Relative Humidity Research Articles

Concentration of particulate matter and atmospheric pollutants in the residential area of Kathmandu Valley: a case study of March–April 2021 Forest fire events

Forest fires have become more intense and frequent in recently changing climates. The wide variety of pollutants released by forest fire include greenhouse gases, photochemically reactive compounds, and fine and coarse particulate matter. This study investigated the impact of forest fire events on air quality in the Kathmandu Valley during March-April 2021 using ground air quality monitoring stations and satellite data. The three fire periods were studied (a) Pre-fire from 21st - 23rd March (b) first-fire episode from 24th -27th March and (c) second fire episode from 1st – 5th April of 2021. The concentrations of PM2.5 reached to maximum 199 μg/m3 during pre-fire period, 371 μg/m3 and 280 μg/m3 during first and second fire event respectively. The second fire episode had lower PM2.5 concentration despite higher fire counts (449) compared to the first episode suggesting influence of fire activities near to vicinity of Kathmandu valley during second fire episode. There was a two-day lag between the beginning of forest fire events and an increase in PM2.5 levels in Kathmandu. Satellite observation showed varying patterns for different pollutants. HCHO levels responded quickly to fire activity, while AOD and CO levels increased after a few days. Also, low wind speed, low temperature, and low relative humidity additionally elevated these pollutants in Kathmandu. This study emphasizes the extent of the impact of forest fires on air quality and the importance of considering meteorological and satellite data to understand the distribution of pollutants during such events.

IAQ and ventilation measurements at the “ZEB Laboratory” office building in Norway

This study aims to assess indoor environmental quality (IEQ) within a Zero Emission Building (ZEB) office in Norway, focusing on occupant impact (CO2, temperature, humidity) and materials/substances influence (formaldehyde, particulate matter (PM2.5), total volatile organic compounds (TVOC)). It presents a detailed data collection spanning 14 months from March 30th, 2022, to June 1st, 2023.Occupancy varied significantly, affecting measured indoor air quality (IAQ) parameters, with the lowest temperatures recorded on the second floor and specific areas like the canteen experiencing temperature drops during low usage times. Relative humidity levels remained over 20% in winter despite the building's low occupancy, a notable aspect given Norway's dry winters. PM2.5 levels stayed below World Health Organization (WHO) guidelines, indicating effective pollution management.The study also evaluates the impact of reducing the ventilation rates on IAQ, noting no significant IAQ compromise. An analysis correlating IAQ measurements with building occupants' satisfaction post-intervention revealed that temperature is the most significant factor affecting satisfaction levels, excluding acoustic satisfaction. Occupants generally reported satisfaction with the indoor environmental quality (IEQ), with specific dissatisfaction tied to thermal environment and IAQ, suggesting the importance of temperature control in occupant perception.This research not only provides valuable insights into IEQ management in Zero Energy and Zero Emission office buildings but also emphasizes the critical role of indoor temperature and the potential of wooden structures to stabilize humidity levels, contributing to occupant comfort and satisfaction.

Effects of the surface properties and particle size of hydrated lime on desulfurization

In the gas treatment center in smelters, hydrogen fluoride (HF) is separated from the outlet gases of electrolysis cells, which are used to produce aluminum from alumina. However, SO2 largely remains in the effluent gas. Another method has to be developed to separate this gas which is harmful to the environment. In this study, semi-dry desulfurization of a SO2 containing gas was performed at low SO2 concentrations using hydrated lime [Ca(OH)2] as a catalytic desulfurizer under specific humidity conditions. The low reaction temperature of 100 °C and minimal use of the Ca-based desulfurizer under 17 % relative humidity achieved more than 95 % removal of SO2. The morphological changes and presence of sulfur in different lime samples were analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Brunauer–Emmett–Teller (BET) analysis showed changes in the surface properties of hydrated lime after desulfurization. X-ray photoelectron spectroscopy (XPS) analysis provided the phase and composition identification of the sulfur species on hydrated lime and the CaSO3/CaSO4 product ratio. Based on the experimental results, the optimum catalyst surface area with a specific particle size is critical to the effective conversion of Ca(OH)2 into CaSO3 and CaSO4. The practicality of a Ca-based desulfurizer and its ability to convert into the required product may be the key to reducing the overall cost of desulfurization in aluminum industry.

