In recent years, anion exchange membrane fuel cells (AEMFCs) have drawn more attention by showing high performance and potentially allowing catalysts based on more abundant materials. One frequently overlooked parameter in these systems is membranes permeability, often referred to as gas crossover. This undesirable phenomenon creates mixed potentials and also hotspots with temperatures high enough to cause membrane defects and pinholes. Therefore, it is important to investigate it quantitatively at conditions where a fuel cell often operates. In this study, hydrogen and oxygen crossover of several Aemion anion exchange membranes (AEMs) are measured with mass spectrometer (MS) at various relative humidities (RHs) and temperatures. The proton exchange membrane (PEM) Nafion is also investigated for a comparison. AEMs are generally less permeable to oxygen and hydrogen than PEM. The first‐generation AEMs show a decreasing trend in permeability with RH, opposite to PEM. The second‐generationAEMs are much less affected by RH levels. The measured oxygen crossover was two to six times lower compared to hydrogen crossover, depending on the membrane type and RH. The influence of membrane interface on crossover is evaluated to be higher for reinforced membranes, but overall smaller compared to the bulk contribution. Overall, AEMs show lower crossover than PEM, and from that perspective making them more suitable and a safer choice for fuel cell and electrolysis applications.

Electrocatalytic CO2 reduction (ECO2R) to high-value chemicals is a promising method to upcycle emitted CO2, but it is also a fascinating scientific challenge. Catalyst materials, as well as cell configurations, play a pivotal role in the efficacy and efficiency of the ECO2R reaction, which also dictates reaction pathways and product selectivity. In this work, we employ the isotopological Zr- and Ce-based UiO-67 metal-organic frameworks (MOFs) that contain Pd species in a zero-gap gas diffusion cathode electrode configuration, where the water content, i.e., relative humidity (RH) level, in the CO2 gas stream can be varied. We show that only UiO-67-based MOFs containing Pd embedded in their pores can produce syngas, while the product selectivity can be controlled by varying the RH levels in the gas stream. The pristine MOFs (precatalysts) undergo chemical and structural transformation during the ECO2R reaction, forming the active catalysts toward CO2 electroreduction to syngas. Our work highlights the effect of water content on the selectivity during ECO2R, but also the need for predictive catalyst design for effective electroreduction of CO2 to high-value chemicals.

Survival of Salmonella enterica in chocolate formulated with contaminated coconut flakes, raisins, and cocoa nibs under varying temperature and humidity conditions.

The aim of this study was to determine the effect of relative air humidity (RH) on the dimensional changes of oak wood (Quercus robur L.) subjected to hydrothermal treatment and thermomechanical modification. Dimensional changes in the anatomical directions (radial, tangential, longitudinal) and volumetric swelling of oak wood were analysed at five levels of relative air humidity: 9 %, 34 %, 55 %, 75 %, and 98 %. Oak wood after hydrothermal treatment and densification (variants V and VI) was the most dimensionally unstable in the radial direction compared to non-modified oak wood (variant I) and to oak wood subjected to hydrothermal treatment (variants II and III) or densification (variant IV). Regardless of the oak wood modification variant, the dimensional changes in tangential direction were similar in climates with a given relative air humidity level. However, in the climate with the highest relative air humidity, i.e., 98 %, significant variation in test results was observed, from approximately 6 % in the case of oak wood after hydrothermal treatment for 150 min (variant II) to approximately 9 % for oak wood after hydrothermal treatment for 300 min and densification (variant VI). The non-modified oak wood (variant I) was characterized by the smallest volumetric changes. In a climate with a relative air humidity of 98 %, comparable volumetric swelling values, i.e., approximately 12 %, were recorded for all tested modified oak wood variants. The findings provide valuable insights for optimising wood modification processes and support the selection of processing technologies in relation to anticipated service conditions under variable humidity, which is relevant for both scientific research and the wood and furniture industries.

