Many attempts have been made to estimate calorific value of bagasse using mathematical equations, which were created based on data from proximate, ultimate, physical and chemical analysis. Questions have been raised o...Many attempts have been made to estimate calorific value of bagasse using mathematical equations, which were created based on data from proximate, ultimate, physical and chemical analysis. Questions have been raised on the applicability of these equations in different parts of the globe. This study was initiated to tackle these problems and also check the most suited mathematical models for the Law Heating Value of Cameroonian bagasse. Data and bagasse samples were collected at the Cameroonian sugarcane factory. The effects of cane variety, age of harvesting, source, moisture content, and sucrose on the LHV of Cameroon bagasse have been tested. It was shown that humidity does not change within a variety, but changes from the dry season to the rainy season;the sugar in the rainy season is significantly different from that collected in the dry season. Samples of the same variety have identical LHV. LHV in the dry season is significantly different from LHV in the rainy season. According to the fact that this study was done for cane with different ages of harvesting, the maturity of Cameroonian sugarcane does not affect LHV of bagasse. Tree selected models are much superior tool for the prediction of the LHV for bagasse in Cameroon compared to others. The standard deviation of these validated models is around 200 kJ/kg compared to the experimental. Thus, the models determined in foreign countries, are not necessarily applicable in predicting the LHV of bagasse in other countries with the same accuracy as that in their native country. There was linear relationship between humidity, ash and sugar content in the bagasse. It is possible to build models based on data from physical composition of bagasse using regression analysis.展开更多
Farm animals are sources of meat, milk and eggs for the humans, and animal health ensures the quality and security of these agricultural and sideline products. The animal raising conditions in livestock stations and p...Farm animals are sources of meat, milk and eggs for the humans, and animal health ensures the quality and security of these agricultural and sideline products. The animal raising conditions in livestock stations and poultry houses play vital roles in both animal health and production. One of the major factors affecting raising conditions, relative humidity, has not received much attention even though it is important for animal husbandry. In this review, we summarize the impacts of relative humidity on animal health and welfare to draw attention for its importance in the improvement of animal raising conditions in the future.展开更多
Nitrous acid, HNO2, is an important precursor of OH radicals in the troposphere. Measurements of HNO2 and NO2, using differential optical absorption spectroscopy (DOAS), were performed in Shanghai, China for a perio...Nitrous acid, HNO2, is an important precursor of OH radicals in the troposphere. Measurements of HNO2 and NO2, using differential optical absorption spectroscopy (DOAS), were performed in Shanghai, China for a period from October 22, 2004 to January 4, 2005. The mean (and median) hourly concentrations of HNO2 and NO2 during this period were 1.1 (0.7) ppb and 24 (21.4) ppb respectively. A correlation between HNO2/NO2 and PM10 mass concentrations was obtained. This correlation suggests that significant heterogeneous chemical production of HNO2 may occur through NO2 reactions on aerosol surfaces. This hypothesis was further supported by detailed analysis of selected pollution episodes in this study. At the same time, the water dependence of HNO2 formation was studied by analysis of relative humidity (RH). It showed that the maximum HNO2/NO2 ratio was increased along with RH below 70% and inhibited at RH〉70%.展开更多
The cooling and humidifying effects of urban parks are an essential component of city ecosystems in terms of regulating microclimates or mitigating urban heat islands(UHIs).Air temperature and relative humidity are tw...The cooling and humidifying effects of urban parks are an essential component of city ecosystems in terms of regulating microclimates or mitigating urban heat islands(UHIs).Air temperature and relative humidity are two main factors of thermal environmental comfort and have a critical impact on the urban environmental quality of human settlements.We measured the 2-m height air temperature and relative humidity at the Beijing Olympic Park and a nearby building roof for more than 1 year to elucidate seasonal variations in air temperature and relative humidity,as well as to investigate the outdoor thermal comfort.The results showed that the lawn of the park could,on average,reduce the air temperature by(0.80±0.19)℃,and increase the relative humidity by(5.24±2.91)% relative to the values measured at the building roof during daytime.During the nighttime,the lawn of the park reduced the air temperature by(2.64±0.64)℃ and increased the relative humidity by(10.77±5.20)%.The park was cooler and more humid than surrounding building area,especially in night period(more pronounced cooling with 1.84℃).Additionally,the lawn of the park could improve outdoor thermal comfort through its cooling and humidifying effects.The level of thermal comfort in the park was higher than that around the building roof for a total of 11 days annually in which it was above one or more thermal comfort levels(average reduced human comfort index of 0.92)except during the winter.展开更多
Objective Although many studies have examined the effects of ambient temperatures on mortality, little evidence is on health impacts of atmospheric pressure and relative humidity. This study aimed to assess the impact...Objective Although many studies have examined the effects of ambient temperatures on mortality, little evidence is on health impacts of atmospheric pressure and relative humidity. This study aimed to assess the impacts of atmospheric pressure and relative humidity on mortality in Guangzhou, China. Methods This study included 213,737 registered deaths during 2003-2011 in Guangzhou, China. A quasi-Poisson regression with a distributed lag non-linear model was used to assess the effects of atmospheric pressure/relative humidity. Results We found significant effect of low atmospheric pressure/relative humidity on mortality. There was a 1.79% (95% confidence interval: 0.38%-3.22%) increase in non-accidental mortality and a 2.27% (0.07%-4.51%) increase in cardiovascular mortality comparing the 5th and 25th percentile of atmospheric pressure. A 3.97% (0.67%-7.39%) increase in cardiovascular mortality was also observed comparing the 5th and 25th percentile of relative humidity. Women were more vulnerable to decrease in atmospheric pressure and relative humidity than men. Age and education attainment were also potential effect modifiers. Furthermore, low atmospheric pressure and relative humidity increased temperature-related mortality. Conclusion Both low atmospheric pressure and relative humidity are important risk factors of mortality. Our findings would be helpful to develop health risk assessment and climate policy interventions that would better protect vulnerable subgroups of the population.展开更多
The relationship between autogenous deformation and internal relative humidity(IRH) of high-strength concrete and high-strength expansive concrete were investigated.The experimental results indicate that,there exist...The relationship between autogenous deformation and internal relative humidity(IRH) of high-strength concrete and high-strength expansive concrete were investigated.The experimental results indicate that,there exists a good linear relationship between autogenous shrinkage and IRH of high-strength concrete but a nonlinear relationship between autogenous deformation and IRH of high-strength expansive concrete with expansive agent.The new autogenous deformation curve can be obtained by transforming the autogenous deformation data of high-strength expansive concrete,and there exists linear relationship between the autogenous deformation and IRH.The concept of "critical internal relative humidity" was proposed,which is defined as the value of IRH when autogenous deformation is zero,to effectively reflect the autogenous deformation characteristic of expansive concrete.展开更多
