Proficiency testing of temperature and relative humidity in clean environments: evaluation of inspection and testing organizations in china

Estudaram-se a ingestão de alimentos e de água e a ruminação em vacas primíparas e multíparas da raça Holandesa, com alta produção de leite, criadas em sistema de confinamento do tipo free stall, em diferentes combinações de temperatura ambiente e umidade relativa do ar. Foram realizadas três coletas de dados nos meses de verão e três nos de inverno, todas elas com duração de 24 horas. As atividades de alimentação e ruminação foram monitoradas em intervalos de 15 minutos e a de ingestão de água, continuamente ao longo das 24 horas. A temperatura ambiente e a umidade relativa do ar foram observadas em intervalos de uma hora. O binômio temperatura ambiente/umidade do ar alteraram significativamente (P<0,05) o padrão de alimentação de vacas e novilhas nas coletas de verão, período de alimentação esperado de 6h-18h, para o intervalo de 18h-24h. A ruminação foi afetada principalmente pelo padrão diário de alimentação. O padrão de ingestão de água, da mesma forma, variou significativamente (P<0,05) em função do comportamento de alimentação e das condições ambientais (temperatura ambiente e umidade do ar), marcadamente no lote de vacas.

Chemical protection personnel need to wear closed clothing to work in harsh environment. Continuous sweating and outward heat dissipation will lead to high temperature and high humidity inside the chemical protection clothing, which will increase the physical load of chemical protection personnel. In the environment of high temperature and humidity for a long time, the thermoregulation function of chemical prevention personnel is easy to be maladjusted, such as heat stroke, heat spasm, heat failure, etc., which will lead to vague consciousness and even shock. Therefore, accurate monitoring and evaluation of the physical load of chemical protection personnel in high temperature and humidity environment is very important to optimize the operation process and ensure the safety of workers. Firstly, the temperature and humidity of the environment were controlled by simulation experiment, and the core temperature, surface skin temperature, heart rate, blood oxygen, sweating amount and sweat evaporation amount were measured when the chemical protection personnel were wearing chemical protective clothing. The change rules of each index were studied by using statistical analysis method, and the sensitive physical load evaluation index was revealed. Then, the weight coefficient of each index is calculated based on factor analysis method to simplify the independent variable factors of physical load evaluation model. Finally, the regression model of physical load was constructed by combining subjective feelings and physiological indexes. Sixteen healthy men aged 19–25 years participated in the test. The environment temperature and humidity were divided into normal temperature and humidity (23 ℃, 45%), low temperature and high humidity (10 ℃, 70%) and high temperature and humidity (35 ℃ and 60%). The core temperature was measured by anus and Cor-temp capsule temperature sensor. The results showed that the core temperature of chemical prevention personnel in normal temperature and humidity environment was relatively stable, while the core temperature in low temperature and high humidity, normal temperature and high humidity environment increased by 0.74 ℃, 1.03 ℃ and 2 ℃ respectively. There was significant difference in the core temperature of chemical prevention personnel under different temperature and humidity environment (P < 0.05), which proved that the core temperature can be used as a sensitive index to evaluate physical load. The surface skin temperature of shoulder, chest, arm, waist, neck, hand, thigh and lower leg was measured by temperature inspection instrument. The results showed that the surface skin temperature of chemical protection personnel in high temperature and humidity environment increased significantly (up to 39 ℃). There were significant differences in the skin temperature of chemical protection personnel under different temperature and humidity conditions (P < 0.05), indicating that the surface skin temperature can be used as a sensitive index to evaluate physical load. The heart rate data were measured using the ECG band developed by polar team. The results showed that the heart rate of the chemical protection personnel wearing protective clothing was the fastest (up to 180 bpm) in high temperature and humidity environment. There was significant difference in heart rate under different temperature and humidity (P < 0.05), which proved that heart rate can be used as a sensitive index to evaluate physical load. The blood oxygen saturation was measured by finger cuff sensor. The results showed that the oxygen saturation of the chemical protection personnel in the normal temperature and humidity environment was 95%, and the oxygen saturation of the chemical protection personnel wearing protective clothing in the low temperature and high humidity environment, the normal temperature and normal humidity environment and the high temperature and high humidity environment decreased gradually, which were 94%, 93% and 91%, respectively. There was significant difference in blood oxygen saturation among chemical workers under different temperature and humidity (P < 0.05), which proved that blood oxygen saturation could be used as a sensitive index to evaluate physical load. The results showed that the amount of sweat and evaporation increased with the increase of ambient temperature. The average sweating amount was 1.25 kg, accounting for 1.6% of body weight, which reached the limit of human sweating capacity. There were significant differences in the amount of sweat and the amount of sweat evaporation in different temperature and humidity environment (P < 0.05), which proved that the amount of sweat and the amount of sweat evaporation can be used as a sensitive index to evaluate the physical load. The weight coefficient obtained by factor analysis showed that the temperature index was the most important indexes in the evaluation of physical load in high temperature and humidity environment. There are two key factors, core temperature and heart rate, in the stepwise regression equation of physical load established between subjective feelings and sensitive indicators. The fitting degree of the model is as high as 0.917 under the hypothesis test of homogeneity of variance.KeywordsChemical protection personnelPhysical loadEvaluation indexHigh temperature environmentHigh humidity environment