Nano-sized ZnO particles were successfully synthesized via a green, efficient, and chitosan-assisted method, which is both cost-effective and environmentally friendly. The nanoscale characteristics of the synthesized particles were confirmed through various analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption–desorption isotherms, diffuse reflectance spectroscopy (DRS), and Fourier-Transform Infrared Spectroscopy (FTIR). This study primarily investigated the photocatalytic performance of ZnO/TiO₂ composites prepared by a simple mechanical mixing approach for the degradation of isopropanol (IPA) in a continuous-flow system under UVA irradiation at room temperature. A range of experimental conditions, including initial IPA concentrations, gas flow rates, relative humidity levels, and the number of UV lamps, were systematically explored. The mechanically mixed ZnO/TiO₂ nanomaterial exhibited enhanced photocatalytic activity compared to pure ZnO. Notably, while commercial TiO₂ showed reduced IPA removal efficiency under humid conditions, the ZnO/TiO₂ composite maintained superior performance, achieving a removal efficiency of 45% over a 3-hour period at 30% relative humidity with an inlet IPA concentration of about 1200 ppmv, a flow rate of 3 L/h, and illumination by four UV lamps. Copyright © 2025 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

This article reports the variations in volatile organic compound (VOC) emission rates from Scots pine wood under varying relative humidity (RH) conditions. The experiment encompassed both heartwood and sapwood, involving recently sawn (“new”) wood, and aged (“old”) wood that had been stored indoors for 15 years. Individual specimens were placed in climate chambers, wherein specific RH levels were maintained in the following sequence: 20%, 40%, 60%, 80%, 60%, 40%, and 20%, 1 month each. VOC samples were systematically collected at the end of each RH period and analyzed using TD-GC-MS system. The results demonstrate a direct relationship between RH levels and VOC emission rates in all specimen categories. Old wood indicated significantly lower emission rates compared to new wood, with distinct differences in emitted compound composition. As the experiment progressed, the initial differences between old and new specimens diminished, reaching minimum difference by the last measurement. Aldehydes were among the two most prevalent compound groups in all sample types. Terpenes were the most abundantly emitted group during the first VOC collection. However, their emissions subsequently declined, followed by an increase in all main chemical groups at 80% RH. Additionally, more polar compounds were emitted as RH increased. This study contributes to the discussion regarding the suitability of standard emission tests performed in fixed 50 ± 5% RH for hygroscopic materials. More attention should be given to the influence of RH on VOC emissions to ensure a comprehensive understanding of wood material’s emission behavior.

We present a tunable manufacturing platform for copper nanoparticles (CuNPs) on polyethylene terephthalate (PET) that addresses the critical challenge of processing this air-sensitive material under ambient conditions. By precisely controlling laser parameters, we demonstrate that a single CuNPs-PET precursor can produce two distinct functional composites. Low laser powers result in a purely metallic composite within the polymer matrix by simultaneously sintering and encapsulating CuNPs. In contrast, higher laser powers shift the process toward polymer carbonization and graphitization, creating a durable copper-assisted laser-induced graphene (Cu-LIG) hybrid embedded in PET. High-speed visualization enables real-time analysis of the mechanisms involved, revealing the sintering, encapsulation, and integration of CuNPs into the polymer. Chemical and structural analyses show that the laser process also reduces native copper oxide on pristine NPs, resulting in a metallic copper composite with a sheet resistance as low as 0.13 Ω sq-1 and significant stability under harsh conditions, including exposure to high relative humidity (RH) levels above 95% for several days. We demonstrate practical applications of these composites by creating highly robust, flexible devices, including thermocouples with a Seebeck coefficient of 14.6 μV °C-1 and high-load capacitive pressure sensors. This work redefines laser processing as a versatile approach for digitally selecting material functionality, advancing the manufacturing of flexible electronics.

