• 제목/요약/키워드: Percentage Relative Humidity

검색결과 63건 처리시간 0.023초

The effect of seasonal thermal stress on milk production and milk compositions of Korean Holstein and Jersey cows

  • Lim, Dong-Hyun;Mayakrishnan, Vijayakumar;Ki, Kwang-Seok;Kim, Younghoon;Kim, Tae-Il
    • Animal Bioscience
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    • 제34권4호
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    • pp.567-574
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    • 2021
  • Objective: In this study we investigated the effect of seasonal thermal stress on milk production and milk compositions between Holstein and Jersey dairy cows under the temperate-climate in Korea. Methods: A total of 9 Holstein lactating dairy cows (2.0±0.11 parity) which had a daily milk yield of 29.77±0.45 kg, and days in milk of 111.2±10.29 were selected similarly at the beginning of the experiments in each season. Also, a total of 9 Jersey lactating dairy cows (1.7±0.12 parity) which had a daily milk yield of 20.01±0.43 kg, and days in milk of 114.0±9.74 were selected similarly at the beginning of the experiments. Results: Results showed that the average ambient temperature (℃) and temperature-humidity index (THI) were higher in summer, and were lower in winter (p<0.05). The average relative humidity (RH, %) was higher in autumn than that of other seasons (p<0.05). Milk production was significantly decreased (Holstein 29.02 kg/d and Jersey 19.75 kg/d) in autumn than in other seasons (Holstein 30.14 kg/d and Jersey 20.96 kg/d). However, the milk production was negatively correlated in Holstein cows, and positively correlated in Jersey cows with THI values increased from 16 to 80. In addition, milk yield was increased by 15% in Holstein cows and decreased by 11% in Jersey cows with the THI values increased from 16 to 20. The fat and protein content percentage was significantly higher in Jersey milk than in Holstein milk, furthermore the fat and protein content yield was higher in Jersey cow milk than that of Holstein cow's milk with all THIs. Conclusion: From the study results, we concluded that Jersey cows might be less adaptable to low temperature of the winter, and this would have a negative impact on dairy farmer income since Korea's milk price estimation system places a higher value on milk yield than on milk compositions or sanitary grades.

무기체계의 환경시험을 위한 한반도의 온도기준 설정에 관한 연구 (A study on the temperature guidelines for weapon system test and evaluation in the Korean peninsula)

  • 문자영;김동길;성인철;홍연웅
    • Journal of the Korean Data and Information Science Society
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    • 제27권6호
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    • pp.1593-1600
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    • 2016
  • 환경시험의 목적은 시험대상 제품이 수명주기 중 겪을 수 있는 환경에 노출되었을 때 정상적인 기능을 수행할 수 있는지 설계 제조되었는지를 시험 평가하는 것이다. 본 논문은 한반도 내륙에서 운용할 군수장비의 운용환경조건에 대한 온도시험의 설계 기준을 제안한다. 온도기준은 과도하거나 과소하지 않게 합리적으로 설계되어야하는데 본 연구에서는 한국에서 가장 더웠던 지역과 가장 추웠던 지역을 기준으로 고온 및 저온에 대한 다양한 백분위별 발생빈도를 제시한다. 1904년부터 2014년까지 132개 관측지점의 기온 자료를 분석한 결과 1개월 기준으로 가장 더운 지역은 대구, 가장 추운 지역은 양평으로 확인되었다. 한반도 내륙의 운용 환경에서 고온과 저온의 1% 발생빈도값은 각각 $38.7^{\circ}C$와 -$29.0^{\circ}C$로 추정되었다. 아울러 상대습도, 풍속, 태양복사를 포함하는 고온과 저온의 일주기표도 제시한다.

Hargreaves식에 의한 필요수량산정에 관한 소고 (Method for Estimating Irrigation Requirements by G.H. Hargreaves.)

