[ Objective] The research aimed to study differences of temperature and humidity and vertical distribution of human comfort between city and countryside of Heilongjiang in summer. [Method] By using temperature, humidi...[ Objective] The research aimed to study differences of temperature and humidity and vertical distribution of human comfort between city and countryside of Heilongjiang in summer. [Method] By using temperature, humidity and wind velocity data at 10 and 70 m of two iron towers in urban and rural districts of Heilongjiang from June 1 to August 31,2010, the characteristics at temperature and humidity fields and change rule of human comfort index in urban and rural areas in summer were analyzed. [Result] Compared with rural areas, heat island effect of urban districts was obvious, and it was the strongest during 21：00 -23：00 and the weakest during 05：00 -06：00. Daily change rules of wind velocity at 10 m of two anemometer towers were basically consistent. Wind velocity was big at daytime and small at night. Daily change of wind velocity at 70 m of urban districts was consistent with that at 10 m, while wind velocity change at 70 m of rural areas was different from that at 10 m, which had obvious high-altitude wind characteristics. Daily change rules of humidity in two towers were basically consistent, and occurrence time of extremum at 70 m delayed for 1 h. At vertical height, humidity at 10 m was higher than that at 70 m at daytime, and was lower than that at 70 m at night. [ Conclusion] The city had obvious wet island effect during 00：00 -06：00 and dry island effect at nightfall. Comfort index of urban districts was higher than that in rural areas, and difference was the maximum during 19：00 -21：00. Comfort index at 10 m was higher than that at 70 m at daytime in the city and countryside, and was lower than that at 70 m at night. Occurrence frequencies of Grade Zero of comfort at 10 and 70 m of urban districts were both over 60%, while occurrence frequency of ≥ Grade Three of comfort was very small. At vertical height, human comfort had small difference at night. At daytime, as height rise, human comfort index significantly declined, and human feeling was more comfortable than that at low layer.展开更多
Upper limit of thermal stability and subsequent rise of thermoregulatory functions are affected by body temperature. This study was designed to determine the effects of rectal temperature (RT) on dairy cows’ performa...Upper limit of thermal stability and subsequent rise of thermoregulatory functions are affected by body temperature. This study was designed to determine the effects of rectal temperature (RT) on dairy cows’ performance (heart rates (HR), respiratory rates (RR), milk yield (MY), dry matter intake (DMI), digestibility, plasma concentration of vitamin C under hot climate. This study was carried out in 2009, in north-west of Tunisia using 30 Holstein cows in mid lactation. The experiment was performed in spring (15th of February-15th of March: P1) and summer (1st-30th of August: P2). On each test day, temperature-humidity index (THI), RT, HR, RR, MY, DMI, digestibility and plasma VC concentration were determined. All this parameters were affected (P < 0.001) when the THI increased from 65.62 (P1) to 83.27 (P2). Regression analyses were carried out between THI index and some parameters (HR, RR, MY, DMI, digestibility, plasma concentration of vitamin C) and between RT and same parameters (HR, RR, MY, DMI, digestibility, plasma concentration of vitamin C). Characteristics of regression analyses in the two modes were different as also were R<sup>2</sup> and r (correlation coefficient) of the regressions. R<sup>2</sup> in regressions on RT (R<sup>2</sup> (RT, DMI) = 0.92 (P < 0.01);R<sup>2</sup> (RT, MY) = 0.91 (P < 0.001)) was markedly higher relative to R<sup>2</sup> in regressions on THI (R<sup>2</sup> (THI, DMI) = 0.76 (P < 0.001);R<sup>2 </sup>(THI, MY) = 0.63 (P < 0.001)). The two regressions modes suggest that increasing R<sup>2</sup> in regressions on RT confirms that rectal temperature constitutes a larger component of total variance of responses in dairy cows to hot environmental temperature.展开更多