Evaluating Various Lactose Types as Solid Carriers for Improving Curcumin Solubility in Solid Self-Nanoemulsifying Drug Delivery Systems (S-SNEDDSs) for Oral Administration

Curcumin, a bioactive compound derived from turmeric, possesses numerous pharmaceutical properties; however, its poor aqueous solubility and permeability result in low bioavailability. This study aims to develop a solid self-nanoemulsifying drug delivery system (S-SNEDDS) using different lactose types as solid carriers for the oral administration of curcumin to enhance its solubility. The system comprised curcumin, an oil phase, and a surfactant. Jasmine oil, as the oil phase, and Cremophor® RH40, as the surfactant, were selected due to their superior ability to solubilize curcumin. A microemulsion was then prepared using a ternary phase diagram. The liquid SNEDDSs were converted into S-SNEDDSs by employing three solid carriers: Tablettose® 80, FlowLac® 100, and GranuLac® 200. Dissolution studies conducted in simulated gastric fluid demonstrated a significant improvement in curcumin solubility in the S-SNEDDS formulations compared to curcumin powder. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analyses confirmed the appearance of curcumin in the S-SNEDDS, while Fourier-transform infrared (FTIR) spectroscopy indicated compatibility between the excipients and curcumin. Additionally, an accelerated stability study conducted over four weeks at 40 °C and 75% relative humidity showed no significant changes in the physical appearance of the S-SNEDDS formulations. These findings suggest that the S-SNEDDS formulation effectively enhances curcumin’s solubility, potentially improving its bioavailability for oral administration.

Preparation of high temperature proton exchange membrane through covalent organic framework doped polyvinylidene fluoride nanofibers

Covalent organic framework (COF) exhibits the great potential to promote proton conduction under low relative humidity for proton exchange membranes (PEMs). In this research, quick and stable proton conduction has been achieved since the prepared COF and polyvinylidene fluoride (PVDF) nanofibers are believed to constitute successive proton conduction channels. The PVDF-COF nanofibers membrane is prepared through the in-situ growth of COF along PVDF nanofibers. The fine compatibility can drive the stable combination of COF with the PVDF nanofibers in PVDF-COF nanofibers. Most importantly, the fibrous PVDF nanofibers accelerate proton conduction through confining the proton conduction pathways. Additionally, ionic liquids of 1-butyl-3-methylimidazolium chloride (BmimCl) and 1-butyl-3-methylimidazole hexafluorophosphate (BmimPF6) as proton conduction carriers have been introduced to accelerate proton conduction in the prepared PVDF-COF/BmimCl/PA and PVDF-COF/BmimPF6/PA membranes. Phosphoric acid (PA) molecules are combined by COF and ionic liquid cations with the formation of intermolecular hydrogen bonds. As a result, the PVDF-COF/BmimPF6/PA membrane exhibits the proton conductivity of (1.81 ± 0.07) × 10−1 S/cm at 160 °C. The long-term proton conductivity stability is determined, deriving from the proton conductivities of 1.77×10−2 S/cm at 80 °C and 1.42×10−2 S/cm at 110 °C in the 400 h non-stop measurement. The single fuel cell equipped with the PVDF-COF/BmimPF6/PA membrane represents the open circuit voltage of 0.927 V and the peak power density of 178.8 mW/cm2 at 100 °C, 0.907 V and 326.5 mW/cm2 at 120 °C.

