447,373 results on '"Relative humidity"'
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2. Study on the control effectiveness of relative humidity by various ventilation systems for the conservation of cultural relics
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Liu, Benli, He, Chenchen, Zhang, Guobin, Xu, Ruihong, Zhan, Hongtao, Wu, Fasi, and He, Dongpeng
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- 2024
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3. Impact of temperature and relative humidity variations on coda waves in concrete
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Diewald, Fabian, Denolle, Marine, Timothy, Jithender J., and Gehlen, Christoph
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- 2024
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4. Impact of temperature and relative humidity variability on children’s allergic diseases and critical time window identification
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Yu, Shumin, Bigambo, Francis Manyori, Zhou, Zhiyu, Mzava, Sabitina Mrisho, Qin, Haiyue, Gao, Ling, and Wang, Xu
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- 2024
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5. Investigation of the effect of relative humidity on micro lime consolidation of degraded earthen structures
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Zeng, Renjian and Schwantes, Gesa
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- 2024
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6. Constrained temperature and relative humidity predictive control: Agricultural greenhouse case of study
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Hafsa Hamidane, Samira EL Faiz, Iliass Rkik, Mohamed El Khayat, Mohammed Guerbaoui, Abdelali Ed-Dahhak, and Abdeslam Lachhab
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Constrained model predictive control ,Greenhouse ,MISO systems ,Optimization ,Relative humidity ,Temperature ,Agriculture (General) ,S1-972 ,Information technology ,T58.5-58.64 - Abstract
The importance of Model Predictive Control (MPC) has significant applications in the agricultural industry, more specifically for greenhouse’s control tasks. However, the complexity of the greenhouse and its limited prior knowledge prevent an exact mathematical description of the system. Subspace methods provide a promising solution to this issue through their capacity to identify the system’s comportment using the fit between model output and observed data. In this paper, we introduce an application of Constrained Model Predictive Control (CMPC) for a greenhouse temperature and relative humidity. For this purpose, two Multi Input Single Output (MISO) systems, using Numerical Subspace State Space System Identification (N4SID) algorithm, are firstly suggested to identify the temperature and the relative humidity comportment to heating and ventilation actions. In this sense, linear state space models were adopted in order to evaluate the robustness of the control strategy. Once the system is identified, the MPC technique is applied for the temperature and the humidity regulation. Simulation results show that the regulation of the temperature and the relative humidity under constraints was guaranteed, both parameters respect the ranges 15 °C ≤ Tint ≤ 30 °C and 50 % ≤ Hint ≤ 70 % respectively. On the other hand, the control signals uf and uh applied to the fan and the heater, respect the hard constraints notion, the control signals for the fan and the heater did not exceed 0 ≤ uf ≤ 4.3 Volts and 0 ≤ uh ≤ 5 Volts, respectively, which proves the effectiveness of the MPC and the tracking tasks. Moreover, we show that with the proposed technique, using a new optimization toolbox, the computational complexity has been significantly reduced. The greenhouse in question is devoted to Schefflera Arboricola cultivation.
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- 2024
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7. Study on the control effectiveness of relative humidity by various ventilation systems for the conservation of cultural relics
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Benli Liu, Chenchen He, Guobin Zhang, Ruihong Xu, Hongtao Zhan, Fasi Wu, and Dongpeng He
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Cultural relics preservation ,Dadiwan F901 ,Relative humidity ,Numerical simulation ,Ventilation systems ,Fine Arts ,Analytical chemistry ,QD71-142 - Abstract
Abstract The Dadiwan F901 site, boasting a history of over 5000 years, stands as the largest and most intricately crafted large-scale housing structure from China’s prehistoric era. The early renovation efforts, incorporating a sealed glass curtain wall, led to a continuous rise in relative humidity within the site, triggering outbreaks of microbial diseases. Subsequent measures successfully restored stability to the thermal and humid environment. This paper employs on-site real-time environmental monitoring and numerical simulation methods to assess the ventilation effectiveness and relative humidity changes before and after multiple interior modifications of the Dadiwan F901 site museum. The results indicate that the fully enclosed glass curtain wall can suppress the dependence of indoor humidity fluctuations on external weather fluctuations but has generated unintended consequences, leading to increased air relative humidity and even reaching saturation in the museum space. The strategic deployment of louvered windows and duct fans proved effective in enhancing internal airflow dynamics and overall air exchange capacity. It was possible to ensure that the relative humidity inside the site remained at approximately 70%, meeting the essential requirements for the preservation of cultural relics. This study is of great significance for alleviating the deterioration problem of enclosed exhibition halls of earthen relics. Graphical Abstract
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- 2024
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8. Impact of temperature and relative humidity variations on coda waves in concrete
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Fabian Diewald, Marine Denolle, Jithender J. Timothy, and Christoph Gehlen
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Coda wave interferometry ,Quality factor ,Ultrasound ,Monitoring ,Temperature ,Relative humidity ,Medicine ,Science - Abstract
Abstract The microstructure of concrete can be affected by many factors, from non-destructive environmental factors through to destructive damage induced by transient stresses. Coda wave interferometry is a technique that is sensitive enough to detect weak changes within concrete by evaluating the ultrasonic signal perturbation compared to a reference state. As concrete microstructure is sensitive to many factors, it is important to separate their contributions to the observables. In this study, we characterize the relationships between the concrete elastic and inelastic properties, and temperature and relative humidity. We confirm previous theoretical studies that found a linear relationship between temperature changes and velocity variation of the ultrasonic waves for a given concrete mix, and provide scaling factors per Kelvin for multiple settings. We also confirm an anti-correlation with relative humidity using long-term conditioning. Furthermore, we explore beyond the existing studies to establish the relationship linking humidity and temperature changes to ultrasonic wave attenuation.
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- 2024
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9. Impact of temperature and relative humidity variability on children’s allergic diseases and critical time window identification
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Shumin Yu, Francis Manyori Bigambo, Zhiyu Zhou, Sabitina Mrisho Mzava, Haiyue Qin, Ling Gao, and Xu Wang
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Temperature ,Relative humidity ,Childhood allergic diseases ,Childhood allergies ,Critical time window ,Public aspects of medicine ,RA1-1270 - Abstract
Abstract Background The effects of temperature and relative humidity on different types of children’s allergic diseases have not been comprehensively evaluated so far. This study aims to assess the impact of temperature and relative humidity variability on children’s allergic diseases and to identify the critical time window. Methods We collected outpatient data on allergen testing in children between July 2020 and January 2022 from the Affiliated Children’s Hospital of Nanjing Medical University. We defined the 1st, 10th, 90th, and 99th percentiles as extreme cold, moderate cold, moderate hot, and extreme hot for temperature, and as low, moderate high, and extreme high for relative humidity, respectively. A distributed lag nonlinear model (DLNM) combined with a binomial regression model was used to assess the possible nonlinear relationship at different periods. Subgroup analysis by gender and age was conducted. Results We found that extreme and moderate cold temperatures were positively associated with skin allergies and total allergies (28 days: OR = 4.69, 95% CI: 2.88, 7.63; OR = 3.36, 95% CI: 2.39, 4.73) and (28 days: OR = 3.76, CI: 2.43, 5.81; OR = 2.71, 95% CI: 2.00, 3.68), respectively. Moderate and extreme hot temperatures were negatively associated with food allergies (28 days: OR = 0.13, 95% CI: 0.04, 0.41 and OR = 0.04; 95% CI: 0.01, 0.27). Low relative humidity was negatively associated with respiratory allergies, skin allergies, and total allergic diseases (28 days: OR = 0.26, 95% CI: 0.10, 0.71; OR = 0.29, 95% CI: 0.15, 0.55; and OR = 0.42, 95% CI: 0.26, 0.68). Meanwhile, extreme high relative humidity was negatively associated with respiratory allergies, and positively associated with skin allergies, food allergies, and total allergies (28 days: OR = 0.16, 95%CI: 0.07, 0.37; OR = 3.60, 95% CI: 2.52, 5.14; OR = 15.61, 95% CI: 3.23, 75.56; and OR = 2.33, 95% CI: 1.73, 3.15). A stronger relationship between temperature, relative humidity, and allergic diseases was observed in children under 5 years, specifically girls. Conclusions Our study provides evidence that temperature and relative humidity variability may be associated with allergic diseases, however, the directionality of the relationship differs by allergic type.
