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Sample records for absolute humidity modulates

  1. Absolute humidity and the seasonal onset of influenza in the continental United States.

    Directory of Open Access Journals (Sweden)

    Jeffrey Shaman

    2010-02-01

    Full Text Available Much of the observed wintertime increase of mortality in temperate regions is attributed to seasonal influenza. A recent reanalysis of laboratory experiments indicates that absolute humidity strongly modulates the airborne survival and transmission of the influenza virus. Here, we extend these findings to the human population level, showing that the onset of increased wintertime influenza-related mortality in the United States is associated with anomalously low absolute humidity levels during the prior weeks. We then use an epidemiological model, in which observed absolute humidity conditions temper influenza transmission rates, to successfully simulate the seasonal cycle of observed influenza-related mortality. The model results indicate that direct modulation of influenza transmissibility by absolute humidity alone is sufficient to produce this observed seasonality. These findings provide epidemiological support for the hypothesis that absolute humidity drives seasonal variations of influenza transmission in temperate regions.

  2. Study on absolute humidity influence of NRL-1 measuring apparatus for radon

    International Nuclear Information System (INIS)

    Shan Jian; Xiao Detao; Zhao Guizhi; Zhou Qingzhi; Liu Yan; Qiu Shoukang; Meng Yecheng; Xiong Xinming; Liu Xiaosong; Ma Wenrong

    2014-01-01

    The absolute humidity and temperature's effects on the NRL-1 measuring apparatus for radon were studied in this paper. By controlling the radon activity concentration of the radon laboratory in University of South China and improving the temperature and humidity adjust strategy, different correction factor values under different absolute humidities were obtained. Moreover, a correction curve between 1.90 and 14.91 g/m"3 was also attained. The results show that in the case of absolute humidity, when it is less than 2.4 g/m"3, collection efficiency of the NRL-1 measuring apparatus for radon tends to be constant, and the correction factor of the absolute humidity closes to 1. However, the correction factor increases nonlinearly along with the absolute humidity. (authors)

  3. Regional and site-specific absolute humidity data for use in tritium dose calculations

    International Nuclear Information System (INIS)

    Etnier, E.L.

    1980-01-01

    Due to the potential variability in average absolute humidity over the continental U.S., and the dependence of atmospheric 3 H specific activity on absolute humidity, availability of regional absolute humidity data is of value in estimating the radiological significance of 3 H releases. Most climatological data are in the form of relative humidity, which must be converted to absolute humidity for dose calculations. Absolute humidity was calculated for 218 points across the U.S., using the 1977 annual summary of U.S. Climatological Data, and is given in a table. Mean regional values are shown on a map. (author)

  4. Absolute humidity and the human nose: A reanalysis of climate zones and their influence on nasal form and function.

    Science.gov (United States)

    Maddux, Scott D; Yokley, Todd R; Svoma, Bohumil M; Franciscus, Robert G

    2016-10-01

    Investigations into the selective role of climate on human nasal variation commonly divide climates into four broad adaptive zones (hot-dry, hot-wet, cold-dry, and cold-wet) based on temperature and relative humidity. Yet, absolute humidity-not relative humidity-is physiologically more important during respiration. Here, we investigate the global distribution of absolute humidity to better clarify ecogeographic demands on nasal physiology. We use monthly observations from the Climatic Research Unit Timeseries 3 (CRU TS3) database to construct global maps of average annual temperature, relative humidity and absolute humidity. Further, using data collected by Thomson and Buxton (1923) for over 15,000 globally-distributed individuals, we calculate the actual amount of heat and water that must be transferred to inspired air in different climatic regimes to maintain homeostasis, and investigate the influence of these factors on the nasal index. Our results show that absolute humidity, like temperature, generally decreases with latitude. Furthermore, our results demonstrate that environments typically characterized as "cold-wet" actually exhibit low absolute humidities, with values virtually identical to cold-dry environments and significantly lower than hot-wet and even hot-dry environments. Our results also indicate that strong associations between the nasal index and absolute humidity are, potentially erroneously, predicated on individuals from hot-dry environments possessing intermediate (mesorrhine) nasal indices. We suggest that differentially allocating populations to cold-dry or cold-wet climates is unlikely to reflect different selective pressures on respiratory physiology and nasal morphology-it is cold-dry, and to a lesser degree hot-dry environments, that stress respiratory function. Our study also supports assertions that demands for inspiratory modification are reduced in hot-wet environments, and that expiratory heat elimination for thermoregulation is a

  5. Methodology for the characterization of the humidity behavior inside CPV modules

    Directory of Open Access Journals (Sweden)

    Carmine Cancro

    2015-10-01

    Full Text Available In this study the characterization of the humidity behavior inside concentrating photovoltaic (CPV modules is addressed. To this purpose, several experimental tests have been carried out by using two different CPV modules and three different breathers, collecting in each analyzed case the evolution of temperature, relative and specific humidity of the air volume contained inside the module for many days. Results indicates that, for each of the CPV modules analyzed, it is possible to construct a characteristic curve in the temperature-specific humidity psychrometric chart, that can be used for estimating the specific humidity of the air inside the CPV module as a function of the internal air temperature. The characteristic curve can be also used to estimate the saturation temperature of the air inside the CPV module, and consequently to detect the eventuality of moisture condensation during cloudy days or night-time, namely when the temperature of the air inside the module is low and reaches the external ambient one. This methodology can be used in CPV modules design for the choice of the breather and of the construction materials, in order to obtain a saturation temperature as low as possible.

  6. Statistical modeling reveals the effect of absolute humidity on dengue in Singapore.

    Directory of Open Access Journals (Sweden)

    Hai-Yan Xu

    2014-05-01

    Full Text Available Weather factors are widely studied for their effects on indicating dengue incidence trends. However, these studies have been limited due to the complex epidemiology of dengue, which involves dynamic interplay of multiple factors such as herd immunity within a population, distinct serotypes of the virus, environmental factors and intervention programs. In this study, we investigate the impact of weather factors on dengue in Singapore, considering the disease epidemiology and profile of virus serotypes. A Poisson regression combined with Distributed Lag Non-linear Model (DLNM was used to evaluate and compare the impact of weekly Absolute Humidity (AH and other weather factors (mean temperature, minimum temperature, maximum temperature, rainfall, relative humidity and wind speed on dengue incidence from 2001 to 2009. The same analysis was also performed on three sub-periods, defined by predominant circulating serotypes. The performance of DLNM regression models were then evaluated through the Akaike's Information Criterion. From the correlation and DLNM regression modeling analyses of the studied period, AH was found to be a better predictor for modeling dengue incidence than the other unique weather variables. Whilst mean temperature (MeanT also showed significant correlation with dengue incidence, the relationship between AH or MeanT and dengue incidence, however, varied in the three sub-periods. Our results showed that AH had a more stable impact on dengue incidence than temperature when virological factors were taken into consideration. AH appeared to be the most consistent factor in modeling dengue incidence in Singapore. Considering the changes in dominant serotypes, the improvements in vector control programs and the inconsistent weather patterns observed in the sub-periods, the impact of weather on dengue is modulated by these other factors. Future studies on the impact of climate change on dengue need to take all the other contributing

  7. Statistical modeling reveals the effect of absolute humidity on dengue in Singapore.

    Science.gov (United States)

    Xu, Hai-Yan; Fu, Xiuju; Lee, Lionel Kim Hock; Ma, Stefan; Goh, Kee Tai; Wong, Jiancheng; Habibullah, Mohamed Salahuddin; Lee, Gary Kee Khoon; Lim, Tian Kuay; Tambyah, Paul Anantharajah; Lim, Chin Leong; Ng, Lee Ching

    2014-05-01

    Weather factors are widely studied for their effects on indicating dengue incidence trends. However, these studies have been limited due to the complex epidemiology of dengue, which involves dynamic interplay of multiple factors such as herd immunity within a population, distinct serotypes of the virus, environmental factors and intervention programs. In this study, we investigate the impact of weather factors on dengue in Singapore, considering the disease epidemiology and profile of virus serotypes. A Poisson regression combined with Distributed Lag Non-linear Model (DLNM) was used to evaluate and compare the impact of weekly Absolute Humidity (AH) and other weather factors (mean temperature, minimum temperature, maximum temperature, rainfall, relative humidity and wind speed) on dengue incidence from 2001 to 2009. The same analysis was also performed on three sub-periods, defined by predominant circulating serotypes. The performance of DLNM regression models were then evaluated through the Akaike's Information Criterion. From the correlation and DLNM regression modeling analyses of the studied period, AH was found to be a better predictor for modeling dengue incidence than the other unique weather variables. Whilst mean temperature (MeanT) also showed significant correlation with dengue incidence, the relationship between AH or MeanT and dengue incidence, however, varied in the three sub-periods. Our results showed that AH had a more stable impact on dengue incidence than temperature when virological factors were taken into consideration. AH appeared to be the most consistent factor in modeling dengue incidence in Singapore. Considering the changes in dominant serotypes, the improvements in vector control programs and the inconsistent weather patterns observed in the sub-periods, the impact of weather on dengue is modulated by these other factors. Future studies on the impact of climate change on dengue need to take all the other contributing factors into

  8. Calibration-free absolute frequency response measurement of directly modulated lasers based on additional modulation.

    Science.gov (United States)

    Zhang, Shangjian; Zou, Xinhai; Wang, Heng; Zhang, Yali; Lu, Rongguo; Liu, Yong

    2015-10-15

    A calibration-free electrical method is proposed for measuring the absolute frequency response of directly modulated semiconductor lasers based on additional modulation. The method achieves the electrical domain measurement of the modulation index of directly modulated lasers without the need for correcting the responsivity fluctuation in the photodetection. Moreover, it doubles measuring frequency range by setting a specific frequency relationship between the direct and additional modulation. Both the absolute and relative frequency response of semiconductor lasers are experimentally measured from the electrical spectrum of the twice-modulated optical signal, and the measured results are compared to those obtained with conventional methods to check the consistency. The proposed method provides calibration-free and accurate measurement for high-speed semiconductor lasers with high-resolution electrical spectrum analysis.

  9. Seasonality of absolute humidity explains seasonality of influenza-like illness in Vietnam.

    Science.gov (United States)

    Thai, Pham Quang; Choisy, Marc; Duong, Tran Nhu; Thiem, Vu Dinh; Yen, Nguyen Thu; Hien, Nguyen Tran; Weiss, Daniel J; Boni, Maciej F; Horby, Peter

    2015-12-01

    Experimental and ecological studies have shown the role of climatic factors in driving the epidemiology of influenza. In particular, low absolute humidity (AH) has been shown to increase influenza virus transmissibility and has been identified to explain the onset of epidemics in temperate regions. Here, we aim to study the potential climatic drivers of influenza-like illness (ILI) epidemiology in Vietnam, a tropical country characterized by a high diversity of climates. We specifically focus on quantifying and explaining the seasonality of ILI. We used 18 years (1993-2010) of monthly ILI notifications aggregated by province (52) and monthly climatic variables (minimum, mean, maximum temperatures, absolute and relative humidities, rainfall and hours of sunshine) from 67 weather stations across Vietnam. Seasonalities were quantified from global wavelet spectra, using the value of the power at the period of 1 year as a measure of the intensity of seasonality. The 7 climatic time series were characterized by 534 summary statistics which were entered into a regression tree to identify factors associated with the seasonality of AH. Results were extrapolated to the global scale using simulated climatic times series from the NCEP/NCAR project. The intensity of ILI seasonality in Vietnam is best explained by the intensity of AH seasonality. We find that ILI seasonality is weak in provinces experiencing weak seasonal fluctuations in AH (annual power power >17.6). In Vietnam, AH and ILI are positively correlated. Our results identify a role for AH in driving the epidemiology of ILI in a tropical setting. However, in contrast to temperate regions, high rather than low AH is associated with increased ILI activity. Fluctuation in AH may be the climate factor that underlies and unifies the seasonality of ILI in both temperate and tropical regions. Alternatively, the mechanism of action of AH on disease transmission may be different in cold-dry versus hot-humid settings

  10. Extended Pulse-Powered Humidity-Freeze Cycling for Testing Module-Level Power Electronics

    Energy Technology Data Exchange (ETDEWEB)

    Hacke, Peter L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rodriguez, Miguel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kempe, Michael D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Repins, Ingrid L [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-11-28

    An EMI suppression capacitor (polypropylene film type) failed by 'popcorning' due to vapor outgassing in pulse powered humidity-freeze cycles. No shorts or shunts could be detected despite mildly corroded metallization visible in the failed capacitor. Humidity-freeze cycling is optimized to break into moisture barriers. However, further studies will be required on additional module level power electronic (MLPE) devices to optimize the stress testing for condensation to precipitate any weakness to short circuiting and other humidity/bias failure modes.

  11. Standard Test Methods for Photovoltaic Modules in Cyclic Temperature and Humidity Environments

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 These test methods provide procedures for stressing photovoltaic modules in simulated temperature and humidity environments. Environmental testing is used to simulate aging of module materials on an accelerated basis. 1.2 Three individual environmental test procedures are defined by these test methods: a thermal cycling procedure, a humidity-freeze cycling procedure, and an extended duration damp heat procedure. Electrical biasing is utilized during the thermal cycling procedure to simulate stresses that are known to occur in field-deployed modules. 1.3 These test methods define mounting methods for modules undergoing environmental testing, and specify parameters that must be recorded and reported. 1.4 These test methods do not establish pass or fail levels. The determination of acceptable or unacceptable results is beyond the scope of these test methods. 1.5 Any of the individual environmental tests may be performed singly, or may be combined into a test sequence with other environmental or non-envir...

  12. Humidity fluctuations in the marine boundary layer measured at a coastal site with an infrared humidity sensor

    DEFF Research Database (Denmark)

    Sempreviva, A.M.; Gryning, Sven-Erik

    1996-01-01

    An extensive set of humidity turbulence data has been analyzed from 22-m height in the marine boundary layer. Fluctuations of humidity were measured by an ''OPHIR'', an infrared humidity sensor with a 10 Hz scanning frequency and humidity spectra were produced. The shapes of the normalized spectra...... follow the established similarity functions. However the 10-min time averaged measurements underestimate the value of the absolute humidity. The importance of the humidity flux contribution in a marine environment in calculating the Obukhov stability length has been studied. Deviations from Monin......-Obukhov similarity theory seem to be connected to a low correlation between humidity and temperature....

  13. Ground-based lidar and microwave radiometry synergy for high vertical resolution absolute humidity profiling

    Science.gov (United States)

    Barrera-Verdejo, María; Crewell, Susanne; Löhnert, Ulrich; Orlandi, Emiliano; Di Girolamo, Paolo

    2016-08-01

    Continuous monitoring of atmospheric humidity profiles is important for many applications, e.g., assessment of atmospheric stability and cloud formation. Nowadays there are a wide variety of ground-based sensors for atmospheric humidity profiling. Unfortunately there is no single instrument able to provide a measurement with complete vertical coverage, high vertical and temporal resolution and good performance under all weather conditions, simultaneously. For example, Raman lidar (RL) measurements can provide water vapor with a high vertical resolution, albeit with limited vertical coverage, due to sunlight contamination and the presence of clouds. Microwave radiometers (MWRs) receive water vapor information throughout the troposphere, though their vertical resolution is poor. In this work, we present an MWR and RL system synergy, which aims to overcome the specific sensor limitations. The retrieval algorithm combining these two instruments is an optimal estimation method (OEM), which allows for an uncertainty analysis of the retrieved profiles. The OEM combines measurements and a priori information, taking the uncertainty of both into account. The measurement vector consists of a set of MWR brightness temperatures and RL water vapor profiles. The method is applied to a 2-month field campaign around Jülich (Germany), focusing on clear sky periods. Different experiments are performed to analyze the improvements achieved via the synergy compared to the individual retrievals. When applying the combined retrieval, on average the theoretically determined absolute humidity uncertainty is reduced above the last usable lidar range by a factor of ˜ 2 with respect to the case where only RL measurements are used. The analysis in terms of degrees of freedom per signal reveal that most information is gained above the usable lidar range, especially important during daytime when the lidar vertical coverage is limited. The retrieved profiles are further evaluated using

  14. Indoor air humidity, air quality, and health - An overview.

    Science.gov (United States)

    Wolkoff, Peder

    2018-04-01

    There is a long-standing dispute about indoor air humidity and perceived indoor air quality (IAQ) and associated health effects. Complaints about sensory irritation in eyes and upper airways are generally among top-two symptoms together with the perception "dry air" in office environments. This calls for an integrated analysis of indoor air humidity and eye and airway health effects. This overview has reviewed the literature about the effects of extended exposure to low humidity on perceived IAQ, sensory irritation symptoms in eyes and airways, work performance, sleep quality, virus survival, and voice disruption. Elevation of the indoor air humidity may positively impact perceived IAQ, eye symptomatology, and possibly work performance in the office environment; however, mice inhalation studies do not show exacerbation of sensory irritation in the airways by low humidity. Elevated humidified indoor air appears to reduce nasal symptoms in patients suffering from obstructive apnea syndrome, while no clear improvement on voice production has been identified, except for those with vocal fatigue. Both low and high RH, and perhaps even better absolute humidity (water vapor), favors transmission and survival of influenza virus in many studies, but the relationship between temperature, humidity, and the virus and aerosol dynamics is complex, which in the end depends on the individual virus type and its physical/chemical properties. Dry and humid air perception continues to be reported in offices and in residential areas, despite the IAQ parameter "dry air" (or "wet/humid air") is semantically misleading, because a sensory organ for humidity is non-existing in humans. This IAQ parameter appears to reflect different perceptions among other odor, dustiness, and possibly exacerbated by desiccation effect of low air humidity. It is salient to distinguish between indoor air humidity (relative or absolute) near the breathing and ocular zone and phenomena caused by moisture

  15. Effect of humidity on radon exhalation rate from concrete

    International Nuclear Information System (INIS)

    Yamanishi, Hirokuni; Obayashi, Haruo; Tsuji, Naruhito; Nakayoshi, Hisao

    1998-01-01

    The objective of the present study is evaluation of seasonal humidity effect on radon exhalation rate from concrete. Three concrete pieces have been placed in three different fixed humidity circumstances for about a year. The three fixed humidities are selected 3, 10, 25 g m -3 in absolute humidity, those correspond to dry condition as control, winter and summer, respectively. Radon exhalation rate from each concrete piece is measured every one month during humidity exposure. Under the lower humidity, radon exhalation rate from concrete is small. On the contrary, radon exhalation rate is large in the higher humidity circumstance. This trend is consistent with the seasonal variation of indoor air radon concentration in low air-exchange-rate room. (author)

  16. The effect of environmental humidity and temperature on skin barrier function and dermatitis

    DEFF Research Database (Denmark)

    Engebretsen, K A; Johansen, J D; Kezic, S

    2016-01-01

    existing dermatoses. We searched the literature for studies that evaluated the mechanisms behind this phenomenon. Commonly used meteorological terms such as absolute humidity, relative humidity and dew point are explained. Furthermore, we review the negative effect of low humidity, low temperatures...

  17. Modeling of the influence of humidity on H1N1 flu in China

    Science.gov (United States)

    PEI, Y.; Tian, H.; Xu, B.

    2015-12-01

    In 2009, a heavy Flu hit the whole world. It was caused by the virus H1N1. The influenza first broke out in Mexico in March and the United States in April, 2009. The World Health Organization (WHO) announced that the H1N1 influenza became pandemic, alert to a warning phase of six. By the end of 2011, 181302 H1N1 cases were reported in mainland China. To improve our understanding on the impact of environmental factors on the disease transmission, we constructed an SIR (Susceptible - Infectious - Recovered) model incorporating environmental factors. It was found that the absolute humidity was a dominant environmental factor. The study interpolated the humidity data monitored with 340 weather stations from 1951 to 2011 in mainland China. First, the break point of the trend for the absolutely humidity was detected by the BFAST (Break For Additive Season and Trend) method. Then, the SIR model with and without the absolutely humidity incorporated in the model was built and tested. Finally, the results with the two scenarios were compared. Results indicate that lower absolutely humidity may promote the transmission of the H1N1 cases. The calculated basic reproductive number ranges from 1.65 to 3.66 with a changing absolute humidity. This is consistent with the former study result with basic reproductive number ranging from 2.03 to 4.18. The average recovery duration was estimated to be 5.7 days. The average duration to get immunity from the influenza is 399.02 days. A risk map is also produced to illustrate the model results.

  18. Effective refractive index modulation based optical fiber humidity sensor employing etched fiber Bragg grating

    Science.gov (United States)

    Mundendhar, Pathi; Khijwania, Sunil K.

    2015-09-01

    Relative humidity (RH) sensor employing etched fiber Bragg grating (FBG) is reported where RH variations are captured using effective-index-modulation, rather than traditional strain-modulation. Additionly, linear sensor response over wide dynamic range with optimum characteristics is focused. Comprehensive experimental investigation is carried out for the sensor that comprises uniformly etched cladding in the FBG region. Obtained results are observed to be in agreement with the theoretical analysis. Sensor response is observed to be linear over dynamic range 3-94%RH with ~ 0.082 pm/%RH sensitivity, ~0.6%RH resolution, ~ +/-2.5%RH accuracy, ~ +/-0.2 pm average discrepancy and ~ 0.2s response time during humidification/desiccation.

  19. Cryptanalyzing an improved security modulated chaotic encryption scheme using ciphertext absolute value

    International Nuclear Information System (INIS)

    Alvarez, G.; Montoya, F.; Romera, M.; Pastor, G.

    2005-01-01

    This paper describes the security weakness of a recently proposed improved chaotic encryption method based on the modulation of a signal generated by a chaotic system with an appropriately chosen scalar signal. The aim of the improvement is to avoid the breaking of chaotic encryption schemes by means of the return map attack introduced by Perez and Cerdeira. A method of attack based on taking the absolute value of the ciphertext is presented, that allows for the cancellation of the modulation scalar signal and the determination of some system parameters that play the role of system key. The proposed improved method is shown to be compromised without any knowledge of the chaotic system parameter values and even without knowing the transmitter structure

  20. The sensitivity to humidity of radon monitoring instruments

    International Nuclear Information System (INIS)

    Schmied, H.

    1984-01-01

    In a project funded by the Swedish Building Research Council (BFR) a continuous radon monitoring instrument (RGA-400 EDA Instr. Inc.) with electrostatic field collection has been calibrated. The original calibration factor gave no reliable radon readings and was therefore corrected for relative humidity by EDA. From four calibrations in the radon chamber at the Swedish Radiation Protection Board (SSI) it was clear that the instrument was sensitive to absolute humidity, which gave better agreement than relative humidity or temperature. Sensitivity to humidity for this principle of measure ment has been presented in various papers without presenting any combined influence with temperature, which can lead to the wrong conclusions, especially when the temperature levels differ. Some laboratories use humidity absorbants to overcome this humidity dependence. In this paper the calibration results for the FGA-400 radon readings only, are presented. (Author)

  1. The Climatology Module CLIMAT

    National Research Council Canada - National Science Library

    Avara, Elton

    1998-01-01

    ... (temperature, dew point temperature, absolute humidity, relative humidity, horizontal visibility, sea level pressure, wind speed, wind direction, cloudbase height, cloud cover, and Pasquill stability category...

  2. The Use of Ambient Humidity Conditions to Improve Influenza Forecast

    Science.gov (United States)

    Shaman, J. L.; Kandula, S.; Yang, W.; Karspeck, A. R.

    2017-12-01

    Laboratory and epidemiological evidence indicate that ambient humidity modulates the survival and transmission of influenza. Here we explore whether the inclusion of humidity forcing in mathematical models describing influenza transmission improves the accuracy of forecasts generated with those models. We generate retrospective forecasts for 95 cities over 10 seasons in the United States and assess both forecast accuracy and error. Overall, we find that humidity forcing improves forecast performance and that forecasts generated using daily climatological humidity forcing generally outperform forecasts that utilize daily observed humidity forcing. These findings hold for predictions of outbreak peak intensity, peak timing, and incidence over 2- and 4-week horizons. The results indicate that use of climatological humidity forcing is warranted for current operational influenza forecast and provide further evidence that humidity modulates rates of influenza transmission.

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

    Science.gov (United States)

    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 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.

  4. Comparison of Single-Point and Continuous Sampling Methods for Estimating Residential Indoor Temperature and Humidity.

    Science.gov (United States)

    Johnston, James D; Magnusson, Brianna M; Eggett, Dennis; Collingwood, Scott C; Bernhardt, Scott A

    2015-01-01

    Residential temperature and humidity are associated with multiple health effects. Studies commonly use single-point measures to estimate indoor temperature and humidity exposures, but there is little evidence to support this sampling strategy. This study evaluated the relationship between single-point and continuous monitoring of air temperature, apparent temperature, relative humidity, and absolute humidity over four exposure intervals (5-min, 30-min, 24-hr, and 12-days) in 9 northern Utah homes, from March-June 2012. Three homes were sampled twice, for a total of 12 observation periods. Continuous data-logged sampling was conducted in homes for 2-3 wks, and simultaneous single-point measures (n = 114) were collected using handheld thermo-hygrometers. Time-centered single-point measures were moderately correlated with short-term (30-min) data logger mean air temperature (r = 0.76, β = 0.74), apparent temperature (r = 0.79, β = 0.79), relative humidity (r = 0.70, β = 0.63), and absolute humidity (r = 0.80, β = 0.80). Data logger 12-day means were also moderately correlated with single-point air temperature (r = 0.64, β = 0.43) and apparent temperature (r = 0.64, β = 0.44), but were weakly correlated with single-point relative humidity (r = 0.53, β = 0.35) and absolute humidity (r = 0.52, β = 0.39). Of the single-point RH measures, 59 (51.8%) deviated more than ±5%, 21 (18.4%) deviated more than ±10%, and 6 (5.3%) deviated more than ±15% from data logger 12-day means. Where continuous indoor monitoring is not feasible, single-point sampling strategies should include multiple measures collected at prescribed time points based on local conditions.

  5. Influenza and humidity--Why a bit more damp may be good for you!

    Science.gov (United States)

    Metz, Jane A; Finn, Adam

    2015-06-01

    Influenza viruses cause much winter-time morbidity and death in temperate regions. We still do not understand why 'flu is more common in winter. Since the 1960s, investigators have studied the role of relative humidity and temperature on viral survival, transmission and infection rates but results have demonstrated only inconclusive trends. Over the past few years however, a series of exciting studies have instead focussed on absolute humidity and demonstrated highly significant correlations with viral survival and transmission rates in both laboratory and epidemiological models. Here we review the evidence for a causal association between absolute humidity and 'flu transmission and outline how this could lead to a new approach to curbing this and perhaps other viral epidemics in the winter months. Copyright © 2015. Published by Elsevier Ltd.

  6. Sensitivity of honeybee hygroreceptors to slow humidity changes and temporal humidity variation detected in high resolution by mobile measurements.

    Science.gov (United States)

    Tichy, Harald; Kallina, Wolfgang

    2014-01-01

    The moist cell and the dry cell on the antenna of the male honeybee were exposed to humidities slowly rising and falling at rates between -1.5%/s and +1.5%/s and at varying amplitudes in the 10 to 90% humidity range. The two cells respond to these slow humidity oscillations with oscillations in impulse frequency which depend not only on instantaneous humidity but also on the rate with which humidity changes. The impulse frequency of each cell was plotted as a function of these two parameters and regression planes were fitted to the data points of single oscillation periods. The regression slopes, which estimate sensitivity, rose with the amplitude of humidity oscillations. During large-amplitude oscillations, moist and dry cell sensitivity for instantaneous humidity and its rate of change was high. During small-amplitude oscillations, their sensitivity for both parameters was low, less exactly reflecting humidity fluctuations. Nothing is known about the spatial and temporal humidity variations a honeybee may encounter when flying through natural environments. Microclimatic parameters (absolute humidity, temperature, wind speed) were measured from an automobile traveling through different landscapes of Lower Austria. Landscape type affected extremes and mean values of humidity. Differences between peaks and troughs of humidity fluctuations were generally smaller in open grassy fields or deciduous forests than in edge habitats or forest openings. Overall, fluctuation amplitudes were small. In this part of the stimulus range, hygroreceptor sensitivity is not optimal for encoding instantaneous humidity and the rate of humidity change. It seems that honeybee's hygroreceptors are specialized for detecting large-amplitude fluctuations that are relevant for a specific behavior, namely, maintaining a sufficiently stable state of water balance. The results suggest that optimal sensitivity of both hygroreceptors is shaped not only by humidity oscillation amplitudes but also

  7. Overview of humidity driven reliability issues of electronics

    DEFF Research Database (Denmark)

    Ambat, Rajan

    2017-01-01

    Electronic control units, power modules, and consumer electronics are used today in a wide variety of varying climatic conditions. Varying external climatic conditions of temperature and humidity can cause an uncontrolled local climate inside the device enclosure. Uncontrolled humidity together w...

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

    Science.gov (United States)

    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.

  9. Creation of tunable absolute bandgaps in a two-dimensional anisotropic photonic crystal modulated by a nematic liquid crystal

    International Nuclear Information System (INIS)

    Liu Chenyang

    2008-01-01

    Photonic crystals (PCs) have many potential applications because of their ability to control light-wave propagation. We have investigated the tunable absolute bandgap in a two-dimensional anisotropic photonic crystal structures modulated by a nematic liquid crystal. The PC structure composed of an anisotropic-dielectric cylinder in the liquid crystal medium is studied by solving Maxwell's equations using the plane wave expansion method. The photonic band structures are found to exhibit absolute bandgaps for the square and triangular lattices. Numerical simulations show that the absolute bandgaps can be continuously tuned in the square and triangular lattices consisting of anisotropic-dielectric cylinders by infiltrating nematic liquid crystals. Such a mechanism of bandgap adjustment should open up a new application for designing components in photonic integrated circuits

  10. A multi-channel humidity control system based on LabVIEW

    International Nuclear Information System (INIS)

    Zhang Aiwu; Xie Yuguang; Liu Hongbang; Liu Yingbiao; Cai Xiao; Yu Boxiang; Lu Junguang; Zhou Li

    2011-01-01

    A real time multi-channel humidity control system was designed based on LabVIEW, using the dry air branch of BESⅢ drying system. The hardware of this control system consist of mini humidity and temperature sensors, intelligent collection module, switch quantity controller and electromagnetic valves. The humidity can be controlled at arbitrary value from air humidity to 3% with accuracy better than 2%. Multi microenvironment with different humidity can be easily controlled and monitored in real time by this system. It can also be extended to hybrid control of multi channel humidity and temperature. (authors)

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

    Science.gov (United States)

    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.

  12. Changes of pressure and humidity affect olfactory function.

    Science.gov (United States)

    Kuehn, Michael; Welsch, Heiko; Zahnert, Thomas; Hummel, Thomas

    2008-03-01

    The present study aimed at investigating the question whether olfactory function changes in relation to barometric pressure and humidity. Using climate chambers, odor threshold and discrimination for butanol were tested in 75 healthy volunteers under hypobaric and hyperbaric, and different humidity conditions. Among other effects, olfactory sensitivity at threshold level, but not suprathreshold odor discrimination, was impaired in a hypobaric compared to a hyperbaric milieu, and thresholds were lower in humid, compared to relatively dry conditions. In conclusion, environmental conditions modulate the sense of smell, and may, consecutively, influence results from olfactory tests.

  13. Seasonality of absolute humidity explains seasonality of influenza-like illness in Vietnam

    Directory of Open Access Journals (Sweden)

    Pham Quang Thai

    2015-12-01

    Conclusions: Our results identify a role for AH in driving the epidemiology of ILI in a tropical setting. However, in contrast to temperate regions, high rather than low AH is associated with increased ILI activity. Fluctuation in AH may be the climate factor that underlies and unifies the seasonality of ILI in both temperate and tropical regions. Alternatively, the mechanism of action of AH on disease transmission may be different in cold-dry versus hot-humid settings.

  14. Absolute, pressure-dependent validation of a calibration-free, airborne laser hygrometer transfer standard (SEALDH-II from 5 to 1200 ppmv using a metrological humidity generator

    Directory of Open Access Journals (Sweden)

    B. Buchholz

    2018-01-01

    Full Text Available Highly accurate water vapor measurements are indispensable for understanding a variety of scientific questions as well as industrial processes. While in metrology water vapor concentrations can be defined, generated, and measured with relative uncertainties in the single percentage range, field-deployable airborne instruments deviate even under quasistatic laboratory conditions up to 10–20 %. The novel SEALDH-II hygrometer, a calibration-free, tuneable diode laser spectrometer, bridges this gap by implementing a new holistic concept to achieve higher accuracy levels in the field. We present in this paper the absolute validation of SEALDH-II at a traceable humidity generator during 23 days of permanent operation at 15 different H2O mole fraction levels between 5 and 1200 ppmv. At each mole fraction level, we studied the pressure dependence at six different gas pressures between 65 and 950 hPa. Further, we describe the setup for this metrological validation, the challenges to overcome when assessing water vapor measurements on a high accuracy level, and the comparison results. With this validation, SEALDH-II is the first airborne, metrologically validated humidity transfer standard which links several scientific airborne and laboratory measurement campaigns to the international metrological water vapor scale.

  15. Inactivation of Avian Influenza Viruses on Porous and Non-porous Surfaces is Enhanced by Elevating Absolute Humidity.

    Science.gov (United States)

    Guan, J; Chan, M; VanderZaag, A

    2017-08-01

    This study was to evaluate the effect of absolute humidity (AH), a combined factor of temperature and relative humidity (RH), on inactivation of avian influenza viruses (AIVs) on surfaces. Suspensions of the H9N2 or H6N2 AIV were deposited onto carrier surfaces that were either porous (pine wood) or non-porous (stainless steel, synthetic rubber and glass). The inoculated carriers were incubated at 23, 35 or 45°C with 25% or 55% RH for up to 28 days. After incubation, virus was recovered and quantified by chicken embryo assays. The time required to obtain a log 10 reduction in virus infectivity (D-value) was estimated using a linear regression model. At AH of 5.2 g/m 3 (23°C & 25% RH), both viruses survived up to 14 days on the porous surface and for at least 28 days on the non-porous surfaces. The corresponding D-values for H9N2 and H6N2 were 1.49 and 6.90 days on the porous surface and 7.81 and 12.5 days on the non-porous surfaces, respectively. In comparison, at AH of 9.9 g/m 3 (35°C & 25% RH) or 11.3 g/m 3 (23°C & 55% RH), the D-values for H9N2 and H6N2 dropped to ≤0.76 day on the porous surface and to ≤1.81 days on the non-porous surfaces. As the AH continued to rise from 11.3 to 36.0 g/m 3 , the D-value for both viruses decreased further. The relationship between D-value and AH followed a form of y = ax -b for both viruses. The D-values for H9N2 virus were significantly lower (P < 0.05) than those for H6N2 virus. Exposure to ammonia gas at concentrations of 86 and 173 ppm did not significantly alter test results. The findings give evidence that increasing the AH in poultry buildings following an outbreak of disease could greatly reduce the length of time required for their decontamination. © Her Majesty the Queen in Right of Canada 2016.

  16. Humidity Data for 9975 Shipping Packages with Softwood Fiberboard

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, W. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-01-12

    The 9975 surveillance program is developing a technical basis to support extending the storage period of 9975 packages in K-Area Complex beyond the currently approved 15 years. A key element of this effort is developing a better understanding of degradation of the fiberboard assembly under storage conditions. This degradation is influenced greatly by the moisture content of the fiberboard, which is not well characterized on an individual package basis. Direct measurements of humidity and fiberboard moisture content have been made on two test packages with softwood fiberboard and varying internal heat levels from 0 up to 19W. Comparable measurements with cane fiberboard have been reported previously. With an internal heat load, a temperature gradient in the fiberboard assembly leads to varying relative humidity in the air around the fiberboard. However, the absolute humidity tends to remain approximately constant throughout the package, especially at lower heat loads.

  17. The use of ambient humidity conditions to improve influenza forecast.

    Science.gov (United States)

    Shaman, Jeffrey; Kandula, Sasikiran; Yang, Wan; Karspeck, Alicia

    2017-11-01

    Laboratory and epidemiological evidence indicate that ambient humidity modulates the survival and transmission of influenza. Here we explore whether the inclusion of humidity forcing in mathematical models describing influenza transmission improves the accuracy of forecasts generated with those models. We generate retrospective forecasts for 95 cities over 10 seasons in the United States and assess both forecast accuracy and error. Overall, we find that humidity forcing improves forecast performance (at 1-4 lead weeks, 3.8% more peak week and 4.4% more peak intensity forecasts are accurate than with no forcing) and that forecasts generated using daily climatological humidity forcing generally outperform forecasts that utilize daily observed humidity forcing (4.4% and 2.6% respectively). These findings hold for predictions of outbreak peak intensity, peak timing, and incidence over 2- and 4-week horizons. The results indicate that use of climatological humidity forcing is warranted for current operational influenza forecast.

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

    Directory of Open Access Journals (Sweden)

    Nilius G

    2018-05-01

    Full Text Available Georg Nilius,1,2 Ulrike Domanski,1 Maik Schroeder,1 Holger Woehrle,3,4 Andrea Graml,4 Karl-Josef Franke,1,2 1Helios Klinik Hagen-Ambrock, Department of Pneumology, Hagen, Germany; 2Department of Internal Medicine, Witten-Herdecke University, Witten, Germany; 3Sleep and Ventilation Center Blaubeuren, Respiratory Center Ulm, Ulm, Germany; 4ResMed Science Center, ResMed Germany, Martinsried, Germany 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. Keywords: continuous positive

  19. A CMOS smart temperature and humidity sensor with combined readout.

    Science.gov (United States)

    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.

  20. The use of ambient humidity conditions to improve influenza forecast.

    Directory of Open Access Journals (Sweden)

    Jeffrey Shaman

    2017-11-01

    Full Text Available Laboratory and epidemiological evidence indicate that ambient humidity modulates the survival and transmission of influenza. Here we explore whether the inclusion of humidity forcing in mathematical models describing influenza transmission improves the accuracy of forecasts generated with those models. We generate retrospective forecasts for 95 cities over 10 seasons in the United States and assess both forecast accuracy and error. Overall, we find that humidity forcing improves forecast performance (at 1-4 lead weeks, 3.8% more peak week and 4.4% more peak intensity forecasts are accurate than with no forcing and that forecasts generated using daily climatological humidity forcing generally outperform forecasts that utilize daily observed humidity forcing (4.4% and 2.6% respectively. These findings hold for predictions of outbreak peak intensity, peak timing, and incidence over 2- and 4-week horizons. The results indicate that use of climatological humidity forcing is warranted for current operational influenza forecast.

  1. Wide-field absolute transverse blood flow velocity mapping in vessel centerline

    Science.gov (United States)

    Wu, Nanshou; Wang, Lei; Zhu, Bifeng; Guan, Caizhong; Wang, Mingyi; Han, Dingan; Tan, Haishu; Zeng, Yaguang

    2018-02-01

    We propose a wide-field absolute transverse blood flow velocity measurement method in vessel centerline based on absorption intensity fluctuation modulation effect. The difference between the light absorption capacities of red blood cells and background tissue under low-coherence illumination is utilized to realize the instantaneous and average wide-field optical angiography images. The absolute fuzzy connection algorithm is used for vessel centerline extraction from the average wide-field optical angiography. The absolute transverse velocity in the vessel centerline is then measured by a cross-correlation analysis according to instantaneous modulation depth signal. The proposed method promises to contribute to the treatment of diseases, such as those related to anemia or thrombosis.

  2. Experience with humidity monitoring and leak detection system SMU-V at the Jaslovske Bohunice V-1 NPP

    International Nuclear Information System (INIS)

    Macko, O.

    1996-01-01

    Within the paper a brief technical description of SMU-V system is presented including algorithms for measured data evaluation, assessment of experience acquired the system operation and prospective VUEZ activities aimed at the developed of systems for NPP primary circuit leak detection based on humidity monitoring. System SMU-V is used to diagnose dangerous conditions during which integrity of the pipeline could be impaired resulting in absolute humidity increase in the monitored volume. (author)

  3. Fabrication and Evaluation of a Graphene Oxide-Based Capacitive Humidity Sensor.

    Science.gov (United States)

    Feng, Jinfeng; Kang, Xiaoxu; Zuo, Qingyun; Yuan, Chao; Wang, Weijun; Zhao, Yuhang; Zhu, Limin; Lu, Hanwei; Chen, Juying

    2016-03-01

    In this study, a CMOS compatible capacitive humidity sensor structure was designed and fabricated on a 200 mm CMOS BEOL Line. A top Al interconnect layer was used as an electrode with a comb/serpent structure, and graphene oxide (GO) was used as sensing material. XRD analysis was done which shows that GO sensing material has a strong and sharp (002) peak at about 10.278°, whereas graphite has (002) peak at about 26°. Device level CV and IV curves were measured in mini-environments at different relative humidity (RH) level, and saturated salt solutions were used to build these mini-environments. To evaluate the potential value of GO material in humidity sensor applications, a prototype humidity sensor was designed and fabricated by integrating the sensor with a dedicated readout ASIC and display/calibration module. Measurements in different mini-environments show that the GO-based humidity sensor has higher sensitivity, faster recovery time and good linearity performance. Compared with a standard humidity sensor, the measured RH data of our prototype humidity sensor can match well that of the standard product.

  4. EDITORIAL: Humidity sensors Humidity sensors

    Science.gov (United States)

    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

  5. Humidity data for 9975 shipping packages with cane fiberboard

    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, W. L. [Savannah River Site (SRS), Aiken, SC (United States)

    2016-05-01

    The 9975 surveillance program is developing a technical basis to support extending the storage period of 9975 packages in K-Area Complex beyond the currently approved 15 years. A key element of this effort is developing a better understanding of degradation of the fiberboard assembly under storage conditions. This degradation is influenced greatly by the moisture content of the fiberboard, which is not well characterized on an individual package basis. Direct measurements of humidity and fiberboard moisture content have been made on two test packages with cane fiberboard and varying internal heat levels from 0 up to 19W. With an internal heat load, a temperature gradient in the fiberboard assembly leads to varying relative humidity in the air around the fiberboard. However, the absolute humidity tends to remain approximately constant throughout the package. The moisture content of fiberboard varies under the influence of several phenomena. Changes in local fiberboard temperature (from an internal heat load) can cause fiberboard moisture changes through absorption or evaporation. Fiberboard degradation at elevated temperature will produce water as a byproduct. And the moisture level within the package is constantly seeking equilibrium with that of the surrounding room air, which varies on a daily and seasonal basis. One indicator of the moisture condition within a 9975 package might be obtained by measuring the relative humidity in the upper air space, by inserting a humidity probe through a caplug hole. However, the data indicate that for the higher internal heat loads (15 and 19 watts), a large variation in internal moisture conditions produces little or no variation in the air space relative humidity. Therefore, this approach does not appear to be sensitive to fiberboard moisture variations at the higher heat loads which are of most interest to maintaining fiberboard integrity.

  6. Fabrication and Evaluation of a Graphene Oxide-Based Capacitive Humidity Sensor

    Directory of Open Access Journals (Sweden)

    Jinfeng Feng

    2016-03-01

    Full Text Available In this study, a CMOS compatible capacitive humidity sensor structure was designed and fabricated on a 200 mm CMOS BEOL Line. A top Al interconnect layer was used as an electrode with a comb/serpent structure, and graphene oxide (GO was used as sensing material. XRD analysis was done which shows that GO sensing material has a strong and sharp (002 peak at about 10.278°, whereas graphite has (002 peak at about 26°. Device level CV and IV curves were measured in mini-environments at different relative humidity (RH level, and saturated salt solutions were used to build these mini-environments. To evaluate the potential value of GO material in humidity sensor applications, a prototype humidity sensor was designed and fabricated by integrating the sensor with a dedicated readout ASIC and display/calibration module. Measurements in different mini-environments show that the GO-based humidity sensor has higher sensitivity, faster recovery time and good linearity performance. Compared with a standard humidity sensor, the measured RH data of our prototype humidity sensor can match well that of the standard product.

  7. Ground calibration of DREAMS-H relative humidity device

    Science.gov (United States)

    Komu, M.; Genzer, M.; Nikkanen, T.; Schmidt, W.; Haukka, H.; Kemppinen, O.; Harri, A.-M.

    2014-04-01

    DREAMS (Dust Characterization, Risk Assessment and Environmental Analyzer on the Martian Surface) instrument suite is to be launched as part of ESA ExoMars 2016/Entry, Descent and Landing Demonstration Module (EDM). DREAMS consists of an environmental package for monitoring temperature, pressure, relative humidity, winds and dust opacity, as well as atmospheric electricity of Martian atmosphere. DREAMS instruments and scientific goals are described in [1]. Here we describe ground calibration of the relative humidity device, DREAMS-H, provided to DREAMS payload by Finnish Meteorological Institute and based on proprietary technology of Vaisala, Inc. Same kind of device is part of REMS instrument package onboard MSL Curiosity Rover [2][3].

  8. Humidity Sensors Printed on Recycled Paper and Cardboard

    Directory of Open Access Journals (Sweden)

    Matija Mraović

    2014-07-01

    Full Text Available Research, design, fabrication and results of various screen printed capacitive humidity sensors is presented in this paper. Two types of capacitive humidity sensors have been designed and fabricated via screen printing on recycled paper and cardboard, obtained from the regional paper and cardboard industry. As printing ink, commercially available silver nanoparticle-based conductive ink was used. A considerable amount of work has been devoted to the humidity measurement methods using paper as a dielectric material. Performances of different structures have been tested in a humidity chamber. Relative humidity in the chamber was varied in the range of 35%–80% relative humidity (RH at a constant temperature of 23 °C. Parameters of interest were capacitance and conductance of each sensor material, as well as long term behaviour. Process reversibility has also been considered. The results obtained show a mainly logarithmic response of the paper sensors, with the only exception being cardboard-based sensors. Recycled paper-based sensors exhibit a change in value of three orders of magnitude, whereas cardboard-based sensors have a change in value of few 10s over the entire scope of relative humidity range (RH 35%–90%. Two different types of capacitor sensors have been investigated: lateral (comb type sensors and modified, perforated flat plate type sensors. The objective of the present work was to identify the most important factors affecting the material performances with humidity, and to contribute to the development of a sensor system supported with a Radio Frequency Identification (RFID chip directly on the material, for use in smart packaging applications. Therefore, the authors built a passive and a battery-supported wireless module based on SL900A smart sensory tag’s IC to achieve UHF-RFID functionality with data logging capability.

  9. Sealed Attics Exposed to Two Years of Weathering in a Hot and Humid Climate

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William A [ORNL; Railkar, Sudhir [GAF; Shiao, Ming C [ORNL; Desjarlais, Andre Omer [ORNL

    2016-01-01

    Field studies in a hot, humid climate were conducted to investigate the thermal and hygrothermal performance of ventilated attics and non-ventilated semi-conditioned attics sealed with open-cell and with closed-cell spray polyurethane foam insulation. Moisture pin measurements made in the sheathing and absolute humidity sensor data from inside the foam and from the attic air show that moisture is being stored in the foam. The moisture in the foam diffuses to and from the sheathing dependent on the pressure gradient at the foam-sheathing interface which is driven by the irradiance and night-sky radiation. Ventilated attics in the same hot, humid climate showed less moisture movement in the sheathing than those sealed with either open- or closed-cell spray foam. In the ventilated attics the relative humidity drops as the attic air warms; however, the opposite was observed in the sealed attics. Peaks in measured relative humidity in excess of 80 90% and occasionally near saturation (i.e., 100%) were observed from solar noon till about 8 PM on hot, humid days. The conditioned space of the test facility is heated and cooled by an air-to-air heat pump. Therefore the partial pressure of the indoor air during peak irradiance is almost always less than that observed in the sealed attics. Field data will be presented to bring to light the critical humidity control issues in sealed attics exposed to hot, humid climates.

  10. Mars Science Laboratory (MSL) - First Results of Relative Humidity Observations

    Science.gov (United States)

    Genzer, Maria; Harri, Ari-Matti; Kemppinen, Osku; Gómez-Elvira, Javier; Renno, Nilton; Savijärvi, Hannu; Schmidt, Walter; Polkko, Jouni; Rodríquez-Manfredi, Jose Antonio; de la Torre Juárez, Manuel; Mischna, Michael; Martín-Torres, Javier; Haukka, Harri; Paz Zorzano-Mier, Maria; Rafkin, Scott; Paton, Mark; MSL Science Team

    2013-04-01

    The Mars Science laboratory (MSL) called Curiosity made a successful landing at Gale crater early August 2012. MSL has an environmental instrument package called the Rover Environmental Monitoring Station (REMS) as a part of its scientific payload. REMS comprises instrumentation for the observation of atmospheric pressure, temperature of the air, ground temperature, wind speed and direction, relative humidity, and UV measurements. The REMS instrument suite is described at length in [1]. We concentrate on describing the first results from the REMS relative humidity observations and comparison of the measurements with modeling results. The REMS humidity device is provided by the Finnish Meteorological Institute. It is based on polymeric capacitive humidity sensors developed by Vaisala Inc. The humidity device makes use of one transducer electronics section placed in the vicinity of the three (3) humidity sensor heads. The humidity device is mounted on the REMS boom 2 providing ventilation with the ambient atmosphere through a filter protecting the device from airborne dust. The absolute accuracy of the humidity device is temperature dependent, and is of the order of 2% at the temperature range of -30 to -10 °C, and of the order of 10% at the temperature range of -80 to -60 °C. This enables the investigations of atmospheric humidity variations of both diurnal and seasonal scale. The humidity device measurements will have a lag, when a step-wise change in humidity is taking place. This lag effect is increasing with decreasing temperature, and it is of the order of a few hours at the temperature of -75 °C. To compensate for the lag effect we used an algorithm developed by Mäkinen [2]. The humidity observations were validated after tedious efforts. This was needed to compensate for the artifacts of the transducer electronics. The compensation process includes an assumption that the relative humidity at Mars in the temperature range of 0 to -30 °C is about zero. The

  11. Toward a New Generation of Photonic Humidity Sensors

    Science.gov (United States)

    Kolpakov, Stanislav A.; Gordon, Neil T.; Mou, Chengbo; Zhou, Kaiming

    2014-01-01

    This review offers new perspectives on the subject and highlights an area in need of further research. It includes an analysis of current scientific literature mainly covering the last decade and examines the trends in the development of electronic, acoustic and optical-fiber humidity sensors over this period. The major findings indicate that a new generation of sensor technology based on optical fibers is emerging. The current trends suggest that electronic humidity sensors could soon be replaced by sensors that are based on photonic structures. Recent scientific advances are expected to allow dedicated systems to avoid the relatively high price of interrogation modules that is currently a major disadvantage of fiber-based sensors. PMID:24577524

  12. Low Humidity Characteristics of Polymer-Based Capacitive Humidity Sensors

    OpenAIRE

    Majewski Jacek

    2017-01-01

    Polymer-based capacitive humidity sensors emerged around 40 years ago; nevertheless, they currently constitute large part of sensors’ market within a range of medium (climatic and industrial) humidity 20−80%RH due to their linearity, stability and cost-effectiveness. However, for low humidity values (0−20%RH) that type of sensor exhibits increasingly nonlinear characteristics with decreasing of humidity values. This paper presents the results of some experimental trials of CMOS polymer-based ...

  13. Angle-tip Fiber Probe as Humidity Sensor

    Directory of Open Access Journals (Sweden)

    Pabitra NATH

    2010-05-01

    Full Text Available In this paper, I present a simple fiber optic relative humidity sensor (FORHS using an angled-tip multimode optical fiber. The sensing region is fabricated by coating moisture sensitive Cobalt Chloride (CoCl2 doped polyvinyl alcohol (PVA film on the surface of fiber optic tip. Light signal introducing from flat-end of the fiber is back-reflected at the fiber tip-air interface by the effect of total internal refection. The change of relative humidity (RH in the outstanding medium affects of evanescent field absorption at the fiber tip-sensing film interface thus, modulates the back-reflected signal. With the present sensing investigation, RH ranging from 5 % to 95 % can be measured with high degree of repeatability and has a fast response time of about 2 seconds.

  14. The design of multi temperature and humidity monitoring system for incubator

    Science.gov (United States)

    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.

  15. A Low-Power Integrated Humidity CMOS Sensor by Printing-on-Chip Technology

    Directory of Open Access Journals (Sweden)

    Chang-Hung Lee

    2014-05-01

    Full Text Available A low-power, wide-dynamic-range integrated humidity sensing chip is implemented using a printable polymer sensing material with an on-chip pulse-width-modulation interface circuit. By using the inkjet printing technique, poly(3,4-ethylene-dioxythiophene/polystyrene sulfonate that has humidity sensing features can be printed onto the top metal layer of a 0.35 μm CMOS IC. The developed printing-on-chip humidity sensor achieves a heterogeneous three dimensional sensor system-on-chip architecture. The humidity sensing of the implemented printing-on-chip sensor system is experimentally tested. The sensor shows a sensitivity of 0.98% to humidity in the atmosphere. The maximum dynamic range of the readout circuit is 9.8 MΩ, which can be further tuned by the frequency of input signal to fit the requirement of the resistance of printed sensor. The power consumption keeps only 154 μW. This printing-on-chip sensor provides a practical solution to fulfill an ultra-small integrated sensor for the applications in miniaturized sensing systems.

  16. A low-power integrated humidity CMOS sensor by printing-on-chip technology.

    Science.gov (United States)

    Lee, Chang-Hung; Chuang, Wen-Yu; Cowan, Melissa A; Wu, Wen-Jung; Lin, Chih-Ting

    2014-05-23

    A low-power, wide-dynamic-range integrated humidity sensing chip is implemented using a printable polymer sensing material with an on-chip pulse-width-modulation interface circuit. By using the inkjet printing technique, poly(3,4-ethylene-dioxythiophene)/polystyrene sulfonate that has humidity sensing features can be printed onto the top metal layer of a 0.35 μm CMOS IC. The developed printing-on-chip humidity sensor achieves a heterogeneous three dimensional sensor system-on-chip architecture. The humidity sensing of the implemented printing-on-chip sensor system is experimentally tested. The sensor shows a sensitivity of 0.98% to humidity in the atmosphere. The maximum dynamic range of the readout circuit is 9.8 MΩ, which can be further tuned by the frequency of input signal to fit the requirement of the resistance of printed sensor. The power consumption keeps only 154 μW. This printing-on-chip sensor provides a practical solution to fulfill an ultra-small integrated sensor for the applications in miniaturized sensing systems.

  17. Absolute air filtering equipment in the nuclear industrie. Design - Safety - Experience

    International Nuclear Information System (INIS)

    Lucas, J.C.

    1977-01-01

    The problems encountered in the design of absolute filters (HEPA FILTERS) are presented: glass-fibre filter papers; standards and characteristics: efficiency, fire-resistance, humidity-resistance, radiation-resistance, etc; various types of paper folding: deep folds and small folds, dihedrally mounted; filtering elements; designs; characteristics and quality control; The design of filtration equipment is also analysed: mounting in metal or concrete casings. French and American designs (Regulatory Guide 1-52); and gas-tight casings allowing contaminated filters to be renewed without breaking the gas-tight seal

  18. Comparison of the temperature and humidity in the anesthetic breathing circuit among different anesthetic workstations: Updated guidelines for reporting parallel group randomized trials.

