Increase In Relative Air Humidity Research Articles

Powdery midlew is a dangerous disease of spring triticale in the far east

The studies were carried out in 2015–2022. in order to determine the degree of damage to collection samples of spring triticale by powdery mildew in the soil and climatic conditions of the Khabarovsk Territory of the Far East. The object of research is 84 samples of various ecological and geographical origins. The weather conditions during the research period were contrasting; with the normal precipitation for April–August being 466 mm, the excess was 16…263 mm; waterlogging contributed to an increase in relative air humidity to 100 %. The soil of the experimental plot is heavy loamy meadow-brown podzolized-gley. The distribution (R) of powdery mildew in triticale crops was high (80…100 %), the intensity of development (P) reached epiphytotic values annually. Collection varieties of spring triticale were distributed according to the intensity of disease development: moderately susceptible (13 samples), susceptible (35 samples), highly susceptible (36 samples). High correlation coefficients were calculated between the amount of precipitation in the booting-earing phase and the degree of infection of plants with powdery mildew (r = 0.861…0.897), and a linear regression equation was compiled that shows the dependence of the intensity of development of the powdery mildew pathogen and the amount of precipitation in the second ten days of June. Thus, spring triticale varieties were identified that have average susceptibility to powdery mildew pathogens (P = 30…40 %): Amore, Saur, Prag 409, Dagvo (Russia), Lana, Lotos (Belarus), Zgurivskiy, Oberig Kharkovskiy (Ukraine), 70 HN 458 (Canada), Je 57 (USA), Anoas 5, MX 51 (Mexico), Tleridal (Switzerland).

ADVANCING THE UNDERSTANDING OF PM FILTER MASS STABILITY: UNVEILING THE INFLUENCE OF HUMIDITY AND TEMPERATURE

The intricate interplay between humidity and temperature on PM filter performance has remaineda subject of profound scientific interest. By employing fully-automated weighing method anda two-factor regression model, the study aimed to evaluate mass variations of unloaded PM filtersunder diverse humidity and temperature conditions. Existing guidelines, as posited by the USEPA and the European Standard (EN), have demonstrated a pronounced disparity. The US EPAadvocates a narrow humidity range of 30–40% RH, while the EN suggests a broader range of40–50% RH. The results of this investigation confirm the US EPA’s guidelines, which exhibitedsuperior filter mass stability under varying humidity. In controlled stable temperature conditionsof 20C, the research unveiled significant variations in filter mass as RH% increased from 50%to 55%. It has been proven that under stable temperature conditions (20C) inside a weighingrobot, an increase in relative air humidity from 50% to 55% results in filters mass addition by15 μg (Q, quartz fibre filters); by 93 μg (PTFE filters); by 9 μg (G, glass fibre filters); by 112 μg (PA,polyamide filters) and by 20 μg (PC, polycarbonate filters). Further exploration of the conditioningranges prescribed by the EN 12341:2014 standard, the study highlighted glass fibre filters as beingnotably stable, while polyamide membrane filters posed intriguing challenges potentially relatedto ionization insufficiencies during the equilibration stage. These findings bear significance forfilter manufacturing and conditioning protocols, potentially enhancing the precision of air qualitymonitoring practices.

Multi-hollow Surface Dielectric Barrier Discharge: Production of Gaseous Species Under Various Air Flow Rates and Relative Humidities

An evaluation of the gaseous species production by the discharge, i.e., discharge chemical activity, is very important for determining its potential for practical applications. In this work, production of gaseous species by the multi-hollow surface dielectric barrier discharge generated in a perforated ceramic substrate with the air-exposed electrode is investigated under conditions of various discharge powers (1–5 W), air flow rates (0.25–2.4 L/min) and air relative humidities (0–80%). Production of ozone O3, nitrous oxide N2O, nitric oxide NO, nitrogen dioxide NO2, dinitrogen pentoxide N2O5 and nitric acid HNO3 is evaluated in terms of concentration (ppm), production yield (g/kWh) and production rate (mg/h). The work demonstrates a critical impact of both air flow rate and relative humidity on prevailing discharge mode (“O3 mode” vs. “NOx mode”) and, thus, on overall composition and concentration of produced gaseous species. For low discharge power, the discharge operates in the “O3 mode”, when O3, N2O, N2O5 and HNO3 are dominant gaseous products. With the increasing power, the discharge transfers into the “NOx mode”, when N2O and HNO3 along with NO and NO2 are mostly produced. In dry air, transition from “O3 mode” to “NOx mode” is found for the specific input energy of 1000–1100 J/L. With an increase of air relative humidity from 20 to 80%, the transition gradually decreases from approximately 600 to 450 J/L, respectively.

