• Asian-Australasian Journal of Animal Sciences
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• 제18권10호
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• pp.1403-1406
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• 2005

The present study was undertaken to study the effect of thermal stress on sexual behaviour of superovulated ewes. Fourteen adult Bharat Merino ewes with an average body weight of 29.4${\pm}$2.34 kg were randomly allocated into two groups of 7 each. All the animals were grazed on natural pasture in the morning and evening hours and housed in shed during night. Animals of Group-1 were housed in shed from 10:00 to 16:00 h while the animals of Group-2 were exposed to thermal stress in a hot chamber ($40^{\circ}C$ /6 h/day). All the animals were offered drinking water once a day at 16:30 h. Meteorological observations i.e. dry bulb, wet bulb, minimum and maximum temperature were recorded daily inside the shed as well as in hot chamber throughout the experimental period. For superovulation of animals, standard protocol developed at the Institute, using FSH (Ovagen 5.4 mg in eight injections) and PMSG (200 IU) was followed. Various sexual behaviour parameters (circling, tail fanning, head turning, standing and approaching to ram) and estrus incidence (onset of estrus and estrus duration) were observed in both the groups. The different estrus symptoms were graded subjectively on arbitrary scale of 0-5 where 0 representing no sexual behaviour (0%) and 5 representing maximum intensity in sexual behaviour (100%). Estrus was detected with the help of a marked aproned ram of proven vigor at six hourly intervals. The average percent values for sexual behaviour parameters recorded in Group-1 and Group-2 animals were 53.7${\pm}$3.76 vs. 41.1${\pm}$2.18 for circling, 71.8${\pm}$5.42 vs. 49.0${\pm}$4.41 for tail fanning, 64.7${\pm}$3.30 vs. 44.5${\pm}$4.34 for head turning, 90.1${\pm}$3.16 vs. 75.8${\pm}$4.02 for standing and 63.8${\pm}$4.8 vs. 41.9${\pm}$4.58 for approaching to ram. Animals exposed to thermal stress had significantly lower values of these sexual behaviour parameters. The animals kept in shed exhibited estrus earlier (25.4${\pm}$1.12 h) and duration was higher (37.7${\pm}$1.59 h) as compared to animals exposed to thermal stress i.e. 30.6${\pm}$1.16 h and 31.7${\pm}$3.57 h, respectively. The findings of the study indicate that thermal stress reduces the intensity of sexual behaviour in ewes and may result in failure of the animal to mate and conceive.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.455-456
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• 2010

• Structural Engineering and Mechanics
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• 제62권5호
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• pp.595-606
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• 2017

During their life span, post-tensioned concrete structures may be exposed to thermal loads. Therefore, there has been a growing interest in research on the advanced analysis and design of post-tensioned concrete slabs subjected to thermal loads. This paper investigates the structural behaviour of post-tensioned one-way spanning concrete slabs. A nonlinear finite element model for the analysis of post- tensioned unbonded and bonded concrete slabs at elevated temperatures was developed. The interface between the tendon and surrounding concrete was also modelled, allowing the tendon to retain its profile shape during the deformation of the slab. The load-deflection behaviour, load-force behaviour in the tendon, and the failure modes are presented. The numerical analysis was conducted by the finite element ANSYS software and was carried out on two different one-way concrete slabs chosen from literature. A parametric study was conducted to investigate the effect of several selected parameters on the overall behavior of post-tensioned one-way concrete slab. These parameters include the effect of tendon bonding, the effect of thermal loading and the effect of tendon profile. Comparison between uniform thermal loading and nonuniform thermal loading showed that restrained post tensioned slab with bottom surface hotter has smaller failure load capacity.

• 한국생산제조학회지
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• 제5권4호
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• pp.90-97
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• 1996

The thermal deformation of a machine tool spindle influences the performance of the manufacturing systems for precision products. In this research, thermal analysis of a high speed machine tool spindle with the rolling bearing and the built-in motor is carried out by using Finite Difference Method. The thermal boundary conditions describing the heat generation in the bearing and built-in motor are considered in the simulation. And various convective boundary conditions are assumed with the empirical formula in the references. From the simulation results, the characteristics of each element affecting the dynamic thermal behaviour of the machine tool spindle system have been clarified. Therefore, this model can be well applied to the future development of the high speed spindle systems.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1995년도 춘계학술대회 논문집
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• pp.9-16
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• 1995

The thermal deformation of machine tool spindle influences the performance of the manufacturing systems for precision products. In this research thermal analysis of a high speed machine tool spindle with the rolling bearing and the built-in motor is carried out using Finite Difference Method. The thermal boundary conditions describing the hear generation in the bearing and built-in motor are considered in the simulation. And various convective boundary conditions are assumed with the empirical formula in the references. From the simulation results the characteristics of each element affecting the dynamic thermal behaviour of the machine tool spindle systems have been clarified. This model can be well applied to the future development of the high speed spindle systems.

