Integrated analysis of internal moisture diffusion and surface moisture evaporation in the surface hardening phenomena of yam slices.

Buffer materials are critical for engineered barrier systems (EBS) to handle high-level radioactive waste (HLW) in geological repositories. The water content and volume change of the buffer block during storage and installation are affected by environmental conditions, such as relative humidity and the initial water content of blocks. This paper investigated the drying process of bentonite buffer blocks by using a water transport model coupled with the capillary liquid flow and vapor diffusion, and the process was experimentally verified by desiccation tests. The model represents vapor-liquid equilibrium as the driving force for vapor diffusion, considering the effect of pore capillaries on thermodynamic activity. The theoretical relationship between relative humidity and water saturation is basically consistent with experimental measurements, and the established model can predict the drying rate under different relative humidity conditions. At the same time, the volume change of the buffer block during the drying process was analyzed. Based on the results, the effect of different environmental relative humidity and initial moisture content on block drying was evaluated. The results show that the block with lower initial saturation is less affected by the relative humidity of the environment than the block with higher initial saturation, and the environment with lower relative humidity is more likely to change the moisture content and volume of the block. This study can be used to predict the effect of different environmental conditions on the distribution and deformation of soil interior saturation. INTRODUCTION The disposal of spent fuel from nuclear power plants is a global concern, and the deep geological repository is widely considered to be the solution for the long-term storage of nuclear waste, as shown in Fig. 1 (Choi et al., 1999; Fukuda et al., 2003; Cho and Kim, 2016; Salonen et al., 2021). Spent fuel is stored in specially designed containers and placed in tunnels dug deep in stable geological formations (Hedin & Olsson, 2016). The buffer material between the canister and the bedrock prevents groundwater from flowing into the deposition holes and keeps the canister centered in the hole, the buffer material also prevents the diffusion of radioactive material into the bedrock in the event of a canister rupture (Salo & Kukkola, 1989; Lee et al., 2007; Yoon et al., 2018; Larson et al., 2020). Bentonite or its modified soil is often used as a buffer material because of its extremely low permeability in the saturated state (Suzuki et al., 2013; Choi et al., 2022).

The effect of relative humidity (RH) of air on the mechanical properties of roasted turkey breast was studied using a rheological model. The raw turkey breast with a moisture content of ca. 75%, protein content of ca. 24% and fat content of ca. 1% was roasted in a convection steam oven at 180C and five RH levels (0, 20, 50, 70 and 90%). The elastic modulus decreased, whereas the flow consistency index and the flow limit increased with an increase in RH from 0 to 70%. Significant differences were observed in elastic modulus between RH levels of 0 and 20% versus 50, 70 and 90%. As regard the flow consistency index and the flow limit, significant differences were observed between 0 versus 50 and 70% RH levels. No significant differences in those values were reported at RH exceeding 50%. The flow consistency index was independent of RH of air level.Practical ApplicationsThe proposed method can be used to determine the effect of treatment parameters on the rheological properties of the analyzed product, and to assess its final quality. The presented mathematical model allows to evaluate the rheological properties of turkey breast meat roasted in a convection steam oven independently of the type of mechanical tests used to determine those values. The obtained results support the selection of roasting parameters (relative humidity) aimed at yielding a product with the desired rheological properties.

