Finite Element Analysis of Spreader Bar by Utilizing the Arrangement and Connection of Padeyes

Heavy lifting is one of several methods used for marine installation of heavy equipment while spreader bar (SB) is widely used in heavy lifting. The application of SB is mainly to avoid an overstress in the structure when being lifts which due to sling arrangement in bridle. SB is typically made of high strength tubular pipe with padeye/trunnion attached. Comparison between 3 types of padeye arrangements on SB is made based on its strength properties as reflected in API RP 2A 22nd edition to ensure its optimum design centred on material’s weight and welding work criteria. The buckling load for lightest pipe among 3 types of SB is then calculated. Finite element analysis (FEA) is performed to verify design stresses and buckling load of selected pipe. From observation, the thickness of tubular pipe can be reduced up to 50 percent compared to other SB types by setting the centre line (CL) of upper padeye to be in line with tubular pipe axis

Characterization and optical properties of erbium oxide doped ZnO-SLS glass for potential optical and optoelectronic materials

Erbium doped ZnO–SLS (soda lime silica) glass system have been prepared by the conventional melt quenching technique. The physical, structural and optical properties are explained by analysing the data obtained from Energy Dispersive X-ray Fluorescence (EDXRF), density (ρ), molar volume (V m), X-ray diffraction (XRD), fourier transform infra-red (FTIR) and UV-visible (UV-Vis) results. The measured physical parameters like density and molar volume are found to vary linearly and exponentially with increasing Er2O3 content, respectively. X-ray powder diffractrogram show broad peaks which conforms glassy nature of the sample. FTIR spectroscopy reveals the presence of SiO4, ZnO4 and Er–O vibration groups in the glass samples. The optical absorption spectra were measured in the wavelength range from 300 to 800 nm and the optical band gaps were determined. The optical absorption spectra of Er3+ ions in these glasses show three bands and are assigned to the transitions level. It was found that the optical band gap decreases from 3.083 to 3.037 eV with an increase in Er2O3 concentration

Relationship between the Corynebacterium pseudotuberculosis, phospholipase D inoculation and the fertility characteristics of crossbred Boer bucks

The aim of this study was to investigate the effects of Corynebacterium pseudotuberculosis and phospholipase D (PLD) on buck's fertility, specifically, testosterone concentration, scrotal circumference and semen quality. Crossbred Boer goats (n=13) aged 12–14 months were divided into three groups. The first group (n=3) was inoculated with one ml sterile phosphate buffer saline subcutaneously into subaxillary area as the control. The second group (n=5) was inoculated with live C. pseudotuberculosis 1×109 cfu subcutaneously into subaxillary area. The third group (n=5) was inoculated with PLD 1 ml/20 kg BW intravenously into jugular vein. Blood collection was done twice a week over a period of three months for testosterone analyses. Semen was collected using electro-ejaculator once every two weeks whilst scrotal circumference was measured once every three weeks. Semen volume, semen pH and sperm progressive motility, concentration, live/dead percentage and morphology were evaluated. Bucks were euthanized three months' post inoculation and histopathological examination of the testicles and epididymis was performed. The results showed seven folds' significant decrease (P<0.05) in testosterone concentration in both C. pseudotuberculosis and PLD inoculated groups compared to the control. Semen volume, percentage of dead/live and abnormal sperm morphology showed significant increase (P<0.05) in both inoculated groups compared to the control. The following sperm defects were observed; tapered sperm, decapitated and knobbed head, thickened midpiece, distal and proximal droplet, sterilizing tail and folded tail. Scrotal circumference, semen pH, semen wave pattern, sperm motility and concentration showed significant decrease (P<0.05) in both inoculated groups compared to the control. The testicles showed varied degrees of degeneration and necrosis with shrunken seminferous tubules. In conclusion, testosterone concentration, scrotal circumference and semen quality were negatively affected in both inoculated groups. Moreover, percentages of live/dead and abnormal sperm morphology were also increased. The results suggest that both C. pseudotuberculosis and PLD had detrimental effects on buck's fertility

Synthesis and characterization of wollastonite glass-ceramics from eggshell and waste glass

Abundance of waste products disposed by communities has huge environmental impacts which lead to serious problems. Some waste products such as eggshells (ES) and soda lime silica (SLS) glass waste can be used as CaO and SiO2 resources to bring on new potentially CaSiO3, wollastonite glass ceramics (WGC) materials. Three samples labelled as S1, S2 and S3 with different compositions, each with of ES (15, 20, 25 weight%) and SLS glass (85, 80, 75 weight%) respectively, were prepared via solid state reaction method. All the samples were sintered at 800°C, 900°C and 1000°C. The elemental analysis of the raw materials and the WGC samples has been determined using the X-Ray Fluorescence (XRF) system where the experimental results show that the samples were mainly contained of CaO and SiO2. The density of the WGC samples increase linearly with the sintering temperatures. The XRD results reveal that the optimum crystalline phase of the WGC samples was at around 900°C

Comprehensive study on structural and optical properties of Tm2O3 doped zinc silicate based glass–ceramics

