The response of clay plaster to temperature and RH sinusoidal variations

Hygroscopic finishing materials can be used to moderate indoor humidity levels; they have the capacity to adsorb and release moisture from and to the surrounding air, depending on the indoor relative humidity levels. To determine the moisture buffering properties of materials several protocols have been introduced. However, testing procedures are based on a time-response method, where humidity variations are under a square wave function and temperature remains constant. Therefore, the ability of these methods to simulate material behaviour under real conditions, where cyclical humidity variations are more gradual, and temperature is variable, has been called into question. The aim of this study is to perform a standard moisture buffering test, by substituting the step-variation method, with a sinusoidal humidity function at different temperatures. Clay has been used to perform the tests in a climatic chamber, where a small increase of relative humidity have been set, in order to obtain a quasi-sinusoidal curve. The relative humidity variation are limited by low humidity (33% RH) and high humidity (75% RH) and temperature variation between 18 °C and 28 °C. Materials tested present a lag in the response to the peak relative humidity to peak mass gain, which suggests an alternative way to consider the rate of sorption and the moisture storage function. The significance of the paper is to develop a laboratory test that can be more readily compared with the behaviour real buildings, which operate under more of a sine waveform

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The Effects of Temperature and Relative Humidity on the Viability of the SARS Coronavirus

Advances in Virology ◽

10.1155/2011/734690 ◽

2011 ◽

Vol 2011 ◽

pp. 1-7 ◽

Cited By ~ 270

Author(s):

K. H. Chan ◽

J. S. Malik Peiris ◽

S. Y. Lam ◽

L. L. M. Poon ◽

K. Y. Yuen ◽

...

Keyword(s):

Relative Humidity ◽

Smooth Surfaces ◽

Sars Coronavirus ◽

Route Of Transmission ◽

Different Temperatures ◽

Low Humidity ◽

The Stability ◽

Community Outbreaks ◽

Respiratory Droplets ◽

Humidity Environment

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

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High Temperatures Decrease the Flight Capacity of Diaphorina citri Kuwayama (Hemiptera: Liviidae)

Insects ◽

10.3390/insects12050394 ◽

2021 ◽

Vol 12 (5) ◽

pp. 394

Author(s):

Carlos A. Antolinez ◽

Tobias Moyneur ◽

Xavier Martini ◽

Monique J. Rivera

Keyword(s):

Relative Humidity ◽

High Temperatures ◽

Insect Pest ◽

The United States ◽

Diaphorina Citri ◽

Long Distance ◽

Flight Duration ◽

Custom Made ◽

Flight Capacity ◽

Low Humidity

Diaphorina citri Kuwayama (Hemiptera: Liviidae), commonly known as Asian citrus psyllid (ACP), is an invasive insect pest and the vector of the bacterium causing Huanglongbing (HLB), a lethal disease of citrus. In the United States, ACP has been established in all citrus-producing zones, all of which have different environmental conditions. The spread of ACP and, more importantly, HLB, has progressed differently depending on the state, with more rapid spread in Florida and Texas than in California. Climatic variations between the regions are likely a strong factor in the difference in the rate of spread. Despite this, it is unknown how the flight capacity of D. citri is influenced by high temperatures (>30 °C) and subsequently, low humidity experienced in California but not in Texas or Florida. In this study, by using a custom-made, temperature-controlled flight mill arena, we assessed the effect of high temperatures on the flight capacity and flight propensity of D. citri under low (20–40%) and high (76–90%) relative humidity conditions. We found that temperature and humidity influence the propensity to engage in short or long-distance flight events. Psyllids exposed to temperatures above 43 °C only performed short flights (˂60 s), and a high relative humidity significantly decrease the proportion of long flights (≥60 s) at 26 and 40 °C. The flight capacity for insects who engaged in short and long flights was significantly affected by temperature but not by humidity. For long flyers, temperature (in the 26–43 °C range) was negatively correlated with distance flown and flight duration. The most favorable temperature for long dispersion was 26 °C, with suboptimal temperatures in the range of 32–37 °C and the least favorable temperatures at 40 and 43 °C. In conclusion, D. citri is able to fly in a broad range of temperatures and efficiently fly in high and low humidity. However, temperatures above 40 °C, similar to those experienced in semi-arid environments like Southern California or Arizona, are detrimental for its flight capacity.

