Low Air Humidity Research Articles

Spatial distribution and controls of snowmelt runoff in a sublimation-dominated environment in the semiarid Andes of Chile

Abstract. Sublimation is the main ablation component of snow in the upper areas of the semiarid Andes (∼ 26 to ∼ 32∘ S and ∼ 69 to ∼ 71∘ W). This region has elevations up to 6000 m, is characterized by scarce precipitation, high solar radiation receipt, and low air humidity, and has been affected by a severe drought since 2010. In this study, we suggest that most of the snowmelt runoff originates from specific areas with topographic and meteorological features that allow large snow accumulation and limited mass removal. To test this hypothesis, we quantify the spatial distribution of snowmelt runoff and sublimation in a catchment of the semiarid Andes using a process-based snow model that is forced with field data. Model simulations over a 2-year period reproduce point-scale records of snow depth (SD) and snow water equivalent (SWE) and are also in good agreement with an independent SWE reconstruction product as well as satellite snow cover area and indices of winter snow absence and summer snow persistence. We estimate that 50 % of snowmelt runoff is produced by 21 %–29 % of the catchment area, which we define as “snowmelt hotspots”. Snowmelt hotspots are located at mid-to-lower elevations of the catchment on wind-sheltered, low-angle slopes. Our findings show that sublimation is not only the main ablation component: it also plays an important role shaping the spatial variability in total annual snowmelt. Snowmelt hotspots might be connected with other hydrological features of arid and semiarid mountain regions, such as areas of groundwater recharge, rock glaciers, and mountain peatlands. We recommend more detailed snow and hydrological monitoring of these sites, especially in the current and projected scenarios of scarce precipitation.

Minimizing pathogen transmission through indoor environment optimization using central composite design of experiment

The human respiratory emission mechanism generates virus particles such as the COVID-19 virus that exists in both aerosols and water droplets form. Trajectories of airborne pathogens transmitted from coughing are influenced by the air flow pattern surrounding the transmission source, making it challenging to predict. ANSYS Fluent 2022 R1 is employed in this study to visualize the airborne pathogen transmission in indoor space of different environmental conditions with steady-state and periodic wind velocity. The effect of five different indoor parameters on airborne transmission is studied, which include wind velocity, air temperature, relative humidity of the air, particle residence time after emission, and the physical distancing of 3 feet, 6 feet, and 10 feet between two humans. The characteristics between airborne transmission and varying indoor conditions have motivated this study to correlate their dynamic relationship. Due to the limitation in controlling indoor conditions, obtaining optimum indoor conditions with minimal airborne transmission remains challenging. Simulation-based design of experiment of central composite design type yields optimum indoor condition with a wind velocity of 4.337 m/s, air temperature of 24.26 °C, and relative humidity of 40.14% showed 58.14% reduction in deposited particle mass relative to the base condition at a similar physical distancing of 3 feet. Surrounding air with higher relative humidity leads to a larger mean diameter of particles due to the hygroscopic growth effect. In comparison, the evaporation effect dominates in lower air humidity, leading to particle shrinkage. Particle deposition from human to human is lower with longer distances between humans, with comparable behaviour of particle transmission at each successive time step, suggesting prolonged exposure risk of the healthy individual as time progresses. This research focuses on adopting engineering simulation to find optimum indoor conditions with minimal human-to-human airborne transmission to strengthen safety and health judgement during a pandemic.

THE INFLUENCE OF CLIMATIC CONDITIONS ON THE OCCURRENCE OF LARGE FOREST FIRES: A CASE STUDY OF STARA PLANINA NATURE PARK IN 2007 AND 2019

This work investigates the relationship between the occurrence of large forest fires (more than 1,000 ha) and meteorological data. Specifically, it analyzes the characteristics of large forest fires in July 2007 (2,500 ha) and October 2019 (2,108 ha) in Serbia’s Stara Planina Nature Park (NP). The results show that at these times, forest fires occurred during long heatwaves with low relative humidity and high air temperature. Dry climatic conditions in the preceding months also contributed to the occurrence of large forest fires, alongside the presence of wind. The study uses climate indices based on the combination of air temperature and precipitation. Forest drought index (FAI) data show that 2007 and 2019 were drier than the 1961–1990 climate period. According to the Lang Precipitation Factor Index (AILang), the periods June–July 2007 and July–October 2019 can be classified as dry. The De Martonne Drought Index (ImDM) shows that July 2007 and October 2019 had the characteristic of areism. These were also the periods when large wildfires were recorded. The results of this study could be used for wildfire risk assessment in protected areas and for fire prevention and suppression planning.

