scholarly journals Microclimate in silvipastoral systems with eucalyptus in rank with different heights

2010 ◽  
Vol 39 (3) ◽  
pp. 685-694 ◽  
Author(s):  
Wander de Souza ◽  
Orlando Rus Barbosa ◽  
Jair de Araújo Marques ◽  
Marco Aurélio Teixeira Costa ◽  
Eliane Gasparino ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Air Temperature ◽  
Thermal Load ◽  
Heat Load ◽  
Temperature Humidity Index ◽  
Heat Load Index ◽  
Humidity Index ◽  
Globe Temperature ◽  
Black Globe Temperature

The aim of this work was to verify if the presence of trees and its height in formed silvipastoral systems with eucalyptus planted in rank can modify the microclimate and improve the environment for bovine raising during the day in summer. It was evaluated the microclimate of the environment in formed silvipastoral systems in rank of eucalyptus with 8 m, 18 m and 28 meters of height, compared to a system no shade in the summer. The experimental design was a split plot with six hour time in sub parcels. The systems are made up of parcels and the months as block in four replications and the interaction hour × system. The air temperature, black globe temperature, relative humidity and wind speed were observed to create the following indexes for thermal comfort: temperature-humidity index; black globe-humidity index; heat load index and the radiant thermal load. Excepted for the relative humidity, there was interaction for time × system for all variables and indexes. Interaction occurred for: air temperature at 10 a.m. and 6 p.m.; wind speed from 8 a.m. to 4 p.m.; temperature humidity index at 10 a.m. and 12 p.m.; black globe temperature, black globe humidity index, heat load index, and radiant thermal load at all the hours. During the summer, the system with shade of 28 m trees had the lowest average of black globe temperature; wind speed; black globe humidity index; radiant thermal load index; and heat load index. There was a reduction of wind speed average in systems 8 m, 18 m and 28 m trees in, respectively, 20.7; 50.0 and 48.0% in relation to no shade system; however it was not proportional to the height, with influence of the rank porosity and pantries height. Nevertheless, for radiant thermal load index the reduction was proportional to the height of the trees with 10.24; 12.49 and 20.76%, respectively, for 8 m, 18 m and 28 meters of height. There was a reduction of the thermal stress in the environment due to the presence of trees, being the heat load index thermal the index that better demonstrated the effect, despite of not being proportional to the rank height.

Developing a heat load index for lactating dairy cows

2018 ◽  
Vol 58 (8) ◽  
pp. 1387 ◽  
Author(s):  
J. C. Lees ◽  
A. M. Lees ◽  
J. B. Gaughan
Keyword(s):  
Logistic Regression ◽  
Wind Speed ◽  
Relative Humidity ◽  
Dairy Cows ◽  
Heat Load ◽  
Heat Load Index ◽  
Lactating Dairy Cows ◽  
Globe Temperature ◽  
Panting Score ◽  
Black Globe Temperature

The temperature humidity index (THI) has been extensively used in the Australian dairy industry as an indicator of heat load conditions. However, there are limitations to the THI, where it does not account for solar radiation or wind speed. In addition, the THI has not been formulated in conjunction with physiological data. Thus, it is not apparent whether the THI provides the best prediction for impact of heat load on lactating dairy cattle. The aim of the present study was to develop a dairy heat load index (DHLI), based on the physiological responses of lactating dairy cows to environmental conditions. The study was undertaken at The University of Queensland, Gatton Campus, Australia, over three summers and two winters. Observations were conducted four times daily at 0800 hours, 1200 hours, 1400 hours and 1700 hours. Weather data were obtained every 10 min from an onsite, automated weather station. Panting score data were used to calculate a mean panting score of the herd. Developing the DHLI encompassed three different modelling techniques, including (1) linear regression, (2) broken stick regression and (3) non-linear logistic regression. Comparisons between the models indicated there was an increase in accuracy when using non-linear logistic regression (R2 = 0.542). The DHLI model developed was based on mean panting score, black globe temperature (°C) and relative humidity. By utilising the black globe temperature, the DHLI is able to incorporate the combined effects of ambient temperature, relative humidity, solar radiation and wind speed in a single unit measure. By combining climatic conditions and a physiological response, i.e. panting score, the DHLI model may become a more accurate prediction of heat load for lactating dairy cows. The DHLI produces a unit value between 0 and 100. When DHLI is 0, there would be no panting and, when DHLI is 100, all cows within the herd would be panting.