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- 2024
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10. The equations of coffee Brixter index: the boosting of sugar concentration in post-harvest by using low temperature, low relative humidity
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Jitjaroen, Wanphen, Kongngoen, Rungtiwa, and Panjai, Lachinee
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- 2024
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11. Cracks propagation mechanism of intergranular corrosion in Al–Cu–Li AA2195 alloys governed by constant relative humidity
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Jingxin Zhao, Zhenhua Dan, Hui Chang, and Lian Zhou
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Al-Cu-Li AA2195 alloys ,Constant relative humidity ,Thin electrolyte layers ,Secondary precipitated phase ,Intergranular corrosion crack propagation ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Atmospheric corrosion of Al–Cu–Li AA2195 alloys was investigated in constant relative humidity (RH) controlled by saturated salt solutions. Corrosion process was governed by RH, especially for the transformation of corrosion products and crack growth. The deceleration corrosion kinetics and maximum pit depth were found to be in accordance with the power laws. The corrosion products gradually transformed from γ-Al(OH)3 and γ-AlOOH into NaAlCO3(OH)2 and γ-Al(OH)3 affected by RH and exposure time. The localized formation of pitting, filiform and exfoliation corrosion was induced by the presence of Cu/Mg/Li-containing secondary precipitates, including T1(Al2CuLi), θ'(Al2Cu) and S'(Al2CuMg) phases. Secondary precipitates with lower potential were prone to triggering intergranular corrosion. The primary cracks penetrated into the internal matrix along large angular grain boundaires. Secondary cracks propagated along corrosion channels of the stress-concentrated triple grain boundaries with higher schimd factors, larger Kernel average misorientation and higher geometrically necessary dislocation densities. A crack propagation mechanism controlled by RH was proposed.
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- 2024
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12. Investigation of the effect of relative humidity on micro lime consolidation of degraded earthen structures
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Renjian Zeng and Gesa Schwantes
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Consolidation effect ,Earthen structures ,Relative humidity ,Micro lime ,Lime clay interaction ,Fine Arts ,Analytical chemistry ,QD71-142 - Abstract
Abstract Micro lime, hydrated lime (Ca (OH)2) with particle sizes of 1-3μ dispersed in isopropanol, can be used to reinforce deteriorated earthen structures. The consolidation effect depends on the amount of moisture present in the structure or in the ambient air. This study investigates the influence of different levels of relative humidity (RH) on the consolidation effect of micro lime on earthen structures, the chemical processes responsible for the consolidation and the physical changes to the structure. The aim is to gain a deeper understanding of the underlying chemical reactions and to identify a potential limit to the applicability of this consolidation method in low RH environments. The fact that many of these sites are located in arid climates greatly influences the practical application of micro lime in the conservation of historical earthen structures. To characterize the consolidation effect of micro lime, unconfined compressive strength and exposure to wet and dry cycles were used. The properties of the reaction products and the bonding between soil particles and micro lime were investigated using thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). At RH levels of 25%, 45%, 65% and 90%, the unconfined compressive strength (UCS) and the modulus of deformation at 50% strength (E50) of the micro lime-reinforced specimens demonstrated an increase with humidity. This led to a significant improvement in their ability to resist the effects of dry–wet cycles. Results from thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) indicate that micro lime interacts with the soil matrix via carbonation, with the reaction rate increasing with humidity. At 25% RH, vaterite was produced and residual free lime was observed, whereas at humidity levels of 45% and above, the reaction yielded vaterite and aragonite. The lime treatment did not significantly alter the pore structure of the soil specimens. The total porosity of the specimens was only slightly reduced, with the main effect of the lime treatment being a reduction in the number of large pores.
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- 2024
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13. Unraveling the spatiotemporal dynamics of relative humidity in major Saudi Arabian cities: A synergy of climate modeling, regression analysis, and wavelet coherence
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Al-Ramadan, Baqer, Aldosary, Adel S., Kafy, Abdulla Al, Alsulamy, Saleh, and Rahaman, Zullyadini A.
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- 2024
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14. Variability in Donor Lung Culture and Relative Humidity Impact the Stability of 2009 Pandemic H1N1 Influenza Virus on Nonporous Surfaces.
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Qian, Zhihong, Morris, Dylan, Avery, Annika, Kormuth, Karen, Le Sage, Valerie, Myerburg, Michael, Lloyd-Smith, James, Marr, Linsey, and Lakdawala, Seema
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fomite ,influenza virus ,relative humidity ,stability ,surface material ,Humans ,Influenza A Virus ,H1N1 Subtype ,Influenza ,Human ,Humidity ,Copper ,Influenza A virus ,Plastics ,Lung - Abstract
Respiratory viruses can be transmitted by multiple modes, including contaminated surfaces, commonly referred to as fomites. Efficient fomite transmission requires that a virus remain infectious on a given surface material over a wide range of environmental conditions, including different relative humidities. Prior work examining the stability of influenza viruses on surfaces has relied upon virus grown in media or eggs, which does not mimic the composition of virus-containing droplets expelled from the human respiratory tract. In this study, we examined the stability of the 2009 pandemic H1N1 (H1N1pdm09) virus on a variety of nonporous surface materials at four different humidities. Importantly, we used virus grown in primary human bronchial epithelial cell (HBE) cultures from different donors to recapitulate the physiological microenvironment of expelled viruses. We observed rapid inactivation of H1N1pdm09 on copper under all experimental conditions. In contrast to copper, viruses were stable on polystyrene plastic, stainless steel, aluminum, and glass, at multiple relative humidities, but greater decay on acrylonitrile butadiene styrene (ABS) plastic was observed at short time points. However, the half-lives of viruses at 23% relative humidity were similar among noncopper surfaces and ranged from 4.5 to 5.9 h. Assessment of H1N1pdm09 longevity on nonporous surfaces revealed that virus persistence was governed more by differences among HBE culture donors than by surface material. Our findings highlight the potential role of an individuals respiratory fluid on viral persistence and could help explain heterogeneity in transmission dynamics. IMPORTANCE Seasonal epidemics and sporadic pandemics of influenza cause a large public health burden. Although influenza viruses disseminate through the environment in respiratory secretions expelled from infected individuals, they can also be transmitted by contaminated surfaces where virus-laden expulsions can be deposited. Understanding virus stability on surfaces within the indoor environment is critical to assessing influenza transmission risk. We found that influenza virus stability is affected by the host respiratory secretion in which the virus is expelled, the surface material on which the droplet lands, and the ambient relative humidity of the environment. Influenza viruses can remain infectious on many common surfaces for prolonged periods, with half-lives of 4.5 to 5.9 h. These data imply that influenza viruses are persistent in indoor environments in biologically relevant matrices. Decontamination and engineering controls should be used to mitigate influenza virus transmission.
