Humidity Effects on Fragmentation in Plasma-Based Ambient Ionization Sources

NASA Astrophysics Data System (ADS)

Newsome, G. Asher; Ackerman, Luke K.; Johnson, Kevin J.

2016-01-01

Post-plasma ambient desorption/ionization (ADI) sources are fundamentally dependent on surrounding water vapor to produce protonated analyte ions. There are two reports of humidity effects on ADI spectra. However, it is unclear whether humidity will affect all ADI sources and analytes, and by what mechanism humidity affects spectra. Flowing atmospheric pressure afterglow (FAPA) ionization and direct analysis in real time (DART) mass spectra of various surface-deposited and gas-phase analytes were acquired at ambient temperature and pressure across a range of observed humidity values. A controlled humidity enclosure around the ion source and mass spectrometer inlet was used to create programmed humidity and temperatures. The relative abundance and fragmentation of molecular adduct ions for several compounds consistently varied with changing ambient humidity and also were controlled with the humidity enclosure. For several compounds, increasing humidity decreased protonated molecule and other molecular adduct ion fragmentation in both FAPA and DART spectra. For others, humidity increased fragment ion ratios. The effects of humidity on molecular adduct ion fragmentation were caused by changes in the relative abundances of different reagent protonated water clusters and, thus, a change in the average difference in proton affinity between an analyte and the population of water clusters. Control of humidity in ambient post-plasma ion sources is needed to create spectral stability and reproducibility.

Humidity Effects on Fragmentation in Plasma-Based Ambient Ionization Sources.

PubMed

Newsome, G Asher; Ackerman, Luke K; Johnson, Kevin J

2016-01-01

Post-plasma ambient desorption/ionization (ADI) sources are fundamentally dependent on surrounding water vapor to produce protonated analyte ions. There are two reports of humidity effects on ADI spectra. However, it is unclear whether humidity will affect all ADI sources and analytes, and by what mechanism humidity affects spectra. Flowing atmospheric pressure afterglow (FAPA) ionization and direct analysis in real time (DART) mass spectra of various surface-deposited and gas-phase analytes were acquired at ambient temperature and pressure across a range of observed humidity values. A controlled humidity enclosure around the ion source and mass spectrometer inlet was used to create programmed humidity and temperatures. The relative abundance and fragmentation of molecular adduct ions for several compounds consistently varied with changing ambient humidity and also were controlled with the humidity enclosure. For several compounds, increasing humidity decreased protonated molecule and other molecular adduct ion fragmentation in both FAPA and DART spectra. For others, humidity increased fragment ion ratios. The effects of humidity on molecular adduct ion fragmentation were caused by changes in the relative abundances of different reagent protonated water clusters and, thus, a change in the average difference in proton affinity between an analyte and the population of water clusters. Control of humidity in ambient post-plasma ion sources is needed to create spectral stability and reproducibility.

Research on Environmental Adjustment of Cloud Ranch Based on BP Neural Network PID Control

NASA Astrophysics Data System (ADS)

Ren, Jinzhi; Xiang, Wei; Zhao, Lin; Wu, Jianbo; Huang, Lianzhen; Tu, Qinggang; Zhao, Heming

2018-01-01

In order to make the intelligent ranch management mode replace the traditional artificial one gradually, this paper proposes a pasture environment control system based on cloud server, and puts forward the PID control algorithm based on BP neural network to control temperature and humidity better in the pasture environment. First, to model the temperature and humidity (controlled object) of the pasture, we can get the transfer function. Then the traditional PID control algorithm and the PID one based on BP neural network are applied to the transfer function. The obtained step tracking curves can be seen that the PID controller based on BP neural network has obvious superiority in adjusting time and error, etc. This algorithm, calculating reasonable control parameters of the temperature and humidity to control environment, can be better used in the cloud service platform.

3. DETAIL OF RACKS AND TEMPERATURE/HUMIDITY CONTROL SYSTEM IN CURING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. DETAIL OF RACKS AND TEMPERATURE/HUMIDITY CONTROL SYSTEM IN CURING ROOM ON LEVEL 6; LOOKING SOUTHEAST; ENVIRONMENT INSIDE THE CURING ROOM WAS CONTROLLED BY NIAGARA MODEL 87007 SPRAY COOLER AND BUFFALO FORGE CENTRIFUGAL FAN IN BACKGROUND - Rath Packing Company, Cooler Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

Comparative Transcriptomic Analysis in Paddy Rice under Storage and Identification of Differentially Regulated Genes in Response to High Temperature and Humidity.

PubMed

Zhao, Chanjuan; Xie, Junqi; Li, Li; Cao, Chongjiang

2017-09-20

The transcriptomes of paddy rice in response to high temperature and humidity were studied using a high-throughput RNA sequencing approach. Effects of high temperature and humidity on the sucrose and starch contents and α/β-amylase activity were also investigated. Results showed that 6876 differentially expressed genes (DEGs) were identified in paddy rice under high temperature and humidity storage. Importantly, 12 DEGs that were downregulated fell into the "starch and sucrose pathway". The quantitative real-time polymerase chain reaction assays indicated that expression of these 12 DEGs was significantly decreased, which was in parallel with the reduced level of enzyme activities and the contents of sucrose and starch in paddy rice stored at high temperature and humidity conditions compared to the control group. Taken together, high temperature and humidity influence the quality of paddy rice at least partially by downregulating the expression of genes encoding sucrose transferases and hydrolases, which might result in the decrease of starch and sucrose contents.

An intelligent FFR with a self-adjustable ventilation fan.

PubMed

Zhou, Song; Li, Hui; Shen, Shengnan; Li, Siyu; Wang, Wei; Zhang, Xiaotie; Yang, James

2017-11-01

This article presents an intelligent Filtering Facepiece Respirator (FFR) with a self-adjustable ventilation fan for improved comfort. The ventilation fan with an intelligent control aims to reduce temperature, relative humidity, and CO 2 concentrations inside the facepiece. Compared with a previous version of the FFR, the advantage of this new FFR is the intelligent control of the fan's rotation speed based on the change in temperature and relative humidity in the FFR dead space. The design of the control system utilizes an 8-bit, ultra-low power STC15W404AS microcontroller (HongJin technology, Shenzhen, China), and adopts a high-precision AM2320 device (AoSong electronic, Guangzhou, China) as temperature and relative humidity sensor so that control of temperature and relative humidity is realized in real time within the FFR dead space. The ventilation fan is intelligently driven and runs on a rechargeable lithium battery with a power-save mode that provides a correspondingly longer operational time. Meanwhile, the design is simplistic. Two experiments were performed to determine the best location to place the fan.

International Space Station Environmental Control and Life Support System Acceptance Testing for Node 1 Temperature and Humidity Control Subsystem

NASA Technical Reports Server (NTRS)

Williams, David E.

2011-01-01

The International Space Station (ISS) Node 1 Environmental Control and Life Support (ECLS) System is comprised of five subsystems: Atmosphere Control and Storage (ACS), Atmosphere Revitalization (AR), Fire Detection and Suppression (FDS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). This paper will provide a summary of the Node 1 ECLS THC subsystem design and a detailed discussion of the ISS ECLS Acceptance Testing methodology utilized for this subsystem.The International Space Station (ISS) Node 1 Environmental Control and Life Support (ECLS) System is comprised of five subsystems: Atmosphere Control and Storage (ACS), Atmosphere Revitalization (AR), Fire Detection and Suppression (FDS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). This paper will provide a summary of the Node 1 ECLS THC subsystem design and a detailed discussion of the ISS ECLS Acceptance Testing methodology utilized for this subsystem.

Effects of Temperature and Relative Humidity on DNA Methylation

PubMed Central

Bind, Marie-Abele; Zanobetti, Antonella; Gasparrini, Antonio; Peters, Annette; Coull, Brent; Baccarelli, Andrea; Tarantini, Letizia; Koutrakis, Petros; Vokonas, Pantel; Schwartz, Joel

2014-01-01

Background Previous studies have found relationships between DNA methylation and various environmental contaminant exposures. Associations with weather have not been examined. Because temperature and humidity are related to mortality even on non-extreme days, we hypothesized that temperature and relative humidity may affect methylation. Methods We repeatedly measured methylation on long interspersed nuclear elements (LINE-1), Alu, and 9 candidate genes in blood samples from 777 elderly men participating in the normative aging Study (1999–2009). We assessed whether ambient temperature and relative humidity are related to methylation on LINE-1 and Alu, as well as on genes controlling coagulation, inflammation, cortisol, DNA repair, and metabolic pathway. We examined intermediate-term associations of temperature, relative humidity, and their interaction with methylation, using distributed lag models. Results Temperature or relative humidity levels were associated with methylation on tissue factor (F3), intercellular adhesion molecule 1 (ICAM-1), toll-like receptor 2 (TRL-2), carnitine O-acetyltransferase (CRAT), interferon gamma (IFN-γ), inducible nitric oxide synthase (iNOS), and glucocorticoid receptor, LINE-1, and Alu. For instance, a 5°c increase in 3-week average temperature in ICAM-1 methylation was associated with a 9% increase (95% confidence interval: 3% to 15%), whereas a 10% increase in 3-week average relative humidity was associated with a 5% decrease (−8% to −1%). The relative humidity association with ICAM-1 methylation was stronger on hot days than mild days. Conclusions DNA methylation in blood cells may reflect biological effects of temperature and relative humidity. Temperature and relative humidity may also interact to produce stronger effects. PMID:24809956

Effects of temperature and relative humidity on DNA methylation.

PubMed

Bind, Marie-Abele; Zanobetti, Antonella; Gasparrini, Antonio; Peters, Annette; Coull, Brent; Baccarelli, Andrea; Tarantini, Letizia; Koutrakis, Petros; Vokonas, Pantel; Schwartz, Joel

2014-07-01

Previous studies have found relationships between DNA methylation and various environmental contaminant exposures. Associations with weather have not been examined. Because temperature and humidity are related to mortality even on non-extreme days, we hypothesized that temperature and relative humidity may affect methylation. We repeatedly measured methylation on long interspersed nuclear elements (LINE-1), Alu, and 9 candidate genes in blood samples from 777 elderly men participating in the Normative Aging Study (1999-2009). We assessed whether ambient temperature and relative humidity are related to methylation on LINE-1 and Alu, as well as on genes controlling coagulation, inflammation, cortisol, DNA repair, and metabolic pathway. We examined intermediate-term associations of temperature, relative humidity, and their interaction with methylation, using distributed lag models. Temperature or relative humidity levels were associated with methylation on tissue factor (F3), intercellular adhesion molecule 1 (ICAM-1), toll-like receptor 2 (TRL-2), carnitine O-acetyltransferase (CRAT), interferon gamma (IFN-γ), inducible nitric oxide synthase (iNOS), and glucocorticoid receptor, LINE-1, and Alu. For instance, a 5°C increase in 3-week average temperature in ICAM-1 methylation was associated with a 9% increase (95% confidence interval: 3% to 15%), whereas a 10% increase in 3-week average relative humidity was associated with a 5% decrease (-8% to -1%). The relative humidity association with ICAM-1 methylation was stronger on hot days than mild days. DNA methylation in blood cells may reflect biological effects of temperature and relative humidity. Temperature and relative humidity may also interact to produce stronger effects.

Modeling and Designing of A Nonlineartemperature-Humidity Controller Using Inmushroom-Drying Machine

NASA Astrophysics Data System (ADS)

Wu, Xiuhua; Luo, Haiyan; Shi, Minhui

Drying-process of many kinds of farm produce in a close room, such as mushroom-drying machine, is generally a complicated nonlinear and timedelay cause, in which the temperature and the humidity are the main controlled elements. The accurate controlling of the temperature and humidity is always an interesting problem. It's difficult and very important to make a more accurate mathematical model about the varying of the two. A math model was put forward after considering many aspects and analyzing the actual working circumstance in this paper. Form the model it can be seen that the changes of temperature and humidity in drying machine are not simple linear but an affine nonlinear process. Controlling the process exactly is the key that influences the quality of the dried mushroom. In this paper, the differential geometry theories and methods are used to analyze and solve the model of these smallenvironment elements. And at last a kind of nonlinear controller which satisfied the optimal quadratic performance index is designed. It can be proved more feasible and practical than the conventional controlling.

Chicken barn climate and hazardous volatile compounds control using simple linear regression and PID

NASA Astrophysics Data System (ADS)

Abdullah, A. H.; Bakar, M. A. A.; Shukor, S. A. A.; Saad, F. S. A.; Kamis, M. S.; Mustafa, M. H.; Khalid, N. S.

2016-07-01

The hazardous volatile compounds from chicken manure in chicken barn are potentially to be a health threat to the farm animals and workers. Ammonia (NH3) and hydrogen sulphide (H2S) produced in chicken barn are influenced by climate changes. The Electronic Nose (e-nose) is used for the barn's air, temperature and humidity data sampling. Simple Linear Regression is used to identify the correlation between temperature-humidity, humidity-ammonia and ammonia-hydrogen sulphide. MATLAB Simulink software was used for the sample data analysis using PID controller. Results shows that the performance of PID controller using the Ziegler-Nichols technique can improve the system controller to control climate in chicken barn.

Application for temperature and humidity monitoring of data center environment

NASA Astrophysics Data System (ADS)

Albert, Ş.; Truşcǎ, M. R. C.; Soran, M. L.

2015-12-01

The technology and computer science registered a large development in the last years. Most systems that use high technologies require special working conditions. The monitoring and the controlling are very important. The temperature and the humidity are important parameters in the operation of computer systems, industrial and research, maintaining it between certain values to ensure their proper functioning being important. Usually, the temperature is maintained in the established range using an air conditioning system, but the humidity is affected. In the present work we developed an application based on a board with own firmware called "AVR_NET_IO" using a microcontroller ATmega32 type for temperature and humidity monitoring in Data Center of INCDTIM. On this board, temperature sensors were connected to measure the temperature in different points of the Data Center and outside of this. Humidity monitoring is performed using data from integrated sensors of the air conditioning system, thus achieving a correlation between humidity and temperature variation. It was developed a software application (CM-1) together with the hardware, which allows temperature monitoring and register inside Data Center and trigger an alarm when variations are greater with 3°C than established limits of the temperature.

Environmental chamber for in situ dynamic control of temperature and relative humidity during x-ray scattering

NASA Astrophysics Data System (ADS)

Salas-de la Cruz, David; Denis, Jeffrey G.; Griffith, Matthew D.; King, Daniel R.; Heiney, Paul A.; Winey, Karen I.

2012-02-01

We have designed, constructed, and evaluated an environmental chamber that has in situ dynamic control of temperature (25 to 90 °C) and relative humidity (0% to 95%). The compact specimen chamber is designed for x-ray scattering in transmission with an escape angle of 2θ = ±30°. The specimen chamber is compatible with a completely evacuated system such as the Rigaku PSAXS system, in which the specimen chamber is placed inside a larger evacuated chamber (flight path). It is also compatible with x-ray systems consisting of evacuated flight tubes separated by small air gaps for sample placement. When attached to a linear motor (vertical displacement), the environmental chamber can access multiple sample positions. The temperature and relative humidity inside the specimen chamber are controlled by passing a mixture of dry and saturated gas through the chamber and by heating the chamber walls. Alternatively, the chamber can be used to control the gaseous environment without humidity. To illustrate the value of this apparatus, we have probed morphology transformations in Nafion® membranes and a polymerized ionic liquid as a function of relative humidity in nitrogen.

Apparatus and method to control atmospheric water vapor composition and concentration during dynamic cooling of biological tissues in conjunction with laser irradiations

DOEpatents

Nelson, J. Stuart; Anvari, Bahman; Tanenbaum, B. Samuel; Milner, Thomas E.

1999-01-01

Cryogen spray cooling of skin surface with millisecond cryogen spurts is an effective method for establishing a controlled temperature distribution in tissue and protecting the epidermis from nonspecific thermal injury during laser mediated dermatological procedures. Control of humidity level, spraying distance and cryogen boiling point is material to the resulting surface temperature. Decreasing the ambient humidity level results in less ice formation on the skin surface without altering the surface temperature during the cryogen spurt. For a particular delivery nozzle, increasing the spraying distance to 85 millimeters lowers the surface temperature. The methodology comprises establishing a controlled humidity level in the theater of operation of the irradiation site of the biological tissues before and/or during the cryogenic spray cooling of the biological tissue. At cold temperatures calibration was achieved by mounting a thermistor on a thermoelectric cooler. The thermal electric cooler was cooled from from 20.degree. C. to about -20.degree. C. while measuring its infrared emission.

Analysis of Heat Stress and the Indoor Climate Control Requirements for Movable Refuge Chambers

PubMed Central

Hao, Xiaoli; Guo, Chenxin; Lin, Yaolin; Wang, Haiqiao; Liu, Heqing

2016-01-01

Movable refuge chambers are a new kind of rescue device for underground mining, which is believed to have a potential positive impact on reducing the rate of fatalities. It is likely to be hot and humid inside a movable refuge chamber due to the metabolism of trapped miners, heat generated by equipment and heat transferred from outside. To investigate the heat stress experienced by miners trapped in a movable refuge chamber, the predicted heat strain (PHS) model was used to simulate the heat transfer process between the person and the thermal environment. The variations of heat stress with the temperature and humidity inside the refuge chamber were analyzed. The effects of air temperature outside the refuge chamber and the overall heat transfer coefficient of the refuge chamber shell on the heat stress inside the refuge chamber was also investigated. The relationship between the limit of exposure duration and the air temperature and humidity was numerically analyzed to determine the upper limits of temperature and humidity inside a refuge chamber. Air temperature of 32 °C and relative humidity of 70% are recommended as the design standard for internal thermal environment control of movable refuge chambers. PMID:27213422

Analysis of Heat Stress and the Indoor Climate Control Requirements for Movable Refuge Chambers.

PubMed

Hao, Xiaoli; Guo, Chenxin; Lin, Yaolin; Wang, Haiqiao; Liu, Heqing

2016-05-20

Movable refuge chambers are a new kind of rescue device for underground mining, which is believed to have a potential positive impact on reducing the rate of fatalities. It is likely to be hot and humid inside a movable refuge chamber due to the metabolism of trapped miners, heat generated by equipment and heat transferred from outside. To investigate the heat stress experienced by miners trapped in a movable refuge chamber, the predicted heat strain (PHS) model was used to simulate the heat transfer process between the person and the thermal environment. The variations of heat stress with the temperature and humidity inside the refuge chamber were analyzed. The effects of air temperature outside the refuge chamber and the overall heat transfer coefficient of the refuge chamber shell on the heat stress inside the refuge chamber was also investigated. The relationship between the limit of exposure duration and the air temperature and humidity was numerically analyzed to determine the upper limits of temperature and humidity inside a refuge chamber. Air temperature of 32 °C and relative humidity of 70% are recommended as the design standard for internal thermal environment control of movable refuge chambers.

Humidity May Modify the Relationship between Temperature and Cardiovascular Mortality in Zhejiang Province, China

PubMed Central

Zeng, Jie; Zhang, Xuehai; Yang, Jun; Bao, Junzhe; Dear, Keith; Liu, Qiyong; Lin, Shao; Lin, Aihua; Huang, Cunrui

2017-01-01

Background: The evidence of increased mortality attributable to extreme temperatures is widely characterized in climate-health studies. However, few of these studies have examined the role of humidity on temperature-mortality association. We investigated the joint effect between temperature and humidity on cardiovascular disease (CVD) mortality in Zhejiang Province, China. Methods: We collected data on daily meteorological and CVD mortality from 11 cities in Zhejiang Province during 2010–2013. We first applied time-series Poisson regression analysis within the framework of distributed lag non-linear models to estimate the city-specific effect of temperature and humidity on CVD mortality, after controlling for temporal trends and potential confounding variables. We then applied a multivariate meta-analytical model to pool the effect estimates in the 11 cities to generate an overall provincial estimate. The joint effects between them were calculated by the attributable fraction (AF). The analyses were further stratified by gender, age group, education level, and location of cities. Results: In total, 120,544 CVD deaths were recorded in this study. The mean values of temperature and humidity were 17.6 °C and 72.3%. The joint effect between low temperature and high humidity had the greatest impact on the CVD death burden over a lag of 0–21 days with a significant AF of 31.36% (95% eCI: 14.79–38.41%), while in a condition of low temperature and low humidity with a significant AF of 16.74% (95% eCI: 0.89, 24.44). The AFs were higher at low temperature and high humidity in different subgroups. When considering the levels of humidity, the AFs were significant at low temperature and high humidity for males, youth, those with a low level of education, and coastal area people. Conclusions: The combination of low temperature and high humidity had the greatest impact on the CVD death burden in Zhejiang Province. This evidence has important implications for developing CVD interventions. PMID:29135955

Humidity May Modify the Relationship between Temperature and Cardiovascular Mortality in Zhejiang Province, China.

PubMed

Zeng, Jie; Zhang, Xuehai; Yang, Jun; Bao, Junzhe; Xiang, Hao; Dear, Keith; Liu, Qiyong; Lin, Shao; Lawrence, Wayne R; Lin, Aihua; Huang, Cunrui

2017-11-14

Background : The evidence of increased mortality attributable to extreme temperatures is widely characterized in climate-health studies. However, few of these studies have examined the role of humidity on temperature-mortality association. We investigated the joint effect between temperature and humidity on cardiovascular disease (CVD) mortality in Zhejiang Province, China. Methods : We collected data on daily meteorological and CVD mortality from 11 cities in Zhejiang Province during 2010-2013. We first applied time-series Poisson regression analysis within the framework of distributed lag non-linear models to estimate the city-specific effect of temperature and humidity on CVD mortality, after controlling for temporal trends and potential confounding variables. We then applied a multivariate meta-analytical model to pool the effect estimates in the 11 cities to generate an overall provincial estimate. The joint effects between them were calculated by the attributable fraction (AF). The analyses were further stratified by gender, age group, education level, and location of cities. Results : In total, 120,544 CVD deaths were recorded in this study. The mean values of temperature and humidity were 17.6 °C and 72.3%. The joint effect between low temperature and high humidity had the greatest impact on the CVD death burden over a lag of 0-21 days with a significant AF of 31.36% (95% eCI: 14.79-38.41%), while in a condition of low temperature and low humidity with a significant AF of 16.74% (95% eCI: 0.89, 24.44). The AFs were higher at low temperature and high humidity in different subgroups. When considering the levels of humidity, the AFs were significant at low temperature and high humidity for males, youth, those with a low level of education, and coastal area people. Conclusions : The combination of low temperature and high humidity had the greatest impact on the CVD death burden in Zhejiang Province. This evidence has important implications for developing CVD interventions.

40 CFR 86.605-88 - Maintenance of records; submittal of information.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., pressure increase across the pump, and the temperature set point of the temperature control system. (2... samples are being collected. (3) Humidity of dilution air. (4) Manufacturer, model, type and serial number..., ambient temperature and humidity. (2) Data and time of day. (ii) In lieu of recording test equipment...

40 CFR 86.605-88 - Maintenance of records; submittal of information.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., pressure increase across the pump, and the temperature set point of the temperature control system. (2... samples are being collected. (3) Humidity of dilution air. (4) Manufacturer, model, type and serial number..., ambient temperature and humidity. (2) Data and time of day. (ii) In lieu of recording test equipment...

40 CFR 86.605-88 - Maintenance of records; submittal of information.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., pressure increase across the pump, and the temperature set point of the temperature control system. (2... samples are being collected. (3) Humidity of dilution air. (4) Manufacturer, model, type and serial number..., ambient temperature and humidity. (2) Data and time of day. (ii) In lieu of recording test equipment...

Responses of the pituitary-adrenal system of mice to an environment of high temperature and humidity.

PubMed

Nabeshima, T; Banno, S; Kameyama, T

1982-10-01

1. Changes in plasma glucose and corticosterone levels under an environment of high temperature and humidity similar to summers in Japan were investigated. 2. When mice were exposed to high temperature (30-40 degrees C) and humidity (70%), the plasma glucose levels increased with a short-term exposure and decreased with a long-term exposure compared to that of the control mice housed at room temperature (23 degrees C) and humidity (55%). 3. The magnitude of increase of plasma corticosterone levels depended on the degree of ambient temperature and the duration of exposure to the stressful conditions. The plasma corticosterone concentration was highest at 2 hr after initiation of the temperature stress and was reduced at 4 and 6 hr after the treatment: The plasma corticosterone had returned to the control level at 8 hr after the exposure. 4. The dexamethasone treatment inhibited the increase of plasma corticosterone in stress-mice. 5. These results suggest that the response of the plasma corticosterone is a better index than that of glucose for estimation of stress-degree.

The interrelationship between dengue incidence and diurnal ranges of temperature and humidity in a Sri Lankan city and its potential applications

PubMed Central

Ehelepola, N. D. B.; Ariyaratne, Kusalika

2015-01-01

Background Temperature, humidity, and other weather variables influence dengue transmission. Published studies show how the diurnal fluctuations of temperature around different mean temperatures influence dengue transmission. There are no published studies about the correlation between diurnal range of humidity and dengue transmission. Objective The goals of this study were to determine the correlation between dengue incidence and diurnal fluctuations of temperature and humidity in the Sri Lankan city of Kandy and to explore the possibilities of using that information for better control of dengue. Design We calculated the weekly dengue incidence in Kandy during the period 2003–2012, after collecting data on all of the reported dengue patients and estimated midyear populations. Data on daily maximum and minimum temperatures and night-time and daytime humidity were obtained from two weather stations, averaged, and converted into weekly data. The number of days per week with a diurnal temperature range (DTR) of >10°C and <10°C and the number of days per week with a diurnal humidity range (DHR) of >20 and <15% were calculated. Wavelet time series analysis was performed to determine the correlation between dengue incidence and diurnal ranges of temperature and humidity. Results There were negative correlations between dengue incidence and a DTR >10°C and a DHR >20% with 3.3-week and 4-week lag periods, respectively. Additionally, positive correlations between dengue incidence and a DTR <10°C and a DHR <15% with 3- and 4-week lag periods, respectively, were discovered. Conclusions These findings are consistent with the results of previous entomological studies and theoretical models of DTR and dengue transmission correlation. It is important to conduct similar studies on diurnal fluctuations of humidity in the future. We suggest ways and means to use this information for local dengue control and to mitigate the potential effects of the ongoing global reduction of DTR on dengue incidence. PMID:26632645

Humidity does not appear to trigger leaf out in woody plants

NASA Astrophysics Data System (ADS)

Zipf, Lucy; Primack, Richard B.

2017-12-01

In order to anticipate the ecological impacts of climate change and model changes to forests, it is important to understand the factors controlling spring leaf out. Leaf out phenology in woody trees and shrubs is generally considered to be strongly controlled by a combination of spring warming, winter chilling requirement, and photoperiod. However, researchers have recently suggested that temperature-related air humidity, rather than temperature itself, might be the main trigger of the spring leaf-out of woody plants. Here, we sought to examine the relationship between air humidity and leaf-out across a range of humidities and plant functional groups. We did not find any consistent, measurable effect of high humidity advancing leaf-out in the 15 woody shrubs and trees examined in this study, and we did not see progressive patterns of earlier leaf-out in successively higher humidities. Our results indicate that more work must be done on this topic before researchers can properly determine the effect of humidity on the leafing out process for woody species.

Relation of Temperature and Humidity to the Risk of Recurrent Gout Attacks

PubMed Central

Neogi, Tuhina; Chen, Clara; Niu, Jingbo; Chaisson, Christine; Hunter, David J.; Choi, Hyon; Zhang, Yuqing

2014-01-01

Gout attack risk may be affected by weather (e.g., because of volume depletion). We therefore examined the association of temperature and humidity with the risk of recurrent gout attacks by conducting an internet-based case-crossover study in the United States (in 2003–2010) among subjects with a diagnosis of gout who had 1 or more attacks during 1 year of follow-up. We examined the association of temperature and humidity over the prior 48 hours with the risk of gout attacks using a time-stratified approach and conditional logistic regression. Among 632 subjects with gout, there was a significant dose-response relationship between mean temperature in the prior 48 hours and the risk of subsequent gout attack (P = 0.01 for linear trend). Higher temperatures were associated with approximately 40% higher risk of gout attack compared with moderate temperatures. There was a reverse J-shaped relationship between mean relative humidity and the risk of gout attacks (P = 0.03 for quadratic trend). The combination of high temperature and low humidity had the greatest association (odds ratio = 2.04, 95% confidence interval: 1.26, 3.30) compared with moderate temperature and relative humidity. Thus, high ambient temperature and possibly extremes of humidity were associated with an increased risk of gout attack, despite the likelihood that individuals are often in climate-controlled indoor environments. PMID:24993733

Artificial Fruit: Postharvest Online Monitoring of Agricultural Food by Measuring Humidity and Temperature

NASA Astrophysics Data System (ADS)

Hübert, T.; Lang, C.

2012-09-01

An online monitoring of environmental and inherent product parameters is required during transportation and storage of fruit and vegetables to avoid quality degradation and spoilage. The control of transpiration losses is suggested as an indicator for fruit freshness by humidity measurements. For that purpose, an electronic sensor is surrounded by a wet porous fiber material which is in contact with the outer atmosphere. Transpiration reduces the water content of the porous material and thus also the internal water activity. The sensor system, known as "artificial fruit," measures the relative humidity and temperature inside the wet material. Humidity and temperature data are collected and transmitted on demand by a miniaturized radio communication unit. The decrease in the measured relative humidity has been calibrated against the mass loss of tomatoes under different external influencing parameters such as temperature, humidity, and air flow. Current battery life allows the sensor system, embedded in a fruit crate, to transmit data on transpiration losses via radio transmission for up to two weeks.

THE INFLUENCE OF VARIABLE TEMPERATURE AND HUMIDITY ON THE PREDATION EFFICIENCY OF P. PERSIMILIS, N. CALIFORNICUS AND N. FALLACIS.

PubMed

Audenaert, J; Vangansbeke, D; Verhoeven, R; De Clercq, P; Tirry, L; Gobin, B

2014-01-01

Predatory mites like Phytoseiulus persimilis Athias-Henriot, Neoseiulus californicus McGregor and N. fallacis (Garman) (Acari: Phytoseiidae) are essential in sustainable control strategies of the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) in warm greenhouse cultures to complement imited available pesticides and to tackle emerging resistance. However, in response to high energy prices, greenhouse plant breeders have recently changed their greenhouse steering strategies, allowing more variation in temperature and humidity. The impact of these variations on biological control agents is poorly understood. Therefore, we constructed functional response models to demonstrate the impact of realistic climate variations on predation efficiency. First, two temperature regimes were compared at constant humidity (70%) and photoperiod (16L:8D): DIF0 (constant temperature) and DIF15 (variable temperature with day-night difference of 15°C). At mean temperatures of 25°C, DIF15 had a negative influence on the predation efficiency of P. persimilis and N. californicus, as compared to DIF0. At low mean temperatures of 15°C, however, DIF15 showed a higher predation efficiency for P. persimilis and N. californicus. For N. fallacis no difference was observed at both 15°C and 25°C. Secondly, two humidity regimes were compared, at a mean temperature of 25°C (DIFO) and constant photoperiod (16L:8D): RHCTE (constant 70% humidity) and RHALT (alternating 40% L:70%D humidity). For P. persimilis and N. fallacis RHCTE resulted in a higher predation efficiency than RHALT, for N. californicus this effect was opposite. This shows that N. californicus is more adapted to dry climates as compared to the other predatory mites. We conclude that variable greenhouse climates clearly affect predation efficiency of P. persimilis, N. californicus and N. fallacis. To obtain optimal control efficiency, the choice of predatory mites (including dose and application frequency) should be adapted to the actual greenhouse climate.

Summer indoor heat exposure and respiratory and cardiovascular distress calls in New York City, NY, U.S

PubMed Central

Uejio, C. K.; Tamerius, J. D.; Vredenburg, J.; Asaeda, G.; Isaacs, D. A.; Braun, J.; Quinn, A.; Freese, J. P.

2016-01-01

Most extreme heat studies relate outdoor weather conditions to human morbidity and mortality. In developed nations, individuals spend ~90% of their time indoors. This pilot study investigated the indoor environments of people receiving emergency medical care in New York City, NY, U.S., from July to August 2013. The first objective was to determine the relative influence of outdoor conditions as well as patient characteristics and neighborhood sociodemographics on indoor temperature and specific humidity (N = 764). The second objective was to determine whether cardiovascular or respiratory cases experience hotter and more humid indoor conditions as compared to controls. Paramedics carried portable sensors into buildings where patients received care to passively monitor indoor temperature and humidity. The case–control study compared 338 respiratory cases, 291 cardiovascular cases, and 471 controls. Intuitively, warmer and sunnier outdoor conditions increased indoor temperatures. Older patients who received emergency care tended to occupy warmer buildings. Indoor-specific humidity levels quickly adjusted to outdoor conditions. Indoor heat and humidity exposure above a 26 °C threshold increased (OR: 1.63, 95% CI: 0.98–2.68, P = 0.056), but not significantly, the proportion of respiratory cases. Indoor heat exposures were similar between cardiovascular cases and controls. PMID:26086869

Changes in volatile compounds in whey protein concentrate stored at elevated temperature and humidity

USDA-ARS?s Scientific Manuscript database

Whey protein concentrate (WPC) has been recommended for use in emergency aid programs, but it is often stored overseas without temperature and relative humidity (RH) control, which may cause it to be rejected because of yellowing, off-flavors, or clumping. Therefore, the volatile compounds present ...

Seasonal Variation in Food Consumption, Assimilation, and Conversion Efficiency of Indian Bivoltine Hybrid Silkworm, Bombyx mori

PubMed Central

Rahmathulla, V. K.; Suresh, H. M.

2012-01-01

Food consumption and utilization is influenced by various biotic and abiotic factors. Under different environmental, feeding, and nutritional conditions, and with ingestion of the same amount of mulberry leaves, the silkworm shows significant difference in its ability to digest, absorb, and convert food to body matter. Here, influences of season, temperature, and humidity on food intake, assimilation, and conversion efficiency of the Indian bivoltine hybrid (CSR2 × CSR4) Bombyx mori L. (Lepidoptera: Bombycidae) were studied. The results indicated that food ingestion and assimilation were significantly higher among silkworm batches where optimum temperature and humidity were maintained compared with silkworm batches exposed to natural climatic conditions of the respective season. However, during summer the nutritional efficiency parameters were significantly higher among silkworms reared under natural temperature and humidity conditions when compared with the control. During the winter and rainy season, the nutritional efficiency parameters were significantly higher in control batches, where optimum temperature and humidity were maintained. Ingesta and digesta required to produce one gram of cocoon/shell were also lower in control batches for all seasons except summer. This may be due to the physiological adaptation of silkworms to overcome stress during the summer season. PMID:23414194

Improving Comfort in Hot-Humid Climates with a Whole-House Dehumidifier, Windermere, Florida (Fact Sheet)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2013-11-01

Maintaining comfort in a home can be challenging in hot-humid climates. At the common summer temperature set point of 75 degrees F, the perceived air temperature can vary by 11 degrees F because higher indoor humidity reduces comfort. Often the air conditioner (AC) thermostat set point is lower than the desirable cooling level to try to increase moisture removal so that the interior air is not humid or "muggy." However, this method is not always effective in maintaining indoor relative humidity (RH) or comfort. In order to quantify the performance of a combined whole-house dehumidifier (WHD) AC system, researchers frommore » the U.S. Department of Energy's Building America team Consortium of Advanced Residential Buildings (CARB) monitored the operation of two Lennox AC systems coupled with a Honeywell DH150 TrueDRY whole-house dehumidifier for a six-month period. By using a WHD to control moisture levels (latent cooling) and optimizing a central AC to control temperature (sensible cooling), improvements in comfort can be achieved while reducing utility costs. Indoor comfort for this study was defined as maintaining indoor conditions at below 60% RH and a humidity ratio of 0.012 lbm/lbm while at common dry bulb set point temperatures of 74 degrees -80 degrees F. In addition to enhanced comfort, controlling moisture to these levels can reduce the risk of other potential issues such as mold growth, pests, and building component degradation. Because a standard AC must also reduce dry bulb air temperature in order to remove moisture, a WHD is typically needed to support these latent loads when sensible heat removal is not desired.« less

International Space Station Temperature and Humidity Control Subsystem Verification for Node 1

NASA Technical Reports Server (NTRS)

Williams, David E.

2007-01-01

The International Space Station (ISS) Node 1 Environmental Control and Life Support (ECLS) System is comprised of five subsystems: Atmosphere Control and Supply (ACS), Atmosphere Revitalization (AR), Fire Detection and Suppression (FDS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). This paper provides a summary of the nominal operation of the Node 1 THC subsystem design. The paper will also provide a discussion of the detailed Element Verification methodologies for nominal operation of the Node 1 THC subsystem operations utilized during the Qualification phase.

Strain rate, temperature, and humidity on strength and moduli of a graphite/epoxy composite

NASA Technical Reports Server (NTRS)

Lifshitz, J. M.

1981-01-01

Results of an experimental study of the influence of strain rate, temperature and humidity on the mechanical behavior of a graphite/epoxy fiber composite are presented. Three principal strengths (longitudinal, transverse and shear) and four basic moduli (E1, E2, G12 and U12) of a unidirectional graphite/epoxy composite were followed as a function of strain rate, temperature and humidity. Each test was performed at a constant tensile strain rate in an environmental chamber providing simultaneous temperature and humidity control. Prior to testing, specimens were given a moisture preconditioning treatment at 60 C. Values for the matrix dominated moduli and strength were significantly influenced by both environmental and rate parameters, whereas the fiber dominated moduli were not. However, the longitudinal strength was significantly influenced by temperature and moisture content. A qualitative explanation for these observations is presented.

Utilization of ultrasonic atomization for dust control in underground mining

NASA Astrophysics Data System (ADS)

Okawa, Hirokazu; Nishi, Kentaro; Kawamura, Youhei; Kato, Takahiro; Sugawara, Katsuyasu

2017-07-01

This study examined dust suppression using water particles generated by ultrasonic atomization (2.4 MHz) at low temperature (10 °C). Green tuff (4 µm), green tuff (6 µm), kaolin, and silica were used as dust samples. Even though ultrasonic atomization makes fine water particles, raising relative air humidity immediately was difficult at low temperature. However, remaining water particles that did not change to water vapor contributed to suppression of dust dispersion. Additionally, the effect of water vapor amount (absolute humidity) and water particles generated by ultrasonic atomization on the amount of dust dispersion was investigated using experimental data at temperatures of 10, 20, and 30 °C. Utilization of ultrasound atomization at low temperature has the advantages of low humidity increments in the working space and water particles remaining stable even with low relative air humidity.

Humidity trends imply increased sensitivity to clouds in a warming Arctic

DOE PAGES

Cox, Christopher J.; Walden, Von P.; Rowe, Penny M.; ...

2015-12-10

Infrared radiative processes are implicated in Arctic warming and sea-ice decline. The infrared cloud radiative effect (CRE) at the surface is modulated by cloud properties; however, CRE also depends on humidity because clouds emit at wavelengths that are semi-transparent to greenhouse gases, most notably water vapour. Here we show how temperature and humidity control CRE through competing influences between the mid- and far-infrared. At constant relative humidity, CRE does not decrease with increasing temperature/absolute humidity as expected, but rather is found to be approximately constant for temperatures characteristic of the Arctic. This stability is disrupted if relative humidity varies. Ourmore » findings explain observed seasonal and regional variability in Arctic CRE of order 10Wm 2. With the physical properties of Arctic clouds held constant, we calculate recent increases in CRE of 1–5Wm 2 in autumn and winter, which are projected to reach 5–15Wm 2 by 2050, implying increased sensitivity of the surface to clouds.« less

Humidity trends imply increased sensitivity to clouds in a warming Arctic.

PubMed

Cox, Christopher J; Walden, Von P; Rowe, Penny M; Shupe, Matthew D

2015-12-10

Infrared radiative processes are implicated in Arctic warming and sea-ice decline. The infrared cloud radiative effect (CRE) at the surface is modulated by cloud properties; however, CRE also depends on humidity because clouds emit at wavelengths that are semi-transparent to greenhouse gases, most notably water vapour. Here we show how temperature and humidity control CRE through competing influences between the mid- and far-infrared. At constant relative humidity, CRE does not decrease with increasing temperature/absolute humidity as expected, but rather is found to be approximately constant for temperatures characteristic of the Arctic. This stability is disrupted if relative humidity varies. Our findings explain observed seasonal and regional variability in Arctic CRE of order 10 W m(-2). With the physical properties of Arctic clouds held constant, we calculate recent increases in CRE of 1-5 W m(-2) in autumn and winter, which are projected to reach 5-15 W m(-2) by 2050, implying increased sensitivity of the surface to clouds.

Humidity trends imply increased sensitivity to clouds in a warming Arctic

PubMed Central

Cox, Christopher J.; Walden, Von P.; Rowe, Penny M.; Shupe, Matthew D.

2015-01-01

Infrared radiative processes are implicated in Arctic warming and sea-ice decline. The infrared cloud radiative effect (CRE) at the surface is modulated by cloud properties; however, CRE also depends on humidity because clouds emit at wavelengths that are semi-transparent to greenhouse gases, most notably water vapour. Here we show how temperature and humidity control CRE through competing influences between the mid- and far-infrared. At constant relative humidity, CRE does not decrease with increasing temperature/absolute humidity as expected, but rather is found to be approximately constant for temperatures characteristic of the Arctic. This stability is disrupted if relative humidity varies. Our findings explain observed seasonal and regional variability in Arctic CRE of order 10 W m−2. With the physical properties of Arctic clouds held constant, we calculate recent increases in CRE of 1–5 W m−2 in autumn and winter, which are projected to reach 5–15 W m−2 by 2050, implying increased sensitivity of the surface to clouds. PMID:26657324

International Space Station Common Cabin Air Assembly Condensing Heat Exchanger Hydrophilic Coating Operation, Recovery, and Lessons Learned

NASA Technical Reports Server (NTRS)

Balistreri, Steven F.; Steele, John W.; Caron, Mark E.; Laliberte, Yvon J.; Shaw, Laura A.

2013-01-01

The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The CHX is the primary component responsible for control of temperature and humidity. The CCAA CHX contains a chemical coating that was developed to be hydrophilic and thus attract water from the humid influent air. This attraction forms the basis for water removal and therefore cabin humidity control. However, there have been several instances of CHX coatings becoming hydrophobic and repelling water. When this behavior is observed in an operational CHX in the ISS segments, the unit s ability to remove moisture from the air is compromised and the result is liquid water carryover into downstream ducting and systems. This water carryover can have detrimental effects on the ISS cabin atmosphere quality and on the health of downstream hardware. If the water carryover is severe and widespread, this behavior can result in an inability to maintain humidity levels in the USOS. This paper will describe the operation of the five CCAAs within the USOS, the potential causes of the hydrophobic condition, and the impacts of the resulting water carryover to downstream systems. It will describe the history of this behavior and the actual observed impacts to the ISS USOS. Information on mitigation steps to protect the health of future CHX hydrophilic coatings as well as remediation and recovery of the full heat exchanger will be discussed.

International Space Station Common Cabin Air Assembly Condensing Heat Exchanger Hydrophilic Coating Failures and Lessons Learned

NASA Technical Reports Server (NTRS)

Balistreri, Steven F.; Shaw, Laura A.; Laliberte, Yvon

2010-01-01

The ability to control the temperature and humidity of an environment or habitat is critical for human survival. These factors are important to maintaining human health and comfort, as well as maintaining mechanical and electrical equipment in good working order to support the human and to accomplish mission objectives. The temperature and humidity of the International Space Station (ISS) United States On-orbit Segment (USOS) cabin air is controlled by the Common Cabin Air Assembly (CCAA). The CCAA consists of a fan, a condensing heat exchanger (CHX), an air/water separator, temperature and liquid sensors, and electrical controlling hardware and software. The CHX is the primary component responsible for control of temperature and humidity. The CCAA CHX contains a chemical coating that was developed to be hydrophilic and thus attract water from the humid influent air. This attraction forms the basis for water removal and therefore cabin humidity control. However, there have been several instances of CHX coatings becoming hydrophobic and repelling water. When this behavior is observed in an operational CHX, the unit s ability to remove moisture from the air is compromised and the result is liquid water carryover into downstream ducting and systems. This water carryover can have detrimental effects on the cabin atmosphere quality and on the health of downstream hardware. If the water carryover is severe and widespread, this behavior can result in an inability to maintain humidity levels in the USOS. This paper will describe the operation of the five CCAAs within in the USOS, the potential causes of the hydrophobic condition, and the impacts of the resulting water carryover to downstream systems. It will describe the history of this behavior and the actual observed impacts to the ISS USOS. Information on mitigation steps to protect the health of future CHX hydrophilic coatings and potential remediation techniques will also be discussed.

Assessing the efficacy of a novel temperature and humidity control machine to minimize house dust mite allergen exposure and clinical symptoms in allergic rhinitis children sensitized to dust mites: a pilot study.

PubMed

Manuyakorn, Wiparat; Padungpak, Savitree; Luecha, Orawin; Kamchaisatian, Wasu; Sasisakulporn, Cherapat; Vilaiyuk, Soamarat; Monyakul, Veerapol; Benjaponpitak, Suwat

2015-06-01

House dust mite avoidance is advised in dust mite sensitized patients to decrease the risk to develop allergic symptoms. Maintaining a relative humidity (RH) of less than 50% in households is recommended to prevent dust mite proliferation. To investigate the efficacy of a novel temperature and humidity machine to control the level of dust mite allergens and total nasal symptom score (TNSS) in dust mite sensitized allergic rhinitis children. Children (8-15 years) with dust mite sensitized persistent allergic rhinitis (AR) were enrolled. The temperature and humidity control machine was installed in the bedroom where the enrolled children stayed for 6 months. TNSS was assessed before and every month after machine set up and the level of dust mite allergen (Der p 1 and Der f 1) from the mattress were measured before and every 2 months after machine set up using enzyme-linked immunosorbent assay (ELISA). A total of 7 children were enrolled. Noticeable reduction of Der f 1 was observed as early as 2 months after installing the machine, but proper significant differences appeared 4 months after and remained low until the end of the experiment (p <0.05). Although no correlation was observed between TNSS and the level of dust mite allergens, there was a significant reduction in TNSS at 2 and 4 months (p <0.05) and 70% of the patients were able to stop using their intranasal corticosteroids by the end of the experiment. The level of house dust mite in mattresses was significantly reduced after using the temperature and humidity control machine. This machine may be used as an effective tool to control clinical symptoms of dust mite sensitized AR children.

The design of remote temperature monitoring system

NASA Astrophysics Data System (ADS)

Li, Biqing; Li, Zhao; Wei, Liuren

2017-08-01

This design is made on the basis of the single-chip microcomputer remote temperature monitoring system. STC89C51RC is the main core part, this design use the sensor DHT11 of temperature or humidity and wireless transceiver NRF24L01 the temperature of the test site for long-range wireless measurement and monitoring. The design contains the main system and the small system, of which the main system can show the actual test site temperature and humidity values, voice broadcast, out of control and receive data alarm function; The small system has the function of temperature and humidity, temperature monitoring and sending data. After debugging, the user customizable alarm upper and lower temperature, when the temperature exceeds limit value, the main system of buzzer alarm immediately. The system has simple structure, complete functions and can alarm in time, it can be widely used remote temperature acquisition and monitoring of the site.

Verification of Energy Reduction Effect through Control Optimization of Supply Air Temperature in VRF-OAP System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Je; Yoon, Hyun; Im, Piljae

This paper developed an algorithm that controls the supply air temperature in the variable refrigerant flow (VRF), outdoor air processing unit (OAP) system, according to indoor and outdoor temperature and humidity, and verified the effects after applying the algorithm to real buildings. The VRF-OAP system refers to a heating, ventilation, and air conditioning (HVAC) system to complement a ventilation function, which is not provided in the VRF system. It is a system that supplies air indoors by heat treatment of outdoor air through the OAP, as a number of indoor units and OAPs are connected to the outdoor unit inmore » the VRF system simultaneously. This paper conducted experiments with regard to changes in efficiency and the cooling capabilities of each unit and system according to supply air temperature in the OAP using a multicalorimeter. Based on these results, an algorithm that controlled the temperature of the supply air in the OAP was developed considering indoor and outdoor temperatures and humidity. The algorithm was applied in the test building to verify the effects of energy reduction and the effects on indoor temperature and humidity. Loads were then changed by adjusting the number of conditioned rooms to verify the effect of the algorithm according to various load conditions. In the field test results, the energy reduction effect was approximately 15–17% at a 100% load, and 4–20% at a 75% load. However, no significant effects were shown at a 50% load. The indoor temperature and humidity reached a comfortable level.« less

Verification of Energy Reduction Effect through Control Optimization of Supply Air Temperature in VRF-OAP System

DOE PAGES

Lee, Je; Yoon, Hyun; Im, Piljae; ...

2017-12-27

This paper developed an algorithm that controls the supply air temperature in the variable refrigerant flow (VRF), outdoor air processing unit (OAP) system, according to indoor and outdoor temperature and humidity, and verified the effects after applying the algorithm to real buildings. The VRF-OAP system refers to a heating, ventilation, and air conditioning (HVAC) system to complement a ventilation function, which is not provided in the VRF system. It is a system that supplies air indoors by heat treatment of outdoor air through the OAP, as a number of indoor units and OAPs are connected to the outdoor unit inmore » the VRF system simultaneously. This paper conducted experiments with regard to changes in efficiency and the cooling capabilities of each unit and system according to supply air temperature in the OAP using a multicalorimeter. Based on these results, an algorithm that controlled the temperature of the supply air in the OAP was developed considering indoor and outdoor temperatures and humidity. The algorithm was applied in the test building to verify the effects of energy reduction and the effects on indoor temperature and humidity. Loads were then changed by adjusting the number of conditioned rooms to verify the effect of the algorithm according to various load conditions. In the field test results, the energy reduction effect was approximately 15–17% at a 100% load, and 4–20% at a 75% load. However, no significant effects were shown at a 50% load. The indoor temperature and humidity reached a comfortable level.« less

Description and testing of three moisture sensors for measuring surface wetness on carbonate building stones

USGS Publications Warehouse

See, R.B.; Reddy, M.M.; Martin, R.G.

1987-01-01

Three sensors were tested on building stones exposed to conditions that produce deposition of moisture. A relative humidity probe, a gypsum collected circuit grid, and a limestone block resistor were tested as sensors for determining surface wetness. Sensors were tested under laboratory conditions of constant relative humidity and temperature and also under on-site conditions of variable relative humidity and temperature for 8 weeks at Newcomb, New York. Laboratory tests indicated that relative humidity alone did not cause sensors to become saturated. However, relative humidity did control the rate at which sensors dried after being saturated with distilled water. On-site testing of the relative humidity probe and the gypsum coated circuit grid indicated that they respond to a diurnal wetting and drying cycle; the limestone block resistor only responded to rainfall. (Author 's abstract)

Morphology of U 3O 8 materials following storage under controlled conditions of temperature and relative humidity

DOE PAGES

Tamasi, Alison L.; Cash, Leigh J.; Mullen, William Tyler; ...

2016-07-05

Changes in the visual characteristics of uranium oxide surfaces and morphology following storage under different conditions of temperature and relative humidity may provide insight into the history of an unknown sample. Sub-samples of three α-U 3O 8 materials—one that was phase-pure and two that were phase-impure—were stored under controlled conditions for two years. We used scanning electron microscopy to image the oxides before and after storage, and a morphology lexicon was used to characterize the images. Finally, temporal changes in morphology were observed in some sub-samples, and changes were greatest following exposure to high relative humidity.

On the Choice of Variable for Atmospheric Moisture Analysis

NASA Technical Reports Server (NTRS)

Dee, Dick P.; DaSilva, Arlindo M.; Atlas, Robert (Technical Monitor)

2002-01-01

The implications of using different control variables for the analysis of moisture observations in a global atmospheric data assimilation system are investigated. A moisture analysis based on either mixing ratio or specific humidity is prone to large extrapolation errors, due to the high variability in space and time of these parameters and to the difficulties in modeling their error covariances. Using the logarithm of specific humidity does not alleviate these problems, and has the further disadvantage that very dry background estimates cannot be effectively corrected by observations. Relative humidity is a better choice from a statistical point of view, because this field is spatially and temporally more coherent and error statistics are therefore easier to obtain. If, however, the analysis is designed to preserve relative humidity in the absence of moisture observations, then the analyzed specific humidity field depends entirely on analyzed temperature changes. If the model has a cool bias in the stratosphere this will lead to an unstable accumulation of excess moisture there. A pseudo-relative humidity can be defined by scaling the mixing ratio by the background saturation mixing ratio. A univariate pseudo-relative humidity analysis will preserve the specific humidity field in the absence of moisture observations. A pseudorelative humidity analysis is shown to be equivalent to a mixing ratio analysis with flow-dependent covariances. In the presence of multivariate (temperature-moisture) observations it produces analyzed relative humidity values that are nearly identical to those produced by a relative humidity analysis. Based on a time series analysis of radiosonde observed-minus-background differences it appears to be more justifiable to neglect specific humidity-temperature correlations (in a univariate pseudo-relative humidity analysis) than to neglect relative humidity-temperature correlations (in a univariate relative humidity analysis). A pseudo-relative humidity analysis is easily implemented in an existing moisture analysis system, by simply scaling observed-minus background moisture residuals prior to solving the analysis equation, and rescaling the analyzed increments afterward.

Synthesis and humidity sensing analysis of ZnS nanowires

NASA Astrophysics Data System (ADS)

Okur, Salih; Üzar, Neslihan; Tekgüzel, Nesli; Erol, Ayşe; Çetin Arıkan, M.

2012-03-01

ZnS nanowires synthesized by the vapor-liquid-solid (VLS) method and humidity sensing properties of obtained ZnS nanowires were investigated by quartz crystal microbalance (QCM) method and electrical measurements. The synthesized nanowires were exposed to relative humidity (RH) between 22% and 97% under controlled environment. Our experimental results show that ZnS nanowires have a great potential for humidity sensing applications in room temperature operations.

Cooling Effects of Wearer-Controlled Vaporization for Extravehicular Activity.

PubMed

Tanaka, Kunihiko; Nagao, Daiki; Okada, Kosuke; Nakamura, Koji

2017-04-01

The extravehicular activity suit currently used by the United States in space includes a liquid cooling and ventilation garment (LCVG) that controls thermal conditions. Previously, we demonstrated that self-perspiration for evaporative cooling (SPEC) garment effectively lowers skin temperature without raising humidity in the garment. However, the cooling effect is delayed until a sufficient dose of water permeates and evaporates. In the present study, we hypothesized that wearer-controlled vaporization improves the cooling effect. Six healthy subjects rode a cycle ergometer under loads of 30, 60, 90, and 120 W for durations of 3 min each. Skin temperature and humidity on the back were measured continuously. Subjects wore and tested three garments: 1) a spandex garment without any cooling device (Normal); 2) a simulated LCVG (s-LCVG) or spandex garment knitted with a vinyl tube for flowing and permeating water; and 3) a garment that allowed wearer-controlled vaporization (SPEC-W). The use of s-LCVG reduced skin temperature by 1.57 ± 0.14°C during 12 min of cooling. Wearer-controlled vaporization of the SPEC-W effectively and significantly lowered skin temperature from the start to the end of cycle exercise. This decrease was significantly larger than that achieved using s-LCVG. Humidity in the SPEC-W was significantly lower than that in s-LCVG. This preliminary study suggests that SPEC-W is effective in lowering skin temperature without raising humidity in the garment. The authors think it would be useful in improving the design of a cooling system for extravehicular activity.Tanaka K, Nagao D, Okada K, Nakamura K. Cooling effects of wearer-controlled vaporization for extravehicular activity. Aerosp Med Hum Perform. 2017; 88(4):418-422.

NBC Contamination Survivability, Large Item Exteriors

DTIC Science & Technology

1998-04-17

environment. Ability to control temperature , relative humidity (RH), and wind speed is required. The facility must be designed to ensure safe and...2.2 Instrumentation. Measuring Devices Permissible Error of Measurement Air temperature ±0.5°C Relative humidity (RH) ±5 % Wind speed ±0.1 rm/sec Still...process, excluding monitoring, should last no longer than 75 minutes. (3) The item surface temperature is 30’C and exterior wind speed is no greater

[Effect of cooling therapy on the heart rate and mean arterial pressure of rats with the second-degree scald burn in hot and humid environment].

PubMed

Li, Ya-jie; Zhang, Li-ying; Luo, Bing-de; Li, Yi-lei; Lin, Ni

2004-03-01

To observe the changes of heart rate (HR) and mean arterial pressure MAP after immediate cooling therapy (ICT) in rats with superficial second-degree scald burn in hot and humid environment, and assess the effect of the cooling dressing materials. Twenty-four Wistar rats were randomized equally into 4 groups including normal temperature control (NTC) group, normal temperature cooling therapy (NCT) group, hot and humid control (HHC) group and hot and humid cooling therapy (HCT) group. Different interventions were applied as indicated in the rats with superficial second-degree scald burn, with the dry bulb temperature Tdb at 26.33+/-1.29 degrees celsius; and relative humidity (rh) of 71.05%+/-4.57% for two normal temperature groups, and Tdb at 35.33+/-0.35 degrees Celsius; and rh of 70.81%+/-1.38% for the two hot and humid groups. The exposure time was 120 min in NCT and HCT groups, and the HR and MAP were measured every 20 min. MAP is not influenced by environmental temperature and the cooling therapy (P>0.05), whereas HR was higher in HHC than in NTC group and also in HCT than in NCT group (P=0.003), lower in HCT and NCT groups than in HHC and NTC groups (P=0.002), respectively. HR did not undergo any significant changes during the observation in the 4 groups (P>0.05). HR was higher in HHC and HCT than in NTC and NCT groups at 65, 85, 105 and 125 min after the burns, but compared with the two control groups, cooling therapy decreased HR at 5, 25, 45 and 85 min. Cooling therapy does not affect MAP but efficiently decreases HR, which may prevent further heat injury.

PID temperature controller in pig nursery: spatial characterization of thermal environment

NASA Astrophysics Data System (ADS)

de Souza Granja Barros, Juliana; Rossi, Luiz Antonio; Menezes de Souza, Zigomar

2018-05-01

The use of enhanced technologies of temperature control can improve the thermal conditions in environments of livestock facilities. The objective of this study was to evaluate the spatial distribution of the thermal environment variables in a pig nursery with a heating system with two temperature control technologies based on the geostatistical analysis. The following systems were evaluated: overhead electrical resistance with Proportional, Integral, and Derivative (PID) controller and overhead electrical resistance with a thermostat. We evaluated the climatic variables: dry bulb temperature (Tbs), air relative humidity (RH), temperature and humidity index (THI), and enthalpy in the winter, at 7:00, 12:00, and 18:00 h. The spatial distribution of these variables was mapped by kriging. The results showed that the resistance heating system with PID controllers improved the thermal comfort conditions in the pig nursery in the coldest hours, maintaining the spatial distribution of the air temperature more homogeneous in the pen. During the hottest weather, neither system provided comfort.

PID temperature controller in pig nursery: spatial characterization of thermal environment

NASA Astrophysics Data System (ADS)

de Souza Granja Barros, Juliana; Rossi, Luiz Antonio; Menezes de Souza, Zigomar

2017-11-01

The use of enhanced technologies of temperature control can improve the thermal conditions in environments of livestock facilities. The objective of this study was to evaluate the spatial distribution of the thermal environment variables in a pig nursery with a heating system with two temperature control technologies based on the geostatistical analysis. The following systems were evaluated: overhead electrical resistance with Proportional, Integral, and Derivative (PID) controller and overhead electrical resistance with a thermostat. We evaluated the climatic variables: dry bulb temperature (Tbs), air relative humidity (RH), temperature and humidity index (THI), and enthalpy in the winter, at 7:00, 12:00, and 18:00 h. The spatial distribution of these variables was mapped by kriging. The results showed that the resistance heating system with PID controllers improved the thermal comfort conditions in the pig nursery in the coldest hours, maintaining the spatial distribution of the air temperature more homogeneous in the pen. During the hottest weather, neither system provided comfort.

Core-shell microstructured nanocomposites for synergistic adjustment of environmental temperature and humidity

NASA Astrophysics Data System (ADS)

Zhang, Haiquan; Yuan, Yanping; Zhang, Nan; Sun, Qingrong; Cao, Xiaoling

2016-11-01

The adjustment of temperature and humidity is of great importance in a variety of fields. Composites that can perform both functions are prepared by mixing phase change materials (PCMs) with hygroscopic materials. However, the contact area between the adsorbent and humid air is inevitably decreased in such structures, which reduces the number of mass transfer channels for water vapor. An approach entailing the increase in the mass ratio of the adsorbent is presented here to improve the adsorption capacity. A core-shell CuSO4/polyethylene glycol (PEG) nanomaterial was developed to satisfy the conflicting requirements of temperature control and dehumidification. The results show that the equilibrium adsorption capacity of the PEG coating layer was enhanced by a factor of 188 compared with that of the pure PEG powder. The coating layer easily concentrates vapor, providing better adsorption properties for the composite. Furthermore, the volume modification of the CuSO4 matrix was reduced by 80% by the PEG coated layer, a factor that increases the stability of the composite. For the phase change process, the crystallization temperature of the coating layer was adjusted between 37.2 and 46.3 °C by interfacial tension. The core-shell CuSO4/PEG composite reported here provides a new general approach for the simultaneous control of temperature and humidity.

Effect of ambient temperature and relative humidity on interfacial temperature during early stages of drop evaporation.

PubMed

Fukatani, Yuki; Orejon, Daniel; Kita, Yutaku; Takata, Yasuyuki; Kim, Jungho; Sefiane, Khellil

2016-04-01

Understanding drop evaporation mechanisms is important for many industrial, biological, and other applications. Drops of organic solvents undergoing evaporation have been found to display distinct thermal patterns, which in turn depend on the physical properties of the liquid, the substrate, and ambient conditions. These patterns have been reported previously to be bulk patterns from the solid-liquid to the liquid-gas drop interface. In the present work the effect of ambient temperature and humidity during the first stage of evaporation, i.e., pinned contact line, is studied paying special attention to the thermal information retrieved at the liquid-gas interface through IR thermography. This is coupled with drop profile monitoring to experimentally investigate the effect of ambient temperature and relative humidity on the drop interfacial thermal patterns and the evaporation rate. Results indicate that self-generated thermal patterns are enhanced by an increase in ambient temperature and/or a decrease in humidity. The more active thermal patterns observed at high ambient temperatures are explained in light of a greater temperature difference generated between the apex and the edge of the drop due to greater evaporative cooling. On the other hand, the presence of water humidity in the atmosphere is found to decrease the temperature difference along the drop interface due to the heat of adsorption, absorption and/or that of condensation of water onto the ethanol drops. The control, i.e., enhancement or suppression, of these thermal patterns at the drop interface by means of ambient temperature and relative humidity is quantified and reported.

Improved protocol and data analysis for accelerated shelf-life estimation of solid dosage forms.

PubMed

Waterman, Kenneth C; Carella, Anthony J; Gumkowski, Michael J; Lukulay, Patrick; MacDonald, Bruce C; Roy, Michael C; Shamblin, Sheri L

2007-04-01

To propose and test a new accelerated aging protocol for solid-state, small molecule pharmaceuticals which provides faster predictions for drug substance and drug product shelf-life. The concept of an isoconversion paradigm, where times in different temperature and humidity-controlled stability chambers are set to provide a critical degradant level, is introduced for solid-state pharmaceuticals. Reliable estimates for temperature and relative humidity effects are handled using a humidity-corrected Arrhenius equation, where temperature and relative humidity are assumed to be orthogonal. Imprecision is incorporated into a Monte-Carlo simulation to propagate the variations inherent in the experiment. In early development phases, greater imprecision in predictions is tolerated to allow faster screening with reduced sampling. Early development data are then used to design appropriate test conditions for more reliable later stability estimations. Examples are reported showing that predicted shelf-life values for lower temperatures and different relative humidities are consistent with the measured shelf-life values at those conditions. The new protocols and analyses provide accurate and precise shelf-life estimations in a reduced time from current state of the art.

No-reheat air-conditioning

NASA Technical Reports Server (NTRS)

Obler, H. D.

1980-01-01

Air conditioning system, for environmentally controlled areas containing sensitive equipment, regulates temperature and humidity without wasteful and costly reheating. System blends outside air with return air as dictated by various sensors to ensure required humidity in cooled spaces (such as computer room).

A comparison of THI indices leads to a sensible heat-based heat stress index for shaded cattle that aligns temperature and humidity stress.

PubMed

Berman, A; Horovitz, Talia; Kaim, M; Gacitua, H

2016-10-01

The combined temperature-humidity heat stress is estimated in farm animals by indices derived of an index based on human thermal comfort sensation. The latter index consists of temperature and humidity measures that sum to form the temperature-humidity index (THI). The hitherto unknown relative contribution of temperature and humidity to the THI was examined. A temperature-humidity data set (temperature 20-42 °C and relative humidity 10-70 %) was used to assess by regression procedures the relative weights of temperature and humidity in the variance of THI values produced by six commonly used heat stress indices. The temperature (Ta) effect was predominant (0.82-0.95 of variance) and humidity accounted for only 0.05 to 0.12 of THI variance, half of the variance encountered in animal responses to variable humidity heat stress. Significant difference in THI values was found between indices in the relative weights of temperature and humidity. As in THI indices, temperature and humidity are expressed in different physical units, their sum has no physical attributes, and empirical evaluations assess THI relation to animal responses. A sensible heat THI was created, in which at higher temperatures humidity reaches 0.25 of sensible heat, similarly to evaporative heat loss span in heat stressed animals. It relates to ambient temperature-humidity similarly to present THI; its values are similar to other THI but greater at higher humidity. In warm conditions, mean animal responses are similar in both indices. The higher sensitivity to humidity makes this index preferable for warm-humid conditions.

Controlling morphology, mesoporosity, crystallinity, and photocatalytic activity of ordered mesoporous TiO2 films prepared at low temperature

NASA Astrophysics Data System (ADS)

Elgh, Björn; Yuan, Ning; Cho, Hae Sung; Magerl, David; Philipp, Martine; Roth, Stephan V.; Yoon, Kyung Byung; Müller-Buschbaum, Peter; Terasaki, Osamu; Palmqvist, Anders E. C.

2014-11-01

Partly ordered mesoporous titania films with anatase crystallites incorporated into the pore walls were prepared at low temperature by spin-coating a microemulsion-based reaction solution. The effect of relative humidity employed during aging of the prepared films was studied using SEM, TEM, and grazing incidence small angle X-ray scattering to evaluate the mesoscopic order, porosity, and crystallinity of the films. The study shows unambiguously that crystal growth occurs mainly during storage of the films and proceeds at room temperature largely depending on relative humidity. Porosity, pore size, mesoscopic order, crystallinity, and photocatalytic activity of the films increased with relative humidity up to an optimum around 75%.

Spatiotemporal Variability of Humidity Across the Contiguous United States and Southern Canada Using Regional Networks

NASA Astrophysics Data System (ADS)

Behnke, Ruben John

The objective of this dissertation was to show that there is now enough observed humidity data available so that estimates of humidity, along with their necessary assumptions, can be replaced by measured humidity data. The range of applications that depend on humidity data is huge, ranging from water use efficiency of plants and plant stress to human health and agricultural practices. Biases due to the use of estimated humidity can be expected to have short and long impacts, decreasing the accuracy and precision of these, and many other, applications. Data from local, regional, and national observation networks was gathered, and custom quality control routines were written to remove bad data points from over 45000 stations, leaving 12533 usable stations. While still not at the same number of observations as temperature or precipitation, this number is nearly ten times as high as two decades ago. The work I performed consists of three major components, corresponding to the three main chapters of this dissertation. In chapter one, I describe data sources and quality control methods, along with some basic statistics of humidity, describing which geographic variables often used to predict temperature and precipitation can be used to do the same for humidity. Chapter two defines specific diurnal patterns (or "types") of dew point across the United States, including their attributes, causes, and potential influences. Chapter three analyzes biases in evapotranspiration, heat indices, and relative humidity levels that are a direct result of using estimated humidity data. Chapter four discusses contributions this work makes to the scientific community, and potential further research to build on what is presented here. While it may seem that the science of humidity should be well beyond data gathering and bias analysis, the fact remains that humidity is still very commonly estimated through the use of minimum temperature, and diurnal changes in dew point are often ignored. My hope is that this work makes a dent in often deeply entrenched practices, leading others to make the effort to incorporate measured humidity data into their work and study.

[An early warning method of cucumber downy mildew in solar greenhouse based on canopy temperature and humidity modeling].

PubMed

Wang, Hui; Li, Mei-lan; Xu, Jian-ping; Chen, Mei-xiang; Li, Wen-yong; Li, Ming

2015-10-01

The greenhouse environmental parameters can be used to establish greenhouse nirco-climate model, which can combine with disease model for early warning, with aim of ecological controlling diseases to reduce pesticide usage, and protecting greenhouse ecological environment to ensure the agricultural product quality safety. Greenhouse canopy leaf temperature and air relative humidity, models were established using energy balance and moisture balance principle inside the greenhouse. The leaf temperature model considered radiation heat transfer between the greenhouse crops, wall, soil and cover, plus the heat exchange caused by indoor net radiation and crop transpiration. Furthermore, the water dynamic balance in the greenhouse including leaf transpiration, soil evaporation, cover and leaf water vapor condensation, was considered to develop a relative humidity model. The primary infection and latent period warning models for cucumber downy mildew (Pseudoperonospora cubensis) were validated using the results of the leaf temperature and relative humidity model, and then the estimated disease occurrence date of cucumber downy mildew was compared with actual disease occurrence date of field observation. Finally, the results were verified by the measured temperature and humidity data of September and October, 2014. The results showed that the root mean square deviations (RMSDs) of the measured and estimated leaf temperature were 0.016 and 0.024 °C, and the RMSDs of the measured and estimated air relative humidity were 0.15% and 0.13%, respectively. Combining the result of estimated temperature and humidity models, a cucumber disease early warning system was established to forecast the date of disease occurrence, which met with the real date. Thus, this work could provide the micro-environment data for the early warning system of cucumber diseases in solar greenhouses.

Study of the association of atmospheric temperature and relative humidity with bulk tank milk somatic cell count in dairy herds using Generalized additive mixed models.

PubMed

Testa, Francesco; Marano, Giuseppe; Ambrogi, Federico; Boracchi, Patrizia; Casula, Antonio; Biganzoli, Elia; Moroni, Paolo

2017-10-01

Elevated bulk tank milk somatic cell count (BMSCC) has a negative impact on milk production, milk quality, and animal health. Seasonal increases in herd level somatic cell count (SCC) are commonly associated with elevated environmental temperature and humidity. The Temperature Humidity Index (THI) has been developed to measure general environmental stress in dairy cattle; however, additional work is needed to determine a specific effect of the heat stress index on herd-level SCC. Generalized Additive Model methods were used for a flexible exploration of the relationships between daily temperature, relative humidity, and bulk milk somatic cell count. The data consist of BMSCC and meteorological recordings collected between March 2009 and October 2011 of 10 dairy farms. The results indicate that, an average increase of 0.16% of BMSCC is expected for an increase of 1°C degree of temperature. A complex relationship was found for relative humidity. For example, increase of 0.099%, 0.037% and 0.020% are expected in correspondence to an increase of relative humidity from 50% to 51%, 80% to 81%; and 90% to 91%, respectively. Using this model, it will be possible to provide evidence-based advice to dairy farmers for the use of THI control charts created on the basis of our statistical model. Copyright © 2017 Elsevier Ltd. All rights reserved.