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The Effect of Temperature and Humidity May Reduce the Growth Rate of the Coronavirus Disease 2019 Epidemic

10.21203/rs.3.rs-27890/v1 ◽

2020 ◽

Author(s):

Lei Qin ◽

Qiang Sun ◽

Jiani Shao ◽

Yang Chen ◽

Xiaomei Zhang ◽

...

Keyword(s):

Growth Rate ◽

Relative Humidity ◽

Effect Of Temperature ◽

Average Temperature ◽

Temperature And Humidity ◽

Scatter Plots ◽

Low Humidity ◽

Average Relative Humidity ◽

Effects Of Temperature ◽

The Relationship

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.

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STUDIES OF THE AGING OF CONIDIA OF MONILINIA FRUCTICOLA (WINT.) HONEY: I.GERMINATION RATES AND LONGEVITY

Canadian Journal of Botany ◽

10.1139/b57-053 ◽

1957 ◽

Vol 35 (5) ◽

pp. 635-645 ◽

Cited By ~ 8

Author(s):

S. H. Z. Naqvi ◽

H. M. Good

Keyword(s):

Relative Humidity ◽

Storage Temperature ◽

Potato Dextrose Agar ◽

Monilinia Fructicola ◽

High Humidity ◽

Percentage Germination ◽

Low Humidity ◽

Nutrient Solutions

Conidia of Monilinia fructicola (Wint.) Honey were stored 1–10 months at temperatures of 5°, 25°, and 35 °C. and at constant relative humidities approximating 0, 15, 45, 75, and 90%. The germination of these spores was tested on potato dextrose agar containing 6% glucose, and curves of the percentage germination against time are given for representative samples.A pronounced delay in germination developed under all conditions of storage. The rate at which this delay developed was virtually independent of the storage temperature. All spore samples gave 100% germination after 3 months but only those at 5 °C. gave; any germination after 10 months. Storage in a relative humidity of 75% gave the best preservation of spore vigor, there being evidence in other conditions of either high humidity or low humidity injury. Of the nutrient solutions tested, glucose was the only one which gave substantially better germination than water, the effect being most marked on spores stored for some months at high humidity. With glucose, such spores sometimes germinated faster than those stored at intermediate humidities.

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HIGROSCOPICITY OF CHARCOAL PRODUCED IN DIFFERENT TEMPERATURES

CERNE ◽

10.1590/01047760201622032175 ◽

2016 ◽

Vol 22 (4) ◽

pp. 423-430 ◽

Cited By ~ 8

Author(s):

Ananias Francisco Dias Júnior ◽

Lucas Pereira Pirola ◽

Saly Takeshita ◽

Artur Queiroz Lana ◽

José Otávio Brito ◽

...

Keyword(s):

Relative Humidity ◽

Moisture Content ◽

Adsorption Capacity ◽

Carbonization Temperature ◽

Salt Solutions ◽

Final Temperature ◽

Different Temperatures ◽

Humidity Environment ◽

Adsorbed Moisture

ABSTRACT This research aimed to evaluate hygroscopicity of charcoal produced under four different final carbonization temperatures. For evaluation of hygroscopicity charcoal samples were conditioned in environments with controlled temperature and relative humidity, using saturated salt solutions. The final carbonization temperature significantly influenced the products yields and the properties of charcoal. The charcoal produced in the final temperature of 750 °C showed the highest adsorption capacity of water, indicated by the moisture content after conditioning, in the higher relative humidity environment. Correlations were observed between adsorbed moisture and the porosity of charcoal produced.