MAIN PERIODS OF GROWTH AND DEVELOPMENT OF F1 CUCUMBER HYBRIDS AND THEIR YIELDS DEPENDING ON WEATHER

Purpose. To evaluate effects of weather on growth and development of cucumber plants, lengths of the main interphase periods, and cucumber yield the Left-Bank Forest-Steppe of Ukraine; to select breedingvaluable genotypes for heterosis breeding under climatic changes. Methods. Field, analytical, measuring, statistical. Results. The study was conducted outdoors at the Institute of Vegetable and Melon Growing of NAAS in 2019–2020. The weather in the study years varied significantly, allowing us to assess its influence on phenological processes of growth and development of cucumber plants. Summarizing the results, we established that sufficiently high average daily air temperature (25.3–25.8 °С), a large amount of unevenly distributed precipitation (0–104 mm), with little or no precipitation during certain phases of cucumber development, significantly affected the growing period length and yield of the cucumber hybrids under investigation. We found that the onset of mass anthesis of female flowers did not vary significantly across the years, averaging 33–36 days. (35 days in the check accession). Fructification started on day 37–40 in 2019 and on day 42–45 in 2020, which was 4–6 days later. Fructification lasted 32–40 days in 2019 and 20–24 days in 2020, which was 12–16 days longer. Analysis of the cucumber yield dynamics over the study years showed that the weather in 2019 was more favorable for the growth and development of cucumber plants. Thus, in 2019, the total yields of hybrids ranged 20.8 t/ha to 64.9 t/ha. In 2020, at high temperatures and low air humidity, the total yield was 12.7–26.9 t/ha, which was significantly lower (by 41.4–61.0 %). Conclusions. The weather in the study years reflected the climate instability in the Forest-Steppe of Ukraine. The lengths the main periods of the growth and development of cucumber hybrid plants and their yields were revealed to vary significantly under variable growing conditions. We selected hybrids with annual parameters that would be valuable for further breeding: by early ripeness – F1 ‘BD 96-18’ / ‘Tsezar’, F1 ‘RD 96 2-95’/ ‘Dzherelo’, F1 ‘RD 96 2-95’ / ‘Heim’ and F1 ‘Mah-62’ / ‘Toma-18’ (42 days); by fructification length – F1 ‘RD 96 2-95’/‘Dzherelo’ (35 days), F1 ‘Mah-62’ / ‘Toma-18’, F1 ‘BD 96-18’/ ‘Heim’ and F1 ‘RD 96 2-95/‘Heim’ (32 days); by yield capacity – F1 ‘Mah-62’ / ‘Toma-18’ (45,9 t/ha), F1 ‘BD 96-18’/ ‘Toma-18’ (39,3 t/ha), F1 ‘Krak’ / ‘RD-96 2-95’ (36,8 t/ha), F1 ‘RD 96 2-95’/ ‘Heim’ (35,8 t/ha), F1 ‘BD 96-18’/ ‘Heim’ (34,6 t/ha), and F1 ‘RD 96 2-95’/ ‘Dzherelo’ (34.2 t/ha). The selected hybrids yielded significantly more than the check F1 hybrid ‘Ajax’ (by 80-142 % or by 19.0 t/ha).