Drying characteristics of hui ink at 25 °C and 35 °C

NASA Astrophysics Data System (ADS)

Fu, Yang; Yao, Yao; Liu, Le; Wang, Fengwen; Yang, Shuyun

2018-05-01

Temperature and humidity are the main factors affecting the drying of Hui ink. For the experiment, fresh Hui ink billets from two big ink industries were selected. We tried to find the fast and efficient drying conditions of Hui ink and calculate effective diffusion coefficient by performing manual control of temperature and relative humidity (RH). Several dry kinetic models were fitted. A constant temperature incubator was utilized for temperature control, while humidification and dehumidification were implemented accordingly for RH control. Setups of 25 °C and 35 °C were designed, and a relative humidity of 60%, 65%, 70%, and 75% was applied for each temperature. The process of ink drying was recorded, and the drying effect of Hui ink was estimated through expert decision. The appropriate drying temperature and humidity of the Jinbuhuan(J) and Huangshansongyan(H) ink billets from Lao Hu Kai Wen Ink Industry are at (31.99 ± 1.41) °C and (55.84 ± 10.38)% RH, whereas those of the Songyantanhei(ST), Chunyouyan(CY), and Quansongyan(QS) ink billets from Ju Mo Tang Ink Industry are at (23.70 ± 2.19) °C and (60.56 ± 2.16)% RH or (34.56 ± 2.37) °C and (59.16 ± 6.38)% RH; Initial moisture content of Hui ink has great influence on the water loss in the drying process; The effective diffusion coefficient of the ink lump ranges from 8.41538E-07 to 1.95891E-06 m2·s-1, and increases mainly with the temperature's rising; Logarithmic model fits best of the chosen models.

Design and Applications of a Climatic Chamber for in-situ Neutron Imaging Experiments

NASA Astrophysics Data System (ADS)

Mannes, David; Schmid, Florian; Wehmann, Timon; Lehmann, Eberhard

Due to the high sensitivity for hydrogen, the detection and quantification of moisture and moisture transport processes are some of the key topics in neutron imaging. Especially when dealing with hygroscopic material, such as wood and other porous media, it is crucial for quantitative analyses to know and control the ambient conditions of the sample precisely. In this work, a neutron transparent climatic chamber is presented, which was designed and built for the imaging facilities at the Paul Scherrer Institut (PSI), Villigen (CH). The air-conditioned measuring system consists of the actual sample chamber and a moisture generator providing air with adjustable temperature and relative humidity (%RH) (up to a dew point temperature of 70 °C). The two components are connected with a flexible tube, which features insulation, a heating system and temperature sensors to prevent condensation within the tube. The sample chamber itself is equipped with neutron transparent windows, insulating double walls with three feed-through openings for the rotation stage, sensors for humidity and temperature. Thermoelectric modules allow to control the chamber temperature in the range of -20 °C to 100 °C. The chamber allows to control the climatic conditions either in a static mode (stable temperature and %RH) or in dynamic mode (humidity or temperature cycles). The envisaged areas of application are neutron radiography and tomography investigations of dynamic processes in building materials (e.g. wood, concrete), food science and any other application necessitating the control of the climatic conditions.

Artifactual degradation of secondary amine-containing drugs during accelerated stability testing when saturated sodium nitrite solutions are used for humidity control.

PubMed

Sluggett, Gregory W; Zelesky, Todd; Hetrick, Evan M; Babayan, Yelizaveta; Baertschi, Steven W

2018-02-05

Accelerated stability studies of pharmaceutical products are commonly conducted at various combinations of temperature and relative humidity (RH). The RH of the sample environment can be controlled to set points using humidity-controlled stability chambers or via storage of the sample in a closed container in the presence of a saturated aqueous salt solution. Herein we report an unexpected N-nitrosation reaction that occurs upon storage of carvedilol- or propranolol-excipient blends in a stability chamber in the presence of saturated sodium nitrite (NaNO 2 ) solution to control relative humidity (∼60% RH). In both cases, the major products were identified as the corresponding N-nitroso derivatives of the secondary amine drugs based on mass spectrometry, UV-vis and retention time. These degradation products were not observed upon storage of the samples at the same temperature and humidity but in the presence of saturated potassium iodide (KI) solution (∼60% RH) for humidity control. The levels of the N-nitrosamine derivatives varied with the pH of various NaNO 2 batches. The presence of volatile NOx species in the headspace of a container containing saturated NaNO 2 solution was confirmed via the Griess assay. The process for formation of the N-nitrosamine derivatives is proposed to involve volatilization of nitric oxide (NO) from aqueous nitrite solution into the headspace of the container followed by diffusion into the solid drug-excipient blend and subsequent reaction of NOx with the secondary amine. Copyright © 2017 Elsevier B.V. All rights reserved.

Using a Novel Wireless-Networked Decentralized Control Scheme under Unpredictable Environmental Conditions

PubMed Central

Chang, Chung-Liang; Huang, Yi-Ming; Hong, Guo-Fong

2015-01-01

The direction of sunshine or the installation sites of environmental control facilities in the greenhouse result in different temperature and humidity levels in the various zones of the greenhouse, and thus, the production quality of crop is inconsistent. This study proposed a wireless-networked decentralized fuzzy control scheme to regulate the environmental parameters of various culture zones within a greenhouse. The proposed scheme can create different environmental conditions for cultivating different crops in various zones and achieve diversification or standardization of crop production. A star-type wireless sensor network is utilized to communicate with each sensing node, actuator node, and control node in various zones within the greenhouse. The fuzzy rule-based inference system is used to regulate the environmental parameters for temperature and humidity based on real-time data of plant growth response provided by a growth stage selector. The growth stage selector defines the control ranges of temperature and humidity of the various culture zones according to the leaf area of the plant, the number of leaves, and the cumulative amount of light. The experimental results show that the proposed scheme is stable and robust and provides basis for future greenhouse applications. PMID:26569264

Effects of humidity and interlayer cations on the frictional strength of montmorillonite

NASA Astrophysics Data System (ADS)

Tetsuka, Hiroshi; Katayama, Ikuo; Sakuma, Hiroshi; Tamura, Kenji

2018-04-01

We developed a humidity control system in a biaxial friction testing machine to investigate the effect of relative humidity and interlayer cations on the frictional strength of montmorillonite. We carried out the frictional experiments on Na- and Ca-montmorillonite under controlled relative humidities (ca. 10, 30, 50, 70, and 90%) and at a constant temperature (95 °C). Our experimental results show that frictional strengths of both Na- and Ca-montmorillonite decrease systematically with increasing relative humidity. The friction coefficients of Na-montmorillonite decrease from 0.33 (at relative humidity of 10%) to 0.06 (at relative humidity of 93%) and those of Ca-montmorillonite decrease from 0.22 (at relative humidity of 11%) to 0.04 (at relative humidity of 91%). Our results also show that the frictional strength of Na-montmorillonite is higher than that of Ca-montmorillonite at a given relative humidity. These results reveal that the frictional strength of montmorillonite is sensitive to hydration state and interlayer cation species, suggesting that the strength of faults containing these clay minerals depends on the physical and chemical environment.[Figure not available: see fulltext.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Welch, B.L.; Briggs, S.F.; Johansen, J.H.

Big sagebrush (Artemisia tridentata Nutt.) seeds were stored in three different environments; cool, constant temperature (refrigerator 10 degs. C); room temperature (14 to 24 degs. C); and a nonheated warehouse (-28 to +44 degs. C). In all three cases, humidity was held constant and equal. Significant drop in seed viability occurred first in the seed stored in the nonheated warehouse, followed by seed stored at room temperatures, and then seed stored at cool temperatures. It appeared from this study and studies by others that humidity control is more important to maintaining seed viability than temperature control. The old adage simplymore » states `store seeds in a cool and dry place` - but first make sure the seeds have been properly dried. Drying sagebrush seed during the cool, wet weather of the harvesting period creates special challenges to the producer.« less

Core-shell microstructured nanocomposites for synergistic adjustment of environmental temperature and humidity

PubMed Central

Zhang, Haiquan; Yuan, Yanping; Zhang, Nan; Sun, Qingrong; Cao, Xiaoling

2016-01-01

The adjustment of temperature and humidity is of great importance in a variety of fields. Composites that can perform both functions are prepared by mixing phase change materials (PCMs) with hygroscopic materials. However, the contact area between the adsorbent and humid air is inevitably decreased in such structures, which reduces the number of mass transfer channels for water vapor. An approach entailing the increase in the mass ratio of the adsorbent is presented here to improve the adsorption capacity. A core-shell CuSO4/polyethylene glycol (PEG) nanomaterial was developed to satisfy the conflicting requirements of temperature control and dehumidification. The results show that the equilibrium adsorption capacity of the PEG coating layer was enhanced by a factor of 188 compared with that of the pure PEG powder. The coating layer easily concentrates vapor, providing better adsorption properties for the composite. Furthermore, the volume modification of the CuSO4 matrix was reduced by 80% by the PEG coated layer, a factor that increases the stability of the composite. For the phase change process, the crystallization temperature of the coating layer was adjusted between 37.2 and 46.3 °C by interfacial tension. The core-shell CuSO4/PEG composite reported here provides a new general approach for the simultaneous control of temperature and humidity. PMID:27845371

40 CFR 1066.701 - Applicability and general provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Cold Temperature Test Procedures § 1066.701 Applicability and...) temperature range. (b) Do not apply the humidity correction factor in § 1066.615(a) for cold temperature...

The physical model for research of behavior of grouting mixtures

NASA Astrophysics Data System (ADS)

Hajovsky, Radovan; Pies, Martin; Lossmann, Jaroslav

2016-06-01

The paper deals with description of physical model designed for verification of behavior of grouting mixtures when applied below underground water level. Described physical model has been set up to determine propagation of grouting mixture in a given environment. Extension of grouting in this environment is based on measurement of humidity and temperature with the use of combined sensors located within preinstalled special measurement probes around grouting needle. Humidity was measured by combined capacity sensor DTH-1010, temperature was gathered by a NTC thermistor. Humidity sensors measured time when grouting mixture reached sensor location point. NTC thermistors measured temperature changes in time starting from initial of injection. This helped to develop 3D map showing the distribution of grouting mixture through the environment. Accomplishment of this particular measurement was carried out by a designed primary measurement module capable of connecting 4 humidity and temperature sensors. This module also takes care of converting these physical signals into unified analogue signals consequently brought to the input terminals of analogue input of programmable automation controller (PAC) WinPAC-8441. This controller ensures the measurement itself, archiving and visualization of all data. Detail description of a complex measurement system and evaluation in form of 3D animations and graphs is supposed to be in a full paper.

Humidity control and hydrophilic glue coating applied to mounted protein crystals improves X-ray diffraction experiments

PubMed Central

Baba, Seiki; Hoshino, Takeshi; Ito, Len; Kumasaka, Takashi

2013-01-01

Protein crystals are fragile, and it is sometimes difficult to find conditions suitable for handling and cryocooling the crystals before conducting X-ray diffraction experiments. To overcome this issue, a protein crystal-mounting method has been developed that involves a water-soluble polymer and controlled humid air that can adjust the moisture content of a mounted crystal. By coating crystals with polymer glue and exposing them to controlled humid air, the crystals were stable at room temperature and were cryocooled under optimized humidity. Moreover, the glue-coated crystals reproducibly showed gradual transformations of their lattice constants in response to a change in humidity; thus, using this method, a series of isomorphous crystals can be prepared. This technique is valuable when working on fragile protein crystals, including membrane proteins, and will also be useful for multi-crystal data collection. PMID:23999307

Effects of humid heat exposure in later sleep segments on sleep stages and body temperature in humans

NASA Astrophysics Data System (ADS)

Okamoto-Mizuno, Kazue; Tsuzuki, Kazuyo; Mizuno, Koh

2005-03-01

This study sought to investigate the effects of humid heat exposure in later sleep segments on sleep stages and body temperature in humans. The subjects were eight healthy males, from whom informed consent had been obtained. The experiments were carried out under three different sets of conditions: a control climate [air temperature (Ta)=26°C, relative humidity (RH)=50%] (C); a humid heat climate (Ta=32°C, RH=80%) (H); and a humid heat exposure in later sleep segments (C for the first 3 h 45 min, followed by a 30-min transition to H, which was then maintained for the last 3 h 45 min) (C H). Electroencephalogram, EOG, and mental electromyogram, rectal temperature (Tre), and skin temperature (Tsk) were continuously measured. The total amount of wakefulness was significantly increased in H compared to C H or C. Compared to C, wakefulness in C H and H was significantly increased during later sleep segments. Tre and mean Tsk were significantly higher in H than in C H or C. In C H, Tsk and Tre increased to levels equal to those observed in H after Ta and RH increase. Whole body sweat loss was significantly lower in C H and C than in H. These results suggest that humid heat exposure in the later sleep segment reduces thermal load as compared to full-night humid heat exposure. In daily life, the use of air conditioning in the initial sleep hours can protect sleep and thermoregulation.

Wireless sensor for temperature and humidity measurement

NASA Astrophysics Data System (ADS)

Drumea, Andrei; Svasta, Paul

2010-11-01

Temperature and humidity sensors have a broad range of applications, from heating and ventilation of houses to controlled drying of fruits, vegetables or meat in food industry. Modern sensors are integrated devices, usually MEMS, factory-calibrated and with digital output of measured parameters. They can have power down modes for reduced energy consumption. Such an integrated device allows the implementation of a battery powered wireless sensor when coupled with a low power microcontroller and a radio subsystem. A radio sensor can work independently or together with others in a radio network. Presented paper focuses mainly on measurement and construction aspects of sensors for temperature and humidity designed and implemented by authors; network aspects (communication between two or more sensors) are not analyzed.

Non-linear effects of mean temperature and relative humidity on dengue incidence in Guangzhou, China.

PubMed

Wu, Xiaocheng; Lang, Lingling; Ma, Wenjun; Song, Tie; Kang, Min; He, Jianfeng; Zhang, Yonghui; Lu, Liang; Lin, Hualiang; Ling, Li

2018-07-01

Dengue fever is an important infectious disease in Guangzhou, China; previous studies on the effects of weather factors on the incidence of dengue fever did not consider the linearity of the associations. This study evaluated the effects of daily mean temperature, relative humidity and rainfall on the incidence of dengue fever. A generalized additive model with splines smoothing function was performed to examine the effects of daily mean, minimum and maximum temperatures, relative humidity and rainfall on incidence of dengue fever during 2006-2014. Our analysis detected a non-linear effect of mean, minimum and maximum temperatures and relative humidity on dengue fever with the thresholds at 28°C, 23°C and 32°C for daily mean, minimum and maximum temperatures, 76% for relative humidity, respectively. Below the thresholds, there was a significant positive effect, the excess risk in dengue fever for each 1°C in the mean temperature at lag7-14days was 10.21%, (95% CI: 6.62% to 13.92%), 7.10% (95% CI: 4.99%, 9.26%) for 1°C increase in daily minimum temperature in lag 11days, and 2.27% (95% CI: 0.84%, 3.72%) for 1°C increase in daily maximum temperature in lag 10days; and each 1% increase in relative humidity of lag7-14days was associated with 1.95% (95% CI: 1.21% to 2.69%) in risk of dengue fever. Future prevention and control measures and epidemiology studies on dengue fever should consider these weather factors based on their exposure-response relationship. Copyright © 2018. Published by Elsevier B.V.

Some recent developments in spacecraft environmental control/life support subsystems

NASA Technical Reports Server (NTRS)

Gillen, R. J.; Olcott, T. M.

1974-01-01

The subsystems considered include a flash evaporator for heat rejection, a regenerable carbon dioxide and humidity control subsystem, an iodinating subsystem for potable water, a cabin contaminant control subsystem, and a wet oxidation subsystem for processing spacecraft wastes. The flash evaporator discussed is a simple unit which efficiently controls life support system temperatures over a wide range of heat loads. For certain advanced spacecraft applications the control of cabin carbon dioxide and humidity can be successfully achieved by a regenerable solid amine subsystem.

Influence of heat, wind, and humidity on ultraviolet radiation injury.

PubMed

Owens, D W; Knox, J M

1978-12-01

We investigated the influence of heat, wind, and humidity on UVR-induced acute and chronic skin damage of experimental animals housed in environmental chambers and irradiated under controlled conditions. Hairless mice (strain HRS/J) irradiated after an increase of 10 degrees F in skin temperature had more skin damage than irradiated controls. Significantly more Swiss albino mice irradiated for 400 days while maintained at 90 degrees F developed tumors than did those receiving the same amount of UVR but maintained at room temperature. Mice exposed to UVR daily for 4 weeks while kept in wind of 7 mph had greater damage and slower recovery than animals irradiated but protected from wind. Wind also accelerated tumorigenesis in mice than received chronic UVR. Mice kept at 80% relative humidity and given a single dose of UVR had greater skin injury than animals irradiated while at 5% relative humidity. High midity also appears to accelerate skin cancer formation in animals that were exposed to chronic UVR.

Mask humidity during CPAP: influence of ambient temperature, heated humidification and heated tubing.

PubMed

Nilius, Georg; Domanski, Ulrike; Schroeder, Maik; Woehrle, Holger; Graml, Andrea; Franke, Karl-Josef

2018-01-01

Mucosal drying during continuous positive airway pressure (CPAP) therapy is problematic for many patients. This study assessed the influence of ambient relative humidity (rH) and air temperature (T) in winter and summer on mask humidity during CPAP, with and without mask leak, and with or without heated humidification ± heated tubing. CPAP (8 and 12 cmH 2 O) without humidification (no humidity [nH]), with heated humidification controlled by ambient temperature and humidity (heated humidity [HH]) and HH plus heated tubing climate line (CL), with and without leakage, were compared in 18 subjects with OSA during summer and winter. The absolute humidity (aH) and the T inside the mask during CPAP were significantly lower in winter versus summer under all applied conditions. Overall, absolute humidity differences between summer and winter were statistically significant in both HH and CL vs. nH ( p < 0.05) in the presence and absence of mouth leak. There were no significant differences in aH between HH and CL. However, in-mask temperature during CL was higher ( p < 0.05) and rH lower than during HH. In winter, CPAP with CL was more likely to keep rH constant at 80% than CPAP without humidification or with standard HH. Clinically-relevant reductions in aH were documented during CPAP given under winter conditions. The addition of heated humidification, using a heated tube to avoid condensation is recommended to increase aH, which could be useful in CPAP users complaining of nose and throat symptoms.

Mask humidity during CPAP: influence of ambient temperature, heated humidification and heated tubing

PubMed Central

Nilius, Georg; Domanski, Ulrike; Schroeder, Maik; Woehrle, Holger; Graml, Andrea; Franke, Karl-Josef

2018-01-01

Purpose Mucosal drying during continuous positive airway pressure (CPAP) therapy is problematic for many patients. This study assessed the influence of ambient relative humidity (rH) and air temperature (T) in winter and summer on mask humidity during CPAP, with and without mask leak, and with or without heated humidification ± heated tubing. Methods CPAP (8 and 12 cmH2O) without humidification (no humidity [nH]), with heated humidification controlled by ambient temperature and humidity (heated humidity [HH]) and HH plus heated tubing climate line (CL), with and without leakage, were compared in 18 subjects with OSA during summer and winter. Results The absolute humidity (aH) and the T inside the mask during CPAP were significantly lower in winter versus summer under all applied conditions. Overall, absolute humidity differences between summer and winter were statistically significant in both HH and CL vs. nH (p < 0.05) in the presence and absence of mouth leak. There were no significant differences in aH between HH and CL. However, in-mask temperature during CL was higher (p < 0.05) and rH lower than during HH. In winter, CPAP with CL was more likely to keep rH constant at 80% than CPAP without humidification or with standard HH. Conclusion Clinically-relevant reductions in aH were documented during CPAP given under winter conditions. The addition of heated humidification, using a heated tube to avoid condensation is recommended to increase aH, which could be useful in CPAP users complaining of nose and throat symptoms. PMID:29750062

The effect of simulated field storage conditions on the accuracy of rapid user-friendly blood pathogen detection kits.

PubMed

Bienek, Diane R; Charlton, David G

2012-05-01

Being able to test for the presence of blood pathogens at forward locations could reduce morbidity and mortality in the field. Rapid, user-friendly blood typing kits for detecting Human Immunodeficiency Virus (HIV), Hepatitis C Virus (HCV), and Hepatitis B Virus (HBV) were evaluated to determine their accuracy after storage at various temperatures/humidities. Rates of positive tests of control groups, experimental groups, and industry standards were compared (Fisher's exact chi2, p < or = 0.05). Compared to the control group, 2 of 10 HIV detection devices were adversely affected by exposure to high temperature/high humidity or high temperature/low humidity. With one exception, none of the environmentally exposed HCV or HBV detection devices exhibited significant differences compared to those stored under control conditions. For HIV, HCV, and HBV devices, there were differences compared to the industry standard. Collectively, this evaluation of pathogen detection kits revealed that diagnostic performance varies among products and storage conditions, and that the tested products cannot be considered to be approved for use to screen blood, plasma, cell, or tissue donors.

Sensor fabrication method for in situ temperature and humidity monitoring of light emitting diodes.

PubMed

Lee, Chi-Yuan; Su, Ay; Liu, Yin-Chieh; Chan, Pin-Cheng; Lin, Chia-Hung

2010-01-01

In this work micro temperature and humidity sensors are fabricated to measure the junction temperature and humidity of light emitting diodes (LED). The junction temperature is frequently measured using thermal resistance measurement technology. The weakness of this method is that the timing of data capture is not regulated by any standard. This investigation develops a device that can stably and continually measure temperature and humidity. The device is light-weight and can monitor junction temperature and humidity in real time. Using micro-electro-mechanical systems (MEMS), this study minimizes the size of the micro temperature and humidity sensors, which are constructed on a stainless steel foil substrate (40 μm-thick SS-304). The micro temperature and humidity sensors can be fixed between the LED chip and frame. The sensitivities of the micro temperature and humidity sensors are 0.06±0.005 (Ω/°C) and 0.033 pF/%RH, respectively.

Effects of humidity on sterilization of Geobacillus stearothermophilus spores with plasma-excited neutral gas

NASA Astrophysics Data System (ADS)

Matsui, Kei; Ikenaga, Noriaki; Sakudo, Noriyuki

2015-06-01

We investigate the effects of relative humidity on the sterilization process using a plasma-excited neutral gas that uniformly sterilizes both the space and inner wall of the reactor chamber at atmospheric pressure. Only reactive neutral species such as plasma-excited gas molecules and radicals were separated from the plasma and sent to the reactor chamber for chemical sterilization. The plasma source gas is nitrogen mixed with 0.1% oxygen, and the relative humidity in the source gas is controlled by changing the mixing ratio of water vapor. The relative humidity near the sample in the reactor chamber is controlled by changing the sample temperature. As a result, the relative humidity near the sample should be kept in the range from 60 to 90% for the sterilization of Geobacillus stearothermophilus spores. When the relative humidity in the source gas increases from 30 to 90%, the sterilization effect is enhanced by the same degree.

Thermal control extravehicular life support system

NASA Technical Reports Server (NTRS)

1975-01-01

The results of a comprehensive study which defined an Extravehicular Life Support System Thermal Control System (TCS) are presented. The design of the prototype hardware and a detail summary of the prototype TCS fabrication and test effort are given. Several heat rejection subsystems, water management subsystems, humidity control subsystems, pressure control schemes and temperature control schemes were evaluated. Alternative integrated TCS systems were studied, and an optimum system was selected based on quantitative weighing of weight, volume, cost, complexity and other factors. The selected subsystem contains a sublimator for heat rejection, bubble expansion tank for water management, a slurper and rotary separator for humidity control, and a pump, a temperature control valve, a gas separator and a vehicle umbilical connector for water transport. The prototype hardware complied with program objectives.

Compensating for Effects of Humidity on Electronic Noses

NASA Technical Reports Server (NTRS)

Homer, Margie; Ryan, Margaret A.; Manatt, Kenneth; Zhou, Hanying; Manfreda, Allison

2004-01-01

A method of compensating for the effects of humidity on the readouts of electronic noses has been devised and tested. The method is especially appropriate for use in environments in which humidity is not or cannot be controlled for example, in the vicinity of a chemical spill, which can be accompanied by large local changes in humidity. Heretofore, it has been common practice to treat water vapor as merely another analyte, the concentration of which is determined, along with that of the other analytes, in a computational process based on deconvolution. This practice works well, but leaves room for improvement: changes in humidity can give rise to large changes in electronic-nose responses. If corrections for humidity are not made, the large humidity-induced responses may swamp smaller responses associated with low concentrations of analytes. The present method offers an improvement. The underlying concept is simple: One augments an electronic nose with a separate humidity and a separate temperature sensor. The outputs of the humidity and temperature sensors are used to generate values that are subtracted from the readings of the other sensors in an electronic nose to correct for the temperature-dependent contributions of humidity to those readings. Hence, in principle, what remains after corrections are the contributions of the analytes only. Laboratory experiments on a first-generation electronic nose have shown that this method is effective and improves the success rate of identification of analyte/ water mixtures. Work on a second-generation device was in progress at the time of reporting the information for this article.

Elevated relative humidity increases the incidence of boron deficiency in bedding plants

USDA-ARS?s Scientific Manuscript database

High relative humidity (RH) can cause lower concentrations of B accumulating in plants. The common greenhouse practice of controlling excess temperatures by applying mist irrigation to youngplants (plugs) results in elevated RH levels. Reports of boron (B) deficiency have become more prevalent ove...

Development of automated control system for wood drying

NASA Astrophysics Data System (ADS)

Sereda, T. G.; Kostarev, S. N.

2018-05-01

The article considers the parameters of convective wood drying which allows changing the characteristics of the air that performs drying at different stages: humidity, temperature, speed and direction of air movement. Despite the prevalence of this type of drying equipment, the main drawbacks of it are: the high temperature and humidity, negatively affecting the working conditions of maintenance personnel when they enter the drying chambers. It makes the automation of wood drying process necessary. The synthesis of a finite state of a machine control of wood drying process is implemented on a programmable logic device Omron.

Application of a Novel Liquid Nitrogen Control Technique for Heat Stress and Fire Prevention in Underground Mines.

PubMed

Shi, Bobo; Ma, Lingjun; Dong, Wei; Zhou, Fubao

2015-01-01

With the continually increasing mining depths, heat stress and spontaneous combustion hazards in high-temperature mines are becoming increasingly severe. Mining production risks from natural hazards and exposures to hot and humid environments can cause occupational diseases and other work-related injuries. Liquid nitrogen injection, an engineering control developed to reduce heat stress and spontaneous combustion hazards in mines, was successfully utilized for environmental cooling and combustion prevention in an underground mining site named "Y120205 Working Face" (Y120205 mine) of Yangchangwan colliery. Both localized humidities and temperatures within the Y120205 mine decreased significantly with liquid nitrogen injection. The maximum percentage drop in temperature and humidity of the Y120205 mine were 21.9% and 10.8%, respectively. The liquid nitrogen injection system has the advantages of economical price, process simplicity, energy savings and emission reduction. The optimized heat exchanger used in the liquid nitrogen injection process achieved superior air-cooling results, resulting in considerable economic benefits.

Environmental Control and Life Support Systems

NASA Technical Reports Server (NTRS)

Engel, Joshua Allen

2017-01-01

The Environmental Control System provides a controlled air purge to Orion and SLS. The ECS performs this function by processing 100% ambient air while simultaneously controlling temperature, pressure, humidity, cleanliness and purge distribution.

Design of indoor temperature and humidity detection system based on single chip microcomputer

NASA Astrophysics Data System (ADS)

Fu, Xiuwei; Fu, Li; Ma, Tianhui

2018-03-01

The indoor temperature and humidity detection system based on STC15F2K60S2 is designed in this paper. The temperature and humidity sensor DHT22 to monitor the indoor temperature and humidity are used, and the temperature and humidity data to the user's handheld device are wirelessly transmitted, when the temperature reaches or exceeds the user set the temperature alarm value, and the system sound and light alarm, to remind the user.

[An automatic dew-point hygrometer making use of beta-ray backscattering (author's transl)].

PubMed

Matsumoto, S; Kobayashi, H

1981-04-01

A proportional control system was employed on this hygrometer. The hygrometer was used in a box in which the temperature and the humidity were constantly regulated. The range of measured dew-point was from -26 degrees C to 60 degrees C in the atmospheric temperature of 0 degree C to 60 degrees C, that was the relative humidity of 12% to 100%, and the accuracy of the measurement was +/- 1 degree C.

Effects of atmospheric temperature and humidity on outbreak of diseases.

PubMed

Choi, Sung Hyuk; Lee, Sung Woo; Hong, Yun Sik; Kim, Su Jin; Kim, Nak Hoon

2007-12-01

The present study aimed to determine the plausibility of forecasting the outbreak of diseases based on the weather by analysing the impact of atmospheric temperature and humidity on the occurrence of different diseases. The subjects of the present study were the 30,434 patients who visited the ED in 1 year from 1 February 2005 to 3 February 2006. The present study analysed the correlation between the daily number of patients who suffered from 22 types of traumatic and non-traumatic diseases and the data on atmospheric temperature and humidity provided by the Korea Meteorological Administration. With traumatic disease, the occurrence tended to increase in proportion to the rise in temperature and humidity; whereas with non-traumatic disease, the occurrence tended to increase according to the rise in temperature, irrespective of humidity changes. The research on the impact of atmospheric temperature and humidity on different diseases revealed a high level of distribution of most diseases in an environment with high temperature and humidity. However, in the case of pulmonary diseases and trauma to multiple body regions, the occurrence increased in environments with low temperature and high humidity for pulmonary diseases, and with low temperature and low humidity for trauma to multiple body regions. Most diseases tend to increase in proportion to the rise in atmospheric temperature whereas being less affected by humidity. However, an increase in humidity in an optimum range of atmospheric temperature (12 degrees C or higher) triggers an increase in the occurrence of diseases.

The effect of heat and moisture exchanger and gas flow on humidity and temperature in a circle anaesthetic system.

PubMed

Poopalalingam, R; Goh, M H; Chan, Y W

2002-11-01

The aim of the study was to measure the humidity and temperature of the inspired gas in a circle absorber system at fresh gas flows of 11/min and 31/min and assess the need of a heat and moisture exchanger (HME). This prospective randomised controlled study received the Hospital Ethics Committee approval and informed consent. Forty adult ASA 1 and 11 patients were randomised into four groups to receive with or without HME fresh gas flow of 1L/min or 3L/min. Temperature and the relative humidity readings were taken at the start and every 10 minutes for the first hour of anaesthesia. There was a significantly higher relative humidity, absolute humidity and temperatures of the inspired gases at fresh gas flow of 1L/min and 3L/min with a HME compared to 3L/min without HME. Patients receiving fresh gas flows of lL/min had higher relative and absolute humidity than patients with fresh gas flows of 3L/min. However, the addition of the HME improved the absolute and relative humidity of the inspired gas in patients receiving fresh gas flow of 3l/min to a comparable level. However, the addition of a HME to a fresh gas flow of 1L/min did not significantly improve the humidity of the inspired gas. This suggests that the inherent humidifying property of the circle system at low fresh gas flow of 1L/min was sufficient in short surgeries lasting less than one hour and that the addition of a HME may not be necessary.

Fully Stretchable and Humidity-Resistant Quantum Dot Gas Sensors.

PubMed

Song, Zhilong; Huang, Zhao; Liu, Jingyao; Hu, Zhixiang; Zhang, Jianbing; Zhang, Guangzu; Yi, Fei; Jiang, Shenglin; Lian, Jiabiao; Yan, Jia; Zang, Jianfeng; Liu, Huan

2018-05-25

Stretchable gas sensors that accommodate the shape and motion characteristics of human body are indispensable to a wearable or attachable smart sensing system. However, these gas sensors usually have poor response and recovery kinetics when operated at room temperature, and especially suffer from humidity interference and mechanical robustness issues. Here, we demonstrate the first fully stretchable gas sensors which are operated at room temperature with enhanced stability against humidity. We created a crumpled quantum dot (QD) sensing layer on elastomeric substrate with flexible graphene as electrodes. Through the control over the prestrain of the flexible substrate, we achieved a 5.8 times improvement in NO 2 response at room temperature with desirable stretchability even under 1000 stretch/relax cycles mechanism deformation. The uniformly wavy structural configuration of the crumpled QD gas-sensing layer enabled an improvement in the antihumidity interference. The sensor response shows a minor vibration of 15.9% at room temperature from relative humidity of 0 to 86.7% compared to that of the flat-film sensors with vibration of 84.2%. The successful assembly of QD solids into a crumpled gas-sensing layer enabled a body-attachable, mechanically robust, and humidity-resistant gas sensor, opening up a new pathway to room-temperature operable gas sensors which may be implemented in future smart sensing systems such as stretchable electronic nose and multipurpose electronic skin.

Apparatus for investigating the reactions of soft-bodied invertebrates to controlled humidity gradients

PubMed Central

Russell, Joshua; Pierce-Shimomura, Jonathan T.

2015-01-01

Background While many studies have assayed behavioral responses of animals to chemical, temperature and light gradients, fewer studies have assayed how animals respond to humidity gradients. Our novel humidity chamber has allowed us to study the neuromolecular basis of humidity sensation in the nematode Caenorhabditis elegans (Russell et al. 2014). New Method We describe an easy-to-construct, low-cost humidity chamber to assay the behavior of small animals, including soft-bodied invertebrates, in controlled humidity gradients. Results We show that our humidity-chamber design is amenable to soft-bodied invertebrates and can produce reliable gradients ranging 0.3–8% RH/cm across a 9-cm long x 7.5-cm wide gel-covered arena. Comparison with Existing Method(s) Previous humidity chambers relied on circulating dry and moist air to produce a steep humidity gradient in a small arena (e.g. Sayeed & Benzer, 1996). To remove the confound of moving air that may elicit mechanical responses independent of humidity responses, our chamber controlled the humidity gradient using reservoirs of hygroscopic materials. Additionally, to better observe the behavioral mechanisms for humidity responses, our chamber provided a larger arena. Although similar chambers have been described previously, these approaches were not suitable for soft-bodied invertebrates or for easy imaging of behavior because they required that animals move across wire or fabric mesh. Conclusion The general applicability of our humidity chamber overcomes limitations of previous designs and opens the door to observe the behavioral responses of soft-bodied invertebrates, including genetically powerful C. elegans and Drosophila larvae. PMID:25176025

Dropwise condensation dynamics in humid air

NASA Astrophysics Data System (ADS)

Castillo Chacon, Julian Eduardo

Dropwise condensation of atmospheric water vapor is important in multiple practical engineering applications. The roles of environmental factors and surface morphology/chemistry on the condensation dynamics need to be better understood to enable efficient water-harvesting, dehumidication, and other psychrometric processes. Systems and surfaces that promote faster condensation rates and self-shedding of condensate droplets could lead to improved mass transfer rates and higher water yields in harvesting applications. The thesis presents the design and construction of an experimental facility that allows visualization of the condensation process as a function of relative humidity. Dropwise condensation experiments are performed on a vertically oriented, hydrophobic surface at a controlled relative humidity and surface subcooling temperature. The distribution and growth of water droplets are monitored across the surface at different relative humidities (45%, 50%, 55%, and 70%) at a constant surface subcooling temperature of 15 °C below the ambient temperature. The droplet growth dynamics exhibits a strong dependency on relative humidity in the early stages during which there is a large population of small droplets on the surface and single droplet growth dominates over coalescence effects. At later stages, the dynamics of droplet growth is insensitive to relative humidity due to the dominance of coalescence effects. The overall volumetric rate of condensation on the surface is also assessed as a function of time and ambient relative humidity. Low relative humidity conditions not only slow the absolute rate of condensation, but also prolong an initial transient regime over which the condensation rate remains significantly below the steady-state value. The current state-of-the-art in dropwise condensation research indicates the need for systematic experimental investigations as a function of relative humidity. The improved understanding of the relative humidity effects on the growth of single and distributed droplets offered in this thesis can improve the prediction of heat and mass transfer during dropwise condensation of humid air under differing environmental conditions. This knowledge can be used to engineer condenser systems and surfaces that are adapted for local ambient relative humidity and temperature conditions.

Influence of Temperature and Relative Humidity on the Insecticidal Efficacy of Metarhizium anisopliae against Larvae of Ephestia kuehniella (Lepidoptera: Pyralidae) on Wheat.

PubMed

Athanassiou, Christos G; Kavallieratos, Nickolas G; Rumbos, Christos I; Kontodimas, Demetrius C

2017-01-01

A series of laboratory bioassays were conducted for the evaluation of the insecticidal efficacy of an isolate of Metarhizium anisopliae (Metschnikoff) Sorokin (Ascomycota: Hypocreales) against larvae of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), under various temperature-relative humidity (r.h.) conditions. The fungus was applied at four doses (0, 8 × 106, 8 × 108, and 8 × 1010 conidia ml-1) on wheat and insect mortality was assessed after exposure of 1, 2, 7, and 14 d. Bioassays were conducted at three temperatures (20, 25, and 30 °C) and two r.h. levels (55 and 75%). Although complete control was not achieved in any case, the fungus provided a considerable level of insect control. Mortality of E. kuehniella larvae on wheat treated with M. anisopliae ranged between 41.1 and 93.3% after 14 d of exposure, whereas the respective mortality levels in control dishes never exceeded 28.3%. The increase of temperature resulted in most cases to higher efficacy, indicating that temperature is an important factor for the performance of the fungus. In contrast, in most cases r.h. did not significantly affect the efficacy of the fungus, at least for the humidity levels tested. © The Author 2017. Published by Oxford University Press on behalf of the Entomological Society of America.

Fixing atmospheric CO2 by environment adaptive sorbent and renewable energy

NASA Astrophysics Data System (ADS)

Wang, T.; Liu, J.; Ge, K.; Fang, M.

2014-12-01

Fixing atmospheric CO2, followed by geologic storage in remote areas is considered an environmentally secure approach to climate mitigation. A moisture swing sorbent was investigated in the laboratory for CO2 capture at a remote area with humid and windy conditions. The energy requirement of moisture swing absorption could be greatly reduced compared to that of traditional high-temperature thermal swing, by assuming that the sorbent can be naturally dried and regenerated at ambient conditions. However, for currently developed moisture swing materials, the CO2 capacity would drop significantly at high relative humidity. The CO2 capture amount can be reduced by the poor thermodynamics and kinetics at high relative humidity or low temperature. Similar challenges also exist for thermal or vacuum swing sorbents. Developing sorbent materials which adapt to specific environments, such as high humidity or low temperature, can ensure sufficient capture capacity on the one hand, and realize better economics on the other hand (Figure 1) .An environment adaptive sorbent should have the abilities of tunable capacity and fast kinetics at extreme conditions, such as high humidity or low temperature. In this presentation, the possibility of tuning CO2 absorption capacity of a polymerized ionic liquid material is discussed. The energy requirement evaluation shows that tuning the CO2 binding energy of sorbent, rather than increasing the temperature or reducing the humidity of air, could be much more economic. By determining whether the absorption process is controlled by physical diffusion controlled or chemical reaction, an effective approach to fast kinetics at extreme conditions is proposed. A shrinking core model for mass transfer kinetics is modified to cope with the relatively poor kinetics of air capture. For the studied sample which has a heterogeneous structure, the kinetic analysis indicates a preference of sorbent particle size optimization, rather than support layer optimization. Chemical reaction kinetics could be enhanced by stronger binding energy or higher temperature. However, the total kinetics can only be significantly improved by chemical reaction enhancement if the physical diffusion is fast enough.

Synergistic effects of temperature and humidity on the symptoms of COPD patients

NASA Astrophysics Data System (ADS)

Mu, Zhe; Chen, Pei-Li; Geng, Fu-Hai; Ren, Lei; Gu, Wen-Chao; Ma, Jia-Yun; Peng, Li; Li, Qing-Yun

2017-11-01

This panel study investigates how temperature, humidity, and their interaction affect chronic obstructive pulmonary disease (COPD) patients' self-reported symptoms. One hundred and six COPD patients from Shanghai, China, were enrolled, and age, smoking status, St. George Respiratory Questionnaire (SGRQ) score, and lung function index were recorded at baseline. The participants were asked to record their indoor temperature, humidity, and symptoms on diary cards between January 2011 and June 2012. Altogether, 82 patients finished the study. There was a significant interactive effect between temperature and humidity ( p < 0.0001) on COPD patients. When the indoor humidity was low, moderate, and high, the indoor temperature ORs were 0.969 (95% CI 0.922 to 1.017), 0.977 (0.962 to 0.999), and 0.920 (95% CI 0.908 to 0.933), respectively. Low temperature was a risk factor for COPD patients, and high humidity enhanced its risk on COPD. The indoor temperature should be kept at least on average at 18.2 °C, while the humidity should be less than 70%. This study demonstrates that temperature and humidity were associated with COPD patients' symptoms, and high humidity would enhance the risk of COPD due to low temperature.

Relationship between the humidity and temperature of inspired gas and the function of the airway mucosa.

PubMed

Williams, R; Rankin, N; Smith, T; Galler, D; Seakins, P

1996-11-01

To review the available literature on the relationship between the humidity and temperature of inspired gas and airway mucosal function. International computerized databases and published indices, experts in the field, conference proceedings, bibliographies. Two hundred articles/texts on respiratory tract physiology and humidification were reviewed. Seventeen articles were selected from 40 articles for inclusion in the published data verification of the model. Selection was by independent reviewers. Extraction was by consensus, and was based on finding sufficient data. A relationship exists between inspired gas humidity and temperature, exposure time to a given humidity level, and mucosal function. This relationship can be modeled and represented as an inspired humidity magnitude vs. exposure time map. The model is predictive of mucosal function and can be partially verified by the available literature. It predicts that if inspired humidity deviates from an optimal level, a progressive mucosal dysfunction begins. The greater the humidity deviation, the faster the mucosal dysfunction progresses. A model for the relationship between airway mucosal dysfunction and the combination of the humidity of inspired gas and the duration over which the airway mucosa is exposed to that humidity is proposed. This model suggests that there is an optimal temperature and humidity above which, and below which, there is impaired mucosal function. This optimal level of temperature and humidity is core temperature and 100% relative humidity. However, existing data are only sufficient to test this model for gas conditions below core temperature and 100% relative humidity. These data concur with the model in that region. No studies have yet looked at this relationship beyond 24 hrs. Longer exposure times to any given level of inspired humidity and inspired gas temperatures and humidities above core temperature and 100% relative humidity need to be studied to fully verify the proposed model.

A Fine-Tuned Metal-Organic Framework for Autonomous Indoor Moisture Control.

PubMed

AbdulHalim, Rasha G; Bhatt, Prashant M; Belmabkhout, Youssef; Shkurenko, Aleksander; Adil, Karim; Barbour, Leonard J; Eddaoudi, Mohamed

2017-08-09

Conventional adsorbents, namely zeolites and silica gel, are often used to control humidity by adsorbing water; however, adsorbents capable of the dual functionality of humidification and dehumidification, offering the desired control of the moisture level at room temperature, have yet to be explored. Here we report Y-shp-MOF-5, a hybrid microporous highly connected rare-earth-based metal-organic framework (MOF), with dual functionality for moisture control within the recommended range of relative humidity (45%-65% RH) set by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). Y-shp-MOF-5 exhibits exceptional structural integrity, robustness, and unique humidity-control performance, as confirmed by the large number (thousand) of conducted water vapor adsorption-desorption cycles. The retained structural integrity and the mechanism of water sorption were corroborated using in situ single-crystal X-ray diffraction (SCXRD) studies. The resultant working water uptake of 0.45 g·g -1 is solely regulated by a simple adjustment of the relative humidity, positioning this hydrolytically stable MOF as a prospective adsorbent for humidity control in confined spaces, such as space shuttles, aircraft cabins, and air-conditioned buildings.

Strong Influence of Humidity on Low-Temperature Thin-Film Fabrication via Metal Aqua Complex for High Performance Oxide Semiconductor Thin-Film Transistors.

PubMed

Lim, Keon-Hee; Huh, Jae-Eun; Lee, Jinwon; Cho, Nam-Kwang; Park, Jun-Woo; Nam, Bu-Il; Lee, Eungkyu; Kim, Youn Sang

2017-01-11

Oxide semiconductors thin film transistors (OS TFTs) with good transparency and electrical performance have great potential for future display technology. In particular, solution-processed OS TFTs have been attracted much attention due to many advantages such as continuous, large scale, and low cost processability. Recently, OS TFTs fabricated with a metal aqua complex have been focused because they have low temperature processability for deposition on flexible substrate as well as high field-effect mobility for application of advanced display. However, despite some remarkable results, important factors to optimize their electrical performance with reproducibility and uniformity have not yet been achieved. Here, we newly introduce the strong effects of humidity to enhance the electrical performance of OS TFTs fabricated with the metal aqua complex. Through humidity control during the spin-coating process and annealing process, we successfully demonstrate solution-processed InO x /SiO 2 TFTs with a good electrical uniformity of ∼5% standard deviation, showing high average field-effect mobility of 2.76 cm 2 V -1 s -1 and 15.28 cm 2 V -1 s -1 fabricated at 200 and 250 °C, respectively. Also, on the basis of the systematic analyses, we demonstrate the mechanism for the change in electrical properties of InO x TFTs depending on the humidity control. Finally, on the basis of the mechanism, we extended the humidity control to the fabrication of the AlO x insulator. Subsequently, we successfully achieved humidity-controlled InO x /AlO x TFTs fabricated at 200 °C showing high average field-effect mobility of 9.5 cm 2 V -1 s -1 .

The interaction effects of temperature and humidity on emergency room visits for respiratory diseases in Beijing, China.

PubMed

Su, Qin; Liu, Hongsheng; Yuan, Xiaoling; Xiao, Yan; Zhang, Xian; Sun, Rongju; Dang, Wei; Zhang, Jianbo; Qin, Yuhong; Men, Baozhong; Zhao, Xiaodong

2014-11-01

Few epidemiological studies have been reported as to whether there was any interactive effect between temperature and humidity on respiratory morbidity, especially in Asian countries. The present study used time-series analysis to explore the modification effects of humidity on the association between temperature and emergency room (ER) visits for respiratory, upper respiratory tract infection (URI), pneumonia, and bronchitis in Beijing between 2009 and 2011. Results showed that an obvious joint effect of temperature and humidity was revealed on ER visits for respiratory, URI, pneumonia, and bronchitis. Below temperature threshold, the temperature effect was stronger in low humidity level and presented a trend fall with humidity level increase. The effect estimates per 1 °C increase in temperature in low humidity level were -2.88 % (95 % confidence interval (CI) -3.08, -2.67) for all respiratory, -3.24 % (-3.59, -2.88) for URI, -1.48 % (-1.93, -1.03) for pneumonia, and -3.79 % (-4.37, -3.21) for bronchitis ER visits, respectively. However, above temperature threshold, temperature effect was greater in high humidity level and trending upward with humidity level increasing. In high humidity level, a 1 °C increase in temperature, the effect estimates were 1.84 % (1.55, 2.13) for all respiratory, 1.76 % (1.41, 2.11) for URI, and 7.48 % (4.41, 10.65) for bronchitis ER visits. But, there was no statistically significant for pneumonia. This suggests that the modifying effects of the humidity should be considered when analyzing health impacts of temperature.

Effects of desiccation stress on adult female longevity in Aedes aegypti and Ae. albopictus (Diptera: Culicidae): results of a systematic review and pooled survival analysis.

PubMed

Schmidt, Chris A; Comeau, Genevieve; Monaghan, Andrew J; Williamson, Daniel J; Ernst, Kacey C

2018-04-25

Transmission dynamics of mosquito-borne viruses such as dengue, Zika and chikungunya are affected by the longevity of the adult female mosquito. Environmental conditions influence the survival of adult female Aedes mosquitoes, the primary vectors of these viruses. While the association of temperature with Aedes mortality has been relatively well-explored, the role of humidity is less established. The current study's goals were to compile knowledge of the influence of humidity on adult survival in the important vector species Aedes aegypti and Ae. albopictus, and to quantify this relationship while accounting for the modifying effect of temperature. We performed a systematic literature review to identify studies reporting experimental results informing the relationships among temperature, humidity and adult survival in Ae. aegypti and Ae. albopictus. Using a novel simulation approach to harmonize disparate survival data, we conducted pooled survival analyses via stratified and mixed effects Cox regression to estimate temperature-dependent associations between humidity and mortality risk for these species across a broad range of temperatures and vapor pressure deficits. After screening 1517 articles, 17 studies (one in semi-field and 16 in laboratory settings) met inclusion criteria and collectively reported results for 192 survival experiments. We review and synthesize relevant findings from these studies. Our stratified model estimated a strong temperature-dependent association of humidity with mortality in both species, though associations were not significant for Ae. albopictus in the mixed effects model. Lowest mortality risks were estimated around 27.5 °C and 21.5 °C for Ae. aegypti and Ae. albopictus, respectively, and mortality increased non-linearly with decreasing humidity. Aedes aegypti had a survival advantage relative to Ae. albopictus in the stratified model under most conditions, but species differences were not significant in the mixed effects model. Humidity is associated with mortality risk in adult female Ae. aegypti in controlled settings. Data are limited at low humidities, temperature extremes, and for Ae. albopictus, and further studies should be conducted to reduce model uncertainty in these contexts. Desiccation is likely an important factor in Aedes population dynamics and viral transmission in arid regions. Models of Aedes-borne virus transmission may be improved by more comprehensively representing humidity effects.

High Performance Composites and Adhesives for V/STOL Aircraft.

DTIC Science & Technology

1984-02-22

out to examine the effect of humidity and out-time on the processing behavior and the mechanical properties of C-10/T-300 composites. 39 M&ffcici...stored at room temperature in two separate environmental chambers, controlled at l6% and 95/« relative humidity , respective- ly. At the end of every...NBS Special Publication 563, 17 (Oct 1979). " Effects of Prepreg Out-time and Humidity on the Composition and Processing of Polyimide/Graphite

Rheological behaviors of edible casein-based packaging films under extreme environmental conditions, using humidity-controlled dynamic mechanical analysis

USDA-ARS?s Scientific Manuscript database

Thin casein films for food packaging applications possess good strength and low oxygen permeability but low water-resistance and elasticity. Customizing the mechanical properties of the films to target specific behaviors depending on temperature and humidity changes would enable a variety of commerc...

Building environment analysis based on temperature and humidity for smart energy systems.

PubMed

Yun, Jaeseok; Won, Kwang-Ho

2012-10-01

In this paper, we propose a new HVAC (heating, ventilation, and air conditioning) control strategy as part of the smart energy system that can balance occupant comfort against building energy consumption using ubiquitous sensing and machine learning technology. We have developed ZigBee-based wireless sensor nodes and collected realistic temperature and humidity data during one month from a laboratory environment. With the collected data, we have established a building environment model using machine learning algorithms, which can be used to assess occupant comfort level. We expect the proposed HVAC control strategy will be able to provide occupants with a consistently comfortable working or home environment.

Frost Growth and Densification on a Flat Surface in Laminar Flow with Variable Humidity

NASA Technical Reports Server (NTRS)

Kandula, M.

2012-01-01

Experiments are performed concerning frost growth and densification in laminar flow over a flat surface under conditions of constant and variable humidity. The flat plate test specimen is made of aluminum-6031, and has dimensions of 0.3 mx0.3 mx6.35 mm. Results for the first variable humidity case are obtained for a plate temperature of 255.4 K, air velocity of 1.77 m/s, air temperature of 295.1 K, and a relative humidity continuously ranging from 81 to 54%. The second variable humidity test case corresponds to plate temperature of 255.4 K, air velocity of 2.44 m/s, air temperature of 291.8 K, and a relative humidity ranging from 66 to 59%. Results for the constant humidity case are obtained for a plate temperature of 263.7 K, air velocity of 1.7 m/s, air temperature of 295 K, and a relative humidity of 71.6 %. Comparisons of the data with the author's frost model extended to accommodate variable humidity suggest satisfactory agreement between the theory and the data for both constant and variable humidity.

Air Pressure Controlled Mass Measurement System

NASA Astrophysics Data System (ADS)

Zhong, Ruilin; Wang, Jian; Cai, Changqing; Yao, Hong; Ding, Jin'an; Zhang, Yue; Wang, Xiaolei

Mass measurement is influenced by air pressure, temperature, humidity and other facts. In order to reduce the influence, mass laboratory of National Institute of Metrology, China has developed an air pressure controlled mass measurement system. In this system, an automatic mass comparator is installed in an airtight chamber. The Chamber is equipped with a pressure controller and associate valves, thus the air pressure can be changed and stabilized to the pre-set value, the preferred pressure range is from 200 hPa to 1100 hPa. In order to keep the environment inside the chamber stable, the display and control part of the mass comparator are moved outside the chamber, and connected to the mass comparator by feed-throughs. Also a lifting device is designed for this system which can easily lift up the upper part of the chamber, thus weights can be easily put inside the mass comparator. The whole system is put on a marble platform, and the temperature and humidity of the laboratory is very stable. The temperature, humidity, and carbon dioxide content inside the chamber are measured in real time and can be used to get air density. Mass measurement cycle from 1100 hPa to 200 hPa and back to 1100 hPa shows the effective of the system.

Enhanced water vapor separation by temperature-controlled aligned-multiwalled carbon nanotube membranes.

PubMed

Jeon, Wonjae; Yun, Jongju; Khan, Fakhre Alam; Baik, Seunghyun

2015-09-14

Here we present a new strategy of selectively rejecting water vapor while allowing fast transport of dry gases using temperature-controlled aligned-multiwalled carbon nanotubes (aligned-MWNTs). The mechanism is based on the water vapor condensation at the entry region of nanotubes followed by removing aggregated water droplets at the tip of the superhydrophobic aligned-MWNTs. The first condensation step could be dramatically enhanced by decreasing the nanotube temperature. The permeate-side relative humidity was as low as ∼17% and the helium-water vapor separation factor was as high as 4.62 when a helium-water vapor mixture with a relative humidity of 100% was supplied to the aligned-MWNTs. The flow through the interstitial space of the aligned-MWNTs allowed the permeability of single dry gases an order of magnitude higher than the Knudsen prediction regardless of membrane temperature. The water vapor separation performance of hydrophobic polytetrafluoroethylene membranes could also be significantly enhanced at low temperatures. This work combines the membrane-based separation technology with temperature control to enhance water vapor separation performance.

Phase 1 engineering and technical data report for the thermal control extravehicular life support system

NASA Technical Reports Server (NTRS)

1975-01-01

A shuttle EVLSS Thermal Control System (TCS) is defined. Thirteen heat rejection subsystems, thirteen water management subsystems, nine humidity control subsystems, three pressure control schemes and five temperature control schemes are evaluated. Sixteen integrated TCS systems are studied, and an optimum system is selected based on quantitative weighting of weight, volume, cost, complexity and other factors. The selected sybsystem contains a sublimator for heat rejection, a bubble expansion tank for water management, and a slurper and rotary separator for humidity control. Design of the selected subsystem prototype hardware is presented.

Temperature and humidity control in indirect calorimeter chambers

USDA-ARS?s Scientific Manuscript database

A three-chamber, indirect calorimeter has been a part of the Environmental Laboratory at the U.S. Meat Animal Research Center (MARC) for over 25 yr. Corrosion of the animal chambers and unreliable temperature control forced either major repairs or complete replacement. There is a strong demand for...

7 CFR 28.301 - Measurement: humidity; temperature.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70 °F. ...

7 CFR 28.301 - Measurement: humidity; temperature.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70 °F. ...

7 CFR 28.301 - Measurement: humidity; temperature.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70° F. ...

7 CFR 28.301 - Measurement: humidity; temperature.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70 °F. ...

7 CFR 28.301 - Measurement: humidity; temperature.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Measurement: humidity; temperature. 28.301 Section 28... for Length of Staple § 28.301 Measurement: humidity; temperature. The length of staple of any cotton... its fibers under a relative humidity of the atmosphere of 65 percent and a temperature of 70 °F. ...

Challenges to Cabin Humidity Removal Presented by Intermittent Condensing Conditions

NASA Technical Reports Server (NTRS)

vonJouanne, Roger G.; Williams, David E.

2007-01-01

On-orbit temperature and humidity control (THC) is more easily accomplished when the THC hardware is either consistently dry (i.e., no humidity control is occurring), or consistently wet. The system is especially challenged when intermittent wet/dry conditions occur. The first six years of on-orbit ISS operations have revealed specific concerns within the THC system, specifically in the condensing heat exchanger and the downstream air/water separator. Failed or degraded hardware has been returned to ground and investigated. This paper presents the investigation findings, and the recommended hardware and procedural revisions to prevent and recover from the effects of intermittent condensing conditions.

Measurement and Control System Based on Wireless Senor Network for Granary

NASA Astrophysics Data System (ADS)

Song, Jian

A wireless measurement and control system for granary is developed for the sake of overcoming the shortcoming of the wired measurement and control system such as complex wiring and low anti-interference capacity. In this system, Zigbee technology is applied with Zigbee protocol stack development platform by TI, and wireless senor network is used to collect and control the temperature and the humidity. It is composed of the upper PC, central control node based on CC2530, sensor nodes, sensor modules and the executive device. The wireless sensor node is programmed by C language in IAR Embedded Workbench for MCS-51 Evaluation environment. The upper PC control system software is developed based on Visual C++ 6.0 platform. It is shown by experiments that data transmission in the system is accurate and reliable and the error of the temperature and humidity is below 2%, meeting the functional requirements for the granary measurement and control system.

Insufficient Humidification of Respiratory Gases in Patients Who Are Undergoing Therapeutic Hypothermia at a Paediatric and Adult Intensive Care Unit.

PubMed

Tanaka, Yukari; Iwata, Sachiko; Kinoshita, Masahiro; Tsuda, Kennosuke; Tanaka, Shoichiro; Hara, Naoko; Shindou, Ryota; Harada, Eimei; Kijima, Ryouji; Yamaga, Osamu; Ohkuma, Hitoe; Ushijima, Kazuo; Sakamoto, Teruo; Yamashita, Yushiro; Iwata, Osuke

2017-01-01

For cooled newborn infants, humidifier settings for normothermic condition provide excessive gas humidity because absolute humidity at saturation is temperature-dependent. To assess humidification of respiratory gases in patients who underwent moderate therapeutic hypothermia at a paediatric/adult intensive care unit, 6 patients were studied over 9 times. Three humidifier settings, 37-default (chamber-outlet, 37°C; Y-piece, 40°C), 33.5-theoretical (chamber-outlet, 33.5°C; Y-piece, 36.5°C), and 33.5-adjusted (optimised setting to achieve saturated vapour at 33.5°C using feedback from a thermohygrometer), were tested. Y-piece gas temperature/humidity and the incidence of high (>40.6 mg/L) and low (<32.9 mg/L) humidity relative to the target level (36.6 mg/L) were assessed. Y-piece gas humidity was 32.0 (26.8-37.3), 22.7 (16.9-28.6), and 36.9 (35.5-38.3) mg/L {mean (95% confidence interval)} for 37-default setting, 33.5-theoretical setting, and 33.5-adjusted setting, respectively. High humidity was observed in 1 patient with 37-default setting, whereas low humidity was seen in 5 patients with 37-default setting and 8 patients with 33.5-theoretical setting. With 33.5-adjusted setting, inadequate Y-piece humidity was not observed. Potential risks of the default humidifier setting for insufficient respiratory gas humidification were highlighted in patients cooled at a paediatric/adult intensive care unit. Y-piece gas conditions can be controlled to the theoretically optimal level by adjusting the setting guided by Y-piece gas temperature/humidity.

Insufficient Humidification of Respiratory Gases in Patients Who Are Undergoing Therapeutic Hypothermia at a Paediatric and Adult Intensive Care Unit

PubMed Central

Tanaka, Yukari; Iwata, Sachiko; Kinoshita, Masahiro; Tsuda, Kennosuke; Tanaka, Shoichiro; Hara, Naoko; Shindou, Ryota; Harada, Eimei; Kijima, Ryouji; Yamaga, Osamu; Ohkuma, Hitoe; Ushijima, Kazuo; Sakamoto, Teruo; Yamashita, Yushiro

2017-01-01

For cooled newborn infants, humidifier settings for normothermic condition provide excessive gas humidity because absolute humidity at saturation is temperature-dependent. To assess humidification of respiratory gases in patients who underwent moderate therapeutic hypothermia at a paediatric/adult intensive care unit, 6 patients were studied over 9 times. Three humidifier settings, 37-default (chamber-outlet, 37°C; Y-piece, 40°C), 33.5-theoretical (chamber-outlet, 33.5°C; Y-piece, 36.5°C), and 33.5-adjusted (optimised setting to achieve saturated vapour at 33.5°C using feedback from a thermohygrometer), were tested. Y-piece gas temperature/humidity and the incidence of high (>40.6 mg/L) and low (<32.9 mg/L) humidity relative to the target level (36.6 mg/L) were assessed. Y-piece gas humidity was 32.0 (26.8–37.3), 22.7 (16.9–28.6), and 36.9 (35.5–38.3) mg/L {mean (95% confidence interval)} for 37-default setting, 33.5-theoretical setting, and 33.5-adjusted setting, respectively. High humidity was observed in 1 patient with 37-default setting, whereas low humidity was seen in 5 patients with 37-default setting and 8 patients with 33.5-theoretical setting. With 33.5-adjusted setting, inadequate Y-piece humidity was not observed. Potential risks of the default humidifier setting for insufficient respiratory gas humidification were highlighted in patients cooled at a paediatric/adult intensive care unit. Y-piece gas conditions can be controlled to the theoretically optimal level by adjusting the setting guided by Y-piece gas temperature/humidity. PMID:28512388

Integrated energy balance analysis for Space Station Freedom

NASA Technical Reports Server (NTRS)

Tandler, John

1991-01-01

An integrated simulation model is described which characterizes the dynamic interaction of the energy transport subsystems of Space Station Freedom for given orbital conditions and for a given set of power and thermal loads. Subsystems included in the model are the Electric Power System (EPS), the Internal Thermal Control System (ITCS), the External Thermal Control System (ETCS), and the cabin Temperature and Humidity Control System (THC) (which includes the avionics air cooling, cabin air cooling, and intermodule ventilation systems). Models of the subsystems were developed in a number of system-specific modeling tools and validated. The subsystem models are then combined into integrated models to address a number of integrated performance issues involving the ability of the integrated energy transport system of Space Station Freedom to provide power, controlled cabin temperature and humidity, and equipment thermal control to support operations.

Improving the performance of air-conditioning systems in an ASEAN (Association of South East Asian Nations) climate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Busch, J.F.; Warren, M.L.

1988-09-01

This paper describes an analysis of air conditioning performance under hot and humid tropical climate conditions appropriate to the Association of South East Asian Nations (ASEAN) countries. This region, with over 280 million people, has one of the fastest economic and energy consumption growth rates in the world. The work reported here is aimed at estimating the conservation potential derived from good design and control of air conditioning systems in commercial buildings. To test the performance of different air conditioning system types and control options, whole building energy performance was simulated using DOE-2. The 5100 m/sup 2/ (50,000 ft/sup 2/)more » prototype office building module was previously used in earlier commercial building energy standards analysis for Malaysia and Singapore. In general, the weather pattern for ASEAN countries is uniform, with hot and humid air masses known as ''monsoons'' dictating the weather patterns. Since a concentration of cities occurs near the tip of the Malay peninsula, hourly temperature, humidity, and wind speed data for Kuala Lumpur was used for the analysis. Because of the absence of heating loads in ASEAN regions, we have limited air conditioning configurations to two pipe fan coil, constant volume, variable air volume, powered induction, and ceiling bypass configurations. Control strategies were varied to determine the conservation potential in both energy use and peak electric power demands. Sensitivities including fan control, pre-cooling and night ventilation, supply air temperature control, zone temperature set point, ventilation and infiltration, daylighting and internal gains, and system sizing were examined and compared with a base case which was a variable air volume system with no reheat or economizer. Comfort issues, such as over-cooling and space humidity, were also examined.« less

Projected regional changes in the characteristics of dry and moist heat waves in the United States derived from downscaled CMIP5 models

NASA Astrophysics Data System (ADS)

Schoof, J. T.

2017-12-01

Extreme temperatures affect society in multiple ways, but the impacts are often different depending on the concurrent humidity. For example, the greatest impacts on human morbidity and mortality result when the temperature and humidity are both elevated. Conversely, high temperatures coupled with low humidity often lead to agricultural impacts resulting in lower yields. Despite the importance of humidity in determining heat wave impacts, relatively few students of future temperature extremes have also considered possible changes in humidity. In a recent study, we investigated recent historical changes in the frequency and intensity and low humidity and high humidity extreme temperature events using a framework based on isobaric equivalent temperature. Here, we extend this approach to climate projections from CMIP5 models to explore possible regional changes in extreme heat characteristics. After using quantile mapping to bias correct and downscale the CMIP5 model outputs, we analyze results from two future periods (2031-2055 and 2061-2085) and two representative concentration pathways, RCP 4.5 and RCP 8.5, corresponding to moderate and high levels of radiative forcing from greenhouse gases. For each of seven US regions, we consider changes in extreme temperature frequency, changes in the proportion of extreme temperature days characterized by high humidity, and changes in the magnitude of temperature and humidity on extreme temperature days.

Effects of Temperature and Humidity on Laser Diffraction Measurements to Jet Nebulizer and Comparison with NGI.

PubMed

Song, Xinghan; Hu, Junhua; Zhan, Shuyao; Zhang, Rui; Tan, Wen

2016-04-01

Laser diffraction (LD) and next generation impactor (NGI) are commonly used for the evaluation of inhaled drug formulations. In this study, the effect of temperature and humidity on the assessment of the nebulizer particle size distribution (PSD) by LD was investigated, and the consistency between NGI and LD measurements was evaluated. There was an increase in particle size with higher temperature or lower humidity. The particle population with a diameter less than 1 μm was significant at a temperature of 5°C or at relative humidity >90%; however, the same particle population became undetectable when temperature increased to 39°C or at relative humidity of 30-45%. The results of the NGI and LD measurements of aerosol generated from three types of jet nebulizers were compared. A poor correlation between the NGI and LD measurements was observed for PARI LC (2.2 μm) (R (2) = 0.893) and PARI LC (2.9 μm) (R (2) = 0.878), while a relatively good correlation (R (2) = 0.977) was observed for the largest particle size nebulizer (PARI TIA (8.6 μm)). We conclude that the ambient environment and the nebulizer have significant impacts on the performance and consistency between these instruments. These factors should be controlled in the evaluation of inhaled aerosol drug formulations when these instruments are used individually or in combination.

The anthropogenic influence on heat and humidity in the US Midwest

NASA Astrophysics Data System (ADS)

Inda Diaz, H. A.; O'Brien, T. A.; Stone, D. A.

2016-12-01

Heatwaves, and extreme temperatures in general, have a wide range of negative impacts on society, and particularly on human health. In addition to temperature, humidity plays a key role in regulating human body temperature, with higher humidities tending to reduce the effectiveness of perspiration. There is recent theoretical and observational evidence that co-occurring extreme heat and humidity can potentially have a much more dramatic impact on human health than either extreme in isolation. There is an abundance of observational evidence indicating that anthropogenic increases in greenhouse gas (GHG) forcing have contributed to an increase in the intensity and frequency of temperature extremes on a global scale. However, aside from purely thermodynamically-driven increases in near-surface humidity, there is a paucity of similar evidence for anthropogenic impacts on humidity. Thermodynamic scaling would suggest that air masses originating from the ocean would be associated with higher specific humidity in a warmer world, and transpiration from irrigated crops could further increase humidity in warm air masses. In order to explore the role of anthropogenic GHG forcing on the co-occurrence of temperature and humidity extremes in the Midwestern United States (US), we evaluate a large ensemble of global climate model simulations with and without anthropogenic GHG forcing. In particular, we examine differences between the probability distributions of near-surface temperature, humidity, wet-bulb temperature, and the joint distribution of temperature and humidity in this ensemble. Finally, we explore augmenting this experimental framework with additional simulations to explore the role of anthropogenic changes in the land surface, and in particular irrigated crops, on co-occurring extreme heat and humidity.

Development of Algorithms for Control of Humidity in Plant Growth Chambers

NASA Technical Reports Server (NTRS)

Costello, Thomas A.

2003-01-01

Algorithms were developed to control humidity in plant growth chambers used for research on bioregenerative life support at Kennedy Space Center. The algorithms used the computed water vapor pressure (based on measured air temperature and relative humidity) as the process variable, with time-proportioned outputs to operate the humidifier and de-humidifier. Algorithms were based upon proportional-integral-differential (PID) and Fuzzy Logic schemes and were implemented using I/O Control software (OPTO-22) to define and download the control logic to an autonomous programmable logic controller (PLC, ultimate ethernet brain and assorted input-output modules, OPTO-22), which performed the monitoring and control logic processing, as well the physical control of the devices that effected the targeted environment in the chamber. During limited testing, the PLC's successfully implemented the intended control schemes and attained a control resolution for humidity of less than 1%. The algorithms have potential to be used not only with autonomous PLC's but could also be implemented within network-based supervisory control programs. This report documents unique control features that were implemented within the OPTO-22 framework and makes recommendations regarding future uses of the hardware and software for biological research by NASA.

A dynamic tester to evaluate the thermal and moisture behaviour of the surface of textiles.

PubMed

Li, Wenbin; Xu, Weilin; Wang, Hao; Wang, Xin

2016-01-01

The thermal and moisture behaviour of the microclimate of textiles is crucial in determining the physiological comfort of apparel, but it has not been investigated sufficiently due to the lack of particular evaluation techniques. Based on sensing, temperature controlling and wireless communicating technology, a specially designed tester has been developed in this study to evaluate the thermal and moisture behaviour of the surface of textiles in moving status. A temperature acquisition system and a temperature controllable hotplate have been established to test temperature and simulate the heat of human body, respectively. Relative humidity of the surface of fabric in the dynamic process has been successfully tested through sensing. Meanwhile, wireless communication technology was applied to transport the acquired data of temperature and humidity to computer for further processing. Continuous power supply was achieved by intensive contact between an elastic copper plate and copper ring on the rotating shaft. This tester provides the platform to evaluate the thermal and moisture behaviour of textiles. It enables users to conduct a dynamic analysis on the temperature and humidity together with the thermal and moisture transport behaviour of the surface of fabric in moving condition. Development of this tester opens the door of investigation on the micro-climate of textiles in real time service, and eventually benefits the understanding of the sensation comfort and wellbeing of apparel wearers. Copyright © 2015 Elsevier Ltd. All rights reserved.

Oxidation and Hydration of U 3O 8 Materials Following Controlled Exposure to Temperature and Humidity

DOE PAGES

Tamasi, Alison L.; Boland, Kevin S.; Czerwinski, Kenneth; ...

2015-03-18

Chemical signatures correlated with uranium oxide processing are of interest to forensic science for inferring sample provenance. Identification of temporal changes in chemical structures of process uranium materials as a function of controlled temperatures and relative humidities may provide additional information regarding sample history. In our study, a high-purity α-U 3O 8 sample and three other uranium oxide samples synthesized from reaction routes used in nuclear conversion processes were stored under controlled conditions over 2–3.5 years, and powder X-ray diffraction analysis and X-ray absorption spectroscopy were employed to characterize chemical speciation. We measured signatures from the α-U 3O 8 samplemore » indicated that the material oxidized and hydrated after storage under high humidity conditions over time. Impurities, such as uranyl fluoride or schoepites, were initially detectable in the other uranium oxide samples. After storage under controlled conditions, the analyses of the samples revealed oxidation over time, although the signature of the uranyl fluoride impurity diminished. The presence of schoepite phases in older uranium oxide material is likely indicative of storage under high humidity and should be taken into account for assessing sample history. Finally, the absence of a signature from a chemical impurity, such as uranyl fluoride hydrate, in an older material may not preclude its presence at the initial time of production.« less

Oxidation and Hydration of U 3 O 8 Materials Following Controlled Exposure to Temperature and Humidity

DOE PAGES

Tamasi, Alison L.; Boland, Kevin S.; Czerwinski, Kenneth; ...

