• 제목/요약/키워드: Physical components

검색결과 1,545건 처리시간 0.023초

LES에 의한 원관 내 난류의 유동 해석 (Large Eddy Simulation of Turbulent Pipe Flow)

  • 고상철
    • Journal of Advanced Marine Engineering and Technology
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    • 제27권3호
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    • pp.437-446
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    • 2003
  • A large eddy simulation (LES) is performed for turbulent pipe flow. The simulation code is constructed by using a general coordinate system based on the physical contravariant velocity components. The effects of grid fineness which can be well prediction of turbulent behavior in near wall region is investigated. The subgrid scale turbulent models are applied and validated emphasis is placed on the flow details of turbulent pipe flow The calculated Reynolds number is 360 based on the wall shear velocity and the inlet pipe diameter. The predicted turbulent statistics are evaluated by comparing with the DNS data of turbulent pipe flow Performed by Eggels et al. The agreement of LES with DNS data is shown to be satisfactory. The proper grid fineness of the well prediction of turbulent pipe flow is suggested and the turbulent behavior is analyzed by depict the contour plot of fluctuating velocity components.

Fractional order thermoelastic wave assessment in a two-dimension medium with voids

  • Hobiny, Aatef D.;Abbas, Ibrahim A.
    • Geomechanics and Engineering
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    • 제21권1호
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    • pp.85-93
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    • 2020
  • In this article, the generalized thermoelastic theory with fractional derivative is presented to estimate the variation of temperature, the components of stress, the components of displacement and the changes in volume fraction field in two-dimensional porous media. Easily, the exact solutions in the Laplace domain are obtained. By using Laplace and Fourier transformations with the eigenvalues method, the physical quantities are obtained analytically. The numerical results for all the physical quantities considered are implemented and presented graphically. The results display that the present model with the fractional derivative is reduced to the Lord and Shulman (LS) and the classical dynamical coupled (CT) theories when the fractional parameter is equivalent to one and the delay time is equal to zero and respectively.

Optimization of Lactic Acid Production in SSF by Lactobacillus amylovorus NRRL B-4542 Using Taguchi Methodology

  • Nagarijun Pyde Acharya;Rao Ravella Sreenivas;Rajesham Swargam;Rao Linga Venkateswar
    • Journal of Microbiology
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    • 제43권1호
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    • pp.38-43
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    • 2005
  • Lactic acid production parameter optimization using Lactobacillus amylovorus NRRL B-4542 was performed using the design of experiments (DOE) available in the form of an orthogonal array and a software for automatic design and analysis of the experiments, both based on Taguchi protocol. Optimal levels of physical parameters and key media components namely temperature, pH, inoculum size, moisture, yeast extract, $MgSO_4{\cdot}7H_20$, Tween 80, and corn steep liquor (CSL) were determined. Among the physical parameters, temperature contributed higher influence, and among media components, yeast extract, $MgSO_4{\cdot}7H_20$, and Tween 80 played important roles in the conversion of starch to lactic acid. The expected yield of lactic acid under these optimal conditions was 95.80% and the actual yield at optimum conditions was 93.50%.

A study on thermo-elastic interactions in 2D porous media with-without energy dissipation

  • Alzahrani, Faris;Abbas, Ibrahim A.
    • Steel and Composite Structures
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    • 제38권5호
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    • pp.523-531
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    • 2021
  • The generalized thermoelastic analysis problem of a two-dimension porous medium with and without energy dissipation are obtained in the context of Green-Naghdi's (GNIII) model. The exact solutions are presented to obtain the studying fields due to the pulse heat flux that decay exponentially in the surface of porous media. By using Laplace and Fourier transform with the eigenvalues scheme, the physical quantities are analytically presented. The surface is shocked by thermal (pulse heat flux problems) and applying the traction free on its outer surfaces (mechanical boundary) through transport (diffusion) process of temperature to observe the analytical complete expression of the main physical fields. The change in volume fraction field, the variations of the displacement components, temperature and the components of stress are graphically presented. Suitable discussion and conclusions are presented.

Effect of two-temperature in an orthotropic thermoelastic media with fractional order heat transfer

  • Lata, Parveen;Himanshi, Himanshi
    • Composite Materials and Engineering
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    • 제3권3호
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    • pp.241-262
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    • 2021
  • In this article, we studied the effect of two-temperature in a two-dimensional orthotropic thermoelastic media with fractional order heat transfer in generalized thermoelasticity with three-phase-lags due to thermomechanical sources. The boundary of the surface is subjected to linearly distributed and concentrated loads (mechanical and thermal source). The solution of the problem is obtained with the help of Laplace and Fourier transform techniques. The expressions for displacement components, stress components and conductive temperature are derived in transformed domain. Numerical inversion technique is used to obtain the results in physical domain. The effect of two-temperature on all the physical quantities has been depicted with the help graphs. Some special cases are also discussed in the present investigation.

Open Space Design Elements and Social Support Design In Healing Facilities

  • Kim, Sunyoung
    • International Journal of Advanced Culture Technology
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    • 제10권2호
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    • pp.53-61
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    • 2022
  • This study suggested the environmental components for open space in a healing environment based on the social support approach for integrating and enhancing users' activities and interactions. The physical environments of the open space in healing facilities should be suggested by social support design and support the interactions of various users. Particularly architectural environment conditions should reinforce the contribution to the revitalization of medical facilities based on improving the healing effect of patients through mutual exchange of users. The open space environment conditions influence users' healing process with physical design factors and users' interactions, and the flexible environments based on the social support that is crucial for circulation and mutual exchange of users. The open space transformation, integration of technology, and wayfinding system with color and signage also allow users to improve the space experience and easy access. The environmental components of open space design should include easy access for user inflow, flexible layout for comfort, access to outdoor spaces, integration of warm color schemes for relaxation, personalization of spaces with artwork, and visual interest through the use of textures and materials.