Introduction Many exercise enthusiasts have started participating in sports in the high-temperature environment in recent years due to the increasing popularity of these sports habits. However, their scientific studies still have a gap in their safety and effectiveness. Objective Measure the energy supply characteristics of fat and sugar oxidation during exercise in different high-temperature and humidity environments. Methods 20 healthy adult subjects were exposed to fixed-intensity exercise for 20 minutes at 30-33 oC, 20% relative humidity (RH), and 50% RH, respectively. Results Under the silent exposure condition, compared with RH 20% and RH 50% under high temperature, sugar oxidation was significantly increased (P&lt;0.01), while fat oxidation was significantly reduced (P&lt;0.01), and total energy consumption was significantly increased (P&lt;0.01). Under the condition of 65% VO2 max exercise, compared with RH 20% and RH 50% at high temperatures, the amount of sugar oxidation was significantly reduced (P&lt;0.05), and the total energy consumption was significantly reduced (P&lt;0.05). Conclusion Under 65% exercise under VO2 max in the high temperature and humidity-controlled environment, the high temperature and medium humidity (RH 50%) environment consumes more energy, and there is a greater amount of sugar oxidation. Level of evidence II; Therapeutic studies - investigating treatment outcomes.

BackgroundTemperature and relative humidity (RH) are very important factors affecting embryo development, hatchability, and posthatch performance. This study aimed at characterizing embryonic metabolic and behavioural response to a harsh incubation environment generated by manipulations (elevations and drops) in these two key factors. This study was aimed at establishing patterns of metabolic and behavioural response, as well as mortality and the development of malformations, all of which can potentially be used in monitoring incubating operations and diagnosing problems with faulty equipment.ResultsOf all the parameters monitored throughout embryonic development the ones shown to be most affected were: albumen-weight to egg-weight ratio (AR); yolk-weight to egg-weight ratio (YR); embryo-weight to egg-weight ratio (ER); heart rate (HR); voluntary movements per minute (VMM); mortality rates; malformation prevalence and type.The most significant changes in the evolution of AR and YR throughout incubation involved delay and reduction in the amplitude of the expected drop in albumen and yolk levels, reflecting lower nutrient consumption by the embryo. ER tended to grow more slowly and remain lower than the established normal, especially in embryos challenged with temperature treatments. HR and VMM were considered to be strong indicators of embryonic stress, as all treatments applied resulted in elevated heart rate and decreased embryo movement.Mortality rates for both temperature-related treatments were higher during the first four days of incubation. Changes in relative humidity have produced less radical effects on mortality. Malformation rates were higher for embryos subjected to high incubation temperatures and were most prominently related to the abdominal wall, head, skull and limbs.Overall, manipulations in environmental (incubator) temperature during incubation produced more drastic changes in embryo development than humidity-related manipulations, especially where mortality and malformation rates were concerned.ConclusionsThis paper describes changes in embryonic metabolism and behaviour, as well as in mortality and malformation rates, in response to manipulations in environmental temperature and relative humidity. Together with further studies, these patterns may prove helpful in the diagnosis of equipment malfunctions relating to temperature or relative humidity.

