INFLUENCE OF RELATIVE HUMIDITY ON SOLAR RADIATION UNDER PLASTIC-HOUSE CONDITIONS

1988 ◽  
pp. 3342-3346
Author(s):  
A.D. Iyada ◽  
A.W. Al-Kayssi ◽  
E.A. Al-Kereem ◽  
S.A. Beker
Keyword(s):  
Relative Humidity ◽  
Solar Radiation

scholarly journals Detrended Multiple Cross-Correlation Coefficient applied to solar radiation, air temperature and relative humidity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrea de Almeida Brito ◽  
Heráclio Alves de Araújo ◽  
Gilney Figueira Zebende
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Solar Energy ◽  
Correlation Coefficient ◽  
Air Temperature ◽  
Cross Correlation ◽  
Global Solar Radiation ◽  
Meteorological Variables ◽  
Hourly Data ◽  
Cross Correlations

AbstractDue to the importance of generating energy sustainably, with the Sun being a large solar power plant for the Earth, we study the cross-correlations between the main meteorological variables (global solar radiation, air temperature, and relative air humidity) from a global cross-correlation perspective to efficiently capture solar energy. This is done initially between pairs of these variables, with the Detrended Cross-Correlation Coefficient, ρDCCA, and subsequently with the recently developed Multiple Detrended Cross-Correlation Coefficient, $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2. We use the hourly data from three meteorological stations of the Brazilian Institute of Meteorology located in the state of Bahia (Brazil). Initially, with the original data, we set up a color map for each variable to show the time dynamics. After, ρDCCA was calculated, thus obtaining a positive value between the global solar radiation and air temperature, and a negative value between the global solar radiation and air relative humidity, for all time scales. Finally, for the first time, was applied $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2 to analyze cross-correlations between three meteorological variables at the same time. On taking the global radiation as the dependent variable, and assuming that $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}={\bf{1}}$$DMCx2=1 (which varies from 0 to 1) is the ideal value for the capture of solar energy, our analysis finds some patterns (differences) involving these meteorological stations with a high intensity of annual solar radiation.

scholarly journals Solar Radiation, Air Temperature, Relative Humidity, and Dew Point Study: Damak, Jhapa, Nepal

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Arun Kumar Shrestha ◽  
Arati Thapa ◽  
Hima Gautam
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Air Temperature ◽  
Gaussian Function ◽  
Great Influence ◽  
Dew Point ◽  
Upward Trend ◽  
Summer Maximum ◽  
Online Calculator ◽  
Climatic Phenomenon

Monitoring and prediction of the climatic phenomenon are of keen interest in recent years because it has great influence in the lives of people and their environments. This paper is aimed at reporting the variation of daily and monthly solar radiation, air temperature, relative humidity (RH), and dew point over the year of 2013 based on the data obtained from the weather station situated in Damak, Nepal. The result shows that on a clear day, the variation of solar radiation and RH follows the Gaussian function in which the first one has an upward trend and the second one has a downward trend. However, the change in air temperature satisfies the sine function. The dew point temperature shows somewhat complex behavior. Monthly variation of solar radiation, air temperature, and dew point shows a similar pattern, lower at winter and higher in summer. Maximum solar radiation (331 Wm-2) was observed in May and minimum (170 Wm-2) in December. Air temperature and dew point had the highest value from June to September nearly at 29°C and 25°C, respectively. The lowest value of the relative humidity (55.4%) in April indicates the driest month of the year. Dew point was also calculated from the actual readings of air temperature and relative humidity using the online calculator, and the calculated value showed the exact linear relationship with the observed value. The diurnal and nocturnal temperature of each month showed that temperature difference was relatively lower (less than 10°C) at summer rather than in winter.

scholarly journals DESENVOLVIMENTO DE MUDAS DE CAFEEIRO PRODUZIDAS EM TUBETES SOB MALHAS TERMO-REFLETORAS E MALHA NEGRA

Irriga ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 52 ◽  
Author(s):  
Vinícios Maia Costa ◽  
Marcos Vinícios Folegatti ◽  
Roberto Terumi Atarassi ◽  
Sérgio Nascimento Duarte ◽  
Nildo Da Silva Dias ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Leaf Area ◽  
Coffea Arabica ◽  
Dry Matter ◽  
Significant Difference ◽  
Stalk Diameter ◽  
E Mail ◽  
Coffea Arabica L

