Identification of stressors and validation of a questionnaire survey to quantify the stress among Veterinary Students of India

Background As an intensive professional training program veterinary education presents high academic and non-academic stressors to students. Identifying the stressors responsible and measuring the stress among veterinary students can prove useful to design any coping strategies to safeguard the mental health of students. Methods With the aim to identify the stressors responsible, measure the level of stress, relation of stress with variables such as gender and family income 44 item based cross sectional questionnaire survey was designed and distributed among veterinary students of India. Results The questionnaire yielded high internal consistency. More than 95% students were found to be under stress. Maximum students reported high stress due to academic related stressors. Female students reported high overall stress, academic stress, and intrapersonal and interpersonal related stress than male students. Students with lower family incomes experienced more overall stress as well as family responsibilities related stress. Conclusions Gender, family income, academic stressors, intrapersonal, interpersonal and conflict related stressors, and social activities related stressors positively predicted the overall stress among the students and thus these factors can be given special emphasis while designing any stress combating or reducing measures for veterinary students of India.

Identification of stressors and quantification of stress among veterinary students in India using a cross-sectional questionnaire survey

As an intensive professional training program veterinary education presents high academic and non-academic stressors to students. Identifying the stressors responsible and measuring the stress among veterinary students can prove useful to design any coping strategies to safeguard the mental health of students. The study aimed to identify the responsible stressors, measure the level of stress caused by each kind of stressor, the relation of stress with variables such as gender and family income. For this, 44 items based cross-sectional questionnaire survey was designed and distributed among veterinary students of India. On statistical analysis, the questionnaire yielded high internal consistency. More than 95% of students were found to be under stress. Maximum students reported the highest stress due to academic-related stressors. Female students reported high overall stress, academic stress, and intrapersonal and interpersonal-related stress than male students. Students with lower family incomes experienced more overall stress as well as family responsibilities-related stress. Gender, family income, academic stressors, intrapersonal, interpersonal, and conflict-related stressors, and social activities-related stressors positively predicted the overall stress among the students and thus these factors should be given special emphasis while designing any stress combating or reducing measures for veterinary students of India.

Recycling Al-Si Alloy by Semisolid Material Dragged during Continuous-Casting Strip Processing

Recycled Al–Si (9.2%) alloy contaminated with Fe (0.3%), Pb (3.1%) and Sn (11.4 %) was cast and poured at 650 oC, approximately 50 oC above the liquidus line. A cooling slope was used to obtain a semisolid material that feeds a ceramic nozzle designed to function as a good contact area for solidification and improve the quality of strip casting. The internally cooled material rolls in soluble oil (1 oil / 9 water) at a rate of 0.2 l/s and works as a heat exchanger which drags the metallic slurry puddle generated at the roll surface at a speed of 0.12 m/s. This forms a metallic strip with a thickness of 2 mm and a width varying from approximately 45 mm to 60 mm. The cooling system of the rolls, combined with four springs placed at the housing screw, prevented adhering of the metallic strip during production at a pressure of approximately 450 N. Cracks were observed on the strip surfaces; however, these defects did not interrupt the continuous flow of the solidified strip during manufacturing. The strip’s poor surface quality could be related to the Pb and Sn contamination as well as cold cracks due to the low pouring temperature. Al-Si eutectics positioned at a grain boundary of α-Al globular structures, as well as the presence of a Sn phase, resulted in a metallic strip with a yield stress, maximum stress and elongation of 94.5 MPa, 100.2 MPa and 1.6%, respectively.

Predicting Probability of Liquefaction Susceptibility based on a wide range of CPT data

In the present study, three efficient soft computing techniques i.e. GP, RVM, and MARS are utilized to predict the probabilistic liquefaction susceptibility of soils based on reliability analysis. For this, a sum of 253 Cone Penetration Test (CPT) data of nineteen major earthquakes occurred between 1964 and 2011 has been collected from the literature. Six liquefaction parameters such as corrected cone penetration resistance, total vertical stress, total effective stress, maximum horizontal acceleration, magnitude moment, and depth of penetration. To evaluate the overall performance of the proposed models, rank analysis has been carried out. Based on the values of performance indices, the GP model outperforms the other two models in terms of RMSE=0.15, R2 =0.77, and VAF=76.86 in the training stage while the same has been found 0.14, 0.81, and 80.46 in the testing phase. Also, the Rank Analysis confirms the superiority of the GP model in predicting the probability of liquefaction susceptibility of soils at all stages.

Identification of the haemodynamic environment permissive for plaque erosion

Endothelial erosion of atherosclerotic plaques is the underlying cause of approximately 30% of acute coronary syndromes (ACS). As the vascular endothelium is profoundly affected by the haemodynamic environment to which it is exposed, we employed computational fluid dynamic (CFD) analysis of the luminal geometry from 17 patients with optical coherence tomography (OCT)-defined plaque erosion, to determine the flow environment permissive for plaque erosion. Our results demonstrate that 15 of the 17 cases analysed occurred on stenotic plaques with median 31% diameter stenosis (interquartile range 28–52%), where all but one of the adherent thrombi located proximal to, or within the region of maximum stenosis. Consequently, all flow metrics related to elevated flow were significantly increased (time averaged wall shear stress, maximum wall shear stress, time averaged wall shear stress gradient) with a reduction in relative residence time, compared to a non-diseased reference segment. We also identified two cases that did not exhibit an elevation of flow, but occurred in a region exposed to elevated oscillatory flow. Our study demonstrates that the majority of OCT-defined erosions occur where the endothelium is exposed to elevated flow, a haemodynamic environment known to evoke a distinctive phenotypic response in endothelial cells.