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Low-Humidity Sensing Properties of Multi-Layered Graphene Grown by Chemical Vapor Deposition

Sensors ◽

10.3390/s20113174 ◽

2020 ◽

Vol 20 (11) ◽

pp. 3174 ◽

Cited By ~ 1

Author(s):

Filiberto Ricciardella ◽

Sten Vollebregt ◽

Tiziana Polichetti ◽

Pasqualina M. Sarro ◽

Georg S. Duesberg

Keyword(s):

Chemical Vapor Deposition ◽

Relative Humidity ◽

Vapor Deposition ◽

Chemical Vapor ◽

Morphological Properties ◽

Humidity Sensing ◽

Sensing Properties ◽

Force Microscopy ◽

Sensing Material ◽

Low Humidity

Humidity sensing is fundamental in some applications, as humidity can be a strong interferent in the detection of analytes under environmental conditions. Ideally, materials sensitive or insensitive towards humidity are strongly needed for the sensors used in the first or second case, respectively. We present here the sensing properties of multi-layered graphene (MLG) upon exposure to different levels of relative humidity. We synthesize MLG by chemical vapor deposition, as shown by Raman spectroscopy, Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). Through an MLG-based resistor, we show that MLG is scarcely sensitive to humidity in the range 30%–70%, determining current variations in the range of 0.005%/%relative humidity (RH) well below the variation induced by other analytes. These findings, due to the morphological properties of MLG, suggest that defective MLG is the ideal sensing material to implement in gas sensors operating both at room temperature and humid conditions.

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Experimental model of ammonia elimination by ozone in the air

Research in Agricultural Engineering ◽

10.17221/54/2012-rae ◽

2013 ◽

Vol 59 (No. 2) ◽

pp. 39-45

Author(s):

P. Hutla ◽

B. Petráčková ◽

J. Kára

Keyword(s):

Weight Loss ◽

Relative Humidity ◽

Experimental Model ◽

Ammonia Concentration ◽

Experimental Device ◽

Air Purification ◽

Air Humidity ◽

Glass Vessel ◽

Air Volume ◽

Different Temperatures

Experimental device was created to model stable atmosphere. The device consists of the glass vessel filled with air. Volume of the vessel is 30 litres. The ammonia concentration is similar to stable air. Amount of ozone in 2.4 mg was added and subsequently weight loss of ammonia was measured. Measurements were performed at different temperatures (20°C, 45°C) and different air humidity. The observed ratio of reacting ozone and ammonia is 5.2:1. It was also found, that this ratio is practically independent of temperature and relative humidity that occur in a stable environment. The results are the basis for the design of ozone air purification technology.  

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Modulation of arginine vasotocin secretion in chicks by dehydration during embryogenesis

Journal of Endocrinology ◽

10.1677/joe.0.1420153 ◽

1994 ◽

Vol 142 (1) ◽

pp. 153-160 ◽

Cited By ~ 2

Author(s):

S M Kisliuk ◽

R Grossmann

Keyword(s):

Relative Humidity ◽

Environmental Temperature ◽

Arginine Vasotocin ◽

Plasma Sodium ◽

White Leghorn ◽

Control Groups ◽

Additional Increase ◽

Male And Female ◽

White Leghorn Chicken ◽

Low Humidity

Abstract The influence of low humidity during incubation (LHI) on arginine vasotocin (AVT) secretion in male and female White Leghorn chicken embryos and chicks was investigated. LHI embryos were incubated from day 8 (E8) to E18 at a relative humidity of 32–35%, while control embryos were incubated at 58–62%. In the control groups, plasma AVT gradually increased from E15 to E18, increased sharply during hatching and returned to the El8 level within 4 h. LHI did not alter the level of AVT until E18. LHI E19 males had concentrations of AVT twice as high as those of control males (39 ± 3·9 vs 15 ± 1·6 pmol/l, P<0·001). Augmentation persisted during hatching and 4 h afterwards. In LHI females additional elevation reached significant levels only at 4 h after hatching (58 ± 13 vs 16 ± 1·7 pmol/l, P<0·01). Deprivation of water caused an increase in plasma sodium concentrations in the 2-day-old chicks of the control groups, while no significant changes were observed in the LHI group. Deprivation of water together with a high environmental temperature caused an additional increase in AVT only in the LHI groups (42 ± 5·2 vs 22 ± 3·9 pmol/l, P<0·01 for males; 32 ± 3·4 vs 19 ± 2·8 pmol/l, P<0·01 for females). The results clearly showed that LHI leads to a more pronounced response of the AVT system on subsequent osmotic and non-osmotic challenges, especially in males. Embryonal activation of the AVT system probably helps the organism to cope with hatching and posthatching stresses. Journal of Endocrinology (1994) 142, 153–160

