• Title/Summary/Keyword: Temperature-humidity Index

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Estimation of the genetic milk yield parameters of Holstein cattle under heat stress in South Korea

  • Lee, SeokHyun;Do, ChangHee;Choy, YunHo;Dang, ChangGwon;Mahboob, Alam;Cho, Kwanghyun
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.3
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    • pp.334-340
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    • 2019
  • Objective: The objective of this study was to investigate the genetic components of daily milk yield and to re-rank bulls in South Korea by estimated breeding value (EBV) under heat stress using the temperature-humidity index (THI). Methods: This study was conducted using 125,312 monthly test-day records, collected from January 2000 to February 2017 for 19,889 Holstein cows from 647 farms in South Korea. Milk production data were collected from two agencies, the Dairy Cattle Genetic Improvement Center and the Korea Animal Improvement Association, and meteorological data were obtained from 41 regional weather stations using the Automated Surface Observing System (ASOS) installed throughout South Korea. A random regression model using the THI was applied to estimate genetic parameters of heat tolerance based on the test-day records. The model included herd-year-season, calving age, and days-in-milk as fixed effects, as well as heat tolerance as an additive genetic effect, permanent environmental effect, and direct additive and permanent environmental effect. Results: Below the THI threshold (${\leq}72$; no heat stress), the variance in heat tolerance was zero. However, the heat tolerance variance began to increase as THI exceeded the threshold. The covariance between the genetic additive effect and the heat tolerance effect was -0.33. Heritability estimates of milk yield ranged from 0.111 to 0.176 (average: 0.128). Heritability decreased slightly as THI increased, and began to increase at a THI of 79. The predicted bull EBV ranking varied with THI. Conclusion: We conclude that genetic evaluation using the THI function could be useful for selecting bulls for heat tolerance in South Korea.

Evaluation of the Wet Bulb Globe Temperature (WBGT) Index for Digital Fashion Application in Outdoor Environments

  • Kwon, JuYoun;Parsons, Ken
    • Journal of the Ergonomics Society of Korea
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    • v.36 no.1
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    • pp.23-36
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    • 2017
  • Objective: This paper presents a study to evaluate the WBGT index for assessing the effects of a wide range of outdoor weather conditions on human responses. Background: The Wet Bulb Globe Temperature (WBGT) index was firstly developed for the assessment of hot outdoor conditions. It is a recognised index that is used world-wide. It may be useful over a range of outdoor conditions and not just for hot climates. Method: Four group experiments, involving people performing a light stepping activity, were conducted to determine human responses to outside conditions in the U.K. They were conducted in September 2007 (autumn), December 2007 (winter), March 2008 (spring) and June 2008 (summer). Environmental measurements included WBGT, air temperature, radiant temperature (including solar load), humidity and wind speed all measured at 1.2m above the ground, as well as weather data measured by a standard weather station at 3m to 4m above the ground. Participants' physiological and subjective responses were measured. When the overall results of the four seasons are considered, WBGT provided a strong prediction of physiological responses as well as subjective responses if aural temperature, heart rate and sweat production were measured. Results: WBGT is appropriate to predict thermal strain on a large group of ordinary people in moderate conditions. Consideration should be given to include the WBGT index in warning systems for a wide range of weather conditions. However, the WBGT overestimated physiological responses of subjects. In addition, tenfold Borg's RPE was significantly different with heart rate measured for the four conditions except autumn (p<0.05). Physiological and subjective responses over 60 minutes consistently showed a similar tendency in the relationships with the $WBGT_{head}$ and $WBGT_{abdomen}$. Conclusion: It was found that either $WBGT_{head}$ or $WBGT_{abdomen}$ could be measured if a measurement should be conducted at only one height. The relationship between the WBGT values and weather station data was also investigated. There was a significant relationship between WBGT values at the position of a person and weather station data. For UK daytime weather conditions ranging from an average air temperature of $6^{\circ}C$ to $21^{\circ}C$ with mean radiant temperatures of up to $57^{\circ}C$, the WBGT index could be used as a simple thermal index to indicate the effects of weather on people. Application: The result of evaluation of WBGT might help to develop the smart clothing for workers in industrial sites and improve the work environment in terms of considering workers' wellness.