    Science.gov (United States)

    Choi, Yoon Ji; Min, Sam Hong; Park, Jeong Jun; Cho, Jang Eun; Yoon, Seung Zhoo; Yoon, Suk Min

    2017-06-01

    For patients undergoing general anesthesia, adequate warming and humidification of the inspired gases is very important. The aim of this study was to evaluate the differences in the heat and moisture content of the inspired gases with low-flow anesthesia using 4 different anesthesia machines. The patients were divided into 11 groups according to the anesthesia machine used (Ohmeda, Excel; Avance; Dräger, Cato; and Primus) and the fresh gas flow (FGF) rate (0.5, 1, and 4 L/min). The temperature and absolute humidity of the inspired gas in the inspiratory limbs were measured at 5, 10, 15, 30, 45, 60, 75, 90, 105, and 120 minutes in 9 patients scheduled for total thyroidectomy or cervical spine operation in each group. The anesthesia machines of Excel, Avance, Cato, and Primus did not show statistically significant changes in the inspired gas temperatures over time within each group with various FGFs. They, however, showed statistically significant changes in the absolute humidity of the inspired gas over time within each group with low FGF anesthesia (P humidity of the inspired gas over time within each group with an FGF of 4 L/min (P humidities of the inspired gas for all anesthesia machines were lower than the recommended values. There were statistical differences in the provision of humidity among different anesthesia workstations. The Cato and Primus workstations were superior to Excel and Avance. However, even these were unsatisfactory in humans. Therefore, additional devices that provide inspired gases with adequate heat and humidity are needed for those undergoing general anesthetic procedures.

  19. ACRE: Absolute concentration robustness exploration in module-based combinatorial networks

    KAUST Repository

    Kuwahara, Hiroyuki; Umarov, Ramzan; Almasri, Islam; Gao, Xin

    2017-01-01

    To engineer cells for industrial-scale application, a deep understanding of how to design molecular control mechanisms to tightly maintain functional stability under various fluctuations is crucial. Absolute concentration robustness (ACR) is a category of robustness in reaction network models in which the steady-state concentration of a molecular species is guaranteed to be invariant even with perturbations in the other molecular species in the network. Here, we introduce a software tool, absolute concentration robustness explorer (ACRE), which efficiently explores combinatorial biochemical networks for the ACR property. ACRE has a user-friendly interface, and it can facilitate efficient analysis of key structural features that guarantee the presence and the absence of the ACR property from combinatorial networks. Such analysis is expected to be useful in synthetic biology as it can increase our understanding of how to design molecular mechanisms to tightly control the concentration of molecular species. ACRE is freely available at https://github.com/ramzan1990/ACRE.

  20. ACRE: Absolute concentration robustness exploration in module-based combinatorial networks

    KAUST Repository

    Kuwahara, Hiroyuki

    2017-03-01

    To engineer cells for industrial-scale application, a deep understanding of how to design molecular control mechanisms to tightly maintain functional stability under various fluctuations is crucial. Absolute concentration robustness (ACR) is a category of robustness in reaction network models in which the steady-state concentration of a molecular species is guaranteed to be invariant even with perturbations in the other molecular species in the network. Here, we introduce a software tool, absolute concentration robustness explorer (ACRE), which efficiently explores combinatorial biochemical networks for the ACR property. ACRE has a user-friendly interface, and it can facilitate efficient analysis of key structural features that guarantee the presence and the absence of the ACR property from combinatorial networks. Such analysis is expected to be useful in synthetic biology as it can increase our understanding of how to design molecular mechanisms to tightly control the concentration of molecular species. ACRE is freely available at https://github.com/ramzan1990/ACRE.

  1. Advancements in accuracy of the alanine dosimetry system. Part 1. The effects of environmental humidity

    International Nuclear Information System (INIS)

    Sleptchonok, Olga F.; Nagy, Vitaly; Desrosiers, Marc F.

    2000-01-01

    A one-year study of the EPR signal of γ-irradiated ( 60 Co) L-α-alanine with simultaneous monitoring of the cavity Q-factor was undertaken. The widespread opinion that the EPR signal remains absolutely stable under normal laboratory storage conditions is inaccurate. At 0% humidity, the signal can be regarded as stable within ±1% of its initial value for 6 months for 1 and 10 kGy doses, but for only 3 months for 100 kGy. When stored at the same relative humidity values up to 60%, the fading rates for dosimeters irradiated to 1 and 10 kGy are similar, whereas signals of dosimeters irradiated to 100 kGy fade considerably faster for all humidities. The rates of fading increase with the relative humidity, especially above 60% R. H. Environmental humidity also deteriorates the accuracy of alanine dosimetry by changing the resonant cavity Q-factor. This is particularly important when irradiated alanine dosimeters are used as instrument calibration standards. Short-term changes in alanine EPR signal amplitudes were recorded upon removal of the irradiated dosimeters from their storage environments. The importance of an in situ standard to correct for measurement errors due to environmental effects is demonstrated. (author)

  2. Methods of humidity determination Part II: Determination of material humidity

    OpenAIRE

    Rübner, Katrin; Balköse, Devrim; Robens, E.

    2008-01-01

    Part II covers the most common methods of measuring the humidity of solid material. State of water near solid surfaces, gravimetric measurement of material humidity, measurement of water sorption isotherms, chemical methods for determination of water content, measurement of material humidity via the gas phase, standardisation, cosmonautical observations are reviewed.

  3. Accelerated Testing and Modeling of Potential-Induced Degradation as a Function of Temperature and Relative Humidity

    DEFF Research Database (Denmark)

    Hacke, Peter; Spataru, Sergiu; Terwilliger, Kent

    2015-01-01

    An acceleration model based on the Peck equation was applied to power performance of crystalline silicon cell modules as a function of time and of temperature and humidity, the two main environmental stress factors that promote potential-induced degradation. This model was derived from module pow...

  4. Effect of relative humidity on solar potential

    International Nuclear Information System (INIS)

    Soezen, Adnan; Arcaklioglu, Erol

    2005-01-01

    In this study, the effect of relative humidity on solar potential is investigated using artificial neural-networks. Two different models are used to train the neural networks. Meteorological and geographical data (latitude, longitude, altitude, month, mean sunshine-duration, and mean temperature) are used in the input layer of the network (Model 1). But, relative humidity values are added to one network in model (Model 2). In other words, the only difference between the models is relative humidity. New formulae based on meteorological and geographical data, have been developed to determine the solar energy potential in Turkey using the networks' weights for both models. Scaled conjugate gradient (SCG) and Levenberg-Marquardt (LM) learning algorithms and a logistic sigmoid transfer-function were used in the network. The best approach was obtained by the SCG algorithm with nine neurons for both models. Meteorological data for the four years, 2000-2003, for 18 cities (Artvin, Cesme, Bozkurt, Malkara, Florya, Tosya, Kizilcahamam, Yenisehir, Edremit, Gediz, Kangal, Solhan, Ergani, Selcuk, Milas, Seydisehir, Siverek and Kilis) spread over Turkey have been used as data in order to train the neural network. Solar radiation is in output layer. One month for each city was used as test data, and these months have not been used for training. The maximum mean absolute percentage errors (MAPEs) for Tosya are 2.770394% and 2.8597% for Models 1 and 2, respectively. The minimum MAPEs for Seydisehir are 1.055205% and 1.041% with R 2 (99.9862%, 99.9842%) for Models 1 and 2, respectively, in the SCG algorithm with nine neurons. The best value of R 2 for Models 1 and 2 are for Seydisehir. The minimum value of R 2 for Model 1 is 99.8855% for Tosya, and the value for Model 2 is 99.9001% for Yenisehir. Results show that the humidity has only a negligible effect upon the prediction of solar potential using artificial neural-networks

  5. Evaluating humidity recovery efficiency of currently available heat and moisture exchangers: a respiratory system model study

    Directory of Open Access Journals (Sweden)

    Jeanette Janaina Jaber Lucato

    2009-06-01

    Full Text Available OBJECTIVES: To evaluate and compare the efficiency of humidification in available heat and moisture exchanger models under conditions of varying tidal volume, respiratory rate, and flow rate. INTRODUCTION: Inspired gases are routinely preconditioned by heat and moisture exchangers to provide a heat and water content similar to that provided normally by the nose and upper airways. The absolute humidity of air retrieved from and returned to the ventilated patient is an important measurable outcome of the heat and moisture exchangers' humidifying performance. METHODS: Eight different heat and moisture exchangers were studied using a respiratory system analog. The system included a heated chamber (acrylic glass, maintained at 37°C, a preserved swine lung, a hygrometer, circuitry and a ventilator. Humidity and temperature levels were measured using eight distinct interposed heat and moisture exchangers given different tidal volumes, respiratory frequencies and flow-rate conditions. Recovery of absolute humidity (%RAH was calculated for each setting. RESULTS: Increasing tidal volumes led to a reduction in %RAH for all heat and moisture exchangers while no significant effect was demonstrated in the context of varying respiratory rate or inspiratory flow. CONCLUSIONS: Our data indicate that heat and moisture exchangers are more efficient when used with low tidal volume ventilation. The roles of flow and respiratory rate were of lesser importance, suggesting that their adjustment has a less significant effect on the performance of heat and moisture exchangers.

  6. Comparisons of Upper Tropospheric Humidity Retrievals from TOVS and METEOSAT

    Science.gov (United States)

    Escoffier, C.; Bates, J.; Chedin, A.; Rossow, W. B.; Schmetz, J.

    1999-01-01

    Two different methods for retrieving Upper Tropospheric Humidities (UTH) from the TOVS (TIROS Operational Vertical Sounder) instruments aboard NOAA polar orbiting satellites are presented and compared. The first one, from the Environmental Technology Laboratory, computed by J. Bates and D. Jackson (hereafter BJ method), estimates UTH from a simplified radiative transfer analysis of the upper tropospheric infrared water vapor channel at wavelength measured by HIRS (6.3 micrometer). The second one results from a neural network analysis of the TOVS (HIRS and MSU) data developed at, the Laboratoire de Meteorologie Dynamique (hereafter the 3I (Improved Initialization Inversion) method). Although the two methods give very similar retrievals in temperate regions (30-60 N and S), an absolute bias up to 16% appears in the convective zone of the tropics. The two datasets have also been compared with UTH retrievals from infrared radiance measurements in the 6.3 micrometer channel from the geostationary satellite METEOSAT (hereafter MET method). The METEOSAT retrievals are systematically drier than the TOVS-based results by an absolute bias between 5 and 25%. Despite the biases, the spatial and temporal correlations are very good. The purpose of this study is to explain the deviations observed between the three datasets. The sensitivity of UTH to air temperature and humidity profiles is analysed as are the clouds effects. Overall, the comparison of the three retrievals gives an assessment of the current uncertainties in water vapor amounts in the upper troposphere as determined from NOAA and METEOSAT satellites.

  7. Absolute Soft X-ray Emission Measurements at the Nike Laser

    Science.gov (United States)

    Weaver, J.; Atkin, R.; Boyer, C.; Colombant, D.; Feldman, U.; Fielding, D.; Gardner, J.; Holland, G.; Klapisch, M.; Mostovych, A. N.; Obenscain, S.; Seely, J. F.

    2002-11-01

    Recent experiments at the Nike laser facility have demonstrated that, when a low intensity prepulse ( 2main laser intensity) is used to heat a thin Au or Pd coating on a planar CH target, the growth of non-uniformities due to laser imprint can be reduced from the growth observed for an uncoated CH target. The absolute radiation intensity in the soft x-ray region (0.1-1 keV) has a important role in the energy balance for layered targets. There is an ongoing effort to characterize the soft x-ray emission using an absolutely calibrated transmission grating spectrometer and filtered diode modules. Measurements of the angular distribution of the emission from unlayered solid targets (Au, Pd, CH) have recently been made using an array of moveable filtered diode modules. The data from the angular distribution studies will be presented. A new absolutely calibrated, time-resolving transmission grating spectrometer has been installed at the Nike. The new version has improved spectral resolution, selectable transmission filters, and the potential for simultaneous temporal, spatial, and spectral resolution. Preliminary data from the new spectrometer will be presented and future experiments will be briefly discussed. *Work was supported by DoE

  8. Age Modulates Physiological Responses during Fan Use under Extreme Heat and Humidity.

    Science.gov (United States)

    Gagnon, Daniel; Romero, Steven A; Cramer, Matthew N; Kouda, Ken; Poh, Paula Y S; Ngo, Hai; Jay, Ollie; Crandall, Craig G

    2017-11-01

    We examined the effect of electric fan use on cardiovascular and thermoregulatory responses of nine young (26 ± 3 yr) and nine aged (68 ± 4 yr) adults exposed to extreme heat and humidity. While resting at a temperature of 42°C, relative humidity increased from 30% to 70% in 2% increments every 5 min. On randomized days, the protocol was repeated without or with fan use. HR, core (Tcore) and mean skin (Tsk) temperatures were measured continuously. Whole-body sweat loss was measured from changes in nude body weight. Other measures of cardiovascular (cardiac output), thermoregulatory (local cutaneous and forearm vascular conductance, local sweat rate), and perceptual (thermal and thirst sensations) responses were also examined. When averaged over the entire protocol, fan use resulted in a small reduction of HR (-2 bpm, 95% confidence interval [CI], -8 to 3), and slightly greater Tcore (+0.05°C; 95% CI, -0.13 to 0.23) and Tsk (+0.03°C; 95% CI, -0.36 to 0.42) in young adults. In contrast, fan use resulted in greater HR (+5 bpm; 95% CI, 0-10), Tcore (+0.20°C; 95% CI, 0.00-0.41), and Tsk (+0.47°C; 95% CI, 0.18-0.76) in aged adults. A greater whole-body sweat loss during fan use was observed in young (+0.2 kg; 95% CI, -0.2 to 0.6) but not aged (0.0 kg; 95% CI, -0.2 to 0.2) adults. Greater local sweat rate and cutaneous vascular conductance were observed with fan use in aged adults. Other measures of cardiovascular, thermoregulatory, and perceptual responses were unaffected by fan use in both groups. During extreme heat and humidity, fan use elevates physiological strain in aged, but not young, adults.

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

    Science.gov (United States)

    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

  10. Stable and Selective Humidity Sensing Using Stacked Black Phosphorus Flakes.

    Science.gov (United States)

    Yasaei, Poya; Behranginia, Amirhossein; Foroozan, Tara; Asadi, Mohammad; Kim, Kibum; Khalili-Araghi, Fatemeh; Salehi-Khojin, Amin

    2015-10-27

    Black phosphorus (BP) atomic layers are known to undergo chemical degradation in humid air. Yet in more robust configurations such as films, composites, and embedded structures, BP can potentially be utilized in a large number of practical applications. In this study, we explored the sensing characteristics of BP films and observed an ultrasensitive and selective response toward humid air with a trace-level detection capability and a very minor drift over time. Our experiments show that the drain current of the BP sensor increases by ∼4 orders of magnitude as the relative humidity (RH) varies from 10% to 85%, which ranks it among the highest ever reported values for humidity detection. The mechanistic studies indicate that the operation principle of the BP film sensors is based on the modulation in the leakage ionic current caused by autoionization of water molecules and ionic solvation of the phosphorus oxoacids produced on moist BP surfaces. Our stability tests reveal that the response of the BP film sensors remains nearly unchanged after prolonged exposures (up to 3 months) to ambient conditions. This study opens up the route for utilizing BP stacked films in many potential applications such as energy generation/storage systems, electrocatalysis, and chemical/biosensing.

  11. Environmental testing of flat plate solar cell modules

    Science.gov (United States)

    Griffith, J.; Dumas, L.; Hoffman, A.

    1978-01-01

    Commercially available flat-plate solar cell modules have been subjected to a variety of environmental tests designed to simulate service conditions. Among the tests are those simulating heat and rain, wind-driven rains, humidity and freezing, humidity and heat, humidity with a voltage bias, salt fog, hail impact, and fungus infestation. Tests for optical surface soiling and the combined effects of temperature, humidity and UV irradiation are under development. A correlation has been demonstrated between degradation caused by the qualification tests and such observed field effects as power loss.

  12. Humidity Sensing in Drosophila.

    Science.gov (United States)

    Enjin, Anders; Zaharieva, Emanuela E; Frank, Dominic D; Mansourian, Suzan; Suh, Greg S B; Gallio, Marco; Stensmyr, Marcus C

    2016-05-23

    Environmental humidity influences the fitness and geographic distribution of all animals [1]. Insects in particular use humidity cues to navigate the environment, and previous work suggests the existence of specific sensory mechanisms to detect favorable humidity ranges [2-5]. Yet, the molecular and cellular basis of humidity sensing (hygrosensation) remains poorly understood. Here we describe genes and neurons necessary for hygrosensation in the vinegar fly Drosophila melanogaster. We find that members of the Drosophila genus display species-specific humidity preferences related to conditions in their native habitats. Using a simple behavioral assay, we find that the ionotropic receptors IR40a, IR93a, and IR25a are all required for humidity preference in D. melanogaster. Yet, whereas IR40a is selectively required for hygrosensory responses, IR93a and IR25a mediate both humidity and temperature preference. Consistent with this, the expression of IR93a and IR25a includes thermosensory neurons of the arista. In contrast, IR40a is excluded from the arista but is expressed (and required) in specialized neurons innervating pore-less sensilla of the sacculus, a unique invagination of the third antennal segment. Indeed, calcium imaging showed that IR40a neurons directly respond to changes in humidity, and IR40a knockdown or IR93a mutation reduced their responses to stimuli. Taken together, our results suggest that the preference for a specific humidity range depends on specialized sacculus neurons, and that the processing of environmental humidity can happen largely in parallel to that of temperature. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Relative Humidity Sensor Based on No-Core Fiber Coated by Agarose-Gel Film

    Directory of Open Access Journals (Sweden)

    Wei Xu

    2017-10-01

    Full Text Available A relative humidity (RH sensor based on single-mode–no-core–single-mode fiber (SNCS structure is proposed and experimentally demonstrated. The agarose gel is coated on the no-core fiber (NCF as the cladding, and multimode interference (MMI occurs in the SNCS structure. The transmission spectrum of the sensor is modulated at different ambient relative humidities due to the tunable refractive index property of the agarose gel film. The relative humidity can be measured by the wavelength shift and intensity variation of the dip in the transmission spectra. The humidity response of the sensors, coated with different concentrations and coating numbers of the agarose solution, were experimentally investigated. The wavelength and intensity sensitivity is obtained as −149 pm/%RH and −0.075 dB/%RH in the range of 30% RH to 75% RH, respectively. The rise and fall time is tested to be 4.8 s and 7.1 s, respectively. The proposed sensor has a great potential in real-time RH monitoring.

  14. Theory, Electro-Optical Design, Testing, and Calibration of a Prototype Atmospheric Supersaturation, Humidity, and Temperature Sensor.

    Science.gov (United States)

    1982-07-15

    Voltage versus Aspirated Dew Point 94 Hygrometer Reading in Degrees Celsius (10 Second Averages) Fig. (7.5)(b) Scatter Diagram - NCAR Lyman-Alpha...Hygrometer Output Voltage versus Aspirated Dew Point Hygrometer Reading in Degrees Celsius (10 Second Averages) Fig. (7.6) Ophir Air Temperature...goal thus translates to an absolute humidity accuracy of 1% of reading or better over a dynamic r-dnj(! ,(f i(jul. 4 uder. of magnitude. 29 - ITI VAP

  15. Ultrahigh humidity sensitivity of graphene oxide.

    Science.gov (United States)

    Bi, Hengchang; Yin, Kuibo; Xie, Xiao; Ji, Jing; Wan, Shu; Sun, Litao; Terrones, Mauricio; Dresselhaus, Mildred S

    2013-01-01

    Humidity sensors have been extensively used in various fields, and numerous problems are encountered when using humidity sensors, including low sensitivity, long response and recovery times, and narrow humidity detection ranges. Using graphene oxide (G-O) films as humidity sensing materials, we fabricate here a microscale capacitive humidity sensor. Compared with conventional capacitive humidity sensors, the G-O based humidity sensor has a sensitivity of up to 37800% which is more than 10 times higher than that of the best one among conventional sensors at 15%-95% relative humidity. Moreover, our humidity sensor shows a fast response time (less than 1/4 of that of the conventional one) and recovery time (less than 1/2 of that of the conventional one). Therefore, G-O appears to be an ideal material for constructing humidity sensors with ultrahigh sensitivity for widespread applications.

  16. Adaptive neuro-fuzzy inference system for temperature and humidity profile retrieval from microwave radiometer observations

    Science.gov (United States)

    Ramesh, K.; Kesarkar, A. P.; Bhate, J.; Venkat Ratnam, M.; Jayaraman, A.

    2015-01-01

    The retrieval of accurate profiles of temperature and water vapour is important for the study of atmospheric convection. Recent development in computational techniques motivated us to use adaptive techniques in the retrieval algorithms. In this work, we have used an adaptive neuro-fuzzy inference system (ANFIS) to retrieve profiles of temperature and humidity up to 10 km over the tropical station Gadanki (13.5° N, 79.2° E), India. ANFIS is trained by using observations of temperature and humidity measurements by co-located Meisei GPS radiosonde (henceforth referred to as radiosonde) and microwave brightness temperatures observed by radiometrics multichannel microwave radiometer MP3000 (MWR). ANFIS is trained by considering these observations during rainy and non-rainy days (ANFIS(RD + NRD)) and during non-rainy days only (ANFIS(NRD)). The comparison of ANFIS(RD + NRD) and ANFIS(NRD) profiles with independent radiosonde observations and profiles retrieved using multivariate linear regression (MVLR: RD + NRD and NRD) and artificial neural network (ANN) indicated that the errors in the ANFIS(RD + NRD) are less compared to other retrieval methods. The Pearson product movement correlation coefficient (r) between retrieved and observed profiles is more than 92% for temperature profiles for all techniques and more than 99% for the ANFIS(RD + NRD) technique Therefore this new techniques is relatively better for the retrieval of temperature profiles. The comparison of bias, mean absolute error (MAE), RMSE and symmetric mean absolute percentage error (SMAPE) of retrieved temperature and relative humidity (RH) profiles using ANN and ANFIS also indicated that profiles retrieved using ANFIS(RD + NRD) are significantly better compared to the ANN technique. The analysis of profiles concludes that retrieved profiles using ANFIS techniques have improved the temperature retrievals substantially; however, the retrieval of RH by all techniques considered in this paper (ANN, MVLR and

  17. Precision temperature monitoring (PTM) and Humidity monitoring (HM) sensors of the CMS electromagnetic calorimeter

    CERN Multimedia

    2006-01-01

    A major aspect for the ECAL detector control is the monitoring of the system temperature and the verification that the required temperature stability of the crystal volume and the APDs, expected to be (18 ± 0.05)C, is achieved. The PTM is designed to read out thermistors, placed on both the front and back of the crystals, with a relative precision better than 0.01 C. In total there are ten sensors per supermodule. The humidity level in the electronics compartment is monitored by the HM system and consists of one humidity sensor per module.

  18. Air humidity requirements for human comfort

    DEFF Research Database (Denmark)

    Toftum, Jørn; Fanger, Povl Ole

    1999-01-01

    level near 100% rh. For respiratory comfort are the requirements much more stringent and results in lower permissible indoor air humidities. Compared with the upper humidity limit specified in existing thermal comfort standards, e.g. ASHRAE Addendum 55a, the humidity limit based on skin humidity......Upper humidity limits for the comfort zone determined from two recently presented models for predicting discomfort due to skin humidity and insufficient respiratory cooling are proposed. The proposed limits are compared with the maximum permissible humidity level prescribed in existing standards...... for the thermal indoor environment. The skin humidity model predicts discomfort as a function of the relative humidity of the skin, which is determined by existing models for human heat and moisture transfer based on environmental parameters, clothing characteristics and activity level. The respiratory model...

  19. Absolute rate measurement by light modulation - ESR technique

    Energy Technology Data Exchange (ETDEWEB)

    Choo, K Y; Gaspar, P P

    1977-01-01

    A rate constant is deduced for the reaction of tert-butoxy radicals and trimethylsilane from the measurement of the phase shift between the modulated light source and the ESR signal of trimethylsilyl radical. The rate constant was found to be 3 x 10/sup -2/M/sup -1/. sec/sup -1/ at -50/sup 0/C.

  20. Radon prevention coating in hot and humid environment

    International Nuclear Information System (INIS)

    Yang Yushan; Dong Faqin; Deng Yuequan; Qu Ruixue

    2013-01-01

    The radon prevention performance of a new self-made radon prevention coating was researched in the radon contamination provided by the releasing radon modules. With coating thickness of 0.8 mm, the radon mitigation efficiency in 1 # radon module concentration is optimal when the addition of defoaming agent is 0.3% (mass fraction). The radon mitigation efficiency increases with the coating thickness when the defoaming agent of 0.3% is added, but the radon mitigation efficiency tends to be stable as the coating thickness is more than 2.0 mm. The radon mitigation efficiency of radon prevention coating appended precipitated barium sulphate decreases obviously, and the addition of ash calcium, white cement and gesso don't decrease radon mitigation efficiency. The addition of white cement and gesso addition affects the radon prevention stability, while radon mitigation efficiency of radon prevention coating with ash calcium keeps a good performance. Under the hot and humid environment, the radon prevention coating still has good radon mitigation efficiency in 2 # radon module concentration. (authors)

  1. Absolute risk, absolute risk reduction and relative risk

    Directory of Open Access Journals (Sweden)

    Jose Andres Calvache

    2012-12-01

    Full Text Available This article illustrates the epidemiological concepts of absolute risk, absolute risk reduction and relative risk through a clinical example. In addition, it emphasizes the usefulness of these concepts in clinical practice, clinical research and health decision-making process.

  2. An absolute distance interferometer with two external cavity diode lasers

    International Nuclear Information System (INIS)

    Hartmann, L; Meiners-Hagen, K; Abou-Zeid, A

    2008-01-01

    An absolute interferometer for length measurements in the range of several metres has been developed. The use of two external cavity diode lasers allows the implementation of a two-step procedure which combines the length measurement with a variable synthetic wavelength and its interpolation with a fixed synthetic wavelength. This synthetic wavelength is obtained at ≈42 µm by a modulation-free stabilization of both lasers to Doppler-reduced rubidium absorption lines. A stable reference interferometer is used as length standard. Different contributions to the total measurement uncertainty are discussed. It is shown that the measurement uncertainty can considerably be reduced by correcting the influence of vibrations on the measurement result and by applying linear regression to the quadrature signals of the absolute interferometer and the reference interferometer. The comparison of the absolute interferometer with a counting interferometer for distances up to 2 m results in a linearity error of 0.4 µm in good agreement with an estimation of the measurement uncertainty

  3. Modulator-free quadrature amplitude modulation signal synthesis

    Science.gov (United States)

    Liu, Zhixin; Kakande, Joseph; Kelly, Brian; O'Carroll, John; Phelan, Richard; Richardson, David J.; Slavík, Radan

    2014-12-01

    The ability to generate high-speed on-off-keyed telecommunication signals by directly modulating a semiconductor laser’s drive current was one of the most exciting prospective applications of the nascent field of laser technology throughout the 1960s. Three decades of progress led to the commercialization of 2.5 Gbit s-1-per-channel submarine fibre optic systems that drove the growth of the internet as a global phenomenon. However, the detrimental frequency chirp associated with direct modulation forced industry to use external electro-optic modulators to deliver the next generation of on-off-keyed 10 Gbit s-1 systems and is absolutely prohibitive for today’s (>)100 Gbit s-1 coherent systems, which use complex modulation formats (for example, quadrature amplitude modulation). Here we use optical injection locking of directly modulated semiconductor lasers to generate complex modulation format signals showing distinct advantages over current and other currently researched solutions.

  4. Study on the Correlation between Humidity and Material Strains in Separable Micro Humidity Sensor Design

    Directory of Open Access Journals (Sweden)

    Chih-Yuan Chang

    2017-05-01

    Full Text Available Incidents of injuries caused by tiles falling from building exterior walls are frequently reported in Taiwan. Humidity is an influential factor in tile deterioration but it is more difficult to measure the humidity inside a building structure than the humidity in an indoor environment. Therefore, a separable microsensor was developed in this study to measure the humidity of the cement mortar layer with a thickness of 1.5–2 cm inside the external wall of a building. 3D printing technology is used to produce an encapsulation box that can protect the sensor from damage caused by the concrete and cement mortar. The sensor is proven in this study to be capable of measuring temperature and humidity simultaneously and the measurement results are then used to analyze the influence of humidity on external wall tile deterioration.

  5. ATLAS ALFA—measuring absolute luminosity with scintillating fibres

    CERN Document Server

    Franz, S

    2009-01-01

    ALFA is a high-precision scintillating fibre tracking detector under construction for the absolute determination of the LHC luminosity at the ATLAS interaction point. This detector, mounted in so-called Roman Pots, will track protons elastically scattered under μrad angles at IP1.In total there are four pairs of vertically arranged detector modules which approach the LHC beam axis to mm distance. Each detector module consists of ten layers of two times 64 scintillating fibres each (U and V planes). The fibres are coupled to 64 channels Multi-Anodes PhotoMultipliers Tubes read out by compact front-end electronics. Each detector module is complemented by so-called overlap detectors: Three layers of two times 30 scintillating fibres which will be used to measure the relative positioning of two vertically arranged main detectors. The total number of channels is about 15000. Conventional plastic scintillator tiles are mounted in front of the fibre detectors and will serve as trigger counter. The extremely restric...

  6. Graphene based humidity-insensitive films

    KAUST Repository

    Tai, Yanlong

    2017-09-08

    A humidity nonsensitive material based on reduced-graphene oxide (r-GO) and methods of making the same are provided, in an embodiment, the materia! has a resistance/humidity variation of about -15% to 15% based on different sintering time or temperature. In an aspect, the resistance variation to humidity can be close to zero or -0.5% to 0.5%, showing a humidity non sensitivity property. In an embodiment, a humidity nonsensitive material based on the r-GO and carbon nanotube (CNT) composites is provided, wherein the ratio of CNT to r-GO is adjusted. The ratio can be adjusted based on the combined contribution of carbon nanotube (positive resistance variation) and reduced- graphene oxide (negative resistance variation) behaviors.

  7. Ambient humidity and the skin: the impact of air humidity in healthy and diseased states.

    Science.gov (United States)

    Goad, N; Gawkrodger, D J

    2016-08-01

    Humidity, along with other climatic factors such as temperature and ultraviolet radiation, can have an important impact on the skin. Limited data suggest that external humidity influences the water content of the stratum corneum. An online literature search was conducted through Pub-Med using combinations of the following keywords: skin, skin disease, humidity, dermatoses, dermatitis, eczema, and mist. Publications included in this review were limited to (i) studies in humans or animals, (ii) publications showing relevance to the field of dermatology, (iii) studies published in English and (iv) publications discussing humidity as an independent influence on skin function. Studies examining environmental factors as composite influences on skin health are only included where the impact of humidity on the skin is also explored in isolation of other environmental factors. A formal systematic review was not feasible for this topic due to the heterogeneity of the available research. Epidemiological studies indicated an increase in eczema with low internal (indoors) humidity and an increase in eczema with external high humidity. Other studies suggest that symptoms of dry skin appear with low humidity internal air-conditioned environments. Murine studies determined that low humidity caused a number of changes in the skin, including the impairment of the desquamation process. Studies in humans demonstrated a reduction in transepidermal water loss (TEWL) (a measure of the integrity of the skin's barrier function) with low humidity, alterations in the water content in the stratum corneum, decreased skin elasticity and increased roughness. Intervention with a humidifying mist increased the water content of the stratum corneum. Conversely, there is some evidence that low humidity conditions can actually improve the barrier function of the skin. Ambient relative humidity has an impact on a range of parameters involved in skin health but the literature is inconclusive. Further

  8. Influence of sample temperature and environmental humidity on measurements of benzene in ambient air by transportable GC-PID

    Directory of Open Access Journals (Sweden)

    C. Romero-Trigueros

    2017-10-01

    Full Text Available Calibration of in situ analysers of air pollutants is usually done with dry standards. In this paper, the influence of sample temperature and environmental humidity on benzene measurements by gas chromatography coupled with a photoionisation detector (GC-PID is studied. Two reference gas mixtures (40 and 5 µg m−3 nominal concentration benzene in air were subjected to two temperature cycles (20/5/20 °C and 20/35/20 °C and measured with two identical GC-PIDs. The change in sample temperature did not produce any significant change in readings. Regarding ambient humidity, the chromatographs were calibrated for benzene with dry gases and subjected to measure reference standards with humidity (20 and 80 % at 20 °C. When measuring a concentration of 0.5 µg m−3 benzene in air, the levels of humidity tested did not produce any significant interference in measurements taken with any of the analysers. However, when measuring a concentration of 40 µg m−3, biases in measurements of 18 and 21 % for each respective analyser were obtained when the relative humidity of the sample was 80 % at 20 °C. Further tests were carried out to study the nature of this interference. Results show that humidity interference depends on both the amount fractions of water vapour and benzene. If benzene concentrations in an area are close to its annual limit value (5 µg m−3, biases of 2.2 % can be expected when the absolute humidity is 8.6 g cm−3 – corresponding to a relative humidity of 50 % at 20 °C. This can be accounted for in the uncertainty budget of measurements with no need for corrections. If benzene concentrations are above the annual limit value, biases become higher. Thus, in these cases, actions should be taken to reduce the humidity interference, as an underestimation of benzene concentrations may cause a mismanagement of air quality in these situations.

  9. Humidity Sensor Based on Bragg Gratings Developed on the End Facet of an Optical Fiber by Sputtering of One Single Material

    Directory of Open Access Journals (Sweden)

    Joaquin Ascorbe

    2017-04-01

    Full Text Available The refractive index of sputtered indium oxide nanocoatings has been altered just by changing the sputtering parameters, such as pressure. These induced changes have been exploited for the generation of a grating on the end facet of an optical fiber towards the development of wavelength-modulated optical fiber humidity sensors. A theoretical analysis has also been performed in order to study the different parameters involved in the fabrication of this optical structure and how they would affect the sensitivity of these devices. Experimental and theoretical results are in good agreement. A sensitivity of 150 pm/%RH was obtained for relative humidity changes from 20% to 60%. This kind of humidity sensors shows a maximum hysteresis of 1.3% relative humidity.

  10. Encasing the Absolutes

    Directory of Open Access Journals (Sweden)

    Uroš Martinčič

    2014-05-01

    Full Text Available The paper explores the issue of structure and case in English absolute constructions, whose subjects are deduced by several descriptive grammars as being in the nominative case due to its supposed neutrality in terms of register. This deduction is countered by systematic accounts presented within the framework of the Minimalist Program which relate the case of absolute constructions to specific grammatical factors. Each proposal is shown as an attempt of analysing absolute constructions as basic predication structures, either full clauses or small clauses. I argue in favour of the small clause approach due to its minimal reliance on transformations and unique stipulations. Furthermore, I propose that small clauses project a singular category, and show that the use of two cases in English absolute constructions can be accounted for if they are analysed as depictive phrases, possibly selected by prepositions. The case of the subject in absolutes is shown to be a result of syntactic and non-syntactic factors. I thus argue in accordance with Minimalist goals that syntactic case does not exist, attributing its role in absolutes to other mechanisms.

  11. Accelerated Testing and Modeling of Potential-Induced Degradation as a Function of Temperature and Relative Humidity

    DEFF Research Database (Denmark)

    Hacke, Peter; Spataru, Sergiu; Terwilliger, Kent

    2015-01-01

    An acceleration model based on the Peck equation was applied to power performance of crystalline silicon cell modules as a function of time and of temperature and humidity, which are the two main environmental stress factors that promote potential-induced degradation (PID). This model was derived...

  12. New calculation method for thermodynamic properties of humid air in humid air turbine cycle – The general model and solutions for saturated humid air

    International Nuclear Information System (INIS)

    Wang, Zidong; Chen, Hanping; Weng, Shilie

    2013-01-01

    The article proposes a new calculation method for thermodynamic properties (i.e. specific enthalpy, specific entropy and specific volume) of humid air in humid air turbine cycle. The research pressure range is from 0.1 MPa to 5 MPa. The fundamental behaviors of dry air and water vapor in saturated humid air are explored in depth. The new model proposes and verifies the relationship between total gas mixture pressure and gas component pressures. This provides a good explanation of the fundamental behaviors of gas components in gas mixture from a new perspective. Another discovery is that the water vapor component pressure of saturated humid air equals P S , always smaller than its partial pressure (f·P S ) which was believed in the past researches. In the new model, “Local Gas Constant” describes the interaction between similar molecules. “Improvement Factor” is proposed for the first time by this article, and it quantitatively describes the magnitude of interaction between dissimilar molecules. They are combined to fully describe the real thermodynamic properties of humid air. The average error of Revised Dalton's Method is within 0.1% compared to experimentally-based data. - Highlights: • Our new model is suitable to calculate thermodynamic properties of humid air in HAT cycle. • Fundamental behaviors of dry air and water vapor in saturated humid air are explored in depth. • Local-Gas-Constant describes existing alone component and Improvement Factor describes interaction between different components. • The new model proposes and verifies the relationship between total gas mixture pressure and component pressures. • It solves saturated humid air thoroughly and deviates from experimental data less than 0.1%

  13. The effects of non-invasive respiratory support on oropharyngeal temperature and humidity: a neonatal manikin study.

    Science.gov (United States)

    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/

  14. A high Reliability Module with Thermoelectric Device by Molding Technology for M2M Wireless Sensor Network

    International Nuclear Information System (INIS)

    Nakagawa, K; Tanaka, T; Suzuki, T

    2014-01-01

    This paper presents the fabrication of a new energy harvesting module that used the thermoelectric device (TED) by using molding technology. The output voltage per heater temperature of the TED module at 20 °C ambient temperature is 8mV/K and similar to the result with the aluminium heat sink which is almost the same fin size as the TED module. The accelerated environmental tests are performed on damp heat test that is an aging test under high temperature and high humidity, cold test and highly accelerated temperature and humidity stress test (HAST) for the purpose of evaluating the electrical reliability in harsh environments. Every result of tests indicates that the TED and circuit board can be properly protected from harsh temperature and humidity by using molding technology, because the output voltage of after tested modules is reduced by less than 5%.This study presents a novel fabrication method for a high reliability TED-installed module appropriate for Machine to Machine wireless sensor networks

  15. Absolute advantage

    NARCIS (Netherlands)

    J.G.M. van Marrewijk (Charles)

    2008-01-01

    textabstractA country is said to have an absolute advantage over another country in the production of a good or service if it can produce that good or service using fewer real resources. Equivalently, using the same inputs, the country can produce more output. The concept of absolute advantage can

  16. Determination of equilibrium humidities using temperature and humidity controlled X-ray diffraction (RH-XRD)

    International Nuclear Information System (INIS)

    Linnow, Kirsten; Steiger, Michael

    2007-01-01

    Confined growth of crystals in porous building materials is generally considered to be a major cause of damage. We report on the use of X-ray diffraction under controlled conditions of temperature and relative humidity (RH-XRD) for the investigation of potentially deleterious phase transition reactions. An improved procedure based on rate measurements is used for the accurate and reproducible determination of equilibrium humidities of deliquescence and hydration reactions. The deliquescence humidities of NaCl (75.4 ± 0.5% RH) and Ca(NO 3 ) 2 .4H 2 O (50.8 ± 0.7% RH) at 25 deg. C determined with this improved RH-XRD technique are in excellent agreement with available literature data. Measurement of the hydration of anhydrous Ca(NO 3 ) 2 to form Ca(NO 3 ) 2 .2H 2 O revealed an equilibrium humidity of 10.2 ± 0.3%, which is also in reasonable agreement with available data. In conclusion, dynamic X-ray diffraction measurements are an appropriate method for the accurate and precise determination of equilibrium humidities with a number of interesting future applications

  17. Decline in temperature and humidity increases the occurrence of influenza in cold climate

    Science.gov (United States)

    2014-01-01

    Background Both temperature and humidity may independently or jointly contribute to the risk of influenza infections. We examined the relations between the level and decrease of temperature, humidity and the risk of influenza A and B virus infections in a subarctic climate. Methods We conducted a case-crossover study among military conscripts (n = 892) seeking medical attention due to respiratory symptoms during their military training period and identified 66 influenza A and B cases by PCR or serology. Meteorological data such as measures of average and decline in ambient temperature and absolute humidity (AH) during the three preceding days of the onset (hazard period) and two reference periods, prior and after the onset were obtained. Results The average temperature preceding the influenza onset was −6.8 ± 5.6°C and AH 3.1 ± 1.3 g/m3. A decrease in both temperature and AH during the hazard period increased the occurrence of influenza so that a 1°C decrease in temperature and 0.5 g decrease per m3 in AH increased the estimated risk by 11% [OR 1.11 (1.03 to 1.20)] and 58% [OR 1.58 (1.28 to 1.96)], respectively. The occurrence of influenza infections was positively associated with both the average temperature [OR 1.10 per 1°C (95% confidence interval 1.02 to 1.19)] and AH [OR 1.25 per g/m3 (1.05 to 1.49)] during the hazard period prior to onset. Conclusion Our results demonstrate that a decrease rather than low temperature and humidity per se during the preceding three days increase the risk of influenza episodes in a cold climate. PMID:24678699

  18. Reaction velocity of sodium hydration in humid air and sodium carbonation in humid carbon dioxide atmosphere. Fundamental study on sodium carbonate process in FBR bulk sodium coolant disposal technology

    International Nuclear Information System (INIS)

    Tadokoro, Yutaka; Yoshida, Eiichi

    1999-11-01

    A sodium carbonate processing method, which changes sodium to sodium carbonate and/or sodium bicarbonate by humid carbon dioxide, has been examined and about to be applied to large test loops dismantling. However, that the basic data regarding the progress of the reaction is insufficient on the other hand, is a present condition. The present report therefore aims at presenting basic data regarding the reaction velocity of sodium hydration in humid air and sodium carbonation in humid carbon dioxide atmosphere, and observing the reaction progress, for the application to large test loops dismantling. The test result is summarized as follows. (1) Although the reaction velocity of sodium varied with sodium specimen sizes and velocity measurement methods, the reaction velocity of sodium hydration was in about 0.16 ∼ 0.34 mmh -1 (0.016 ∼ 0.033g cm -2 h -1 , 6.8x10 -4 ∼ 1.4x10 -3 mol cm -2 h -1 ) and that of sodium carbonation was in about 0.16 ∼ 0.27mmh -1 (0.016 ∼ 0.023g cm -2 h -1 , 6.8x10 -4 ∼ 1.1x10 -3 mol cm -2 h -1 ) (26 ∼ 31degC, RH 100%). (2) The reaction velocity of sodium in carbon dioxide atmosphere was greatly affected by vapor partial pressure (absolutely humidity). And the velocity was estimated in 0.08 ∼ 0.12mmh -1 (0.008 ∼ 0.012g cm -2 h -1 , 3.4x10 -4 ∼ 5.2x10 -4 mol cm -2 h -1 ) in the carbon dioxide atmosphere, whose temperature of 20degC and relative humidity of 80% are assumed real sodium carbonate process condition. (3) By the X-ray diffraction method, NaOH was found in humid air reaction product. Na 2 CO 3 , NaHCO 3 were found in carbon dioxide atmosphere reaction product. It was considered that Sodium changes to NaOH, and subsequently to NaHCO 3 through Na 2 CO 3 . (4) For the application to large test loops dismantling, it is considered possible to change sodium to a target amount of sodium carbonate (or sodium bicarbonate) by setting up gas supply quantity and also processing time appropriately according to the surface area

  19. Maple (Computer Algebra System) in Teaching Pre-Calculus: Example of Absolute Value Function

    Science.gov (United States)

    Tuluk, Güler

    2014-01-01

    Modules in Computer Algebra Systems (CAS) make Mathematics interesting and easy to understand. The present study focused on the implementation of the algebraic, tabular (numerical), and graphical approaches used for the construction of the concept of absolute value function in teaching mathematical content knowledge along with Maple 9. The study…

  20. Absolutely relative or relatively absolute: violations of value invariance in human decision making.

    Science.gov (United States)

    Teodorescu, Andrei R; Moran, Rani; Usher, Marius

    2016-02-01

    Making decisions based on relative rather than absolute information processing is tied to choice optimality via the accumulation of evidence differences and to canonical neural processing via accumulation of evidence ratios. These theoretical frameworks predict invariance of decision latencies to absolute intensities that maintain differences and ratios, respectively. While information about the absolute values of the choice alternatives is not necessary for choosing the best alternative, it may nevertheless hold valuable information about the context of the decision. To test the sensitivity of human decision making to absolute values, we manipulated the intensities of brightness stimuli pairs while preserving either their differences or their ratios. Although asked to choose the brighter alternative relative to the other, participants responded faster to higher absolute values. Thus, our results provide empirical evidence for human sensitivity to task irrelevant absolute values indicating a hard-wired mechanism that precedes executive control. Computational investigations of several modelling architectures reveal two alternative accounts for this phenomenon, which combine absolute and relative processing. One account involves accumulation of differences with activation dependent processing noise and the other emerges from accumulation of absolute values subject to the temporal dynamics of lateral inhibition. The potential adaptive role of such choice mechanisms is discussed.

  1. Humidity scanning quartz crystal microbalance with dissipation monitoring setup for determination of sorption-desorption isotherms and rheological changes

    Energy Technology Data Exchange (ETDEWEB)

    Björklund, Sebastian, E-mail: sebastianbjorklund@gmail.com; Kocherbitov, Vitaly [Department of Biomedical Science, Faculty of Health and Society, Malmö University, Malmö (Sweden); Biofilms—Research Center for Biointerfaces, Malmö University, Malmö (Sweden)

    2015-05-15

    A new method to determine water sorption-desorption isotherms with high resolution in the complete range of water activities (relative humidities) is presented. The method is based on quartz crystal microbalance with dissipation monitoring (QCM-D). The QCM-D is equipped with a humidity module in which the sample film is kept in air with controlled humidity. The experimental setup allows for continuous scanning of the relative humidity from either dry to humid conditions or vice versa. The amount of water sorbed or desorbed from the sample is determined from the resonance frequencies of the coated quartz sensor, via analysis of the overtone dependence. In addition, the method allows for characterization of hydration induced changes of the rheological properties from the dissipation data, which is closely connected to the viscoelasticity of the film. The accuracy of the humidity scanning setup is confirmed in control experiments. Sorption-desorption isotherms of pig gastric mucin and lysozyme, obtained by the new method, show good agreement with previous results. Finally, we show that the deposition technique used to coat the quartz sensor influences the QCM-D data and how this issue can be used to obtain further information on the effect of hydration. In particular, we demonstrate that spin-coating represents an attractive alternative to obtain sorption-desorption isotherms, while drop-coating provides additional information on changes of the rheological properties during hydration.

  2. Uncertainly Analysis of Two Types of Humidity Sensors by a Humidity Generator with a Divided-Flow System

    Science.gov (United States)

    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

  3. Uncertainly Analysis of Two Types of Humidity Sensors by a Humidity Generator with a Divided-Flow System.

    Science.gov (United States)

    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.

  4. Graphene based humidity-insensitive films

    KAUST Repository

    Tai, Yanlong; Lubineau, Gilles

    2017-01-01

    A humidity nonsensitive material based on reduced-graphene oxide (r-GO) and methods of making the same are provided, in an embodiment, the materia! has a resistance/humidity variation of about -15% to 15% based on different sintering time

  5. Controlled humidity gas circulators

    International Nuclear Information System (INIS)

    Gruner, S.M.

    1981-01-01

    A programmable circulator capable of regulating the humidity of a gas stream over a wide range of humidity is described. An optical dew-point hygrometer is used as a feedback element to control the addition or removal of water vapor. Typical regulation of the gas is to a dew-point temperature of +- 0.2 0 C and to an accuracy limited by the dew-point hygrometer

  6. Superheterodyne configuration for two-wavelength interferometry applied to absolute distance measurement

    International Nuclear Information System (INIS)

    Le Floch, Sebastien; Salvade, Yves; Droz, Nathalie; Mitouassiwou, Rostand; Favre, Patrick

    2010-01-01

    We present a new superheterodyne technique for long-distance measurements by two-wavelength interferometry (TWI). While conventional systems use two acousto-optic modulators to generate two different heterodyne frequencies, here the two frequencies result from synchronized sweeps of optical and radio frequencies. A distributed feedback laser source is injected in an intensity modulator that is driven at the half-wave voltage mode. A radio-frequency signal is applied to this intensity modulator to generate two optical sidebands around the optical carrier. This applied radio frequency consists of a digital ramp between 13 and 15 GHz, with 1 ms duration and with an accuracy of better than 1 ppm. Simultaneously, the laser source is frequency modulated by a current modulation that is synchronized on the radio-frequency ramp as well as on a triangle waveform. These two frequency-swept optical signals at the output of the modulator illuminate a Michelson interferometer and create two distinct distance-dependent heterodyne frequencies on the photodetector. The superheterodyne signal is then detected and bandpass filtered to retrieve the absolute distance measurement. Experiments between 1 and 15 m confirm the validity of this new concept, leading to a distance accuracy of ± 50 μm for a 1 ms acquisition time.

  7. Development of Smart Ventilation Control Algorithms for Humidity Control in High-Performance Homes in Humid U.S. Climates

    Energy Technology Data Exchange (ETDEWEB)

    Less, Brennan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Walker, Iain [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ticci, Sara [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-04-11

    Past field research and simulation studies have shown that high performance homes experience elevated indoor humidity levels for substantial portions of the year in humid climates. This is largely the result of lower sensible cooling loads, which reduces the moisture removed by the cooling system. These elevated humidity levels lead to concerns about occupant comfort, health and building durability. Use of mechanical ventilation at rates specified in ASHRAE Standard 62.2-2013 are often cited as an additional contributor to humidity problems in these homes. Past research has explored solutions, including supplemental dehumidification, cooling system operational enhancements and ventilation system design (e.g., ERV, supply, exhaust, etc.). This project’s goal is to develop and demonstrate (through simulations) smart ventilation strategies that can contribute to humidity control in high performance homes. These strategies must maintain IAQ via equivalence with ASHRAE Standard 62.2-2013. To be acceptable they must not result in excessive energy use. Smart controls will be compared with dehumidifier energy and moisture performance. This work explores the development and performance of smart algorithms for control of mechanical ventilation systems, with the objective of reducing high humidity in modern high performance residences. Simulations of DOE Zero-Energy Ready homes were performed using the REGCAP simulation tool. Control strategies were developed and tested using the Residential Integrated Ventilation (RIVEC) controller, which tracks pollutant exposure in real-time and controls ventilation to provide an equivalent exposure on an annual basis to homes meeting ASHRAE 62.2-2013. RIVEC is used to increase or decrease the real-time ventilation rate to reduce moisture transport into the home or increase moisture removal. This approach was implemented for no-, one- and two-sensor strategies, paired with a variety of control approaches in six humid climates (Miami

  8. A Quantitative Analysis of Photovoltaic Modules Using Halved Cells

    Directory of Open Access Journals (Sweden)

    S. Guo

    2013-01-01

    Full Text Available In a silicon wafer-based photovoltaic (PV module, significant power is lost due to current transport through the ribbons interconnecting neighbour cells. Using halved cells in PV modules is an effective method to reduce the resistive power loss which has already been applied by some major PV manufacturers (Mitsubishi, BP Solar in their commercial available PV modules. As a consequence, quantitative analysis of PV modules using halved cells is needed. In this paper we investigate theoretically and experimentally the difference between modules made with halved and full-size solar cells. Theoretically, we find an improvement in fill factor of 1.8% absolute and output power of 90 mW for the halved cell minimodule. Experimentally, we find an improvement in fill factor of 1.3% absolute and output power of 60 mW for the halved cell module. Also, we investigate theoretically how this effect confers to the case of large-size modules. It is found that the performance increment of halved cell PV modules is even higher for high-efficiency solar cells. After that, the resistive loss of large-size modules with different interconnection schemes is analysed. Finally, factors influencing the performance and cost of industrial halved cell PV modules are discussed.

  9. Humidity control device in a reactor container

    International Nuclear Information System (INIS)

    Aizawa, Motohiro; Igarashi, Hiroo; Osumi, Katsumi; Kimura, Takashi.

    1986-01-01

    Purpose: To provide a device capable of maintaining the inside of a container under high humidity circumstantial conditions causing less atmospheric corrosions, in order to prevent injuries due to atmospheric corrosions to smaller diameter stainless steel pipeways in the reactor container. Constitution: Stress corrosion cracks (SCC) to the smaller diameter stainless steel pipeways are caused dependent on the relative humidity and it is effective as the countermeasure against SCC to maintain the relative humidity at a low level less than 30 % or high level greater than 60 %. Based on the above findings, a humidity control device is disposed so as to maintain the relative humidity for the atmosphere within a reactor core on a higher humidity region. The device is adapted such that recycling gas in the dry-well coolant circuit is passed through an orifice to atomize the water introduced from feedwater pipe and introduce into a reactor core or such that the recycling gases in the dry-well cooling circuit are bubbled into water to remove chlorine gas in the reactor container gas thereby increasing the humidity in the reactor container. (Kamimura, M.)

  10. Upper limits for air humidity based on human comfort

    DEFF Research Database (Denmark)

    Toftum, Jørn; Fanger, Povl Ole; Jørgensen, Anette S.

    1998-01-01

    respiratory cooling. Human subjects perceived the condition of their skin to be less acceptable with increasing skin humidity. Inhaled air was rated warmer, more stuffy and less acceptable with increasing air humidity and temperature. Based on the subjects' comfort responses, new upper limits for air humidity......The purpose of this study was to verify the hypothesis that insufficient respiratory cooling and a high level of skin humidity are two reasons for thermal discomfort at high air humidities, and to prescribe upper limits for humidity based on discomfort due to elevated skin humidity and insufficient...

  11. ABSOLUTE NEUTRINO MASSES

    DEFF Research Database (Denmark)

    Schechter, J.; Shahid, M. N.

    2012-01-01

    We discuss the possibility of using experiments timing the propagation of neutrino beams over large distances to help determine the absolute masses of the three neutrinos.......We discuss the possibility of using experiments timing the propagation of neutrino beams over large distances to help determine the absolute masses of the three neutrinos....

  12. Humidity and Buildings. Technical Paper No. 188.

    Science.gov (United States)

    Hutcheon, N. B.

    Modified and controlled relative humidity in buildings for certain occupancies is discussed. New criteria are used in determining the needs, desirability and problems associated with humidities in a building. Severe winter climate requires that special attention be given to the problems associated with increased indoor humidities during cold…

  13. Humidity Graphs for All Seasons.

    Science.gov (United States)

    Esmael, F.

    1982-01-01

    In a previous article in this journal (Vol. 17, p358, 1979), a wet-bulb depression table was recommended for two simple experiments to determine relative humidity. However, the use of a graph is suggested because it gives the relative humidity directly from the wet and dry bulb readings. (JN)

  14. Humid Heat Waves at different warming levels

    Science.gov (United States)

    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.

  15. 7 CFR 28.301 - Measurement: humidity; temperature.

    Science.gov (United States)

    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. ...

  16. Humidity detection using chitosan film based sensor

    Science.gov (United States)

    Nasution, T. I.; Nainggolan, I.; Dalimunthe, D.; Balyan, M.; Cuana, R.; Khanifah, S.

    2018-02-01

    A humidity sensor made of the natural polymer chitosan has been successfully fabricated in the film form by a solution casting method. Humidity testing was performed by placing a chitosan film sensor in a cooling machine room, model KT-2000 Ahu. The testing results showed that the output voltage values of chitosan film sensor increased with the increase in humidity percentage. For the increase in humidity percentage from 30 to 90% showed that the output voltage of chitosan film sensor increased from 32.19 to 138.75 mV. It was also found that the sensor evidenced good repeatability and stability during the testing. Therefore, chitosan has a great potential to be used as new sensing material for the humidity detection of which was cheaper and environmentally friendly.

  17. Humidity requirements in WSCF Laboratories

    International Nuclear Information System (INIS)

    Evans, R.A.

    1994-01-01

    The purpose of this paper is to develop and document a position on Relative Humidity (RH) requirements in the WSCF Laboratories. A current survey of equipment vendors for Organic, Inorganic and Radiochemical laboratories indicate that 25% - 80% relative humidity may meet the environmental requirements for safe operation and protection of all the laboratory equipment

  18. Absolute nuclear material assay

    Science.gov (United States)

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  19. Thermodynamics of negative absolute pressures

    International Nuclear Information System (INIS)

    Lukacs, B.; Martinas, K.

