• 제목/요약/키워드: Heat Balance

검색결과 658건 처리시간 0.03초

Effects of Supplemental Levels of Saccharomyces cerevisiae Fermentation Product on Lactation Performance in Dairy Cows under Heat Stress

  • Zhu, W.;Zhang, B.X.;Yao, K.Y.;Yoon, I.;Chung, Y.H.;Wang, J.K.;Liu, J.X.
    • Asian-Australasian Journal of Animal Sciences
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    • 제29권6호
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    • pp.801-806
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    • 2016
  • The objectives of this study were to evaluate the effects of different supplemental levels of Saccharomyces cerevisiae fermentation product (SCFP; Original XP; Diamond V) on lactation performance in Holstein dairy cows under heat stress. Eighty-one multiparous Holstein dairy cows were divided into 27 blocks of 3 cows each based on milk yield ($23.6{\pm}0.20kg/d$), parity ($2.88{\pm}0.91$) and day in milk ($204{\pm}46d$). The cows were randomly assigned within blocks to one of three treatments: 0 (control), 120, or 240 g/d of SCFP mixed with 240, 120, or 0 g of corn meal, respectively. The experiment was carried out during the summer season of 2014, starting from 14 July 2014 and lasting for 9 weeks with the first week as adaption period. During the experimental period, average daily temperature-humidity index (measured at 08:00, 14:00, and 20:00) was above 68, indicating that cows were exposed to heat stress throughout the study. Rectal temperatures tended to decrease linearly (p = 0.07) for cows supplemented with SCFP compared to the control cows at 14:30, but were not different at 06:30 (p>0.10). Dry matter intake was not affected by SCFP supplementation (p>0.10). Milk yield increased linearly (p<0.05) with increasing levels of SCFP. Feed efficiency (milk yield/ dry matter intake) was highest (p<0.05) for cows fed 240 g/d SCFP. Cows supplemented with SCFP gained (p<0.01) body weight, while cows in the control lost body weight. Net energy balance also increased linearly (p<0.01) with increasing levels of SCFP. Concentrations of milk urea nitrogen (p<0.01) decreased linearly with increasing levels of SCFP, while no difference (p>0.10) was observed among the treatments in conversion of dietary crude protein to milk protein yield. In summary, supplementation of SCFP alleviated the negative effect of heat stress in lactating Holstein dairy cows and allowed cows to maintain higher milk production, feed efficiency and net energy balance. Effects of SCFP were dose-dependent and greater effects were observed from higher doses.

낙동강 유역에서 관측된 에디 공분산 자료의 품질 관리 및 플럭스 특성 (Quality Control and Characteristic of Eddy Covariance Data in the Region of Nakdong River)

  • 이영희;이병주;강금아;김수진;홍선옥
    • 대기
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    • 제23권3호
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    • pp.307-320
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    • 2013
  • We performed comprehensive quality control for eddy-covariance measurements from 3 farmland sites and 1 industrial site adjacent to Nakdong river. The quality control program is based on Foken and Wichura (1996) and Vicker and Mahrt (1997) and we added criteria for trend and standard deviation for scalar variables and modified criteria for non-stationarity condition of Foken and Wichura (1996) to consider random error of fluxes. The classification of data quality is designed for the raw data and the processed flux data, separately. Use of added criteria efficiently reduces the number of outlier for water vapor and $CO_2$ fluxes and use of modified criteria for non-stationarity reduces the number of outlier for scalar fluxes and increases the number of data with accepted quality for further work. Energy balance ratio is higher in farmlands than industrial site, which is due to neglect of heat storage term in industrial site. Among farmland sites, C4 site shows higher energy balance ratio than other sites. This is due to more homogeneous surface of C4 site than other farmland sites. However, energy balance ratio is very low or even negative at night. Mismatch between the flux footprint and the other energy component footprint over the heterogeneous surface is main cause for energy imbalance at night. Other possible causes are also discussed.

The effect of two artificial salivas on the adhesion of Candida albicans to heat-polymerized acrylic resin

  • Oncul, Burcin;Karakis, Duygu;Al, Funda Dogruman
    • The Journal of Advanced Prosthodontics
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    • 제7권2호
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    • pp.93-97
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    • 2015
  • PURPOSE. Xerostomia can diminish the quality of life, leads to changes in normal chemical composition of saliva and oral microbiata, and increases the risk for opportunistic infections, such as Candida albicans. Various artificial salivas have been considered for patients with xerostomia. However, the knowledge on the antifungal and antiadhesive activity of artificial saliva substitutes is limited. The aim of the present study was to evaluate influence of two artificial salivas on the adhesion of Candida albicans to the polymethylmethacrylate disc specimens. MATERIALS AND METHODS. Two commercial artificial salivas (Saliva Orthana and Biotene Oral Balance Gel) were selected. 45 polymethylmethacrylate disc specimens were prepared and randomly allocated into 3 groups; Saliva Orthana, Biotene-Oral Balance gel and distilled water. Specimens were stored in the artificial saliva or in the sterile distilled water for 60 minutes at $37^{\circ}C$. Then they were exposed to yeast suspensions including Candida albicans. Yeast cells were counted using ${\times}40$ magnification under a light microscope and data were analysed. RESULTS. Analysis of data indicated statistically significant difference in adhesion of Candida albicans among all experimental groups (P=.000). Findings indicated that Saliva Orthana had higher adhesion scores than the Biotene Oral Balance gel and distilled water (P<.05). CONCLUSION. In comparison of Saliva Orthana, the use of Biotene Oral Balance Gel including lysozyme, lactoferrin and peroxidase may be an appropriate treatment method to prevent of adhesion of Candida albicans and related infections in patients with xerostomia.