Recently,the China Meteorological Administration(CMA)released a new Global Atmospheric Reanalysis(CRA-40)dataset for the period 1979−2018.In this study,surface relative humidity(RH)from CRA-40 and other current reanal...Recently,the China Meteorological Administration(CMA)released a new Global Atmospheric Reanalysis(CRA-40)dataset for the period 1979−2018.In this study,surface relative humidity(RH)from CRA-40 and other current reanalyses(e.g.,CFSR,ERA5,ERA-Interim,JRA-55,and MERRA-2)is comprehensively evaluated against homogenized observations over China.The results suggest that most reanalyses overestimate the observations by 15%−30%(absolute difference)over the Tibetan Plateau but underestimate the observations by 5%−10%over most of northern China.The CRA-40 performs relatively well in describing the long-term change and variance seen in the observed surface RH over China.Most of the reanalyses reproduce the observed surface RH climatology and interannual variations well,while few reanalyses can capture the observed long-term RH trends over China.Among these reanalyses,the CFSR does poorly in describing the interannual changes in the observed RH,especially in Southwest China.An empirical orthogonal function(EOF)analysis also suggests that the CRA-40 performs better than other reanalyses to capture the first two leading EOF modes revealed by the observations.The results of this study are expected to improve understanding of the strengths and weaknesses of the current reanalysis products and thus facilitate their application.展开更多
The fate of Polycyclic Aromatic Hydrocarbons (PAHs) residing in the atmosphere has received enormous attention in recent years due to their mutagenic and carcinogenic risks on human health. In this context, the stab...The fate of Polycyclic Aromatic Hydrocarbons (PAHs) residing in the atmosphere has received enormous attention in recent years due to their mutagenic and carcinogenic risks on human health. In this context, the stability of pyrene (as a representative PAHs) on quartz, alumina, montmorillonite, kaolinite, humic acid and quartz coated with sorbed humic acid was investigated at controlled relative humidity (RH: i.e. 5% and 30%) without light irradiation in order to detect the presence of catalytic effect of mineral surface on PAHs decomposition. The stability of pyrene was found to depend strongly on the physicochemical properties of the substrates. Quartz showed a strong catalytic effect for the decomposition of pyrene even though it was coated with sorbed humic acid. Pyrene sorbed on montmorillonite and humic acid remained stable during the experimental period (i.e. 3 days). Moisture in the experimental cell also affected the stability of pyrene in particular minerals. Especially, pyrene sorbed on alumina was rapidly decomposed at higher RH. However, there were almost no effect in the case of quartz, kaolinite and humic acid. Depending on the physicochemical properties of aerosols and RH, PAHs associated with minerals in the atmosphere would be decomposed and/or stably reside in the atmosphere.展开更多
Few studies have specifically focused on the validation and spatiotemporal distribution of planetary boundary layer height (PBLH) and relative humidity (RH) data in China. In this analysis, continuous PBLH and sur...Few studies have specifically focused on the validation and spatiotemporal distribution of planetary boundary layer height (PBLH) and relative humidity (RH) data in China. In this analysis, continuous PBLH and surface-level RH data simulated from GEOS-5 between 2004 and 2012, were validated against ground-based observations. Overall, the simulated RH was consistent with the statistical data from meteorological stations, with a correlation coefficient of 0.78 and a slope of 0.9. However, the simulated PBLH was underestimated compared to LIDAR data by a factor of approximately two, which was primarily because of poor simulation in late summer and early autumn. We further examined the spatiotemporal distribution characteristics of two factors in four regions--North China, South China, Northwest China, and the Tibetan Plateau. The results showed that the annual PBLH trends in all regions were fairly moderate but sensitive to solar radiation and precipitation, which explains why the PBLH values were ranked in order from largest to smallest as follows: Tibetan Plateau, Northwest China, North China, and South China. Strong seasonal variation of the PBLH exhibited high values in summer and low values in winter, which was also consistent with the turbulent vertical exchange. Not surprisingly, the highest RH in South China and the lowest RH in desert areas of Northwest China (less than 30%). Seasonally, South China exhibited little variation, whereas Northwest China exhibited its highest humidity in winter and lowest humidity in spring, the maximum values in the other regions were obtained from July to September.展开更多
The effect of relative humidity on the corrosion-resisting property of fluorocarbon coating was investigated by water vapor transmission technique and electrochemical impedance spectroscopy technique. Measuremerits we...The effect of relative humidity on the corrosion-resisting property of fluorocarbon coating was investigated by water vapor transmission technique and electrochemical impedance spectroscopy technique. Measuremerits were carried out on samples, which were tested in an accelerated corrosion environment for the same time (300, 500, 800 and 1000 h ). The experimental results were obtained as follows: (i) The water absorption, coating resistance and corrosion rate of metal under the coating changed with relative humidity and aging time, the results obtained by EIS are good consistent with those by water vapor transmission technique ; ( ii ) when the subject investigated presented two time constant, the goodness of fit by EEC R ( C ( R ( CR ) ) ) was inferior to that by EEC R( C( R(QR) ) ), but the error of parameters acquired from the former was smaller, by which we could analyze the experiment result quantitatively. With the appearance of diffusion layer on the metal, the difference of metal capacitance was aggravated, the error of parameters acquired from EEC R( C( R( C(RW) ) ) )was bigger than that from EEC R( C( R( Q( RW) ) ) ) .展开更多
Weather and climate conditions drive the evolution of tropical glaciers which play an important role as water reservoirs for Peruvian inhabitants in the arid coast and semi-arid Andean region.The scarcity of long-term...Weather and climate conditions drive the evolution of tropical glaciers which play an important role as water reservoirs for Peruvian inhabitants in the arid coast and semi-arid Andean region.The scarcity of long-term high-quality observations over Peruvian glaciers has motivated the extensive use of reanalysis data to describe the climatic evolution of these glaciers.However,the representativeness and uncertainties of these reanalysis products over these glaciers are still poorly constrained.This study evaluates the ability of the ERA-Land reanalysis(ERAL)to reproduce hourly and monthly 2 m air temperature and relative humidity(T2m and Rh2m,respectively)over several Peruvian glaciers.We compared the ERAL with data from four on-glacier automatic weather stations(AWS),whose hourly time series were completed with nearby stations,for the period January 2017 to December 2019.Results indicates a better performance of the reanalysis for T2m(r>0.80)than for Rh2m(~0.4<r<~0.6)in all four glaciers.Concerning the observations,both parameters show a daily cycle influenced by the presence of the glacier.This influence is more prominent during the dry months when the so-called glacier damping and cooling effects are stronger.On a monthly time scale,the ERAL validation for both parameters are better in wet outer tropical sites(RMSE between±0.2℃ for T2m and between 3%-7% for Rh2m)rather than in dry outer tropical sites(RMSE between±0.2℃ for T2m and between 3%-7% for Rh2m).Among all sites considered in the study,the Rh2m bias is the highest in the Cavalca glacier(correlation of 0.81;RMSE 13%,MAE 11% and bias 8.3%)and the lowest in Artesonraju glacier(correlation of 0.96;RMSE 3%;MAE 2.3% and bias-0.8%).Based on certain considerations outlined in this paper,it is appropriate to use ERAL to characterize T2m and Rh2m conditions on Peruvian glaciers,particularly in the wet outer tropics.展开更多