Effect of air gap induction on the morphological microstructure of polyether sulfone hollow fiber membrane

AbstractPolyether sulfone hollow fiber membrane was prepared via nonsolvent‐induced phase separation process using dimethylacetamide (DMAc) as a solvent, Polyvinylpyrrolidone (PVP‐K30) and water as additives. The mechanism of air gap environment in the membrane structure formation was studied. The scanning electron microscope microstructure morphology revealed that the air gap environment induced the microstructure formation of membranes. The low humidity air gap environment was not conducive to the surface pore formation and hard to obtain surface pores until lowering the dope solution temperature. The high humidity can easily induce the formation of large out surface pore structure along with the decreases of the surface pore uniformity. As air gap humidity and distance increased, the membrane cross section structure near the outer surface tends to be looser and that near the inner surface became denser, while the proportion of finger‐like pores in the cross section initially increased and stabilized. At 100 RH, the average outer surface pore size increased from 0.192 μm at an air gap distance of 20 cm to 0.351 μm at 50 cm, the corresponding pore density decreased from 2.66 to 1.13 pores/μm2, and the percentage of the inner skin layer thickness increased from 3.26% to 7.69%.

Transmission and Growth Characteristics of Severe PM2.5 Pollution Events from 2013 to 2021 in Xingtai, Hebei

The correlation between the growth rate of PM2.5 with transport source, atmospheric circulation, and wind field were analyzed, focusing on the severe and above pollution process (SAAP) in Xingtai, Hebei Province from 2013 to 2021. The results showed that from 2013 to 2021, a total of 164 pollution processes and 103 SAAP occurred in Xingtai. In the ground circulation, although the probability occurrence of the inverted trough was low, the probability of pollution was the highest (61.1%), followed by the high-pressure control type (>50.0%). In the 500 hPa, the control of the straight westerly wind belt had the highest probability of severe and above pollution (20.7%), followed by the post-trough type (16.1%), with the highest occurrence frequency. In SAAP, the distribution of the PM2.5 hourly growth rate (ΔPM2.5) was mainly concentrated between ±150 μg·(m3·h)-1, and the PM2.5 hourly growth rate was positive (+ΔPM2.5), contributing 61.7%. Among them, the average proportion of explosive growth was 13.9% (from 2013 to 2021), and the overall trend was decreasing annually. In the full wind speed, in terms of occurrence frequency and pollution probability, north-east (NE) was the wind direction most closely related to air pollution, especially severe and above pollution. The mean value of ΔPM2.5 in SAAP was lower than that of quiet wind in most wind directions. However, in some of the east-north (EN) and south-west (SW) wind direction intervals, the mean ΔPM2.5 in moderate wind speed was significantly higher than that of quiet wind (related to pollution transmission). The impact of larger wind speed on ΔPM2.5 was more complicated. The backward trajectories showed that the backward trajectories of slow, rapid, and explosive growth in SAAP could be divided into three main paths:west-north, east-north, and south. With the acceleration of the growth rate, the proportion of the west-north air mass gradually increased. The humidity (RH) of the slow-growth air mass was relatively large (more than 80% RH>50%), the relative humidity of the rapidly growing air mass was relatively concentrated (mainly distributed in 35%-55%), and the proportion of low-humidity (<50%) air masses increased significantly (by approximately 63%) in the explosive growth. The simulation analysis showed that the types of SAAP pollution could be divided into five categories:local accumulation, east-northern transmission, north-west transmission, mixed transmission, and south transmission. Among them, the proportion of mixed transmission was the highest, followed by that of the north-west transmission. The high and low-altitude configurations with the highest occurrence probability among the southerly transmission, the local accumulation type, and the north-easterly transport type were all high-altitude trough rear type combined with ground equalization field type. Among the north-westerly type, the high-pressure on the ground with the behind trough on high-altitude had the highest probability of occurrence. In mixed transmission, the probabilities of various circulation ratios were relatively balanced.