In order to find the optimal environmental temperature and relative humidity (RH) during cigarette making, the relationships of the change rate of long strands proportion, individual cigarette weight, and ratio of loose-end cigarettes with environmental temperature and relative humidity were studied for flue-cured type cigarettes of different classes. The results showed that the cigarettes of Class A, B and C made under 24℃ and RH57%, 25.5℃ and RH60%, and 26.5℃ and RH62%, respectively, possessed the lowest individual weight and loose-end ratio. It is appropriate to set ambient temperature and relative humidity in cigarette making workshop according to the class of the cigarettes being made, possibly, to make cigarettes of different classes in different zones or different periods of time separately where necessary for pursuing better cigarette quality.

Hybrid personal cooling systems (HPCS) incorporated with ventilation fans and phase change materials (PCMs) have shown its superior capability for mitigating workers’ heat strain while performing heavy labor work in hot environments. In a previous study, the effects of thermal resistance of insulation pads, and latent heat and melting temperature of PCMs on the HPCS’s thermal performance have been investigated. In addition to the aforementioned factors, environmental conditions, i.e., ambient temperature and relative humidity, also significantly affect the thermal performance of the HPCS. In this paper, a numerical parametric study was performed to investigate the effects of the environmental temperature and relative humidity (RH) on the thermal management of the HPCS. Five levels of air temperature under RH = 50% (i.e., 32, 34, 36, 38 and 40 °C) and four levels of environmental RH at two ambient temperatures of 36 and 40 °C were selected (i.e., RH = 30, 50, 70 and 90%) for the numerical analysis. Results show that high environmental temperatures could accelerate the PCM melting process and thereby weaken the cooling performance of HPCS. In the moderately hot environment (36 °C), HPCS presented good cooling performance with the maximum core temperature at around 37.5 °C during excise when the ambient RH ≤ 70%, whereas good cooling performance could be only seen under RH ≤ 50% in the extremely hot environment (40 °C). Thus, it may be concluded that the maximum environmental RH under which the HPCS exhibiting good cooling performance decreases with an increase in the environmental temperature.

The main route of transmission of SARS CoV infection is presumed to be respiratory droplets. However the virus is also detectable in other body fluids and excreta. The stability of the virus at different temperatures and relative humidity on smooth surfaces were studied. The dried virus on smooth surfaces retained its viability for over 5 days at temperatures of 22–25°C and relative humidity of 40–50%, that is, typical air-conditioned environments. However, virus viability was rapidly lost (>3 log10) at higher temperatures and higher relative humidity (e.g., 38°C, and relative humidity of >95%). The better stability of SARS coronavirus at low temperature and low humidity environment may facilitate its transmission in community in subtropical area (such as Hong Kong) during the spring and in air-conditioned environments. It may also explain why some Asian countries in tropical area (such as Malaysia, Indonesia or Thailand) with high temperature and high relative humidity environment did not have major community outbreaks of SARS.