The main objective of this study was to comprehensively evaluate the effects of key barn microclimate parameters, including air temperature, relative humidity, air velocity, lighting level, and gas composition, on the milk productivity and quality characteristics of dairy cattle. The study was conducted at the ―Qaliqanuly‖ dairy farm, located 20 km from the city of Semey in the Abai region. Black-and-white dairy cows were used in the experiment. Microclimate parameters in the barn were measured using specialized instruments across different seasons, and the obtained data were comparatively analyzed in relation to total milk yield, fat content, protein content, milk density, and solids-not-fat (SNF). The results revealed that deviations of microclimate parameters from recommended standards had a significant impact on the physiological condition and productivity of the animals. According to the findings, unfavorable air temperature and relative humidity levels led to a reduction in milk yield by up to 10–15%. In addition, insufficient lighting and low air movement negatively affected milk quality, particularly fat and protein contents. During the summer period, high temperatures combined with increased humidity caused heat stress in cows, resulting in decreased milk production. Overall, the results demonstrate that optimizing the barn microclimate plays a crucial role in increasing milk production and can serve as a scientific basis for developing effective management strategies in the livestock sector.

Long-Term Survival of Cronobacter sakazakii, Salmonella enterica, Listeria monocytogenes, and Enterobacter spp. in Powdered Infant Formula Based on Relative Humidity.

Abstract This work investigated the effect of reducing the waist diameter of tapered optical fibers (TOFs) on their relative humidity (RH) sensing performance. The TOFs were fabricated using a fast and simple method, the flame brushing technique, to produce waist diameters of 2 µm, 4 µm, and 6 µm. The fabricated TOFs perform sensing based on the evanescent-wave principle. The sensing characteristics were evaluated for RH levels ranging from 25% to 60%. This study revealed that reducing the waist diameter significantly increases the sensor’s sensitivity. Specifically, the 2 µm TOF recorded the highest sensitivity and linearity at 61 pm/%RH and 96.59%, respectively. This result demonstrates a promising sensor for future development, particularly for the next phase of the study involving coating with sensitive materials.

Bed bugs (Cimex lectularius L.) are blood feeders whose survival is significantly influenced by environmental factors such as temperature and relative humidity (RH). Despite their adaptations to survive in harsh environments such as a low net transpiration rate and high critical thermal maximum, their physiological limits to heat and humidity remain underexplored. This study aims to determine the lethal temperature and RH combinations for bed bugs to improve non-chemical pest management strategies. Adult male bed bugs were exposed to 5 temperatures (25, 37, 38, 39, and 40 °C) and 3 RH levels (10%, 45%, and 90%) in controlled incubators for 14 d. Median survival times (MSTs) and hazard ratios were determined using Kaplan-Meier survival analysis. The results revealed that at 37 °C, bed bugs exhibited relatively higher survival (MST > 14 d), particularly at 45% and 90% RH suggesting that physiological mechanisms may mitigate heat stress. However, survival declined to 12 d at 37 °C with 10% RH, and this reduction at low RH was amplified at higher temperatures, where MST fell to 4-6 d at 39 °C and only 3 d at 40 °C. These results demonstrate that dry environments exacerbate thermal stress. At 40 °C, mortality was highest across all RH levels, with the shortest survival time (1 d) observed at 90% RH, which indicates that heat in combination with high humidity is most effective at inducing heat-related mortality in C. lectularius. These findings highlight bed bugs' vulnerability to environmental stressors outside their temperate origins.

The study used the Optical Properties of Aerosols and Clouds (OPAC 4.0) database to obtain the microphysical characteristics of urban aerosols and performed numerical analyses of the analytical formulas describing how equilibrium relative humidity (RH), effective radius, hygroscopic growth, and the corresponding absolute and fractional changes in these parameters respond to surface-tension influences (Kelvin effect) on atmospheric aerosols. It was determined that the Kelvin effect increase with the increase in water soluble and RH, and for the water activity it increased with the increase in RH but decreased with the increase in water soluble. The three models analyzed, are, two of one parameter models and one of three parameters model. The analysis of the extracted data shows that, to first-order accuracy, variations in equilibrium RH, effective radius, and effective hygroscopic growth are influenced by aerosol composition. Results from all three models further indicate that the fractional changes in ambient RH, effective radius, and hygroscopic growth likewise depend on the aerosol makeup. Overall, the study found that the strength of the Kelvin effect and its resulting impact on atmospheric aerosols is determined by the hygroscopic properties of the aerosols. For lower RHs, (50 and 70) the range of the over estimations of the effective hygroscopic growth and effective radii are less that 1%. As RH increases, the degree of overestimation also rises following a power-law relationship with RH. This indicates a growing deviation from ideal behavior at higher RH, likely due to the electrolytic characteristics of the ionic aerosol mixtures. Consequently, more complex formulations are needed to maintain accuracy at elevated RH levels. Overall, these findings underscore the importance of applying Kelvin corrections when modeling effective hygroscopic growth and effective radii of atmospheric aerosols, particularly under high-RH conditions.