Water Harvesting by Molecular Sieves Using Self-sustained Continuous Flow

A way of harvesting water from the air that avoids the discontinuity of the adsorption/desorption cycles is theoretically analyzed. A rectangular prism-shaped adsorbent bed is immersed in low-humidity air, at an angle to the horizontal and subject to a temperature gradient between two opposite and open faces. The other four faces of the prism remain isolated. Water is adsorbed on the adsorbent colder face, causing a density gradient in the surrounding air, parallel to the surface, that results in a self-sustained continuous air flow. On the opposite face, a self-sustained continuous air flow parallel to the surface also arises, but this time due to a temperature gradient in the air surrounding the hot bed face. In addition, its higher temperature causes the desorption of water from the adsorbent. This overall water exchange produces the enrichment of water content in one of the air streams that is crucial to produce water harvesting. The performance of Al-Fumarate, MOF-303, SAPO-34 and Zeolite 13X is tested, unveiling the key factors that increase flow rate and water concentration at the enriched phase. It has been found that the diffusive mass transport at the air-solid interphase is the bottleneck of water harvesting in continuous flow conditions. Therefore, if high concentration of water is desired, it is necessary to use porous materials with very high diffusitivities. These findings provide the foundations for the design of continuous water harvesting devices.

Effect of wearing a face mask on microclimate around the eyes and the tear film

Eye discomfort is a major complaint reported in indoor spaces and has been suggested to be exacerbated by environmental conditions such as low humidity and high air velocity. Wearing face masks, which has become essential in our daily lives during the COVID-19 pandemic, can also cause eye discomfort by affecting the microclimate around the eyes. We conducted a pilot study to evaluate the effect of wearing masks on eye discomfort by measuring the physical environment around the eyes and short-term physiological and psychological responses and comparing them with and without surgical face masks. The results showed that when the participant wore a mask, exhaled air flowed out through the gap at the top edge of the mask, resulting in a higher air velocity and absolute humidity around the eyes than when the mask was not worn. No significant differences were found in subjective discomfort, tear-film stability, ocular surface temperature or blink frequency. However, the tear evaporation rate, estimated based on physical measurements, was greater when wearing a mask than when not wearing it. This study revealed that wearing face masks can negatively affect the environment around the eyes in terms of tear-film health.

System integration analysis of a zeolite 13x thermal energy storage

Nowadays a major energy transition aimed at cutting CO2 emissions has begun, with the ambitious goal of drastically reducing the dependence on fossil fuels and promoting the use of renewable energy sources. In this context, energy storage systems play a key role in ensuring a stable, secure and time-aligned energy availability. Open sorption thermal energy storages (TESs) can contribute to such transition, since they are simple and cheap devices able to provide a hot airflow with a high energy density and to store energy for long time. In this work, open sorption TES systems operated with Zeolite13X are investigated with a focus on the integration in practical applications. First, the experimental analysis and modelling of the sole TES system is described. Then, the integration of the TES at system level is carried out. The analysis evidences that a significant reduction of storage capacity occurs if air humidification is necessary before the adsorption process or afterwards to keep adequate indoor comfort conditions for the occupants. For the exemplary case study considered, an energy density of 150 kWhm−3 can drop to 40 kWhm−3 in case of complete compensation of the adsorbed water through a humidifier. This paper provides useful guidelines for evaluating the performance of a TES integrated system in terms of specific energy and efficiency. It also identifies applications involving high latent loads (e.g., swimming pools, locker rooms) or for which low relative air humidity is required (e.g. interior of vehicles to prevent condensation on windows) as particularly beneficial for using a TES system.

Experimental evaluation of a hybrid solar dryer with flexible open sorption thermal energy storage unit on demand for burdock root drying

Solar drying represents an attractive way to implement an efficient and green development strategy. The viability of open sorption thermal energy storage (OSTES) can compensate for the inherent shortcomings of intermittency and instability of solar energy for ensuring the continuity of the drying process. Nevertheless, the existing solar-powered OSTES technologies only allow a batch mode while being severely restricted by sunlight's availability, thereby heavily limiting the flexibility in managing OSTES on demand. Herein, a novel proof-of-concept that a standalone solar dryer integrated with a reversible solid-gas OSTES unit is presented. Using in situ electrothermal heating (in situ ETH) could rapidly release adsorbed water of activated carbon fibers (ACFs) in an energy-efficient manner to achieve a charging process with faster kinetics. Applying electrical power by a photovoltaic (PV) module, particularly during sunlight-absent or insufficient time, allowed multiple OSTES cycles to proceed. Moreover, ACFs cylindrical cartridges can be flexibly interconnected in either series or parallel, forming universal assemblies with well-controlled in situ ETH capacity. The mass storage density of ACFs with a water sorption capacity of 570 mg/g is 0.24 kW·h·kg-1. The desorption efficiencies of ACFs are higher than 90%, corresponding to 0.057 kW·h maximum energy consumption. The resulting prototype can diminish the fluctuation of air humidity along the night and provide a relatively steady and lower air humidity for the drying chamber. The energy-exergy and environment analysis of the drying section for both setups are estimated, respectively.