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- 2023
15. Determination of daily relative humidity estimation patterns in various climates and months in Iran
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Farzandi, Mahboobeh and Seyyed Nezhad Golkhatmi, Nafiseh
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- 2023
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16. Relative Humidity Modulates the Physicochemical Processing of Secondary Brown Carbon Formation from Nighttime Oxidation of Furan and Pyrrole.
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Chen, Kunpeng, Hamilton, Caitlin, Ries, Bradley, Lum, Michael, Mayorga, Raphael, Tian, Linhui, Bahreini, Roya, Zhang, Haofei, and Lin, Ying-Hsuan
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Light-absorbing secondary organic aerosols (SOAs), also known as secondary brown carbon (BrC), are major components of wildfire smoke that can have a significant impact on the climate system; however, how environmental factors such as relative humidity (RH) influence their formation is not fully understood, especially for heterocyclic precursors. We conducted chamber experiments to investigate secondary BrC formation from the nighttime oxidation of furan and pyrrole, two primary heterocyclic precursors in wildfires, in the presence of pre-existing particles at RH < 20% and ∼ 50%. Our findings revealed that increasing RH significantly affected the size distribution dynamics of both SOAs, with pyrrole SOA showing a stronger potential to generate ultrafine particles via intensive nucleation processes. Higher RH led to increased mass fractions of oxygenated compounds in both SOAs, suggesting enhanced gas-phase and/or multiphase oxidation under humid conditions. Moreover, higher RH reduced the mass absorption coefficients of both BrC, contrasting with those from homocyclic precursors, due to the formation of non-absorbing high-molecular-weight oxygenated compounds and the decreasing mass fractions of molecular chromophores. Overall, our findings demonstrate the unique RH dependence of secondary BrC formation from heterocyclic precursors, which may critically modulate the radiative effects of wildfire smoke on climate change.
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- 2024
17. Lifetime of vertical giant soap films: role of the relative humidity and film dimensions
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Pasquet, Marina, Boulogne, François, Restagno, Frédéric, and Rio, Emmanuelle
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Condensed Matter - Soft Condensed Matter ,Physics - Fluid Dynamics - Abstract
We consider the lifetime of rectangular vertical soap films and we explore the influence of relative humidity and both dimensions on the stability of large soap films, reaching heights of up to 1.2 m. Using an automated rupture detection system, we achieve a robust statistical measurement of their lifetimes and we also measure the film thinning dynamics. We demonstrate that drainage has a negligible impact on the film stability as opposed to evaporation. To do so, we compare the measured lifetimes with predictions from the Boulogne \& Dollet model \cite{BoulogneDollet2018}, originally designed to describe the convective evaporation of hydrogels. Interestingly, we show that this model can predict a maximum film lifetime for all sizes.
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- 2024
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18. A Method for Predicting Wear Behaviours of Roller Linear Guides Under the Influence of the Relative Humidity and Ambient Temperature
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Hung-Van Pham and Huyen-Nguyen Thi Ngoc
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wear of roller linear guides ,tribology in roller linear guideways ,relative humidity ,tropical monsoon climate ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
The wear of roller linear guides (RLG) has a direct impact on the tooling precision of CNC machine tool. Wear depends on working conditions: load P, speed V, work environment which includes relative humidity RH and ambient temperature T. In this paper the mathematical regression function describes the relationship between the wear amount U of RLG with the three factors P, RH and T built on the basis of experimental research. The results show that the wear regression function U has an exponential form, which is consistent with experiments about the influence of climatic environment. It describes the simultaneous impact of three factors P, RH, T that affect wear of CNC machine tool rolling guide. With Vietnam's hot and humid environmental conditions, relative humidity RH% = 51 - 99%, temperature T = 15 - 450C, and load P = 2 - 6kgf, the influence on rolling guide wear of normal load P is 2 times the humidity RH% and about 3.8 times that of temperature T. Therefore, it is possible to predict the change in wear amount according to two environmental factors when loading P at certain values.
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- 2024
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19. Effects of high temperature and high relative humidity drying on moisture distribution, starch microstructure and cooking characteristics of extruded whole buckwheat noodles
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Linghan Meng, Xuyang Sun, Yan Zhang, and Xiaozhi Tang
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Extruded whole buckwheat noodle ,High temperature and high relative humidity drying ,Moisture distribution ,Starch microstructure ,Cooking characteristics ,Food processing and manufacture ,TP368-456 - Abstract
ABSTRACT: Drying is a key step in starch noodle production. The effects of high temperature (60, 70, 80°C) and high relative humidity (65%, 75%, 85%) drying (HTHD) on the moisture distribution, starch microstructure and cooking characteristics of extruded whole buckwheat noodles were investigated. Compared to the conventional hot-air drying (CHAD) at 40°C, the increase in drying temperature (60–80°C) and the decrease in relative humidity (85%–65%) significantly improved drying efficiency of the extruded noodles. By adjusting drying temperature and relative humidity, the rate of moisture migration in noodles and phase transition of starch could be appropriately controlled. The optimum drying parameters (T70H75, 70°C drying temperature and 75% relative humidity) showed smooth and dense network structure, resulting in the lowest cooking loss (6.61%), broken rate (0%), highest hardness (1 695.17 g) and springiness (0.92). However, the total flavonoid content (TFC) and the total phenolic content (TPC) reduced by 6.81%–28.50% and 7.19%–53.23% in contrast to CHAD, and the color of buckwheat noodles became darker through HTHD. These findings showed the potential of HTHD for increasing drying efficiency and improving buckwheat noodle quality. The appropriate drying parameters could maintain a balanced relationship between moisture migration in noodles and phase transition of starch, which resulted in better cooking quality for extruded whole buckwheat noodles. Such a study is valuable for regulating the process conditions of buckwheat-based foods and promoting its commercial utilization.
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- 2024
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20. Hybrid noise reduction-based data-driven modeling of relative humidity in Khulna, Bangladesh
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Shuvendu Pal Shuvo, Joarder MdAshikuzzaman, Shirshendu Pal Shibazee, Goutam Paul, Pritam Banerjee, Kazi Mashfiq Fahmid, and Ashiqur Rahman
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Relative humidity ,Empirical mode decomposition (EMD) and support vector machine (SVM) ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
In this study, a hybrid Machine Learning (ML) approach is proposed for Relative Humidity (RH) prediction with a combination of Empirical Mode Decomposition (EMD) to improve the prediction accuracy over the traditional prediction technique using a Machine Learning (ML) algorithm called Support Vector Machine (SVM). The main objective of proposing this hybrid technique is to deal with the extremely nonlinear and noisy humidity pattern in Khulna, Bangladesh, which is experiencing rapid urbanization and environmental change. To develop the model, data on temperature, relative humidity, rainfall, and wind speed were collected from the Bangladesh Meteorological Department (BMD), and the data was divided into three phases: 70 % of the historical dataset as training data for the model, 15 % of the data set as the validation phase, and the remaining 15 % of the data set as the test phase of the model. Employing the Particle Swarm Optimization (PSO) algorithm, the SVM model determines its best hypermeters within this research. In the present research, performance analysis is carried out utilizing the Mean Square Error (MSE), Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE) and Coefficient of Determination (R2). Results show that the increase in R2 values resulting from the EMD-based approach is significant: 21.05 % in H1(Traditional model), 19.48 % in H2 (Traditional model), 76.92 % in H3 (Traditional model), 55.93 % in H4 (Traditional model), and 64.29 % in H5 (Traditional model) and H6 (Traditional model). The analytical results show that the proposed EMD-based technique efficiently filters and processes noisy, highly nonlinear humidity data during prediction in the Khulna region. It is recommended that this technique could be applied to other geological areas.
