Influence Of Humidity Research Articles

Shear behavior of cold region clay-concrete interface under temperature-controlled direct shear tests

The shear properties of the permafrost-structure interface play a crucial role in analyzing the performance of engineering structures in cold regions. Direct shear tests were carried out on the permafrost-concrete structural interface by means of self-improved and optimized temperature-controlled direct shear apparatus to investigate the effects of temperature, moisture content and freeze-thaw cycles. Test results were used to establish a shear characteristic model under coupled influence of temperature and humidity. Preparation of specimens consisting of precast C30 concrete blocks and soil samples taken from borehole cores of the pile foundation of the Middle Bridge No. 3 on the road from Sai Township to Qiuluo Village, Sakya County, Tibet, China, and were treated to different effective confining pressure (σn = 300 kPa, 400 kPa, 500 kPa and 600 kPa), different temperatures (T = −20 °C, −15 °C, −5 °C, 0 °C, 5 °C, 15 °C, and 20 °C), different moisture contents (ω = 5 %, 10 %, 15 %, and 20 %), and different numbers of freeze-thaw cycles (N = 0, 1, 3, 5, 7and11) from −15 °C to 15 °C, test results are given and analyzed. The peak shear stress (τp) is significantly higher than the residual stress (τr) at negative temperature, τp is greater than 1.5 times to 3.2 times of τr. τp is greatly affected by temperature changes, τp under negative temperature is 17 % higher than that under positive temperature, because the water in the soil freezes at negative temperatures, forming a concrete-ice-soil bond interface, which increases the peak strength of the interface. While τr is insensitive to temperature changes. At negative temperatures, the cohesion (c') changes less with increasing water content (ω), and the effect of ω on the external friction angle (φ′) is more significant. At positive temperature, the cohesion decreases with increasing ω, and the effect of ω on the external friction angle is not significant. When N < 5, the cohesion increases with the increase of N; when N = 5, c' reaches the maximum value; when N > 5, c' decreases with the increase of N. Moreover, regardless of the type of shear behavior, the first five freeze-thaw cycles have the greatest impact on the external friction angle. Compared with the sample that has not experienced freeze-thaw cycles, when N = 5, the total decrease in the external friction angle of the sample is 25.6 %.

Moisture Transformation in Warm Air Intrusions Into the Arctic: Process Attribution With Stable Water Isotopes

AbstractWarm Airmass Intrusions (WAIs) from the mid‐latitudes significantly impact the Arctic water budget. Here, we combine water vapor isotope measurements from the MOSAiC expedition, with a Lagrangian‐based process attribution diagnostic to track moisture transformation in the central Arctic Ocean during two WAIs, under contrasting sea‐ice concentrations (SIC). During winter with high SIC, two moisture supplies are identified. The first is Arctic moisture, locally‐sourced over the sea ice, with isotopic composition influenced by kinetic fractionation during ice‐cloud formation and vapor deposition. This moisture is rapidly overprinted by low‐latitude moisture advected poleward during WAI. In summer under low SIC, moisture is supplied through evaporation from land and ocean, with moisture removal via liquid‐cloud and dew formation. The isotopic composition reflects the influence of higher relative humidity at the evaporation sites. Given the projected increase of frequency and duration of WAIs, our study contributes to assessing process changes in the Arctic water cycle.

Development of an assay for the detection of the federally threatened Florida eastern indigo snake (Drymarchon couperi) using soil eDNA