  • 엄태영;홍종진
    • 한국농공학회지
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    • 제18권3호
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    • pp.4195-4205
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    • 1976
  • The purpose of this study is to evaluate the existing methods for calculating or estimating the consumptive use (Evaportranspiration) of any agricutural development project area. In determing the consumptive use water in the project area, there will require the best way for estimating irrigation requirement. Many methods for computing the evaportranspiration have been used, each of them with its merits and demerits at home and abroad. Some of these methods are listed as follows: 1.The Penman's formula 2.The B1aney-Criddle method 3.The Munson P.E. Index method 4.The Atmometer method 5.The Texas Water Rights Commission (TWRC) method 6.The Jensen-Haise method 7.The Christiasen method Therefore, the authors will introduce the more widely used method for calculating Consumptive Use by G.H. Hargreaves. The formula is expressed in the form Ep= K·d·T (1.0-0.01·Hn) Hn=1.0+0.4H+0.005H2. This method was adopted for the first time to determine the Irrigation requirements of Ogseo Comprehensive Agricultual Development project (Benefited area:100,500ha) in Korea. This method is presented in somewhat greater detail than the others. Formula is given for the computation of evaportranspiration (with various levels of data availability) Sampel computation of irrigation requirements for Ogseo irrigation project is included. The results and applied materials are summarized as follows. 1. In calculating the Hargreaves formula, the mean temperature relative, humidity, length of day, and percentage of sunshine from three stations of Iri, Jeonju, and Gunsan were used. 2. Monthly evaporation values were calculated by using the formula. 3. Meteological data from the three stations records for the ten years (1963∼1972) were used. 4. The annual irrigation requirements is 1,186mm per hectare, but the case to consider effective rainfall amount takes the annual irrigation demand being 700mm per hectare.

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Effects of Low-Dose Aspirin Therapy on Thermoregulation in Firefighters

  • McEntire, Serina J.;Reis, Steven E.;Suman, Oscar E.;Hostler, David
    • Safety and Health at Work
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    • 제6권3호
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    • pp.256-262
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    • 2015
  • Background: Heart attack is the most common cause of line-of-duty death in the fire service. Daily aspirin therapy is a preventative measure used to reduce the morbidity of heart attacks but may decrease the ability to dissipate heat by reducing skin blood flow. Methods: In this double-blind, placebo-controlled, crossover study, firefighters were randomized to receive 14 days of therapy (81-mg aspirin or placebo) before performing treadmill exercise in thermal-protective clothing in a hot room [$38.8{\pm}2.1^{\circ}C$, $24.9{\pm}9.1%$ relative humidity (RH)]. Three weeks without therapy was provided before crossing to the other arm. Firefighters completed a baseline skin blood-flow assessment via laser Doppler flowmetry; skin was heated to $44^{\circ}C$ to achieve maximal cutaneous vasodilation. Skin blood flow was measured before and after exercise in a hot room, and at 0 minutes, 10 minutes, 20 minutes, and 30 minutes of recovery under temperature conditions ($25.3{\pm}1.2^{\circ}C$, $40.3{\pm}13.7%\;RH$). Platelet clotting time was assessed before drug administration, and before and after exercise. Results: Fifteen firefighters completed the study. Aspirin increased clotting time before and after exercise compared with placebo (p = 0.003). There were no differences in absolute skin blood flow between groups (p = 0.35). Following exercise, cutaneous vascular conductance (CVC) was $85{\pm}42%$ of maximum in the aspirin and $76{\pm}37%$ in the placebo groups. The percentage of maximal CVC did not differ by treatment before or after recovery. Neither maximal core body temperature nor heart rate responses to exercise differed between trials. Conclusion: There were no differences in skin blood flow during uncompensable heat stress following exercise after aspirin or placebo therapy.

Effects of Sonication, Osmotic Priming and Modified Drum Priming on the Germination of Tomato Seeds

  • Kim, Min Geun;Kang, Won Sik;Kim, Du Hyun
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2018년도 추계학술대회
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    • pp.88-88
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    • 2018
  • In order to increase the germination speed and uniformity of tomato seeds, sonication and modified drum priming treatments were investigated to produce high quality seeds for export. Sonication treatment was performed for 5, 10 and 20minutes at an intensity of 5.2, 10.4 and 15.7kHz in water at $15^{\circ}C$. After sonication treatment, seeds were primed with water or 100mM $KNO_3$ for 4days. 40, 50 and 60% seed moisture content (SMC) of hydrated seeds were incubated for 60, 72 and 84h in a container with a relative humidity of 99% at 26rpm for a modified drum priming treatments. Germination speed were highly improved by sonication with osmotic priming. The seed treatment of osmotic priming or hydro priming after sonication or sonication without priming enhanced germination percentage (GP) on the $2^{rd}$day after sowing to 46%, 43% and 28%, respectively, while untreated seeds resulted in only 1% GP. These treatments also highly improved mean germination time (MGT) to 1.4, 1.8 and 2.6days, respectively, when compared to 3.5days MGT of untreated seeds. The modified drum priming treatment (72h incubation after 60% SMC hydration) significantly improved results of 74% GP(on the $3^{rd}$day after sowing), 2.6days MGT and $39%{\cdot}day^{-1}$ germination rate (GR), however, untreated seeds showed 19% GP, 4.1 MGT, and $25%{\cdot}day^{-1}$ GR. Although osmotic priming after sonication, hydro priming showed similar improved germination characteristics, however, modified drum priming is considered as an industrially promising treatment methods considering the shortening of the treatment period and environment-friendly aspects.