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- 2024
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21. Novel Nafion nanocomposite membranes embedded with TiO2-decorated MWCNTs for high-temperature/low relative humidity fuel cell systems
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Nicotera, Isabella, Coppola, Luigi, and Simari, Cataldo
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- 2024
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22. Joint multifractal analysis of air temperature, relative humidity and reference evapotranspiration in the middle zone of the Guadalquivir river valley
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Ariza-Villaverde, A. B., Pavon-Dominguez, P., Carmona-Cabezas, R., de Rave, E. Gutierrez, and Jimenez-Hornero, F. J.
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Physics - Atmospheric and Oceanic Physics - Abstract
Previous works have analysed the relationship existing between reference evapotranspiration (ET0) and other climatic variables under a one-at-a-time perturbation condition. However, due to the physical relationships between these climatic variables is advisable to study their joint influence on ET0. The box-counting joint multifractal algorithm describes the relations between variables using relevant information extracted from the data singularities. This work investigated the use of this algorithm to describe the simultaneous behaviour of ET0, calculated by means of Penman-Monteith (PM) equation, and relative humidity (RH) and air temperature (T), influencing on it in the middle zone of the Guadalquivir river valley, Andalusia, southern Spain. The studied cases were grouped according to the fractal dimension values, which were related to their probability of occurrence. The most likely cases were linked to smooth behaviour and weak dependence between variables, both circumstances were detected in the local multifractal analysis. For these cases, the rest of Penman Monteith (PM) equation variables, neither the T nor the RH, seemed to influence on ET0 determination, especially when low T values were involved. By contrast, the least frequent cases were those with variables showing high fluctuations and strong relationship between them. In these situations, when T is low, the ET0 is affected by the rest of PM equation variables. This fact confirmed T as main driver of ET0 because the higher T values the lesser influence of other climate variables on ET0. Joint multifractal analysis shows some limitations when it is applied to large number of variables, the results reported are promising and suggest the convenience of exploring the relationships between ET0 and other climatic variables not considered here with this framework such as wind speed and net radiation., Comment: 40 pages, 10 figures
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- 2023
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23. Measuring relative humidity from evaporation with a wet-bulb thermometer: the psychrometer
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Corpart, Marie, Restagno, Frédéric, and Boulogne, François
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Physics - Physics Education - Abstract
Measuring the relative humidity of air is an important challenge for meteorological measurements, food conservation, building design, and evaporation control, among other applications. Relative humidity can be measured with a psychrometer, which is a hygrometer composed of two identical thermometers. The bulb of one thermometer is covered by a wick soaked with water so that evaporative cooling makes it indicate a lower temperature than the dry-bulb thermometer; it is possible to determine the relative humidity from the difference between these readings. We describe both a model and an experimental setup to illustrate the principle of a psychrometer for a pedagogical laboratory. The science of psychrometry could be more broadly taught at the undergraduate level to help introduce students to aspects of measurement techniques, fluid mechanics, heat transfer, and non-equilibrium thermodynamics.
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- 2023
24. Expanding Mars Climate Modeling: Interpretable Machine Learning for Modeling MSL Relative Humidity
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Abdelmoneim, Nour, Dhuri, Dattaraj B., Atri, Dimitra, and Martínez, Germán
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Astrophysics - Earth and Planetary Astrophysics ,Astrophysics - Instrumentation and Methods for Astrophysics ,Computer Science - Machine Learning - Abstract
For the past several decades, numerous attempts have been made to model the climate of Mars with extensive studies focusing on the planet's dynamics and the understanding of its climate. While physical modeling and data assimilation approaches have made significant progress, uncertainties persist in comprehensively capturing and modeling the complexities of Martian climate. In this work, we propose a novel approach to Martian climate modeling by leveraging machine learning techniques that have shown remarkable success in Earth climate modeling. Our study presents a deep neural network designed to accurately model relative humidity in Gale Crater, as measured by NASA's Mars Science Laboratory ``Curiosity'' rover. By utilizing simulated meteorological variables produced by the Mars Planetary Climate Model, a robust Global Circulation Model, our model accurately predicts relative humidity with a mean error of 3\% and an $R^2$ score of 0.92. Furthermore, we present an approach to predict quantile ranges of relative humidity, catering to applications that require a range of values. To address the challenge of interpretability associated with machine learning models, we utilize an interpretable model architecture and conduct an in-depth analysis of its internal mechanisms and decision making processes. We find that our neural network can effectively model relative humidity at Gale crater using a few meteorological variables, with the monthly mean surface H$_2$O layer, planetary boundary layer height, convective wind speed, and solar zenith angle being the primary contributors to the model predictions. In addition to providing a fast and efficient method to modeling climate variables on Mars, this modeling approach can also be used to expand on current datasets by filling spatial and temporal gaps in observations., Comment: 13 pages, 7 figures
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- 2023
25. Interaction between ambient CO and temperature or relative humidity on the risk of stroke hospitalization
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Liu, Zhuo, Meng, Hua, Wang, Xingtian, Lu, Wenwen, Ma, Xiaojuan, Geng, Yuhui, Su, Xinya, Pan, Dongfeng, and Liang, Peifeng
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- 2024
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26. What Controls Near‐Surface Relative Humidity Over the Ocean?
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Callum J. Shakespeare and Michael L. Roderick
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relative humidity ,climate ,ocean ,convection ,theory ,Physical geography ,GB3-5030 ,Oceanography ,GC1-1581 - Abstract
Abstract Observations and models show that near‐surface relative humidity is nearly constant at ∼80% over the ocean in the current climate, and almost invariant in the global mean in projected future climates. Here, this behavior is investigated through the development of a simple theoretical model for near‐surface relative humidity by considering the moisture balance above a uniform ocean surface. The relative humidity is predicted to depend on only the near‐surface wind speed, air‐surface temperature difference, surface wetness and large‐scale moisture convergence. Although developed in the context of moist over‐ocean convection, the theory is able to determine the relative humidity in a suite of idealized simulations over both wet and dry surfaces with a root‐mean‐square error of less than 3%. The theory also predicts the climatology of relative humidity over the ocean with a root‐mean‐square error of less than 3%. The theory thus provides a theoretical basis for investigating changes in relative humidity over the ocean, water vapor feedbacks and the water cycle in current and future climates.
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- 2024
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27. Integrated drying model of lychee as a function of temperature and relative humidity
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Shafaet Ahmed, Md Salatul Islam Mozumder, Wahidu Zzaman, Md Yasin, and Shuvo Das
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Drying kinetics ,Mathematical model ,Relative humidity ,Temperature ,Moisture ratio ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Drying is a universal method applied for food preservation. To date, several models have been developed to evaluate drying kinetics. In this study, lychee was dried employing a hot air dryer, and the drying kinetics was evaluated by comparing the Newtonian model, Henderson and Pabis model, Page model, and Logarithmic model. However, temperature and relative humidity, the key driving forces for drying kinetics, are not considered by these models. Thus, an integrated drying model, as a function of temperature and relative humidity, was developed to predict the hot air-drying kinetics and mass transfer phenomena of lychee followed by the calibration and validation of the model with independent experimental datasets. The model validation consisted of Nash- Sutcliffe model coefficient (E), coefficient of determination (R2) and index of agreement (d) and all of them were found close to 1 indicating perfect model fit. Besides, the developed model was applied for process optimization and scenario analysis. The drying rate constant was found as a function of temperature and relative humidity that was high at high temperature and low relative humidity. Interestingly, temperature showed a higher effect on the drying rate constant compared to relative humidity. Overall, the present study will open a new window to developing further drying model of lychee to optimize quality its quality parameters.