2015-03-18

Chemical signatures correlated with uranium oxide processing are of interest to forensic science for inferring sample provenance. Identification of temporal changes in chemical structures of process uranium materials as a function of controlled temperatures and relative humidities may provide additional information regarding sample history. In our study, a high-purity α-U 3O 8 sample and three other uranium oxide samples synthesized from reaction routes used in nuclear conversion processes were stored under controlled conditions over 2–3.5 years, and powder X-ray diffraction analysis and X-ray absorption spectroscopy were employed to characterize chemical speciation. We measured signatures from the α-U 3O 8 samplemore » indicated that the material oxidized and hydrated after storage under high humidity conditions over time. Impurities, such as uranyl fluoride or schoepites, were initially detectable in the other uranium oxide samples. After storage under controlled conditions, the analyses of the samples revealed oxidation over time, although the signature of the uranyl fluoride impurity diminished. The presence of schoepite phases in older uranium oxide material is likely indicative of storage under high humidity and should be taken into account for assessing sample history. Finally, the absence of a signature from a chemical impurity, such as uranyl fluoride hydrate, in an older material may not preclude its presence at the initial time of production. LA-UR-15-21495.« less

An accelerated exposure and testing apparatus for building joint sealants

NASA Astrophysics Data System (ADS)

White, C. C.; Hunston, D. L.; Tan, K. T.; Hettenhouser, J.; Garver, J. D.

2013-09-01

The design, fabrication, and implementation of a computer-controlled exposure and testing apparatus for building joint sealants are described in this paper. This apparatus is unique in its ability to independently control and monitor temperature, relative humidity, ultraviolet (UV) radiation, and mechanical deformation. Each of these environmental factors can be controlled precisely over a wide range of conditions during periods of a month or more. Moreover, as controlled mechanical deformations can be generated, in situ mechanical characterization tests can be performed without removing specimens from the chamber. Temperature and humidity were controlled during our experiments via a precision temperature regulator and proportional mixing of dry and moisture-saturated air; while highly uniform UV radiation was attained by attaching the chamber to an integrating sphere-based radiation source. A computer-controlled stepper motor and a transmission system were used to provide precise movement control. The reliability and effectiveness of the apparatus were demonstrated on a model sealant material. The results clearly show that this apparatus provides an excellent platform to study the long-term durability of building joint sealants.

An accelerated exposure and testing apparatus for building joint sealants.

PubMed

White, C C; Hunston, D L; Tan, K T; Hettenhouser, J; Garver, J D

2013-09-01

The design, fabrication, and implementation of a computer-controlled exposure and testing apparatus for building joint sealants are described in this paper. This apparatus is unique in its ability to independently control and monitor temperature, relative humidity, ultraviolet (UV) radiation, and mechanical deformation. Each of these environmental factors can be controlled precisely over a wide range of conditions during periods of a month or more. Moreover, as controlled mechanical deformations can be generated, in situ mechanical characterization tests can be performed without removing specimens from the chamber. Temperature and humidity were controlled during our experiments via a precision temperature regulator and proportional mixing of dry and moisture-saturated air; while highly uniform UV radiation was attained by attaching the chamber to an integrating sphere-based radiation source. A computer-controlled stepper motor and a transmission system were used to provide precise movement control. The reliability and effectiveness of the apparatus were demonstrated on a model sealant material. The results clearly show that this apparatus provides an excellent platform to study the long-term durability of building joint sealants.

Biological activity of two new pyrrole derivatives against stored-product species: influence of temperature and relative humidity.

PubMed

Boukouvala, M C; Kavallieratos, N G; Athanassiou, C G; Hadjiarapoglou, L P

2016-08-01

Members of the pyrrole group are likely to have interesting properties that merit additional investigation as insecticides at the post-harvest stages of agricultural commodities. In the present work, the insecticidal effect of two new pyrrole derivatives, ethyl 3-(benzylthio)-4,6-dioxo-5-phenyl-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrrole-carboxylate (3i) and isopropyl 3-(benzylthio)-4,6-dioxo-5-phenyl-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrrole-carboxylate (3k) were studied as stored-wheat protectants against two major stored-product insect species, the confused flour beetle, Tribolium confusum Jaquelin du Val adults and larvae and the Mediterranean flour moth, Ephestia kuehniella Zeller larvae at different doses (0.1, 1 and 10 ppm), exposure intervals (7, 14 and 21 days), temperatures (20, 25 and 30°C) and relative humidity (55 and 75%) levels. For T. confusum adults, in the case of the pyrrole derivative 3i, mortality was low and it did not exceed 32.2% in wheat treated with 10 ppm 3i at 30°C and 55% relative humidity. Progeny production was very low (<1 individual/vial) in all combinations of 55% relative humidity, including control. In the case of the pyrrole derivative 3k, mortality reached 67.8% at 30°C and 55% relative humidity in wheat treated with 10 ppm after 21 days of exposure. Progeny production was low in all tested combinations (≤0.7 individuals/vial) of 55% relative humidity, including control. For T. confusum larvae, in the case of the pyrrole derivative 3i, at the highest dose, mortality was 82.2% at 25°C and 55% relative humidity whereas in the case of 3k it reached 77.8% at the same combination. In contrast, mortality at 75% relative humidity remained very low and did not exceed 13.3%. For E. kuehniella larvae, the highest mortalities, 44.4 and 63.3%, were observed in 10 ppm at 25°C and 55% relative humidity for both pyrrole derivatives. The compounds tested here have a certain insecticidal effect, but this effect is moderated by the exposure, the target species, the temperature and the relative humidity.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rudd, A.

This document covers a description of the need and applied solutions for supplemental dehumidification in warm-humid climates, especially for energy efficient homes where the sensible cooling load has been dramatically reduced. In older homes in warm-humid climates, cooling loads are typically high and cooling equipment runs a lot to cool the air. The cooling process also removes indoor moisture, reducing indoor relative humidity. However, at current residential code levels, and especially for above-code programs, sensible cooling loads have been so dramatically reduced that the cooling system does not run a lot to cool the air, resulting in much less moisturemore » being removed. In these new homes, cooling equipment is off for much longer periods of time especially during spring/fall seasons, summer shoulder months, rainy periods, some summer nights, and some winter days. In warm-humid climates, those long off periods allow indoor humidity to become elevated due to internally generated moisture and ventilation air change. Elevated indoor relative humidity impacts comfort, indoor air quality, and building material durability. Industry is responding with supplemental dehumidification options, but that effort is really in its infancy regarding year-round humidity control in low-energy homes. Available supplemental humidity control options are discussed. Some options are less expensive but may not control indoor humidity as well as more expensive and comprehensive options. The best performing option is one that avoids overcooling and avoids adding unnecessary heat to the space by using waste heat from the cooling system to reheat the cooled and dehumidified air to room-neutral temperature.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rudd, Armin

This document covers a description of the need and applied solutions for supplemental dehumidification in warm-humid climates, especially for energy efficient homes where the sensible cooling load has been dramatically reduced. Cooling loads are typically high and cooling equipment runs a lot to cool the air in older homes in warm-humid climates. The cooling process also removes indoor moisture, reducing indoor relative humidity. However, at current residential code levels, and especially for above-code programs, sensible cooling loads have been so dramatically reduced that the cooling system does not run a lot to cool the air, resulting in much less moisturemore » being removed. In these new homes, cooling equipment is off for much longer periods of time especially during spring/fall seasons, summer shoulder months, rainy periods, some summer nights, and winter days. In warm-humid climates, those long-off periods allow indoor humidity to become elevated due to internally generated moisture and ventilation air change. Elevated indoor relative humidity impacts comfort, indoor air quality, and building material durability. Industry is responding with supplemental dehumidification options, but that effort is really in its infancy regarding year-round humidity control in low-energy homes. Available supplemental humidity control options are discussed. Some options are less expensive but may not control indoor humidity as well as more expensive and comprehensive options. The best performing option is one that avoids overcooling and adding unnecessary heat to the space by using waste heat from the cooling system to reheat the cooled and dehumidified air to room-neutral temperature.« less

Ultra-accelerated natural sunlight exposure testing

DOEpatents

Jorgensen, Gary J.; Bingham, Carl; Goggin, Rita; Lewandowski, Allan A.; Netter, Judy C.

2000-06-13

Process and apparatus for providing ultra accelerated natural sunlight exposure testing of samples under controlled weathering without introducing unrealistic failure mechanisms in exposed materials and without breaking reciprocity relationships between flux exposure levels and cumulative dose that includes multiple concurrent levels of temperature and relative humidity at high levels of natural sunlight comprising: a) concentrating solar flux uniformly; b) directing the controlled uniform sunlight onto sample materials in a chamber enclosing multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors for a sufficient period of time in days to provide a corresponding time of about at least a years worth of representative weathering of the sample materials.

Building Environment Analysis based on Temperature and Humidity for Smart Energy Systems

PubMed Central

Yun, Jaeseok; Won, Kwang-Ho

2012-01-01

In this paper, we propose a new HVAC (heating, ventilation, and air conditioning) control strategy as part of the smart energy system that can balance occupant comfort against building energy consumption using ubiquitous sensing and machine learning technology. We have developed ZigBee-based wireless sensor nodes and collected realistic temperature and humidity data during one month from a laboratory environment. With the collected data, we have established a building environment model using machine learning algorithms, which can be used to assess occupant comfort level. We expect the proposed HVAC control strategy will be able to provide occupants with a consistently comfortable working or home environment. PMID:23202004

Measured impacts of supermarket humidity level on defrost performance and refrigerating system energy use

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henderson, H.I.; Khattar, M.

This paper presents field-monitor data from two supermarkets where the impact of space humidity on refrigerating system energy use was evaluated. Direct digital control (DDC) systems were used at both stores to collect 15-minute monitored data. At Store A in Minneapolis, the DDC system was used to monitor system performance as well as to implement temperature-terminated control in place of time-terminated control on 16 refrigerated zones using hot gas defrost. At Store B in Indianapolis, the DDC system was used to quantify the performance trends for the single compressor rack system with electric defrost. The results at Store B showedmore » that refrigerating system energy use decreases by nearly 10 kWh/day for each 1% drop in space relative humidity, or about 0.4% of average annual system energy use. This value includes the impact of reduced latent loads, the reduction in direct energy use and imposed load from reduced electric defrost heater operation, and the smaller imposed load from reduced anti-sweat heater energy use. The measured reductions agree well with the impact predicted using the calculation methods developed by Howell (1933b) in ASHRAE Research Project 596. At Store A, the measured data show that implementing temperature-terminated defrost reduced refrigerating system energy use by nearly 70 kWh/day over the winter period when the average space humidity was 22% RH. The savings from temperature-terminated defrost increase by 4 kWh/day per each 1% drop in relative humidity. At both stores, the same type of mechanical controls were used to duty cycle the anti-sweat heaters based on store dew point. Anti-sweat heater electricity use was observed to decrease by 4.6 kWh/day at Store B and 3.4 kWh/day at Store A for each 1% drop in relative humidity. At Store A, a more aggressive control scheme was implemented with the DDC system that reduced anti-sweat heater energy use by 7.8 kWh/day per % RH. The more aggressive control approach was reported to properly control fogging and condensation on display case surfaces. The overall energy reduction factor at the two stores was 12 kWh/day per % RH at Store A and 15 kWh/day per % RH at Store B. With more aggressive anti-sweat heater control, reduction factors as high as 20 kWh/day per % RH appear to be possible.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baba, Seiki; Hoshino, Takeshi; Ito, Len

A new crystal-mounting method has been developed that involves a combination of controlled humid air and polymer glue for crystal coating. This method is particularly useful when applied to fragile protein crystals that are known to be sensitive to subtle changes in their physicochemical environment. Protein crystals are fragile, and it is sometimes difficult to find conditions suitable for handling and cryocooling the crystals before conducting X-ray diffraction experiments. To overcome this issue, a protein crystal-mounting method has been developed that involves a water-soluble polymer and controlled humid air that can adjust the moisture content of a mounted crystal. Bymore » coating crystals with polymer glue and exposing them to controlled humid air, the crystals were stable at room temperature and were cryocooled under optimized humidity. Moreover, the glue-coated crystals reproducibly showed gradual transformations of their lattice constants in response to a change in humidity; thus, using this method, a series of isomorphous crystals can be prepared. This technique is valuable when working on fragile protein crystals, including membrane proteins, and will also be useful for multi-crystal data collection.« less

Increased water retention in polymer electrolyte membranes at elevated temperatures assisted by capillary condensation.

PubMed

Park, Moon Jeong; Downing, Kenneth H; Jackson, Andrew; Gomez, Enrique D; Minor, Andrew M; Cookson, David; Weber, Adam Z; Balsara, Nitash P

2007-11-01

We establish a new systematic methodology for controlling the water retention of polymer electrolyte membranes. Block copolymer membranes comprising hydrophilic phases with widths ranging from 2 to 5 nm become wetter as the temperature of the surrounding air is increased at constant relative humidity. The widths of the moist hydrophilic phases were measured by cryogenic electron microscopy experiments performed on humid membranes. Simple calculations suggest that capillary condensation is important at these length scales. The correlation between moisture content and proton conductivity of the membranes is demonstrated.

Hydration forces between aligned DNA helices undergoing B to A conformational change: In-situ X-ray fiber diffraction studies in a humidity and temperature controlled environment.

PubMed

Case, Ryan; Schollmeyer, Hauke; Kohl, Phillip; Sirota, Eric B; Pynn, Roger; Ewert, Kai E; Safinya, Cyrus R; Li, Youli

2017-12-01

Hydration forces between DNA molecules in the A- and B-Form were studied using a newly developed technique enabling simultaneous in situ control of temperature and relative humidity. X-ray diffraction data were collected from oriented calf-thymus DNA fibers in the relative humidity range of 98%-70%, during which DNA undergoes the B- to A-form transition. Coexistence of both forms was observed over a finite humidity range at the transition. The change in DNA separation in response to variation in humidity, i.e. change of chemical potential, led to the derivation of a force-distance curve with a characteristic exponential decay constant of∼2Å for both A- and B-DNA. While previous osmotic stress measurements had yielded similar force-decay constants, they were limited to B-DNA with a surface separation (wall-to-wall distance) typically>5Å. The current investigation confirms that the hydration force remains dominant even in the dry A-DNA state and at surface separation down to∼1.5Å, within the first hydration shell. It is shown that the observed chemical potential difference between the A and B states could be attributed to the water layer inside the major and minor grooves of the A-DNA double helices, which can partially interpenetrate each other in the tightly packed A phase. The humidity-controlled X-ray diffraction method described here can be employed to perform direct force measurements on a broad range of biological structures such as membranes and filamentous protein networks. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of vulcanization temperature and humidity on the properties of RTV silicone rubber

NASA Astrophysics Data System (ADS)

Wu, Xutao; Li, Xiuguang; Hao, Lu; Wen, Xishan; Lan, Lei; Yuan, Xiaoqing; Zhang, Qingping

2017-06-01

In order to study the difference in performance of room temperature vulcanized (RTV) silicone rubber in vulcanization environment with different temperature and humidity, static contact angle method, FTIR and TG is utilized to depict the properties of hydrophobicity, transfer of hydrophobicity, functional groups and thermal stability of RTV silicone rubber. It is found that different vulcanization conditions have effects on the characteristics of RTV silicone rubber, which shows that the hydrophobicity of RTV silicone rubber changes little with the vulcanization temperature but a slight increase with the vulcanization humidity. Temperature and humidity have obvious effects on the hydrophobicity transfer ability of RTV silicone rubber, which is better when vulcanization temperature is 5°C or vulcanization humidity is 95%. From the Fourier transform infrared spectroscopy, it can be concluded that humidity and temperature of vulcanization conditions have great effect on the functional groups of silicone rubber, and vulcanization conditions also have effect on thermal stability of RTV silicone rubber. When vulcanization temperature is 5°C or vulcanization humidity is 15% or 95%, the thermal stability of silicone rubber becomes worse.

[Effects of forest gap size and uprooted microsite on the microclimate in Pinus koraiensis-dominated broad-leaved mixed forest].

PubMed

Duan, Wen-biao; Du, Shan; Chen, Li-xin; Wang, Li-xia; Wei, Quan-shuai; Zhao, Jian-hui

2013-08-01

Three representative forest gaps with pit-mound microsites formed by uprooted trees were selected within the 2.55 hm2 plot in a Pinus koraiensis-dominated broad-leaved mixed forest in Xiao Xing'an Mountains of Northeast China. The cleared land and closed stand were set up as the controls, and the PAR, air temperature and relative humidity in the centers of different size gaps and in mound top as well as the total radiation and precipitation in the gap centers were measured between July and September, 2011 by using multichannel automatic meteorological stations. The differences of the microclimate between the gap centers and mound top in different months were compared, and the monthly and diurnal variations of the microclimatic factors in the gap centers and in the mound top under typical weather conditions were analyzed. The results showed that the mean monthly PAR and air temperature in the three gaps of different sizes were in the order of large gap > medium gap > small gap, and the mean monthly relative humidity was in the order of small gap > medium gap > large gap. For the same size gap, the mean monthly PAR and air temperature were higher in the mound top than in the gap center, whereas the mean monthly relative humidity was higher in the gap center than in the mound top. Both the mean monthly total radiation and the mean monthly air temperature in the forest gaps and in the controls were in the order of July > August > September and of cleared land > large gap > medium gap > small gap > closed stand, while the mean monthly relative humidity was in the order of closed stand > small gap > medium gap > large gap > cleared land. The differences in the mean monthly relative humidity between closed stand and various gaps and between closed stand and cleared land reached significant level. The monthly precipitation from July to September decreased in the order of cleared land > large gap > medium gap > small gap > closed stand. Whether in sunny days or in overcast days, the mean daily PAR and air temperature were higher in mound top than in gap center, and the mean daily relative humidity was in opposite. Whether in mound top or in gap center, the mean daily PAR and air temperature were higher in sunny days than in overcast days, while the mean daily relative humidity was higher in overcast days than in sunny days.

Assessment of the Microbial Control Measures for the Temperature and Humidity Control Subsystem Condensing Heat Exchanger of the International Space Station

NASA Technical Reports Server (NTRS)

Roman, Monsi C.; Steele, John W.; Marsh, Robert W.; Callahan, David M.; VonJouanne, Roger G.

1999-01-01

In August 1997 NASA/ Marshall Space Flight Center (MSFC) began a test with the objective of monitoring the growth of microorganisms on material simulating the surface of the International Space Station (ISS) Temperature and Humidity Control (THC) Condensing Heat Exchanger (CHX). The test addressed the concerns of potential uncontrolled microbial growth on the surface of the THC CHX subsystem. For this study, humidity condensate from a closed manned environment was used as a direct challenge to the surfaces of six cascades in a test set-up. The condensate was collected using a Shuttle-type CHX within the MSFC End-Use Equipment Testing Facility. Panels in four of the six cascades tested were coated with the ISS CHX silver impregnated hydrophilic coating. The remainder two cascade panels were coated with the hydrophilic coating without the antimicrobial component, silver. Results of the fourteen-month study are discussed in this paper. The effects on the microbial population when drying vs. not-drying the simulated THC CHX surface are also discussed.

40 CFR 1066.105 - Ambient controls and vehicle cooling fans.

Code of Federal Regulations, 2014 CFR

2014-07-01

... range of ambient temperature and humidity. Use good engineering judgment to maintain relatively uniform temperatures throughout the test cell before testing. You are generally not required to maintain uniform temperatures throughout the test cell while the vehicle is running due to the heat generated by the vehicle...

Effects of Heat and Moisture Exchangers and Exhaled Humidity on Aerosol Deposition in a Simulated Ventilator-Dependent Adult Lung Model.

PubMed

Ari, Arzu; Alwadeai, Khalid S; Fink, James B

2017-05-01

Many in vitro models report higher inhaled dose with dry versus heated humidity. Heat-and-moisture exchangers (HMEs) provide passive humidity in ventilator-dependent patients but act as a barrier to aerosol. The HMEs designed to allow aerosol delivery (HME-ADs) have not been well described. The purpose of this study is to determine the impact on aerosol deposition of HME-ADs with and without active exhaled humidity in a simulated ventilator-dependent adult model. We used an in vitro lung model consisting of an intubated teaching mannequin with an endotracheal tube of 8.0 mm inner diameter with bronchi directly attached to a collecting filter and passive rubber test lung to provide testing without active exhaled humidity. To simulate exhaled humidity, a Cascade humidifier (37°C and 100% relative humidity) was placed between the collecting filter and test lung, simulating body temperature and pressure saturated exhaled humidity at the bronchi. Albuterol sulfate (2.5 mg/3 mL) was administered with a mesh nebulizer (Aerogen Solo) placed in the inspiratory limb of the ventilator circuit at the Y-piece, with no HME in place (control) and with 3 HME-AD devices, including the CircuVent, Humid-Flo, and AirLife, with and without exhaled humidity. Drug was eluted from the collecting filter and analyzed with spectrophotometry. Student t tests and analysis of variance were used for data analysis ( P < .05). The percentage of drug dose delivered (mean ± SD) distal to the bronchi in the control experiments was greater than all of the HME-ADs without exhaled humidity 18 ± 0.7 and with active exhaled humidity 10.8 ± 0.2% ( P < .005). Without exhaled humidity, aerosol delivery with the CircuVent (12.6 ± 0.8), Humid-Flo (15.3 ± 0.8), and AirLife (12.0 ± 0.5) was less than control ( P < .001, P = .01 and P < .001, respectively). In contrast, with exhaled humidity, no difference was found between control and HME-ADs ( P = .89). Also, a greater variation between control and the 3 HME-ADs was observed without exhaled humidity. Drug delivery without exhaled humidity exceeded aerosol deposition obtained with exhaled humidity in all conditions tested in this study. In this model simulating active exhaled humidity, aerosol drug delivery was lower and more consistent with both control and the HME-ADs than with the standard nonhumidified model. Further studies are needed to determine whether greater deposition in a dry model is an artifact of the model that does not simulate exhaled humidity. Copyright © 2017 by Daedalus Enterprises.

Humidity sensing properties of morphology-controlled ordered silicon nanopillar

NASA Astrophysics Data System (ADS)

Li, Wei; Hu, Mingyue; Ge, Pengpeng; Wang, Jing; Guo, YanYan

2014-10-01

Ordered silicon nanopillar array (Si-NPA) was fabricated by nanosphere lithography. The size of silicon nanopillars can be easily controlled by an etching process. The period and density of nanopillar arrays are determined by the initial diameter of polystyrene (PS) spheres. It was studied as a sensing material to detect humidity. Room temperature current sensitivity of Si-NPA sensor was investigated at a relative humidity (RH) ranging from 50 to 70%. As a result, the measured current showed there was a significant increase at 70% RH. The response and recovery time was about 10 s and 15 s. These excellent sensing characteristics indicate that Si-NPA might be a practical sensing material.

Twin-cuvette measurement technique for investigation of dry deposition of O3 and PAN to plant leaves under controlled humidity conditions

NASA Astrophysics Data System (ADS)

Sun, Shang; Moravek, Alexander; von der Heyden, Lisa; Held, Andreas; Sörgel, Matthias; Kesselmeier, Jürgen

2016-02-01

We present a dynamic twin-cuvette system for quantifying the trace-gas exchange fluxes between plants and the atmosphere under controlled temperature, light, and humidity conditions. Compared with a single-cuvette system, the twin-cuvette system is insensitive to disturbing background effects such as wall deposition. In combination with a climate chamber, we can perform flux measurements under constant and controllable environmental conditions. With an Automatic Temperature Regulated Air Humidification System (ATRAHS), we are able to regulate the relative humidity inside both cuvettes between 40 and 90 % with a high precision of 0.3 %. Thus, we could demonstrate that for a cuvette system operated with a high flow rate (> 20 L min-1), a temperature-regulated humidification system such as ATRAHS is an accurate method for air humidification of the flushing air. Furthermore, the fully automatic progressive fill-up of ATRAHS based on a floating valve improved the performance of the entire measurement system and prevented data gaps. Two reactive gas species, ozone (O3) and peroxyacetyl nitrate (PAN), were used to demonstrate the quality and performance of the twin-cuvette system. O3 and PAN exchange with Quercus ilex was investigated over a 14 day measurement period under controlled climate chamber conditions. By using O3 mixing ratios between 32 and 105 ppb and PAN mixing ratios between 100 and 350 ppt, a linear dependency of the O3 flux as well as the PAN flux in relation to its ambient mixing ratio could be observed. At relative humidity (RH) of 40 %, the deposition velocity ratio of O3 and PAN was determined to be 0.45. At that humidity, the deposition of O3 to the plant leaves was found to be only controlled by the leaf stomata. For PAN, an additional resistance inhibited the uptake of PAN by the leaves. Furthermore, the formation of water films on the leaf surface of plants inside the chamber could be continuously tracked with our custom built leaf wetness sensors. Using this modified leaf wetness sensor measuring the electrical surface conductance on the leaves, an exponential relationship between the ambient humidity and the electrical surface conductance could be determined.

Twin-cuvette measurement technique for investigation of dry deposition of O3 and PAN to plant leaves under controlled humidity conditions

NASA Astrophysics Data System (ADS)

Sun, S.; Moravek, A.; von der Heyden, L.; Held, A.; Sörgel, M.; Kesselmeier, J.

2015-11-01

We present a dynamic twin-cuvette system for quantifying the trace gas exchange fluxes between plants and the atmosphere under controlled temperature, light and humidity conditions. Compared with a single cuvette system, the twin-cuvette system is insensitive for disturbing background effects such as wall deposition. In combination with a climate chamber we can perform flux measurements under constant and controllable environmental conditions. With an Automatic Temperature Regulated Air Humidification System (ATRAHS) we are able to regulate the relative humidity inside both cuvettes between 40 to 90 % with a high precision of 0.3 %. Thus, we could demonstrate that for a cuvette system operated with a high flow rate (> 20 L min-1) such a temperature regulated humidification system as ATRAHS is an accurate method for air humidification of the flushing air. Furthermore, the fully automatic progressive fill-up of ATRAHS based on a floating valve improved the performance of the entire measurement system and prevented data gaps. Two reactive gas species, ozone (O3) and peroxyacetyl nitrate (PAN), were used to demonstrate the quality and performance of the twin-cuvette system. O3 and PAN exchange with Quercus ilex was investigated over a 14 day measurement period under controlled climate chamber conditions. By using O3 mixing ratios between 32-105 ppb and PAN mixing ratios between 100-350 ppt a linear dependency of the O3 flux as well as the PAN flux in relation to its ambient mixing ratio could be observed. At relative humidity (RH) of 40 %, the deposition velocity ratio of O3 and PAN was determined to be 0.45. At that humidity, the deposition of O3 to the plant leaves was found to be only controlled by the leaf stomata. For PAN an additional resistance inhibited the uptake of PAN by the leaves. Furthermore, the formation of water films on the leaf surface of plants inside the chamber could be continuously tracked with our custom built leaf wetness sensors. Using this modified leaf wetness sensor measuring the electrical surface conductance on the leaves, an exponential relationship between the ambient humidity and the electrical surface conductance could be determined.

Evaporative cooling system for storage of fruits and vegetables - a review.

PubMed

Lal Basediya, Amrat; Samuel, D V K; Beera, Vimala

2013-06-01

Horticultural produce are stored at lower temperature because of their highly perishable nature. There are many methods to cool the environment. Hence, preserving these types of foods in their fresh form demands that the chemical, bio-chemical and physiological changes are restricted to a minimum by close control of space temperature and humidity. The high cost involved in developing cold storage or controlled atmosphere storage is a pressing problem in several developing countries. Evaporative cooling is a well-known system to be an efficient and economical means for reducing the temperature and increasing the relative humidity in an enclosure and this effect has been extensively tried for increasing the shelf life of horticultural produce in some tropical and subtropical countries. In this review paper, basic concept and principle, methods of evaporative cooling and their application for the preservation of fruits and vegetables and economy are also reported. Thus, the evaporative cooler has prospect for use for short term preservation of vegetables and fruits soon after harvest. Zero energy cooling system could be used effectively for short-duration storage of fruits and vegetables even in hilly region. It not only reduces the storage temperature but also increases the relative humidity of the storage which is essential for maintaining the freshness of the commodities.

Discussion on fresh air volume in Temperature and Humidity Independent Control of Air-conditioning System

NASA Astrophysics Data System (ADS)

Cheng, Xiaolong; Liu, Jinxiang; Wang, Yu; Yuan, Xiaolei; Jin, Hui

2018-05-01

The fresh air volume in Temperature and Humidity Independent Control of Air-conditioning System(THIC) of a typical office was comfirmed, under the premise of adopting the refrigeration dehumidifying fresh air unit(7°C/12°C). By detailed calculating the space moisture load and the fresh air volume required for dehumidification in 120 selected major cities in China, it can be inferred that the minimum fresh air volume required for dehumidification in THIC is mainly determined by the local outdoor air moisture and the outdoor wind speed; Then the mathematical fitting software Matlab was used to fit the three parameters, and a simplified formula for calculating the minimum per capita fresh air volume required for dehumidification was obtained; And the indoor relative humidity was simulated by the numerical software Airpak and the results by using the formula data and the data for hygiene were compared to verify the relibility of the simplified formula.

Production of Pycnidia and Conidia by Guignardia bidwellii, the Causal Agent of Grape Black Rot, as Affected by Temperature and Humidity.

PubMed

Onesti, G; González-Domínguez, E; Rossi, V

2017-02-01

Black rot, caused by the fungus Guignardia bidwellii, is a polycyclic disease affecting grape leaves and berries. In environmentally controlled experiments and in a 3-year field study, the effects of temperature and relative humidity (RH) were assessed on the following growth parameters of G. bidwellii: (i) formation of pycnidia and cirri in grape leaf lesions, (ii) production and germination of conidia, and (iii) length of the period between lesion appearance and pycnidia production. Pycnidia were produced between 5 and 35°C and at 90 to 100% RH but more pycnidia were produced between 20 and 30°C. No pycnidia were produced at RH < 90%. The first pycnidia were produced in approximately 2 days after lesion appearance at ≥20°C and in 8 days at 5°C; pycnidia continued to be produced on the same lesion for 5 to 16 days after lesion appearance, depending on the temperature. Models were developed to describe the effect of temperature and RH on pycnidia production, accounting for 95 and 97% of variability, respectively. Cirri were extruded only between 15 and 35°C and mainly at 100% RH. Field experiments confirmed that pycnidia are produced for several days on a leaf lesion and that the length of the period between lesion appearance and pycnidia production depends on temperature. Overall, the findings showed that production of conidia requires high humidity; under field conditions, some hours at high humidity, which usually occur at nighttime, rather than constant high humidity may be sufficient.

Inspired gas humidity and temperature during mechanical ventilation with the Stephanie ventilator.

PubMed

Preo, Bianca L; Shadbolt, Bruce; Todd, David A

2013-11-01

To measure inspired gas humidity and temperature delivered by a Stephanie neonatal ventilator with variations in (i) circuit length; (ii) circuit insulation; (iii) proximal airway temperature probe (pATP) position; (iv) inspiratory temperature (offset); and (v) incubator temperatures. Using the Stephanie neonatal ventilator, inspired gas humidity and temperature were measured during mechanical ventilation at the distal inspiratory limb and 3 cm down the endotracheal tube. Measurements were made with a long or short circuit; with or without insulation of the inspiratory limb; proximal ATP (pATP) either within or external to the incubator; at two different inspiratory temperature (offset) of 37(-0.5) and 39(-2.0)°C; and at three different incubator temperatures of 32, 34.5, and 37°C. Long circuits produced significantly higher inspired humidity than short circuits at all incubator settings, while only at 32°C was the inspired temperature higher. In the long circuits, insulation further improved the inspired humidity especially at 39(-2.0)°C, while only at incubator temperatures of 32 and 37°C did insulation significantly improve inspired temperature. Positioning the pATP outside the incubator did not result in higher inspired humidity but did significantly improve inspired temperature. An inspiratory temperature (offset) of 39(-2.0)°C delivered significantly higher inspired humidity and temperature than the 37(-0.5)°C especially when insulated. Long insulated Stephanie circuits should be used for neonatal ventilation when the infant is nursed in an incubator. The recommended inspiratory temperature (offset) of 37(-0.5)°C produced inspired humidity and temperature below international standards, and we suggest an increase to 39(-2.0)°C. © 2013 John Wiley & Sons Ltd.

Low-temperature forced-air drying of Appalachian hardwoods

Treesearch

Donald G. Cuppett; E. Paul Craft

1975-01-01

Low-temperature forced-air drying involves drying green lumber in heated buildings with forced-air circulation and partial control of temperature and humidity conditions. The lumber is dried to about 20 percent moisture content at dry-bulb temperatures of 70º to 110ºF and with air velocities of 300 to 600 feet per minute. Equipment, methods, and...

Effects of Temperature and Humidity on the Characterization of C-4 Explosive Threats

NASA Astrophysics Data System (ADS)

Miller, C. J.; Yoder, T. S.

2012-06-01

Both the quantity and the amount of time that an explosive is present on the surface of a material is dependent upon the amount of explosive originally deposited on the surface, the adhesive forces, temperature and humidity, as well as other environmental factors. This laboratory study focused on evaluating RDX crystal morphology changes resulting from variations in temperature and humidity conditions of the sample. The temperature and humidity conditions were controlled using a Tenney THRJ environmental chamber and a Tenney T11RC-1.5 environmental chamber. These chambers allow the temperature and humidity to be held within ±3 °C and ±5 % RH. The temperature and humidity conditions used for this test series were: 4 °C/40 %RH, 21 °C/20 %RH (samples left on benchtop), 21 °C/70 %RH, 21 °C/95 %RH, 35 °C/40 %RH, 35 °C/70 %RH, and 35 °C/95 %RH. These temperature and humidity set points were chosen to represent a wide range of conditions that may be found in real world scenarios. C-4 (RDX crystals and binder material) was deposited on the surface of one of six substrates by placing a fingerprint from the explosive block onto the matrix surface. The substrates were chosen to provide a range of items that are commonly used. Six substrate types were used during these tests: 50 % cotton/50 % polyester as found in T-shirts, 100 % cotton with a smooth surface such as that found in a cotton dress shirt, 100 % cotton on a rough surface such as that found on canvas or denim, suede leather such as might be found on jackets, purses, or shoes, painted metal obtained from a car hood, and a computer diskette. The samples were not pre-cleaned prior to testing and contained sizing agents, and in the case of the metal: oil, dirt, scratches, and rust spots. The substrates were photographed at various stages of testing, using a Zeiss Discover V12 stereoscope with Axiocam ICc1 3 megapixel digital camera, to determine any changes in the crystalline morphology. Some of the samples were examined using scanning electron microscopy and atomic force microscopy in an attempt to determine how the explosive was bound to the substrate. This is the second article in a series on the effects of temperature and relative humidity on trace explosive threats.

Characterization of simultaneous heat and mass transfer phenomena for water vapour condensation on a solid surface in an abiotic environment--application to bioprocesses.

PubMed

Tiwari, Akhilesh; Kondjoyan, Alain; Fontaine, Jean-Pierre

2012-07-01

The phenomenon of heat and mass transfer by condensation of water vapour from humid air involves several key concepts in aerobic bioreactors. The high performance of bioreactors results from optimised interactions between biological processes and multiphase heat and mass transfer. Indeed in various processes such as submerged fermenters and solid-state fermenters, gas/liquid transfer need to be well controlled, as it is involved at the microorganism interface and for the control of the global process. For the theoretical prediction of such phenomena, mathematical models require heat and mass transfer coefficients. To date, very few data have been validated concerning mass transfer coefficients from humid air inflows relevant to those bioprocesses. Our study focussed on the condensation process of water vapour and developed an experimental set-up and protocol to study the velocity profiles and the mass flux on a small size horizontal flat plate in controlled environmental conditions. A closed circuit wind tunnel facility was used to control the temperature, hygrometry and hydrodynamics of the flow. The temperature of the active surface was controlled and kept isothermal below the dew point to induce condensation, by the use of thermoelectricity. The experiments were performed at ambient temperature for a relative humidity between 35-65% and for a velocity of 1.0 ms⁻¹. The obtained data are analysed and compared to available theoretical calculations on condensation mass flux.

Whole-body pre-cooling and heat storage during self-paced cycling performance in warm humid conditions.

PubMed

Kay, D; Taaffe, D R; Marino, F E

1999-12-01

The aim of this study was to establish the effect that pre-cooling the skin without a concomitant reduction in core temperature has on subsequent self-paced cycling performance under warm humid (31 degrees C and 60% relative humidity) conditions. Seven moderately trained males performed a 30 min self-paced cycling trial on two separate occasions. The conditions were counterbalanced as control or whole-body pre-cooling by water immersion so that resting skin temperature was reduced by approximately 5-6 degrees C. After pre-cooling, mean skin temperature was lower throughout exercise and rectal temperature was lower (P < 0.05) between 15 and 25 min of exercise. Consequently, heat storage increased (P < 0.003) from 84.0+/-8.8 W x m(-2) to 153+/-13.1 W x m(-2) (mean +/- s(mean)) after pre-cooling, while total body sweat fell from 1.7+/-0.1 l x h(-1) to 1.2+/-0.1 l h(-1) (P < 0.05). The distance cycled increased from 14.9+/-0.8 to 15.8+/-0.7 km (P < 0.05) after pre-cooling. The results indicate that skin pre-cooling in the absence of a reduced rectal temperature is effective in reducing thermal strain and increasing the distance cycled in 30 min under warm humid conditions.

Effect of Air Temperature and Relative Humidity at Various Fuel-Air Ratios on Exhaust Emissions on a Per-Mode Basis of an AVCO Lycoming 0-320 Diad Light Aircraft Engine: Volume 1: Results and Plotted Data

NASA Technical Reports Server (NTRS)

Skorobatckyi, M.; Cosgrove, D. V.; Meng, P. R.; Kempe, E. E., Jr.

1978-01-01

A carbureted four cylinder air cooled 0-320 DIAD Lycoming aircraft engine was tested to establish the effects of air temperature and humidity at various fuel-air ratios on the exhaust emissions on a per-mode basis. The test conditions include carburetor lean out at air temperatures of 50, 59, 80, and 100 F at relative humidities of 0, 30, 60, and 80 percent. Temperature humidity effects at the higher values of air temperature and relative humidity tested indicated that the HC and CO emissions increased significantly, while the NOx emissions decreased. Even at a fixed fuel air ratio, the HC emissions increase and the NOx emissions decrease at the higher values of air temperature and humidity.

Effect of air temperature and relative humidity at various fuel-air ratios on exhaust emissions on a per-mode basis of an Avco Lycoming 0-320 DIAD light aircraft engine. Volume 2: Individual data points

NASA Technical Reports Server (NTRS)

Skorobatckyi, M.; Cosgrove, D. V.; Meng, P. R.; Kempke, E. R.

1976-01-01

A carbureted four cylinder air cooled 0-320 DIAD Lycoming aircraft engine was tested to establish the effects of air temperature and humidity at various fuel-air ratios on the exhaust emissions on a per-mode basis. The test conditions included carburetor lean-out at air temperatures of 50, 59, 80, and 100 F at relative humidities of 0, 30, 60, and 80 percent. Temperature-humidity effects at the higher values of air temperature and relative humidity tested indicated that the HC and CO emissions increased significantly, while the NOx emissions decreased. Even at a fixed fuel-air ratio, the HC emissions increase and the NOx emissions decrease at the higher values of air temperature and humidity. Volume II contains the data taken at each of the individual test points.

EDITORIAL: Humidity sensors Humidity sensors

NASA Astrophysics Data System (ADS)

Regtien, Paul P. L.

2012-01-01

All matter is more or less hygroscopic. The moisture content varies with vapour concentration of the surrounding air and, as a consequence, most material properties change with humidity. Mechanical and thermal properties of many materials, such as the tensile strength of adhesives, stiffness of plastics, stoutness of building and packaging materials or the thermal resistivity of isolation materials, all decrease with increasing environmental humidity or cyclic humidity changes. The presence of water vapour may have a detrimental influence on many electrical constructions and systems exposed to humid air, from high-power systems to microcircuits. Water vapour penetrates through coatings, cable insulations and integrated-circuit packages, exerting a fatal influence on the performance of the enclosed systems. For these and many other applications, knowledge of the relationship between moisture content or humidity and material properties or system behaviour is indispensable. This requires hygrometers for process control or test and calibration chambers with high accuracy in the appropriate temperature and humidity range. Humidity measurement methods can roughly be categorized into four groups: water vapour removal (the mass before and after removal is measured); saturation (the air is brought to saturation and the `effort' to reach that state is measured); humidity-dependent parameters (measurement of properties of humid air with a known relation between a specific property and the vapour content, for instance the refractive index, electromagnetic spectrum and acoustic velocity); and absorption (based on the known relation between characteristic properties of non-hydrophobic materials and the amount of absorbed water from the gas to which these materials are exposed). The many basic principles to measure air humidity are described in, for instance, the extensive compilations by Wexler [1] and Sonntag [2]. Absorption-type hygrometers have small dimensions and can be produced at relatively low cost. Therefore, they find wide use in lots of applications. However, the method requires a material that possesses some conflicting properties: stable and reproducible relations between air humidity, moisture uptake and a specific property (for instance the length of a hair, the electrical impedance of the material), fast absorption and desorption of the water vapour (to obtain a short response time), small hysteresis, wide range of relative humidity (RH) and temperature-independent output (only responsive to RH). For these reasons, much research is done and is still going on to find suitable materials that combine high performance and low price. In this special feature, three of the four papers report on absorption sensors, all with different focus. Aziz et al describe experiments with newly developed materials. The surface structure is extensively studied, in view of its ability to rapidly absorb water vapour and exhibit a reproducible change in the resistance and capacitance of the device. Sanchez et al employ optical fibres coated with a thin moisture-absorbing layer as a sensitive humidity sensor. They have studied various coating materials and investigated the possibility of using changes in optical properties of the fibre (here the lossy mode resonance) due to a change in humidity of the surrounding air. The third paper, by Weremczuk et al, focuses on a cheap fabrication method for absorption-based humidity sensors. The inkjet technology appears to be suitable for mass fabrication of such sensors, which is demonstrated by extensive measurements of the electrical properties (resistance and capacitance) of the absorbing layers. Moreover, they have developed a model that describes the relation between humidity and the electrical parameters of the moisture-sensitive layer. Despite intensive research, absorption sensors still do not meet the requirements for high accuracy applications. The dew-point temperature method is more appropriate, since it uses the accurately known relation between temperature and saturation vapour pressure in air. When an object exposed to humid air is cooled down below the dew-point water vapour condenses as drops on its cold surface. The temperature can be kept exactly at the dew point by controlling the amount of dew (equilibrium between evaporation and condensation). In most dew-point hygrometers dew is detected with optical or capacitive means. In the former the dew drops on a reflective surface (chilled mirror) scatter incident light, and the capacitive method uses the change in capacitance due to the large dielectric constant of liquid water (80) compared to air (1). Kunze et al, in the fourth paper of this special feature, use another property of water to detect dew: the relatively high value of the thermal capacitance of liquid water. In traditional technology this method would not be sensitive enough, but with MEMS technology a sufficient detectivity of dew can be achieved, which is demonstrated in this paper. A control system keeps the temperature of the substrate just at the dew-point temperature, the latter being measured by an on-chip diode. The accuracy achieved is comparable with traditional dew-point hygrometers. These four papers in this issue are nice examples of research leading to significant advances in hygrometry. References [1] Wexler A (ed) 1965 Humidity and Moisture. Vol. I: Principles and Methods of Measuring Humidity in Gases; Vol. II: Applications; Vol. III: Fundamentals and Standards; Vol. IV: Principles and Methods of Measuring Moisture in Liquids and Solids (New York: Reinhold) [2] Sonntag D 1966-1968 Hygrometrie (Berlin: Akademie Verlag)

The Environment and the Microbial Ecology of Human Skin

PubMed Central

McBride, Mollie E.; Duncan, W. Christopher; Knox, J. M.

1977-01-01

Microbial flora of the skin of three human population groups representing different natural environments was examined quantitatively and qualitatively to determine whether environmental differences in temperature and humidity can influence the microbial flora of normal skin. Five anatomical skin sites - hands, back, axillae, groin, and feet - were sampled from 10 subjects working in a high-humidity, high-temperature environment, 10 subjects from a low-temperature, high-humidity environment, and 10 subjects working in a moderate-temperature and low-humidity environment. Bacterial populations were significantly larger from the back, axillae, and feet in individuals from the high-temperature and high-humidity environment as compared to the moderate-temperature, low-humidity environment. High humidity and low temperature had no significant effect on total populations, but this group showed a higher frequency of isolation of fungi, and gram-negative bacteria from the back and feet. Although there was an indication that increase in the environmental humidity could result in an increased frequency of isolation of gram-negative bacteria, there was no evidence that an increase in either temperature or humidity altered the relative proportions of gram-negative bacteria in the predominantly gram-positive microbial flora found on normal skin. It was concluded that, although climatic changes may cause fluctation in microbial populations from certain sites, they are not a major influence on the ecology of the microbial flora of normal skin in the natural environment. The variables introduced by studying individuals in their natural environment and the influence of these on the results are discussed. PMID:16345214

[Impact of canopy structural characteristics on inner air temperature and relative humidity of Koelreuteria paniculata community in summer].

PubMed

Qin, Zhong; Li, Zhan-dong; Cheng, Fang-yun; Sha, Hai-feng

2015-06-01

To investigate the diurnal variation of the correlations between the cooling and humidifying effects and canopy structural characteristics of the Koelreuteria paniculata community, the measurements of air temperature, relative humidity, canopy density, leaf area index (LAI) and mean leaf angle (MLA) were performed on calm sunny summer days in the community in Beijing Olympic Forest Park, China. There were significant correlations between the canopy density, LAI and MLA, which affected the cooling and humidifying effects together. The cooling effect reached its maximum by 12:00, whereas the humidifying effect reached its peak at 10:00. Compared with the control open space site, the community appeared to lower the air temperature by 0.43 to 7.53 °C and to increase the relative humidity by 1%-22% during the daytime. However, the cooling and humidifying effects seem to be not effective during the night. The canopy density and LAI were better for determining the cooling and humidifying effects from 9:00 to 12:00. However, these effects were largely controlled only by the canopy density from 12:00 to 14:00 and were significantly correlated with the canopy density and LAI afterwards until 18:00.

Influence of Temperature and Humidity on the Stability of Carotenoids in Biofortified Maize (Zea mays L.) Genotypes during Controlled Postharvest Storage.

PubMed

Ortiz, Darwin; Rocheford, Torbert; Ferruzzi, Mario G

2016-04-06

Maize is a staple crop that has been the subject of biofortification efforts to increase the natural content of provitamin A carotenoids. Although significant progress toward increasing provitamin A carotenoid content in maize varieties has been made, postharvest handling factors that influence carotenoid stability during storage have not been fully established. The objectives of this study were to determine carotenoid profiles of six selected provitamin A biofortified maize genotypes at various developmental stages and assess the stability of carotenoids in maize kernels during controlled storage conditions (12 month period), including elevated temperature and relative humidity. There were no significant changes in the content of individual carotenoids within genotypes during kernel development from 45 days after pollination through the time of harvest. Carotenoid losses through traditional grain drying were also minimal (<9%). However, the stability of carotenoids in maize kernels over storage time after harvest was found to be dependent on both temperature and humidity, with variation observed among genotypes. Different forms of provitamin A carotenoids follow similar degradation rates. The genotype C17xDE3 had a degradation rate 2 times faster than those of the other genotypes evaluated (P < 0.001). These differences in carotenoid stability under controlled storage were attributed, in part, to observed differences in the physical properties of the kernels (surface area and porosity). These results support the notion that effective control of moisture content and temperature of the kernels during storage conditions is essential to reduce the speed of degradative reactions.

Nonlinear and Interactive Effects of Temperature and Humidity on Childhood Hand, Foot and Mouth Disease in Hefei, China.

PubMed

Wu, Jinju; Cheng, Jian; Xu, Zhiwei; Zhao, Kefu; Zhao, Desheng; Xie, Mingyu; Yang, Huihui; Wen, Liying; Li, Kesheng; Su, Hong

2016-10-01

Hand, foot and mouth disease (HFMD) is one of the major infectious diseases among children and remains a health threat, especially among Asian countries. Many epidemiologic studies suggested significant association of air temperature and humidity with childhood HFMD; however, evidence on the temperature effects on childhood HFMD in temperate cities is limited, and the interactive effects of temperature and humidity have not been studied yet. Daily counts of HFMD in children younger than 15 years of age and daily meteorologic variables during 2010 to 2012 were obtained in Hefei, China. A distributed lag nonlinear model was applied to estimate the potential nonlinear association between temperature and childhood HFMD. The interactive effects between temperature and humidity on childhood HFMD were also investigated. Temperature rise was associated with higher risk of childhood HFMD. Within the incubation period of HFMD, temperature rise appeared to have the acute effects on childhood HFMD, and a 5°C increase of temperature at lag 0-6 days was associated with 24.8% (95% confidence interval: 11.94%-39.10%) increase of childhood HFMD. Females and children of 0-4 years of agewere more vulnerable to temperature rise. Notably, there were obvious combined effects between temperature and humidity on childhood HFMD-the risk of childhood HFMD elevated at higher temperature and humidity level. This study provides evidence that temperature and humidity may jointly affect childhood HFMD, and such interactive impact needs to be considered when evaluating the temperature-childhood HFMD relationship.

Joint Networking Command and Control (C2) Communications Among Distributed Operations, JCAS, and Joint Fires

DTIC Science & Technology

2007-06-01

fasteners. Enviromental Spec Storage Temperature: -26 to 160 °F, Operating Temperature: -22 to 160 °F, Operating Humidity Range: 5% to 100% Non...Accessories Double 90° tongue and groove case design, with anti-tamper fasteners. Enviromental Spec Storage Temperature: -26 to 160 °F, Operating

The Evaporative Function of Cockroach Hygroreceptors

PubMed Central

Tichy, Harald; Kallina, Wolfgang

2013-01-01

Insect hygroreceptors associate as antagonistic pairs of a moist cell and a dry cell together with a cold cell in small cuticular sensilla on the antennae. The mechanisms by which the atmospheric humidity stimulates the hygroreceptive cells remain elusive. Three models for humidity transduction have been proposed in which hygroreceptors operate either as mechanical hygrometers, evaporation detectors or psychrometers. Mechanical hygrometers are assumed to respond to the relative humidity, evaporation detectors to the saturation deficit and psychrometers to the temperature depression (the difference between wet-bulb and dry-bulb temperatures). The models refer to different ways of expressing humidity. This also means, however, that at different temperatures these different types of hygroreceptors indicate very different humidity conditions. The present study tested the adequacy of the three models on the cockroach’s moist and dry cells by determining whether the specific predictions about the temperature-dependence of the humidity responses are indeed observed. While in previous studies stimulation consisted of rapid step-like humidity changes, here we changed humidity slowly and continuously up and down in a sinusoidal fashion. The low rates of change made it possible to measure instantaneous humidity values based on UV-absorption and to assign these values to the hygroreceptive sensillum. The moist cell fitted neither the mechanical hygrometer nor the evaporation detector model: the temperature dependence of its humidity responses could not be attributed to relative humidity or to saturation deficit, respectively. The psychrometer model, however, was verified by the close relationships of the moist cell’s response with the wet-bulb temperature and the dry cell’s response with the dry-bulb temperature. Thus, the hygroreceptors respond to evaporation and the resulting cooling due to the wetness or dryness of the air. The drier the ambient air (absolutely) and the higher the temperature, the greater the evaporative temperature depression and the power to desiccate. PMID:23342058

The evaporative function of cockroach hygroreceptors.

PubMed

Tichy, Harald; Kallina, Wolfgang

2013-01-01

Insect hygroreceptors associate as antagonistic pairs of a moist cell and a dry cell together with a cold cell in small cuticular sensilla on the antennae. The mechanisms by which the atmospheric humidity stimulates the hygroreceptive cells remain elusive. Three models for humidity transduction have been proposed in which hygroreceptors operate either as mechanical hygrometers, evaporation detectors or psychrometers. Mechanical hygrometers are assumed to respond to the relative humidity, evaporation detectors to the saturation deficit and psychrometers to the temperature depression (the difference between wet-bulb and dry-bulb temperatures). The models refer to different ways of expressing humidity. This also means, however, that at different temperatures these different types of hygroreceptors indicate very different humidity conditions. The present study tested the adequacy of the three models on the cockroach's moist and dry cells by determining whether the specific predictions about the temperature-dependence of the humidity responses are indeed observed. While in previous studies stimulation consisted of rapid step-like humidity changes, here we changed humidity slowly and continuously up and down in a sinusoidal fashion. The low rates of change made it possible to measure instantaneous humidity values based on UV-absorption and to assign these values to the hygroreceptive sensillum. The moist cell fitted neither the mechanical hygrometer nor the evaporation detector model: the temperature dependence of its humidity responses could not be attributed to relative humidity or to saturation deficit, respectively. The psychrometer model, however, was verified by the close relationships of the moist cell's response with the wet-bulb temperature and the dry cell's response with the dry-bulb temperature. Thus, the hygroreceptors respond to evaporation and the resulting cooling due to the wetness or dryness of the air. The drier the ambient air (absolutely) and the higher the temperature, the greater the evaporative temperature depression and the power to desiccate.

Dehydration of Traditional Dried Instant Noodle (Mee Siput) Using Controlled Temperature & Humidity Dryer

NASA Astrophysics Data System (ADS)

Mamat, K. A.; Yusof, M. S.; Yusoff, Wan Fauziah Wan; Zulafif Rahim, M.; Hassan, S.; Rahman, M. Qusyairi. A.; Karim, M. A. Abd

2017-05-01

Drying process is an essential step to produce instant noodles. Yet, the industries especially Small and Medium Enterprises (SMEs), is seeking for an efficient method to dry the noodles. This paper discusses the performance of an invented drying system which employed heating and humidifying process. The drying system was tested using 30 kilogram of the raw noodle known as “Mee Siput”. Temperature controlled system were used in the study to control the temperature of the drying process and prevent the dried noodles from damage by maintaining the temperature of lower than 80°C. The analysis shows that the system was drastically decreased the humidity from 80% to 40% just after 200 minutes of the drying process. The complete dehydration time of noodle has also decreased to only 4 hours from 16 hours when using traditional drying system without sacrificed the good quality of the dried noodle. In overall, the invented system believed to increase the production capacity of the noodle, reduce cost of production which would highly beneficial for Small Medium Industries (SMEs) in Malaysia.

Daily indoor-to-outdoor temperature and humidity relationships: a sample across seasons and diverse climatic regions

PubMed Central

Nguyen, Jennifer L.; Dockery, Douglas W.

2015-01-01

The health consequences of heat and cold are usually evaluated based on associations with outdoor measurements at the nearest weather reporting station. However, people in the developed world spend little time outdoors, especially during extreme temperature events. We examined the association between indoor and outdoor temperature and humidity in a range of climates. We measured indoor temperature, apparent temperature, relative humidity, dew point, and specific humidity (a measure of moisture content in air) for one calendar year (2012) in a convenience sample of eight diverse locations ranging from the equatorial region (10°N) to the Arctic (64°N). We then compared the indoor conditions to outdoor values recorded at the nearest airport weather station. We found that the shape of the indoor-to-outdoor temperature and humidity relationships varied across seasons and locations. Indoor temperatures showed little variation across season and location. There was large variation in indoor relative humidity between seasons and between locations which was independent of outdoor, airport measurements. On the other hand, indoor specific humidity, and to a lesser extent dew point, tracked with outdoor, airport measurements both seasonally and between climates, across a wide range of outdoor temperatures. Our results suggest that, depending on the measure, season, and location, outdoor weather measurements can be reliably used to represent indoor exposures and that, in general, outdoor measures of actual moisture content in air better capture indoor exposure than temperature and relative humidity. Therefore, absolute measures of water vapor should be examined in conjunction with other measures (e.g. temperature, relative humidity) in studies of the effect of weather and climate on human health. PMID:26054827

A New Primary Dew-Point Generator at TUBITAK UME

NASA Astrophysics Data System (ADS)

Oğuz Aytekin, S.; Karaböce, N.; Heinonen, M.; Sairanen, H.

2018-05-01

An implementation of a new low-range primary humidity generator as a part of an international collaboration between TUBITAK UME and VTT MIKES was initiated as a EURAMET Project Number 1259. The dew-point generator was designed and constructed within the scope of the cooperation between TUBITAK UME and VTT MIKES in order to extend the dew-point temperature measurement capability of Humidity Laboratory of TUBITAK UME down to - 80 °C. The system was thoroughly characterized and validated at TUBITAK UME to support the evidence for dew-point temperature uncertainties. The new generator has a capability of operating in the range of - 80 °C to +10 °C, but at the moment, it was characterized down to - 60 °C. The core of the generator system is a saturator which is fully immersed in a liquid bath. Dry air is supplied to the saturator through a temperature-controlled pre-saturator. The operation of the system is based on the single-pressure generation method with a single pass, i.e., the dew-point temperature is only controlled by the saturator temperature, and the humidity-controlled air is not returned to the system after leaving of the saturator. The metrological performance of the saturator was investigated thoroughly at both National Metrology Institutes. The pre-saturator was also tested using a thermostatic bath at VTT MIKES prior to sending them to TUBITAK UME. This paper describes the principle and design of the generator in detail. The dew-point measurement system and the corresponding uncertainty analysis of the dew-point temperature scale realized with the generator in the range from - 60 °C to 10 °C is also presented.

Greenhouse intelligent control system based on microcontroller

NASA Astrophysics Data System (ADS)

Zhang, Congwei

2018-04-01

As one of the hallmarks of agricultural modernization, intelligent greenhouse has the advantages of high yield, excellent quality, no pollution and continuous planting. Taking AT89S52 microcontroller as the main controller, the greenhouse intelligent control system uses soil moisture sensor, temperature and humidity sensors, light intensity sensor and CO2 concentration sensor to collect measurements and display them on the 12864 LCD screen real-time. Meantime, climate parameter values can be manually set online. The collected measured values are compared with the set standard values, and then the lighting, ventilation fans, warming lamps, water pumps and other facilities automatically start to adjust the climate such as light intensity, CO2 concentration, temperature, air humidity and soil moisture of the greenhouse parameter. So, the state of the environment in the greenhouse Stabilizes and the crop grows in a suitable environment.

Automated Test Systems for Toxic Vapor Detectors

NASA Technical Reports Server (NTRS)

Mattson, C. B.; Hammond, T. A.; Schwindt, C. J.

1997-01-01

The NASA Toxic Vapor Detection Laboratory (TVDL) at the Kennedy Space Center (KSC), Florida, has been using Personal Computer based Data Acquisition and Control Systems (PCDAS) for about nine years. These systems control the generation of toxic vapors of known concentrations under controlled conditions of temperature and humidity. The PCDAS also logs the test conditions and the test article responses in data files for analysis by standard spreadsheets or custom programs. The PCDAS was originally developed to perform standardized qualification and acceptance tests in a search for a commercial off-the-shelf (COTS) toxic vapor detector to replace the hydrazine detectors for the Space Shuttle launch pad. It has since become standard test equipment for the TVDL and is indispensable in producing calibration standards for the new hydrazine monitors at the 10 part per billion (ppb) level. The standard TVDL PCDAS can control two toxic vapor generators (TVG's) with three channels each and two flow/ temperature / humidity (FTH) controllers and it can record data from up to six toxic vapor detectors (TVD's) under test and can deliver flows from 5 to 50 liters per minute (L/m) at temperatures from near zero to 50 degrees Celsius (C) using an environmental chamber to maintain the sample temperature. The concentration range for toxic vapors depends on the permeation source installed in the TVG. The PCDAS can provide closed loop control of temperature and humidity to two sample vessels, typically one for zero gas and one for the standard gas. This is required at very low toxic vapor concentrations to minimize the time required to passivate the sample delivery system. Recently, there have been several requests for information about the PCDAS by other laboratories with similar needs, both on and off KSC. The purpose of this paper is to inform the toxic vapor detection community of the current status and planned upgrades to the automated testing of toxic vapor detectors at the Kennedy Space Center.

Automated Test Systems for Toxic Vapor Detectors

NASA Technical Reports Server (NTRS)

Mattson, C. B.; Hammond, T. A.; Schwindt, C. J.

1997-01-01

The NASA Toxic Vapor Detection Laboratory (TVDL) at the Kennedy Space Center (KSC), Florida, has been using Personal Computer based Data Acquisition and Control Systems (PCDAS) for about nine years. These systems control the generation of toxic vapors of known concentrations under controlled conditions of temperature and humidity. The PCDAS also logs the test conditions and the test article responses in data files for analysis by standard spreadsheets or custom programs. The PCDAS was originally developed to perform standardized qualification and acceptance tests in a search for a commercial off-the-shelf (COTS) toxic vapor detector to replace the hydrazine detectors for the Space Shuttle launch pad. It has since become standard test equipment for the TVDL and is indispensable in producing calibration standards for the new hydrazine monitors at the 10 part per billion (ppb) level. The standard TVDL PCDAS can control two toxic vapor generators (TVG's) with three channels each and two flow/temperature/humidity (FIFH) controllers and it can record data from up to six toxic vapor detectors (TVD's) under test and can deliver flows from 5 to 50 liters per minute (L/m) at temperatures from near zero to 50 degrees Celsius (C) using an environmental chamber to maintain the sample temperature. The concentration range for toxic vapors depends on the permeation source installed in the TVG. The PCDAS can provide closed loop control of temperature and humidity to two sample vessels, typically one for zero gas and one for the standard gas. This is required at very low toxic vapor concentrations to minimize the time required to passivate the sample delivery system. Recently, there have been several requests for information about the PCDAS by other laboratories with similar needs, both on and off KSC. The purpose of this paper is to inform the toxic vapor detection community of the current status and planned upgrades to the automated testing of toxic vapor detectors at the Kennedy Space Center.

Moisture uptake of polyoxyethylene glycol glycerides used as matrices for drug delivery: kinetic modelling and practical implications.

PubMed

Qi, Sheng; Belton, Peter; McAuley, William; Codoni, Doroty; Darji, Neerav

2013-04-01

Gelucire 50/13, a polyoxyethylene glycol glyceride mixture, has been widely used in drug delivery, but its moisture uptake behaviour is still poorly understood. In this study, the effects of relative humidity, temperature, and drug incorporation on the moisture uptake of Gelucire are reported in relation to their practical implications for preparation of solid dispersions using this material. DVS combined with kinetics modelling was used as the main experimental method to study the moisture uptake behaviour of Gelucire. Thermal and microscopic methods were employed to investigate the effect of moisture uptake on the physical properties of the material and drug loaded solid dispersions. The moisture uptake by Gelucire 50/13 is temperature and relative humidity dependent. At low temperatures and low relative humidities, moisture sorption follows a GAB model. The model fitting indicated that at high relative humidities the sorption is a complex process, potentially involving PEG being dissolved and the PEG solution acting as solvent to dissolve other components. Careful control of the storage and processing environmental conditions are required when using Gelucire 50/13. The incorporation of model drugs not only influences the moisture uptake capacity of Gelucire 50/13 but also the solidification behaviour.

Thermoregulatory responses to skin wetting during prolonged treadmill running.

PubMed

Bassett, D R; Nagle, F J; Mookerjee, S; Darr, K C; Ng, A V; Voss, S G; Napp, J P

1987-02-01

We examined the physiological responses to skin wetting during a 120-min level treadmill run to assess whether skin wetting would reduce the dehydration and the increase in core temperature associated with prolonged exercise. Testing was conducted in an environmental chamber (T = 29.5 degrees C, wind velocity = 3 m X sec-1) under two different humidity conditions (33 or 66% relative humidity). Ten male subjects performed two runs in each humidity condition; one served as a control run. The other included spraying the body with 50 ml of water (T = 29.5 degrees C) every 10 min. Spraying had no effect on rectal temperature (Tre), heart rate, oxygen consumption, perceived exertion, sweat loss, or percent change in plasma volume in both the humid and the dry conditions. Spraying produced a significant reduction in mean skin temperature (Tsk), which increased the (Tre - Tsk) gradient. At the same time, overall skin conductance (K) was decreased, presumably as a result of cutaneous vasoconstriction due to the low Tsk. Since heat transfer from the body's core to the skin is expressed by the equation: heat transfer = K X (Tre - Tsk) the spraying had no effect on heat transfer away from the core, and Tre remained unchanged.

Identifying Changes in the Probability of High Temperature, High Humidity Heat Wave Events

NASA Astrophysics Data System (ADS)

Ballard, T.; Diffenbaugh, N. S.

2016-12-01

Understanding how heat waves will respond to climate change is critical for adequate planning and adaptation. While temperature is the primary determinant of heat wave severity, humidity has been shown to play a key role in heat wave intensity with direct links to human health and safety. Here we investigate the individual contributions of temperature and specific humidity to extreme heat wave conditions in recent decades. Using global NCEP-DOE Reanalysis II daily data, we identify regional variability in the joint probability distribution of humidity and temperature. We also identify a statistically significant positive trend in humidity over the eastern U.S. during heat wave events, leading to an increased probability of high humidity, high temperature events. The extent to which we can expect this trend to continue under climate change is complicated due to variability between CMIP5 models, in particular among projections of humidity. However, our results support the notion that heat wave dynamics are characterized by more than high temperatures alone, and understanding and quantifying the various components of the heat wave system is crucial for forecasting future impacts.

The Plant Research Unit: An International Space Station Habitat

NASA Technical Reports Server (NTRS)

Morrow, Robert; Reiss-Bubenheim, Debra; Schaefer, Ronald L.

2003-01-01

The Plant Research Unit (PRU) is one of six life science habitats being developed as part of the Space Station Biological Research Program. The PRU is designed for experiments in microgravity and will utilize the ISS Centrifuge Facility to provide gravity levels between microgravity and 29. The PRU will provide and control all aspects of a plant s needs in a nearly closed system. In other words, the shoot and root environments will not be open to the astronaut s environment except for experiment maintenance such as planting, harvesting and plant sampling. This also means that all lighting, temperature and humidity control, "watering," and air filtering and cleaning .must be done within strict limitations of volume, weight, power, and crew time while at the same time providing a very high level of reliability and a service life in excess of 10 years. The PRU will contain two plant chambers 31.5 cm tall, each with independent control of temperature, humidity, light level and photoperiod, CO2 level, nutrient and water delivery, and video and data acquisition. The PRU is currently in the preliminary design phase and a number of subsystem components have been prototyped for testing, including the temperature and humidity control systems, the plant chambers, the LED lighting system, the atmospheric control system and a variety of nutrient delivery systems. The LED prototype provides independent feedback control of 5 separate spectral bands and variable output between 0 and 1000 micro-mol sq m/sec. The water and nutrient delivery system (WNDS) prototypes have been used to test particulate based, thin film, and gel-based WNDS configurations.

The effects of thermal manipulations during embryogenesis of broiler chicks on growth of embryo and skeletal traits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aygün, Ali, E-mail: aaygun@selcuk.edu.tr; Narinç, Doğan, E-mail: narincd@gmail.com

Incubation temperature is one of the important environmental factors that can induce epigenetic thermal adaptation of different physiological control systems. Thus, post hatch thermo tolerance ability of birds may be gained using these manipulations during different incubation periods. The current study was carried out to reveal the effects of temperature manipulations during early and late embryogenesis on weight of embryo and size of skeletal bilateral traits (face, wings, metatarsus, tibia, and femur) in broiler chicken embryos. One thousand commercial broiler eggs from 46 week old breeder flock were used in study. Treatments consisted of eggs incubated at 37.8°C and 55%more » relative humidity throughout (control; DG1), heated to 36.9°C and supplied 60% relative humidity for 6 hours daily from day 0 to 8 (DG2), heated to 36.9°C and supplied 60% relative humidity for 6 hours daily from day 10 to 18 (DG3), heated to 41°C and supplied 65% relative humidity for 3 hours daily from day 8 to 10 (DG4), and heated to 41°C and supplied 65% relative humidity for 3 hours daily from day 16 to 18 (DG5). Measurements of embryo weight and bilateral traits were obtained at 20 day of incubation and at hatch (at day 21). It was determined that the live weights of embryo and chick were affected significantly by treatment; DG3 group has shown higher mean values than the other treatment groups (P<0.05). There were differences in lengths of femur, tibia and metatarsus among treatment groups at hatch. Particularly, the high incubator temperatures at the second half of incubation accelerated growth of body and bone in embryos. These consequences of the treatments performed at different temperatures and times indicate that the different metabolic shifts realized by the embryos.« less

The effects of thermal manipulations during embryogenesis of broiler chicks on growth of embryo and skeletal traits

NASA Astrophysics Data System (ADS)

Aygün, Ali; Narinç, Doǧan

2016-04-01

Incubation temperature is one of the important environmental factors that can induce epigenetic thermal adaptation of different physiological control systems. Thus, post hatch thermo tolerance ability of birds may be gained using these manipulations during different incubation periods. The current study was carried out to reveal the effects of temperature manipulations during early and late embryogenesis on weight of embryo and size of skeletal bilateral traits (face, wings, metatarsus, tibia, and femur) in broiler chicken embryos. One thousand commercial broiler eggs from 46 week old breeder flock were used in study. Treatments consisted of eggs incubated at 37.8°C and 55% relative humidity throughout (control; DG1), heated to 36.9°C and supplied 60% relative humidity for 6 hours daily from day 0 to 8 (DG2), heated to 36.9°C and supplied 60% relative humidity for 6 hours daily from day 10 to 18 (DG3), heated to 41°C and supplied 65% relative humidity for 3 hours daily from day 8 to 10 (DG4), and heated to 41°C and supplied 65% relative humidity for 3 hours daily from day 16 to 18 (DG5). Measurements of embryo weight and bilateral traits were obtained at 20 day of incubation and at hatch (at day 21). It was determined that the live weights of embryo and chick were affected significantly by treatment; DG3 group has shown higher mean values than the other treatment groups (P<0.05). There were differences in lengths of femur, tibia and metatarsus among treatment groups at hatch. Particularly, the high incubator temperatures at the second half of incubation accelerated growth of body and bone in embryos. These consequences of the treatments performed at different temperatures and times indicate that the different metabolic shifts realized by the embryos.

Effects of Temperature and Humidity on the Characterization of C-4 Explosive Threats

DOE Office of Scientific and Technical Information (OSTI.GOV)

C. J. Miller

The amount of time that an explosive is present on the surface of a material is dependent upon the original amount of explosive on the surface, adhesive forces, temperature and humidity, as well as other environmental factors. This laboratory study focused on evaluating RDX crystal morphology changes resulting from variations in temperature and humidity conditions of the sample. The temperature and humidity conditions were controlled using a Tenney THRJ environmental chamber and a Tenney T11RC-1.5 environmental chamber. These chambers allow the temperature and humidity to be held within ±3°C and ±5% RH. The temperature and humidity conditions used for thismore » test series were: 40°F/40%RH, ~70°F/20%RH (samples left on benchtop), 70°F/70%RH, 70°F/95%RH, 95°F/40%RH, 95°F/70%RH, and 95°F/95%RH. These temperature and humidity set points were chosen to represent a wide range of conditions that may be found in real world scenarios. C-4 (RDX crystals and binder material) was deposited on the surface of one of six substrates by placing a fingerprint from the explosive block onto the matrix surface. The substrates were chosen to provide a range of items that are commonly used. Six substrate types were used during these tests: 50% cotton/50% polyester as found in T-shirts, 100% cotton with a smooth surface such as that found in a cotton dress shirt, 100% cotton on a rough surface such as that found on canvas or denim, suede leather such as might be found on jackets, purses, or shoes, painted metal obtained from a junked car hood, and a computer diskette. The samples were not pre-cleaned prior to testing and contained sizing agents, and in the case of the metal: oil, dirt, scratches, and rust spots. The substrates were photographed at various stages of testing, using a Zeiss Discover V12 stereoscope with Axiocam ICc1 3 megapixel digital camera, to determine any changes in the crystalline morphology. Some of the samples were examined using scanning electron microscopy (SEM) and atomic force microscopy (AFM) in an attempt to determine how the explosive was bound to the substrate.« less

Mechanical degradation of fuel cell membranes under fatigue fracture tests

NASA Astrophysics Data System (ADS)

Khorasany, Ramin M. H.; Sadeghi Alavijeh, Alireza; Kjeang, Erik; Wang, G. G.; Rajapakse, R. K. N. D.