In this research, Tm2O3 doped zinc silicate based glass–ceramics were prepared by using conventional melt-quenching method and has been successfully derived from ZnO-WRHA glasses with control heat treatment process. The formation of zinc silicate phase affected by heat treatment process was investigated using X-ray diffraction. Fourier transform infrared reflection spectroscopy (FTIR) analysis was used to determine the crystallization of Zn2SiO4 in the glass matrix. FTIR analysis showed the appearance of Zn2SiO4 and SiO2 bands that supported the formation of Zn2SiO4 crystal phase in the glass matrix. The optical absorption and energy band gap of the glass and glass–ceramics was investigated using UV–Vis spectroscopy. The absorption edge shows the movement towards longer wavelength with increasing heat treatment temperature. Besides, the energy band gap decreased with the progression of heat treatment. This ability to enhance optical properties in glass–ceramics was expected to have bright future in the opto-electronics devices

Effect of sintering temperature on structural and morphological properties of europium (III) oxide doped willemite

Willemite- (Zn2SiO4-) based glass ceramics doped with various amounts of europium oxide (Eu2O3) were prepared by solid state melting and quenching method. Effect of sintering temperature (600–1000∘ C) on structural and morphological properties of the doped samples was investigated. Phase composition, phase evolution, functional groups, and microstructure analysis were, respectively, characterized using X-ray diffractometer (XRD), fourier transform infrared spectroscopy, field emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray. XRD analysis detected the presence of rhombohedral crystalline phase in the doped samples sintered at different temperatures. FE-SEM and bulk density results confirmed that doping of the willemite with Eu2O3 effectively enhanced densification. The microstructural analysis of the doped samples showed that the average grain size increased with the increase of sintering temperature

Evaluation of whole body vibration and back pain problem among Light Rapid Transit (LRT) drivers

A cross sectional study was conducted to evaluate whole body vibration (WBV) and back pain problem among light rail transit (LRT) driver. This study was carried out to determine exposure level of whole body vibration and identify back pain problem due to whole body vibration exposure among LRT driver. Standardized Nordic questionnaire was used for the analysis of musculoskeletal symptoms, to identify the prevalence of back pain, information about health history, working time duration, and working experiences was obtained from 52 drivers of light rail transit (LRT) train. HVM 100 Larson Davis was used to measure whole body vibration measurement of eight LRTs with different vehicle number. The measurement of whole body vibration was done during operation working time. The data collected from HVM 100 were transferred to the Blaze software for getting the vibration magnitude of the experiment while data collected from survey were analyzed by using Statistical Package for the Social Sciences (SPSS) for statistical analysis. The analysis of graph patterns and the differentiation of magnitude value from each LRT were studied to determine the exposure level of vibration. A high prevalence of back pain (82.7%) among LRT drivers was found and high daily exposure level was obtained. The finding showed that, there are relations between back pain and daily vibration exposure which resulted in a correlation coefficient of 0.709, with significant at α = 0.05. In conclusion, it was expected that the individuals subjected to the high vibration levels would tend to report back pain

Structural and optical properties of Er3+-doped willemite glass-ceramics from waste materials

The production of Er3+-doped willemite glass-ceramic using waste soda lime silica (SLS) glass was reported in this study. The precursor glass and glass-ceramics were prepared using conventional melt-quenching technique with empirical formula (Er2O3)x[(ZnO)0.5(SLS)0.5]1-x where x = 1 wt.% and sintered at various temperatures. The trend of density and the linear shrinkage of the glass-ceramic samples were increased with the progression of sintering temperature. The crystallization behaviour and surface morphology of the glass-ceramics was studied using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). It was revealed that at a lower sintering temperature (700 °C), the stable state of α-willemite (α-Zn2SiO4) phase was formed. Fourier transform infrared (FTIR) spectroscopy reveals that the presence of different functional groups in the samples. Three transition states of excitation were shown in UV–visible (UV–vis) spectra which arise from the ground state 4I15/2 to the excited states 4F7/2, 2H11/2, 4F9/2. Broad green emission at 557 nm under excitation 385 nm was obtained. These spectra reveal that the luminescence of the samples was increased with the progression of sintering temperature due to the presence of Er3+ ions into the willemite crystal. Such luminescence of glass and glass-ceramics are expected to have potential applications in optoelectronic devices

Fabrication and Crystallization of ZnO-SLS Glass Derived Willemite Glass-Ceramics as a Potential Material for Optics Applications

Willemite glass-ceramics were successfully derived from conventional melt-quench ZnO-SLS precursor glass by an isothermal heat treatment process. The effect of heat treatment temperatures on the physical properties was investigated by Archimedes principle and linear shrinkage. The generation of willemite crystal phase and morphology with increase in heat treatment temperature was examined by X-ray diffraction (XRD), Fourier transform infrared (FTIR), and field emission scanning electron microscopy (FESEM) techniques. X-ray diffraction revealed that the metastable -Zn 2 SiO 4 and thermodynamically stable zinc orthosilicateZn 2 SiO 4 phases can be observed at temperatures above 700 ∘ C. The experimental results indicated that the density and shrinkage of the glass-ceramic vary with increasing the sintering temperature. FTIR studies showed that the structure of glass-ceramic consists of SiO 2 and ZnO 4 units and exhibits the structural evolution of willemite glass-ceramics. The characteristic of strong vibrational bands can be related to the [SiO 4 ] 4− tetrahedron corresponding to reference spectra of willemite