• Title/Summary/Keyword: Temperature-dependent development model

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Frequency characteristics and sensitivity analysis of a size-dependent laminated nanoshell

  • Dai, Zuocai;Jiang, Zhiyong;Zhang, Liang;Habibi, Mostafa
    • Advances in nano research
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    • v.10 no.2
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    • pp.175-189
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    • 2021
  • In this article, frequency characteristics, and sensitivity analysis of a size-dependent laminated composite cylindrical nanoshell under bi-directional thermal loading using Nonlocal Strain-stress Gradient Theory (NSGT) are presented. The governing equations of the laminated composite cylindrical nanoshell in thermal environment are developed using Hamilton's principle. The thermodynamic equations of the laminated cylindrical nanoshell are obtained using First-order Shear Deformation Theory (FSDT) and Fourier-expansion based Generalized Differential Quadrature element Method (FGDQM) is implemented to solve these equations and obtain natural frequency and critical temperature of the presented model. The novelty of the current study is to consider the effects of bi-directional temperature loading and sensitivity parameter on the critical temperature and frequency characteristics of the laminated composite nanostructure. Apart from semi-numerical solution, a finite element model was presented using the finite element package to simulate the response of the laminated cylindrical shell. The results created from finite element simulation illustrates a close agreement with the semi-numerical method results. Finally, the influences of temperature difference, ply angle, length scale and nonlocal parameters on the critical temperature, sensitivity, and frequency of the laminated composite nanostructure are investigated, in details.

Temperature-dependent Development and Its Model of the Melon Aphid, Aphis gossypii Glover (Homoptera: Aphididae) (목화진딧물(Aphis gossypii Glover)의 온도발육과 발육모형)

  • 김지수;김용헌;김태흥;김정환;변영웅;김광호
    • Korean journal of applied entomology
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    • v.43 no.2
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    • pp.111-116
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    • 2004
  • The development of Aphis gossypii was studied at various constant temperatures ranging from 15 to 35$^{\circ}C$, with 60-70% RH, and photoperiod of 16:8 (L:D h). Mortality of A. gossypii was high in the early developmental stages, and at high temperatures. The total immature developmental period ranged from 4.6 to 11.5 days. The lower developmental threshold temperature and effective cumulated temperature for all immature stages were 5.0$^{\circ}C$ and 106.8 degree-day, respective. The nonlinear shape of temperature-dependent development was well described by the modified Sharpe and DeMichele model. The normalized cumulative frequency distributions of developmental period for each life stage were fitted to the three-parameter Weibull function.

NUMERICAL INVESTIGATION OF THE SPREADING AND HEAT TRANSFER CHARACTERISTICS OF EX-VESSEL CORE MELT

  • Ye, In-Soo;Kim, Jeongeun Alice;Ryu, Changkook;Ha, Kwang Soon;Kim, Hwan Yeol;Song, Jinho
    • Nuclear Engineering and Technology
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    • v.45 no.1
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    • pp.21-28
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    • 2013
  • The flow and heat transfer characteristics of the ex-vessel core melt (corium) were investigated using a commercial CFD code along with the experimental data on the spreading of corium available in the literature (VULCANO VE-U7 test). In the numerical simulation of the unsteady two-phase flow, the volume-of-fluid model was applied for the spreading and interfacial surface formation of corium with the surrounding air. The effects of the key parameters were evaluated for the corium spreading, including the radiation, decay heat, temperature-dependent viscosity and initial temperature of corium. The results showed a reasonable trend of corium progression influenced by the changes in the radiation, decay heat, temperature-dependent viscosity and initial temperature of corium. The modeling of the viscosity appropriate for corium and the radiative heat transfer was critical, since the front progression and temperature profiles were strongly dependent on the models. Further development is required for the code to consider the formation of crust on the surfaces of corium and the interaction with the substrate.