    1984-03-01

    The authors show that the possibility of negative absolute pressure can be incorporated into the axiomatic thermodynamics, analogously to the negative absolute temperature. There are examples for such systems (GUT, QCD) processing negative absolute pressure in such domains where it can be expected from thermodynamical considerations. (author)

  20. A high reliability module with thermoelectric device by molding technology for M2M wireless sensor network

    International Nuclear Information System (INIS)

    Nakagawa, K; Tanaka, T; Suzuki, T

    2015-01-01

    This paper presents the fabrication of a new energy harvesting module that uses a thermoelectric device (TED) by using molding technology. Through molding technology, the TED and circuit board can be properly protected and a heat-radiating fin structure can be simultaneously constructed. The output voltage per heater temperature of the TED module at 20 °C ambient temperature is 8 mV K −1 , similar to the result with the aluminum heat sink which is almost the same fin size as the TED module. The accelerated environmental tests are performed on a damp heat test, which is an aging test under high temperature and high humidity, highly accelerated temperature, and humidity stress test (HAST) for the purpose of evaluating the electrical reliability in harsh environments, cold test and thermal cycle test to evaluate degrading characteristics by cycling through two temperatures. All test results indicate that the TED and circuit board can be properly protected from harsh temperature and humidity by using molding technology because the output voltage of after-tested modules is reduced by less than 5%. This study presents a novel fabrication method for a high reliability TED-installed module appropriate for Machine to Machine wireless sensor networks. (paper)

  1. Humidity Response of Polyaniline Based Sensor

    Directory of Open Access Journals (Sweden)

    Mamta PANDEY

    2010-02-01

    Full Text Available Abstract: This paper presents hitherto unreported humidity sensing capacity of emeraldine salt form of polyaniline. Humidity plays a major role in different processes in industries ranging from food to electronic goods besides human comfort and therefore its monitoring is an essential requirement during various processes. Polyaniline has a wide use for making sensors as it can be easily synthesized and has long stability. Polyaniline is synthesized here by chemical route and is found to sense humidity as it shows variation in electrical resistance with variation in relative humidity. Results are presented here for a range of 15 to 90 RH%. The resistance falls from 5.8 to 0.72 Giga ohms as RH varies from 15 to 65 % and then falls to 13.9 Mega ohms as RH approaches 90 %. The response and recovery times are also measured.

  2. Short-term heart rate variability in asthmatic obese children: effect of exhaustive exercise and different humidity conditions.

    Science.gov (United States)

    Rezvan, K; Dabidi Roshan, V; Mahmudi, S A

    2015-11-01

    Asthmatic obese children experience changes in functional capacity and autonomic control. Previous heart rate variability (HRV) studies were based on 24-hour recordings, little research has been conducted on the short-term HRV in asthmatic obese children, primarily during physical effort indifferent environmental humidity conditions. The aim of this study was to evaluate the effect of aerobic activity on short-term HRV in asthmatic obese children under two different environmental humidity conditions. Ten obese boys with mild asthma as experimental group and 15 obese healthy boys with the same conditions were involved as a control group. Protocol included progressive and exhaustive aerobic activities on a calibrated ergometer pedal bicycle in two various environmental humidity 35±5% and 65±5%. HRV was measured by PADSY MEDSET Holter monitoring device during three phases; pre-test, mid-test and post-test. Then, short-term HRV was assessed from calculation of the mean R-R interval measured on HRV at each phases. HRV significantly decreased at mid-test and post-test among asthmatic and health children. However, the aforesaid changes were significantly higher in the asthmatic than health children following. Moreover, decrease of short-term HRV was significantly greater in the 35±5% than 65±5% environmental humidity. Our findings suggest from the autonomic standpoint, asthmatic and non-asthmatic children respond differently to exhaustive exercise induced stress. Aerobic exercise at an environment with high humidity compared with the low humidity appears to have additional benefits on short-term HRV in that it enhances the parasympathetic and autonomic modulation of the heart in asthmatic obese children.

  3. Fast humidity sensors based on CeO2 nanowires

    International Nuclear Information System (INIS)

    Fu, X Q; Wang, C; Yu, H C; Wang, Y G; Wang, T H

    2007-01-01

    Fast humidity sensors are reported that are based on CeO 2 nanowires synthesized by a hydrothermal method. Both the response and recovery time are about 3 s, and are independent of the humidity. The sensitivity increases gradually as the humidity increases, and is up to 85 at 97% RH. The resistance decreases exponentially with increasing humidity, implying ion-type conductivity as the humidity sensing mechanism. A model based on the morphology and surface energy of the nanowires is given to explain these results further. Our experimental results indicate a pathway to improving the performance of humidity sensors

  4. Digital evaluation of absolute marginal discrepancy: A comparison of ceramic crowns fabricated with conventional and digital techniques.

    Science.gov (United States)

    Liang, Shanshan; Yuan, Fusong; Luo, Xu; Yu, Zhuoren; Tang, Zhihui

    2018-04-05

    Marginal discrepancy is key to evaluating the accuracy of fixed dental prostheses. An improved method of evaluating marginal discrepancy is needed. The purpose of this in vitro study was to evaluate the absolute marginal discrepancy of ceramic crowns fabricated using conventional and digital methods with a digital method for the quantitative evaluation of absolute marginal discrepancy. The novel method was based on 3-dimensional scanning, iterative closest point registration techniques, and reverse engineering theory. Six standard tooth preparations for the right maxillary central incisor, right maxillary second premolar, right maxillary second molar, left mandibular lateral incisor, left mandibular first premolar, and left mandibular first molar were selected. Ten conventional ceramic crowns and 10 CEREC crowns were fabricated for each tooth preparation. A dental cast scanner was used to obtain 3-dimensional data of the preparations and ceramic crowns, and the data were compared with the "virtual seating" iterative closest point technique. Reverse engineering software used edge sharpening and other functional modules to extract the margins of the preparations and crowns. Finally, quantitative evaluation of the absolute marginal discrepancy of the ceramic crowns was obtained from the 2-dimensional cross-sectional straight-line distance between points on the margin of the ceramic crowns and the standard preparations based on the circumferential function module along the long axis. The absolute marginal discrepancy of the ceramic crowns fabricated using conventional methods was 115 ±15.2 μm, and 110 ±14.3 μm for those fabricated using the digital technique was. ANOVA showed no statistical difference between the 2 methods or among ceramic crowns for different teeth (P>.05). The digital quantitative evaluation method for the absolute marginal discrepancy of ceramic crowns was established. The evaluations determined that the absolute marginal discrepancies were

  5. 40 CFR 89.326 - Engine intake air humidity measurement.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air humidity measurement... Test Equipment Provisions § 89.326 Engine intake air humidity measurement. (a) Humidity conditioned air... type of intake air supply, the humidity measurements must be made within the intake air supply system...

  6. 40 CFR 91.310 - Engine intake air humidity measurement.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air humidity measurement... Provisions § 91.310 Engine intake air humidity measurement. This section refers to engines which are supplied... air, the ambient testcell humidity measurement may be used. (a) Humidity conditioned air supply. Air...

  7. 40 CFR 90.310 - Engine intake air humidity measurement.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air humidity measurement... Emission Test Equipment Provisions § 90.310 Engine intake air humidity measurement. This section refers to... for the engine intake air, the ambient test cell humidity measurement may be used. (a) Humidity...

  8. Humidity Sensor Based on Multi-Walled Carbon Nanotube Thin Films

    International Nuclear Information System (INIS)

    Cao, C.L.; Hu, C.G.; Fang, L.; Wang, S.X.; Cao, C.L.; Tian, Y.S.; Pan, C.Y.

    2009-01-01

    The properties of the humidity sensors made of chemically treated and untreated multi-walled carbon nano tube (MWCNT) thin films are investigated systematically. It shows that both the chemically treated and untreated MWCNT thin films demonstrate humidity sensitive properties, but the former have stronger sensitivity than the latter. In the range of 11%-98% relative humidity (RH), the resistances of the chemically treated and untreated MWCNT humidity sensors increase 120% and 28%, respectively. Moreover, the treated humidity sensors showed higher sensitivity and better stability. In addition, the response and recover properties, and stabilization of the humidity sensors are measured, and the humidity sensitive mechanisms of the sensors are analyzed. The humidity sensitivity of carbon nano tube thin films indicates it promise as a kind of humidity sensitive material

  9. Qualification standard for photovoltaic concentrator modules

    Energy Technology Data Exchange (ETDEWEB)

    McConnell, R.; Kurtz, S.; Bottenberg, W. R.; Hammond, R.; Jochums, S. W.; McDanal, A. J.; Roubideaux, D.; Whitaker, C.; Wohlgemuth, J.

    2000-05-05

    The paper describes a proposed qualification standard for photovoltaic concentrator modules. The standard's purpose is to provide stress tests and procedures to identify any component weakness in photovoltaic concentrator modules intended for power generation applications. If no weaknesses are identified during qualification, both the manufacturer and the customer can expect a more reliable product. The qualification test program for the standard includes thermal cycles, humidity-freeze cycles, water spray, off-axis beam damage, hail impact, hot-spot endurance, as well as electrical tests for performance, ground continuity, isolation, wet insulation resistance, and bypass diodes. Because concentrator module performance can not be verified using solar simulator and reference cell procedures suitable for flat-plate modules, the standard specifies an outdoor I-V test analysis allowing a performance comparison before and after a test procedure. Two options to this complex analysis are the use of a reference concentrator module for side-by-side outdoor comparison with modules undergoing various tests and a dark I-V performance check.

  10. Humidity effects on wire insulation breakdown strength.

    Energy Technology Data Exchange (ETDEWEB)

    Appelhans, Leah

    2013-08-01

    Methods for the testing of the dielectric breakdown strength of insulation on metal wires under variable humidity conditions were developed. Two methods, an ASTM method and the twisted pair method, were compared to determine if the twisted pair method could be used for determination of breakdown strength under variable humidity conditions. It was concluded that, although there were small differences in outcomes between the two testing methods, the non-standard method (twisted pair) would be appropriate to use for further testing of the effects of humidity on breakdown performance. The dielectric breakdown strength of 34G copper wire insulated with double layer Poly-Thermaleze/Polyamide-imide insulation was measured using the twisted pair method under a variety of relative humidity (RH) conditions and exposure times. Humidity at 50% RH and below was not found to affect the dielectric breakdown strength. At 80% RH the dielectric breakdown strength was significantly diminished. No effect for exposure time up to 140 hours was observed at 50 or 80%RH.

  11. Is Obsidian Hydration Dating Affected by Relative Humidity?

    Science.gov (United States)

    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.

  12. Humidity correction in the standard measurement of exposure

    International Nuclear Information System (INIS)

    Ibaraki, Yasuyuki; Katoh, Akira

    1980-01-01

    This paper deals with the humidity correction to be made in the standard measurement of the exposure to the measured ionization current in the humid air for the purpose of excluding the influence of the water vapour that is not included in the definition of the exposure. First, formulae giving the humidity correction factors for a parallel plate free air chamber and a cavity chamber have been derived respectively in the case where the contributions of air and water vapour to the ionization are independent. Next, in the case where the contributions are not independent, i.e., the Jesse effect is taken into account, a formula to obtain the W-value for humid air has been derived on the basis of the Niatel's experimental result. Using this formula, formulae to obtain the humidity correction factors for the free air chamber and the cavity chamber are derived. The humidity calculated by the latter formulae show good agreements with the results by Niatel and Guiho, respectively. (author)

  13. Multiwavelength Absolute Phase Retrieval from Noisy Diffractive Patterns: Wavelength Multiplexing Algorithm

    Directory of Open Access Journals (Sweden)

    Vladimir Katkovnik

    2018-05-01

    Full Text Available We study the problem of multiwavelength absolute phase retrieval from noisy diffraction patterns. The system is lensless with multiwavelength coherent input light beams and random phase masks applied for wavefront modulation. The light beams are formed by light sources radiating all wavelengths simultaneously. A sensor equipped by a Color Filter Array (CFA is used for spectral measurement registration. The developed algorithm targeted on optimal phase retrieval from noisy observations is based on maximum likelihood technique. The algorithm is specified for Poissonian and Gaussian noise distributions. One of the key elements of the algorithm is an original sparse modeling of the multiwavelength complex-valued wavefronts based on the complex-domain block-matching 3D filtering. Presented numerical experiments are restricted to noisy Poissonian observations. They demonstrate that the developed algorithm leads to effective solutions explicitly using the sparsity for noise suppression and enabling accurate reconstruction of absolute phase of high-dynamic range.

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

    Science.gov (United States)

    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.

  15. A Trial Intercomparison of Humidity Generators at Extremes of Range Using Relative Humidity Transmitters

    Science.gov (United States)

    Stevens, M.; Benyon, R.; Bell, S. A.; Vicente, T.

    2008-10-01

    In order to effectively implement the Mutual Recognition Arrangement (MRA) of the International Committee for Weights and Measures (CIPM), national metrology institutes (NMIs) are required to support their claims of calibration and measurement capability (CMC) with a quality system compliant with ISO/IEC 17025, and with suitable evidence of participation in key or supplementary comparisons. The CMC review process, both at regional and inter-regional levels, uses criteria that combine the provisions mentioned above, together with additional evidence demonstrating scientific and technical competence of the institutes. For dew-point temperatures, there are key comparisons in progress under the Consultative Committee for Thermometry (CCT) and under the European regional metrology organisation (EUROMET), together with information available on past regional supplementary comparisons. However, for relative humidity there are, to date, no such comparisons available to support CMC entries. This paper presents and discusses the results of a preliminary investigation of the use of relative humidity and temperature transmitters in order to determine their suitability for the intercomparison of standard humidity generators in support of CMC claims for the calibration of relative humidity instruments. The results of a recent bilateral comparison between 2 NMIs at the extremes of the range up to 98%rh at 70 °C, and down to 1%rh at -40 °C are reported. Specific precautions and recommendations on the use of the devices as transfer standards are presented.

  16. Danish Towns during Absolutism

    DEFF Research Database (Denmark)

    This anthology, No. 4 in the Danish Urban Studies Series, presents in English recent significant research on Denmark's urban development during the Age of Absolutism, 1660-1848, and features 13 articles written by leading Danish urban historians. The years of Absolutism were marked by a general...

  17. Adjustment of web-building initiation to high humidity: a constraint by humidity-dependent thread stickiness in the spider Cyrtarachne.

    Science.gov (United States)

    Baba, Yuki G; Kusahara, Miki; Maezono, Yasunori; Miyashita, Tadashi

    2014-07-01

    Cyrtarachne is an orb-weaving spider belonging to the subfamily Cyrtarachninae (Araneidae) which includes triangular-web-building Pasilobus and bolas spiders. The Cyrtarachninae is a group of spiders specialized in catching moths, which is thought to have evolved from ordinary orb-weaving araneids. Although the web-building time of nocturnal spiders is in general related to the time of sunset, anecdotal evidence has suggested variability of web-building time in Cyrtarachne and its closely related genera. This study has examined the effects of temperature, humidity, moonlight intensity, and prey (moths) availability on web-building time of Cyrtarachne bufo, Cyrtarachne akirai, and Cyrtarachne nagasakiensis. Generalized linear mixed model (GLMM) have revealed that humidity, and not prey availability, was the essential variable that explained the daily variability of web-building time. Experiments measuring thread stickiness under different humidities showed that, although the thread of Cyrtarachne was found to have strong stickiness under high humidity, low humidity caused a marked decrease of thread stickiness. By contrast, no obvious change in stickiness was seen in an ordinary orb-weaving spider, Larinia argiopiformis. These findings suggest that Cyrtarachne adjusts its web-building time to favorable conditions of high humidity maintaining strong stickiness, which enables the threads to work efficiently for capturing prey.

  18. Absolute analytical prediction of photonic crystal guided mode resonance wavelengths

    International Nuclear Information System (INIS)

    Hermannsson, Pétur Gordon; Vannahme, Christoph; Smith, Cameron L. C.; Kristensen, Anders

    2014-01-01

    A class of photonic crystal resonant reflectors known as guided mode resonant filters are optical structures that are widely used in the field of refractive index sensing, particularly in biosensing. For the purposes of understanding and design, their behavior has traditionally been modeled numerically with methods such as rigorous coupled wave analysis. Here it is demonstrated how the absolute resonance wavelengths of such structures can be predicted by analytically modeling them as slab waveguides in which the propagation constant is determined by a phase matching condition. The model is experimentally verified to be capable of predicting the absolute resonance wavelengths to an accuracy of within 0.75 nm, as well as resonance wavelength shifts due to changes in cladding index within an accuracy of 0.45 nm across the visible wavelength regime in the case where material dispersion is taken into account. Furthermore, it is demonstrated that the model is valid beyond the limit of low grating modulation, for periodically discontinuous waveguide layers, high refractive index contrasts, and highly dispersive media.

  19. Elimination of residual amplitude modulation in tunable diode laser wavelength modulation spectroscopy using an optical fiber delay line.

    Science.gov (United States)

    Chakraborty, Arup Lal; Ruxton, Keith; Johnstone, Walter; Lengden, Michael; Duffin, Kevin

    2009-06-08

    A new fiber-optic technique to eliminate residual amplitude modulation in tunable diode laser wavelength modulation spectroscopy is presented. The modulated laser output is split to pass in parallel through the gas measurement cell and an optical fiber delay line, with the modulation frequency / delay chosen to introduce a relative phase shift of pi between them. The two signals are balanced using a variable attenuator and recombined through a fiber coupler. In the absence of gas, the direct laser intensity modulation cancels, thereby eliminating the high background. The presence of gas induces a concentration-dependent imbalance at the coupler's output from which the absolute absorption profile is directly recovered with high accuracy using 1f detection.

  20. Roles of inter-SWCNT junctions in resistive humidity response

    International Nuclear Information System (INIS)

    Zhang, Kang; Zou, Jianping; Zhang, Qing

    2015-01-01

    As a promising chemiresistor for gas sensing, the single-walled carbon nanotube (SWCNT) network has not yet been fully utilized for humidity detection. In this work, it is found that as humidity increases from 10% to 85%, the resistance of as-grown SWCNT networks first decreases and then increases. This non-monotonic resistive response to humidity limits their sensing capabilities. The competition between SWCNT resistance and inter-tube junction resistance changes is then found to be responsible for the non-monotonic resistive humidity responses. Moreover, creating sp"3 scattering centers on the SWCNT sidewall by monovalent functionalization of four-bromobenzene diazonium tetrafluoroborate is shown to be capable of eliminating the influence from the inter-tube junctions, resulting in a continuous resistance drop as humidity increases from 10% to 85%. Our results revealed the competing resistive humidity sensing process in as-grown SWCNT networks, which could also be helpful in designing and optimizing as-grown SWCNT networks for humidity sensors and other gas sensors. (paper)

  1. Impacts of Present and Future Climate Variability On Agriculture and Forestry in the Humid and Sub-Humid Tropics

    International Nuclear Information System (INIS)

    Zhao, Y.; Wang, C.; Wang, S.; Tibig, Lourdes V.

    2005-01-01

    Although there are different results from different studies, most assessments indicate that climate variability would have negative effects on agriculture and forestry in the humid and sub-humid tropics. Cereal crop yields would decrease generally with even minimal increases in temperature. For commercial crops, extreme events such as cyclones, droughts and floods lead to larger damages than only changes of mean climate. Impacts of climate variability on livestock mainly include two aspects; impacts on animals such as increase of heat and disease stress-related death, and impacts on pasture. As to forestry, climate variability would have negative as well as some positive impacts on forests of humid and sub-humid tropics. However, in most tropical regions, the impacts of human activities such as deforestation will be more important than climate variability and climate change in determining natural forest cover

  2. A high sensitivity nanomaterial based SAW humidity sensor

    Energy Technology Data Exchange (ETDEWEB)

    Wu, T-T; Chou, T-H [Institute of Applied Mechanics, National Taiwan University, Taipei 106, Taiwan (China); Chen, Y-Y [Department of Mechanical Engineering, Tatung University, Taipei 104, Taiwan (China)], E-mail: wutt@ndt.iam.ntu.edu.tw

    2008-04-21

    In this paper, a highly sensitive humidity sensor is reported. The humidity sensor is configured by a 128{sup 0}YX-LiNbO{sub 3} based surface acoustic wave (SAW) resonator whose operating frequency is at 145 MHz. A dual delay line configuration is realized to eliminate external temperature fluctuations. Moreover, for nanostructured materials possessing high surface-to-volume ratio, large penetration depth and fast charge diffusion rate, camphor sulfonic acid doped polyaniline (PANI) nanofibres are synthesized by the interfacial polymerization method and further deposited on the SAW resonator as selective coating to enhance sensitivity. The humidity sensor is used to measure various relative humidities in the range 5-90% at room temperature. Results show that the PANI nanofibre based SAW humidity sensor exhibits excellent sensitivity and short-term repeatability.

  3. Attribution of observed surface humidity changes to human influence.

    Science.gov (United States)

    Willett, Katharine M; Gillett, Nathan P; Jones, Philip D; Thorne, Peter W

    2007-10-11

    Water vapour is the most important contributor to the natural greenhouse effect, and the amount of water vapour in the atmosphere is expected to increase under conditions of greenhouse-gas-induced warming, leading to a significant feedback on anthropogenic climate change. Theoretical and modelling studies predict that relative humidity will remain approximately constant at the global scale as the climate warms, leading to an increase in specific humidity. Although significant increases in surface specific humidity have been identified in several regions, and on the global scale in non-homogenized data, it has not been shown whether these changes are due to natural or human influences on climate. Here we use a new quality-controlled and homogenized gridded observational data set of surface humidity, with output from a coupled climate model, to identify and explore the causes of changes in surface specific humidity over the late twentieth century. We identify a significant global-scale increase in surface specific humidity that is attributable mainly to human influence. Specific humidity is found to have increased in response to rising temperatures, with relative humidity remaining approximately constant. These changes may have important implications, because atmospheric humidity is a key variable in determining the geographical distribution and maximum intensity of precipitation, the potential maximum intensity of tropical cyclones, and human heat stress, and has important effects on the biosphere and surface hydrology.

  4. A Standard CMOS Humidity Sensor without Post-Processing

    OpenAIRE

    Nizhnik, Oleg; Higuchi, Kohei; Maenaka, Kazusuke

    2011-01-01

    A 2 ?W power dissipation, voltage-output, humidity sensor accurate to 5% relative humidity was developed using the LFoundry 0.15 ?m CMOS technology without post-processing. The sensor consists of a woven lateral array of electrodes implemented in CMOS top metal, a Intervia Photodielectric 8023?10 humidity-sensitive layer, and a CMOS capacitance to voltage converter.

  5. Do honeybees, Apis mellifera scutellata, regulate humidity in their nest?

    Science.gov (United States)

    Human, Hannelie; Nicolson, Sue W.; Dietemann, Vincent

    2006-08-01

    Honeybees are highly efficient at regulating the biophysical parameters of their hive according to colony needs. Thermoregulation has been the most extensively studied aspect of nest homeostasis. In contrast, little is known about how humidity is regulated in beehives, if at all. Although high humidity is necessary for brood development, regulation of this parameter by honeybee workers has not yet been demonstrated. In the past, humidity was measured too crudely for a regulation mechanism to be identified. We reassess this issue, using miniaturised data loggers that allow humidity measurements in natural situations and at several places in the nest. We present evidence that workers influence humidity in the hive. However, there are constraints on potential regulation mechanisms because humidity optima may vary in different locations of the nest. Humidity could also depend on variable external factors, such as water availability, which further impair the regulation. Moreover, there are trade-offs with the regulation of temperature and respiratory gas exchanges that can disrupt the establishment of optimal humidity levels. As a result, we argue that workers can only adjust humidity within sub-optimal limits.

  6. Biochars as Innovative Humidity Sensing Materials

    Directory of Open Access Journals (Sweden)

    Daniele Ziegler

    2017-12-01

    Full Text Available In this work, biochar-based humidity sensors were prepared by drop-coating technique. Polyvinylpyrrolidone (PVP was added as an organic binder to improve the adhesion of the sensing material onto ceramic substrates having platinum electrodes. Two biochars obtained from different precursors were used. The sensors were tested toward relative humidity (RH at room temperature and showed a response starting around 5 RH%, varying the impedance of 2 orders of magnitude after exposure to almost 100% relative humidity. In both cases, biochar materials are behaving as p-type semiconductors under low amounts of humidity. On the contrary, for higher RH values, the impedance decreased due to water molecules adsorption. When PVP is added to SWP700 biochar, n-p heterojunctions are formed between the two semiconductors, leading to a higher sensitivity at low RH values for the sensors SWP700-10% PVP and SWP700-20% PVP with respect to pure SWP700 sensor. Finally, response and recovery times were both reasonably fast (in the order of 1 min.

  7. All-Optical Graphene Oxide Humidity Sensors

    Directory of Open Access Journals (Sweden)

    Weng Hong Lim

    2014-12-01

    Full Text Available The optical characteristics of graphene oxide (GO were explored to design and fabricate a GO-based optical humidity sensor. GO film was coated onto a SU8 polymer channel waveguide using the drop-casting technique. The proposed sensor shows a high TE-mode absorption at 1550 nm. Due to the dependence of the dielectric properties of the GO film on water content, this high TE-mode absorption decreases when the ambient relative humidity increases. The proposed sensor shows a rapid response (<1 s to periodically interrupted humid air flow. The transmission of the proposed sensor shows a linear response of 0.553 dB/% RH in the range of 60% to 100% RH.

  8. All-optical graphene oxide humidity sensors.

    Science.gov (United States)

    Lim, Weng Hong; Yap, Yuen Kiat; Chong, Wu Yi; Ahmad, Harith

    2014-12-17

    The optical characteristics of graphene oxide (GO) were explored to design and fabricate a GO-based optical humidity sensor. GO film was coated onto a SU8 polymer channel waveguide using the drop-casting technique. The proposed sensor shows a high TE-mode absorption at 1550 nm. Due to the dependence of the dielectric properties of the GO film on water content, this high TE-mode absorption decreases when the ambient relative humidity increases. The proposed sensor shows a rapid response (<1 s) to periodically interrupted humid air flow. The transmission of the proposed sensor shows a linear response of 0.553 dB/% RH in the range of 60% to 100% RH.

  9. Humidity level In psychrometric processes

    International Nuclear Information System (INIS)

    Mojsovski, Filip

    2008-01-01

    When a thermal engineer needs to control, rather than merely moderate humidity, he must focus on the moisture level as a separate variable - not simply an addition of temperature control. Controlling humidity generally demands a correct psychrometric approach dedicated to that purpose [1].Analysis of the humidity level in psychrometric thermal processes leads to relevant data for theory and practice [2]. This paper presents: (1) the summer climatic curve for the Skopje region, (2) selected results of investigation on farm dryers made outside laboratories. The first purpose of such activity was to examine relations between weather conditions and drying conditions. The estimation of weather condition for the warmest season of the year was realized by a summer climatic curve. In the science of drying, basic drying conditions are temperature, relative humidity and velocity of air, thickness of dried product and dryer construction. The second purpose was to realize correct prediction of drying rates for various psychrometrics drying processes and local products. Test runs with the dryer were carried out over a period of 24 h, using fruits and vegetables as experimental material. Air flow rate through the dryer of 150 m3/h, overall drying rate of 0.04 kg/h and air temperature of 65 oC were reached. Three types of solar dryers, were exploited in the research.

  10. Some basic requirements for the application of electrokinetic methods for the reconstruction of masonry with rising humidity

    Energy Technology Data Exchange (ETDEWEB)

    Friese, P; Jacobasch, H J; Boerner, M

    1987-12-01

    Based on some theoretical statements concerning the electro-osmosis the most important requirements for the application of electrokinetic methods for drying masonry with rising humidity are described. Samples of brick masonry (brick and mortar) were examined by means of an electrokinetic measuring system (EKM) with different electrolytes (CaSO/sub 4/ and KCl) being used for different concentrations. It was found for all samples, that the zeta potential is provided with a negative sign and that the absolute value of the zeta potential approaches zero with increasing electrolyte concentration. Based on these measurements, an upper limit of the electrolyte concentration of 0.1 Mol/liter is established for the application of electrokinetic methods for drying masonry.

  11. Ion track based tunable device as humidity sensor: a neural network approach

    Science.gov (United States)

    Sharma, Mamta; Sharma, Anuradha; Bhattacherjee, Vandana

    2013-01-01

    Artificial Neural Network (ANN) has been applied in statistical model development, adaptive control system, pattern recognition in data mining, and decision making under uncertainty. The nonlinear dependence of any sensor output on the input physical variable has been the motivation for many researchers to attempt unconventional modeling techniques such as neural networks and other machine learning approaches. Artificial neural network (ANN) is a computational tool inspired by the network of neurons in biological nervous system. It is a network consisting of arrays of artificial neurons linked together with different weights of connection. The states of the neurons as well as the weights of connections among them evolve according to certain learning rules.. In the present work we focus on the category of sensors which respond to electrical property changes such as impedance or capacitance. Recently, sensor materials have been embedded in etched tracks due to their nanometric dimensions and high aspect ratio which give high surface area available for exposure to sensing material. Various materials can be used for this purpose to probe physical (light intensity, temperature etc.), chemical (humidity, ammonia gas, alcohol etc.) or biological (germs, hormones etc.) parameters. The present work involves the application of TEMPOS structures as humidity sensors. The sample to be studied was prepared using the polymer electrolyte (PEO/NH4ClO4) with CdS nano-particles dispersed in the polymer electrolyte. In the present research we have attempted to correlate the combined effects of voltage and frequency on impedance of humidity sensors using a neural network model and results have indicated that the mean absolute error of the ANN Model for the training data was 3.95% while for the validation data it was 4.65%. The corresponding values for the LR model were 8.28% and 8.35% respectively. It was also demonstrated the percentage improvement of the ANN Model with respect to the

  12. The influence of humidity fluxes on offshore wind speed profiles

    DEFF Research Database (Denmark)

    Barthelmie, Rebecca Jane; Sempreviva, Anna Maria; Pryor, Sara

    2010-01-01

    extrapolation from lower measurements. With humid conditions and low mechanical turbulence offshore, deviations from the traditional logarithmic wind speed profile become significant and stability corrections are required. This research focuses on quantifying the effect of humidity fluxes on stability corrected...... wind speed profiles. The effect on wind speed profiles is found to be important in stable conditions where including humidity fluxes forces conditions towards neutral. Our results show that excluding humidity fluxes leads to average predicted wind speeds at 150 m from 10 m which are up to 4% higher...... than if humidity fluxes are included, and the results are not very sensitive to the method selected to estimate humidity fluxes....

  13. A CMOS Humidity Sensor for Passive RFID Sensing Applications

    Directory of Open Access Journals (Sweden)

    Fangming Deng

    2014-05-01

    Full Text Available This paper presents a low-cost low-power CMOS humidity sensor for passive RFID sensing applications. The humidity sensing element is implemented in standard CMOS technology without any further post-processing, which results in low fabrication costs. The interface of this humidity sensor employs a PLL-based architecture transferring sensor signal processing from the voltage domain to the frequency domain. Therefore this architecture allows the use of a fully digital circuit, which can operate on ultra-low supply voltage and thus achieves low-power consumption. The proposed humidity sensor has been fabricated in the TSMC 0.18 μm CMOS process. The measurements show this humidity sensor exhibits excellent linearity and stability within the relative humidity range. The sensor interface circuit consumes only 1.05 µW at 0.5 V supply voltage and reduces it at least by an order of magnitude compared to previous designs.

  14. A CMOS Humidity Sensor for Passive RFID Sensing Applications

    Science.gov (United States)

    Deng, Fangming; He, Yigang; Zhang, Chaolong; Feng, Wei

    2014-01-01

    This paper presents a low-cost low-power CMOS humidity sensor for passive RFID sensing applications. The humidity sensing element is implemented in standard CMOS technology without any further post-processing, which results in low fabrication costs. The interface of this humidity sensor employs a PLL-based architecture transferring sensor signal processing from the voltage domain to the frequency domain. Therefore this architecture allows the use of a fully digital circuit, which can operate on ultra-low supply voltage and thus achieves low-power consumption. The proposed humidity sensor has been fabricated in the TSMC 0.18 μm CMOS process. The measurements show this humidity sensor exhibits excellent linearity and stability within the relative humidity range. The sensor interface circuit consumes only 1.05 μW at 0.5 V supply voltage and reduces it at least by an order of magnitude compared to previous designs. PMID:24841250

  15. A CMOS humidity sensor for passive RFID sensing applications.

    Science.gov (United States)

    Deng, Fangming; He, Yigang; Zhang, Chaolong; Feng, Wei

    2014-05-16

    This paper presents a low-cost low-power CMOS humidity sensor for passive RFID sensing applications. The humidity sensing element is implemented in standard CMOS technology without any further post-processing, which results in low fabrication costs. The interface of this humidity sensor employs a PLL-based architecture transferring sensor signal processing from the voltage domain to the frequency domain. Therefore this architecture allows the use of a fully digital circuit, which can operate on ultra-low supply voltage and thus achieves low-power consumption. The proposed humidity sensor has been fabricated in the TSMC 0.18 μm CMOS process. The measurements show this humidity sensor exhibits excellent linearity and stability within the relative humidity range. The sensor interface circuit consumes only 1.05 µW at 0.5 V supply voltage and reduces it at least by an order of magnitude compared to previous designs.

  16. Effects of temperature and relative humidity on DNA methylation.

    Science.gov (United States)

    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.

  17. In-Situ Measurement of Power Loss for Crystalline Silicon Modules Undergoing Thermal Cycling and Mechanical Loading Stress Testing

    DEFF Research Database (Denmark)

    Spataru, Sergiu; Hacke, Peter; Sera, Dezso

    We analyze the degradation of multi-crystalline silicon photovoltaic modules undergoing simultaneous thermal, mechanical, and humidity-freeze stress testing to develop a dark environmental chamber in-situ measurement procedure for determining module power loss. We analyze dark I-V curves measured...

  18. Mars Science Laboratory relative humidity observations: Initial results.

    Science.gov (United States)

    Harri, A-M; Genzer, M; Kemppinen, O; Gomez-Elvira, J; Haberle, R; Polkko, J; Savijärvi, H; Rennó, N; Rodriguez-Manfredi, J A; Schmidt, W; Richardson, M; Siili, T; Paton, M; Torre-Juarez, M De La; Mäkinen, T; Newman, C; Rafkin, S; Mischna, M; Merikallio, S; Haukka, H; Martin-Torres, J; Komu, M; Zorzano, M-P; Peinado, V; Vazquez, L; Urqui, R

    2014-09-01

    The Mars Science Laboratory (MSL) made a successful landing at Gale crater early August 2012. MSL has an environmental instrument package called the Rover Environmental Monitoring Station (REMS) as a part of its scientific payload. REMS comprises instrumentation for the observation of atmospheric pressure, temperature of the air, ground temperature, wind speed and direction, relative humidity (REMS-H), and UV measurements. We concentrate on describing the REMS-H measurement performance and initial observations during the first 100 MSL sols as well as constraining the REMS-H results by comparing them with earlier observations and modeling results. The REMS-H device is based on polymeric capacitive humidity sensors developed by Vaisala Inc., and it makes use of transducer electronics section placed in the vicinity of the three humidity sensor heads. The humidity device is mounted on the REMS boom providing ventilation with the ambient atmosphere through a filter protecting the device from airborne dust. The final relative humidity results appear to be convincing and are aligned with earlier indirect observations of the total atmospheric precipitable water content. The water mixing ratio in the atmospheric surface layer appears to vary between 30 and 75 ppm. When assuming uniform mixing, the precipitable water content of the atmosphere is ranging from a few to six precipitable micrometers. Atmospheric water mixing ratio at Gale crater varies from 30 to 140 ppmMSL relative humidity observation provides good dataHighest detected relative humidity reading during first MSL 100 sols is RH75.

  19. Influence of air humidity on polymeric microresonators

    International Nuclear Information System (INIS)

    Schmid, S; Kühne, S; Hierold, C

    2009-01-01

    The influence of air humidity on polymeric microresonators is investigated by means of three different resonator types. SU-8 microbeams, SU-8 microstrings and a silicon micromirror with SU-8 hinges are exposed to relative humidities between 3% and 60%. The shifts of the resonant frequencies as a function of the relative humidity (RH) are explained based on mechanical models which are extended with water absorption models in polymer materials. The dominant effect causing the resonant frequency change is evaluated for each structure type. The eigenfrequency of the microstrings and the micromirror in the out-of-plane mode, which both mainly are defined by the pre-stress of the polymeric structures, are found to be highly sensitive to changes of air humidity. The humidity-induced (hygrometric) volume expansion reversibly reduces the pre-stress which results in relative frequency changes of up to 0.78%/%RH for the microstrings. A maximum coefficient of humidity-induced volume expansion for SU-8 of α hyg = 52.3 ppm/%RH is evaluated by fitting the data with the analytical model. It was found that microstrings that were stored at 150 °C over 150 h are more moisture sensitive compared to structures that were stored at room temperature. For the SU-8 microbeams and the micromirror in the tilt mode, the eigenfrequency is mainly defined by the modulus of the polymer material. The measured relative resonant frequency changes were below 1% for the given RH range. For low RH values, antiplasticization is observed (the modulus increases) followed by a plasticization for increasing RH values

  20. Bag-like contaminant control work module

    International Nuclear Information System (INIS)

    Buchanan, H.; Jacobson, E.B.

    1982-01-01

    A bag-like contaminant control work module is formed from a flexible impervious membrane which is inflated inside of an enclosed workspace to protect workers in the module from contaminants. The workspace, such as in a nuclear power steam generator, has a portal or manway opening into the workspace into which the module is secured by a module passageway. The module includes one or more glove boxes, in which the workers perform their assigned tasks after passing through the passageway and portal. The module includes one or more absolute filters allowing passage of air flow through the module passageway and into the workspace only through the filters. The module may include an auxiliary passageway secured to the outside of the module passageway and also secured in the portal opening and through which items can be passed back and forth to the worker in the glove box from outside the portal. The module is invertible so that it can be pulled out of the workspace trapping all the contaminants therein and disposed of without handling the contaminants

  1. Reversible adhesion switching of porous fibrillar adhesive pads by humidity.

    Science.gov (United States)

    Xue, Longjian; Kovalev, Alexander; Dening, Kirstin; Eichler-Volf, Anna; Eickmeier, Henning; Haase, Markus; Enke, Dirk; Steinhart, Martin; Gorb, Stanislav N

    2013-01-01

    We report reversible adhesion switching on porous fibrillar polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP) adhesive pads by humidity changes. Adhesion at a relative humidity of 90% was more than nine times higher than at a relative humidity of 2%. On nonporous fibrillar adhesive pads of the same material, adhesion increased only by a factor of ~3.3. The switching performance remained unchanged in at least 10 successive high/low humidity cycles. Main origin of enhanced adhesion at high humidity is the humidity-induced decrease in the elastic modulus of the polar component P2VP rather than capillary force. The presence of spongelike continuous internal pore systems with walls consisting of P2VP significantly leveraged this effect. Fibrillar adhesive pads on which adhesion is switchable by humidity changes may be used for preconcentration of airborne particulates, pollutants, and germs combined with triggered surface cleaning.

  2. Clinker mineral hydration at reduced relative humidities

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Lachowski, Eric E.

    1999-01-01

    and experimental data are presented showing that C(3)A can hydrate at lower humidities than either C3S or C2S. It is suggested that the initiation of hydration during exposure to water vapour is nucleation controlled. When C(3)A hydrates at low humidity, the characteristic hydration product is C(3)AH(6......Vapour phase hydration of purl cement clinker minerals at reduced relative humidities is described. This is relevant to modern high performance concrete that may self-desiccate during hydration and is also relevant to the quality of the cement during storage. Both the oretical considerations...

  3. Laboratory setup for temperature and humidity measurements

    CERN Document Server

    Eimre, Kristjan

    2015-01-01

    In active particle detectors, the temperature and humidity conditions must be under constant monitoring and control, as even small deviations from the norm cause changes to detector characteristics and result in a loss of precision. To monitor the temperature and humidity, different kinds of sensors are used, which must be calibrated beforehand to ensure their accuracy. To calibrate the large number of sensors that are needed for the particle detectors and other laboratory work, a calibration system is needed. The purpose of the current work was to develop a laboratory setup for temperature and humidity sensor measurements and calibration.

  4. Near threshold absolute TDCS: First results

    International Nuclear Information System (INIS)

    Roesel, T.; Schlemmer, P.; Roeder, J.; Frost, L.; Jung, K.; Ehrhardt, H.

    1992-01-01

    A new method, and first results for an impact energy 2 eV above the threshold of ionisation of helium, are presented for the measurement of absolute triple differential cross sections (TDCS) in a crossed beam experiment. The method is based upon measurement of beam/target overlap densities using known absolute total ionisation cross sections and of detection efficiencies using known absolute double differential cross sections (DDCS). For the present work the necessary absolute DDCS for 1 eV electrons had also to be measured. Results are presented for several different coplanar kinematics and are compared with recent DWBA calculations. (orig.)

  5. Absolute entropy of ions in methanol

    International Nuclear Information System (INIS)

    Abakshin, V.A.; Kobenin, V.A.; Krestov, G.A.

    1978-01-01

    By measuring the initial thermoelectromotive forces of chains with bromo-silver electrodes in tetraalkylammonium bromide solutions the absolute entropy of bromide-ion in methanol is determined in the 298.15-318.15 K range. The anti Ssub(Brsup(-))sup(0) = 9.8 entropy units value is used for calculation of the absolute partial molar entropy of alkali metal ions and halogenide ions. It has been found that, absolute entropy of Cs + =12.0 entropy units, I - =14.0 entropy units. The obtained ion absolute entropies in methanol at 298.15 K within 1-2 entropy units is in an agreement with published data

  6. A Novel Passive Wireless Sensor for Concrete Humidity Monitoring

    Directory of Open Access Journals (Sweden)

    Shuangxi Zhou

    2016-09-01

    Full Text Available This paper presents a passive wireless humidity sensor for concrete monitoring. After discussing the transmission of electromagnetic wave in concrete, a novel architecture of wireless humidity sensor, based on Ultra-High Frequency (UHF Radio Frequency Identification (RFID technology, is proposed for low-power application. The humidity sensor utilizes the top metal layer to form the interdigitated electrodes, which were then filled with polyimide as the humidity sensing layer. The sensor interface converts the humidity capacitance into a digital signal in the frequency domain. A two-stage rectifier adopts a dynamic bias-voltage generator to boost the effective gate-source voltage of the switches in differential-drive architecture. The clock generator employs a novel structure to reduce the internal voltage swing. The measurement results show that our proposed wireless humidity can achieve a high linearity with a normalized sensitivity of 0.55% %RH at 20 °C. Despite the high losses of concrete, the proposed wireless humidity sensor achieves reliable communication performances in passive mode. The maximum operating distance is 0.52 m when the proposed wireless sensor is embedded into the concrete at the depth of 8 cm. The measured results are highly consistent with the results measured by traditional methods.

  7. A Novel Passive Wireless Sensor for Concrete Humidity Monitoring.

    Science.gov (United States)

    Zhou, Shuangxi; Deng, Fangming; Yu, Lehua; Li, Bing; Wu, Xiang; Yin, Baiqiang

    2016-09-20

    This paper presents a passive wireless humidity sensor for concrete monitoring. After discussing the transmission of electromagnetic wave in concrete, a novel architecture of wireless humidity sensor, based on Ultra-High Frequency (UHF) Radio Frequency Identification (RFID) technology, is proposed for low-power application. The humidity sensor utilizes the top metal layer to form the interdigitated electrodes, which were then filled with polyimide as the humidity sensing layer. The sensor interface converts the humidity capacitance into a digital signal in the frequency domain. A two-stage rectifier adopts a dynamic bias-voltage generator to boost the effective gate-source voltage of the switches in differential-drive architecture. The clock generator employs a novel structure to reduce the internal voltage swing. The measurement results show that our proposed wireless humidity can achieve a high linearity with a normalized sensitivity of 0.55% %RH at 20 °C. Despite the high losses of concrete, the proposed wireless humidity sensor achieves reliable communication performances in passive mode. The maximum operating distance is 0.52 m when the proposed wireless sensor is embedded into the concrete at the depth of 8 cm. The measured results are highly consistent with the results measured by traditional methods.

  8. A Novel Passive Wireless Sensor for Concrete Humidity Monitoring

    Science.gov (United States)

    Zhou, Shuangxi; Deng, Fangming; Yu, Lehua; Li, Bing; Wu, Xiang; Yin, Baiqiang

    2016-01-01

    This paper presents a passive wireless humidity sensor for concrete monitoring. After discussing the transmission of electromagnetic wave in concrete, a novel architecture of wireless humidity sensor, based on Ultra-High Frequency (UHF) Radio Frequency Identification (RFID) technology, is proposed for low-power application. The humidity sensor utilizes the top metal layer to form the interdigitated electrodes, which were then filled with polyimide as the humidity sensing layer. The sensor interface converts the humidity capacitance into a digital signal in the frequency domain. A two-stage rectifier adopts a dynamic bias-voltage generator to boost the effective gate-source voltage of the switches in differential-drive architecture. The clock generator employs a novel structure to reduce the internal voltage swing. The measurement results show that our proposed wireless humidity can achieve a high linearity with a normalized sensitivity of 0.55% %RH at 20 °C. Despite the high losses of concrete, the proposed wireless humidity sensor achieves reliable communication performances in passive mode. The maximum operating distance is 0.52 m when the proposed wireless sensor is embedded into the concrete at the depth of 8 cm. The measured results are highly consistent with the results measured by traditional methods. PMID:27657070

  9. Temperature-dependent deliquescence relative humidities and water activities using humidity controlled thermogravimetric analysis with application to malonic acid.

    Science.gov (United States)

    Beyer, Keith D; Schroeder, Jason R; Kissinger, Jared A

    2014-04-03

    We utilize a new experimental technique, humidity-controlled thermogravimetric analysis (HTGA), to determine temperature-dependent deliquescence relative humidities (DRH) and to determine the equilibrium concentration of a solution at a given temperature and relative humidity. To that end, we have investigated the malonic acid/water system determining the DRH and concentration/RH relationship in the temperature range 303-278 K. Excellent agreement is found with literature values for the DRH of malonic acid as a function of temperature and for the concentration/RH relationship at several temperatures. Thus, we extend the DRH and concentration/RH relationship to a broader temperature range and are using the HTGA experiments to investigate other organic acids.

  10. Study on Applicability of Conceptual Hydrological Models for Flood Forecasting in Humid, Semi-Humid Semi-Arid and Arid Basins in China

    Directory of Open Access Journals (Sweden)

    Guangyuan Kan

    2017-09-01

    Full Text Available Flood simulation and forecasting in various types of watersheds is a hot issue in hydrology. Conceptual hydrological models have been widely applied to flood forecasting for decades. With the development of economy, modern China faces with severe flood disasters in all types of watersheds include humid, semi-humid semi-arid and arid watersheds. However, conceptual model-based flood forecasting in semi-humid semi-arid and arid regions is still challenging. To investigate the applicability of conceptual hydrological models for flood forecasting in the above mentioned regions, three typical conceptual models, include Xinanjiang (XAJ, mix runoff generation (MIX and northern Shannxi (NS, are applied to 3 humid, 3 semi-humid semi-arid, and 3 arid watersheds. The rainfall-runoff data of the 9 watersheds are analyzed based on statistical analysis and information theory, and the model performances are compared and analyzed based on boxplots and scatter plots. It is observed the complexity of drier watershed data is higher than that of the wetter watersheds. This indicates the flood forecasting is harder in drier watersheds. Simulation results indicate all models perform satisfactorily in humid watersheds and only NS model is applicable in arid watersheds. Model with consideration of saturation excess runoff generation (XAJ and MIX perform better than the infiltration excess-based NS model in semi-humid semi-arid watersheds. It is concluded more accurate mix runoff generation theory, more stable and efficient numerical solution of infiltration equation and rainfall data with higher spatial-temporal resolution are main obstacles for conceptual model-based flood simulation and forecasting.

  11. Role of Temperature, Humidity and Rainfall on Influenza Transmission in Guatemala, El Salvador and Panama

    Science.gov (United States)

    Soebiyanto, Radina P.; Bonilla, Luis; Jara, Jorge; McCracken, John; Azziz?-Baumgartner, Eduardo; Widdowson, Marc-Alain; Kiang, Richard

    2012-01-01

    Worldwide, seasonal influenza causes about 500,000 deaths and 5 million severe illnesses per year. The environmental drivers of influenza transmission are poorly understood especially in the tropics. We aimed to identify meteorological factors for influenza transmission in tropical Central America. We gathered laboratory-confirmed influenza case-counts by week from Guatemala City, San Salvador Department (El Salvador) and Panama Province from 2006 to 2010. The average total cases per year were: 390 (Guatemala), 99 (San Salvador) and 129 (Panama). Meteorological factors including daily air temperature, rainfall, relative and absolute humidity (RH, AH) were obtained from ground stations, NASA satellites and land models. For these factors, we computed weekly averages and their deviation from the 5-yr means. We assessed the relationship between the number of influenza case-counts and the meteorological factors, including effects lagged by 1 to 4 weeks, using Poisson regression for each site. Our results showed influenza in San Salvador would increase by 1 case within a week of every 1 day with RH>75% (Relative Risk (RR)= 1.32, p=.001) and every 1C increase in minimum temperature (RR=1.29, p=.007) but it would decrease by 1 case for every 1mm-above mean weekly rainfall (RR=0.93,pGuatemala had 1 case increase for every 1C increase in minimum temperature in the previous week (RR=1.21, p<.001), and for every 1mm/day-above normal increase of rainfall rate (RR=1.03, p=.03) (model pseudo-R2=0.54). Our findings that cases increase with temperature and humidity differ from some temperate-zone studies. But they indicate that climate parameters such as humidity and temperature could be predictive of influenza activity and should be incorporated into country-specific influenza transmission models

  12. Humidity measurements in the precast concrete

    International Nuclear Information System (INIS)

    Hurez, M.

    1986-01-01

    The precast concrete industry manufactures requires a good knowledge and control of the humidity factor: during the manufacturing process, in order to regulate the water content of aggregates, or the fresh concrete workability: during the quality control of the product characteristics. The principles of measurements: conductivity, dielectric characteristics and neutron moisture meters are compared for cost, humidity range, accuracy, temperature dependence, interfering elements, density dependence, grain size and shape [fr

  13. Temperature and Humidity Control in Livestock Stables

    DEFF Research Database (Denmark)

    Hansen, Michael; Andersen, Palle; Nielsen, Kirsten M.

    2010-01-01

    The paper describes temperature and humidity control of a livestock stable. It is important to have a correct air flow pattern in the livestock stable in order to achieve proper temperature and humidity control as well as to avoid draught. In the investigated livestock stable the air flow...

  14. Modulation of Terrestrial Convection by Tropospheric Humidity, and Implications for Other Planets

    Science.gov (United States)

    Genio, Anthony Del

    2013-01-01

    For decades, deep cumulus convection was viewed as consisting partly of undilute plumes that do not interact with their surrounding environment in order to explain their observed tendency to reach or penetrate the tropical tropopause. This behavior was built into all cumulus parameterizations used in terrestrial global climate and numerical weather prediction models, and it still persists in some models today. In the past decade, though, some embarrassing failures of global models have come to light, notably their tendency to rain over land near noon rather than in late afternoon or evening as observed, and the absence in the models of the Madden-Julian Oscillation (MJO), the major source of intraseasonal (30-90 day) precipitation variability in the Indian Ocean, West Pacific, and surrounding continental regions. In the past decade it has become clear that an important missing component of parameterizations is strong turbulent entrainment of drier environmental air into cumulus updrafts, which reduces the buoyancy of the updrafts and thus limits their vertical development. Tropospheric humidity thus serves as a throttle on convective penetration to high altitudes and delays the convective response to large-scale destabilizing influences in the environment.

  15. Effect of relative humidity on growth of sodium oxide aerosols

    International Nuclear Information System (INIS)

    Sundarajan, A.R.; Mitragotri, D.S.; Mukunda Rao, S.R.

    1982-01-01

    Behavior of aerosol resulting from sodium fires in a closed vessel is investigated and the changes in the particle size distribution of the aerosol due to coagulation and humidity have been studied. The initial mass concentration is in the range of 80 -- 500 mg/m 3 and the relative humidity is varied between 50 to 98%. The initial size of the released aerosol is found to be 0.9 μm. Equilibrium diameters of particles growing in humid air have been computed for various humidity levels using water activity of sodium hydroxide. Both theoretical and experimental results have yielded growth ratios of about 3 at about 95% relative humidity. It is recommended that the computer codes dealing with aerosol coagulation behavior in reactor containment should include an appropriate humidity-growth function. (author)

  16. A Humidity Sensing Organic-Inorganic Composite for Environmental Monitoring

    Directory of Open Access Journals (Sweden)

    Khasan S. Karimov

    2013-03-01

    Full Text Available In this paper, we present the effect of varying humidity levels on the electrical parameters and the multi frequency response of the electrical parameters of an organic-inorganic composite (PEPC+NiPc+Cu2O-based humidity sensor. Silver thin films (thickness ~200 nm were primarily deposited on plasma cleaned glass substrates by the physical vapor deposition (PVD technique. A pair of rectangular silver electrodes was formed by patterning silver film through standard optical lithography technique. An active layer of organic-inorganic composite for humidity sensing was later spun coated to cover the separation between the silver electrodes. The electrical characterization of the sensor was performed as a function of relative humidity levels and frequency of the AC input signal. The sensor showed reversible changes in its capacitance with variations in humidity level. The maximum sensitivity ~31.6 pF/%RH at 100 Hz in capacitive mode of operation has been attained. The aim of this study was to increase the sensitivity of the previously reported humidity sensors using PEPC and NiPc, which has been successfully achieved.

  17. Hands-on Humidity.

    Science.gov (United States)

    Pankiewicz, Philip R.

    1992-01-01

    Presents five hands-on activities that allow students to detect, measure, reduce, and eliminate moisture. Students make a humidity detector and a hygrometer, examine the effects of moisture on different substances, calculate the percent of water in a given food, and examine the absorption potential of different desiccants. (MDH)

  18. Humidity Responsive Photonic Sensor based on a Carboxymethyl Cellulose Mechanical Actuator

    OpenAIRE

    Hartings, Matthew; Douglass, Kevin O.; Neice, Claire; Ahmed, Zeeshan

    2017-01-01

    We describe an intuitive and simple method for exploiting humidity-driven volume changes in carboxymethyl cellulose (CMC) to fabricate a humidity responsive actuator on a glass fiber substrate. We optimize this platform to generate a photonic-based humidity sensor where CMC coated on a fiber optic containing a fiber Bragg grating (FBG) actuates a mechanical strain in response to humidity changes. The humidity-driven mechanical deformation of the FBG results in a large lin...

  19. Humidity sensation requires both mechanosensory and thermosensory pathways in Caenorhabditis elegans.

    Science.gov (United States)

    Russell, Joshua; Vidal-Gadea, Andrés G; Makay, Alex; Lanam, Carolyn; Pierce-Shimomura, Jonathan T

    2014-06-03

    All terrestrial animals must find a proper level of moisture to ensure their health and survival. The cellular-molecular basis for sensing humidity is unknown in most animals, however. We used the model nematode Caenorhabditis elegans to uncover a mechanism for sensing humidity. We found that whereas C. elegans showed no obvious preference for humidity levels under standard culture conditions, worms displayed a strong preference after pairing starvation with different humidity levels, orienting to gradients as shallow as 0.03% relative humidity per millimeter. Cell-specific ablation and rescue experiments demonstrate that orientation to humidity in C. elegans requires the obligatory combination of distinct mechanosensitive and thermosensitive pathways. The mechanosensitive pathway requires a conserved DEG/ENaC/ASIC mechanoreceptor complex in the FLP neuron pair. Because humidity levels influence the hydration of the worm's cuticle, our results suggest that FLP may convey humidity information by reporting the degree that subcuticular dendritic sensory branches of FLP neurons are stretched by hydration. The thermosensitive pathway requires cGMP-gated channels in the AFD neuron pair. Because humidity levels affect evaporative cooling, AFD may convey humidity information by reporting thermal flux. Thus, humidity sensation arises as a metamodality in C. elegans that requires the integration of parallel mechanosensory and thermosensory pathways. This hygrosensation strategy, first proposed by Thunberg more than 100 y ago, may be conserved because the underlying pathways have cellular and molecular equivalents across a wide range of species, including insects and humans.