For modern infrastructures, structural concrete has been widely adopted for various components and structures such as railway stations, platforms, walkways, railway bridges, tunnelling, concrete sleepers, concrete foundation of overhead wiring structures, etc. These infrastructures are subject to various changes of time, operation, and environment. Environmental conditions are a considerably influential factor to life cycle and durability of concrete structures. This study aims at identifying the influence of climate change on the performance and durability of concrete structures using statistical regression analysis of a number of pertinent experimental and field data. The study into the influence of elevated temperature on compressive strength and splitting tensile strength also has been carried out using experimental data on the basis of environmental temperature and relative humidity, as well as CO2 concentration to the concrete carbonation and steel corrosion rates. The results indicate that environmental temperature, CO2 concentration, and a certain range of relative humidity play an important role in the concrete carbonation rates. Temperature and relative humidity affect the rate of steel corrosion as well. In addition, it is found that there exists a nearly direct correlation between the environmental temperature and the concrete carbonation rates, as well as the corrosion rate of steel embedded in concrete from 25 °C to 60 °C, and a nearly inverse proportion between the environmental relative humidity and the concrete carbonization from 48.75% to 105%. Indeed, the results exhibit that even in extreme natural high temperature, the capacity of compressive strength and splitting tensile strength is not affected significantly.

This paper presents the laboratory experimental results in relation to tangent force between a wheel and a rail under different environmental conditions. In the experiments, we used two types of cylindrical test specimens (with / without fine unevenness on contact surface) assuming actual wheels, and investigated the relation of tangent force to the cases of with / without fine unevenness on contact surface under the conditions of different environmental temperature and relative humidity. Consequently, under the conditions of without fine unevenness on the contact surface of a test specimen, it showed that there is a tendency in the tangent force which turned out low whence relative humidity is over 60%, regardless of environmental temperature. However, on the conditions which have fine unevenness on the contact surface of a test specimen, we could not observe the effect of environmental temperature and relative humidity on the tangent force. In addition, running stability analysis of railway vehicle was carried out for the cases of with / without fine unevenness on wheel tread of railway vehicle under the condition of different relative humidity. As a result, it was shown that the critical hunting velocity under the condition of without fine unevenness becomes low while increasing relative humidity.

A study was conducted to investigate the influence of temperature and relative humidity (RH) on the bond strengths of several recently developed dentin bonding systems. Six environmental conditions, (A) 25+/-0.5 degrees C, 50+/-5% RH, (B) 25+/-0.5 degrees C, 80+/-5% RH, (C) 25+/-0.5 degrees C, 95+/-5 % RH, (D) 37+/-0.5 degrees C, 50 +/-5 % RH, (E) 37+/-0.5 degrees C, 80+/-5% RH, (F) 37+/-0.5 degrees C, 95+/-5 % RH were used. Bovine mandibular incisors were mounted in self-curing resin and the facial surfaces were ground on wet #600 SiC paper to expose the dentin. After the tooth surface had been treated according to each manufacturer's instructions, adhesives were applied, followed by condensation of resin composites into a mold placed on the dentin surface. Fifteen specimens per group were stored in distilled water at 37 degrees C for 24 h, and then shear-tested at a cross-head speed of 1.0 mm/min. Statistical analysis was carried out with two-way ANOVA followed by Tukey's test (P<0.05). Dentin bond strengths decreased with increasing relative humidity but were not influenced by environmental temperature. Even though one-bottle adhesive systems require a wet dentin surface, their bond strengths are affected by an increase in environmental humidity.

The coupled action of concrete carbonation and repeated loading strongly influences the safety of reinforced concrete (RC) structures and substantially reduces service life. A novel corrosion-fatigue life prediction model for RC structures under coupled carbonation and repeated loading was developed. The effect of fatigue damage on concrete carbonation and carbonation-induced corrosion rate was considered, and the acceleration of fatigue damage accumulation due to reinforcement corrosion was considered in this approach. The proposed corrosion-fatigue life prediction model was illustrated by a 6 m-span RC slab in a simply supported slab bridge for the highway, and the effects of traffic frequency, overloading, carbonation environment grade, and environmental temperature and relative humidity on corrosion-fatigue life were discussed. The results indicate that the proposed model can predict the corrosion-fatigue life of RC structures simply and conveniently. Traffic frequency, overloading, carbonation environment grade, and environmental temperature and relative humidity can decrease the corrosion-fatigue life of the RC slab by up to 66.86%, 58.90%, 77.45%, and 44.95%, respectively. The research is expected to provide a framework for the corrosion-fatigue life prediction of RC structures under coupled carbonation and repeated loading.