Fog Droplet Collection by Corona Discharge in a Needle–Cylinder Electrostatic Precipitator with a Water Cooling System

In this study, a needle–cylinder electrostatic precipitator with a water cooling system was designed to enhance the harvest of atmospheric water in wet flue gas. The effects of flow rate, temperature and particles on the collection of fog droplets were investigated. Meanwhile, the energy efficiency of water collection was analyzed at different voltages. The results show that the current decreases with the increase of air relative humidity under the same voltage, and the breakdown voltage increases obviously. Concurrently, by appropriately reducing the wet flue gas flow velocity, the residence time of fog droplets in the electric field can be increased, fully charging the droplets and improving the water collection efficiency. Moreover, experiments revealed that through decreasing the flue gas temperature, both the water collection rate and energy efficiency can be improved. In addition, the presence of particles in wet gas can improve the water collection rate by 5~8% at different discharge voltages. Finally, based on energy efficiency analysis, with the increase of voltage, although the water collection rate increased, the energy efficiency decreased.

Behavior of pigs subjected to climate control system in the Semiarid Region of Pernambuco, Brazil

The objective was to thermally characterize the facilities during the growth and finishing phases of pigs and to evaluate the influence of climate control systems on the expression of the behaviors of pigs. The experiment was conducted at the Federal Rural University of Pernambuco, Serra Talhada, PE, Brazil, during the spring of 2019. Twenty-seven pigs aged 63 days were used. The animals were submitted to pens without climate control system, with forced ventilation, and with an evaporative adiabatic cooling system. Dry bulb temperature (°C), relative air humidity (%), black globe temperature (°C), and swine behavioral responses were recorded, submitted to multivariate analysis, using the principal component technique. Pens with the evaporative adiabatic cooling system showed a significant reduction in air temperature and an increase in relative air humidity, during the two phases. Pigs submitted to evaporative cooling showed greater ingestive activity and lethargic behavior, typical of the studied phases

The effect of air relative humidity on the evaporation temperature of water-ethanol droplets

Using the method of infrared thermography, an experimental study of the temperature of evaporating droplets of a water-ethanol solution of different concentrations suspended on polypropylene thread at different air relative humidity was carried out. It is shown that the amplitude of the diminution in droplet temperature during evaporation decreases with an increase in relative air humidity for all considered concentrations of the water-ethanol solution. It is shown that the pattern of decreasing the minimum temperature of cooling of the evaporating droplets with increasing ethanol concentration is characteristic of all the studied air relative humidity. The obtained experimental data are generalized and can be used when calculating the heat and mass transfer of evaporating droplets of the water-ethanol solution.

Environmental assessment of the impact of the meteorological conditions on technogenic formaldehyde and carbon black pollution of the air in Voronezh

Based on the Voronezh hydrometeorological service official statistics analysis, the pollutants (formaldehyde and carbon black) dynamics regularities depending on the various meteorological parameters combination - air temperature, wind speed, relative humidity. A positive relationship was established between atmospheric pollution growth with formaldehyde and air temperature. As the wind speed and the air relative humidity increase, the formaldehyde and soot concentration in the urban atmosphere, as a rule, decreases. The carcinogenic risk maximum permissible level to public health, causing concern, has been established. The obtained patterns can be used to predict the city’s atmosphere technogenic pollution level depending on meteorological conditions. Based on the official statistic analysis from the Voronezh Hydrometeorological Service, the pollutants (formaldehyde and carbon black) dynamics patterns are investigated depending on various meteorological parameters’ combination - air temperature, wind speed, relative air humidity. A positive relationship has been established between the increase in atmospheric pollution with formaldehyde and air temperature. With increasing wind speed and relative humidity, the formaldehyde and soot concentration in the city atmosphere, as a rule, decrease. The maximum permissible carcinogenic risk level to public health has been established, causing concern. The obtained patterns can be used to predict the city’s atmosphere technogenic pollution level, depending on meteorological conditions.