  20. Durable crystalline Si photovoltaic modules based on silicone-sheet encapsulants

    Science.gov (United States)

    Hara, Kohjiro; Ohwada, Hiroto; Furihata, Tomoyoshi; Masuda, Atsushi

    2018-02-01

    Crystalline Si photovoltaic (PV) modules were fabricated with sheets of poly(dimethylsiloxane) (silicone) as an encapsulant. The long-term durability of the silicone-encapsulated PV modules was experimentally investigated. The silicone-based modules enhanced the long-term durability against potential-induced degradation (PID) and a damp-heat (DH) condition at 85 °C with 85% relative humidity (RH). In addition, we designed and fabricated substrate-type Si PV modules based on the silicone encapsulant and an Al-alloy plate as the substratum, which demonstrated high impact resistance and high incombustible performance. The high chemical stability, high volume resistivity, rubber-like elasticity, and incombustibility of the silicone encapsulant resulted in the high durability of the modules. Our results indicate that silicone is an attractive encapsulation material, as it improves the long-term durability of crystalline Si PV modules.

  1. Urban-Rural Humidity Contrasts in Mexico City

    Science.gov (United States)

    Jáuregui, E.; Tejeda, A.

    1997-02-01

    Data from one pair of urban-suburban (Tacubaya and Airport) andone pair of urban-rural (School of Mines and Plan Texcoco) temperature and humidity measuring stations were used to illustrate specific humidity(q) contrasts in Mexico City. Results show a marked seasonal variation of q from around 7.9 g kg-1 during the dry months to 10 g kg-1 in the wet season (May-October) on both urban and suburban sites. The mean monthly contrasts for this pair of stations, albeit small, show that the city air is somewhat drier during the first half of the year. Comparison of urban and rural q on an hourly basis shows that although urban air is more humid at night the reverse is true during the afternoon. Areal distribution of q shows two centres of maximum humidity over the city at night and a corresponding minimum during the afternoon. On average the urban-rural contrasts in q were found to be somewhat smaller than the estimated uncertainty. The above results are in agreement with mid-latitude experience.

  2. Fabrication and Characterization of a CMOS-MEMS Humidity Sensor

    Science.gov (United States)

    Dennis, John-Ojur; Ahmed, Abdelaziz-Yousif; Khir, Mohd-Haris

    2015-01-01

    This paper reports on the fabrication and characterization of a Complementary Metal Oxide Semiconductor-Microelectromechanical System (CMOS-MEMS) device with embedded microheater operated at relatively elevated temperatures (40 °C to 80 °C) for the purpose of relative humidity measurement. The sensing principle is based on the change in amplitude of the device due to adsorption or desorption of humidity on the active material layer of titanium dioxide (TiO2) nanoparticles deposited on the moving plate, which results in changes in the mass of the device. The sensor has been designed and fabricated through a standard 0.35 µm CMOS process technology and post-CMOS micromachining technique has been successfully implemented to release the MEMS structures. The sensor is operated in the dynamic mode using electrothermal actuation and the output signal measured using a piezoresistive (PZR) sensor connected in a Wheatstone bridge circuit. The output voltage of the humidity sensor increases from 0.585 mV to 30.580 mV as the humidity increases from 35% RH to 95% RH. The output voltage is found to be linear from 0.585 mV to 3.250 mV as the humidity increased from 35% RH to 60% RH, with sensitivity of 0.107 mV/% RH; and again linear from 3.250 mV to 30.580 mV as the humidity level increases from 60% RH to 95% RH, with higher sensitivity of 0.781 mV/% RH. On the other hand, the sensitivity of the humidity sensor increases linearly from 0.102 mV/% RH to 0.501 mV/% RH with increase in the temperature from 40 °C to 80 °C and a maximum hysteresis of 0.87% RH is found at a relative humidity of 80%. The sensitivity is also frequency dependent, increasing from 0.500 mV/% RH at 2 Hz to reach a maximum value of 1.634 mV/% RH at a frequency of 12 Hz, then decreasing to 1.110 mV/% RH at a frequency of 20 Hz. Finally, the CMOS-MEMS humidity sensor showed comparable response, recovery, and repeatability of measurements in three cycles as compared to a standard sensor that directly

  3. Fabrication and Characterization of a CMOS-MEMS Humidity Sensor.

    Science.gov (United States)

    Dennis, John-Ojur; Ahmed, Abdelaziz-Yousif; Khir, Mohd-Haris

    2015-07-10

    This paper reports on the fabrication and characterization of a Complementary Metal Oxide Semiconductor-Microelectromechanical System (CMOS-MEMS) device with embedded microheater operated at relatively elevated temperatures (40 °C to 80 °C) for the purpose of relative humidity measurement. The sensing principle is based on the change in amplitude of the device due to adsorption or desorption of humidity on the active material layer of titanium dioxide (TiO2) nanoparticles deposited on the moving plate, which results in changes in the mass of the device. The sensor has been designed and fabricated through a standard 0.35 µm CMOS process technology and post-CMOS micromachining technique has been successfully implemented to release the MEMS structures. The sensor is operated in the dynamic mode using electrothermal actuation and the output signal measured using a piezoresistive (PZR) sensor connected in a Wheatstone bridge circuit. The output voltage of the humidity sensor increases from 0.585 mV to 30.580 mV as the humidity increases from 35% RH to 95% RH. The output voltage is found to be linear from 0.585 mV to 3.250 mV as the humidity increased from 35% RH to 60% RH, with sensitivity of 0.107 mV/% RH; and again linear from 3.250 mV to 30.580 mV as the humidity level increases from 60% RH to 95% RH, with higher sensitivity of 0.781 mV/% RH. On the other hand, the sensitivity of the humidity sensor increases linearly from 0.102 mV/% RH to 0.501 mV/% RH with increase in the temperature from 40 °C to 80 °C and a maximum hysteresis of 0.87% RH is found at a relative humidity of 80%. The sensitivity is also frequency dependent, increasing from 0.500 mV/% RH at 2 Hz to reach a maximum value of 1.634 mV/% RH at a frequency of 12 Hz, then decreasing to 1.110 mV/% RH at a frequency of 20 Hz. Finally, the CMOS-MEMS humidity sensor showed comparable response, recovery, and repeatability of measurements in three cycles as compared to a standard sensor that directly

  4. Projective absoluteness for Sacks forcing

    NARCIS (Netherlands)

    Ikegami, D.

    2009-01-01

    We show that Sigma(1)(3)-absoluteness for Sacks forcing is equivalent to the nonexistence of a Delta(1)(2) Bernstein set. We also show that Sacks forcing is the weakest forcing notion among all of the preorders that add a new real with respect to Sigma(1)(3) forcing absoluteness.

  5. Forecasting Error Calculation with Mean Absolute Deviation and Mean Absolute Percentage Error

    Science.gov (United States)

    Khair, Ummul; Fahmi, Hasanul; Hakim, Sarudin Al; Rahim, Robbi

    2017-12-01

    Prediction using a forecasting method is one of the most important things for an organization, the selection of appropriate forecasting methods is also important but the percentage error of a method is more important in order for decision makers to adopt the right culture, the use of the Mean Absolute Deviation and Mean Absolute Percentage Error to calculate the percentage of mistakes in the least square method resulted in a percentage of 9.77% and it was decided that the least square method be worked for time series and trend data.

  6. On the distribution of relative humidity in cirrus clouds

    Directory of Open Access Journals (Sweden)

    P. Spichtinger

    2004-01-01

    Full Text Available We have analysed relative humidity statistics from measurements in cirrus clouds taken unintentionally during the Measurement of OZone by Airbus In-service airCraft project (MOZAIC. The shapes of the in-cloud humidity distributions change from nearly symmetric in relatively warm cirrus (warmer than −40°C to considerably positively skew (i.e. towards high humidities in colder clouds. These results are in agreement to findings obtained recently from the INterhemispheric differences in Cirrus properties from Anthropogenic emissions (INCA campaign (Ovarlez et al., 2002. We interprete the temperature dependence of the shapes of the humidity distributions as an effect of the length of time a cirrus cloud needs from formation to a mature equilibrium stage, where the humidity is close to saturation. The duration of this transitional period increases with decreasing temperature. Hence cold cirrus clouds are more often met in the transitional stage than warm clouds.

  7. The effect of humidity on the detection of radon

    International Nuclear Information System (INIS)

    Money, M.; Heaton, B.

    1976-01-01

    As part of the investigation into the performance of a radon monitoring system the effect of altering the humidity on the levels of radon detected by the system whilst attempting to keep other factors constant, has been investigated. The variations in the levels of radon detected in four experiments, as the humidity of the surrounding atmosphere was artificially raised, are shown graphically together with the variations in temperature and water vapour pressure, as calculated from the relative humidity and saturation vapour pressure. In each case a general rise and fall in radon detected follows a similar rise and fall in humidity, but temperature rise has only a small effect on the radon emanation rate. As the levels of humidity do not alter the rate of emanation it is assumed that the efficiency of collection is altered in some way. Mechanisms are discussed. (U.K.)

  8. Humidity dependence of adhesion for silane coated microcantilevers

    International Nuclear Information System (INIS)

    De Boer, Maarten P.; Mayer, Thomas M.; Carpick, Robert W.; Michalske, Terry A.; Srinivasan, U.; Maboudian, R.

    1999-01-01

    This study examines adhesion between silane-coated micromachined surfaces that are exposed to humid conditions. Our quantitative values for interfacial adhesion energies are determined from an in-situ optical measurement of deformations in partly-adhered cantilever beams. We coated micromachined cantilevers with either ODTS (C(sub 18)H(sub 37)SiCl(sub 3)) or FDTS (C(sub 8)F(sub 17)C(sub 2)H(sub 4)SiCl(sub 3)) with the objective of creating hydrophobic surfaces whose adhesion would be independent of humidity. In both cases, the adhesion energy is significantly lower than for uncoated, hydrophilic surfaces. For relative humidities (RH) less than 95% (ODTS) and 80% (FDTS) the adhesion energy was extremely low and constant. In fact, ODTS-coated beams exposed to saturated humidity conditions and long (48 hour) exposures showed only a factor of two increase in adhesion energy. Surprisingly, FDTS coated beams, which initially have a higher contact angle (115(degree)) with water than do ODTS coated beams (112(degree)), proved to be much more sensitive to humidity. The FDTS coated surfaces showed a factor of one hundred increase in adhesion energy after a seven hour exposure to 90% RH. Atomic force microscopy revealed agglomerated coating material after exposed to high RH, suggesting a redistribution of the monolayer film. This agglomeration was more prominent for FDTS than ODTS. These findings suggest a new mechanism for uptake of moisture under high humidity conditions. At high humidities, the silane coatings can reconfigure from a surface to a bulk phase leaving behind locally hydrophilic sites which increase the average measured adhesion energy. In order for the adhesion increase to be observed, a significant fraction of the monolayer must be converted from the surface to the bulk phase

  9. Humidity effects on scanning polarization force microscopy imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yue, E-mail: shenyue@isl.ac.cn [Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008 (China); Key Laboratory of Interfacial Physics and Technology of Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Zhou, Yuan, E-mail: zhouy@isl.ac.cn [Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008 (China); Sun, Yanxia; Zhang, Lijuan [Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Ying; Hu, Jun; Zhang, Yi [Key Laboratory of Interfacial Physics and Technology of Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2017-08-01

    Highlights: • The humidity dramatically affects the contrast of scanning polarization force microscopy (SPFM) imaging on mica surface. • This influence roots in the sensitive dielectric constant of mica surface to the humidity change. • A strategy of controllable and repeatable imaging the local dielectric properties of nanomaterials with SPFM is proposed. - Abstract: Scanning polarization force microscopy (SPFM) is a useful surface characterization technique to visually characterize and distinguish nanomaterial with different local dielectric properties at nanometer scale. In this paper, taking the individual one-atom-thick graphene oxide (GO) and reduced graphene oxide (rGO) sheets on mica as examples, we described the influences of environmental humidity on SPFM imaging. We found that the apparent heights (AHs) or contrast of SPFM imaging was influenced significantly by relative humidity (RH) at a response time of a few seconds. And this influence rooted in the sensitive dielectric constant of mica surface to the RH change. While dielectric properties of GO and rGO sheets were almost immune to the humidity change. In addition, we gave the method to determine the critical humidity at which the contrast conversion happened under different conditions. And this is important to the contrast control and repeatable imaging of SPFM through RH adjusting. These findings suggest a strategy of controllable and repeatable imaging the local dielectric properties of nanomaterials with SPFM, which is critically important for further distinguishment, manipulation, electronic applications, etc.

  10. Climate change, humidity, and mortality in the United States

    Science.gov (United States)

    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

  11. Fabrication and Characterization of Polyaniline/PVA Humidity Microsensors

    Directory of Open Access Journals (Sweden)

    Ming-Zhi Yang

    2011-08-01

    Full Text Available This study presents the fabrication and characterization of a humidity microsensor that consists of interdigitated electrodes and a sensitive film. The area of the humidity microsensor is about 2 mm2. The sensitive film is polyaniline doping polyvinyl alcohol (PVA that is prepared by the sol-gel method, and the film has nanofiber and porous structures that help increase the sensing reaction. The commercial 0.35 mm Complimentary Metal Oxide Semiconductor (CMOS process is used to fabricate the humidity microsensor. The sensor needs a post-CMOS process to etch the sacrificial layer and to coat the sensitive film on the interdigitated electrodes. The sensor produces a change in resistance as the polyaniline/PVA film absorbs or desorbs vapor. Experimental results show that the sensitivity of the humidity sensor is about 12.6 kΩ/%RH at 25 °C.

  12. The humidity in a Dräger Primus anesthesia workstation using low or high fresh gas flow and with or without a heat and moisture exchanger in pediatric patients.

    Science.gov (United States)

    Bicalho, Gustavo P; Braz, Leandro G; de Jesus, Larissa S B; Pedigone, Cesar M C; de Carvalho, Lídia R; Módolo, Norma S P; Braz, José R C

    2014-10-01

    An inhaled gas absolute humidity of 20 mg H2O·L is the value most considered as the threshold necessary for preventing the deleterious effects of dry gas on the epithelium of the airways during anesthesia. Because children have small minute ventilation, we hypothesized that the humidification of a circle breathing system is lower in children compared with adults. The Primus anesthesia workstation (Dräger Medical, Lübeck, Germany) has a built-in hotplate to heat the patient's exhaled gases. A heat and moisture exchanger (HME) is a device that can be used to further humidify and heat the inhaled gases during anesthesia. To evaluate the humidifying properties of this circle breathing system during pediatric anesthesia, we compared the temperature and humidity of inhaled gases under low or high fresh gas flow (FGF) conditions and with or without an HME. Forty children were randomly allocated into 4 groups according to the ventilation of their lungs by a circle breathing system in a Dräger Primus anesthesia workstation with low (1 L·min) or high (3 L·min) FGF without an HME (1L and 3L groups) or with an HME (Pall BB25FS, Pall Biomedical, East Hills, NY; HME1L and HME3L groups). The temperature and absolute humidity of inhaled gases were measured at 10, 20, 40, 60, and 80 minutes after connecting the patient to the breathing circuit. The mean inhaled gas temperature was higher in HME groups (HME1L: 30.3°C ± 1.1°C; HME3L: 29.3°C ± 1.2°C) compared with no-HME groups (1L: 27.0°C ± 1.2°C; 3L: 27.1°C ± 1.5°C; P [HME3L: 23 ± 2 mg H2O·L] > [1L: 17 ± 1 mg H2O·L] > [3L: 14 ± 1 mg H2O·L]; P pediatric circle breathing system, the use of neither high nor low FGF provides the minimum humidity level of the inhaled gases thought to reduce the risk of dehydration of airways. Insertion of an HME increases the humidity and temperature of the inhaled gases, bringing them closer to physiological values. The use of a low FGF enhances the HME efficiency and

  13. Self-calibrated humidity sensor in CMOS without post-processing.

    Science.gov (United States)

    Nizhnik, Oleg; Higuchi, Kohei; Maenaka, Kazusuke

    2012-01-01

    A 1.1 μW power dissipation, voltage-output humidity sensor with 10% relative humidity accuracy was developed in the LFoundry 0.15 μm CMOS technology without post-processing. The sensor consists of a woven lateral array of electrodes implemented in CMOS top metal, a humidity-sensitive layer of Intervia Photodielectric 8023D-10, a CMOS capacitance to voltage converter, and the self-calibration circuitry.

  14. Self-Calibrated Humidity Sensor in CMOS without Post-Processing

    OpenAIRE

    Nizhnik, Oleg; Higuchi, Kohei; Maenaka, Kazusuke

    2011-01-01

    A 1.1 μW power dissipation, voltage-output humidity sensor with 10% relative humidity accuracy was developed in the LFoundry 0.15 μm CMOS technology without post-processing. The sensor consists of a woven lateral array of electrodes implemented in CMOS top metal, a humidity-sensitive layer of Intervia Photodielectric 8023D-10, a CMOS capacitance to voltage converter, and the self-calibration circuitry.

  15. Deformation of high performance concrete plate under humid tropical weather

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  17. Temperature, humidity and time. Combined effects on radiochromic film dosimeters

    DEFF Research Database (Denmark)

    Abdel-Fattah, A.A.; Miller, A.

    1996-01-01

    The effects of both relative humidity and temperature during irradiation on the dose response of FWT-60-00 and Riso B3 radiochromic film dosimeters have been investigated in the relative humidity (RH) range 11-94% and temperature range 20-60 degrees C for irradiation by Co-60 photons and 10-Me......V electrons. The results show that humidity and temperature cannot be treated as independent variables, rather there appears to be interdependence between absorbed dose, temperature, and humidity. Dose rate does not seem to play a significant role. The dependence of temperature during irradiation is +0.......25 +/- 0.1% per degrees C for the FWT-60-00 dosimeters and +0.5 +/- 0.1% per degrees C For Riso B3 dosimeters at temperatures between 20 and 50 degrees C and at relative humidities between 20 and 53%. At extreme conditions both with respect to temperature and to humidity, the dosimeters show much stronger...

  18. The anthropogenic influence on heat and humidity in the US Midwest

    Science.gov (United States)

    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.

  19. On the Humidity Sensitivity of Hot-Wire Measurements

    DEFF Research Database (Denmark)

    Larsen, Søren Ejling; Busch, N. E.

    1980-01-01

    The influence of humidity changes on hot-wire measurements is discussed. Indications are that the humidity sensitivity parameters obtained by the authors in an earlier paper should be changed. This means, however, that the agreement between predicted and measured sensitivities ceases to exist...

  20. Preparation and Humidity Sensing Properties of KCl/MCM-41 Composite

    International Nuclear Information System (INIS)

    Li, Liu; Lian-Yuan, Wang; Wei, Li; Li-Ying, Kou; Zhi-Cheng, Zhong; Li-Fang, Liu

    2010-01-01

    KCl/mobil composition of matter-41 (MCM-41) composite has been synthesized via a heat-treating process and characterized by x-ray diffraction, high resolution transmission electron microscopy, and nitrogen adsorption/desorption isotherms. In contrast with pure MCM-41, KCl/MCM-41 composite exhibits improved humidity sensing properties within the relative humidity range of 11–95%. The impedance of KCl/MCM-41 composite changes by about four orders of magnitude over the whole humidity range with the response time and the recovery times are about 30 s and 35 s, respectively. Small humidity hysteresis and good stability are also observed based on our product. These results make our product a good candidate in fabricating humidity sensors with high performances and low synthetic complexity

  1. Recent Developments in Fiber Optics Humidity Sensors.

    Science.gov (United States)

    Ascorbe, Joaquin; Corres, Jesus M; Arregui, Francisco J; Matias, Ignacio R

    2017-04-19

    A wide range of applications such as health, human comfort, agriculture, food processing and storage, and electronic manufacturing, among others, require fast and accurate measurement of humidity. Sensors based on optical fibers present several advantages over electronic sensors and great research efforts have been made in recent years in this field. The present paper reports the current trends of optical fiber humidity sensors. The evolution of optical structures developed towards humidity sensing, as well as the novel materials used for this purpose, will be analyzed. Well-known optical structures, such as long-period fiber gratings or fiber Bragg gratings, are still being studied towards an enhancement of their sensitivity. Sensors based on lossy mode resonances constitute a platform that combines high sensitivity with low complexity, both in terms of their fabrication process and the equipment required. Novel structures, such as resonators, are being studied in order to improve the resolution of humidity sensors. Moreover, recent research on polymer optical fibers suggests that the sensitivity of this kind of sensor has not yet reached its limit. Therefore, there is still room for improvement in terms of sensitivity and resolution.

  2. Behavior of HEPA filters under high humidity airflows

    International Nuclear Information System (INIS)

    Ricketts, C.I.

    1992-10-01

    To help determine and improve the safety margins of High Efficiency Particulate Air (HEPA) filter units in nuclear facilities under possible accident conditions, the structural limits and failure mechanisms of filter in high-humidity airflows were established and the fundamental physical phenomena underlying filter failure or malfunction in humid air were identified. Empirical models for increases in filter pressure drop with time in terms of the relevant airstream parameters were also developed. The weaknesses of currently employed humidity countermeasures used in filter protection are discussed and fundamental explanations for reported filter failures in normal service are given. (orig./DG) [de

  3. Temperature, humidity and time., Combined effects on radiochromic film dosimeters

    International Nuclear Information System (INIS)

    Abdel-Fattah, A.A.; Miller, A.

    1996-01-01

    The effects of both relative humidity and temperature during irradiation on the dose response of FWT-60-00 and Riso B3 radiochromic film dosimeters have been investigated in the relative humidity (RH) range 11-94% and temperature range 20-60 o C for irradiation by 60 Co photons and 10-MeV electrons. The results show that humidity and temperature cannot be treated as independent variables, rather there appears to be interdependence between absorbed dose, temperature, and humidity. Dose rate does not seem to play a significant role. The dependence of temperature during irradiation is + 0.25 ± 0.1% per o C for the FWT-60-00 dosimeters and +0.5 ± 0.1% per o C for Riso B3 dosimeters at temperatures between 20 and 50 o C and at relative humidities between 20 and 53%. At extreme conditions both with respect to temperature and to humidity, the dosimeters show much stronger dependences. Whenever possible one should use dosimeters sealed in pouches under controlled intermediate humidity conditions (30-50%) or, if that is impractical, one should maintain conditions of calibration as close as possible to the conditions of use. Without that precaution, severe dosimetry errors may result. (author)

  4. Variance computations for functional of absolute risk estimates.

    Science.gov (United States)

    Pfeiffer, R M; Petracci, E

    2011-07-01

    We present a simple influence function based approach to compute the variances of estimates of absolute risk and functions of absolute risk. We apply this approach to criteria that assess the impact of changes in the risk factor distribution on absolute risk for an individual and at the population level. As an illustration we use an absolute risk prediction model for breast cancer that includes modifiable risk factors in addition to standard breast cancer risk factors. Influence function based variance estimates for absolute risk and the criteria are compared to bootstrap variance estimates.

  5. Energy-Efficient Management of Mechanical Ventilation and Relative Humidity in Hot-Humid Climates

    Energy Technology Data Exchange (ETDEWEB)

    Withers, Jr., Charles R. [Building America Partnership for Improved Residential Construction, Cocoa, FL (United States)

    2016-12-01

    In hot and humid climates, it is challenging to energy-efficiently maintain indoor RH at acceptable levels while simultaneously providing required ventilation, particularly in high performance low cooling load homes. The fundamental problem with solely relying on fixed capacity central cooling systems to manage moisture during low sensible load periods is that they are oversized for cooler periods of the year despite being 'properly sized' for a very hot design cooling day. The primary goals of this project were to determine the impact of supplementing a central space conditioning system with 1) a supplemental dehumidifier and 2) a ductless mini-split on seasonal energy use and summer peak power use as well as the impact on thermal distribution and humidity control inside a completely furnished lab home that was continuously ventilated in accordance with ASHRAE 62.2-2013.

  6. Investigations of microelectronic humidity sensors made of composite oxides thin films

    International Nuclear Information System (INIS)

    Pogossyan, A.S.; Arutyunyan, V.M.

    1996-01-01

    Basic characteristics (the moisture sensitivity, lag, hysteresis and stability) of humidity sensors made of Fe 2 O 3 thin films with different K 2 content, as well as CaSiO 3 and NaBiTi 2 O 6 films,-new materials for the humidity sensors, are investigated. A composition Fe 2 O 3 (K) is found to be optimal with respect to high moisture sensitivity, speed of response, and a linearity in a wide range of the relative humidity. A mechanism of the moisture-sensitivity of films investigated is discussed. Criteria for the design parameters of the high-impedance humidity sensors are defined with the aim to broadening of the working range of the relative humidity in a side way of low values of the humidity.10 refs

  7. Absolute determination of the deuterium content of heavy water, measurement of absolute density

    International Nuclear Information System (INIS)

    Ceccaldi, M.; Riedinger, M.; Menache, M.

    1975-01-01

    The absolute density of two heavy water samples rich in deuterium (with a grade higher than 99.9%) was determined with the hydrostatic method. The exact isotopic composition of this water (hydrogen and oxygen isotopes) was very carefully studied. A theoretical estimate enabled us to get the absolute density value of isotopically pure D 2 16 O. This value was found to be 1104.750 kg.m -3 at t 68 =22.3 0 C and under the pressure of one atmosphere. (orig.) [de

  8. Relationship between relative humidity and the dew point ...

    African Journals Online (AJOL)

    This research was aimed at determining the relationship between relative humidity and the dew point temperature in Benin City, Edo State, Nigeria. The dew point temperature was approximated from the measured air temperature and relative humidity with the aid of a currently self-designed weather monitoring system.

  9. The effect of humidity on annealing of polymer optical fibre bragg gratings

    DEFF Research Database (Denmark)

    Woyessa, Getinet; Nielsen, Kristian; Bang, Ole

    2015-01-01

    The effect of humidity on annealing of PMMA based microstructured polymer optical fiber (mPOF) Bragg gratings is studied. Polymer optical fibers (POFs) are annealed in order to release stress formed during the fabrication process. Un-annealed fibers will have high hysteresis and low sensitivity...... to humidity, particularly when operated at high temperature. Typically annealing of PMMA POFs is done at 80oC in an oven with no humidity control and therefor at low humidity. The response to humidity of PMMA FBGs annealed at different levels of humidity at the same temperature has also been studied. PMMA...

  10. Rates of cuticular penetration of chelated Fe(III): role of humidity, concentration, adjuvants, temperature, and type of chelate.

    Science.gov (United States)

    Schönherr, Jörg; Fernández, Victoria; Schreiber, Lukas

    2005-06-01

    hydroxide precipitates on CMs. These results explain why in the past foliar application of Fe compounds had limited success. Inorganic Fe salts are instable and phytotoxic because of low pH, while Fe chelates penetrate slowly and 100% humidity is required for significant penetration rates. Concentrations as low as reasonably possible should be used. These physical facts are expected to apply to stomatous leaf surfaces as well, but absolute rates probably depend on leaf age and plant species. High humidity in stagnant air layers may favor penetration rates across stomatous leaf surfaces when humidity in bulk air is below 100%.

  11. Testing flat plate photovoltaic modules for terrestrial environment

    Science.gov (United States)

    Hoffman, A. R.; Arnett, J. C.; Ross, R. G., Jr.

    1979-01-01

    New qualification tests have been developed for flat plate photovoltaic modules. Temperature cycling, cyclic pressure load, and humidity exposure are especially useful for detecting design and fabrication deficiencies. There is positive correlation between many of the observed field effects, such as power loss, and qualification test induced degradation. The status of research efforts for the development of test methodology for field-related problems is reviewed.

  12. Humidity : a review and primer on atmospheric moisture and human health.

    OpenAIRE

    David, R.E.; McGregor, G.R.; Enfield, K.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 importa...

  13. The absolute environmental performance of buildings

    DEFF Research Database (Denmark)

    Brejnrod, Kathrine Nykjær; Kalbar, Pradip; Petersen, Steffen

    2017-01-01

    Our paper presents a novel approach for absolute sustainability assessment of a building's environmental performance. It is demonstrated how the absolute sustainable share of the earth carrying capacity of a specific building type can be estimated using carrying capacity based normalization factors....... A building is considered absolute sustainable if its annual environmental burden is less than its share of the earth environmental carrying capacity. Two case buildings – a standard house and an upcycled single-family house located in Denmark – were assessed according to this approach and both were found...... to exceed the target values of three (almost four) of the eleven impact categories included in the study. The worst-case excess was for the case building, representing prevalent Danish building practices, which utilized 1563% of the Climate Change carrying capacity. Four paths to reach absolute...

  14. Absolute Summ

    Science.gov (United States)

    Phillips, Alfred, Jr.

    Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that Absolute cosmological ideas, not unlike those of I. Newton, may be consistent with dynamic multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an Absolute Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  17. Influence of fine water droplets to temperature and humidity

    Science.gov (United States)

    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.

  18. Influence of humidity on the graphene band gap

    International Nuclear Information System (INIS)

    Zakaryan, H.A.; Aroutiounian, V.M.

    2015-01-01

    Influences of the humidity on graphene properties are studied and comparisons of graphene and polymer humidity sensors are carried out. Graphene sensors have remarkable response compare to nanoporous polymer membranes. The resistance of polymer sensors is 150 GOhm and decreases in 7.5 times at 60 per cent of the relative humidity. For graphene, resistance drops 4 times starting from ~100 kOhm. This is connected with the extension of graphene band gap. The reason of this is adsorbed water, which can create defects in the lattice or can transfer charge which depends on relative position of HOMO/LUMO of water and Dirac point of graphene

  19. Absolute flux scale for radioastronomy

    International Nuclear Information System (INIS)

    Ivanov, V.P.; Stankevich, K.S.

    1986-01-01

    The authors propose and provide support for a new absolute flux scale for radio astronomy, which is not encumbered with the inadequacies of the previous scales. In constructing it the method of relative spectra was used (a powerful tool for choosing reference spectra). A review is given of previous flux scales. The authors compare the AIS scale with the scale they propose. Both scales are based on absolute measurements by the ''artificial moon'' method, and they are practically coincident in the range from 0.96 to 6 GHz. At frequencies above 6 GHz, 0.96 GHz, the AIS scale is overestimated because of incorrect extrapolation of the spectra of the primary and secondary standards. The major results which have emerged from this review of absolute scales in radio astronomy are summarized

  20. Searching for new solutions Humidity measurements in the environments

    Directory of Open Access Journals (Sweden)

    Gianina Creţu

    2008-05-01

    Full Text Available More attention is nowadays being paid to thequality of the air we breathe, resulting in an increasingneed for humidity measurements in the home and officeenvironments. Maintaining the proper level of relativehumidity is also necessary to avoid conditions of extremehumidity condensation in buildings.The facts that construction problems and excessive waterand humidity often go together is well-known around theworld today. Moisture and water damage is a wellknown problem in construction in many countries.Problems of all construction are caused by humidity and50 per cent of all buildings have some kind of moisturerelatedproblems. Growing awareness of percentages suchas these has led to greater attention being paid toconstruction humidity and its measurement throughoutthe world in recent years.This paper presents a condensed review of nowadayshumidity sensors technology, problem implicated andsome modern tendencies.

  1. Opposing effects of humidity on rhodochrosite surface oxidation.

    Science.gov (United States)

    Na, Chongzheng; Tang, Yuanzhi; Wang, Haitao; Martin, Scot T

    2015-03-03

    Rhodochrosite (MnCO3) is a model mineral representing carbonate aerosol particles containing redox-active elements that can influence particle surface reconstruction in humid air, thereby affecting the heterogeneous transformation of important atmospheric constituents such as nitric oxides, sulfur dioxides, and organic acids. Using in situ atomic force microscopy, we show that the surface reconstruction of rhodochrosite in humid oxygen leads to the formation and growth of oxide nanostructures. The oxidative reconstruction consists of two consecutive processes with distinctive time scales, including a long waiting period corresponding to slow nucleation and a rapid expansion phase corresponding to fast growth. By varying the relative humidity from 55 to 78%, we further show that increasing humidity has opposing effects on the two processes, accelerating nucleation from 2.8(±0.2) × 10(-3) to 3.0(±0.2) × 10(-2) h(-1) but decelerating growth from 7.5(±0.3) × 10(-3) to 3.1(±0.1) × 10(-3) μm(2) h(-1). Through quantitative analysis, we propose that nanostructure nucleation is controlled by rhodochrosite surface dissolution, similar to the dissolution-precipitation mechanism proposed for carbonate mineral surface reconstruction in aqueous solution. To explain nanostructure growth in humid oxygen, a new Cabrera-Mott mechanism involving electron tunneling and solid-state diffusion is proposed.

  2. Humidity-insensitive water evaporation from molecular complex fluids.

    Science.gov (United States)

    Salmon, Jean-Baptiste; Doumenc, Frédéric; Guerrier, Béatrice

    2017-09-01

    We investigated theoretically water evaporation from concentrated supramolecular mixtures, such as solutions of polymers or amphiphilic molecules, using numerical resolutions of a one-dimensional model based on mass transport equations. Solvent evaporation leads to the formation of a concentrated solute layer at the drying interface, which slows down evaporation in a long-time-scale regime. In this regime, often referred to as the falling rate period, evaporation is dominated by diffusive mass transport within the solution, as already known. However, we demonstrate that, in this regime, the rate of evaporation does not also depend on the ambient humidity for many molecular complex fluids. Using analytical solutions in some limiting cases, we first demonstrate that a sharp decrease of the water chemical activity at high solute concentration leads to evaporation rates which depend weakly on the humidity, as the solute concentration at the drying interface slightly depends on the humidity. However, we also show that a strong decrease of the mutual diffusion coefficient of the solution enhances considerably this effect, leading to nearly independent evaporation rates over a wide range of humidity. The decrease of the mutual diffusion coefficient indeed induces strong concentration gradients at the drying interface, which shield the concentration profiles from humidity variations, except in a very thin region close to the drying interface.

  3. Comparison of land surface humidity between observations and CMIP5 models

    Science.gov (United States)

    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

  4. Factors controlling upper tropospheric relative humidity

    Directory of Open Access Journals (Sweden)

    B. Kärcher

    2004-03-01

    Full Text Available Factors controlling the distribution of relative humidity in the absence of clouds are examined, with special emphasis on relative humidity over ice (RHI under upper tropospheric and lower stratospheric conditions. Variations of temperature are the key determinant for the distribution of RHI, followed by variations of the water vapor mixing ratio. Multiple humidity modes, generated by mixing of different air masses, may contribute to the overall distribution of RHI, in particular below ice saturation. The fraction of air that is supersaturated with respect to ice is mainly determined by the distribution of temperature. The nucleation of ice in cirrus clouds determines the highest relative humdity that can be measured outside of cirrus clouds. While vertical air motion and ice microphysics determine the slope of the distributions of RHI, as shown in a separate study companion (Haag et al., 2003, clouds are not required to explain the main features of the distributions of RHI below the ice nucleation threshold. Key words. Atmospheric composition and structure (pressure, density and temperature; troposphere – composition and chemistry; general or miscellaneous

  5. Factors controlling upper tropospheric relative humidity

    Directory of Open Access Journals (Sweden)

    B. Kärcher

    2004-03-01

    Full Text Available Factors controlling the distribution of relative humidity in the absence of clouds are examined, with special emphasis on relative humidity over ice (RHI under upper tropospheric and lower stratospheric conditions. Variations of temperature are the key determinant for the distribution of RHI, followed by variations of the water vapor mixing ratio. Multiple humidity modes, generated by mixing of different air masses, may contribute to the overall distribution of RHI, in particular below ice saturation. The fraction of air that is supersaturated with respect to ice is mainly determined by the distribution of temperature. The nucleation of ice in cirrus clouds determines the highest relative humdity that can be measured outside of cirrus clouds. While vertical air motion and ice microphysics determine the slope of the distributions of RHI, as shown in a separate study companion (Haag et al., 2003, clouds are not required to explain the main features of the distributions of RHI below the ice nucleation threshold.

    Key words. Atmospheric composition and structure (pressure, density and temperature; troposphere – composition and chemistry; general or miscellaneous

  6. Lead Oxide- PbO Humidity Sensor

    Directory of Open Access Journals (Sweden)

    Sk. Khadeer Pasha

    2010-11-01

    Full Text Available Alcohol thermal route has been used to synthesize nanocrystalline PbO at a low temperature of 75 oC using lead acetate. The synthesized PbO (P75 was annealed in the temperatures ranging from 200-500 oC for 2 h to study the effect of crystal structure and phase changes and were labeled as P200, P300, P400 and P500, respectively. X-Ray diffraction and FT-IR spectroscopy were carried out to identify the structural phases and vibrational stretching frequencies respectively. The TEM images revealed the porous nature of P75 sample which is an important criterion for the humidity sensor. The dc resistance measurements were carried out in the relative humidity (RH range 5-98 %. Among the different prepared, P75 possessed the highest humidity sensitivity of 6250, while the heat treated sample P500 have a low sensitivity of 330. The response and recovery characteristics of the maximum sensitivity sample P75 were 170 s and 40 s respectively.

  7. Long-term Effects of Relative Humidity on Properties of Microwave Hardened Moulding Sand with Sodium Silicate

    Directory of Open Access Journals (Sweden)

    Stachowicz M.

    2017-09-01

    Full Text Available Moulding sands containing sodium silicate (water-glass belong to the group of porous mixture with low resistance to increased humidity. Thanks to hydrophilic properties of hardened or even overheated binder, possible is application of effective methods of hydrous reclamation consisting in its secondary hydration. For the same reason (hydrophilia of the binder, moulds and foundry cores made of high-silica moulding sands with sodium silicate are susceptible to the action of components of atmospheric air, including the contained steam. This paper presents results of a research on the effect of (relative humidity on mechanical and technological properties of microwave-hardened moulding mixtures. Specimens of the moulding sand containing 1.5 wt% of sodium water-glass with module 2.5 were subjected, in a laboratory climatic chamber, to long-term action of steam contained in the chamber atmosphere. Concentration of water in atmospheric air was stabilized for 28 days (672 h according to the relative humidity parameter that was ca. 40%, 60% and 80% at constant temperature 20 °C. In three cycles of the examinations, the specimens were taken out from the chamber every 7 days (168 h and their mechanical and technological parameters were determined. It was found on the grounds of laboratory measurements that moulds and cores hardened with microwaves are susceptible to action of atmospheric air and presence of water (as steam intensifies action of the air components on glassy film of sodium silicate. Microwave-hardened moulding sands containing sodium silicate may be stored on a long-term basis in strictly determined atmospheric conditions only, at reduced humidity. In spite of a negative effect of steam contained in the air, the examined moulding mixtures maintain a part of their mechanical and technological properties, so the moulds and foundry cores stored in specified, controlled conditions could be still used in manufacture.

  8. Density of loose-fill insulation material exposed to cyclic humidity conditions

    DEFF Research Database (Denmark)

    Rasmussen, Torben Valdbjørn

    the granulated loose-fill material is exposed to a climate that is characterised as cyclic humidity conditions (a constant temperature and a relative humidity alternating between two predetermined constant relative humidity levels). A better understanding of the behaviour of granulated loose-fill material...

  9. Evaluation of PV modules integrated with roofing materials; Kenzai ittaigata taiyo denchi module no hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Morizane, M.; Yagiura, T.; Nakashima, S.; Yagi, H.; Murata, K.; Uchihashi, K.; Tsuda, S.; Nakano, S. [Sanyo Electric Co. Ltd., Osaka (Japan); Ito, M.; Kurimoto, T.; Yamakawa, H.; Fujiwara, T. [Kubota Corp., Osaka (Japan)

    1997-11-25

    PV modules unified with building materials which are low in cost, easy to install and excellent in designing were developed and were evaluated in various tests. As to the basic structure of this module, seamless and unified construction with the back metal plate was adopted considering improvement in fire prevention and cost reduction. About the installation, module is easy to install by just fit connection with the frame, and easy to remove with no use of special tools. Concerning intensity and durability requested for this module, tests on reliability such as torsion strength and wind pressure resistance were conducted according to JIS standards, and it was confirmed that there were no problems. Also on the long-term durability, tests on long-term reliability were carried out by doubling test terms of the temperature/humidity cycle test, salt water resistance test, etc., and the reliability the same as that of the existing type was confirmed. In the verification test using a model house, no changes were seen in electrical characteristics and appearance, and waterproof was also favorable one and a half year after the installation. 4 refs., 7 figs., 5 tabs.

  10. Humidity Detection Using Metal Organic Framework Coated on QCM

    KAUST Repository

    Kosuru, Lakshmoji; Bouchaala, Adam M.; Jaber, Nizar; Younis, Mohammad I.

    2016-01-01

    of a quartz crystal microbalance. The resonance frequencies of these sensors with varying relative humidity (RH) from 22% RH to 69% RH are measured using impedance analysis method. The sensitivity, humidity hysteresis, response, and recovery times

  11. Study of some Mg-based ferrites as humidity sensors

    International Nuclear Information System (INIS)

    Rezlescu, N; Rezlescu, E; Doroftei, C; Popa, P D

    2005-01-01

    The micostructure and humidity sensitivity of MgFe 2 O 4 + CaO, Mg 0.5 Cu 0.5 Fe 1.8 Ga 0.2 O 4 , Mg 0.5 Zn 0.5 Fe 2 O 4 + KCl and MgMn 0.2 Fe 1.8 O 4 ferrites were investigated. We have found that the humidity sensitivity largely depends on composition, crystallite size, surface area and porosity. The best results concerning humidity sensitivity were obtained for MgMn 0.2 Fe 1.8 O 4 ferrite

  12. A global algorithm for estimating Absolute Salinity

    Science.gov (United States)

    McDougall, T. J.; Jackett, D. R.; Millero, F. J.; Pawlowicz, R.; Barker, P. M.

    2012-12-01

    The International Thermodynamic Equation of Seawater - 2010 has defined the thermodynamic properties of seawater in terms of a new salinity variable, Absolute Salinity, which takes into account the spatial variation of the composition of seawater. Absolute Salinity more accurately reflects the effects of the dissolved material in seawater on the thermodynamic properties (particularly density) than does Practical Salinity. When a seawater sample has standard composition (i.e. the ratios of the constituents of sea salt are the same as those of surface water of the North Atlantic), Practical Salinity can be used to accurately evaluate the thermodynamic properties of seawater. When seawater is not of standard composition, Practical Salinity alone is not sufficient and the Absolute Salinity Anomaly needs to be estimated; this anomaly is as large as 0.025 g kg-1 in the northernmost North Pacific. Here we provide an algorithm for estimating Absolute Salinity Anomaly for any location (x, y, p) in the world ocean. To develop this algorithm, we used the Absolute Salinity Anomaly that is found by comparing the density calculated from Practical Salinity to the density measured in the laboratory. These estimates of Absolute Salinity Anomaly however are limited to the number of available observations (namely 811). In order to provide a practical method that can be used at any location in the world ocean, we take advantage of approximate relationships between Absolute Salinity Anomaly and silicate concentrations (which are available globally).

  13. Effect of humidity on thoron adsorption in activated charcoal bed

    International Nuclear Information System (INIS)

    Sudeep Kumara, K.; Karunakara, N.; Yashodhara, I.; Sapra, B.K.; Sahoo, B.K.; Gaware, J.J.; Kanse, S.D.; Mayya, Y.S.

    2014-01-01

    Activated charcoal is a well-known adsorber of 222 Rn and 220 Rn gases. This property can be effectively used for remediation of these gases in the workplaces of uranium and thorium processing facilities. However, the adsorption on charcoal is sensitive to variation in temperature and humidity. The successful designing and characterization of adsorption systems require an adequate understanding of these sensitivities. The study has been carried out towards this end, to delineate the effect of relative humidity on the efficacy of 220 Rn mitigations in a charcoal bed. Air carrying 220 Rn from a Pylon source was passed through a column filled with coconut shell-based granular activated charcoal. The relative humidity of the air was controlled, and the transmission characteristics were examined at relative humidity varying from 45% to 60%. The mitigation factor was found to decrease significantly with an increase of humidity in the air. (author)

  14. Surface-type humidity sensor based on cellulose-PEPC for telemetry systems

    International Nuclear Information System (INIS)

    Karimov, Kh. S.; Saleem, M.; Qasuria, T. A.; Farooq, M.

    2011-01-01

    Au/cellulose-PEPC/Au surface-type humidity sensors were fabricated by drop-casting cellulose and poly-N-epoxypropylcarbazole (PEPC) blend thin films. A blend of 2wt% of each cellulose and PEPC in benzol was used for the deposition of humidity sensing films. Blend films were deposited on glass substrates with preliminary deposited surface-type gold electrodes. Films of different thicknesses of cellulose and PEPC composite were deposited by drop-casting technique. A change in electrical resistance and capacitance of the fabricated devices was observed by increasing the relative humidity in the range of 0-95% RH. It was observed that the capacitances of the sensors increase, while their resistances decrease with increasing the relative humidity. The sensors were connected to op-amp square wave oscillators. It was observed that with increasing the relative humidity, the oscillator's frequencies were also increased in the range of 4.2-12.0 kHz for 65 μm thick film sample, 4.1-9.0 kHz for 88 μm thick film sample, and 4.2-9.0 kHz for 210 μm sample. Effects of film thickness on the oscillator's frequency with respect to humidity were also investigated. This polymer humidity sensor controlled oscillator can be used for short-range and long-range remote systems at environmental monitoring and assessment of the humidity level. (semiconductor integrated circuits)

  15. Automated Data Collection for Determining Statistical Distributions of Module Power Undergoing Potential-Induced Degradation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hacke, P.; Spataru, S.

    2014-08-01

    We propose a method for increasing the frequency of data collection and reducing the time and cost of accelerated lifetime testing of photovoltaic modules undergoing potential-induced degradation (PID). This consists of in-situ measurements of dark current-voltage curves of the modules at elevated stress temperature, their use to determine the maximum power at 25 degrees C standard test conditions (STC), and distribution statistics for determining degradation rates as a function of stress level. The semi-continuous data obtained by this method clearly show degradation curves of the maximum power, including an incubation phase, rates and extent of degradation, precise time to failure, and partial recovery. Stress tests were performed on crystalline silicon modules at 85% relative humidity and 60 degrees C, 72 degrees C, and 85 degrees C. Activation energy for the mean time to failure (1% relative) of 0.85 eV was determined and a mean time to failure of 8,000 h at 25 degrees C and 85% relative humidity is predicted. No clear trend in maximum degradation as a function of stress temperature was observed.

  16. Humidity effects on the electronic transport properties in carbon based nanoscale device

    International Nuclear Information System (INIS)

    He, Jun; Chen, Ke-Qiu

    2012-01-01

    By applying nonequilibrium Green's functions in combination with the density functional theory, we investigate the effect of humidity on the electronic transport properties in carbon based nanoscale device. The results show that different humidity may form varied localized potential barrier, which is a very important factor to affect the stability of electronic transport in the nanoscale system. A mechanism for the humidity effect is suggested. -- Highlights: ► Electronic transport in carbon based nanoscale device. ► Humidity affects the stability of electronic transport. ► Different humidity may form varied localized potential barrier.

  17. Humidity sensing in insects-from ecology to neural processing.

    Science.gov (United States)

    Enjin, Anders

    2017-12-01

    Humidity is an omnipresent climatic factor that influences the fitness, reproductive behavior and geographic distribution of animals. Insects in particular use humidity cues to navigate the environment. Although the sensory neurons of this elusive sense were first described more than fifty years ago, the transduction mechanism of humidity sensing (hygrosensation) remains unknown. Recent work has uncovered some of the key molecules involved, opening up for novel approaches to study hygrosensory transduction. In this review, I will discuss this progress made toward understanding hygrosensation in insects. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Dynamics of electrostatically driven granular media: Effects of humidity

    International Nuclear Information System (INIS)

    Howell, D. W.; Aronson, Igor S.; Crabtree, G. W.

    2001-01-01

    We performed experimental studies of the effect of humidity on the dynamics of electrostatically driven granular materials. Both conducting and dielectric particles undergo a phase transition from an immobile state (granular solid) to a fluidized state (granular gas) with increasing applied field. Spontaneous precipitation of solid clusters from the gas phase occurs as the external driving is decreased. The clustering dynamics in conducting particles is primarily controlled by screening of the electric field but is aided by cohesion due to humidity. It is shown that humidity effects dominate the clustering process with dielectric particles

  19. Efficiency improvements by Metal Wrap Through technology for n-type Si solar cells and modules

    Energy Technology Data Exchange (ETDEWEB)

    Wenchao, Zhao; Jianming, Wang; Yanlong, Shen; Ziqian, Wang; Yingle, Chen; Shuquan, Tian; Zhiliang, Wan; Bo, Yu; Gaofei, Li; Zhiyan, Hu; Jingfeng, Xiong [Yingli Green Energy Holding Co., Ltd, 3399 North Chaoyang Avenue, Baoding (China); Guillevin, N.; Heurtault, B.; Aken, B.B. van; Bennett, I.J.; Geerligs, L.J.; Weeber, A.W.; Bultman, J.H. [ECN Solar Energy, Petten (Netherlands)

    2012-09-15

    N-type Metal Wrap Through (n-MWT) is presented as an industrially promising back-contact technology to reach high performance of silicon solar cells and modules. It can combine benefits from both n-type base and MWT metallization. In this paper, the efficiency improvements of commercial industrial n-type bifacial Si solar cells (239 cm{sup 2}) and modules (60 cells) by the integration of the MWT technique are described. For the cell, after the optimization of integration, over 0.3% absolute efficiency gain was achieved over the similar non-MWT technology, and Voc gain and Isc gain up to 0.9% and 3.5%, respectively. These gains are mainly attributed to reduced shading loss and surface recombination. Besides the front pattern optimization, a 0.1m{Omega} reduction of Rs in via part will induce further 0.06% absolute efficiency improvement. For the module part, a power output of n-MWT module up to 279W was achieved, corresponding to a module efficiency of about 17.7%.

  20. Standard Practice for Visual Inspections of Photovoltaic Modules

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This practice covers procedures and criteria for visual inspections of photovoltaic modules. 1.2 Visual inspections of photovoltaic modules are normally performed before and after modules have been subjected to environmental, electrical, or mechanical stress testing, such as thermal cycling, humidity-freeze cycling, damp heat exposure, ultraviolet exposure, mechanical loading, hail impact testing, outdoor exposure, or other stress testing that may be part of photovoltaic module testing sequence. 1.3 This practice does not establish pass or fail levels. The determination of acceptable or unacceptable results is beyond the scope of this practice. 1.4 There is no similar or equivalent ISO standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  1. Environmental testing of terrestrial flat plate photovoltaic modules

    Science.gov (United States)

    Hoffman, A.; Griffith, J.

    1979-01-01

    The Low-Cost Solar Array (LSA) Project at the Jet Propulsion Laboratory has as one objective: the development and implementation of environmental tests for flat plate photovoltaic modules as part of the Department of Energy's terrestrial photovoltaic program. Modules procured under this program have been subjected to a variety of laboratory tests intended to simulate service environments, and the results of these tests have been compared to available data from actual field service. This comparison indicates that certain tests (notably temperature cycling, humidity cycling, and cyclic pressure loading) are effective indicators of some forms of field failures. Other tests have yielded results useful in formulating module design guidelines. Not all effects noted in field service have been successfully reproduced in the laboratory, however, and work is continuing in order to improve the value of the test program as a tool for evaluating module design and workmanship. This paper contains a review of these ongoing efforts and an assessment of significant test results to date.

  2. Modeling of humidity-related reliability in enclosures with electronics

    DEFF Research Database (Denmark)

    Hygum, Morten Arnfeldt; Popok, Vladimir

    2015-01-01

    Reliability of electronics that operate outdoor is strongly affected by environmental factors such as temperature and humidity. Fluctuations of these parameters can lead to water condensation inside enclosures. Therefore, modelling of humidity distribution in a container with air and freely exposed...

  3. Nanocrystalline SnO2-TiO2 thin film deposited on base of equilateral prism as an opto-electronic humidity sensor

    Science.gov (United States)

    Yadav, B. C.; Verma, Nidhi; Singh, Satyendra

    2012-09-01

    Present paper reports the synthesis of SnO2-TiO2 nanocomposite, its characterization and performance as opto-electronic humidity sensor. Nanocrystalline SnO2-TiO2 film was deposited on the base of an equilateral prism using a photo resist spinner and the as prepared film was annealed at 200 °C for 2 h. The crystal structure of the prepared film was investigated using X-ray diffraction (XRD). Minimum crystallite size of the material was found 7 nm. Surface morphology of the film was investigated by Scanning electron microscope (SEM LEO-0430, Cambridge). SEM image shows that the film is porous. Differential scanning calorimetry (DSC) of as synthesized material shows two exothermic peaks at about 40 and 110 °C, respectively which are due to the evaporation of chemical impurities and water. Further the prepared film was investigated through the exposure of humidity and relative humidity (%RH) was measured directly in terms of modulation in the intensity of light recorded on a digital power meter. The maximum sensitivity of sensor was found 4.14 μW/%RH, which is quite significant for sensor fabrication purposes.

  4. Effect of humidity on the filter pressure drop

    International Nuclear Information System (INIS)

    Vendel, J.; Letourneau, P.

    1995-01-01

    The effects of humidity on the filter pressure drop have been reported in some previous studies in which it is difficult to draw definite conclusions. These studies show contradictory effects of humidity on the pressure drop probably due to differences in the hygroscopicity of the test aerosols. The objective of this paper is to present experimental results on the evolution of the filter pressure drop versus mass loading, for different test aerosols and relative humidities. Present results are compared to those found in various publication. An experimental device has been designed to measure filter pressure drop as the function of the areal density for relative humidity varying in the range of 9 % to 85 %. Experiments have been conducted with hygroscopic: (CsOH) and nonhygroscopic aerosols (TiO 2 ). Cesium hydroxyde (CsOH) of size of 2 μ M AMMD has been generated by an ultrasonic generator and the 0.7 μm AMMD titanium oxyde has been dispersed by a open-quotes turn-tableclose quotes generator. As it is noted in the BISWAS'publication [3], present results show, in the case of nonhygroscopic aerosols, a linear relationship of pressure drop to mass loading. For hygroscopic aerosols two cases must be considered: for relative humidity below the deliquescent point of the aerosol, the relationship of pressure drop to mass loading remains linear; above the deliquescent point, the results show a sudden increase in the pressure drop and the mass capacity of the filter is drastically reduced

  5. Effect of humidity on the filter pressure drop

    Energy Technology Data Exchange (ETDEWEB)

    Vendel, J.; Letourneau, P. [Institut de Protection et de Surete Nucleaire, Gif-sur-Yvette (France)

    1995-02-01

    The effects of humidity on the filter pressure drop have been reported in some previous studies in which it is difficult to draw definite conclusions. These studies show contradictory effects of humidity on the pressure drop probably due to differences in the hygroscopicity of the test aerosols. The objective of this paper is to present experimental results on the evolution of the filter pressure drop versus mass loading, for different test aerosols and relative humidities. Present results are compared to those found in various publication. An experimental device has been designed to measure filter pressure drop as the function of the areal density for relative humidity varying in the range of 9 % to 85 %. Experiments have been conducted with hygroscopic: (CsOH) and nonhygroscopic aerosols (TiO{sub 2}). Cesium hydroxyde (CsOH) of size of 2 {mu} M AMMD has been generated by an ultrasonic generator and the 0.7 {mu}m AMMD titanium oxyde has been dispersed by a {open_quotes}turn-table{close_quotes} generator. As it is noted in the BISWAS`publication [3], present results show, in the case of nonhygroscopic aerosols, a linear relationship of pressure drop to mass loading. For hygroscopic aerosols two cases must be considered: for relative humidity below the deliquescent point of the aerosol, the relationship of pressure drop to mass loading remains linear; above the deliquescent point, the results show a sudden increase in the pressure drop and the mass capacity of the filter is drastically reduced.