Playing an important role in global warming and plant growth,relative humidity(RH)has profound impacts on production and living,and can be used as an integrated indicator for evaluating the wet-dry conditions in the a...Playing an important role in global warming and plant growth,relative humidity(RH)has profound impacts on production and living,and can be used as an integrated indicator for evaluating the wet-dry conditions in the arid and semi-arid area.However,information on the spatial-temporal variation and the influencing factors of RH in these regions is still limited.This study attempted to use daily meteorological data during 1966–2017 to reveal the spatial-temporal characteristics of RH in the arid region of Northwest China through rotated empirical orthogonal function and statistical analysis method,and the path analysis was used to clarify the impact of temperature(T),precipitation(P),actual evapotranspiration(ETa),wind speed(W)and sunshine duration(S)on RH.The results demonstrated that climatic conditions in North Xinjiang(NXJ)was more humid than those in Hexi Corridor(HXC)and South Xinjiang(SXJ).RH had a less significant downtrend in NXJ than that in HXC,but an increasingly rising trend was observed in SXJ during the last five decades,implying that HXC and NXJ were under the process of droughts,while SXJ was getting wetter.There was a turning point for the trend of RH in Xinjiang,which occurred in 2000.Path analysis indicated that RH was negatively correlated to T,ETa,W and S,but it increased with increase of P.S,T and W had the greatest direct effects on RH in HXC,NXJ and SXJ,respectively.ETa was the factor which had the greatest indirect effect on RH in HXC and NXJ,while T was the dominant factor in SXJ.展开更多
The use of bio-based materials in buildings has become more and more significant last years.In most of the cases,their health properties and natural provenance have made them a great solution to face global climate wa...The use of bio-based materials in buildings has become more and more significant last years.In most of the cases,their health properties and natural provenance have made them a great solution to face global climate warming and the new policies to reduce building energy consumption.In many thermal problems,biobased materials can allow to optimize the building thermal behavior according to its energy consumption and inside comfort conditions.So it is when they are used as an insulation material in the building.However,it is not the case in this paper.In fact,the bio-based matter is rather used as a desiccant wheel to control air conditioning inside the building.The aim of this paper is to numerically verify if it is possible to use a bed of wood chips as a hygroscopic material(or a desiccant matter)in order to modify the relative humidity inside the building in Reunion Island and so improve thermal comfort.A simple model of heat and mass transfer between a bed of wood chips and building inside air has been set up and implemented into a validated building simulation code named ISOLAB.Numerical simulations were set up for the four climate zones of the island regulations and a focus has been made on the low altitude one(with high,solar irradiation,temperature and relative humidity).Simulation results give the thermal behavior of the building particularly the temperature and relative humidity of inside air temperature,and temperature and moisture content of wood chips.The obtained results lead to determine if the wood chips bed is suitable for the reference building and to verify its technical feasibility(wood species,size of the bed,integration to the building,etc.).The results show that the use of a WCB help to decrease the building inside air temperature and water content up to 10°C less and 11.6 g.kg-1 less.These are the ways to improve inside comfort conditions.Indeed,comfort analysis have shown the possibility to significantly increase building users’thermal comfort when coupled with a fan and natural ventilation,like the regulation needs for low altitude climate.In this case,a gain of 68%of year time is achieved for a building equipped with WCB system compared to one without it(6308 hours of comfort over a year with the WCB against 350 hours without WCB).So the WCB seems to be able to help reducing cooling loads in tropical climate conditions.展开更多
The influence of KOH concentration (8 and 12 M) and curing conditions as temperature (40℃ and 60℃), time (7 and 28 days) and relative humidity (85% and 95% RH), on compressive strength of metakaolin-based geopolymer...The influence of KOH concentration (8 and 12 M) and curing conditions as temperature (40℃ and 60℃), time (7 and 28 days) and relative humidity (85% and 95% RH), on compressive strength of metakaolin-based geopolymers (MK-based GP) was evaluated. Derived from the experimental design technique, and using a factorial design 2<sup>K</sup> with two replications in the center point, eighteen experiments were conducted. The results reveal that the best performance conditions of geopolymerization to develop a higher compressive strength of 20 MPa are 12 M KOH to 60℃ and 85% RH at 28 curing days. With these conditions, the value of relative humidity of 85%, promotes high strength compact samples, and a maximum of 42 MPa at 90 days. The results of significant, compressive design of GP showed that KOH concentration and curing relative humidity were the most important factors, followed by curing time and temperature. The GP were characterized by XRD, and their evolution on compression strength was followed by SEM.展开更多
Effects of pressure and temperature in the chamber during vacuum drying on the relative humidity and evaporation of wood surface were investigated by using the vacuum chamber.The setting temperature during vacuum dryi...Effects of pressure and temperature in the chamber during vacuum drying on the relative humidity and evaporation of wood surface were investigated by using the vacuum chamber.The setting temperature during vacuum drying included dry-bulb temperature td, the wet-bulb temperature tw and the temperature difference between the air in the vacuum chamber and the cooling water in the condenser.Results indicated that relative humidity during vacuum drying was affected by the dry-bulb temperature td, the wet-bulb temperature tw and the temperature difference between the air in the vacuum chamber and the water in the condenser.Relative humidity of wood decreased with the increase in temperature at the given temperature of the water in the condenser.The relative humidity was affected slightly by pressure in the vacuum chamber pA, and it decreased from 70% to 65% with pA increased from 50 kPa to 101 kPa.Moreover, there was nearly no evaporation under the vacuum without external heating.展开更多
The influence of relative humidity( RH) on the properties of electrospun polyvinyl alcohol( PVA) nanofibers that might determine the application of nanofibers in high-efficiency air filters is not clear. PVA nanofiber...The influence of relative humidity( RH) on the properties of electrospun polyvinyl alcohol( PVA) nanofibers that might determine the application of nanofibers in high-efficiency air filters is not clear. PVA nanofiber mat was prepared between two hot airthrough ES( polyethyene( PE) and polypropylene( PP) composite fiber) non-woven substrates as a sandwich structure nanofiber composite filter using an electrospinning technique combining with an ultrasonic sewing process. The filtering mechanism of the composite was discussed in detail. The effects of nanofiber diameters,nanofiber layer thickness and RH in environment on the properties of PVA nanofibers were investigated by scanning electron microscopy( SEM), X-ray diffraction( XRD), automatic filter tester and universal strength tester. The results showed that the PVA nanofiber composite fabrics had high filtration efficiency with lowpressure drop and there was a negative correlation between filtration efficiency and nanofiber diameter. After keeping in a high RH environment for several hours, the mechanical property of PVA nanofiber composites was deteriorated but the high filtration efficiency was increased.展开更多