Sulfide-based solid electrolytes offering superior ionic conductivities are promising candidates for solid-state batteries (SSBs). However, their sensitivity to moisture remains a critical bottleneck for scalable manufacturing. Even trace moisture exposure can initiate hydrolysis reactions, generating hazardous H2S gas and forming unstable interphases that severely degrade thermal stability. While laboratory fabrication is typically conducted in inert glovebox conditions, commercial-scale production relies on dry rooms where residual humidity poses risks. To evaluate the effect of moisture exposure, environments with controlled relative humidity levels of 0.004%, 0.5%, 1.5%, and 5% were analyzed. Thermal stability was assessed at both the material and full-cell levels, using Li metal as the anode, Li3PS4 as the solid electrolyte and LiNi0.6Mn0.2Co0.2O2 as the cathode active material. This work demonstrates that moisture exposure can lead to increased H2S evolution, lower exothermic onset temperatures, and accelerated self-heating, all of which heighten the risk of thermal runaway. Based on these mechanistic insights, we develop a cell-level thermal safety map, bridging the gap between controlled lab-scale environments and practical manufacturing conditions.

Context: Reliable seed storage is fundamental to successful pasture establishment and sustainable forage production systems yet seed deterioration during storage represents a major challenge for both commercial suppliers and farmers. Aims: This study investigated storage environment effects on seed longevity in red fescue (Festuca rubra L.), a key cool-season perennial grass used extensively in pasture mixtures and turf systems. Methods: Seeds of two commercial varieties ('Maxima' and 'Sergei') were equilibrated at relative humidity levels of 30-70% and stored at 45 °C under three storage systems: hermetic packaging, vacuum storage, and open warehouse-style storage. Seed viability data were analyzed using generalized linear models with probit link functions to derive viability equation parameters. Key results: Under hermetic storage conditions, viability constants were estimated as KE = 5.28 and CW = 1.91, with no significant varietal differences. Parameters for vacuum storage were similar, but open storage systems showed reduced longevity performance (CW = 1.63). Practical storage predictions indicate that seed lots with 95% initial viability stored in typical warehouse conditions (15 °C, 60% RH) would decline to 89.6% viability after 243 days. Conclusions: Red fescue seeds showed measurable viability decline under typical storage conditions, with hermetic storage providing significantly better longevity parameters compared to open storage systems. Implications: These findings provide essential parameters for optimizing red fescue seed storage in commercial and on-farm situations, supporting reliable pasture establishment and reducing economic losses from seed deterioration.