<span style="font-family:Verdana;">This study examines the correlation between solar UVB and different weather parameters in Kuwait climate. To achieve that purpose, an experimental outdoor facility is...<span style="font-family:Verdana;">This study examines the correlation between solar UVB and different weather parameters in Kuwait climate. To achieve that purpose, an experimental outdoor facility is designed and set up at the College of Technological Studies, Kuwait for regular monitoring of solar global radiation, UVB radiation and ambient temperature in Kuwait from beginning of January 1</span><sup><span style="font-family:Verdana;">st</span></sup><span style="font-family:Verdana;"> 2014 until the end of December 2019. Outcomes reveal that the change of solar UVB as well as global radiation through the whole day inaugurate the same behavior for t</span><span style="font-family:Verdana;">he recorded data in clear day times. Statistical analysis is carried out to ob</span><span style="font-family:Verdana;">tain a correlation linking UVB radiation and both ambient temperature and </span><span style="font-family:Verdana;">global solar radiation. Regression analysis of the current work shows that ther</span><span style="font-family:Verdana;">e is a solid correlation among UVB radiation and both ambient temperature and g</span><span style="font-family:Verdana;">lobal solar radiation, especially for intermedia</span><span style="font-family:Verdana;">te to small global solar radiation ranges. In addition, UV index is evaluated for various months at all day times. It is important to record that UV index with the maximum values is attained in May-August months through midday period. Also, UV index values do not surpass the accepted extreme value which is higher than 9 during any time of the study period.</span>展开更多
The objective of this work is to analyze the temporal and spatial variability of the monthly mean aerosol index (AI) obtained from the Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI) in c...The objective of this work is to analyze the temporal and spatial variability of the monthly mean aerosol index (AI) obtained from the Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI) in comparison with the available ground observations in Nigeria during 1984-2013. It also aims at developing a regression model to allow the estimation of the values of AI in Nigeria based on the data from ground observations. TOMS and OMI data are considered and treated separately to provide continuity and consistency in the long-term data observations, together with the meteorological variable such as wind speed, visibility, air temperature and relative humidity that can be used to characterize the dust activity in Nigeria. The results revealed a strong seasonal pattern of the monthly distribution and variability of absorbing aerosols along a north to south gradient. The monthly mean AI showed higher values during the dry months (Harmattan) and lower values during the wet months (Summer) in all zones. From December to February, higher AI values are observed in the southern region, decreasing progressively towards the north, while during March-October, the opposite pattern is observed. The AI showed clear maximum values of 2.06, 1.93, and 1.87 (TOMS) and 2.32, 2.27 and 2.24 (OMI) in the month of January and minimum values in September over the north-central, southern and coastal zones, while showing maximum values of 1.76 (TOMS) and 2.10 (OMI) during March in the Sahel. New empirical algorithms for predicting missing AI data were proposed using TOMS data and multiple linear regression, and the model co-efficient was determined. The generated coefficients were applied to another dataset for cross-validation. The accuracy of the model was determined using the coefficient of determination R<sup>2</sup> and the root mean square error (RMSE) calculated at the 95% confidence level. The AI values for the missing years were retrieved, plotted and compared with the measured monthly AI cycle. It is concluded that the meteorological variables can significantly explain the AI variability and can be used efficiently to predict the missing AI data.展开更多
The influence of daytime tropical heat stress in the summer was studied in Holstein and Jersey heifers already acclimatized to tropical environments to determine their physiological response based on body thermal patt...The influence of daytime tropical heat stress in the summer was studied in Holstein and Jersey heifers already acclimatized to tropical environments to determine their physiological response based on body thermal patterns and respiratory alterations according to psychrometric caloric indicators. Daytime psychrometric elements showed a tropical caloric potential for developing moderate to severe heat stress in dairy cattle. Body temperature and respiratory rate increased in both breeds open and pregnant (P < 0.01). Thermal body overload and respiratory works increased from 09 am to 12 md (P < 0.001);reaching and sustaining hyperthermia under the highest caloric pressure from 12 md to 03 pm. Rectal temperature increased +1.5˚C in open Holstein (OH), +1.3˚C in pregnant Holstein (PH), +0.8˚C in open jersey (OJ) and +0.8˚C in pregnant Jersey (PJ). The lowest heat stress index (HSI) was at 06 am, where OH and PH showed a HIS +2.25 and +2.30 and OJ and PJ +2.34 and +2.38. Maximum heat stress occurred at 12 md where OH averaged +3.28 and Pregnant Holsteins showed +3.85 at 03 pm. Open