114 research outputs found

    Proposed Framework to Investigate Perceived Alternative Job Opportunities as a Moderator on the Relationship between Job Embeddedness, Pay Satisfaction and Actual Voluntary Turnover

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    Globally, the issue of actual voluntary turnover is a phenomenon that hinders organisations from accomplishing objectives. While prior studies have examined several factors that elucidate why employees voluntarily quit their jobs, however, only a handful have made efforts to link job embeddedness and pay satisfaction. In fact the few, if any reported conflicting results. Hence, as a contribution, this paper proposes a framework that explores the relationship between job embeddedness, pay satisfaction and actual voluntary turnover with a moderating role of perceived alternative job opportunities among former faculty members in Nigeria. Keywords: Actual voluntary turnover, job embeddedness, pays satisfaction, perceived alternative job opportunitie

    Mechanical Properties of Direct Recycling Metal Matrix Composite (MMC-AlR) AA7075 Aircraft Aluminium Alloy

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    Recycling of aluminium aerospace alloys represents a major challenge to both the aluminium and aerospace industries. Ecological manageability in assembling is these days is a dire and exceptional issue and the principle concerns are identified with increasingly proficient utilization of energy and materials. Recycling allowed saving large amount greenhouse gas emission, particularly in the case of aluminium. Metal matrix composites spur the possibility of advancing typical monolithic material properties. Offering great strength, lightweight and being able to withstand high temperatures are the main behaviours of the metal matrix composite. To that extent, many practitioners in either automotive or aerospace industries employed metal matrix composite in most of the critical parts. Forming metal matrix composite via solid state processing is considered innovative, as most of the metal matrix composite forming process took place either in liquid or gaseous processing. An experimental investigation was conducted to investigate the mechanical properties of a recycled aluminium shifting alumina sum from 1 to 5 wt. % that had been presented to recycled aluminium chip employing hot press forging. Aluminium chip was obtained by milling AA7075-T1 bulk to a certain parameter. The medium size chips were cleaned, dried and mixed with alumina particles before being poured into a closed-die mould. The main responses investigated were ultimate tensile strength and elongation to failure and microstructure analysis. Out of all fractions, 4 wt. % of alumina shows the highest Ultimate tensile strength when the value increased from 155.214 MPa (1 wt. %) to 187.183 MPa. Further addition of alumina would enhance the composite strength, but in contrary, it also could prone the material performance

    In silico annotation of the genes involved in biosynthesis of lipopolysaccharide for Burkholderia pseudomallei.

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    Burkholderia pseudomallei is the causative agent of melioidosis, a serious disease of man and animals. The high mortality of B. pseudomallei infections may cause by lipopolysaccharides, an endotoxin. The biosynthesis of LPS is complex comprising three components, lipid A, core ohgosaccharide and O-specific antigen. In the current study, by using the available B. pseudomallei genome database provided by Wellcome. The study demonstrated that the bioinformatics comparative technique was able to annotate LPS genes in Burkholderia pseudomallei. By developing a simple and easy flow chart including the using of Artemis software, total of 44 putative ORFs involved in biosynthesis of lipopolysaccharide for B. pseudomallei and the genetic mapping for the ORFs have been successfully determined using bioinformatics and laboratory approach. It is about 95.7% of success for annotation based on the 46 genes that act as references. In near future, a suitable vaccine or antimicrobial may be developed by targeting the genes encoding the various components essential in LPS biosynthesis and survival of the pathogen