The Temperature-Dependent Development Characteristic of Predatory Natural Enemy, Propylea japonica Thunberg (Coleoptera: Coccinellidae) (꼬마남생이무당벌레[Propylea japonica (Thunberg)]의 온도발육모형)

  • Lee, Sang-Ku;Park, Bueyong;Jeon, Sung-Wook;Jeong, In-Hong;Park, Se-Keun;Kim, Jeong-Hwan;Ji, Chang-Woo;Lee, Sang-Bum
    • Korean Journal of Organic Agriculture
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    • v.25 no.4
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    • pp.861-873
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    • 2017
  • The present study was conducted to investigate the developmental characteristics of Propylea japonica Thunberg (Coleoptera : Coccinellidae), a predator of aphids under laboratory conditions. The development times of the egg and immature stages of Propylea japonica were investigated at ten constant temperatures(15, 17.5, 20, 22.5, 25, 27.5, 30, 32.5, 35 and $38{\pm}1^{\circ}C$; 14L:10D; $60{\pm}5%$ RH). Development time was longest at $17.5^{\circ}C$. The developmental periods of P. japonica from the time of egg oviposited to adult emergence was 36.9 days at $17.5^{\circ}C$, and it decreased ash temperature increasing. Threshold temperature of development and degree days of the P. japonica from egg to adult were $11.9^{\circ}C$ and 196.0 respectively. The Briere 2 and Lactin 2 modes were best fitted for all development stages. The distribution of completion of each development stage was explain relatively well that 2-parameter, 3-parameter and Logistic model except egg and pupal stage.

The Effect of Thermal Properties on Temperature Development of Concrete (열적성질을 고려한 콘크리트의 수화발열특성에 관한 연구)

  • Shon, Myung-Soo;Park, Yon-Dong;Kim, Hoon;Kim, Ho-Young;Lee, Yang-Soo;Kang, Suck-Hwa
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.97-102
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    • 1997
  • In this study, a predictive method which was modified from KIshi's model for the temperature development of concrete was developed by using mineral compounds of clinker and pozzolans. Temperature dependent heat generation of reaction was also considered. Specific heat considering the effect of mix proportion and temperature was calculated with experimental data in the literatures. Thermal conductivity considering the effect of mix proportion and temperature was experimentally investigated. Through this research it was found that the developed method considering thermal properties accurately predicted adiabatic temperature rise of concrete without the experiment. It was also found that the thermal conductivity of concrete could be predicted by the volume ratio of each component of mix proportion and was independent of temperature within the normal climatic range.

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Time Dependent Interaction between Electromagnetic Wave and Dielectric Barrier Discharge Plasma Using Fluid Model (유체 모델을 이용한 유전체 장벽 방전 플라즈마와 전자기파 간의 시간 의존적 상호 작용 분석)

  • Kim, Yuna;Oh, Il-Young;Jung, Inkyun;Hong, Yongjun;Yook, Jong-Gwan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.8
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    • pp.857-863
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    • 2014
  • In determining interaction between plasma and electromagnetic wave, plasma frequency and collision frequency are two key parameters. They are derived from electron density and temperature, which vary in an extremely wide range, depending on a plasma generator. Because the parameters are usually unknown, traditional researches have utilized simplified electron density model and constant electron temperature approximation. Introduction of plasma fluid model to electromagnetics is suggested to utilize relatively precise time dependent variables for given generator. Dielectric barrier discharge(DBD) generator is selected due to its simple geometry which allows us to use one dimensional analysis. Time dependent property is analyzed when microwave is launched toward parallel plate DBD plasma. Afterwards, attenuation tendency with the change of electron density and temperature is demonstrated.

