2,727 research outputs found

    In situ imaging of microstructure formation in electronic interconnections

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    The development of microstructure during melting, reactive wetting and solidification of solder pastes on Cu-plated printed circuit boards has been studied by synchrotron radiography. Using Sn-3.0Ag-0.5Cu/Cu and Sn-0.7Cu/Cu as examples, we show that the interfacial Cu6Sn5 layer is present within 0.05 s of wetting, and explore the kinetics of flux void formation at the interface between the liquid and the Cu6Sn5 layer. Quantification of the nucleation locations and anisotropic growth kinetics of primary Cu6Sn5 crystals reveals a competition between the nucleation of Cu6Sn5 in the liquid versus growth of Cu6Sn5 from the existing Cu6Sn5 layer. Direct imaging confirms that the β-Sn nucleates at/near the Cu6Sn5 layer in Sn-3.0Ag-0.5Cu/Cu joints

    A simple method to screen for azo-dye-degrading bacteria

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    A stab-culture method was adapted to screen for azo dyes-decolorizing bacteria from soil and water samples. Decolorized azo dye in the lower portion of the solid media indicates the presence of anaerobic azo dyes-decolorizing bacteria, while aerobic decolorizing bacteria decolorizes the surface portion of the solid media. Of twenty soil samples tested, one soil sample shows positive results for the decolourisation of two azo dyes; Biebrich scarlet (BS) and Direct blue 71 (DB) under anaerobic conditions. A gram negative and oxidase negative bacterial isolate was found to be the principal azo dyes degrader The isolate was identified by using the Biolog identification system as Serratia marcescens

    Performance of Well Known Packet Scheduling Algorithms in the Downlink 3GPP LTE System

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    This paper investigates the performance of well known packet scheduling algorithms developed for single carrier wireless systems from a real time video streaming perspective. The performance evaluation is conducted using the downlink third generation partnership project long term evolution (3GPP LTE) system as the simulation platform. This paper contributes to the identification of a suitable packet scheduling algorithm for use in the downlink 3GPP LTE system supporting video streaming services. Simulation results show that, in the downlink 3GPP LTE system supporting video streaming services, maximum-largest weighted delay first (M-LWDF) algorithm outperforms other packet scheduling algorithms by providing a higher system throughput, supporting a higher number of users and guaranteeing fairness at a satisfactory level

    Strength improvement of lime-treated clay with sodium chloride

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    Lime stabilisation of organic clay has often been studied in the past. However, there is some evidence in the literature that the presence of high concentrations of organic matter in clay soil can lessen the chemical reaction between lime and clay minerals and can have detrimental effects on the engineering properties of soil. Hence, in this paper, the stress–strain behaviour and strength properties of organic soil treated with lime and sodium chloride (NaCl) are analysed. A soil mixture, prepared with 5% lime content and 1·5% humic acid, was stabilised with varying quantities of sodium chloride (0·5, 2·0 and 5·0%). Consolidated undrained and drained triaxial tests were carried out on specimens at curing periods of 7 and 28 d with applied confining pressures of 50 and 100 kPa. Scanning electron microscopy and X-ray diffraction analysis were used to observe the microstructural changes resulting from cementation materials. It was found that the introduction of sodium chloride improved considerably the strength properties of the lime-treated organic clay. The microstructural analysis also confirmed the presence of calcium silicate hydrate in a salt-treated organic clay, which was the main contributing factor to the enhanced engineering properties of the clay

    Characterization of an azo-dye-degrading white rot fungus isolated from Malaysia

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    Sixty-three local white-rot fungi were isolated from soil and wood samples on potato dextrose agar (PDA). All these isolates were screened for their ability to degrade 4 textile azo dyes;Ponceau 2R (C.I. 16450), Orange G (C.I. 16230), Direct Blue 71 (C.I. 34140) and Biebrich Scarlet (C.I. 26905). Out of 40 isolates that gave positive results, only 1 promising isolate which completely degrades all 4 dyes in the minimum amount of time was selected for further investigation. This isolate was sourced from University Putra Malaysia (UPM) Serdang campus.The isolate was tentatively identified as Coriolopsis sp. Strain arf5 based on the analysis of the internal transcribed spacer (ITS) region. Nutritional studies on defined solid medium showed that this isolate was only able to degrade the 4 azo dyes under nitrogen-limiting conditions and an additional carbon source (glucose) need to be added to provide sufficient energy for the degradation to occur. Various parameters were optimized

    Secondary metabolites, antioxidant, and antiproliferative activities of Dioscorea bulbifera Leaf Collected from Endau Rompin, Johor, Malaysia