Effects of Daily Weather on Aedes Genus (Culicidae: Diptera) Arthropod Mosquito Vectors Profusion and Dengue Epidemics Transmission: A Systematic Review

Dengue is a vector borne flavivirus usually caused by DENV1 virus, and a quantity of cases reported with DENV2, DENV3, and DENV4 viruses transmitted by Aedes aegypti and Aedes albopictus (Diptera) day biting female vector mosquitoes, belongs to Culicidae family. The symptoms of dengue were first clinically confirmed in Japan during 1943, and later, it was recorded simultaneously in the Asia, Africa, and North America during the 1980. Dengue epidemics situation was reported in the 142 countries across the world Dengue and severe dengue, (Global Strategy for dengue prevention and control, (2012–2020), 2020) and the epidemics had been changed to endemic situation in many of the countries for the past 2 decades, and the people who have been living in the epidemic countries estimated at risk about 450 million. The occurrence of dengue outbreaks and it’s extend have been reported in the tropical and sub-tropical countries across the globe largely in metropolitan, small towns, and semi-urban settlements. The climate variables viz. temperature, relative humidity, saturation deficiency, and rainfall, are fuelled for conducing environment for the vector longevity, survival and also for dengue virus incubations in mosquitoes. Temperature ranges between > 21 and < 34, and relative humidity >70% and <90% has influence on the impact of variations on the vector survival, fecundity, fertility and longevity of female Aedes aegypti and flying capacity is reduced with temperature < 10 0C, and laying egg is reduced with increase of mean temperature >35 0C. Dengue epidemics clusters are directly correlated with abundance of Aedes species mosquitoes which are controlled by the annual average precipitation 300 mm to 1200 mm. The longitudinal dengue epidemics transmissions are mainly associated with monsoon and tend to have seasonal patterns, particularly, during and after the monsoon. Climatic factors are playing important role in the increase or decrease of vector mosquitoes as well as dengue epidemics. Therefore, the present study is addressed on the echelon of daily weather and seasonal change in climate condition and its control on the incidence of dengue outbreaks.

Indoor Air Quality in Laboratories and Its Relationship with Psychological Performance Among University Students in Malaysia

Introduction: Poor indoor air quality (IAQ) in work environments can reduce productivity and decrease overall performance. This study examines IAQ in university laboratories and its relationship with psychological performance among students in Malaysia. Methods: This cross-sectional study was conducted from October to November 2023 in six laboratories at a Malaysian university, categorised into chemical and non-chemical. A total of 117 students aged 18 to 40 participated. IAQ was measured in real-time for 8 hours during weekdays using instruments for particulate matter (PM2.5, PM10), carbon monoxide (CO), total volatile organic compounds (TVOC), airborne microorganisms, carbon dioxide (CO2), temperature in °C, relative humidity (RH), and air movement. Psychological performance was assessed using the General Health Questionnaire (GHQ-12) and Post Occupancy Evaluation (POE). Data analysis was performed using Kruskal-Wallis, One-Way ANOVA, and Chi-Square tests. Results and Discussion: Significant differences in IAQ parameters were observed for PM2.5 (p=0.007), PM10 (p=0.020), CO2 (p=0.024) and RH (p=0.043). Psychological distress affected 41.9% of students based on the predefined threshold. High CO levels (≥0.67 ppm) and elevated temperatures (≥23.28°C) were significantly associated with increased psychological distress (p=0.011). Students exposed to these conditions were 1.3 times more likely to experience distress (OR=1.3). Conclusion: Specific IAQ parameters, particularly CO and temperature, critically impact students’ psychological well-being. Improving IAQ by reducing CO levels and maintaining optimal temperatures may enhance mental health and performance. Improving IAQ by reducing CO levels and maintaining optimal temperatures may enhance mental health and performance. However, external factors such as personal stressors could not be entirely controlled.

Bayesian Modeling of INGARCHX Models for Cellulitis Related to Meteorological Factors in Mahasarakham and Roi-Et HospitalsMahasarakham and Roi-Et Hospitals

The objective of this research is to develop integer-valued generalized autoregressive conditional heteroscedasticity (INGARCH) models to represent the weekly incidence of cellulitis cases in relation to two exogenous variables: seasonality and the weekly average of either relative humidity or maximum temperature. The key to the proposed model is its capacity to explain overdispersion and lag dependence. For predictions and model parameters, we employ the Bayesian Markov Chain Monte Carlo (MCMC) approach, as supported by both a simulation study and an empirical study. To assess different models, we apply the deviance information criterion (DIC) criterion to the weekly cellulitis case sample data with two independent variables. In addition, we offer a one-week prediction to help Mahasarakham and Roi-Et Hospitals manage the increasing volume of hospital admissions by estimating the weekly cellulitis case incidence rate.