Synoptic Conditions of Droughts and Dry Winds in the Black Sea Steppe Province Under Recent Decades

The features of regional atmosphere circulation, which accompanied simultaneously by two high impact hydrometeorological phenomena such as droughts and dry winds in the Black Sea Steppe zone of Ukraine were considered. Dry wind as a complex phenomenon is widespread throughout Ukraine during warm season of the year. Dry winds often accompany a drought, but they appear as peripheral processes in contrast to the droughts, which usually are formed in central parts of anticyclones. The number of days with dry wind at the Steppe stations varies in average from 10-20 cases to 40-50 cases per warm season, while in the coastal zone the number of days decreases sharply due to common increase of air relative humidity. Analysis of the interannual dynamics of dry winds showed that the number of days with dry wind increases significantly in seasons characterized by a high aridity, according to values of used drought index. Two time intervals with high and low frequency of seasonal droughts and dry winds were detected during the considered period 1995-2015. These phenomena have become more intense after 2004, compared to the previous decade. Backwards trajectories of air particles shown that the most cases of dry winds origin in air masses, which forming at surface level to the east or north-east outside the territory of Ukraine and pass to study area during five days.

Passage through phenophases by milkvetches introduced into the environments of the Kulunda Steppe

Background. Recently, more and more attention has been paid to the study of plant phenology in the context of the global climate change. By now, the question of how climate factors affect the phenophases of plants has not yet been fully investigated. Accurate forecasts for biological responses of plant species to climate change require profound understanding of the impact produced by meteorological factors on plant phenology.Materials and methods. The research was targeted at Astragalus L. spp. introduced into the dry steppe areas of the Kulunda Plain. Meteorological indicators were selected for agrometeorological description of the plant introduction site to assess its hydrothermal conditions. The Pearson correlation coefficient was used to identify the level of correlations between the studied parameters.Results. High air temperature shortened the growing season of Astragalus cicer L., but lengthened its flowering and fruiting phases. An increase in relative air humidity shortened the flowering in A. cicer. Meteorological indicators did not significantly affect the duration of the phenophases in A. sulcatus L. For A. onobrychis L., an increase in the average relative humidity reduced the budding phase, while an increase in the average and maximum air temperature and an increase in the amount of precipitation increased the flowering period. A decrease in air temperature and average relative humidity, and an increase in the total precipitation lengthened the duration of fruiting in A. onobrychis. Increased average temperature and humidity reduced its fruiting phase.Conclusion. A. sulcatus is tolerant to the dry steppe environments. The phenophases of A. cicer and A. onobrychis are more responsive to changes in meteorological indicators. In A. onobrychis, the fruiting phase is susceptible to the combined impact of climate factors. The limiting factors for A. cicer are relative humidity, total precipitation and mean temperature during the growing season.

Leaf structural and hydraulic adjustment with respect to air humidity and canopy position in silver birch (Betula pendula).

Climate change scenarios predict an increase in air temperature and precipitation in northern temperate regions of Europe by the end of the century. Increasing atmospheric humidity inevitably resulting from more frequent rainfall events reduces water flux through vegetation, influencing plants' structure and functioning. We investigated the extent to which artificially elevated air humidity affects the anatomical structure of the vascular system and hydraulic conductance of leaves in Betula pendula. A field experiment was carried out at the Free Air Humidity Manipulation (FAHM) site with a mean increase in relative air humidity (RH) by 7% over the ambient level across the growing period. Leaf hydraulic properties were determined with a high-pressure flow meter; changes in leaf anatomical structure were studied by means of conventional light microscopy and digital image processing techniques. Leaf development under elevated RH reduced leaf-blade hydraulic conductance and petiole conductivity and had a weak effect on leaf vascular traits (vessel diameters decreased), but had no significant influence on stomatal traits or tissue proportions in laminae. Both hydraulic traits and relevant anatomical characteristics demonstrated pronounced trends with respect to leaf location in the canopy-they increased from crown base to top. Stomatal traits were positively correlated with several petiole and leaf midrib vascular traits. The reduction in leaf hydraulic conductance in response to increasing air humidity is primarily attributable to reduced vessel size, while higher hydraulic efficiency of upper-crown foliage is associated with vertical trends in the size of vascular bundles, vessel number and vein density. Although we observed co-ordinated adjustment of vascular and hydraulic traits, the reduced leaf hydraulic efficiency could lead to an imbalance between hydraulic supply and transpiration demand under the extreme environmental conditions likely to become more frequent in light of global climate change.