  6. A global algorithm for estimating Absolute Salinity

    Directory of Open Access Journals (Sweden)

    T. J. McDougall

    2012-12-01

    Full Text Available The International Thermodynamic Equation of Seawater – 2010 has defined the thermodynamic properties of seawater in terms of a new salinity variable, Absolute Salinity, which takes into account the spatial variation of the composition of seawater. Absolute Salinity more accurately reflects the effects of the dissolved material in seawater on the thermodynamic properties (particularly density than does Practical Salinity.

    When a seawater sample has standard composition (i.e. the ratios of the constituents of sea salt are the same as those of surface water of the North Atlantic, Practical Salinity can be used to accurately evaluate the thermodynamic properties of seawater. When seawater is not of standard composition, Practical Salinity alone is not sufficient and the Absolute Salinity Anomaly needs to be estimated; this anomaly is as large as 0.025 g kg−1 in the northernmost North Pacific. Here we provide an algorithm for estimating Absolute Salinity Anomaly for any location (x, y, p in the world ocean.

    To develop this algorithm, we used the Absolute Salinity Anomaly that is found by comparing the density calculated from Practical Salinity to the density measured in the laboratory. These estimates of Absolute Salinity Anomaly however are limited to the number of available observations (namely 811. In order to provide a practical method that can be used at any location in the world ocean, we take advantage of approximate relationships between Absolute Salinity Anomaly and silicate concentrations (which are available globally.

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

    Science.gov (United States)

    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 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.

  8. 40 CFR 1065.670 - NOX intake-air humidity and temperature corrections.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false NOX intake-air humidity and... NOX intake-air humidity and temperature corrections. See the standard-setting part to determine if you may correct NOX emissions for the effects of intake-air humidity or temperature. Use the NOX intake...

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

    Science.gov (United States)

    Russell, Joshua; Pierce-Shimomura, Jonathan T

    2014-11-30

    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). 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. 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 × 7.5-cm wide gel-covered arena. Previous humidity chambers relied on circulating dry and moist air to produce a steep humidity gradient in a small arena (e.g. Sayeed and 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. 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. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Effect of fabric texture and material on perceived discomfort at high humidity

    DEFF Research Database (Denmark)

    Toftum, Jørn; Rasmussen, Leif W.; Mackeprang, Jørgen

    1999-01-01

    This study investigated the effect of material (cotton/polyester) and texture (woven/knitted) of the inner layer of a clothing ensemble on human discomfort at high skin humidity. No clear effect on discomfort of material and texture could be detected. However, acceptability of skin humidity de......-crea-sed with increasing relative skin humidity. A model was developed that predicts the percentage of persons dissatisfied due to humid skin as a function of relative skin humidity. The model applies for woven and knitted cot-ton and polyester materials and for activity levels typical for office work. Even at very high...

  11. Highly Sensitive and Fast Response Colorimetric Humidity Sensors Based on Graphene Oxides Film.

    Science.gov (United States)

    Chi, Hong; Liu, Yan Jun; Wang, FuKe; He, Chaobin

    2015-09-16

    Uniform graphene oxide (GO) film for optical humidity sensing was fabricated by dip-coating technique. The resulting GO thin film shows linear optical shifts in the visible range with increase of humidity in the whole relative humidity range (from dry state to 98%). Moreover, GO films exhibit ultrafast sensing to moisture within 250 ms because of the unique atomic thinness and superpermeability of GO sheets. The humidity sensing mechanism was investigated using XRD and computer simulation. The ultrasensitive humidity colorimetric properties of GOs film may enable many potential applications such as disposable humidity sensors for packaging, health, and environmental monitoring.

  12. Development of La3+ Doped CeO2 Thick Film Humidity Sensors

    Directory of Open Access Journals (Sweden)

    Chunjie Wang

    2014-01-01

    Full Text Available The humidity sensitive characteristics of the sensor fabricated from 10 mol% La2O3 doped CeO2 nanopowders with particle size 17.26 nm synthesized via hydrothermal method were investigated at different frequencies. It was found that the sensor shows high humidity sensitivity, rapid response-recovery characteristics, and narrow hysteresis loop at 100 Hz in the relative humidity range from 11% to 95%. The impedance of the sensor decreases by about five orders of magnitude as relative humidity increases. The maximum humidity hysteresis is about 6% RH, and the response and recovery time is 12 and 13 s, respectively. These results indicate that the nanosized La2O3 doped CeO2 powder has potential application as high-performance humidity sensor.

  13. Humidity insensitive TOPAS polymer fiber Bragg grating sensor

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Khan, Lutul; Webb, David J.

    2011-01-01

    We report the first experimental demonstration of a humidity insensitive polymer optical fiber Bragg grating (FBG), as well as the first FBG recorded in a TOPAS polymer optical fiber in the important low loss 850nm spectral region. For the demonstration we have fabricated FBGs with resonance...... wavelength around 850 nm and 1550 nm in single-mode microstructured polymer optical fibers made of TOPAS and the conventional poly (methyl methacrylate) (PMMA). Characterization of the FBGs shows that the TOPAS FBG is more than 50 times less sensitive to humidity than the conventional PMMA FBG in both...... wavelength regimes. This makes the TOPAS FBG very appealing for sensing applications as it appears to solve the humidity sensitivity problem suffered by the PMMA FBG....

  14. Invariant and Absolute Invariant Means of Double Sequences

    Directory of Open Access Journals (Sweden)

    Abdullah Alotaibi

    2012-01-01

    Full Text Available We examine some properties of the invariant mean, define the concepts of strong σ-convergence and absolute σ-convergence for double sequences, and determine the associated sublinear functionals. We also define the absolute invariant mean through which the space of absolutely σ-convergent double sequences is characterized.

  15. Absolute measurement of a tritium standard

    International Nuclear Information System (INIS)

    Hadzisehovic, M.; Mocilnik, I.; Buraei, K.; Pongrac, S.; Milojevic, A.

    1978-01-01

    For the determination of a tritium absolute activity standard, a method of internal gas counting has been used. The procedure involves water reduction by uranium and zinc further the measurement of the absolute disintegration rate of tritium per unit of the effective volume of the counter by a compensation method. Criteria for the choice of methods and procedures concerning the determination and measurement of gaseous 3 H yield, parameters of gaseous hydrogen, sample mass of HTO and the absolute disintegration rate of tritium are discussed. In order to obtain gaseous sources of 3 H (and 2 H), the same reversible chemical reaction was used, namely, the water - uranium hydride - hydrogen system. This reaction was proved to be quantitative above 500 deg C by measuring the yield of the gas obtained and the absolute activity of an HTO standard. A brief description of the measuring apparatus is given, as well as a critical discussion of the brass counter quality and the possibility of obtaining equal working conditions at the counter ends. (T.G.)

  16. Cryogenic, Absolute, High Pressure Sensor

    Science.gov (United States)

    Chapman, John J. (Inventor); Shams. Qamar A. (Inventor); Powers, William T. (Inventor)

    2001-01-01

    A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

  17. A developmental study of latent absolute pitch memory.

    Science.gov (United States)

    Jakubowski, Kelly; Müllensiefen, Daniel; Stewart, Lauren

    2017-03-01

    The ability to recall the absolute pitch level of familiar music (latent absolute pitch memory) is widespread in adults, in contrast to the rare ability to label single pitches without a reference tone (overt absolute pitch memory). The present research investigated the developmental profile of latent absolute pitch (AP) memory and explored individual differences related to this ability. In two experiments, 288 children from 4 to12 years of age performed significantly above chance at recognizing the absolute pitch level of familiar melodies. No age-related improvement or decline, nor effects of musical training, gender, or familiarity with the stimuli were found in regard to latent AP task performance. These findings suggest that latent AP memory is a stable ability that is developed from as early as age 4 and persists into adulthood.

  18. Testing and ground calibration of DREAMS-H relative humidity device

    Science.gov (United States)

    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

  19. Thin plasma-polymerized layers of hexamethyldisiloxane for humidity sensor development

    International Nuclear Information System (INIS)

    Guermat, N.; Bellel, A.; Sahli, S.; Segui, Y.; Raynaud, P.

    2009-01-01

    The response of resistive-type sensors based on thin hexamethyldisiloxane layers to relative humidity (RH) was evaluated. Humidity sensitive layers were plasma polymerized at low frequency glow discharge using a capacitively coupled parallel plate reactor. The sensor design comprises the absorbing layer deposited on clean glass substrate with comb-shape aluminum electrodes (interdigitated structure). The change in electrical impedance of the sensing film was monitored as the device was exposed to humidity. The variation of the plasma-polymerization parameters resulted in different humidity sensing properties which could be correlated to the results of Fourier transform infrared spectroscopy (FTIR). The deposited films exhibited a detectable response to RH ranging from 30 to 95% with low hysteresis, good reproducibility and stability in long-term use. Films with a greater thickness showed a significant decrease in the humidity sensing capability. FTIR analysis revealed the presence of SiH bonding groups, which are frequently linked to the film density. The increase in the plasma discharge power induced also a significant decrease in the diffusion process of water vapor inside the sensitive layer bulk.

  20. Performance limit of daytime radiative cooling in warm humid environment

    Directory of Open Access Journals (Sweden)

    Takahiro Suichi

    2018-05-01

    Full Text Available Daytime radiative cooling potentially offers efficient passive cooling, but the performance is naturally limited by the environment, such as the ambient temperature and humidity. Here, we investigate the performance limit of daytime radiative cooling under warm and humid conditions in Okayama, Japan. A cooling device, consisting of alternating layers of SiO2 and poly(methyl methacrylate on an Al mirror, is fabricated and characterized to demonstrate a high reflectance for sunlight and a selective thermal radiation in the mid-infrared region. In the temperature measurement under the sunlight irradiation, the device shows 3.4 °C cooler than a bare Al mirror, but 2.8 °C warmer than the ambient of 35 °C. The corresponding numerical analyses reveal that the atmospheric window in λ = 16 ∼ 25 μm is closed due to a high humidity, thereby limiting the net emission power of the device. Our study on the humidity influence on the cooling performance provides a general guide line of how one can achieve practical passive cooling in a warm humid environment.

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

    Science.gov (United States)

    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.

  2. Study on radon concentration monitoring using activated charcoal canisters in high humidity environments

    International Nuclear Information System (INIS)

    Wang Yuexing; Wang Haijun; Yang Yifang; Qin Sichang; Wang Zhentao; Zhang Zhenjiang

    2009-01-01

    The effects of humidity on the sensitivity using activated charcoal canisters for measuring radon concentrations in high humidity environments were studied. Every canister filled with 80 g of activated charcoal, and they were exposed to 48 h or 72 h in the relative humidity of 68%, 80%, 88% and 96% (28 degree C), respectively. The amount of radon absorbed in the canisters was determined by counting the gamma rays from 214 Pb and 214 Bi (radon progeny). The results showed that counts decreased with the increase of relative humidity. There was a negative linear relationship between count and humidity. In the relative humidity range of 68%-96%, the sensitivity of radon absorption decreased about 2.4% for every 1% (degree)rise in humidity. The results also showed that the exposure time of the activated charcoal canisters should be less than 3 days. (authors)

  3. Variations of relative humidity in relation to meningitis in Africa

    Science.gov (United States)

    Seefeldt, M. W.; Hopson, T. M.

    2011-12-01

    The meningitis belt is a region covering Sub-Saharan Africa from the Sahel of West Africa eastward to western Ethiopia. The region is prone to meningitis epidemics during the dry season extending from approximately January to May, depending on the region. Relative humidity has been found to be a critical environmental factor indicating the susceptibility of a region to meningitis epidemics. This study evaluates the variation of relative humidity across West Africa over 30 dry-seasons (1979 - 2009) using the NASA-MERRA dataset. The method of self-organizing maps is employed to characterize the changes in relative humidity patterns across the region within a given dry season as well as changes over the 30 years. A general pattern of changes in relative humidity is indicated as the rainbelt retreats to the south at the onset of the dry season and then returns to the region at the end of the dry season. Within each dry season there is a unique pattern. The climatological conditions of relative humidity at the onset of the dry season provide an indication of the moisture environment for the entire dry season. Year to year variation in the relative humidity patterns are found to be gradual. Future applications involve using the results from the SOM evaluation to be used for future decisions involving prevention of meningitis epidemics.

  4. Effect of humidity and interlayer cation on frictional strength of montmorillonite

    Science.gov (United States)

    Tetsuka, H.; Katayama, I.; Sakuma, H.; Tamura, K.

    2016-12-01

    Smectite has been ubiquitously seen in fault gouge (Schleicher et al., 2006; Kuo et al., 2009; Si et al., 2014; Kameda, 2015) and is characteristic by low frictional coefficient (Saffer et al., 2001; Ikari et al., 2007); consequently, it has a key role in fault dynamics. The frictional strength of montmorillonite (a typical type of smectite) is affected by mainly two factors, 1) hydration state and 2) interlayer cation. Previous laboratory experiments have shown that the frictional strength of montmorillonite changes with hydration state (Ikari et al., 2007) and with interlayer cation (Behnsen and Faulkner, 2013). However, experimental study for frictional strengths of interlayer cation-exchanged montmorillonite under controlled hydration state has not been reported. We are developing humidity control system in biaxial friction testing machine and try to investigate the effect of relative humidity and interlayer cation on frictional strength of montmorillonite. The humidity control system consists of two units, 1) the pressure vessel (core holder) unit controlled by a constant temperature and 2) the vapor generating unit controlled by variable temperature. We control relative humidity around sample, which is calculated from the temperature around sample and the vapor pressure at vapor generating unit. Preliminary experiments under controlled humidity show frictional coefficient of montmorillonite decrease with increasing relative humidity. In the meeting, we will report the systematic study of frictional coefficient as function of relative humidity and interlayer cation species.

  5. Analysis scheme of density modulation experiments for particle confinements study

    International Nuclear Information System (INIS)

    Tanaka, K.; Michael, C.; Kawanata, K.; Tokuzawa, T.; Shoji, M.; Toi, K.; Gao, X.; Jie, Y.X.

    2005-01-01

    Density modulation experiments are one of the powerful experimental schemas to study particle confinements. The diffusion coefficients (D) and convection velocity (V), which is impossible to evaluated from particle balance in equilibrium state, can be separately obtained. And the estimated value of D and V are determined independent of absolute value of particle source rate, which is difficult to be obtained experimentally. However sensitivities and interpretation of D and V from modulation experiments should be taken care. In this paper, numerical techniques to solve particle balance equation of modulation components are described. Examples of analysis are shown from the data of LHD. And interpretations of results of modulation experiments are studied. (author)

  6. High temperature humidity sensing materials

    International Nuclear Information System (INIS)

    Tsai, P.P.; Tanase, S.; Greenblatt, M.

    1989-01-01

    This paper reports on new proton conducting materials prepared and characterized for potential applications in humidity sensing at temperatures higher than 100 degrees C by complex impedance or galvanic cell type techniques. Calcium metaphosphate, β-Ca(PO 3 ) 2 as a galvanic cell type sensor material yields reproducible signals in the range from 5 to 200 mm Hg water vapor pressure at 578 degrees C, with short response time (∼ 30 sec). Polycrystalline samples of α-Zr(HPO 4 ) 2 and KMo 3 P 5.8 Si 2 O 25 , and the gel converted ceramic, 0.10Li 2 O-0.25P 2 O 5 -0.65SiO 2 as impedance sensor materials show decreases in impedance with increasing humidity in the range from 9 mm Hg to 1 atm water vapor pressure at 179 degrees C

  7. Humidity evolution (breathing effect) in enclosures with electronics

    DEFF Research Database (Denmark)

    Hygum, Morten Arnfeldt; Popok, Vladimir

    2015-01-01

    Packaging and enclosures used for protecting power electronics operating outdoors are designed to withstand the local climatic and environmental changes. Hermetic enclosures are expensive and therefore other solutions for protecting the electronics from a harsh environment are required. One...... of the dangerous parameters is high humidity of air. Moisture can inevitable reach the electronics either due to diffusion through the wall of an enclosure or small holes, which are designed for electrical or other connections. A driving force for humid air movement is the temperature difference between...... the operating electronics and the surrounding environment. This temperature, thus, gives rise to a natural convection, which we also refer to as breathing. Robust and intelligent enclosure designs must account for this breathing as it can significantly change the humidity distribution in the enclosure...

  8. Advancing Absolute Calibration for JWST and Other Applications

    Science.gov (United States)

    Rieke, George; Bohlin, Ralph; Boyajian, Tabetha; Carey, Sean; Casagrande, Luca; Deustua, Susana; Gordon, Karl; Kraemer, Kathleen; Marengo, Massimo; Schlawin, Everett; Su, Kate; Sloan, Greg; Volk, Kevin

    2017-10-01

    We propose to exploit the unique optical stability of the Spitzer telescope, along with that of IRAC, to (1) transfer the accurate absolute calibration obtained with MSX on very bright stars directly to two reference stars within the dynamic range of the JWST imagers (and of other modern instrumentation); (2) establish a second accurate absolute calibration based on the absolutely calibrated spectrum of the sun, transferred onto the astronomical system via alpha Cen A; and (3) provide accurate infrared measurements for the 11 (of 15) highest priority stars with no such data but with accurate interferometrically measured diameters, allowing us to optimize determinations of effective temperatures using the infrared flux method and thus to extend the accurate absolute calibration spectrally. This program is integral to plans for an accurate absolute calibration of JWST and will also provide a valuable Spitzer legacy.

  9. Calibration of Relative Humidity Sensors using a Dew Point Generator

    OpenAIRE

    Brooks, Milo

    2010-01-01

    A relative humidity sensor can be calibrated using a dew point generator to continuously supply an air stream of known constant humidity and a temperature chamber to control the dew point and ambient temperature.

  10. Desiccant wheel thermal performance modeling for indoor humidity optimal control

    International Nuclear Information System (INIS)

    Wang, Nan; Zhang, Jiangfeng; Xia, Xiaohua

    2013-01-01

    Highlights: • An optimal humidity control model is formulated to control the indoor humidity. • MPC strategy is used to implement the optimal operation solution. • Practical applications of the MPC strategy is illustrated by the case study. - Abstract: Thermal comfort is an important concern in the energy efficiency improvement of commercial buildings. Thermal comfort research focuses mostly on temperature control, but humidity control is an important aspect to maintain indoor comfort too. In this paper, an optimal humidity control model (OHCM) is presented. Model predictive control (MPC) strategy is applied to implement the optimal operation of the desiccant wheel during working hours of a commercial building. The OHCM is revised to apply the MPC strategy. A case is studied to illustrate the practical applications of the MPC strategy

  11. A Humidity-Dependent Lifetime Derating Factor for DC Film Capacitors

    DEFF Research Database (Denmark)

    Wang, Huai; Reigosa, Paula Diaz; Blaabjerg, Frede

    2015-01-01

    accelerated testing of film capacitors under different humidity conditions, enabling a more justified lifetime prediction of film capacitors for DC-link applications under specific climatic environments. The analysis of the testing results and the detailed discussion on the derating factor with different......Film capacitors are widely assumed to have superior reliability performance than Aluminum electrolytic capacitors in DC-link design of power electronic converters. However, the assumption needs to be critically judged especially for applications under high humidity environments. This paper proposes...... a humidity-dependent lifetime derating factor for a type of plastic-boxed metallized DC film capacitors. It overcomes the limitation that the humidity impact is not considered in the state-of-the-art DC film capacitor lifetime models. The lifetime derating factor is obtained based on a total of 8,700 hours...

  12. Effects of PV Module Soiling on Glass Surface Resistance and Potential-Induced Degradation: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hacke, Peter; Burton, Patrick; Hendrickson, Alex; Spartaru, Sergiu; Glick, Stephen; Terwilliger, Kent

    2015-12-03

    The sheet resistance of three soil types (Arizona road dust, soot, and sea salt) on glass were measured by the transmission line method as a function of relative humidity (RH) between 39% and 95% at 60 degrees C. Sea salt yielded a 3.5 order of magnitude decrease in resistance on the glass surface when the RH was increased over this RH range. Arizona road dust showed reduced sheet resistance at lower RH, but with less humidity sensitivity over the range tested. The soot sample did not show significant resistivity change compared to the unsoiled control. Photovoltaic modules with sea salt on their faces were step-stressed between 25% and 95% RH at 60 degrees C applying -1000 V bias to the active cell circuit. Leakage current from the cell circuit to ground ranged between two and ten times higher than that of the unsoiled controls. Degradation rate of modules with salt on the surface increased with increasing RH and time.

  13. A Correction Method for UAV Helicopter Airborne Temperature and Humidity Sensor

    Directory of Open Access Journals (Sweden)

    Longqing Fan

    2017-01-01

    Full Text Available This paper presents a correction method for UAV helicopter airborne temperature and humidity including an error correction scheme and a bias-calibration scheme. As rotor downwash flow brings measurement error on helicopter airborne sensors inevitably, the error correction scheme constructs a model between the rotor induced velocity and temperature and humidity by building the heat balance equation for platinum resistor temperature sensor and the pressure correction term for humidity sensor. The induced velocity of a spatial point below the rotor disc plane can be calculated by the sum of the induced velocities excited by center line vortex, rotor disk vortex, and skew cylinder vortex based on the generalized vortex theory. In order to minimize the systematic biases, the bias-calibration scheme adopts a multiple linear regression to achieve a systematically consistent result with the tethered balloon profiles. Two temperature and humidity sensors were mounted on “Z-5” UAV helicopter in the field experiment. Overall, the result of applying the calibration method shows that the temperature and relative humidity obtained by UAV helicopter closely align with tethered balloon profiles in providing measurements of the temperature profiles and humidity profiles within marine atmospheric boundary layers.

  14. The influence of humidity on the kinetics of local anodic oxidation

    International Nuclear Information System (INIS)

    BartosIk, M; Skoda, D; Tomanec, O; Kalousek, R; Jansky, P; Zlamal, J; Spousta, J; Sikola, T

    2007-01-01

    In this paper the influence of relative humidity on fabrication of nanostructures at GaAs (100) surfaces by local anodic oxidation (LAO) is reported. The attention was paid both to the dimensions of oxide nanolines prepared at different relative humidities for tip-surface voltages of 6 - 9 V and tip speeds of 10 - 200 nm/s, and to the profiles corresponding to line trenches (etched in HCl after the nanoxidation). Contrary to the expectations the height and the half-width of oxide nanolines did not increase with relative humidity in the whole interval from 35% to 90%, but for lower relative humidities (< 50%) the lines were comparable in size to those prepared at 90%. However, this was accompanied with instabilities in the oxidation process resulting most probably from enhanced size variations of the water meniscus between the tip and the surface at these low humidities

  15. High Accuracy Acoustic Relative Humidity Measurement inDuct Flow with Air

    Directory of Open Access Journals (Sweden)

    Cees van der Geld

    2010-08-01

    Full Text Available 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.

  16. Crystallization speed of salbutamol as a function of relative humidity and temperature.

    Science.gov (United States)

    Zellnitz, Sarah; Narygina, Olga; Resch, Christian; Schroettner, Hartmuth; Urbanetz, Nora Anne

    2015-07-15

    Spray dried salbutamol sulphate and salbutamol base particles are amorphous as a result of spray drying. As there is always the risk of recrystallization of amorphous material, the aim of this work is the evaluation of the temperature and humidity dependent recrystallization of spray dried salbutamol sulphate and base. Therefore in-situ Powder X-ray Diffraction (PXRD) studies of the crystallization process at various temperature (25 and 35 °C) and humidity (60%, 70%, 80%, 90% relative humidity) conditions were performed. It was shown that the crystallization speed of salbutamol sulphate and base is a non-linear function of both temperature and relative humidity. The higher the relative humidity the higher is the crystallization speed. At 60% relative humidity salbutamol base as well as salbutamol sulphate were found to be amorphous even after 12 h, however samples changed optically. At 70% and 90% RH recrystallization of salbutamol base is completed after 3 h and 30 min and recrystallization of salbutamol sulphate after 4h and 1h, respectively. Higher temperature (35 °C) also leads to increased crystallization speeds at all tested values of relative humidity. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Rapid, Time-Division Multiplexed, Direct Absorption- and Wavelength Modulation-Spectroscopy

    Directory of Open Access Journals (Sweden)

    Alexander Klein

    2014-11-01

    Full Text Available We present a tunable diode laser spectrometer with a novel, rapid time multiplexed direct absorption- and wavelength modulation-spectroscopy operation mode. The new technique allows enhancing the precision and dynamic range of a tunable diode laser absorption spectrometer without sacrificing accuracy. The spectroscopic technique combines the benefits of absolute concentration measurements using calibration-free direct tunable diode laser absorption spectroscopy (dTDLAS with the enhanced noise rejection of wavelength modulation spectroscopy (WMS. In this work we demonstrate for the first time a 125 Hz time division multiplexed (TDM-dTDLAS-WMS spectroscopic scheme by alternating the modulation of a DFB-laser between a triangle-ramp (dTDLAS and an additional 20 kHz sinusoidal modulation (WMS. The absolute concentration measurement via the dTDLAS-technique allows one to simultaneously calibrate the normalized 2f/1f-signal of the WMS-technique. A dTDLAS/WMS-spectrometer at 1.37 µm for H2O detection was built for experimental validation of the multiplexing scheme over a concentration range from 50 to 3000 ppmV (0.1 MPa, 293 K. A precision of 190 ppbV was achieved with an absorption length of 12.7 cm and an averaging time of two seconds. Our results show a five-fold improvement in precision over the entire concentration range and a significantly decreased averaging time of the spectrometer.

  18. Lower-tropospheric humidity: climatology, trends and the relation to the ITCZ

    Directory of Open Access Journals (Sweden)

    Alexander Läderach

    2013-07-01

    Full Text Available The tropical region is an area of maximum humidity and serves as the major humidity source of the globe. Among other phenomena, it is governed by the so-called Inter-Tropical Convergence Zone (ITCZ which is commonly defined by converging low-level winds or enhanced precipitation. Given its importance as a humidity source, we investigate the humidity fields in the tropics in different reanalysis data sets, deduce the climatology and variability and assess the relationship to the ITCZ. Therefore, a new analysis method of the specific humidity distribution is introduced which allows detecting the location of the humidity maximum, the strength and the meridional extent. The results show that the humidity maximum in boreal summer is strongly shifted northward over the warm pool/Asia Monsoon area and the Gulf of Mexico. These shifts go along with a peak in the strength in both areas; however, the extent shrinks over the warm pool/Asia Monsoon area, whereas it is wider over the Gulf of Mexico. In winter, such connections between location, strength and extent are not found. Still, a peak in strength is again identified over the Gulf of Mexico in boreal winter. The variability of the three characteristics is dominated by inter-annual signals in both seasons. The results using ERA-interim data suggest a positive trend in the Gulf of Mexico/Atlantic region from 1979 to 2010, showing an increased northward shift in the recent years. Although the trend is only weakly confirmed by the results using MERRA reanalysis data, it is in phase with a trend in hurricane activity – a possible hint of the importance of the new method on hurricanes. Furthermore, the position of the maximum humidity coincides with one of the ITCZ in most areas. One exception is the western and central Pacific, where the area is dominated by the double ITCZ in boreal winter. Nevertheless, the new method enables us to gain more insight into the humidity distribution, its variability and

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

    Science.gov (United States)

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

    2017-04-01

    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

  20. Effects of air humidity on ionization chamber response

    International Nuclear Information System (INIS)

    Meger, C.; DeLuca, P.M. Jr.; Pearson, D.W.; Venci, R.

    1983-01-01

    A study of the effect of air humidity on four different ionization chamber cap materials verified earlier studies (Kristensen and Sundbom, 1981; Mijnheer et al., 1983) and extended our understanding of the problem. We found nylon and A-150 plastic caps swell as they absorb water from the air. This accounts for as much as 2.5% increase in ionization response. Graphite chambers readily absorb and desorb water from the air. This creates a problem in maintaining dry air in a wet graphite chamber. Humid air has a different density and W value than dry air (Niatel, 1969, 1975). This decreases the charge collected in a wet graphite chamber. We observe a decrease in response of approximately 2%, a value greater than can be accounted for by these effects alone. Polyethylene chambers are unaffected by humid air. 4 refs., 9 figs

  1. Anomalous water expulsion from carbon-based rods at high humidity

    Science.gov (United States)

    Nune, Satish K.; Lao, David B.; Heldebrant, David J.; Liu, Jian; Olszta, Matthew J.; Kukkadapu, Ravi K.; Gordon, Lyle M.; Nandasiri, Manjula I.; Whyatt, Greg; Clayton, Chris; Gotthold, David W.; Engelhard, Mark H.; Schaef, Herbert T.

    2016-09-01

    Three water adsorption-desorption mechanisms are common in inorganic materials: chemisorption, which can lead to the modification of the first coordination sphere; simple adsorption, which is reversible; and condensation, which is irreversible. Regardless of the sorption mechanism, all known materials exhibit an isotherm in which the quantity of water adsorbed increases with an increase in relative humidity. Here, we show that carbon-based rods can adsorb water at low humidity and spontaneously expel about half of the adsorbed water when the relative humidity exceeds a 50-80% threshold. The water expulsion is reversible, and is attributed to the interfacial forces between the confined rod surfaces. At wide rod spacings, a monolayer of water can form on the surface of the carbon-based rods, which subsequently leads to condensation in the confined space between adjacent rods. As the relative humidity increases, adjacent rods (confining surfaces) in the bundles are drawn closer together via capillary forces. At high relative humidity, and once the size of the confining surfaces has decreased to a critical length, a surface-induced evaporation phenomenon known as solvent cavitation occurs and water that had condensed inside the confined area is released as a vapour.

  2. BPM Offset Determination by Sinusoidal Quadrupole K-modulation

    CERN Document Server

    Baer, T; Wenninger, J

    2011-01-01

    To ensure an adequate orbit steering that maximizes the machine aperture, a good knowledge of the BPM measurement offsets is crucial. During this MD, a sinusoidal k-modulation of individually powered quadrupoles was performed to determine the offsets of the nearby BPMs. An accuracy of 10µm for the determination of the absolute beam position is reached.

  3. Humidity effects on hydrophilic film dosimeter systems

    International Nuclear Information System (INIS)

    Gehringer, P.; Eschweiler, H.; Proksch, E.

    1979-11-01

    At dose-rates typical for 60 Co-gamma irradiation sources the radiation response of hexahydroxyethyl pararosanilin cyanide/50μm nylon radachromic films is dependent upon dose-rate as well as upon the moisture content of the film. Under equilibrium moisture conditions, the response measured at 606 nm 24 hours after end of irradiation shows its highest dose-rate dependence at about 32 % r.h. A decrease in dose-rate from 2.8 to 0.039 Gy.s -1 results in decrease in response by 17%. At higher humidities, the sensitivity of the film as well as the rate dependence decreases and at 86% r.h. no discernible dose-rate effect could be found. At nominal 0 % r.h. a second absorption band at 412 nm appears which is converted completely to an additional 606 nm absorption by exposure to a humid atmosphere. After that procedure the resultant response is somewhat lower but shows almost the same dose-rate dependence as at 32% r.h. Preliminary results concerning the influence of humidity on the response of Blue Cellophane are given, too. (author)

  4. Multi-channel fiber optic dew and humidity sensor

    Science.gov (United States)

    Limodehi, Hamid E.; Mozafari, Morteza; Amiri, Hesam; Légaré, François

    2018-03-01

    In this article, we introduce a multi-channel fiber optic dew and humidity sensor which works using a novel method based on relation between surface plasmon resonance (SPR) and water vapor condensation. The proposed sensor can instantly detect moisture or dew formation through its fiber optic channels, separately situated in different places. It enables to simultaneously measure the ambient Relative Humidity (RH) and dew point temperature of several environments with accuracy of 5%.

  5. Numerical Modelling Of Humid Air Flow Around A Porous Body

    Directory of Open Access Journals (Sweden)

    Bohojło-Wiśniewska Aneta

    2015-09-01

    Full Text Available This paper presents an example of humid air flow around a single head of Chinese cabbage under conditions of complex heat transfer. This kind of numerical simulation allows us to create a heat and humidity transfer model between the Chinese cabbage and the flowing humid air. The calculations utilize the heat transfer model in porous medium, which includes the temperature difference between the solid (vegetable tissue and fluid (air phases of the porous medium. Modelling and calculations were performed in ANSYS Fluent 14.5 software.

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

    Science.gov (United States)

    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.

  7. Effect of humidity and temperature on the survival of Listeria monocytogenes on surfaces.

    Science.gov (United States)

    Redfern, J; Verran, J

    2017-04-01

    Listeria monocytogenes is a pathogenic bacterium, with human disease and infection linked to dairy products, seafood, ready-to-eat meat and raw & undercooked meats. Stainless steel is the most common food preparation surface and therefore, it is important to understand how food storage conditions such as surface materials, temperature and relative humidity can affect survival of L. monocytogenes. In this study, survival of L. monocytogenes on stainless steel was investigated at three temperatures (4, 10 and 21°C), each approx. 11, 50 and 85% humidity. Results indicate that the lower the temperature, the more cells were recovered in all three humidity environments, while medium humidity enhances survival, irrespective of temperature. Lower humidity decreases recovery at all temperatures. These data support the guidance noted above that humidity control is important, and that lower humidity environments are less likely to support retention of viable L. monocytogenes on a stainless steel surface. Understanding survival of potential food-borne pathogens is essential for the safe production and preparation of food. While it has long been 'common knowledge' that relative humidity can affect the growth and survival of micro-organisms, this study systematically describes the survival of L. monocytogenes on stainless steel under varying humidity and temperatures for the first time. The outcomes from this paper will allow those involved with food manufacture and preparation to make informed judgement on environmental conditions relating to humidity control, which is lacking in the food standards guidelines. © 2017 The Society for Applied Microbiology.

  8. NGS Absolute Gravity Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NGS Absolute Gravity data (78 stations) was received in July 1993. Principal gravity parameters include Gravity Value, Uncertainty, and Vertical Gradient. The...

  9. Calculation of humidity parameters and uncertainties using different formulations and softwares

    OpenAIRE

    Orlando, Alcir de Faro; Brionizio, Júlio Dutra; Lima, L. A.

    2004-01-01

    The increase of importance of humidity instruments in the last 10 years brought their applications to several parts of industry, like automotive, pharmaceutical, food and laboratories to comply with regulations and quality requirements. As consequence, there has been a growing interest of manufacturers and secondary laboratories in having more accurate humidity measurements. That was the moment to consider performance evaluation and calibration issues. A humidity calibration laboratory sho...

  10. Absolute isotopic abundances of Ti in meteorites

    International Nuclear Information System (INIS)

    Niederer, F.R.; Papanastassiou, D.A.; Wasserburg, G.J.

    1985-01-01

    The absolute isotope abundance of Ti has been determined in Ca-Al-rich inclusions from the Allende and Leoville meteorites and in samples of whole meteorites. The absolute Ti isotope abundances differ by a significant mass dependent isotope fractionation transformation from the previously reported abundances, which were normalized for fractionation using 46 Ti/ 48 Ti. Therefore, the absolute compositions define distinct nucleosynthetic components from those previously identified or reflect the existence of significant mass dependent isotope fractionation in nature. We provide a general formalism for determining the possible isotope compositions of the exotic Ti from the measured composition, for different values of isotope fractionation in nature and for different mixing ratios of the exotic and normal components. The absolute Ti and Ca isotopic compositions still support the correlation of 50 Ti and 48 Ca effects in the FUN inclusions and imply contributions from neutron-rich equilibrium or quasi-equilibrium nucleosynthesis. The present identification of endemic effects at 46 Ti, for the absolute composition, implies a shortfall of an explosive-oxygen component or reflects significant isotope fractionation. Additional nucleosynthetic components are required by 47 Ti and 49 Ti effects. Components are also defined in which 48 Ti is enhanced. Results are given and discussed. (author)

  11. Studies on the effect of the relative humidity of the atmosphere on the growth and physiology of rice [Oryza sativa] plants, 10: Effect of ambient humidity on the translocation of assimilated 13C in leaves

    International Nuclear Information System (INIS)

    Hirai, G.; Okumura, T.; Takeuchi, S.; Tanaka, O.; Chujo, H.; Tanaka, N.

    1996-01-01

    13C-labeled CO2 was fed to rice seedlings for 60 min in the light under low (60%) or high (90%) humidity. The amount of 13C assimilated by the leaves under high humidity was much greater than that by the plants under low humidity. The 13C-labeled CO2 was fed to the plants for 60 min at 75% humidity and then the plants were kept at 60 or 90% humidity under illumination. In 10 hours after the end of 13C feeding, the amount of 13C and 13C content increased in the roots of the plants kept under high humidity. On the other hand, they increased in the sixth leaf and the transfer of 13C to the roots was very low in the plants kept under low humidity. These results support our previous observations that dry matter production of the plants grown under high humidity was higher than that of the plants grown under low humidity, that the dry matter increase of roots in the plants grown under high humidity was higher than that of the plants grown under low humidity and that the stress caused by low humidity increased the partition of dry matter to the top of plants

  12. Evaluation of RO modules for the SSP ETC/LSS.

    Science.gov (United States)

    Jasionowski, W. J.; Bambenek, R. A.

    1973-01-01

    During the past eight years the NASA Manned Spacecraft Center has supported the development of an Integrated Water and Waste Management System for use in the Space Station Prototype (SSP) Environmental Thermal Control/Life-Support System (ETC/LSS). This system includes the reverse osmosis (RO) process for recycling wash water and the compression distillation process for recovering useable water from urine, urinal flush water, humidity condensate, commode flush water and the wash water concentrated by RO. This paper summarizes the experimental work performed during the past four years to select the best commercially available RO module for this system and to also define which surfactants and germicides are most compatible with the selected module.

  13. Frequency locking of compact laser-diode modules at 633 nm

    Science.gov (United States)

    Nölleke, Christian; Leisching, Patrick; Blume, Gunnar; Jedrzejczyk, Daniel; Pohl, Johannes; Feise, David; Sahm, Alexander; Paschke, Katrin

    2018-02-01

    This work reports on a compact diode-laser module emitting at 633 nm. The emission frequency can be tuned with temperature and current, while optical feedback of an internal DBR grating ensures single-mode operation. The laser diode is integrated into a micro-fabricated package, which includes optics for beam shaping, a miniaturized optical isolator, and a vapor cell as frequency reference. The achieved absolute frequency stability is below 10-8 , while the output power can be more than 10 mW. This compact absolute frequency-stabilized laser system can replace gas lasers and may be integrated in future quantum technology devices.

  14. Relative Humidity Sensing Properties Of Cu2O Doped ZnO Nanocomposite

    International Nuclear Information System (INIS)

    Pandey, N. K.; Tiwari, K.; Tripathi, A.; Roy, A.; Rai, A.; Awasthi, P.

    2009-01-01

    In this paper we report application of Cu 2 O doped ZnO composite prepared by solid state reaction route as humidity sensor. Pellet samples of ZnO-Cu 2 O nanocrystalline powders with 2, 5 and 10 weight% of Cu 2 O in ZnO have been prepared. Pellets have been annealed at temperatures of 200-500 deg. C and exposed to humidity. It is observed that as relative humidity increases, resistance of the pellet decreases for the humidity from 10% to 90%. Sample with 5% of Cu 2 O doped in ZnO and annealed at 500 deg. C shows best results with sensitivity of 1.50 MΩ/%RH. In this case the hysteresis is low and the reproducibility high, making it the suitable candidate for humidity sensing.

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

    Science.gov (United States)

    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.

  16. Change in radiosensitivity of seeds depending on their humidity data and methods of moistening

    International Nuclear Information System (INIS)

    Savin, B.N.; Labrada, A.R.

    1980-01-01

    Investigated was the change in readiosensitivity of maize seeds depending on their humidity, method of moistening and initial humidity before moistening. Maize seeds of Krasnodarskaya 303 TV breed were irradiated with γ-rays. It was shown that seeds of the same humidity had different radiosensitivity depending on the method of moistening. When moistening seeds in water, they had the highest radiostability at 20-24% humidity but when moistening them in exsiccator, this index was the highest at 15% humidity. Along with the method of moistening initial humidity before moistening also effected the radiosensitivity. The necessity to take this factor into account during presowing irradiation was noted

  17. Coupled effects of the temperature and the relative humidity on gecko adhesion

    International Nuclear Information System (INIS)

    Peng, Zhilong; Yang, Yazheng; Chen, Shaohua

    2017-01-01

    To explain the inconsistent results of experiments on temperature-dependent gecko adhesion, a theoretical peeling model is established wherein a nano-thin film is adopted to simulate a gecko spatula. The model considers not only the respective effects of temperature and environmental humidity on the peel-off force but also the coupled effect of both factors. Increasing temperature is found to lead to a decreasing peel-off force if the environmental humidity is uncontrolled. However, if the environmental humidity is constant, the peel-off force is insensitive to the temperature and remains almost constant. The synthetic theoretical analysis demonstrates that the seemingly contradictory results of temperature-dependent gecko adhesion experiments are actually consistent under their respective experimental conditions. This inconsistency is mainly due to the environmental humidity, which varies with the changing temperature if it is not artificially controlled. The results cannot only reasonably explain the different experimental results for the effect of temperature on gecko adhesion but can also facilitate the design of temperature-controlled or humidity-controlled adhesion sensors by tuning the environmental humidity or temperature. (paper)

  18. Test-to-Failure of Crystalline Silicon Modules: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hacke, P.; Terwilliger, K.; Glick, S.; Trudell, D.; Bosco, N.; Johnston, S.; Kurtz, S. R.

    2010-10-01

    Accelerated lifetime testing of five crystalline silicon module designs was carried out according to the Terrestrial Photovoltaic Module Accelerated Test-to-Failure Protocol. This protocol compares the reliability of various module constructions on a quantitative basis. The modules under test are subdivided into three accelerated lifetime testing paths: 85..deg..C/85% relative humidity with system bias, thermal cycling between ?40..deg..C and 85..deg..C, and a path that alternates between damp heat and thermal cycling. The most severe stressor is damp heat with system bias applied to simulate the voltages that modules experience when connected in an array. Positive 600 V applied to the active layer with respect to the grounded module frame accelerates corrosion of the silver grid fingers and degrades the silicon nitride antireflective coating on the cells. Dark I-V curve fitting indicates increased series resistance and saturation current around the maximum power point; however, an improvement in junction recombination characteristics is obtained. Shunt paths and cell-metallization interface failures are seen developing in the silicon cells as determined by electroluminescence, thermal imaging, and I-V curves in the case of negative 600 V bias applied to the active layer. Ability to withstand electrolytic corrosion, moisture ingress, and ion drift under system voltage bias are differentiated.

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

    Science.gov (United States)

    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

  20. Suspension of Egg Hatching Caused by High Humidity and Submergence in Spider Mites.

    Science.gov (United States)

    Ubara, Masashi; Osakabe, Masahiro

    2015-08-01

    We tested the effects of high humidity and submergence on egg hatching of spider mites. In both the high humidity and submergence treatments, many Tetranychus and Panonychus eggs did not hatch until after the hatching peak of the lower humidity or unsubmerged controls. However, after humidity decreased or water was drained, many eggs hatched within 1-3 h. This was observed regardless of when high humidity or submergence treatments were implemented: either immediately after oviposition or immediately before hatching was due. Normal eyespot formation was observed in most eggs in the high humidity and submergence treatments, which indicates that spider mite embryos develop even when eggs are underwater. Therefore, delays in hatching are not caused by delayed embryonic development. A delay in hatching was always observed in Panonychus citri (McGregor) but was more variable in Tetranychus urticae Koch and Tetranychus kanzawai Kishida. The high humidity and submergence treatments affected but did not suppress larval development in these species. In contrast, many Oligonychus eggs died following the high humidity treatments. In Tetranychus and Panonychus spider mites, suspension of egg hatching may mitigate the adverse effects of rainfall. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Investigating Absolute Value: A Real World Application

    Science.gov (United States)

    Kidd, Margaret; Pagni, David

    2009-01-01

    Making connections between various representations is important in mathematics. In this article, the authors discuss the numeric, algebraic, and graphical representations of sums of absolute values of linear functions. The initial explanations are accessible to all students who have experience graphing and who understand that absolute value simply…

  2. The effects of lithographic residues and humidity on graphene field ...

    Indian Academy of Sciences (India)

    humidity at graphene field effect transistors (GFETs). While the exact means of humidity interacting with hydropho- bic graphene remains unknown, this work examines pristine and lithographic-process-applied graphene surfaces with surface ... temperature quantum Hall effect, linear electron dispersion at the vicinity of the ...

  3. Small-scale variability in tropical tropopause layer humidity

    Science.gov (United States)

    Jensen, E. J.; Ueyama, R.; Pfister, L.; Karcher, B.; Podglajen, A.; Diskin, G. S.; DiGangi, J. P.; Thornberry, T. D.; Rollins, A. W.; Bui, T. V.; Woods, S.; Lawson, P.

    2016-12-01

    Recent advances in statistical parameterizations of cirrus cloud processes for use in global models are highlighting the need for information about small-scale fluctuations in upper tropospheric humidity and the physical processes that control the humidity variability. To address these issues, we have analyzed high-resolution airborne water vapor measurements obtained in the Airborne Tropical TRopopause EXperiment over the tropical Pacific between 14 and 20 km. Using accurate and precise 1-Hz water vapor measurements along approximately-level aircraft flight legs, we calculate structure functions spanning horizontal scales ranging from about 0.2 to 50 km, and we compare the water vapor variability in the lower (about 14 km) and upper (16-19 km) Tropical Tropopause Layer (TTL). We also compare the magnitudes and scales of variability inside TTL cirrus versus in clear-sky regions. The measurements show that in the upper TTL, water vapor concentration variance is stronger inside cirrus than in clear-sky regions. Using simulations of TTL cirrus formation, we show that small variability in clear-sky humidity is amplified by the strong sensitivity of ice nucleation rate to supersaturation, which results in highly-structured clouds that subsequently drive variability in the water vapor field. In the lower TTL, humidity variability is correlated with recent detrainment from deep convection. The structure functions indicate approximately power-law scaling with spectral slopes ranging from about -5/3 to -2.

  4. Polymer-embedded stannic oxide nanoparticles as humidity sensors

    International Nuclear Information System (INIS)

    Hatamie, Shadie; Dhas, Vivek; Kale, B.B.; Mulla, I.S.; Kale, S.N.

    2009-01-01

    Stannic oxide (SnO 2 ) nanoparticles have been suspended in polyvinyl alcohol (PVA) matrix in different PVA:SnO 2 molar ratios ranging from 1:1 to 1:5 using simple chemical route. This suspension was deposited on ceramic substrate and upon drying was carefully detached from the substrate. SnO 2 -embedded self-standing, transparent and flexible thin films were hence synthesized. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques show the rutile tetragonal structure of SnO 2 with particle size ∼ 5 nm. UV-Visible spectroscopy demonstrates the band gap of 3.9 eV, which does not alter when embedded in polymer. Fourier transform infrared spectroscopy (FTIR) reveals that the properties of SnO 2 do not modify due to incorporation in the PVA matrix. The structures work as excellent humidity sensors at room temperature. For a critical PVA:SnO 2 molar ratio of 1:3, the resistance changes to five times of magnitude in 92% humidity within fraction of second when compared with resistance at 11% humidity. The sample regains its original resistance almost instantaneously after being removed from humid chamber. Nanodimensions of SnO 2 particles and percolation mechanism related to transport through polymer matrix and water molecule as a carrier has been used to understand the mechanism.

  5. An Inexpensive, Stable, and Accurate Relative Humidity Measurement Method for Challenging Environments.

    Science.gov (United States)

    Zhang, Wei; Ma, Hong; Yang, Simon X

    2016-03-18

    In this research, an improved psychrometer is developed to solve practical issues arising in the relative humidity measurement of challenging drying environments for meat manufacturing in agricultural and agri-food industries. The design in this research focused on the structure of the improved psychrometer, signal conversion, and calculation methods. The experimental results showed the effect of varying psychrometer structure on relative humidity measurement accuracy. An industrial application to dry-cured meat products demonstrated the effective performance of the improved psychrometer being used as a relative humidity measurement sensor in meat-drying rooms. In a drying environment for meat manufacturing, the achieved measurement accuracy for relative humidity using the improved psychrometer was ±0.6%. The system test results showed that the improved psychrometer can provide reliable and long-term stable relative humidity measurements with high accuracy in the drying system of meat products.

  6. Modelling and Control of Ionic Electroactive Polymer Actuators under Varying Humidity Conditions

    Directory of Open Access Journals (Sweden)

    S. Sunjai Nakshatharan

    2018-02-01

    Full Text Available In this work, we address the problem of position control of ionic electroactive polymer soft actuators under varying relative humidity conditions. The impact of humidity on the actuation performance of ionic actuators is studied through frequency response and impedance spectroscopy analysis. Considering the uncertain performance of the actuator under varying humidity conditions, an adaptable model using the neural network method is developed. The model uses relative humidity magnitude as one of the model parameters, making it robust to different environmental conditions. Utilizing the model, a closed-loop controller based on the model predictive controller is developed for position control of the actuator. The developed model and controller are experimentally verified and found to be capable of predicting and controlling the actuators with excellent tracking accuracy under relative humidity conditions varying in the range of 10–90%.

  7. Effects of Humidity and Surfaces on the Melt Crystallization of Ibuprofen

    Directory of Open Access Journals (Sweden)

    Il Won Kim

    2012-08-01

    Full Text Available 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.

  8. Approach To Absolute Zero

    Indian Academy of Sciences (India)

    more and more difficult to remove heat as one approaches absolute zero. This is the ... A new and active branch of engineering ... This temperature is called the critical temperature, Te' For sulfur dioxide the critical ..... adsorbent charcoal.

  9. Low-cost personal cooling in hot humid offices

    DEFF Research Database (Denmark)

    Gunnarsen, Lars Bo; Santos, A.

    This report presents a low cost solution to avoid heat stress in a hot and humid environment based on a solar powered drying of supply air. The air drying facilities and a validation of the benefits through comprehensive human exposure studies are described. The study represents an example...... of applied participative research performed in a developing country. The report may be used as a background for the improvement of the indoor climate in poor, hot and humid regions without increased use of electricity....

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

    Science.gov (United States)

    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.

  11. Effect of Humidity in Air on Performance and Long-Term Durability of SOFCs

    DEFF Research Database (Denmark)

    Hagen, Anke; Chen, Ming; Neufeld, Kai

    2009-01-01

    Anode supported SOFCs based on Ni-YSZ anodes, YSZ electrolytes, and LSM-YSZ cathodes were studied with respect to durability in humid air (~4%) over typically 1500 hours. Operating temperature and current density were varied between 750 and 850 oC and 0.25-0.75 A/cm2, respectively. It was found...... that the introduction of humidity affected the cell voltage under polarization of the cell and that this effect was (at least partly) reversible upon switching off the humidity, probably related to a segregation of impurities towards the three phase boundary in the presence of humidity. Generally, the studied cells...... were successfully operated in humid air under technologically relevant conditions. Improvements at the cathode/electrolyte interface made it possible to obtain highly stable cells, which can be operated under high current density and at 750 oC in humid air - conditions that are known to cause...

  12. Design of a Humidity Sensor Tag for Passive Wireless Applications.

    Science.gov (United States)

    Wu, Xiang; Deng, Fangming; Hao, Yong; Fu, Zhihui; Zhang, Lihua

    2015-10-07

    This paper presents a wireless humidity sensor tag for low-cost and low-power applications. The proposed humidity sensor tag, based on radio frequency identification (RFID) technology, was fabricated in a standard 0.18 μm complementary metal oxide semiconductor (CMOS) process. The top metal layer was deposited to form the interdigitated electrodes, which were then filled with polyimide as the humidity sensing layer. A two-stage rectifier adopts a dynamic bias-voltage generator to boost the effective gate-source voltage of the switches in differential-drive architecture, resulting in a flat power conversion efficiency curve. The capacitive sensor interface, based on phase-locked loop (PLL) theory, employs a simple architecture and can work with 0.5 V supply voltage. The measurement results show that humidity sensor tag achieves excellent linearity, hysteresis and stability performance. The total power-dissipation of the sensor tag is 2.5 μW, resulting in a maximum operating distance of 23 m under 4 W of radiation power of the RFID reader.

  13. Room temperature humidity sensor based on polyaniline-tungsten disulfide composite

    Science.gov (United States)

    Manjunatha, S.; Chethan, B.; Ravikiran, Y. T.; Machappa, T.

    2018-05-01

    Polyaniline-tungsten disulfide (PANI-WS2) composite was synthesized using in situ polymerization technique by adding finely grinded powder of WS2 during the polymerization of aniline. Field emission scanning electron microscopy (FESEM) images showed the granular morphology with porous nature. Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of carbon, nitrogen, chlorine of PANI, tungsten and sulfur elements of WS2. Humidity sensing property of the composite was investigated by plotting change in its resistance with different relative humidity environments ranging from 10 to 97% RH. Decrease in resistance of the composite was observed with increase in relative humidity. Maximum sensing response of the composite was found to be 88.46%. Response and recovery times of the composite at 97%RH were fair enough to fabricate a sensor based on it. Stability of the composite with respect to the humidity sensing behavior was observed to be unchanged even after two months.

  14. MetHumi - Humidity Device for Mars MetNet Lander

    Science.gov (United States)

    Genzer, Maria; Polkko, Jouni; Harri, Ari-Matti; Schmidt, Walter; Leinonen, Jussi; Mäkinen, Teemu; Haukka, Harri

    2010-05-01

    MetNet Mars Mission focused for Martian atmospheric science is based on a new semihard landing vehicle called the MetNet Lander (MNL). The MNL will have a versatile science payload focused on the atmospheric science of Mars. The scientific payload of the MetNet Mission encompasses separate instrument packages for the atmospheric entry and descent phase and for the surface operation phase. MetHumi is the humidity sensor of MetNet Lander designed to work on Martian surface. It is based on Humicap® technology developed by Vaisala, Inc. MetHumi is a capacitive type of sensing device where an active polymer film changes capacitance as function of relative humidity. One MetHumi device package consists of one humidity transducer including three Humicap® sensor heads, an accurate temperature sensor head (Thermocap® by Vaisala, Inc.) and constant reference channels. MetHumi is very small, lightweighed and has low power consumption. It weighs only about 15 g without wires, and consumes 15 mW of power. MetHumi can make meaningful relative humidity measurements in range of 0 - 100%RH down to -70°C ambient temperature, but it survives even -135°C ambient temperature.

  15. Relative Humidity in the Tropopause Saturation Layer

    Science.gov (United States)

    Selkirk, H. B.; Schoeberl, M. R.; Pfister, L.; Thornberry, T. D.; Bui, T. V.

    2017-12-01

    The tropical tropopause separates two very different atmospheric regimes: the stable lower stratosphere where the air is both extremely dry and nearly always so, and a transition layer in the uppermost tropical troposphere, where humidity on average increases rapidly downward but can undergo substantial temporal fluctuations. The processes that control the humidity in this layer below the tropopause include convective detrainment (which can result in either a net hydration or dehydration), slow ascent, wave motions and advection. Together these determine the humidity of the air that eventually passes through the tropopause and into the stratosphere, and we refer to this layer as the tropopause saturation layer or TSL. We know from in situ water vapor observations such as Ticosonde's 12-year balloonsonde record at Costa Rica that layers of supersaturation are frequently observed in the TSL. While their frequency is greatest during the local rainy season from June through October, supersaturation is also observed in the boreal winter dry season when deep convection is well south of Costa Rica. In other words, local convection is not a necessary condition for the presence of supersaturation. Furthermore, there are indications from airborne measurements during the recent POSIDON campaign at Guam that if anything deep convection tends to `reset' the TSL locally to a state of just-saturation. Conversely, it may be that layers of supersaturation are the result of slow ascent. To explore these ideas we take Ticosonde water vapor observations from the TSL, stratify them on the basis of relative humidity and report on the differences in the the history of upstream convective influence between supersaturated parcels and those that are not.