The effect of acidity and relative humidity on bulk isoprene aerosol parameters has been investigated in several studies; however, few measurements have been conducted on individual aerosol compounds. The focus of this study has been the examination of the effect of acidity and relative humidity on secondary organic aerosol (SOA) chemical composition from isoprene photooxidation in the presence of nitrogen oxide (NOx). A detailed characterization of SOA at the molecular level was also investigated. Experiments were conducted in a 14.5 m3 smog chamber operated in flow mode. Based on a detailed analysis of mass spectra obtained from gas chromatography–mass spectrometry of silylated derivatives in electron impact and chemical ionization modes, ultra-high performance liquid chromatography/electrospray ionization/time-of-flight high-resolution mass spectrometry, and collision-induced dissociation in the negative ionization modes, we characterized not only typical isoprene products but also new oxygenated compounds. A series of nitroxy-organosulfates (NOSs) were tentatively identified on the basis of high-resolution mass spectra. Under acidic conditions, the major identified compounds include 2-methyltetrols (2MT), 2-methylglyceric acid (2mGA), and 2MT-OS. Other products identified include epoxydiols, mono- and dicarboxylic acids, other organic sulfates, and nitroxy- and nitrosoxy-OS. The contribution of SOA products from isoprene oxidation to PM2.5 was investigated by analyzing ambient aerosol collected at rural sites in Poland. Methyltetrols, 2mGA, and several organosulfates and nitroxy-OS were detected in both the field and laboratory samples. The influence of relative humidity on SOA formation was modest in non-acidic-seed experiments and stronger under acidic seed aerosol. Total secondary organic carbon decreased with increasing relative humidity under both acidic and non-acidic conditions. While the yields of some of the specific organic compounds decreased with increasing relative humidity, others varied in an indeterminate manner from changes in the relative humidity.

With increasing walnut production in California, walnuts are stored for longer times. It is increasingly important to optimize storage conditions, wherever possible, to reduce quality degradation. We examined the effects of temperature (5, 15, and 25 °C) and relative humidity (20%, 40%, and 60% in year 1 and 40%, 60%, and 80% in year 2) on the rate of quality degradation of four walnut varieties. The relationship between water activity and moisture content was investigated for each variety. In addition, the effects of harvest timing (early vs. late) and storage as shelled or in-shell product were investigated. Later harvested walnuts had darker kernel color (P < 0.001), and walnuts stored as kernels (shelled) had higher rates of peroxide formation and free fatty acid development than walnuts stored in-shell. Temperature had a significant effect on quality with faster degradation at higher temperatures. There was a significant interaction between temperature and relative humidity effects on quality. The effects of relative humidity were often not significant at storage temperatures of 5 °C but were apparent at 15 °C and at 25 °C. Managing relative humidity during walnut storage is difficult under typical commercial storage conditions; however, when low temperature storage is used, quality is preserved even when relative humidity is not controlled, although storage at 80% relative humidity should be avoided. To reduce the rate of color darkening and rancidity development during commercial storage, operators should emphasize storage at lower temperatures, at least below 15 °C.

The drying characteristics (changes of mass (moisture content), volume, drying surface area, and surface and internal temperature of sample during drying) of Japanese yam (Dioscorea opposita Thunb.) were measured under various operating conditions (temperature, relative humidity, and absolute pressure (vacuum level)). Japanese yam was dried by two methods, hot air drying and continuous vacuum drying. The effects of temperature, relative humidity, and absolute pressure on the drying rate of the sample were investigated. The moisture content change of the sample was analyzed under two conditions, considering or not considering the drying surface area change. When surface area change is considered, two periods, the constant rate period and the falling rate period, existed in both hot air drying and vacuum drying of the sample. In each case, mathematical models to describe the changes of the moisture content were derived, and the measured data agreed well with the values calculated from the models. The effects of temperature, relative humidity, and vacuum level on the drying rate constant were investigated. The drying rate constants were related to the temperature and relative humidity for hot air drying, or the temperature and vacuum level for vacuum drying using empirical equations which are modified form an Arrhenius-type equation.

Torsional fretting wear behaviour of 7075 aluminium alloy in various relative humidity environments

