Conceptual Design Of Shielded Metal Arc Welding Workstation: Work Posture And Bead Dimension Consideration

The aim of this study was to propose a conceptual design of SMAW workstation which considered work postures of welders and weld bead dimensions. This study applied full factorial design of experiment. The independent variables were table height, table surface inclination, and work position whereas the dependent variables were bead height, bead width, and RULA score. Results of analysis of variance showed that the table height, table surface inclination, and work position had an effect on bead width and bead height. This study concluded that the proposed SMAW workstation can offer acceptable bead dimensions when it is designed with adjustable table height, flat table surface (0°), and standing work position. However, the work posture still requires further investigation

Comparative analysis of fliC Gene from Salmonella enterica sub-species for biosensor probe design and phylogenetic tree construction

In tandem to the Salmonellosis infection worldwide, a study was conducted to determine the conserved and nonconserved region in Salmonella enterica sub-species so that it can be used to design probes in biosensors for the detection of Salmonella enterica as a species or sub-species distinctively. The region was selected for this study through fliC gene that is present in all Salmonella sub-species, encodes the Salmonella flagella or flagellin determines the serotype due to its H antigen and provides virulence to the bacteria. All sub-species were analyzed in a group of six and then analyzed individually in groups of two with all possible combinations to determine the overlapping regions. Based on the study, the predominant conserved region for S. enterica sub-species is between 103 and 158, whereas the non-conserved region is from 1245 to 1285. A phylogenetic tree was constructed for the S. enterica sub-species to determine the evolution of the Salmonella sub-species

Effective Synthesis of Silicon Carbide Nanotubes by Microwave Heating of Blended Silicon Dioxide and Multi-Walled Carbon Nanotube

<div><p>Silicon carbide nanotube (SiCNTs) has been proven as a suitable material for wide applications in high power, elevated temperature and harsh environment. For the first time, we reported in this article an effective synthesis of SiCNTs by microwave heating of SiO2 and MWCNTs in molar ratio of 1:1, 1:3, 1:5 and 1:7. Blend of SiO2 and MWCNTs in the molar ratio of 1:3 was proven to be the most suitable for the high yield synthesis of β-SiCNTs as confirmed by X-ray diffraction pattern. Only SiCNTs were observed from the blend of MWCNTs and SiO2 in the molar ratio of 1:3 from field emission scanning electron microscopy imaging. High magnification transmission electron microscopy showed that tubular structure of MWCNT was preserved with the inter-planar spacing of 0.25 nm. Absorption bands of Si-C bond were detected at 803 cm-1 in Fourier transform infrared spectrum. Thermal gravimetric analysis revealed that SiCNTs from ratio of 1:3 showed the lowest weight loss. Thus, our synthetic process indicates high yield conversion of SiO2 and MWCNTs to SiCNTs was achieved for blend of SiO2 and MWCNTs in molar ratio of 1:3.</p></div