Effect of microwave drying of the spines of book blocks on the quality of printed materials

Based on the main provisions of the theory of heat and mass transfer, we examined the kinetics of natural and microwave drying of the spines of book blocks. The existence of three periods of drying is proven: a period of warming the block (when the moisture content of paper reduces along a certain curve); a period of constant rate (when moisture content reduces by the law of a straight line); a period of falling rate (when there is a redistribution of moisture removal and it becomes uniform for all layers, thereby ensuring product quality). Based on the graph-analytic analysis of curves of the intensity of microwave drying and mathematical modeling, we demonstrated relationship between the time of drying, temperature, and the type of paper. Thus, an increase in relative air humidity by 20 % results in a decrease in the intensity of drying by about 2 times (for the blocks made from chalk overlay paper) and by 1.5 times (for the blocks made from offset paper). An increase in air temperature by 10 °C results in a reduction in the drying time of blocks made from chalk overlay paper by about 1.5 minutes, and of the blocks made from offset paper – by 1 minute. We established optimal modes of microwave drying of book blocks (3–5 minutes at a temperature of 40 °C). We have proven a positive effect of microwave drying on the performance indicators of books: resistance of blocks to the sign-alternating loads on the spine, maximal effort of breaking the blocks and pulling sheets out of the blocks. The study that we conducted is important to ensure quality in the book manufacturing process, as well as strength of book structure for its intensive use by readers

Variation in NEE and its response to environmental factors in an extremely arid desert wetland ecosystem

In order to study the net ecosystem CO2 exchange (NEE) variation and its response to environmental factors, CO2 flux and related environmental factors were monitored from May until September. The diurnal NEE variations in this region showed a U-shaped distribution. The average daily CO2 absorption in July was the largest. The study area is a carbon sink during the growing season. At the soil depth of 40 and 80 cm, due to the influence of underground water, the soil water content had a significantly negative correlation with NEE. The increase in relative air humidity can facilitate stomata opening, which also improves CO2 absorption. Additionally, the increase in air temperature, soil temperature and photosynthetically active radiation (PAR) all promote plant photosynthesis, which leads to a negative correlation with NEE.

Numerical Investigation of Ventilation and Human Thermoregulation for Predicting Thermal Comfort of a Rider Wearing Ventilated Helmet

Effectiveness of ventilated helmets in providing thermal comfort to a motorcycle rider is studied. Computational fluid dynamics (CFD) simulations of human thermoregulation system and the air flow in the air gap of a full-face motorcycle helmet are carried out. The thermal comfort of a rider is predicted using apparent temperature (AT) and wet-bulb global temperature (WBGT) heat indices. The effect of an increase in ambient temperature and relative humidity (RH) of air on the air flow and temperature in the region above the head is studied to predict the thermal comfort of the rider wearing full-face helmets. The effect of increasing the air gap between the head and the helmet is also studied. The results are then compared with the conditions when the rider is not wearing helmet. It is observed that the ventilated helmet is effective in providing thermal comfort to the rider only if the ambient air temperature is less than normal body temperature. For air temperature higher than the body temperature, vents do not provide any cooling to the head and the nonventilated helmet is more comfortable. Furthermore, CFD simulations are performed to investigate the effect of increase in RH in the ambient air on the thermal comfort of the rider. The increase in RH of air from 50% to 90% at a fixed ambient air temperature leads to an increase in AT and WBGT, indicating reduced thermal comfort of the rider.

