to explore consumer or potential consumer perception

    The characterization and thermo-physical property investigations of SiO2/HFE7000 nanorefrigerants

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    This paper presents the characterizations and thermo-physical properties investigation of SiO2/HFE7000 nanorefrigerants for 0.005–0.02% volume concentrations and temperature ranges of 283–303 K. SiO2 nanoparticles were dispersed in HFE7000 refrigerants by utilizing the two-step method. The measurements of thermal conductivity and dynamic viscosity were performed by using KD2 Pro Thermal Properties Analyzer and LVDV-III Rheometer, respectively. The SiO2/HFE7000 nanorefrigerants shows high stability with the SiO2 nanoparticles remains suspended when observed for more than 90 days. The thermal conductivity is found increases by concentrations, but decreases by temperature. The highest thermal conductivity enhancement of 27% is observed at 0.02% volume concentration. Meanwhile, the dynamic viscosity of SiO2/HFE7000 nanorefrigerants increases by volume concentrations however decreases by temperatures. The nanorefrigerants behaved as Newtonian fluids. As a conclusion, the present novel SiO2/HFE7000 nanorefrigerants have potential in various heat transfer applications with great stability and thermo-physical properties behaviours

    Judicial Review on the Loss of Land or Conflict of Land in the Criminal Law Perspective

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    [Full Paper] to pdf Copyright (c) 2020 Meraja journa

    The Schur multiplier of pairs of groups of order p3q

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    Let (G, N) be a pair of groups in which N is a normal subgroup of G. Then, the Schur multiplier of pairs of groups (G, N), denoted by M (G, N), is an extension of the Schur multiplier of a group G, which is a functorial abelian group. In this research, the Schur multiplier of pairs of all groups of order p3q where p is an odd prime and p<q is determined

    CO2 laser spot welding of thin sheets AISI 321 austenitic stainless steel

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    Purpose: The present work aims to investigate the influence of CO2 laser spot welding (LSW) parameters on welding profile and mechanical properties of lap joint of AISI 321 thin sheet metals, and analyze the welding profile numerically by finite element (FE) method. Design/methodology/approach: The weld carried out using 150 W CO2 continues wave laser system. The impact of exposure time and laser power on the welding profile was investigated using an optical microscope. Microhardness and tensile strength tests were used to evaluate the mechanical properties of the joint. Ansys software was utilized to simulate the welding profile numerically. Findings: The results revealed that 2 s exposure time and 50 W power have led to uniform welding profile and highest shear force (340 N), lower hardness gradient across the heat affected zone (HAZ) and fusion zone (FZ). Finite element (FE) analysis of the welding profile showed good agreement with experimental analysis. Research limitations/implications: The selection of laser spot welding parameters for thin sheet metal was critical due to the probability of metal vaporisation with extra heat input during welding. Practical implications: Laser welding of AISI 321 steel is used in multiple industrial sectors such as power plants, petroleum refinement stations, pharmaceutical industry, and households. Thus, selecting the best welding parameters ensures high-quality joint. Originality/value: The use of CO2 laser in continuous wave (CW) mode instead of pulse mode for spot welding of thin sheet metal of AISI 321 austenitic stainless steel consider a real challenge because of the difficulty of control the heat input via proper selection of the welding parameters in order to not burn the processed target. Besides, the maintenance is easier and operation cost is lower in continuous CO2 than pulse mode

    Magnetic probe measurements in INTI plasma focus to determine dependence of axial speed with pressure in neon

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    Current sheath dynamics generated in INTI plasma focus device operated with neon gas has been studied. A 3-Turn Rogowski coil design has been used to measure derivative current. A new magnetic probe was designed and used to study of current sheath arrival time, current profile and velocity variation in the axial phase at different experimental conditions. The current sheath's average velocity was found to vary with pressure-0.51 with a R2 value of 0.9 which agrees well with the theoretically expected variation of pressure -0.5
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