Experimental investigation and effectiveness analysis of a desiccant wheel dehumidification system with low air humidity

The desiccant wheel dehumidification system is a feasible approach to realize the deep-dehumidification process to produce supply air with dew point temperature below 0 °C in modern architecture fields. However, actual dehumidification performance of the desiccant wheel system under low humidity condition and its difference from normal humidity dehumidification process have not been experimentally demonstrated. This study, therefore, carried out experiments to investigate the dehumidification performance as well as the thermodynamic effectiveness of the desiccant wheel deep dehumidification system. The results reveal that the desiccant wheel dehumidification system show relatively higher relative dehumidification capacity under low inlet process air conditions, reaching 77.4% under the regeneration air state of 75 °C and 4 g/kg by supplying air humidity under 1 g/kg. The sensitivity of dehumidification performance varying with regeneration humidity is reduced when the desiccant wheel is operated at high regeneration temperature. The deep dehumidification process also shows much greater isenthalpic deviation and surplus temperature deviation than normal dehumidification process due to larger irreversible heat loss, and the thermodynamic effectiveness is also highly related to the regeneration parameters. The study provides theoretical and experimental reference for the effective and efficient design of the desiccant wheel assisted deep dehumidification system.

Moist‐Electric Generator with Efficient Output and Scalable Integration Based on Carbonized Polymer Dot and Liquid Metal Active Electrode

AbstractMoisture‐enabled electricity generation (MEG) is highly promising in next‐generation energy conversion. However, the practical applications of existing MEG devices are limited due to their low current and voltage outputs, strong dependence on high moisture, and inflexible nature. Herein, an efficient MEG integrated with flexible, all‐weather, and scalable fabrication characteristics based on the rational combination of carbonized polymer dots (CPDs) and liquid metal (LM) active electrodes is developed for the first time. Remarkably, the fabricated MEG device can produce a stable voltage output of 800 mV and a record high current density of 1640 µA cm−2. Even at a low air humidity of 15%, the MEG device can provide a high voltage output of 0.65 V and a considerable current density of 12 µA cm−2. The prompted diffusion of hydrogen ions in CPDs and the additional metal ions ionized from the LM electrode contribute synergistically to the high electricity generation. Additionally, the device can be easily integrated on various flexible substrates and generate an ultrahigh voltage of 210 V to power commercial electronics, showing great potential in large‐scale fabrication and application.

In Situ Time-Dependent Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy of a Powdered Specimen in a Controlled Atmosphere: Monitoring Sorption and Desorption of Water Vapor.

Attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy is a powerful instrumental method of chemical analysis of solids and liquids. The majority of published studies by in situ ATR FT-IR spectroscopy describe analysis of homogeneous samples, such as liquid solutions under circulation, or films on the ATR crystal that react with the gas of interest. The in situ ATR FT-IR spectroscopic studies of specimens in physical shape of crystals or powder that react with a gas or vapor are rare. This work describes a modification of in situ time-dependent ATR FT-IR spectroscopy to allow monitoring heterogeneous reaction "solid-gas" of powder in controlled atmosphere and in the time domain. Also, we describe a new facile gas flow chamber attachment to ATR FT-IR spectrometer which allows creating controlled atmosphere surrounding the specimen on the ATR crystal. Additionally, the capabilities of the described in situ time-dependent ATR FT-IR spectroscopy experiment in controlled atmosphere are enhanced by the sensor for in situ time-dependent monitoring the relative humidity (RH) of air surrounding the specimen. The operation of the setup for in situ time-dependent ATR FT-IR spectroscopy in controlled atmosphere is demonstrated by monitoring reaction of gradual desorption of water vapor from color-indicating molecular sieves under controlled low air humidity. Further, the described spectroscopic method and apparatus is applied to monitor the reverse process, namely sorption of water vapor by color-indicating molecular sieves under controlled elevated air humidity. Water molecules are found to reversibly interact with two distinct sorption sites in the sorbent: the Si-O backbone and the color-indicating Co(II) centers. The reported variant of in situ time-dependent ATR FT-IR spectroscopy in controlled atmosphere is powerful, yet facile and straightforward. It is promising for mechanistic, in situ studies of sorption, desorption, chemosensing, heterogeneous catalysis and photocatalysis, and analysis of chemical kinetics of various "solid-gas" reactions.