AbstractAccurate information on species range contraction is the cornerstone of effective biodiversity conservation. The eastern indigo snake (Drymarchon couperi) is an apex predator in Florida and, similar to many species native to Florida, is threatened by widespread habitat destruction. Environmental deoxyribonucleic acid (eDNA) monitoring of this elusive snake would provide a non‐invasive approach to improve our knowledge of the species' range and distribution. We designed and tested an eDNA assay that can detect the presence of D. couperi from soil samples from their natural scrub habitat in Florida. We validated our assay in silico, in vitro, and in situ. Furthermore, we investigated the influence of temperature and humidity on the degradation rate of eDNA over time. We successfully amplified the cytochrome b gene for D. couperi at concentrations as low as 3 × 10−3 ng/μL and successfully detected the presence of D. couperi in 2 of 30 in situ field soil samples. The degradation experiment resulted in detectable DNA for 10 days. Interestingly, temperature and humidity had no effect on the degradation rate of eDNA in our experimental conditions. This study provides support for soil eDNA applications to detect the presence of a federally threatened species in their natural environment bolstering our ability to monitor the conservation and management of imperiled species. Environmental DNA provides an additional conservation tool to quickly and effectively monitor species range shifts driven by multiple anthropogenic stressors to promote the persistence of imperiled species.

A clean and novel drying method for bamboo colorization and in-situ surface wax utilization

Round bamboo is considered an environmentally friendly product, with surface color crucial to its value. Surface wax is crucial for the growth and development of bamboo, but can alter the color of round bamboo and easily detach under the influence of heat and humidity, leading to uneven colorization. By controlling the drying temperature at 90 ℃, the surface wax can be uniformly levelled on the bamboo’s surface, enhancing its color to a consistent deep red. Chromaticity measurements show L* values between 29.58 and 34.68 and a* values from 5.58 to 6.04 at 90 ℃. DSC test shows that the wax completely melted and levelled evenly at 90 ℃, solidifying uniformly on the bamboo surface upon drying, thus realising in-situ utilization of the wax. FTIR, GC-MS and XPS analyses reveal that drying at 90 ℃ leads to an increase in chromogenic substances within the wax and bamboo green, along with heightened intensity of unsaturated functional groups, and deepening of surface color, ultimately achieving the colorization of the round bamboo. Furthermore, the prepared round bamboo exhibits excellent pencil hardness (5 H), adhesion, and glossiness (5.38 GU), while maintaining its mechanical properties. This innovative method integrates drying, colorization, and wax utilization in one step, offering a novel strategy for enhancing round bamboo’s quality.

Species Diversity and Seasonal Abundance of Stomoxyinae (Diptera: Muscidae) and Tabanid Flies (Diptera: Tabanidae) on a Beef Cattle and a Buffalo Farm in Nakhon Si Thammarat Province, Southern Thailand.

This study investigated species diversity and seasonal abundance of Stomoxyinae and tabanid flies, which are significant pests and vectors of animal pathogens, on a beef cattle and a buffalo farm in Nakhon Si Thammarat province, southern Thailand. During a one-year period from December 2020 to November 2021, flies were collected using Nzi traps from 6 a.m. to 6 p.m. over three consecutive days each month, resulting in the capture of 1912 biting flies, representing seven Stomoxyinae and nine tabanid species. The five most prevalent species were Tabanus megalops, Haematobia irritans exigua, Stomoxys calcitrans, Stomoxys indicus, and Stomoxys uruma. Fly density was notably higher on the beef cattle farm compared to the buffalo farm, with most species peaking during the rainy season, except for H. i. exigua, which was more abundant during the dry season. This study also examined the influence of temperature, relative humidity, and rainfall on fly density, revealing species-specific patterns. These findings offer updated insights into species diversity and seasonal trends, providing critical baseline data essential for the development of effective control strategies aimed at mitigating the impact of these flies on livestock health.

The impact of relative humidity on the nanoindentation relaxation in calcium silicate hydrates

Despite extensive research efforts, understanding the time-dependent behavior of concrete remains an enigma due to the complex nature of cement microstructure. In this study, the statistical nanoindentation was employed to investigate the influence of relative humidity (RH) on the relaxation behavior of calcium silicate hydrates (C-S-H) in a cement paste. Our experiments, performed at RH levels of 33 % and 86 %, revealed significant enhancements in both the indentation modulus and hardness of the C-S-H as RH increased. Remarkably, the internal water exerted a significant influence on the asymptotic relaxation behavior, displaying a clear power-law fashion. Further analysis identified the presence of short- and long-term viscoelastic behaviors within the C-S-H, distinguished by a transition observed within the initial seconds. These findings advance the understanding of nanoscale mechanisms driving concrete creep under different humidity conditions.