The triboelectric response of ceramic coatings has attracted attention for multifunctional applications in structural engineering, where durability and self-powered sensing are critical. This research investigates the triboelectric properties of thermal spray ceramic coating on heavy-duty building components steel matrix coatings. Ceramic coatings of magnesium spinel (MgAl 2 O 4 ) and Alumina (Al 2 O 3 ) were deposited onto a steel matrix for heavy-duty building components using atmospheric plasma spraying (APS) and high-velocity oxy-fuel (HVOF) processes. The triboelectric behavior was evaluated in terms of dielectric strength, surface charge generation, charge retention, and electrical resistivity under varying environmental conditions. Scanning electron microscopy (SEM) was used to observe surface morphology and porosity, while X-ray diffraction (XRD) identified phase composition and crystallinity. Surface profilometry quantified roughness, a key factor influencing triboelectric charge density. Electrical properties were evaluated using direct current (DC) resistance measures, electrochemical impedance spectroscopy (EIS), and the dielectric breakdown test. Triboelectric performance was further assessed by measuring surface potential and charge output under repeated contact–separation cycles. Tests were conducted across relative humidity (RH) levels ([Formula: see text] at elevated temperatures (50–[Formula: see text]C). Results showed that HVOF-deposited MgAl 2 O 4 coatings exhibited superior dielectric breakdown strength, stable resistivity, and consistent triboelectric charge output under high-humidity conditions. In contrast, Al 2 O 3 coatings demonstrated higher charge density at low humidity and were more sensitive to moisture-induced charge dissipation. It demonstrates the thermal spray ceramic coatings’ possibilities in improving both mechanical and triboelectric properties of steel matrices, enabling smart, energy-harvesting building structures with long-term reliability.

In this study, 101 and 102 rainwater samples were collected from April 2020 to February 2024 in a coastal and marine area, respectively. The results show that the Cl/Na ratios in both study areas were lower than the seawater value (1.17), suggesting chloride depletion. The chloride depletion rates in both areas decreased after the COVID-19 lockdown period. The molar ratio of NH4+ to non-sea-salt sulfate (nss-SO42−) was 1.54, with a mixture of (NH4)2SO4 and NH4HSO4 in the coastal area, and 0.83, with NH4HSO4 as the main form, in the marine area. A decreasing trend attributed to high O3 and relative humidity (RH) levels occurred in 2022. Among the dissolved organic nitrogen (DON) species, DON accounted for 24% and 32% of the total dissolved nitrogen (TDN) in the coastal and marine areas, respectively, indicating a greater relative contribution under lower anthropogenic influence. On the basis of the correlation between the species and source analysis results, NO3− mainly originated from fossil fuel combustion, NH4+ originated from agricultural emissions and secondary aerosols, and DON originated from secondary aerosols via combustion processes and natural emissions. In terms of the flux, due to lockdown activities, the Dissolved Inorganic Nitrogen (DIN) flux decreased significantly from 40.6 to 19.3 mmol m−2 yr−1 in the coastal area and from 27.7 to 15.1 mmol m−2 yr−1 in the marine area. Additionally, a slight decrease occurred in the DON flux, from 21.6 to 19.3 mmol m−2 yr−1 and from 27.7 to 15.1 mmol m−2 yr−1, respectively. Regarding new production, based on nitrogen input, the level in the coastal area decreased from 5.83 to 2.10 g C m−2 yr−1, and that in the marine area decreased from 3.92 to 1.55 g C m−2 yr−1, indicating a significant reduction during the COVID-19 lockdown.

ABSTRACT Conventional hypergolic propellants cause technical problems due to their toxicity and carcinogenic properties, which increase development costs and lead to significant environmental issues. These challenges can be addressed by incorporating additives with low‐toxicity fuels to render them hypergolic. It is necessary to approach the storage stability challenges associated with these low‐toxicity hypergolic propellants. In this study, the storage characteristics of a NaBH 4 ‐promoted hypergolic fuel were investigated. A reactive fuel was prepared by dissolving 4 wt.% sodium borohydride as the ignition agent. Fuel stability tests were performed in air, dry air, nitrogen, and vacuum to determine oxidation effects. Tests were also performed at relative humidity levels of 10%, 40%, and 80% to analyze the effect of moisture on the degree of fuel oxidation. The degree of fuel deterioration was evaluated based on changes in density, viscosity, chemical composition, and ignition performance. The relative influence of oxygen on fuel deterioration was confirmed in the order of air > dry air > nitrogen > vacuum. Fuel deterioration accelerated with increasing relative humidity. NaBO 2 was the main sediment, and the degree of oxidation was more pronounced with moisture than with oxygen.