Assessment of Dust, Chemical, Microbiological Pollutions and Microclimatic Parameters of Indoor Air in Sports Facilities.

The aim of this study was to analyse the quality of indoor air in sport facilities in one of the sport centres in Poland with respect to microclimatic parameters (temperature, humidity, and air flow velocity), particulate matter concentrations (PM10, PM4, PM2.5, and PM1), gas concentrations (oxygen, ozone, hydrogen sulphide, sulphur dioxide, volatile organic compounds, and benzopyrene), and microbial contamination (the total number of bacteria, specifically staphylococci, including Staphylococcus aureus, haemolytic bacteria, Enterobacteriaceae, Pseudomonas fluorescens, actinomycetes, and the total number of fungi and xerophilic fungi). Measurements were made three times in May 2022 at 28 sampling points in 5 different sporting areas (the climbing wall, swimming pool, swimming pool changing room, and basketball and badminton courts) depending on the time of day (morning or afternoon) and on the outside building. The obtained results were compared with the standards for air quality in sports facilities. The air temperature (21−31 °C) was at the upper limit of thermal comfort, while the air humidity (RH < 40%) in the sports halls in most of the locations was below demanded values. The values for dust pollution in all rooms, except the swimming pool, exceeded the permissible limits, especially in the afternoons. Climatic conditions correlated with a high concentration of dust in the indoor air. Particulate matter concentrations of all fractions exceeded the WHO guidelines in all researched premises; the largest exceedances of standards occurred for PM2.5 (five-fold) and for PM10 (two-fold). There were no exceedances of gaseous pollutant concentrations in the air, except for benzopyrene, which resulted from the influence of the outside air. The total number of bacteria (5.1 × 101−2.0 × 104 CFU m−3) and fungi (3.0 × 101−3.75 × 102 CFU m−3) was exceeded in the changing room and the climbing wall hall. An increased number of staphylococci in the afternoon was associated with a large number of people training. The increased concentration of xerophilic fungi in the air correlated with the high dust content and low air humidity. Along with the increase in the number of users in the afternoon and their activities, the concentration of dust (several times) and microorganisms (1−2 log) in the air increased by several times and 1−2 log, respectively. The present study indicates which air quality parameters should be monitored and provides guidelines on how to increase the comfort of those who practice sports and work in sports facilities.

Results of Field Experiments for the Creation of Artificial Updrafts and Clouds

This study documents results from a series of field experiments on the creation of artificial updrafts and convective clouds at a test site in the United Arab Emirates (UAE). The proposed method incorporates a vertically directed jet from an aircraft turbojet engine saturated with active hygroscopic aerosols for the purpose of energetically feeding the jet with water vapor condensation heat below cloud base level. This paper presents the description and main characteristics of the experimental equipment, methodology of experiments and atmospheric conditions, analysis of the obtained results, and prospects for further development of the proposed method. On the whole, the experiments showed that under the conditions of low air humidity, typical for the UAE, and the slowness of the condensation process, the replenishment of the jet energy by the heat of condensation is too small, and the power of the used jet engine in the experiments is insufficient to overcome surface temperature inversions, horizontal winds, and initiation of deep convection. Nevertheless, the results of field experiments and numerical simulation made it possible to outline promising directions for further research on improving the considered method for creating artificial clouds and precipitation.