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- 2024
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28. Relative humidity over ice as a key variable for Northern Hemisphere midlatitude tropopause inversion layers
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D. Köhler, P. Reutter, and P. Spichtinger
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Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The tropopause inversion layer (TIL) is a prominent feature of the midlatitude tropopause region, constituting a transport barrier. Adiabatic and diabatic processes might contribute to the formation and sharpening of the inversion. For both types of processes, relative humidity over ice is ideal for attribution; from theory and former model case studies, we expect enhanced relative humidity values with a sharp TIL. We use high-resolution radiosonde and ERA5 reanalysis data to show very good qualitative and quantitative agreement in terms of TIL features; thus, coarser ERA5 data can be used for further investigations. Next, we investigate the connection between TIL features and relative humidity measures in both radiosonde and ERA5 data, revealing a clear relationship. Moister profiles, on average, exhibit significantly higher maximum values of the Brunt–Väisälä frequency (N2), indicating a more stable stratification of the tropopause in these cases. This result holds true in both radiosonde measurements and ERA5 data. For TIL thickness, an inverse pattern emerges: moister, more stable TILs exhibit lower thickness. Because of the good agreement between radiosonde and ERA5 data, we use ERA5 data for seasonal and regional investigations. These analyses reveal consistent TIL properties in various midlatitude regions of the Northern Hemisphere under different meteorological conditions. However, differences in the strength of the dependence of TIL properties on relative humidity over ice are evident between the different regions.
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- 2024
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29. Light- and Relative Humidity-Regulated Hypersensitive Cell Death and Plant Immunity in Chinese Cabbage Leaves by a Non-adapted Bacteria Xanthomonas campestris pv. vesicatoria
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Young Hee Lee, Yun-Hee Kim, and Jeum Kyu Hong
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chinese cabbage ,environmental changes ,hypersensitive cell death ,non-host plant immunity ,pathovar ,Plant culture ,SB1-1110 - Abstract
Inoculation of Chinese cabbage leaves with high titer (107 cfu/ml) of the non-adapted bacteria Xanthomonas campestris pv. vesicatoria (Xcv) strain Bv5-4a.1 triggered rapid leaf tissue collapses and hypersensitive cell death (HCD) at 24 h. Electrolyte leakage and lipid peroxidation markedly increased in the Xcv-inoculated leaves. Defence-related gene expressions (BrPR1, BrPR4, BrChi1, BrGST1 and BrAPX1) were preferentially activated in the Xcv-inoculated leaves. The Xcv-triggered HCD was attenuated by continuous light but accelerated by a dark environment, and the prolonged high relative humidity also alleviated the HCD. Constant dark and increased relative humidity provided favorable conditions for the Xcv bacterial growth in the leaves. Pretreated fluridone (biosynthetic inhibitor of endogenous abscisic acid [ABA]) increased the HCD in the Xcv-inoculated leaves, but exogenous ABA attenuated the HCD. The pretreated ABA also reduced the Xcv bacterial growth in the leaves. These results highlight that the onset of HCD in Chinese cabbage leaves initiated by non-adapted pathogen Xcv Bv5-4a.1 and in planta bacterial growth was differently modulated by internal and external conditional changes.
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- 2024
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30. Interaction between ambient CO and temperature or relative humidity on the risk of stroke hospitalization
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Zhuo Liu, Hua Meng, Xingtian Wang, Wenwen Lu, Xiaojuan Ma, Yuhui Geng, Xinya Su, Dongfeng Pan, and Peifeng Liang
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Ambient CO ,Meteorological factors ,Stroke ,Short-term effects ,Interaction ,Medicine ,Science - Abstract
Abstract Although the independent effects of ambient CO, temperature or humidity on stroke have been confirmed, it is still unclear where there is an interaction between these factors and who is sensitive populations for these. The stroke hospitalization and ambient CO, temperature, humidity data were collected in 22 Counties and districts of Ningxia, China in 2014–2019. The lagged effect of ambient CO, temperature or humidity were analyze by the generalized additive model; the interaction were evaluated by the bivariate response surface model and stratified analysis with relative excessive risk (RERI). High temperature and CO levels had synergistic effects on hemorrhagic stroke (RERI = 0.05, 95% CI 0.033–0.086) and ischemic stroke (RERI = 0.035, 95% CI 0.006–0.08). Low relative humidity and CO were synergistic in hemorrhagic stroke (RERI = 0.192, 95% CI 0.184–0.205) and only in ischemic stroke in the elderly group (RERI = 0.056, 95% CI 0.025–0.085). High relative humidity and CO exhibited antagonistic effects on the risk of ischemic stroke hospitalization in both male and female groups (RERI = − 0.088, 95% CI − 0.151to − 0.031; RERI = − 0.144, 95% CI − 0.216 to − 0.197). Exposure to CO increases the risk of hospitalization related to hemorrhagic and ischemic strokes. CO and temperature or humidity interact with risk of stroke hospitalization with sex and age differences.
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- 2024
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31. Effects of temperature, relative humidity, and illumination on the entomological parameters of Aedes albopictus: an experimental study
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Cai, Xiaoshuang, Zhao, Jianguo, Deng, Hui, Xiao, Jianpeng, Liu, Tao, Zeng, Weilin, Li, Xing, Hu, Jianxiong, Huang, Cunrui, Zhu, Guanghu, and Ma, Wenjun
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- 2023
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32. Relative humidity driven nocturnal HONO formation mechanism in autumn haze events of Beijing
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Xuan, Huiying, Liu, Jun, Zhao, Yaqi, Cao, Qing, Chen, Tianzeng, Wang, Yonghong, Liu, Zirui, Sun, Xu, Li, Hao, Zhang, Peng, Chu, Biwu, Ma, Qingxin, and He, Hong
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- 2024
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33. Optimization and establishment of laboratory rearing conditions for Cimex lectularius L. against variable temperature and relative humidity
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Banerjee, Amartya, Saha, Achintya, Das, Parikshit, Kakati, Ajay, Saha, Buddhadeb, Goyary, Danswrang, Bhutia, Yangchen D., Karmakar, Sanjeev, Kishor, Sumit, Rahaman, Saidur, and Chattopadhyay, Pronobesh
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- 2024
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34. Relative-Humidity Dependence of Electrochemically Active Surface Area in Porous Carbon Catalyst Layers
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Chowdhury, Anamika, Radke, Clayton J, and Weber, Adam Z
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Engineering ,Materials Engineering ,Macromolecular and Materials Chemistry ,Physical Chemistry (incl. Structural) ,Energy ,Physical chemistry ,Materials engineering - Abstract
Polymer-electrolyte fuel cells (PEFCs) utilize porous catalyst layers (CLs) formed of carbon supports on which Pt particles are deposited and ionomer films are distributed. Carbon supports themselves have varying degrees of porosity, where high-surface-area carbon (HSC) supports possess nanometer-sized interior pores that are suitable for Pt nanoparticle deposition but prevent deleterious ionomer penetration. However, this requires protons to transport through water pathways inside the pores. To understand the generation of such pathways, we examine the various mechanisms of water uptake by PEFC CLs, and the subsequent impact of water uptake on Pt utilization through developing a multiphysics model of the water wetting phenomena as a function of relative humidity. The model details water uptake via ionomer absorption, capillary condensation in the hydrophilic pores, and surface adsorption using molecular potential that account for various water and surface dipole interactions. The results quantify how mesoporous carbons with highly hydrophilic pores increase Pt utilization through the development of wetted layers, which at the same time enable optimized gas-transport pathways. It also demonstrates the impact of pore-size distribution (PSD) and physical and chemical parameters on the water uptake phenomena, allowing for future CL particle and structure optimization.