Design and analysis of a pressure vessel according to EU 2014/29

In this study, the production and analysis of a composite vessel were performed. The materials selected for the design of the composite materials were glass fiber/epoxy, carbon fiber/epoxy and Kevlar fiber/epoxy material. Anti-symmetric orientation angles of (30°-30°), (45°-45°), (60°-60°) and (75°-75°) were used for each material. In the design of the vessel, the total thickness of the wall is defined as 3 mm. The containers were modeled using the SOLIDWORKS package program with the wall thickness of 10 and 20 layers. The containers modeled are then analyzed to determine maximum deformation and maximum stress by using the ANSYS WORKBENCH 14.0 package program which analyzes according to the finite element method. While making solutions, a pressure of 1.65 MPa as the test pressure of the vessel was defined as hydrostatic from the inner surface of the vessel, and von-Mises stress and total deformations were determined. As a result of this study, it has been determined that a 60°-60° orientation angle is the most appropriate design angle considering both the deformation values and maximum stress. Maximum stress in the design of composite containers was far below the flow limit and remained within acceptable limits for shape changes.

PERANCANGAN DAN ANALISIS CARBODY LOKOMOTIF DENGAN METODE ELEMEN HINGGA

A locomotive is one of critical part in train set, because a locomotive had to bear a big load and has operational time which long enough. So in a locomotive design required more in depth analysis compared to the other means of transportation. The purpose of this research is to make a design locomotive carbody according to those standards applied and analyze stress happened to carbody locomotive designed. In the design of this to analyze carbody locomotive construction strength, the analysis are done using finite element methode(FEM) with help of Ansys software. The simulation of loads working on the structure was made approaching the real loading. Structure of locomotive carbody should be able to hold the loads working on carbody construction. From the design results locomotive carbody that have been made, this locomotive carbody sized length 19000 mm, width 2790 mm, and high 3700 mm. Materials that used for the locomotive carbody design isSS 400 and SM 490A with Yield stress of 245 MPa dan 325 MPa. The analysis results received a value of von mises stress maximum of 195,429 MPa that occurs at the part of the end of underframe (end center sill), where the sress value are still below of Yield stress materials which are in the form of SM 490 at 325 MPa. From the analysis result suggests that overall locomotive carbody structure can be expressed as safe and able to hold the loads operational.

Flexural Damage of Honeycomb Paperboard—A Numerical and Experimental Study

This paper presents an experimental and numerical analysis using the finite element method (FEM) of the bending of honeycomb-core panel. Segments of honeycomb paperboard of several thicknesses were subjected to four-point flexure tests to determine their bending stiffness and maximum load. Several mechanical properties of orthotropic materials were taken into account to account for the experimental results. The numerical analysis of the damage prediction was conducted by using well-known failure criteria such as maximum stress, maximum strain and Tsai-Wu. The present study revealed how to model the honeycomb panel to obtain curves close to experimental ones. This approach can be useful for modelling more complex structures made of honeycomb paperboard. Moreover, thanks to the use of variously shaped cells in numerical models, i.e., the shape of a regular hexagon and models with a real shape of the core cell, results of the calculation were comparable with the results of the measurements. It turned out that the increase of maximum loads and rise in stiffness for studied samples were almost either linearly proportional or quadratically proportional as a function of the panel thickness, respectively. On the basis of failure criteria, slightly lower maximum loads were attained in a comparison to empiric maximum loads.

Modeling and Analysis of Piston using Various Piston Crown Geometries

Piston is the essential part of an IC engine and due to increase in manufacturing of automobiles of various types based on performance and power, the piston of an IC engine is under significant stress which causes wear of the piston. Piston is under mechanical and thermal loads due to combustion of the fuel and generation of high pressure gases. To reduce the damage incurred on an IC piston by the combustion of fuel the crown geometry of the piston can be modified. This reduces the wear incurred on an IC engine piston and increases the life of the IC engine piston. To understand the impact of mechanical loads on the piston static structural analysis has to be performed and to understand the impact of thermal loads, thermal analysis has to be performed. In this paper we have modeled three dimensional pistons with four different crown geometries using CATIA and performed static structural and thermal analysis in ANSYS to find total deformation, equivalent (von-misses) stress, maximum shear stress, temperature and heat flux. So we can find the best crown geometry for the manufacturing of IC engine piston.

Comparison of bone biomechanical properties after bone marrow mesenchymal stem cell or alendronate treatment in an osteoporotic animal model

The aim of this study was to explore the effects of bone marrow mesenchymal stem cells (BMMSCs) and alendronate sodium (ALN) intervention on osteoporosis (OP). Sixty-eight 6-month-old healthy female Sprague Dawley (SD) rats were used to generate an OP model by removal of the ovaries. After 12 weeks, rats were treated with BMMSCs (BMMSC group) or ALN (ALN group) for 5 weeks. Serum type I collagen C terminal peptide (CTX_1), procollagen type I N-terminal propeptide (PINP), and bone alkaline phosphatase (BALP) were tested along with the femur bone density and other properties, including bone mineral density (BMD), BALP, percent trabecular area (BV/TV), trabecular thickness (Tb.Th), trabecular number (TbN), maximum load, maximum stress, maximum strain, and elastic modulus. BMD, BALP, BV/TV, Tb.Th, TbN, maximum load, maximum stress, maximum strain, and elastic modulus values were higher in the BMMSC group versus the ALN group relative to the control group (p < 0.05); CTX_1, PINP, trabecular separation (Tb.Sp), and osteoclast number (OC.N) were lowest in the BMMSC group versus the ALN group relative to the control group (p < 0.05). Both BMMSCs and ALN could improve the metabolic function and bone quality in osteoporotic mice while restoring the strength and toughness of bones. The intervention effects of BMMSCs are better than ALN in this model.