CO2 emissions from reed litter in the air and on the soil surface in the Yellow River Delta, China

The decay of litter in the air (that is, standing litter) and on the ground is an essential process of litter decomposition for many plant species. However, the contribution of standing litter to litter decomposition (e.g., CO2 emission) is still ambiguous, especially for non-leaf litter. In this study, we examined the CO2 emission from reed litter (Phragmites communis) in coastal wetlands in the Yellow River Delta (YRD), China. The results showed that the soil litter released more CO2 than the standing litter due to its rapid loss of labile organic carbon and high enzyme activities (that is, invertase and β-glucosidase). In contrast, cumulative CO2 emissions from standing litter were equivalent to 56%–70% of those on the soil surface, indicating that CO2 emissions from standing litter cannot be ignored. The sheath litter had the highest cumulative CO2 emission per unit of dry biomass among the three types of litter. Taking into account the biomass per unit area, the non-leaf litter (that is, culm and sheath) emitted more CO2 than leaf litter. On the daily scale, the litter released more CO2 at night than in the daytime, because low air temperature and high relative air humidity at night can help dew formation, accelerating CO2 emission at night. On the seasonal scale, air temperature and relative air humidity were positively related to CO2 emission, leading to rapid CO2 emission in summer and fall. The Q10 value of CO2 emission from standing litter (an average of 1.44) was lower than that of litter on the ground (an average of 2.16) due to a low residual rate of recalcitrant organic carbon in standing litter. Our findings highlight that standing litter decomposition should not be overlooked and suggest that more attention should be paid to the decay of non-leaf litter in the coastal wetland of the YRD.

O impacto das variações climáticas na demanda de crianças e adolescentes aos serviços de emergência

OBJECTIVE: To assess the impact of climatic variations on the demand of children and adolescents in emergency services. METHODS: Ecological study conducted in a city countryside of São Paulo, which analysis of 39,336 emergency room visits in 2018 and correlation with meteorological data obtained from the meteorological station of the College of Agronomic Sciences of the municipality. Poisson regression models were fitted considering the season, temperature, relative humidity and precipitation. RESULTS: The greatest demand for care was in the age group between 0 and 5 years (65.2%) with acute nasopharyngitis (8.7%) being the most frequent morbidity, followed by unspecified fever (6.1%); acute upper airway infection: 5.5%; acute tonsillitis: 5.2%; nausea and vomiting: 5%; diarrhea and gastroenteritis: 4.8%; cough: 4.6%; asthma: 4.2%; bronchopneumonia: 2.9% and acute pain: 2.4%. In summer, the most frequent morbidities were fever and diarrhea; in autumn: acute nasopharyngitis; in winter: IVA and fever; in spring: fever, acute nasopharyngitis. Acute nasopharyngitis, acute upper airway infection and bronchopneumonia mainly affect younger children and these diseases are more likely to occur at lower temperatures and in low air humidity. CONCLUSIONS: There is a different frequency of morbidities in the different seasons of the year, as the chance of occurrence change depending on age, average temperature, average humidity and has no correlation with precipitation. Therefore, from the analysis of the climate, health services can anticipate to promote preventive measures and meet a greater or lesser demand of patients.

Ефективність застосування мікродобрив в інтенсивному саду яблуні ТОВ «Харківська фруктова компанія»