Poultry farming generates significant poultry litter (broiler litter and laying hen manure), posing environmental and human health risks. Heat treatment, particularly through drying, can mitigate these adverse effects. This paper aimed to explore the impact of various drying methods of poultry litter on key process indicators. The literature review showed that the drying kinetics of the broiler litter in a hot air dryer is affected by the manure depth, air velocity, drying temperature, and air relative humidity. Nevertheless, the effect of the air relative humidity is insignificant on drying laying hen manure. Hot air drying, freeze drying, and oven drying have significant effects on the nutrient content of the broiler litter. In drying both broiler litter and laying hen manure, the specific energy consumption decreases as air temperature and relative humidity rise. Low temperatures cause poor bacteria destruction in poultry litter, but at temperatures over 50°C, Salmonella is completely destroyed. The ammonia release from laying hen manure and broiler litter is very sensitive to moisture content. Generally, air temperature, air velocity, manure depth, and air relative humidity positively correlate with ammonia emission. The average ammonia emission during belt drying of laying hen manure is about 209.3 mg NH3 d-1 hen-1. Finally, the lack of comprehensive research on poultry litter drying with modern drying methods (ultrasound, microwave, infrared rays, and freeze drying) is evident. One approach that may offer new opportunities is hybrid methods, such as a combination of dryers that use hot air drying agents with these modern drying methods.

Effect of relative humidity on the enhancement of the triboelectrification efficiency utilizing water bridges between triboelectric materials

SummaryTo investigate the effect of temperature and relative humidity (RH) on the absorption kinetics of self‐activated and moisture‐activated O2 scavengers for packaged food, kinetic parameters of each O2 scavenger were evaluated at 43%, 75% or 100% RH and at 10, 25 and 40 °C respectively. Absorption kinetics was well described by a first‐order reaction with an Arrhenius type behaviour. For moisture‐activated O2 scavengers, a proper high RH was needed to ensure a high O2 absorption capacity, as average O2 absorption capacity was 3.82 mL at 43% RH and 43.40 mL at 75% RH. When the temperature increased, O2 absorption rate constant ascended from 10 °C to 40 °C on an average of 0.153 and 0.306 h−1 in moisture‐activated and self‐activated O2 scavengers respectively. We could take the effect of temperature and RH into account when we chose different types of iron‐based O2 scavengers for packaged food.

Four air temperature levels of 23, 25, 27 and 29C, three humidity levels of 85, 90 and 95%R.H. and two photosynthetic photon flux (PPF) levels of 30 and 50 jumol m-2 s-1 were provided to investigate the effects of air temperature, relative humidity and light intensity on the evapotranspiration rate (EVTR) of watermelon grafted seedlings. EVTR of grafted seedlings increased with increasing air temperature and the passage of time after grafting. Also EVTR increased with decreasing relative humidity. EVTR of grafted seedlings at dark period reduced by half of those at photoperiod. Effect of relative humidity on the EVTR of grafted seedlings was distinctly shown at relatively high PPF. As the vapor pressure deficit decreased, the graft-taking of grafted seedlings increased. Under the high humidity more than 90%, EVTR was gradually increased with days after grafting and thus the scion and rootstock were also smoothly joined together. It is required to control optimally the environment for decreasing the vapor pressure deficit and preventing the wilting of grafted seedlings under artificial lighting during first 2–3 days after grafting. And then it is suggested to lower the relative humidity and raise the PPF by steps for the robust joining of grafted seedlings.

The effects of air temperature, relative and specific humidity, wind speed, solar shortwave radiation, thermal longwave radiation, and rain on the performance of participants in the annual Stockholm Marathon from 1980 to 2008 were analysed statistically. The objective was to validate and extend previous studies by including data on finishing times of slower male and female runners and on the percentage of non-finishers. Due to decadal trends in the finishing time not related to weather, the finishing time anomaly (FTA) was calculated as the deviation of the annual finishing time from the linear trend of the finishing time. In all categories of runners, the single weather parameter with highest correlation with the FTA was the air temperature (correlation coefficient r = 0.66-0.73, with the highest values for slowest runners). Also, the solar shortwave radiation (r = 0.41-0.71), air relative humidity (r = -0.57 to -0.44) and, for male runners, the occurrence of rain (r = -0.51 to -0.42) reached a statistically significant correlation with the FTA, but the effects of the relative humidity and rain only arose from their negative correlation with the air temperature. The percentage of non-finishers (PNF) was significantly affected by the air temperature and specific humidity (r = 0.72 for multiple regression), which is a new result. Compared to faster runners, the results of slower runners were more affected by unfavourable weather conditions; this was previously known for runners with finishing times of 2.1-3 h, and now extended to finishing times of 4.7 h. Effects of warm weather were less evident for female than male runners, which was probably partly due to female runners' larger ratio of surface area to body mass and slower running speed.