Effect of a five-week high-fat diet on serum-lipid composition and LPL mRNA expression in rat skeletal muscles

  • Cheon, Wookwang;Kim, Mijin
    • 운동영양학회지
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    • 제17권2호
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    • pp.49-55
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    • 2013
  • Our purpose was to investigate the effect of a 5-week high-fat diet on the body weight, blood components [triglycerides (TGs), free fatty acids (FFAs), and glucose], and lipoprotein lipase (LPL) mRNA expression in the skeletal muscles of rats. Body weight increased overtime in experimental and control groups without significant differences. In terms of the blood components, the density of TG was significantly lower in the high-fat diet group compared to the control, whereas FFA and glucose levels were similar in the two groups. Although the levels of glyceraldehyde 3-phosphate dehydrogenase(GAPDH) mRNA expression were similar between the groups, LPL mRNA expression was significantly higher in the high-fat diet group than that in the control group. The results of this study suggest that a high-fat diet enhances LPL mRNA expression, as well as possibly increases fat metabolism. For a better understanding of the relationship between diet patterns and fat metabolism, further analysis of genes related to the fat metabolism is warranted.

과학 교육 개혁 운동에 관련된 보고서 분석을 통한 과학 성취 개념의 재정의 (Science Achievement: Synthesis of Current Conceptions in Major Reform Documents in the United States and Korea)

  • 백성혜;이옥희
    • 한국초등과학교육학회지:초등과학교육
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    • 제18권2호
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    • pp.1-19
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    • 1999
  • Based on the analysis of commonalities and differences in the views of science achievement in major reform documents in the United States and Korea, an aggregated view of science achievement is presented in this paper Science achievement is conceived of in terms of science content and science process. The components of science content include: (a) concepts and theories I n physical, life, and earth and space science;(b) science, mathematics, and technology;(c) science in personal and social perspectives;(d)history and nature of science;and (e) unifying themes. The components of science process include: (a) scientific understanding;(b) scientific investigation;(c) scientific communication; and (d) scientific habits of mind. The components of science process.cut across and intersect with the components of science content. The components of science achievement overlap and are related to one another. Despite such an overlap, understanding the rot e that each component plays provides insight into its unique contributions as well as its interactions with other components. A definition of science achievement and identification of its components based on major reform documents provides a guideline for science assessment as well a s science teaching and learning.

일 농촌 지역 노인의 대사증후군 유병률과 관련요인 (Prevalence of the Metabolic Syndrome and Its associated Factors among Elders in a Rural Community)

  • 김봉정
    • 지역사회간호학회지
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    • 제24권2호
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    • pp.225-235
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    • 2013
  • Purpose: The purpose of this study is to identify the prevalence of the metabolic syndrome (MS) and factors associated with it among elders in a rural community. Methods: Data were collected from 683 subjects with a questionnaire, physical measurement, and blood test. The prevalence of the MS was determined by AHA/NHLBI and waist circumference cutoff points for Koreans. Results: The prevalence of the MS was 50.5% in total (41.6% in men, 56.3% in women) while the prevalence of 5 metabolic risk factors was 67.7% for elevated blood pressure, 51.0% for low HDL-cholesterol, and 50.2% for abdominal obesity. Risk factors associated with the prevalence of the MS included family history, BMI, and physical activity; significant factors associated with that of metabolic components included family history, BMI, smoking, drinking, and physical activity. Especially, a higher BMI was a strong risk factor of the prevalence of abdominal obesity as well as the MS and its components. Conclusion: The findings indicate that nurses should care for elders based on each metabolic component regarding its prevalence level and concentrate primarily on reducing elevated blood pressure, low HDL-cholesterol by controlling the main risk factor, abdominal obesity through lifestyle modification.

Physical Layer Security Scheme Based on Polarization Modulation and WFRFT Processing for Dual-polarized Satellite Systems

  • Luo, Zhangkai;Wang, Huali;Zhou, Kaijie
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권11호
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    • pp.5610-5624
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    • 2017
  • A novel scheme based on polarization modulation and the weighted fractional Fourier transform (PM-WFRFT) is proposed in this paper to enhance the physical layer security of dual-polarized satellite systems. This scheme utilizes the amplitude and phase of the carrier as information-bearing parameters to transmit the normal signal and conceals the confidential information in the carrier's polarization state (PS). After being processed by WFRFT, the characteristics of the transmit signal (including amplitude, phase and polarization state) vary randomly and in nearly Gaussian distribution. This makes the signal very difficult for an eavesdropper to recognize or capture. The WFRFT parameter is also encrypted by a pseudo-random sequence and updated in real time, which enhances its anti-interception performance. Furthermore, to prevent the polarization-based impairment to PM-WFRFT caused by depolarization in the wireless channel, two components of the polarized signal are transmitted respectively in two symbol periods; this prevents any mutual interference between the two orthogonally polarized components. Demodulation performance in the system was also assessed, then the proposed scheme was validated with a simulated dual-polarized satellite system.