Comparison of Thermal Environment and Biotope Area Rate according to Land Cover Types of Outside Space of School located in Chung-ju (충주시 학교외부공간 피복유형에 따른 온열환경 및 생태면적률 비교)

  • Ju, Jin-Hee;Ban, Jong-Heu;Yoon, Yong-Han
    • Journal of Environmental Science International
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    • v.19 no.9
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    • pp.1103-1108
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    • 2010
  • This study was conducted to be used as basic data of environmental friendly construction planning by comparing and analyzing thermal environment, find particles and biotope area rate according to land cover types of outside space of schools located in Chung-ju. When meteorological factors were analyzed according to land cover types, for temperature planting area and paved area showed low-and high-temperature ranges, respectively, and relative humidity was negatively related with temperature as low-and high-temperature ranges corresponded to high-and low-humidity ranges, respectively. For Wet Bulb Globe Temperature Index (WBGT) by land cover types, it was observed to be artificial grass> bare land> natural grass. Find particles were different according to land cover types of playground with being bare land> artificial grass> natural grass in the order. Bare land playground, where there were artificial factors and no absorption of fine particles through stomata of leaves as a function of natural circulation, recorded the highest level of $39.8\;{\mu}g/m^3$ and the level was relatively higher compared to the levels by season in Chung-ju. Biotope area rate showed the order of M elementary school> K elementary school> C commercial high school. That was considered to be caused by the difference of land cover type of school playground accounting for a large part of a school.

Heat tolerance of goats to increased daily maximum temperature and low salinity of drinking water in tropical humid regions

  • Asep Indra Munawar Ali;Sofia Sandi;Lili Warly;Armina Fariani;Anggriawan Naidilah Tetra Pratama;Abdullah Darussalam
    • Animal Bioscience
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    • v.37 no.6
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    • pp.1130-1139
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    • 2024
  • Objective: The daily maximum temperature and seawater level continuously increase as global warming continues. We examined the adaptability and production performance of heat-stressed goats with a supply of low-saline drinking water. Methods: Twelve Kacang and Kacang Etawah cross goats were exposed to two climatic conditions (control, 25℃ to 33℃, 83% relative humidity [RH], temperature humidity index [THI]: 76 to 86; and hot environment, 26℃ to 39℃, 81% RH, THI: 77 to 94) and two salt levels in drinking water (0% and 0.4% NaCl). The experimental design was a Latin Square (4×4) with four treatments and four periods (28 days each). Results: Temperature of the rectal, skin, and udder, and respiration rate rose, reached a maximum level on the first day of heat exposures, and then recovered. Plasma sodium rose at 0.4% NaCl level, while the hot environment and salinity treatments increased the drinking water to dry matter (DM) intake ratio. Water excretion was elevated in the hot environment but lowered by the increase in salinity. Total lying time increased, whereas change position frequency decreased in the hot condition. Lying and ruminating and total ruminating time increased and explained the enhanced DM digestibility in the hot conditions. Conclusion: The goats exhibited a high level of plasma sodium as salinity increased, and they demonstrated physiological and behavioral alterations while maintaining their production performances under increasing daily maximum temperatures.

Study on Control of Thermal Environmental Factors for Improvement of Productivity of Laying Hens in Summer (여름철 산란계사 내 열환경인자 중 제어요소에 관한 연구)