Assessment of a Cowl-Incorporated Wind-Powered Forced-Air Evaporative Cooler for Preservation of Fruit and Vegetables

This paper reports the performance of a cowl-incorporated wind-powered forced-air evaporative cooler for preservation of fruit and vegetables. The evaluation took place in the Department of Mechanical Engineering, Obafemi Awolowo University, Ile-Ife in October. Freshly harvested tomatoes were used in the evaluation as tomatoes were common locally and are highly perishable. The produce (2.5 kg) was kept in the cooling chamber of the evaporative cooler, and the changes in weight were observed three times daily until the produce had lost more than 7 % of its weight. The no-load cool air temperatures ranged between 27.3and 34.5oC corresponding to ambient dry bulb temperatures 29.0and 43.9oC respectively. The no-load cool air relative humidity ranged between 63.0 and 87.2% corresponding to ambient relative humidity of 40.8 and 79.5% respectively. The evaporative cooler no-load cooling efficiency was 66.7% while the cooling efficiency when loaded was 50.0%. The evaporative cooler was able to preserve tomatoes for 9 days losing 4.8 % weight. The evaporative cooler had the potential of effectively preserving fruit and vegetables without dependence on electricity. If used in windier and less humid regions, the average cooling efficiency of the evaporativecooler would be higher than that observed in this research.

Tillandsia-Inspired Ultra-Efficient Thermo-Responsive Hygroscopic Nanofibers for Solar-Driven Atmospheric Water Harvesting.

Sorption-based atmospheric water harvesting (SAWH) is a promising approach for supplying water in off-grid arid regions. However, it is difficult to improve the SAWH efficiency because water undergoes multiple phase transformations, such as water vapor-water (desorption and condensation) in the desorption phase. To address this issue, an ultrahygroscopic temperature-responsive hydrogel nanofiber inspired by Tillandsia is developed, comprising poly N-isopropylacrylamide, poly N-dimethylacetamide, and carbon nanotubes and impregnated with lithium chloride (PCP@LiCl). The hydrophobicity of the nanofiber membrane is enhanced with increasing temperature, facilitating water separation from the hydrogel in liquid form. Moreover, PCP@LiCl exhibits unique kinetics at 25 °C and 15%-30% relative humidity, capable of adsorbing moisture to saturation within 2h, and oozing liquid water within 5min under sunlight. Through global potential modeling, it is demonstrated that PCP@LiCl has potential applications in arid and semiarid regions. This study provides new insights into the design of high-performance composites for solar-powered atmospheric water harvesting.

Porous PDMS-ZnO Wearable Gas Sensor for Acetone Biomarker Detection and Breath Analysis.

In response to the growing demand for global health monitoring, we report a nonintrusive health detection method using a compact, conformal wearable ultraviolet (UV)-assisted gas-sensing system based on an intrinsically flexible porous polydimethylsiloxane (PDMS)-zinc oxide (ZnO) composite layer (PPZL) for the breath acetone (BrAce) detection and breath event analysis. The enhanced acetone response is attributed to the synergistic effect of UV irradiation and the high surface area of the porous structure, which also improves the mechanical robustness. The UV-assisted wearable sensor reliably detects acetone concentrations ranging from 1 to 100 ppm at room temperature under 4.05 mW/cm2 UV intensity, even under mechanical strains such as a bending radius of 5 mm and 60% tensile strain. It accurately analyzes different breathing patterns (12-20 breaths per minute) and BrAce concentrations, maintaining a stable performance over 20 days with less than 5% signal degradation. The sensor exhibits response and recovery times of average 110-150 and 130-180 s, respectively, and maintains a consistent 3 ppm BrAce response under varying humidity levels up to 70% relative humidity, ensuring accurate detection of BrAce concentrations during real-world breath tests. Additionally, the sensor targets only specific gases, and the sensor's selectivity is not a key concern. This flexible acetone gas sensor offers a portable solution for health management and a fabrication method for designing flexible metal oxide materials.