  16. Humidity measurement using alpha-ray and beta-ray

    International Nuclear Information System (INIS)

    Matsumoto, Shigeaki; Kobayashi, Hisanobu

    1981-01-01

    Two new hygrometers using radioisotopes were proposed, and the results of tests are described. The one is a dew-point hygrometer utilizing the backscattering phenomena of beta-ray by dew, and the other is a hygrometer by measuring the variation of ionization current by alpha ray due to humidity. The backscattering of beta-ray depends on the atomic number of scatters and the energy of beta-ray. Therefore, the backscattering from dew on a gold plate is different from that from the gold itself. The temperature dependence of the backscattering intensity was measured with a GM counter. Decrease of the intensity was seen at the dew point. A control circuit was designed to measure the dew point automatically. The error of the measurement was within 1 degree C. An alpha-ray ionization hygrometer was constructed. The dependence of ionization current on humidity was measured with an operational amplifier. The resolution of humidity measurement was within 5 percent. (Kato, T.)

  17. Humidity effects on surface dielectric barrier discharge for gaseous naphthalene decomposition

    Science.gov (United States)

    Abdelaziz, Ayman A.; Ishijima, Tatsuo; Seto, Takafumi

    2018-04-01

    Experiments are performed using dry and humid air to clarify the effects of water vapour on the characteristics of surface dielectric barrier discharge (SDBD) and investigate its impact on the performance of the SDBD for decomposition of gaseous naphthalene in air stream. The current characteristics, including the discharge and the capacitive currents, are deeply analyzed and the discharge mechanism is explored. The results confirmed that the humidity affected the microdischarge distribution without affecting the discharge mode. Interestingly, it is found that the water vapour had a significant influence on the capacitance of the reactor due to its deposition on the discharge electrode and the dielectric, which, in turn, affects the power loss in the dielectric and the total power consumed in the reactor. Thus, the factor of the humidity effect on the power loss in the dielectric should be considered in addition to its effect on the attachment coefficient. Additionally, there was an optimum level of the humidity for the decomposition of naphthalene in the SDBD, and its value depended on the gas composition, where the maximum naphthalene decomposition efficiency in O2/H2O is achieved at the humidity level ˜10%, which was lower than that obtained in air/H2O (˜28%). The results also revealed that the role of the humidity in the decomposition efficiency was not significant in the humidified O2 at high power level. This was attributed to the significant increase in oxygen-derived species (such as O atoms and O3) at high power, which was enough to overcome the negative effects of the humidity.

  18. Temperature insensitive hysteresis free highly sensitive polymer optical fiber Bragg grating humidity sensor

    DEFF Research Database (Denmark)

    Woyessa, Getinet; Nielsen, Kristian; Stefani, Alessio

    2016-01-01

    The effect of humidity on annealing of poly (methyl methacrylate) (PMMA) based microstructured polymer optical fiber Bragg gratings (mPOFBGs) and the resulting humidity responsivity are investigated. Typically annealing of PMMA POFs is done in an oven without humidity control around 80°C...

  19. Cross Linking Polymers (PVA & PEG with TiO2 Nanoparticles for Humidity Sensing

    Directory of Open Access Journals (Sweden)

    Monika Joshi

    2009-11-01

    Full Text Available Humidity Sensors of different types are being used for various applications. Resistive Humidity Sensor has advantage over others for being small, low cost, interchangeable and long term stable. This makes them suitable for industrial, commercial and residential applications. In the present investigation humidity sensing behavior of various composite films made of Polyvinyl Alcohol (PVA, Polyethylene glycol (PEG, alkalies and oxide nanoparticles has been studied. It was found that relationship of resistance v/s relative humidity (RH was linear from 40 RH to 60 RH for a composite film made of PVA + PEG+ alkalies .The film can work with reliable efficiency for more than 100 days for the above range of humidity at room temperature. In order to improve the efficiency of composite polymer film TiO2 nanoparticles were added in the film and studied for resistance vs. RH responses. It was found that humidity range expands from 30 RH to 65 RH indicating the proportional decrease in resistance with increase in humidity at both ends as a result of the presence of TiO2 nanoparticles. The composite film with TiO2 nanoparticles can thus be used for wider range of humidity with reasonable stability and consistency. The observed behavior of the film has been attributed to the transportation of charge through TiO2 nanoparticles enhancing the conduction with the cross linked polymers.

  20. Absolute spectrophotometry of Nova Cygni 1975

    International Nuclear Information System (INIS)

    Kontizas, E.; Kontizas, M.; Smyth, M.J.

    1976-01-01

    Radiometric photoelectric spectrophotometry of Nova Cygni 1975 was carried out on 1975 August 31, September 2, 3. α Lyr was used as reference star and its absolute spectral energy distribution was used to reduce the spectrophotometry of the nova to absolute units. Emission strengths of Hα, Hβ, Hγ (in W cm -2 ) were derived. The Balmer decrement Hα:Hβ:Hγ was compared with theory, and found to deviate less than had been reported for an earlier nova. (author)

  1. Effects of Humidity and Surfaces on the Melt Crystallization of Ibuprofen

    OpenAIRE

    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 t...

  2. Possible stretched exponential parametrization for humidity absorption in polymers.

    Science.gov (United States)

    Hacinliyan, A; Skarlatos, Y; Sahin, G; Atak, K; Aybar, O O

    2009-04-01

    Polymer thin films have irregular transient current characteristics under constant voltage. In hydrophilic and hydrophobic polymers, the irregularity is also known to depend on the humidity absorbed by the polymer sample. Different stretched exponential models are studied and it is shown that the absorption of humidity as a function of time can be adequately modelled by a class of these stretched exponential absorption models.

  3. The Pragmatics of "Unruly" Dative Absolutes in Early Slavic

    Directory of Open Access Journals (Sweden)

    Daniel E. Collins

    2011-08-01

    Full Text Available This chapter examines some uses of the dative absolute in Old Church Slavonic and in early recensional Slavonic texts that depart from notions of how Indo-European absolute constructions should behave, either because they have subjects coreferential with the (putative main-clause subjects or because they function as if they were main clauses in their own right. Such "noncanonical" absolutes have generally been written off as mechanistic translations or as mistakes by scribes who did not understand the proper uses of the construction. In reality, the problem is not with literalistic translators or incompetent scribes but with the definition of the construction itself; it is quite possible to redefine the Early Slavic dative absolute in a way that accounts for the supposedly deviant cases. While the absolute is generally dependent semantically on an adjacent unit of discourse, it should not always be regarded as subordinated syntactically. There are good grounds for viewing some absolutes not as dependent clauses but as independent sentences whose collateral character is an issue not of syntax but of the pragmatics of discourse.

  4. Humidification during high-frequency oscillatory ventilation for adults: a bench study.

    Science.gov (United States)

    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.

  5. Kinetic model of vibrational relaxation in a humid-air pulsed corona discharge

    International Nuclear Information System (INIS)

    Komuro, Atsushi; Ono, Ryo; Oda, Tetsuji

    2010-01-01

    The effect of humidity on the vibrational relaxation of O 2 (v) and N 2 (v) in a humid-air pulsed corona discharge is studied using a kinetic model. We previously showed that humidity markedly increases the vibration-to-translation (V-T) rate of molecules in a humid-air pulsed corona discharge by measuring O 2 (v) density (Ono et al 2010 Plasma Sources Sci. Technol. 19 015009). In this paper, we numerically calculate the vibrational kinetics of O 2 , N 2 and H 2 O to study the reason behind the acceleration of V-T in the presence of humidity. The calculation closely reproduces the measured acceleration of V-T due to humidity, and shows that the increase in the V-T rate is caused by the fast vibration-to-vibration (V-V) processes of O 2 -H 2 O and N 2 -H 2 O and the subsequent rapid V-T process of H 2 O-H 2 O. In addition, it is shown that O atom density is also important in the vibrational kinetics owing to the rapid V-T process of O 2 -O.

  6. Strategies for humidity control

    Energy Technology Data Exchange (ETDEWEB)

    Baumgarth, S

    1987-01-01

    Humidity and temperature control in air-conditioning systems mostly involves coupled closed-loop control circuits. The author discusses their uncoupling and resulting consequences as well as energy-optimized control of recirculation air flaps or enthalpy recovering systems (h-x control) in detail. Special reference is made of the application of the DDC technology and its scope, limits and preconditions. In conclusions, the author presents pertinent measurement results. (orig.).

  7. Fuel Oxidizer Reaction Products (FORP) Contamination of Service Module (SM) and Release of N-nitrosodimethylamine(NDMA)in a Humid Environment from Crew EVA Suits Contaminated with FORP

    Science.gov (United States)

    Schmidl, William; Mikatarian, Ron; Lam, Chiu-Wing; West, Bil; Buchanan, Vanessa; Dee, Louis; Baker, David; Koontz, Steve

    2004-01-01

    The Service Module (SM) is an element of the Russian Segment of the International Space Station (ISS). One of the functions of the SM is to provide attitude control for the ISS using thrusters when the U.S. Control Moment Gyros (CMG's) must be desaturated. Prior to an Extravehicular Activity (EVA) on the Russian Segment, the Docking Compartment (DC1) is depressurized, as it is used as an airlock. When the DC1 is depressurized, the CMG's margin of momentum is insufficient and the SM attitude control thrusters need to fire to desaturate the CMG's. SM roll thruster firings induce contamination onto adjacent surfaces with Fuel Oxidizer Reaction Products (FORP). FORP is composed of both volatile and non-volatile components. One of the components of FORP is the potent carcinogen N-nitrosdimethylamine (NDMA). Since the EVA crewmembers often enter the area surrounding the thrusters for tasks on the aft end of the SM and when translating to other areas of the Russian Segment, the presence of FORP is a concern. This paper will discuss FORP contamination of the SM surfaces, the release of NDMA in a humid environment from crew EVA suits, if they happen to be contaminated with FORP, and the toxicological risk associated with the NDMA release.

  8. Absolutyzm i pluralizm (ABSOLUTISM AND PLURALISM

    Directory of Open Access Journals (Sweden)

    Renata Ziemińska

    2005-06-01

    Full Text Available Alethic absolutism is a thesis that propositions can not be more or less true, that they are true or false for ever (if true at all and that their truth is independent on any circumstances of their assertion. In negative version, easier to defend, alethic absolutism claims the very same proposition can not be both true and false relative to circumstances of its assertion. Simple alethic pluralism is a thesis that we have many concepts of truth. It is a very good way to dissolve the controversy between alethic relativism and absolutism. Many philosophical concepts of truth are the best reason for such pluralism. If concept is meaning of a name, we have many concepts of truth because the name 'truth' was understood in many ways. The variety of meanings however can be superficial. Under it we can find one idea of truth expressed in correspondence truism or schema (T. The content of the truism is too poor to be content of anyone concept of truth, so it usually is connected with some picture of the world (ontology and we have so many concepts of truth as many pictures of the world. The authoress proposes the hierarchical pluralism with privileged classic (or correspondence in weak sense concept of truth as absolute property.Other author's publications:

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

  11. Sensor Fabrication Method for in Situ Temperature and Humidity Monitoring of Light Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Chi-Yuan Lee

    2010-04-01

    Full Text Available 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.

  12. A physically based analytical spatial air temperature and humidity model

    Science.gov (United States)

    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...

  13. Introducing the Mean Absolute Deviation "Effect" Size

    Science.gov (United States)

    Gorard, Stephen

    2015-01-01

    This paper revisits the use of effect sizes in the analysis of experimental and similar results, and reminds readers of the relative advantages of the mean absolute deviation as a measure of variation, as opposed to the more complex standard deviation. The mean absolute deviation is easier to use and understand, and more tolerant of extreme…

  14. Development of TGS2611 methane sensor and SHT11 humidity and temperature sensor for measuring greenhouse gas on peatlands in south kalimantan, indonesia

    Science.gov (United States)

    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

  15. Development of TGS2611 methane sensor and SHT11 humidity and temperature sensor for measuring greenhouse gas on peatlands in South Kalimantan, indonesia

    International Nuclear Information System (INIS)

    Sugriwan, I; Soesanto, O

    2017-01-01

    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 cm 3 . 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 V RL = 0.561 ln n – 2.2641 volt, with n is a various concentrations and V RL in volt. The microcontroller maintained the voltage signal than interfaced it to liquid crystal displays and personal computer (laptop) to display result of the

  16. Fabrication of Porous Silicon Based Humidity Sensing Elements on Paper

    Directory of Open Access Journals (Sweden)

    Tero Jalkanen

    2015-01-01

    Full Text Available A roll-to-roll compatible fabrication process of porous silicon (pSi based sensing elements for a real-time humidity monitoring is described. The sensing elements, consisting of printed interdigitated silver electrodes and a spray-coated pSi layer, were fabricated on a coated paper substrate by a two-step process. Capacitive and resistive responses of the sensing elements were examined under different concentrations of humidity. More than a three orders of magnitude reproducible decrease in resistance was measured when the relative humidity (RH was increased from 0% to 90%. A relatively fast recovery without the need of any refreshing methods was observed with a change in RH. Humidity background signal and hysteresis arising from the paper substrate were dependent on the thickness of sensing pSi layer. Hysteresis in most optimal sensing element setup (a thick pSi layer was still noticeable but not detrimental for the sensing. In addition to electrical characterization of sensing elements, thermal degradation and moisture adsorption properties of the paper substrate were examined in connection to the fabrication process of the silver electrodes and the moisture sensitivity of the paper. The results pave the way towards the development of low-cost humidity sensors which could be utilized, for example, in smart packaging applications or in smart cities to monitor the environment.

  17. High-resolution humidity profiles retrieved from wind profiler radar measurements

    Science.gov (United States)

    Saïd, Frédérique; Campistron, Bernard; Di Girolamo, Paolo

    2018-03-01

    The retrieval of humidity profiles from wind profiler radars has already been documented in the past 30 years and is known to be neither as straightforward and nor as robust as the retrieval of the wind velocity. The main constraint to retrieve the humidity profile is the necessity to combine measurements from the wind profiler and additional measurements (such as observations from radiosoundings at a coarser time resolution). Furthermore, the method relies on some assumptions and simplifications that restrict the scope of its application. The first objective of this paper is to identify the obstacles and limitations and solve them, or at least define the field of applicability. To improve the method, we propose using the radar capacity to detect transition levels, such as the top level of the boundary layer, marked by a maximum in the radar reflectivity. This forces the humidity profile from the free troposphere and from the boundary layer to coincide at this level, after an optimization of the calibration coefficients, and reduces the error. The resulting mean bias affecting the specific humidity profile never exceeds 0.25 g kg-1. The second objective is to explore the capability of the algorithm to retrieve the humidity vertical profiles for an operational purpose by comparing the results with observations from a Raman lidar.

  18. MoS2-modified ZnO quantum dots nanocomposite: Synthesis and ultrafast humidity response

    International Nuclear Information System (INIS)

    Ze, Lu; Yueqiu, Gong; Xujun, Li; Yong, Zhang

    2017-01-01

    Highlights: • MoS 2 @ZnO QDs composite structure was synthesized by two-steps methods. • Ultrafast humidity sensing response is achieved by MoS 2 @ZnO QDs humidity sensor. • Sensor performs excellent cycle stability from 11% to 95% RH. • Humidity sensor could detect wide humidity range (11–95%). - Abstract: In this work, ZnO quantum dots (QDs), layered MoS 2 and MoS 2 -modified ZnO QDs (MoS 2 @ZnO QDs) nanocomposite were synthesized and then applied as humidity sensor. The crystal structure, morphology and element distribution of ZnO QDs, MoS 2 and MoS 2 @ZnO QDs were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectrometry, respectively. The humidity sensing characteristics of the MoS 2 and MoS 2 @ZnO QDs against various relative humidity were measured at room temperature. The results show that the MoS 2 @ZnO QDs sensor exhibits high sensitivity with an impedance variation of three or four orders of magnitude to relative humidity range of 11–95% and it exhibits a short response-recovery time (1 s for adsorption and 20 s for desorption) and excellent repeatability. The mechanisms of the excellent performance for humidity sensing of MoS 2 @ZnO QDs sensor were discussed based on its impedance properties. Our work could offer guidelines to design higher performance especially ultrafast humidity response sensor utilizing the nanocomposite structure with two dimensional material and QDs.

  19. Evolution of temperature and humidity in an underground repository over the exploitation period

    International Nuclear Information System (INIS)

    Benet, L.V.; Tulita, C.; Calsyn, L.; Wendling, J.

    2012-01-01

    Document available in extended abstract form only. The ANDRA waste repository will be operated for about a hundred years. During this period, the ventilation scheme will follow the development of the different storage zones. The ventilation system will ensure adequate air condition for the staff in the working zone and prevent high humidity and temperature damageable for the infrastructures. The untreated incoming air is characterized by great temperature and humidity variations in time, between day and night as well as between winter and summer time. The air from the surface enters the repository through the supply shaft and flows in full section along the main galleries of the central zone until the storage zones. In each storage zone, the air is distributed between storage modules via access galleries and collected at the outflow of each module before being extracted from the repository, retreated and finally released into the atmosphere. Throughout its journey within the repository, the ventilation air will undergo a set of temperature and moisture changes by interacting with its host environment. The aim of this study is to foresee how the air condition will evolve in time all over the exploitation period, along the ventilation network. Air condition assessment in the waste repository has been achieved by means of numerical simulation and analyzed in terms of bulk temperature and moisture in the air and on contact with walls. The physical modeling takes into account (i) air/wall heat exchanges due to forced and free advection, (ii) advection flux in the air, (iii) thermal storage and conduction flux into concrete structure and host rock, (iv) condensation flux on the wall, (v) time functions of wall evaporation flux and (vi) climate variations data from 7 years of meteorological measurements at the site of Bure. In bi-flux galleries, air/air heat exchanges between incoming air in full section and outgoing air through ceiling ducts are modeled. Temperature and

  20. Fringe image analysis based on the amplitude modulation method.

    Science.gov (United States)

    Gai, Shaoyan; Da, Feipeng

    2010-05-10

    A novel phase-analysis method is proposed. To get the fringe order of a fringe image, the amplitude-modulation fringe pattern is carried out, which is combined with the phase-shift method. The primary phase value is obtained by a phase-shift algorithm, and the fringe-order information is encoded in the amplitude-modulation fringe pattern. Different from other methods, the amplitude-modulation fringe identifies the fringe order by the amplitude of the fringe pattern. In an amplitude-modulation fringe pattern, each fringe has its own amplitude; thus, the order information is integrated in one fringe pattern, and the absolute fringe phase can be calculated correctly and quickly with the amplitude-modulation fringe image. The detailed algorithm is given, and the error analysis of this method is also discussed. Experimental results are presented by a full-field shape measurement system where the data has been processed using the proposed algorithm. (c) 2010 Optical Society of America.

  1. Computational speech segregation based on an auditory-inspired modulation analysis

    DEFF Research Database (Denmark)

    May, Tobias; Dau, Torsten

    2014-01-01

    A monaural speech segregation system is presented that estimates the ideal binary mask from noisy speech based on the supervised learning of amplitude modulation spectrogram (AMS) features. Instead of using linearly scaled modulation filters with constant absolute bandwidth, an auditory- inspired...... about speech activity present in neighboring time-frequency units. In order to evaluate the generalization performance of the system to unseen acoustic conditions, the speech segregation system is trained with a limited set of low signal-to-noise ratio (SNR) conditions, but tested over a wide range...

  2. Absolute calibration in vivo measurement systems

    International Nuclear Information System (INIS)

    Kruchten, D.A.; Hickman, D.P.

    1991-02-01

    Lawrence Livermore National Laboratory (LLNL) is currently investigating a new method for obtaining absolute calibration factors for radiation measurement systems used to measure internally deposited radionuclides in vivo. Absolute calibration of in vivo measurement systems will eliminate the need to generate a series of human surrogate structures (i.e., phantoms) for calibrating in vivo measurement systems. The absolute calibration of in vivo measurement systems utilizes magnetic resonance imaging (MRI) to define physiological structure, size, and composition. The MRI image provides a digitized representation of the physiological structure, which allows for any mathematical distribution of radionuclides within the body. Using Monte Carlo transport codes, the emission spectrum from the body is predicted. The in vivo measurement equipment is calibrated using the Monte Carlo code and adjusting for the intrinsic properties of the detection system. The calibration factors are verified using measurements of existing phantoms and previously obtained measurements of human volunteers. 8 refs

  3. Model, Proxy and Isotopic Perspectives on the East African Humid Period

    Science.gov (United States)

    Tierney, Jessica E.; Lewis, Sophie C.; Cook, Benjamin I.; LeGrande, Allegra N.; Schmidt, Gavin A.

    2011-01-01

    Both North and East Africa experienced more humid conditions during the early and mid-Holocene epoch (11,000-5000yr BP; 11-5 ka) relative to today. The North African Humid Period has been a major focus of paleoclimatic study, and represents a response of the hydrological cycle to the increase in boreal summer insolation and associated ocean, atmosphere and land surface feedbacks. Meanwhile, the mechanisms that caused the coeval East African Humid Period are poorly understood. Here, we use results from isotopeenabled coupled climate modeling experiments to investigate the cause of the East African Humid Period. The modeling results are interpreted alongside proxy records of both water balance and the isotopic composition of rainfall. Our simulations show that the orbitally-induced increase in dry season precipitation and the subsequent reduction in precipitation seasonality can explain the East African Humid Period, and this scenario agrees well with regional lake level and pollen paleoclimate data. Changes in zonal moisture flux from both the Atlantic and Indian Ocean account for the simulated increase in precipitation from June through November. Isotopic paleoclimate data and simulated changes in moisture source demonstrate that the western East African Rift Valley in particular experienced more humid conditions due to the influx of Atlantic moisture and enhanced convergence along the Congo Air Boundary. Our study demonstrates that zonal changes in moisture advection are an important determinant of climate variability in the East African region.

  4. The impact of relative humidity and atmospheric pressure on mortality in Guangzhou, China.

    Science.gov (United States)

    Ou, Chun Quan; Yang, Jun; Ou, Qiao Qun; Liu, Hua Zhang; Lin, Guo Zhen; Chen, Ping Yan; Qian, Jun; Guo, Yu Ming

    2014-12-01

    Although many studies have examined the effects of ambient temperatures on mortality, little evidence is on health impacts of atmospheric pressure and relative humidity. This study aimed to assess the impacts of atmospheric pressure and relative humidity on mortality in Guangzhou, China. This study included 213,737 registered deaths during 2003-2011 in Guangzhou, China. A quasi-Poisson regression with a distributed lag non-linear model was used to assess the effects of atmospheric pressure/relative humidity. We found significant effect of low atmospheric pressure/relative humidity on mortality. There was a 1.79% (95% confidence interval: 0.38%-3.22%) increase in non-accidental mortality and a 2.27% (0.07%-4.51%) increase in cardiovascular mortality comparing the 5th and 25th percentile of atmospheric pressure. A 3.97% (0.67%-7.39%) increase in cardiovascular mortality was also observed comparing the 5th and 25th percentile of relative humidity. Women were more vulnerable to decrease in atmospheric pressure and relative humidity than men. Age and education attainment were also potential effect modifiers. Furthermore, low atmospheric pressure and relative humidity increased temperature-related mortality. Both low atmospheric pressure and relative humidity are important risk factors of mortality. Our findings would be helpful to develop health risk assessment and climate policy interventions that would better protect vulnerable subgroups of the population. Copyright © 2014 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  5. Hydrogen Detection With a Gas Sensor Array – Processing and Recognition of Dynamic Responses Using Neural Networks

    Directory of Open Access Journals (Sweden)

    Gwiżdż Patryk

    2015-03-01

    Full Text Available An array consisting of four commercial gas sensors with target specifications for hydrocarbons, ammonia, alcohol, explosive gases has been constructed and tested. The sensors in the array operate in the dynamic mode upon the temperature modulation from 350°C to 500°C. Changes in the sensor operating temperature lead to distinct resistance responses affected by the gas type, its concentration and the humidity level. The measurements are performed upon various hydrogen (17-3000 ppm, methane (167-3000 ppm and propane (167-3000 ppm concentrations at relative humidity levels of 0-75%RH. The measured dynamic response signals are further processed with the Discrete Fourier Transform. Absolute values of the dc component and the first five harmonics of each sensor are analysed by a feed-forward back-propagation neural network. The ultimate aim of this research is to achieve a reliable hydrogen detection despite an interference of the humidity and residual gases.

  6. Incorrect Weighting of Absolute Performance in Self-Assessment

    Science.gov (United States)

    Jeffrey, Scott A.; Cozzarin, Brian

    Students spend much of their life in an attempt to assess their aptitude for numerous tasks. For example, they expend a great deal of effort to determine their academic standing given a distribution of grades. This research finds that students use their absolute performance, or percentage correct as a yardstick for their self-assessment, even when relative standing is much more informative. An experiment shows that this reliance on absolute performance for self-evaluation causes a misallocation of time and financial resources. Reasons for this inappropriate responsiveness to absolute performance are explored.

  7. Integrated passive and wireless sensor for magnetic fields, temperature and humidity

    KAUST Repository

    Li, Bodong; Yassine, Omar; Kosel, Jü rgen

    2013-01-01

    This paper presents a surface acoustic wave-based passive and wireless sensor that can measure magnetic field, temperature and humidity. A thin film giant magnetoimpedance sensor, a thermally sensitive LiNbO3 substrate and a humidity sensitive hydrogel are integrated together with a surface acoustic wave transducer to realize the multifunctional sensor. The device is characterized using a network analyzer under sequentially changing humidity, temperature and magnetic field conditions. The first hand results show the sensor response to all three sensing parameters with small temperature interference on the magnetic signals. © 2013 IEEE.

  8. Effects of atmospheric humidity on uptake of elemental iodine by plants

    International Nuclear Information System (INIS)

    Angeletti, L.; Guenot, J.; Caput, C.

    1983-01-01

    A laboratory study was performed under controlled experimental conditions in order to evaluate the effects of the relative humidity and the exposure time on the velocity of deposition of vapour iodine onto aerials parts of plants. The results show that: - the deposition velocity increases by a factor of 2 for each increase of relative humidity of 25%, - the deposition velocity is independent of the exposure time. The foliar uptake of vapour iodine seems to be related both to stomatal opening and cuticular sorption. The importance of cuticular sorption increases rapidly with the relative humidity [fr

  9. Integrated passive and wireless sensor for magnetic fields, temperature and humidity

    KAUST Repository

    Li, Bodong

    2013-11-01

    This paper presents a surface acoustic wave-based passive and wireless sensor that can measure magnetic field, temperature and humidity. A thin film giant magnetoimpedance sensor, a thermally sensitive LiNbO3 substrate and a humidity sensitive hydrogel are integrated together with a surface acoustic wave transducer to realize the multifunctional sensor. The device is characterized using a network analyzer under sequentially changing humidity, temperature and magnetic field conditions. The first hand results show the sensor response to all three sensing parameters with small temperature interference on the magnetic signals. © 2013 IEEE.

  10. Long-term corrosion/oxidation studies under controlled humidity conditions

    International Nuclear Information System (INIS)

    Gdowski, G.

    1997-01-01

    Independent of thermal loading scenarios, the waste packages at the potential repository at Yucca Mountain, Nevada will be exposed to environmental conditions where there is the possibility of significant water film formation occurring on the waste packages. Water films can cause aggressive aqueous film electrochemical corrosion on susceptible metals or alloys. Water film formation will be facilitated when relative humidities are high, when hygroscopic salts are present on the surfaces, when corrosion products are hygroscopic, and when particles form crevices with the surfaces (capillary effect). Also certain gaseous contaminants, such as, NO x and SO 2 , can facilitate water film formation. It should be noted that water film formation can occur at isolated spots (e.g. surface defects and salt particles) and need not cover the entire surface for electrochemical corrosion to occur. This activity will characterize the long term corrosion of metal specimens at two nominal relative humidities (50 and 85%) and at 80 C. Under the low relative humidity (50%) condition, water film formation is expected to be limited and therefore aqueous film electrochemical corrosion is expected also to be limited. Under the high relative humidity (85%) condition, significant water film formation is expected to occur under some test conditions, and subsequently aqueous film electrochemical corrosion will occur on susceptible materials

  11. Modulation of Late Cretaceous and Cenozoic climate by variable drawdown of atmospheric pCO2 from weathering of basaltic provinces on continents drifting through the equatorial humid belt

    Directory of Open Access Journals (Sweden)

    D. V. Kent

    2013-03-01

    Full Text Available The small reservoir of carbon dioxide in the atmosphere (pCO2 that modulates climate through the greenhouse effect reflects a delicate balance between large fluxes of sources and sinks. The major long-term source of CO2 is global outgassing from sea-floor spreading, subduction, hotspot activity, and metamorphism; the ultimate sink is through weathering of continental silicates and deposition of carbonates. Most carbon cycle models are driven by changes in the source flux scaled to variable rates of ocean floor production, but ocean floor production may not be distinguishable from being steady since 180 Ma. We evaluate potential changes in sources and sinks of CO2 for the past 120 Ma in a paleogeographic context. Our new calculations show that decarbonation of pelagic sediments by Tethyan subduction contributed only modestly to generally high pCO2 levels from the Late Cretaceous until the early Eocene, and thus shutdown of this CO2 source with the collision of India and Asia at the early Eocene climate optimum at around 50 Ma was inadequate to account for the large and prolonged decrease in pCO2 that eventually allowed the growth of significant Antarctic ice sheets by around 34 Ma. Instead, variation in area of continental basalt terranes in the equatorial humid belt (5° S–5° N seems to be a dominant factor controlling how much CO2 is retained in the atmosphere via the silicate weathering feedback. The arrival of the highly weatherable Deccan Traps in the equatorial humid belt at around 50 Ma was decisive in initiating the long-term slide to lower atmospheric pCO2, which was pushed further down by the emplacement of the 30 Ma Ethiopian Traps near the equator and the southerly tectonic extrusion of SE Asia, an arc terrane that presently is estimated to account for 1/4 of CO2 consumption from all basaltic provinces that account for ~1/3 of the total CO2 consumption by continental silicate weathering (Dessert et al., 2003. A negative climate

  12. Retrieval of relative humidity from CSIR-NLC mobile LIDAR backscatter measurements

    CSIR Research Space (South Africa)

    Tesfaye, M

    2009-09-01

    Full Text Available data was collected over 23 hours. The above data sets were used to determine the retrieved relative humidity and compared with Irene (near to Pretoria) weather balloon humidity measurements. The results of the comparative study are presented...

  13. Experimental study of humidity distribution inside electronic enclosure and effect of internal heating

    DEFF Research Database (Denmark)

    Conseil, Helene; Jellesen, Morten Stendahl; Ambat, Rajan

    2016-01-01

    on the humidity and temperature profile inside typical electronic enclosures. Defined parameters include external temperature and humidity conditions, temperature and time of the internal heat cycle, thermal mass, and ports/openings size. The effect of the internal humidity on electronic reliability has been......Corrosion reliability of electronic products is a key factor for electronics industry, and today there is a large demand for performance reliability in a wide range of temperature and humidity during day and night time periods. Corrosion failures are still a challenge due to the combined effects...... of temperature, humidity and corrosion accelerating species in the atmosphere. Moreover the surface region of printed circuit board assemblies is often contaminated by various aggressive chemical species.This study describes the overall effect of the exposure to severe climate conditions and internal heat cycles...

  14. Correction for Metastability in the Quantification of PID in Thin-film Module Testing: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hacke, Peter L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Johnston, Steven [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Spataru, Sergiu [Aalborg University

    2017-10-01

    A fundamental change in the analysis for the accelerated stress testing of thin-film modules is proposed, whereby power changes due to metastability and other effects that may occur due to the thermal history are removed from the power measurement that we obtain as a function of the applied stress factor. The power of reference modules normalized to an initial state - undergoing the same thermal and light- exposure history but without the applied stress factor such as humidity or voltage bias - is subtracted from that of the stressed modules. For better understanding and appropriate application in standardized tests, the method is demonstrated and discussed for potential-induced degradation testing in view of the parallel-occurring but unrelated physical mechanisms that can lead to confounding power changes in the module.

  15. Calibration of a neutron probe for determining the humidity in deep alluvial soils

    International Nuclear Information System (INIS)

    Ferrer, A.; Rivero, H.; Lopez, F.; Cantillo, O.

    1993-01-01

    Preliminary data for the calibration of a neutron probe in deep alluvial soils for determining the humidity are reported. Comparisons of Neutron flow behaviour with the depth of the land are established. A characteristic curve of amount of detected neutrons according to the humidity percentage (from 50 to 100 % of the field humidity) is obtained

  16. The impact of temperature and humidity on perception and emission of indoor air pollutants

    DEFF Research Database (Denmark)

    Fang, Lei; Clausen, Geo; Fanger, Povl Ole

    1996-01-01

    Sensory response to air polluted by five building materials under different combinations of temperature and humidity in the ranges 18°C-28°C and 30%-70% was studied in the laboratory. The experiments were designed to study separately the impact of temperature and humidity on the perception of air...... polluted by materials, and on the emission of pollutants from the materials. At all tested pollution levels of the five materials, the air was perceived significantly less acceptable with increasing temperature and humidity, and the impact of temperature and humidity on perception decreased with increasing...... pollution level. A significant linear correlation between acceptability and enthalpy of the air was found to describe the influence of temperature and humidity on perception. The impact of temperature and humidity on sensory emission was less significant than the impact on perception; however, the sensory...

  17. Passive Wireless SAW Humidity Sensors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal describes the preliminary development of passive wireless surface acoustic wave (SAW) based humidity sensors for NASA application to distributed...

  18. Autogenous Deformation and Change of the Relative Humidity in Silica Fume-Modified Cement Paste

    DEFF Research Database (Denmark)

    Jensen, Ole mejlhede; Hansen, Per Freiesleben

    1996-01-01

    Even during sealed curing and at a constant temperature a hardening cement paste will deform and the relative humidity within its pores will lower. This autogenous deformation and autogenous relative humidity change may be so significant that the cement paste cracks if the deformation is restrained....... This article focuses on the influence of silica fume addition on autogenous deformation and autogenous relative humidity change. Continuous measurement of autogenous deformation and autogenous relative humidity change for more than 1 year and 1« years, respectively, was performed. The investigations show...... thatsilica fume addition markedly increases the autogenous shrinkage as well as the autogenous relative humidity change....

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  1. 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.

    Science.gov (United States)

    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 Phumidity 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.

  2. Absolute instrumental neutron activation analysis at Lawrence Livermore Laboratory

    International Nuclear Information System (INIS)

    Heft, R.E.

    1977-01-01

    The Environmental Science Division at Lawrence Livermore Laboratory has in use a system of absolute Instrumental Neutron Activation Analysis (INAA). Basically, absolute INAA is dependent upon the absolute measurement of the disintegration rates of the nuclides produced by neutron capture. From such disintegration rate data, the amount of the target element present in the irradiated sample is calculated by dividing the observed disintegration rate for each nuclide by the expected value for the disintegration rate per microgram of the target element that produced the nuclide. In absolute INAA, the expected value for disintegration rate per microgram is calculated from nuclear parameters and from measured values of both thermal and epithermal neutron fluxes which were present during irradiation. Absolute INAA does not depend on the concurrent irradiation of elemental standards but does depend on the values for thermal and epithermal neutron capture cross-sections for the target nuclides. A description of the analytical method is presented

  3. Impact of Humidity on In Vitro Human Skin Permeation Experiments for Predicting In Vivo Permeability.

    Science.gov (United States)

    Ishida, Masahiro; Takeuchi, Hiroyuki; Endo, Hiromi; Yamaguchi, Jun-Ichi

    2015-12-01

    In vitro skin permeation studies have been commonly conducted to predict in vivo permeability for the development of transdermal therapeutic systems (TTSs). We clarified the impact of humidity on in vitro human skin permeation of two TTSs having different breathability and then elucidated the predictability of in vivo permeability based on in vitro experimental data. Nicotinell(®) TTS(®) 20 and Frandol(®) tape 40mg were used as model TTSs in this study. The in vitro human skin permeation experiments were conducted under humidity levels similar to those used in clinical trials (approximately 50%) as well as under higher humidity levels (approximately 95%). The skin permeability values of drugs at 95% humidity were higher than those at 50% humidity. The time profiles of the human plasma concentrations after TTS application fitted well with the clinical data when predicted based on the in vitro permeation parameters at 50% humidity. On the other hand, those profiles predicted based on the parameters at 95% humidity were overestimated. The impact of humidity was higher for the more breathable TTS; Frandol(®) tape 40mg. These results show that in vitro human skin permeation experiments should be investigated under realistic clinical humidity levels especially for breathable TTSs. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  4. Relationship of the moisture content of Finnish wheat flour and relative humidity

    Directory of Open Access Journals (Sweden)

    Yu-Yen Linko

    1968-01-01

    Full Text Available Changes in the moisture content of Finnish commercial wheat flour stored at variable relative humidities, representing the conditions typical of flour storage in Finland, were investigated. It could be shown that flour of 15 % moisture at the time of packing tends to dry considerably during normal storage conditions. Owing to the hysteresis effect, the moisture content of once dried flour is not likely to reach detrimental levels during normal storage, even if the relative humidity would exceed the critical level of 75—80 % for short periods. Minimum warehouse relative humidity was observed during Januay, at which time flour moisture had decreased to 6.7 %. The equilibrium humidity for flour of 15 % original moisture content was found to be about 70 %.

  5. Absolute Navigation Information Estimation for Micro Planetary Rovers

    Directory of Open Access Journals (Sweden)

    Muhammad Ilyas

    2016-03-01

    Full Text Available This paper provides algorithms to estimate absolute navigation information, e.g., absolute attitude and position, by using low power, weight and volume Microelectromechanical Systems-type (MEMS sensors that are suitable for micro planetary rovers. Planetary rovers appear to be easily navigable robots due to their extreme slow speed and rotation but, unfortunately, the sensor suites available for terrestrial robots are not always available for planetary rover navigation. This makes them difficult to navigate in a completely unexplored, harsh and complex environment. Whereas the relative attitude and position can be tracked in a similar way as for ground robots, absolute navigation information, unlike in terrestrial applications, is difficult to obtain for a remote celestial body, such as Mars or the Moon. In this paper, an algorithm called the EASI algorithm (Estimation of Attitude using Sun sensor and Inclinometer is presented to estimate the absolute attitude using a MEMS-type sun sensor and inclinometer, only. Moreover, the output of the EASI algorithm is fused with MEMS gyros to produce more accurate and reliable attitude estimates. An absolute position estimation algorithm has also been presented based on these on-board sensors. Experimental results demonstrate the viability of the proposed algorithms and the sensor suite for low-cost and low-weight micro planetary rovers.

  6. Colorimetric humidity sensor based on liquid composite materials for the monitoring of food and pharmaceuticals.

    Science.gov (United States)

    Bridgeman, Devon; Corral, Javier; Quach, Ashley; Xian, Xiaojun; Forzani, Erica

    2014-09-09

    Using supported ionic-liquid membrane (SILM)-inspired methodologies, we have synthesized, characterized, and developed a humidity sensor by coating a liquid composite material onto a hygroscopic, porous substrate. Similar to pH paper, the sensor responds to the environment's relative humidity and changes color accordingly. The humidity indicator is prepared by casting a few microliters of low-toxicity reagents on a nontoxic substrate. The sensing material is a newly synthesized liquid composite that comprises a hygroscopic medium for environmental humidity capture and a color indicator that translates the humidity level into a distinct color change. Sodium borohydride was used to form a liquid composite medium, and DenimBlu30 dye was used as a redox indicator. The liquid composite medium provides a hygroscopic response to the relative humidity, and DenimBlu30 translates the chemical changes into a visual change from yellow to blue. The borate-redox dye-based humidity sensor was prepared, and then Fourier transform infrared spectroscopy, differential scanning calorimetry, and image analysis methods were used to characterize the chemical composition, optimize synthesis, and gain insight into the sensor reactivity. Test results indicated that this new sensing material can detect relative humidity in the range of 5-100% in an irreversible manner with good reproducibility and high accuracy. The sensor is a low-cost, highly sensitive, easy-to-use humidity indicator. More importantly, it can be easily packaged with products to monitor humidity levels in pharmaceutical and food packaging.

  7. Human-Finger Electronics Based on Opposing Humidity-Resistance Responses in Carbon Nanofilms

    KAUST Repository

    Tai, Yanlong; Lubineau, Gilles

    2017-01-01

    Carbon nanomaterials have excellent humidity sensing properties. Here, it is demonstrated that multiwalled carbon-nanotube (MWCNT)- and reduced-graphene-oxide (rGO)-based conductive films have opposite humidity/electrical resistance responses

  8. The influence of humidity on strengths and durability of light guides fibers

    International Nuclear Information System (INIS)

    Karimov, S.N.; Kuksenko, V.S.; Sultonov, U.; Abdumanonov, A.; Shamsidinov, M.I.

    1993-01-01

    Humidity influence on durability and light water durability fibres is studied are studied in this article. Humidity energy under influence of process destruction decreases activity, durability and durability decreases is shown

  9. Systematic approach for the calibration of humidity sensitive polyimide recoated fibre Bragg gratings for measuring humidity and temperature and their application for measuring moisture absorption in polymers

    International Nuclear Information System (INIS)

    Young, T J; Lodeiro, M J; Gower, M R L; Sassi, M B

    2013-01-01

    This paper describes a systematic method for calibrating polyimide recoated fibre Bragg grating (FBG) optical fibres and the associated models used to measure temperature and relative humidity (RH) from 20 to 70 °C and 20% RH to 80% RH. The method was validated by comparing known values of temperature and RH with calculated values from two FBG sensors with different thicknesses of polyimide recoat. Results show good agreement, with a standard deviation error of 0.5 °C and 4.8% RH for temperature and humidity respectively. Drift in the measured wavelength was observed for both thicknesses of polyimide coating under the combined effect of elevated temperature and high humidity. This drift was reversed after a reduction in the humidity. Additional results are provided on the use of embedded polyimide recoated FBG optical fibres for measuring moisture ingress within polymers and composites. (paper)

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

    Science.gov (United States)

    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 body temperature decreased from 36.5 +/- 0.1 degrees C to 33.8 +/- 0.2 degrees C following precooling (P 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.

  11. Effect of the irradiation temperature and relative humidity on PVG dosifilm

    International Nuclear Information System (INIS)

    Jia Haishun; Chen Wenxiu; Shen Yuxin

    1999-01-01

    The effect of environmental factors, such as irradiation temperature and relative humidity, on the PVG dosifilm irradiated by EB was tested. Experiments show that the temperature coefficient of irradiated PVG dosifilm was 0.008 deg. C -1 from 20 deg. C to 55 deg. C, and the humidity coefficient was 0.006 per r.h. (%) from r.h. 0% to 76%. The PVG dosifilm can be used as a routine dosimeter for dose measurement for low-energy EB processing. The absorbed dose values for various irradiation temperature and humidity can be corrected based on experimental data. (author)

  12. Effect of Humid Aging on the Oxygen Adsorption in SnO₂ Gas Sensors.

    Science.gov (United States)

    Suematsu, Koichi; Ma, Nan; Watanabe, Ken; Yuasa, Masayoshi; Kida, Tetsuya; Shimanoe, Kengo

    2018-01-16

    To investigate the effect of aging at 580 °C in wet air (humid aging) on the oxygen adsorption on the surface of SnO₂ particles, the electric properties and the sensor response to hydrogen in dry and humid atmospheres for SnO₂ resistive-type gas sensors were evaluated. The electric resistance in dry and wet atmospheres at 350 °C was strongly increased by humid aging. From the results of oxygen partial pressure dependence of the electric resistance, the oxygen adsorption equilibrium constants ( K ₁; for O - adsorption, K ₂; for O 2- adsorption) were estimated on the basis of the theoretical model of oxygen adsorption. The K ₁ and K ₂ in dry and wet atmospheres at 350 °C were increased by humid aging at 580 °C, indicating an increase in the adsorption amount of both O - and O 2- . These results suggest that hydroxyl poisoning on the oxygen adsorption is suppressed by humid aging. The sensor response to hydrogen in dry and wet atmosphere at 350 °C was clearly improved by humid aging. Such an improvement of the sensor response seems to be caused by increasing the oxygen adsorption amount. Thus, the humid aging offers an effective way to improve the sensor response of SnO₂ resistive-type gas sensors in dry and wet atmospheres.

  13. Floral humidity as a reliable sensory cue for profitability assessment by nectar-foraging hawkmoths.

    Science.gov (United States)

    von Arx, Martin; Goyret, Joaquín; Davidowitz, Goggy; Raguso, Robert A

    2012-06-12

    Most research on plant-pollinator communication has focused on sensory and behavioral responses to relatively static cues. Floral rewards such as nectar, however, are dynamic, and foraging animals will increase their energetic profit if they can make use of floral cues that more accurately indicate nectar availability. Here we document such a cue--transient humidity gradients--using the night blooming flowers of Oenothera cespitosa (Onagraceae). The headspace of newly opened flowers reaches levels of about 4% above ambient relative humidity due to additive evapotranspirational water loss through petals and water-saturated air from the nectar tube. Floral humidity plumes differ from ambient levels only during the first 30 min after anthesis (before nectar is depleted in wild populations), whereas other floral traits (scent, shape, and color) persist for 12-24 h. Manipulative experiments indicated that floral humidity gradients are mechanistically linked to nectar volume and therefore contain information about energy rewards to floral visitors. Behavioral assays with Hyles lineata (Sphingidae) and artificial flowers with appropriate humidity gradients suggest that these hawkmoth pollinators distinguish between subtle differences in relative humidity when other floral cues are held constant. Moths consistently approached and probed flowers with elevated humidity over those with ambient humidity levels. Because floral humidity gradients are largely produced by the evaporation of nectar itself, they represent condition-informative cues that facilitate remote sensing of floral profitability by discriminating foragers. In a xeric environment, this level of honest communication should be adaptive when plant reproductive success is pollinator limited, due to intense competition for the attention of a specialized pollinator.

  14. Floral humidity as a reliable sensory cue for profitability assessment by nectar-foraging hawkmoths

    Science.gov (United States)

    von Arx, Martin; Goyret, Joaquín; Davidowitz, Goggy; Raguso, Robert A.

    2012-01-01

    Most research on plant–pollinator communication has focused on sensory and behavioral responses to relatively static cues. Floral rewards such as nectar, however, are dynamic, and foraging animals will increase their energetic profit if they can make use of floral cues that more accurately indicate nectar availability. Here we document such a cue—transient humidity gradients—using the night blooming flowers of Oenothera cespitosa (Onagraceae). The headspace of newly opened flowers reaches levels of about 4% above ambient relative humidity due to additive evapotranspirational water loss through petals and water-saturated air from the nectar tube. Floral humidity plumes differ from ambient levels only during the first 30 min after anthesis (before nectar is depleted in wild populations), whereas other floral traits (scent, shape, and color) persist for 12–24 h. Manipulative experiments indicated that floral humidity gradients are mechanistically linked to nectar volume and therefore contain information about energy rewards to floral visitors. Behavioral assays with Hyles lineata (Sphingidae) and artificial flowers with appropriate humidity gradients suggest that these hawkmoth pollinators distinguish between subtle differences in relative humidity when other floral cues are held constant. Moths consistently approached and probed flowers with elevated humidity over those with ambient humidity levels. Because floral humidity gradients are largely produced by the evaporation of nectar itself, they represent condition-informative cues that facilitate remote sensing of floral profitability by discriminating foragers. In a xeric environment, this level of honest communication should be adaptive when plant reproductive success is pollinator limited, due to intense competition for the attention of a specialized pollinator. PMID:22645365

  15. New test and characterization methods for PV modules and cells

    Energy Technology Data Exchange (ETDEWEB)

    Van Aken, B.; Sommeling, P. [ECN Solar Energy, Petten (Netherlands); Scholten, H. [Solland, Heerlen (Netherlands); Muller, J. [Moser-Baer, Eindhoven (Netherlands); Grossiord, N. [Holst Centre, Eindhoven (Netherlands); Smits, C.; Blanco Mantecon, M. [Holland Innovative, Eindhoven (Netherlands); Verheijen, M.; Van Berkum, J. [Philips Innovation Services, Eindhoven (Netherlands)

    2012-08-15

    The results of the project geZONd (shared facility for solar module analysis and reliability testing) are described. The project was set up by Philips, ECN, Holst, Solland, OM and T and Holland Innovative. The partners have shared most of their testing and analysis equipment for PV modules and cells, and together developed new or improved methods (including the necessary application know-how). This enables faster and more efficient innovation projects for each partner, and via commercial exploitation for other interested parties. The project has concentrated on five failure modes: corrosion, delamination, moisture ingress, UV irradiation, and mechanical bending. Test samples represented all main PV technologies: wafer based PV and rigid and flexible thin-film PV. Breakthroughs are in very early detection of corrosion, in quantitative characterization of adhesion, in-situ detection of humidity and oxygen inside modules, and ultra-fast screening of materials on UV stability.

  16. Coexistence of Dunes and Humid Conditions at Titan's Tropics

    Science.gov (United States)

    Radebaugh, Jani; Lorenz, R. D.; Lunine, J. I.; Kirk, R. L.; Ori, G. G.; Farr, T. G.; Malaska, M.; Le Gall, A.; Liu, Z. Y. C.; Encrenaz, P. J.; Paillou, P.; Hayes, A.; Lopes, R. M. C.; Turtle, E. P.; Wall, S. D.; Stofan, E. R.; Wood, C. A.; Cassini RADAR Team

    2012-10-01

    At Titan's equatorial latitudes there are tens of thousands of dunes, a landform typical of desert environments where sand does not become anchored by vegetation or fluids. Model climate simulations predict generally dry conditions at the equator and humid conditions near the poles of Titan, where lakes of methane/ethane are found. However, moderate relative methane humidity was observed at the Huygens landing site, recent rainfall was seen by Cassini ISS near the Belet Sand Sea, and a putative transient lake in Shangri-La was observed by Cassini VIMS, all of which indicate abundant fluids may be present, at least periodically, at Titan's equatorial latitudes. Terrestrial observations and studies demonstrate dunes can exist and migrate in conditions of high humidity. Active dunes are found in humid climates, indicating the movement of sand is not always prohibited by the presence of fluids. Sand mobility is related to precipitation, evaporation and wind speed and direction. If dune surfaces become wetted by rainfall or rising subsurface fluids, they can become immobilized. However, winds can act to dry the uppermost layers, freeing sands for saltation and enabling dune migration in wet conditions. Active dunes are found in tropical NE Brazil and NE Australia, where there are alternating dry and wet periods, a condition possible for Titan's tropics. Rising and falling water levels lead to the alteration of dune forms, mainly from being anchored by vegetation, but also from cementation by carbonates or clays. Studies of Titan's dunes, which could undergo anchoring of organic sediments by hydrocarbon fluids, could inform the relative strength of vegetation vs. cementation at humid dune regions on Earth. Furthermore, a comprehensive survey of dune morphologies near regions deemed low by SARTopo and stereo, where liquids may collect in wet conditions, could reveal if bodies of liquid have recently existed at Titan's tropics.

  17. TiO2-TiO2 composite resistive humidity sensor: ethanol crosssensitivity

    International Nuclear Information System (INIS)

    Ghalamboran, Milad; Saedi, Yasin

    2016-01-01

    The fabrication method and characterization results of a TiO 2 -TiO 2 composite bead used for humidity sensing along with its negative cross-sensitivity to ethanol vapor are reported. The bead shaped resistive sample sensors are fabricated by the drop-casting of a TiO 2 slurry on two Pt wire segments. The dried bead is pre-fired at 750°C and subsequently impregnated with a Ti-based sol. The sample is ready for characterization after a thermal annealing at 600°C in air. Structurally, the bead is a composite of the micron-sized TiO 2 crystallites embedded in a matrix of nanometric TiO 2 particle aggregates. The performance of the beads as resistive humidity sensors is recorded at room temperature in standard humidity level chambers. Results evince the wide dynamic range of the sensors fabricated in the low relative humidity range. While the sensor conductance is not sensitive to ethanol vapor in dry air, in humid air, sensor's responses are negatively affected by the contaminant. (paper)

  18. AC Response to Humidity and Propane of Sprayed Fe-Zn Oxide Films

    Directory of Open Access Journals (Sweden)

    Alejandro AVILA-GARCÍA

    2009-09-01

    Full Text Available Iron-zinc oxide films with different Zn contents were ultrasonically sprayed on glass substrates and inter-digital gold electrodes were evaporated upon them. Films were deposited from solutions containing 2, 10 and 30 at. % Zn. Hematite, amorphous and Franklinite structures turned out, respectively. They were assessed as humidity and propane detectors under alternating-current conditions for frequencies from 1 to 105 Hz and temperatures 30 and 250 oC. Their impedances in dry air, humid air and humid air plus propane were determined from voltage measurements with a Lock-In amplifier. Sensitivities to humidity (53 % RH. and 189, 500 and 786 ppm of propane from the response of the resistance, reactance and also the total impedance were determined as functions of frequency. The maximum sensitivity to humidity ranges from 24 % up to 308 %. For propane, the maximum sensitivity ranges from 45 % up to 711 %. The largest sensitivity values correspond in all cases to reactance. From the dynamical response, the response and recovery times are determined, along with the concentration-dependence of the sensitivity. The sensing mechanisms are commented.

  19. Exploiting the igloo principle and greenhouse effect to regulate humidity and temperature

    Directory of Open Access Journals (Sweden)

    Prabhu Karthick

    2006-01-01

    Full Text Available Background: Toxic epidermal necrolysis can be fatal and nursing care with careful monitoring of temperature and humidity can improve survival rate. We adapted the greenhouse and igloo principle using a common hood to monitor the temperature and humidity. Methods: A small heater with a regulator was placed in a mini hood and temperature was recorded inside the uncovered hood and hood covered with green cloth and aluminium foil separately. The regular hood was placed over a volunteer and the temperature was measured inside the open hood and hood covered with green cloth and aluminium foil separately. The relative humidity was also monitored using Zeal mercury dry - wet bulb hygrometer. Results: Temperature increase was most marked in the foil-covered hood followed by cloth-covered hood, both with the heater and the volunteer. Similarly, in the volunteer study, the humidity was best maintained inside the aluminium foil-covered hood. Conclusion: We recommend the use of regular hood with suitable cover to monitor the humidity and temperature of patients with toxic epidermal necrolysis.

  20. Absolute-magnitude distributions of supernovae

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, Dean; Wright, John [Department of Physics, Xavier University of Louisiana, New Orleans, LA 70125 (United States); Jenkins III, Robert L. [Applied Physics Department, Richard Stockton College, Galloway, NJ 08205 (United States); Maddox, Larry, E-mail: drichar7@xula.edu [Department of Chemistry and Physics, Southeastern Louisiana University, Hammond, LA 70402 (United States)

    2014-05-01

    The absolute-magnitude distributions of seven supernova (SN) types are presented. The data used here were primarily taken from the Asiago Supernova Catalogue, but were supplemented with additional data. We accounted for both foreground and host-galaxy extinction. A bootstrap method is used to correct the samples for Malmquist bias. Separately, we generate volume-limited samples, restricted to events within 100 Mpc. We find that the superluminous events (M{sub B} < –21) make up only about 0.1% of all SNe in the bias-corrected sample. The subluminous events (M{sub B} > –15) make up about 3%. The normal Ia distribution was the brightest with a mean absolute blue magnitude of –19.25. The IIP distribution was the dimmest at –16.75.