Effect of heat load and dietary protein on oxygen pulse and energy cost for locomotion in heifers

2019 ◽  
Vol 59 (9) ◽  
pp. 1611
Author(s):  
E. E. L. Valente ◽  
V. T. Filipini ◽  
L. C. Araújo ◽  
M. Stahlhofer ◽  
B. V. R. Melo ◽  
...  
Keyword(s):  
Heart Rate ◽  
Energy Expenditure ◽  
Dietary Protein ◽  
Energy Cost ◽  
Heat Load ◽  
Protein Concentration ◽  
Oxygen Pulse ◽  
Humidity Index ◽  
Globe Temperature ◽  
Black Globe Temperature

The objectives of the present study were to evaluate the effect of heat load, bodyweight and dietary protein on oxygen pulse of heifers, to obtain the energy cost of walking on flat and sloping terrain, and to compare the energy cost of heifers during continuous walking and intermittent walking. In Experiment 1, the correlations of oxygen consumption, heart rate and oxygen pulse (O2P) with bodyweight, black globe temperature and temperature and humidity index were examined. Moreover, the effect of dietary protein on O2P was evaluated. The temperature and humidity index and black globe temperature had a low positive correlation with O2P and oxygen consumption, and a low negative correlation with heart rate. However, weight had no correlation with O2P. There was a linear increase in O2P with a very low adjustment with an increasing dietary crude protein concentration. In Experiment 2, the energy cost of heifers walking continuously at a constant speed in a terrain with 0%, 6% and 12% gradient was measured. The energy expenditure was similar among the terrain gradients. The heifers walking had a 16.6% higher energy expenditure than when they were standing. In Experiment 3, a comparison of the energy cost was made among heifers standing, continuously walking and intermittently walking at a constant speed on flat ground. The energy cost for walking was similar between continuous and intermittent walking. The heat load, bodyweight and dietary protein concentration had a low effect on O2P in dairy heifers. Therefore, measurements over a short time (5–15 min) are a reliable estimator of O2P through the day. Both intermittent and continuous walking can be used to evaluate energy expenditure.

scholarly journals Perubahan Temperature Humidity Index (THI) di Pulau Jawa sejak 1981 hingga 2019

2021 ◽  
Vol 35 (2) ◽  
Author(s):  
Qurrata A'yun Kartika ◽  
Rahmat Hidayat ◽  
Rista Hernandi Virgianto
Keyword(s):  
Thermal Stress ◽  
Relative Humidity ◽  
Air Temperature ◽  
Pearson Correlation ◽  
Surface Air Temperature ◽  
North Coast ◽  
Anthropogenic Activity ◽  
Temperature Humidity Index ◽  
The North ◽  
Humidity Index

Abstrak Pulau Jawa mengalami peningkatan jumlah penduduk dari waktu ke waktu. Peningkatan ini berdampak pada tingginya aktivitas antropogenik yang menghasilkan emisi yang diantaranya dapat menyebabkan perubahan suhu udara. Suhu udara sangat berkaitan dengan thermal stress yang mempengaruhi kenyamanan bahkan kesehatan manusia. Thermal stress dapat diukur dengan Temperature Humidity Index (THI) dengan suhu udara rata-rata permukaan dan Relative Humidity (RH) sebagai variabel bebas. Penelitian ini menganalisis sejauh mana perubahan suhu udara permukaan, RH dan THI terhadap waktu. Kemudian daerah dengan perubahan THI yang paling besar akan dianalisis keterkaitannya jumlah penduduk menggunakan korelasi Pearson. Berdasarkan hasil penelitian diketahui terjadi perubahan suhu udara udara permukaan sebesar -0.27 hingga 1.17⁰C diikuti perubahan RH sebesar -2.21% hingga 0.77% dan terjadi perubahan THI hingga 0,72⁰C sejak 1981 hingga 2019 terutama di pesisir utara bagian barat Pulau Jawa. Selain itu, THI di sekitar DKI Jakarta juga memiliki nilai korelasi simultan yang tinggi dengan jumlah penduduk sebesar 0,81, korelasi lag 1 tahun sebesar 0,69, sementara korelasi lag 2 tahun sebesar 0,67. Temuan ini mengindikasikan peningkatan jumlah penduduk berdampak terhadap peningkatan THI pada DKI Jakarta. Abstract Java has experienced an increase in population from time to time. This increase has an impact on high anthropogenic activity which results in emissions, which can cause changes in air temperature. Air temperature is closely related to thermal stress which affects comfort and even human health. Thermal stress can be measured by the Temperature Humidity Index (THI) with the average surface air temperature and Relative Humidity (RH) as the independent variable. This study analyzes the extent of changes in surface air temperature, RH and THI with time. Then the areas with the greatest THI changes will be analyzed for their correlation using the Pearson correlation. Based on the research results, it is found that there has been a change in surface air temperature of -0.27 to 1.17⁰C followed by changes in RH from -2.21% to 0.77% and there has been a change in THI to 0.72⁰C from 1981 to 2019, especially on the north coast of the western part of Java. In addition, THI around DKI Jakarta also has a high simultaneous correlation value with a population of 0.81, a 1-year lag correlation of 0.69, while a 2-year lag correlation of 0.67. These findings indicate an increase in population has an impact on increasing THI in DKI Jakarta. 