Distribution of Air pollutant Concentration and Ammonium conversion rate in Livestock Areas: Focusing on Boryeong

Objectives:The association between the generation of fine particulate matter (PM2.5) and ammonia is well-established, highlighting the importance of managing ammonia as a primary means to reduce particulate matter. However, domestic research on ammonia emissions, particularly in livestock areas, which are major sources of ammonia, is insufficient. This study aims to contribute to pollutant management on a national scale by conducting air pollutant measurements and analyses in livestock areas. Methods:Real-time analysis and monitoring of air and weather conditions were carried out in Boryeong, Chungcheongnam-do, from 2021 to 2022. Statistical analysis was then employed to investigate the correlation between observed air pollutants (ammonia, nitrogen oxides, sulfur oxides, ozone and particle matters) and PM2.5. Results and Discussion:As a result of the analysis, the concentration of air pollutants in Boryeong showed a seasonal tendancy to decrease in summer and increase after that. Most substances such as NO2, SO2, and PM10 were observed within the standard values. In the case of ammonia, domestic air environment standards are not in place, but the annual average was found to be 61.5 ± 55.3 ppb, higher than in other research results. This discrepancy is attributed to the influence of nearby livestock houses. It was also observed that PM2.5 exceeded the annual standard value of 15 μg/m3 in spring (30.1 μg/m3), summer (18.3 μg/m3), autumn (25.3 μg/m3) and winter (31.7 μg/m3), respectively. During this period, ammonium (NH4+, 32.8%), nitrate (NO3-, 35.9%), and sulfate (SO42-, 19.7%) comprised the majority of particulate pollutants in PM2.5. The ammonia-ammonium conversion rate (NHR) was 0.08 annual average, and it was found that gas/ion phase changes were affected by seasonal weather conditions (temperature and relative humidity). As a result of analyzing the NHR according to the PM2.5 concentration, it was found that the higher the PM2.5 concentration, the higher the NHR. Furthermore, although the measurement area of this study exhibited high ammonia concentration, the NHR was low. This suggests that the contribution rate of ammonia to PM2.5 was relatively low compared to the other studies.Conclusion:As a result, there is a need for measures to reduce the high concentrations of ammonia in livestock areas. Simultaneously, considering the diverse mechanisms involved in particulate matter formation, it is suggested that management of pollutants such as nitrogen oxides, sulfur oxides including ammonia should be implemented.

A Comparative Study on the Behaviour of Various Methods of Curing Concrete

Abstract: The properties of cement-based products, especially their durability, are predominantly influenced by curing, since it has a remarkable effect on the hydration of the cement. Proper curing of cement-based products is crucial to obtaining design strength and maximum durability. The curing period depends on the type of cement works, the purpose for which it is to be used and the surrounding atmosphere, namely temperature and relative humidity. Curing is designed primarily to maintain the moisture, by avoiding the loss of moisture from the period in which it is gaining strength. Curing may be applied in a number of different processes and the mass appropriate means of curing may be directed by the site or the construction method. In this critique, a paper struggle has been made to understand the working and efficiency of curing system which are generally adopted in the construction industry and compared with the standard water curing method.

Climatic Parameters Use for Evaluating Water Budget and Drought Analysis in Erbil Sub-basin, Kurdistan Region, Northern-Iraq

Major theoretical and practical hydrological issues may be solved using methods to maintain water balance. Evaluating the climate characteristics and environmental circumstances to be employed in the methods of water managing approach used in the Erbil sub-basin, northern Iraq, is the primary goal of this study. The studied area is a part of the region influenced by the Mediterranean climatological system. The climatic parameters of the research region were evaluated using the climatic data collected in the Erbil meteorological station for the period 1980-2022. The research result shows that the mean annual rainfall is 411.26 mm/year and the average monthly relative humidity is 41.12 %, the mean temperature is 20.62 °C, mean sunshine duration 8.35 hr./day and annual pan evaporation is 1200.96 mm / year. Potential evapotranspiration considered by Thornthwaite method is 1588.94 mm. The water surplus and deficit are 216.14 mm and 1393.81 mm, respectively. The surface runoff calculating from soil conservation system (SCS) technique which is about 86 mm / year and groundwater recharge is about 130.14 mm / year. The groundwater Budgets is about 187661880 m3 / year. The climatic situation in the area is variety from winter its wet to the summer its dry climates. Also, it could be measured that the climate in the area is determined was (Humid to very humid). The draught index according to SPI analysis show that the drought was observed during Moderately drought in (1983, 1999, 2000, 2010, 2015, and 2021) to severely drought in (2022.