Climate change will have a noteworthy bearing on survival, development, and population dynamics of insect pests. Therefore, we contemplated the survival and development of beet army worm, <em>Spodoptera exigua&l...Climate change will have a noteworthy bearing on survival, development, and population dynamics of insect pests. Therefore, we contemplated the survival and development of beet army worm, <em>Spodoptera exigua</em> under different temperatures, (15<span style="white-space:nowrap;">°</span>C, 25<span style="white-space:nowrap;">°</span>C, 35<span style="white-space:nowrap;">°</span>C, and 45<span style="white-space:nowrap;">°</span>C), CO<sub>2</sub> (350, 550, 750 ppm) and relative humidity (55%, 65%, 75% and 85%) regimes. Maximum larval and pupal weights were recorded in insects reared at 25<span style="white-space:nowrap;">°</span>C. The growth of <em>S. exigua</em> was faster at 35<span style="white-space:nowrap;">°</span>C (larval period 7.4 days and pupal period 4.5 days) than at lower temperatures. At 15<span style="white-space:nowrap;">°</span>C, the larval period was extended for 61.4 days and there was no adult emergence from the pupae till 90 days. The <em>S. exigua</em> hatchling was absent at 45<span style="white-space:nowrap;">°</span>C. The larval survival ranged from 31.6% - 57.2%, maximum survival was recorded at 25<span style="white-space:nowrap;">°</span>C, and minimum at 45<span style="white-space:nowrap;">°</span>C. The maximum (84.27%) and minimum adult emergence were recorded in insects reared at 25<span style="white-space:nowrap;">°</span>C and 35<span style="white-space:nowrap;">°</span>C respectively. Maximum fecundity (384.3 eggs/female) and egg viability (51.97%) were recorded in insects reared at 25<span style="white-space:nowrap;">°</span>C. Larval and pupal periods increased with an increase in CO<sub>2</sub> concentration. The highest pupal weights (128.6 mg/larva) were recorded at 550 ppm. The highest larval survival (73.50%) was recorded at 550 ppm and minimum (37.00%) at 750 ppm CO<sub>2</sub>. Fecundity was the highest in insects reared at 550 ppm CO<sub>2</sub> (657.4 eggs/female), and the lowest at 750 ppm. Maximum larval and pupal weights were recorded in insects reared at 75% relative humidity (RH). The growth rate of<em> S. exigua</em> was faster at 85% RH than at lower RH. The larval survival ranged between 40.0% - 58.5%. Maximum adult emergence (88.91%) was recorded in insects reared at 75% RH and minimum at 85% RH. Maximum fecundity (447.6 eggs/female) and the highest egg viability (72.95%) were recorded in insects reared at 75% and 65% RH respectively. Elevated temperatures and relative moistness will diminish the life cycle, while hoisted CO<sub>2</sub> will drag the life expectancy. Therefore, there is a need for thorough assessment of the impact of climatic factors on the population dynamics of insect pests, crop losses, and sustainability of crop production.展开更多
In this paper we access the effects of two atmospheric variables (temperatureand relative humidity) on two important pollutants in the atmosphere(Nitrogen oxides (NOx) and carbon monoxide (CO)) by using one year(2016)...In this paper we access the effects of two atmospheric variables (temperatureand relative humidity) on two important pollutants in the atmosphere(Nitrogen oxides (NOx) and carbon monoxide (CO)) by using one year(2016) data of Addis Ababa. Temperature has impact on atmosphericmixing and cause for the reduction of NOx as temperature increases.There are positive correlation between temperature and CO concentrationfrom January to April with (R^2 = 0.69), negative correlation from Mayto August with (R2 = 0.92) and no correlation for the remaining months.NOx and CO have moderate positive and negative correlation with relativehumidity during the months January-April (R^2 = 0.294 for NOx and R^2 =0291 for CO) and in the months May-August are R2 = 0.97 and R2 = 0.15for NOx and CO respectively. But there are no clear correlation betweenthe NOx and CO with relative humidity from September-December.NOx concentrations during wet season was almost about twice that of thedry season, but no such difference was observed in the case of CO. Theseasonal average air temperature in wet season is relatively lower than dryseason. NOx exhibited positive and CO negative seasonal correlations withrelative humidity.展开更多
The combined stress of high temperature and high relative air humidity is one of the most serious agrometeorological disasters that restricts the production capacity of protected agriculture.However,there is little in...The combined stress of high temperature and high relative air humidity is one of the most serious agrometeorological disasters that restricts the production capacity of protected agriculture.However,there is little information about the precise interaction between them on tomato fruit quality.The objectives of this study were to explore the effects of the combined stress of high temperature and relative humidity on the sugar and acid metabolism and fruit quality of tomato fruits,and to determine the best relative air humidity for fruit quality under high temperature environments.Four temperature treatments(32℃,35℃,38℃,41℃),three relative air humidity(50%,70%,90%)and four duration(3,6,9,12 d)orthogonal experiments were conducted,with 28℃,50%as control.The results showed that under high temperature and relative air humidity,the activity of sucrose metabolizing enzymes in young tomato fruits changed,which reduced fruits soluble sugar content;in addition,enzyme activities involved phosphopyruvate carboxylase(PEPC),mitochondria aconitase(MDH)and citrate synthetase(CS)increased which increased the content of organic acids(especially malic acid).Eventually,vitamin C,total sugar and sugar-acid ratio decreased significantly,while the titratable acid increased,resulting in a decrease in fruit flavor quality and nutritional quality in ripe fruit.Specifically,a temperature of 32℃and a relative air humidity of 70%were the best cultivation conditions for tomato reproductive growth period under high temperature.Our results indicating that fruit quality reduced under high temperature at the flowering stage,while increasing the relative air humidity to 70%could alleviate this negative effect.Our results are benefit to better understand the interaction between microclimate parameters under specific climatic conditions in the greenhouse environment and their impact on tomato flavor quality.展开更多
Low desulfurization efficiency impedes the wide application of dry desulfurization technology,which is a low-cost and simple process,and one significant solution is the development and manufacture of high-performance ...Low desulfurization efficiency impedes the wide application of dry desulfurization technology,which is a low-cost and simple process,and one significant solution is the development and manufacture of high-performance desulfurizers.In this study,firstly,a steam jet mill was used to digest quicklime;then,we utilized numerical simulation to study the flow field distribution and analyze the driving factors of quicklime digestion;and lastly,the desulfurization performance of the desulfurizer was evaluated under different relative humidities.The results show that the desulfurizer prepared via the steam jet mill had better apparent activity than traditional desulfurizers.Also,the entire jet flow field of the steam jet mill is in a supersonic and highly turbulent flow state,with high crushing intensity and good particle acceleration performance.Sufficient contact with the nascent surface maximizes the formation of slaked lime.The experiments demonstrated that the operating time with 100%desulfurization efficiency and the“break-through”time for the desulfurizer prepared via the steam jet mill is longer than that of traditional desulfurizers,and has significant advantages,especially at low flue gas relative humidity.Compared with traditional desulfurizers,the desulfurizer prepared via steam jet mill expands the range of acceptable flue gas temperature,and the failure temperature is 1.625 times that of traditional desulfurizers.This work breaks through the technical bottleneck of low dry desulfurization efficiency,which is an important step in pushing forward the application of dry desulfurization.展开更多
文摘Many attempts have been made to estimate calorific value of bagasse using mathematical equations, which were created based on data from proximate, ultimate, physical and chemical analysis. Questions have been raised on the applicability of these equations in different parts of the globe. This study was initiated to tackle these problems and also check the most suited mathematical models for the Law Heating Value of Cameroonian bagasse. Data and bagasse samples were collected at the Cameroonian sugarcane factory. The effects of cane variety, age of harvesting, source, moisture content, and sucrose on the LHV of Cameroon bagasse have been tested. It was shown that humidity does not change within a variety, but changes from the dry season to the rainy season;the sugar in the rainy season is significantly different from that collected in the dry season. Samples of the same variety have identical LHV. LHV in the dry season is significantly different from LHV in the rainy season. According to the fact that this study was done for cane with different ages of harvesting, the maturity of Cameroonian sugarcane does not affect LHV of bagasse. Tree selected models are much superior tool for the prediction of the LHV for bagasse in Cameroon compared to others. The standard deviation of these validated models is around 200 kJ/kg compared to the experimental. Thus, the models determined in foreign countries, are not necessarily applicable in predicting the LHV of bagasse in other countries with the same accuracy as that in their native country. There was linear relationship between humidity, ash and sugar content in the bagasse. It is possible to build models based on data from physical composition of bagasse using regression analysis.
