• Title/Summary/Keyword: Gradation

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Depth-dependent evaluation of residual material properties of fire-damaged concrete

  • Kim, Gyu-Jin;Kwak, Hyo-Gyoung
    • Computers and Concrete
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    • v.20 no.4
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    • pp.503-509
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    • 2017
  • In this study, fire-damaged concrete was investigated by a nonlinear resonance vibration (NRV) technique, in order to evaluate its residual material properties. For the experiments, five cubic concrete specimens were prepared and four of them were damaged at different temperatures using a furnace. With a thermal insulator wrapped at the sides of specimen, thermal gradation was applied to the samples. According to the peak temperatures and depths of the samples, nonlinearity parameters were calculated with the NRV technique before the tendency of the parameters was evaluated. In addition, compressive strength and dynamic elastic modulus were measured for each sample and a comparison with the nonlinearity parameter was carried out. Through the experimental results, the possibility of the NRV technique as a method for evaluating residual material properties was evaluated.

Up-gradation in Human Resource Management Practices for the Biotech Industry in India

  • Kumari, Neeraj
    • The Journal of Asian Finance, Economics and Business
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    • v.2 no.2
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    • pp.27-34
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    • 2015
  • The 21st century belongs to biotechnology as it made profound impact in the field of health, food, agriculture and environmental protection. India's biotechnology industry is poised to record substantial growth, perhaps even overtake the robust IT industry. The objectives of the study are to determine the existing HR practices in Biotech Industry and to understand the need for the up gradation in existing HR Policies. Conclusive and descriptive research design has been used. Data is collected from 122 employees in 23 companies of Biotech Industry. It was found that Biotechnology companies require managers with unique qualities. The lack of solid managerial training and the associated risk of failure often have long-term consequences for the careers of research professionals. The efforts to achieve excellence through a focus on learning, quality, teamwork, and reengineering are driven by the way organizations get things done and how they treat people. Biotech industry is trying to establish itself in India for last one decade but is not showing any phenomenal growth because they still do not valuing their human resource as much they should be.

A review of effects of partial dynamic loading on dynamic response of nonlocal functionally graded material beams

  • Ahmed, Ridha A.;Fenjan, Raad M.;Hamad, Luay Badr;Faleh, Nadhim M.
    • Advances in materials Research
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    • v.9 no.1
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    • pp.33-48
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    • 2020
  • With the use of differential quadrature method (DQM), forced vibrations and resonance frequency analysis of functionally graded (FG) nano-size beams rested on elastic substrate have been studied utilizing a shear deformation refined beam theory which contains shear deformations influence needless of any correction coefficient. The nano-size beam is exposed to uniformly-type dynamical loads having partial length. The two parameters elastic substrate is consist of linear springs as well as shear coefficient. Gradation of each material property for nano-size beam has been defined in the context of Mori-Tanaka scheme. Governing equations for embedded refined FG nano-size beams exposed to dynamical load have been achieved by utilizing Eringen's nonlocal differential law and Hamilton's rule. Derived equations have solved via DQM based on simply supported-simply supported edge condition. It will be shown that forced vibrations properties and resonance frequency of embedded FG nano-size beam are prominently affected by material gradation, nonlocal field, substrate coefficients and load factors.

Static stability analysis of axially functionally graded tapered micro columns with different boundary conditions

  • Akgoz, Bekir
    • Steel and Composite Structures
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    • v.33 no.1
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    • pp.133-142
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    • 2019
  • In the present study, microstructure-dependent static stability analysis of inhomogeneous tapered micro-columns is performed. It is considered that the micro column is made of functionally graded materials and has a variable cross-section. The material and geometrical properties of micro column vary continuously throughout the axial direction. Euler-Bernoulli beam and modified couple stress theories are used to model the nonhomogeneous micro column with variable cross section. Rayleigh-Ritz solution method is implemented to obtain the critical buckling loads for various parameters. A detailed parametric study is performed to examine the influences of taper ratio, material gradation, length scale parameter, and boundary conditions. The validity of the present results is demonstrated by comparing them with some related results available in the literature. It can be emphasized that the size-dependency on the critical buckling loads is more prominent for bigger length scale parameter-to-thickness ratio and changes in the material gradation and taper ratio affect significantly the values of critical buckling loads.

Comparative study on the bending of exponential and sigmoidal sandwich beams under thermal conditions

  • Aman, Garg;Mohamed-Ouejdi, Belarbi;Li, Li;Hanuman D., Chalak;Abdelouahed, Tounsi
    • Structural Engineering and Mechanics
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    • v.85 no.2
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    • pp.217-231
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    • 2023
  • The bending analysis of sandwich functionally graded (FG) beams under temperature circumstances is performed in this article utilizing Navier's solution-based parabolic shear deformation theory. For the first time, a comparative study has been carried out between the exponential and sigmoidal sandwich FGM beams under thermal conditions. During this investigation, temperature-dependent material characteristics are postulated. Both symmetric and unsymmetric sandwich examples have been studied. The effect of gradation law, gradation coefficient, and thickness scheme on beam behavior has been thoroughly investigated. Three possible temperature combinations at the top and bottom surfaces of the beam are also investigated. Beams with a higher proportion of ceramic to metal are shown to be more resistant to thermal stresses than beams with a higher proportion of metal.

Generating Safe Path with a Gradation Grid Map (점층적 격자지도를 이용한 안전한 경로 계획)

  • Choi, Sunglok;Lee, Jae Yeong;Lee, Yu-Cheol;Park, Seung-Hwan;Yu, Wonpil
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.11a
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    • pp.311-312
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    • 2009
  • $A^*$ 알고리즘을 이용한 경로 계획은 이동 로봇이나 게임 유닛이 주어진 환경에서 장애물과 충돌 없이 이동 가능한 경로를 찾는데 많이 사용된다. 그러나 $A^*$ 알고리즘은 출발 지점에서 목적 지점까지의 최단 거리를 갖는 경로를 찾는다. 두 지점 사이에 장애물이 있는 경우, 최단 경로는 보통 두 지점 사이의 장애물의 모서리를 스치는 경로이다. 따라서 로봇이나 게임 유닛이 최단 경로로 이동할 때, 장애물의 모서리에 부딪힐 수 있는 위험성이 커진다. 일반적인 격자 지도의 한 셀은 장애물이 있는 경우의 무한대의 비용과 장애물이 없는 경우의 비용을 갖는다. 본 논문에서는 장애물에 가까울수록 장애물이 없는 경우보다 높은 비용을 갖는 점층적 격자 지도(gradation grid map)를 이용한다. 점층적 격자 지도를 통해 $A^*$ 알고리즘은 장애물 근처의 높은 비용을 갖는 셀을 되도록 통과하지 않는 경로, 즉 보다 안전한 경로를 생성한다.