Continuous Graded Catalyst Layers for PEM Fuel Cells with Improved Humidity Range Tolerance

Abstract Grading electrodes is a promising approach to reduce ohmic and mass transport-related voltage losses in proton exchange membrane fuel cells. In graded electrodes, the ionomer and/or catalyst are spatially non-uniformly distributed to optimize performance over a wide operating range. In this study, through-plane ionomer gradients were fabricated with a simple wet-layer deposition technique that can readily be adapted in a roll-to-roll process. The presence of ionomer gradients was verified using scanning transmission electron microscopy and the profiles were found to be continuous despite using only two coating steps. Single cell tests revealed that the gradients outperform conventional electrodes and maintain the optimal performance for different relative humidities. These improvements were traced back to enhanced mass transport and protonic conduction properties identified by detailed electrochemical analysis. This manufacturing approach for electrodes offers an accessible toolbox to produce versatile and specialized multi-layered catalyst layers for different applications.

Quantitative and Qualitative Experimental Assessment of Water Vapor Condensation in Atmospheric Air Transonic Flows in Convergent–Divergent Nozzles

Atmospheric air, being also a moist gas, is present as a working medium in various areas of technology, including the areas of airframe aerodynamics and turbomachinery. Issues related to the condensation of water vapor contained in atmospheric air have been intensively studied analytically, experimentally and numerically since the 1950s. An effort is made in this paper to present new, unique and complementary results of the experimental testing of moist air expansion in the de Laval nozzle. The results of the measurements, apart from the static pressure distribution on the nozzle wall and the images obtained using the Schlieren technique, additionally contain information regarding the quantity and quality of the condensate formed due to spontaneous condensation at the transition from the subsonic to the supersonic flow in the nozzle. The liquid phase was identified using the light extinction method (LEM). The experiments were performed for three geometries of convergent–divergent nozzles with different expansion rates of 3000, 2500 and 2000 s−1. It is shown that as the expansion rate increases, the phenomenon of water vapor spontaneous condensation appears closer to the critical cross-section of the nozzle. A study was performed of the impact of the air relative humidity and pollution on the process of condensation of the water vapor contained in the air. As indicated by the results, both these parameters have a significant effect on the flow field and the pressure distribution in the nozzle. The results of the experimental analyses show that in the case of the atmospheric air flow, in addition to the pressure, temperature and velocity, other parameters must also be taken into account as boundary parameters for possible numerical analyses. Omitting information about the air humidity and pollution can lead to incorrect results in numerical simulations of transonic flows of atmospheric air. The presented results of the measurements of the moist air transonic flow field are original and fill the research gap in the field of experimental studies on the phenomenon of water vapor spontaneous condensation.

Biological Parameters and Feeding Potential of Micromus timidus Hagen (Neuroptera: Hemerobiidae) on Selected Aphid Species

In the present study, we investigated on the developmental biology, adult longevity and fecundity of Micromus timidus Hagen on Aphis craccivora (Koch), Aphis gossypii Glover, Rhopalosiphum maidis (Fitch) and Uroleucon compositae (Theobald) at room temperature (28±20C) and relative humidity of 70%. The study design followed was completely randomized design (CRD). The study was conducted with three replications with 10 larvae in each replication for biology studies and for adult parameters 3 replications with 10 pairs in each replication used. Shortest incubation period, II instar and III instar duration, total larval period, pre-pupal period, and egg to adult period of M. timidus were recorded on A. craccivora, shortest I instar duration was recorded on U. compositae and least pupal period on A. gossypii. The developmental periods for all trait were extended when fed on R. maidis. The reproductive traits viz., oviposition period and adult longevity (male and female) were maximum when M. timidus adults fed on A. gossypii, and the highest fecundity was recorded when fed on A. craccivora. Feeding potential in M. timidus increases progressively across successive instars, with III instar larvae exhibiting the highest aphid predation rate, and first instar larvae displaying the lowest feeding activity. The maximum feeding potential of the larva was noted on A. craccivora (142.47 ± 31.66), while, the adult feeding potential increased when it was given with A. gossypii (1335.10 ± 192.74).