2015-01-01

The effects of cyclic stresses on the fatigue and mechanical stability of perfluorosulfonic acid (PFSA) membranes are experimentally investigated under standard fuel cell conditions. The experiments are conducted ex-situ by subjecting membrane specimens to cyclic uniaxial tension at controlled temperature and relative humidity. The fatigue lifetime is measured in terms of the number of cycles until ultimate fracture. The results indicate that the membrane fatigue lifetime is a strong function of the applied stress, temperature, and relative humidity. The fatigue life increases exponentially with reduced stresses in all cases. The effect of temperature is found to be more significant than that of humidity, with reduced fatigue life at high temperatures. The maximum membrane strain at fracture is determined to decrease exponentially with increasing membrane lifetime. At a given fatigue life, a membrane exposed to fuel cell conditions is shown to accommodate more plastic strain before fracture than one exposed to room conditions. Overall, the proposed ex-situ membrane fatigue experiment can be utilized to benchmark the fatigue lifetime of new materials in a fraction of the time and cost associated with conventional in-situ accelerated stress testing methods.

Evaluation of Diesel Exhaust Continuous Monitors in Controlled Environmental Conditions

PubMed Central

Yu, Chang Ho; Patton, Allison P.; Zhang, Andrew; Fanac, Zhi-Hua (Tina); Weisel, Clifford P.; Lioy, Paul J.

2015-01-01

Diesel exhaust (DE) contains a variety of toxic air pollutants, including diesel particulate matter (DPM) and gaseous contaminants (e.g., carbon monoxide (CO)). DPM is dominated by fine (PM2.5) and ultrafine particles (UFP), and can be representatively determined by its thermal-optical refractory as elemental carbon (EC) or light-absorbing characteristics as black carbon (BC). The currently accepted reference method for sampling and analysis of occupational exposure to DPM is the National Institute for Occupational Safety and Health (NIOSH) Method 5040. However, this method cannot provide in-situ short-term measurements of DPM. Thus, real-time monitors are gaining attention to better examine DE exposures in occupational settings. However, real-time monitors are subject to changing environmental conditions. Field measurements have reported interferences in optical sensors and subsequent real-time readings, under conditions of high humidity and abrupt temperature changes. To begin dealing with these issues, we completed a controlled study to evaluate five real-time monitors: Airtec real-time DPM/EC Monitor, TSI SidePak Personal Aerosol Monitor AM510 (PM2.5), TSI Condensation Particle Counter 3007, microAeth AE51 BC Aethalometer, and Langan T15n CO Measurer. Tests were conducted under different temperatures (55, 70, and 80 °F), relative humidity (10, 40, and 80%), and DPM concentrations (50 and 200 µg/m3) in a controlled exposure facility. The 2-hour averaged EC measurements from the Airtec instrument showed relatively good agreement with NIOSH Method 5040 (R2=0.84; slope=1.17±0.06; N=27) and reported ~17% higher EC concentrations than the NIOSH reference method. Temperature, relative humidity, and DPM levels did not significantly affect relative differences in 2-hour averaged EC concentrations obtained by the Airtec instrument versus the NIOSH method (p<0.05). Multiple linear regression analyses, based on 1-min averaged data, suggested combined effects of up to 5% from relative humidity and temperature on real-time measurements. The overall deviations of these real-time monitors from the NIOSH method results were ≤20%. However, simultaneous monitoring of temperature and relative humidity is recommended in field investigations to understand and correct for environmental impacts on real-time monitoring data. PMID:25894766

A temperature/humidity tolerance index for transporting Beagle dogs in hot weather.

DOT National Transportation Integrated Search

1987-11-01

Male beagle dogs were subjected to various hot air temperature/humidity combinations in an attempt to develop a safe temperature/humidity index for dogs being transported by aircraft. Only those environments in which all exposed dogs could maintain a...

System-in Package of Integrated Humidity Sensor Using CMOS-MEMS Technology.

PubMed

Lee, Sung Pil

2015-10-01

Temperature/humidity microchips with micropump were fabricated using a CMOS-MEMS process and combined with ZigBee modules to implement a sensor system in package (SIP) for a ubiquitous sensor network (USN) and/or a wireless communication system. The current of a diode temperature sensor to temperature and a normalized current of FET humidity sensor to relative humidity showed linear characteristics, respectively, and the use of the micropump has enabled a faster response. A wireless reception module using the same protocol as that in transmission systems processed the received data within 10 m and showed temperature and humidity values in the display.

Testing the effects of temperature and humidity on printed passive UHF RFID tags on paper substrate

NASA Astrophysics Data System (ADS)

Linnea Merilampi, Sari; Virkki, Johanna; Ukkonen, Leena; Sydänheimo, Lauri

2014-05-01

This article is an interesting substrate material for environmental-friendly printable electronics. In this study, screen-printed RFID tags on paper substrate are examined. Their reliability was tested with low temperature, high temperature, slow temperature cycling, high temperature and high humidity and water dipping test. Environmental stresses affect the tag antenna impedance, losses and radiation characteristics due to their impact on the ink film and paper substrate. Low temperature, temperature cycling and high humidity did not have a radical effect on the measured parameters: threshold power, backscattered signal power or read range of the tags. However, the frequency response and the losses of the tags were slightly affected. Exposure to high temperature was found to even improve the tag performance due to the positive effect of high temperature on the ink film. The combined high humidity and high temperature had the most severe effect on the tag performance. The threshold power increased, backscattered power decreased and the read range was shortened. On the whole, the results showed that field use of these tags in high, low and changing temperature conditions and high humidity conditions is possible. Use of these tags in combined high-humidity and high-temperature conditions should be carefully considered.

Dehydration of trehalose dihydrate at low relative humidity and ambient temperature.

PubMed

Jones, Matthew D; Hooton, Jennifer C; Dawson, Michelle L; Ferrie, Alan R; Price, Robert

2006-04-26

The physico-chemical behaviour of trehalose dihydrate during storage at low relative humidity and ambient temperature was investigated, using a combination of techniques commonly employed in pharmaceutical research. Weight loss, water content determinations, differential scanning calorimetry and X-ray powder diffraction showed that at low relative humidity (0.1% RH) and ambient temperature (25 degrees C) trehalose dihydrate dehydrates forming the alpha-polymorph. Physical examination of trehalose particles by scanning electron microscopy and of the dominant growth faces of trehalose crystals by environmentally controlled atomic force microscopy revealed significant changes in surface morphology upon partial dehydration, in particular the formation of cracks. These changes were not fully reversible upon complete rehydration at 50% RH. These findings should be considered when trehalose dihydrate is used as a pharmaceutical excipient in situations where surface properties are key to behaviour, for example as a carrier in a dry powder inhalation formulations, as morphological changes under common processing or storage conditions may lead to variations in formulation performance.

Bias Correction for Assimilation of Retrieved AIRS Profiles of Temperature and Humidity

NASA Technical Reports Server (NTRS)

Blakenship, Clay; Zavodsky, Bradley; Blackwell, William

2014-01-01

The Atmospheric Infrared Sounder (AIRS) is a hyperspectral radiometer aboard NASA's Aqua satellite designed to measure atmospheric profiles of temperature and humidity. AIRS retrievals are assimilated into the Weather Research and Forecasting (WRF) model over the North Pacific for some cases involving "atmospheric rivers". These events bring a large flux of water vapor to the west coast of North America and often lead to extreme precipitation in the coastal mountain ranges. An advantage of assimilating retrievals rather than radiances is that information in partly cloudy fields of view can be used. Two different Level 2 AIRS retrieval products are compared: the Version 6 AIRS Science Team standard retrievals and a neural net retrieval from MIT. Before assimilation, a bias correction is applied to adjust each layer of retrieved temperature and humidity so the layer mean values agree with a short-term model climatology. WRF runs assimilating each of the products are compared against each other and against a control run with no assimilation. Forecasts are against ERA reanalyses.

Membrane humidification--a new method for humidification of respiratory gases in ventilator treatment of neonates.

PubMed Central

Hanssler, L; Tennhoff, W; Roll, C

1992-01-01

A humidifier system for neonatology that functions according to the 'membrane humidification' principle was subjected to a performance test in our laboratory. Humidification and heating of the respiratory gases took place in a module consisting of a net of hollow fibres placed inside the incubator. In 18 measurement combinations flow, respiratory gas temperature, and incubator temperature were varied. At respiratory gas temperatures within the range of 33-37 degrees C the minimum international standard for the absolute air humidity in the respiratory gas was achieved or exceeded in all measurements. No controlled clinical tests regarding the importance and long term effects of different temperatures and different humidity levels in the inspiratory air are yet available for the ventilation treatment of neonates. PMID:1444554

High Accuracy Acoustic Relative Humidity Measurement in Duct Flow with Air

PubMed Central

van Schaik, Wilhelm; Grooten, Mart; Wernaart, Twan; van der Geld, Cees

2010-01-01

An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH) instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0–12 m/s with an error of ±0.13 m/s, temperature 0–100 °C with an error of ±0.07 °C and relative humidity 0–100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments. PMID:22163610

High accuracy acoustic relative humidity measurement in duct flow with air.

PubMed

van Schaik, Wilhelm; Grooten, Mart; Wernaart, Twan; van der Geld, Cees

2010-01-01

An acoustic relative humidity sensor for air-steam mixtures in duct flow is designed and tested. Theory, construction, calibration, considerations on dynamic response and results are presented. The measurement device is capable of measuring line averaged values of gas velocity, temperature and relative humidity (RH) instantaneously, by applying two ultrasonic transducers and an array of four temperature sensors. Measurement ranges are: gas velocity of 0-12 m/s with an error of ± 0.13 m/s, temperature 0-100 °C with an error of ± 0.07 °C and relative humidity 0-100% with accuracy better than 2 % RH above 50 °C. Main advantage over conventional humidity sensors is the high sensitivity at high RH at temperatures exceeding 50 °C, with accuracy increasing with increasing temperature. The sensors are non-intrusive and resist highly humid environments.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rohles, F.H. Jr.

Studies by the Institute for Environmental Research, Kansas State University, show that in terms of comfort, health, and performance, humidity control is an important element of environmental control and should not be eliminated for the sake of energy conservation. A constant level of comfort can be maintained if the humidity is increased and the temperature is decreased and vice versa; school absenteeism due to upper respiratory infection is related to classroom humidifcation; and psychomotor performance is better under warm, dry conditions than under warm, moist conditions. Humidification may be valuable in thermostat-setback programs by making cooler conditions comfortable.

[The association between emergency clinic visits for asthmatic attacks and fluctuating environmental factors].

PubMed

Shimizu, S; Kagawa, J; Ishiguro, M

2001-07-01

The number of nocturnal visits of asthmatic attack patients to the emergency room of Yokohama Medical Association's Clinic from January 1990 to December 1991 was compared to daily levels of air pollution (NO, NO2, SO2 and SPM) and weather (temperature and relative humidity) variables measured in Yokohama City. Trend-cycle components (Trend) that control for the weekly effects, other irregular variance for asthmatic attack incidence and environmental parameter measurements were estimated from the original data series using the method of Akaike and Ishiguro (1980). The rate of increase for each environmental parameter was then calculated from its trend-cycle components. We classified the data into four stages on the basis of rising and falling temperature and humidity. For each stage of temperature and humidity, fluctuation we estimated correlations between the number of asthmatic attack visits and original data series measurements, estimated trend-cycle components, and calculated rates of increase for each of the air pollutants. The daily number of asthmatic attack visits was negatively correlated to the daily mean values of all air pollutants, but positively correlated to the daily mean temperature and relative humidity. The trend-cycle components of the air pollutants were also negatively correlated to the frequencies of asthmatic attacks (p < 0.01 for all pollutants except NO2). In contrast, the number of asthmatic attack visits were in general positively correlated with increasing levels of pollutants. Furthermore, when both temperature and relative humidity decreased, significant correlations (r > 0.31, p < 0.001) between the number of asthmatic attacks and increased rates of all air pollutants were observed (r: NO2 > NO > SO2 > SPM).

Impact of intraoperative temperature and humidity on healing of intestinal anastomoses.

PubMed

Glatz, Torben; Boldt, Johannes; Timme, Sylvia; Kulemann, Birte; Seifert, Gabriel; Holzner, Philipp Anton; Chikhladze, Sophia; Grüneberger, Jodok Matthias; Küsters, Simon; Sick, Olivia; Höppner, Jens; Hopt, Ulrich Theodor; Marjanovic, Goran

2014-04-01

Clinical data indicate that laparoscopic surgery has a beneficial effect on intestinal wound healing and is associated with a lower incidence of anastomotic leakage. This observation is based on weak evidence, and little is known about the impact of intraoperative parameters during laparoscopic surgery, e.g., temperature and humidity. A small-bowel anastomosis was formed in rats inside an incubator, in an environment of stable humidity and temperature. Three groups of ten Wistar rats were operated: a control group (G1) in an open surgical environment and two groups (G2 and G3) in the incubator at a humidity of 60 % and a temperature of 30 and 37 °C (G2 and G3, respectively). After 4 days, bursting pressure and hydroxyproline concentration of the anastomosis were analyzed. The tissue was histologically examined. Serum levels of C-reactive-protein (CRP) were measured. No significant changes were seen in the evaluation of anastomotic stability. Bursting pressure was very similar among the groups. Hydroxyproline concentration in G3 (36.3 μg/g) was lower by trend (p = 0.072) than in G1 (51.7 μg/g) and G2 (46.4 μg/g). The histological evaluation showed similar results regarding necrosis, inflammatory cells, edema, and epithelization for all groups. G3 (2.56) showed a distinctly worse score for submucosal bridging (p = 0.061) than G1 (1.68). A highly significant increase (p = 0.008) in CRP was detected in G3 (598.96 ng/ml) compared to G1 (439.49 ng/ml) and G2 (460 ng/ml). A combination of high temperature and humidity during surgery induces an increased systemic inflammatory response and seems to be attenuating the early regeneration process in the anastomotic tissue.

A Radiosonde Using a Humidity Sensor Array with a Platinum Resistance Heater and Multi-Sensor Data Fusion

PubMed Central

Shi, Yunbo; Luo, Yi; Zhao, Wenjie; Shang, Chunxue; Wang, Yadong; Chen, Yinsheng

2013-01-01

This paper describes the design and implementation of a radiosonde which can measure the meteorological temperature, humidity, pressure, and other atmospheric data. The system is composed of a CPU, microwave module, temperature sensor, pressure sensor and humidity sensor array. In order to effectively solve the humidity sensor condensation problem due to the low temperatures in the high altitude environment, a capacitive humidity sensor including four humidity sensors to collect meteorological humidity and a platinum resistance heater was developed using micro-electro-mechanical-system (MEMS) technology. A platinum resistance wire with 99.999% purity and 0.023 mm in diameter was used to obtain the meteorological temperature. A multi-sensor data fusion technique was applied to process the atmospheric data. Static and dynamic experimental results show that the designed humidity sensor with platinum resistance heater can effectively tackle the sensor condensation problem, shorten response times and enhance sensitivity. The humidity sensor array can improve measurement accuracy and obtain a reliable initial meteorological humidity data, while the multi-sensor data fusion technique eliminates the uncertainty in the measurement. The radiosonde can accurately reflect the meteorological changes. PMID:23857263

A radiosonde using a humidity sensor array with a platinum resistance heater and multi-sensor data fusion.

PubMed

Shi, Yunbo; Luo, Yi; Zhao, Wenjie; Shang, Chunxue; Wang, Yadong; Chen, Yinsheng

2013-07-12

This paper describes the design and implementation of a radiosonde which can measure the meteorological temperature, humidity, pressure, and other atmospheric data. The system is composed of a CPU, microwave module, temperature sensor, pressure sensor and humidity sensor array. In order to effectively solve the humidity sensor condensation problem due to the low temperatures in the high altitude environment, a capacitive humidity sensor including four humidity sensors to collect meteorological humidity and a platinum resistance heater was developed using micro-electro-mechanical-system (MEMS) technology. A platinum resistance wire with 99.999% purity and 0.023 mm in diameter was used to obtain the meteorological temperature. A multi-sensor data fusion technique was applied to process the atmospheric data. Static and dynamic experimental results show that the designed humidity sensor with platinum resistance heater can effectively tackle the sensor condensation problem, shorten response times and enhance sensitivity. The humidity sensor array can improve measurement accuracy and obtain a reliable initial meteorological humidity data, while the multi-sensor data fusion technique eliminates the uncertainty in the measurement. The radiosonde can accurately reflect the meteorological changes.

Analysis of building envelope insulation performance utilizing integrated temperature and humidity sensors.

PubMed

Hung, San-Shan; Chang, Chih-Yuan; Hsu, Cheng-Jui; Chen, Shih-Wei

2012-01-01

A major cause of high energy consumption for air conditioning in indoor spaces is the thermal storage characteristics of a building's envelope concrete material; therefore, the physiological signals (temperature and humidity) within concrete structures are an important reference for building energy management. The current approach to measuring temperature and humidity within concrete structures (i.e., thermocouples and fiber optics) is limited by problems of wiring requirements, discontinuous monitoring, and high costs. This study uses radio frequency integrated circuits (RFIC) combined with temperature and humidity sensors (T/H sensors) for the design of a smart temperature and humidity information material (STHIM) that automatically, regularly, and continuously converts temperature and humidity signals within concrete and transmits them by radio frequency (RF) to the Building Physiology Information System (BPIS). This provides a new approach to measurement that incorporates direct measurement, wireless communication, and real-time continuous monitoring to assist building designers and users in making energy management decisions and judgments.

Analysis of Building Envelope Insulation Performance Utilizing Integrated Temperature and Humidity Sensors

PubMed Central

Hung, San-Shan; Chang, Chih-Yuan; Hsu, Cheng-Jui; Chen, Shih-Wei

2012-01-01

A major cause of high energy consumption for air conditioning in indoor spaces is the thermal storage characteristics of a building's envelope concrete material; therefore, the physiological signals (temperature and humidity) within concrete structures are an important reference for building energy management. The current approach to measuring temperature and humidity within concrete structures (i.e., thermocouples and fiber optics) is limited by problems of wiring requirements, discontinuous monitoring, and high costs. This study uses radio frequency integrated circuits (RFIC) combined with temperature and humidity sensors (T/H sensors) for the design of a smart temperature and humidity information material (STHIM) that automatically, regularly, and continuously converts temperature and humidity signals within concrete and transmits them by radio frequency (RF) to the Building Physiology Information System (BPIS). This provides a new approach to measurement that incorporates direct measurement, wireless communication, and real-time continuous monitoring to assist building designers and users in making energy management decisions and judgments. PMID:23012529

Advanced extravehicular protective systems

NASA Technical Reports Server (NTRS)

Sutton, J. G.; Heimlich, P. F.; Tepper, E. H.

1972-01-01

New technologies are identified and recommended for developing a regenerative portable life support system that provides protection for extravehicular human activities during long duration missions on orbiting space stations, potential lunar bases, and possible Mars landings. Parametric subsystems analyses consider: thermal control, carbon dioxide control, oxygen supply, power supply, contaminant control, humidity control, prime movers, and automatic temperature control.

Measurement of Temperature and Relative Humidity with Polymer Optical Fiber Sensors Based on the Induced Stress-Optic Effect

PubMed Central

Pontes, Maria José

2018-01-01

This paper presents a system capable of measuring temperature and relative humidity with polymer optical fiber (POF) sensors. The sensors are based on variations of the Young’s and shear moduli of the POF with variations in temperature and relative humidity. The system comprises two POFs, each with a predefined torsion stress that resulted in a variation in the fiber refractive index due to the stress-optic effect. Because there is a correlation between stress and material properties, the variation in temperature and humidity causes a variation in the fiber’s stress, which leads to variations in the fiber refractive index. Only two photodiodes comprise the sensor interrogation, resulting in a simple and low-cost system capable of measuring humidity in the range of 5–97% and temperature in the range of 21–46 °C. The root mean squared errors (RMSEs) between the proposed sensors and the reference were 1.12 °C and 1.36% for the measurements of temperature and relative humidity, respectively. In addition, fiber etching resulted in a sensor with a 2 s response time for a relative humidity variation of 10%, which is one of the lowest recorded response times for intrinsic POF humidity sensors. PMID:29558387

Measurement of Temperature and Relative Humidity with Polymer Optical Fiber Sensors Based on the Induced Stress-Optic Effect.

PubMed

Leal-Junior, Arnaldo; Frizera-Neto, Anselmo; Marques, Carlos; Pontes, Maria José

2018-03-20

This paper presents a system capable of measuring temperature and relative humidity with polymer optical fiber (POF) sensors. The sensors are based on variations of the Young's and shear moduli of the POF with variations in temperature and relative humidity. The system comprises two POFs, each with a predefined torsion stress that resulted in a variation in the fiber refractive index due to the stress-optic effect. Because there is a correlation between stress and material properties, the variation in temperature and humidity causes a variation in the fiber's stress, which leads to variations in the fiber refractive index. Only two photodiodes comprise the sensor interrogation, resulting in a simple and low-cost system capable of measuring humidity in the range of 5-97% and temperature in the range of 21-46 °C. The root mean squared errors (RMSEs) between the proposed sensors and the reference were 1.12 °C and 1.36% for the measurements of temperature and relative humidity, respectively. In addition, fiber etching resulted in a sensor with a 2 s response time for a relative humidity variation of 10%, which is one of the lowest recorded response times for intrinsic POF humidity sensors.

Socioeconomic and Outdoor Meteorological Determinants of Indoor Temperature and Humidity in New York City Dwellings

PubMed Central

Tamerius, JD; Perzanowski, MS; Acosta, LM; Jacobson, JS; Goldstein, IF; Quinn, JW; Rundle, AG; Shaman, J

2013-01-01

Background Numerous mechanisms link outdoor weather and climate conditions to human health. It is likely that many health conditions are more directly affected by indoor rather than outdoor conditions. Yet, the relationship between indoor temperature and humidity conditions to outdoor variability, and the heterogeneity of the relationship among different indoor environments are largely unknown. Methods We use 5–14 day measures of indoor temperature and relative humidity from 327 dwellings in New York City for the years 2008–2011 to investigate the relationship between indoor climate, outdoor meteorological conditions, socioeconomic conditions, and building descriptors. Study households were primarily middle-income and located across the boroughs of Brooklyn, Queens, Bronx, and Manhattan. Results Indoor temperatures are positively associated with outdoor temperature during the warm season and study dwellings in higher socioeconomic status neighborhoods are significantly cooler. During the cool season, outdoor temperatures have little effect on indoor temperatures; however, indoor temperatures can range more than 10 °C between dwellings despite similar outdoor temperatures. Apartment buildings tend to be significantly warmer than houses and dwellings on higher floors are also significantly warmer than dwellings on lower floors. Outdoor specific humidity is positively associated with indoor specific and relative humidity, but there is no consistent relationship between outdoor and indoor relative humidity. Conclusions In New York City, the relationship between indoor and outdoor temperature and humidity conditions vary significantly between dwellings. These results can be used to inform studies of health outcomes for which temperature or humidity is an established factor affecting human health and highlights the need for more research on the determinants of indoor climate. PMID:24077420

Optimum drying temperature to prevent oxidative stain in soft maple

Treesearch

Michael C. Wiemann; Mark Knaebe; Scott A. Bowe

2011-01-01

The objective of this paper is to determine the kiln conditions necessary to avoid interior enzymatic oxidative discoloration in soft maple. Three drying chambers were designed and constructed to control temperature and relative humidity of maple test samples. The tests showed that drying as soon as possible after harvest at temperatures below 42°C will...

Temperature and Humidity Effects on Hospital Morbidity in Darwin, Australia.

PubMed

Goldie, James; Sherwood, Steven C; Green, Donna; Alexander, Lisa

2015-01-01

Many studies have explored the relationship between temperature and health in the context of a changing climate, but few have considered the effects of humidity, particularly in tropical locations, on human health and well-being. To investigate this potential relationship, this study assessed the main and interacting effects of daily temperature and humidity on hospital admission rates for selected heat-relevant diagnoses in Darwin, Australia. Univariate and bivariate Poisson generalized linear models were used to find statistically significant predictors and the admission rates within bins of predictors were compared to explore nonlinear effects. The analysis indicated that nighttime humidity was the most statistically significant predictor (P < 0.001), followed by daytime temperature and average daily humidity (P < 0.05). There was no evidence of a significant interaction between them or other predictors. The nighttime humidity effect appeared to be strongly nonlinear: Hot days appeared to have higher admission rates when they were preceded by high nighttime humidity. From this analysis, we suggest that heat-health policies in tropical regions similar to Darwin need to accommodate the effects of temperature and humidity at different times of day. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Ambient temperature, humidity and hand, foot, and mouth disease: A systematic review and meta-analysis.

PubMed

Cheng, Qiang; Bai, Lijun; Zhang, Yanwu; Zhang, Heng; Wang, Shusi; Xie, Mingyu; Zhao, Desheng; Su, Hong

2018-06-01

The relationship between ambient temperature, humidity and hand, foot, and mouth disease (HFMD) has been highlighted in East and Southeast Asia, which showed multiple different results. Therefore, our goal is to conduct a meta-analysis to further clarify this relationship and to quantify the size of these effects as well as the susceptible populations. PubMed, Web of science, and Cochrane library were searched up to November 22, 2017 for articles analyzing the relationships between ambient temperature, humidity and incidence of HFMD. We assessed sources of heterogeneity by study design (temperature measure and exposed time resolution), population vulnerability (national income level and regional climate) and evaluated pooled effect estimates for the subgroups identified in the heterogeneity analysis. We identified 11 studies with 19 estimates of the relationship between ambient temperature, humidity and incidence of HFMD. It was found that per 1°C increase in the temperature and per 1% increase in the relative humidity were both significantly associated with increased incidence of HFMD (temperature: IRR, 1.05; 95% CI, 1.02-1.08; relative humidity: IRR, 1.01; 95% CI, 1.00-1.02). Subgroup analysis showed that people living in subtropical and middle income areas had a higher risk of incidence of HFMD. Ambient temperature and humidity may increase the incidence of HFMD in Asia-Pacific regions. Further studies are needed to clarify the relationship between ambient temperature, humidity and incidence of HFMD in various settings with distinct climate, socioeconomic, and demographic features. Copyright © 2018. Published by Elsevier B.V.

Biomass Production System (BPS) plant growth unit.

PubMed

Morrow, R C; Crabb, T M

2000-01-01

The Biomass Production System (BPS) was developed under the Small Business Innovative Research (SBIR) program to meet science, biotechnology and commercial plant growth needs in the Space Station era. The BPS is equivalent in size to a double middeck locker, but uses its own custom enclosure with a slide out structure to which internal components mount. The BPS contains four internal growth chambers, each with a growing volume of more than 4 liters. Each of the growth chambers has active nutrient delivery, and independent control of temperature, humidity, lighting, and CO2 set-points. Temperature control is achieved using a thermoelectric heat exchanger system. Humidity control is achieved using a heat exchanger with a porous interface which can both humidify and dehumidify. The control software utilizes fuzzy logic for nonlinear, coupled temperature and humidity control. The fluorescent lighting system can be dimmed to provide a range of light levels. CO2 levels are controlled by injecting pure CO2 to the system based on input from an infrared gas analyzer. The unit currently does not scrub CO2, but has been designed to accept scrubber cartridges. In addition to providing environmental control, a number of features are included to facilitate science. The BPS chambers are sealed to allow CO2 and water vapor exchange measurements. The plant chambers can be removed to allow manipulation or sampling of specimens, and each chamber has gas/fluid sample ports. A video camera is provided for each chamber, and frame-grabs and complete environmental data for all science and hardware system sensors are stored on an internal hard drive. Data files can also be transferred to 3.5-inch disks using the front panel disk drive.

Biomass Production System (BPS) Plant Growth Unit

NASA Astrophysics Data System (ADS)

Morrow, R. C.; Crabb, T. M.

The Biomass Production System (BPS) was developed under the Small Business Innovative Research (SBIR) program to meet science, biotechnology and commercial plant growth needs in the Space Station era. The BPS is equivalent in size to a double middeck locker, but uses it's own custom enclosure with a slide out structure to which internal components mount. The BPS contains four internal growth chambers, each with a growing volume of more than 4 liters. Each of the growth chambers has active nutrient delivery, and independent control of temperature, humidity, lighting, and CO2 set-points. Temperature control is achieved using a thermoelectric heat exchanger system. Humidity control is achieved using a heat exchanger with a porous interface which can both humidify and dehumidify. The control software utilizes fuzzy logic for nonlinear, coupled temperature and humidity control. The fluorescent lighting system can be dimmed to provide a range of light levels. CO2 levels are controlled by injecting pure CO2 to the system based on input from an infrared gas analyzer. The unit currently does not scrub CO2, but has been designed to accept scrubber cartridges. In addition to providing environmental control, a number of features are included to facilitate science. The BPS chambers are sealed to allow CO2 and water vapor exchange measurements. The plant chambers can be removed to allow manipulation or sampling of specimens, and each chamber has gas/fluid sample ports. A video camera is provided for each chamber, and frame-grabs and complete environmental data for all science and hardware system sensors are stored on an internal hard drive. Data files can also be transferred to 3.5-inch disks using the front panel disk drive

The Humidity in a Low-Flow Dräger Fabius Anesthesia Workstation with or without Thermal Insulation or a Heat and Moisture Exchanger: A Prospective Randomized Clinical Trial.

PubMed

de Oliveira, Sergius A R; Lucio, Lorena M C; Modolo, Norma S P; Hayashi, Yoko; Braz, Mariana G; de Carvalho, Lídia R; Braz, Leandro G; Braz, José Reinaldo C

2017-01-01

During anesthesia, as compared with intensive care, the time of the tracheal intubation is much shorter. An inhaled gas minimum humidity of 20 mgH2O.L-1 is recommended to reduce the deleterious effects of dry gas on the airways during anesthesia with tracheal intubation. The Fabius GS Premium® anesthesia workstation (Dräger Medical, Lübeck, Germany) has a built-in hotplate to heat gases in the breathing circuit. A heat and moisture exchanger (HME) is used to further heat and humidify the inhaled gas. The humidity of the gases in the breathing circuit is influenced by the ambient temperature. We compared the humidity of the inhaled gases from a low-flow Fabius anesthesia workstation with or without thermal insulation (TI) of the breathing circuit and with or without an HME. We conducted a prospective randomized trial in 41 adult female patients who underwent elective abdominal surgery. The patients were allocated into four groups according to the devices used to ventilate their lungs using a Dräger Fabius anesthesia workstation with a low gas flow (1 L.min-1): control, with TI, with an HME or with TI and an HME (TIHME). The mean temperature and humidity of the inhaled gases were measured during 2-h after connecting the patients to the breathing circuit. The mean inhaled gas temperature and absolute humidity were higher in the HME (29.2±1.3°C; 28.1±2.3 mgH2O·L-1) and TIHME (30.1±1.2°C; 29.4±2.0 mgH2O·L-1) groups compared with the control (27.5±1.0°C; 25.0±1.8 mgH2O·L-1) and TI (27.2±1.1°C; 24.9±1.8 mgH2O·L-1) groups (P = 0.003 and P<0.001, respectively). The low-flow Fabius GS Premium breathing circuit provides the minimum humidity level of inhaled gases to avoid damage to the tracheobronchial epithelia during anesthesia. TI of the breathing circuit does not increase the humidity of the inhaled gases, whereas inserting an HME increases the moisture of the inhaled gases closer to physiological values.

A better indicator to measure the effects of meteorological factors on cardiovascular mortality: heat index.

PubMed

Yin, Qian; Wang, Jinfeng

2018-05-31

Although many studies have examined the correlation between temperature and mortality from cardiovascular diseases (CVD), other meteorological factors, such as relative humidity, may modify the relationship. Yet the studies on this aspect are relatively few. We chose a heat index (HI, which is an index that combines air temperature and relative humidity) as an alternative indicator of temperature, and used a distributed lag nonlinear model (DLNM) to analyze the combined effects of temperature and relative humidity on CVD mortality among all of the Beijing residents and subsociodemographic groups by age, sex, and occupation. The heat index can better reflect the human-perceived temperature when relative humidity is combined with air temperature. The results show that females, elderly people, and outdoor workers have higher vulnerability levels in regard to a high heat index. The strongest effect of heat index was found among females, for which the highest mortality risk was about 2.4 (95% CI 1.8-3) times greater than the lowest mortality risk. In addition, we found that there is a significant interaction effect of temperature and relative humidity on CVD mortality. The impact of extreme high temperature may be exacerbated by increases in humidity. Based on these results, we draw the risk level map of CVD death under different temperatures and grades of relative humidity. These findings may aid governments in the development of more accurate heat alerts and the provision of measures to prevent or reduce temperature-related deaths.

Experimental research on the indoor temperature and humidity fields in radiant ceiling air-conditioning system under natural ventilation

NASA Astrophysics Data System (ADS)

Huang, Tao; Xiang, Yutong; Wang, Yonghong

2017-05-01

In this paper, the indoor temperature and humidity fields of the air in a metal ceiling radiant panel air conditioning system with fresh air under natural ventilation were researched. The temperature and humidity distributions at different height and different position were compared. Through the computation analysis of partial pressure of water vapor, the self-recovery characteristics of humidity after the natural ventilation was discussed.

Projections of rising heat stress over the western Maritime Continent from dynamically downscaled climate simulations

NASA Astrophysics Data System (ADS)

Im, Eun-Soon; Kang, Suchul; Eltahir, Elfatih A. B.

2018-06-01

This study assesses the future changes in heat stress in response to different emission scenarios over the western Maritime Continent. To better resolve the region-specific changes and to enhance the performance in simulating extreme events, the MIT Regional Climate Model with a 12-km horizontal resolution is used for the dynamical downscaling of three carefully selected CMIP5 global projections forced by two Representative Concentration Pathway (RCP4.5 and RCP8.5) scenarios. Daily maximum wet-bulb temperature (TWmax), which includes the effect of humidity, is examined to describe heat stress as regulated by future changes in temperature and humidity. An ensemble of projections reveals robust pattern in which a large increase in temperature is accompanied by a reduction in relative humidity but a significant increase in wet-bulb temperature. This increase in TWmax is relatively smaller over flat and coastal regions than that over mountainous region. However, the flat and coastal regions characterized by warm and humid present-day climate will be at risk even under modest increase in TWmax. The regional extent exposed to higher TWmax and the number of days on which TWmax exceeds its threshold value are projected to be much higher in RCP8.5 scenario than those in RCP4.5 scenario, thus highlighting the importance of controlling greenhouse gas emissions to reduce the adverse impacts on human health and heat-related mortality.

A CMOS smart temperature and humidity sensor with combined readout.

PubMed

Eder, Clemens; Valente, Virgilio; Donaldson, Nick; Demosthenous, Andreas

2014-09-16

A fully-integrated complementary metal-oxide semiconductor (CMOS) sensor for combined temperature and humidity measurements is presented. The main purpose of the device is to monitor the hermeticity of micro-packages for implanted integrated circuits and to ensure their safe operation by monitoring the operating temperature and humidity on-chip. The smart sensor has two modes of operation, in which either the temperature or humidity is converted into a digital code representing a frequency ratio between two oscillators. This ratio is determined by the ratios of the timing capacitances and bias currents in both oscillators. The reference oscillator is biased by a current whose temperature dependency is complementary to the proportional to absolute temperature (PTAT) current. For the temperature measurement, this results in an exceptional normalized sensitivity of about 0.77%/°C at the accepted expense of reduced linearity. The humidity sensor is a capacitor, whose value varies linearly with relative humidity (RH) with a normalized sensitivity of 0.055%/% RH. For comparison, two versions of the humidity sensor with an area of either 0.2 mm2 or 1.2 mm2 were fabricated in a commercial 0.18 μm CMOS process. The on-chip readout electronics operate from a 5 V power supply and consume a current of approximately 85 µA.

Lessons Learned from the Node 1 Temperature and Humidity Control Subsystem Design

NASA Technical Reports Server (NTRS)

Williams, David E.

2010-01-01

Node 1 flew to the International Space Station (ISS) on Flight 2A during December 1998. To date the National Aeronautics and Space Administration (NASA) has learned a lot of lessons from this module based on its history of approximately two years of acceptance testing on the ground and currently its twelve years on-orbit. This paper will provide an overview of the ISS Environmental Control and Life Support (ECLS) design of the Node 1 Temperature and Humidity Control (THC) subsystem and it will document some of the lessons that have been learned to date for this subsystem and it will document some of the lessons that have been learned to date for these subsystems based on problems prelaunch, problems encountered on-orbit, and operational problems/concerns. It is hoped that documenting these lessons learned from ISS will help in preventing them in future Programs. 1

Phenophysiological variation of a bee that regulates hive humidity, but not hive temperature.

PubMed

Ayton, Sasha; Tomlinson, Sean; Phillips, Ryan D; Dixon, Kingsley W; Withers, Philip C

2016-05-15

Seasonal acclimatisation of thermal tolerance, evaporative water loss and metabolic rate, along with regulation of the hive environment, are key ways whereby hive-based social insects mediate climatic challenges throughout the year, but the relative importance of these traits remains poorly understood. Here, we examined seasonal variation in metabolic rate and evaporative water loss of worker bees, and seasonal variation of hive temperature and relative humidity (RH), for the stingless bee Austroplebeia essingtoni (Apidae: Meliponini) in arid tropical Australia. Both water loss and metabolic rate were lower in the cooler, dry winter than in the hot, wet summer at most ambient temperatures between 20°C and 45°C. Contrary to expectation, thermal tolerance thresholds were higher in the winter than in the summer. Hives were cooler in the cooler, dry winter than in the hot, wet summer, linked to an apparent lack of hive thermoregulation. The RH of hives was regulated at approximately 65% in both seasons, which is higher than unoccupied control hives in the dry season, but less than unoccupied control hives in the wet season. Although adaptations to promote water balance appear more important for survival of A. essingtoni than traits related to temperature regulation, their capacity for water conservation is coincident with increased thermal tolerance. For these small, eusocial stingless bees in the arid tropics, where air temperatures are relatively high and stable compared with temperate areas, regulation of hive humidity appears to be of more importance than temperature for maintaining hive health. © 2016. Published by The Company of Biologists Ltd.

The Effect of Cushion Properties on Skin Temperature and Humidity at the Body-Support Interface.

PubMed

Hsu, Tzu-Wen; Yang, Shu-Yu; Liu, Jung-Tai; Pan, Cheng-Tang; Yang, Yu-Sheng

2016-09-29

To explore the effects of various cushions on skin temperature and moisture at the body-seat interface during a 2-h period of continuous sitting. Seventy-eight participants were randomly assigned to sit on one of the three types of wheelchair cushion for unrelieved sitting over 2 h. Skin temperature and relative humidity (RH) were measured under the subjects' ischial tuberosities and thighs bilaterally with digital temperature and humidity sensors. Data were collected before sitting and at 15-min intervals thereafter. Participants sitting on foam-fluid hybrid cushions showed significantly lower skin temperatures than those sitting on air-filled and foam cushions (p < 0.05), but RH did not differ significantly among the cushions (p = 0.97). The three cushions produced a similar increasing trend in RH over time and RH reached a plateau during the 2-h sitting period. In order to select the appropriate wheelchair cushion, the microclimate (heat and moisture control) between the body-seat interface should be considered as well as pressure distribution. In comparison with foam-fluid hybrid cushions, the air-filled rubber and foam cushions tended to increase skin temperature by several degrees after prolonged sitting. However, cushion materials did not have significant differences in moisture accumulations.

The effect of cushion properties on skin temperature and humidity at the body-support interface.

PubMed

Hsu, Tzu-Wen; Yang, Shu-Yu; Liu, Jung-Tai; Pan, Cheng-Tang; Yang, Yu-Sheng

2016-09-29

The purpose of this study is to explore the effects of various cushions on skin temperature and moisture at the body-seat interface during a 2-hour period of continuous sitting. Seventy-eight participants were randomly assigned to sit on one of the three types of wheelchair cushions for unrelieved sitting for over 2 hours. Skin temperature and relative humidity (RH) were measured under the subjects' ischial tuberosities and thighs bilaterally with digital temperature and humidity sensors. Data were collected before sitting and at 15-minute intervals thereafter. Participants sitting on foam-fluid hybrid cushions showed significantly lower skin temperatures than those sitting on air-filled and foam cushions (p < 0.05), but RH did not differ significantly among the cushions (p = 0.97). The three cushions produced a similar increasing trend in RH over time and RH reached a plateau during the 2-hour sitting period. To select the appropriate wheelchair cushion, the microclimate (heat and moisture control) between the body-seat interface should be considered as well as pressure distribution. In comparison with foam-fluid hybrid cushions, the air-filled rubber and foam cushions tended to increase skin temperature by several degrees after prolonged sitting. However, cushion materials did not have significant differences in moisture accumulations.

Simultaneous measurement of relative humidity and temperature with PCF-MZI cascaded by fiber Bragg grating

NASA Astrophysics Data System (ADS)

Zhang, Shuqin; Dong, Xinyong; Li, Tao; Chan, Chi Chiu; Shum, Perry P.

2013-08-01

Simultaneous measurement of relative humidity and temperature has been realized by using an optical fiber sensor formed by cascading a photonic crystal fiber (PCF)-based in-fiber Mach-Zehnder interferometer (MZI) and a fiber Bragg grating (FBG). The PCF-MZI was fabricated by using a short PCF fusion-spliced between two single-mode fibers with its air holes in the cladding area being collapsed in the splicing regions. It was then coated with a layer of polyvinyl alcohol (PVA), whose refractive index is sensitive to humidity. Because the PCF-MZI and FBG have different responses to humidity and temperature, simultaneous measurement has been achieved with resolutions of 0.13% RH and 1.0 °C for humidity and temperature, respectively. The relative humidity measurement range is up to 30%-95% RH.

Influence of humidity on spectral performance for near-infrared detection of fruit

NASA Astrophysics Data System (ADS)

Zhou, Ying; Fu, Xiaping; Ying, Yibin

2006-10-01

Spectral performance would be affected by many factors such as temperature, equipment parameters and so on. Humidity fluctuations may occur in practice because of varying weather conditions. The objective of this research was to find out whether the change of humidity would influence the near infrared spectrum of samples. In this trial, an airproof, humidity-controllable test-bed was established to change the humidity of the mini environment. At 40%, 50%, 60%, 70% and 80% degrees of humidity, each sample's final spectrum was attained by removing the background's spectrum from the sample's. For whether the influence of the sample's and the background's spectrum are equal was not known, This trial was divided into two groups: detecting background and sample at each degree of humidity (group 1) and background's detecting just happened at 40% degree of humidity (group 2). This research was based on the hardware of NEXUS intelligent FT-IR spectrometer, made by Nicolet instrument company U.S.A, with using fiber optic diffuse reflectance accessory. The final spectrum was analysed using single variance analysis and Mahalanobis Distance methods. The result shows that neither in group 1 nor 2, humidity had little influence on NIR.

Uncertainty Analysis in Humidity Measurements by the Psychrometer Method

PubMed Central

Chen, Jiunyuan; Chen, Chiachung

2017-01-01

The most common and cheap indirect technique to measure relative humidity is by using psychrometer based on a dry and a wet temperature sensor. In this study, the measurement uncertainty of relative humidity was evaluated by this indirect method with some empirical equations for calculating relative humidity. Among the six equations tested, the Penman equation had the best predictive ability for the dry bulb temperature range of 15–50 °C. At a fixed dry bulb temperature, an increase in the wet bulb depression increased the error. A new equation for the psychrometer constant was established by regression analysis. This equation can be computed by using a calculator. The average predictive error of relative humidity was <0.1% by this new equation. The measurement uncertainty of the relative humidity affected by the accuracy of dry and wet bulb temperature and the numeric values of measurement uncertainty were evaluated for various conditions. The uncertainty of wet bulb temperature was the main factor on the RH measurement uncertainty. PMID:28216599

Uncertainty Analysis in Humidity Measurements by the Psychrometer Method.

PubMed

Chen, Jiunyuan; Chen, Chiachung

2017-02-14

The most common and cheap indirect technique to measure relative humidity is by using psychrometer based on a dry and a wet temperature sensor. In this study, the measurement uncertainty of relative humidity was evaluated by this indirect method with some empirical equations for calculating relative humidity. Among the six equations tested, the Penman equation had the best predictive ability for the dry bulb temperature range of 15-50 °C. At a fixed dry bulb temperature, an increase in the wet bulb depression increased the error. A new equation for the psychrometer constant was established by regression analysis. This equation can be computed by using a calculator. The average predictive error of relative humidity was <0.1% by this new equation. The measurement uncertainty of the relative humidity affected by the accuracy of dry and wet bulb temperature and the numeric values of measurement uncertainty were evaluated for various conditions. The uncertainty of wet bulb temperature was the main factor on the RH measurement uncertainty.

A physically based analytical spatial air temperature and humidity model

Treesearch

Yang Yang; Theodore A. Endreny; David J. Nowak

2013-01-01

Spatial variation of urban surface air temperature and humidity influences human thermal comfort, the settling rate of atmospheric pollutants, and plant physiology and growth. Given the lack of observations, we developed a Physically based Analytical Spatial Air Temperature and Humidity (PASATH) model. The PASATH model calculates spatial solar radiation and heat...

Relationship between ambient temperature and humidity and visits to mental health emergency departments in Québec.

PubMed

Vida, Stephen; Durocher, Martin; Ouarda, Taha B M J; Gosselin, Pierre

2012-11-01

This study examined whether the number of emergency department visits for "mental and psychosocial problems" varies with temperature or humidity. The number of visits in three geographic areas of Québec were examined as a function of temperature and humidity by using routinely collected May-September data for 1995-2007 (N=347,552 visits). Data for two age groups (under age 65 and age 65 and older) were examined. Incidence rate ratios for mean temperature and humidity were estimated by using Poisson regression and generalized additive models. The number of visits tended to increase with increasing mean temperature. At 22.5 °C (72.5 °F) and 25 °C (77.0 °F), the number was usually significantly higher than average. Visits increased with humidity in the younger age group. Results suggest increased use of emergency departments for mental and psychosocial problems with higher mean temperature and humidity, especially in metropolitan areas and in southern Québec. Climate change may make this effect increasingly important.

[Distribution of environmental temperature and relative humidity according to the number of conditioned air changes in laboratory animals rooms].

PubMed

Fujita, S; Obara, T; Tanaka, I; Yamauchi, C

1981-01-01

The relation of the rate of circulating air change to room temperature and relative humidity in animal quarters with a central air-conditioning system during heating and cooling seasons was investigated, with the results as follows: During the period of heating, the ambient temperature generally rose with a fall of relative humidity as the number of conditioned air changes per hour was increased. Vertical differences in temperature and humidity between levels of 0.5 and 1.5 m above the floor also diminished with increasing air change rate. This tendency was more conspicuous in small animals rooms with outer walls facing north and west. With increasing rate of air changes, the room temperature was prone to decline and the relative humidity to rise during the period of cooling. There were less vertical differences in temperature and humidity during this period. The velocity of air circulation within the animal quarters and its variations tended to increase progressively with increasing rate of ventilation, though the changes were modest.

Identification of weather variables sensitive to dysentery in disease-affected county of China.

PubMed

Liu, Jianing; Wu, Xiaoxu; Li, Chenlu; Xu, Bing; Hu, Luojia; Chen, Jin; Dai, Shuang

2017-01-01

Climate change mainly refers to long-term change in weather variables, and it has significant impact on sustainability and spread of infectious diseases. Among three leading infectious diseases in China, dysentery is exclusively sensitive to climate change. Previous researches on weather variables and dysentery mainly focus on determining correlation between dysentery incidence and weather variables. However, the contribution of each variable to dysentery incidence has been rarely clarified. Therefore, we chose a typical county in epidemic of dysentery as the study area. Based on data of dysentery incidence, weather variables (monthly mean temperature, precipitation, wind speed, relative humidity, absolute humidity, maximum temperature, and minimum temperature) and lagged analysis, we used principal component analysis (PCA) and classification and regression trees (CART) to examine the relationships between the incidence of dysentery and weather variables. Principal component analysis showed that temperature, precipitation, and humidity played a key role in determining transmission of dysentery. We further selected weather variables including minimum temperature, precipitation, and relative humidity based on results of PCA, and used CART to clarify contributions of these three weather variables to dysentery incidence. We found when minimum temperature was at a high level, the high incidence of dysentery occurred if relative humidity or precipitation was at a high level. We compared our results with other studies on dysentery incidence and meteorological factors in areas both in China and abroad, and good agreement has been achieved. Yet, some differences remain for three reasons: not identifying all key weather variables, climate condition difference caused by local factors, and human factors that also affect dysentery incidence. This study hopes to shed light on potential early warnings for dysentery transmission as climate change occurs, and provide a theoretical basis for the control and prevention of dysentery. Copyright © 2016 Elsevier B.V. All rights reserved.

A newly developed tool for intra-tracheal temperature and humidity assessment in laryngectomized individuals: the Airway Climate Explorer (ACE)

PubMed Central

Zuur, J. K.; Muller, S. H.; de Jongh, F. H. C.; van der Horst, M. J.; Shehata, M.; van Leeuwen, J.; Sinaasappel, M.

2007-01-01

The aim of this study is to develop a postlaryngectomy airway climate explorer (ACE) for assessment of intratracheal temperature and humidity and of influence of heat and moisture exchangers (HMEs). Engineering goals were within-device condensation prevention and fast response time characteristics. The ACE consists of a small diameter, heated air-sampling catheter connected to a heated sensor house, containing a humidity sensor. Air is sucked through the catheter by a controlled-flow pump. Validation was performed in a climate chamber using a calibrated reference sensor and in a two-flow system. Additionally, the analyser was tested in vivo. Over the clinically relevant range of humidity values (5–42 mg H2O/l air) the sensor output highly correlates with the reference sensor readings (R2 > 0.99). The 1–1/e response times are all <0.5 s. A first in vivo pilot measurement was successful. The newly developed, verified, fast-responding ACE is suitable for postlaryngectomy airway climate assessment. PMID:17629761

Desiccant outdoor air preconditioners maximize heat recovery ventilation potentials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meckler, M.

1995-12-31

Microorganisms are well protected indoors by the moisture surrounding them if the relative humidity is above 70%. They can cause many acute diseases, infections, and allergies. Humidity also has an effect on air cleanliness and causes the building structure and its contents to deteriorate. Therefore, controlling humidity is a very important factor to human health and comfort and the structural longevity of a building. To date, a great deal of research has been done, and is continuing, in the use of both solid and liquid desiccants. This paper introduces a desiccant-assisted system that combines dehumidification and mechanical refrigeration by meansmore » of a desiccant preconditioning module that can serve two or more conventional air-conditioning units. It will be demonstrated that the proposed system, also having indirect evaporative cooling within the preconditioning module, can reduce energy consumption and provide significant cost savings, independent humidity and temperature control, and, therefore, improved indoor air quality and enhanced occupant comfort.« less

Incorporating the effects of humidity in a mechanistic model of Anopheles gambiae mosquito population dynamics in the Sahel region of Africa

PubMed Central

2013-01-01

Background Low levels of relative humidity are known to decrease the lifespan of mosquitoes. However, most current models of malaria transmission do not account for the effects of relative humidity on mosquito survival. In the Sahel, where relative humidity drops to levels <20% for several months of the year, we expect relative humidity to play a significant role in shaping the seasonal profile of mosquito populations. Here, we present a new formulation for Anopheles gambiae sensu lato (s.l.) mosquito survival as a function of temperature and relative humidity and investigate the effect of humidity on simulated mosquito populations. Methods Using existing observations on relationships between temperature, relative humidity and mosquito longevity, we developed a new equation for mosquito survival as a function of temperature and relative humidity. We collected simultaneous field observations on temperature, wind, relative humidity, and anopheline mosquito populations for two villages from the Sahel region of Africa, which are presented in this paper. We apply this equation to the environmental data and conduct numerical simulations of mosquito populations using the Hydrology, Entomology and Malaria Transmission Simulator (HYDREMATS). Results Relative humidity drops to levels that are uncomfortable for mosquitoes at the end of the rainy season. In one village, Banizoumbou, water pools dried up and interrupted mosquito breeding shortly after the end of the rainy season. In this case, relative humidity had little effect on the mosquito population. However, in the other village, Zindarou, the relatively shallow water table led to water pools that persisted several months beyond the end of the rainy season. In this case, the decrease in mosquito survival due to relative humidity improved the model’s ability to reproduce the seasonal pattern of observed mosquito abundance. Conclusions We proposed a new equation to describe Anopheles gambiae s.l. mosquito survival as a function of temperature and relative humidity. We demonstrated that relative humidity can play a significant role in mosquito population and malaria transmission dynamics. Future modeling work should account for these effects of relative humidity. PMID:23938022

What the R & D Man Needs in Scientific Furniture and Why.

ERIC Educational Resources Information Center

Hallenberg, E.X.

1964-01-01

The complexity of today's research laboratories requires a completely controllable environmental surrounding. Research facilities require carefully controlled temperatures, relative humidity, and moisture, and must be free of interference from air-borne sound, mechanical vibrations, and electrical sources. Also desirable are special power…

40 CFR 86.000-2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., solar thermal load, ambient temperature, and humidity control or simulation which meets the requirements... while the vehicle's air conditioning system is operating, as described in § 86.160-00 over the SC03...

40 CFR 86.000-2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., solar thermal load, ambient temperature, and humidity control or simulation which meets the requirements... while the vehicle's air conditioning system is operating, as described in § 86.160-00 over the SC03...

Effects of humidity and surfaces on the melt crystallization of ibuprofen.

PubMed

Lee, Dong-Joo; Lee, Suyang; Kim, Il Won

2012-01-01

Melt crystallization of ibuprofen was studied to understand the effects of humidity and surfaces. The molecular self-assembly during the amorphous-to-crystal transformation was examined in terms of the nucleation and growth of the crystals. The crystallization was on Al, Au, and self-assembled monolayers with -CH(3), -OH, and -COOH functional groups. Effects of the humidity were studied at room temperature (18-20 °C) with relative humidity 33%, 75%, and 100%. Effects of the surfaces were observed at -20 °C (relative humidity 36%) to enable close monitoring with slower crystal growth. The nucleation time of ibuprofen was faster at high humidity conditions probably due to the local formation of the unfavorable ibuprofen melt/water interface. The crystal morphologies of ibuprofen were governed by the nature of the surfaces, and they could be associated with the growth kinetics by the Avrami equation. The current study demonstrated the effective control of the melt crystallization of ibuprofen through the melt/atmosphere and melt/surface interfaces.

Diurnal flight behavior of Ichneumonoidea (Insecta: Hymenoptera) related to environmental factors in a tropical dry forest.

PubMed

González-Moreno, A; Bordera, S; Leirana-Alcocer, J; Delfín-González, H

2012-06-01

The biology and behavior of insects are strongly influenced by environmental conditions such as temperature and precipitation. Because some of these factors present a within day variation, they may be causing variations on insect diurnal flight activity, but scant information exists on the issue. The aim of this work was to describe the patterns on diurnal variation of the abundance of Ichneumonoidea and their relation with relative humidity, temperature, light intensity, and wind speed. The study site was a tropical dry forest at Ría Lagartos Biosphere Reserve, Mexico; where correlations between environmental factors (relative humidity, temperature, light, and wind speed) and abundance of Ichneumonidae and Braconidae (Hymenoptera: Ichneumonoidea) were estimated. The best regression model for explaining abundance variation was selected using the second order Akaike Information Criterion. The optimum values of temperature, humidity, and light for flight activity of both families were also estimated. Ichneumonid and braconid abundances were significantly correlated to relative humidity, temperature, and light intensity; ichneumonid also showed significant correlations to wind speed. The second order Akaike Information Criterion suggests that in tropical dry conditions, relative humidity is more important that temperature for Ichneumonoidea diurnal activity. Ichneumonid wasps selected toward intermediate values of relative humidity, temperature and the lowest wind speeds; while Braconidae selected for low values of relative humidity. For light intensity, braconids presented a positive selection for moderately high values.

Technology Solutions Case Study: Improving Comfort in Hot-Humid Climates with a Whole-House Dehumidifier

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2013-11-01

In order to quantify the performance of a combined whole-house dehumidifier (WHD) AC system, researchers from the Consortium of Advanced Residential Buildings (CARB) team monitored the operation of two Lennox AC systems coupled with a Honeywell DH150 TrueDRY whole-house dehumidifier for a six-month period. By using a WHD to control moisture levels (latent cooling) and optimizing a central AC to control temperature (sensible cooling), improvements in comfort can be achieved while reducing utility costs. Indoor comfort for this study was defined as maintaining indoor conditions at below 60% RH and a humidity ratio of 0.012 lbm/lbm while at common drymore » bulb set point temperatures of 74°-80°F. In addition to enhanced comfort, controlling moisture to these levels can reduce the risk of other potential issues such as mold growth, pests, and building component degradation. Because a standard AC must also reduce dry bulb air temperature in order to remove moisture, a WHD is typically needed to support these latent loads when sensible heat removal is not desired.« less

Anodized aluminum coatings for thermal control. I - Coating process and stresses

NASA Technical Reports Server (NTRS)

Alwitt, R. S.; Mcclung, R. C.; Jacobs, S.

1992-01-01

Anodized aluminum is a candidate material for use as a thermal radiator surface on Space Station Freedom. Here, results of measurements of coating stress at room temperature are presented. The effects of coating process conditions and also subsequent exposure to different humidities, from above ambient to vacuum, are reported. The most important observation with regard to space applications is that the coating stress is very dependent on humidity, changing from compressive at ambient humidity to strongly tensile in 10 exp -6 torr vacuum. The increase in stress is accompanied by loss of water from the coating, and the process is reversible.

Control methods and systems for indirect evaporative coolers

DOEpatents

Woods, Jason; Kozubal, Erik

2015-09-22

A control method for operating an indirect evaporative cooler to control temperature and humidity. The method includes operating an airflow control device to provide supply air at a flow rate to a liquid desiccant dehumidifier. The supply air flows through the dehumidifier and an indirect evaporative cooler prior to exiting an outlet into a space. The method includes operating a pump to provide liquid desiccant to the liquid desiccant dehumidifier and sensing a temperature of an airstream at the outlet of the indirect evaporative cooler. The method includes comparing the temperature of the airstream at the outlet to a setpoint temperature at the outlet and controlling the pump to set the flow rate of the liquid desiccant. The method includes sensing space temperature, comparing the space temperature with a setpoint temperature, and controlling the airflow control device to set the flow rate of the supply air based on the comparison.

Dynamic temperature and humidity environmental profiles: impact for future emergency and disaster preparedness and response.

PubMed

Ferguson, William J; Louie, Richard F; Tang, Chloe S; Paw U, Kyaw Tha; Kost, Gerald J

2014-02-01

During disasters and complex emergencies, environmental conditions can adversely affect the performance of point-of-care (POC) testing. Knowledge of these conditions can help device developers and operators understand the significance of temperature and humidity limits necessary for use of POC devices. First responders will benefit from improved performance for on-site decision making. To create dynamic temperature and humidity profiles that can be used to assess the environmental robustness of POC devices, reagents, and other resources (eg, drugs), and thereby, to improve preparedness. Surface temperature and humidity data from the National Climatic Data Center (Asheville, North Carolina USA) was obtained, median hourly temperature and humidity were calculated, and then mathematically stretched profiles were created to include extreme highs and lows. Profiles were created for: (1) Banda Aceh, Indonesia at the time of the 2004 Tsunami; (2) New Orleans, Louisiana USA just before and after Hurricane Katrina made landfall in 2005; (3) Springfield, Massachusetts USA for an ambulance call during the month of January 2009; (4) Port-au-Prince, Haiti following the 2010 earthquake; (5) Sendai, Japan for the March 2011 earthquake and tsunami with comparison to the colder month of January 2011; (6) New York, New York USA after Hurricane Sandy made landfall in 2012; and (7) a 24-hour rescue from Hawaii USA to the Marshall Islands. Profiles were validated by randomly selecting 10 days and determining if (1) temperature and humidity points fell inside and (2) daily variations were encompassed. Mean kinetic temperatures (MKT) were also assessed for each profile. Profiles accurately modeled conditions during emergency and disaster events and enclosed 100% of maximum and minimum temperature and humidity points. Daily variations also were represented well with 88.6% (62/70) of temperature readings and 71.1% (54/70) of relative humidity readings falling within diurnal patterns. Days not represented well primarily had continuously high humidity. Mean kinetic temperature was useful for severity ranking. Simulating temperature and humidity conditions clearly reveals operational challenges encountered during disasters and emergencies. Understanding of environmental stresses and MKT leads to insights regarding operational robustness necessary for safe and accurate use of POC devices and reagents. Rescue personnel should understand these principles before performing POC testing in adverse environments.

The effects of temperature and humidity on formaldehyde emission from UF-bonded boards : a literature critique

Treesearch

George E. Myers

1985-01-01

An analysis has been conducted on available data related to temperature and humidity effects on formaldehyde concentrations that are produced by emission from particleboard and hardwood plywood paneling. Temperature changes are described by an exponential relation while a linear relation suffices for humidity effects. Large variations exist in the results from...

Temperature, humidity, and precipitation ... at the redwood experimental forest

Treesearch

Kenneth N. Boe

1970-01-01

Temperature and humidity were compared and precipitation measured during an 8-year period (1958-1966) for two types of harvest cuttings on the Redwood Experimental Forest, north coastal California. Only small differences in temperature and humidity were found between clearcuttings and selection cuttings in old-growth stands on west-facing and east-facing aspects, and...

Boundaries for biofilm formation: humidity and temperature.

PubMed

Else, Terry Ann; Pantle, Curtis R; Amy, Penny S

2003-08-01

Environmental conditions which define boundaries for biofilm production could provide useful ecological information for biofilm models. A practical use of defined conditions could be applied to the high-level nuclear waste repository at Yucca Mountain. Data for temperature and humidity conditions indicate that decreases in relative humidity or increased temperature severely affect biofilm formation on three candidate canister metals.

Continuous Hypergolic Monitor Network for Shipboard Applications

DTIC Science & Technology

2005-08-30

PEI Oxidizers MON-25 Polyamines and Polycarbonyls Ethanol SXFA Acetone PEO Octane Poly(ethylene-co-vinyl acetate) ( PEVA ), Polyisobutylene...polyvinylacetate ( PEVA ). These tests were performed under variable humidity and temperature (Figure 13) and under low humidity at ambient temperature...Test of Chemoselective Polymers Against Interferents with Variable Temperature and Humidity. Key: PEVA black; PEI red; SXFA blue; NmA yellow

Hygrothermal Analysis of Indoor Environment of Residential Prefabricated Buildings

NASA Astrophysics Data System (ADS)

Kraus, Michal

2017-10-01

Recent studies show that the relative humidity and the indoor air temperature constitute an important determinant of the quality of indoor air. Hygrothermal microclimate has a significant impact on occupant’s health and their comfort. The study presents the results of experimental measurement of indoor air temperature and relative humidity in selected apartment in prefabricated panel house situated in Ostrava, Czechia. The contribution describes and analysis the relation between indoor air temperature [°C] and relative humidity [%] in this apartment. The experimental object is selected with respect to the housing stock in the Czech Republic. A third of the housing stock in the Czech Republic is composed of prefabricated panel houses. Regeneration and revitalization of these buildings were in the focus of interest during recent years. Building modifications, such as thermal insulation of building envelope or window replacement, lead to a significantly higher level of airtightness of these objects. Humidity and indoor air temperature are measured in 10-minute cycles for two periods. The values of temperature and humidity are measured for the non-heating and the heating season. The length of each experimental period is 30 days. The mean value of indoor air temperature is 22.21 °C and average relative humidity is 45.87% in the non-heating period. The values of 22.62 °C and 35.20% represent average values for the heating period. A slight increase of the average temperature of the indoor environment (+1.85%) is observed. The decrease of the relative humidity is evident at first glance. The relative humidity of the internal environment is approximately 10% lower in the heating period. Long-term decline of relative humidity below 30% brings many problems. It is necessary to take measures to increase of relative humidity in residential prefabricated building. The aquarium appears to be ineffective. The solution may be forced artificial ventilation or humidifiers.

[Effect of humidity and temperature on filter and gravimetric measurement of ambient particulate matter in a balance room].

PubMed

Su, Wen-jin; Wang, Li-min; Weng, Shao-fan; Wang, Hai-jiao; Du, Li-li; Liu, Yue-wei; Yang, Lei; Chen, Wei-hong

2008-04-01

To assess the effects of the alteration of humidity and (or) temperature on weight of filters without and with ambient particulate matter in a balance room. The mass of blank dust sampling filters were weighed under (18 +/- 1) degrees C and (28 +/- 1) degrees C respectively, with the humidity varying from 35% relative humidity (RH) to 100% RH in a balance room. Then the blank filters were divided into two groups and were used to sample total dust and respirable dust. After sampling, the loaded filters were re-weighed under above conditions and the mass difference before and after the sampling were compared and analyzed. The vibration of the average mass of filters varied from 0.10 to 0.13 mg and from 0.06 to 0.09 mg under the temperatures of (18 +/- 1) degrees C and (28 +/- 1) degrees C respectively; When both the temperature and humidity changed, it varied from 0.12 to 0.16 mg. The deviation of average mass difference ranged from 0.07 to 0.10 mg and from 0.04 to 0.08 mg under the two temperatures mentioned above; When both the temperature and humidity changed, it varied from 0.09 to 0.14 mg. The average mass of blank filters and loaded filters were all positively correlated with the change of humidity (P < 0.01). No effects of humidity on the average mass difference of the loaded filters were observed. The average mass differences of loaded filters and blank filters under (18 +/- 1) degrees C were significantly higher than that under (28 +/- 1) degrees C (P < 0.01) when humidity was not changed. The alteration of humidity and (or) temperature in a balance room attributes to the deviation of the measurement of the mass of filters and thus affects the gravimetric measurements of ambient particulate matter.

Laboratory method for fermentation of meat and poultry sausages in fibrous casings.

PubMed

Johnson, M G; Acton, J C

1975-06-01

The construction and operation of a relatively inexpensive cabinet for sausage fermentation studies is described. Temperature can be controlled to +/-1 C with a relative humidity of approximately 95%.

Dependence of Tritium Release from Stainless Steel on Temperature and Water Vapor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shmayda, W. T.; Sharpe, M.; Boyce, A. M.

The impact of water vapor and temperature on the release of tritium from stainless steel was studied. Degreased stainless steel samples loaded with tritium at room temperature following a 24-h degassing in vacuum at room temperature were subjected to increasing temperatures or humidity. In general, increasing either the sample temperature or the humidity causes an increased quantity of tritium to be removed. Increasing the temperature to 300°C in a dry gas stream results in a significant release of tritium and is therefore an effective means for reducing the tritium inventory in steel. For humid purges at 30°C, a sixfold increasemore » in humidity results in a tenfold increase in the peak outgassing rate. Increasing the humidity from 4 parts per million (ppm) to 1000 ppm when the sample temperature is 100°C causes a significant increase in the tritium outgassing rate. Finally, a simple calculation shows that only 15% of the activity present in the sample was removed in these experiments, suggesting that the surface layer of adsorbed water participates in regulating tritium desorption from the surface.« less

Dependence of Tritium Release from Stainless Steel on Temperature and Water Vapor

DOE PAGES

Shmayda, W. T.; Sharpe, M.; Boyce, A. M.; ...

2015-09-15

The impact of water vapor and temperature on the release of tritium from stainless steel was studied. Degreased stainless steel samples loaded with tritium at room temperature following a 24-h degassing in vacuum at room temperature were subjected to increasing temperatures or humidity. In general, increasing either the sample temperature or the humidity causes an increased quantity of tritium to be removed. Increasing the temperature to 300°C in a dry gas stream results in a significant release of tritium and is therefore an effective means for reducing the tritium inventory in steel. For humid purges at 30°C, a sixfold increasemore » in humidity results in a tenfold increase in the peak outgassing rate. Increasing the humidity from 4 parts per million (ppm) to 1000 ppm when the sample temperature is 100°C causes a significant increase in the tritium outgassing rate. Finally, a simple calculation shows that only 15% of the activity present in the sample was removed in these experiments, suggesting that the surface layer of adsorbed water participates in regulating tritium desorption from the surface.« less

Trends in continental temperature and humidity directly linked to ocean warming.

PubMed

Byrne, Michael P; O'Gorman, Paul A

2018-05-08

In recent decades, the land surface has warmed substantially more than the ocean surface, and relative humidity has fallen over land. Amplified warming and declining relative humidity over land are also dominant features of future climate projections, with implications for climate-change impacts. An emerging body of research has shown how constraints from atmospheric dynamics and moisture budgets are important for projected future land-ocean contrasts, but these ideas have not been used to investigate temperature and humidity records over recent decades. Here we show how both the temperature and humidity changes observed over land between 1979 and 2016 are linked to warming over neighboring oceans. A simple analytical theory, based on atmospheric dynamics and moisture transport, predicts equal changes in moist static energy over land and ocean and equal fractional changes in specific humidity over land and ocean. The theory is shown to be consistent with the observed trends in land temperature and humidity given the warming over ocean. Amplified land warming is needed for the increase in moist static energy over drier land to match that over ocean, and land relative humidity decreases because land specific humidity is linked via moisture transport to the weaker warming over ocean. However, there is considerable variability about the best-fit trend in land relative humidity that requires further investigation and which may be related to factors such as changes in atmospheric circulations and land-surface properties.

The design of multi temperature and humidity monitoring system for incubator

NASA Astrophysics Data System (ADS)

Yu, Junyu; Xu, Peng; Peng, Zitao; Qiang, Haonan; Shen, Xiaoyan

2017-01-01

Currently, there is only one monitor of the temperature and humidity in an incubator, which may cause inaccurate or unreliable data, and even endanger the life safety of the baby. In order to solve this problem,we designed a multi-point temperature and humidity monitoring system for incubators. The system uses the STC12C5A60S2 microcontrollers as the sender core chip which is connected to four AM2321 temperature and humidity sensors. We select STM32F103ZET6 core development board as the receiving end,cooperating with Zigbee wireless transmitting and receiving module to realize data acquisition and transmission. This design can realize remote real-time observation data on the computer by communicating with PC via Ethernet. Prototype tests show that the system can effectively collect and display the information of temperature and humidity of multiple incubators at the same time and there are four monitors in each incubator.

Influence of relative humidity and temperature on quantity of electric charge of static protective clothing used in petrochemical industry

NASA Astrophysics Data System (ADS)

Zhang, Yunpeng; Liu, Quanzhen; Liu, Baoquan; Li, Yipeng; Zhang, Tingting

2013-03-01

In this paper, the working principle of static protective clothing and its testing method of quantity of electric charge are introduced, and the influence of temperature and relative humidity on the quantity of electric charge (qe) of static protective clothing is studied by measuring qe of different clothing samples. The result shows that temperature and relative humidity can influence qe of static protective clothing to some extent and the influence of relative humidity is bigger than that of temperature. According to experimental results, the relationship of qe and relative humidity and temperature was analysed, and the safety boundary of quantity of electric charge is discussed. In order to reduce the occurrence of electrostatic accidents and ensure safe production and operation of petrochemical industry, some suggestions on choosing and using of static protective clothing are given for guaranteeing its static protective performance.

Calibration of Heat Stress Monitor and its Measurement Uncertainty

NASA Astrophysics Data System (ADS)

Ekici, Can

2017-07-01

Wet-bulb globe temperature (WBGT) equation is a heat stress index that gives information for the workers in the industrial areas. WBGT equation is described in ISO Standard 7243 (ISO 7243 in Hot environments—estimation of the heat stress on working man, based on the WBGT index, ISO, Geneva, 1982). WBGT is the result of the combined quantitative effects of the natural wet-bulb temperature, dry-bulb temperature, and air temperature. WBGT is a calculated parameter. WBGT uses input estimates, and heat stress monitor measures these quantities. In this study, the calibration method of a heat stress monitor is described, and the model function for measurement uncertainty is given. Sensitivity coefficients were derived according to GUM. Two-pressure humidity generators were used to generate a controlled environment. Heat stress monitor was calibrated inside of the generator. Two-pressure humidity generator, which is located in Turkish Standard Institution, was used as the reference device. This device is traceable to national standards. Two-pressure humidity generator includes reference temperature Pt-100 sensors. The reference sensor was sheltered with a wet wick for the calibration of natural wet-bulb thermometer. The reference sensor was centred into a black globe that has got 150 mm diameter for the calibration of the black globe thermometer.