Analysis of relationship between condensation activity of surface aerosol and its chemical composition and relative air humidity according to measurements at the Zvenigorod Scientific Station

Data of IR transmission spectra of aerosol samples and measurements of optical characteristics of surface aerosol at the Zvenigorod Scientific Station are used to study the statistical relationship between the Hanel condensation activity parameter and relative air humidity and the basic chemical components of aerosol, namely, sulfate, nitrate, and mineral components, contained in particles with diameters of 1–2 μm. It is found that the Hanel parameter of nitrate-containing surface aerosol decreases with an increase in relative air humidity. An increase in the fraction of nitrates in micron particles is likely to lead to a minor increase in the Hanel parameter. Poorly soluble mineral particles present in the 2-micron fraction of aerosol lead to a decrease in the Hanel parameter. Values of the Hanel parameter, characteristic for sulfate aerosol, are likely to be in the range of 0.4–0.6. Seasonal variations in the Hanel parameter are caused by changes in the aerosol chemical composition, to some degree.

Potential Use of Tropical Grass for Deferment in Semi-Arid Region

Management evaluation of Panicum maximum cv. massai (Massai guineagrass) under deferment contributes as a strategic reserve of forage in the Brazilian semi-arid region. The objective of this study was to evaluate biomass production and nutritive value of massai guineagrass in an area of thinned caatinga vegetation in two deferment periods (60 and 90 days after plot-leveling cut) and four use periods (30, 60, 90 and 120 days after the end of the rain season), in a random blocks design arranged in a split-plot (2 × 4), with three replications. Extending the deferment period of massai guineagrass promoted elevation of the biomass components, but compromised the pasture quality due to increasing stem biomass. The massai guineagrass deferred 30 days after raining season started and should use 90 days after raining season ended to ensure a forage supply of appropriate nutritional value. The increase in relative air humidity and the occurrence of rainfall after water restriction stimulate regrowth, resulting in improved nutritional value of the grass.

Population dynamics of Aceria guerreronis (Acari: Eriophyidae) and other mites associated with coconut fruits in Una, state of Bahia, northeastern Brazil

Aceria guerreronis Keifer is a major coconut pest in the Americas, Africa and some Asian countries, and occurs in high population levels in northeastern Brazil. The determination of the climatic conditions that favorably affect its population growth and the prevalence and abundance of predatory mites can promote more efficient control practices. Our objective was to evaluate the pattern of occurrence and population dynamics of A. guerreronis, their associated predators and other mites during a 2year period in a hybrid coconut plantation in the municipality of Una, state of Bahia, northeastern Brazil. Monthly samples of fruits were taken from June 2008 to May 2010 for qualitative and quantitative evaluation of mites. Aceria guerreronis represented 99.9% of the mites. An average density of 1,117 mites per fruit and a maximum of 23,596 mites per fruit indicated that the level of infestation can be high in Bahia. Bdella ueckermanni Hernandes, Daud and Feres was the most abundant and frequent predator. Population increase of A. guerreronis was directly related to the temperature rise and inversely related to both the increase of air relative humidity and rainfall. The highest population densities occurred from November to March. The largest A. guerreronis populations occurred in fruits with 32 and 48% of damaged surface. The relationship between prevailing wind direction and incidence of A. guerreronis could not be corroborated or refuted.

The influence of weather conditions on the course of pollen seasons of alder (Alnus spp.), hazel (Corylus spp.) and birch (Betula spp.) in Lublin (2001-2006)

The start and rate of florescence of <i>Alnus</i>, <i>Corylus</i> and <i>Betula</i> are dependent on meteorological conditions. In the present paper we have analysed the effect of mean, maximum and minimum temperature, relative air humidity and precipitation on the onset of the pollen season as well as on its length and annual count of pollen grains in alder, hazel and birch. The measurement of pollen fall was done by the gravimetric methods with the use of Durham sampler. Correlation coefficients were calculated between the determined characteristics of the pollen season and weather conditions. In the six-year research period 2001-2006 it was observed that low temperatures in January produced a delayed start of the pollen season in alder, hazel and birch. The beginning of flowering in these taxa was also influenced by thermal conditions prevailing directly before the season (ca. 10 days). The pollen season of the trees in question tended to be prolonged alongside with the increase in relative air humidity, but it was shortened due to higher temperatures. The volume of alder and hazel pollen release increased together with the rise in relative air humidity and precipitation. The annual counts of birch pollen increased along with rising temperature and decreasing relative air humidity and precipitation in the season.