  • Kim, Seong-Wan;Lee, Tae-Hoon;Cha, Gwang-Jun;Gutierrez, Winson M.;Chang, Hong-Hee
    • Journal of agriculture & life science
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    • v.53 no.2
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    • pp.121-129
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    • 2019
  • This study carried out to determine control factors for the improvement of productivity of laying hens suffering heat stress during hot weather. A total of 48,451 ISA Brown layers were housed in a farm located in Gyeongsangnam-do, Republic of Korea. Five thermo-hydrometer loggers were installed inside the house to collect data of dry-bulb temperature and relative humidity. The experiment continued for 81 days when the summer season begins from 19th June to 7th September, 2018. This study analyzed the correlations among layers' production index and daily average, highest, and lowest temperature; daily average, highest, and lowest relative humidity; and daily average, minimum, and maximum THI. The result indicated that feed consumption, hen-day egg production, egg weight, and FCR decreased as the daily average, highest and lowest dry-bulb temperature and THI rise (p<0.01). On the other hand, water intake increased as the daily average, highest and lowest dry-bulb temperature and THI rise (p<0.001). The relative humidity was not considered to have direct correlations to the layers' production index (p>0.05). However, it was noticeable that the mortality did not have significant relations with daily average and highest temperature; THI; or daily average, highest and lowest relative humidity while it was relevant to the daily lowest temperature and THI (p<0.05). In conclusion, to enhance the productivity of laying hens in a hot climate, it is recommended that daily average, highest, and lowest dry-bulb temperature and THI are maintained as low as possible. Especially, the daily lowest temperature is needed to lower to 20℃, which is the lowest critical temperature for layers.

A Study on the Evaluation Methods of Indoor Thermal Comfort Index in Building (실내(室內) 온열환경지표(溫熱環境指標)의 평가방법에 관한 연구)

  • Jeong, Chang-Won;Horikoshi, Tetsumi;Yoon, In;Choi, Young-Sik
    • Journal of the Korean Society of Industry Convergence
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    • v.2 no.2
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    • pp.11-21
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    • 1999
  • This objective of this paper is to investigate the evaluation and indiction of human thermal comfort in building environment. The issue of defining the boundaries of acceptable thermal comfort conditions in buildings and urban may have significant implication for building design and also may have urban design by climate considerations. And then it is to apply the thermal comfort condition to environmental design by using passive methods in Korea. Since 1920. architects have conducted studies to measure thermal comfort in houses under hot and humid conditions, while industrial hygienists have studied the effects of temperature and humidity on the performance of factory workers. Thermal comfort can be influenced by many variables. This paper conducted to review the previous researches and the human heat balance equation, and to analyse in order to reveal the meaning and usage of the thermal comfort index in two traditional essays, Fanger's PMV and Gagge's ET* Their comfort indexes compared with each other. They were based on human heat balance equation and psychological and physiological responses in the laboratory tests. The researchers and the architectural engineers using thermal comfort index shall be careful in decided the use of indexes and be necessary to recognize the value concept of the design criteria for thermal comfort. Therefore, The opinion of the authors is that different comfort standards have to apply for each building and urban with different climatic conditions.

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Relation of the Natural Amenity and Population Change (자연어메니티가 인구 변화에 미치는 영향에 관한 연구)

  • Park, Mee-Jeong;Nam, Nam-Su;Jang, Min-Won;Lee, Jeong-Jae
    • Journal of Korean Society of Rural Planning
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    • v.14 no.4
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    • pp.1-9
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    • 2008
  • Many urban people are attracted to the recreational opportunities and attractions of rural areas, such as beautiful scenery, lakes, mountains, forests, and resorts. Furthermore, rural development planning increasingly emphasizes the integration of resource extractive industries with non-market-based recreational and amenity values. This article outlines a method to estimate an amenity level of rural areas such as natural amenities index and shows the relation of the natural amenity and population growth. The results revealed that natural amenity classifying each region can be explained with geographical characteristics, temperature-humidity, and sunshine duration time. In analysis with population, natural amenity does not exactly explain that but can be one of the important factor of population change.