    Fabrication Of TiOâ‚‚ Nanoflowers Powder with Various Concentration Of CTAB

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    Nanostructures titanium dioxide (TiOâ‚‚) such as nanoflowers and nanorods have contribute in many application. Among TiOâ‚‚ nanostructures, TiOâ‚‚ nanoflowers gives high surface area that contribute in good binding properties and reducing internal stress and increasing strength of the ceramics.This paper presents fabrication of TiOâ‚‚ nanoflowers powder to overcome the cracking problem in ceramic industry. In this study, fabricated rutile-phased TiOâ‚‚ nanoflower powder has been successfully synthesized by using hydrothermal method and the surface morphology, structural properties, and the composition of TiOâ‚‚ nanoflower powder also identified. The fabricated TiOâ‚‚ are characterized using Field Emission Scanning Electron Microscopy (FESEM) to observe the surface morphology of TiOâ‚‚, X-ray Dispersion (XRD) was used to determine the crystallite phase and EDX for element composition in fabricated TiOâ‚‚ powder. The synthesized TiOâ‚‚ powder was obtained from the reaction between deionized water (DI), hydrochloric acid (HCl), Titanium Butoxide (TBOT) and Cetyltrimethylammonium Bromide (CTAB). The hydrothermal temperature is 150  ÌŠC with fixed hydrothermal time of 10 hours. The parameters varied is the mass of surfactant used, CTAB. The hydrothermal method is proven suitable to fabricate semiconductor materials due to its advantages that parameters are easily modified and can be performed under closed system with low operational temperature. Increased amount of CTAB used make the gap between the nanorod become closer and stronger. The diffraction peaks of all sample hardly changed, but the intensity for each sample was enhanced as the mass of CTAB used increased. The structure also become well crystallined in rutile phase structure

    Hot extrusion followed by a hot ecap consolidation combined technique in the production of Boron Carbide (B4C) reinforced with aluminium chips (AA6061) composite

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    A new and promising MMC approach to the reduction of pollution, greenhouse effects, and emissions is to develop a technology related to materials composite forming. Hot extrusion followed by hot ECAP is a combination of solid-state recycling method (direct recycling) that consists of chip preparations, cold compaction, and hot extrusion, followed by the ECAP process. The developed process is used to consolidate the chips for direct chip recycling purposes without the remelting phase. In this study, finished or semi-finished products from B4C-reinforced particles and AA6061 aluminium chips were produced. The samples made by hot extrusion were compared with samples obtained from hot extrusion followed by the hot ECAP process in terms of mechanical properties. Additional plastic deformation by hot ECAP after hot extrusion significantly increased the mechanical properties of the MMC compared with the samples obtained from the hot extrusion only. The density and microstructure of the samples were also determined

    Methicillin-susceptible Staphylococcus aureus from clinical and community sources are genetically diverse.

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    Despite the association of methicillin-susceptible S. aureus (MSSA) with several life-threatening diseases, relatively little is known about their clinical epidemiology in Malaysia. We characterized MSSA isolates (n=252) obtained from clinical and community (carriage) sources based on spa sequencing and multilocus sequence typing (MLST). The prevalence of several important virulence genes was determined to further define the molecular characteristics of MSSA clones circulating in Malaysia. Among the 142 clinical and 110 community-acquired MSSA isolates, 98 different spa types were identified, corresponding to 8 different spa clonal clusters (spa-CCs). In addition, MLST analysis revealed 22 sequence types (STs) with 5 singletons corresponding to 12 MLST-CCs. Interestingly, spa-CC084/085 (MLST-CC15) (p=0.038), spa-non-founder 2 (MLST-ST188) (p=0.002), and spa-CC127 (MLST-CC1) (p=0.049) were identified significantly more often among clinical isolates. spa-CC3204 (MLST-CC121) (p=0.02) and spa-CC015 (MLST-CC45) (p=0.0002) were more common among community isolates. Five dominant MLST-CCs (CC8, CC121, CC1, CC45, and CC5) having clear counterparts among the major MRSA clones were also identified in this study. While the MSSA strains are usually genetically heterogeneous, a relatively high frequency (19/7.5%) of ST188 (t189) strains was found, with 57.8% of these strains carrying the Panton-Valentine leukocidin (PVL). Analysis of additional virulence genes showed a frequency of 36.5% and 36.9% for seg and sei and 0.8% and 6.3% for etb and tst genes, respectively. Arginine catabolic mobile element (ACME) was detected in 4 community isolates only. These represent the first isolates harbouring this gene in an Asian region. In conclusion, MSSA from the Malaysian community and their clinical counterparts are genetically diverse, but certain clones occur more often among clinical isolates than among carriage isolates and vice versa