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보건의료시설의 실내 예상 평균 온열감(PMV), 이산화탄소 농도, 소음도, 조도의 통합실내쾌적도(IEQh)를 통한 연간 실내 쾌적도 평가 (Evaluation of Annual Indoor Environment Quality in Hospitals using Various Comfort-related Factors)

  • 이보람;이대엽;반현경;이세원;김규상;이기영
    • 한국환경보건학회지
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    • 제43권3호
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    • pp.214-222
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    • 2017
  • Objectives: A hospital is a complex building that serves many different purposes. The indoor environment in a hospital plays a major role in patient well-being and the work efficiency of the hospital staff. This study was conducted to evaluate overall comfort in two major hospitals over the course of one year. Methods: Various indoor environmental conditions were measured in two general hospitals for one year (April 2014 to April 2015). Monitoring alternated between the hospitals at one month per respective monitoring session. The indoor air temperature, relative humidity (RH), mean radiant temperature and air velocity were measured in order to calculate the predicted mean vote (PMV). Carbon dioxide concentration, noise level and illumination level were concurrently measured and applied to the overall IEQ acceptance model for the hospitals (IEQh). Results: The IEQh at the two general hospitals was different at five spaces within a building. The IEQh for summer and winter were significantly different. Real-time IEQh demonstrated that indoor comfort was affected by the hospital's operating hours due to operation of the HVAC system. The percentage of indoor comfort in the hospitals was higher using PMV than IEQh. Conclusion: IEQh in the hospitals was different at locations with different purposes. Indoor comfort assessment using IEQh was stricter than with PMV. Additional research is needed in order to optimize the IEQh model.

한반도 연해안지역 환경시험기준의 테일러링을 위한 온도기준 설정에 관한 연구 (A study on the temperature guidelines of weapon systems test & evaluation in the coastal environment of the Korean peninsula)

  • 윤성현;김시옥;조유습;홍연웅
    • Journal of the Korean Data and Information Science Society
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    • 제28권6호
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    • pp.1437-1445
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    • 2017
  • 환경시험의 목적은 시험대상 제품이 수명주기 중 겪을 수 있는 환경에 노출되었을 때 정상적인 기능을 수행할 수 있도록 설계 제조되었는지를 시험 평가하는 것이다. 본 논문은 한반도 연해안지역에서 운용할 군수장비의 운용환경조건에 대한 온도시험의 설계 기준을 제안한다. 온도기준은 과도하거나 과소하지 않게 합리적으로 설계되어야하는데 본 연구에서는 한반도 해안지역에서 가장 더웠던 지역과 가장 추웠던 지역을 기준으로 고온 및 저온에 대한 다양한 백분위별 발생빈도를 제시하여 사용군이 선택할 수 있도록 한다. 1904년부터 2015년까지 한반도 28개 연해안 지역 관측지점의 기온 자료를 분석한 결과 1개월 기준으로 가장 더운 지역은 포항, 가장 추운 지역은 신의주로 확인되었다. 한반도 해안 환경에서 고온과 저온의 1% 발생빈도값은 각각 $37.7^{\circ}C$$-23.7^{\circ}C$로 추정되었다. 아울러 상대습도, 풍속, 태양복사를 포함하는 고온과 저온의 일주기표도 제시한다.

Effect of Ripening and Peeling Methods on Composition and Quality of Canned Freestone Peaches