Wheelchair cushion effect on skin temperature, heat flux, and relative humidity.

PubMed

Stewart, S F; Palmieri, V; Cochran, G V

1980-05-01

For patients subject to decubitus ulcers, wheelchair cushions should be prescribed with knowledge of the cushion's effect on the thermal as well as mechanical environment of the skin. To define thermal effects that may be encountered during routine use, tests werr made on 24 commercially available cushions. Skin temperature, heat flux and relative humidity were measured under the ischial tuberosities of a normal 24-year-old man during a 1-hour period of sitting on each cushion. After 1 hour, skin temperatures increased by means of 3.4 C and 2.8 C on foams and viscoelastic foams and there were slight decreases in heat flux as compared with control values in air. On gels, skin temperatures remained constant and heat flux increased, while water "floatation" pads caused a mean skin temperature decreased of 2.7 C along with a marked increase in heat flux. Relative humidity at the skin cushion interface increased by 10.4%, 22.8% and 19.8% on foams, gels and water floatation pads, as compared with room air values. Representative cushions from each of the general types (foam, viscoelastic foam, gel and water floatation) also were subjected to 2-hour tests which indicated the measured parameters continued to change asymptotically.

Development of a Capacitive Ice Sensor to Measure Ice Growth in Real Time

PubMed Central

Zhi, Xiang; Cho, Hyo Chang; Wang, Bo; Ahn, Cheol Hee; Moon, Hyeong Soon; Go, Jeung Sang

2015-01-01

This paper presents the development of the capacitive sensor to measure the growth of ice on a fuel pipe surface in real time. The ice sensor consists of pairs of electrodes to detect the change in capacitance and a thermocouple temperature sensor to examine the ice formation situation. In addition, an environmental chamber was specially designed to control the humidity and temperature to simulate the ice formation conditions. From the humidity, a water film is formed on the ice sensor, which results in an increase in capacitance. Ice nucleation occurs, followed by the rapid formation of frost ice that decreases the capacitance suddenly. The capacitance is saturated. The developed ice sensor explains the ice growth providing information about the icing temperature in real time. PMID:25808770

Development of a capacitive ice sensor to measure ice growth in real time.

PubMed

Zhi, Xiang; Cho, Hyo Chang; Wang, Bo; Ahn, Cheol Hee; Moon, Hyeong Soon; Go, Jeung Sang

2015-03-19

This paper presents the development of the capacitive sensor to measure the growth of ice on a fuel pipe surface in real time. The ice sensor consists of pairs of electrodes to detect the change in capacitance and a thermocouple temperature sensor to examine the ice formation situation. In addition, an environmental chamber was specially designed to control the humidity and temperature to simulate the ice formation conditions. From the humidity, a water film is formed on the ice sensor, which results in an increase in capacitance. Ice nucleation occurs, followed by the rapid formation of frost ice that decreases the capacitance suddenly. The capacitance is saturated. The developed ice sensor explains the ice growth providing information about the icing temperature in real time.

Future shift of the relative roles of precipitation and temperature in controlling annual runoff in the conterminous United States

NASA Astrophysics Data System (ADS)

Duan, Kai; Sun, Ge; McNulty, Steven G.; Caldwell, Peter V.; Cohen, Erika C.; Sun, Shanlei; Aldridge, Heather D.; Zhou, Decheng; Zhang, Liangxia; Zhang, Yang

2017-11-01

This study examines the relative roles of climatic variables in altering annual runoff in the conterminous United States (CONUS) in the 21st century, using a monthly ecohydrological model (the Water Supply Stress Index model, WaSSI) driven with historical records and future scenarios constructed from 20 Coupled Model Intercomparison Project Phase 5 (CMIP5) climate models. The results suggest that precipitation has been the primary control of runoff variation during the latest decades, but the role of temperature will outweigh that of precipitation in most regions if future climate change follows the projections of climate models instead of the historical tendencies. Besides these two key factors, increasing air humidity is projected to partially offset the additional evaporative demand caused by warming and consequently enhance runoff. Overall, the projections from 20 climate models suggest a high degree of consistency on the increasing trends in temperature, precipitation, and humidity, which will be the major climatic driving factors accounting for 43-50, 20-24, and 16-23 % of the runoff change, respectively. Spatially, while temperature rise is recognized as the largest contributor that suppresses runoff in most areas, precipitation is expected to be the dominant factor driving runoff to increase across the Pacific coast and the southwest. The combined effects of increasing humidity and precipitation may also surpass the detrimental effects of warming and result in a hydrologically wetter future in the east. However, severe runoff depletion is more likely to occur in the central CONUS as temperature effect prevails.

Deformation of high performance concrete plate under humid tropical weather

NASA Astrophysics Data System (ADS)

Niken, C.; Elly, T.; Supartono, FX; Laksmi, I.

2018-03-01

This paper presents the relationship between surrounding relative humidity and temperature on deformation behavior of one sample concrete plate with compressive strength of 60MPa. This research was done in Indonesia that is in humid tropical weather. A specimens measuring 3000 mm × 1600 mm × 150 mm were used. The behavior was obtained by using four embedded vibrating wire strain gauges (VWESG). As a result there is a very strong relationship between humidity and deformation at the age range of 7 until 21 days. The largest deformation occurs in the corner and the fluctuation of deformation in side position is larger than in the corner and in the middle. The peaks of surrounding relative humidity were fully followed by the deepest valley of deformation on time in the corner, while in another position the range delay time was 8 - 11 hours. There is a strong relationship between surrounding temperature and deformation at the range of 7 until 14 days. The influenced of surrounding relative humidity to concrete behavior is faster and longer than surrounding temperature. The influence of surrounding temperature in humid tropical weather was shorter than in non-humid tropical weather.

Four-channel temperature and humidity microwave scanning radiometer

NASA Astrophysics Data System (ADS)

Xu, Pei-Yuan

1994-06-01

A compact four-channel microwave scanning radiometer for tropospheric remote sensing is being developed. A pair of 53.85 and 56.02 GHz and a pair of 23.87 and 31.65 GHz are adopted as temperature and humidity channels' frequencies respectively. For each pair of frequencies it has an offset reflector antenna and a Dicke-switching receiver. The pair of receivers is assembled in an enclosure, which is mounted on the rotating table of an azimuth mounting and the pair of antennas is connected with the rotating table of an azimuth mounting in the opposite side by a pair of elevation arms. Each antenna is composed of a 90 degree off-set paraboloid and a conical corrugated horn. Each antenna patterrn of four channels has nearly same HPBW, low side lobes, and low VSWR. The dual band humidity receiver is a time sharing type with 0.2K sensitivity at 1-sec integration time. The dual band temperature receiver is a band sharing type with 0.2K sensitivity at 10-sec integration time. The radiometer and observation are controlled by a single chip microcomputer to realize the unattended operation.

Statistical Tools Applied in the Characterisation and Evaluation of a Thermo-Hygrometric Corrective Action Carried out at the Noheda Archaeological Site (Noheda, Spain)

PubMed Central

Valero, Miguel Ángel; Merello, Paloma; Navajas, Ángel Fernández; García-Diego, Fernando-Juan

2014-01-01

The Noheda archaeological site is unique and exceptional for its size, and the quality and conservation condition of the Roman mosaic pavement covering its urban pars. In 2008 a tent was installed as protection from rain and sun. Being of interest to characterise the microclimate of the remains, six probes with relative humidity and temperature sensors were installed in 2013 for this purpose. Microclimate monitoring allowed us to check relative humidity differences resulting from the groundwater level, as well as inner sensors reaching maximum temperatures higher than the outdoors ones as a consequence of the non-ventilated tent covering the archaeological site. Microclimatic conditions in the archaeological site were deemed detrimental for the conservation of the mosaics. Thus, in summer 2013, expanded clay and geotextile were installed over the mosaics as a corrective action. The outcomes of this study have proven the effectiveness of this solution to control temperature and relative humidity, helping to configure a more stable microclimate suitable for preservation of the mosaic. PMID:24445414

Statistical tools applied in the characterisation and evaluation of a thermo-hygrometric corrective action carried out at the Noheda archaeological site (Noheda, Spain).

PubMed

Valero, Miguel Ángel; Merello, Paloma; Navajas, Ángel Fernández; García-Diego, Fernando-Juan

2014-01-17

The Noheda archaeological site is unique and exceptional for its size, and the quality and conservation condition of the Roman mosaic pavement covering its urban pars. In 2008 a tent was installed as protection from rain and sun. Being of interest to characterise the microclimate of the remains, six probes with relative humidity and temperature sensors were installed in 2013 for this purpose. Microclimate monitoring allowed us to check relative humidity differences resulting from the groundwater level, as well as inner sensors reaching maximum temperatures higher than the outdoors ones as a consequence of the non-ventilated tent covering the archaeological site. Microclimatic conditions in the archaeological site were deemed detrimental for the conservation of the mosaics. Thus, in summer 2013, expanded clay and geotextile were installed over the mosaics as a corrective action. The outcomes of this study have proven the effectiveness of this solution to control temperature and relative humidity, helping to configure a more stable microclimate suitable for preservation of the mosaic.

Electrospray-printed nanostructured graphene oxide gas sensors

NASA Astrophysics Data System (ADS)

Taylor, Anthony P.; Velásquez-García, Luis F.

2015-12-01

We report low-cost conductometric gas sensors that use an ultrathin film made of graphene oxide (GO) nanoflakes as transducing element. The devices were fabricated by lift-off metallization and near-room temperature, atmospheric pressure electrospray printing using a shadow mask. The sensors are sensitive to reactive gases at room temperature without requiring any post heat treatment, harsh chemical reduction, or doping with metal nanoparticles. The sensors’ response to humidity at atmospheric pressure tracks that of a commercial sensor, and is linear with changes in humidity in the 10%-60% relative humidity range while consuming <6 μW. Devices with GO layers printed by different deposition recipes yielded nearly identical response characteristics, suggesting that intrinsic properties of the film control the sensing mechanism. The gas sensors successfully detected ammonia at concentrations down to 500 ppm (absolute partial pressure of ˜5 × 10-4 T) at ˜1 T pressure, room temperature conditions. The sensor technology can be used in a great variety of applications including air conditioning and sensing of reactive gas species in vacuum lines and abatement systems.

Electrospray-printed nanostructured graphene oxide gas sensors.

PubMed

Taylor, Anthony P; Velásquez-García, Luis F

2015-12-18

We report low-cost conductometric gas sensors that use an ultrathin film made of graphene oxide (GO) nanoflakes as transducing element. The devices were fabricated by lift-off metallization and near-room temperature, atmospheric pressure electrospray printing using a shadow mask. The sensors are sensitive to reactive gases at room temperature without requiring any post heat treatment, harsh chemical reduction, or doping with metal nanoparticles. The sensors' response to humidity at atmospheric pressure tracks that of a commercial sensor, and is linear with changes in humidity in the 10%-60% relative humidity range while consuming <6 μW. Devices with GO layers printed by different deposition recipes yielded nearly identical response characteristics, suggesting that intrinsic properties of the film control the sensing mechanism. The gas sensors successfully detected ammonia at concentrations down to 500 ppm (absolute partial pressure of ∼5 × 10(-4) T) at ∼1 T pressure, room temperature conditions. The sensor technology can be used in a great variety of applications including air conditioning and sensing of reactive gas species in vacuum lines and abatement systems.

Design of sports clothing for hot environments.

PubMed

Varadaraju, R; Srinivasan, J

2018-02-22

The clothing design based on sweat distribution pattern is called as body mapping clothing. Comparisons of three designs of body mapped and one conventional design of T-shirt was done in a wearer testing at a controlled chamber of 33 °C and 60% relativity humidity in a treadmill at 12 km/h for 40 min followed by 10 min resting. It is concluded that with the full body mapped T-shirt the increase in skin temperature is reduced in the chest area, shoulder, the body back by 47%,44% and 55% respectively; the increase in skin micro climate relative humidity is reduced in the chest area, shoulder, the body back by 54%,39.2% and 53% respectively; the increase in heart beat rate is reduced by 5.1%; the subjective perceptions of skin temperature, skin moisture and comfort are better; the wearer will be able to improve the running performance due better comfort level in terms lesser increase skin temperature, skin micro climate relative humidity and heart beat rate. Copyright © 2018 Elsevier Ltd. All rights reserved.

The simulation of temperature distribution and relative humidity with liquid concentration of 50% using computational fluid dynamics

NASA Astrophysics Data System (ADS)

Yohana, Eflita; Yulianto, Mohamad Endy; Kwang-Hwang, Choi; Putro, Bondantio; Yohanes Aditya W., A.

2015-12-01

The study of humidity distribution simulation inside a room has been widely conducted by using computational fluid dynamics (CFD). Here, the simulation was done by employing inputs in the experiment of air humidity reduction in a sample house. Liquid dessicant CaCl2was used in this study to absorb humidity in the air, so that the enormity of humidity reduction occured during the experiment could be obtained.The experiment was conducted in the morning at 8 with liquid desiccant concentration of 50%, nozzle dimension of 0.2 mms attached in dehumidifier, and the debit of air which entered the sample house was 2.35 m3/min. Both in inlet and outlet sides of the room, a DHT 11 censor was installed and used to note changes in humidity and temperature during the experiment. In normal condition without turning on the dehumidifier, the censor noted that the average temperature inside the room was 28°C and RH of 65%.The experiment result showed that the relative humidity inside a sample house was decreasing up to 52% in inlet position. Further, through the results obtained from CFD simulation, the temperature distribution and relative humidity inside the sample house could be seen. It showed that the concentration of liquid desiccant of 50% experienced a decrease while the relative humidity distribution was considerably good since the average RH was 55% followed by the increase in air temperature of 29.2° C inside the sample house.

Environmental Control for Regional Library Facilities. RR-80-3.

ERIC Educational Resources Information Center

King, Richard G., Jr.

This report presents an overview of the damage to library materials caused by uncontrollable environmental variables. The control of atmospheric pollutants, temperature, and humidity are discussed with regard to damage, standards, and the costs of deterioration due to these factors. Twelve references are listed. (FM)

Fuzzy comprehensive evaluation of multiple environmental factors for swine building assessment and control.

PubMed

Xie, Qiuju; Ni, Ji-Qin; Su, Zhongbin

2017-10-15

In confined swine buildings, temperature, humidity, and air quality are all important for animal health and productivity. However, the current swine building environmental control is only based on temperature; and evaluation and control methods based on multiple environmental factors are needed. In this paper, fuzzy comprehensive evaluation (FCE) theory was adopted for multi-factor assessment of environmental quality in two commercial swine buildings using real measurement data. An assessment index system and membership functions were established; and predetermined weights were given using analytic hierarchy process (AHP) combined with knowledge of experts. The results show that multi-factors such as temperature, humidity, and concentrations of ammonia (NH 3 ), carbon dioxide (CO 2 ), and hydrogen sulfide (H 2 S) can be successfully integrated in FCE for swine building environment assessment. The FCE method has a high correlation coefficient of 0.737 compared with the method of single-factor evaluation (SFE). The FCE method can significantly increase the sensitivity and perform an effective and integrative assessment. It can be used as part of environmental controlling and warning systems for swine building environment management to improve swine production and welfare. Copyright © 2017 Elsevier B.V. All rights reserved.

Establishment and analysis of a High-Resolution Assimilation Dataset of the water-energy cycle in China

NASA Astrophysics Data System (ADS)

Wen, Xiaohang; Dong, Wenjie; Yuan, Wenping; Zheng, Zhiyuan

For better prediction and understanding of land-atmospheric interaction, in-situ observed meteorological data acquired from the China Meteorological Administration (CMA) were assimilated in the Weather Research and Forecasting (WRF) model and the monthly Green Vegetation Coverage (GVF) data, which was calculated using the Normalized Difference Vegetation Index (NDVI) of the Earth Observing System Moderate-Resolution Imaging Spectroradiometer (EOS-MODIS) and Digital Elevation Model (DEM) data of the Shuttle Radar Topography Mission (SRTM) system. Furthermore, the WRF model produced a High-Resolution Assimilation Dataset of the water-energy cycle in China (HRADC). This dataset has a horizontal resolution of 25 km for near surface meteorological data, such as air temperature, humidity, wind vectors and pressure (19 levels); soil temperature and moisture (four levels); surface temperature; downward/upward short/long radiation; 3-h latent heat flux; sensible heat flux; and ground heat flux. In this study, we 1) briefly introduce the cycling 3D-Var assimilation method and 2) compare results of meteorological elements, such as 2 m temperature and precipitation generated by the HRADC with the gridded observation data from CMA, and surface temperature and specific humidity with Global Land Data Assimilation System (GLDAS) output data from the National Aeronautics and Space Administration (NASA). We find that the simulated results of monthly 2 m temperature from HRADC is improved compared with the control simulation and has effectively reproduced the observed patterns. The simulated special distribution of ground surface temperature and specific humidity from HRADC are much closer to GLDAS outputs. The spatial distribution of root mean square errors (RMSE) and bias of 2 m temperature between observations and HRADC is reduced compared with the bias between observations and the control run. The monthly spatial distribution of surface temperature and specific humidity from HRADC is consistent with the GLDAS outputs over China. This study could improve the land surface parameters by utilizing remote sensing data and could further improve atmospheric elements with a data assimilation system. This work provides an effective attempt at combining multi-source data with different spatial and temporal scales into numerical simulations, and the simulated results could be used in further research on the long-term climatic effects and characteristics of the water-energy cycle over China.

Boundaries for Biofilm Formation: Humidity and Temperature

PubMed Central

Else, Terry Ann; Pantle, Curtis R.; Amy, Penny S.

2003-01-01

Environmental conditions which define boundaries for biofilm production could provide useful ecological information for biofilm models. A practical use of defined conditions could be applied to the high-level nuclear waste repository at Yucca Mountain. Data for temperature and humidity conditions indicate that decreases in relative humidity or increased temperature severely affect biofilm formation on three candidate canister metals. PMID:12902302

Formaldehyde emissions from ULEF- and NAF-bonded commercial hardwood plywood as influenced by temperature and relative humidity

Treesearch

Charles R. Frihart; James M. Wescott; Michael J. Birkeland; Kyle M. Gonner

2010-01-01

It is well documented in the literature that temperature and humidity can influence formaldehyde emissions from composite panels that are produced using urea-formaldehyde (UF) adhesives. This work investigates the effect of temperature and humidity on newer, ultra-low emitting formaldehyde urea formaldehyde (ULEF-UF) and no-added formaldehyde (NAF) adhesives. A...

Improved running performance in hot humid conditions following whole body precooling.

PubMed

Booth, J; Marino, F; Ward, J J

1997-07-01

On two separate occasions, eight subjects controlled speed to run the greatest distance possible in 30 min in a hot, humid environment (ambient temperature 32 degrees C, relative humidity 60%). For the experimental test (precooling), exercise was preceeded by cold-water immersion. Precooling increased the distance run by 304 +/- 166 m (P < 0.05). Precooling decreased the pre-exercise rectal and mean skin temperature by 0.7 degrees C and 5.9 degrees C, respectively (P < 0.05). Rectal and mean skin temperature were decreased up to 20 and 25 min during exercise, respectively (P < 0.05). Mean body temperature decreased from 36.5 +/- 0.1 degrees C to 33.8 +/- 0.2 degrees C following precooling (P < 0.05) and remained lower throughout exercise (P < 0.01) and at the end of exercise (by 0.8 degrees C; P < 0.05). The rate of heat storage at the end of exercise increased from 113 +/- 45 to 249 +/- 55 W.m-2 (P < 0.005). Precooling lowered the heart rate at rest (13%), 5 (9%), and 10 min (10%) exercise (P < 0.05) and increased the end of exercise blood lactate from 4.9 +/- 0.5 to 7.4 +/- 0.9 mmol.L-1 (P < 0.01). The VO2 at 10 and 20 min of exercise and total body sweating are not different between tests. In conclusion, water immersion precooling increased exercise endurance in hot, humid conditions with an enhanced rate of heat storage and decreased thermoregulatory strain.

Buoyancy-corrected gravimetric analysis of lightly loaded filters.

PubMed

Rasmussen, Pat E; Gardner, H David; Niu, Jianjun

2010-09-01

Numerous sources of uncertainty are associated with the gravimetric analysis of lightly loaded air filter samples (< 100 microg). The purpose of the study presented here is to investigate the effectiveness and limitations of air buoyancy corrections over experimentally adjusted conditions of temperature (21-25 degrees C) and relative humidity (RH) (16-60% RH). Conditioning (24 hr) and weighing were performed inside the Archimedes M3 environmentally controlled chamber. The measurements were performed using 20 size-fractionated samples of resuspended house dust loaded onto Teflo (PTFE) filters using a Micro-Orifice Uniform Deposit Impactor representing a wide range of mass loading (7.2-3130 microg) and cut sizes (0.056-9.9 microm). By maintaining tight controls on humidity (within 0.5% RH of control setting) throughout pre- and postweighing at each stepwise increase in RH, it was possible to quantify error due to water absorption: 45% of the total mass change due to water absorption occurred between 16 and 50% RH, and 55% occurred between 50 and 60% RH. The buoyancy corrections ranged from -3.5 to +5.8 microg in magnitude and improved relative standard deviation (RSD) from 21.3% (uncorrected) to 5.6% (corrected) for a 7.2 microg sample. It is recommended that protocols for weighing low-mass particle samples (e.g., nanoparticle samples) should include buoyancy corrections and tight temperature/humidity controls. In some cases, conditioning times longer than 24 hr may be warranted.

Impacts of Climatic Variability on Vibrio parahaemolyticus Outbreaks in Taiwan

PubMed Central

Hsiao, Hsin-I; Jan, Man-Ser; Chi, Hui-Ju

2016-01-01

This study aimed to investigate and quantify the relationship between climate variation and incidence of Vibrio parahaemolyticus in Taiwan. Specifically, seasonal autoregressive integrated moving average (ARIMA) models (including autoregression, seasonality, and a lag-time effect) were employed to predict the role of climatic factors (including temperature, rainfall, relative humidity, ocean temperature and ocean salinity) on the incidence of V. parahaemolyticus in Taiwan between 2000 and 2011. The results indicated that average temperature (+), ocean temperature (+), ocean salinity of 6 months ago (+), maximum daily rainfall (current (−) and one month ago (−)), and average relative humidity (current and 9 months ago (−)) had significant impacts on the incidence of V. parahaemolyticus. Our findings offer a novel view of the quantitative relationship between climate change and food poisoning by V. parahaemolyticus in Taiwan. An early warning system based on climate change information for the disease control management is required in future. PMID:26848675

Impacts of Climatic Variability on Vibrio parahaemolyticus Outbreaks in Taiwan.

PubMed

Hsiao, Hsin-I; Jan, Man-Ser; Chi, Hui-Ju

2016-02-03

This study aimed to investigate and quantify the relationship between climate variation and incidence of Vibrio parahaemolyticus in Taiwan. Specifically, seasonal autoregressive integrated moving average (ARIMA) models (including autoregression, seasonality, and a lag-time effect) were employed to predict the role of climatic factors (including temperature, rainfall, relative humidity, ocean temperature and ocean salinity) on the incidence of V. parahaemolyticus in Taiwan between 2000 and 2011. The results indicated that average temperature (+), ocean temperature (+), ocean salinity of 6 months ago (+), maximum daily rainfall (current (-) and one month ago (-)), and average relative humidity (current and 9 months ago (-)) had significant impacts on the incidence of V. parahaemolyticus. Our findings offer a novel view of the quantitative relationship between climate change and food poisoning by V. parahaemolyticus in Taiwan. An early warning system based on climate change information for the disease control management is required in future.

Relative Effects of Temperature, Light, and Humidity on Clinging Behavior of Metacercariae-Infected Ants.

PubMed

Botnevik, C F; Malagocka, J; Jensen, A B; Fredensborg, B L

2016-10-01

The lancet fluke, Dicrocoelium dendriticum, is perhaps the best-known example of parasite manipulation of host behavior, which is manifested by a radically changed behavior that leaves infected ants attached to vegetation at times when transmission to an herbivore host is optimal. Despite the publicity surrounding this parasite, curiously little is known about factors inducing and maintaining behavioral changes in its ant intermediate host. This study examined the importance of 3 environmental factors on the clinging behavior of red wood ants, Formica polyctena , infected with D. dendriticum . This behavior, hypothesized to involve cramping of the mandibular muscles in a state of tetany, was observed in naturally infected F. polyctena under controlled temperature, light, and humidity conditions. We found that low temperature significantly stimulated and maintained tetany in infected ants while light, humidity, ant size, and infection intensity had no influence on this behavior. Under none of the experimental conditions did uninfected ants attach to vegetation, demonstrating that tetany was induced by D. dendriticum . Temperature likely has a direct impact on the initiation of clinging behavior, but it may also serve as a simple but reliable indicator of the encounter rate between infected ants and ruminant definitive hosts. In addition, temperature-sensitive behavior manipulation may protect infected ants from exposure to temperatures in the upper thermal range of the host.

Effect of temperature and humidity on formaldehyde emissions in temporary housing units.

PubMed

Parthasarathy, Srinandini; Maddalena, Randy L; Russell, Marion L; Apte, Michael G

2011-06-01

The effect of temperature and humidity on formaldehyde emissions from samples collected from temporary housing units (THUs) was studied. The THUs were supplied by the U.S. Federal Emergency Management Administration (FEMA) to families that lost their homes in Louisiana and Mississippi during the Hurricane Katrina and Rita disasters. On the basis of a previous study, four of the composite wood surface materials that dominated contributions to indoor formaldehyde were selected to analyze the effects of temperature and humidity on the emission factors. Humidity equilibration experiments were carried out on two of the samples to determine how long the samples take to equilibrate with the surrounding environmental conditions. Small chamber experiments were then conducted to measure emission factors for the four surface materials at various temperature and humidity conditions. The samples were analyzed for formaldehyde via high-performance liquid chromatography. The experiments showed that increases in temperature or humidity contributed to an increase in emission factors. A linear regression model was built using the natural log of the percent relative humidity (RH) and inverse of temperature (in K) as independent variables and the natural log of emission factors as the dependent variable. The coefficients for the inverse of temperature and log RH with log emission factor were found to be statistically significant for all of the samples at the 95% confidence level. This study should assist in retrospectively estimating indoor formaldehyde exposure of occupants of THUs.

Controlled meteorological (CMET) free balloon profiling of the Arctic atmospheric boundary layer around Spitsbergen compared to ERA-Interim and Arctic System Reanalyses

NASA Astrophysics Data System (ADS)

Roberts, Tjarda J.; Dütsch, Marina; Hole, Lars R.; Voss, Paul B.

2016-09-01

Observations from CMET (Controlled Meteorological) balloons are analysed to provide insights into tropospheric meteorological conditions (temperature, humidity, wind) around Svalbard, European High Arctic. Five Controlled Meteorological (CMET) balloons were launched from Ny-Ålesund in Svalbard (Spitsbergen) over 5-12 May 2011 and measured vertical atmospheric profiles over coastal areas to both the east and west. One notable CMET flight achieved a suite of 18 continuous soundings that probed the Arctic marine boundary layer (ABL) over a period of more than 10 h. Profiles from two CMET flights are compared to model output from ECMWF Era-Interim reanalysis (ERA-I) and to a high-resolution (15 km) Arctic System Reanalysis (ASR) product. To the east of Svalbard over sea ice, the CMET observed a stable ABL profile with a temperature inversion that was reproduced by ASR but not captured by ERA-I. In a coastal ice-free region to the west of Svalbard, the CMET observed a stable ABL with strong wind shear. The CMET profiles document increases in ABL temperature and humidity that are broadly reproduced by both ASR and ERA-I. The ASR finds a more stably stratified ABL than observed but captured the wind shear in contrast to ERA-I. Detailed analysis of the coastal CMET-automated soundings identifies small-scale temperature and humidity variations with a low-level flow and provides an estimate of local wind fields. We demonstrate that CMET balloons are a valuable approach for profiling the free atmosphere and boundary layer in remote regions such as the Arctic, where few other in situ observations are available for model validation.

Testing and ground calibration of DREAMS-H relative humidity device

NASA Astrophysics Data System (ADS)

Genzer, Maria; Hieta, Maria; Nikkanen, Timo; Schmidt, Walter; Kemppinen, Osku; Harri, Ari-Matti; Haukka, Harri

2015-04-01

DREAMS (Dust Characterization, Risk Assessment and Environmental Analyzer on the Martian Surface) instrument suite is to be launched as part of the ESA ExoMars 2016/Schiaparelli lander. DREAMS consists of an environmental package for monitoring temperature, pressure, relative humidity, winds and dust opacity, as well as atmospheric electricity of Martian atmosphere. The DREAMS instruments and scientific goals are described in [1]. Here we describe testing and ground calibration of the relative humidity device, DREAMS-H, provided to the DREAMS payload by the Finnish Meteorological Institute and based on proprietary technology of Vaisala, Inc. The same kind of device is part of the REMS instrument package onboard MSL Curiosity Rover [2][3]. DREAMS-H is based on Vaisala Humicap® technology adapted for use in Martian environment by the Finnish Meteorological Institute. The device is very small and lightweighed, with total mass less than 20 g and consuming only 15 mW of power. The Humicap® sensor heads contain an active polymer film that changes its capacitance as function of relative humidity, with 0% to 100% RH measurement range. The dynamic range of the device gets smaller with sensor temperature, being in -70°C approximately 30% of the dynamic range in 0°C [3]. Good-quality relative humidity measurements require knowing the temperature of the environment in which relative humidity is measured. An important part of DREAMS-H calibration was temperature calibration of Vaisala Thermocap® temperature sensors used for housekeeping temperature measurements of the DREAMS-H device. For this, several temperature points in the desired operational range were measured with 0.1°C accuracy traceable to national standards. The main part of humidity calibration of DREAMS-H flight models was done in subzero temperatures in a humidity generator of the Finnish Center of Metrology and Accreditation (MIKES). Several relative humidity points ranging from almost dry to almost wet were measured at several temperature points between 0°C and -70°C. Dry baseline was established in vacuum measurements at the Finnish Meteorological Institute. In addition to stable relative humidity points, measurements in changing relative humidity and temperature were done in order to get information about the lag of the sensor. References: 1] Esposito, F. et al: The DREAMS Experiment on the ExoMars 2016 Mission for the Study of Martian Environment during the Dust Storm Season, The Fifth International Workshop on the Mars Atmosphere, 13-16 January 2014, Oxford, UK, 2014. [2] Gómez-Elvira, J. et al.: REMS: The Environmental Sensor Suite for the Mars Science Laboratory Rover, Space Sci. Rev., 170, pp. 583-640, 2012. [3] Harri, A.-M. et al.: Mars Science Laboratory Relative Humidity Observations - Initial Results, JGR Planets, Vol 119 Issue 9, pp. 2132-2147, 2014.

EDUCATION, CHILDREN AND COMFORT.

ERIC Educational Resources Information Center

Iowa Univ., Iowa City.

TWO SIMILAR CLASSROOMS WERE SET UP IN THE LENNOX LIVING LABORATORY, DES MOINES, IOWA, ONE FOR EXPERIMENTAL GROUPS AND ONE FOR CONTROL GROUPS. TEMPERATURE, AIR CIRCULATION AND HUMIDITY CAN BE CONTROLLED AND MEASURED IN BOTH ROOMS. THE ROOMS ARE OF SIMILAR SIZE, LAYOUT AND CONSTRUCTION, THE THERMAL ENVIRONMENT BEING THE ONLY VARIABLE. THE FOLLOWING…

Improving the Traceability of Meteorological Measurements at Automatic Weather Stations in Thailand

NASA Astrophysics Data System (ADS)

Keawprasert, T.; Sinhaneti, T.; Phuuntharo, P.; Phanakulwijit, S.; Nimsamer, A.

2017-08-01

A joint project between the National Institute of Metrology Thailand (NIMT) and the Thai Meteorology Department (TMD) was established for improving the traceability of meteorology measurements at automatic weather stations (AWSs) in Thailand. The project aimed to improve traceability of air temperature, relative humidity and atmospheric pressure by implementing on-site calibration facilities and developing of new calibration procedures. First, new portable calibration facilities for air temperature, humidity and pressure were set up as working standard of the TMD. A portable humidity calibrator was applied as a uniform and stable source for calibration of thermo-hygrometers. A dew-point hygrometer was employed as reference hygrometer and a platinum resistance thermometer (PRT) traceable to NIMT was used as reference thermometer. The uniformity and stability in both temperature and relative humidity were characterized at NIMT. A transportable pressure calibrator was used for calibration of air pressure sensor. The estimate overall uncertainty of the calibration setup is 0.2 K for air temperature, 1.0 % for relative humidity and 0.2 hPa for atmospheric pressure, respectively. Second, on-site calibration procedures were developed and four AWSs in the central part and the northern of Thailand were chosen as pilot stations for on-site calibration using the new calibration setups and developed calibration procedures. At each station, the calibration was done at the minimum temperature, average temperature and maximum temperature of the year, for air temperature, 20 %, 55 % and 90 % for relative humidity at the average air temperature of that station and at a one-year statistics pressure range for atmospheric pressure at ambient temperature. Additional in-field uncertainty contributions such as the temperature dependence on relative humidity measurement were evaluated and included in the overall uncertainty budget. Preliminary calibration results showed that using a separate PRT probe at these AWSs would be recommended for improving the accuracy of air temperature measurement. In case of relative humidity measurement, the data logger software is needed to be upgraded for achieving higher accuracy of less than 3 %. For atmospheric pressure measurement, a higher accuracy barometer traceable to NIMT could be used to reduce the calibration uncertainty to below 0.2 hPa.

The Humidity in a Low-Flow Dräger Fabius Anesthesia Workstation with or without Thermal Insulation or a Heat and Moisture Exchanger: A Prospective Randomized Clinical Trial

PubMed Central

de Oliveira, Sergius A. R.; Lucio, Lorena M. C.; Modolo, Norma S. P.; Hayashi, Yoko; Braz, Mariana G.; de Carvalho, Lídia R.; Braz, Leandro G.; Braz, José Reinaldo C.

2017-01-01

Background During anesthesia, as compared with intensive care, the time of the tracheal intubation is much shorter. An inhaled gas minimum humidity of 20 mgH2O.L-1 is recommended to reduce the deleterious effects of dry gas on the airways during anesthesia with tracheal intubation. The Fabius GS Premium® anesthesia workstation (Dräger Medical, Lübeck, Germany) has a built-in hotplate to heat gases in the breathing circuit. A heat and moisture exchanger (HME) is used to further heat and humidify the inhaled gas. The humidity of the gases in the breathing circuit is influenced by the ambient temperature. We compared the humidity of the inhaled gases from a low-flow Fabius anesthesia workstation with or without thermal insulation (TI) of the breathing circuit and with or without an HME. Methods We conducted a prospective randomized trial in 41 adult female patients who underwent elective abdominal surgery. The patients were allocated into four groups according to the devices used to ventilate their lungs using a Dräger Fabius anesthesia workstation with a low gas flow (1 L.min-1): control, with TI, with an HME or with TI and an HME (TIHME). The mean temperature and humidity of the inhaled gases were measured during 2-h after connecting the patients to the breathing circuit. Results The mean inhaled gas temperature and absolute humidity were higher in the HME (29.2±1.3°C; 28.1±2.3 mgH2O·L-1) and TIHME (30.1±1.2°C; 29.4±2.0 mgH2O·L-1) groups compared with the control (27.5±1.0°C; 25.0±1.8 mgH2O·L-1) and TI (27.2±1.1°C; 24.9±1.8 mgH2O·L-1) groups (P = 0.003 and P<0.001, respectively). Conclusions The low-flow Fabius GS Premium breathing circuit provides the minimum humidity level of inhaled gases to avoid damage to the tracheobronchial epithelia during anesthesia. TI of the breathing circuit does not increase the humidity of the inhaled gases, whereas inserting an HME increases the moisture of the inhaled gases closer to physiological values. PMID:28129353

Cold temperature and low humidity are associated with increased occurrence of respiratory tract infections.

PubMed

Mäkinen, Tiina M; Juvonen, Raija; Jokelainen, Jari; Harju, Terttu H; Peitso, Ari; Bloigu, Aini; Silvennoinen-Kassinen, Sylvi; Leinonen, Maija; Hassi, Juhani

2009-03-01

The association between cold exposure and acute respiratory tract infections (RTIs) has remained unclear. The study examined whether the development of RTIs is potentiated by cold exposure and lowered humidity in a northern population. A population study where diagnosed RTI episodes, outdoor temperature and humidity among conscripts (n=892) were analysed. Altogether 643 RTI episodes were diagnosed during the follow-up period. Five hundred and ninety-five episodes were upper (URTI) and 87 lower (LRTI) RTIs. The mean average daily temperature preceding any RTIs was -3.7+/-10.6; for URTI and LRTI they were -4.1+/-10.6 degrees C and -1.1+/-10.0 degrees C, respectively. Temperature was associated with common cold (p=0.017), pharyngitis (p=0.011) and LRTI (p=0.048). Absolute humidity was associated with URTI (p<0.001). A 1 degrees C decrease in temperature increased the estimated risk for URTI by 4.3% (p<0.0001), for common cold by 2.1% (p=0.004), for pharyngitis by 2.8% (p=0.019) and for LRTI by 2.1% (p=0.039). A decrease of 1g/m(-3) in absolute humidity increased the estimated risk for URTI by 10.0% (p<0.001) and for pharyngitis by 10.8% (p=0.023). The average outdoor temperature decreased during the preceding three days of the onset of any RTIs, URTI, LRTI or common cold. The temperature for the preceding 14 days also showed a linear decrease for any RTI, URTI or common cold. Absolute humidity decreased linearly during the preceding three days before the onset of common cold, and during the preceding 14 days for all RTIs, common cold and LRTI. Cold temperature and low humidity were associated with increased occurrence of RTIs, and a decrease in temperature and humidity preceded the onset of the infections.

Shading effect on microclimate and thermal comfort indexes in integrated crop-livestock-forest systems in the Brazilian Midwest

NASA Astrophysics Data System (ADS)

Karvatte, Nivaldo; Klosowski, Elcio Silvério; de Almeida, Roberto Giolo; Mesquita, Eduardo Eustáquio; de Oliveira, Caroline Carvalho; Alves, Fabiana Villa

2016-12-01

The objective of this paper was to perform a microclimate evaluation and determine the indexes of thermal comfort indexes, in sun and shade, in integrated crop-livestock-forest systems with different arrangements of eucalyptus and native trees, in the Brazilian Midwest. The experiment was conducted at Embrapa Beef Cattle in Campo Grande, state of Mato Grosso do Sul, Brazil, from July to September 2013. The evaluations were conducted on four consecutive days, from 8:00 a.m. to 5:00 p.m., local time (GMT -4:00), with 1 hour intervals, recording the microclimate parameters: air temperature (°C), black globe temperature (°C), wet bulb temperature (°C), relative humidity (%), and wind speed (m.s-1), for the subsequent calculation of the Temperature and Humidity Index, the Black Globe Temperature and Humidity Index, and the Radiant Thermal Load. The largest changes in microclimate parameters were found in the full sun, between 12:00 p.m. and 1:00 p.m., in less dense eucalyptus system, followed by the scattered native trees system, resulting in a maximum Temperature and Humidity Index of 81, Black Globe Temperature and Humidity Index of 88 and Radiant Thermal Load of 794 W m-2. Therefore, it is observed that with the presence of trees in pastures were possible reductions of up to 3.7 % in Temperature and Humidity Index, 10.2 % in the Black Globe Temperature and Humidity Index, and 28.3 % of the Radiant Thermal Load in the shade. Thus, one can conclude that the presence of trees and their arrangement in the systems provide better microclimate conditions and animal thermal comfort in pastures.

Shading effect on microclimate and thermal comfort indexes in integrated crop-livestock-forest systems in the Brazilian Midwest.

PubMed

Karvatte, Nivaldo; Klosowski, Elcio Silvério; de Almeida, Roberto Giolo; Mesquita, Eduardo Eustáquio; de Oliveira, Caroline Carvalho; Alves, Fabiana Villa

2016-12-01

The objective of this paper was to perform a microclimate evaluation and determine the indexes of thermal comfort indexes, in sun and shade, in integrated crop-livestock-forest systems with different arrangements of eucalyptus and native trees, in the Brazilian Midwest. The experiment was conducted at Embrapa Beef Cattle in Campo Grande, state of Mato Grosso do Sul, Brazil, from July to September 2013. The evaluations were conducted on four consecutive days, from 8:00 a.m. to 5:00 p.m., local time (GMT -4:00), with 1 hour intervals, recording the microclimate parameters: air temperature (°C), black globe temperature (°C), wet bulb temperature (°C), relative humidity (%), and wind speed (m.s -1 ), for the subsequent calculation of the Temperature and Humidity Index, the Black Globe Temperature and Humidity Index, and the Radiant Thermal Load. The largest changes in microclimate parameters were found in the full sun, between 12:00 p.m. and 1:00 p.m., in less dense eucalyptus system, followed by the scattered native trees system, resulting in a maximum Temperature and Humidity Index of 81, Black Globe Temperature and Humidity Index of 88 and Radiant Thermal Load of 794 W m -2 . Therefore, it is observed that with the presence of trees in pastures were possible reductions of up to 3.7 % in Temperature and Humidity Index, 10.2 % in the Black Globe Temperature and Humidity Index, and 28.3 % of the Radiant Thermal Load in the shade. Thus, one can conclude that the presence of trees and their arrangement in the systems provide better microclimate conditions and animal thermal comfort in pastures.

Formaldehyde Emissions from Urea-Formaldehyde- and no-added-formaldehyde-Bonded particleboard as Influenced by Temperature and Relative Humidity

Treesearch

Charles R. Frihart; James M. Wescott; Timothy L. Chaffee; Kyle M. Gonner

2012-01-01

It is well documented that temperature and humidity can influence formaldehyde emissions from composite panels that are produced using urea-formaldehyde (UF)–type adhesives. This work investigates the effect of temperature and humidity on newer commercial California Air Resources Board (CARB) phase II–compliant particleboard produced with UF-type adhesives. These...

Control of heat and humidity in German mines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schlotte, W.

1999-07-01

In order to increase the economic efficiency of West European hard coal, great efforts are being made at present in the coal-producing countries to lower production costs. This aim is to be achieved in Germany, among other things, by a drastic increase in the saleable output per working face up to an average of 10,000 t/d in these cases where very long longwall faces (400 m {+-} 50 m) are possible. With the substantially greater heat input into the air stream which this involves, there is the danger that climatic limits will be exceeded even at longwall faces with lowermore » than average rock temperatures. Working in high temperatures and/or humidities can lead to risky lack of concentration of the miners to heat collapse and extremely dangerous heat stroke. In order to minimize the costs for mine climate control well-proven planning software and climitization technology is necessary for underground workings. With the DMT climate simulation programs, both the dry and the extremely significant humid heat transfer can be calculated and the optimum air cooling system for a mine can be designed with due regard to technical and economic aspects.« less

Searching for the best modeling specification for assessing the effects of temperature and humidity on health: a time series analysis in three European cities.

PubMed

Rodopoulou, Sophia; Samoli, Evangelia; Analitis, Antonis; Atkinson, Richard W; de'Donato, Francesca K; Katsouyanni, Klea

2015-11-01

Epidemiological time series studies suggest daily temperature and humidity are associated with adverse health effects including increased mortality and hospital admissions. However, there is no consensus over which metric or lag best describes the relationships. We investigated which temperature and humidity model specification most adequately predicted mortality in three large European cities. Daily counts of all-cause mortality, minimum, maximum and mean temperature and relative humidity and apparent temperature (a composite measure of ambient and dew point temperature) were assembled for Athens, London, and Rome for 6 years between 1999 and 2005. City-specific Poisson regression models were fitted separately for warm (April-September) and cold (October-March) periods adjusting for seasonality, air pollution, and public holidays. We investigated goodness of model fit for each metric for delayed effects up to 13 days using three model fit criteria: sum of the partial autocorrelation function, AIC, and GCV. No uniformly best index for all cities and seasonal periods was observed. The effects of temperature were uniformly shown to be more prolonged during cold periods and the majority of models suggested separate temperature and humidity variables performed better than apparent temperature in predicting mortality. Our study suggests that the nature of the effects of temperature and humidity on mortality vary between cities for unknown reasons which require further investigation but may relate to city-specific population, socioeconomic, and environmental characteristics. This may have consequences on epidemiological studies and local temperature-related warning systems.

Searching for the best modeling specification for assessing the effects of temperature and humidity on health: a time series analysis in three European cities

NASA Astrophysics Data System (ADS)

Rodopoulou, Sophia; Samoli, Evangelia; Analitis, Antonis; Atkinson, Richard W.; de'Donato, Francesca K.; Katsouyanni, Klea

2015-11-01

Epidemiological time series studies suggest daily temperature and humidity are associated with adverse health effects including increased mortality and hospital admissions. However, there is no consensus over which metric or lag best describes the relationships. We investigated which temperature and humidity model specification most adequately predicted mortality in three large European cities. Daily counts of all-cause mortality, minimum, maximum and mean temperature and relative humidity and apparent temperature (a composite measure of ambient and dew point temperature) were assembled for Athens, London, and Rome for 6 years between 1999 and 2005. City-specific Poisson regression models were fitted separately for warm (April-September) and cold (October-March) periods adjusting for seasonality, air pollution, and public holidays. We investigated goodness of model fit for each metric for delayed effects up to 13 days using three model fit criteria: sum of the partial autocorrelation function, AIC, and GCV. No uniformly best index for all cities and seasonal periods was observed. The effects of temperature were uniformly shown to be more prolonged during cold periods and the majority of models suggested separate temperature and humidity variables performed better than apparent temperature in predicting mortality. Our study suggests that the nature of the effects of temperature and humidity on mortality vary between cities for unknown reasons which require further investigation but may relate to city-specific population, socioeconomic, and environmental characteristics. This may have consequences on epidemiological studies and local temperature-related warning systems.

Fine PM measurements: personal and indoor air monitoring.

PubMed

Jantunen, M; Hänninen, O; Koistinen, K; Hashim, J H

2002-12-01

This review compiles personal and indoor microenvironment particulate matter (PM) monitoring needs from recently set research objectives, most importantly the NRC published "Research Priorities for Airborne Particulate Matter (1998)". Techniques and equipment used to monitor PM personal exposures and microenvironment concentrations and the constituents of the sampled PM during the last 20 years are then reviewed. Development objectives are set and discussed for personal and microenvironment PM samplers and monitors, for filter materials, and analytical laboratory techniques for equipment calibration, filter weighing and laboratory climate control. The progress is leading towards smaller sample flows, lighter, silent, independent (battery powered) monitors with data logging capacity to store microenvironment or activity relevant sensor data, advanced flow controls and continuous recording of the concentration. The best filters are non-hygroscopic, chemically pure and inert, and physically robust against mechanical wear. Semiautomatic and primary standard equivalent positive displacement flow meters are replacing the less accurate methods in flow calibration, and also personal sampling flow rates should become mass flow controlled (with or without volumetric compensation for pressure and temperature changes). In the weighing laboratory the alternatives are climatic control (set temperature and relative humidity), and mechanically simpler thermostatic heating, air conditioning and dehumidification systems combined with numerical control of temperature, humidity and pressure effects on flow calibration and filter weighing.

Heat and Humidity in the City: Neighborhood Heat Index Variability in a Mid-Sized City in the Southeastern United States

PubMed Central

Hass, Alisa L.; Ellis, Kelsey N.; Reyes Mason, Lisa; Hathaway, Jon M.; Howe, David A.

2016-01-01

Daily weather conditions for an entire city are usually represented by a single weather station, often located at a nearby airport. This resolution of atmospheric data fails to recognize the microscale climatic variability associated with land use decisions across and within urban neighborhoods. This study uses heat index, a measure of the combined effects of temperature and humidity, to assess the variability of heat exposure from ten weather stations across four urban neighborhoods and two control locations (downtown and in a nearby nature center) in Knoxville, Tennessee, USA. Results suggest that trees may negate a portion of excess urban heat, but are also associated with greater humidity. As a result, the heat index of locations with more trees is significantly higher than downtown and areas with fewer trees. Trees may also reduce heat stress by shading individuals from incoming radiation, though this is not considered in this study. Greater amounts of impervious surfaces correspond with reduced evapotranspiration and greater runoff, in terms of overall mass balance, leading to a higher temperature, but lower relative humidity. Heat index and relative humidity were found to significantly vary between locations with different tree cover and neighborhood characteristics for the full study time period as well as for the top 10% of heat index days. This work demonstrates the need for high-resolution climate data and the use of additional measures beyond temperature to understand urban neighborhood exposure to extreme heat, and expresses the importance of considering vulnerability differences among residents when analyzing neighborhood-scale impacts. PMID:26761021

Heat and Humidity in the City: Neighborhood Heat Index Variability in a Mid-Sized City in the Southeastern United States.

PubMed

Hass, Alisa L; Ellis, Kelsey N; Reyes Mason, Lisa; Hathaway, Jon M; Howe, David A

2016-01-11

Daily weather conditions for an entire city are usually represented by a single weather station, often located at a nearby airport. This resolution of atmospheric data fails to recognize the microscale climatic variability associated with land use decisions across and within urban neighborhoods. This study uses heat index, a measure of the combined effects of temperature and humidity, to assess the variability of heat exposure from ten weather stations across four urban neighborhoods and two control locations (downtown and in a nearby nature center) in Knoxville, Tennessee, USA. Results suggest that trees may negate a portion of excess urban heat, but are also associated with greater humidity. As a result, the heat index of locations with more trees is significantly higher than downtown and areas with fewer trees. Trees may also reduce heat stress by shading individuals from incoming radiation, though this is not considered in this study. Greater amounts of impervious surfaces correspond with reduced evapotranspiration and greater runoff, in terms of overall mass balance, leading to a higher temperature, but lower relative humidity. Heat index and relative humidity were found to significantly vary between locations with different tree cover and neighborhood characteristics for the full study time period as well as for the top 10% of heat index days. This work demonstrates the need for high-resolution climate data and the use of additional measures beyond temperature to understand urban neighborhood exposure to extreme heat, and expresses the importance of considering vulnerability differences among residents when analyzing neighborhood-scale impacts.

Extreme heat in India and anthropogenic climate change

NASA Astrophysics Data System (ADS)

van Oldenborgh, Geert Jan; Philip, Sjoukje; Kew, Sarah; van Weele, Michiel; Uhe, Peter; Otto, Friederike; Singh, Roop; Pai, Indrani; Cullen, Heidi; AchutaRao, Krishna

2018-01-01

On 19 May 2016 the afternoon temperature reached 51.0 °C in Phalodi in the northwest of India - a new record for the highest observed maximum temperature in India. The previous year, a widely reported very lethal heat wave occurred in the southeast, in Andhra Pradesh and Telangana, killing thousands of people. In both cases it was widely assumed that the probability and severity of heat waves in India are increasing due to global warming, as they do in other parts of the world. However, we do not find positive trends in the highest maximum temperature of the year in most of India since the 1970s (except spurious trends due to missing data). Decadal variability cannot explain this, but both increased air pollution with aerosols blocking sunlight and increased irrigation leading to evaporative cooling have counteracted the effect of greenhouse gases up to now. Current climate models do not represent these processes well and hence cannot be used to attribute heat waves in this area. The health effects of heat are often described better by a combination of temperature and humidity, such as a heat index or wet bulb temperature. Due to the increase in humidity from irrigation and higher sea surface temperatures (SSTs), these indices have increased over the last decades even when extreme temperatures have not. The extreme air pollution also exacerbates the health impacts of heat. From these factors it follows that, from a health impact point of view, the severity of heat waves has increased in India. For the next decades we expect the trend due to global warming to continue but the surface cooling effect of aerosols to diminish as air quality controls are implemented. The expansion of irrigation will likely continue, though at a slower pace, mitigating this trend somewhat. Humidity will probably continue to rise. The combination will result in a strong rise in the temperature of heat waves. The high humidity will make health effects worse, whereas decreased air pollution would decrease the impacts.

Predictive control of thermal state of blast furnace

NASA Astrophysics Data System (ADS)

Barbasova, T. A.; Filimonova, A. A.

2018-05-01

The work describes the structure of the model for predictive control of the thermal state of a blast furnace. The proposed model contains the following input parameters: coke rate; theoretical combustion temperature, comprising: natural gas consumption, blasting temperature, humidity, oxygen, blast furnace cooling water; blast furnace gas utilization rate. The output parameter is the cast iron temperature. The results for determining the cast iron temperature were obtained following the identification using the Hammerstein-Wiener model. The result of solving the cast iron temperature stabilization problem was provided for the calculated values of process parameters of the target area of the respective blast furnace operation mode.

Real-time indoor monitoring system based on wireless sensor networks

NASA Astrophysics Data System (ADS)

Wu, Zhengzhong; Liu, Zilin; Huang, Xiaowei; Liu, Jun

2008-10-01

Wireless sensor networks (WSN) greatly extend our ability to monitor and control the physical world. It can collaborate and aggregate a huge amount of sensed data to provide continuous and spatially dense observation of environment. The control and monitoring of indoor atmosphere conditions represents an important task with the aim of ensuring suitable working and living spaces to people. However, the comprehensive air quality, which includes monitoring of humidity, temperature, gas concentrations, etc., is not so easy to be monitored and controlled. In this paper an indoor WSN monitoring system was developed. In the system several sensors such as temperature sensor, humidity sensor, gases sensor, were built in a RF transceiver board for monitoring indoor environment conditions. The indoor environmental monitoring parameters can be transmitted by wireless to database server and then viewed throw PC or PDA accessed to the local area networks by administrators. The system, which was also field-tested and showed a reliable and robust characteristic, is significant and valuable to people.

Environmental Standards for Storage of Books and Manuscripts

ERIC Educational Resources Information Center

Banks, Paul N.

1974-01-01

Deals with those factors included in building planning that can influence preservation, deterioration, or destruction of books--temperature, humidity, light, air cleanness, ventilation, exhibition, shelving and transportation, storage of microfilm, disaster control, and monitoring systems. (CH)

Laboratory Method for Fermentation of Meat and Poultry Sausages in Fibrous Casings1

PubMed Central

Johnson, Michael G.; Acton, James C.

1975-01-01

The construction and operation of a relatively inexpensive cabinet for sausage fermentation studies is described. Temperature can be controlled to ±1 C with a relative humidity of approximately 95%. PMID:16350019

Dose uniformity of budesonide Easyhaler® under simulated real-life conditions and with low inspiration flow rates.

PubMed

Haikarainen, Jussi; Rytilä, Paula; Roos, Sirkku; Metsärinne, Sirpa; Happonen, Anita

2017-01-01

Budesonide Easyhaler® multidose dry powder inhaler is approved for the treatment of asthma. Objectives were to determine the delivered dose (DD) uniformity of budesonide Easyhaler® in simulated real-world conditions and with different inspiration flow rates (IFRs). Three dose delivery studies were performed using 100, 200, and 400 µg/dose strengths of budesonide. Dose uniformity was assessed during in-use periods of 4-6 months after exposure to high temperature (30°C) and humidity (60% relative humidity) and after dropping and vibration testing. The influence of various IFRs (31, 43, and 54 L/min) on the DD was also investigated. Acceptable dose uniformity was declared when mean DD were within 80-120% of expected dose; all data reported descriptively. DD was constant (range: 93-109% of expected dose) at all in-use periods and after exposure to high temperature and humidity for a duration of up to 6 months. DD post-dropping and -vibration were unaffected (range 98-105% of expected dose). Similarly, DD was constant and within 10% of expected dose across all IFRs. Results indicate that budesonide Easyhaler® delivers consistently accurate doses in various real-life conditions. Budesonide Easyhaler® can be expected to consistently deliver a uniform dose and improve asthma control regardless of high temperature and humidity or varying IFR.

Advancements in water vapor electrolysis technology. [for Space Station ECLSS

NASA Technical Reports Server (NTRS)

Chullen, Cinda; Heppner, Dennis B.; Sudar, Martin

1988-01-01

The paper describes a technology development program whose goal is to develop water vapor electrolysis (WVE) hardware that can be used selectively as localized topping capability in areas of high metabolic activity without oversizing the central air revitalization system on long-duration manned space missions. The WVE will be used primarily to generate O2 for the crew cabin but also to provide partial humidity control by removing water vapor from the cabin atmosphere. The electrochemically based WVE interfaces with cabin air which is controlled in the following ranges: dry bulb temperature of 292 to 300 K; dew point temperature of 278 to 289 K; relative humidity of 25 to 75 percent; and pressure of 101 + or - 1.4 kPa. Design requirements, construction details, and results for both single-cell and multicell module testing are presented, and the preliminary sizing of a multiperson subsystem is discussed.

Water vapor recovery from plant growth chambers

NASA Technical Reports Server (NTRS)

Ray, R. J.; Newbold, D. D.; Colton, R. H.; Mccray, S. B.

1991-01-01

NASA is investigating the use of plant growth chambers (PGCs) for space missions and for bases on the moon and Mars. Key to successful development of PGCs is a system to recover and reuse the water vapor that is transpired from the leaves of the plants. A design is presented for a simple, reliable, membrane-based system that allows the recovery, purification, and reuse of the transpired water vapor through control of temperature and humidity levels in PGCs. The system is based on two membrane technologies: (1) dehumidification membrane modules to remove water vapor from the air, and (2) membrane contactors to return water vapor to the PGC (and, in doing so, to control the humidity and temperature within the PGC). The membrane-based system promises to provide an ideal, stable growth environment for a variety of plants, through a design that minimizes energy usage, volume, and mass, while maximizing simplicity and reliability.

Thermal comfort, perceived air quality, and cognitive performance when personally controlled air movement is used by tropically acclimatized persons.

PubMed

Schiavon, S; Yang, B; Donner, Y; Chang, V W-C; Nazaroff, W W

2017-05-01

In a warm and humid climate, increasing the temperature set point offers considerable energy benefits with low first costs. Elevated air movement generated by a personally controlled fan can compensate for the negative effects caused by an increased temperature set point. Fifty-six tropically acclimatized persons in common Singaporean office attire (0.7 clo) were exposed for 90 minutes to each of five conditions: 23, 26, and 29°C and in the latter two cases with and without occupant-controlled air movement. Relative humidity was maintained at 60%. We tested thermal comfort, perceived air quality, sick building syndrome symptoms, and cognitive performance. We found that thermal comfort, perceived air quality, and sick building syndrome symptoms are equal or better at 26°C and 29°C than at the common set point of 23°C if a personally controlled fan is available for use. The best cognitive performance (as indicated by task speed) was obtained at 26°C; at 29°C, the availability of an occupant-controlled fan partially mitigated the negative effect of the elevated temperature. The typical Singaporean indoor air temperature set point of 23°C yielded the lowest cognitive performance. An elevated set point in air-conditioned buildings augmented with personally controlled fans might yield benefits for reduced energy use and improved indoor environmental quality in tropical climates. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A novel method for in-situ monitoring of local voltage, temperature and humidity distributions in fuel cells using flexible multi-functional micro sensors.

PubMed

Lee, Chi-Yuan; Fan, Wei-Yuan; Chang, Chih-Ping

2011-01-01

In this investigation, micro voltage, temperature and humidity sensors were fabricated and integrated for the first time on a stainless steel foil using micro-electro-mechanical systems (MEMS). These flexible multi-functional micro sensors have the advantages of high temperature resistance, flexibility, smallness, high sensitivity and precision of location. They were embedded in a proton exchange membrane fuel cell (PEMFC) and used to simultaneously measure variations in the inner voltage, temperature and humidity. The accuracy and reproducibility of the calibrated results obtained using the proposed micro sensors is excellent. The experimental results indicate that, at high current density and 100%RH or 75%RH, the relative humidity midstream and downstream saturates due to severe flooding. The performance of the PEM fuel cell can be stabilized using home-made flexible multi-functional micro sensors by the in-situ monitoring of local voltage, temperature and humidity distributions within it.

A Novel Method for In-Situ Monitoring of Local Voltage, Temperature and Humidity Distributions in Fuel Cells Using Flexible Multi-Functional Micro Sensors

PubMed Central

Lee, Chi-Yuan; Fan, Wei-Yuan; Chang, Chih-Ping

2011-01-01

In this investigation, micro voltage, temperature and humidity sensors were fabricated and integrated for the first time on a stainless steel foil using micro-electro-mechanical systems (MEMS). These flexible multi-functional micro sensors have the advantages of high temperature resistance, flexibility, smallness, high sensitivity and precision of location. They were embedded in a proton exchange membrane fuel cell (PEMFC) and used to simultaneously measure variations in the inner voltage, temperature and humidity. The accuracy and reproducibility of the calibrated results obtained using the proposed micro sensors is excellent. The experimental results indicate that, at high current density and 100%RH or 75%RH, the relative humidity midstream and downstream saturates due to severe flooding. The performance of the PEM fuel cell can be stabilized using home-made flexible multi-functional micro sensors by the in-situ monitoring of local voltage, temperature and humidity distributions within it. PMID:22319361

Is Obsidian Hydration Dating Affected by Relative Humidity?

USGS Publications Warehouse

Friedman, I.; Trembour, F.W.; Smith, G.I.; Smith, F.L.

1994-01-01

Experiments carried out under temperatures and relative humidities that approximate ambient conditions show that the rate of hydration of obsidian is a function of the relative humidity, as well as of previously established variables of temperature and obsidian chemical composition. Measurements of the relative humidity of soil at 25 sites and at depths of between 0.01 and 2 m below ground show that in most soil environments, at depths below about 0.25 m, the relative humidity is constant at 100%. We have found that the thickness of the hydrated layer developed on obsidian outcrops exposed to the sun and to relative humidities of 30-90% is similar to that formed on other portions of the outcrop that were shielded from the sun and exposed to a relative humidity of approximately 100%. Surface samples of obsidian exposed to solar heating should hydrate more rapidly than samples buried in the ground. However, the effect of the lower mean relative humidity experiences by surface samples tends to compensate for the elevated temperature, which may explain why obsidian hydration ages of surface samples usually approximate those derived from buried samples.

The influence of temperature and humidity on the incidence of hand, foot, and mouth disease in Japan.

PubMed

Onozuka, Daisuke; Hashizume, Masahiro

2011-12-01

The increasing evidence for rapid global climate change has highlighted the need for investigations examining the relationship between weather variability and infectious diseases. However, the impact of weather fluctuations on hand, foot, and mouth disease (HFMD), which primarily affects children, is not well understood. We acquired data related to cases of HFMD and weather parameters of temperature and humidity in Fukuoka, Japan between 2000 and 2010, and used time-series analyses to assess the possible relationship of weather variability with pediatric HFMD cases, adjusting for seasonal and interannual variations. Our analysis revealed that the weekly number of HFMD cases increased by 11.2% (95% CI: 3.2-19.8) for every 1°C increase in average temperature and by 4.7% (95% CI: 2.4-7.2) for every 1% increase in relative humidity. Notably, the effects of temperature and humidity on HFMD infection were most significant in children under the age of 10 years. Our study provides quantitative evidence that the number of HFMD cases increased significantly with increasing average temperature and relative humidity, and suggests that preventive measures for limiting the spread of HFMD, particularly in younger children, should be considered during extended periods of high temperature and humidity. Copyright © 2011 Elsevier B.V. All rights reserved.

Evaluation of temperature and relative humidity on two types of zero energy cool chamber (ZECC) in South Sulawesi, Indonesia

NASA Astrophysics Data System (ADS)

Dirpan, Andi; Tahir Sapsal, Muhammad; Kadir Muhammad, Abdul; Tahir, Mulyati M.; Rahimuddin

2017-12-01

Zero Energy Cool Chamber (ZECC) is a cooling chamber for storing fruits and vegetables from the viewpoints of low cost and energy savings. The aim of the present study is to evaluate temperature and relative humidity (RH) on two types of zero energy cool chamber (ZECC) in South Sulawesi, Indonesia. The first category was placed underground while the second category was on the surface. Then, the performance of the ZECC was measured by calculating temperature and relative humidity. The results show that the ZECC was constructed on the surface produce lower temperature and higher RH compare to ZECC which placed underground. In average, the temperature in the outside (28.0°C) is greater than in inside (26.2°C) of the ZECC. On the other hand, the relative humidity in the outside (72.9%) is less than in inside (87.2%) of the ZECC. It was concluded that the ZECC where was constructed on the surface is more suitable than ZECC in the underground for decreasing temperature and increasing relative humidity.

Ventilation requirements for control of occupancy odor and tobacco smoke odor: laboratory studies. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cain, W.S.; Isseroff, R.; Leaderer, B.P.

1981-04-01

Experiments on occupancy odor addressed the question of why required ventilation rate per occupant increased progressively with increases in the number of persons in a space. In order to investigate ventilation requirements under approximately ideal conditions, we constructed an aluminum-lined environmental chamber with excellent control over environmental conditions and a ventilation system that provided rapid and uniform mixing of air. Psychophysical experiments on occupancy odor explored 47 different combinations of occupancy density, temperature and humidity, and ventilation rate. The experiments collected judgements both from visitors, who smelled air from the chamber only once every few minutes, and from occupants, whomore » remained in the chamber for an hour at a time. The judgements of visitors revealed that occupancy odor increased only gradually over time and rarely reached very high or objectionable levels. Judgements of occupants also revealed rather minor dissatisfaction. Only during combinations of high temperature and humidity did objectionability become more than a minor issue to either group. Experiments on cigarette smoking explored rates of 4, 8, and 16 cigarettes per hour under various environmental conditions and with ventilation rates as high as 68 cfm (34 L.s/sup -1/) per occupant. As soon as occupants lit cigarettes in the chamber, the odor level increased dramatically. At ventilation rates far greater than necessary to control occupancy odor, the odor from cigarette smoking remained quite intense. In general, the odor proved impossible to control adequately even with a ventilation rate of 68 cfm (34 L.s/sup -1/) per occupant (4 occupants) and even when only one occupant smoked at a time. As in the case of occupancy odor, a combination of high temperature and humidity exacerbated the odor problem.« less

Effects of Humidity and Surfaces on the Melt Crystallization of Ibuprofen

PubMed Central

Lee, Dong-Joo; Lee, Suyang; Kim, Il Won

2012-01-01

Melt crystallization of ibuprofen was studied to understand the effects of humidity and surfaces. The molecular self-assembly during the amorphous-to-crystal transformation was examined in terms of the nucleation and growth of the crystals. The crystallization was on Al, Au, and self-assembled monolayers with –CH3, –OH, and –COOH functional groups. Effects of the humidity were studied at room temperature (18–20 °C) with relative humidity 33%, 75%, and 100%. Effects of the surfaces were observed at −20 °C (relative humidity 36%) to enable close monitoring with slower crystal growth. The nucleation time of ibuprofen was faster at high humidity conditions probably due to the local formation of the unfavorable ibuprofen melt/water interface. The crystal morphologies of ibuprofen were governed by the nature of the surfaces, and they could be associated with the growth kinetics by the Avrami equation. The current study demonstrated the effective control of the melt crystallization of ibuprofen through the melt/atmosphere and melt/surface interfaces. PMID:22949861

The effect of procedure room temperature and humidity on LASIK outcomes.

PubMed

Seider, Michael I; McLeod, Stephen D; Porco, Travis C; Schallhorn, Steven C

2013-11-01

To determine whether procedure room temperature or humidity during LASIK affect refractive outcomes in a large patient sample. Retrospective cohort study. A total of 202 394 eyes of 105 712 patients aged 18 to 75 years who underwent LASIK at an Optical Express, Inc., location in their United Kingdom and Ireland centers from January 1, 2008, to June 30, 2011, who met inclusion criteria. Patient age, gender, flap creation technique, pre- and 1-month post-LASIK manifest refraction, and ambient temperature and humidity during LASIK were recorded. Effect size determination and univariate and multivariate analyses were performed to characterize the relationships between LASIK procedure room temperature and humidity and postoperative refractive outcome. One month post-LASIK manifest refraction. No clinically significant effect of procedure room temperature or humidity was found on LASIK refractive outcomes. When considering all eyes in our population, an increase of 1°C during LASIK was associated with a 0.003 diopter (D) more hyperopic refraction 1 month postoperatively, and an increase in 1% humidity was associated with a 0.0004 more myopic refraction. These effect sizes were the same or similar when considering only myopic eyes, only hyperopic eyes, and subgroups of eyes stratified by age and preoperative refractive error. Neither procedure room temperature nor humidity during LASIK were found to have a clinically significant relationship with postoperative manifest refraction in our population. Copyright © 2013 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

The effect of procedure room temperature and humidity on LASIK outcomes

PubMed Central

Seider, Michael I.; McLeod, Stephen D.; Porco, Travis C.; Schallhorn, Steven C.

2013-01-01

Objective To determine if procedure room temperature and humidity during LASIK affects refractive outcomes in a very large patient sample. Design Retrospective cohort study. Participants 202,394 eyes of 105,712 patients aged 18 to 75 years old who underwent LASIK at an Optical Express, Inc. location in their United Kingdom and Ireland centers from January 1, 2008 to June 30, 2011 who met inclusion criteria. Methods Patient age, gender, pre- and one month post-LASIK manifest refraction and flap creation technique were recorded as well as the ambient temperature and humidity during LASIK. Effect size determination, in addition to univariate and multivariate analysis was performed to characterize the relationships between LASIK procedure room temperature and humidity and post-operative refractive outcome. Main Outcome Measures One month post-LASIK manifest refraction. Results No clinically significant effect of procedure room temperature or humidity was found on LASIK refractive outcomes. When considering all eyes in our population, an increase of one degree Celsius during LASIK was associated with a 0.003 diopter more hyperopic refraction one month post-operatively and an increase in one percent humidity was associated with a 0.0004 more myopic refraction. These effect sizes were the same or similar when considering only myopic eyes, only hyperopic eyes and subgroups of eyes stratified by age and pre-operative refractive error. Conclusions Procedure room temperature or humidity during LASIK was found to have no clinically significant relationship with post-operative manifest refraction in our population. PMID:23769199

High performance humidity sensor and photodetector based on SnSe nanorods

NASA Astrophysics Data System (ADS)

Pawbake, Amit S.; Jadkar, Sandesh R.; Late, Dattatray J.

2016-10-01

Tin selenide (SnSe) nanorods were synthesized using a one-step solvothermal route and their humidity sensing and photodetection performance at room temperature were investigated. The results depict that SnSe nanorod-based humidity and photosensors have good long-term stability, are highly sensitive and have fast response and recovery times. In the case of the humidity sensor it was observed that the resistance of the films decreased with increasing relative humidity (RH). The humidity sensing behaviors were investigated in the range 11-97% RH at room temperature. A response time of ˜68 s and recovery time of ˜149 s were observed for the humidity sensor. The photosensing behavior showed typical response /recovery times of ˜3 s with highly reproducible behavior.

Effects of acute supplementation of caffeine on cardiorespiratory responses during endurance running in a hot & humid climate.

PubMed

Ping, Wong Chee; Keong, Chen Chee; Bandyopadhyay, Amit

2010-07-01

Athletes in Malaysia need to perform in a hot and humid climate. Chronic supplementation of caffeine on endurance performance have been studied extensively in different populations. However, concurrent research on the effects of acute supplementation of caffeine on cardiorespiratory responses during endurance exercise in the Malaysian context especially in a hot and humid environment is unavailable. Nine heat adapted recreational Malaysian male runners (aged: 25.4+/-6.9 yr) who were nonusers of caffeine (23.7+/-12.6 mg per day) were recruited in this placebo--controlled double--blind randomized study. Caffeine (5 mg per kg of body weight) or placebo was ingested in the form of a capsule one hour prior to the running exercise trial at 70 per cent of VO2max on a motorised treadmill in a heat-controlled laboratory (31 degrees C, 70% relative humidity). Subjects drank 3 ml of cool water per kg of body weight every 20 min during the running trials to avoid the adverse effects of dehydration. Heart rate, core body temperature and rate of perceived exertion (RPE) were recorded at intervals of 10 min, while oxygen consumption was measured at intervals of 20 min. Running time to exhaustion was significantly (P<0.05) higher in the caffeine trial compared to the placebo trial. Heart rate, core body temperature, oxygen uptake and RPE did not show any significant variation between the trials but it increased significantly during exercise from their respective resting values in both trials (P<0.001). Our study showed that ingestion of 5 mg of caffeine per kg of body weight improved the endurance running performance but did not impose any significant effect on other individual cardiorespiratory parameters of heat-acclimated recreational runners in hot and humid conditions.