This paper presents the research on sensitivity characteristics in the packaged 8–10 GHz GaAs MMIC-based inline RF MEMS power sensors under different temperature and humidity environments. In order to achieve inline self-detection systems in RF receivers and transmitters under different operation environments, the effects of the temperature between 5 °–75 ° and the relative humidity between 25%–95% on the linearity and the sensitivity of the packaged power sensors are investigated. Measured results show that the packaged inline power sensors under different temperature and relative humidity maintain the good linearity of the output response at 8–10 GHz. Furthermore, experiments demonstrate that the effects of the temperature on the output thermovoltages and the sensitivity are larger at 8–10 GHz, which result in the 33.3% increase in sensitivity at 10 GHz for the temperature from 5 ° to 75 °. While the effects of the relative humidity on that are smaller at 8–10 GHz, which result in only the 7.9% increase in sensitivity at 10 GHz for the relative humidity from 25% to 95%.

This study examined whether different neurotransmitters are presented at exercise fatigue in different temperature and relative humidity (RH) environments in athletes. Eight trained male athletes performed exercise in five different environmental conditions: 21°C/20% RH (Normal); 33°C/20 % RH (Hot 20%), 33°C/40% RH (Hot 40%), 33°C/60% RH (Hot 60%), and 33°C/80% RH (Hot 80%). Exercise group performed VO2max test in five conditions. Blood samples were taken pre‐ and post‐exercise and analyzed for noradrenaline (NA), adrenaline (Ad), dopamine (DA), serontonin (5‐HT), 5‐hydroxyindoleacetic acid (5‐HIAA), prolactin (PRL). Compare to Normal condition, Hot 20%, Hot 40% and Hot 80% have lower VO2max (P &lt; 0.05). A comparison between the means indicated that in Hot 20%, Hot 40%, Hot 60% and Hot 80% conditions the RPEmax was higher than the Normal condition (P &lt; 0.01 or P &lt; 0.05). There was a significant effect for time in NE (P &lt; 0.0001), PRL (P &lt; 0.0001), 5‐HT (P = 0.002), 5‐HIAA (P = 0.029), DA (P = 0.016) during exercise in different conditions. However, Ad did not show any significant effect between pre and post exercise (P &gt;; 0.05). In different humidity and heat environments, exercise fatigue is determined by the collaboration of the different neurotransmitter systems, with the most important role possibly being for the NE, 5‐HT and DA.This work was supported by Grants from Ministry of Science and Technology of the People's Republic of China (2010–05).

In order to investigate the impact of environmental temperature and atmospheric humidity on the leakage and diffusion of hydrogen fluoride (HF) gas, this study focused on the real scenario of an HF chemical industrial park. Based on the actual dispersion scenario of HF gas, a proportionally scaled-down experimental platform for HF gas leakage was established to validate the accuracy and feasibility of numerical simulations under complex conditions. Using the validated model, the study calculated the complex scenarios of HF leakage and diffusion within the temperature range of 293 K to 313 K and the humidity range of 0% to 100%. The simulation results indicated that different environmental temperatures had a relatively small impact on the hazardous areas (the lethal area, severe injury area, light injury area, and maximum allowable concentration (MAC) area) formed by HF gas leakage. At 600 s of dispersion, the fluctuation range of hazardous area sizes under different temperature conditions was between 3.11% and 13.07%. In contrast to environmental temperature, atmospheric relative humidity had a more significant impact on the dispersion trend of HF leakage. Different relative humidity levels mainly affected the areas of the lethal zone, light injury zone, and MAC zone. When HF continued to leak and disperse for 600 s, compared to 0% relative humidity, 100% relative humidity reduced the lethal area by 35.7%, while increasing the light injury area and MAC area by 27.26% and 111.6%, respectively. The impact on the severe injury area was relatively small, decreasing by 1.68%. The results of this study are crucial for understanding the dispersion patterns of HF gas under different temperature and humidity conditions.

Variability of soybean yield and seed quality depending on environmental hydrothermal factors