The effects of varying relative humidity on some aspects of biology of Ephestia cautella Walker (Lepidoptera: Pyralidae) were examined in the laboratory. Different relative humidities (22, 28, 32, 40, 54, 57, and 100%) were maintained in enclosed desiccators with H2SO4. The fecundity of E. cautella at 57% relative humidity was significantly higher than that of any other relative humidities studied. A relative humidity of 22% caused 100% inhibition of egg viability in less than 24 h, which was significantly lower (p < 0.05) than egg viability at 32 to 100% relative humidity. Relative humidities of 57 and 100% favoured adult emergence from third instar larvae and showed a significant difference from the effect of lower relative humidity. Adult male mortality of 96.7% was achieved at 22% relative humidity, and 70% adult female mortality was obtained under similar relative humidity conditions within 48 h. E. cautella males were more susceptible to low relative humidity than those of E. cautella females. There...

Objectives: This study was performed to examine bioaerosols in indoor air in public restrooms, as well as to assess the effects of air temperature and relative humidity on bioaerosol levels. Methods: A cross-sectional survey was performed in ten male and ten female restrooms. An air sampler (Anderson type) was used for sampling total suspended bacteria (TSB), Gram-negative bacteria (GNB), Gram-positive bacteria (GPB), opportunistic bacteria (OP), Staphylococcus spp., and total suspended fungi (TSF). Results: The levels of TSB were <TEX>$10-10^2CFU/m^3$</TEX> and TSF <TEX>$10-10^2CFU/m^3$</TEX>, respectively. The GNB level was <TEX>$0-10CFU/m^3$</TEX>, and GPB and OP levels were <TEX>$10-10^2CFU/m^3$</TEX>. Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) were detected in 90% of the restrooms. The GPB level was higher in the female restrooms than in the male restrooms (p < 0.05). TSB, GNB, and TSF showed higher levels in restrooms in buildings over 30 years old (p < 0.01). The main effect of air temperature or relative humidity and interaction effect of the two factors on the TSB level were significant (p < 0.05), while the effect of relative humidity on the TSF level was significant (p < 0.001). Conclusions: These results indicate that there is a wide variation in the bioaerosol levels among different restrooms. The observed differences in bioaerosol levels reflect different building histories. The effects of air temperature and/or relative humidity reveal that bioaerosol levels may vary according to season or time of day. Future research is needed to further characterize the relation between the bioaerosol levels and surface contamination in restrooms.

The energy used by information technology (IT) equipment and the supporting data center equipment keeps rising as data center proliferation continues unabated. In order to contain the rising computing costs, data center administrators are resorting to cost cutting measures such as not tightly controlling the temperature and humidity levels and in many cases installing air side economizers with the associated risk of introducing particulate and gaseous contaminations into their data centers. The ASHRAE TC9.9 subcommittee, on Mission Critical Facilities, Data Centers, Technology Spaces, and Electronic Equipment, has accommodated the data center administrators by allowing short period excursions outside the recommended temperature-humidity range, into allowable classes A1-A3. Under worst case conditions, the ASHRAE A3 envelope allows electronic equipment to operate at temperature and humidity as high as 24°C and 85% relative humidity for short, but undefined periods of time. This paper addresses the IT equipment reliability issues arising from operation in high humidity and high temperature conditions, with particular attention paid to the question of whether it is possible to determine the all-encompassing x-factors that can capture the effects of temperature and relative humidity on equipment reliability. The role of particulate and gaseous contamination and the aggravating effects of high temperature and high relative humidity will be presented and discussed. A method to determine the temperature and humidity x-factors, based on testing in experimental data centers located in polluted geographies, will be proposed.

Effect of relative humidity on the uptake, translocation, and efficacy of glufosinate ammonium in wild oat ( Avena fatua)