Jersey (OJ) showed a maximum HSI at 12 md (3.54) and PJ resulted in +3.89 at 03 pm. Open and pregnant Jersey heifers were more tolerant to heat stress based on lower body mass, insulation, feed consumption and greater relation between body surface and metabolic body size for thermolysis. Acclimatization between five and twenty-five months under tropical heat stress allowed Holstein and Jersey heifers to develop thermal tolerance. Middle thermal acclimatization lowered thermal sensitivity, hyperthermia and hyperpnea in Holstein and Jersey heifers in the morning;however, pregnant heifers in both breeds showed higher thermal alteration in the afternoon. Tropical acclimatization at low altitudes could be integrated with environmental improvements and nutritional and health management to reduce influences of severe heat stress and improve physiological comfort and welfare in Holstein and Jersey heifers in the summer. Those combined strategies will reduce daytime thermal and respiratory responses and allow growth, pregnancy and health with lower body heat overload and less hyperthermia.展开更多
文摘[ Objective] The research aimed to study differences of temperature and humidity and vertical distribution of human comfort between city and countryside of Heilongjiang in summer. [Method] By using temperature, humidity and wind velocity data at 10 and 70 m of two iron towers in urban and rural districts of Heilongjiang from June 1 to August 31,2010, the characteristics at temperature and humidity fields and change rule of human comfort index in urban and rural areas in summer were analyzed. [Result] Compared with rural areas, heat island effect of urban districts was obvious, and it was the strongest during 21：00 -23：00 and the weakest during 05：00 -06：00. Daily change rules of wind velocity at 10 m of two anemometer towers were basically consistent. Wind velocity was big at daytime and small at night. Daily change of wind velocity at 70 m of urban districts was consistent with that at 10 m, while wind velocity change at 70 m of rural areas was different from that at 10 m, which had obvious high-altitude wind characteristics. Daily change rules of humidity in two towers were basically consistent, and occurrence time of extremum at 70 m delayed for 1 h. At vertical height, humidity at 10 m was higher than that at 70 m at daytime, and was lower than that at 70 m at night. [ Conclusion] The city had obvious wet island effect during 00：00 -06：00 and dry island effect at nightfall. Comfort index of urban districts was higher than that in rural areas, and difference was the maximum during 19：00 -21：00. Comfort index at 10 m was higher than that at 70 m at daytime in the city and countryside, and was lower than that at 70 m at night. Occurrence frequencies of Grade Zero of comfort at 10 and 70 m of urban districts were both over 60%, while occurrence frequency of ≥ Grade Three of comfort was very small. At vertical height, human comfort had small difference at night. At daytime, as height rise, human comfort index significantly declined, and human feeling was more comfortable than that at low layer.
文摘Upper limit of thermal stability and subsequent rise of thermoregulatory functions are affected by body temperature. This study was designed to determine the effects of rectal temperature (RT) on dairy cows’ performance (heart rates (HR), respiratory rates (RR), milk yield (MY), dry matter intake (DMI), digestibility, plasma concentration of vitamin C under hot climate. This study was carried out in 2009, in north-west of Tunisia using 30 Holstein cows in mid lactation. The experiment was performed in spring (15th of February-15th of March: P1) and summer (1st-30th of August: P2). On each test day, temperature-humidity index (THI), RT, HR, RR, MY, DMI, digestibility and plasma VC concentration were determined. All this parameters were affected (P < 0.001) when the THI increased from 65.62 (P1) to 83.27 (P2). Regression analyses were carried out between THI index and some parameters (HR, RR, MY, DMI, digestibility, plasma concentration of vitamin C) and between RT and same parameters (HR, RR, MY, DMI, digestibility, plasma concentration of vitamin C). Characteristics of regression analyses in the two modes were different as also were R<sup>2</sup> and r (correlation coefficient) of the regressions. R<sup>2</sup> in regressions on RT (R<sup>2</sup> (RT, DMI) = 0.92 (P < 0.01);R<sup>2</sup> (RT, MY) = 0.91 (P < 0.001)) was markedly higher relative to R<sup>2</sup> in regressions on THI (R<sup>2</sup> (THI, DMI) = 0.76 (P < 0.001);R<sup>2 </sup>(THI, MY) = 0.63 (P < 0.001)). The two regressions modes suggest that increasing R<sup>2</sup> in regressions on RT confirms that rectal temperature constitutes a larger component of total variance of responses in dairy cows to hot environmental temperature.