基金provided by the National Key R&D Program of China(2016YFD0500501)the National Science and Technology Support Program of China(2012BAD39B02)the Agricultural Science and Technology Innovation Program,China(ASTIP-IAS07)
文摘Farm animals are sources of meat, milk and eggs for the humans, and animal health ensures the quality and security of these agricultural and sideline products. The animal raising conditions in livestock stations and poultry houses play vital roles in both animal health and production. One of the major factors affecting raising conditions, relative humidity, has not received much attention even though it is important for animal husbandry. In this review, we summarize the impacts of relative humidity on animal health and welfare to draw attention for its importance in the improvement of animal raising conditions in the future.
基金The National Natural Science Foundation of China (No. 20277006) and the Fudan University Foundation for Young Scientists (No.EXH 6286301)
文摘Nitrous acid, HNO2, is an important precursor of OH radicals in the troposphere. Measurements of HNO2 and NO2, using differential optical absorption spectroscopy (DOAS), were performed in Shanghai, China for a period from October 22, 2004 to January 4, 2005. The mean (and median) hourly concentrations of HNO2 and NO2 during this period were 1.1 (0.7) ppb and 24 (21.4) ppb respectively. A correlation between HNO2/NO2 and PM10 mass concentrations was obtained. This correlation suggests that significant heterogeneous chemical production of HNO2 may occur through NO2 reactions on aerosol surfaces. This hypothesis was further supported by detailed analysis of selected pollution episodes in this study. At the same time, the water dependence of HNO2 formation was studied by analysis of relative humidity (RH). It showed that the maximum HNO2/NO2 ratio was increased along with RH below 70% and inhibited at RH〉70%.
基金Under the auspices of National Natural Science Foundation of China(No.41871343)Major Project of National Natural Science Foundation of China(No.41590842)Strategic Priority Research Program A of the Chinese Academy of Sciences(No.XDA23100201)
文摘The cooling and humidifying effects of urban parks are an essential component of city ecosystems in terms of regulating microclimates or mitigating urban heat islands(UHIs).Air temperature and relative humidity are two main factors of thermal environmental comfort and have a critical impact on the urban environmental quality of human settlements.We measured the 2-m height air temperature and relative humidity at the Beijing Olympic Park and a nearby building roof for more than 1 year to elucidate seasonal variations in air temperature and relative humidity,as well as to investigate the outdoor thermal comfort.The results showed that the lawn of the park could,on average,reduce the air temperature by(0.80±0.19)℃,and increase the relative humidity by(5.24±2.91)% relative to the values measured at the building roof during daytime.During the nighttime,the lawn of the park reduced the air temperature by(2.64±0.64)℃ and increased the relative humidity by(10.77±5.20)%.The park was cooler and more humid than surrounding building area,especially in night period(more pronounced cooling with 1.84℃).Additionally,the lawn of the park could improve outdoor thermal comfort through its cooling and humidifying effects.The level of thermal comfort in the park was higher than that around the building roof for a total of 11 days annually in which it was above one or more thermal comfort levels(average reduced human comfort index of 0.92)except during the winter.
基金funded by National Nature Science Foundation of China[81102207]Science and Technology Planning Project of Guangdong Province,China[2013B021800041]GUO Yu Ming is supported by NHMRC Centre for air quality and health research and evaluation,Australia[APP 1030259]
文摘Objective Although many studies have examined the effects of ambient temperatures on mortality, little evidence is on health impacts of atmospheric pressure and relative humidity. This study aimed to assess the impacts of atmospheric pressure and relative humidity on mortality in Guangzhou, China. Methods This study included 213,737 registered deaths during 2003-2011 in Guangzhou, China. A quasi-Poisson regression with a distributed lag non-linear model was used to assess the effects of atmospheric pressure/relative humidity. Results We found significant effect of low atmospheric pressure/relative humidity on mortality. There was a 1.79% (95% confidence interval: 0.38%-3.22%) increase in non-accidental mortality and a 2.27% (0.07%-4.51%) increase in cardiovascular mortality comparing the 5th and 25th percentile of atmospheric pressure. A 3.97% (0.67%-7.39%) increase in cardiovascular mortality was also observed comparing the 5th and 25th percentile of relative humidity. Women were more vulnerable to decrease in atmospheric pressure and relative humidity than men. Age and education attainment were also potential effect modifiers. Furthermore, low atmospheric pressure and relative humidity increased temperature-related mortality. Conclusion Both low atmospheric pressure and relative humidity are important risk factors of mortality. Our findings would be helpful to develop health risk assessment and climate policy interventions that would better protect vulnerable subgroups of the population.
基金Funded by National Natural Science Foundation of china (No. 50508034)Guangxi Key Laboratory for the Advanced Materials and New Preparation Technology(No. 063006-5C-13)China,and National Basic Research Programof China(No.2009CB623201)
文摘The relationship between autogenous deformation and internal relative humidity(IRH) of high-strength concrete and high-strength expansive concrete were investigated.The experimental results indicate that,there exists a good linear relationship between autogenous shrinkage and IRH of high-strength concrete but a nonlinear relationship between autogenous deformation and IRH of high-strength expansive concrete with expansive agent.The new autogenous deformation curve can be obtained by transforming the autogenous deformation data of high-strength expansive concrete,and there exists linear relationship between the autogenous deformation and IRH.The concept of "critical internal relative humidity" was proposed,which is defined as the value of IRH when autogenous deformation is zero,to effectively reflect the autogenous deformation characteristic of expansive concrete.