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Life history and feeding biology of the predatory thrips, Aleurodothrips fasciapennis (Thysanoptera: Phlaeothripidae)

Bulletin of Entomological Research ◽

10.1017/s0007485300025979 ◽

1998 ◽

Vol 88 (3) ◽

pp. 351-357 ◽

Cited By ~ 4

Author(s):

D.M. Watson ◽

T.Y. Du ◽

M. Li ◽

J.J. Xiong ◽

D.G. Liu ◽

...

Keyword(s):

Life History ◽

Relative Humidity ◽

Sex Ratio ◽

Intrinsic Rate ◽

Natural Increase ◽

Adult Longevity ◽

Female Fecundity ◽

Adult Sex Ratio ◽

Survival And Reproduction ◽

Low Humidity

AbstractDetails of the life history, the effects of relative humidity and temperature on survival and reproduction, and the predatory ability of Aleurodothrips fasciapennis Franklin were examined under laboratory conditions. Stage-specific development and adult longevity were similar between sexes, and the adult sex ratio was 1:1. Females laid 23.3 ± 18.0 eggs of which 83% hatched. The survival rate of first instars to adulthood was 82%. The intrinsic rate of natural increase (rm) was 0.04, assuming a zero or 5.4 day pre-oviposition interval. Temperature did not affect the proportion of eggs that hatched, the proportion of first instars surviving to adulthood or adult sex ratios. However, female fecundity was dependent on temperature being highest at 24 ndash 28°C. Relative humidity did not affect adult sex ratio or female fecundity but the proportion of eggs hatched and the survival of first instars to adulthood increased as relative humidity increased. Few eggs hatched when relative humidity was <65%. Larval and adult female A. fasciapennis were voracious feeders but the number of prey killed per progeny was high, suggesting A. fasciapennis was inefficient at converting prey into progeny biomass. The potential value of A. fasciapennis as a biocontrol agent of Aonidiella aurantii (Maskell) on Australian citrus is discussed in terms of its rm, prey killing power and environmental adaptability. It is concluded that population growth of A. fasciapennis should exceed that of A. aurantii under field conditions but A. fasciapennis may be of little value against A. aurantii on citrus grown under conditions of high temperature and low humidity, or when prey densities are low.

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Drying and rehydration of oyster mushroom

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132010000400025 ◽

2010 ◽

Vol 53 (4) ◽

pp. 945-952 ◽

Cited By ~ 13

Author(s):

Giannini Pasiznick Apati ◽

Sandra Aparecida Furlan ◽

João Borges Laurindo

Keyword(s):

Experimental Data ◽

Relative Humidity ◽

Pleurotus Ostreatus ◽

Water Sorption ◽

Room Temperature ◽

Sorption Isotherms ◽

Moisture Sorption ◽

Fruiting Bodies ◽

Different Temperatures ◽

Water Sorption Isotherms

Dehydration and rehydration processes of Pleurotus ostreatus fruiting bodies were investigated in this work. Mushroom samples were dehydrated at 40, 50 and 60 ºC, using drying air with relative humidity of 75 %. The rehydration was investigated at different temperatures of immersion water (25, 55 and 85 ºC) and different immersion times (30, 75 and 120 minutes). The best rehydration occurred for the samples dried at 40 ºC. The rehydration could be done in water at room temperature, during 30 minutes. Water sorption isotherms of samples were determined at 30, 40 and 50 ºC. Both GAB and BET models satisfactorily represented the experimental data of moisture sorption of dried mushrooms.

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