• Tribology and Lubricants
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• 제5권2호
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• pp.42-47
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• 1989

The thermal behaviour of layerd solids, typified in practice by surface coated materials, is evaluated for the specific case of a fast moving heat source. This is intended to represent the particular instance of solids in sliding contact and the consequences of friction. The finite difference method has been utilised to establish the temperature distributions at the surface and also the sub-surface region for coating materials which are either less conductive or more conductive than the substrate to which they are attached. The effects of variation in layer thickness, and also the load, speed and friction coefficient, are evaluated.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.45-50
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• 2000

While braking cars, a large amount of energy is taken into the brake system in a short period of time. This leads to some problems ; cracking of the disc, non-uniform wear of pad and disc, fade. Thus it is important to measure the contact thermal behaviour precisely between disc and pad. The measurements must be considered to design the brake system. The paper describes methods to analysis the problem of the thermal behavior on the ventilated disc with ANSYS-a program of FEA and a brake dynamometer. According to this way, the paper can present the error between the data by the dynamometer and the results of analysis by ANSYS.

• Nuclear Engineering and Technology
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• 제54권7호
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• pp.2367-2375
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• 2022

In this work, we propose a new mechanistic model for the treatment of helium behaviour at the grain boundaries in oxide nuclear fuel. The model provides a rate-theory description of helium inter-granular behaviour, considering diffusion towards grain edges, trapping in lenticular bubbles, and thermal resolution. It is paired with a rate-theory description of helium intra-granular behaviour that includes diffusion towards grain boundaries, trapping in spherical bubbles, and thermal re-solution. The proposed model has been implemented in the meso-scale software designed for coupling with fuel performance codes SCIANTIX. It is validated against thermal desorption experiments performed on doped UO₂ samples annealed at different temperatures. The overall agreement of the new model with the experimental data is improved, both in terms of integral helium release and of the helium release rate. By considering the contribution of helium at the grain boundaries in the new model, it is possible to represent the kinetics of helium release rate at high temperature. Given the uncertainties involved in the initial conditions for the inter-granular part of the model and the uncertainties associated to some model parameters for which limited lower-length scale information is available, such as the helium diffusivity at the grain boundaries, the results are complemented by a dedicated uncertainty analysis. This assessment demonstrates that the initial conditions, chosen in a reasonable range, have limited impact on the results, and confirms that it is possible to achieve satisfying results using sound values for the uncertain physical parameters.

• 화약ㆍ발파
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• 제29권1호
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• pp.34-40
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• 2011

본 연구에서는 가곡광산 화강암의 변형거동에 열응력과 수압이 미치는 영향을 평가하였다. 열응력과 수압이 미치는 영향을 해석하기 위하여 화강암 시험편에 열을 가하여 200, 300, 400, 500, 600, $700^{\circ}C$ 예열시험편을 제작하였고, 500, 600, $700^{\circ}C$ 예열시험편에 7.5MPa의 수압을 가하였다. 예열시험편에 대한 일축압축시험 결과 예열온도가 증가함에 따라 시험편의 축변형률 및 횡변형률이 증가하는 것으로 나타났으며 특히 $600^{\circ}C$ 이상 시험편에서 변형률의 증가가 현저한 것으로 나타났다. 온도에 따라 시험편의 일축압축강도와 탄성계수는 지수적으로 감소하는 것으로 측정되었다. 수압을 받은 시험편은 그렇지 않은 시험편에 비해 비탄성적인 변형거동이 큰 것으로 나타났으며 이는 수압이 예열시험편 내에 존재하는 균열의 확장과 개구에 영향을 미친다는 것을 뜻한다.

• Computers and Concrete
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• 제21권6호
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• pp.637-647
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• 2018

Numerical approach using finite element method has been used to evaluate the behaviour of reinforced concrete frame structure subjected to fire. The structure is previously designed in accordance with Eurocode standards for the design of structures for earthquake resistance, for the ductility class M. Thermal and structural response are obtained using a commercially available software ANSYS. Temperature-dependent nonlinear thermal and mechanical properties are adopted according to Eurocode standards, with the application of constitutive model for the triaxial behaviour of concrete with a smeared crack approach. Discrete modelling of concrete and reinforcement has enabled monitoring of the behaviour at a global, as well as at a local level, providing information on the level of damage occurring during fire. Critical regions in frame structures are identified and assessed, based on temperatures, displacements, variations of internal forces magnitudes and achieved plastic deformations of main reinforcement bars. Parametric analyses are conducted for different fire scenarios and different types of concrete aggregate to determine their effect on global deformations of frame structures. According to analyses results, the three-dimensional finite element model can be used to evaluate the insulation and mechanical resistance criteria of reinforced concrete frame structures subjected to nominal fire curves.