基金This work was supported by grants from the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDA19030402 and XDA19030401)the China Meteorological Administration Special Public Welfare Research Fund(Grant No.GYHY201506002),the National Natural Science Foundation of China(Grant Nos.41675094,41975115)+1 种基金the Natural Science Foundation of Shaanxi Province(Grant No.2021JQ-166),Chinese Universities Scientific Fund(Grant No.2452019224)Open Research Fund of Key Laboratory of the Loess Plateau Soil Erosion and Water Process and Control,Ministry of Water Resources of China(Grant No.HTGY202002).
文摘Recently,the China Meteorological Administration(CMA)released a new Global Atmospheric Reanalysis(CRA-40)dataset for the period 1979−2018.In this study,surface relative humidity(RH)from CRA-40 and other current reanalyses(e.g.,CFSR,ERA5,ERA-Interim,JRA-55,and MERRA-2)is comprehensively evaluated against homogenized observations over China.The results suggest that most reanalyses overestimate the observations by 15%−30%(absolute difference)over the Tibetan Plateau but underestimate the observations by 5%−10%over most of northern China.The CRA-40 performs relatively well in describing the long-term change and variance seen in the observed surface RH over China.Most of the reanalyses reproduce the observed surface RH climatology and interannual variations well,while few reanalyses can capture the observed long-term RH trends over China.Among these reanalyses,the CFSR does poorly in describing the interannual changes in the observed RH,especially in Southwest China.An empirical orthogonal function(EOF)analysis also suggests that the CRA-40 performs better than other reanalyses to capture the first two leading EOF modes revealed by the observations.The results of this study are expected to improve understanding of the strengths and weaknesses of the current reanalysis products and thus facilitate their application.
文摘The fate of Polycyclic Aromatic Hydrocarbons (PAHs) residing in the atmosphere has received enormous attention in recent years due to their mutagenic and carcinogenic risks on human health. In this context, the stability of pyrene (as a representative PAHs) on quartz, alumina, montmorillonite, kaolinite, humic acid and quartz coated with sorbed humic acid was investigated at controlled relative humidity (RH: i.e. 5% and 30%) without light irradiation in order to detect the presence of catalytic effect of mineral surface on PAHs decomposition. The stability of pyrene was found to depend strongly on the physicochemical properties of the substrates. Quartz showed a strong catalytic effect for the decomposition of pyrene even though it was coated with sorbed humic acid. Pyrene sorbed on montmorillonite and humic acid remained stable during the experimental period (i.e. 3 days). Moisture in the experimental cell also affected the stability of pyrene in particular minerals. Especially, pyrene sorbed on alumina was rapidly decomposed at higher RH. However, there were almost no effect in the case of quartz, kaolinite and humic acid. Depending on the physicochemical properties of aerosols and RH, PAHs associated with minerals in the atmosphere would be decomposed and/or stably reside in the atmosphere.
基金supported by the National Key R&D Program of China (2016YFC0201507)the National Natural Science Foundation of China (Grant Nos. 41471367, 91543128 and 41571417)
文摘Few studies have specifically focused on the validation and spatiotemporal distribution of planetary boundary layer height (PBLH) and relative humidity (RH) data in China. In this analysis, continuous PBLH and surface-level RH data simulated from GEOS-5 between 2004 and 2012, were validated against ground-based observations. Overall, the simulated RH was consistent with the statistical data from meteorological stations, with a correlation coefficient of 0.78 and a slope of 0.9. However, the simulated PBLH was underestimated compared to LIDAR data by a factor of approximately two, which was primarily because of poor simulation in late summer and early autumn. We further examined the spatiotemporal distribution characteristics of two factors in four regions--North China, South China, Northwest China, and the Tibetan Plateau. The results showed that the annual PBLH trends in all regions were fairly moderate but sensitive to solar radiation and precipitation, which explains why the PBLH values were ranked in order from largest to smallest as follows: Tibetan Plateau, Northwest China, North China, and South China. Strong seasonal variation of the PBLH exhibited high values in summer and low values in winter, which was also consistent with the turbulent vertical exchange. Not surprisingly, the highest RH in South China and the lowest RH in desert areas of Northwest China (less than 30%). Seasonally, South China exhibited little variation, whereas Northwest China exhibited its highest humidity in winter and lowest humidity in spring, the maximum values in the other regions were obtained from July to September.
文摘The effect of relative humidity on the corrosion-resisting property of fluorocarbon coating was investigated by water vapor transmission technique and electrochemical impedance spectroscopy technique. Measuremerits were carried out on samples, which were tested in an accelerated corrosion environment for the same time (300, 500, 800 and 1000 h ). The experimental results were obtained as follows: (i) The water absorption, coating resistance and corrosion rate of metal under the coating changed with relative humidity and aging time, the results obtained by EIS are good consistent with those by water vapor transmission technique ; ( ii ) when the subject investigated presented two time constant, the goodness of fit by EEC R ( C ( R ( CR ) ) ) was inferior to that by EEC R( C( R(QR) ) ), but the error of parameters acquired from the former was smaller, by which we could analyze the experiment result quantitatively. With the appearance of diffusion layer on the metal, the difference of metal capacitance was aggravated, the error of parameters acquired from EEC R( C( R( C(RW) ) ) )was bigger than that from EEC R( C( R( Q( RW) ) ) ) .
基金funded by the Ministry of Science and Innovation of Spain through the research project(PID2020-113247RA-C22)by the National Fund for Scientific and Technological Development of Peru trough the PERMAFROST ENSO research project(081-2021)。
文摘Weather and climate conditions drive the evolution of tropical glaciers which play an important role as water reservoirs for Peruvian inhabitants in the arid coast and semi-arid Andean region.The scarcity of long-term high-quality observations over Peruvian glaciers has motivated the extensive use of reanalysis data to describe the climatic evolution of these glaciers.However,the representativeness and uncertainties of these reanalysis products over these glaciers are still poorly constrained.This study evaluates the ability of the ERA-Land reanalysis(ERAL)to reproduce hourly and monthly 2 m air temperature and relative humidity(T2m and Rh2m,respectively)over several Peruvian glaciers.We compared the ERAL with data from four on-glacier automatic weather stations(AWS),whose hourly time series were completed with nearby stations,for the period January 2017 to December 2019.Results indicates a better performance of the reanalysis for T2m(r>0.80)than for Rh2m(~0.4<r<~0.6)in all four glaciers.Concerning the observations,both parameters show a daily cycle influenced by the presence of the glacier.This influence is more prominent during the dry months when the so-called glacier damping and cooling effects are stronger.On a monthly time scale,the ERAL validation for both parameters are better in wet outer tropical sites(RMSE between±0.2℃ for T2m and between 3%-7% for Rh2m)rather than in dry outer tropical sites(RMSE between±0.2℃ for T2m and between 3%-7% for Rh2m).Among all sites considered in the study,the Rh2m bias is the highest in the Cavalca glacier(correlation of 0.81;RMSE 13%,MAE 11% and bias 8.3%)and the lowest in Artesonraju glacier(correlation of 0.96;RMSE 3%;MAE 2.3% and bias-0.8%).Based on certain considerations outlined in this paper,it is appropriate to use ERAL to characterize T2m and Rh2m conditions on Peruvian glaciers,particularly in the wet outer tropics.