Objective Tacrolimus is a potent macrolide immunosuppressant widely utilized in solid organ transplantation and the management of autoimmune disorders. The current study aimed to investigate the compatibility of tacrolimus with four commonly used excipients, including sodium croscarmellose, hydroxypropyl methylcellulose (HPMC), magnesium stearate, and lactose monohydrate. Significance The design of Experiments transforms drug-excipient compatibility studies by allowing for a precise, data-driven evaluation of multiple key factors with minimal experimental runs, ensuring reliable formulation development while saving time and resources. Methods A total of 14 experimental runs were generated using Design-Expert® software, incorporating three critical variables: temperature, relative humidity (RH), and drug-to-excipient ratio for each excipient. Tacrolimus was blended with the respective excipients at predetermined ratio and subjected to controlled storage conditions under varying temperature and RH levels. Post-incubation, the residual tacrolimus content was quantified via HPLC. Additionally, to further assess physicochemical interactions, DSC and FT-IR were employed for selected samples. Results The model-fitting analysis revealed that all excipients, except HPMC, followed a linear pattern, whereas HPMC exhibited quadratic behavior. In all experimental groups, increasing RH significantly accelerated tacrolimus degradation. Notably, elevated temperature and higher excipient ratio further reduced the remaining drug concentration in all formulations except those containing magnesium stearate. The DSC thermograms revealed no significant alterations. FTIR spectroscopic analysis confirmed that only magnesium stearate-containing formulations exhibited distinct spectral patterns compared to pure tacrolimus. Conclusion These findings underscore the need for careful consideration when using magnesium stearate in tacrolimus formulations.

Water adsorption and phase transitions on NaCl surfaces before dissolution play a crucial role in understanding interfacial water-solid interactions. In this study, we employ variable-pressure scanning probe microscopy (SPM) to systematically investigate nanoscale morphological and tribological changes across a wide range of relative humidity (RH). At extremely low RH (<10-2%), water shows a strong affinity for Na+ ions, leading to increased friction, particularly at surface defects such as step edges. As RH increases to several tens of percent, this high-friction region expands across entire terrace areas. Below ∼40% RH, hydrated ion clusters form, locally reducing friction due to their liquid-like nature. Above ∼40% RH, these hydrated ion clusters disperse, resulting in a global decrease in surface friction. At higher RH levels, increased lubrication facilitates NaCl nanostructure movement, reducing pre-existing surface anisotropy and accelerating dissolution dynamics until deliquescence (∼75% RH). Our findings indicate that Cl- ion release is enhanced by water clusters, while strongly bonded Na+ ions remain exposed, acting as preferential sites for further adsorption. By utilizing SPM across a broad RH spectrum (10-7 to ∼75%), this study provides new insights into the fundamental nanoscale mechanisms governing water adsorption, phase changes, and dissolution at the NaCl-water interface.

Powdery mildew (PM) caused by (Sphaerothe cafuliginea fungus) is a major foliar disease affecting greenhouse and field-grown watermelons worldwide. Infection at an early stage of watermelon plant by S. fuliginea reduces seedling and vigor causing premature desiccation of leaves. This research investigates the effects of temperature and relative humidity on the conidial germination and in vivo infection of Sphaerotheca fuliginea on healthy watermelon plants. The experiment was laid out on Completely Randomized Design (CRD) in the laboratory with (5) replications in each case. Conidia of Sphaerotheca fuliginea was subjected to different temperatures and relative humidity of (30, 35, 40, 45 oC and 52%, 63%, 86%, and 94%, respectively) for conidial germination, mycelium length, width, and in vivo infection. Results showed that lower temperature ranges (30 °C-35 oC) and higher relative humidity (&gt;70%) often enhance the conidial germination of Sphaerotheca fuliginea and in vivo infection, research revealed how Powdery Mildew be triggered by lower temperature of 30 OC and high relative humidity of ~94% in watermelon (Citrullus lanatus) in Shagari Local Government Area of Sokoto State. Based on the result obtained, the best time for Watermelon cuttivation around Shagari Local Government Area should be from February to May, in which temperature and relative humidity levels are not favourable for developing Powdery Mildew.