  1. Fiber optic humidity sensor using water vapor condensation.

    Science.gov (United States)

    Limodehi, Hamid E; Légaré, François

    2017-06-26

    The rate of vapor condensation on a solid surface depends on the ambient relative humidity (RH). Also, surface plasmon resonance (SPR) on a metal layer is sensitive to the refractive index change of its adjacent dielectric. The SPR effect appears as soon as a small amount of moisture forms on the sensor, resulting in a decrease in the amount of light transmitted due to plasmonic loss. Using this concept, we developed a fiber optic humidity sensor based on SPR. It can measure the ambient RH over a dynamic range from 10% to 85% with an accuracy of 3%.

  2. Influence of Temperature and Humidity on Bakelite Resistivity

    CERN Document Server

    Arnaldi, R; Barret, V; Bastid, N; Blanchard, G; Chiavassa, E; Cortese, P; Crochet, Philippe; Dellacasa, G; De Marco, N; Dupieux, P; Espagnon, B; Fargeix, J; Ferretti, A; Gallio, M; Lamoine, L; Luquin, Lionel; Manso, F; Mereu, P; Métivier, V; Musso, A; Oppedisano, C; Piccotti, A; Rahmani, A; Royer, L; Roig, O; Scalas, E; Scomparin, E; Vercellin, Ermanno

    1999-01-01

    Presentation made at RPC99 and submitted to Elsevier PreprintThe use of phenolic or melaminic bakelite as RPC electrodes is widespread. The electrode resistivity is an important parameter for the RPC performance. As recent studies have pointed out, the bakelite resistivity changes with temperature and is influenced by humidity. In order to gain a quantitative understanding on the influence of temperature and humidity on RPC electrodes, we assembled an apparatus to measure resistivity in well-controlled conditions. A detailed description of the experimental set-up as well as the first resistivity measurements for various laminates in different environmental conditions are presented.

  3. Calibration with Absolute Shrinkage

    DEFF Research Database (Denmark)

    Øjelund, Henrik; Madsen, Henrik; Thyregod, Poul

    2001-01-01

    In this paper, penalized regression using the L-1 norm on the estimated parameters is proposed for chemometric je calibration. The algorithm is of the lasso type, introduced by Tibshirani in 1996 as a linear regression method with bound on the absolute length of the parameters, but a modification...

  4. Effect of feed-gas humidity on nitrogen atmospheric-pressure plasma jet for biological applications.

    Science.gov (United States)

    Stephan, Karl D; McLean, Robert J C; DeLeon, Gian; Melnikov, Vadim

    2016-11-14

    We investigate the effect of feed-gas humidity on the oxidative properties of an atmospheric-pressure plasma jet using nitrogen gas. Plasma jets operating at atmospheric pressure are finding uses in medical and biological settings for sterilization and other applications involving oxidative stress applied to organisms. Most jets use noble gases, but some researchers use less expensive nitrogen gas. The feed-gas water content (humidity) has been found to influence the performance of noble-gas plasma jets, but has not yet been systematically investigated for jets using nitrogen gas. Low-humidity and high-humidity feed gases were used in a nitrogen plasma jet, and the oxidation effect of the jet was measured quantitatively using a chemical dosimeter known as FBX (ferrous sulfate-benzoic acid-xylenol orange). The plasma jet using high humidity was found to have about ten times the oxidation effect of the low-humidity jet, as measured by comparison with the addition of measured amounts of hydrogen peroxide to the FBX dosimeter. Atmospheric-pressure plasma jets using nitrogen as a feed gas have a greater oxidizing effect with a high level of humidity added to the feed gas.

  5. Wireless sensor for temperature and humidity measurement

    Science.gov (United States)

    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.

  6. Development of ceramic humidity sensor for the Korean next generation reactor

    International Nuclear Information System (INIS)

    Lee, Na Young; Hwang, Il Soon; Yoo, Han Ill; Song, Chang Rock; Park, Sang Duk; Yang, Jun Seog

    1997-01-01

    For the Korean Next Generation Reactor(KNGR) development, LBB is considered for the Main Steam Line(MSL) piping inside its containment to achieve cost and safety improvement. To apply LBB concept to MSL, leak sensors highly sensitive to humidity is required. In this paper, a ceramic material, MgCr 2 O 4 -TiO 2 has been developed as a humidity sensor for MSL applications. Experiments performed to characterize the electrical conductivity shows that the conductivity of MgCr 2 O 4 -TiO 2 responds sensitively to both temperature and humidity changes. At a constant temperature below 100 .deg. C, the conductivity increases as the relative humidity increases, which makes the sensor favorable for application to the outside of MSL insulation layer. But as temperature increases beyond 100 .deg. C, the sensor composition should be adjusted for the application to KNGR is to be made at temperature above 100 .deg. C

  7. Morphological and Relative Humidity Sensing Properties of Pure ZnO Nanomaterial

    Directory of Open Access Journals (Sweden)

    N. K. Pandey

    2010-11-01

    Full Text Available In this paper we report the resistive type humidity sensing properties of pure ZnO nanomaterial prepared by solid-state reaction method. Pellets of pure ZnO nanocrystalline powder have been made with 10 weight % of glass powder at pressure of 260 MPa by hydraulic press machine for 3 hours. These pellets have been sintered at temperatures 200 °C - 500 °C in an electric muffle furnace for 3 hours at heating rate of 5°C/min. After sintering, these pellets have been exposed to humidity in a specially designed humidity chamber at room temperature. It has been observed that as relative humidity increases, resistance of the pellets decreases for entire range of humidity i.e. 10 % to 90 %. The sensing element of ZnO shows best results with sensitivity of 11.13 MΩ/%RH for the annealing temperature of 400 °C. This sensing element manifests lower hysteresis, less effect of aging and high reproducibility for annealing temperature 400 °C. SEM micrographs show that the sensing elements manifest porous structure with a network of pores that are expected to provide sites for humidity adsorption. The average grain size calculated from SEM micrograph is 236 nm. XRD pattern shows peaks of hexagonal zincite. As calculated from Scherer’s formula, the average crystalline size for this sensing element is 59.4 nm. For this sensing element, the values of activation energy from the Arrhenius plot is 0.041 eV for temperature range 200 °C - 400 °C and 0.393 eV for temperature range 400 °C - 500 °C. The adsorption of water molecules on the surface takes place via a dissociative chemisorption process leading to release of electrons. ZnO has electron vacancy. Hence, because of this reaction, the electrons are accumulated at the ZnO surface and consequently, the resistance of the sensing element decreases with increase in relative humidity.

  8. Efficacy of intrahepatic absolute alcohol in unrespectable hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Farooqi, J.I.; Hameed, K.; Khan, I.U.; Shah, S.

    2001-01-01

    To determine efficacy of intrahepatic absolute alcohol injection in researchable hepatocellular carcinoma. A randomized, controlled, experimental and interventional clinical trial. Gastroenterology Department, PGMI, Hayatabad Medical Complex, Peshawar during the period from June, 1998 to June, 2000. Thirty patients were treated by percutaneous, intrahepatic absolute alcohol injection sin repeated sessions, 33 patients were not given or treated with alcohol to serve as control. Both the groups were comparable for age, sex and other baseline characteristics. Absolute alcohol therapy significantly improved quality of life of patients, reduced the tumor size and mortality as well as showed significantly better results regarding survival (P< 0.05) than the patients of control group. We conclude that absolute alcohol is a beneficial and safe palliative treatment measure in advanced hepatocellular carcinoma (HCC). (author)

  9. Analysis of Humid Air Turbine Cycle with Low- or Medium-Temperature Solar Energy

    International Nuclear Information System (INIS)

    Hongbin Zhao, H.; Yue, P.; Cao, L.

    2009-01-01

    A new humid air turbine cycle that uses low- or medium-temperature solar energy as assistant heat source was proposed for increasing the mass flow rate of humid air. Based on the combination of the first and second laws of thermodynamics, this paper described and compared the performances of the conventional and the solar HAT cycles. The effects of some parameters such as pressure ratio, turbine inlet temperature (TIT), and solar collector efficiency on humidity, specific work, cycle's exergy efficiency, and solar energy to electricity efficiency were discussed in detail. Compared with the conventional HAT cycle, because of the increased humid air mass flow rate in the new system, the humidity and the specific work of the new system were increased. Meanwhile, the solar energy to electricity efficiency was greatly improved. Additionally, the exergy losses of components in the system under the given conditions were also studied and analyzed.

  10. Effect of Humidity in Air on Performance and Long-Term Durability of SOFCs

    DEFF Research Database (Denmark)

    Hagen, Anke; Neufeld, Kai; Liu, Yi-Lin

    2010-01-01

    Anode-supported solid oxide fuel cells (SOFCs) based on Ni–yttria-stabilized zirconia (YSZ) anodes, YSZ electrolytes, and lanthanum strontium manganite (LSM)–YSZ cathodes were studied with respect to durability in humid air (~4%) typically over 1500 h. Operating temperature and current density were...... varied between 750 and 850°C and 0.25–0.75 A/cm2, respectively. The introduction of humidity affected the cell voltage under polarization of the cell, and this effect was (at least partly) reversible upon switching off the humidity. Generally, the studied cells were operated in humid air under...... technologically relevant conditions over more than 1500 h. Improvements at the cathode/electrolyte interface made it possible to obtain highly stable cells, which can be operated under high current density and at 750°C in humid air, conditions that cause significant cell voltage degradation in dry air on cells...

  11. Repeatability and Reversibility of the Humidity Sensor Based on Photonic Crystal Fiber Interferometer

    Science.gov (United States)

    Hindal, S. S.; Taher, H. J.

    2018-05-01

    The RH sensor operation based on water vapor adsorption and desorption at the silica-air interface within the PCF. Sensor fabrication is simple; it includes splicing and cleaving the PCF with SMF only. PCF (LMA-10) with a certain length spliced to SMF (Corning-28). The PCFI spectrum exhibits good sensitivity to the variations of humidity. The PCFI response is observed for range of relative humidity values from (27% RH to 85% RH), the interference peaks position is found to be shifted to longer wavelength as the humidity increases. In this work, a 6cm length of PCFs is used, and it shows a sensitivity of (2.41pm / %RH), good repeatability, and reversible in nature. This humidity sensor has distinguished features as that the sensor does not require the use of a hygroscopic material, robust, compact size, immunity to electromagnetic interference, and it has potential applications for high humidity environments.

  12. Impact of humidity on functionality of on-paper printed electronics.

    Science.gov (United States)

    Bollström, Roger; Pettersson, Fredrik; Dolietis, Peter; Preston, Janet; Osterbacka, Ronald; Toivakka, Martti

    2014-03-07

    A multilayer coated paper substrate, combining barrier and printability properties was manufactured utilizing a pilot-scale slide curtain coating technique. The coating structure consists of a thin mineral pigment layer coated on top of a barrier layer. The surface properties, i.e. smoothness and surface porosity, were adjusted by the choice of calendering parameters. The influence of surface properties on the fine line printability and conductivity of inkjet-printed silver lines was studied. Surface roughness played a significant role when printing narrow lines, increasing the risk of defects and discontinuities, whereas for wider lines the influence of surface roughness was less critical. A smooth, calendered surface resulted in finer line definition, i.e. less edge raggedness. Dimensional stability and its influence on substrate surface properties as well as on the functionality of conductive tracks and transistors were studied by exposure to high/low humidity cycles. The barrier layer of the multilayer coated paper reduced the dimensional changes and surface roughness increase caused by humidity and helped maintain the conductivity of the printed tracks. Functionality of a printed transistor during a short, one hour humidity cycle was maintained, but a longer exposure to humidity destroyed the non-encapsulated transistor.

  13. Retrofit device and method to improve humidity control of vapor compression cooling systems

    Science.gov (United States)

    Roth, Robert Paul; Hahn, David C.; Scaringe, Robert P.

    2016-08-16

    A method and device for improving moisture removal capacity of a vapor compression system is disclosed. The vapor compression system is started up with the evaporator blower initially set to a high speed. A relative humidity in a return air stream is measured with the evaporator blower operating at the high speed. If the measured humidity is above the predetermined high relative humidity value, the evaporator blower speed is reduced from the initially set high speed to the lowest possible speed. The device is a control board connected with the blower and uses a predetermined change in measured relative humidity to control the blower motor speed.

  14. Influence of Air Humidity and Water Particles on Dust Control Using Ultrasonic Atomization

    Science.gov (United States)

    Okawa, Hirokazu; Nishi, Kentaro; Shindo, Dai; Kawamura, Youhei

    2012-07-01

    The influence of air humidity and water particles on dust control was examined using ultrasonic atomization at 2.4 MHz, an acrylic box (61 L), and four types of ore dust samples: green tuff (4 µm), green tuff (6 µm), kaolin, and silica. It was clearly demonstrated that ultrasonic atomization was effective in raising humidity rapidly. However, at high relative air humidity, the water particles remained stable in the box without changing to water vapor. Ultrasonic atomization was applied to suppress dust dispersion and 40-95% dust reduction was achieved at 83% relative air humidity. Dust dispersion was more effective with ultrasonic atomization than without.

  15. Short term change in relative humidity during the festival of Diwali in India

    Science.gov (United States)

    Ganguly, Nandita D.

    2015-07-01

    The changes in humidity levels during the Diwali festivities have been examined over a period of 13 years at three Indian metro cities: Ahmedabad, New Delhi and Kolkata. A small short term increase in relative humidity even in the absence of transport of humid air from Arabian Sea and Bay of Bengal has been observed. The relative humidity levels were found to be exceeding the ambient levels during night and lying below the ambient levels during morning hours, indicating an increase in the survival rates of viruses responsible for the transmission of viral infections, as well as triggering immune-mediated illnesses such as asthma during Diwali.

  16. Planck absolute entropy of a rotating BTZ black hole

    Science.gov (United States)

    Riaz, S. M. Jawwad

    2018-04-01

    In this paper, the Planck absolute entropy and the Bekenstein-Smarr formula of the rotating Banados-Teitelboim-Zanelli (BTZ) black hole are presented via a complex thermodynamical system contributed by its inner and outer horizons. The redefined entropy approaches zero as the temperature of the rotating BTZ black hole tends to absolute zero, satisfying the Nernst formulation of a black hole. Hence, it can be regarded as the Planck absolute entropy of the rotating BTZ black hole.

  17. Absolute nuclear material assay using count distribution (LAMBDA) space

    Science.gov (United States)

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2012-06-05

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  18. Differential network analysis reveals genetic effects on catalepsy modules.

    Directory of Open Access Journals (Sweden)

    Ovidiu D Iancu

    Full Text Available We performed short-term bi-directional selective breeding for haloperidol-induced catalepsy, starting from three mouse populations of increasingly complex genetic structure: an F2 intercross, a heterogeneous stock (HS formed by crossing four inbred strains (HS4 and a heterogeneous stock (HS-CC formed from the inbred strain founders of the Collaborative Cross (CC. All three selections were successful, with large differences in haloperidol response emerging within three generations. Using a custom differential network analysis procedure, we found that gene coexpression patterns changed significantly; importantly, a number of these changes were concordant across genetic backgrounds. In contrast, absolute gene-expression changes were modest and not concordant across genetic backgrounds, in spite of the large and similar phenotypic differences. By inferring strain contributions from the parental lines, we are able to identify significant differences in allelic content between the selected lines concurrent with large changes in transcript connectivity. Importantly, this observation implies that genetic polymorphisms can affect transcript and module connectivity without large changes in absolute expression levels. We conclude that, in this case, selective breeding acts at the subnetwork level, with the same modules but not the same transcripts affected across the three selections.

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

    Science.gov (United States)

    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

  20. All-optical, thermo-optical path length modulation based on the vanadium-doped fibers.

    Science.gov (United States)

    Matjasec, Ziga; Campelj, Stanislav; Donlagic, Denis

    2013-05-20

    This paper presents an all-fiber, fully-optically controlled, optical-path length modulator based on highly absorbing optical fiber. The modulator utilizes a high-power 980 nm pump diode and a short section of vanadium-co-doped single mode fiber that is heated through absorption and a non-radiative relaxation process. The achievable path length modulation range primarily depends on the pump's power and the convective heat-transfer coefficient of the surrounding gas, while the time response primarily depends on the heated fiber's diameter. An absolute optical length change in excess of 500 µm and a time-constant as short as 11 ms, were demonstrated experimentally. The all-fiber design allows for an electrically-passive and remote operation of the modulator. The presented modulator could find use within various fiber-optics systems that require optical (remote) path length control or modulation.

  1. Humidity Detection Using Metal Organic Framework Coated on QCM

    KAUST Repository

    Kosuru, Lakshmoji

    2016-06-28

    Quartz crystal microbalance (QCM) coated with poly-4-vinylpyridine (PVP) and metal organic framework HKUST-1 are investigated and compared for humidity sensing. Drop casting method is employed to coat the PVP and HKUST-1 solutions onto the surface of a quartz crystal microbalance. The resonance frequencies of these sensors with varying relative humidity (RH) from 22% RH to 69% RH are measured using impedance analysis method. The sensitivity, humidity hysteresis, response, and recovery times of these sensors are studied. The sensitivities of uncoated, PVP, and HKUST-1 coated QCM sensors are 7 Hz, 48 Hz, and 720 Hz, respectively, in the range of 22% RH–69% RH. The extraction of desorption rate and adsorption energy associated with the adsorption and desorption of water molecules on these surfaces reveals that HKUST-1 has better sensing properties than PVP and uncoated QCM sensors. In this work, the HKUST-1 coated QCM is shown to be a promising material for moisture detection.

  2. Humidity Detection Using Metal Organic Framework Coated on QCM

    Directory of Open Access Journals (Sweden)

    Lakshmoji Kosuru

    2016-01-01

    Full Text Available Quartz crystal microbalance (QCM coated with poly-4-vinylpyridine (PVP and metal organic framework HKUST-1 are investigated and compared for humidity sensing. Drop casting method is employed to coat the PVP and HKUST-1 solutions onto the surface of a quartz crystal microbalance. The resonance frequencies of these sensors with varying relative humidity (RH from 22% RH to 69% RH are measured using impedance analysis method. The sensitivity, humidity hysteresis, response, and recovery times of these sensors are studied. The sensitivities of uncoated, PVP, and HKUST-1 coated QCM sensors are 7 Hz, 48 Hz, and 720 Hz, respectively, in the range of 22% RH–69% RH. The extraction of desorption rate and adsorption energy associated with the adsorption and desorption of water molecules on these surfaces reveals that HKUST-1 has better sensing properties than PVP and uncoated QCM sensors. In this work, the HKUST-1 coated QCM is shown to be a promising material for moisture detection.

  3. A nafion coated capacitive humidity sensor on a flexible PET substrate

    KAUST Repository

    Sapsanis, Christos

    2017-03-07

    This paper reports a simple and low-cost technique for fabricating low-power capacitive humidity sensors without the use of a cleanroom environment. A maskless laser engraving system was utilized to fabricate two different gold electrode structures, interdigitated electrodes and Hilbert\\'s fifth-order fractal. The capacitive structures were implemented on a flexible PET substrate. The usage of Nafion, a well-known polymer for its hydrophilic properties as a sensing film, was attempted on the PET and outperformed the current efforts in flexible substrates. Its humidity sensing properties were evaluated in an automated gas setup with a relative humidity (RH %) ranging from 15% to 95 %.

  4. A nafion coated capacitive humidity sensor on a flexible PET substrate

    KAUST Repository

    Sapsanis, Christos; Buttner, Ulrich; Omran, Hesham; Belmabkhout, Youssef; Shekhah, Osama; Eddaoudi, Mohamed; Salama, Khaled N.

    2017-01-01

    This paper reports a simple and low-cost technique for fabricating low-power capacitive humidity sensors without the use of a cleanroom environment. A maskless laser engraving system was utilized to fabricate two different gold electrode structures, interdigitated electrodes and Hilbert's fifth-order fractal. The capacitive structures were implemented on a flexible PET substrate. The usage of Nafion, a well-known polymer for its hydrophilic properties as a sensing film, was attempted on the PET and outperformed the current efforts in flexible substrates. Its humidity sensing properties were evaluated in an automated gas setup with a relative humidity (RH %) ranging from 15% to 95 %.

  5. PREPARATION OF THE SINGLE MODE PLANAR OPTICAL SPLITTER MODULES AND THEIR CHARACTERIZATIONS

    Directory of Open Access Journals (Sweden)

    Vu Doan Mien

    2017-11-01

    Full Text Available Optical splitter modules have been prepared based on 1x8 single mode silica planar waveguide optical splitter chips with 250 µm spacing and v-groove fiber arrays for applications in fiber optic communications. We report the technology of precise optical coupling and packaging of the splitter modules and the measurements of the insertion loss (< 11 dB,  uniformity (< 0.80 dB and polarization dependence loss (PLD < 0.10 dB as well as the lateral profile and the image of the input and output lights for the wavelengths of 1310 nm and 1550 nm. The main characteristics of the prepared splitter modules are about the same for the commercial available products. The prepared modules have been tested for operation in the conditions of wide temperature range (5–80°C and humidity range (50–98% and no changes in the main characteristics were observed.

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

    Science.gov (United States)

    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.

  7. Analysis of Humid Air Turbine Cycle with Low- or Medium-Temperature Solar Energy

    Directory of Open Access Journals (Sweden)

    Hongbin Zhao

    2009-01-01

    Full Text Available A new humid air turbine cycle that uses low- or medium-temperature solar energy as assistant heat source was proposed for increasing the mass flow rate of humid air. Based on the combination of the first and second laws of thermodynamics, this paper described and compared the performances of the conventional and the solar HAT cycles. The effects of some parameters such as pressure ratio, turbine inlet temperature (TIT, and sollar collector efficiency on humidity, specific work, cycle's exergy efficiency, and solar energy to electricity efficiency were discussed in detail. Compared with the conventional HAT cycle, because of the increased humid air mass flow rate in the new system, the humidity and the specific work of the new system were increased. Meanwhile, the solar energy to electricity efficiency was greatly improved. Additionally, the exergy losses of components in the system under the given conditions were also studied and analyzed.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    Jie Zeng

    2017-11-01

    Full Text Available 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

  12. MoS{sub 2}-modified ZnO quantum dots nanocomposite: Synthesis and ultrafast humidity response

    Energy Technology Data Exchange (ETDEWEB)

    Ze, Lu [School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105 (China); Yueqiu, Gong, E-mail: yqgong@xtu.edu.cn [School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105 (China); Xujun, Li; Yong, Zhang [School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105 (China)

    2017-03-31

    Highlights: • MoS{sub 2}@ZnO QDs composite structure was synthesized by two-steps methods. • Ultrafast humidity sensing response is achieved by MoS{sub 2}@ZnO QDs humidity sensor. • Sensor performs excellent cycle stability from 11% to 95% RH. • Humidity sensor could detect wide humidity range (11–95%). - Abstract: In this work, ZnO quantum dots (QDs), layered MoS{sub 2} and MoS{sub 2}-modified ZnO QDs (MoS{sub 2}@ZnO QDs) nanocomposite were synthesized and then applied as humidity sensor. The crystal structure, morphology and element distribution of ZnO QDs, MoS{sub 2} and MoS{sub 2}@ZnO QDs were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectrometry, respectively. The humidity sensing characteristics of the MoS{sub 2} and MoS{sub 2}@ZnO QDs against various relative humidity were measured at room temperature. The results show that the MoS{sub 2}@ZnO QDs sensor exhibits high sensitivity with an impedance variation of three or four orders of magnitude to relative humidity range of 11–95% and it exhibits a short response-recovery time (1 s for adsorption and 20 s for desorption) and excellent repeatability. The mechanisms of the excellent performance for humidity sensing of MoS{sub 2}@ZnO QDs sensor were discussed based on its impedance properties. Our work could offer guidelines to design higher performance especially ultrafast humidity response sensor utilizing the nanocomposite structure with two dimensional material and QDs.

  13. The effect of changing ambient humidity on moisture condition in timber elements

    DEFF Research Database (Denmark)

    Hozjan, Tomaẑ; Turk, Goran; Srpĉiĉ, Stanislav

    2012-01-01

    a fully coupled transport model including a model for the influential sorption hysteresis of wood is used. The coupled model accounts for both vapor transport in pores and bound water transport in wood tissue. Moisture state history influences relationship between moisture state of wood and air humidity......This paper deals with the effect of the changing ambient humidity on moisture conditions in timber elements. The naturally varying humidity is possible to model as a relative combination of different harmonic cycles, with different periods and amplitudes. For the determination of the moisture field......, it must therefore be taken into account. In order to include history dependency, a hysteresis model is used here. Results from numerical calculations for timber specimen exposed to combined daily and annually cyclic variation of outside humidity are presented. Copyright © (2012) by WCTE 2012 Committee....

  14. Polymer Optical Fibre Bragg Grating Humidity Sensor at 100ºC

    DEFF Research Database (Denmark)

    Woyessa, Getinet; Fasano, Andrea; Markos, Christos

    2016-01-01

    We have demonstrated a polymer optical fibre Bragg grating humidity sensor that can be operated up to 100ºC. The sensor has been fabricated from a polycarbonate (PC) microstructured polymer optical fibre Bragg grating (mPOFBG). PC mPOFBG gave a relative humidity (RH) sensitivity of 6.95±0.83 pm...

  15. Approach to Absolute Zero

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 10. Approach to Absolute Zero Below 10 milli-Kelvin. R Srinivasan. Series Article Volume 2 Issue 10 October 1997 pp 8-16. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/002/10/0008-0016 ...

  16. Population-based absolute risk estimation with survey data

    Science.gov (United States)

    Kovalchik, Stephanie A.; Pfeiffer, Ruth M.

    2013-01-01

    Absolute risk is the probability that a cause-specific event occurs in a given time interval in the presence of competing events. We present methods to estimate population-based absolute risk from a complex survey cohort that can accommodate multiple exposure-specific competing risks. The hazard function for each event type consists of an individualized relative risk multiplied by a baseline hazard function, which is modeled nonparametrically or parametrically with a piecewise exponential model. An influence method is used to derive a Taylor-linearized variance estimate for the absolute risk estimates. We introduce novel measures of the cause-specific influences that can guide modeling choices for the competing event components of the model. To illustrate our methodology, we build and validate cause-specific absolute risk models for cardiovascular and cancer deaths using data from the National Health and Nutrition Examination Survey. Our applications demonstrate the usefulness of survey-based risk prediction models for predicting health outcomes and quantifying the potential impact of disease prevention programs at the population level. PMID:23686614

  17. Absolute marine gravimetry with matter-wave interferometry.

    Science.gov (United States)

    Bidel, Y; Zahzam, N; Blanchard, C; Bonnin, A; Cadoret, M; Bresson, A; Rouxel, D; Lequentrec-Lalancette, M F

    2018-02-12

    Measuring gravity from an aircraft or a ship is essential in geodesy, geophysics, mineral and hydrocarbon exploration, and navigation. Today, only relative sensors are available for onboard gravimetry. This is a major drawback because of the calibration and drift estimation procedures which lead to important operational constraints. Atom interferometry is a promising technology to obtain onboard absolute gravimeter. But, despite high performances obtained in static condition, no precise measurements were reported in dynamic. Here, we present absolute gravity measurements from a ship with a sensor based on atom interferometry. Despite rough sea conditions, we obtained precision below 10 -5  m s -2 . The atom gravimeter was also compared with a commercial spring gravimeter and showed better performances. This demonstration opens the way to the next generation of inertial sensors (accelerometer, gyroscope) based on atom interferometry which should provide high-precision absolute measurements from a moving platform.

  18. Tropospheric profiles of wet refractivity and humidity from the combination of remote sensing data sets and measurements on the ground

    Directory of Open Access Journals (Sweden)

    F. Hurter

    2013-11-01

    40% for the lower troposphere. We further added 189 radio occultations that met our requirements. They mostly improved the accuracy in the upper troposphere. Maximum median offsets have decreased from 120% relative error to 44% at 8 km height. Dew point temperature profiles after the conversion with radiometer temperatures compare to radiosonde profiles as to: absolute dew point temperature errors in the lower troposphere have a maximum median offset of −2 K and maximum quartiles of 4.5 K. For relative humidity, we get a maximum mean offset of 7.3%, with standard deviations of 12–20%. The methodology presented allows us to reconstruct humidity profiles at any location where temperature profiles, but no atmospheric humidity measurements other than from GPS are available. Additional data sets of wet refractivity are shown to be easily integrated into the framework and strongly aid the reconstruction. Since the used data sets are all operational and available in near-realtime, we envisage the methodology of this paper to be a tool for nowcasting of clouds and rain and to understand processes in the boundary layer and at its top.

  19. Cubic mesoporous Ag@CN: a high performance humidity sensor.

    Science.gov (United States)

    Tomer, Vijay K; Thangaraj, Nishanthi; Gahlot, Sweta; Kailasam, Kamalakannan

    2016-12-01

    The fabrication of highly responsive, rapid response/recovery and durable relative humidity (%RH) sensors that can precisely monitor humidity levels still remains a considerable challenge for realizing the next generation humidity sensing applications. Herein, we report a remarkably sensitive and rapid %RH sensor having a reversible response using a nanocasting route for synthesizing mesoporous g-CN (commonly known as g-C 3 N 4 ). The 3D replicated cubic mesostructure provides a high surface area thereby increasing the adsorption, transmission of charge carriers and desorption of water molecules across the sensor surfaces. Owing to its unique structure, the mesoporous g-CN functionalized with well dispersed catalytic Ag nanoparticles exhibits excellent sensitivity in the 11-98% RH range while retaining high stability, negligible hysteresis and superior real time %RH detection performances. Compared to conventional resistive sensors based on metal oxides, a rapid response time (3 s) and recovery time (1.4 s) were observed in the 11-98% RH range. Such impressive features originate from the planar morphology of g-CN as well as unique physical affinity and favourable electronic band positions of this material that facilitate water adsorption and charge transportation. Mesoporous g-CN with Ag nanoparticles is demonstrated to provide an effective strategy in designing high performance %RH sensors and show great promise for utilization of mesoporous 2D layered materials in the Internet of Things and next generation humidity sensing applications.

  20. Modeling of an Aged Porous Silicon Humidity Sensor Using ANN Technique

    Directory of Open Access Journals (Sweden)

    Tarikul ISLAM

    2006-10-01

    Full Text Available Porous silicon (PS sensor based on capacitive technique used for measuring relative humidity has the advantages of low cost, ease of fabrication with controlled structure and CMOS compatibility. But the response of the sensor is nonlinear function of humidity and suffers from errors due to aging and stability. One adaptive linear (ADALINE ANN model has been developed to model the behavior of the sensor with a view to estimate these errors and compensate them. The response of the sensor is represented by third order polynomial basis function whose coefficients are determined by the ANN technique. The drift in sensor output due to aging of PS layer is also modeled by adapting the weights of the polynomial function. ANN based modeling is found to be more suitable than conventional physical modeling of PS humidity sensor in changing environment and drift due to aging. It helps online estimation of nonlinearity as well as monitoring of the fault of the PS humidity sensor using the coefficients of the model.

  1. Temperature and relative humidity dependence of radiochromic film dosimeter response to gamma electron radiation

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Puhl, J.M.; Miller, A.

    1995-01-01

    on some earlier studies, their response functions have been reported to be dependent on the temperature and relative humidity during irradiation. The present study investigates differences in response over practical ranges of temperature, relative humidity, dose, and for different recent batches of films...... humidity) and should be calibrated under environmental conditions (temperature) at which they will be used routinely....

  2. Relative and absolute risk in epidemiology and health physics

    International Nuclear Information System (INIS)

    Goldsmith, R.; Peterson, H.T. Jr.

    1983-01-01

    The health risk from ionizing radiation commonly is expressed in two forms: (1) the relative risk, which is the percentage increase in natural disease rate and (2) the absolute or attributable risk which represents the difference between the natural rate and the rate associated with the agent in question. Relative risk estimates for ionizing radiation generally are higher than those expressed as the absolute risk. This raises the question of which risk estimator is the most appropriate under different conditions. The absolute risk has generally been used for radiation risk assessment, although mathematical combinations such as the arithmetic or geometric mean of both the absolute and relative risks, have also been used. Combinations of the two risk estimators are not valid because the absolute and relative risk are not independent variables. Both human epidemiologic studies and animal experimental data can be found to illustrate the functional relationship between the natural cancer risk and the risk associated with radiation. This implies that the radiation risk estimate derived from one population may not be appropriate for predictions in another population, unless it is adjusted for the difference in the natural disease incidence between the two populations

  3. Redetermination and absolute configuration of atalaphylline

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2010-02-01

    Full Text Available The title acridone alkaloid [systematic name: 1,3,5-trihydroxy-2,4-bis(3-methylbut-2-enylacridin-9(10H-one], C23H25NO4, has previously been reported as crystallizing in the chiral orthorhombic space group P212121 [Chantrapromma et al. (2010. Acta Cryst. E66, o81–o82] but the absolute configuration could not be determined from data collected with Mo radiation. The absolute configuration has now been determined by refinement of the Flack parameter with data collected using Cu radiation. All features of the molecule and its crystal packing are similar to those previously described.

  4. Calculation principles of humid air in a reversed Brayton cycle

    Energy Technology Data Exchange (ETDEWEB)

    Backman, J [Lappeenranta Univ. of Technology (Finland). Dept. of Energy Technology

    1998-12-31

    The article presents a calculation method for reversed Brayton cycle that uses humid air as working medium. The reversed Brayton cycle can be employed as an air dryer, a heat pump or a refrigerating machine. In this research the use of humid air as a working fluid has an environmental advantage, as well. In this method especially the expansion process in the turbine is important because of the condensation of the water vapour in the humid air. This physical phenomena can have significant effects on the level of performance of the application. The expansion process differs physically from the compression process, when the water vapour in the humid air begins to condensate. In the thermodynamic equilibrium of the flow, the water vapour pressure in humid air cannot exceed the pressure of saturated water vapour in corresponding temperature. Expansion calculation during operation around the saturation zone is based on a quasistatic expansion, in which the system after the turbine is in thermodynamical equilibrium. The state parameters are at every moment defined by the equation of state, and there is no supercooling in the vapour. Following simplifications are used in the calculations: The system is assumed to be adiabatic. This means that there is no heat transfer to the surroundings. This is a common practice, when the temperature differences are moderate as here; The power of the cooling is omitted. The cooling construction is very dependent on the machine and the distribution of the losses; The flow is assumed to be one-dimensional, steady-state and homogenous. The water vapour condensing in the turbine can cause errors, but the errors are mainly included in the efficiency calculation. (author) 11 refs.

  5. Calculation principles of humid air in a reversed Brayton cycle

    Energy Technology Data Exchange (ETDEWEB)

    Backman, J. [Lappeenranta Univ. of Technology (Finland). Dept. of Energy Technology

    1997-12-31

    The article presents a calculation method for reversed Brayton cycle that uses humid air as working medium. The reversed Brayton cycle can be employed as an air dryer, a heat pump or a refrigerating machine. In this research the use of humid air as a working fluid has an environmental advantage, as well. In this method especially the expansion process in the turbine is important because of the condensation of the water vapour in the humid air. This physical phenomena can have significant effects on the level of performance of the application. The expansion process differs physically from the compression process, when the water vapour in the humid air begins to condensate. In the thermodynamic equilibrium of the flow, the water vapour pressure in humid air cannot exceed the pressure of saturated water vapour in corresponding temperature. Expansion calculation during operation around the saturation zone is based on a quasistatic expansion, in which the system after the turbine is in thermodynamical equilibrium. The state parameters are at every moment defined by the equation of state, and there is no supercooling in the vapour. Following simplifications are used in the calculations: The system is assumed to be adiabatic. This means that there is no heat transfer to the surroundings. This is a common practice, when the temperature differences are moderate as here; The power of the cooling is omitted. The cooling construction is very dependent on the machine and the distribution of the losses; The flow is assumed to be one-dimensional, steady-state and homogenous. The water vapour condensing in the turbine can cause errors, but the errors are mainly included in the efficiency calculation. (author) 11 refs.

  6. Absolute calibration of sniffer probes on Wendelstein 7-X

    International Nuclear Information System (INIS)

    Moseev, D.; Laqua, H. P.; Marsen, S.; Stange, T.; Braune, H.; Erckmann, V.; Gellert, F.; Oosterbeek, J. W.

    2016-01-01

    Here we report the first measurements of the power levels of stray radiation in the vacuum vessel of Wendelstein 7-X using absolutely calibrated sniffer probes. The absolute calibration is achieved by using calibrated sources of stray radiation and the implicit measurement of the quality factor of the Wendelstein 7-X empty vacuum vessel. Normalized absolute calibration coefficients agree with the cross-calibration coefficients that are obtained by the direct measurements, indicating that the measured absolute calibration coefficients and stray radiation levels in the vessel are valid. Close to the launcher, the stray radiation in the empty vessel reaches power levels up to 340 kW/m 2 per MW injected beam power. Furthest away from the launcher, i.e., half a toroidal turn, still 90 kW/m 2 per MW injected beam power is measured.

  7. Absolute calibration of sniffer probes on Wendelstein 7-X

    Science.gov (United States)

    Moseev, D.; Laqua, H. P.; Marsen, S.; Stange, T.; Braune, H.; Erckmann, V.; Gellert, F.; Oosterbeek, J. W.

    2016-08-01

    Here we report the first measurements of the power levels of stray radiation in the vacuum vessel of Wendelstein 7-X using absolutely calibrated sniffer probes. The absolute calibration is achieved by using calibrated sources of stray radiation and the implicit measurement of the quality factor of the Wendelstein 7-X empty vacuum vessel. Normalized absolute calibration coefficients agree with the cross-calibration coefficients that are obtained by the direct measurements, indicating that the measured absolute calibration coefficients and stray radiation levels in the vessel are valid. Close to the launcher, the stray radiation in the empty vessel reaches power levels up to 340 kW/m2 per MW injected beam power. Furthest away from the launcher, i.e., half a toroidal turn, still 90 kW/m2 per MW injected beam power is measured.

  8. Absolute calibration of sniffer probes on Wendelstein 7-X

    Energy Technology Data Exchange (ETDEWEB)

    Moseev, D., E-mail: dmitry.moseev@ipp.mpg.de; Laqua, H. P.; Marsen, S.; Stange, T.; Braune, H.; Erckmann, V. [Max-Planck-Institut für Plasmaphysik, Greifswald (Germany); Gellert, F. [Max-Planck-Institut für Plasmaphysik, Greifswald (Germany); Ernst-Moritz-Arndt-Universität Greifswald, Greifswald (Germany); Oosterbeek, J. W. [Eindhoven University of Technology, Eindhoven (Netherlands)

    2016-08-15

    Here we report the first measurements of the power levels of stray radiation in the vacuum vessel of Wendelstein 7-X using absolutely calibrated sniffer probes. The absolute calibration is achieved by using calibrated sources of stray radiation and the implicit measurement of the quality factor of the Wendelstein 7-X empty vacuum vessel. Normalized absolute calibration coefficients agree with the cross-calibration coefficients that are obtained by the direct measurements, indicating that the measured absolute calibration coefficients and stray radiation levels in the vessel are valid. Close to the launcher, the stray radiation in the empty vessel reaches power levels up to 340 kW/m{sup 2} per MW injected beam power. Furthest away from the launcher, i.e., half a toroidal turn, still 90 kW/m{sup 2} per MW injected beam power is measured.

  9. Stomata of the CAM plant Tillandsia recurvata respond directly to humidity.

    Science.gov (United States)

    Lange, O L; Medina, E

    1979-01-01

    Under controlled conditions, CO 2 exchange of Tillandsia recurvata showed all characteristics of CAM. During the phase of nocturnal CO 2 fixation stomata of the plant responded sensitively to changes in ambient air humidity. Dry air resulted in an increase, moist air in a decrease of diffusion resistance. The evaporative demand of the air affected the level of stomatal resistance during the entire night period. Due to stomatal closure, the total nocturnal water loss of T. recurvata was less at low than at high humidity. It is concluded that stomata respond directly to humidity and not via bulk tissue water conditions of the leaves. Such control of transpiration may optimize water use efficiency for this almost rootless, extreme epiphyte.

  10. Humidity Sensors Principle, Mechanism, and Fabrication Technologies: A Comprehensive Review

    Directory of Open Access Journals (Sweden)

    Hamid Farahani

    2014-04-01

    Full Text Available Humidity measurement is one of the most significant issues in various areas of applications such as instrumentation, automated systems, agriculture, climatology and GIS. Numerous sorts of humidity sensors fabricated and developed for industrial and laboratory applications are reviewed and presented in this article. The survey frequently concentrates on the RH sensors based upon their organic and inorganic functional materials, e.g., porous ceramics (semiconductors, polymers, ceramic/polymer and electrolytes, as well as conduction mechanism and fabrication technologies. A significant aim of this review is to provide a distinct categorization pursuant to state of the art humidity sensor types, principles of work, sensing substances, transduction mechanisms, and production technologies. Furthermore, performance characteristics of the different humidity sensors such as electrical and statistical data will be detailed and gives an added value to the report. By comparison of overall prospects of the sensors it was revealed that there are still drawbacks as to efficiency of sensing elements and conduction values. The flexibility offered by thick film and thin film processes either in the preparation of materials or in the choice of shape and size of the sensor structure provides advantages over other technologies. These ceramic sensors show faster response than other types.

  11. Thermal Effectiveness of Wall Indoor Fountain in Warm Humid Climate

    Science.gov (United States)

    Seputra, J. A. P.

    2018-03-01

    Nowadays, many buildings wield indoor water features such as waterfalls, fountains, and water curtains to improve their aesthetical value. Despite the provision of air cooling due to water evaporation, this feature also has adverse effect if applied in warm humid climate since evaporation might increase air humidity beyond the comfort level. Yet, there are no specific researches intended to measure water feature’s effect upon its thermal condition. In response, this research examines the influence of evaporative cooling on indoor wall fountain toward occupant’s thermal comfort in warm humid climate. To achieve this goal, case study is established in Waroeng Steak Restaurant’s dining room in Surakarta-Indonesia. In addition, SNI 03-6572-2001 with comfort range of 20.5–27.1°C and 40-60% of relative humidity is utilized as thermal criterion. Furthermore, Computational Fluid Dynamics (CFD) is employed to process the data and derive conclusions. Research variables are; feature’s height, obstructions, and fan types. As results, Two Bumps Model (ToB) is appropriate when employs natural ventilation. However, if the room is mechanically ventilated, Three Bumps Model (TeB) becomes the best choice. Moreover, application of adaptive ventilation is required to maintain thermal balance.

  12. Humidity Sensors Principle, Mechanism, and Fabrication Technologies: A Comprehensive Review

    Science.gov (United States)

    Farahani, Hamid; Wagiran, Rahman; Hamidon, Mohd Nizar

    2014-01-01

    Humidity measurement is one of the most significant issues in various areas of applications such as instrumentation, automated systems, agriculture, climatology and GIS. Numerous sorts of humidity sensors fabricated and developed for industrial and laboratory applications are reviewed and presented in this article. The survey frequently concentrates on the RH sensors based upon their organic and inorganic functional materials, e.g., porous ceramics (semiconductors), polymers, ceramic/polymer and electrolytes, as well as conduction mechanism and fabrication technologies. A significant aim of this review is to provide a distinct categorization pursuant to state of the art humidity sensor types, principles of work, sensing substances, transduction mechanisms, and production technologies. Furthermore, performance characteristics of the different humidity sensors such as electrical and statistical data will be detailed and gives an added value to the report. By comparison of overall prospects of the sensors it was revealed that there are still drawbacks as to efficiency of sensing elements and conduction values. The flexibility offered by thick film and thin film processes either in the preparation of materials or in the choice of shape and size of the sensor structure provides advantages over other technologies. These ceramic sensors show faster response than other types. PMID:24784036

  13. Development of an Air-Source Heat Pump Integrated with a Water Heating / Dehumidification Module

    Energy Technology Data Exchange (ETDEWEB)

    Rice, C Keith [ORNL; Uselton, Robert B. [Lennox Industries, Inc; Shen, Bo [ORNL; Baxter, Van D [ORNL; Shrestha, Som S [ORNL

    2014-01-01

    A residential-sized dual air-source integrated heat pump (AS-IHP) concept is under development in partnership between ORNL and a manufacturer. The concept design consists of a two-stage air-source heat pump (ASHP) coupled on the air distribution side with a separate novel water heating/dehumidification (WH/DH) module. The motivation for this unusual equipment combination is the forecast trend for home sensible loads to be reduced more than latent loads. Integration of water heating with a space dehumidification cycle addresses humidity control while performing double-duty. This approach can be applied to retrofit/upgrade applications as well as new construction. A WH/DH module capable of ~1.47 L/h water removal and ~2 kW water heating capacity was assembled by the manufacturer. A heat pump system model was used to guide the controls design; lab testing was conducted and used to calibrate the models. Performance maps were generated and used in a TRNSYS sub-hourly simulation to predict annual performance in a well-insulated house. Annual HVAC/WH energy savings of ~35% are predicted in cold and hot-humid U.S. climates compared to a minimum efficiency baseline.

  14. A Sensor Based on LiCl/NaA Zeolite Composites for Effective Humidity Sensing.

    Science.gov (United States)

    Zhang, Ying; Xiang, Hongyu; Sun, Liang; Xie, Qiuhong; Liu, Man; Chen, Yu; Ruan, Shengping

    2018-03-01

    LiCl/NaA zeolite composites were successfully prepared by doping 1 wt%, 2 wt%, 5 wt%, and 8 wt% of LiCl into NaA zeolite. The humidity sensing properties of LiCl/NaA composites were investigated among 11% 95% relative humidity (RH). The LiCl/NaA composites exhibited better humidity sensing properties than pure NaA zeolite. The sensor made by 2 wt% Li-doped NaA zeolite possesses the best linearly in the whole RH. These results demonstrate that the LiCl/NaA composites have the potential application in humidity sensing.

  15. Humidity Testing of PME and BME Ceramic Capacitors with Cracks

    Science.gov (United States)

    Teverovsky, Alexander A.; Herzberger, Jaemi

    2014-01-01

    Cracks in ceramic capacitors are one of the major causes of failures during operation of electronic systems. Humidity testing has been successfully used for many years to verify the absence of cracks and assure quality of military grade capacitors. Traditionally, only precious metal electrode (PME) capacitors were used in high reliability applications and the existing requirements for humidity testing were developed for this type of parts. With the advance of base metal electrode (BME) capacitors, there is a need for assessment of the applicability of the existing techniques for the new technology capacitors. In this work, variety of different PME and BME capacitors with introduced cracks were tested in humid environments at different voltages and temperatures. Analysis of the test results indicates differences in the behavior and failure mechanisms for BME and PME capacitors and the need for different testing conditions.

  16. Sol-gel zinc oxide humidity sensors integrated with a ring oscillator circuit on-a-chip.

    Science.gov (United States)

    Yang, Ming-Zhi; Dai, Ching-Liang; Wu, Chyan-Chyi

    2014-10-28

    The study develops an integrated humidity microsensor fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The integrated humidity sensor consists of a humidity sensor and a ring oscillator circuit on-a-chip. The humidity sensor is composed of a sensitive film and branch interdigitated electrodes. The sensitive film is zinc oxide prepared by sol-gel method. After completion of the CMOS process, the sensor requires a post-process to remove the sacrificial oxide layer and to coat the zinc oxide film on the interdigitated electrodes. The capacitance of the sensor changes when the sensitive film adsorbs water vapor. The circuit is used to convert the capacitance of the humidity sensor into the oscillation frequency output. Experimental results show that the output frequency of the sensor changes from 84.3 to 73.4 MHz at 30 °C as the humidity increases 40 to 90%RH.

  17. Quality controls in intensity-modulated conformational radiotherapy. S.F.P.M. report nr 26, January 2010

    International Nuclear Information System (INIS)

    Valinta, Danielle; Poinsignon, Anne; Caron, Jerome; Dejean, Catherine; Corsetti, Dominique; Marcie, Serge; Mazurier, Jocelyne; Naudy, Suzanne; Aget, Helene; Marchesi, Vincent; Vieillevigne, Laure; Dedieu, Veronique; Bramoule, Celine; Caselles, Olivier; Lacaze, Brigitte; Mazurier, Jocelyne

    2009-08-01

    This report proposes a comprehensive presentation of the different controls which can be performed for the implementation of 3D intensity-modulated conformal radiation therapy (IMCR). The authors first present the IMCR principle by describing modes of production of modulated beams, the practical realisation of intensity modulation with Multi Leaf Collimator (MLC), multi leaf collimators, and the inverse planning system. They present the quality control of the accelerator (pre-requisites, linearity of the monitor chamber, symmetry and homogeneity), the quality control of multi leaf collimators (prerequisites, leaf absolute calibration, static mode, dynamic mode), the quality control of the treatment planning system (prerequisites, tests specific to IMCR, example in dynamic mode with the chair test), the quality control of the treatment plan (objective, necessary equipment and software solutions, measurement of point absolute dose, control of dose distribution, independent calculation of the number of monitor units), and the treatment verification (pre-treatment verification, patient repositioning during treatment). Finally, they indicate human means required for IMCR implementation, and formulate some recommendations for this implementation

  18. SIZE DISTRIBUTION OF SEA-SALT EMISSIONS AS A FUNCTION OF RELATIVE HUMIDITY

    Science.gov (United States)

    This note presents a straightforward method to correct sea-salt-emission particle-size distributions according to local relative humidity. The proposed method covers a wide range of relative humidity (0.45 to 0.99) and its derivation incorporates recent laboratory results on sea-...

  19. Absolute magnitudes by statistical parallaxes

    International Nuclear Information System (INIS)

    Heck, A.

    1978-01-01

    The author describes an algorithm for stellar luminosity calibrations (based on the principle of maximum likelihood) which allows the calibration of relations of the type: Msub(i)=sup(N)sub(j=1)Σqsub(j)Csub(ij), i=1,...,n, where n is the size of the sample at hand, Msub(i) are the individual absolute magnitudes, Csub(ij) are observational quantities (j=1,...,N), and qsub(j) are the coefficients to be determined. If one puts N=1 and Csub(iN)=1, one has q 1 =M(mean), the mean absolute magnitude of the sample. As additional output, the algorithm provides one also with the dispersion in magnitude of the sample sigmasub(M), the mean solar motion (U,V,W) and the corresponding velocity ellipsoid (sigmasub(u), sigmasub(v), sigmasub(w). The use of this algorithm is illustrated. (Auth.)

  20. Roller compaction: Effect of relative humidity of lactose powder.

    Science.gov (United States)

    Omar, Chalak S; Dhenge, Ranjit M; Palzer, Stefan; Hounslow, Michael J; Salman, Agba D

    2016-09-01

    The effect of storage at different relative humidity conditions, for various types of lactose, on roller compaction behaviour was investigated. Three types of lactose were used in this study: anhydrous lactose (SuperTab21AN), spray dried lactose (SuperTab11SD) and α-lactose monohydrate 200M. These powders differ in their amorphous contents, due to different manufacturing processes. The powders were stored in a climatic chamber at different relative humidity values ranging from 10% to 80% RH. It was found that the roller compaction behaviour and ribbon properties were different for powders conditioned to different relative humidities. The amount of fines produced, which is undesirable in roller compaction, was found to be different at different relative humidity. The minimum amount of fines produced was found to be for powders conditioned at 20-40% RH. The maximum amount of fines was produced for powders conditioned at 80% RH. This was attributed to the decrease in powder flowability, as indicated by the flow function coefficient ffc and the angle of repose. Particle Image Velocimetry (PIV) was also applied to determine the velocity of primary particles during ribbon production, and it was found that the velocity of the powder during the roller compaction decreased with powders stored at high RH. This resulted in less powder being present in the compaction zone at the edges of the rollers, which resulted in ribbons with a smaller overall width. The relative humidity for the storage of powders has shown to have minimal effect on the ribbon tensile strength at low RH conditions (10-20%). The lowest tensile strength of ribbons produced from lactose 200M and SD was for powders conditioned at 80% RH, whereas, ribbons produced from lactose 21AN at the same condition of 80% RH showed the highest tensile strength. The storage RH range 20-40% was found to be an optimum condition for roll compacting three lactose powders, as it resulted in a minimum amount of fines in the

  1. Direct versus indirect effects of tropospheric humidity changes on the hydrologic cycle

    International Nuclear Information System (INIS)

    Sherwood, S C

    2010-01-01

    Abundant evidence indicates that tropospheric specific humidity increases in a warmer atmosphere, at rates roughly comparable to those at constant relative humidity. While the implications for the planetary energy budget and global warming are well recognized, it is the net atmospheric cooling (or surface heating) that controls the hydrologic cycle. Relative humidity influences this directly through gas-phase radiative transfer, and indirectly by affecting cloud cover (and its radiative effects) and convective heating. Simple calculations show that the two indirect impacts are larger than the direct impact by roughly one and two orders of magnitude respectively. Global or regional relative humidity changes could therefore have significant indirect impacts on energy and water cycles, especially by altering deep convection, even if they are too small to significantly affect global temperature. Studies of climate change should place greater emphasis on these indirect links, which may not be adequately represented in models.

  2. Immobilization of Bovine Serum Albumin Upon Multiwall Carbon Nanotube for High Speed Humidity Sensing Application.

    Science.gov (United States)

    Bhattacharya, Sankhya; Sasmal, Milan

    2016-01-01

    We present a high-speed humidity sensor based on immobilization of bovine serum albumin upon multiwall carbon nanotube (IBC). A simple and versatile drop casting technique was employed to make the humidity sensor using novel material IBC at room temperature. IBC was synthesized using easy solution process technique. The working principle of the IBC humidity sensor depends upon the variation of output current or conductance with the exposure of different humidity level. Humidity sensing properties of our device is explained on the basis of charge transfer from water molecules to IBC and bovine serum albumin to multiwall carbon nanotube (MWCNT). Our sensor exhibits faster response time around 1.2 s and recovery time 1.5 s respectively.

  3. The Design of Temperature and Humidity Chamber Monitor and Controller

    OpenAIRE

    Tibebu, Simachew

    2016-01-01

    The temperature and humidity chamber, (climate chamber) is a device located at the Technobothnia Education and Research Center that simulates different climate conditions. The simulated environment is used to test the capabilities of electrical equipment in different temperature and humidity conditions. The climate chamber, among other things houses a dedicated computer, the control PC, and a control software running in it which together are responsible for running and control-ling these simu...

  4. The Influence Of Switching-Off The Big Lamps On The Humidity Operation Hall

    International Nuclear Information System (INIS)

    Wiranto, Slamet; Sriawan

    2001-01-01

    When there is no activity in the Operation Hall, the big lamps in this are switched off. Due to the water trap of ventilation system is not in good function, the humidity of the Operation Hall increases. In any point of time the humidity rise over the permitted limit value. To avoid this problem it is needed to investigate the characteristic by measuring the humidity of the Operation Hall at various condition and situation. From the characteristic, it can be determined that for normal condition, the Operation Hall big lamps should be switched off, and 2 days before start-up reactor, the all operation building lamps should be switched on for about 5 days as the operation building humidity back to normal value

  5. Effect of Humid Aging on the Oxygen Adsorption in SnO2 Gas Sensors

    Directory of Open Access Journals (Sweden)

    Koichi Suematsu

    2018-01-01

    Full Text Available To investigate the effect of aging at 580 °C in wet air (humid aging on the oxygen adsorption on the surface of SnO2 particles, the electric properties and the sensor response to hydrogen in dry and humid atmospheres for SnO2 resistive-type gas sensors were evaluated. The electric resistance in dry and wet atmospheres at 350 °C was strongly increased by humid aging. From the results of oxygen partial pressure dependence of the electric resistance, the oxygen adsorption equilibrium constants (K1; for O− adsorption, K2; for O2− adsorption were estimated on the basis of the theoretical model of oxygen adsorption. The K1 and K2 in dry and wet atmospheres at 350 °C were increased by humid aging at 580 °C, indicating an increase in the adsorption amount of both O− and O2−. These results suggest that hydroxyl poisoning on the oxygen adsorption is suppressed by humid aging. The sensor response to hydrogen in dry and wet atmosphere at 350 °C was clearly improved by humid aging. Such an improvement of the sensor response seems to be caused by increasing the oxygen adsorption amount. Thus, the humid aging offers an effective way to improve the sensor response of SnO2 resistive-type gas sensors in dry and wet atmospheres.