Space Environment Effects on Stability of Medications Flown on Space Shuttles and the International Space Station (ISS)

NASA Technical Reports Server (NTRS)

Daniels, Vernie; Du, Jianping; Crady, Camille; Satterfield, Rick; Putcha, Lakshmi

2007-01-01

The purpose is to assess physical and chemical degradation of select pharmaceutical formulations from the Shuttle and ISS medical kits. Eleven pharmaceuticals dispensed as different dosage forms were selected based on their physical / chemical characteristics and susceptibility to environmental factors such as, temperature, humidity and light sensitivity. When available, ground-controls of the study medications with matching brand and lot numbers were used for comparison. Samples retrieved from flight were stored along with their matching controls in a temperature and humidity controlled environmental chamber. Temperature, humidity, and radiation data from the Shuttle and ISS were retrieved from onboard HOBO U12 Temp/RH Data Loggers, and from passive dosimeters. Physical and chemical analyses of the pharmaceuticals were conducted using validated United States Pharmacopeia (USP) methods. Results indicated degradation of 6 of the 11 formulations returned from space flights. Four formulations, Amoxicillin / Clavulanate, promethazine, sulfamethoxazole / trimethoprim, and ciprofloxacin tablets depicted discoloration after flight. Chemical content analyses using High or Ultra Performance Liquid Chromatography (HPLC / UPLC) methods revealed that dosage forms of Amoxicillin / Clavulanate, promethazine, sulfamethoxazole / trimethoprim, lidocaine, ciprofloxacin and mupirocin contained less than 95% of manufacturer s labeled claim of active drug compound. Shuttle and ISS environments affect stability and shelf life of certain mediations flown on these missions. Data analysis is in progress to examine the effect of specific space flight environmental factors on pharmaceutical stability. The degradation profiles generated from ground studies in analog environments will be useful in establishing predictive shelf-life profiles for medications intended for use during long-term space exploration missions.

Environmental and management factors affecting the welfare of chickens on commercial farms in the United Kingdom and Denmark stocked at five densities.

PubMed

Jones, T A; Donnelly, C A; Stamp Dawkins, M

2005-08-01

Data from a large commercial-scale experiment in which 10 major broiler producer companies stocked whole houses of birds at 30, 34, 38, 42, and 46 kg/m2 were analyzed to identify 1) temperature and humidity profiles achieved throughout the growth cycle, 2) management practices and equipment that contributed to observed variation in environmental conditions, and 3) the extent to which environmental variables affected bird welfare. The study involved a total of 2.7 million birds in 114 houses on commercial farms with measurement of a wide range of environmental and bird variables. Much of the variation in broiler health and welfare was associated with the percentage of time a company could maintain house temperature and RH within limits recommended by the breeder company. RH in the first week of life was particularly important to later health, suggesting that better control of humidity might lead to improved welfare. Key management factors affecting bird welfare were those relating to good ventilation and air control such as the type of ventilation, type of drinker, numbers of stockmen, and litter type. Controlling the environment, particularly temperature, humidity, and air and litter quality, is crucial to broiler chicken welfare. This does not mean that stocking density is unimportant, but lowering stocking density on its own, without regard to the environment the birds experience, is not sufficient. Genuine improvements in bird welfare will come from setting standards that combine stocking density, safeguards on the environment, and the genetic makeup of the birds.

Effect of ambient temperature and internal relative humidity on spectral sensitivity of broadband UV detectors

NASA Astrophysics Data System (ADS)

Huber, Martin; Blumthaler, Mario; Schreder, Josef

2002-01-01

Within the frame of the Austrian UV Monitoring Network, repeated recalibrations of Solar Light Sunburn Meters between December 1997 and March 2000 have shown significant temporal changes in the instruments' relative spectral response function as well as in their absolute calibration. Therefore, laboratory investigations of the effects of ambient temperature and internal relative humidity on the behavior of two Sunburn Meters have been performed. Despite internal temperature stabilization, both instruments show significant dependence of their spectral response function on ambient temperature. When the outside temperature of the detector's housing varies between 13 degree(s)C and 44 degree(s)C, spectral sensitivity changes by up to 10% in the UVB range and by up to a factor of 2 in the UVA range, depending on internal relative humidity. As a consequence, output voltage variations of 10% are observed when the detector is mounted in front of a 1000 W halogen lamp and its internal relative humidity is changed while its ambient temperature is kept constant. Whereas temperature effects take place within several hours, instabilities due to variations in internal relative humidity show typical time constants in the order of several days.

Investigation of Changes in Extreme Temperature and Humidity Over China Through a Dynamical Downscaling Approach

NASA Astrophysics Data System (ADS)

Zhu, Jinxin; Huang, Gordon; Wang, Xiuquan; Cheng, Guanhui

2017-11-01

Impacts of climate change relating to public health are often determined by multiple climate variables. The health-related metrics combining high-temperature and relative humidity are most concerned. Temperatures, relative humidity and relationship among them are investigated here for a comprehensive assessment of climate change impacts over China. A projection of combined temperatures and humidity through the PRECIS model is addressed. The PRECIS model's skill in reproducing the historical climate over China was first gauged through validating its historical simulation with the observation data set in terms of the two contributing variables. With good results of validation, a plausible range of combined temperatures and relative humidity were generated under RCPs. The results suggested that the annual mean temperature of China will increase up to 6°C at the end of 21st century. Opposite to the significantly change in the temperature, the maximum magnitude of changes in relative humidity is only 8% from the value in the baseline period. The dew point temperature is projected to be 14.9°C (within the comfortable interval) over the whole nation under high radiative forcing scenario at the end of this century. Therefore, the combination effects of high temperatures and relative humidity are substantially smaller than generally anticipated for China. Even though the impact-relevant metric like the dew point temperature is not projected as bad as the generally anticipated, we found that the frequency of high-temperature extremes increases up to 40% and the duration increases up to 150% in China. China is still expected to have more number of extremely hot days, more frequent high-temperature extremes, and longer duration of warm spell than before. Regionally, South China has the smallest changes in the mean, maximum and minimum temperatures while the largest increases in all five high-temperature indices. Consequently, the climate over South China for two future periods will be changing more drastically than the baseline period. Extra cautions need to be given to South China in the future.

Repeatability of a new method for measuring tear evaporation rates.

PubMed

Petznick, Andrea; Tan, Jen Hong; Boo, Shiao Khee; Lee, Sze Yee; Acharya, U Rajendra; Tong, Louis

2013-04-01

The purpose of this study was to evaluate the repeatability of tear evaporimetry based on infrared thermography in a clinical room setting and to test the effect of changing environmental humidity on ocular surface temperature (OST) and tear evaporation rates (TERs) in a controlled adverse environmental (CAE) chamber. Twenty-six healthy participants were enrolled, of whom 16 underwent repeatability measurements in a clinical room and 10 were exposed to a constant temperature of 30°C with a humidity of 45 and 65% in a CAE. Participants were acclimatized to each condition for at least 20 minutes before OSTs were taken. Tear film breakup time was assessed in the CAE only. Number of blinks and OSTs were continuously measured for 20 seconds for the cornea, conjunctiva, and overall ocular surface with an infrared camera; corresponding TERs were calculated. The OSTs and TERs showed acceptable strength of agreement between the first and second measurements. The coefficients of repeatability were 0.4°C for OST and 6.0 W m for TER. An increase in chamber humidity (from 45 to 65%) increased OST (p < 0.05). The TER was not changed significantly (p > 0.05). The tear film breakup time and number of blinks were not significantly affected by different humidity conditions. This technique has acceptable repeatability and has potential to document individual tear evaporation changes with time where humidity may differ by less than 20%.

Seasonal mapping of NICU temperature.

PubMed

Thomas, Karen A; Magbalot, Almita; Shinabarger, Kelley; Mokhnach, Larisa; Anderson, Marilyn; Diercks, Kristi; Millar, April; Thorngate, Lauren; Walker, Wendy; Dilback, Nancy; Berkan, Maureen

2010-04-01

To create a thermal map of ambient air, radiant, and evaporative temperatures and humidity throughout the NICU nursery by season across a calendar year. Each cubicle of the 32-bed NICU, distributed across 5 rooms, in a level III nursery was measured. Temperatures were recorded at a consistent time on one day during January, April, July, and October. An electronic monitor (QUESTemp degrees 34; Quest Technologies, Oconomowoc, Wisconsin) was used to measure dry bulb, wet bulb, and globe thermometer temperatures. Analysis of variance revealed statistically significant (P < .000) differences in season, room, and season by room interaction. Room ambient air temperatures differed by less than 2 degrees F across season. Radiant temperature paralleled air temperature. Humidity, the predominant difference across season, produced evaporative temperatures considerably lower than room air temperature, and the gradient between mean nursery dry bulb temperature and wet bulb temperature was 9.3 degrees F in summer and 16.8 degrees F in winter. The thermal map revealed seasonal thermal differences, particularly in humidity level and evaporative temperature. Room temperature alone does not reflect the total thermal environment. Recommendations include periodic assessment of nurseries along with air, evaporative, and radiant temperatures as well as humidity to fully appreciate the impact of the thermal environment on infants.

Seasonal mapping of NICU temperature.

PubMed

Thomas, Karen A; Magbalot, Almita; Shinabarger, Kelley; Mokhnach, Larisa; Anderson, Marilyn; Diercks, Kristi; Millar, April; Thorngate, Lauren; Walker, Wendy; Dilback, Nancy; Berkan, Maureen

2010-10-01

To create a thermal map of ambient air, radiant, and evaporative temperatures and humidity throughout the NICU nursery by season across a calendar year. Each cubicle of the 32-bed NICU, distributed across 5 rooms, in a level III nursery was measured. Temperatures were recorded at a consistent time on one day during January, April, July, and October. : An electronic monitor (QUESTemp ° 34; Quest Technologies, Oconomowoc, Wisconsin) was used to measure dry bulb, wet bulb, and globe thermometer temperatures. Analysis of variance revealed statistically significant (P ≤ .000) differences in season, room, and season by room interaction. Room ambient air temperatures differed by less than 2 ° F across season. Radiant temperature paralleled air temperature. Humidity, the predominant difference across season, produced evaporative temperatures considerably lower than room air temperature, and the gradient between mean nursery dry bulb temperature and wet bulb temperature was 9.3 ° F in summer and 16.8 ° F in winter. The thermal map revealed seasonal thermal differences, particularly in humidity level and evaporative temperature. Room temperature alone does not reflect the total thermal environment. Recommendations include periodic assessment of nurseries along with air, evaporative, and radiant temperatures as well as humidity to fully appreciate the impact of the thermal environment on infants.

Calibration of Relative Humidity Devices in Low-pressure, Low-temperature CO2 Environment

NASA Astrophysics Data System (ADS)

Genzer, Maria; Polkko, Jouni; Nikkanen, Timo; Hieta, Maria; Harri, Ari-Matti

2017-04-01

Calibration of relative humidity devices requires in minimum two humidity points - dry (0%RH) and (near)saturation (95-100%RH) - over the expected operational temperature and pressure range of the device. In terrestrial applications these are relatively easy to achieve using for example N2 gas as dry medium, and water vapor saturation chambers for producing saturation and intermediate humidity points. But for example in applications intended for meteorological measurements on Mars there is a need to achieve at least dry and saturation points in low-temperature, low-pressure CO2 environment. We have developed a custom-made, small, relatively low-cost calibration chamber able to produce both dry points and saturation points in Martian range pressure CO2, in temperatures down to -70°C. The system utilizes a commercially available temperature chamber for temperature control, vacuum vessels and pumps. The main pressure vessel with the devices under test inside is placed inside the temperature chamber, and the pressure inside is controlled by pumps and manual valves and monitored with a commercial pressure reference with calibration traceable to national standards. Air, CO2, or if needed another gas like N2, is used for filling the vessel until the desired pressure is achieved. Another pressure vessel with a dedicated pressure pump is used as the saturation chamber. This vessel is placed in the room outside the temperature chamber, partly filled with water and used for achieving saturated water vapor in room-temperature low-pressure environment. The saturation chamber is connected to the main pressure vessel via valves. In this system dry point, low-pressure CO2 environment is achieved by filling the main pressure vessel with dry CO2 gas until the desired pressure is achieved. A constant flow of gas is maintained with the pump and valves and monitored with the pressure reference. The saturation point is then achieved by adding some water vapor from the saturation chamber to the main pressure vessel. The amount of water vapor added is also monitored with the pressure reference. For example in -70°C, very small absolute amount of water vapor corresponding to 1 Pa [1][2] pressure rise in the main chamber results in humidity saturation. As the flow of both CO2 and water vapor is kept constant, the main chamber is served with water vapor all the time, keeping the uniform saturation conditions inside the vessel even if some of the water freezes on the vessel and pipe walls. [1] Goff, J. A., and S. Gratch (1946) Low-pressure properties of water from -160 to 212 °F, Transactions of the American Society of Heating and Ventilating Engineers [2] Goff, J. A. (1957) Saturation pressure of water on the new Kelvin temperature scale, Transactions of the American Society of Heating and Ventilating Engineers

40 CFR 1065.670 - NOX intake-air humidity and temperature corrections.

Code of Federal Regulations, 2012 CFR

2012-07-01

... combustion air humidity to calculate this correction if your combustion air humidity remains within a...-air humidity. You may use a time-weighted mean combustion air humidity to calculate this correction if your combustion air humidity remains within a tolerance of ±0.0025 mol/mol of the mean value over the...

40 CFR 1065.670 - NOX intake-air humidity and temperature corrections.

Code of Federal Regulations, 2013 CFR

2013-07-01

... combustion air humidity to calculate this correction if your combustion air humidity remains within a...-air humidity. You may use a time-weighted mean combustion air humidity to calculate this correction if your combustion air humidity remains within a tolerance of ±0.0025 mol/mol of the mean value over the...

40 CFR 1065.670 - NOX intake-air humidity and temperature corrections.

Code of Federal Regulations, 2014 CFR

2014-07-01

... combustion air humidity to calculate this correction if your combustion air humidity remains within a...-air humidity. You may use a time-weighted mean combustion air humidity to calculate this correction if your combustion air humidity remains within a tolerance of ±0.0025 mol/mol of the mean value over the...

Design and implementation of temperature and humidity monitoring system for poultry farm

NASA Astrophysics Data System (ADS)

Purnomo, Hindriyanto Dwi; Somya, Ramos; Fibriani, Charitas; Purwoko, Angga; Sadiyah, Ulfa

2016-10-01

Automatic monitoring system gains significant interest in poultry industry due to the need of consistent environment condition. Appropriate environment increase the feed conversion ratio as well as birds productivity. This will increase the competitiveness of the poultry industry. In this research, a temperature and humidity monitoring system is proposed to observer the temperature and relative humidity of a poultry house. The system is intended to be applied in the poultry industry with partnership schema. The proposed system is equipped with CCTV for visual monitoring. The measured temperature and humidity implement wireless sensor network technology. The experiment results reveals that proposed system have the potential to increase the effectiveness of monitoring of poultry house in poultry industry with partnership schema.

Effect of Climatic Factors on Hand, Foot, and Mouth Disease in South Korea, 2010-2013.

PubMed

Kim, Bryan Inho; Ki, Hyunok; Park, Sunhee; Cho, Eunhi; Chun, Byung Chul

2016-01-01

Hand, foot, and mouth disease (HFMD) causes characteristic blisters and sores mainly in infants and children, and has been monitored in South Korea through sentinel surveillance since 2009. We described the patterns of HFMD occurrence and analyzed the effect of climatic factors on national HFMD incidence. Weekly clinically diagnosed HFMD case rates (per 1,000 outpatients) in sentinel sites and weekly climatic factors, such as average temperature, relative humidity, duration of sunshine, precipitation, and wind speed from 2010 to 2013, were used in this study. A generalized additive model with smoothing splines and climatic variables with time lags of up to 2 weeks were considered in the modeling process. To account for long-term trends and seasonality, we controlled for each year and their corresponding weeks. The autocorrelation issue was also adjusted by using autocorrelation variables. At an average temperature below 18°C, the HFMD rate increased by 10.3% for every 1°C rise in average temperature (95% confidence interval (CI): 8.4, 12.3%). We also saw a 6.6% increase in HFMD rate (95% CI: 3.6, 9.7%) with every 1% increase in relative humidity under 65%, with a 1.5% decrease in HFMD rate observed (95% CI: 0.4, 2.7%) with each 1% humidity increase above 65%. Modeling results have shown that average temperature and relative humidity are related to HFMD rate. Additional research on the environmental risk factors of HFMD transmission is required to understand the underlying mechanism between climatic factors and HFMD incidence.

Effect of meteorological variables on the incidence of hand, foot, and mouth disease in children: a time-series analysis in Guangzhou, China.

PubMed

Huang, Yong; Deng, Te; Yu, Shicheng; Gu, Jing; Huang, Cunrui; Xiao, Gexin; Hao, Yuantao

2013-03-13

Over the last decade, major outbreaks of hand, foot, and mouth disease (HFMD) have been reported in Asian countries, resulting in thousands of deaths among children. However, less is known regarding the effect of meteorological variables on the incidence of HFMD in children. This study aims at quantifying the relationship between meteorological variables and the incidence of HFMD among children in Guangzhou, China. The association between weekly HFMD cases in children aged <15 years and meteorological variables in Guangzhou from 2008 to 2011 were analyzed using the generalized additive model (GAM) and time-series method, after controlling for long-term trend and seasonality, holiday effects, influenza period and delayed effects. Temperature and relative humidity with one week lag were significantly associated with HFMD infection among children. We found that a 1°C increase in temperature led to an increase of 1.86% (95% CI: 0.92, 2.81%) in the weekly number of cases in the 0-14 years age group. A one percent increase in relative humidity may lead to an increase of 1.42% (95% CI: 0.97, 1.87%) in the weekly number of cases in the 0-14 years age group. This study provides quantitative evidence that the incidence of HFMD in children was associated with high average temperature and high relative humidity. The one-week delay in the effects of temperature and relative humidity on HFMD is consistent with the enterovirus incubation period and the potential time lag between onset of children's sickness and parental awareness and response.

Within-Crop Air Temperature and Humidity Outcomes on Spatio-Temporal Distribution of the Key Rose Pest Frankliniella occidentalis.

PubMed

Fatnassi, Hicham; Pizzol, Jeannine; Senoussi, Rachid; Biondi, Antonio; Desneux, Nicolas; Poncet, Christine; Boulard, Thierry

2015-01-01

Frankliniella occidentalis (Pergande) is a key pest of various crops worldwide. In this study, we analyse the dependence of the infestation of this pest on spatially distributed micro climatic factors in a rose greenhouse. Despite the importance of this subject, the few existing studies have been realized in laboratory rather than in greenhouse conditions. However, recent progress on greenhouse microclimate characterisation has highlighted the strong indoor climate heterogeneity that may influence the within-crop pest distribution. In this study, both microclimate (air temperature and humidity) and thrips distribution were simultaneously mapped in a rose greenhouse. The measurements were sensed in a horizontal plane situated at mid-height of the rose crop inside the greenhouse. Simultaneously, thrips population dynamics were assessed after an artificial and homogeneous infestation of the rose crop. The spatio-temporal distribution of climate and thrips within the greenhouse were compared, and links between thrips infestation and climatic conditions were investigated. A statistical model was used to define the favourable climate conditions for thrips adults and larvae. Our results showed that (i) the air temperature and air humidity were very heterogeneously distributed within the crop, (ii) pest populations aggregated in the most favourable climatic areas and (iii) the highest population density of thrips adults and larvae were recorded at 27°C and 22°C for temperature and 63% and 86% for humidity, respectively. These findings confirm, in real rose cropping conditions, previous laboratory studies on the F. occidentalis climatic optimum and provide a solid scientific support for climatic-based control methods against this pest.

Within-Crop Air Temperature and Humidity Outcomes on Spatio-Temporal Distribution of the Key Rose Pest Frankliniella occidentalis

PubMed Central

Fatnassi, Hicham; Pizzol, Jeannine; Senoussi, Rachid; Biondi, Antonio; Desneux, Nicolas; Poncet, Christine; Boulard, Thierry

2015-01-01

Frankliniella occidentalis (Pergande) is a key pest of various crops worldwide. In this study, we analyse the dependence of the infestation of this pest on spatially distributed micro climatic factors in a rose greenhouse. Despite the importance of this subject, the few existing studies have been realized in laboratory rather than in greenhouse conditions. However, recent progress on greenhouse microclimate characterisation has highlighted the strong indoor climate heterogeneity that may influence the within-crop pest distribution. In this study, both microclimate (air temperature and humidity) and thrips distribution were simultaneously mapped in a rose greenhouse. The measurements were sensed in a horizontal plane situated at mid-height of the rose crop inside the greenhouse. Simultaneously, thrips population dynamics were assessed after an artificial and homogeneous infestation of the rose crop. The spatio-temporal distribution of climate and thrips within the greenhouse were compared, and links between thrips infestation and climatic conditions were investigated. A statistical model was used to define the favourable climate conditions for thrips adults and larvae. Our results showed that (i) the air temperature and air humidity were very heterogeneously distributed within the crop, (ii) pest populations aggregated in the most favourable climatic areas and (iii) the highest population density of thrips adults and larvae were recorded at 27°C and 22°C for temperature and 63% and 86% for humidity, respectively. These findings confirm, in real rose cropping conditions, previous laboratory studies on the F. occidentalis climatic optimum and provide a solid scientific support for climatic-based control methods against this pest. PMID:26011275

Humidity: A review and primer on atmospheric moisture and human health.

PubMed

Davis, Robert E; McGregor, Glenn R; Enfield, Kyle B

2016-01-01

Research examining associations between weather and human health frequently includes the effects of atmospheric humidity. A large number of humidity variables have been developed for numerous purposes, but little guidance is available to health researchers regarding appropriate variable selection. We examine a suite of commonly used humidity variables and summarize both the medical and biometeorological literature on associations between humidity and human health. As an example of the importance of humidity variable selection, we correlate numerous hourly humidity variables to daily respiratory syncytial virus isolates in Singapore from 1992 to 1994. Most water-vapor mass based variables (specific humidity, absolute humidity, mixing ratio, dewpoint temperature, vapor pressure) exhibit comparable correlations. Variables that include a thermal component (relative humidity, dewpoint depression, saturation vapor pressure) exhibit strong diurnality and seasonality. Humidity variable selection must be dictated by the underlying research question. Despite being the most commonly used humidity variable, relative humidity should be used sparingly and avoided in cases when the proximity to saturation is not medically relevant. Care must be taken in averaging certain humidity variables daily or seasonally to avoid statistical biasing associated with variables that are inherently diurnal through their relationship to temperature. Copyright © 2015 Elsevier Inc. All rights reserved.

Heat and mass transfer of a low-pressure Mars greenhouse: Simulation and experimental analysis

NASA Astrophysics Data System (ADS)

Hublitz, Inka

Biological life support systems based on plant growth offer the advantage of producing fresh food for the crew during a long surface stay on Mars. Greenhouses on Mars are also used for air and water regeneration and waste treatment. A major challenge in developing a Mars greenhouse is its interaction with the thin and cold Mars environment. Operating a Mars greenhouse at low interior pressure reduces the pressure differential across the structure and therefore saves structural mass as well as reduces leakage. Experiments were conducted to analyze the heating requirements as well as the temperature and humidity distribution within a small-scale greenhouse that was placed in a chamber simulating the temperatures, pressure and light conditions on Mars. Lettuce plants were successfully grown inside of the Mars greenhouse for up to seven days. The greenhouse atmosphere parameters, including temperature, total pressure, oxygen and carbon dioxide concentration were controlled tightly; radiation level, relative humidity and plant evapo-transpiration rates were measured. A vertical stratification of temperature and humidity across the greenhouse atmosphere was observed. Condensation formed on the inside of the greenhouse when the shell temperature dropped below the dew-point. During the night cycles frost built up on the greenhouse base plate and the lower part of the shell. Heat loss increased significantly during the night cycle. Due to the placement of the heating system and the fan blowing warm air directly on the upper greenhouse shell, condensation above the plants was avoided and therefore the photosynthetically active radiation at plant level was kept constant. Plant growth was not affected by the temperature stratification due to the tight temperature control of the warmer upper section of the greenhouse, where the lettuce plants were placed. A steady state and a transient heat transfer model of the low pressure greenhouse were developed for the day and the night cycle. Furthermore, low pressure psychrometric relations for closed systems and modified atmospheres were generated to calculate the properties of the moist air in order to predict condensate formation. The results of this study improve the design of the environmental control system leading to an optimization of plant growth conditions.

[Ecological basis of epiphytic Dendrobium officinale growth on cliff].

PubMed

Liu, Xiu-Juan; Zhu, Yan; Si, Jin-Ping; Wu, Ling-Shang; Cheng, Xue-Liang

2016-08-01

In order to make Dendrobium officinale return to the nature, the temperature and humidity in whole days of the built rock model with different slopes and aspects in the natural distribution of wild D. officinale in Tianmu Mountain were recorded by MH-WS01 automatic recorder. The results showed that the slope has a significant impact on the extreme temperature on the surface of the rocks. In summer, the extreme temperature on the surface of horizontal or soft rock can reach to 69.4 ℃, while the temperatures were lower than 50 ℃ on the vertical rock. In winter, the temperatures on the surface of vertical rock were higher and the low temperature duration was shorter than those on the horizontal or soft rock. Also, the humidity of the rocks was significantly influenced by the slope. The monthly average humidity on the surface of vertical rock was above 80%RH. Furthermore, the aspect had a significant impact on the temperature and humidity on the surface of the rocks, but had no significant effect on the daily mean temperature and extreme temperature on the surface of vertical rock. Therefore, the slope affects the survival of D. officinale by affecting the extreme temperature of rocks and affects the growth of D. officinale by affecting the humidity. The choice of slope is the key to the success of cliff epiphytic cultivation for D. officinale. Copyright© by the Chinese Pharmaceutical Association.

40 CFR 86.311-79 - Miscellaneous equipment; specifications.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Intake air humidity and temperature measurements. (1) Humidity conditioned air supply. Air that has had... supply, the humidity measurements must be made within the intake air supply system, and after the humidity conditioning has taken place. (2) Nonconditioned air supply. Humidity measurements in non...

Investigation of drying stresses on proteins during lyophilization: differentiation between primary and secondary-drying stresses on lactate dehydrogenase using a humidity controlled mini freeze-dryer.

PubMed

Luthra, Sumit; Obert, Jean-Philippe; Kalonia, Devendra S; Pikal, Michael J

2007-01-01

This article describes the design, performance testing, and application of a controlled humidity mini-freeze-dryer in studying the physical stability of lactate dehydrogenase during lyophilization. Performance evaluation of the mini-freeze-dryer was conducted with tests, namely water sublimation, radiation heat exchange, lowest achievable temperature, and leak testing. Protein stability studies were conducted by comparing protein activity at various stages of lyophilization with the initial activity. The shelf and condenser temperature were stable at <-40 degrees C, wall temperature was within 2 degrees C of the shelf temperature, and the leak rate was small. The chamber pressure was controlled by the ice on the condenser and the product temperature during sublimation was equal to the shelf temperature. Addition of Tween 80 prevented activity loss in solution and after freeze-thaw. No activity loss was observed after primary-drying even in absence of lyoprotectants and with collapse of cake structure. Five percent (w/w) sucrose concentration was required to achieve full stabilization. In conclusion, performance testing established that the mini-freeze-dryer was suitable for mechanistic freeze-drying studies. Secondary-drying was the critical step for protein stability. The concentration of sucrose required to stabilize the protein completely was several orders of magnitude higher than that required to satisfy the direct interaction requirement of the protein. (c) 2006 Wiley-Liss, Inc. and the American Pharmacists Association.

[Thermal energy utilization analysis and energy conservation measures of fluidized bed dryer].

PubMed

Xing, Liming; Zhao, Zhengsheng

2012-07-01

To propose measures for enhancing thermal energy utilization by analyzing drying process and operation principle of fluidized bed dryers,in order to guide optimization and upgrade of fluidized bed drying equipment. Through a systematic analysis on drying process and operation principle of fluidized beds,the energy conservation law was adopted to calculate thermal energy of dryers. The thermal energy of fluidized bed dryers is mainly used to make up for thermal consumption of water evaporation (Qw), hot air from outlet equipment (Qe), thermal consumption for heating and drying wet materials (Qm) and heat dissipation to surroundings through hot air pipelines and cyclone separators. Effective measures and major approaches to enhance thermal energy utilization of fluidized bed dryers were to reduce exhaust gas out by the loss of heat Qe, recycle dryer export air quantity of heat, preserve heat for dry towers, hot air pipes and cyclone separators, dehumidify clean air in inlets and reasonably control drying time and air temperature. Such technical parameters such air supply rate, air inlet temperature and humidity, material temperature and outlet temperature and humidity are set and controlled to effectively save energy during the drying process and reduce the production cost.

Control of membrane permeability in air-stable droplet interface bilayers

DOE PAGES

Mruetusatorn, Prachya; Polizos, Georgios; Datskos, Panos G.; ...

2015-03-19

Air-stable droplet interface bilayers (airDIBs) on oil-infused surfaces are versatile model membranes for synthetic biology applications, including biosensing of airborne species. However, air-DIBs are subject to evaporation, which can, over time, destabilize them and reduce their useful lifetime compared to traditional DIBs that are fully submerged in oil. Here, we show that lifetimes of air-DIBs can be extended by as much as an order of magnitude by maintaining them at a temperature just above the dew point. We find that raising the temperature from near the dew point (7 C at 38.5 % relative humidity) to room temperature results inmore » loss of water molecules of hydration from the polar head groups of the lipid bilayer membrane due to evaporation in an irreversible process that increases the overall entropy of the system. This dehydration transition affects primarily the bilayer resistance, by increasing ion permeability through the increasingly disordered polar head group region of the bilayer. Temperature and/or relative humidity are conveniently tunable parameters for controlling the stability and composition of air-DIBs membranes, while still allowing for operation in ambient environments.« less

The application of the Accelerated Stability Assessment Program (ASAP) to quality by design (QbD) for drug product stability.

PubMed

Waterman, Kenneth Craig

2011-09-01

An isoconversion paradigm, where times in different temperature and humidity-controlled stability chambers are set to provide a fixed degradant level, is shown to compensate for the complex, non-single order kinetics of solid drug products. A humidity-corrected Arrhenius equation provides reliable estimates for temperature and relative humidity effects on degradation rates. A statistical protocol is employed to determine best fits for chemical stability data, which in turn allows for accurate estimations of shelf life (with appropriate confidence intervals) at any storage condition including inside packaging (based on the moisture vapor transmission rate of the packaging and moisture sorption isotherms of the internal components). These methodologies provide both faster results and far better predictions of chemical stability limited shelf life (expiry) than previously possible. Precise shelf-life estimations are generally determined using a 2-week, product-specific protocol. Once the model for a product is developed, it can play a critical role in providing the product understanding necessary for a quality by design (QbD) filing for product approval and enable rational control strategies to assure product stability. Moreover, this Accelerated Stability Assessment Program (ASAP) enables the coupling of product attributes (e.g., moisture content, packaging options) to allow for flexibility in how control strategies are implemented to provide a balance of cost, speed, and other factors while maintaining adequate stability.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hatley, Darrel D.; Underhill, Ronald M.

Document describes an onsite workshop and building retuning training conducted in Guam in August 2010. Document reports on issues identified during an audit of several buildings and recommendations to save energy throughout the site. During the workshop, it became apparent that as site personnel maintain the facilities at Guam, the following retuning efforts and strategies should be prioritized: (1) Controlling the mechanical systems operational hours and zone temperature set points appeared to present the best opportunities for savings; (2) Zone temperature set points in some buildings are excessively low, especially at night, when the zone temperatures are so cold thatmore » they approached the dewpoint; and (3) Manually-set outside air dampers are providing excessive outside air, especially for spaces that are unoccupied. Two of the larger schools, one on the Naval Base and one on Anderson AFB, are in need of a significant recommissioning effort. These facilities are relatively new, with direct digital controls (DDC) but are significantly out of balance. The pressure in one school is extremely negative, which is pulling humid air through the facility each time a door is opened. The draft can be felt several feet down the halls. The pressure in the other school is extremely positive relative to the outside, and you can stand 20-feet outside and still feel cool drafts of air exiting the building. It is recommended that humidity sensors be installed in all new projects and retrofitted into exist facilities. In this humid climate, control of humidity is very important. There are significant periods of time when the mechanical systems in many buildings can be unloaded and dehumidification is not required. The use of CO{sub 2} sensors should also be considered in representative areas. CO{sub 2} sensors determine whether spaces are occupied so that fresh air is only brought into the space when needed. By reducing the amount of outside air brought into the space, the humidity load is also substantially reduced. CO{sub 2} and humidity sensors, combined with outside air sensors, can be used to predict whether conditions are amenable to mold growth and to automatically adjust systems to help prevent mold without using extra energy. The goal of this training is to give the building operators the knowledge needed to make positive changes in the operation of building systems. As class participants apply this knowledge, building systems will run more efficiently, occupant comfort should improve, while saving energy and reducing greenhouse gas emissions.« less

GmSBH1, a homeobox transcription factor gene, relates to growth and development and involves in response to high temperature and humidity stress in soybean.

PubMed

Shu, Yingjie; Tao, Yuan; Wang, Shuang; Huang, Liyan; Yu, Xingwang; Wang, Zhankui; Chen, Ming; Gu, Weihong; Ma, Hao

2015-11-01

GmSBH1 involves in response to high temperature and humidity stress. Homeobox transcription factors are key switches that control plant development processes. Glycine max H1 Sbh1 (GmSBH1) was the first homeobox gene isolated from soybean. In the present study, the full ORF of GmSBH1 was isolated, and the encoded protein was found to be a typical class I KNOX homeobox transcription factor. Subcellular localization and transcriptional activation assays showed that GmSBH1 is a nuclear protein and possesses transcriptional activation activity in the homeodomain. The KNOX1 domain was found to play a clear role in suppressing the transcriptional activation activity of GmSBH1. GmSBH1 showed different expression levels among different soybean tissues and was involved in response to high temperature and humidity (HTH) stress in developing soybean seeds. The overexpression of GmSBH1 in Arabidopsis altered leaf and stoma phenotypes and enhanced seed tolerance to HTH stress. Overall, our results indicated that GmSBH1 is involved in growth, development, and enhances tolerance to pre-harvest seed deterioration caused by HTH stress in soybean.

Flight mill performance of the lacewing Chrysoperla sinica (Neuroptera: Chrysopidae) as a function of age, temperature, and relative humidity.

PubMed

Liu, Zhongfang; McNeil, Jeremy N; Wu, Kongming

2011-02-01

The lacewing Chrysoperla sinica (Tjeder) (Neuroptera: Chrysopidae) is an important predator of several insect pests in China and has considerable potential as a biological control agent. An inoculative approach would be the releasing adults early in the season to ensure that populations are present before pest densities increase. However, an understanding of adult flight activity under different conditions is necessary to develop appropriate release strategies. Therefore, we used a 32-channel, computer-monitored flight mill system to determine the effect of age on the flight activity of unmated female and male adults. Both sexes had high total flight activity levels as well as the longest individual flight bouts 2 and 3 d after emergence. The effects of temperature (between 13 and 33 degrees C at 75% RH) and relative humidity (between 30 and 90% RH at 23 degrees C) on the flight activity of 3-d-old unmated adults also were determined. Flight activity declined at the lowest (13 degrees C) and highest (33 degrees C) temperatures tested, as well as at the lowest relative humidity (30% RH). These findings are discussed within the context of selecting the appropriate environmental conditions for releasing C. sinica.

Design of extensible meteorological data acquisition system based on FPGA

NASA Astrophysics Data System (ADS)

Zhang, Wen; Liu, Yin-hua; Zhang, Hui-jun; Li, Xiao-hui

2015-02-01

In order to compensate the tropospheric refraction error generated in the process of satellite navigation and positioning. Temperature, humidity and air pressure had to be used in concerned models to calculate the value of this error. While FPGA XC6SLX16 was used as the core processor, the integrated silicon pressure sensor MPX4115A and digital temperature-humidity sensor SHT75 are used as the basic meteorological parameter detection devices. The core processer was used to control the real-time sampling of ADC AD7608 and to acquire the serial output data of SHT75. The data was stored in the BRAM of XC6SLX16 and used to generate standard meteorological parameters in NEMA format. The whole design was based on Altium hardware platform and ISE software platform. The system was described in the VHDL language and schematic diagram to realize the correct detection of temperature, humidity, air pressure. The 8-channel synchronous sampling characteristics of AD7608 and programmable external resources of FPGA laid the foundation for the increasing of analog or digital meteorological element signal. The designed meteorological data acquisition system featured low cost, high performance, multiple expansions.

Bias Correction for Assimilation of Retrieved AIRS Profiles of Temperature and Humidity

NASA Technical Reports Server (NTRS)

Blankenship, Clay; Zavodsky, Brad; Blackwell, William

2014-01-01

Atmospheric Infrared Sounder (AIRS) is a hyperspectral radiometer aboard NASA's Aqua satellite designed to measure atmospheric profiles of temperature and humidity. AIRS retrievals are assimilated into the Weather Research and Forecasting (WRF) model over the North Pacific for some cases involving "atmospheric rivers". These events bring a large flux of water vapor to the west coast of North America and often lead to extreme precipitation in the coastal mountain ranges. An advantage of assimilating retrievals rather than radiances is that information in partly cloudy fields of view can be used. Two different Level 2 AIRS retrieval products are compared: the Version 6 AIRS Science Team standard retrievals and a neural net retrieval from MIT. Before assimilation, a bias correction is applied to adjust each layer of retrieved temperature and humidity so the layer mean values agree with a short-term model climatology. WRF runs assimilating each of the products are compared against each other and against a control run with no assimilation. This paper will describe the bias correction technique and results from forecasts evaluated by validation against a Total Precipitable Water (TPW) product from CIRA and against Global Forecast System (GFS) analyses.

Investigating the effects of climate variations on bacillary dysentery incidence in northeast China using ridge regression and hierarchical cluster analysis

PubMed Central

Huang, Desheng; Guan, Peng; Guo, Junqiao; Wang, Ping; Zhou, Baosen

2008-01-01

Background The effects of climate variations on bacillary dysentery incidence have gained more recent concern. However, the multi-collinearity among meteorological factors affects the accuracy of correlation with bacillary dysentery incidence. Methods As a remedy, a modified method to combine ridge regression and hierarchical cluster analysis was proposed for investigating the effects of climate variations on bacillary dysentery incidence in northeast China. Results All weather indicators, temperatures, precipitation, evaporation and relative humidity have shown positive correlation with the monthly incidence of bacillary dysentery, while air pressure had a negative correlation with the incidence. Ridge regression and hierarchical cluster analysis showed that during 1987–1996, relative humidity, temperatures and air pressure affected the transmission of the bacillary dysentery. During this period, all meteorological factors were divided into three categories. Relative humidity and precipitation belonged to one class, temperature indexes and evaporation belonged to another class, and air pressure was the third class. Conclusion Meteorological factors have affected the transmission of bacillary dysentery in northeast China. Bacillary dysentery prevention and control would benefit from by giving more consideration to local climate variations. PMID:18816415

Device and method for measuring the energy content of hot and humid air streams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosen, H. N.; Girod, G. F.; Kent, A. C.

1985-12-24

a portable device and method for measuring enthalpy and humidity of humid air from a space or flow channel at temperatures from 80/sup 0/ to 400/sup 0/ F. is described. the device consists of a psychrometer for measuring wet-bulb temperature, a vacuum pump for inducing sample air flow through the unit, a water-heating system for accurate psychrometer readings, an electronic computer system for evaluation of enthalpy and humidity from corrected and averaged values of wet- and dry- bulb temperatures, and a monitor for displaying the values. The device is programmable by the user to modify evaluation methods as necessary.

Preliminary simulation study on regional climate change in Xinjiang, China

NASA Astrophysics Data System (ADS)

Yuan, Chunqiong; Guo, Qingyu; Xie, Hongbing; Pan, Xiaoling; Anabiek, Subai

2004-01-01

Under the conditions of global warming, the degenerated ecological environment has threatened human survival. Therefore, people will gradually pay more attention to the environmental problem of climate change. This paper analyzes the distribution features of air temperature, relative humidity (precipitation), and the horizontal stream field in Xinjiang for July 1997. In order to do the integration of one month (July, 1997) we ran the model NCAP/PENN MM5V3. Data from WLCCD (the latest World Land Cover Characteristics Database) was used to relate the two research domains of the model, and also to replace the vegetation in the MM5. The data in the WWLCD depends on the actual land surface characteristics. It was found that the general law of air temperature, relative humidity (precipitation) and the horizontal stream field of 1000hPa in Xinjiang in July of 1997 by means of the model. The mean regional data for July helped prefect the theory that humans are controlling the ecological environment in order to prevent and control desertification. Among these results, the simulated air temperature was the best.

Effect of Annealing Temperature on Bi3.25La0.75Ti3O12 Powders for Humidity Sensing Properties

NASA Astrophysics Data System (ADS)

Zhang, Yong; He, Jinping; Yuan, Mengjiao; Jiang, Bin; Li, Peiwen; Tong, Yexing; Zheng, Xuejun

2017-01-01

Bi3.25La0.75Ti3O12 (BLT) powders have been synthesized via the metal-organic decomposition method with annealing of the BLT precursor solution at 350°C, 450°C, 550°C, 650°C or 750°C. The crystalline structure and morphology of the BLT powders were characterized by x-ray diffraction analysis, field-emission scanning electron microscopy, energy-dispersive x-ray spectroscopy, and specific surface and pore size analyses. The humidity sensing properties of the BLT powders annealed at the five temperatures were investigated to determine the effect of annealing temperature. The annealing temperature strongly influenced the grain size, pore size distribution, and specific surface area of the BLT powders, being largely correlated to their humidity sensing properties. The specific surface area of the BLT powder annealed at 550°C was 68.2 m2/g, much larger than for the other annealing temperatures, and the majority of the pores in the BLT powder annealed at 550°C were mesoporous, significantly increasing the adsorption efficiency of water vapor onto the surface of the material. The impedance of the BLT powder annealed at 550°C varied by more than five orders of magnitude over the whole humidity range at working frequency of 100 Hz, being approximately five times greater than for BLT powders annealed at other temperatures. The response time was about 8 s, with maximum hysteresis of around 3% relative humidity. The BLT powder annealed at 550°C exhibited the best humidity sensing properties compared with the other annealing temperatures. We expect that these results will offer useful guidelines for preparation of humidity sensing materials.

Influence of ambient temperature and minute ventilation on passive and active heat and moisture exchangers.

PubMed

Lellouche, François; Qader, Siham; Taillé, Solenne; Lyazidi, Aissam; Brochard, Laurent

2014-05-01

During invasive mechanical ventilation, inspired gases must be humidified. We previously showed that high ambient temperature greatly impaired the hygrometric performance of heated wire-heated humidifiers. The aim of this bench and clinical study was to assess the humidification performance of passive and active heat and moisture exchangers (HMEs) and the impact of ambient temperature and ventilator settings. We first tested on the bench a device with passive and active humidification properties (Humid-Heat, Teleflex), and 2 passive hydrophobic/hygroscopic HMEs (Hygrobac and Hygrobac S, Tyco Healthcare). The devices were tested at 3 different ambient temperatures (from 22 to 30 °C), and at 2 minute ventilation settings (10 and 20 L/min). Inspired gas hygrometry was measured at the Y-piece with the psychrometric method. In addition to the bench study, we measured the hygrometry of inspired gases in 2 different clinical studies. In 15 mechanically ventilated patients, we evaluated Humid-Heat at different settings. Additionally, we evaluated Humid-Heat and compared it with Hygrobac in a crossover study in 10 patients. On the bench, with the Hygrobac and Hygrobac S the inspired absolute humidity was ∼ 30 mg H2O/L, and with the Humid-Heat, slightly < 35 mg H2O/L. Ambient temperature and minute ventilation did not have a clinically important difference on the performance of the tested devices. During the clinical evaluation, Humid-Heat provided inspired humidity in a range from 28.5 to 42.0 mg H2O/L, depending on settings, and was only weakly influenced by the patient's body temperature. In this study both passive and active HMEs had stable humidification performance with negligible influence of ambient temperature and minute ventilation. This contrasts with previous findings with heated wire-heated humidifiers. Although there are no clear data demonstrating that higher humidification impacts outcomes, it is worth noting that humidity was significantly higher with the active HME.

Differences in heat sensitivity between Japanese honeybees and hornets under high carbon dioxide and humidity conditions inside bee balls.

PubMed

Sugahara, Michio; Nishimura, Yasuichiro; Sakamoto, Fumio

2012-01-01

Upon capture in a bee ball (i.e., a dense cluster of Japanese honeybees forms in response to a predatory attack), an Asian giant hornet causes a rapid increase in temperature, carbon dioxide (CO₂), and humidity. Within five min after capture, the temperature reaches 46°C, and the CO₂ concentration reaches 4%. Relative humidity gradually rises to 90% or above in 3 to 4 min. The hornet dies within 10 min of its capture in the bee ball. To investigate the effect of temperature, CO₂, and humidity on hornet mortality, we determined the lethal temperature of hornets exposed for 10 min to different humidity and CO₂/O₂ (oxygen) levels. In expiratory air (3.7% CO₂), the lethal temperature was ≥ 2° lower than that in normal air. The four hornet species used in this experiment died at 44-46°C under these conditions. Hornet death at low temperatures results from an increase in CO₂ level in bee balls. Japanese honeybees generate heat by intense respiration, as an overwintering strategy, which produces a high CO₂ and humidity environment and maintains a tighter bee ball. European honeybees are usually killed in the habitat of hornets. In contrast, Japanese honeybees kill hornets without sacrificing themselves by using heat and respiration by-products and forming tight bee balls.

In the Background

ERIC Educational Resources Information Center

Garibay, Pat

2007-01-01

Educators and administrators are looking for new ways to boost student performance and eliminate barriers to learning. When working to improve the classroom environment, facility managers typically target the physical structure, temperature controls, humidity levels and ventilation. Many heating, ventilating and air conditioning (HVAC) consultants…

46 CFR 160.176-19 - Servicing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... section contains requirements for servicing facilities, manuals, training, guidelines, and records. Other... follow the procedures in the service manual required by this section. (2) Each servicing facility must... strong sunlight, and have appropriate temperature and humidity control as specified in the service manual...

NARSTO EPA SS BALTIMORE JHU MET DATA

Atmospheric Science Data Center

2018-04-09

... Meteorological Station Instrument:  Temperature Probe Humidity Probe Cup Anemometer Rain Gauge Sonic ...   E arthdata Search Parameters:  Air Temperature Humidity Surface Winds Precipitation Amount Heat Flux ...

The impact of temperature and relative humidity on spatiotemporal patterns of infant bronchiolitis epidemics in the contiguous United States.

PubMed

Sloan, Chantel; Heaton, Matthew; Kang, Sorah; Berrett, Candace; Wu, Pingsheng; Gebretsadik, Tebeb; Sicignano, Nicholas; Evans, Amber; Lee, Rees; Hartert, Tina

2017-05-01

Infant bronchiolitis is primarily due to infection by respiratory syncytial virus (RSV), which is highly seasonal. The goal of the study is to understand how circulation of RSV is impacted by fluctuations in temperature and humidity in order to inform prevention efforts. Using data from the Military Health System (MHS) Data Repository (MDR), we calculated rates of infant bronchiolitis for the contiguous US from July 2004 to June 2013. Monthly temperature and relative humidity were extracted from the National Climate Data Center. Using a spatiotemporal generalized linear model for binomial data, we estimated bronchiolitis rates and the effects of temperature and relative humidity while allowing them to vary over location and time. Our results indicate a seasonal pattern that begins in the Southeast during November or December, then spreading in a Northwest direction. The relationships of temperature and humidity were spatially heterogeneous, and we find that climate can partially account for early onset or longer epidemic duration. Small changes in climate may be associated with larger fluctuations in epidemic duration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characteristics of wettedness and equi-skin temperature line in the evaporative regulation region

NASA Astrophysics Data System (ADS)

Mochida, T.

1983-07-01

As a result of the analysis of physiological experimental data, the characteristics of the wettedness were clarified, i.e., the value of the wettedness is not constant but differs in accordance with the environmental humidity even when the skin temperature is the same, and it was shown that the evaporative heat loss from the skin surface is inversely proportional to the wetttedness. Based on the properties of the wetedness observed, a new thermal sensation chart in the evaporative regulation region was proposed as an index for evaluating the warmth or the coldness in the environment. The feature of the present chart is that the locus of the equal skin temperature appears as a curved line on the psychrometric chart and that the wettedness on the equi-skin temperature line is not constant but takes varying values. The curved equal skin temperature line means that the influence of the environmental humidity on thermal sensation becomes smaller as the humidity of the environmental humidity on thermal sensation becomes smaller as the humidity of the environment is lowered.

Mechanophysical Stimulations of Mucin Secretion in Cultures of Nasal Epithelial Cells

PubMed Central

Even-Tzur Davidovich, Nurit; Kloog, Yoel; Wolf, Michael; Elad, David

2011-01-01

Nasal epithelial cells secret mucins and are exposed in vivo to airflow-induced mechanophysical stresses, including wall shear stress (WSS), temperature, and humidity. In this work, human nasal epithelial cells cultured under air-liquid interface conditions were subjected to fields of airflow-induced oscillatory WSS at different temperature and humidity conditions. Changes in mucin secretion due to WSS were measured and the role of the cytoskeleton in mucin secretion was explored. Mucin secretion significantly increased in response to WSS in a magnitude-dependent manner with respect to static cultures and independently of the airflow temperature and humidity. In static cultures, mucin secretion decreased at high humidity with or without elevation of the temperature with respect to cultures at a comfortable climate. In cultures exposed to WSS, mucin secretion increased at high temperature with respect to cultures at comfortable climate conditions. The polymerization of actin microfilaments was shown to increase mucin secretion under WSS, whereas the dynamics of microtubule polymerization did not affect secretion. In conclusion, the data in this study show that mucin secretion is sensitive to oscillatory WSS as well as high temperature and humidity conditions. PMID:21689518

The influence of temperature and relative humidity on the development of Lepidoglyphus destructor (Acari: Glycyphagidae) and its production of allergens: a laboratory experiment.

PubMed

Danielsen, Charlotte; Hansen, Lise Stengård; Nachman, Gösta; Herling, Christian

2004-01-01

Laboratory experiments with Lepidoglyphus destructor on a diet of mainly whole wheat were conducted to study the mite's development and production of a specific allergen, Lep d 2, at four different temperatures (5, 10, 15 and 20 degrees C) and three levels of relative humidity (ca. 70-88%). Statistical models were used to analyse the role played by temperature, relative humidity and time in explaining the observed number of L. destructor and the amount of allergen produced. Moreover, the life stage distributions of the mites were determined and related to the population growth. Based on a statistical model the intrinsic rate of natural increase, rm, was computed for a range of different temperatures and relative humidities. High relative humidity in combination with temperatures at about 25 degrees C will lead to the highest rm (ca. 0.15 day-1). The highest concentration of Lep d 2 was 3 micrograms g-1 grain, found at 20 degrees C and high relative humidity at a mite density of 254 mites g-1 grain. The concentration of allergens in the grain was best explained by a model that incorporated both the current and the cumulative numbers of mites.

Analysis of a membrane-based condesate recovery heat exchanger (CRX)

NASA Technical Reports Server (NTRS)

Newbold, D.D.

1993-01-01

The development of a temperature and humidity control system that can remove heat and recover water vapor is key to the development of an Environmental Control and Life Support System (ECLSS). Large quantities of water vapor must be removed from air, and this operation has proven difficult in the absense of gravity. This paper presents the modeling results from a program to develop a novel membrane-based heat exchanger known as the condensate recovery heat exchanger (CRX). This device cools and dehumidifies humid air and simultaneously recovers water-vapor condensate. In this paper, the CRX is described and the results of an analysis of the heat- and mass-transfer characteristics of the device are given.

Effect of production microclimate on female thermal state with increased temperature and air humidity

NASA Technical Reports Server (NTRS)

Machablishvili, O. G.

1980-01-01

The thermal state of women during the effect of high air temperature and relative humidity with a varying degree of physical loads was studied. Parameters for air temperature, relative humidity, and air movement were established. It was established that in women the thermo-regulatory stress occurs at lower air temperatures and with lower physical loads than in men. The accumulation of heat in women was revealed with lower air temperature than in men. It is concluded that to preserve the normal physiological state of the female organism it is necessary to create more favorable microclimate conditions and decrease the physical loads.

SSMILES.

ERIC Educational Resources Information Center

Sunal, Dennis W., Ed.; Tracy, Dyanne M., Ed.

1993-01-01

Describes an activity in which the students utilize the mathematics concepts of ratio, proportion, and data tabulation to examine the relationship between air pressure, temperature, and humidity. Students learn to approximate partial pressure by using humidity and temperature readings and by interpolating from the vapor pressure-temperature table.…

Thermal Comfort in the Hot Humid Tropics of Australia

PubMed Central

Wyndham, C. H.

1963-01-01

Day and night comfort votes were recorded from Caucasian residents at Weipa, a mission station in the hot humid tropics of North Queensland, Australia. The limit of day comfort for more than 50% of the men was 81·5°F. (27·5°C.) “normal” corrected effective temperature; the night limit was 78·0°F. (25·5°C.). Day comfort limits correlated well with air conditions at which sweat was apparent: night limits correlated with the amount of bed covering. Evidence of a change over 14 days in day comfort limit was found. Limitations in the effective temperature scale for expressing the “oppressive nature” of night air conditions are pointed out. Criticism is voiced of the use of dry bulb temperature instead of the effective temperature scale in conditions of high wet bulb temperatures with high relative humidity, such as in the hot humid tropics. PMID:14002126

Tracheal climate in laryngectomees after use of a heat and moisture exchanger.

PubMed

Keck, Tilman; Dürr, Jochen; Leiacker, Richard; Rettinger, Gerhard; Rozsasi, Ajnacska

2005-03-01

Heat and moisture exchangers (HME) are frequently used in the treatment and prevention of tracheobronchial dryness and infections. In this study, the short-term influence of the HME Prim-Air System (Heimomed, Kerpen, Germany) in laryngectomized patients was tested. Prospective study. After adaptation to the laboratory environment, tracheal humidity and temperature were measured before HME application, 1 minute after HME application, 10 minutes after HME application, 1 minute after removal of the HME, and 10 minutes after removal of the HME. When the HME was placed on the tracheal stoma, the end-inspiratory humidity and temperature increased significantly. Ten minutes after commencement of use of the HME, tracheal humidity further increased significantly. Ten minutes after removal of the HME, tracheal humidity and temperature decreased to values as before start of use of HME. The results indicate that short-term use of the HME Prim-Air system rapidly changes the tracheal climate. The significant increase in tracheal temperature and humidity may have beneficial effects on tracheal dryness in laryngectomized patients.

Recent advances of rearing cabinet instrumentation and control system for insect stock culture

NASA Astrophysics Data System (ADS)

Hermawan, Wawan; Kasmara, Hikmat; Melanie, Panatarani, Camellia; Joni, I. Made

2017-01-01

Helicoverpa armigera (Hubner) is one of a serious pest of horticulture in Indonesia. Helicoverpa armigera Nuclear Polyhedrovirus (HaNPV) has attracted interest for many researchers as a pest control for larvae of this species. Currently, we investigating the agrochemical formulations of HaNPV by introducing nanotechnology. Thus it is required an acceptable efficiency of insect stock cultures equipped with advance instruments to resolve the difficulties on insect stock seasons dependency. In addition, it is important to improve the insect survival with the aid of artificial natural environment and gain high insect production. This paper reports the rearing cabinet used as preparation of stock culture includes air-conditioning system, lighting, i.e. day and night control, and the main principles on recent technical and procedural advances apparatus of the system. The rearing system was moveable, designed and build by allowing air-conditioned cabinet for rearing insects, air motion and distribution as well as temperature and humidity being precisely controlled. The air was heated, humidified, and dehumidified respectively using a heater and ultrasonic nebulizer as actuators. Temperature and humidity can be controlled at any desired levels from room temperature (20°C) to 40 ± 1°C and from 0 to 80% RH with an accuracy of ±3% R.H. It is concluded that the recent design has acceptable performance based on the defined requirement for insect rearing and storage.

Effect of high altitude on blood glucose meter performance.

PubMed

Fink, Kenneth S; Christensen, Dale B; Ellsworth, Allan

2002-01-01

Participation in high-altitude wilderness activities may expose persons to extreme environmental conditions, and for those with diabetes mellitus, euglycemia is important to ensure safe travel. We conducted a field assessment of the precision and accuracy of seven commonly used blood glucose meters while mountaineering on Mount Rainier, located in Washington State (elevation 14,410 ft). At various elevations each climber-subject used the randomly assigned device to measure the glucose level of capillary blood and three different concentrations of standardized control solutions, and a venous sample was also collected for later glucose analysis. Ordinary least squares regression was used to assess the effect of elevation and of other environmental potential covariates on the precision and accuracy of blood glucose meters. Elevation affects glucometer precision (p = 0.08), but becomes less significant (p = 0.21) when adjusted for temperature and relative humidity. The overall effect of elevation was to underestimate glucose levels by approximately 1-2% (unadjusted) for each 1,000 ft gain in elevation. Blood glucose meter accuracy was affected by elevation (p = 0.03), temperature (p < 0.01), and relative humidity (p = 0.04) after adjustment for the other variables. The interaction between elevation and relative humidity had a meaningful but not statistically significant effect on accuracy (p = 0.07). Thus, elevation, temperature, and relative humidity affect blood glucose meter performance, and elevated glucose levels are more greatly underestimated at higher elevations. Further research will help to identify which blood glucose meters are best suited for specific environments.

Intelligent structures technology

NASA Astrophysics Data System (ADS)

Crawley, Edward F.

1991-07-01

Viewgraphs on intelligent structures technology are presented. Topics covered include: embedding electronics; electrical and mechanical compatibility; integrated circuit chip packaged for embedding; embedding devices within composite structures; test of embedded circuit in G/E coupon; temperature/humidity/bias test; single-chip microcomputer control experiment; and structural shape determination.

Intelligent structures technology

NASA Technical Reports Server (NTRS)

Crawley, Edward F.

1991-01-01

Viewgraphs on intelligent structures technology are presented. Topics covered include: embedding electronics; electrical and mechanical compatibility; integrated circuit chip packaged for embedding; embedding devices within composite structures; test of embedded circuit in G/E coupon; temperature/humidity/bias test; single-chip microcomputer control experiment; and structural shape determination.

Fourth floor, view looking from the reception cube (402A) to ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Fourth floor, view looking from the reception cube (402A) to elevator and stair (note radio controlled temperature and humidity device and the water fountain) - Virginia State Capitol, Bank and 10th Streets, Capitol Square, Richmond, Independent City, VA

Climate change, humidity, and mortality in the United States

PubMed Central

Barreca, Alan I.

2014-01-01

This paper estimates the effects of humidity and temperature on mortality rates in the United States (c. 1973–2002) in order to provide an insight into the potential health impacts of climate change. I find that humidity, like temperature, is an important determinant of mortality. Coupled with Hadley CM3 climate-change predictions, I project that mortality rates are likely to change little on the aggregate for the United States. However, distributional impacts matter: mortality rates are likely to decline in cold and dry areas, but increase in hot and humid areas. Further, accounting for humidity has important implications for evaluating these distributional effects. PMID:25328254

Equations for the determination of humidity from dewpoint and psychrometric data

NASA Technical Reports Server (NTRS)

Parish, O. O.; Putnam, T. W.

1977-01-01

A general expression based on the Claperon-Clausius differential equation that relates saturation vapor pressure, absolute temperature, and the latent heat of transformation was derived that expresses saturation vapor pressure as a function of absolute temperature. This expression was then used to derive general expressions for vapor pressure, absolute humidity, and relative humidity as functions of either dewpoint and ambient temperature or psychrometric parameters. Constants for all general expressions were then evaluated to give specific expressions in both the international system of units and U.S. customary units for temperatures above and below freezing.

Controlled meteorological (CMET) balloon profiling of the Arctic atmospheric boundary layer

NASA Astrophysics Data System (ADS)

Roberts, Tjarda; Hole, Lars; Voss, Paul

2017-04-01

We demonstrate profiling of the atmospheric boundary layer over Arctic ice-free and sea-ice covered regions by free-floating controllable CMET balloons. The CMET observations (temperature, humidity, wind-speed, pressure) provide in-situ meteorological datasets in very remote regions for comparison to atmospheric models. Controlled Meteorological (CMET) balloons are small airborne platforms that use reversible lift-gas compression to regulate altitude. These balloons have approximately the same payload mass as standard weather balloons but can float for many days, change altitude on command, and transmit meteorological and system data in near-real time via satellite. Five Controlled Meteorological (CMET) balloons were launched from Ny-Ålesund in Svalbard (Spitsbergen) over 5-12 May 2011 and measured vertical atmospheric profiles (temperature, humidity, wind) over coastal and remote areas to both the east and west. One notable CMET flight achieved a suite of 18 continuous soundings that probed the Arctic atmospheric boundary layer (ABL) over a period of more than 10 h. Profiles from two CMET flights are compared to model output from ECMWF Era-Interim reanalysis (ERA-I) and to a high-resolution (15 km) Arctic System Reanalysis (ASR) product. To the east of Svalbard over sea-ice, the CMET observed a stable ABL profile with a temperature inversion that was reproduced by ASR but not captured by ERA-I. In a coastal ice-free region to the west of Svalbard, the CMET observed a stable ABL with strong wind-shear. The CMET profiles document increases in ABL temperature and humidity that are broadly reproduced by both ASR and ERA-I. The ASR finds a more stably stratified ABL than observed but captured the wind shear in contrast to ERA-I. Detailed analysis of the coastal CMET-automated soundings identifies small-scale temperature and humidity variations with a low-level flow and provides an estimate of local wind fields. We show that CMET balloons are a valuable approach for profiling the free atmosphere and atmospheric boundary layer in remote regions such as the Arctic, where few other in-situ observations are available to trace processes and for model evaluation. References: Roberts, T. J., Dütsch, M., Hole, L. R., and Voss, P. B.: Controlled meteorological (CMET) free balloon profiling of the Arctic atmospheric boundary layer around Spitsbergen compared to ERA-Interim and Arctic System Reanalyses. Atmos. Chem. Phys., 16, 12383-12396, doi:10.5194/acp-16-12383-2016, 2016. Hole L. R., Bello A. P., Roberts T. J., Voss P. B., Vihma T.: Measurements by controlled meteorological balloons in coastal areas of Antarctica. Antarctic Science, 1-8, doi:10.1017/S0954102016000213, 2016. Voss P. B., Hole L. R., Helbling E. F., Roberts T. J.: Continuous in-situ soundings in the arctic boundary layer: a new atmospheric measurement technique using controlled meteorological balloons. Journal of Intelligent Robot Systems, 70, 609-617, doi 10.1007/s10846-012-9758-6, 2013.

EMPFASIS: A Publication of the National Electronics Manufacturing Center of Excellence

DTIC Science & Technology

2010-01-01

for moisture, salt spray, and wind driven rain protection. • Conversion to ruggedized electrical and fluid connectors. • Additional circuitry, if...computer control technology, designed for safe lead free and eutectic rework applications. Available in two models, the RD-500 series features a three-stage...shock, Temperature Humidity Bias (THB) Testing, Highly Accelerated Stress Testing (HAST), salt fog, high temperature storage, or other environmental

Effects Of Moisture On Zinc Orthotitanate Paint

NASA Technical Reports Server (NTRS)

Mon, Gordon R.; Gonzalez, Charles C.; Ross, JR., Ronald g.; Wen, Liang C.; O'Donnell, Timothy

1991-01-01

Report presents results of tests of electrical conductivity and resistance to corrosion of zinc orthotitanate (ZOT) paint. Measured effects of temperature, humidity, and vacuum on ceramic paint. Used as temperature-control coating designed to have low and stable ratio of absorptance to emittance for heat radiation. Helps to prevent buildup of static electric charge and helps to protect electronic circuitry from potentially damaging static discharges.

Influence of fine water droplets to temperature and humidity

NASA Astrophysics Data System (ADS)

Hafidzal, M. H. M.; Hamzah, A.; Manaf, M. Z. A.; Saadun, M. N. A.; Zakaria, M. S.; Roslizar, A.; Jumaidin, R.

2015-05-01

Excessively dry air can cause dry skin, dry eyes and exacerbation of medical conditions. Therefore, many researches have been done in order to increase humidity in our environment. One of the ways is by using water droplets. Nowadays, it is well known in market stand fan equipped with water mister in order to increase the humidity of certain area. In this study, the same concept is applied to the ceiling fan. This study uses a model that combines a humidifier which functions as cooler, ceiling fan and scaled down model of house. The objective of this study is to analyze the influence of ceiling fan humidifier to the temperature and humidity in a house. The mechanism of this small model uses batteries as the power source, connected to the fan and the humidifier. The small water tank's function is to store and supply water to the humidifier. The humidifier is used to cool the room by changing water phase to fine water droplets. Fine water droplets are created from mechanism of the humidifier, which is by increasing the kinetic energy of water molecule using high frequency vibration that overcome the holding force between water molecules. Thus, the molecule of water will change to state of gas or mist. The fan is used to spread out the mist of water to surrounding of the room in order to enhance the humidity. Thermocouple and humidity meter are used to measure temperature and humidity in some period of times. The result shows that humidity increases and temperature decreases with time. This application of water droplet can be applied in the vehicles and engine in order to decrease the temperature.

Design and Construction of an Inexpensive Homemade Plant Growth Chamber

PubMed Central

Katagiri, Fumiaki; Canelon-Suarez, Dario; Griffin, Kelsey; Petersen, John; Meyer, Rachel K.; Siegle, Megan; Mase, Keisuke

2015-01-01

Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W) x 1.8 m (D) x 2 m (H), providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140–250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant growth chamber will tremendously increase research opportunities in experimental plant biology. PMID:25965420

Design and construction of an inexpensive homemade plant growth chamber.

PubMed

Katagiri, Fumiaki; Canelon-Suarez, Dario; Griffin, Kelsey; Petersen, John; Meyer, Rachel K; Siegle, Megan; Mase, Keisuke

2015-01-01

Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W) x 1.8 m (D) x 2 m (H), providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140-250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant growth chamber will tremendously increase research opportunities in experimental plant biology.

Comparison of land surface humidity between observations and CMIP5 models

NASA Astrophysics Data System (ADS)

Dunn, Robert J. H.; Willett, Kate M.; Ciavarella, Andrew; Stott, Peter A.

2017-08-01

We compare the latest observational land surface humidity dataset, HadISDH, with the latest generation of climate models extracted from the CMIP5 archive and the ERA-Interim reanalysis over the period 1973 to present. The globally averaged behaviour of HadISDH and ERA-Interim are very similar in both humidity measures and air temperature, on decadal and interannual timescales. The global average relative humidity shows a gradual increase from 1973 to 2000, followed by a steep decline in recent years. The observed specific humidity shows a steady increase in the global average during the early period but in the later period it remains approximately constant. None of the CMIP5 models or experiments capture the observed behaviour of the relative or specific humidity over the entire study period. When using an atmosphere-only model, driven by observed sea surface temperatures and radiative forcing changes, the behaviour of regional average temperature and specific humidity are better captured, but there is little improvement in the relative humidity. Comparing the observed climatologies with those from historical model runs shows that the models are generally cooler everywhere, are drier and less saturated in the tropics and extra-tropics, and have comparable moisture levels but are more saturated in the high latitudes. The spatial pattern of linear trends is relatively similar between the models and HadISDH for temperature and specific humidity, but there are large differences for relative humidity, with less moistening shown in the models over the tropics and very little at high latitudes. The observed drying in mid-latitudes is present at a much lower magnitude in the CMIP5 models. Relationships between temperature and humidity anomalies (T-q and T-rh) show good agreement for specific humidity between models and observations, and between the models themselves, but much poorer for relative humidity. The T-q correlation from the models is more steeply positive than the observations in all regions, and this over-correlation may be due to missing processes in the models. The observed temporal behaviour appears to be a robust climate feature rather than observational error. It has been previously documented and is theoretically consistent with faster warming rates over land compared to oceans. Thus, the poor replication in the models, especially in the atmosphere-only model, leads to questions over future projections of impacts related to changes in surface relative humidity. It also precludes any formal detection and attribution assessment.

Reference dosimetry using radiochromic film

PubMed Central

Girard, Frédéric; Bouchard, Hugo

2012-01-01

The objectives of this study are to identify and quantify factors that influence radiochromic film dose response and to determine whether such films are suitable for reference dosimetry. The influence of several parameters that may introduce systematic dose errors when performing reference dose measurements were investigated. The effect of the film storage temperature was determined by comparing the performance of three lots of GAFCHROMIC EBT2 films stored at either 4°C or room temperature. The effect of high (>80%) or low (<20%) relative humidity was also determined. Doses measured in optimal conditions with EBT and EBT2 films were then compared with an A12 ionization chamber measurement. Intensity‐modulated radiation therapy quality controls using EBT2 films were also performed in reference dose. The results obtained using reference dose measurements were compared with those obtained using relative dose measurements. Storing the film at 4°C improves the stability of the film over time, but does not eliminate the noncatalytic film development, seen as a rise in optical density over time in the absence of radiation. Relative humidity variations ranging from 80% to 20% have a strong impact on the optical density and could introduce dose errors of up to 15% if the humidity were not controlled during the film storage period. During the scanning procedure, the film temperature influences the optical density that is measured. When controlling for these three parameters, the dose differences between EBT or EBT2 and the A12 chamber are found to be within ±4% (2σ level) over a dose range of 20–350 cGy. Our results also demonstrate the limitation of the Anisotropic Analytical Algorithm for dose calculation of highly modulated treatment plans. PACS numbers: 87.55.Qr; 87.56.Fc PMID:23149793

Air temperature optimisation for humidity-controlled cold storage of the predatory mites Neoseiulus californicus and Phytoseiulus persimilis (Acari: Phytoseiidae).

PubMed

Ghazy, Noureldin Abuelfadl; Suzuki, Takeshi; Amano, Hiroshi; Ohyama, Katsumi

2014-03-01

Humidity-controlled cold storage, in which the water vapour pressure is saturated, can prolong the survival of the predatory mites Neoseiulus californicus (McGregor) and Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae). However, information on the optimum air temperature for long-term storage by this method is limited. The authors evaluated the survival of mated adult females of N. californicus and P. persimilis at 5.0, 7.5, 10.0 and 12.5 °C under saturated water vapour condition (vapour pressure deficit 0.0 kPa). N. californicus showed a longer survival time than P. persimilis at all the air temperatures. The longest mean survival time of N. californicus was 11 weeks at 7.5 °C, whereas that of P. persimilis was 8 weeks at 5.0 °C. After storage at 7.5 °C for 8 weeks, no negative effect on post-storage oviposition was observed in N. californicus, whereas the oviposition of P. persimilis stored at 5.0 °C for 8 weeks was significantly reduced. The interspecific variation in the response of these predators to low air temperature might be attributed to their natural habitat and energy requirements. These results may be useful for the long-term storage of these predators, which is required for cost-effective biological control. © 2013 Society of Chemical Industry.