scholarly journals IDENTIFIKASI IKLIM MIKRO DAN KENYAMAN TERMAL RUANG TERBUKA HIJAU DI KENDARI

NALARs ◽  
2019 ◽  
Vol 18 (1) ◽  
pp. 23
Author(s):  
Santi Santi ◽  
Siti Belinda ◽  
Hapsa Rianty
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Open Space ◽  
Heat Island ◽  
Open Spaces ◽  
Temperature Humidity Index ◽  
Humidity Index ◽  
Urban Heat ◽  
The City

ABSTRAK. Fenomena UHI (Urban Heat Island) mengakibatkan suhu udara perkotaan menjadi tinggi, sehingga menurunkan kualitas lingkungan kota. Untuk dapat meningkatkan kualitas kota dan mengimbangi pertumbuhan kota, maka pemerintah menggalakkan pengembangan infrastruktur hijau perkotaan melalui pengembangan Ruang Terbuka Hijau (RTH). Kota Kendari memiliki beberapa ruang terbuka yang beberapa diantaranya merupakan pusat aktifitas dan interaksi masyarakat kota, diantaranya Taman Walikota dan Pelataran Tugu Religi. Penelitian ini merupakan penelitian deskriptif untuk mengetahui kondisi iklim mikro dan kenyamanan termal ruang terbuka. Data-data yang dikumpulkan berupa karakteristik dan nilai indikator iklim mikro yang meliputi suhu udara, kelembaban relatif, dan kecepatan angin pada sejumlah titik ukur pada siang hari. Data yang dikumpulkan dianalisis menggunakan uji Statistik Independent T Test untuk mengetahui perbedaan iklim mikro antara kedua lokasi dan analisis Temperature Humidity Index (THI) untuk mengetahui tingkat kenyamanannya. Hasil dari uji statistik menunjukkan tingkat perbedaan yang tidak sigifikan antara kedua lokasi, meliputi suhu udara (sig.=0,283); kelembaban relatif (sig.=0,115); dan kecepatan angin (sig.=0,105). Sementara itu, melalui analisia THI menunjukkan nilai index tidak nyaman hampir terjadi pada keseluruhan titik ukur. Nilai THI tertinggi pada lokasi Taman Walikota terletak pada titik A5 (THI=31,9), yaitu pada daerah memiliki kecepatan angin rendah karena posisinya pada bagian tengah kawasan. Sedangkan pada lokasi pelataran Tugu Religi, nilai terendah THI diperoleh pada titik B9 (THI=33,12), yakni titik yang sebagian besar material permukaan lahannya berupa aspal. Kata kunci: ruang terbuka, temperatur, angin, kelembaban relatif, Temperature Humidity Index ABSTRACT. The UHI (Urban Heat Island) phenomenon affected urban air temperatures become high, which decreases the quality of the city environment. To be able to improve the quality of the city and to balance the growth of the city, the government promotes the development of urban green infrastructure through the development of Green Open Space (RTH). Kendari City has several open spaces, some of which are the center of the activities and interactions of urban communities, including the Taman Walikota and the Pelataran Tugu Religi. This research is a descriptive study to determine the microclimate conditions and thermal comfort of open spaces. The data collected is in the form of characteristics and values of microclimate indicators which include air temperature, relative humidity, and wind speed at some measuring points during the day. The collected data were analyzed using the Independent T-Test Statistic Test to determine the differences in microclimate between the two locations and the Temperature Humidity Index (THI) analysis to determine the level of comfort. The results of the statistical tests show a significant level of difference between the two locations, including air temperature (sig. = 0.283); relative humidity (sig. = 0.115); and wind speed (sig. = 0.105). Meanwhile, through THI analysis, the uncomfortable index value almost occurs at the whole measuring point. The highest THI value in the location of the Taman Walikota is located at point A5 (THI = 31.9), which is in the area with low wind speed because of its position in the central part of the city. Whereas in the location of the Pelataran Tugu Religi, the lowest value of THI is obtained at point B9 (THI = 33.12), which is the point where most of the surface material in the land is asphalt. Keywords: open space, temperature, wind, relative humidity, Temperature Humidity Index 