Development and Evaluation of Statistical Prediction Model of Monthly-Mean Winter Surface Air Temperature in Korea (한반도 겨울철 기온의 월별 통계 예측 모형 구축 및 검증)

  • Han, Bo-Reum;Lim, Yuna;Kim, Hye-Jin;Son, Seok-Woo
    • Atmosphere
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    • v.28 no.2
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    • pp.153-162
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    • 2018
  • The statistical prediction model for wintertime surface air temperature, that is based on snow cover extent and Arctic sea ice concentration, is updated by considering $El-Ni{\tilde{n}}o$ Southern Oscillation (ENSO) and Quasi-Biennial Oscillation (QBO). These additional factors, representing leading modes of interannual variability in the troposphere and stratosphere, enhance the seasonal prediction over the Northern Hemispheric surface air temperature, even though their impacts are dependent on the predicted month and region. In particular, the prediction of Korean surface air temperature in midwinter is substantially improved. In December, ENSO improved about 10% of prediction skill compared without it. In January, ENSO and QBO jointly helped to enhance prediction skill up to 36%. These results suggest that wintertime surface air temperature in Korea can be better predicted by considering not only high-latitude surface conditions (i.e., Eurasian snow cover extent and Arctic sea ice concentration) but also equatorial sea surface temperature and stratospheric circulation.

Effects of Temperature on the Development and Reproduction of Matsumuraeses falcana (Lepidoptera: Tortricidae) (어리팥나방(Matsumuraeses falcana)의 발육과 생식에 미치는 온도의 영향)

  • Jeong Joon, Ahn;Eun Young, Kim;Bo Yoon, Seo; Jin Kyo, Jung
    • Korean journal of applied entomology
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    • v.61 no.3
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    • pp.435-447
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    • 2022
  • The soybean podborer, Matsumuraeses falcana (Lepidoptera: Tortricidae), is one of important pests in soybean crop. In the purpose of forecasting population dynamics of M. falcana, we investigated the effects of temperature on development of each life stage, adult longevity and fecundity of Matsumuraeses falcana at seven constant temperatures of 10, 13, 19, 22, 25, 28, and 31℃. Eggs hatched successfully at all temperature subjected. M. falcana developed from egg hatching to adult emergence at the tested temperatures except 10, 13, and 31℃. The developmental period of each life stage and adult longevity of M. falcana decreased as temperature increased. The lower developmental threshold (LDT) and thermal constant (K) from egg hatching to adult emergence of M. falcana were estimated by linear regression as 10.2℃ and 492.04DD, respectively. Lower and higher threshold temperature (TL and TH) were calculated by the Lobry-Rosso-Flandrois (LRF) and Sharpe-Schoolfield-Ikemoto (SSI) models. TL and TH from egg hatching to adult emergence using SSI model were 16.7℃ and 29.1℃. Thermal windows, i.e., the range in temperature between the minimum and maximum rate of development, of M. falcana was 12.4℃. We constructed the adult oviposition model of M. falcana using adult survivorship and fecundity. Temperature-dependent immature development and adult oviposition models will help constructing the population model of M. falcana and developing the strategies of integrated pest management in soybean fields.

The Development of Hazardous Waste Compact Dump incinerator for Low Emissions (저공해 compact 유해폐기물 dump 소각기 개발)

  • 전영남;채종성;정오진
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.6
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    • pp.653-663
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    • 2000
  • A lot of hazardous wastes are discharged as by-products of working process by industrial development. Hazardous wastes is physical characteristics of difficult destruction at hight temperature. Numerical simulation and combustion experiment performed of dump incinerator for hazardous waste incineration. For the numerical simulation, the SIMPLEST algorithm was used to ensure rapid converge A K-$\varepsilon$ model was incorporate for the enclosure of turbulence flow. Combustion model was used by ESCRS (extended simple chemically reacting system) model available of CHEMKIN thermodynamic data for the source term of species conservation equation or energy equation. Radiation model is used by six flux model. A parametric screening studies was carried out through numerical simulation and experiment. Residence time and concentration in the incinerator was strongly dependent on the parameters of mixture velocity, mixture equilibrium ratio, surrogate velocity and surrogate equilibrium ratio.

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