  • Chung, J.I.;Luh, B.S.
    • 한국식품과학회지
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    • 제4권1호
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    • pp.6-12
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    • 1972
  • Fay Elberta freestone peaches were harvested at four maturity levels as judged by skin color and firmness. They were ripened at $68^{\circ}F$ under 80 percent relative humidity for 4, 6, 8 and 10 days respectively prior to canning. Results indicate that both harvest maturity and ripening conditions are important factors influencing quality, flavor and composition of canned freestone peaches. Peaches harvested at $18{\sim}24$ pounds on a Magness-Taylor pressure tester with a 7/16' plunger(M1) failed to ripen satisfactorily. Fruits harvested at $13{\sim}17$ pounds (M2) pressure test ripened successfully at $68^{\circ}F$ within 6 to 8 days; and those harvested at 6 to 12 pounds (M3) needed 4 days for ripening at $68^{\circ}F$. Tree-ripened fruits (M4) were undesirable for canning because of the high percentage of bruised fruits. The optimum firmness for canning appears to be in the range of 1.5 to 3.0 pounds. The titratable acidity of peaches decreased during maturation and ripening. The tannin content of peaches at M1 maturity decreased with ripening at $68^{\circ}F$. But no appreciable change was observed in the M2 and M3 series which were ripened at $68^{\circ}F$ for 4 to 10 days. The volatile reducing substances (V.R.S.) increased as the peaches developed on the tree and also during post-harvest ripening. The effect of harvest maturity and post-harvest ripening on color grade of the canned peaches is presented. Little difference was found in the flavor and composition of peaches peeled by the cup-down lye peeling and the steam-peeling methods. The cup-down lye-peeling method might be most advantageous because of its higher peeling efficiency.

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Comparative Study of the Dissolution Profiles of a Commercial Theophylline Product after Storage

  • Negro, S.;Herrero-Vanrell, R.;Barcia, E.;Villegas, S.
    • Archives of Pharmacal Research
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    • 제24권6호
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    • pp.568-571
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    • 2001
  • The purpose of this work was to study the effect of storage time and temperature on the in vitro release kinetics of a commercial sustained-release dosage form of theophylline, at different pHs of the dissolution medium. The formulation was stored at $35^{\circ}C$ for 16 months and at $45^{\circ}C$ for 8 months, with a relative humidity of 60%. The in vitro release tests were performed at pHs 2, 4, 6 and 7.4. The mean values of the transport coefficient n, were close to 0.5 in all the conditions tested, which indicates that the transport system is not modified after storage of the formulation at $35^{\circ}C$ and $45^{\circ}C$. The mean values of the dissolution rate constant ranged from 0.036 to 0.043 $min^{-n}$, under all the conditions tested. Significant differences (${\alpha}=0.05$) were found between pHs 2, 4 and 6, 7.4 for all the model-independent parameters studied. When the formulation was kept at $35^{\circ}C$ for 16 months, the mean percentage of drug dissolved at 8 hours was 25.61% (pHs 2, 4) and, 36.12% (pHs 6, 7.4), representing a 26% and 24% reduction, respectively. Simitar results were obtained after storing the formulation at $45^{\circ}C$ for 8 months, corresponding to 33.3% (pHs 2, 4) and, 22.5% (pHs 6, 7.4) diminution, respectively. The values of the similarity factory $f_2$, obtained were lower than 50, which indicates the lack of similarity among the dissolution profiles, after storing the formulation under the experimental Conditions tested.

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Water Sorption/Desorption Characteristics of Eutectic LiCl-KCl Salt-Occluded Zeolites

  • Harward, Allison;Gardner, Levi;Oldham, Claire M. Decker;Carlson, Krista;Yoo, Tae-Sic;Fredrickson, Guy;Patterson, Michael;Simpson, Michael F.
    • 방사성폐기물학회지
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    • 제20권3호
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    • pp.259-268
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    • 2022
  • Molten salt consisting primarily of eutectic LiCl-KCl is currently being used in electrorefiners in the Fuel Conditioning Facility at Idaho National Laboratory. Options are currently being evaluated for storing this salt outside of the argon atmosphere hot cell. The hygroscopic nature of eutectic LiCl-KCl makes is susceptible to deliquescence in air followed by extreme corrosion of metallic cannisters. In this study, the effect of occluding the salt into a zeolite on water sorption/desorption was tested. Two zeolites were investigated: Na-Y and zeolite 4A. Na-Y was ineffective at occluding a high percentage of the salt at either 10 or 20wt% loading. Zeolite-4A was effective at occluding the salt with high efficiency at both loading levels. Weight gain in salt occluded zeolite-4A (SOZ) from water sorption at 20% relative humidity and 40℃ was 17wt% for 10% SOZ and 10wt% for 20% SOZ. In both cases, neither deliquescence nor corrosion occurred over a period of 31 days. After hydration, most of the water could be driven off by heating the hydrated salt occluded zeolite to 530℃. However, some HCl forms during dehydration due to salt hydrolysis. Over a wide range of temperatures (320-700℃) and ramp rates (5, 10, and 20℃ min-1), HCl formation was no more than 0.6% of the Cl- in the original salt.