scholarly journals Rumus Indeks Ketidaknyamanan Suatu Wilayah

2013 ◽  
Vol 2 (1) ◽  
pp. 19
Author(s):  
Sugiasih Sugiasih
Keyword(s):  
Wind Speed ◽  
Air Temperature ◽  
Air Humidity ◽  
Comfort Index ◽  
Main Street ◽  
Temperature Humidity Index ◽  
Humidity Index ◽  
Discomfort Index

Index of discomfort can be determined, this value is to accommodate everyone at level how  humans are considered to be comfortable on a place. There are three who wrote formulas i.e., Discomfort Index (DI), temperature Humidity Index (THI) and Comfort Index (CI). In addition to air temperature, air humidity, wind speed there that affect the comfort of a place, such as the density of buildings, distance to the center of the industry, the distance to the center of the trade, the distance to the main street, the coverage of vegetation in the area of the settlements.

scholarly journals Thermal Performance of Single-Story Air-Welled Terraced House in Malaysia: A Field Measurement Approach

2020 ◽  
Vol 13 (1) ◽  
pp. 201
Author(s):  
Pau Chung Leng ◽  
Gabriel Hoh Teck Ling ◽  
Mohd Hamdan Ahmad ◽  
Dilshan Remaz Ossen ◽  
Eeydzah Aminudin ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Thermal Performance ◽  
Field Measurement ◽  
Natural Ventilation ◽  
Residential Buildings ◽  
Wet Bulb Globe Temperature ◽  
Natural Lighting ◽  
Ventilation Performance ◽  
Globe Temperature

The provision requirement of 10% openings of the total floor area stated in the Uniform Building By-Law 1984 Malaysia is essential for natural lighting and ventilation purposes. However, focusing on natural ventilation, the effectiveness of thermal performance in landed residential buildings has never been empirically measured and proven, as most of the research emphasized simulation modeling lacking sufficient empirical validation. Therefore, this paper drawing on field measurement investigates natural ventilation performance in terraced housing with an air-well system. The key concern as to what extent the current air-well system serving as a ventilator is effective to provide better thermal performance is to be addressed. By adopting an existing single-story air-welled terrace house, indoor environmental conditions and thermal performance were monitored and measured using HOBO U12 air temperature and humidity, the HOBO U12 anemometer, and the Delta Ohm HD32.3 Wet Bulb Globe Temperature meter for a six-month duration. The results show that the air temperature of the air well ranged from 27.48 °C to 30.92 °C, with a mean relative humidity of 72.67% to 79.25%. The mean air temperature for a test room (single-sided ventilation room) ranged from 28.04 °C to 30.92 °C, with a relative humidity of 70.16% to 76.00%. These empirical findings are of importance, offering novel policy insights and suggestions. Since the minimum provision of 10% openings has been revealed to be less effective to provide desirable thermal performance and comfort, mandatory compliance with and the necessity of the bylaw requirement should be revisited.

scholarly journals Potential Evapotranspiration Reduction and Its Influence on Crop Yield in the North China Plain in 1961–2014

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Wanlin Dong ◽  
Chao Li ◽  
Qi Hu ◽  
Feifei Pan ◽  
Jyoti Bhandari ◽  
...  
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Crop Yield ◽  
North China Plain ◽  
North China ◽  
Potential Evapotranspiration ◽  
The North ◽  
The North China Plain ◽  
Sunshine Hours ◽  
Humidity Index

Climate change has caused uneven changes in hydrological processes (precipitation and evapotranspiration) on a space-temporal scale, which would influence climate types, eventually impact agricultural production. Based on data from 61 meteorological stations from 1961 to 2014 in the North China Plain (NCP), the spatiotemporal characteristics of climate variables, such as humidity index, precipitation, and potential evapotranspiration (ET0), were analyzed. The sensitivity coefficients and contribution rates were applied to ET0. The NCP has experienced a semiarid to humid climate from north to south due to the significant decline of ET0 (−13.8 mm decade−1). In the study region, 71.0% of the sites showed a “pan evaporation paradox” phenomenon. Relative humidity had the most negative influence on ET0, while wind speed, sunshine hours, and air temperature had a positive effect on ET0. Wind speed and sunshine hours contributed the most to the spatiotemporal variation of ET0, followed by relative humidity and air temperature. Overall, the key climate factor impacting ET0 was wind speed decline in the NCP, particularly in Beijing and Tianjin. The crop yield in Shandong and Henan provinces was higher than that in the other regions with a higher humidity index. The lower the humidity index in Hebei province, the lower the crop yield. Therefore, potential water shortages and water conflict should be considered in the future because of spatiotemporal humidity variations in the NCP.