  6. Relation of temperature and humidity to the risk of recurrent gout attacks.

    Science.gov (United States)

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

    2014-08-15

    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. © The Author 2014. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Strongly nonlinear theory of rapid solidification near absolute stability

    Science.gov (United States)

    Kowal, Katarzyna N.; Altieri, Anthony L.; Davis, Stephen H.

    2017-10-01

    We investigate the nonlinear evolution of the morphological deformation of a solid-liquid interface of a binary melt under rapid solidification conditions near two absolute stability limits. The first of these involves the complete stabilization of the system to cellular instabilities as a result of large enough surface energy. We derive nonlinear evolution equations in several limits in this scenario and investigate the effect of interfacial disequilibrium on the nonlinear deformations that arise. In contrast to the morphological stability problem in equilibrium, in which only cellular instabilities appear and only one absolute stability boundary exists, in disequilibrium the system is prone to oscillatory instabilities and a second absolute stability boundary involving attachment kinetics arises. Large enough attachment kinetics stabilize the oscillatory instabilities. We derive a nonlinear evolution equation to describe the nonlinear development of the solid-liquid interface near this oscillatory absolute stability limit. We find that strong asymmetries develop with time. For uniform oscillations, the evolution equation for the interface reduces to the simple form f''+(βf')2+f =0 , where β is the disequilibrium parameter. Lastly, we investigate a distinguished limit near both absolute stability limits in which the system is prone to both cellular and oscillatory instabilities and derive a nonlinear evolution equation that captures the nonlinear deformations in this limit. Common to all these scenarios is the emergence of larger asymmetries in the resulting shapes of the solid-liquid interface with greater departures from equilibrium and larger morphological numbers. The disturbances additionally sharpen near the oscillatory absolute stability boundary, where the interface becomes deep-rooted. The oscillations are time-periodic only for small-enough initial amplitudes and their frequency depends on a single combination of physical parameters, including the

  8. A Resistive Humidity Sensor Based on Nanostructured WO3-ZnO Composites

    Directory of Open Access Journals (Sweden)

    Karunesh Tiwari

    2011-11-01

    Full Text Available Paper reports morphological and humidity sensing studies of WO3 and WO3-ZnO composite pellets prepared in the weight % ratio of 10:1, 4:1 and 2:1 by solid-state reaction route. The pellets have been annealed at temperatures of 300-500 °C. XRD pattern shows peaks of ZnWO4 formed due to solid state reaction between WO3 and ZnO. SEM micrographs show that the sensing elements manifest porous structure. Granulation and tendency to agglomerate seen in the SEM micrograph are due to the presence of zinc ions in ZnWO4. Nanoparticles are having their sizes in the range 37-182 nm. The average Kelvin radius at 20˚C room temperature is 27 Ả. Humidity sensing application of the pellets has been studied in a humidity control cabinet. It is observed that as relative humidity increases, there is decrease in the resistance of pellets in the range 10-85 % RH. Sensing element of WO3-ZnO in 2:1 weight % ratio shows best results in 10-85 % relative humidity range. The average sensitivity of this sample is 1.25 MΩ/%RH. This sensing element shows good reproducibility, low hysteresis and less effect of aging.

  9. Impact of individually controlled facially applied air movement on perceived air quality at high humidity

    DEFF Research Database (Denmark)

    Skwarczynski, Mariusz; Melikov, Arsen Krikor; Kaczmarczyk, J.

    2010-01-01

    and local air velocity under a constant air temperature of 26 degrees C, namely: 70% relative humidity without air movement, 30% relative humidity without air movement and 70% relative humidity with air movement under isothermal conditions. Personalized ventilation was used to supply room air from the front...

  10. Effect of wind speed and relative humidity on atmospheric dust concentrations in semi-arid climates.

    Science.gov (United States)

    Csavina, Janae; Field, Jason; Félix, Omar; Corral-Avitia, Alba Y; Sáez, A Eduardo; Betterton, Eric A

    2014-07-15

    Atmospheric particulate have deleterious impacts on human health. Predicting dust and aerosol emission and transport would be helpful to reduce harmful impacts but, despite numerous studies, prediction of dust events and contaminant transport in dust remains challenging. In this work, we show that relative humidity and wind speed are both determinants in atmospheric dust concentration. Observations of atmospheric dust concentrations in Green Valley, AZ, USA, and Juárez, Chihuahua, México, show that PM10 concentrations are not directly correlated with wind speed or relative humidity separately. However, selecting the data for high wind speeds (>4m/s at 10 m elevation), a definite trend is observed between dust concentration and relative humidity: dust concentration increases with relative humidity, reaching a maximum around 25% and it subsequently decreases with relative humidity. Models for dust storm forecasting may be improved by utilizing atmospheric humidity and wind speed as main drivers for dust generation and transport. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Sol-Gel Zinc Oxide Humidity Sensors Integrated with a Ring Oscillator Circuit On-a-Chip

    Directory of Open Access Journals (Sweden)

    Ming-Zhi Yang

    2014-10-01

    Full Text Available The study develops an integrated humidity microsensor fabricated using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS process. The integrated humidity sensor consists of a humidity sensor and a ring oscillator circuit on-a-chip. The humidity sensor is composed of a sensitive film and branch interdigitated electrodes. The sensitive film is zinc oxide prepared by sol-gel method. After completion of the CMOS process, the sensor requires a post-process to remove the sacrificial oxide layer and to coat the zinc oxide film on the interdigitated electrodes. The capacitance of the sensor changes when the sensitive film adsorbs water vapor. The circuit is used to convert the capacitance of the humidity sensor into the oscillation frequency output. Experimental results show that the output frequency of the sensor changes from 84.3 to 73.4 MHz at 30 °C as the humidity increases 40 to 90%RH.

  12. Impact of individually controlled facially applied air movement on perceived air quality at high humidity

    Energy Technology Data Exchange (ETDEWEB)

    Skwarczynski, M.A. [Faculty of Environmental Engineering, Institute of Environmental Protection Engineering, Department of Indoor Environment Engineering, Lublin University of Technology, Lublin (Poland); International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Copenhagen (Denmark); Melikov, A.K.; Lyubenova, V. [International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark, Copenhagen (Denmark); Kaczmarczyk, J. [Faculty of Energy and Environmental Engineering, Department of Heating, Ventilation and Dust Removal Technology, Silesian University of Technology, Gliwice (Poland)

    2010-10-15

    The effect of facially applied air movement on perceived air quality (PAQ) at high humidity was studied. Thirty subjects (21 males and 9 females) participated in three, 3-h experiments performed in a climate chamber. The experimental conditions covered three combinations of relative humidity and local air velocity under a constant air temperature of 26 C, namely: 70% relative humidity without air movement, 30% relative humidity without air movement and 70% relative humidity with air movement under isothermal conditions. Personalized ventilation was used to supply room air from the front toward the upper part of the body (upper chest, head). The subjects could control the flow rate (velocity) of the supplied air in the vicinity of their bodies. The results indicate an airflow with elevated velocity applied to the face significantly improves the acceptability of the air quality at the room air temperature of 26 C and relative humidity of 70%. (author)

  13. Fatigue characteristics of polycrystalline silicon thin-film membrane and its dependence on humidity

    International Nuclear Information System (INIS)

    Tanemura, Tomoki; Yamashita, Shuichi; Wado, Hiroyuki; Takeuchi, Yukihiro; Tsuchiya, Toshiyuki; Tabata, Osamu

    2013-01-01

    This paper describes fatigue characteristics of a polycrystalline silicon thin-film membrane under different humidity evaluated by out-of-plane resonant vibration. The membrane, without the surface of sidewalls by patterning of photolithography and etching process, was applied to evaluate fatigue characteristics precisely against the changes in the surrounding humidity owing to narrower deviation in the fatigue lifetime. The membrane has 16 mm square-shaped multilayered films consisting of a 250 or 500 nm thick polysilicon film on silicon dioxide and silicon nitride underlying layers. A circular weight of 12 mm in diameter was placed at the center of the membrane to control the resonant frequency. Stress on the polysilicon film was generated by deforming the membrane oscillating the weight in the out-of-plane direction. The polysilicon film was fractured by fatigue damage accumulation under cyclic stress. The lifetime of the polysilicon membrane extended with lower relative humidity, especially at 5%RH. The results of the fatigue tests were well formulated with Weibull's statistics and Paris’ law. The dependence of fatigue characteristics on humidity has been quantitatively revealed for the first time. The crack growth rate indicated by the fatigue index decreased with the reduction in humidity, whereas the deviation of strength represented by the Weibull modulus was nearly constant against humidity. (paper)

  14. Bilayer-structured nanocomposite of Ag and crosslinked polyelectrolyte for the detection of humidity

    International Nuclear Information System (INIS)

    Li, Yang; Wu, Taotao; Yang, Mujie

    2015-01-01

    Nanocomposites of quaternized and crosslinked poly(4-vinylpyridine) (QC-P4VP) and silver nanoparticles were prepared by a two-step procedure, and characterized by Fourier-transform infrared spectroscopy, Ultraviolet–visible spectroscopy and scanning electron microscopy. Bilayer-structured humidity sensors based on the nanocomposites were fabricated, and the effects of the concentration of silver salt precursor and poly(4-vinylpyridine), the method for the reduction of silver salt, the deposition order of the sensitive layers and environmental temperature on the humidity sensing characteristics of the composite sensor have been examined at room temperature. The composite sensor exhibited low impedance under dry atmosphere due to the introduction of Ag nanoparticles, and could detect very low relative humidity (RH) (down to 1% RH) with good sensitivity (impedance change of 2000% from 1% to 30% RH). In addition, the composite sensor demonstrated very wide measuring range (1–98% RH), and revealed faster response and smaller hysteresis than the sensor based on QC-P4VP alone. The complex impedance spectra of the composite sensor in the environments with different RH levels were investigated to explore its humidity sensing mechanism. - Highlights: • Bilayer-structured nanocomposite of Ag and polyelectrolyte are facilely prepared. • Nanocomposite could measure humidity as low as 1% RH and show small hysteresis. • Nanocomposite is capable of detecting full-range humidity with high sensitivity

  15. Effects of temperature and humidity during irradiation on the response of radiachromic film dosimeters

    International Nuclear Information System (INIS)

    Ningnoi, T.; Ehlermann, D.A.E.

    1994-01-01

    The effects of temperature and humidity during γ irradiation on the response of two types of film dosimeters (Far West radiochromic and GafChromic films) were studied in the dose range of 0.3-3 kGy. Both films show a significant effect of temperature and humidity and a simple correction function is proposed. This correction is usually between 5 and 10% for the range studied. For the GafChromic film, a colour change at temperatures above 50 o C was observed and, consequently, this system cannot be used at these temperatures. At lower temperatures down to -70 o C the sensitivity of both films is reduced and a simple correction is possible. In this study and for the dose ranges used, only a slight dependence on humidity was observed for both films from 0 to 60% r.h. Whereas the GafChromic film at humidities up to 90% r.h. shows only a moderate effect, the Far West film shows a considerable inconsistency for the dose range studied. A simple correction function may be applied for humidity effects, except for the Far West film above 60% r.h. where the effect of humidity is also dose dependent. (author)

  16. Atomic force microscope adhesion measurements and atomistic molecular dynamics simulations at different humidities

    International Nuclear Information System (INIS)

    Seppä, Jeremias; Sairanen, Hannu; Korpelainen, Virpi; Husu, Hannu; Heinonen, Martti; Lassila, Antti; Reischl, Bernhard; Raiteri, Paolo; Rohl, Andrew L; Nordlund, Kai

    2017-01-01

    Due to their operation principle atomic force microscopes (AFMs) are sensitive to all factors affecting the detected force between the probe and the sample. Relative humidity is an important and often neglected—both in experiments and simulations—factor in the interaction force between AFM probe and sample in air. This paper describes the humidity control system designed and built for the interferometrically traceable metrology AFM (IT-MAFM) at VTT MIKES. The humidity control is based on circulating the air of the AFM enclosure via dryer and humidifier paths with adjustable flow and mixing ratio of dry and humid air. The design humidity range of the system is 20–60 %rh. Force–distance adhesion studies at humidity levels between 25 %rh and 53 %rh are presented and compared to an atomistic molecular dynamics (MD) simulation. The uncertainty level of the thermal noise method implementation used for force constant calibration of the AFM cantilevers is 10 %, being the dominant component of the interaction force measurement uncertainty. Comparing the simulation and the experiment, the primary uncertainties are related to the nominally 7 nm radius and shape of measurement probe apex, possible wear and contamination, and the atomistic simulation technique details. The interaction forces are of the same order of magnitude in simulation and measurement (5 nN). An elongation of a few nanometres of the water meniscus between probe tip and sample, before its rupture, is seen in simulation upon retraction of the tip in higher humidity. This behaviour is also supported by the presented experimental measurement data but the data is insufficient to conclusively verify the quantitative meniscus elongation. (paper)

  17. Experimental performance of evaporative cooling pad systems in greenhouses in humid subtropical climates

    International Nuclear Information System (INIS)

    Xu, J.; Li, Y.; Wang, R.Z.; Liu, W.; Zhou, P.

    2015-01-01

    Highlights: • Experimental performance of evaporative cooling in humid climate is investigated. • 5 working modes are studied in the greenhouse. • Vertical and horizontal temperature and relative humidity variations are analysed. • Indoor temperature can be kept in required level by proper working modes. - Abstract: To solve the overheating problem caused by the solar radiation and to keep the indoor temperature and humidity at a proper level for plants or crops, cooling technologies play vital role in greenhouse industry, and among which evaporative cooling is one of the most commonly-used methods. However, the main challenge of the evaporative cooling is its suitability to local climatic and agronomic condition. In this study, the performance of evaporative cooling pads was investigated experimentally in a 2304-m 2 glass multi-span greenhouse in Shanghai in the southeast of China. Temperature and humidity distributions were measured and reported for different working modes, including the use of evaporative cooling alone and the use of evaporative cooling with shading or ventilation. These experiments were conducted in humid subtropical climates where were considered unfavourable for evaporative cooling pad systems. Quantified analyses from the energy perspective are also made based on the experimental results and the evaporative cooling fan–pad system is demonstrated to be an effective option for greenhouse cooling even in the humid climate. Suggestions and possible solutions for further improving the performance of the system are proposed. The results of this work will be useful for the optimisation of the energy management of greenhouses in humid climates and for the validation of the mathematical model in future work

  18. Modeling validation and control analysis for controlled temperature and humidity of air conditioning system.

    Science.gov (United States)

    Lee, Jing-Nang; Lin, Tsung-Min; Chen, Chien-Chih

    2014-01-01

    This study constructs an energy based model of thermal system for controlled temperature and humidity air conditioning system, and introduces the influence of the mass flow rate, heater and humidifier for proposed control criteria to achieve the controlled temperature and humidity of air conditioning system. Then, the reliability of proposed thermal system model is established by both MATLAB dynamic simulation and the literature validation. Finally, the PID control strategy is applied for controlling the air mass flow rate, humidifying capacity, and heating, capacity. The simulation results show that the temperature and humidity are stable at 541 sec, the disturbance of temperature is only 0.14 °C, 0006 kg(w)/kg(da) in steady-state error of humidity ratio, and the error rate is only 7.5%. The results prove that the proposed system is an effective controlled temperature and humidity of an air conditioning system.

  19. Modeling Validation and Control Analysis for Controlled Temperature and Humidity of Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Jing-Nang Lee

    2014-01-01

    Full Text Available This study constructs an energy based model of thermal system for controlled temperature and humidity air conditioning system, and introduces the influence of the mass flow rate, heater and humidifier for proposed control criteria to achieve the controlled temperature and humidity of air conditioning system. Then, the reliability of proposed thermal system model is established by both MATLAB dynamic simulation and the literature validation. Finally, the PID control strategy is applied for controlling the air mass flow rate, humidifying capacity, and heating, capacity. The simulation results show that the temperature and humidity are stable at 541 sec, the disturbance of temperature is only 0.14°C, 0006 kgw/kgda in steady-state error of humidity ratio, and the error rate is only 7.5%. The results prove that the proposed system is an effective controlled temperature and humidity of an air conditioning system.

  20. VAB Temperature and Humidity Study

    Science.gov (United States)

    Lane, John E.; Youngquist, Robert C.; Muktarian, Edward; Nurge, Mark A.

    2014-01-01

    In 2012, 17 data loggers were placed in the VAB to measure temperature and humidity at 10-minute intervals over a one-year period. In 2013, the data loggers were replaced with an upgraded model and slight adjustments to their locations were made to reduce direct solar heating effects. The data acquired by the data loggers was compared to temperature data provided by three wind towers located around the building. It was found that the VAB acts as a large thermal filter, delaying and reducing the thermal oscillations occurring outside of the building. This filtering is typically more pronounced at higher locations in the building, probably because these locations have less thermal connection with the outside. We surmise that the lower elevations respond more to outside temperature variations because of air flow through the doors. Temperatures inside the VAB rarely exceed outdoor temperatures, only doing so when measurements are made directly on a surface with connection to the outside (such as a door or wall) or when solar radiation falls directly on the sensor. A thermal model is presented to yield approximate filter response times for various locations in the building. Appendix A contains historical thermal and humidity data from 1994 to 2009.

  1. Humidity effects on the electrical properties of hexagonal boron nitride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Soltani, A. [Institut d' Electronique, de Microelectronique et de Nanotechnologie/CNRS UMR 8520, Cite Scientifique, Avenue Poincare, 59652 Villeneuve d' Ascq (France)]. E-mail: ali.soltani@iemn.univ-lille1.fr; Thevenin, P. [Laboratoire Materiaux Optiques Photonique et Systemes/CNRS FRE 2304, Universite de Metz and Supelec, 2 rue Edouard Belin, 57070 Metz (France); Bakhtiar, H. [Faculty of Science, Physics Department, Technology University of Malaysia, Karung Berkunci 791, 80990, Johor Bahru, Johor (Malaysia); Bath, A. [Laboratoire Materiaux Optiques Photonique et Systemes/CNRS FRE 2304, Universite de Metz and Supelec, 2 rue Edouard Belin, 57070 Metz (France)]. E-mail: bath@metz.supelec.fr

    2005-01-03

    Thin films of hexagonal boron nitride (h-BN) were grown by a plasma enhanced chemical vapour deposition (PECVD) technique. The quality of the films was assessed by infrared spectroscopy, microRaman spectroscopy as a function of annealing temperature and by X-ray photoelectron spectroscopy. The films proved to be thermally stable up to 1370 K. Current-voltage measurements were performed, as a function of humidity, using metal-insulator-semiconductor and metal-insulator-metal structures. Typical resistivities were found in the range 10{sup 13}-10{sup 14} {omega} cm in dry air and exhibit high sensitivity against humidity. The influence of the mean orientation of the c-axis of the BN films was considered. Sawtooth voltage pulse trains were also applied. Threshold switching phenomena were observed, but only in atmosphere containing humidity. The values of the switching voltages depend strongly on the relative humidity (RH), on the characteristics of the applied sawtooth voltage pulse trains, as well as on the nature of the metallic electrode.

  2. Microwave Determination of Water Mole Fraction in Humid Gas Mixtures

    Science.gov (United States)

    Cuccaro, R.; Gavioso, R. M.; Benedetto, G.; Madonna Ripa, D.; Fernicola, V.; Guianvarc'h, C.

    2012-09-01

    A small volume (65 cm3) gold-plated quasi-spherical microwave resonator has been used to measure the water vapor mole fraction x w of H2O/N2 and H2O/air mixtures. This experimental technique exploits the high precision achievable in the determination of the cavity microwave resonance frequencies and is particularly sensitive to the presence of small concentrations of water vapor as a result of the high polarizability of this substance. The mixtures were prepared using the INRIM standard humidity generator for frost-point temperatures T fp in the range between 241 K and 270 K and a commercial two-pressure humidity generator operated at a dew-point temperature between 272 K and 291 K. The experimental measurements compare favorably with the calculated molar fractions of the mixture supplied by the humidity generators, showing a normalized error lower than 0.8.

  3. Forcing absoluteness and regularity properties

    NARCIS (Netherlands)

    Ikegami, D.

    2010-01-01

    For a large natural class of forcing notions, we prove general equivalence theorems between forcing absoluteness statements, regularity properties, and transcendence properties over L and the core model K. We use our results to answer open questions from set theory of the reals.

  4. Compact Buried Ducts in a Hot-Humid Climate House

    Energy Technology Data Exchange (ETDEWEB)

    Mallay, Dave [Home Innovation Research Labs, Upper Marlboro, MD (United States)

    2016-01-07

    "9A system of compact, buried ducts provides a high-performance and cost-effective solution for delivering conditioned air throughout the building. This report outlines research activities that are expected to facilitate adoption of compact buried duct systems by builders. The results of this research would be scalable to many new house designs in most climates and markets, leading to wider industry acceptance and building code and energy program approval. The primary research question with buried ducts is potential condensation at the outer jacket of the duct insulation in humid climates during the cooling season. Current best practices for buried ducts rely on encapsulating the insulated ducts with closed-cell spray polyurethane foam insulation to control condensation and improve air sealing. The encapsulated buried duct concept has been analyzed and shown to be effective in hot-humid climates. The purpose of this project is to develop an alternative buried duct system that performs effectively as ducts in conditioned space - durable, energy efficient, and cost-effective - in a hot-humid climate (IECC warm-humid climate zone 3A) with three goals that distinguish this project: 1) Evaluation of design criteria for buried ducts that use common materials and do not rely on encapsulation using spray foam or disrupt traditional work sequences; 2) Establishing design criteria for compact ducts and incorporate those with the buried duct criteria to further reduce energy losses and control installed costs; 3) Developing HVAC design guidance for performing accurate heating and cooling load calculations for compact buried ducts.

  5. Building America Case Study: Energy Efficient Management of Mechanical Ventilation and Relative Humidity in Hot-Humid Climates, Cocoa, Florida

    Energy Technology Data Exchange (ETDEWEB)

    2017-01-01

    In hot and humid climates, it is challenging to energy-efficiently maintain indoor RH at acceptable levels while simultaneously providing required ventilation, particularly in high performance low cooling load homes. The fundamental problem with solely relying on fixed capacity central cooling systems to manage moisture during low sensible load periods is that they are oversized for cooler periods of the year despite being 'properly sized' for a very hot design cooling day. The primary goals of this project were to determine the impact of supplementing a central space conditioning system with 1) a supplemental dehumidifier and 2) a ductless mini-split on seasonal energy use and summer peak power use as well as the impact on thermal distribution and humidity control inside a completely furnished lab home that was continuously ventilated in accordance with ASHRAE 62.2-2013.

  6. Ethylene sensitivity and relative air humidity regulate root hydraulic properties in tomato plants.

    Science.gov (United States)

    Calvo-Polanco, Monica; Ibort, Pablo; Molina, Sonia; Ruiz-Lozano, Juan Manuel; Zamarreño, Angel María; García-Mina, Jose María; Aroca, Ricardo

    2017-11-01

    The effect of ethylene and its precursor ACC on root hydraulic properties, including aquaporin expression and abundance, is modulated by relative air humidity and plant sensitivity to ethylene. Relative air humidity (RH) is a main factor contributing to water balance in plants. Ethylene (ET) is known to be involved in the regulation of root water uptake and stomatal opening although its role on plant water balance under different RH is not very well understood. We studied, at the physiological, hormonal and molecular levels (aquaporins expression, abundance and phosphorylation state), the plant responses to exogenous 1-aminocyclopropane-1-carboxylic acid (ACC; precursor of ET) and 2-aminoisobutyric acid (AIB; inhibitor of ET biosynthesis), after 24 h of application to the roots of tomato wild type (WT) plants and its ET-insensitive never ripe (nr) mutant, at two RH levels: regular (50%) and close to saturation RH. Highest RH induced an increase of root hydraulic conductivity (Lp o ) of non-treated WT plants, and the opposite effect in nr mutants. The treatment with ACC reduced Lp o in WT plants at low RH and in nr plants at high RH. The application of AIB increased Lp o only in nr plants at high RH. In untreated plants, the RH treatment changed the abundance and phosphorylation of aquaporins that affected differently both genotypes according to their ET sensitivity. We show that RH is critical in regulating root hydraulic properties, and that Lp o is affected by the plant sensitivity to ET, and possibly to ACC, by regulating aquaporins expression and their phosphorylation status. These results incorporate the relationship between RH and ET in the response of Lp o to environmental changes.

  7. Frequency Dependence of Electrical Parameters of an Organic-Inorganic Hybrid Composite Based Humidity Sensor

    Directory of Open Access Journals (Sweden)

    Rizwan Akram

    2016-05-01

    Full Text Available The present study highlights the interdependence of ambient humidity levels on the electrical parameters of organic-inorganic hybrid composite based humidity sensor at varied AC frequencies of input signal. Starting from the bottom, the layer stack of the fabricated humidity sensor was 200-nm silver (Ag thin film and 4 μm spun-coated PEPC+NiPC+Cu2O active layer. Silver thin films were deposited by thermal evaporator on well cleaned microscopic glass slides, which served as a substrate. Conventional optical lithography procedure was adapted to define pairs of silver-silver surface electrodes with two sorts of configurations, i.e., interdigitated and rectangular. Humidity-sensitive layers of organic-inorganic composite were then spun-cast upon the channel between the silver electrodes. The changes in relative humidity levels induced variation in capacitance and impedance of the sensors. These variations in electrical parameters of sensors were also found to be highly dependent upon frequency of input AC signal. Our findings reveal that the organic-inorganic composite shows higher humidity sensitivity at smaller orders of frequency. This finding is in accordance with the established fact that organic semiconductors-based devices are not applicable for high frequency applications due to their lower charge carrier mobility values. Two distinct geometries of semiconducting medium between the silver electrodes were investigated to optimize the sensing parameters of the humidity sensor. Furthermore, the effect of temperature change on the resistance of organic composite has also been studied.

  8. Visual indication of enviromental humidity by using poly(ionic liquid) photonic crystals.

    Science.gov (United States)

    Huang, Jing; Tao, Cheng-an; An, Qi; Lin, Changxu; Li, Xuesong; Xu, Dan; Wu, Yiguang; Li, Xiaogang; Shen, Dezhong; Li, Guangtao

    2010-06-21

    The combination of poly (ionic liquid) and photonic structure affords a new class of self-reporting humidity sensory materials with excellent reversibility, which are able to rapidly, sensitively and visually indicate environmental humidity with colour change from blue to green, orange, and red, covering the whole visible range.

  9. Absolute calibration of sniffer probes on Wendelstein 7-X

    NARCIS (Netherlands)

    Moseev, D.; Laqua, H.P.; Marsen, S.; Stange, T.; Braune, H.; Erckmann, V.; Gellert, F.J.; Oosterbeek, J.W.

    Here we report the first measurements of the power levels of stray radiation in the vacuum vessel of Wendelstein 7-X using absolutely calibrated sniffer probes. The absolute calibration is achieved by using calibrated sources of stray radiation and the implicit measurement of the quality factor of

  10. Absolute tense forms in Tswana | Pretorius | Journal for Language ...

    African Journals Online (AJOL)

    These views were compared in an attempt to put forth an applicable framework for the classification of the tenses in Tswana and to identify the absolute tenses of Tswana. Keywords: tense; simple tenses; compound tenses; absolute tenses; relative tenses; aspect; auxiliary verbs; auxiliary verbal groups; Tswana Opsomming

  11. Humid-air and aqueous corrosion models for corrosion-allowance barrier material

    International Nuclear Information System (INIS)

    Lee, J.H.; Atkins, J.E.; Andrews, R.W.

    1995-01-01

    Humid-air and aqueous general and pitting corrosion models (including their uncertainties) for the carbon steel outer containment barrier were developed using the corrosion data from literature for a suite of cast irons and carbon steels which have similar corrosion behaviors to the outer barrier material. The corrosion data include the potential effects of various chemical species present in the testing environments. The atmospheric corrosion data also embed any effects of cyclic wetting and drying and salts that may form on the corroding specimen surface. The humid-air and aqueous general corrosion models are consistent in that the predicted humid-air general corrosion rates at relative humidities between 85 and 100% RH are close to the predicted aqueous general corrosion rates. Using the expected values of the model parameters, the model predicts that aqueous pitting corrosion is the most likely failure mode for the carbon steel outer barrier, and an earliest failure (or initial pit penetration) of the 100-mm thick barrier may occur as early as about 500 years if it is exposed continuously to an aqueous condition at between 60 and 70 degrees C

  12. Ozone generation in positive and negative corona discharge fed by humid oxygen and carbon dioxide

    International Nuclear Information System (INIS)

    Skalny, J D; Orszagh, J; MatejcIk, S; Mason, N J

    2008-01-01

    The effect of humidity on ozone generation of positive and negative corona discharges fed by O 2 and CO 2 has been studied in the humidity range of 100-20 000 ppm. The experiments were carried out at an ambient temperature and pressure of 100 kPa. The increase in humidity of CO 2 conspicuously suppressed the ozone generation in negative corona discharge at all values of the input energy densities into the discharge. The effect was less pronounced in oxygen. In contrast to decrease of ozone concentration observed in negative corona discharge, the presence of water both in O 2 and CO 2 acts catalytically. The ozone concentration has been found to increase remarkably (approximately 10 times) in oxygen, if the humidity was increased from 100 to 20 000 ppm. The dependence of ozone concentration on the gas humidity exhibited an extreme. The increase observed at humidity up to approximately 5000 ppm was followed by the marginal reduction in ozone concentration. Anyway, the values of this were considerably higher than those found in dry CO 2 . The effect of humidity on ozone concentration will be discussed in relation to plasma chemical processes in studied discharges and their macroscopic parameters.

  13. Probative value of absolute and relative judgments in eyewitness identification.

    Science.gov (United States)

    Clark, Steven E; Erickson, Michael A; Breneman, Jesse

    2011-10-01

    It is well-accepted that eyewitness identification decisions based on relative judgments are less accurate than identification decisions based on absolute judgments. However, the theoretical foundation for this view has not been established. In this study relative and absolute judgments were compared through simulations of the WITNESS model (Clark, Appl Cogn Psychol 17:629-654, 2003) to address the question: Do suspect identifications based on absolute judgments have higher probative value than suspect identifications based on relative judgments? Simulations of the WITNESS model showed a consistent advantage for absolute judgments over relative judgments for suspect-matched lineups. However, simulations of same-foils lineups showed a complex interaction based on the accuracy of memory and the similarity relationships among lineup members.

  14. Electrically conductive poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate)/polyacrylonitrile fabrics for humidity sensors

    International Nuclear Information System (INIS)

    Panapoy, Manop; Singsang, Witawat; Ksapabutr, Bussarin

    2010-01-01

    Humidity sensors based on poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT-PSS)/polyacrylonitrile (PAN) nanofiber fabric were fabricated by a dip coating of nonwoven PAN nanofiber mat, which was prepared via an electrospinning method, in PEDOT-PSS solution. The influence of PAN solution concentration on their responsiveness to humidity on dynamic testing was monitored as the device was exposed to humidity. With the relative humidity (RH) changing from 0 to 100%, a resistance device response over 110% was achieved, and the curve of the resistance response with RH is of high linearity at the humidity working range of 0-100% RH. The high device reproducibility was demonstrated by carrying out vapor adsorption-desorption dynamic cycles, and the response and recovery times were determined to be of the order of 2-46 and 7-34 s, respectively. These hybrid polymer sensors can be used as disposable handheld instruments due to low cost and light weight.

  15. Synthesis of humidity sensitive zinc stannate nanomaterials and modelling of Freundlich adsorption isotherm model

    Science.gov (United States)

    Sharma, Alfa; Kumar, Yogendra; Shirage, Parasharam M.

    2018-04-01

    The chemi-resistive humidity sensing behaviour of as prepared and annealed ZnSnO3 nanoparticles synthesized using a wet chemical synthesis method was investigated. The effect of stirring temperature over the evolution of varied nanomorphology of zinc stannate is in accordance to Ostwald's ripening law. At room temperature, an excellent humidity sensitivity of ˜800% and response/recovery time of 70s./102s. is observed for ZnSnO3 sample within 08-97% relative humidity range. The experimental data observed over the entire range of RH values well fitted with the Freundlich adsorption isotherm model, and revealing two distinct water adsorption regimes. The excellent humidity sensitivity observed in the nanostructures is attributed to Grotthuss mechanism considering the availability and distribution of available adsorption sites. This present result proposes utilization of low cost synthesis technique of ZnSnO3 holds the promising capabilities as potential candidate for the fabrication of next generation humidity sensors.

  16. Low Loss Polycarbonate Polymer Optical Fiber for High Temperature FBG Humidity Sensing

    DEFF Research Database (Denmark)

    Woyessa, Getinet; Fasano, Andrea; Markos, Christos

    2017-01-01

    We report the fabrication and characterization of a polycarbonate (PC) microstructured polymer optical fiber (mPOF) Bragg grating (FBG) humidity sensor that can operate beyond 100°C. The PC preform, from which the fiber was drawn, was produced using an improved casting approach to reduce...... the attenuation of the fiber. The fiber loss was found reduced by a factor of two compared to the latest reported PC mPOF [20], holding the low loss record in PC based fibers. PC mPOFBG was characterized to humidity and temperature, and a relative humidity (RH) sensitivity of 7.31± 0.13 pm/% RH in the range 10...

  17. Positioning, alignment and absolute pointing of the ANTARES neutrino telescope

    International Nuclear Information System (INIS)

    Fehr, F; Distefano, C

    2010-01-01

    A precise detector alignment and absolute pointing is crucial for point-source searches. The ANTARES neutrino telescope utilises an array of hydrophones, tiltmeters and compasses for the relative positioning of the optical sensors. The absolute calibration is accomplished by long-baseline low-frequency triangulation of the acoustic reference devices in the deep-sea with a differential GPS system at the sea surface. The absolute pointing can be independently verified by detecting the shadow of the Moon in cosmic rays.

  18. Analysis of air temperature and relative humidity: study of microclimates

    OpenAIRE

    Elis Dener Lima Alves; Marcelo Sacardi Biudes

    2012-01-01

    Understanding the variability of climate elements in time and space is fundamental to the knowledge of the dynamics of microclimate. Thus, the objective was to analyze the variability of air temperature and relative humidity on the Cuiabá campus of the Federal University of Mato Grosso, and, through the clustering technique, to analyze the formation of groups to propose a zoning microclimate in the area study. To this end, collection data of air temperature and relative humidity at 15 points ...

  19. Enhancement of humidity sensitivity of graphene through functionalization with polyethylenimine

    International Nuclear Information System (INIS)

    Ben Aziza, Zeineb; Zhang, Kang; Baillargeat, Dominique; Zhang, Qing

    2015-01-01

    In this work, we show that the sensing performance of graphene based humidity sensors can be largely improved through polymer functionalization. Chemical vapor deposited graphene is functionalized with amine rich polymer, leading to electron transfer from amine groups in the polymer to graphene. The functionalized graphene humidity sensor has demonstrated good sensitivity, recovery, and repeatability. Charge transfer between the functionalized graphene and water molecules and the sensing mechanism are studied systemically using field effect transistor geometry and scanning Kelvin probe microscopy

  20. Does Absolute Synonymy exist in Owere-Igbo? | Omego | AFRREV ...

    African Journals Online (AJOL)

    Among Igbo linguistic researchers, determining whether absolute synonymy exists in Owere–Igbo, a dialect of the Igbo language predominantly spoken by the people of Owerri, Imo State, Nigeria, has become a thorny issue. While some linguistic scholars strive to establish that absolute synonymy exists in the lexical ...

  1. The Impact of Upper Tropospheric Humidity from Microwave Limb Sounder on the Midlatitude Greenhouse Effect

    Science.gov (United States)

    Hu, Hua; Liu, W. Timothy

    1998-01-01

    This paper presents an analysis of upper tropospheric humidity, as measured by the Microwave Limb Sounder, and the impact of the humidity on the greenhouse effect in the midlatitudes. Enhanced upper tropospheric humidity and an enhanced greenhouse effect occur over the storm tracks in the North Pacific and North Atlantic. In these areas, strong baroclinic activity and the large number of deep convective clouds transport more water vapor to the upper troposphere, and hence increase greenhouse trapping. The greenhouse effect increases with upper tropospheric humidity in areas with a moist upper troposphere (such as areas over storm tracks), but it is not sensitive to changes in upper tropospheric humidity in regions with a dry upper troposphere, clearly demonstrating that there are different mechanisms controlling the geographical distribution of the greenhouse effect in the midlatitudes.

  2. Effect of ventilated structure on dehumidification. ; Experimental result in winter. Tsuki koho no haishitsu koka ni kansuru kenkyu. ; Toki jikken kekka

    Energy Technology Data Exchange (ETDEWEB)

    Sugai, T; Ozaki, A [Fukuoka University, Fukuoka (Japan). Faculty of Engineering; Katayama, T; Hayashi, T; Shiotsuki, Y [Kyushu University, Fukuoka (Japan)

    1912-09-01

    Temperature and humidity characteristics and condensation within walls under heating and humidification were studied experimentally in winter using two test houses of conventional and ventilated structures. The absolute humidity in conventional one fluctuated depending on temperature gradient, water flux due to humidification and water adsorption onto glass wool, and accumulated water increased with humidification. That in ventilated one was also affected by dehumidification through ventilation layers. Under heating and humidification, the absolute humidity increased depending on temperature rise and water flux within walls. In conventional one, condensation was frequently observed on felt in walls and others because of accumulated humidity, while in ventilated one, humidity was kept lower within walls even under heating, because humidity in walls was discharged through ventilation layers. Condensation was also scarcely observed on waterproof moisture-permeable sheets in walls and others. 3 refs ., 39 figs 1., tab.

  3. Flight prototype CO2 and humidity control system

    Science.gov (United States)

    Rudy, K. M.

    1979-01-01

    A regenerable CO2 and humidity control system is presently being developed for potential use on shuttle as an alternative to the baseline lithium hydroxide system. The system utilizes a sorbent material (designated HS-C) to adsorb CO2 and the latent heat load from the cabin atmosphere and desorb the CO2 and water vapor overboard when exposed to a space vacuum, thus reducing the overall vehicle heat rejection load. Continuous operation is achieved by utilizing two beds which are alternatively cycled between adsorption and desorption. The HS-C material process was verified. Design concepts for the auxiliary components for the HS-C prototype system were generated. Performance testing verified system effectiveness in controlling CO2 partial pressure and humidity.

  4. Mycotoxin production in wheat grains by different Aspergilli in relation to different relative humidities and storage periods.

    Science.gov (United States)

    Atalla, Mohamed Mabrouk; Hassanein, Naziha Mohamed; El-Beih, Ahmed Atef; Youssef, Youssef Abdel-ghany

    2003-02-01

    Four different Aspergilli (Aspergillus oryzae, A. parasiticus, A. terreus and A. versicolor) were grown on wheat grains underdifferent degrees of relative humidity 14, 50, 74, 80 and 90%. Samples of wheat grains were taken monthly for a period of six months and examined for mycotoxin production. A. oryzae was found to produce aflatoxins B1, B2, zearalenone, DON and T-2 toxins under elevated degrees of humidity and prolonged periods of storage. A. parasiticus produced aflatoxins B1, G1, NIV, DON and T-2 toxins in high concentrations during a period of not more than three months storage at 14% relative humidity; at an increased level of relative humidity of 74% ochratoxin A, zearalenone and sterigmatocystin were also produced at high levels. The isolate was drastic in toxin production. A. terrus produced toxins at 14% relative humidity (aflatoxin G2 and DON) at levels much higher than any other prevalent degrees of humidity. A. versicolor is highly sensitive to relative humidity and grain moisture content It produced aflatoxins B1, G1, NIV and DON at a relative humidity of 50% and another toxins (aflatoxin G2, ochratoxins A, B and zearalenone) at 74%. The microorganism can be considered a trichothecene producer under suitable relative humidity.

  5. [Evaluation of the influence of humidity and temperature on the drug stability by initial average rate experiment].

    Science.gov (United States)

    He, Ning; Sun, Hechun; Dai, Miaomiao

    2014-05-01

    To evaluate the influence of temperature and humidity on the drug stability by initial average rate experiment, and to obtained the kinetic parameters. The effect of concentration error, drug degradation extent, humidity and temperature numbers, humidity and temperature range, and average humidity and temperature on the accuracy and precision of kinetic parameters in the initial average rate experiment was explored. The stability of vitamin C, as a solid state model, was investigated by an initial average rate experiment. Under the same experimental conditions, the kinetic parameters obtained from this proposed method were comparable to those from classical isothermal experiment at constant humidity. The estimates were more accurate and precise by controlling the extent of drug degradation, changing humidity and temperature range, or by setting the average temperature closer to room temperature. Compared with isothermal experiments at constant humidity, our proposed method saves time, labor, and materials.

  6. SAW Humidity Sensor Sensitivity Enhancement via Electrospraying of Silver Nanowires

    Directory of Open Access Journals (Sweden)

    Farid Sayar Irani

    2016-11-01

    Full Text Available In this research, we investigated the influence of the surface coatings of silver nanowires on the sensitivity of surface acoustic wave (SAW humidity sensors. Silver nanowires, with poly(vinylpyrrolidone (PVP, which is a hydrophilic capping agent, were chemically synthesized, with an average length of 15 µm and an average diameter of 60 nm. Humidity sensors, with 433 MHz frequency dual-port resonator Rayleigh-SAW devices, were coated by silver nanowires (AgNWs using the electrospray coating method. It was demonstrated that increasing thickness of coated AgNW on the surfaces of SAW devices results in increased sensitivity. The highest frequency shift (262 kHz in these SAW devices was obtained with an injection of 0.5 mL of the AgNW solution with a concentration of 0.5 mg/mL at an injection rate of 1 mL/h. It also showed the highest humidity sensitivity among the other prepared SAW devices.

  7. Designing a robust high-speed CMOS-MEMS capacitive humidity sensor

    International Nuclear Information System (INIS)

    Lazarus, N; Fedder, G K

    2012-01-01

    In our previous work (Lazarus and Fedder 2011 J. Micromech. Microeng. 21 0650281), we demonstrated a CMOS-MEMS capacitive humidity sensor with a 72% improvement in sensitivity over the highest previously integrated on a CMOS die. This paper explores a series of methods for creating a faster and more manufacturable high-sensitivity capacitive humidity sensor. These techniques include adding oxide pillars to hold the plates apart, spin coating polymer to allow sensors to be fabricated more cheaply, adding a polysilicon heater and etching away excess polymer in the release holes. In most cases a tradeoff was found between sensitivity and other factors such as response time or robustness. A robust high-speed sensor was designed with a sensitivity of 0.21% change in capacitance per per cent relative humidity, while dropping the response time constant from 70 to 4s. Although less sensitive than our design, the sensor remains 17% more sensitive than the most sensitive interdigitated designs successfully integrated with CMOS. (paper)

  8. Simulation of electronic circuit sensitivity towards humidity using electrochemical data on water layer

    DEFF Research Database (Denmark)

    Joshy, Salil; Verdingovas, Vadimas; Jellesen, Morten Stendahl

    2015-01-01

    Climatic conditions like temperature and humidity have direct influence on the operation of electronic circuits. The effects of temperature on the operation of electronic circuits have been widely investigated, while the effect of humidity and solder flux residues are not well understood including...... the effect on circuit and PCBA (printed circuit board assembly) layout design. This paper elucidates a methodology for analyzing the sensitivity of an electronic circuit based on parasitic circuit analysis using data on electrical property of the water layer formed under humid as well as contaminated...

  9. Two-user opportunistic scheduling using hierarchical modulations in wireless networks with heterogenous average link gains

    KAUST Repository

    Hossain, Md Jahangir

    2010-03-01

    Our contribution, in this paper, is two-fold. First, we analyze the performance of a hierarchical modulation-assisted two-best user opportunistic scheduling (TBS) scheme, which was proposed by the authors, in a fading environment where different users have different average link gains. Specifically, we present a new expression for the spectral efficiency (SE) of the users and using this expression, we compare the degrees of fairness (DOF) of the TBS scheme with that of classical single user opportunistic scheduling schemes, namely, absolute carrier-to-noise ratio (CNR) based single-best user scheduling (SBS) and normalized CNR based proportional fair scheduling (PFS) schemes. The second contribution is that we propose a new hybrid two-user opportunistic scheduling (HTS) scheme based on our earlier proposed TBS scheme. This HTS scheme selects the first user based on the largest absolute CNR value among all the users while the second user is selected based on the ratios of the absolute CNRs to the corresponding average CNRs of the remaining users. The total transmission rate i.e., the constellation size is selected according to the absolute CNR of the first best user. The total transmission rate is then allocated among these selected users by joint consideration of their absolute CNRs and allocated number of information bit(s) are transmitted to them using hierarchical modulations. Numerical results are presented for a fading environment where different users experience independent but non-identical (i.n.d.) channel fading. These selected numerical results show that the proposed HTS scheme can considerably increase the system\\'s fairness without any degradation of the link spectral efficiency (LSE) i.e., the multiuser diversity gain compared to the classical SBS scheme. These results also show that the proposed HTS scheme has a lower fairness in comparison to the PFS scheme which suffers from a considerable degradation in LSE. © 2010 IEEE.

  10. Moral absolutism and ectopic pregnancy.

    Science.gov (United States)

    Kaczor, C

    2001-02-01

    If one accepts a version of absolutism that excludes the intentional killing of any innocent human person from conception to natural death, ectopic pregnancy poses vexing difficulties. Given that the embryonic life almost certainly will die anyway, how can one retain one's moral principle and yet adequately respond to a situation that gravely threatens the life of the mother and her future fertility? The four options of treatment most often discussed in the literature are non-intervention, salpingectomy (removal of tube with embryo), salpingostomy (removal of embryo alone), and use of methotrexate (MXT). In this essay, I review these four options and introduce a fifth (the milking technique). In order to assess these options in terms of the absolutism mentioned, it will also be necessary to discuss various accounts of the intention/foresight distinction. I conclude that salpingectomy, salpingostomy, and the milking technique are compatible with absolutist presuppositions, but not the use of methotrexate.

  11. Influence of Ambient Humidity on the Voltage Response of Ionic Polymer-Metal Composite Sensor.

    Science.gov (United States)

    Zhu, Zicai; Horiuchi, Tetsuya; Kruusamäe, Karl; Chang, Longfei; Asaka, Kinji

    2016-03-31

    Electrical potential based on ion migration exists not only in natural systems but also in ionic polymer materials. In order to investigate the influence of ambient humidity on voltage response, classical Au-Nafion IPMC was chosen as the reference sample. Voltage response under a bending deformation was measured in two ways: first, continuous measurement of voltage response in the process of absorption and desorption of water to study the tendency of voltage variation at all water states; second, measurements at multiple fixed ambient humidity levels to characterize the process of voltage response quantitatively. Ambient humidity influences the voltage response mainly by varying water content in ionic polymer. Under a step bending, the amplitude of initial voltage peak first increases and then decreases as the ambient humidity and the inherent water content decrease. This tendency is explained semiquantitatively by mass storage capacity related to the stretchable state of the Nafion polymer network. Following the initial peak, the voltage shows a slow decay to a steady state, which is first characterized in this paper. The relative voltage decay during the steady state always decreases as the ambient humidity is lowered. It is ascribed to progressive increase of the ratio between the water molecules in the cation hydration shell to the free water. Under sinusoidal mechanical bending excitation in the range of 0.1-10 Hz, the voltage magnitude increases with frequency at high ambient humidity but decreases with frequency at low ambient humidity. The relationship is mainly controlled by the voltage decay effect and the response speed.

  12. Developmental acclimation to low or high humidity conditions affect starvation and heat resistance of Drosophila melanogaster.

    Science.gov (United States)

    Parkash, Ravi; Ranga, Poonam; Aggarwal, Dau Dayal

    2014-09-01

    Several Drosophila species originating from tropical humid localities are more resistant to starvation and heat stress than populations from high latitudes but mechanistic bases of such physiological changes are largely unknown. In order to test whether humidity levels affect starvation and heat resistance, we investigated developmental acclimation effects of low to high humidity conditions on the storage and utilization of energy resources, body mass, starvation survival, heat knockdown and heat survival of D. melanogaster. Isofemale lines reared under higher humidity (85% RH) stored significantly higher level of lipids and showed greater starvation survival hours but smaller in body size. In contrast, lines reared at low humidity evidenced reduced levels of body lipids and starvation resistance. Starvation resistance and lipid storage level were higher in females than males. However, the rate of utilization of lipids under starvation stress was lower for lines reared under higher humidity. Adult flies of lines reared at 65% RH and acclimated under high or low humidity condition for 200 hours also showed changes in resistance to starvation and heat but such effects were significantly lower as compared with developmental acclimation. Isofemale lines reared under higher humidity showed greater heat knockdown time and heat-shock survival. These laboratory observations on developmental and adult acclimation effects of low versus high humidity conditions have helped in explaining seasonal changes in resistance to starvation and heat of the wild-caught flies of D. melanogaster. Thus, we may suggest that wet versus drier conditions significantly affect starvation and heat resistance of D. melanogaster. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Integrated CMOS dew point sensors for relative humidity measurement

    Science.gov (United States)

    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%.

  14. The absolute flux of protons and helium at the top of the atmosphere using IMAX

    DEFF Research Database (Denmark)

    Menn, W.; Hof, M.; Reimer, O.

    2000-01-01

    isotopes using a superconducting magnet spectrometer together with scintillators, a time-of-flight system, and Cherenkov detectors. Using redundant detectors, an extensive examination of the instrument efficiency was carried out. We present here the absolute spectra of protons and helium corrected...... to the top of the atmosphere and to interstellar space. If demodulated with a solar modulation parameter of phi = 750 MV, the measured interstellar spectra between 20 and 200 GV can be represented by a power law in rigidity, with (1.42 +/- 0.21) x 10(4)R(-2.71+/-0.04) (m(2) GV s sr)(-1) for protons and (3.......15 +/- 1.03) x 10(3)R(-2.79+/-0.08) (m(2) GV s sr)(-1) for helium....

  15. The effect of relative humidity on germination of Sporangia of Phytophthora ramorum

    Science.gov (United States)

    Sporangia of three isolates of P. ramorum representing three different clonal lineages were subjected to relative humidity (RH) levels between 80 and 100% for exposure periods ranging from 1 to 24 h at 20°C in darkness. Airtight snap-lid plastic containers (21.5 x 14.5 x 5 cm) were used as humidity ...

  16. A hybrid humidity sensor using optical waveguides on a quartz crystal microbalance

    International Nuclear Information System (INIS)

    Shinbo, Kazunari; Otuki, Shunya; Kanbayashi, Yuichi; Ohdaira, Yasuo; Baba, Akira; Kato, Keizo; Kaneko, Futao; Miyadera, Nobuo

    2009-01-01

    In this study, slab and ridge optical waveguides (OWGs) made of fluorinated polyimides were deposited on a quartz crystal microbalance (QCM), and hybrid sensors using OWG spectroscopy and the QCM technique were prepared. Polyvinyl alcohol (PVA) film with CoCl 2 was deposited on the OWGs, and the characteristics of humidity sensing were investigated. A prism coupler was used to enter a He-Ne laser beam (λ = 632.8 nm) to the slab OWG. The output light intensity markedly changed due to chromism of the CoCl 2 as a result of humidity sorption, and this change was dependent on the incident angle of the laser beam to the slab OWG. During the measurement of output light, the QCM frequency was simultaneously monitored. The humidity dependence of the sensor with the slab OWG was also investigated in the range from 15 to 85%. For the sensor with the ridge OWG, white light was entered by butt-coupling, and the characteristics of humidity sensing were investigated by observing the output light spectrum and the QCM frequency.

  17. Influence of ambient humidity on the current delivered by air-vented ionization chambers revisited

    International Nuclear Information System (INIS)

    Poirier, Aurelie; Douysset, Guilhem

    2006-01-01

    The influence of ambient humidity on the current delivered by a vented ionization chamber has been re-investigated. A Nucletron 077.091 well-type chamber together with a 192 Ir HDR brachytherapy source was enclosed in a climatic test chamber and the current was recorded for various humidity values. Great care has been taken for the design of the experimental setup in order to obtain reliable measurements of currents and humidity values inside the chamber active volume. A ±0.35% linear variation of the measured currents has been observed over a common range of humidities. This result is larger than the expected variation. No formal explanation of such a discrepancy has been found yet, however the present results could lead to a set of recommendations

  18. Influence of ambient humidity on the current delivered by air-vented ionization chambers revisited

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, Aurelie; Douysset, Guilhem [Laboratoire National Henri Becquerel-LNE, CEA Saclay 91191 Gif-sur-Yvette (France)

    2006-10-07

    The influence of ambient humidity on the current delivered by a vented ionization chamber has been re-investigated. A Nucletron 077.091 well-type chamber together with a {sup 192}Ir HDR brachytherapy source was enclosed in a climatic test chamber and the current was recorded for various humidity values. Great care has been taken for the design of the experimental setup in order to obtain reliable measurements of currents and humidity values inside the chamber active volume. A {+-}0.35% linear variation of the measured currents has been observed over a common range of humidities. This result is larger than the expected variation. No formal explanation of such a discrepancy has been found yet, however the present results could lead to a set of recommendations.

  19. A new heat and moisture exchanger for laryngectomized patients: endotracheal temperature and humidity

    NARCIS (Netherlands)

    Scheenstra, Renske J.; Muller, Saar H.; Vincent, Andrew; Ackerstaff, Annemieke H.; Jacobi, Irene; Hilgers, Frans J. M.

    2011-01-01

    To assess the endotracheal temperature and humidity and clinical effects of 2 models of a new heat and moisture exchanger (HME): Rplus, which has regular breathing resistance, and Lplus, which has lower breathing resistance. We measured endotracheal temperature and humidity in 10 laryngectomized

  20. Absolute and Relative Socioeconomic Health Inequalities across Age Groups.

    Science.gov (United States)

    van Zon, Sander K R; Bültmann, Ute; Mendes de Leon, Carlos F; Reijneveld, Sijmen A

    2015-01-01

    The magnitude of socioeconomic health inequalities differs across age groups. It is less clear whether socioeconomic health inequalities differ across age groups by other factors that are known to affect the relation between socioeconomic position and health, like the indicator of socioeconomic position, the health outcome, gender, and as to whether socioeconomic health inequalities are measured in absolute or in relative terms. The aim is to investigate whether absolute and relative socioeconomic health inequalities differ across age groups by indicator of socioeconomic position, health outcome and gender. The study sample was derived from the baseline measurement of the LifeLines Cohort Study and consisted of 95,432 participants. Socioeconomic position was measured as educational level and household income. Physical and mental health were measured with the RAND-36. Age concerned eleven 5-years age groups. Absolute inequalities were examined by comparing means. Relative inequalities were examined by comparing Gini-coefficients. Analyses were performed for both health outcomes by both educational level and household income. Analyses were performed for all age groups, and stratified by gender. Absolute and relative socioeconomic health inequalities differed across age groups by indicator of socioeconomic position, health outcome, and gender. Absolute inequalities were most pronounced for mental health by household income. They were larger in younger than older age groups. Relative inequalities were most pronounced for physical health by educational level. Gini-coefficients were largest in young age groups and smallest in older age groups. Absolute and relative socioeconomic health inequalities differed cross-sectionally across age groups by indicator of socioeconomic position, health outcome and gender. Researchers should critically consider the implications of choosing a specific age group, in addition to the indicator of socioeconomic position and health outcome