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- 2023
35. Influence of Relative Humidity on the Structure of Complex Fluid Drops during Drying
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Choudhury, Moutushi Dutta, Aggarwal, Nupur, and Kumar, Naveen
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- 2024
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36. Relative humidity driven nocturnal HONO formation mechanism in autumn haze events of Beijing
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Huiying Xuan, Jun Liu, Yaqi Zhao, Qing Cao, Tianzeng Chen, Yonghong Wang, Zirui Liu, Xu Sun, Hao Li, Peng Zhang, Biwu Chu, Qingxin Ma, and Hong He
- Subjects
Environmental sciences ,GE1-350 ,Meteorology. Climatology ,QC851-999 - Abstract
Abstract Nitrous acid (HONO), a key precursor of hydroxyl radicals (OH), is one of the factors affecting atmospheric chemistry and air quality. Currently, the proposed sources of HONO are not able to fully explain observed HONO concentrations. In this study, a comprehensive field observation of HONO was conducted in the autumn of 2021 in urban Beijing. The box model using a default Master Chemical Mechanism (MCM) was unable to reproduce the observed HONO concentrations with a normalized mean bias (NMB) of −92.8%. The NMB improved to −46.1% after the inclusion of seven additional HONO formation pathways. Several factors like vehicle emission factor (1.23%) and nocturnal NO2 heterogeneous uptake coefficient on the ground surface (8.25 × 10−6) were calculated based on observational data. The enhancement factor for nocturnal NO2 heterogeneous conversion was established as a function of relative humidity (RH) and incorporated into the model, which compensated for the missing nocturnal HONO sources and well-reproduced the observed HONO concentrations, with an NMB of −5.1%. The major source of HONO at night was found to be the heterogeneous reaction of NO2 on the ground surface, contributing up to 85.6%. During the daytime, it was the homogeneous reaction of NO with OH, accounting for 41.8%. The daytime primary source of OH was mainly the photolysis of HONO, which constituted 73.6% and therefore promoted the formation of secondary pollutants and exacerbated haze events.
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- 2024
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37. Influence of the Ambient Relative Humidity on the Very-Long-Term DEF
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Thierry Houndonougbo, Boumediene Nedjar, Loic Divet, and Jean-Michel Torrenti
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concrete ,delayed ettringite formation ,relative humidity ,modelling ,Building construction ,TH1-9745 - Abstract
Relative humidity is a key parameter for the development of delayed ettringite formation (DEF). Here, new results of very-long-term experiments (10 years) are presented. It is observed that for a relative humidity of 96%, swelling could occur after several years but with a slower kinetics. A model coupling the kinetics of swelling with the internal relative humidity is presented. It is shown that this model can reproduce the experimental behavior.
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- 2023
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38. Big data analytics for relative humidity time series forecasting based on the LSTM network and ELM
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Kurnianingsih Kurnianingsih, Anindya Wirasatriya, Lutfan Lazuardi, Adi Wibowo, I Ketut Agung Enriko, Wei Hong Chin, and Naoyuki Kubota
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big data analytics ,relative humidity ,time series forecasting ,lstm ,elm ,Electronic computers. Computer science ,QA75.5-76.95 - Abstract
Accurate and reliable relative humidity forecasting is important when evaluating the impacts of climate change on humans and ecosystems. However, the complex interactions among geophysical parameters are challenging and may result in inaccurate weather forecasting. This study combines long short-term memory (LSTM) and extreme learning machines (ELM) to create a hybrid model-based forecasting technique to predict relative humidity to improve the accuracy of forecasts. Detailed experiments with univariate and multivariate problems were conducted, and the results show that LSTM-ELM and ELM-LSTM have the lowest MAE and RMSE results compared to stand-alone LSTM and ELM for the univariate problem. In addition, LSTM-ELM and ELM-LSTM result in lower computation time than stand-alone LSTM. The experiment results demonstrate that the proposed hybrid models outperform the comparative methods in relative humidity forecasting. We employed the recursive feature elimination (RFE) method and showed that dewpoint temperature, temperature, and wind speed are the factors that most affect relative humidity. A higher dewpoint temperature indicates more air moisture, equating to high relative humidity. Humidity levels also rise as the temperature rises.
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- 2023
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39. Design of a Long-term Monitoring Device to Measure Groundwater Temperature and Relative Humidity in the South Bandung Basin Rim
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CAHYADI Willy Anugrah, MUKHTAR Husneni, SUSANTO Kusnahadi, and FAHMI Adhi Muhammad
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soil water sensor ,temperature ,relative humidity ,groundwater ,hydrology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
One of the methods to investigate the possibility of landslides is to observe the water infiltration rate into the soil by measuring the soil's temperature and humidity at several soil depths below the soil surface. Monitoring those variables provides valuable information for assessing groundwater conditions and preventing natural disasters. However, no specifically developed system can monitor those variables in the field until this study is reported. This research focuses on establishing a hardware system for monitoring the soil's temperature and humidity using an array of sensors for hydrological monitoring. Due to extreme weather and limited data transmission networks, employing monitoring systems in harsh environments presents a significant challenge. This investigation involved the monitoring system in monitoring soil temperature and moisture at Mount Malabar. The system comprises an SHT20 sensor array, a microcomputer serving as the central unit and data recorder, a data transmission module, and cloud-based long-term data storage. SHT20 sensors are a fully calibrated type with a temperature accuracy of 99.99%, while relative humidity accuracy ranges from ±3 to ±5. This research has successfully demonstrated soil temperature and relative humidity measurements at depths ranging from 0 cm to 30 cm below the soil surface with a spacing of 5 cm. Monitoring data was continuously tested every 10 minutes and showed the system's reliability and durability for at least three months.
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- 2023
40. Influence of Ambient Relative Humidity on the Shrinkage Strain of Engineered Geopolymer Composites Based on Orthogonal Experimental Design
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Hongyin Wang, Yuelong Zheng, and Zhenyun Yu
- Subjects
engineered geopolymer composites ,orthogonal experiment ,key variables ,relative humidity ,drying shrinkage strain ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
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.
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- 2024
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41. Distribution Characteristics and Prediction of Temperature and Relative Humidity in a South China Greenhouse
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Xinyu Wei, Bin Li, Huazhong Lu, Jiaming Guo, Zhaojie Dong, Fengxi Yang, Enli Lü, and Yanhua Liu
- Subjects
temperature ,relative humidity ,ventilation ,cooling efficiency ,Venlo greenhouse ,Agriculture - Abstract
South China has a climate characteristic of high temperature and high humidity, and the temperature and relative humidity inside a Venlo greenhouse are higher than those in the atmosphere. This paper studied the effect of ventilation conditions on the spatial and temporal distribution of temperature and relative humidity in a Venlo greenhouse. Two ventilation conditions, with and without a fan-pad system, were studied. A GA + BP neural network was applied to predict the temperature and relative humidity in fan-pad ventilation in the greenhouse. The results show that the temperature in the Venlo greenhouse ranged from 15.8 °C to 48.5 °C, and the relative humidity ranged from 24.9% to 100% during the tomato-planting cycle. The percentage of days when the temperature exceeded 35 °C was 67.3%, and the percentage of days when the average relative humidity exceeded 70% was 83.7%. The maximum temperature differences between the three heights under NV (Natural Ventilation) and FPV (Fan-pad Ventilation) conditions were 3.4 °C and 4.5 °C, respectively. The maximum relative humidity differences between the three heights under NV and FPV conditions were 8.4% and 21.7%, respectively. The maximum temperature difference in the longitudinal section under the FPV conditions was 3.2 °C, while the relative humidity was 11.4%. The cooling efficiency of the fan-pad system ranged from 16.6% to 70.2%. The non-uniform coefficients of the temperature under the FPV conditions were higher than those under the NV conditions, while the nonuniform coefficients of the relative humidity were the highest during the day. The R2, MAE, MAPE and RMSE of the temperature-testing model were 0.91, 0.94, 0.11, and 1.33, respectively, while those of relative humidity model were 0.93, 2.83, 0.10, and 3.86, respectively. The results provide a reference for the design and management of Venlo greenhouses in South China.