Effect of relative humidity on passive spore release from substrate surfaces

Fungal spores are abundant in ambient air and exposure to this type of bioaerosols are found to cause significant health and climatic effects. In this study, we investigated the influence of air relative humidity (RH) on the passive release of spores from solid substrates. Preliminary investigations into the effect of RH on fungal spore release indicated an increase in spore flux with reduced air RH. The change in spore emission flux occurred very quickly in response to a change in ambient RH. To verify the hypothesis of extremely rapid drying under lower RH, experiments were conducted using a quartz crystal microbalance with dissipation (QCM-D) to understand the timescales of spore moisture uptake and drying. The analysis of mass transfer of water to and from the spores indicated that the bulk of the transfer occurred within a minute of exposure to any RH. The effect of the ambient RH was explained using a mathematical model with the spotlight on the parameter, E, that represented the energy required to aerosolise one spore. This study demonstrates the application of QCM-D to study interaction between ambient aerosol particles and various vapor phase and gas phase environments. The study enhances the overall understanding and capability to characterise passive fungal spore release under varying humidity conditions in the natural environment.

Influence of relative humidity and aging on the optical properties of organic aerosols from burning African biomass fuels

Influence of relative humidity and aging on the optical properties of organic aerosols from burning African biomass fuels

Review on Influence of Food Technology on the Flavor of Dairy Product

In contemporary society, people's demand for milk and dairy products is growing rapidly, and people's quality requirements for dairy products are gradually increasing. Currently, most research on dairy products focuses on nutritional composition, taste, and flavor. However, research into the changes in external and internal factors and processing and storage technology caused by flavor changes in dairy products is limited and immature. This paper comprehensively discusses the origin of flavor substances in milk and dairy products, the chemical changes caused by compounds affecting flavor, and the influence of temperature and humidity on flavor.

Computational fluid dynamics investigation of pesticide spraying by agricultural drones

Precise control over pesticide spraying by agricultural drones requires fundamental research of multiphase flow, heat and mass transfer of liquid droplets in downwash flow. In this study, water was used as a carrier agent in pesticide formulations, in which the liquid droplets exhibit a Newtonian fluid behavior. A general computational fluid dynamics (CFD) model that characterizes propeller motion coupled with droplet evaporation and deposition was developed. The downwash flow generated by the propeller rotation was simulated using a multiple reference frame method along with the SST-k-ω turbulence model. Spraying of liquid droplets was simulated using a discrete phase model. The flow model validation was conducted by comparing the simulated velocities with experimental data, and the spray model validation was completed by a comparison of droplet depositions from CFD predictions and experiments. The results indicated that the droplet deposition fluctuates with an increase of propeller speed, and that both temperature and relative humidity affect the droplet deposition. In addition, the relation between the number of particles and the impact velocity was identified quantitatively, impact velocity with respect to particle diameter was predicted, and the effects of surface inclination, surface roughness, and crosswind speed on droplet deposition were analyzed. Moreover, an in-depth discussion about the intrinsic relation between downwash flow and droplet spraying was conducted.

Research on Polyurethane Creep Prediction Model Based on BWO-BP

Abstract Polyurethane foam materials can creep under the influence of temperature, humidity, and pressure during use, which seriously affects their safety and state of use. Therefore, studying the creep behavior of polyurethane foam materials and developing corresponding creep mechanism models have significant scientific value for understanding their damage patterns. As a type of machine learning, Backpropagation (BP) neural network can be used for data analysis. However, there are many issues when determining the network structure. Whale Optimization (BWO) algorithm, as a type of swarm intelligence algorithm, can efficiently determine the framework of the BP model. BP which has been optimized through the BWO algorithm, has been utilized to construct a model for the prediction of polyurethane’s creep failure. The optimization process has significantly lowered the mean squared error from 0.30 in the non-optimized BP model to 0.07 in the enhanced BWO-BP model, which validates the effectiveness of the proposed algorithm.