基金This study was supported by the National Natural Science Foundation of China(U1703241)the Key International Cooperation Project of Chinese Academy of Sciences(121311KYSB20160005)the Open Project of Xinjiang Uygur Autonomous Region Key Laboratory of China(2017D04010).
文摘Playing an important role in global warming and plant growth,relative humidity(RH)has profound impacts on production and living,and can be used as an integrated indicator for evaluating the wet-dry conditions in the arid and semi-arid area.However,information on the spatial-temporal variation and the influencing factors of RH in these regions is still limited.This study attempted to use daily meteorological data during 1966–2017 to reveal the spatial-temporal characteristics of RH in the arid region of Northwest China through rotated empirical orthogonal function and statistical analysis method,and the path analysis was used to clarify the impact of temperature(T),precipitation(P),actual evapotranspiration(ETa),wind speed(W)and sunshine duration(S)on RH.The results demonstrated that climatic conditions in North Xinjiang(NXJ)was more humid than those in Hexi Corridor(HXC)and South Xinjiang(SXJ).RH had a less significant downtrend in NXJ than that in HXC,but an increasingly rising trend was observed in SXJ during the last five decades,implying that HXC and NXJ were under the process of droughts,while SXJ was getting wetter.There was a turning point for the trend of RH in Xinjiang,which occurred in 2000.Path analysis indicated that RH was negatively correlated to T,ETa,W and S,but it increased with increase of P.S,T and W had the greatest direct effects on RH in HXC,NXJ and SXJ,respectively.ETa was the factor which had the greatest indirect effect on RH in HXC and NXJ,while T was the dominant factor in SXJ.
文摘The use of bio-based materials in buildings has become more and more significant last years.In most of the cases,their health properties and natural provenance have made them a great solution to face global climate warming and the new policies to reduce building energy consumption.In many thermal problems,biobased materials can allow to optimize the building thermal behavior according to its energy consumption and inside comfort conditions.So it is when they are used as an insulation material in the building.However,it is not the case in this paper.In fact,the bio-based matter is rather used as a desiccant wheel to control air conditioning inside the building.The aim of this paper is to numerically verify if it is possible to use a bed of wood chips as a hygroscopic material(or a desiccant matter)in order to modify the relative humidity inside the building in Reunion Island and so improve thermal comfort.A simple model of heat and mass transfer between a bed of wood chips and building inside air has been set up and implemented into a validated building simulation code named ISOLAB.Numerical simulations were set up for the four climate zones of the island regulations and a focus has been made on the low altitude one(with high,solar irradiation,temperature and relative humidity).Simulation results give the thermal behavior of the building particularly the temperature and relative humidity of inside air temperature,and temperature and moisture content of wood chips.The obtained results lead to determine if the wood chips bed is suitable for the reference building and to verify its technical feasibility(wood species,size of the bed,integration to the building,etc.).The results show that the use of a WCB help to decrease the building inside air temperature and water content up to 10°C less and 11.6 g.kg-1 less.These are the ways to improve inside comfort conditions.Indeed,comfort analysis have shown the possibility to significantly increase building users’thermal comfort when coupled with a fan and natural ventilation,like the regulation needs for low altitude climate.In this case,a gain of 68%of year time is achieved for a building equipped with WCB system compared to one without it(6308 hours of comfort over a year with the WCB against 350 hours without WCB).So the WCB seems to be able to help reducing cooling loads in tropical climate conditions.
文摘The influence of KOH concentration (8 and 12 M) and curing conditions as temperature (40℃ and 60℃), time (7 and 28 days) and relative humidity (85% and 95% RH), on compressive strength of metakaolin-based geopolymers (MK-based GP) was evaluated. Derived from the experimental design technique, and using a factorial design 2<sup>K</sup> with two replications in the center point, eighteen experiments were conducted. The results reveal that the best performance conditions of geopolymerization to develop a higher compressive strength of 20 MPa are 12 M KOH to 60℃ and 85% RH at 28 curing days. With these conditions, the value of relative humidity of 85%, promotes high strength compact samples, and a maximum of 42 MPa at 90 days. The results of significant, compressive design of GP showed that KOH concentration and curing relative humidity were the most important factors, followed by curing time and temperature. The GP were characterized by XRD, and their evolution on compression strength was followed by SEM.
基金supported by National Natural Science Foundation of China (No.30571453)Heilongjiang Postdoc-toral Science-Research Foundation (No. LBH-Q06116).
文摘Effects of pressure and temperature in the chamber during vacuum drying on the relative humidity and evaporation of wood surface were investigated by using the vacuum chamber.The setting temperature during vacuum drying included dry-bulb temperature td, the wet-bulb temperature tw and the temperature difference between the air in the vacuum chamber and the cooling water in the condenser.Results indicated that relative humidity during vacuum drying was affected by the dry-bulb temperature td, the wet-bulb temperature tw and the temperature difference between the air in the vacuum chamber and the water in the condenser.Relative humidity of wood decreased with the increase in temperature at the given temperature of the water in the condenser.The relative humidity was affected slightly by pressure in the vacuum chamber pA, and it decreased from 70% to 65% with pA increased from 50 kPa to 101 kPa.Moreover, there was nearly no evaporation under the vacuum without external heating.
基金National Natural Science Foundation of China(No.51573133)Foundation for the Author of National Excellent Doctoral Dissertation of China(No.201255)+2 种基金Program for New Century Excellent Talents in University of China(No.NCET-12-1063)Tianjin Natural Science Foundation of China(No.14JCYBJC17600)The Science and Technology Plans of Tianjin,China(No.15PTSYJC00230)
文摘The influence of relative humidity( RH) on the properties of electrospun polyvinyl alcohol( PVA) nanofibers that might determine the application of nanofibers in high-efficiency air filters is not clear. PVA nanofiber mat was prepared between two hot airthrough ES( polyethyene( PE) and polypropylene( PP) composite fiber) non-woven substrates as a sandwich structure nanofiber composite filter using an electrospinning technique combining with an ultrasonic sewing process. The filtering mechanism of the composite was discussed in detail. The effects of nanofiber diameters,nanofiber layer thickness and RH in environment on the properties of PVA nanofibers were investigated by scanning electron microscopy( SEM), X-ray diffraction( XRD), automatic filter tester and universal strength tester. The results showed that the PVA nanofiber composite fabrics had high filtration efficiency with lowpressure drop and there was a negative correlation between filtration efficiency and nanofiber diameter. After keeping in a high RH environment for several hours, the mechanical property of PVA nanofiber composites was deteriorated but the high filtration efficiency was increased.