페로니켈 공정의 석탄대체 물질에 대한 열정산 (Heat Balance for the coal substitute materials in the Ferronickel manufacturing process)

  • 김희열
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.161.2-161.2
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    • 2010
  • 페로니켈 제조 공정에 있어서 석탄의 비중은 총 에너지원 중 70%에 상당하며, 온실가스 배출 또한 65%에 달한다. 이에 석탄을 대체할 물질로서 RPF, RDF, Biomass, TDF 등을 고려하였으며, 자체 개발한 열정산 프로그램을 활용하였다. 해석결과 석탄 대체물질의 사용할 경우 페로니켈 제조공정의 에너지 비용을 상당량 저감할 수 있을 것으로 기대된다.

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고체 물질의 고온 처리 공정에 관한 에너지 평가 연구 (Energy Evaluation Studies on Pyroprocessing of Solids)

  • 하대승;최상민
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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    • pp.305-307
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    • 2014
  • Pyroprocessing (or pyrometallurgy) is the way of extracting from materials subjected to high temperatures. Generally, this process has a high energy consumption because of mass production and heating-up. To attain effective and efficient energy management, energetic analysis using 0-dimensional model is usually conducted. However, this model can lead to a misunderstanding about energy evaluation due to many assumptions and limitations. In this study, heat & mass balance using 0-dimensional model was reviewed to systematize problems and considerations in general process energy evaluation.

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온실의 고온극복설비 용량 결정을 위한 열평형 모델의 적용 (Application of Heat Balance Model for Determination of Facilities Capacity to Overcome High Temperature in Greenhouses)

  • 남상운
    • 한국생물환경조절학회:학술대회논문집
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    • 한국생물환경조절학회 2000년도 학술발표논문집
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    • pp.27-30
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    • 2000
  • 여름철 고온기에 시설 이용율을 높이고 안정적인 생산을 하기 위하여는 적극적인 차광 환기시스템과 증발냉각시스템을 도입하는 것이 필요하다. 이러한 시스템을 도입하기 위하여는 적정 설비용량의 결정이 중요하며, 이는 지역별 외부의 설계 기상자료로부터 구할 수 있다. 차광환기시스템에서 차광율은 작물의 종류에 따라서 결정되어야 하며 따라서, 기븐적으로 결정해야될 설계 인자는 목표온도를 달성하기 위한 필요환기율과 증발냉각시스템 의 분무수량이다. (중략)

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제철 소결의 배가스 순환 적용에 따른 가스 조건 변화 (Changes of Gas Conditions of Iron Ore Sintering Process with FGR)

  • 안형준;최상민;조병국
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
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    • pp.19-20
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    • 2012
  • Flue gas recirculation(FGR) is applied to sintering process to cope with issues including plant efficiency and environmental effects. However, it inevitably brings changes of incoming and outgoing gas conditions as plant configurations. Objective of this study was to build a process model for a sintering bed using a flowsheet process simulator and obtain information of mass and heat balance for gas flows over various process configurations with FGR.

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시뮬레이션 기술 적용 해외발전사업 엔지니어링 (Engineering based on Simulation Technique for Overseas Power Plant Projects)

  • 백세현
    • KEPCO Journal on Electric Power and Energy
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    • 제7권1호
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    • pp.63-67
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    • 2021
  • 해외 발전사업의 기술 경쟁력 우위 선점을 위해서는 발전시스템에 대한 최적설계기술 및 발전소 운영 기간 중 최소 비용으로 높은 신뢰도의 설비 관리, 최적 성능 유지를 할 수 있는 O&M 관리 기술이 필요하다. 전력연구원은 해외발전사업 전주기 기술지원을 위한 연구개발을 수행하고 있다.

Characteristics of Southern Ocean Sea Ice Distribution Modeled Using Cavitating Fluid Rheology and Climatological Atmospheric Data

  • Yih, Hyung-Moh;Mechoso, Carlos R.
    • Journal of the korean society of oceanography
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    • 제34권2호
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    • pp.59-72
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    • 1999
  • Cavitating fluid sea ice model of Plato and Hibler (1992) is applied to the Southern Ocean with an idealized, circular Antarctica. Using climatological atmospheric forcing fields averaged in the zonal direction, we show that oceanic heat flux and ice velocity have major effects on the seasonal change of ice edge, as other studies showed. In our model results, there appears a zone of free drift that contains a polynya zone. Thermodynamic forcing functions make dominant contributions to daily increments of ice thickness and compactness, except the zones of ice edge and polynya. The dominant contributions are also shown in distributions of the temperature on ice surface and several to terms in surface heat balance equation, and are also confirmed by those obtained from the thermodynamic-only model with the different locations of ice edge.

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