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- 2024
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42. Effect of Superabsorbent Polymers and Presoaked Coarse Recycled Shale Lightweight Aggregates on Relative Humidity Development in Early-Age Concrete
- Author
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Nan Hu, Dongkang Hu, Shujun Ben, Shuo Chen, and Haitao Zhao
- Subjects
synergistic effect ,relative humidity development ,early-age concrete ,superabsorbent polymer (SAP) ,recycled shale lightweight aggregate (RSLA) ,Building construction ,TH1-9745 - Abstract
Self-desiccation-induced shrinkage may result in cracking at an early age, which is averse to the durability of concrete. Internal curing (IC) agents, such as superabsorbent polymers (SAP), are normally used for moisture regulation and shrinkage reduction. In addition, the make-up of recycled shale lightweight aggregate (RSLA) results in a good absorbing capacity, which makes it a potential candidate for IC. In this paper, the synergistic effect of SAP and RSLA on the relative humidity (RH) variation in early-age concrete under sealed conditions is investigated experimentally in terms of the setting time, relative humidity, and autogenous shrinkage. The results indicate that adding SAP and presoaked RSLA can significantly postpone the initial and final setting times. The initial setting time of RSLA30 and SAP06 is delayed by 127 and 171 min, respectively, compared to the benchmark mixture. In addition, increasing the amounts of SAP and presoaked RSLA can effectively extend the duration of the vapour-saturated stage, reducing the decrease in RH and autogenous shrinkage at 28 days. When the RSLA dosage increases from 0 to 10%, 20%, and 30%, the duration of the vapour-saturated stage is extended by 2, 9.4, and 26 days, respectively. Moreover, due to different water desorption behaviours, more IC water released by RSLA during the initial stage can slow the water release of SAP and lead to a higher RH level at 28 days.
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- 2024
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43. Online Monitoring of the Temperature and Relative Humidity of Recycled Bedding for Dairy Cows on Dairy Farms
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Yong Wei, Kun Liu, Yaao Li, Zhixing Li, Tianyu Zhao, Pengfei Zhao, Yayin Qi, Meiying Li, and Zongyuan Wang
- Subjects
stacking fermentation ,recycled bedding ,temperature and relative humidity ,online monitoring ,Fermentation industries. Beverages. Alcohol ,TP500-660 - Abstract
In large-scale dairy farming, the use of high-temperature-fermented dairy manure bedding instead of rice husk-based bedding and other commercial types of bedding is widely favored. Strip-stacking aerobic fermentation is the main production method of dairy manure bedding, but it has problems including unstable fermentation and the secondary breeding of pathogens. In this work, a multi-probe, integrated, online monitoring system for temperature and relative humidity was used for fermentation process optimization. The effects of the temporal and spatial distribution of fermentation temperature and relative humidity on the nutrient content curve and the moisture and ash content of manure bedding materials were systematically studied. The effect of the fermentation process on the retention rate of effective bedding materials (cellulose, hemicellulose, and lignin) was analyzed. The experiments proved that high-quality bedding material can be obtained through reasonable stacking fermentation. The fabricated bedding material has a total dry base content consisting of cellulose, hemicellulose, and lignin of 78%, an ash content of 6%, and a nutrient content of 17%. The obtained bedding material was produced to increase the bed rest rate and continuously inhibit the bedding bacteria content, keeping it at a low level for 5 days. This study proves that temperature and humidity monitoring can guide the optimization of the strip-stacking fermentation process of dairy manure and that it can be applied to large-scale farms to improve fermentation parameters.
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- 2024
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44. Strong dependency of the tribological behavior of CuZr-based bulk metallic glasses on relative humidity in ambient air
- Author
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Barlemont, Solène, Laffont, Paul, Daudin, Rémi, Lenain, Alexis, Colas, Guillaume, and Cornuault, Pierre-Henri
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- 2023
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45. Influence of Incubation Temperature and Relative Humidity on the Egg Hatchability Pattern of Two-Spotted (Gryllus bimaculatus) and House (Acheta domesticus) Crickets
- Author
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Jamlong Mitchaothai, Rachakris Lertpatarakomol, Tassanee Trairatapiwan, and Achara Lukkananukool
- Subjects
incubation temperature ,relative humidity ,egg hatchability pattern ,two-spotted cricket (Gryllus bimaculatus) ,house cricket (Acheta domesticus) ,Veterinary medicine ,SF600-1100 ,Zoology ,QL1-991 - Abstract
This study aimed to determine the influence and optimal conditions of incubation temperature and relative humidity (RH) on the egg hatchability patterns of two-spotted (Gryllus bimaculatus) and house (Acheta domesticus) crickets. Experiment I involved 100 cricket eggs per hatching box for each species, with six replications for each controlled incubation temperature of 23, 25, 27, 29, 30, 31, 32, and 33 °C at 70% RH. Experiment II used all the same procedures as Experiment I, except for incubation temperatures of 29, 30, 31, and 32 °C tested with varied RH levels of 65%, 70%, and 75%. In Experiment I, two-spotted crickets (9.47 ± 1.99 days) exhibited faster hatching than house crickets (13.70 ± 2.78 days). Additionally, the onset of hatching decreased with higher incubation temperatures for both types of crickets. In Experiment II, an incubation temperature of 31 °C and 70% RH resulted in a hatching rate of 79.75% for two-spotted crickets, with hatching beginning in 6 days. For house cricket eggs, the optimal conditions of 30 °C and 65–75% RH led to a peak daily hatching rate of 62.00–65.50% and hatching onset in 12 days. Thus, this study established the optimal incubation temperature and RH for egg hatching of two-spotted and house crickets.