Radio-Frequency-Based NH3-Selective Catalytic Reduction Catalyst Control: Studies on Temperature Dependency and Humidity Influences

PubMed Central

Dietrich, Markus; Hagen, Gunter; Reitmeier, Willibald; Burger, Katharina; Hien, Markus; Grass, Philippe; Kubinski, David; Visser, Jaco; Moos, Ralf

2017-01-01

The upcoming more stringent automotive emission legislations and current developments have promoted new technologies for more precise and reliable catalyst control. For this purpose, radio-frequency-based (RF) catalyst state determination offers the only approach for directly measuring the NH3 loading on selective catalytic reduction (SCR) catalysts and the state of other catalysts and filter systems. Recently, the ability of this technique to directly control the urea dosing on a current NH3 storing zeolite catalyst has been demonstrated on an engine dynamometer for the first time and this paper continues that work. Therefore, a well-known serial-type and zeolite-based SCR catalyst (Cu-SSZ-13) was investigated under deliberately chosen high space velocities. At first, the full functionality of the RF system with Cu-SSZ-13 as sample was tested successfully. By direct RF-based NH3 storage control, the influence of the storage degree on the catalyst performance, i.e., on NOx conversion and NH3 slip, was investigated in a temperature range between 250 and 400 °C. For each operation point, an ideal and a critical NH3 storage degree was found and analyzed in the whole temperature range. Based on the data of all experimental runs, temperature dependent calibration functions were developed as a basis for upcoming tests under transient conditions. Additionally, the influence of exhaust humidity was observed with special focus on cold start water and its effects to the RF signals. PMID:28704929

Radio-Frequency-Based NH₃-Selective Catalytic Reduction Catalyst Control: Studies on Temperature Dependency and Humidity Influences.

PubMed

Dietrich, Markus; Hagen, Gunter; Reitmeier, Willibald; Burger, Katharina; Hien, Markus; Grass, Philippe; Kubinski, David; Visser, Jaco; Moos, Ralf

2017-07-12

The upcoming more stringent automotive emission legislations and current developments have promoted new technologies for more precise and reliable catalyst control. For this purpose, radio-frequency-based (RF) catalyst state determination offers the only approach for directly measuring the NH₃ loading on selective catalytic reduction (SCR) catalysts and the state of other catalysts and filter systems. Recently, the ability of this technique to directly control the urea dosing on a current NH₃ storing zeolite catalyst has been demonstrated on an engine dynamometer for the first time and this paper continues that work. Therefore, a well-known serial-type and zeolite-based SCR catalyst (Cu-SSZ-13) was investigated under deliberately chosen high space velocities. At first, the full functionality of the RF system with Cu-SSZ-13 as sample was tested successfully. By direct RF-based NH₃ storage control, the influence of the storage degree on the catalyst performance, i.e., on NO x conversion and NH₃ slip, was investigated in a temperature range between 250 and 400 °C. For each operation point, an ideal and a critical NH₃ storage degree was found and analyzed in the whole temperature range. Based on the data of all experimental runs, temperature dependent calibration functions were developed as a basis for upcoming tests under transient conditions. Additionally, the influence of exhaust humidity was observed with special focus on cold start water and its effects to the RF signals.

Physical activity profile of 2014 FIFA World Cup players, with regard to different ranges of air temperature and relative humidity

NASA Astrophysics Data System (ADS)

Chmura, Paweł; Konefał, Marek; Andrzejewski, Marcin; Kosowski, Jakub; Rokita, Andrzej; Chmura, Jan

2017-04-01

The present study attempts to assess changes in soccer players' physical activity profiles under the simultaneous influence of the different combinations of ambient temperature and relative humidity characterising matches of the 2014 FIFA World Cup hosted by Brazil. The study material consisted of observations of 340 players representing 32 national teams taking part in the tournament. The measured indices included total distances covered; distances covered with low, moderate, or high intensity; numbers of sprints performed, and peak running speeds achieved. The analysis was carried out using FIFA official match data from the Castrol Performance Index system. Ultimately, consideration was given to a combination of three air temperature ranges, i.e. below 22 °C, 22-28 °C, and above 28 °C; and two relative humidity ranges below 60 % and above 60 %. The greatest average distance recorded (10.54 ± 0.91 km) covered by players at an air temperature below 22 °C and a relative humidity below 60 %, while the shortest (9.83 ± 1.08 km) characterised the same air temperature range, but conditions of relative humidity above 60 % ( p ≤ 0.001). Two-way ANOVA revealed significant differences ( p ≤ 0.001) in numbers of sprints performed by players, depending on whether the air temperature range was below 22 °C (40.48 ± 11.17) or above 28 °C (30.72 ± 9.40), but only where the relative humidity was at the same time below 60 %. Results presented indicate that the conditions most comfortable for physical activity on the part of players occur at 22 °C, and with relative humidity under 60 %.

Intercomparison Between Microwave Radiometer and Radiosonding Data

NASA Astrophysics Data System (ADS)

Toanca, Florica; Stefan, Sabina

2014-05-01

The aim of this study is to compare relative humidity and temperature vertical profiles measured by ground based Microwave Radiometer (MWR) RPG HATPRO installed at the Romanian Atmospheric Observatory (Magurele, 44.35 N, 26.03 E) and by radio-sounding (RS) (Baneasa, 44.30 N, 26.04 E) provided by National Meteorological Administration. MWR uses passive microwave detection in the 22.335 to 31.4 GHz and 51to 58 GHz bands to obtain the vertical profiles of temperature and relative humidity up to 10km with a temporal resolution of several minutes. The reliability of atmospheric temperature and relative humidity profiles retrieved continuously by the MWR for the winter and summer of year 2013 was studied. The study was conducted, comparing the temperature and humidity profiles from the MWR with the ones from the radio soundings at 0:00 a.m. Two datasets of the humidity show a fairly good agreement for the interval between ground and 1.5 km in the January month for winter and up to 2 km in the July month for summer. Above 2 km, for the both seasons, the humidity profiles present in most of the selected cases the same trend evolution. The temperature vertical profiles agreed in 95% of the cases during summer and 85% during winter. It is very important for intercomparison that for both seasons almost all temperature vertical profiles highlight temperature inversions. Two cases have been analyzed in order to find possible explanations for the discrepancies between vertical profiles, focusing on advantages and disadvantages of MWR measurements.

A practical method for measuring the ion exchange capacity decrease of hydroxide exchange membranes during intrinsic degradation

NASA Astrophysics Data System (ADS)

Kreuer, Klaus-Dieter; Jannasch, Patric

2018-01-01

In this work we present a practical thermogravimetric method for quantifying the IEC (ion exchange capacity) decrease of hydroxide exchange membranes (HEMs) during intrinsic degradation mainly occurring through nucleophilic attack of the anion exchanging group by hydroxide ions. The method involves measuring weight changes under controlled temperature and relative humidity. These conditions are close to these in a fuel cell, i.e. the measured degradation rate includes all effects originating from the polymeric structure, the consumption of hydroxide ions and the release of water. In particular, this approach involves no added solvents or base, thereby avoiding inaccuracies that may arise in other methods due to the presence of solvents (other than water) or co-ions (such as Na+ or K+). We demonstrate the method by characterizing the decomposition of membranes consisting of poly(2,6-dimethyl-1,4-phenylene oxide) functionalized with trimethyl-pentyl-ammonium side chains. The decomposition rate is found to depend on temperature, relative humidity RH (controlling the hydration number λ) and the total water content (controlled by the actual IEC and RH).

Comparative studies of the influence of relative humidity and temperature on the longevity and fecundity of the parasitoid, Cotesia flavipes.

PubMed

G D, Emana

2007-01-01

The parasitoid, Cotesia flavipes (Cameron) (Hymenoptera: Braconidae), was introduced for biological control of the stemborer, Chilo partellus (Swinhoe) (Lepidoptera: Crambidae), in eastern and southern African countries. The parasitoid became firmly established in Ethiopia, with varying density and distribution in various regions of the country indicating that there are factors regulating the success of the parasitoid. From previous studies, it was known that the population of the parasitoid released, the type of host, and temperature highly affect some of the biological parameters of the parasitoid. The current studies were undertaken to understand the individual and interactive effect of temperature and relative humidity on the longevity and fecundity of C. flavipes. The study was conducted on C. flavipes collected from the Melkassa Agricultural Research Center Experimental Field, Ethiopia. C. flavipes was reared in the laboratory on C. partellus feeding on pieces of sorghum stem. The longevity experiment was conducted at 10, 20, 30 and 40 degrees C, while the fecundity experiment was conducted at 20, 25, 28 and 30 degrees C. For both experiments 40-50%, 60-70% and 80-90% relative humidity regimes were used. The results obtained indicate that the interactive effect of temperature and relative humidity significantly affected the longevity, the number of oocytes, and fecundity of C. flavipes implying that the two factors play an important role in the success of the parasitoid as a biocontrol agent against C. partellus. The results obtained suggests the importance of the selection of target release sites for maximum efficiency of the parasitoid, which can have a positive impact on the on-going augmentative release of C. flavipes in Ethiopia.

Humidification of base flow gas during adult high-frequency oscillatory ventilation: an experimental study using a lung model.

PubMed

Shiba, Naoki; Nagano, Osamu; Hirayama, Takahiro; Ichiba, Shingo; Ujike, Yoshihito

2012-01-01

In adult high-frequency oscillatory ventilation (HFOV) with an R100 artificial ventilator, exhaled gas from patient's lung may warm the temperature probe and thereby disturb the humidification of base flow (BF) gas. We measured the humidity of BF gas during HFOV with frequencies of 6, 8 and 10 Hz, maximum stroke volumes (SV) of 285, 205, and 160 ml at the respective frequencies, and, BFs of 20, 30, 40 l/min using an original lung model. The R100 device was equipped with a heated humidifier, Hummax Ⅱ, consisting of a porous hollow fiber in circuit. A 50-cm length of circuit was added between temperature probe (located at 50 cm proximal from Y-piece) and the hollow fiber. The lung model was made of a plastic container and a circuit equipped with another Hummax Ⅱ. The lung model temperature was controlled at 37℃. The Hummax Ⅱ of the R100 was inactivated in study-1 and was set at 35℃ or 37℃ in study-2. The humidity was measured at the distal end of the added circuit in study-1 and at the proximal end in study-2. In study-1, humidity was detected at 6 Hz (SV 285 ml) and BF 20 l/min, indicating the direct reach of the exhaled gas from the lung model to the temperature probe. In study-2 the absolute humidity of the BF gas decreased by increasing SV and by increasing BF and it was low with setting of 35℃. In this study setting, increasing the SV induced significant reduction of humidification of the BF gas during HFOV with R100.

Use of Giovanni System in Public Health Application

NASA Technical Reports Server (NTRS)

Soebiyanto, Radina; Kiang, Richard K.

2012-01-01

The role of environment and climate in propagating infectious disease has long been recognized since the 5th century. The effect is particularly evident in vector-borne diseases such as malaria where temperature, precipitation and humidity influence the lifecycle of the pathogens and mosquitoes. Likewise, the transmission of respiratory diseases is also often associated with climatic factors. For example, a recent study showed that low humidity and temperature provides efficient condition for seasonal influenza transmission. Understanding of how environment and climate affect infectious diseases would essentially provide guides to prevent and control the spread of disease. Toward this end, our group has developed models for infectious disease risk such as for malaria, dengue and influenza that are driven by climatic and environmental inputs. Results will be presented, especially those that used TRMM data from GIOVANNI.

Using Model Helicopters for Meteorological Observations in Support of Tornado Forecasting

NASA Astrophysics Data System (ADS)

Harrison, William; Roscoe, Bryan; Schafer, David; Bluestein, Howard; Lary, David

2012-10-01

In order to gain a better understanding of the physical factors involved in tornadogenesis, a complete 3-D profile of winds, temperature, and humidity in the forward-flank and rear-flank gust front regions in supercells is required. Conventional methods of making comparative measurements in and around storms are very limited. Measurements that comprehensively profile the boundary layer winds and thermodynamics are valuable but rare. A better understanding of the physical properties in these boundary layers will improve forecasts and increase warning times in affected areas. Remote-controlled model helicopters are a uniquely qualified platform for this application, allowing us to fully profile these boundary layers. Our system will consist of a swarm of autonomous acrobatic helicopters, each outfitted with temperature, pressure, humidity, and wind speed sensors.

Evaporative cooling of speleothem drip water

PubMed Central

Cuthbert, M. O.; Rau, G. C.; Andersen, M. S.; Roshan, H.; Rutlidge, H.; Marjo, C. E.; Markowska, M.; Jex, C. N.; Graham, P. W.; Mariethoz, G.; Acworth, R. I.; Baker, A.

2014-01-01

This study describes the first use of concurrent high-precision temperature and drip rate monitoring to explore what controls the temperature of speleothem forming drip water. Two contrasting sites, one with fast transient and one with slow constant dripping, in a temperate semi-arid location (Wellington, NSW, Australia), exhibit drip water temperatures which deviate significantly from the cave air temperature. We confirm the hypothesis that evaporative cooling is the dominant, but so far unattributed, control causing significant disequilibrium between drip water and host rock/air temperatures. The amount of cooling is dependent on the drip rate, relative humidity and ventilation. Our results have implications for the interpretation of temperature-sensitive, speleothem climate proxies such as δ18O, cave microecology and the use of heat as a tracer in karst. Understanding the processes controlling the temperature of speleothem-forming cave drip waters is vital for assessing the reliability of such deposits as archives of climate change. PMID:24895139

Comparison of microclimate in various land-use systems in Sumatra, Indonesia

NASA Astrophysics Data System (ADS)

Shekhar Badu, Chandra; Meijide, Ana; Gunawan, Dodo; Knohl, Alexander

2017-04-01

Deforestation and land-use changes are ongoing problems for rain forests in Indonesia. The conversion of forests to monocultures of rubber and oil palm plantations reduces not only biodiversity and carbon pools but also affects canopy structure, which is an important determinant of microclimate. There is, however, a lack of quantitative information characterizing the effect of land transformation on microclimate with a systematic experimental design. Here, we report observations microclimatic conditions (air temperature, relative humidity, soil moisture and soil temperature) on a daily, weekly and seasonal basis across four land-use systems (rain forest, jungle rubber, rubber plantation, oil palm plantation) in two near-by landscapes. The data set covers a period of approximately three years from April 2013 to March 2016 and includes one of the strongest El Nino-Southern Oscillation (ENSO) of the last decades. Mean air temperature, soil temperature, relative humidity, and vapour pressure deficit differed significantly between the four land-use systems whereas the mean soil moisture differed significantly between two landscapes. Air temperature, vapour pressure deficit and soil temperature were highest in oil palm and rubber plantations whereas lowest in forest and jungle rubber. Canopy openness was the most dominant control of microclimatic differences across the land-use systems. During the ENSO 2015, a significant increase in mean air temperature, soil temperature and vapour pressure deficit but a decrease in relative air humidity and soil moisture in all four land-use systems was found. The relative effect of ENSO was highest in forest and jungle rubber compared to rubber and oil palm plantations. In conclusion, conversion of forest to rubber and oil palm plantations has led to substantially warmer and drier microclimatic conditions than before.

Temperature effect on phase state and reactivity controls atmospheric multiphase chemistry and transport of PAHs.

PubMed

Mu, Qing; Shiraiwa, Manabu; Octaviani, Mega; Ma, Nan; Ding, Aijun; Su, Hang; Lammel, Gerhard; Pöschl, Ulrich; Cheng, Yafang

2018-03-01

Polycyclic aromatic hydrocarbons like benzo( a )pyrene (BaP) in atmospheric particulate matter pose a threat to human health because of their high carcinogenicity. In the atmosphere, BaP is mainly degraded through a multiphase reaction with ozone, but the fate and atmospheric transport of BaP are poorly characterized. Earlier modeling studies used reaction rate coefficients determined in laboratory experiments at room temperature, which may overestimate/underestimate degradation rates when applied under atmospheric conditions. Moreover, the effects of diffusion on the particle bulk are not well constrained, leading to large discrepancies between model results and observations. We show how regional and global distributions and transport of BaP can be explained by a new kinetic scheme that provides a realistic description of the temperature and humidity dependence of phase state, diffusivity, and reactivity of BaP-containing particles. Low temperature and humidity can substantially increase the lifetime of BaP and enhance its atmospheric dispersion through both the planetary boundary layer and the free troposphere. The new scheme greatly improves the performance of multiscale models, leading to better agreement with observed BaP concentrations in both source regions and remote regions (Arctic), which cannot be achieved by less-elaborate degradation schemes (deviations by multiple orders of magnitude). Our results highlight the importance of considering temperature and humidity effects on both the phase state of aerosol particles and the chemical reactivity of particulate air pollutants.

Airway humidification with a heat and moisture exchanger in mechanically ventilated neonates : a preliminary evaluation.

PubMed

Fassassi, Mikaïla; Michel, Fabrice; Thomachot, Laurent; Nicaise, Claire; Vialet, Renaud; Jammes, Yves; Lagier, Pierre; Martin, Claude

2007-02-01

We set out to evaluate the efficacy of passive inspiratory gas conditioning in mechanically ventilated neonates and compared it with that of a heated humidifier (HH). Prospective, randomized, controlled study. Neonatal and pediatric intensive care unit. Fourteen mechanically ventilated neonates nursed in incubators. The HH was set to deliver a temperature of 37 degrees C and an absolute humidity of 40 mgH(2)O/l at the incubator entrance. Inspired temperature (T degrees ) and absolute humidity (AH) were measured by the psychometric method, transpulmonary pressure (Tpres) by means of a differential pressure transducer. Measurements were performed at 5, 10, and 15 min. The values of T degrees were significantly higher using the HH (34.6+/-1.6 degrees C) than the heat and moisture exchanger (HME) (33.8+/2.3, p<0.001). The values of AH were significantly higher using the HH (36.6+/-2.5 mgH(2)O/l) than the HME (32.4+/-2.8 mgH(2)O/l, p<0.001). No significant changes were observed in transpulmonary pressure. A significant positive correlation was observed between incubator temperature and the temperature delivered by the HH (R(2)=0.61, p<0.001). The use of HMEs in neonates made it possible to achieve an absolute humidity of 28 mgH(2)O/l or more and a temperature of 30 degrees C or more. Higher values are obtained using a HH.

Thermoregulatory, cardiovascular, and perceptual responses to intermittent cooling during exercise in a hot, humid outdoor environment.

PubMed

Cleary, Michelle A; Toy, Michelle G; Lopez, Rebecca M

2014-03-01

Decreasing core body temperature during exercise may improve exercise tolerance, facilitate acclimatization, and prevent heat illness during summer training. We sought to evaluate the effectiveness of intermittent superficial cooling on thermoregulatory, cardiovascular, and perceptual responses during exercise in a hot humid environment. We used a randomized, counterbalanced, repeated measures investigation with 2 conditions (control and cooling) during exercise and recovery outdoors on artificial turf in a hot, humid tropical climate in the sun (wet bulb globe temperature outdoors [WBGTo], 27.0 ± 0.8° C; range, 25.8-28.1° C) and in the shade (WBGTo, 25.4 ± 0.9° C; range, 24.3-26.8° C). Participants were 10 healthy males (age, 22.6 ± 1.6 years; height, 176.0 ± 6.9 cm; mass, 76.5 ± 7.8 kg; body fat, 15.6 ± 5.4%) who wore shorts and T-shirt (control) or "phase change cooling" vest (cooling) during 5-minute rest breaks during 60 minutes of intense American football training and conditioning exercises in the heat and 30 minutes of recovery in the shade. Throughout, we measured core (Tgi) and skin (Tchest) temperature, heart rate (HR), thermal and thirst sensations, and rating of perceived exertion. We found significant (p ≤ 0.001) hypohydration (-2.1%); for Tgi, we found no significant differences between conditions (p = 0.674) during exercise and progressive decreases during recovery (p < 0.001). For [INCREMENT]Tg,i we found no significant (p = 0.090) differences. For Tchest, we found significantly (p < 0.001) decreased skin temperature in the cooling condition (Tchest, 31.85 ± 0.43° C) compared with the control condition (Tchest, 34.38 ± 0.43° C) during exercise and significantly (p < 0.001) lower skin temperature in the cooling condition (Tchest, 31.24 ± 0.47° C) compared with the control condition (Tchest, 33.48 ± 0.47° C) during recovery. For HR, we found no significant difference (p = 0.586) between the conditions during exercise; however, we did find significantly (p < 0.001) lower HR during recovery. Thermal sensations were significantly (p = 0.026) decreased in the cooling (4.4 ± 0.2 points) compared with the control (5.0 ± 0.2 points) condition but not for other perceptual responses. The cooling effects of "phase change cooling" material were effective in reducing skin temperature but did not sufficiently reduce core body temperature or cardiovascular strain.

Fast, high sensitivity dewpoint hygrometer

NASA Technical Reports Server (NTRS)

Hoenk, Michael E. (Inventor)

1998-01-01

A dewpoint/frostpoint hygrometer that uses a surface moisture-sensitive sensor as part of an RF oscillator circuit with feedback control of the sensor temperature to maintain equilibrium at the sensor surface between ambient water vapor and condensed water/ice. The invention is preferably implemented using a surface acoustic wave (SAW) device in an RF oscillator circuit configured to generate a condensation-dependent output signal, a temperature sensor to measure the temperature of the SAW device and to distinguish between condensation-dependent and temperature-dependent signals, a temperature regulating device to control the temperature of the SAW device, and a feedback control system configured to keep the condensation-dependent signal nearly constant over time in the presence of time-varying humidity, corrected for temperature. The effect of this response is to heat or cool the surface moisture-sensitive device, which shifts the equilibrium with respect to evaporation and condensation at the surface of the device. The equilibrium temperature under feedback control is a measure of dewpoint or frostpoint.

Humid Heat Waves at different warming levels

NASA Astrophysics Data System (ADS)

Russo, S.; Sillmann, J.; Sterl, A.

2017-12-01

The co-occurrence of consecutive hot and humid days during a heat wave can strongly affect human health. Here, we quantify humid heat wave hazard in the recent past and at different levels of global warming.We find that the magnitude and apparent temperature peak of heat waves, such as the ones observed in Chicago in 1995 and China in 2003, have been strongly amplified by humidity. Climate model projections suggest that the percentage of area where heat wave magnitude and peak are amplified by humidity increases with increasing warming levels. Considering the effect of humidity at 1.5o and 2o global warming, highly populated regions, such as the Eastern US and China, could experience heat waves with magnitude greater than the one in Russia in 2010 (the most severe of the present era).The apparent temperature peak during such humid-heat waves can be greater than 55o. According to the US Weather Service, at this temperature humans are very likely to suffer from heat strokes. Humid-heat waves with these conditions were never exceeded in the present climate, but are expected to occur every other year at 4o global warming. This calls for respective adaptation measures in some key regions of the world along with international climate change mitigation efforts.

The radiative versus entraining effects of overlying humidity on the Lagrangian evolution of subtropical stratocumulus

NASA Astrophysics Data System (ADS)

Eastman, R. M.; Wood, R.

2017-12-01

This study observes the 24-hour Lagrangian evolution of stratocumulus cloud amount and PBL depth in four eastern subtropical ocean basins: the NE Pacific, SE Pacific, SE Atlantic, and E Indian. Nearly 170,000 trajectories are computed using the 2-D wind field at 925mb and cloud properties are sampled along these trajectories twice daily as the A-Train satellite constellation passes overhead. Concurrent measurements of the overlying humidity and temperature profiles are interpolated from the ERA-Interim reanalysis grids. Cloud properties are sampled by MODIS and a measure of planetary boundary layer (PBL) depth is calculated using MODIS cloud top temperatures, CALIPSO lidar observations of cloud top heights, and ERA-Interim sea surface temperatures. High humidity overlying the PBL can reduce cloud top cooling by counteracting radiative cooling and by reducing evaporation within the entrainment zone. Both of these effects can slow the entrainment rate and change cloud evolution. To discern which effect is more important the humidity profile is broken into two distinct components: the specific humidity directly above the inversion, which is entraining into the boundary layer, and the column of specific humidity above that layer, which is radiatively interacting with the PBL, but not directly entraining. These two measures of humidity are compared in the Lagrangian framework. Results suggest that humidity above the PBL has a stronger effect on the Lagrangian PBL deepening rate compared to lower tropospheric stability. A comparison of PBL deepening rates driven by the entraining humidity versus the radiating humidity shows that the radiative effects of overlying humidity are dominant with respect to entrainment. However, the entraining effects of humidity are more important in prolonging cloud lifetime.

Potential impact of climate variability on respiratory diseases in infant and children in Semarang

NASA Astrophysics Data System (ADS)

Budiyono; Rismawati; Jati, S. P.; Ginandjar, P.

2017-02-01

Temperature, humidity, and rainfall may influence respiratory disease, including acute respiratory infection (ARI) and pneumonia. In Semarang, the temperature and humidity has increased 0.1°C and 1.6% respectively during 2002-2011. ARI and pneumonia in children under 5 years had increased during 2012-2014. This study aimed to analyze the relationship of climate variability and ARI and pneumonia incidence. It was an ecological study. Subject consisted of patients visited primary health care of Bandarharjo from 2011 to 2015. Pneumonia was related to infants (<1-year-old) and children (1-4 years old), while ARI was related to children (≥5 years old). Data of climate was obtained from Agency for Meteorology, Climatology and Geophysics (BMKG) Semarang. Pearson correlation (α=0.05) was used to analyse the correlation of the 60 samples. Mean of temperature was 27.96° C, relative humidity was 74.73%, and rainfall was 179.98 mm/month. The total of ARI was 38523 cases and pneumonia was 1558 cases. Temperature, humidity, and rainfall had no correlation to pneumonia. Humidity had a significant correlation to ARI on female children and total ARI (r=0.3 and r=0.26; p-value=0.02 and 0.04 respectively). Rainfall and temperature had no correlation to total ARI. This study concluded humidity has potential impact to ARI.

Physiological responses during continuous work in hot dry and hot humid environments in Indians

NASA Astrophysics Data System (ADS)

Sen Gupta, J.; Swamy, Y. V.; Pichan, G.; Dimri, G. P.

1984-06-01

Studies have been conducted on six young healthy heat acclimatised Indians to determine the physiological changes in prolonged continuous work in thermally neutral and in hot dry and hot humid environments. Physiological responses in maximal efforts i.e. Vo2 max, VE max and Cf max were noted. In addition, duration in continuous work at three sub-maximal rate of work in three simulated environments were also noted. Physiological responses like Vo2, VE and Cf were noted every 15 minutes of work. Besides these responses, rectal temperature (Tre), mean skin temperature (Ts) and mean sweat rate were also recorded during continuous work. Results indicated a significant decrease in maximum oxygen uptake capacity (Vo2 max) in heat with no change in maximum exercise ventilation (VE max) and maximum cardiac frequency. However, the fall in Vo2 max was more severe in the hot humid environment than in the hot dry climate. Cardiac frequency at fixed oxygen consumption of 1.0, 1.5 and 2.0 l/min was distinctly higher in the hot humid environment than in the hot dry and comfortable temperature. The duration in continuous physical effort in various grades of activities decreased in hot dry environment from that in the-comfortable climate and further decreased significantly in hot humid environment. The highest rate of sweating was observed during work in humid heat. The mean skin temperature (Ts) showed a fall in all the three rates of work in comfortable and hot dry conditions whereas in hot humid environment it showed a linear rise during the progress of work. The rectal temperature on the other hand maintained a near steady state while working at 65 and 82 watts in comfortable and hot dry environments but kept on rising during work in hot humid environment. At the highest work rate of 98 watts, the rectal temperature showed a steady increase even in the hot dry condition. It was thus concluded from the study that a hot humid climate imposes more constraints on the thermoregulatory system during work than in the hot dry condition because of less effective heat dissipation so resulting in reduced tolerance to work.

Characterization of humidity-controlling porous ceramics produced from coal fly ash and waste catalyst by co-sintering

NASA Astrophysics Data System (ADS)

Lin, Kae-Long; Ma, Chih-Ming; Lo, Kang-Wei; Cheng, Ta-Wui

2018-04-01

In this study, the following operating conditions were applied to develop humidity-controlling porous ceramic (HCPC) products: sintering temperatures of 800-1000 °C and percentages of coal fly ash in waste catalyst of 0%-40%. The HCPC samples then underwent a flexural strength test, to determine their quality according to the Chinese National Standards (CNS 3298). Their microstructures, crystal structures, and pore volume were determined in terms of equilibrium moisture content, water vapor adsorption/desorption, and hygroscopic sorption properties over 48 h. Nitrogen adsorption/desorption isotherms showed a hydrophobic behavior (type H3 isotherm). The water vapor adsorption/desorption and hygroscopic sorption properties satisfied the JIS A1470 intensity specification for building materials (>29 g/m2). At sintering temperatures of 950-1000 °C, HCPC samples for coal fly ash containing 20%-30% waste catalyst met the JIS A1470 intensity specifications for building materials (<29 g/m2).

Comparative transcriptome profiling of a thermal resistant vs. sensitive silkworm strain in response to high temperature under stressful humidity condition

PubMed Central

Xiao, Jinshu; Wang, La; Liu, Taihang; Wu, Yunfei; Dong, Feifan; Jiang, Yaming; Pan, Minhui; Zhang, Youhong; Lu, Cheng

2017-01-01

Thermotolerance is important particularly for poikilotherms such as insects. Understanding the mechanisms by which insects respond to high temperatures can provide insights into their adaptation to the environment. Therefore, in this study, we performed a transcriptome analysis of two silkworm strains with significantly different resistance to heat as well as humidity; the thermo-resistant strain 7532 and the thermos-sensitive strain Knobbed. We identified in total 4,944 differentially expressed genes (DEGs) using RNA-Seq. Among these, 4,390 were annotated and 554 were novel. Gene Ontology (GO) analysis of 747 DEGs identified between RT_48h (Resistant strain with high-temperature Treatment for 48 hours) and ST_48h (Sensitive strain with high-temperature Treatment for 48 hours) showed significant enrichment of 12 GO terms including metabolic process, extracellular region and serine-type peptidase activity. Moreover, we discovered 12 DEGs that may contribute to the heat-humidity stress response in the silkworm. Our data clearly showed that 48h post-exposure may be a critical time point for silkworm to respond to high temperature and humidity. These results provide insights into the genes and biological processes involved in high temperature and humidity tolerance in the silkworm, and advance our understanding of thermal tolerance in insects. PMID:28542312

Comparative transcriptome profiling of a thermal resistant vs. sensitive silkworm strain in response to high temperature under stressful humidity condition.

PubMed

Xiao, Wenfu; Chen, Peng; Xiao, Jinshu; Wang, La; Liu, Taihang; Wu, Yunfei; Dong, Feifan; Jiang, Yaming; Pan, Minhui; Zhang, Youhong; Lu, Cheng

2017-01-01

Thermotolerance is important particularly for poikilotherms such as insects. Understanding the mechanisms by which insects respond to high temperatures can provide insights into their adaptation to the environment. Therefore, in this study, we performed a transcriptome analysis of two silkworm strains with significantly different resistance to heat as well as humidity; the thermo-resistant strain 7532 and the thermos-sensitive strain Knobbed. We identified in total 4,944 differentially expressed genes (DEGs) using RNA-Seq. Among these, 4,390 were annotated and 554 were novel. Gene Ontology (GO) analysis of 747 DEGs identified between RT_48h (Resistant strain with high-temperature Treatment for 48 hours) and ST_48h (Sensitive strain with high-temperature Treatment for 48 hours) showed significant enrichment of 12 GO terms including metabolic process, extracellular region and serine-type peptidase activity. Moreover, we discovered 12 DEGs that may contribute to the heat-humidity stress response in the silkworm. Our data clearly showed that 48h post-exposure may be a critical time point for silkworm to respond to high temperature and humidity. These results provide insights into the genes and biological processes involved in high temperature and humidity tolerance in the silkworm, and advance our understanding of thermal tolerance in insects.

Effects of Heat Wave on Body Temperature and Blood Pressure in the Poor and Elderly

PubMed Central

Kim, Soyeon; Cheong, Hae-Kwan; Ahn, Byungok; Choi, Kyusik

2012-01-01

Objectives We aimed to investigate the acute effects of heat stress on body temperature and blood pressure of elderly individuals living in poor housing conditions. Methods Repeated measurements of the indoor temperature, relative humidity, body temperature, and blood pressure were conducted for 20 elderly individuals living in low-cost dosshouses in Seoul during hot summer days in 2010. Changes in the body temperature, systolic blood pressure (SBP) and diastolic blood pressure (DBP) according to variations in the indoor and outdoor temperature and humidity were analyzed using a repeated-measures ANOVA controlling for age, sex, alcohol, and smoking. Results Average indoor and outdoor temperatures were 31.47℃ (standard deviation [SD], 0.97℃) and 28.15℃ (SD, 2.03℃), respectively. Body temperature increased by 0.21℃ (95% confidence interval [CI], 0.16 to 0.26℃) and 0.07℃ (95% CI, 0.04 to 0.10℃) with an increase in the indoor and outdoor temperature of 1℃. DBP decreased by 2.05 mmHg (95% CI, 0.05 to 4.05 mmHg), showing a statistical significance, as the indoor temperature increased by 1℃, while it increased by 0.20 mmHg (95% CI, -0.83 to 1.22 mmHg) as outdoor temperature increased by 1℃. SBP decreased by 1.75 mmHg (95% CI, -1.11 to 4.61 mmHg) and 0.35 mmHg (95% CI, -1.04 to 1.73 mmHg), as the indoor and outdoor temperature increased by 1℃, respectively. The effects of relative humidity on SBP and DBP were not statistically significant for both indoor and outdoor. Conclusions The poor and elderly are directly exposed to heat waves, while their vital signs respond sensitively to increase in temperature. Careful adaptation strategies to climate change considering socioeconomic status are therefore necessary. PMID:22888472

Effects of heat wave on body temperature and blood pressure in the poor and elderly.

PubMed

Kim, Young-Min; Kim, Soyeon; Cheong, Hae-Kwan; Ahn, Byungok; Choi, Kyusik

2012-01-01

We aimed to investigate the acute effects of heat stress on body temperature and blood pressure of elderly individuals living in poor housing conditions. Repeated measurements of the indoor temperature, relative humidity, body temperature, and blood pressure were conducted for 20 elderly individuals living in low-cost dosshouses in Seoul during hot summer days in 2010. Changes in the body temperature, systolic blood pressure (SBP) and diastolic blood pressure (DBP) according to variations in the indoor and outdoor temperature and humidity were analyzed using a repeated-measures ANOVA controlling for age, sex, alcohol, and smoking. Average indoor and outdoor temperatures were 31.47℃ (standard deviation [SD], 0.97℃) and 28.15℃ (SD, 2.03℃), respectively. Body temperature increased by 0.21℃ (95% confidence interval [CI], 0.16 to 0.26℃) and 0.07℃ (95% CI, 0.04 to 0.10℃) with an increase in the indoor and outdoor temperature of 1℃. DBP decreased by 2.05 mmHg (95% CI, 0.05 to 4.05 mmHg), showing a statistical significance, as the indoor temperature increased by 1℃, while it increased by 0.20 mmHg (95% CI, -0.83 to 1.22 mmHg) as outdoor temperature increased by 1℃. SBP decreased by 1.75 mmHg (95% CI, -1.11 to 4.61 mmHg) and 0.35 mmHg (95% CI, -1.04 to 1.73 mmHg), as the indoor and outdoor temperature increased by 1℃, respectively. The effects of relative humidity on SBP and DBP were not statistically significant for both indoor and outdoor. The poor and elderly are directly exposed to heat waves, while their vital signs respond sensitively to increase in temperature. Careful adaptation strategies to climate change considering socioeconomic status are therefore necessary.

Weather Regulates Location, Timing, and Intensity of Dengue Virus Transmission between Humans and Mosquitoes.

PubMed

Campbell, Karen M; Haldeman, Kristin; Lehnig, Chris; Munayco, Cesar V; Halsey, Eric S; Laguna-Torres, V Alberto; Yagui, Martín; Morrison, Amy C; Lin, Chii-Dean; Scott, Thomas W

2015-01-01

Dengue is one of the most aggressively expanding mosquito-transmitted viruses. The human burden approaches 400 million infections annually. Complex transmission dynamics pose challenges for predicting location, timing, and magnitude of risk; thus, models are needed to guide prevention strategies and policy development locally and globally. Weather regulates transmission-potential via its effects on vector dynamics. An important gap in understanding risk and roadblock in model development is an empirical perspective clarifying how weather impacts transmission in diverse ecological settings. We sought to determine if location, timing, and potential-intensity of transmission are systematically defined by weather. We developed a high-resolution empirical profile of the local weather-disease connection across Peru, a country with considerable ecological diversity. Applying 2-dimensional weather-space that pairs temperature versus humidity, we mapped local transmission-potential in weather-space by week during 1994-2012. A binary classification-tree was developed to test whether weather data could classify 1828 Peruvian districts as positive/negative for transmission and into ranks of transmission-potential with respect to observed disease. We show that transmission-potential is regulated by temperature-humidity coupling, enabling epidemics in a limited area of weather-space. Duration within a specific temperature range defines transmission-potential that is amplified exponentially in higher humidity. Dengue-positive districts were identified by mean temperature >22°C for 7+ weeks and minimum temperature >14°C for 33+ weeks annually with 95% sensitivity and specificity. In elevated-risk locations, seasonal peak-incidence occurred when mean temperature was 26-29°C, coincident with humidity at its local maximum; highest incidence when humidity >80%. We profile transmission-potential in weather-space for temperature-humidity ranging 0-38°C and 5-100% at 1°C x 2% resolution. Local duration in limited areas of temperature-humidity weather-space identifies potential locations, timing, and magnitude of transmission. The weather-space profile of transmission-potential provides needed data that define a systematic and highly-sensitive weather-disease connection, demonstrating separate but coupled roles of temperature and humidity. New insights regarding natural regulation of human-mosquito transmission across diverse ecological settings advance our understanding of risk locally and globally for dengue and other mosquito-borne diseases and support advances in public health policy/operations, providing an evidence-base for modeling, predicting risk, and surveillance-prevention planning.

Effects of water deprivation on behavioral Changes in BALB/c mice in hot humid climate of north east India.

PubMed

Chattopadhyay, Pronobesh; Pandey, Anurag; Karmakar, Sanjeev; Singh, Lokendra

2011-07-01

Abnormalities in water balance are manifested as hyponatremia and hypernatremia and the present investigation shows the effect of water deprivation in hot and humid climatic condition of north eastern part of India. Twenty four BALB/c mice of either sex (weight 30-40 g) were used for a 13-week experiment to determine the effects of water deprivation on behavioral and physiological changes. Mice were divided into control group (I) (n = 8), given water ad libitum, water-deprivation male group (15 ml/day) (Group II, n=8) and water-deprivation female group (15 ml/day) (Group III, n=8). The water deprivation mice shows significantly (P<0.05) deteriorated of reflex, progressive visual placement, emotional whereas body weight, grip strength and rectal temperature were significantly (P<0.05) increased as compared to the control group. This information is useful to those living or deployed in crisis situations where the water supply limited in a hot-humid climate.

Temperature mediates the effect of humidity on the viscoelasticity of glycoprotein glue within the droplets of an orb-weaving spider's prey capture threads.

PubMed

Stellwagen, Sarah D; Opell, Brent D; Short, Kelly G

2014-05-01

Sticky viscous prey capture threads retain insects that strike araneoid orb-webs. The threads' two axial fibers support a series of glue droplets, each featuring a core of adhesive viscoelastic glycoprotein covered by an aqueous solution. After sticking, the glue extends, summing the adhesion of multiple droplets, and dissipates some of the energy of a struggling prey. As a day progresses, threads experience a drop in humidity and an increase in temperature, environmental variables that have the potential to alter thread and web function. We hypothesize that thread droplets respond to these opposing environmental changes in a manner that stabilizes their performance, and test this by examining threads spun by Argiope aurantia, a species that occupies exposed, weedy habitats. We confirmed that decreased humidity increases glycoprotein viscosity and found that increased temperature had the opposite effect. To evaluate the combined effect of temperature and humidity on a droplet's ability to transfer adhesive force and dissipate energy, we extended a droplet and measured both the deflection of the axial line supporting the droplet and the duration of its tensive load. The cumulative product of these two indices, which reflects the energy required to extend a droplet, was greatest under afternoon (hot and dry) conditions, less under morning (cool and humid) conditions, and least under hot and humid afternoon conditions. Although the opposing effects of temperature and humidity tend to stabilize glycoprotein performance, A. aurantia thread droplets appear to function optimally during the afternoon, equipping this species to capture large orthopterans, which are most active at this time.

The use of inverse gas chromatography and gravimetric vapour sorption to study transitions in amorphous lactose.

PubMed

Ambarkhane, Ameet V; Pincott, Kim; Buckton, Graham

2005-04-27

The aim of this study was to measure the glass transition of amorphous lactose under well-controlled temperature and humidity, using inverse gas chromatography (IGC) and to relate these data to gravimetric vapour sorption experiments. Amorphous lactose (spray-dried) was exposed to a stepwise increment in the relative humidity (%RH) under isothermal conditions in an IGC. At the end of each conditioning step a decane injection was made, and the retention volumes were calculated using the maximum peak height (V(max)) method. The pressure drop across the column was recorded using the pressure transducers. These measurements were performed at various temperatures from 25 to 40 degrees C. The extent of water sorption at identical humidity (%RH) and temperature conditions was determined gravimetrically using dynamic vapour sorption (DVS). At each T, it was possible to determine: (1) a transition at low RH relating to the onset of mobility; (2) changes in retention volume relating to the point, where T(g) = T; (3) changes in pressure drop, which were related to the sample collapse. The rate and extent of water sorption was seen to alter at T(g) and also at a collapse point. Combinations of temperature and critical %RH (%cRH required to lower the dry glass transition temperature to the experimental temperature) obtained from IGC were comparable to those obtained from DVS. It was shown that at each T, the sample spontaneously crystallised, when T(g) was 32 degrees C below T. Inverse gas chromatograph can be used in this novel way to reveal the series of transitions that occur in amorphous materials.

Self-paced cycling performance and recovery under a hot and highly humid environment after cooling.

PubMed

Gonzales, B R; Hagin, V; Guillot, R; Placet, V; Monnier-Benoit, P; Groslambert, A

2014-02-01

This study investigated the effects of pre- and post-cooling on self-paced time-trial cycling performance and recovery of cyclists exercising under a hot and highly humid environment (29.92 °C-78.52% RH). Ten male cyclists performed a self-paced 20-min time trial test (TT20) on a cyclo-ergometer while being cooled by a cooling vest and a refrigerating headband during the warm-up and the recovery period. Heart rate, power output, perceived exertion, thermal comfort, skin and rectal temperatures were recorded. Compared to control condition (222.78 ± 47 W), a significant increase (P<0.05) in the mean power output during the TT20 (239.07 ± 45 W; +7.31%) was recorded with a significant (P<0.05) decrease in skin temperature without affecting perceived exertion, heart rate, or rectal temperature at the end of the TT20. However, pace changes occurred independently of skin or rectal temperatures variations but a significant difference (P<0.05) in the body's heat storage was observed between both conditions. This result suggests that a central programmer using body's heat storage as an input may influence self-paced time-trial performance. During the recovery period, post-cooling significantly decreased heart rate, skin and rectal temperatures, and improved significantly (P<0.05) thermal comfort. Therefore, in hot and humid environments, wearing a cooling vest and a refrigerating headband during warm-up improves self-paced performance, and appears to be an effective mean of reaching skin rest temperatures more rapidly during recovery.

The relationship between indoor and outdoor temperature, apparent temperature, relative humidity, and absolute humidity

PubMed Central

Nguyen, Jennifer L.; Schwartz, Joel; Dockery, Douglas W.

2013-01-01

Introduction Many studies report an association between outdoor ambient weather and health. Outdoor conditions may be a poor indicator of personal exposure because people spend most of their time indoors. Few studies have examined how indoor conditions relate to outdoor ambient weather. Methods and Results The average indoor temperature, apparent temperature, relative humidity (RH), and absolute humidity (AH) measured in 16 homes in Greater Boston, Massachusetts, from May 2011 - April 2012 was compared to measurements taken at Boston Logan airport. The relationship between indoor and outdoor temperatures is non-linear. At warmer outdoor temperatures, there is a strong correlation between indoor and outdoor temperature (Pearson correlation coefficient, r = 0.91, slope, β = 0.41), but at cooler temperatures, the association is weak (r = 0.40, β = 0.04). Results were similar for outdoor apparent temperature. The relationships were linear for RH and AH. The correlation for RH was modest (r = 0.55, β = 0.39). AH exhibited the strongest indoor-to-outdoor correlation (r = 0.96, β = 0.69). Conclusions Indoor and outdoor temperatures correlate well only at warmer outdoor temperatures. Outdoor RH is a poor indicator of indoor RH, while indoor AH has a strong correlation with outdoor AH year-round. PMID:23710826

Environmental Control and Life Support System

NASA Technical Reports Server (NTRS)

Ray, Charles; Adams, Alan

1990-01-01

Viewgraphs on the Environmental Control and Life Support System (ECLSS) for the space station are presented. The ECLSS is divided into six subsystems: temperature and humidity control (THC), atmosphere control and supply (ACS), atmosphere revitalization (AR), fire detection and suppression (FDS), water recovery management (WRM), and waste management (WM). Topics covered include: ECLSS subsystem functions; ECLSS distributed system; ECLSS functional distribution; CO2 removal; CO2 reduction; oxygen generation; urine processor; and potable water recovery.

Development of desiccant based air conditioning for hotels and motels. Final report, phase 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banks, N.J.

1994-10-01

This report contains final reports from two phases of field tests: Phase I at the Marriott Courtyard in West Palm Beach, completed in October 1991, and Phase II at the Walt Disney World Swan Hotel in Orlando, completed in August 1993. The goal was to measure the performance and reliability of the desiccant units. The successfull program proved the value of the gas-fired desiccant technology to the hospitality industry. The desiccant units reduced moisture by 15 to 20% relative humidity. Measurements of temperature, humidity, and wallboard moisture content showed a dramatic reduction in the humidity levels experienced prior to installationmore » of the units and in the control areas without desiccants. Moisture damage was kept in check and remodelling due to it was eliminated.« less

The effects of climate factors on scabies. A 14-year population-based study in Taiwan

PubMed Central

Liu, Jui-Ming; Wang, Hsiao-Wei; Chang, Fung-Wei; Liu, Yueh-Ping; Chiu, Feng-Hsiang; Lin, Yi-Chun; Cheng, Kuan-Chen; Hsu, Ren-Jun

2016-01-01

Scabies is a common infectious disease and can cause severe outbreaks if not controlled quickly. Besides personal contact history, environmental factors are also important. This study analyzed the effects of environmental climate factors on the incidence of scabies in Taiwan. We conducted a 14-year nationwide population-based study: a total of 14,883 patients with scabies infestation were enrolled. Monthly climate data were collected from Taiwan’s Central Weather Bureau, including data on temperature, relative humidity, total rainfall, total rain days, and total sunshine hours. The linear relationships between these climate factors and scabies infestations or other risk factors were examined by Pearson’s correlation analysis. Overall, the incidence of scabies was negatively correlated with temperature (γ = −0.152, p < 0.001), while being positively correlated with humidity (γ = 0.192, p < 0.001). This useful information may provide evidence for lowering humidity at nursing facilities, hospitals, and military camps with scabies infestations, which may help to reduce its spread and prevent outbreaks. PMID:27905271

The effects of climate factors on scabies. A 14-year population-based study in Taiwan.

PubMed

Liu, Jui-Ming; Wang, Hsiao-Wei; Chang, Fung-Wei; Liu, Yueh-Ping; Chiu, Feng-Hsiang; Lin, Yi-Chun; Cheng, Kuan-Chen; Hsu, Ren-Jun

2016-01-01

Scabies is a common infectious disease and can cause severe outbreaks if not controlled quickly. Besides personal contact history, environmental factors are also important. This study analyzed the effects of environmental climate factors on the incidence of scabies in Taiwan. We conducted a 14-year nationwide population-based study: a total of 14,883 patients with scabies infestation were enrolled. Monthly climate data were collected from Taiwan's Central Weather Bureau, including data on temperature, relative humidity, total rainfall, total rain days, and total sunshine hours. The linear relationships between these climate factors and scabies infestations or other risk factors were examined by Pearson's correlation analysis. Overall, the incidence of scabies was negatively correlated with temperature (γ = -0.152, p < 0.001), while being positively correlated with humidity (γ = 0.192, p < 0.001). This useful information may provide evidence for lowering humidity at nursing facilities, hospitals, and military camps with scabies infestations, which may help to reduce its spread and prevent outbreaks. © J.-M. Liu et al., published by EDP Sciences, 2016.

Controlling moisture content of wood samples using a modified soil-pan decay method

Treesearch

Jerrold E. Winandy; Simon F. Curling; Patricia K. Lebow

2005-01-01

In wood, the threshold level below which decay cannot occur varies with species or type of wood product and other factors such as temperature, humidity, and propensity of exposure or service-use to allow rain-induced wetting and subsequent drying. The ability to control wood moisture content (MC) during laboratory decay testing could allow research on the moisture...

Air quality and ventilation fan control based on aerosol measurement in the bi-directional undersea Bømlafjord tunnel.

PubMed

Indrehus, Oddny; Aralt, Tor Tybring

2005-04-01

Aerosol, NO and CO concentration, temperature, air humidity, air flow and number of running ventilation fans were measured by continuous analysers every minute for a whole week for six different one-week periods spread over ten months in 2001 and 2002 at measuring stations in the 7860 m long tunnel. The ventilation control system was mainly based on aerosol measurements taken by optical scatter sensors. The ventilation turned out to be satisfactory according to Norwegian air quality standards for road tunnels; however, there was some uncertainty concerning the NO2 levels. The air humidity and temperature inside the tunnel were highly influenced by the outside metrological conditions. Statistical models for NO concentration were developed and tested; correlations between predicted and measured NO were 0.81 for a partial least squares regression (PLS1) model based on CO and aerosol, and 0.77 for a linear regression model based only on aerosol. Hence, the ventilation control system should not solely be based on aerosol measurements. Since NO2 is the hazardous polluter, modelling NO2 concentration rather than NO should be preferred in any further optimising of the ventilation control.

The role of humidity in determining scenarios of perceived temperature extremes in Europe

NASA Astrophysics Data System (ADS)

Scoccimarro, Enrico; Fogli, Pier Giuseppe; Gualdi, Silvio

2017-11-01

An increase of the 2 m temperature over Europe is expected within the current century. In order to consider health impacts, it is important to evaluate the combined effect of temperature and humidity on the human body. To achieve this, projections of a basic index—the humidex—representative of the perceived temperature, under different scenarios and periods, have been investigated. The simultaneous occurrence of observed extreme temperature events and perceived extreme temperature events is seldom found within the present climate, reinforcing the importance of investigating the combination of the two fields. A set of 10 km resolution regional climate simulations, provided within the EURO-CORDEX multi-model effort, demonstrates an ability in representing moderate to extreme events of perceived temperature over the present climate, and to be useful as a tool for quantifying future changes in geographical patterns of exposed areas over Europe. Following the RCP8.5 emission scenario, an expansion of the area subject to dangerous conditions is suggested from the middle of the current century, reaching 60 °N. The most significant increase of perceived extreme temperature conditions is found comparing the 2066-2095 projections to the 1976-2005 period; bearing in mind that changes in relative humidity may either amplify or offset the health effects of temperature, a less pronounced projected reduction of relative humidity in the north-eastern part of Europe, associated with extreme humidex events, makes northern Europe the most prone region to an increase of moderate to extreme values of perceived temperature. This is in agreement with a pronounced projected specific humidity increase.

Intraperitoneal temperature and desiccation during endoscopic surgery. Intraoperative humidification and cooling of the peritoneal cavity can reduce adhesions.

PubMed

Corona, Roberta; Verguts, Jasper; Koninckx, Robert; Mailova, Karina; Binda, Maria Mercedes; Koninckx, Philippe R

2011-10-01

This study was conducted to document quantitatively the intraperitoneal temperature and desiccation during laparoscopic surgery. The temperature, relative humidity, and flow rate were measured in vitro and during laparoscopic surgery, at the entrance and at the exit of the abdomen. This permitted us to calculate desiccation for various flow rates using either dry CO(2) or CO(2) humidified with 100% relative humidity at any preset temperature between 25 and 37°C. The study showed that desiccation, both in vitro and in vivo, varies as expected with the flow rates and relative humidity while intraperitoneal temperature varies mainly with desiccation. Temperature regulation of bowels is specific and drops to the intraperitoneal temperature without affecting core body temperature. With a modified humidifier, desiccation could be eliminated while maintaining the intraperitoneal temperature between 31 to 32°C. Copyright © 2011 Mosby, Inc. All rights reserved.

Effects of Meteorological Data Quality on Snowpack Modeling

NASA Astrophysics Data System (ADS)

Havens, S.; Marks, D. G.; Robertson, M.; Hedrick, A. R.; Johnson, M.

2017-12-01

Detailed quality control of meteorological inputs is the most time-intensive component of running the distributed, physically-based iSnobal snow model, and the effect of data quality of the inputs on the model is unknown. The iSnobal model has been run operationally since WY2013, and is currently run in several basins in Idaho and California. The largest amount of user input during modeling is for the quality control of precipitation, temperature, relative humidity, solar radiation, wind speed and wind direction inputs. Precipitation inputs require detailed user input and are crucial to correctly model the snowpack mass. This research applies a range of quality control methods to meteorological input, from raw input with minimal cleaning, to complete user-applied quality control. The meteorological input cleaning generally falls into two categories. The first is global minimum/maximum and missing value correction that could be corrected and/or interpolated with automated processing. The second category is quality control for inputs that are not globally erroneous, yet are still unreasonable and generally indicate malfunctioning measurement equipment, such as temperature or relative humidity that remains constant, or does not correlate with daily trends observed at nearby stations. This research will determine how sensitive model outputs are to different levels of quality control and guide future operational applications.

Environmental tests of metallization systems for terrestrial photovoltaic cells

NASA Technical Reports Server (NTRS)

Alexander, P., Jr.

1985-01-01

Seven different solar cell metallization systems were subjected to temperature cycling tests and humidity tests. Temperature cycling excursions were -50 deg C to 150 deg C per cycle. Humidity conditions were 70 deg C at 98% relative humidity. The seven metallization systems were: Ti/Ag, Ti/Pd/Ag, Ti/Pd/Cu, Ni/Cu, Pd/Ni/Solder, Cr/Pd/Ag, and thick film Ag. All metallization systems showed a slight to moderate decrease in cell efficiencies after subjection to 1000 temperature cycles. Six of the seven metallization systems also evidenced slight increases in cell efficiencies after moderate numbers of cycles, generally less than 100 cycles. The copper based systems showed the largest decrease in cell efficiencies after temperature cycling. All metallization systems showed moderate to large decreases in cell efficiencies after 123 days of humidity exposure. The copper based systems again showed the largest decrease in cell efficiencies after humidity exposure. Graphs of the environmental exposures versus cell efficiencies are presented for each metallization system, as well as environmental exposures versus fill factors or series resistance.

Investigating Extreme Heat and Humidity in the Northeast United States from a Joint Hazard Perspective

NASA Astrophysics Data System (ADS)

Horton, R. M.; Coffel, E.; Kushnir, Y.

2014-12-01

Recent years have seen an increasing focus on extreme high temperature events, as our understanding of societal vulnerability to such extremes has grown. Less climate research has been devoted to heat indices that consider the joint hazard posed by high temperatures and high humidity, even though heat indices are being prioritized by utility providers and public health officials. This paper evaluates how well CMIP5 models are able to reproduce the large-scale features and surface conditions associated with joint high heat and humidity events in the Northeast U.S. Projected changes in heat indices are also shown both for the full set of CMIP5 models and for a subset of models that best reproduce the statistics of historical high heat index events. The importance of considering the relationship between 1) temperature and humidity extremes and 2) projected changes in extreme temperature and humidity extremes, rather than investigating each variable independently, will be emphasized. Potential impacts of the findings on human mortality and energy consumption will be briefly discussed.

Development of TGS2611 methane sensor and SHT11 humidity and temperature sensor for measuring greenhouse gas on peatlands in south kalimantan, indonesia

NASA Astrophysics Data System (ADS)

Sugriwan, I.; Soesanto, O.

2017-05-01

The research was focused on development of data acquisition system to monitor the content of methane, relative humidity and temperature on peatlands in South Kalimantan, Indonesia. Methane is one of greenhouse gases that emitted from peatlands; while humidity and temperature are important parameters of microclimate on peatlands. The content of methane, humidity and temperature are three parameters were monitored digitally, real time, continuously and automatically record by data acquisition systems that interfaced to the personal computer. The hardware of data acquisition system consists of power supply unit, TGS2611 methane gas sensor, SHT11 humidity and temperature sensors, voltage follower, ATMega8535 microcontroller, 16 × 2 LCD character and personal computer. ATMega8535 module is a device to manage all part in measuring instrument. The software which is responsible to take sensor data, calculate characteristic equation and send data to 16 × 2 LCD character are Basic Compiler. To interface between measuring instrument and personal computer is maintained by Delphi 7. The result of data acquisition showed on 16 × 2 LCD characters, PC monitor and database with developed by XAMPP. Methane, humidity, and temperature which release from peatlands are trapped by Closed-Chamber Measurement with dimension 60 × 50 × 40 cm3. TGS2611 methane gas sensor and SHT11 humidity and temperature sensor are calibrated to determine transfer function used to data communication between sensors and microcontroller and integrated into ATMega8535 Microcontroller. Calculation of RS and RL of TGS2611 methane gas sensor refer to data sheet and obtained respectively 1360 ohm and 905 ohm. The characteristic equation of TGS2611 satisfies equation VRL = 0.561 ln n - 2.2641 volt, with n is a various concentrations and VRL in volt. The microcontroller maintained the voltage signal than interfaced it to liquid crystal displays and personal computer (laptop) to display result of the measurement. The result of data acquisition saved on excels and database format.

Evaluation of the efficiency of heat and moisture exchangers during paediatric anaesthesia.

PubMed

Luchetti, M; Pigna, A; Gentili, A; Marraro, G

1999-01-01

This study evaluates the efficiency of heat and moisture exchangers (HMEs) in allowing adequate humidification and warming during anaesthesia in children. Eighteen paediatric patients undergoing anaesthesia were divided into two groups: group A ten patients: infants up to 10 kg-->Hygrobaby HME; group B 8 patients: children above 10 kg-->Hygroboy HME. The following parameters were evaluated: body temperature (bT), room temperature (rT), fresh gas temperature, HME warm-up time, inspired and expired gases temperature and humidity, conserving efficiency, and duration of anaesthesia. Gas temperatures were recorded by means of a recorder fitted with four thermal probes. Humidity values were mathematically derived. The correlation between efficiency and rT, bT, and fresh gas temperature was computed. In both groups the inspired gases temperatures were below 30 degrees C. Inspired absolute humidity was never more than 28 mgH2O.l(-1). The conserving efficiency was good (0.93 in both groups). A positive correlation was found between efficiency and fresh gas temperature. HMEs did not meet the minimum standards for humidity and heating during anaesthesia in children, although their conserving efficiency was found to be satisfactory.

Changes in minimum and maximum temperatures at the Pic du Midi in relation with humidity and cloudiness, 1882-1984

NASA Astrophysics Data System (ADS)

Dessens, J.; Bücher, A.

In an attempt to contribute to the investigation on a global climate change, a historical series of minimum and maximum temperature data at the Pic du Midi, a mountain observatory at 2862 m a.s.l. in the French Pyrenees, is updated after correction of a systematic deviation due to a relocation of the station in 1971. These data, which now cover the 1882-1984 period, are examined in parallel with humidity and cloud cover data for the same period. From the beginning to the end of this period, observations show that the mean night-time temperature has increased by 2.39° C/100 yr while the mean daytime temperature has decreased by 0.50° C/100 yr. In consequence, the mean annual diurnal temperature range has dropped by 36%/100 yr. The maximum seasonal decrease is 46%/100 yr in spring. Season-to-season and year-to-year inter-relationships between minimum temperature, maximum temperature, relative humidity and cloud cover suggest that the decrease in maximum temperature is related to a concomitant increase of 15%/100 yr in both relative humidity and cloud cover.

Maritime Detection of Radiological/Nuclear Threats with Hybrid Imaging System

DTIC Science & Technology

2014-01-01

localization system. Each subsystem is housed in a separate 20-ft refrigerated ISO container that provides humidity and temperature control, and...externally via laptop or remotely via wireless communication. A detailed description of each individual subsystem follows. A. Detection...LN2. Each dewar has a cryogenic solenoid valve and a temperature sensor on the exhaust to monitor when the dewar is full. The valves and sensors are

Multivariate thermo-hygrometric characterisation of the archaeological site of Plaza de l'Almoina (Valencia, Spain) for preventive conservation.

PubMed

Fernández-Navajas, Angel; Merello, Paloma; Beltrán, Pedro; García-Diego, Fernando-Juan

2013-07-29

Preventive conservation requires monitoring and control of the parameters involved in the deterioration process, mainly temperature and relative humidity. It is important to characterise an archaeological site prior to carrying out comparative studies in the future for preventive conservation, either by regular studies to verify whether the conditions are constant, or occasional ones when the boundary conditions are altered. There are numerous covered archaeological sites, but few preventive conservation works that give special attention to the type of cover installed. In particular, there is no background of microclimatic studies in sites that are in the ground and, as in the Plaza de l'Almoina (Valencia, Spain), are buried and partially covered by a transparent roof. A large effect of the transparent cover was found by the sensors located below this area, with substantial increases in temperature and a decrease in the relative humidity during the day. Surrounding zones also have values above the recommended temperature values. On the other hand, the influence of a buried water drainage line near the site is notable, causing an increase in relative humidity levels in the surrounding areas. Multivariate statistical analyses enabled us to characterise the microclimate of the archaeological site, allowing future testing to determine whether the conservation conditions have been altered.

Multivariate Thermo-Hygrometric Characterisation of the Archaeological Site of Plaza de l’Almoina (Valencia, Spain) for Preventive Conservation

PubMed Central

Fernández-Navajas, Ángel; Merello, Paloma; Beltrán, Pedro; García-Diego, Fernando-Juan

2013-01-01

Preventive conservation requires monitoring and control of the parameters involved in the deterioration process, mainly temperature and relative humidity. It is important to characterise an archaeological site prior to carrying out comparative studies in the future for preventive conservation, either by regular studies to verify whether the conditions are constant, or occasional ones when the boundary conditions are altered. There are numerous covered archaeological sites, but few preventive conservation works that give special attention to the type of cover installed. In particular, there is no background of microclimatic studies in sites that are in the ground and, as in the Plaza de l’Almoina (Valencia, Spain), are buried and partially covered by a transparent roof. A large effect of the transparent cover was found by the sensors located below this area, with substantial increases in temperature and a decrease in the relative humidity during the day. Surrounding zones also have values above the recommended temperature values. On the other hand, the influence of a buried water drainage line near the site is notable, causing an increase in relative humidity levels in the surrounding areas. Multivariate statistical analyses enabled us to characterise the microclimate of the archaeological site, allowing future testing to determine whether the conservation conditions have been altered. PMID:23899937

Investigating the Strain, Temperature and Humidity Sensitivity of a Multimode Graded-Index Perfluorinated Polymer Optical Fiber with Bragg Grating

PubMed Central

Zheng, Yulong; Bremer, Kort

2018-01-01

In this work we investigate the strain, temperature and humidity sensitivity of a Fiber Bragg Grating (FBG) inscribed in a near infrared low-loss multimode perfluorinated polymer optical fiber based on cyclic transparent optical polymer (CYTOP). For this purpose, FBGs were inscribed into the multimode CYTOP fiber with a core diameter of 50 µm by using a krypton fluoride (KrF) excimer laser and the phase mask method. The evolution of the reflection spectrum of the FBG detected with a multimode interrogation technique revealed a single reflection peak with a full width at half maximum (FHWM) bandwidth of about 9 nm. Furthermore, the spectral envelope of the single FBG reflection peak can be optimized depending on the KrF excimer laser irradiation time. A linear shift of the Bragg wavelength due to applied strain, temperature and humidity was measured. Furthermore, depending on irradiation time of the KrF excimer laser, both the failure strain and strain sensitivity of the multimode fiber with FBG can be controlled. The inherent low light attenuation in the near infrared wavelength range (telecommunication window) of the multimode CYTOP fiber and the single FBG reflection peak when applying the multimode interrogation set-up will allow for new applications in the area of telecommunication and optical sensing. PMID:29734734

Investigating the Strain, Temperature and Humidity Sensitivity of a Multimode Graded-Index Perfluorinated Polymer Optical Fiber with Bragg Grating.

PubMed

Zheng, Yulong; Bremer, Kort; Roth, Bernhard

2018-05-05

In this work we investigate the strain, temperature and humidity sensitivity of a Fiber Bragg Grating (FBG) inscribed in a near infrared low-loss multimode perfluorinated polymer optical fiber based on cyclic transparent optical polymer (CYTOP). For this purpose, FBGs were inscribed into the multimode CYTOP fiber with a core diameter of 50 µm by using a krypton fluoride (KrF) excimer laser and the phase mask method. The evolution of the reflection spectrum of the FBG detected with a multimode interrogation technique revealed a single reflection peak with a full width at half maximum (FHWM) bandwidth of about 9 nm. Furthermore, the spectral envelope of the single FBG reflection peak can be optimized depending on the KrF excimer laser irradiation time. A linear shift of the Bragg wavelength due to applied strain, temperature and humidity was measured. Furthermore, depending on irradiation time of the KrF excimer laser, both the failure strain and strain sensitivity of the multimode fiber with FBG can be controlled. The inherent low light attenuation in the near infrared wavelength range (telecommunication window) of the multimode CYTOP fiber and the single FBG reflection peak when applying the multimode interrogation set-up will allow for new applications in the area of telecommunication and optical sensing.

Extending the potential of evaporative cooling for heat-stress relief.

PubMed

Berman, A

2006-10-01

Factors were analyzed that limit the range of environmental conditions in which stress from heat may be relieved by evaporative cooling in shaded animals. Evaporative cooling reduces air temperature (Ta), but increases humidity. Equations were developed to predict Ta reduction as a function of ambient temperature and humidity and of humidity in cooled air. Predictions indicated that a reduction of Ta becomes marginal at humidities beyond 45%. A reduction of Ta lessens with rising ambient Ta. The impact of increasing humidity on respiratory heat loss (Hre) was estimated from existing data published on Holstein cattle. Respiratory heat loss is reduced by increased humidity up to 45%, but is not affected by higher humidity. Skin evaporative and sensible heat losses are determined not only by the humidity and temperature gradient, but also by air velocity close to the body surface. At higher Ta, the reduction in sensible heat loss is compensated for by an increased demand for Hre. High Hre may become a stressor when panting interferes with resting and rumination. Effects of temperature, humidity, air velocity, and body surface exposure to free air on Hre were estimated by a thermal balance model for lactating Holstein cows yielding 35 kg/d. The predictions of the simulations were supported by respiratory rate observations. The Hre was assumed to act as a stressor when exceeding 50% of the maximal capacity. When the full body surface was exposed to a 1.5 m/s air velocity, humidity (15 to 75%) had no significant predicted effect on Hre. For an air velocity of 0.3 m/s, Hre at 50% of the maximum rate was predicted at 34, 32.5, and 31.5 degrees C for relative humidities of 55, 65, and 75%, respectively. Similar results were predicted for an animal with two-thirds of its body surface exposed to 1.5 m/s air velocity. If air velocity was reduced for such animals to 0.3 m/s, the rise in Hre was expected to occur at approximately 25 degrees C and 50% relative humidity. Maximal rates of Hre were estimated at 27 to 30 degrees C when ambient humidity was 55% relative humidity and higher. High humidity may stress animals in evaporative cooling systems. Humidity stress may be prevented by a higher air velocity on the body surface of the animal, particularly in sheltered areas in which the exposed body surface is reduced, such as mangers and stalls. This may extend the use of evaporative cooling to less dry environments.

Experimental and Theoretical Investigations on the Nanoscale Kinetic Friction in Ambient Environmental Conditions.

PubMed

Gueye, Birahima; Zhang, Yan; Wang, Yujuan; Chen, Yunfei

2015-07-08

The liquid lubrication, thermolubricity and dynamic lubricity due to mechanical oscillations are investigated with an atomic force microscope in ambient environmental conditions with different relative humidity (RH) levels. Experimental results demonstrate that high humidity at low-temperature regime enhances the liquid lubricity while at high-temperature regime it hinders the effect of the thermolubricity due to the formation of liquid bridges. Friction response to the dynamic lubricity in both high- and low-temperature regimes keeps the same trends, namely the friction force decreases with increasing the amplitude of the applied vibration on the tip regardless of the RH levels. An interesting finding is that for the dynamic lubricity at high temperature, high-humidity condition leads to the friction forces higher than that at low-humidity condition while at low temperature the opposite trend is observed. An extended two-dimensional dynamic model accounting for the RH is proposed to interpret the frictional mechanism in ambient conditions.

Weather Measurements around Your School. Mapping Variations in Temperature and Humidity.

ERIC Educational Resources Information Center

Smith, David R.; And Others

1991-01-01

Presented is an activity where students conduct a micrometeorological study in their neighborhood using temperature, humidity measurements, and mapping skills. Included are a discussion of surface weather observations, the experiment, and directions. (KR)

An efficient transmission power control scheme for temperature variation in wireless sensor networks.

PubMed

Lee, Jungwook; Chung, Kwangsue

2011-01-01

Wireless sensor networks collect data from several nodes dispersed at remote sites. Sensor nodes can be installed in harsh environments such as deserts, cities, and indoors, where the link quality changes considerably over time. Particularly, changes in transmission power may be caused by temperature, humidity, and other factors. In order to compensate for link quality changes, existing schemes detect the link quality changes between nodes and control transmission power through a series of feedback processes, but these approaches can cause heavy overhead with the additional control packets needed. In this paper, the change of the link quality according to temperature is examined through empirical experimentation. A new power control scheme combining both temperature-aware link quality compensation and a closed-loop feedback process to adapt to link quality changes is proposed. We prove that the proposed scheme effectively adapts the transmission power to the changing link quality with less control overhead and energy consumption.

Effect of Temperature and Viscoelastic Creep on the Clamp-Up Load in Hybrid Composite/Metal Bolted Joints

DTIC Science & Technology

2009-08-17

aluminum bolted to aluminum specimens. 2. Similarly to the temperature effects on the response of the specimens tested, relative humidity swings have a...bolted to aluminum specimens show the highest susceptibility to relative humidity shifts. This response is believed to be related to their ability to...relaxation stage, little effects are detected from relative humidity fluctuations. 81 9. The data

Improved dewpoint-probe calibration

NASA Technical Reports Server (NTRS)

Stephenson, J. G.; Theodore, E. A.

1978-01-01

Relatively-simple pressure-control apparatus calibrates dewpoint probes considerably faster than conventional methods, with no loss of accuracy. Technique requires only pressure measurement at each calibration point and single absolute-humidity measurement at beginning of run. Several probes can be calibrated simultaneously and points can be checked above room temperature.

The effects of non-invasive respiratory support on oropharyngeal temperature and humidity: a neonatal manikin study.

PubMed

Roberts, Calum T; Kortekaas, Rebecca; Dawson, Jennifer A; Manley, Brett J; Owen, Louise S; Davis, Peter G

2016-05-01

Heating and humidification of inspired gases is routine during neonatal non-invasive respiratory support. However, little is known about the temperature and humidity delivered to the upper airway. The International Standards Organization (ISO) specifies that for all patients with an artificial airway humidifiers should deliver ≥33 g/m(3) absolute humidity (AH). We assessed the oropharyngeal temperature and humidity during different non-invasive support modes in a neonatal manikin study. Six different modes of non-invasive respiratory support were applied at clinically relevant settings to a neonatal manikin, placed in a warmed and humidified neonatal incubator. Oropharyngeal temperature and relative humidity (RH) were assessed using a thermohygrometer. AH was subsequently calculated. Measured temperature and RH varied between devices. Bubble and ventilator continuous positive airway pressure (CPAP) produced temperatures >34°C and AH >38 g/m(3). Variable flow CPAP resulted in lower levels of AH than bubble or ventilator CPAP, and AH decreased with higher gas flow. High-flow (HF) therapy delivered by Optiflow Junior produced higher AH with higher gas flow, whereas with Vapotherm HF the converse was true. Different non-invasive devices deliver inspiratory gases of variable temperature and humidity. Most AH levels were above the ISO recommendation; however, with some HF and variable flow CPAP devices at higher gas flow this was not achieved. Clinicians should be aware of differences in the efficacy of heating and humidification when choosing modes of non-invasive respiratory support. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Temperature and relative humidity estimation and prediction in the tobacco drying process using Artificial Neural Networks.