Eco-friendly construction mortars for heavy metals immobilization – Effect of partial PC replacement by lignite-based fly ash and prolonged high humidity curing on physical and chemical parameters

The study presented in this manuscript concerns the safe immobilization of heavy metals (HMs) present in fly ash (FA) from lignite combustion in Portland cement- (PC-) based blended mortars with an emphasis on the influence of prolonged high humidity curing on material properties. The performed experiments covered both the aspect of the FA-PC replacement ratio as well as the changes in structural, hygric, chemical, and mechanical parameters of the prepared composites after 28, 90, and 180 days of curing. It was shown, that the used FA shows a high pozzolanic activity, which strongly contributed to the mechanical parameters of the developed blended mortars, namely the strength activity index in the range of 0.94–1.06 for 180-day samples. The blended mortars were cautiously studied concerning the HM immobilization efficiency. The immobilization efficiency was analyzed through the HM leaching test, showing that HMs present in the leachates manifested concentrations well below the prescribed limits. In addition, the immobilization effectiveness was found to be higher with a longer curing time. As FA-PC replacement has recently become a highly researched topic, this study adds a significant point of view in terms of the safety and environmental efficiency of the designed composites. Furthermore, the proposed safe handling of hazardous HM-containing FA through their implementation in construction mortars while ensuring high HM-immobilization effectiveness represents the next step in the ongoing research into the decarbonization of the construction industry and minimization of the depletion of natural resources.

The influence of relative humidity during the first 21 days post-hatch on the production performance, biochemical indices, and meat quality of Pekin ducks

The influence of relative humidity during the first 21 days post-hatch on the production performance, biochemical indices, and meat quality of Pekin ducks

Climatic Impact on the Air Pollutant Concentrations Emitted from Gas Stations in Fallujah, Al-Anbar, Western Iraq

The research investigates the influence of climatic elements like temperature, relative humidity, rainfall, evaporation, dust storms, wind direction, and speed on the air pollutant concentrations at gas stations in Fallujah city while examining their impact on humans and the environment. This was achieved by measuring concentrations of CO, NO2, and CH4, suspended particles (TSP, PM10), and Cu, and Pb. It was found that the impact increased in July compared to January, because of the influence of the measured climatic elements. Rising temperatures increase air pollutants' concentrations in the atmosphere, while winds spread them from emission sites to distant locations. Moreover, summer temperatures significantly impacted air pollutant concentrations at the study stations, particularly at Al-Rehab gas station, with the highest recorded temperatures of 48.4°C. Some gas stations also exceeded local environmental limits for TSP, PM10, CO, NO2, and Pb. The study revealed that summer temperatures with wind speeds of 2.1 m/s resulted in the highest air pollutants values, while winter temperatures with wind speeds of 1.9 m/s decreased these values. Higher temperatures increase chemical reactions and temperature inversions, leading to increased pollution concentrations and exacerbating air quality problems in the study area. Strong winds disperse pollutants, reducing concentration in the study area, while low wind speed increases concentrations and stagnation, resulting in poor air quality in the studied sites. The importance of the current study lies in evaluating pollutants in the Fallujah city, determining their causes, the extent of the impact, and contribution of natural and human sources in causing changes in air pollutant concentrations; caused by emission from the source. Moreover, the current study showed its impact on human’s health, and trying to find solutions to limit these effects or reduce their levels to ensure the safety of the environment and health.