文摘Climate change will have a noteworthy bearing on survival, development, and population dynamics of insect pests. Therefore, we contemplated the survival and development of beet army worm, <em>Spodoptera exigua</em> under different temperatures, (15<span style="white-space:nowrap;">°</span>C, 25<span style="white-space:nowrap;">°</span>C, 35<span style="white-space:nowrap;">°</span>C, and 45<span style="white-space:nowrap;">°</span>C), CO<sub>2</sub> (350, 550, 750 ppm) and relative humidity (55%, 65%, 75% and 85%) regimes. Maximum larval and pupal weights were recorded in insects reared at 25<span style="white-space:nowrap;">°</span>C. The growth of <em>S. exigua</em> was faster at 35<span style="white-space:nowrap;">°</span>C (larval period 7.4 days and pupal period 4.5 days) than at lower temperatures. At 15<span style="white-space:nowrap;">°</span>C, the larval period was extended for 61.4 days and there was no adult emergence from the pupae till 90 days. The <em>S. exigua</em> hatchling was absent at 45<span style="white-space:nowrap;">°</span>C. The larval survival ranged from 31.6% - 57.2%, maximum survival was recorded at 25<span style="white-space:nowrap;">°</span>C, and minimum at 45<span style="white-space:nowrap;">°</span>C. The maximum (84.27%) and minimum adult emergence were recorded in insects reared at 25<span style="white-space:nowrap;">°</span>C and 35<span style="white-space:nowrap;">°</span>C respectively. Maximum fecundity (384.3 eggs/female) and egg viability (51.97%) were recorded in insects reared at 25<span style="white-space:nowrap;">°</span>C. Larval and pupal periods increased with an increase in CO<sub>2</sub> concentration. The highest pupal weights (128.6 mg/larva) were recorded at 550 ppm. The highest larval survival (73.50%) was recorded at 550 ppm and minimum (37.00%) at 750 ppm CO<sub>2</sub>. Fecundity was the highest in insects reared at 550 ppm CO<sub>2</sub> (657.4 eggs/female), and the lowest at 750 ppm. Maximum larval and pupal weights were recorded in insects reared at 75% relative humidity (RH). The growth rate of<em> S. exigua</em> was faster at 85% RH than at lower RH. The larval survival ranged between 40.0% - 58.5%. Maximum adult emergence (88.91%) was recorded in insects reared at 75% RH and minimum at 85% RH. Maximum fecundity (447.6 eggs/female) and the highest egg viability (72.95%) were recorded in insects reared at 75% and 65% RH respectively. Elevated temperatures and relative moistness will diminish the life cycle, while hoisted CO<sub>2</sub> will drag the life expectancy. Therefore, there is a need for thorough assessment of the impact of climatic factors on the population dynamics of insect pests, crop losses, and sustainability of crop production.
文摘In this paper we access the effects of two atmospheric variables (temperatureand relative humidity) on two important pollutants in the atmosphere(Nitrogen oxides (NOx) and carbon monoxide (CO)) by using one year(2016) data of Addis Ababa. Temperature has impact on atmosphericmixing and cause for the reduction of NOx as temperature increases.There are positive correlation between temperature and CO concentrationfrom January to April with (R^2 = 0.69), negative correlation from Mayto August with (R2 = 0.92) and no correlation for the remaining months.NOx and CO have moderate positive and negative correlation with relativehumidity during the months January-April (R^2 = 0.294 for NOx and R^2 =0291 for CO) and in the months May-August are R2 = 0.97 and R2 = 0.15for NOx and CO respectively. But there are no clear correlation betweenthe NOx and CO with relative humidity from September-December.NOx concentrations during wet season was almost about twice that of thedry season, but no such difference was observed in the case of CO. Theseasonal average air temperature in wet season is relatively lower than dryseason. NOx exhibited positive and CO negative seasonal correlations withrelative humidity.
基金National Natural Science Foundation of China under Grant No.41775104National Key Research and Development Plan of China under Grant No.2019FYD1002202.
文摘The combined stress of high temperature and high relative air humidity is one of the most serious agrometeorological disasters that restricts the production capacity of protected agriculture.However,there is little information about the precise interaction between them on tomato fruit quality.The objectives of this study were to explore the effects of the combined stress of high temperature and relative humidity on the sugar and acid metabolism and fruit quality of tomato fruits,and to determine the best relative air humidity for fruit quality under high temperature environments.Four temperature treatments(32℃,35℃,38℃,41℃),three relative air humidity(50%,70%,90%)and four duration(3,6,9,12 d)orthogonal experiments were conducted,with 28℃,50%as control.The results showed that under high temperature and relative air humidity,the activity of sucrose metabolizing enzymes in young tomato fruits changed,which reduced fruits soluble sugar content;in addition,enzyme activities involved phosphopyruvate carboxylase(PEPC),mitochondria aconitase(MDH)and citrate synthetase(CS)increased which increased the content of organic acids(especially malic acid).Eventually,vitamin C,total sugar and sugar-acid ratio decreased significantly,while the titratable acid increased,resulting in a decrease in fruit flavor quality and nutritional quality in ripe fruit.Specifically,a temperature of 32℃and a relative air humidity of 70%were the best cultivation conditions for tomato reproductive growth period under high temperature.Our results indicating that fruit quality reduced under high temperature at the flowering stage,while increasing the relative air humidity to 70%could alleviate this negative effect.Our results are benefit to better understand the interaction between microclimate parameters under specific climatic conditions in the greenhouse environment and their impact on tomato flavor quality.
基金supported by the Southwest University of Science and Technology(No.22zx7168)the Sichuan Science and Technology Program(No.2020YFG0186)。
文摘Low desulfurization efficiency impedes the wide application of dry desulfurization technology,which is a low-cost and simple process,and one significant solution is the development and manufacture of high-performance desulfurizers.In this study,firstly,a steam jet mill was used to digest quicklime;then,we utilized numerical simulation to study the flow field distribution and analyze the driving factors of quicklime digestion;and lastly,the desulfurization performance of the desulfurizer was evaluated under different relative humidities.The results show that the desulfurizer prepared via the steam jet mill had better apparent activity than traditional desulfurizers.Also,the entire jet flow field of the steam jet mill is in a supersonic and highly turbulent flow state,with high crushing intensity and good particle acceleration performance.Sufficient contact with the nascent surface maximizes the formation of slaked lime.The experiments demonstrated that the operating time with 100%desulfurization efficiency and the“break-through”time for the desulfurizer prepared via the steam jet mill is longer than that of traditional desulfurizers,and has significant advantages,especially at low flue gas relative humidity.Compared with traditional desulfurizers,the desulfurizer prepared via steam jet mill expands the range of acceptable flue gas temperature,and the failure temperature is 1.625 times that of traditional desulfurizers.This work breaks through the technical bottleneck of low dry desulfurization efficiency,which is an important step in pushing forward the application of dry desulfurization.