PubMed

Martínez-Martínez, Víctor; Baladrón, Carlos; Gomez-Gil, Jaime; Ruiz-Ruiz, Gonzalo; Navas-Gracia, Luis M; Aguiar, Javier M; Carro, Belén

2012-10-17

This paper presents a system based on an Artificial Neural Network (ANN) for estimating and predicting environmental variables related to tobacco drying processes. This system has been validated with temperature and relative humidity data obtained from a real tobacco dryer with a Wireless Sensor Network (WSN). A fitting ANN was used to estimate temperature and relative humidity in different locations inside the tobacco dryer and to predict them with different time horizons. An error under 2% can be achieved when estimating temperature as a function of temperature and relative humidity in other locations. Moreover, an error around 1.5 times lower than that obtained with an interpolation method can be achieved when predicting the temperature inside the tobacco mass as a function of its present and past values with time horizons over 150 minutes. These results show that the tobacco drying process can be improved taking into account the predicted future value of the monitored variables and the estimated actual value of other variables using a fitting ANN as proposed.

Temperature and Relative Humidity Estimation and Prediction in the Tobacco Drying Process Using Artificial Neural Networks

PubMed Central

Martínez-Martínez, Víctor; Baladrón, Carlos; Gomez-Gil, Jaime; Ruiz-Ruiz, Gonzalo; Navas-Gracia, Luis M.; Aguiar, Javier M.; Carro, Belén

2012-01-01

This paper presents a system based on an Artificial Neural Network (ANN) for estimating and predicting environmental variables related to tobacco drying processes. This system has been validated with temperature and relative humidity data obtained from a real tobacco dryer with a Wireless Sensor Network (WSN). A fitting ANN was used to estimate temperature and relative humidity in different locations inside the tobacco dryer and to predict them with different time horizons. An error under 2% can be achieved when estimating temperature as a function of temperature and relative humidity in other locations. Moreover, an error around 1.5 times lower than that obtained with an interpolation method can be achieved when predicting the temperature inside the tobacco mass as a function of its present and past values with time horizons over 150 minutes. These results show that the tobacco drying process can be improved taking into account the predicted future value of the monitored variables and the estimated actual value of other variables using a fitting ANN as proposed. PMID:23202032

FDR Soil Moisture Sensor for Environmental Testing and Evaluation

NASA Astrophysics Data System (ADS)

Linmao, Ye; longqin, Xue; guangzhou, Zhang; haibo, Chen; likuai, Shi; zhigang, Wu; gouhe, Yu; yanbin, Wang; sujun, Niu; Jin, Ye; Qi, Jin

To test the affect of environmental stresses on a adaptability of soil moisture capacitance sensor(FDR) a number of stresses were induced including vibrational shock as well as temperature and humidity through the use of a CH-I constant humidity chamber with variable temperature. A Vibrational platform was used to exam the resistance and structural integrity of the sensor after vibrations simulating the process of using, transporting and handling the sensor. A Impactive trial platform was used to test the resistance and structural integrity of the sensor after enduring repeated mechanical shocks. An CH-I constant humidity chamber with high-low temperature was used to test the adaptability of sensor in different environments with high temperature, low temperature and constant humidity. Otherwise, scope of magnetic force line of sensor was also tested in this paper. Test show:the capacitance type soil moisture sensor spread a feeling machine to bear heat, high wet and low temperature, at bear impact and vibration experiment in pass an examination, is a kind of environment to adapt to ability very strong instrument;Spread a feeling machine moreover electric field strength function radius scope 7 cms.

Effects of moisture controlled charcoal on indoor thermal and air environments

NASA Astrophysics Data System (ADS)

Matsumoto, Hiroshi; Yokogoshi, Midori; Nabeshima, Yuki

2017-10-01

It is crucial to remove and control indoor moisture in Japan, especially in hot and humid summers, in order to improve thermal comfort and save energy in buildings. Charcoal for moisture control made from the waste of wood material has attracted attention among many control strategies to control indoor moisture, and it is beginning to be used in houses. However, the basic characteristics of the charcoal to control moisture and remove chemical compounds in indoor air have not been investigated sufficiently. The objective of this study is to clarify the effect of moisture control charcoal on indoor thermal and air environments by a long-term field measurement using two housing scale models with/without charcoal in Toyohashi, Japan. The comparative experiments to investigate the effect of the charcoal on air temperature and humidity for two models with/without charcoal were conducted from 2015 to 2016. Also, the removal performance of volatile organic compound (VOCs) was investigated in the summer of 2015. Four bags of packed charcoal were set on the floor in the attic for one model during the experiment. As a result of the experiments, a significant effect of moisture control was observed in hot and humid season, and the efficient effect of moisture adsorption was obtained by the periodic humidification experiment using a humidifier. Furthermore, the charcoal showed a remarkable performance of VOC removal from indoor air by the injection experiment of formaldehyde.

Evaluation of measurement errors of temperature and relative humidity from HOBO data logger under different conditions of exposure to solar radiation.

PubMed

da Cunha, Antonio Ribeiro

2015-05-01

This study aimed to assess measurements of temperature and relative humidity obtained with HOBO a data logger, under various conditions of exposure to solar radiation, comparing them with those obtained through the use of a temperature/relative humidity probe and a copper-constantan thermocouple psychrometer, which are considered the standards for obtaining such measurements. Data were collected over a 6-day period (from 25 March to 1 April, 2010), during which the equipment was monitored continuously and simultaneously. We employed the following combinations of equipment and conditions: a HOBO data logger in full sunlight; a HOBO data logger shielded within a white plastic cup with windows for air circulation; a HOBO data logger shielded within a gill-type shelter (multi-plate prototype plastic); a copper-constantan thermocouple psychrometer exposed to natural ventilation and protected from sunlight; and a temperature/relative humidity probe under a commercial, multi-plate radiation shield. Comparisons between the measurements obtained with the various devices were made on the basis of statistical indicators: linear regression, with coefficient of determination; index of agreement; maximum absolute error; and mean absolute error. The prototype multi-plate shelter (gill-type) used in order to protect the HOBO data logger was found to provide the best protection against the effects of solar radiation on measurements of temperature and relative humidity. The precision and accuracy of a device that measures temperature and relative humidity depend on an efficient shelter that minimizes the interference caused by solar radiation, thereby avoiding erroneous analysis of the data obtained.

Pressure and Humidity Measurements at the MSL Landing Site Supported by Modeling of the Atmospheric Conditions

NASA Astrophysics Data System (ADS)

Harri, A.; Savijarvi, H. I.; Schmidt, W.; Genzer, M.; Paton, M.; Kauhanen, J.; Atlaskin, E.; Polkko, J.; Kahanpaa, H.; Kemppinen, O.; Haukka, H.

2012-12-01

The Mars Science Laboratory (MSL) called Curiosity Rover landed safely on the Martian surface at the Gale crater on 6th August 2012. Among the MSL scientific objectives are investigations of the Martian environment that will be addressed by the Rover Environmental Monitoring Station (REMS) instrument. It will investigate habitability conditions at the Martian surface by performing a versatile set of environmental measurements including accurate observations of pressure and humidity of the Martian atmosphere. This paper describes the instrumental implementation of the MSL pressure and humidity measurement devices and briefly analyzes the atmospheric conditions at the Gale crater by modeling efforts using an atmospheric modeling tools. MSL humidity and pressure devices are based on proprietary technology of Vaisala, Inc. Humidity observations make use of Vaisala Humicap® relative humidity sensor heads and Vaisala Barocap® sensor heads are used for pressure observations. Vaisala Thermocap® temperature sensors heads are mounted in a close proximity of Humicap® and Barocap® sensor heads to enable accurate temperature measurements needed for interpretation of Humicap® and Barocap® readings. The sensor heads are capacitive. The pressure and humidity devices are lightweight and are based on a low-power transducer controlled by a dedicated ASIC. The transducer is designed to measure small capacitances in order of a few pF with resolution in order of 0.1fF (femtoFarad). The transducer design has a good spaceflight heritage, as it has been used in several previous missions, for example Mars mission Phoenix as well as the Cassini Huygens mission. The humidity device has overall dimensions of 40 x 25 x 55 mm. It weighs18 g, and consumes 15 mW of power. It includes 3 Humicap® sensor heads and 1 Thermocap®. The transducer electronics and the sensor heads are placed on a single multi-layer PCB protected by a metallic Faraday cage. The Humidity device has measurement range of 0 - 100%RH in temperature range of -70°C - +25°C. Its survival temperature is as low as -135°C. The pressure device has overall dimensions of 62 x 55 x 17 mm. It weighs 35 g, and consumes 15 mW of power. The sensor makes use of two transducers placed on a single multi-layer PCB and protected by box-like FR4 Faraday cages. The transducers of the pressure device can be used in turn, thus providing redundancy and improved reliability. The pressure device measurement range is 0 - 1025 hPa in temperature range of -45°C - +55°C, but its calibration is optimized for the Martian pressure range of 4 - 12 hPa. In support of the in situ measurements we have analyzed the atmospheric conditions at the MSL landing site at the Gale crater by utilizing mesoscale and limited area models. The compatibility of the results of these modeling tools with the actual environmental conditions will be discussed.

Design variability in web geometry of an orb-weaving spider.

PubMed

Vollrath, F; Downes, M; Krackow, S

1997-10-01

We studied the effect of several variables (environmental and physiological) on web geometry in the garden cross spider Araneus diadematus. Variables were: web support, wind, temperature, humidity, and silk supply. All had an effect. The spiders generally attempted to fit their webs to the shape of the supporting frame (standard, small, vertical, or horizontal). Windy conditions (0.5 m s-1) during web construction caused spiders to build smaller and rounder webs, laying down fewer capture spirals while increasing the distances between capture-spiral meshes. Decreasing temperature from 24 degrees to 12 degrees C caused the capture spiral to have fewer and wider spaced meshes, which did not change overall capture area but reduced the length of capture-spiral threads laid down. Subsequent increase of temperature to 24 degrees C restored the number of meshes laid down, but the wider mesh was retained, causing the capture area to be increased over initial control values. Decreased humidity (from 70 to 20% rH) had the effect of reducing web and capture-spiral size, the latter by reducing mesh number while keeping mesh spacing constant. Subsequent increase of humidity to control level (70%) restored web and capture area. However, this was achieved by laying down capture meshes at larger distances, rather than returning to initial mesh numbers. Silk supply also had a strong effect. Webs built in unnaturally rapid succession by the same spider (4 in 24 h when 1 is the norm) became sequentially smaller, had fewer radii, shorter capture spirals, and were wider meshed.

Influences of calcium oxide content in marine fuel oil on emission characteristics of marine furnaces under varying humidity and temperature of the inlet air.

PubMed

Lin, Cherng-Yuan; Chen, Wei-Cheng

2004-01-01

A marine furnace made of stainless steel. combined with an automatic small-size oil-fired burner, was used to experimentally investigate the influences of calcium oxide content in fuel oil on the combustion and emission characteristics under varying temperatures and humidity of the inlet air. Marine fuel oil generally contains various extents of metallic oxides such as CaO, Fe2O3, V2O5, etc which might affect its burning properties. In this study, an air-conditioner was used to adjust the humidity and temperatures of the inlet air to preset values prior to entering the burner. The adjusted inlet air atomized the marine diesel oil A containing a calcium oxide compound, to form a heterogeneous reactant mixture. The reactant mixture was thereafter ignited by a high-voltage electrode in the burner and burned within the marine furnace. The probes of a gas analyzer, H2S analyzer and a K-type thermocouple were inserted into the radial positions of the furnace through the eight rectangular slots which were cut in the upper side of the furnace. The experimental results showed that an increase of either humidity or temperature of the inlet air caused the promotion of the reaction rate of the fuel. The existence of calcium oxide compound in the diesel fuel also facilitated the oxidation reaction in the combustion chamber. The addition of CaO in the diesel fuel under the conditions of higher temperature or higher relative humidity of the inlet air produced the following: higher concentrations of CO2, SO2, and H2S emissions, an increased burning efficiency, a lowered O2 level, production of excess air and NOx emissions as well as a lower thermal loss and a lower burning gas temperature, as compared with the conditions of a lower temperature or a lower humidity of the inlet air. In addition, the burning of diesel fuel with added CaO compound caused a large variation in the burning efficiency, thermal loss, plus CO2, O2, and excess air emissions between the conditions of higher temperature/higher humidity and lower temperature/lower humidity inlet air compared with no CaO addition in the fuel. Moreover, the burning efficiency and the concentrations of excess air and O2 emissions increased, while the thermal loss, burning gas temperature and H2S, SO2, NOx, and CO2 emissions decreased with the increase of the axial distance from the measured location to the burner nozzle.

Humidity Detection and Hygropreference Behavior in Larvae of the Tobacco hornworm, Manduca sexta

PubMed Central

Rowley, Marc; Hanson, Frank

2007-01-01

Water is a critical resource for any terrestrial animal, especially for a soft-bodied insect such as larvae of the tobacco hornworm, Manduca sexta L. (Lepidoptera: Sphingidae). Strategies for coping with a dry environment might include seeking out regions of high relative humidity that reduce desiccative stress, or to find and imbibe liquid water. Desiccated larvae placed in a linear arena with a humidity gradient preferred the humid end, whereas un-desiccated larvae did not. This behavior was not affected by temperature. Ablation or occlusion of the antennae showed that they are required to mediate this behavior. A series of experiments showed that control larvae oriented towards and imbibed liquid water whereas those whose antennae had been occluded with wax did not. Electrophysiological recordings from the lateral basiconic sensillum of the second antennal segment revealed the presence of at least one hygroreceptive unit that greatly increased its firing rate in response to moist air, decreased firing rates in response to dry air, and showed mild post-stimulatory inhibition. PMID:20302460

Effects of Temperature and Humidity on Wilethane 44 Cure

DOE Office of Scientific and Technical Information (OSTI.GOV)

John C. Weigle

Wilethane 44 is a polyurethane adhesive developed by the Materials Team within ESA-MEE at Los Alamos National Laboratory as a replacement for Hexcel Corporation Urethane 7200. Urethane 7200 is used in numerous weapon systems, but it was withdrawn from the market in 1989. The weapons complex requires a replacement material for use in the W76-1 LEP and the W88, as well as for assembly of JTAs for other warheads. All polyurethane systems are susceptible to moisture reacting with unreacted isocyanate groups. This side reaction competes with the curing reaction and results in CO{sub 2} formation. Therefore, a polyurethane adhesive canmore » exhibit foaming if appropriate environmental controls are not in place while it cures. A designed experiment has been conducted at TA-16-304 to determine the effects of ambient conditions on the properties of cured Wilethane 44. Temperature was varied from 15 C to 30 C and relative humidity from 15% to 40%. The density, hardness at 24 hours, and butt tensile strength on aluminum substrates were measured and fitted to quadratic equations over the experimental space. Additionally, the loss and storage moduli during cure were monitored as a function of cure temperature. These experiments provide a stronger basis for establishing appropriate environmental conditions and cure times when using Wilethane 44. The current guidelines are a working time of 90 minutes, a cure time of 18 hours, and a relative humidity of less than 25%, regardless of ambient temperature. Viscosity measurements revealed that the working time is a strong function of temperature and can be as long as 130 minutes at 15 C or as short as 90 minutes at 30 C. The experiments also showed that the gel time is much longer than originally thought, as long as 13 hours at 15 C. Consequently, it may be necessary to extend the required cure time at temperatures below 20 C. Allowable humidity varies as a function of temperature from 34% at 15 C to 15% at 30 C.« less

Integrated CMOS dew point sensors for relative humidity measurement

NASA Astrophysics Data System (ADS)

Savalli, Nicolo; Baglio, Salvatore; Castorina, Salvatore; Sacco, Vincenzo; Tringali, Cristina

2004-07-01

This work deals with the development of integrated relative humidity dew point sensors realized by adopting standard CMOS technology for applications in various fields. The proposed system is composed by a suspended plate that is cooled by exploiting integrated Peltier cells. The cold junctions of the cells have been spread over the plate surface to improve the homogeneity of the temperature distribution over its surface, where cooling will cause the water condensation. The temperature at which water drops occur, named dew point temperature, is a function of the air humidity. Measurement of such dew point temperature and the ambient temperature allows to know the relative humidity. The detection of water drops is achieved by adopting a capacitive sensing strategy realized by interdigited fixed combs, composed by the upper layer of the adopted process. Such a capacitive sensor, together with its conditioning circuit, drives a trigger that stops the cooling of the plate and enables the reading of the dew point temperature. Temperature measurements are achieved by means of suitably integrated thermocouples. The analytical model of the proposed system has been developed and has been used to design a prototype device and to estimate its performances. In such a prototype, the thermoelectric cooler is composed by 56 Peltier cells, made by metal 1/poly 1 junctions. The plate has a square shape with 200 μm side, and it is realized by exploiting the oxide layers. Starting from the ambient temperature a temperature variation of ΔT = 15 K can be reached in 10 ms thus allowing to measure a relative humidity greater than 40%.

CLIMATE CONDITIONS AFFECTING THE WITHIN-PLANT SPREAD OF BROAD MITES ON AZALEA.

PubMed

Mechant, E; Pauwels, E; Gobin, B

2014-01-01

The broad mite Polyphagotarsonemus latus (Banks) is considered a major pest in potted azalea, Flanders' flagship ornamental crop of Rhododendron simsii hybrids. In addition to severe economic damage, the broad mite is dreaded for its increasing resistance to acaricides. Due to restrictions in the use of broad spectrum acaricides, Belgian azalea growers are left with only three compounds, belonging to two mode of action groups and restricted in their number of applications, for broad mite control: abamectin, milbemectin and pyrethrin. Although P. latus can be controlled with predatory mites, the high cost of this system makes it (not yet) feasible for integration into standard azalea pest management systems. Hence, a maximum efficacy of treatments with available compounds is essential. Because abamectin, milbemectin and pyrethrin are contact acaricides with limited trans laminar flow, only broad mites located on shoot tips of azalea plants will be controlled after spraying. Consequently, the efficacy of chemical treatments is influenced by the location and spread of P. latus on the plant. Unfortunately, little is known on broad mites' within-plant spread or how it is affected by climatic conditions like temperature and relative humidity. Therefore, experiments were set up to verify whether climate conditions have an effect on the location and migration of broad mites on azalea. Broad mite infected azalea plants were placed in standard growth chambers under different temperature (T:2.5-25°C) and relative humidity (RH:55-80%) treatments. Within-plant spread was determined by counting mites on the shoot tips and inner leaves of azalea plants. Results indicate that temperature and relative humidity have no significant effect on the within-plant spread of P. latus. To formulate recommendations for optimal spray conditions to maximize the efficacy of broad mite control with acaricides, further experiments on the effect of light intensity and rain are scheduled.

Humid microclimates within the plumage of mallard ducks (Anas platyrhynchos) can potentially facilitate long distance dispersal of propagules

NASA Astrophysics Data System (ADS)

Coughlan, Neil E.; Kelly, Tom C.; Davenport, John; Jansen, Marcel A. K.

2015-05-01

Birds as carriers of propagules are major agents in the dispersal of plants, animals, fungi and microbes. However, there is a lack of empirical data in relation to bird-mediated, epizoochorous dispersal. The microclimate found within the plumage likely plays a pivotal role in survival during flight conditions. To investigate the potential of epizoochory, we have analysed the microclimatic conditions within the plumage of mallard ducks (Anas platyrhynchos). Under similar ambient conditions of humidity and temperature, a sample of mallards showed a consistent microclimatic regime with variation across the body surface. The highest (mean) temperature and specific humidity occurred between feathers of the postpatagium. The lowest humidity was found between feathers of the centre back and the lowest temperature in the crissum. Observed differences in plumage depth and density, and distance from the skin, are all likely to be determining factors of microclimate condition. Specific humidity found within the plumage was on average 1.8-3.5 times greater than ambient specific humidity. Thus, the plumage can supply a microclimate buffered from that of the exterior environment. Extrapolating survival data for Lemna minor desiccation at various temperature and humidity levels to the measured plumage microclimatic conditions of living birds, survival for up to 6 h can be anticipated, especially in crissum, crural and breast plumage. The results are discussed in the context of potential long distance epizoochorous dispersal by A. platyrhynchos and similar species.

Comparison of land-surface humidity between observations and CMIP5 models

NASA Astrophysics Data System (ADS)

Dunn, Robert; Willett, Kate; Ciavarella, Andrew; Stott, Peter; Jones, Gareth

2017-04-01

We compare the latest observational land-surface humidity dataset, HadISDH, with the CMIP5 model archive spatially and temporally over the period 1973-2015. None of the CMIP5 models or experiments capture the observed temporal behaviour of the globally averaged relative or specific humidity over the entire study period. When using an atmosphere-only model, driven by observed sea-surface temperatures and radiative forcing changes, the behaviour of regional average temperature and specific humidity are better captured, but there is little improvement in the relative humidity. Comparing the observed and historical model climatologies show that the models are generally cooler everywhere, are drier and less saturated in the tropics and extra tropics, and have comparable moisture levels but are more saturated in the high latitudes. The spatial pattern of linear trends are relatively similar between the models and HadISDH for temperature and specific humidity, but there are large differences for relative humidity, with less moistening shown in the models over the Tropics, and very little at high atitudes. The observed temporal behaviour appears to be a robust climate feature rather than observational error. It has been previously documented and is theoretically consistent with faster warming rates over land compared to oceans. Thus, the poor replication in the models, especially in the atmosphere only model, leads to questions over future projections of impacts related to changes in surface relative humidity.

Temperature and relative humidity distributions in a medium-size administrative town in southwest Nigeria.

PubMed

Akinbode, O M; Eludoyin, A O; Fashae, O A

2008-04-01

This study was carried out in one of the medium-sized public administrative towns in the southwestern part of Nigeria. Its aim is to highlight the effect of spatial distribution of settlements, population, and socio-economic activities on urban air temperature and humidity in the town. Temperature and relative humidity data from 1992 to 2001 were obtained from three meteorological stations in Akure, the Administrative Capital of Ondo State, Nigeria. The stations are located within the Federal Ministry of Aviation, Akure Airport (FMA), Federal University of Technology, Akure (FUTA) and Federal School of Agriculture (SOA). Air temperature and relative humidity measurements were also obtained from 27 points, which were cited to include road junctions, markets, built up areas, etc., using sling psychrometer. The data were subsequently analysed for spatial and temporal variations using statistical packages (SPSS and Microsoft Excel) and isolines. Actual vapour pressure and dew point temperature were computed using Magnus conversion formulae. The results obtained showed that spatial variation was insignificant, in terms of the temperature and humidity variables. The annual mean temperature (Tmean) ranged between 21.9 and 30.4 degrees C while minimum (Tmin) and maximum (Tmax) temperatures varied from 13 to 26 and 21.5-39.6 degrees C, respectively. Relative humidity (RH), actual vapour pressure (Es) and dew point temperature (Td) values also varied from 39.1% to 98.2%, 19.7-20.8 gm(-3), and 17.3-17.8 degrees C, respectively. A significant relationship (p>0.6; r<0.05) between Tmin, Es and Td was observed while the daytime 'urban heat island' intensity (UHI) ranged between 0.5 and 2.5 degrees C within the study period. The study concluded that there is influence of urban canopy on the microclimate of Akure, and hypothesizes that the urban dwellers may be subjected to some levels of weather related physiological disorderliness.

Wet-bulb globe temperature (WBGT)--its history and its limitations.

PubMed

Budd, Grahame M

2008-01-01

Wet-bulb globe temperature (WBGT) is nowadays the most widely used index of heat stress, yet many users appear to be unaware of its history and its limitations. HISTORY OF WBGT: WBGT was invented and first used during the 1950s as one element in a successful campaign to control serious outbreaks of heat illness in training camps of the United States Army and Marine Corps. Control measures based on air temperature and humidity, and applied to all trainees alike, had proved effective but had entailed excessive compliance costs in the form of lost training time. New control measures introduced in 1956 further reduced heat illness and also lost fewer training hours. Crucial innovations were (1) replacing the temperature and humidity measurements with WBGT, which additionally responds to sun and wind, (2) using epidemiologic analyses of casualty records to identify hazardous levels of WBGT and vulnerable trainees, and (3) protecting the most vulnerable trainees by suspending drill at lower levels of WBGT, and by improving their heat tolerance in special conditioning platoons. This campaign has considerable relevance to the prevention of heat illness in sport. LIMITATIONS OF WBGT: WBGT's most serious limitation is that environments at a given level of the index are more stressful when the evaporation of sweat is restricted (by high humidity or low air movement) than when evaporation is free. As with all indices that integrate elements of the thermal environment, interpretation of the observed levels of WBGT requires careful evaluation of people's activity, clothing, and many other factors, all of which can introduce large errors into any predictions of adverse effects. Moreover, the accuracy of WBGT is being eroded by measurement errors associated with the omission of the globe temperature, with non-standard instrumentation, and with unsatisfactory calibration procedures. Because of the above limitations WBGT can provide only a general guide to the likelihood of adverse effects of heat. A much clearer assessment can be obtained by measuring the individual elements of the thermal environment, and using those measurements to estimate the requirement for evaporative cooling, the likelihood of achieving it, and more accurate and comprehensive indices of heat stress.

Evaluation of 2 Heat-Mitigation Methods in Army Trainees.

PubMed

Sefton, JoEllen M; McAdam, J S; Pascoe, David D; Lohse, K R; Banda, Robert L; Henault, Corbin B; Cherrington, Andrew R; Adams, N E

2016-11-01

 Heat injury is a significant threat to military trainees. Different methods of heat mitigation are in use across military units. Mist fans are 1 of several methods used in the hot and humid climate of Fort Benning, Georgia.  To determine if (1) the mist fan or the cooling towel effectively lowered participant core temperature in the humid environment found at Fort Benning and (2) the mist fan or the cooling towel presented additional physiologic or safety benefits or detriments when used in this environment.  Randomized controlled clinical trial.  Laboratory environmental chamber.  Thirty-five physically active men aged 19 to 35 years.  (1) Mist fan, (2) commercial cooling towel, (3) passive-cooling (no intervention) control. All treatments lasted 20 minutes. Participants ran on a treadmill at 60% V̇o 2 max.  Rectal core temperature, heart rate, thermal comfort, perceived temperature, perceived wetness, and blood pressure.  Average core temperature increased during 20 minutes of cooling (F 1,28 = 64.76, P < .001, η p 2 = 0.70), regardless of group (F 1,28 = 3.41, P = .08, η p 2 = 0.11) or condition (F 1,28 < 1.0). Core temperature, heart rate, and blood pressure did not differ among the 3 conditions. Perceived temperature during 20 minutes of cooling decreased (F 1,30 = 141.19, P < .001, η p 2 = 0.83) regardless of group or condition. Perceived temperature was lower with the mist-fan treatment than with the control treatment (F 1,15 = 7.38, P = .02, η p 2 = 0.32). The mist-fan group perceived themselves to be cooler even at elevated core temperatures.  The mist fan and cooling towel were both ineffective at lowering core temperature. Core temperature continued to increase after exercise in all groups. The mist fan produced feelings of coolness while the core temperature remained elevated, possibly increasing the risk of heat illness.

Evaluation of 2 Heat-Mitigation Methods in Army Trainees

PubMed Central

Sefton, JoEllen M.; McAdam, J. S.; Pascoe, David D.; Lohse, K. R.; Banda, Robert L.; Henault, Corbin B.; Cherrington, Andrew R.; Adams, N. E.

2016-01-01

Context: Heat injury is a significant threat to military trainees. Different methods of heat mitigation are in use across military units. Mist fans are 1 of several methods used in the hot and humid climate of Fort Benning, Georgia. Objectives: To determine if (1) the mist fan or the cooling towel effectively lowered participant core temperature in the humid environment found at Fort Benning and (2) the mist fan or the cooling towel presented additional physiologic or safety benefits or detriments when used in this environment. Design: Randomized controlled clinical trial. Setting: Laboratory environmental chamber. Patients or Other Participants: Thirty-five physically active men aged 19 to 35 years. Intervention(s): (1) Mist fan, (2) commercial cooling towel, (3) passive-cooling (no intervention) control. All treatments lasted 20 minutes. Participants ran on a treadmill at 60% V̇o2max. Main Outcome Measure(s): Rectal core temperature, heart rate, thermal comfort, perceived temperature, perceived wetness, and blood pressure. Results: Average core temperature increased during 20 minutes of cooling (F1,28 = 64.76, P < .001, ηp2 = 0.70), regardless of group (F1,28 = 3.41, P = .08, ηp2 = 0.11) or condition (F1,28 < 1.0). Core temperature, heart rate, and blood pressure did not differ among the 3 conditions. Perceived temperature during 20 minutes of cooling decreased (F1,30 = 141.19, P < .001, ηp2 = 0.83) regardless of group or condition. Perceived temperature was lower with the mist-fan treatment than with the control treatment (F1,15 = 7.38, P = .02, ηp2 = 0.32). The mist-fan group perceived themselves to be cooler even at elevated core temperatures. Conclusions: The mist fan and cooling towel were both ineffective at lowering core temperature. Core temperature continued to increase after exercise in all groups. The mist fan produced feelings of coolness while the core temperature remained elevated, possibly increasing the risk of heat illness. PMID:27710091

Perceptions of temperature, moisture and comfort in clothing during environmental transients.

PubMed

Li, Y

2005-02-22

A study has been carried out to investigate the psychophysical mechanisms of the perception of temperature and moisture sensations in clothing during environmental transients. A series of wear trials was conducted to measure the psychological perception of thermal and moisture sensations and the simultaneous temperature and humidity at the skin surface, fabric surface and in the clothing under simulated moderate rain conditions. Jumpers made from wool and acrylic fibres were used in the trial. Analysis has been carried out to study the relationship between psychological perceptions of temperature and moisture and the objectively measured skin and fabric temperatures and relative humidity in clothing microclimate. The perception of warmth seems to follow Fechner's law and Stevens' power law, having positive relationships with the skin temperature and fabric temperatures. The perception of dampness appears to follow Fechner's law more closely than Stevens' power law with a negative relationship with skin temperature, and is nonlinearly and positively correlated with relative humidity in clothing microclimate. The perception of comfort is positively related to the perception of warmth and negatively to the perception of dampness. This perception of comfort is positively related to the skin temperature, which appears to follow both Fechner's law and Stevens' law, also non-linearly and negatively related to relative humidity in clothing microclimate.

N95 filtering facepiece respirator deadspace temperature and humidity.

PubMed

Roberge, Raymond J; Kim, Jung-Hyun; Benson, Stacey

2012-01-01

The objective of this study was to determine the levels of heat and humidity that develop within the deadspace of N95 filtering facepiece respirators (N95 FFR). Seventeen subjects wore two models each of N95 FFR and N95 FFR with an exhalation valve (N95 FFR/EV) while exercising on a treadmill at a low-moderate work rate for 1 and 2 hr in a temperate ambient environment. FFR deadspace temperature and relative humidity were monitored by a wireless sensor housed within the FFR. Each FFR was weighed pre- and post-testing to determine moisture retention. After 1 hr, FFR deadspace temperature and humidity were markedly elevated above ambient levels, and the FFR deadspace mean apparent heat index was 54°C. N95 FFR/EV use resulted in significantly lower deadspace temperatures than N95 FFR (p = 0.01), but FFR deadspace humidity levels were not significantly different (p = 0.32). Compared with the first hour of use, no significant increase in FFR deadspace heat and humidity occurred over the second hour. FFR mean moisture retention was < 0.3 grams over 2 hr. N95 FFR/EV offer a significant advantage in deadspace heat dissipation over N95 FFR at a low-moderate work rate over 1 hr of continuous use but offered no additional benefit in humidity amelioration. Moisture retention in N95 FFR and N95 FFR/EV is minimal after 2 hr of use. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: a file containing N95 filtering facepiece respirator deadspace mean RH and temperature recordings for 17 subjects treadmill exercising at 5.6 Km/H over 1 hour.].

Measuring Relative Humidity.

ERIC Educational Resources Information Center

Pinkham, Chester A.; Barrett, Kristin Burrows

1992-01-01

Describes four experiments that enable students to explore the phenomena of evaporation and condensation and determine the relative humidity by measuring air temperature and dew point on warm September days. Provides tables to calculate saturation points and relative humidity. (MDH)

A Brief Look at Recent Developments in the Preservation and Conservation of Special Collections.

ERIC Educational Resources Information Center

Hain, Jennifer E.

2003-01-01

Highlights some of the skills and technological advances that have changed the way special collections are preserved in reference to two approaches: item-level conservation and collections conservation. Discusses mechanical paper splitting; computer imaging and mechanization; mass deacidification; controlling temperature, humidity, pests, and…

24 CFR 3280.802 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... supply. (15) Distribution panelboard means a single panel or a group of panel units designed for assembly...) Panelboard means a single panel or group of panel units designed for assembly in the form of a single panel... treatment of air so as to control simultaneously its temperature, humidity, cleanliness, and distribution to...

109. EAST WALL OF MECHANICAL EQUIPMENT ROOM (201), LSB (BLDG. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

109. EAST WALL OF MECHANICAL EQUIPMENT ROOM (201), LSB (BLDG. 751): TEMPERATURE, FLOW RATE, AND HUMIDITY MONITORING CONTROLS FOR SYSTEM 1 AND SYSTEM 2 AIR HANDLING - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

92. EAST WALL OF MECHANICAL EQUIPMENT ROOM (101), LSB (BLDG. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

92. EAST WALL OF MECHANICAL EQUIPMENT ROOM (101), LSB (BLDG. 770). TEMPERATURE, FLOW RATE, AND HUMIDITY MONITORING CONTROLS FOR SYSTEM 1 AND SYSTEM 2 AIR HANDLING. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Advanced Plant Habitat (APH)

NASA Technical Reports Server (NTRS)

Richards, Stephanie E. (Compiler); Levine, Howard G.; Reed, David W.

2016-01-01

The Advanced Plant Habitat (APH) hardware will be a large growth volume plant habitat, capable of hosting multigenerational studies, in which environmental variables (e.g., temperature, relative humidity, carbon dioxide level light intensity and spectral quality) can be tracked and controlled in support of whole plant physiological testing and Bio-regenerative Life Support System investigations.

International Space Station Environmental Control and Life Support System Acceptance Testing for Node 1 Atmosphere Control and Supply Subsystem

NASA Technical Reports Server (NTRS)

Williams, David E.

2009-01-01

The International Space Station (ISS) Node 1 Environmental Control and Life Support (ECLS) System is comprised of five subsystems: Atmosphere Control and Supply (ACS), Atmosphere Revitalization (AR), Fire Detection and Suppression (FDS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). This paper provides a summary of the Node 1 ECLS ACS subsystem design and a detailed discussion of the ISS ECLS Acceptance Testing methodology utilized for that subsystem.

The effects of temperature, relative humidity, light, and resource quality on flight initiation in the red flour beetle, Tribolium castaneum.

PubMed

Drury, Douglas W; Whitesell, Matthew E; Wade, Michael J

2016-03-01

We investigated the environmental conditions that induce a flight response in the red flour beetle, Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), including resource quality, temperature, relative humidity, and light. Over 72-h trial periods, we observed the proportion of individuals emigrating by flight to range from 0.0 in extreme heat or cold to 0.82 with starvation. Resource quality, presence of a light source, and temperature all directly influenced the initiation of the flight response. We did not detect any effect of relative humidity or sudden change in temperature on the incidence of flight. We discuss our findings in the context of Tribolium ecology and evolution.

Encapsulation for smart textile electronics - humidity and temperature sensor.

PubMed

Larsson, Andreas; Tran, Thanh-Nam; Aasmundtveit, Knut E; Seeberg, Trine M

2015-01-01

A combined humidity and temperature sensor was packaged by vacuum casting onto three different types of textiles; cotton, nylon and a waterproof fabric. This was done in order to integrate the sensor in a jacket in a soft and reliable way without changing the sensor performance. A membrane was custom made and integrated into the device to protect the sensor from the environment. The packaged sensors performance was characterized in a climate chamber were the relative humidity and temperature ranged from 25 % to 95 % and -10 °C to 75 °C respectively. The packaged sensors showed insignificant to limited performance degradation.

[A Surface Plasmon Micro-Ring Sensor Suitable for Humidity Sensing].

PubMed

Li, Zhi-quan; An, Dong-yang; Zhang, Xin; Zhao, Ling-ling; Sha, Xiao-peng; Guo, Shi-liang; Li, Wen-chao

2015-09-01

Temperature is a very important parameter in scientific research, production and life. Almost all the properties of materials are related to temperature. The precise measurement of the temperature is a very important task, so the temperature sensor is widely used as a core part in the temperature measuring instrument. A novel surface plasmon micro-ring sensor suitable for humidity sensing is presented in this paper. The sensor uses a multi-layered surface plasmon waveguide structure and choosing Polyimide (Polyimide, PI) as the moisture material. We get the transfer function of surface plasmon micro-ring sensor by using transfer matrix method. Refractive indexes of Polyimide and the multilayer waveguide structure change as environment relative humidity changes, thus leading to an obvious peak drift of output spectrum. The paper mainly discusses the influence of the changes of the refractive index of humidity-sensing parts on the output spectrum, and the transmission characteristics of multilayer waveguide structure. Through the finite element method and the theoretical simulation of Matlab, We can draw: When the length between the two coupling points of the U-shaped waveguide is an integer multiple of circumference of the micro-ring, an obvious drift in the horizontal direction appears, the free spectral range (FSR) doubled and the sensitivity is 0.0005 μm/%RH; When the external environment relative humidity RH changes from 10% to 100% RH, scatter is change between including (including 0.005 m to 0.005 m, compared to other humidity sensor, the Sensitivity of sensor improves 10~50 times and the transmission is very stable. Results show that the design of surface plasma micro ring sensors has better sensitivity, stable performance and can be used in the humidity measurement, achieving a high sensitivity in the sense of humidity when the wide range of filter frequency selection is taken into account, and providing a theoretical basis for the preparation of micro-optics.

A physically based analytical spatial air temperature and humidity model

NASA Astrophysics Data System (ADS)

Yang, Yang; Endreny, Theodore A.; Nowak, David J.

2013-09-01

Spatial variation of urban surface air temperature and humidity influences human thermal comfort, the settling rate of atmospheric pollutants, and plant physiology and growth. Given the lack of observations, we developed a Physically based Analytical Spatial Air Temperature and Humidity (PASATH) model. The PASATH model calculates spatial solar radiation and heat storage based on semiempirical functions and generates spatially distributed estimates based on inputs of topography, land cover, and the weather data measured at a reference site. The model assumes that for all grids under the same mesoscale climate, grid air temperature and humidity are modified by local variation in absorbed solar radiation and the partitioning of sensible and latent heat. The model uses a reference grid site for time series meteorological data and the air temperature and humidity of any other grid can be obtained by solving the heat flux network equations. PASATH was coupled with the USDA iTree-Hydro water balance model to obtain evapotranspiration terms and run from 20 to 29 August 2010 at a 360 m by 360 m grid scale and hourly time step across a 285 km2 watershed including the urban area of Syracuse, NY. PASATH predictions were tested at nine urban weather stations representing variability in urban topography and land cover. The PASATH model predictive efficiency R2 ranged from 0.81 to 0.99 for air temperature and 0.77 to 0.97 for dew point temperature. PASATH is expected to have broad applications on environmental and ecological models.

Use of Normothermic Default Humidifier Settings Causes Excessive Humidification of Respiratory Gases During Therapeutic Hypothermia.

PubMed

Tanaka, Shoichiro; Iwata, Sachiko; Kinoshita, Masahiro; Tsuda, Kennosuke; Sakai, Sayaka; Saikusa, Mamoru; Shindo, Ryota; Harada, Eimei; Okada, Junichiro; Hisano, Tadashi; Kanda, Hiroshi; Maeno, Yasuki; Araki, Yuko; Ushijima, Kazuo; Sakamoto, Teruo; Yamashita, Yushiro; Iwata, Osuke

2016-12-01

Adult patients frequently suffer from serious respiratory complications during therapeutic hypothermia. During therapeutic hypothermia, respiratory gases are humidified close to saturated vapor at 37°C (44 mg/L) despite that saturated vapor reduces considerably depending on temperature reduction. Condensation may cause serious adverse events, such as bronchial edema, mucosal dysfunction, and ventilator-associated pneumonia during cooling. To determine clinical variables associated with inadequate humidification of respiratory gases during cooling, humidity of inspiratory gases was measured in 42 cumulative newborn infants who underwent therapeutic hypothermia. Three humidifier settings of 37-default (chamber outlet, 37°C; distal circuit, 40°C), 33.5-theoretical (chamber outlet, 33.5°C; distal circuit, 36.5°C), and 33.5-adjusted (optimized setting to achieve 36.6 mg/L using feedback from a hygrometer) were tested to identify independent variables of excessively high humidity >40.7 mg/L and low humidity <32.9 mg/L. The mean (SD) humidity at the Y-piece was 39.2 (5.2), 33.3 (4.1), and 36.7 (1.2) mg/L for 37-default, 33.5-theoretical, and 33.5-adjusted, respectively. The incidence of excessive high humidity was 10.3% (37-default, 31.0%; 33.5-theoretical, 0.0%; 33.5-adjusted, 0.0%), which was positively associated with the use of a counter-flow humidifier (p < 0.001), 37-default (compared with 33.5-theoretical and 33.5-adjusted, both p < 0.001) and higher fraction of inspired oxygen (p = 0.003). The incidence of excessively low humidity was 17.5% (37-default, 7.1%; 33.5-theoretical, 45.2%; 33.5-adjusted, 0.0%), which was positively associated with the use of a pass-over humidifier and 33.5-theoretical (both p < 0.001). All patients who used a counter-flow humidifier achieved the target gas humidity at the Y-piece (36.6 ± 0.5 mg/L) required for 33.5-adjusted with 33.5-theoretical. During cooling, 37-default is associated with excessively high humidity, whereas 33.5-theoretical leads to excessively low humidity. Future studies are needed to assess whether a new regimen with optimized Y-piece temperature and humidity control reduces serious respiratory adverse events during cooling.

A History of Spacecraft Environmental Control and Life Support Systems

NASA Technical Reports Server (NTRS)

Daues, Katherine R.

2006-01-01

A spacecraft's Environmental Control and Life Support (ECLS) system enables and maintains a habitable and sustaining environment for its crew. A typical ECLS system provides for atmosphere consumables and revitalization, environmental monitoring, pressure, temperature and humidity control, heat rejection (including equipment cooling), food and water supply and management, waste management, and fire detection and suppression. The following is a summary of ECLS systems used in United States (US) and Russian human spacecraft.

Effect of inlet-air humidity, temperature, pressure, and reference Mach number on the formation of oxides of nitrogen in a gas turbine combustor

NASA Technical Reports Server (NTRS)

Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

1973-01-01

Tests were conducted to determine the effect of inlet air humidity on the formation of oxides of nitrogen (NOx) from a gas turbine combustor. Combustor inlet air temperature ranged from 506 K (450 F) to 838 K (1050 F). The tests were primarily run at a constant pressure of 6 atmospheres and reference Mach number of 0.065. The NOx emission index was found to decrease with increasing inlet air humidity at a constant exponential rate: NOx = NOx0e-19H (where H is the humidity and the subscript 0 denotes the value at zero humidity). the emission index increased exponentially with increasing normalized inlet air temperature to the 1.14 power. Additional tests made to determine the effect of pressure and reference Mach number on NOx showed that the NOx emission index varies directly with pressure to the 0.5 power and inversely with reference Mach number.

Use of Temperature and Humidity Sensors to Determine Moisture Content of Oolong Tea

PubMed Central

Chen, Andrew; Chen, Hsuan-Yu; Chen, Chiachung

2014-01-01

The measurement of tea moisture content is important for processing and storing tea. The moisture content of tea affects the quality and durability of the product. Some electrical devices have been proposed to measure the moisture content of tea leaves but are not practical. Their performance is influenced by material density and packing. The official oven method is time-consuming. In this study, the moisture content of Oolong tea was measured by the equilibrium relative humidity technique. The equilibrium relative humidity, and temperature, of tea materials were measured by using temperature and relative humidity sensors. Sensors were calibrated, and calibration equations were established to improve accuracy. The moisture content was calculated by using an equilibrium moisture content model. The error of the moisture content determined with this method was within 0.5% w.b. at moisture <15% w.b. Uncertainty analysis revealed that the performance of the humidity sensor had a significant effect on the accuracy of moisture determination. PMID:25153142

Mass and heat transfer model of Tubular Solar Still

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahsan, Amimul; Fukuhara, Teruyuki

2010-07-15

In this paper, a new mass and heat transfer model of a Tubular Solar Still (TSS) was proposed incorporating various mass and heat transfer coefficients taking account of the humid air properties inside the still. The heat balance of the humid air and the mass balance of the water vapor in the humid air were formulized for the first time. As a result, the proposed model enabled to calculate the diurnal variations of the temperature, water vapor density and relative humidity of the humid air, and to predict the hourly condensation flux besides the temperatures of the water, cover andmore » trough, and the hourly evaporation flux. The validity of the proposed model was verified using the field experimental results carried out in Fukui, Japan and Muscat, Oman in 2008. The diurnal variations of the calculated temperatures and water vapor densities had a good agreement with the observed ones. Furthermore, the proposed model can predict the daily and hourly production flux precisely. (author)« less

Humidification during high-frequency oscillatory ventilation for adults: a bench study.

PubMed

Chikata, Yusuke; Imanaka, Hideaki; Ueta, Masahiko; Nishimura, Masaji

2010-12-01

High-frequency oscillatory ventilation (HFOV) has recently been applied to acute respiratory distress syndrome patients. However, the issue of humidification during HFOV has not been investigated. In a bench study, we evaluated humidification during HFOV for adults to test if adequate humidification was achieved in 2 different HFOV systems. We tested 2 brands of adult HFOV ventilators, the R100 (Metran, Japan) and the 3100B (SensorMedics, CA), under identical bias flow. A heated humidifier consisting of porous hollow fiber (Hummax II, Metran) was set for the R100, and a passover-type heated humidifier (MR850, Fisher & Paykel) was set for the 3100B, while inspiratory heating wire was applied to both systems. Each ventilator was connected to a lung model in an incubator. Absolute humidity, relative humidity and temperature at the airway opening were measured using a hygrometer under a variety of ventilatory settings: 3 stroke volumes/amplitudes, 3 frequencies, and 2 mean airway pressures. The R100 ventilator showed higher absolute humidity, higher relative humidity, and lower temperature than the 3100B. In the R100, as stroke volume and frequency increased, absolute humidity and temperature increased. In the 3100B, amplitude, frequency, and mean airway pressure minimally affected absolute humidity and temperature. Relative humidity was almost 100% in the R100, while it was 80.5±2.3% in the 3100B. Humidification during HFOV for adults was affected by stroke volume and frequency in the R100, but was not in the 3100B. Absolute humidity was above 33 mgH_2 O/L in these 2 systems under a range of settings.

Design of an Incubator for Premature Infant Based on LabVIEW.

PubMed

Zhang, Lina; Zhou, Runjing

2005-01-01

This paper introduces the system structure, hardware circuits, control algorithms, and software program of the incubator for premature infant based on LabVIEW. The main advantages of this device are that preheating is less time than others, the capability of meeting of emergency is provided, control track of temperature and humidity are visible, operation is easy to clinical practice, and maintainability is possessed.

Humidity-resistant ambient-temperature solid-electrolyte amperometric sensing apparatus and methods

DOEpatents

Zaromb, Solomon

2001-01-01

Apparatus and methods for detecting selected chemical compounds in air or other gas streams at room or ambient temperature includes a liquid-free humidity-resistant amperometric sensor comprising a sensing electrode and a counter and reference electrode separated by a solid electrolyte. The sensing electrode preferably contains a noble metal, such as Pt black. The electrolyte is water-free, non-hygroscopic, and substantially water-insoluble, and has a room temperature ionic conductivity .gtoreq.10.sup.-4 (ohm-cm).sup.-1, and preferably .gtoreq.0.01 (ohm-cm).sup.-1. The conductivity may be due predominantly to Ag+ ions, as in Ag.sub.2 WO.sub.4.4AgI, or to F- ions, as in Ce.sub.0.95 Ca.sub.0.05 F.sub.2.95. Electrical contacts serve to connect the electrodes to potentiostating and detecting circuitry which controls the potential of the sensing electrode relative to the reference electrode, detects the signal generated by the sensor, and indicates the detected signal.

Humidity-resistant ambient-temperature solid-electrolyte amperometric sensing apparatus

DOEpatents

Zaromb, Solomon

1994-01-01

Apparatus and methods for detecting selected chemical compounds in air or other gas streams at room or ambient temperature includes a liquid-free humidity-resistant amperometric sensor comprising a sensing electrode and a counter and reference electrode separated by a solid electrolyte. The sensing electrode preferably contains a noble metal, such as Pt black. The electrolyte is water-free, non-hygroscopic, and substantially water-insoluble, and has a room temperature ionic conductivity .gtoreq.10.sup.-4 (ohm-cm).sup.-1, and preferably .gtoreq.0.01 (ohm-cm).sup.-1. The conductivity may be due predominantly to Ag+ ions, as in Ag.sub.2 WO.sub.4.4AgI, or to F- ions, as in Ce.sub.0.95 Ca.sub.0.05 F.sub.2.95. Electrical contacts serve to connect the electrodes to potentiostating and detecting circuitry which controls the potential of the sensing electrode relative to the reference electrode, detects the signal generated by the sensor, and indicates the detected signal.

Data set: 31 years of spatially distributed air temperature, humidity, precipitation amount and precipitation phase from a mountain catchment in the rain-snow transition zone

USDA-ARS?s Scientific Manuscript database

Thirty one years of spatially distributed air temperature, relative humidity, dew point temperature, precipitation amount, and precipitation phase data are presented for the Reynolds Creek Experimental Watershed. The data are spatially distributed over a 10m Lidar-derived digital elevation model at ...

Investigation of reliability attributes and accelerated stress factors on terrestrial solar cells

NASA Technical Reports Server (NTRS)

Lathrop, J. W.; Prince, J. L.

1980-01-01

Three tasks were undertaken to investigate reliability attributes of terrestrial solar cells: (1) a study of the electrical behavior of cells in the second (reverse) quadrant; (2) the accelerated stress testing of three new state-of-the-art cells; and (3) the continued bias-temperature testing of four block 2 type silicon cells at 78 C and 135 C. Electrical characteristics measured in the second quadrant were determined to be a function of the cell's thermal behavior with breakdown depending on the initiation of localized heating. This implied that high breakdown cells may be more fault tolerant when forced to operate in the second quadrant, a result contrary to conventional thinking. The accelerated stress tests used in the first (power) quadrant were bias-temperature, bias-temperature-humidity, temperature-humidity, thermal shock, and thermal cycle. The new type cells measured included an EFG cell, a polycrystalline cell, and a Czochralski cell. Significant differences in the response to the various tests were observed between cell types. A microprocessed controlled, short interval solar cell tester was designed and construction initiated on a prototype.

Relative humidity effects on the surface electrical properties of resistive plate chamber melaminic laminates uncoated and coated with polymerized linseed oil film

NASA Astrophysics Data System (ADS)

Bearzotti, Andrea; Palummo, Lucrezia

2007-09-01

Relative humidity is an important quantity to control in many manufacturing environments such as semiconductor industry. Humidity and moisture can affect many electronic devices, generally rendering their operation worse. In this study we present results showing that in some specific applications, humidity can improve the performance of an electronic device. Resistive plate chambers are used as trigger detectors of the muon system in LHC (large hadron collider) experiments ATLAS (a toroidal LHC apparatus), CMS (compact muon solenoid) and ALICE (a large ion collider experiment) and as detector in cosmic rays experiment ARGO (astrophysical radiation with ground-based observatory). These detectors are made of phenolic-melaminic laminate electrodes, coated with a polymerized linseed oil film delimiting the gaseous sensitive volume. The loss of some of the detector capability can be progressive in time and due to the intrinsic limits of the detector materials. One of these effects is due to an increase of the total plate resistance, that is correlated to ion migration and relativity humidity phenomena. Our purpose is to understand the relative humidity (RH) influence on the conduction mechanisms on the electrodes surface. Results of amperometric measurements on laminate samples kept at a fixed temperature of 22°C, cycling RH between 10% and 90% are here presented.

Uncertainly Analysis of Two Types of Humidity Sensors by a Humidity Generator with a Divided-Flow System.

PubMed

Chen, Ling-Hsi; Chen, Chiachung

2018-02-21

Humidity measurement is an important technique for the agricultural, foods, pharmaceuticals, and chemical industries. For the sake of convenience, electrical relative humidity (RH) sensors have been widely used. These sensors need to be calibrated to ensure their accuracy and the uncertainty measurement of these sensors has become a major concern. In this study, a self-made divided-flow generator was established to calibrate two types of electrical humidity sensors. The standard reference humidity was calculated from dew-point temperature and air dry-bulb temperature measured by a chilled mirror monitor. This divided-flow generator could produce consistent result of RH measurement results. The uncertainty of the reference standard increased with the increase of RH values. The combined uncertainty with the adequate calibration equations were ranged from 0.82% to 1.45% RH for resistive humidity sensors and 0.63% to 1.4% for capacitive humidity sensors, respectively. This self-made, divided-flow generator, and calibration method are cheap, time-saving, and easy to be used. Thus, the proposed approach can easily be applied in research laboratories.

Uncertainly Analysis of Two Types of Humidity Sensors by a Humidity Generator with a Divided-Flow System

PubMed Central

Chen, Ling-Hsi

2018-01-01

Humidity measurement is an important technique for the agricultural, foods, pharmaceuticals, and chemical industries. For the sake of convenience, electrical relative humidity (RH) sensors have been widely used. These sensors need to be calibrated to ensure their accuracy and the uncertainty measurement of these sensors has become a major concern. In this study, a self-made divided-flow generator was established to calibrate two types of electrical humidity sensors. The standard reference humidity was calculated from dew-point temperature and air dry-bulb temperature measured by a chilled mirror monitor. This divided-flow generator could produce consistent result of RH measurement results. The uncertainty of the reference standard increased with the increase of RH values. The combined uncertainty with the adequate calibration equations were ranged from 0.82% to 1.45% RH for resistive humidity sensors and 0.63% to 1.4% for capacitive humidity sensors, respectively. This self-made, divided-flow generator, and calibration method are cheap, time-saving, and easy to be used. Thus, the proposed approach can easily be applied in research laboratories. PMID:29466313

The Effects of the Heat and Moisture Exchanger on Humidity, Airway Temperature, and Core Body Temperature

DTIC Science & Technology

1999-10-01

was added to the experimental group. Three more measurements were recorded at 10, 30 and 60 minutes after the insertion of the heat and moisture...heat and moisture exchanger provided adequate humidification of the inspired gases. In the experimental group, there was no difference in...exchanger incorporated in the ventilator Heat and Moisture Exchangers 16 circuit (the experimental group) and 10 did not (the control group

Research on the operation control strategy of the cooling ceiling combined with fresh air system

NASA Astrophysics Data System (ADS)

Huang, Tao; Li, Hao

2018-03-01

The cooling ceiling combined with independent fresh air system was built by TRNSYS. And the cooling effects of the air conditioning system of an office in Beijing in a summer typical day were simulated. Based on the “variable temperature” control strategy, the operation strategy of “variable air volume auxiliary adjustment” was put forward. The variation of the indoor temperature, the indoor humidity, the temperature of supplying water and the temperature of returning water were simulated under the two control strategies. The energy consumption of system during the whole summer was compared by utilizing the two control strategies, and the indoor thermal comfort was analyzed. The optimal control strategy was proposed under the condition that the condensation on the surface of the cooling ceiling is not occurred and the indoor thermal comfort is satisfied.

Evaluation of the permeability of agricultural films to various fumigants.

PubMed

Qian, Yaorong; Kamel, Alaa; Stafford, Charles; Nguyen, Thuy; Chism, William J; Dawson, Jeffrey; Smith, Charles W

2011-11-15

A variety of agricultural films are commercially available for managing emissions and enhancing pest control during soil fumigation. These films are manufactured using different materials and processes which can ultimately result in different permeability to fumigants. A systematic laboratory study of the permeability of the agricultural films to nine fumigants was conducted to evaluate the performance of commonly used film products, including polyethylene, metalized, and high-barrier films. The permeability, as expressed by mass transfer coefficient (cm/h), of 27 different films from 13 manufacturers ranged from below 1 × 10(-4) cm/h to above 10 cm/h at 25 °C under ambient relative humidity test conditions. The wide range in permeability of commercially available films demonstrates the need to use films which are appropriate for the fumigation application. The effects of environmental factors, such as temperature and humidity, on the film permeability were also investigated. It was found that high relative humidity could drastically increase the permeability of the high-barrier films. The permeability of some high-barrier films was increased by 2-3 orders of magnitude when the films were tested at high relative humidity. Increasing the temperature from 25 to 40 °C increased the permeability for some high-barrier films up to 10 times more than the permeability at 25 °C, although the effect was minimal for several of these films. Analysis of the distribution of the permeability of the films under ambient humidity conditions to nine fumigants indicated that the 27 films largely followed the material type, although the permeability varied considerably among the films of similar material.

Effects of Temperature and Humidity History on Brittleness of α-Sulfonated Fatty Acid Methyl Ester Salt Crystals.

PubMed

Watanabe, Hideaki; Morigaki, Atsunori; Kaneko, Yukihiro; Tobori, Norio; Aramaki, Kenji

2016-01-01

α-Sulfonated fatty acid methyl ester salts (MES), which were made from vegetable sources, are attractive candidates for eco-friendly washing detergents because they have various special features like excellent detergency, favorable biodegradability, and high stability against enzymes. To overcome some disadvantages of powder-type detergents like caking, sorting, and dusting, we studied how temperature and humidity history, as a model for long-term storage conditions, can affect crystalline structures and reduce the brittleness of MES powder. We characterized the crystalline structure of MES grains using small-angle X-ray scattering, wide-angle X-ray scattering, differential scanning calorimetry, and Fourier transform infrared spectroscopy measurements and determined the yield values, which measure the brittleness of MES grains, in shear stress using dynamic viscoelasticity measurements. This study confirmed that MES crystals form three pseudo-polymorphs via thermal or humidity conditioning: metastable crystals (αsubcell), anhydrous crystals (β subcell), and dihydrate crystals (β' subcell). Further, we found that the yield value increases upon phase transition from the β subcell to the β' subcell and from the β' subcell to the αsubcell. Therefore, controlling the thermal and humidity conditioning of MES grains is an effective way to decrease the brittleness of MES powders and can be used to overcome the above mentioned disadvantages of powder-type detergents in the absence of co-surfactants.

Description and testing of three moisture sensors for measuring surface wetness on carbonate building stones

USGS Publications Warehouse

See, R.B.; Reddy, M.M.; Martin, R.G.

1988-01-01

Three moisture sensors were tested as a means for determining the surface wetness on carbonate building stones exposed to conditions that produce deposition of moisture. A relative-humidity probe, a gypsum-coated circuit grid, and a limestone-block resistor were tested as sensors for determining surface wetness. Sensors were tested under laboratory conditions of constant relative humidity and temperature and also under on-site conditions of variable relative humidity and temperature for eight weeks at Newcomb, NY. Laboratory tests indicated that relative humidity alone did not cause sensors to become saturated with water. However, the rates of drying indicated by the sensors after an initial saturation were inversely related to the relative humidity. On-site testing of the relative-humidity probe and the gypsum-coated ciruit grid indicated that they respond to a diurnal wetting and drying cycle; the limestone-block resistor responded only to rainfall.

Validating a new device for measuring tear evaporation rates.

PubMed

Rohit, Athira; Ehrmann, Klaus; Naduvilath, Thomas; Willcox, Mark; Stapleton, Fiona

2014-01-01

To calibrate and validate a commercially available dermatology instrument to measure tear evaporation rate of contact lens wearers. A dermatology instrument was modified by attaching a swim goggle cup such that the cup sealed around the eye socket. Results for the unmodified instrument are dependent on probe area and enclosed volume. Calibration curves were established using a model eye, to account for individual variations in chamber volume and exposed area. Fifteen participants were recruited and the study included a contact lens wear and a no contact lens wear stage. Day and diurnal variation of the measurements were assessed by taking the measurement three times a day over 2 days. The coefficient of repeatability of the measurement was calculated and a linear mixed model assessed the influence of humidity, temperature, contact lens wear, day and diurnal variations on tear evaporation rate. The associations between variables were assessed using Pearson correlation coefficient. Absolute evaporation rates with and without contact lens wear were calculated based on the new calibration. The measurements were most repeatable during the evening with no lens wear (COR = 49 g m⁻² h) and least repeatable during the evening with contact lens wear (COR = 93 g m⁻² h). Humidity (p = 0.007), and contact lens wear (p < 0.01), significantly affected the tear evaporation rate. However, temperature (p = 0.54) diurnal variation (p = 0.85) and different days (p = 0.65) had no significant effect after controlling for humidity. Tear evaporation rates can be measured using a modified dermatology instrument. Measurements were higher and more variable with lens wear consistent with previous literature. Control of environmental conditions is important as a higher humidity results in a reduced evaporation rate. © 2013 The Authors Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

The Michigan Mars Environmental Chamber: Preliminary Results and Capabilities

NASA Astrophysics Data System (ADS)

Fischer, E.; Martinez, G.; Elliott, H. M.; Borlina, C.; Renno, N. O.

2013-12-01

Introduction: We have developed the Michigan Mars Environmental Chamber (MMEC) to simulate the entire range of Martian surface and shallow subsurface conditions with respect to temperature, pressure, relative humidity, solar radiation and soil wetness. Our goal is to simulate the Martian diurnal cycle for equatorial as well as polar Martian conditions and test the hypothesis that salts known to exist in the Martian regolith can deliquesce and form brine pockets or layers by freeze-thaw cycles. Motivation: Liquid water is one of the necessary ingredients for the development of life as we know it. The behavior of various liquid states of H2O such as liquid brine, undercooled liquid interfacial water, subsurface melt water and ground water has to be understood in order to understand the potential habitability of Mars for microbes and future human exploration. It has been shown that liquid brines are ubiquitous in the Martian polar regions [1, 2, 3] and microbial communities have been seen to survive under similar conditions in Antarctica's Dry Valleys [4]. Chamber Description: The MMEC is a cylindrical environmental chamber with an inside volume of 64 cm diameter by 160 cm length. The temperature range that can be simulated is 145 K to 500 K. The temperature is controlled through an automated control system using a thermal plate system with embedded cartridge heaters and a liquid nitrogen cooling loop. Furthermore, the temperature can be measured at eight variable locations inside the chamber. The pressure is controlled through an automated control system with attainable pressures ranging from 10 Pa to 105 Pa of pure CO2. Additionally, water vapor can be added to the chamber through a separate temperature and pressure controlled H2O bath to change the relative humidity. The relative humidity is determined by measuring the frost point using a chilled mirror hygrometer and the full range of relative humidity values can be achieved. The soil wetness is measured using a microwave ring resonator soil wetness sensor [5]. Also, we can detect brine formation using a Raman spectrometer that measures spectral changes in the O-H stretching vibration region. Spectral reflectance measurements can be performed in the MMEC as well. A Xe-lamp will be used to simulate the solar radiation spectrum reaching the Martian surface and a camera will measure the spectral reflectance of the soil-ice mixture. The obtained soil wetness and spectral reflectance values are very important to support satellite estimations and numerical models. Acknowledgement: This research is supported by a grant from the NASA Astrobiology Program: Exobiology and Evolutionary Biology. Award #09-EXOB09-0050. References: [1] Renno, N. O. et al. (2009) JGR, 114, E00E03. [2] Zorzano, M.-P. et al. (2009) GRL, 36, L20201. [3] Möhlmann, D. and Kereszturi, A. (2010) Icarus, 207, 654-658. [4] Mikucki, J. A. et al. (2009) Science, 324, 397. [5] Sarabandi, K. and Li, E. S. (1997) IEEE GRS, 35, 1223-1231.

A new temperature and humidity dependent surface site density approach for deposition ice nucleation

NASA Astrophysics Data System (ADS)

Steinke, I.; Hoose, C.; Möhler, O.; Connolly, P.; Leisner, T.

2014-07-01

Deposition nucleation experiments with Arizona Test Dust (ATD) as a surrogate for mineral dusts were conducted at the AIDA cloud chamber at temperatures between 220 and 250 K. The influence of the aerosol size distribution and the cooling rate on the ice nucleation efficiencies was investigated. Ice nucleation active surface site (INAS) densities were calculated to quantify the ice nucleation efficiency as a function of temperature, humidity and the aerosol surface area concentration. Additionally, a contact angle parameterization according to classical nucleation theory was fitted to the experimental data in order to relate the ice nucleation efficiencies to contact angle distributions. From this study it can be concluded that the INAS density formulation is a very useful tool to decribe the temperature and humidity dependent ice nucleation efficiency of ATD particles. Deposition nucleation on ATD particles can be described by a temperature and relative humidity dependent INAS density function ns(T, Sice) with ns(xtherm) = 1.88 × 105 \\centerdot exp(0.2659 \\centerdot xtherm) [m-2] (1) where the thermodynamic variable xtherm is defined as xtherm = -(T - 273.2) + (Sice-1) × 100 (2) with Sice>1 and within a temperature range between 226 and 250 K. For lower temperatures, xtherm deviates from a linear behavior with temperature and relative humidity over ice. Two different approaches for describing the time dependence of deposition nucleation initiated by ATD particles are proposed. Box model estimates suggest that the time dependent contribution is only relevant for small cooling rates and low number fractions of ice-active particles.

Weather Regulates Location, Timing, and Intensity of Dengue Virus Transmission between Humans and Mosquitoes

PubMed Central

Campbell, Karen M.; Haldeman, Kristin; Lehnig, Chris; Munayco, Cesar V.; Halsey, Eric S.; Laguna-Torres, V. Alberto; Yagui, Martín; Morrison, Amy C.; Lin, Chii-Dean; Scott, Thomas W.

2015-01-01

Background Dengue is one of the most aggressively expanding mosquito-transmitted viruses. The human burden approaches 400 million infections annually. Complex transmission dynamics pose challenges for predicting location, timing, and magnitude of risk; thus, models are needed to guide prevention strategies and policy development locally and globally. Weather regulates transmission-potential via its effects on vector dynamics. An important gap in understanding risk and roadblock in model development is an empirical perspective clarifying how weather impacts transmission in diverse ecological settings. We sought to determine if location, timing, and potential-intensity of transmission are systematically defined by weather. Methodology/Principal Findings We developed a high-resolution empirical profile of the local weather-disease connection across Peru, a country with considerable ecological diversity. Applying 2-dimensional weather-space that pairs temperature versus humidity, we mapped local transmission-potential in weather-space by week during 1994-2012. A binary classification-tree was developed to test whether weather data could classify 1828 Peruvian districts as positive/negative for transmission and into ranks of transmission-potential with respect to observed disease. We show that transmission-potential is regulated by temperature-humidity coupling, enabling epidemics in a limited area of weather-space. Duration within a specific temperature range defines transmission-potential that is amplified exponentially in higher humidity. Dengue-positive districts were identified by mean temperature >22°C for 7+ weeks and minimum temperature >14°C for 33+ weeks annually with 95% sensitivity and specificity. In elevated-risk locations, seasonal peak-incidence occurred when mean temperature was 26-29°C, coincident with humidity at its local maximum; highest incidence when humidity >80%. We profile transmission-potential in weather-space for temperature-humidity ranging 0-38°C and 5-100% at 1°C x 2% resolution. Conclusions/Significance Local duration in limited areas of temperature-humidity weather-space identifies potential locations, timing, and magnitude of transmission. The weather-space profile of transmission-potential provides needed data that define a systematic and highly-sensitive weather-disease connection, demonstrating separate but coupled roles of temperature and humidity. New insights regarding natural regulation of human-mosquito transmission across diverse ecological settings advance our understanding of risk locally and globally for dengue and other mosquito-borne diseases and support advances in public health policy/operations, providing an evidence-base for modeling, predicting risk, and surveillance-prevention planning. PMID:26222979

Humidity assay for studying plant-pathogen interactions in miniature controlled discrete humidity environments with good throughput

PubMed Central

Jiang, Huawei; Sahu, Binod Bihari; Kambakam, Sekhar; Singh, Prashant; Wang, Xinran; Wang, Qiugu; Bhattacharyya, Madan K.; Dong, Liang

2016-01-01

This paper reports a highly economical and accessible approach to generate different discrete relative humidity conditions in spatially separated wells of a modified multi-well plate for humidity assay of plant-pathogen interactions with good throughput. We demonstrated that a discrete humidity gradient could be formed within a few minutes and maintained over a period of a few days inside the device. The device consisted of a freeway channel in the top layer, multiple compartmented wells in the bottom layer, a water source, and a drying agent source. The combinational effects of evaporation, diffusion, and convection were synergized to establish the stable discrete humidity gradient. The device was employed to study visible and molecular disease phenotypes of soybean in responses to infection by Phytophthora sojae, an oomycete pathogen, under a set of humidity conditions, with two near-isogenic soybean lines, Williams and Williams 82, that differ for a Phytophthora resistance gene (Rps1-k). Our result showed that at 63% relative humidity, the transcript level of the defense gene GmPR1 was at minimum in the susceptible soybean line Williams and at maximal level in the resistant line Williams 82 following P. sojae CC5C infection. In addition, we investigated the effects of environmental temperature, dimensional and geometrical parameters, and other configurational factors on the ability of the device to generate miniature humidity environments. This work represents an exploratory effort to economically and efficiently manipulate humidity environments in a space-limited device and shows a great potential to facilitate humidity assay of plant seed germination and development, pathogen growth, and plant-pathogen interactions. Since the proposed device can be easily made, modified, and operated, it is believed that this present humidity manipulation technology will benefit many laboratories in the area of seed science, plant pathology, and plant-microbe biology, where humidity is an important factor that influences plant disease infection, establishment, and development. PMID:27279932

Apparatus for supplying conditioned air at a substantially constant temperature and humidity

NASA Technical Reports Server (NTRS)

Obler, H. D. (Inventor)

1980-01-01

The apparatus includes a supply duct coupled to a source of supply air for carrying the supply air therethrough. A return duct is coupled to the supply duct for carrying return conditioned air therethrough. A temperature reducing device is coupled to the supply duct for decreasing the temperature of the supply and return conditioned air. A by-pass duct is coupled to the supply duct for selectively directing portions of the supply and return conditioned air around the temperature reducing device. Another by-pass duct is coupled to the return duct for selectively directing portions of the return conditioned air around the supply duct and the temperature reduction device. Controller devices selectively control the flow and amount of mixing of the supply and return conditioned air.

Analysis of Temperature and Humidity Field in a New Bulk Tobacco Curing Barn Based on CFD.

PubMed

Bai, Zhipeng; Guo, Duoduo; Li, Shoucang; Hu, Yaohua

2017-01-31

A new structure bulk tobacco curing barn was presented. To study the temperature and humidity field in the new structure tobacco curing barn, a 3D transient computational fluid dynamics (CFD) model was developed using porous medium, species transport, κ-ε turbulence and discrete phase models. The CFD results demonstrated that (1) the temperature and relative humidity predictions were validated by the experimental results, and comparison of simulation results with experimental data showed a fairly close agreement; (2) the temperature of the bottom and inlet area was higher than the top and outlet area, and water vapor concentrated on the top and outlet area in the barn; (3) tobacco loading density and thickness of tobacco leaves had an explicit effect on the temperature distributions in the barn.