Species diversity and seasonal dynamics of insects in the high altitude tea estate Uttarkhand, India

The study explored the insect communities and their seasonality within tea plantations micro-climate and finds the relatedness of these insects with the environment variables of the terroir. The study carried out at the Ghorakhal Tea Estates of Uttarakhand, collected a total of 2195 insect individuals, belonging to seven orders and 15 families and their population dynamics were measured along with the environmental variables in the estate. The Shannon-Weiver Index (H) indicated moderate species richness (2.94). The most abundant Order was Hymenoptera (30%), followed by Lepidoptera (27%). Family of pollinator bees (24%) and Pierid butterflies (19%) were dominant in the tea plantation area. The highest diversity and evenness of insect communities was observed during the summer season. The study highlights the influence of temperature, air quality, and humidity on the insect population. Canonical Correspondence Analysis suggests a significant relationship between abiotic environmental factors and insect species’ abundance. Distribution of 69.4 per cent was explained by the temperature and humidity, and 30.5 per cent by the air quality. Insect diversity was positively correlated to temperature (0.85) and humidity (0.93) and negatively correlated with air quality (-0.89).

Influence of environmental humidity during filament storage on the structural and mechanical properties of material extrusion 3D-printed poly(lactic acid) parts

Material extrusion (MEX) is one of the most widely used additive manufacturing techniques these days. This study investigates how the properties of MEX 3D-printed objects depend on the relative humidity (RH) conditions in which filaments are stored before and during the manufacturing process. Poly(lactic acid) (PLA) filament was drawn directly from a humidity-controlled chamber into the MEX 3D printer's nozzle. For each set of samples, the filaments were conditioned under different RH conditions, ranging from 10 % to 90 %. The macrostructure of the fabricated products was characterized using computed tomography, revealing increased porosity at higher RH values (from 0.84 % to 4.42 %). The increased porosity at higher storage RH is attributed to under-extrusion and volatile entrapment due to excess moisture. With growing storage RH, the melt flow rate of PLA also gradually increased, indicating a plasticizing effect of humidity on the biopolymer. Gel permeation chromatography and differential scanning calorimetry analyses were conducted to determine whether hydrolytic chain scission took place when PLA was processed in the presence of excessive moisture. Neither measurement indicated any considerable alteration in molecular integrity and crystalline structure as a function of storage RH. Mechanical tests, however, revealed a reduced load-bearing capacity of the manufactured PLA specimens. Flexural strength decreased from 103.0 to 99.6 MPa, and the impact strength dropped from 18.2 to 16.2 kJ/m2, which is ascribed to the increasing size of pores inside the specimens with increasing storage RH. These findings should be taken into account when designing and processing PLA products by MEX-based additive manufacturing.

ZnO Hexagonal Nano- and Microplates Modified with Nanomaterials as a Gas-Sensitive Material for DMS Detection-Extended Studies.

The detection of dimethyl sulphide (DMS) at levels between ppb and ppm is a significant area of research due to the necessity of monitoring the presence of this gas in a variety of environments. These include environmental protection, industrial safety and medical diagnostics. Issues related to certain uncertainties concerning the influence of high humidity on DMS measurements with resistive gas sensors, e.g., in the detection of this marker in exhaled air, of the still unsatisfactory lower detection limit of DMS are the subject of intensive research. This paper presents the results of modifying the composition of the ZnO-based sensor layer to develop a DMS sensor with higher sensitivity and lower detection limit (LOD). Improved performance was achieved by using ZnO in the form of hexagonal nano- and microplates doped with gold nanoparticles (0.75 wt.%) and by using a well-proven sepiolite-based passive filter. The modification of the layer composition with respect to the authors' previous studies contributed to the development of a sensor that is highly sensitive to 1 ppm DMS (S = 11.4) and achieves an LOD of up to 406 ppb, despite the presence of a high water vapour content (90% RH) in the analysed atmosphere.

Influence of Ambient Relative Humidity on the Shrinkage Strain of Engineered Geopolymer Composites Based on Orthogonal Experimental Design.