DESENVOLVIMENTO DE MUDAS DE CAFEEIRO PRODUZIDAS EM TUBETES SOB MALHAS TERMO-REFLETORAS E MALHA NEGRA VINÍCIUS MAIA COSTA1; MARCOS VINÍCIUS FOLEGATTI2; ROBERTO TERUMI ATARASSI3; SÉRGIO NASCIMENTO DUARTE4; NILDO DA SILVA DIAS5 E CLAUDIO RICARDO DA SILVA6.  [1] Mestre em Agronomia, Depto. de Engenharia de Biossistemas, ESALQ-USP, Piracicaba – SP. E-mail: [email protected]. Titular, Depto. de Engenharia de Biossistemas, ESALQ-USP, Piracicaba – SP. E-mail: [email protected] de Ciências Agrárias, UFU, Av. Amazonas, s/n, Bloco 2E, Campus Umuarama, 38400-902, Uberlândia-MG. E-mail: [email protected]. Associado, Depto. de Engenharia de Biossistemas, ESALQ-USP, Piracicaba – SP. E-mail: [email protected] Associado 2, Departamento de Ciências Ambientais e Tecnológicas, Universidade Federal Rural do Semi-Árido, Mossoró, RN. E-mail: [email protected] de Ciências Agrárias, UFU, Av. Amazonas, s/n, Bloco 2E, Campus Umuarama, 38400-902, Uberlândia-MG. E-mail: [email protected].  1 RESUMO Este experimento avaliou, em casa de vegetação, o desenvolvimento de mudas de cafeeiro produzidas em tubetes, sob o efeito de malhas utilizadas para sombreamento. Os tratamentos foram a tradicional malha negra 50% e as malhas termo-refletoras com atenuação da radiação solar de 40, 50, 60 e 70%. O delineamento experimental adotado foi em blocos casualizados contendo os 5 tratamentos, com 4 repetições, totalizando-se assim 20 parcelas. Os resultados mostram que temperatura do ar pouco variou no microclima protegido das parcelas, assim como a umidade relativa do ar e a transmissividade global (TRG) e fotossinteticamente ativa (TRFA). Verificou-se que malhas com menor atenuação da radiação solar apresentaram em geral maior transmissividade. A área foliar não apresentou diferença significativa entre os tratamentos; já para altura da planta e diâmetro do caule, verificou-se que as mudas produzidas sob as malhas termo-refletoras 40 e 50% foram superiores àquelas produzidas sob malha negra 50% e malhas termo-refletoras 60 e 70%, respectivamente. Nas avaliações de matéria seca, verificou-se que as mudas produzidas sob as malhas termo-refletoras 40% e 50% e malha negra 50% acumularam mais matéria seca comparativamente àquelas produzidas sob malhas termo-refletoras 60 e 70%. Assim, concluiu-se que as malhas termo-refletoras 40 e 50% e negra 50% apresentaram melhores resultados que as malhas termo-refletoras 60 e 70%. Palavras-chave: Coffea arábica L., sombreamento, ambiente protegido.  COSTA, V.M.; FOLEGATTI, M.V.; ATARASSI, R.T.; DUARTE, S.N.; DIAS, N.S.; SILVA, C.R. DEVELOPMENT OF COFFEE SEEDLINGS PRODUCED IN PLASTIC TUBESUNDER TERMO-REFLECTIVE AND BLACK SCREENS   2 ABSTRACT This experiment evaluated, in greenhouse conditions, the development of coffee seedlings produced in plastic tubes, under the effect of screens used for shading. The treatments were the traditional black screen 50% and the thermo reflective screens with attenuation of the solar radiation of 40, 50, 60 and 70%. The adopted experimental delineation was randomized blocks with 5 treatments and 4 replicates, making up 20 parcels. The result showed that the temperature of air gently varied in the parcels, as well as the air relative humidity.  Relating to global transmissivity (TRG) and photosynthetically active transmissivity (TRFA), it was verified that screens with less attenuation of the solar radiation presented higher transmissivity in general. The leaf area did not present significant difference among the treatments and seedlings height and stalk diameter, the seedlings produced under thermo-reflective screens 40% and 50% were superior to those produced under black screen 50% and thermo-reflective screen 60% and 70%. In the evaluations of dry matter, the seedlings produced under thermo-reflective screens 40% and 50%, and black screen 50% comparatively accumulated more dry matter than those produced under thermo-reflective screens 60% and 70%. Thus, it can be concluded that the thermo-reflective screens 40% and 50% and black screen 50% presented better results than the thermo-reflective screens 60% and 70%. Keywords: Coffea arábica L., shading, greenhouse.