The use of biostimulating microfertilizers during foliar feeding makes it possible to reduce the introduction of mineral fertilizers into the soil. This method of fertilization is safe for the environment because the nutrients are applied in controlled amounts. The purpose of our research was to evaluate the effect of foliar fertilization of apple trees on productivity, commercial quality of fruits and economic efficiency. As a result of the research, a positive effect of the use of biostimulants in intensive apple plantations of Gala, Pinova, Fuji, Red Jonaprinz varieties was established. In the course of research, biological preparations of the company "Timak Agro Ukraine" of the brands Maxifruit, Fertileader Elite, Fertileader Axis were used. Application of these drugs was carried out according to the scheme: when the average size of the fruits was 30 mm, foliar treatment with biostimulants at the rate of 3 l/ha was carried out, followed by repetition after 10 days. To assess the effect of the biological preparation, apples were sorted into fractions according to the diameter of the fruit - less than 60 mm, 60-69 mm, 70-75 mm, more than 75 mm. They also calculated the yield and evaluated the marketable quality of the harvested fruits. It has been proven that foliar treatment of trees with biological preparations helps to increase the size of fruits, which in turn reduces the number of non-standard products (fruits with a diameter of less than 60 mm) and significantly increases the share of fruits larger than 70 mm. Due to their anti-stress properties, biological preparations had the maximum effect on the fruits of the Pinova variety, which is not sufficiently resistant to high temperatures and low air humidity, increasing the share of fruits larger than 70 mm by 21.4 % compared to the control and the small-fruited Gala variety, for which this increase was equal to 12.9 %. It was established that as a result of increasing yield, improving the size, and therefore the marketability of fruits, the average sale price increased, which in turn increased the economic efficiency of fruit cultivation. Key words: apple tree, variety, foliar fertilization, product quality, yield, economic efficiency.

O IMPACTO DAS VARIAÇÕES CLIMÁTICAS NA DEMANDA DE CRIANÇAS E ADOLESCENTES AOS SERVIÇOS DE EMERGÊNCIA

ABSTRACT GOALS To assess the impact of climatic variations on the demand of children and adolescents in emergency services. METHODS Ecological study conducted in a city countryside of São Paulo, which analysis of 39,336 emergency room visits in 2018 and correlation with meteorological data obtained from the meteorological station of the College of Agronomic Sciences of the municipality. Poisson regression models were fitted considering the season, temperature, relative humidity and precipitation. RESULTS The greatest demand for care was in the age group between 0 and 5 years (65.2%) with acute nasopharyngitis (8.7%) being the most frequent morbidity, followed by unspecified fever (6.1%); acute upper airway infection: 5.5%; acute tonsillitis: 5.2%; nausea and vomiting: 5%; diarrhea and gastroenteritis: 4.8%; cough: 4.6%; asthma: 4.2%; bronchopneumonia: 2.9% and acute pain: 2.4%. In summer, the most frequent morbidities were fever and diarrhea; in autumn: acute nasopharyngitis; in winter: IVA and fever; in spring: fever, acute nasopharyngitis. Acute nasopharyngitis, acute upper airway infection and bronchopneumonia mainly affect younger children and these diseases are more likely to occur at lower temperatures and in low air humidity. CONCLUSIONS There is a different frequency of morbidities in the different seasons of the year, as the chance of occurrence change depending on age, average temperature, average humidity and has no correlation with precipitation. Therefore, from the analysis of the climate, health services can anticipate to promote preventive measures and meet a greater or lesser demand of patients.

Evaluation of antioxidant activity and total phenolics of selected mangrove plants in Sabah

In recent years, research on medicinal plants has attracted much attention due to their wide range of pharmacological significance. Mangroves are biochemically unique, producing a wide array of natural products with unique bioactivity due to their abilityto survive in stressful conditions of high salinity, and low air humidity as well as strong variations therein. Six species of mangrove (Avicennia marina, Bruguiera gymnorrhiza, Ceriops tagal, Rhizohora apiculata, Rhizophora mucronata and Xylocarpus granatum)from different parts of the leaves, stem and roots were extracted successively with ethanol and water. This study aims to measure quantitatively the total phenolic content and assess the radical scavenging activity of the 26 mangrove extracts. All the extractswere subjected to the Follin-Ciocalteu assay for their phenolic content and the DPPH scavenging assay for the antioxidant activity respectively. Based on the results, the highest phenolic content was observed in ethanol extracts of C. tagal leaves (471.78 ± 0.056 mgGAE/g) while the lowest amount of phenolic was observed in water extract of A. marina root (20.40 ± 0.001 mgGAE/g). Interestingly, the ethanolic extract of C. tagal leaves also exhibited the strongest antioxidant activity with an IC50 value of 9.37 ppm. Among the six species investigated, C. tagal leaves extracts showed high total phenolic content and strong antioxidant activities and may be used as a potential source of natural antioxidants against free radical-associated diseases.