With the aim to systematically analyze the ambient relative humidity on the shrinkage strain of Engineered Geopolymer Composites (EGCs), this paper studied four variables (fly ash to ground granulated blast furnace slag mass ratio, alkali content, water-binder ratio, and fiber volume content) though orthogonal experimental design and three different relative humidity values (30%, 60%, and 100% RH). The results indicated that, for EGC specimens under 30% RH and 60% RH, the decrease in slag content and increase in alkali content both resulted in greater drying shrinkage. The addition of fibers effectively reduced the shrinkage strain, while a minor impact on shrinkage was presented by the W/B ratio. The first and second key factors affecting the drying shrinkage strain were the FA/GGBS ratio and the alkali content. The optimal ratio of FA/GGBS, alkali content, and fiber volume fraction were 0/100, 4%, and 1.5%, respectively. Dring shrinkage strain was decreased with the increase in ambient relative humidity. Compared with the shrinkage strain under 30% RH, the reduction in shrinkage strain under 60% RH and 100%RH was up to 46.1% and 107.5%, respectively. At last, a relationship between shrinkage strain and curing age under 30% and 60% RH was established with a fitting degree from 0.9492 to 0.9987, while no clear relationship was presented under 100% RH. The results in this paper provide a practical method for solving the shrinkage problem of EGCs.

Effect of Seasonal Variation on Growth and Nutritive Value of Azolla pinnata under Agro Climatic Condition of Assam

Background: Azolla is a free floating aquatic fern fixes atmospheric nitrogen in association with nitrogen fixing blue green algae. There have been some studies about the differences in temperature, rainfall and humidity influence on Azolla production. Hence, the present experiment was undertaken to study the effect of seasonal variation on growth and nutritive value of Azolla under the agro climatic condition of Assam. Methods: Azolla beds were used to cultivate Azolla pinnata with three replications and the size of the individual beds were (10×4) m. Deep bore well was the source of water for growing with pH 5.8. The fresh Azolla pinnata was collected from the nearby pond of the farm and further cultured. The meteorological data were collected everyday and production data were collected fortnightly. Two samples of fresh Azolla pinnata were collected and analysed for its nutritive value during the month of January and June 2021 in order to evaluate the difference of nutritive value due to seasonal variation. Result: Highest fresh Azolla was recorded in bed 2 (9.5 kg) in the month of May and lowest being recorded by the bed 2 (2.0 kg) during January. The increased Azolla production during May to June was attributed to the rise of temperature prevailed in the surrounding area of ZLRS, Mandira. There were no significant differences between the two seasons regarding the nutrient content of Azolla.

Assessment of clear-sky irradiance from 6S affected by local climatology of India

Accurate estimation of solar power generation is crucial for the effective planning and operation of solar energy sector. Solar potential can be estimated at a location from long-term historical irradiance data processed from atmospheric reanalysis datasets. The current study employs a clear-sky radiative transfer model (6S) to simulate the net surface irradiance at four distinct locations in India, comparing our model's output with mean monthly ground-based measurements of surface irradiance. Our findings reveal that the 6S model marginally underestimates solar irradiance, with potential deviations varying depending on the accuracy of input data. This research evaluates the influence of particulate matter concentration and relative humidity on the scattering and absorption of solar radiation. We also state the variability in surface irradiance across the country with the rainfall trends that enhance assessment accuracy. The study reports an annual deviation of 10–15 % in surface irradiance across the country, where rural settlements show lower deviations in simulations. The radiative transfer calculations mentioned in the study are simplistic yet beneficial for a priori evaluation of solar potential. Transmittance estimated from clear-sky models is further implemented in all-sky (with clouds), and thus, model accuracy is an important parameter. Additionally, we explore the trends in aerosol concentrations and the impact of local climatological factors on surface irradiance, providing insights critical for optimizing solar energy utilization.