Potential of Binahong Leaves (Anredera cordifolia Ten.) and Shallot Skin (Allium cepa L.) Extract as Biopesticides for Biological Control of Rice Bug (Leptocorisa oratorius F.)

The rice bug is a pest causing decrease rice production. Meanwhile, binahong leaves and shallot skin contain potential materials for making biopesticides. This research aimed to analyze potential of binahong leaves and shallot skin extract as biopesticides and toxicity tested against rice bug. The research was carried out using Completely Randomized Design, biopesticides were made in various concentrations, 0% as a control; 10; 20; 30; 40; and 50. The extract was calculated for yield, pH, and phytochemical screening. Then, biopesticide sprayed on the pests at 24, 48, 72, 96, 120, 144, and 168 hours to observe mortality, LC50, morphology, behavior, biotic, and data analysis using ANOVA followed 0.05 Tukey test. The results showed the extract has potential as a biopesticide with yield value 8,3 – 12; pH value 4,84 – 5,37; and positive secondary metabolite. Meanwhile, toxicity tests showed the highest mortality at concentration 50%, LC50 at 144th hours and 168th hours was 4,373 and 2,002. Besides that, biopesticides changes morphology and behavior pest. Observations abiotic factors showed that rice bug can survive in temperature range of 22,75 – 25oC and relative humidity of 77 - 84%. In the future, it hoped biopesticides can be commercialized to reduce dependence on chemical pesticides.

Microclimate of Brown Bear (Ursus arctos L.) Dens and Denning Area.

The aim of this study was to determine the microclimate of brown bear dens depending on their size, their status (active or inactive), and the location of the den. The study included five dens of different sizes and locations in the Velebit Mountains, in the Dinaric Alps. The measurements of air temperature (°C) and relative humidity (%) in dens and the forest stands were carried out over 182 days. The absolute minimum air temperature in inactive dens was between -2.88 °C and -0.38 °C and belonged to the dens with shorter tunnels and without chambers. The exception was inactive den 1, which was situated in a thermophilic forest. No negative absolute minimum air temperatures were recorded in active dens. The absolute minimum air temperatures in the forest stands were lower than in the dens. The relative humidity was significantly higher in all dens than in the forest stands. Dens with a large entrance opening and a short tunnel were strongly influenced by the local microclimate of the forest stand. The greatest temperature difference (den-forest) was between elongated dens with chambers and the associated forest stand, while the smallest temperature differences occurred in dens with a short tunnel, without a chamber, and at the northern exposure. The greatest differences in relative humidity (den-forest) were found in dens with chambers. The den temperatures correlated with the air temperatures in the forest stands.

Temperature and relative humidity in a commercial bread wheat field, recorded by an automated meteorological station and a digital sensor in the Yaqui Valley, Sonora, Mexico

Meteorological parameters determine most agronomic events, with temperature being the climatological factor most closely related to the annual productivity of a crop. The objective of this work was to monitor the temperature and relative humidity at different growth stages of a commercial bread wheat field, during the crop season 2017-2018. The work was carried out with data obtained from December 12, 2017 (sowing date) to April 18, 2018, from a mobile OMEGA OM-EL-USB-2 sensor within the field, sown with the bread wheat cultivar Borlaug 100, located in Block 1020, in the Yaqui Valley, Sonora, Mexico, and from the Block 910-CIANO meteorological station, located 8 km away, which is the closest to the field. Calculations were made for the average temperature, relative humidity and cold units (CU). In addition, the data was filtered by day and night time, considering daytime data from 7:00 to 18:00 and nighttime data from 19:00 to 06:00. The CU recorded by the sensor was higher with 384 than the meteorological station, which accumulated a total of 321. The temperature during the day was on average 2.9 °C higher than that recorded by the meteorological station, and 1.6 °C lower at night. The relative humidity recorded by the sensor was 5 % higher than that recorded by the meteorological station.