94 The Effects of Weather, Body Weight, and Dry Matter Intake on Total Daily Water Intake in Beef Steers

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 49-50
Author(s):  
Zach S McDaniel ◽  
Zachary K Smith ◽  
Cody Wright ◽  
Michael Gonda ◽  
Himali Wickremasinghe ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Water Intake ◽  
Water System ◽  
Beef Steers ◽  
Beef Calves ◽  
Linear Mixed Effects ◽  
Random Intercept ◽  
Daily Water Intake ◽  
Daily Water

Abstract Weaned angus steers (n = 26; 272.92 + 21.29 kg) were selected to study the effects of weather, predicted daily BW, and DMI on total daily water intake (TDWI) from December 2019 to May 2020 (181 days). Calves were provided with ad libitum access to feed and water, under a monoslope barn, for the duration of the study. In periods of cold stress, cattle were provided with corn stalk bedding within the dry lot, away from the monoslope barn. Measurements of feed and water disappearance were obtained by utilizing an automated feed and water system (Insentec RIC, Hokofarm, Marknesse, Netherlands), where disappearance was assumed to be caused by intake. Calves were weighed every 28 days in order to calculate ADG and therefore predict daily BW for each calf. Daily weather records, including windchill (°C), solar radiation (W/m2), and maximum relative humidity (%), were obtained through the South Dakota Mesonet automated weather station located 3.86 km from where the calves were housed. A linear mixed effects model with both random intercept and slope were used to account for the within subject correlations. Increased TDWI was associated with increased wind chill (0.38-kg per 1°C; P < 0.0001), increased solar radiation (1.04-kg per 1 W/m2; P < 0.0001), and decreased maximum relative humidity (-0.14 kg per 1%; P < 0.0001). For every kg increase in DMI, TDWI increased by 1.07 kg (P < 0.0001). Lastly, for every kg increase in BW, TDWI increased by 0.05 kg (P < 0.0001). Effects of DMI, BW, SRAD, windchill, RHMax were predictive of TDWI in beef calves fed during the winter. This model will be useful for predicting TDWI during the winter months where calves are raised in regions where temperatures are regularly below freezing.

scholarly journals Study on the improvement of indoor hot and humid environment in Tibetan-style residential areas in northwest Sichuan

2020 ◽  
Vol 165 ◽  
pp. 04074
Author(s):  
Sun Yidan
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Wall Temperature ◽  
Thermal Environment ◽  
Cold Weather ◽  
Living Room ◽  
Residential Areas ◽  
The West ◽  
Solar Radiation Intensity ◽  
Indoor And Outdoor

Indoor and outdoor thermal environment is under a definite impact on the human body, and to a large extent affects the comfort of people living. In this paper, the indoor and outdoor thermal and humidity parameters of Dongma village in the west of Sichuan Province were measured. On the living room and bedroom hot and humid comfort survey, the outside wall temperature and the local climate to do analysis, get January Dongma village typical residential indoor humidity environment, including the temperature of the living room is 6.6~19.5°C, the relative humidity is 28.9~45.3%rH, the bedroom temperature is 3.5~19.8°C, the relative humidity is 35.7~52.8%rH, the outdoor temperature is 2.4~27.4°C, the temperature in the east is -11.1~-3.3°C, -3.9~11.2°C at the west, -8~2.8°C at the south, -10.4~-2.5 °C at the north, 1.6~29.2 °C at the roof, and the solar radiation intensity is 422~739W/m^2. Combined with the above data, it is found that the overall insulation performance of the wall is good, but by the influence of the cold weather outside, the indoor temperature is still low, it is difficult to respond to the comfort needs of residents. The wall temperature is altered due to solar radiation. In view of the current situation of the indoor thermal environment in Dongma village, a series of optimization suggestions are submitted at the end of the paper.

scholarly journals A Modified Method to Generate Typical Meteorological Years from the Long-Term Weather Database