文摘<span style="font-family:Verdana;">This study examines the correlation between solar UVB and different weather parameters in Kuwait climate. To achieve that purpose, an experimental outdoor facility is designed and set up at the College of Technological Studies, Kuwait for regular monitoring of solar global radiation, UVB radiation and ambient temperature in Kuwait from beginning of January 1</span><sup><span style="font-family:Verdana;">st</span></sup><span style="font-family:Verdana;"> 2014 until the end of December 2019. Outcomes reveal that the change of solar UVB as well as global radiation through the whole day inaugurate the same behavior for t</span><span style="font-family:Verdana;">he recorded data in clear day times. Statistical analysis is carried out to ob</span><span style="font-family:Verdana;">tain a correlation linking UVB radiation and both ambient temperature and </span><span style="font-family:Verdana;">global solar radiation. Regression analysis of the current work shows that ther</span><span style="font-family:Verdana;">e is a solid correlation among UVB radiation and both ambient temperature and g</span><span style="font-family:Verdana;">lobal solar radiation, especially for intermedia</span><span style="font-family:Verdana;">te to small global solar radiation ranges. In addition, UV index is evaluated for various months at all day times. It is important to record that UV index with the maximum values is attained in May-August months through midday period. Also, UV index values do not surpass the accepted extreme value which is higher than 9 during any time of the study period.</span>
文摘The objective of this work is to analyze the temporal and spatial variability of the monthly mean aerosol index (AI) obtained from the Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI) in comparison with the available ground observations in Nigeria during 1984-2013. It also aims at developing a regression model to allow the estimation of the values of AI in Nigeria based on the data from ground observations. TOMS and OMI data are considered and treated separately to provide continuity and consistency in the long-term data observations, together with the meteorological variable such as wind speed, visibility, air temperature and relative humidity that can be used to characterize the dust activity in Nigeria. The results revealed a strong seasonal pattern of the monthly distribution and variability of absorbing aerosols along a north to south gradient. The monthly mean AI showed higher values during the dry months (Harmattan) and lower values during the wet months (Summer) in all zones. From December to February, higher AI values are observed in the southern region, decreasing progressively towards the north, while during March-October, the opposite pattern is observed. The AI showed clear maximum values of 2.06, 1.93, and 1.87 (TOMS) and 2.32, 2.27 and 2.24 (OMI) in the month of January and minimum values in September over the north-central, southern and coastal zones, while showing maximum values of 1.76 (TOMS) and 2.10 (OMI) during March in the Sahel. New empirical algorithms for predicting missing AI data were proposed using TOMS data and multiple linear regression, and the model co-efficient was determined. The generated coefficients were applied to another dataset for cross-validation. The accuracy of the model was determined using the coefficient of determination R<sup>2</sup> and the root mean square error (RMSE) calculated at the 95% confidence level. The AI values for the missing years were retrieved, plotted and compared with the measured monthly AI cycle. It is concluded that the meteorological variables can significantly explain the AI variability and can be used efficiently to predict the missing AI data.
文摘The influence of daytime tropical heat stress in the summer was studied in Holstein and Jersey heifers already acclimatized to tropical environments to determine their physiological response based on body thermal patterns and respiratory alterations according to psychrometric caloric indicators. Daytime psychrometric elements showed a tropical caloric potential for developing moderate to severe heat stress in dairy cattle. Body temperature and respiratory rate increased in both breeds open and pregnant (P < 0.01). Thermal body overload and respiratory works increased from 09 am to 12 md (P < 0.001);reaching and sustaining hyperthermia under the highest caloric pressure from 12 md to 03 pm. Rectal temperature increased +1.5˚C in open Holstein (OH), +1.3˚C in pregnant Holstein (PH), +0.8˚C in open jersey (OJ) and +0.8˚C in pregnant Jersey (PJ). The lowest heat stress index (HSI) was at 06 am, where OH and PH showed a HIS +2.25 and +2.30 and OJ and PJ +2.34 and +2.38. Maximum heat stress occurred at 12 md where OH averaged +3.28 and Pregnant Holsteins showed +3.85 at 03 pm. Open Jersey (OJ) showed a maximum HSI at 12 md (3.54) and PJ resulted in +3.89 at 03 pm. Open and pregnant Jersey heifers were more tolerant to heat stress based on lower body mass, insulation, feed consumption and greater relation between body surface and metabolic body size for thermolysis. Acclimatization between five and twenty-five months under tropical heat stress allowed Holstein and Jersey heifers to develop thermal tolerance. Middle thermal acclimatization lowered thermal sensitivity, hyperthermia and hyperpnea in Holstein and Jersey heifers in the morning;however, pregnant heifers in both breeds showed higher thermal alteration in the afternoon. Tropical acclimatization at low altitudes could be integrated with environmental improvements and nutritional and health management to reduce influences of severe heat stress and improve physiological comfort and welfare in Holstein and Jersey heifers in the summer. Those combined strategies will reduce daytime thermal and respiratory responses and allow growth, pregnancy and health with lower body heat overload and less hyperthermia.