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    Breast cancer is among the most commonly diagnosed cancer and the leading cause of cancer-related death among women globally. Malaysia is a country that is rich in medicinal plant species. Hence, this research aims to explore the secondary metabolites, antioxidant, and antiproliferative activities of Dioscorea bulbifera leaf collected from Endau Rompin, Johor, Malaysia. Antioxidant activity was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) assays, while the cytotoxicity of D. bulbifera on MDA-MB-231 and MCF-7 breast cancer cell lines was tested using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cell cycle analysis and apoptosis were assessed using flow cytometry analysis. Phytochemical profiling was conducted using gas chromatography-mass spectrometry (GC-MS). Results showed that methanol extract had the highest antioxidant activity in DPPH, FRAP, and ABTS assays, followed by ethyl acetate and hexane extracts. D. bulbifera tested against MDA-MB-231 and MCF-7 cell lines showed a pronounced cytotoxic effect with IC50 values of 8.96 μg/mL, 6.88 μg/mL, and 3.27 μg/mL in MCF-7 and 14.29 μg/mL, 11.86 μg/mL, and 7.23 μg/mL in MDA-MB-231, respectively. Cell cycle analysis also indicated that D. bulbifera prompted apoptosis at various stages, and a significant decrease in viable cells was detected within 24 h and substantially improved after 48 h and 72 h of treatment. Phytochemical profiling of methanol extract revealed the presence of 39 metabolites such as acetic acid, n-hexadecanoic acid, acetin, hexadecanoate, 7-tetradecenal, phytol, octadecanoic acid, cholesterol, palmitic acid, and linolenate. Hence, these findings concluded that D. bulbifera extract has promising anticancer and natural antioxidant agents. However, further study is needed to isolate the bioactive compounds and validate the effectiveness of this extract in the In in vivo model

    Correlation Between Cutting Force and Residual Stress in Dry End-Milling of Inconel HX

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    Residual stress in the end-milled subsurface can significantly affect the fatigue performance of end-milled material. In the end-milling process, the generation of residual stress is extremely complex, which is closely related to the spindle speed, feed per tooth and cutting force. Thus, it is crucial to elucidate the influence of spindle speed and feed per tooth on cutting force and residual stress, also the correlation between cutting force and residual stress in terms of spindle speed and feed per tooth. According to this, dry end-milling of Inconel HX was performed by climb-milling using Kennametal KYS40 solid ceramic end-mill. From this experimental test, cutting force and residual stress showed a U-shaped relationship with the increase of spindle speed, while cutting force and residual stress showed a linear relationship with the increase of feed per tooth. Furthermore, for low cutting force and residual stress, the focus should be on choosing the optimum combination of spindle speed (21,400 to 24,100 rpm) and feed per tooth (0.014 to 0.016 mm/tooth)

    Correlation Between Cutting Force and Residual Stress in Dry End-Milling of Inconel HX

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    Residual stress in the end-milled subsurface can significantly affect the fatigue performance of end-milled material. In the end-milling process, the generation of residual stress is extremely complex, which is closely related to the spindle speed, feed per tooth and cutting force. Thus, it is crucial to elucidate the influence of spindle speed and feed per tooth on cutting force and residual stress, also the correlation between cutting force and residual stress in terms of spindle speed and feed per tooth. According to this, dry end-milling of Inconel HX was performed by climb-milling using Kennametal KYS40 solid ceramic end-mill. From this experimental test, cutting force and residual stress showed a U-shaped relationship with the increase of spindle speed, while cutting force and residual stress showed a linear relationship with the increase of feed per tooth. Furthermore, for low cutting force and residual stress, the focus should be on choosing the optimum combination of spindle speed (21,400 to 24,100 rpm) and feed per tooth (0.014 to 0.016 mm/tooth)

    THE INFLUENCES OF JOB PERFORMANCE, WORK-LIFE BALANCE AND ORGANIZATIONAL JUSTICE ON EMPLOYEES’ CAREER SATISFACTION

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    Purpose of study: This study is conducted to identify the relationships between job performance, work-life balance and organizational justice towards employee's career satisfaction from one of the manufacturing companies in the north of Malaysia. Methodology: The study is done by utilizing a random sample of 240 employees in the company. Type of investigation is a correlation study and it is cross-sectional on time horizon. The unit of analysis is an individual level; therefore, all employees in the company have chances to serve as the participants in this study. Data has been analysed from 148 respondents. Results: Results show significant and positive relationships between job performance, work-life balance and organizational justice towards employees' career satisfaction. Organizational justice is the most significant factor in career satisfaction in this study (β=.83, p=.00). Other factors such as job performance (β=.71, p=.00), and work-life balance (β=.71, p=.00) also positively correlated with employees’ career satisfaction. Implications/Applications: These significant results imply that managers should provide good elements of justice in the company to raise the level of their employee's career satisfaction. At the same time, the employees should maintain a higher level of job performance as well as to manage the good working life balance in them

    Fisher profiles and perceptions of sea turtle-fishery interactions: case study of East Coast Peninsular Malaysia

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    The paper focuses on coastal fisheries, particularly examining sea turtle-fishery interactions and determining the socioeconomic profile and perception of local fishers about sea turtle issues along the East Coast of Peninsular Malaysia.Turtle fisheries, Nature conservation, Coastal fisheries, Man-induced effects, ISEW, Malaysia, Malaya, Pahang, Malaysia, Malaya, Kelantan, Malaysia, Malaya, Terengganu,
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