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- 2024
- Full Text
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46. Optical Lossy-mode-resonance Relative Humidity Sensor on a Fiber Tip
- Author
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Ren, Yundong, Li, Mucheng, and Liu, Yuxiang
- Subjects
Physics - Instrumentation and Detectors ,Physics - Optics - Abstract
Real-time measurement of relative humidity (RH) is important to many physical, chemical, and biological processes. However, in processes that involve harsh conditions such as high temperatures, strong electromagnetic interferences, and complex spatial constraints, conventional electrical sensors often fall short due to their intrinsic limitations. Here, we developed an optical lossy-mode-resonance (LMR) RH sensor based on the SnO2 film coated D-shaped fiber tip. Thanks to the high-temperature endurance and electromagnetic interference immunity, the developed optical fiber-tip sensor is ideal for RH sensing in critical environments, such as in the microwave drying process. Furthermore, unlike other reported in-line LMR sensors, our sensor is located at the D-shaped fiber tip with a probe-like form factor, allowing it to be readily implemented in a spatially confined environment. We have developed a custom fabrication setup for the novel D-shaped LMR fiber-tip sensor. The LMR signal from the sensor was experimentally characterized. The lossy mode resonances are understood by the finite element analysis, the results of which agree well with the experimental measurements. The fiber-tip sensor had a linear RH response between 6.1% to 75.0% and a resolution better than 4.0% RH. The fiber-tip sensor demonstrated a response time and reversibility comparable to that of commercial electrical sensors. The novel D-shaped fiber-tip LMR RH sensor developed in this work will benefit many applications that require RH monitoring in a harsh environment. Furthermore, our innovative D-shaped fiber tip design can be readily applied to LMR-based fiber sensors in general. This will allow the design's advantages of small footprint and agile maneuverability to benefit a wide range of LMR fiber sensing applications beyond RH sensing., Comment: 9 pages, 5 figures
- Published
- 2023
47. Relative humidity predominantly determines long‐term biocrust‐forming lichen cover in drylands under climate change
- Author
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Shurong Zhou, Baldauf, Selina, Porada, Philipp, Maestre, Fernando T., Tietjen, Britta, Raggio Quílez, José, Shurong Zhou, Baldauf, Selina, Porada, Philipp, Maestre, Fernando T., Tietjen, Britta, and Raggio Quílez, José
- Abstract
Manipulative experiments typically show a decrease in dryland biocrust cover and altered species composition under climate change. Biocrust-forming lichens, such as the globally distributed Diploschistes diacapsis, are particularly affected and show a decrease in cover with simulated climate change. However, the underlying mechanisms are not fully understood, and long-term interacting effects of different drivers are largely unknown due to the short-term nature of the experimental studies conducted so far. We addressed this gap and successfully parameterised a process-based model for D. diacapsis to quantify how changing atmospheric CO2, temperature, rainfall amount and relative humidity affect its photosynthetic activity and cover. We also mimicked a long-term manipulative climate change experiment to understand the mechanisms underlying observed patterns in the field. The model reproduced observed experimental findings: warming reduced lichen cover, whereas less rainfall had no effect on lichen performance. This warming effect was caused by the associated decrease in relative humidity and non-rainfall water inputs, which are major water sources for biocrust-forming lichens. Warming alone, however, increased cover because higher temperatures promoted photosynthesis during early morning hours with high lichen activity. When combined, climate variables showed non-additive effects on lichen cover, and effects of increased CO2 levelled off with decreasing levels of relative humidity. Synthesis. Our results show that a decrease in relative humidity, rather than an increase in temperature, may be the key factor for the survival of the lichen D. diacapsis under climate change and that effects of increased CO2 levels might be offset by a reduction in non-rainfall water inputs in the future. Because of a global trend towards warmer and drier air and the widespread global distribution of D. diacapsis, this will affect lichen-dominated dryland biocrust communities an, European Research Council, Ministerio de Economía y Competitividad, Depto. de Farmacología, Farmacognosia y Botánica, Fac. de Farmacia, TRUE, pub
- Published
- 2024
48. Fabrication and Implementation of PVA Thin Film-based Relative Humidity Sensor
- Author
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Al-haddar, Mohammed Taha Omar, Sin, Yew-Keong, Al-haddar, Mohammed Taha Omar, and Sin, Yew-Keong
- Abstract
This paper presents the fabrication of polyvinyl alcohol (PVA)-based relative humidity sensors using copper interdigitated electrodes (IDEs). These sensors were fabricated by patterning copper IDEs onto FR4 fiberglass substrates and coating them with a thin film of PVA. By varying the number of IDE electrode pairs and the concentration of PVA, the sensors exhibited different resistance values, demonstrating an inverse relationship with the number of IDE electrodes and PVA concentration. Additionally, the thickness of the sensing layer, controlled by spin coating speed, affected the resistance of the sensors. The fabricated sensors achieved a humidity measurement range from 50% to 99% RH based on resistance changes. Furthermore, an interface circuit was designed to integrate the fabricated sensors with an ESP8266 microcontroller, achieving accurate measurements above 74% RH.
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- 2024
49. Control of Stability and Relative Humidity in the Radiative‐Convective Equilibrium Model Intercomparison Project
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Allison A. Wing and Martin S. Singh
- Subjects
radiative‐convective equilibrium ,stability ,relative humidity ,convective available potential energy ,entrainment ,precipitation efficiency ,Physical geography ,GB3-5030 ,Oceanography ,GC1-1581 - Abstract
Abstract The Radiative‐Convective Equilibrium Model Intercomparison Project (RCEMIP) exhibits a large spread in the simulated climate across models, including in profiles of buoyancy and relative humidity. Here we use simple theory to understand the control of stability, relative humidity, and their responses to warming. Across the RCEMIP ensemble, temperature profiles are systematically cooler than a moist adiabat, and convective available potential energy (CAPE) increases with warming at a rate greater than that expected from the Clausius‐Clapeyron relation. There is higher CAPE (greater instability) in models that are on average moister in the lower‐troposphere. To more explicitly evaluate the drivers of the intermodel spread, we use simple theory to estimate values of entrainment and precipitation efficiency (PE) given the simulated values of CAPE and lower‐tropospheric relative humidity. We then decompose the intermodel spread in CAPE and relative humidity (and their responses to warming) into contributions from variability in entrainment, PE, the temperature of the convecting top, and the inverse water vapor scale height. Model‐to‐model variation in entrainment is a dominant source of intermodel spread in CAPE and its changes with warming, while variation in PE is the dominant source of intermodel spread in relative humidity. We also decompose the magnitude of the CAPE increase with warming and find that atmospheric warming itself contributes most strongly to the CAPE increase, but the indirect effect of increases in the water vapor scale height with warming also contribute to increasing CAPE beyond that expected from Clausius‐Clapeyron.
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- 2024
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50. Teachers’ Health Status About Air Quality (Temperature, Relative Humidity, and Ventilation) in Educational Centers: A Systematic Review
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Farideh Golbabaei, Mohammad Javad SheikhMozafari, Jamal Biganeh, and Soqrat Omari Shekaftik
- Subjects
systematic review ,teacher ,temperature ,relative humidity ,ventilation ,health ,Environmental pollution ,TD172-193.5 - Abstract
Introduction: Studies have demonstrated that teaching carries a substantial burden of health risks. Prevalent health issues among teachers include asthma, respiratory diseases, musculoskeletal problems, and mental disorders. These problems can be attributed to the specific attributes of their work environment. Consequently, this study aims to investigate the correlation between air quality within educational establishments and the overall health of teachers. Material and Methods: This systematic review aims to examine the impact of temperature, humidity, and ventilation rates within educational environments on teachers’ health status and thermal comfort. Relevant studies were searched for using the PubMed and Web of Science databases, employing keywords such as teacher, temperature, humidity, ventilation, school, classroom, health symptoms, and thermal comfort (2000-2022). The inclusion criterion was that articles examined teachers’ health and comfort with temperature, relative humidity, and ventilation of the educational place. Results: Out of the 103 articles found in the initial search, 13 articles were finally reviewed. Six studies investigated the voice abnormalities of teachers due to various factors (including temperature, relative humidity, and the ventilation rate of the educational place) and found that these abnormalities were affected by these factors. Two studies explored the relationship between the prevalence and exacerbation of respiratory symptoms and quality parameters of the indoor environment of educational places. Additionally, five studies investigated the relationship of air quality parameters of educational places with common non-specific symptoms among teachers. Conclusion: Teachers frequently experience symptoms such as voice disorders, respiratory difficulties, allergies, and other nonspecific ailments, which may be associated with the quality parameters of the indoor environment in educational settings. These parameters include temperature, humidity, and ventilation rate. Consequently, controlling and regulating these parameters within the recommended values can help prevent the onset or exacerbation of these symptoms.
- Published
- 2023
Catalog
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