    Efficient control of a nonlinear double-pendulum overhead crane with sensorless payload motion using an improved PSO-tuned PID controller

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    This paper proposes an efficient PID control of a highly nonlinear double-pendulum overhead crane without the need for a payload motion feedback signal. Optimal parameters of the PID controllers are tuned by using an improved particle swarm optimisation (PSO) algorithm based on vertical distance oscillations and potential energy of the crane. In contrast to a commonly used PSO algorithm based on a horizontal distance, the approach resulted in an efficient performance with a less complex controller. To test the effectiveness of the approach, extensive simulations are carried out under various crane operating conditions involving different payload masses and cable lengths. Simulation results show that the proposed controller is superior with a better trolley position response, and lower hook and payload oscillations as compared to the previously developed PSO-tuned PID controller. In addition, the controller provides a satisfactory performance without the need for a payload motion feedback signal

    Genes expression in biosynthesis Lipopolysaccharide of Burkholderia pseudomallei the causative agent of melioidosis.

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    Burkholderia pseudomallei is the causative agent of melioidosis, a serious disease of man and animals. The high mortality of B. pseudomallei infections may cause by Lipopolysaccharides (LPS), an endotoxin. The biosynthesis of LPS is complex comprising three components, lipid A, core oligosaccharide and O-specific antigen. In the current study was designed to further elucidate genes involved in the biosynthesis pathway of LPS in melioidosis agent followed with selected gene product expression with essential function for survival and virulence melioidosis agent. Expression of Bplps0013/lpxA and Bplps0007/rfaF successful expressed the entire proteins in 2 h with sizes of approximately 29 kDa and 43.7 kDa, respectively. The baseline information provided through the present research can be a preliminary approach towards the development of effective therapeutics against melioidosis

    Cloning sequencing and characterization of lipopolysaccharides genes of Vibrio alginolyticus

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    Bacterial lipopolysaccharides are the major outer surface membrane components present in almost all Gram-negative bacteria and act as extremely strong stimulators of innate or natural immunity in diverse eukaryotic species ranging from insects to humans. The DNA sequence of the O-antigen biosynthesis cluster of a putative probiotic and pathogenic strain, Vibrio alginolyticus has been determined. Here, we report the sequence of the LPS biosynthesis genes, wzm, wzt and wbil and the analysis of the genes using Biology Workbench 3.2. From the study, it shows that the sequences of LPS genes in V. alginolyticus are highly homologous to the LPS genes in Vibrio cholerae isolates with more 80% homology. However, several variants of the wbil sequence have been found in the V. alginolyticus isolates compared to the other genes, wzm and wzt

    Polymerase chain reaction and cloning of Burkholderia pseudomallei putative genes.

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    Total of 23 putative Open Read Farms from B. pseudomallei strain D286 was successfully cloned and the nucleotide sequence analysis of the putative genes showed the homologue (98-100%) to strain K96243. The high similarity in gene sequences between these strains is confirmed for presence of the necessary ORF for LPS biosynthesis through PCR amplification the application of the ORFs in the PCR amplification and expression method. The findings of this study have contributed to some information on the molecular bases of the LPS biosynthesis genes in B. pseudomallei specifically for strain D286. PCR amplification, a specific pair of primer for each ORFs was proving specific for amplification of genes in B. pseudomallei strain D286. The PCR mixture with addition of DMSO, formamide and glycerol could ease the PCR optimization where different pairs of primers were involved. The specific primer pairs with the PCR mixture could be used in developing a PCR diagnosis of melioidosis
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