Empirical Equations to Estimate Evapotranspiration in Mosul City

2020 ◽  
Vol 27 (4) ◽  
pp. 98-102
Author(s):  
Haqqi Yasin ◽  
Luma Abdullah
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Air Temperature ◽  
Reference Evapotranspiration ◽  
Sunshine Duration ◽  
Food And Agriculture ◽  
Food And Agriculture Organization ◽  
Daily Data ◽  
Daily Sunshine ◽  
Measured Wind Speed

Average daily data of solar radiation, relative humidity, wind speed and air temperature from 1980 to 2008 are used to estimate the daily reference evapotranspiration in the Mosul City, North of Iraq. ETo calculator software with the Penman Monteith method standardized by the Food and Agriculture Organization is used for calculations. Further, a nonlinear regression approach using SPSS Statistics is utilized to drive the daily reference evapotranspiration relationships in which ETo is function to one or more of the average daily air temperature, actual daily sunshine duration, measured wind speed at 2m height and relative humidity

A practical future-scenarios selection tool to breed for heat tolerance in Australian dairy cattle

2017 ◽  
Vol 57 (7) ◽  
pp. 1488 ◽  
Author(s):  
Thuy T. T. Nguyen ◽  
Ben J. Hayes ◽  
Jennie E. Pryce
Keyword(s):  
Heat Tolerance ◽  
Milk Fat ◽  
Heat Load ◽  
Selection Index ◽  
Dairy Herd ◽  
Breeding Value ◽  
Future Scenarios ◽  
Selection Tool ◽  
Temperature Humidity Index ◽  
Humidity Index

Climate change will have an impact on dairy cow performance. When heat stressed, animals consume less feed, followed by a decline in milk yield. Previously, we have found that there is genetic variation in this decline. Selection for increased milk production, a major breeding objective, is expected to reduce heat tolerance (HT), as these traits are genetically unfavourably correlated. We aimed to develop a future-scenarios selection tool to assist farmers in making selection decisions, that combines the current national dairy selection index, known as the balanced performance index (BPI), with a proposed HT genomic estimated breeding value (GEBV). Heat-tolerance GEBV was estimated for 12 062 genotyped cows and 10 981 bulls, using an established genomic-prediction equation. Publicly available future daily average temperature and humidity data were used to estimate mean daily temperature–humidity index for each dairy herd. An economic estimate of an individual cow’s heat-tolerance breeding value (BV_HT) was calculated by multiplying head-tolerance GEBVs for milk, fat and protein by their respective economic values that are already used in the BPI. This was scaled for each region by multiplying BV_HT by the heat load, which is the temperature–humidity index units exceeding the threshold per year at a particular location. BV_HT were incorporated into the BPI as: BPI_HT = BPI + BV_HT; where BPI_HT is the ‘augmented BPI’ breeding value including HT. A web-based application was developed enabling farmers to predict the future heat load of a herd and take steps to aim at genetic improvement in future generations by selecting bulls and cows that rank high for the ‘augmented BPI’.

The atmospheric conditions affecting sporulation of blue mould in tobacco

1964 ◽  
Vol 4 (13) ◽  
pp. 178 ◽  
Author(s):  
BG Collins
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Air Temperature ◽  
Critical Parameter ◽  
Leaf Surface ◽  
Atmospheric Conditions ◽  
Blue Mould ◽  
Growing Seasons ◽  
Ambient Relative Humidity ◽  
Critical Relative Humidity

Conditions favouring sporulation of blue mould (Peronospora tabacina Adam) having been established in the laboratory, a theoretical model has now been used to express the critical parameter, i.e. the relative humidity near the leaf surface where the spores form, in terms of the ambient atmospheric conditions. To test the validity of this model, wind speed, air temperature, and relative humidity mere measured over four growing seasons in three tobacco crops in the Ovens Valley, Victoria, and related to times of sporulation of the mould observed concurrently in these crops. 'Critical relative humidity,' a function of wind speed, air temperature, and heat loss from the crop is shown to be a more serviceable indicator of likelihood of sporulation than either ambient relative humidity or rainfall.

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