Corrosion initiation time models in RC coastal structures based on reliability approach

  • Djeddi, Lamine;Amirat, Abdelaziz
    • Advances in concrete construction
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    • v.9 no.2
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    • pp.149-159
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    • 2020
  • The present work proposes new engineering models for determining corrosion initiation time in concrete reinforcing steels in marine environment. The models are based on Fick's second law that is commonly used for chloride diffusion. The latter is based on deterministic analyses involving the most influencing parameters such as distance of the concrete structure from the seaside, depth of steel concrete cover, ambient temperature, relative humidity and the water-cement ratio. However, a realistic corrosion initiation time cannot be estimated because of the uncertainties associated to the different parameters of the models. Therefore a reliability approach using FORM/SORM method has been applied to develop the proposed engineering models integrating a limit state function and a reliability index β. As a result, the corrosion initiation time is expressed by new exponential engineering models where the uncertainties are associated to the model parameters. The main emerging result is a realistic decision tool for corrosion planning inspection.

Development of Moisture Loss Index Based on Field Moisture Measurement using Portable Time Domain Reflectometer (TDR) for Cold In-place Recycled Pavements (휴대용 TDR 함수량계로 측정한 현장 함수비를 이용한 현장 상온 재활용 아스팔트 포장의 수분 감소계수 개발)

  • Kim, Yong-Joo;Lee, Ho-Sin David;Im, Soo-Hyok
    • International Journal of Highway Engineering
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    • v.13 no.2
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    • pp.139-145
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    • 2011
  • The practice of asphalt pavement recycling has grown rapidly over the decade, one of which is the cold in-place recycling with the foamed asphalt (CIR-foam) or the emulsified asphalt (CIR-emulsion). Particularly, in Iowa, the CIR has been widely used in rehabilitating the rural highways because it significantly increases the service life of the existing pavement. The CIR layer is typically overlaid by the hot mix asphalt (HMA) to protect it from water ingress and traffic load and obtain the required pavement structure and texture. Most public agencies have different curing requirements based on the number of curing days or the maximum moisture contents for the CIR before placing the overlay. The main objective of this study is to develop a moisture loss index that the public agency can use to monitor the moisture content of CIR layers in preparation for a timely placement of the wearing surface. First, the moisture contents were measured in the field using a portable time domain reflectometry (TDR) device. Second, the weather information in terms of rain fall, air temperature, humidity and wind speed was collected from the same location. Finally, a moisture loss index was developed as a function of initial moisture content, air temperature, humidity and wind speed. The developed moisture loss index based on the field measurements would help the public agency to determine an optimum timing of an overlay placement without continually measuring moisture conditions in the field.

Forecasting the Pepper Gray Mold Rot to Predict the Initial Infection by Botrytis cinerea in Greenhouse Conditions

  • Park, Seon-Hee;Lee, Joon-Taek;Chung, Sung-Ok;Kim, Hee-Kyu
    • The Plant Pathology Journal
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    • v.15 no.4
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    • pp.158-161
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    • 1999
  • We determined threshold environmental factros to initiate infection of pepper plants by Botrytis cinerea, a fungal pathogen of pepper gray mold, in two greenhouse conditions. A new efficient spore-trapping method was developed to estimate population density of airborne conidia in the greenhouses, and spore release was measured using a Kerssies' selective medium. At a given day, spores were released greater during daytime (mostly from 7:30 am to 10:30 am and at 4:30 pm) than nighttime. Diurnal and nocturnal temperatures in the greenhouse-1 were about $25^{\circ}$ and $17^{\circ}$,and relative humidity was 100% for prolonged 24 h due to rain on December 17, 1997. Population density of air-borne conidia was 3.0$\times$103 conidia/ $0.5\textrm{m}^3$ after two days, and the initial infection occurred in ten days. During the same period of time in the greenhouse-2, diurnal temperature was about $25^{\circ}$ and nocturnal temperature was below $15^{\circ}$, and population density of air-borne conidia was 104 conidia/ $0.5\textrm{m}^3$. Under these conditions, the initial infection started in three days. This indicates that the early infection occurs under which diurnal temperature is approximately $25^{\circ}$, nocturnal temperature is maintained below $15^{\circ}$, and population density of air-borne conidia is 104 conidia/ $0.5\textrm{m}^3$ at saturated relative humidity condition.

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