Risk factors for dirty dairy cows in Norwegian freestall systems

Cow cleanliness is important for ensuring hygienic milk production and the well-being of dairy cows. The aim of this cross-sectional field study was to describe cow cleanliness in freestall-housed dairy herds and to examine risk factors related to thigh cleanliness. Cow cleanliness (n=2,335), management-related variables (e.g., ventilation and use of sawdust-bedded stalls), and housing-related variables (e.g., freestall design and number of cows per stall) were recorded in 232 Norwegian freestall-housed dairy herds. Cleanliness was scored on a 4-point scale ranging from clean (1) to very dirty (4). The cows were relatively clean on the udder and belly, dirtier on thigh and the rear part of the body, and dirtiest on the legs, with cleanliness scores (mean ± SD) of 1.64±0.62, 1.62±0.65, 2.02±0.75, 1.77±0.58, and 2.30±0.59, respectively. With dirty thighs as the response variable, several variables were tested in a logistic regression mixed model and with repeated measurements within herd and cow. A high number of cows per freestall [odds ratio (OR)=3.45], no use of sawdust as bedding (OR=3.24) versus use of sawdust, and a low-positioned (<0.85m above stall floor) upper head rail “enclosing” the front of the stall (OR=1.42 to 2.13) versus a position >0.85m were all risk factors for dirty thighs on the cows. Furthermore, liquid manure (score 2) versus more consistent manure (score 1; OR=1.66) and less tame cows (score 2) versus tame cows (score 1) were associated with an increased risk of dirty thighs (OR=1.24). The cleanest cows were associated with indoor temperatures in the range from 10 to 15°C. For each 10-percentage-unit increase in relative air humidity, the risk of dirty thighs increased (OR=1.32). Freestalls with a construction hindering normal lying, rising, and standing movements should be avoided. Furthermore, focus is needed on indoor climate and manure consistency to obtain cows with clean thighs.

Electrization of aerosol wetted in bipolarly ionized air

We studied the influence of the characteristics of the atmospheric ionization and physical-chemical state of condensation nuclei on the electric state of convective cells. Based on the results of experiments in an adiabatic chamber with a volume of 3200 m3, we found that, with increase in relative air humidity H from 40 to 95% with an equivalent ascent rate of 100–400 cm/s, excessive charges in amounts of about 103 or more elementary charges per cm3 may be accumulated on the nuclei. The sign of the charge depends on the chemical composition of the hygroscopic nuclei. For instance, media with insoluble nuclei (porous silica, etc.) typically have prevailing negative charges; those with soluble nuclei (sodium chloride, etc.) are dominated by positive charges. At H = 60−90%, the electrization of soluble nuclei can be interpreted in the diffusion-kinetic models of the ion charging of aerosols. Considerable negative volume charges, which appear on insoluble hygroscopic nuclei during a rise in humidity from 40 to 70%, are explained by the structuring of surface water films, which exhibit a resemblance to negative lightweight ions. At high values (H > 90%), it is necessary to take into account the resemblance of the wetted surfaces to positive lightweight ions. We showed for the first time that, at ion formation rates of 3 and 1010 ion pairs/(cm3 s), the differences in the volume charge and wetting rate of condensation nuclei are insignificant. It is concluded that, in many meteorological situations, the first stage of electrization of the convection-derived cloud media is the ion charging of the condensation nuclei.

Investigation of possibility to use polyamid-polytehylene foil in preservation of equipment

Atmospheric corrosion can be slowed down or entirely stopped by placing metal equipment under a cover made of plastic foil. The results of investigation of the diffusion of water vapor through polyamid-polyethylene foil show that the vapor diffusion increases with the increase in relative air humidity. This characteristic makes polyamid-polyethylene foil no worse than polyethylene-polypropylene foil, which has been widely used so far. .