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Haixiang Zang ◽  
Qingshan Xu ◽  
Pengwei Du ◽  
Katsuhiro Ichiyanagi
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Solar Energy ◽  
Atmospheric Pressure ◽  
Energy Systems ◽  
Global Solar Radiation ◽  
Weather Data ◽  
Radiation Data ◽  
Modified Method

A modified typical meteorological year (TMY) method is proposed for generating TMY from practical measured weather data. A total of eleven weather indices and novel assigned weighting factors are applied in the processing of forming the TMY database. TMYs of 35 cities in China are generated based on the latest and accurate measured weather data (dry bulb temperature, relative humidity, wind velocity, atmospheric pressure, and daily global solar radiation) in the period of 1994–2010. The TMY data and typical solar radiation data are also investigated and analyzed in this paper, which are important in the utilizations of solar energy systems.

scholarly journals Daytime preservation of surface-hoar crystals

1998 ◽  
Vol 26 ◽  
pp. 22-26 ◽  
Author(s):  
Akihiro Hachikubo ◽  
Eizi Akitaya
Keyword(s):  
Shear Strength ◽  
Surface Layer ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Surface Temperature ◽  
Snow Surface ◽  
Previous Night ◽  
Snow Surface Temperature ◽  
Transfer Method

Surface hoar growing for several clear and humid days were observed. During daytime, air and snow-surface temperature increased and relative humidity decreased, hence evaporation (sublimation) occurred at the snow surface. The amount of evaporation calculated using a bulk-transfer method suggests that the surface-hoar crystals which grew during the previous night should have disappeared but they were observed to survive on the snow surface even during the daytime. During the following night, new surface-hoar crystals formed on top of the older ones and grew even larger. This result indicates that, although the surface-hoar crystals evaporated into the air during the daytime, snow grains beneath the surface were warmed by solar radiation and evaporated to the air. They may partially condense into the surface-hoar crystals and make up for the reduction in size. Depth-hoar crystals formed beneath the snow surface for several days and the surface layer, composed of both types of hoar crystal, showed a very weak shear strength.

scholarly journals Development and Evaluation of Two Pecan Scab Prediction Models

Plant Disease ◽  
2012 ◽  
Vol 96 (9) ◽  
pp. 1358-1364 ◽  
Author(s):  
A. F. Payne ◽  
D. L. Smith
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Disease Severity ◽  
Model Building ◽  
Prediction Models ◽  
Correlated Data ◽  
Dew Point ◽  
Total Solar Radiation ◽  
Rain Event ◽  
Pecan Scab

Fusicladium effusum (syn. Cladosporium caryigenum), causal agent of pecan scab, is the most economically important pathogen of pecan (Carya illinoinensis). A weather-based advisory is currently used in Oklahoma to assess the need for fungicide application and requires the accumulation of scab hours. A scab hour is defined as an hour with average temperature ≥21.1°C and relative humidity ≥90%. To assess the validity of the thresholds in the advisory, repeated ratings of disease severity were taken on fruit at five locations during the 1994–96 and 2009–10 growing seasons, resulting in a total of eight site years. Hourly weather variables were also examined, including temperature, relative humidity, dew point, dew point depression, total solar radiation, and total rainfall. Rain and disease severity were converted to binomial variables where a rain event (≥2.5 mm) and disease severity (≥25%) were coded as 1 and all other events as 0. Logistic regression models adjusted for correlated data were developed using generalized estimating equations. Two models were developed: a temperature/relative humidity model and a dew point/dew point depression model. For the temperature/relative humidity model, the best fitting model included all main effects. Using this model, validation exercises assuming no rain and total solar radiation of 22.5 MJ m–2 resulted in a 0.45 probability of pecan scab development when the temperature was 21°C and relative humidity was 90%. Findings of this model were further validated during field studies that evaluated different combinations of temperature and relative humidity thresholds for scheduling fungicide applications. These analyses indicated that the current thresholds of temperature and relative humidity are viable, but a modification of the relative humidity component should be considered. For the dew point/dew point depression model, a reduced model, including dew point, dew point depression, and the binomial rain variable, was considered adequate for explaining scab events, which suggests that future model building to describe pecan scab epidemics should include dew point, dew point depression, rain, and total solar radiation as independent variables. This article originally appeared in the January issue, Volume 96, pages 117-123. It was changed to correct errors in a measurement conversion that appeared throughout.

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