scholarly journals Study on the Characteristics of Formaldehyde Pollution in Typical Teaching Machine Room

2020 ◽  
Vol 143 ◽  
pp. 02001
Author(s):  
Pengpeng Yang ◽  
Mianwu Meng ◽  
Dingding Gao ◽  
Zhihao Lin ◽  
Hua Ding ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Relative Humidity ◽  
Teaching Machine ◽  
Absolute Humidity ◽  
Formaldehyde Concentration ◽  
Monthly Variation ◽  
Temperature And Humidity ◽  
Normal University ◽  
Machine Room ◽  
Variation Rule

This study focused on measuring the pollution characteristics, the monthly and seasonal variation rule of formaldehyde in the teaching machine room of Guangxi Normal University from March 2016 to February 2018, and the correlation between formaldehyde concentration and temperature or humidity were also analyzed. The results indicated that seasonal and monthly variation rule of formaldehyde changed with temperature and humidity in the teaching machine room. The concentration of formaldehyde was higher in summer and autumn, while was lower in winter and spring. Further analysis indicated that there was a strongly positive correlation (R2>0.87, R2>0.85, R2>0.81, p<0.01) between formaldehyde concentration and temperature, relative humidity or absolute humidity. It concluded that the formaldehyde concentration increased with the increase in the temperature and humidity. The maximum concentrations of formaldehyde in sitting breathing area and standing breathing area were 0.442mg/m3, 0.445mg/m3 and 0.184mg/m3, 0.213mg/m3 in July 2016, 2017, respectively. After eleven years, the formaldehyde in the teaching machine room was still seriously exceeded the standard (0.1mol/L), and decreased the temperature or humidity could effective alleviate the level of indoor formaldehyde concentration.

scholarly journals Climate and Covid-19 - Upgrade and solar radiation influences based on Brazil cases

2020 ◽  
Author(s):  
Francisco Mendonça ◽  
Max Anjos ◽  
Erika Collischonn ◽  
Pedro Murara ◽  
Deise Ely F. ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Meteorological Parameter ◽  
Absolute Humidity ◽  
Climatic Conditions ◽  
Dew Point ◽  
Wind Gust ◽  
Pubmed Database ◽  
Temperature And Humidity ◽  
In The Beginning

Abstract Background COVID-19 has confirmed to be a pandemic with global and historical dimensions in the beginning of the 21st century. Climatic conditions are one of the environmental factors that influence communicable diseases, including viral diseases. Despite promising scientific advances into understanding the interaction between climate and COVID-19, a question remains: How can climate influence the pandemic of COVID-19? Methods It was updated the publications available on the climate and COVID-19 using Scopus, Web of Science, and PubMed database from January 1 to May 20, 2020. Statistical analysis, such normality and multicollinearity tests were performed between number of COVID-19 cases and climato-meteorological parameters (temperature, relative humidity, dew point temperature, atmosphere pressure, wind speed, wind gust, rainfall, and solar radiation, nebulosity and insolation ratio) in six Brazilian cities. Results This review reveals that temperature, relative humidity and absolute humidity alone do not able to explain the exponential number of COVID-19 cases. Most studies showed the SARS-CoV-2 satisfactorily can survive in a large range of temperature and humidity in temperature and tropical- humidity climates. Analyzing other meteorological parameter, insolation ratio that is related to the solar radiation and nebulosity, the results and in accordance with other studies suggest the transmission and contagion by SARS-CoV-2 seem to have been enhanced under from medium to low direct solar radiation and covered skies. Conclusions This study showed that the inclusion of other climatic variables, in addition to temperature and humidity, should guide future ecological models on the relationship between climate and COVID-19, especially the insolation ratio influences on the viral transmission in six Brazilian cities. Our findings may support public policies and coordinated actions to reduce and control of COVID-19.

Importance of Temperature and Humidity Control in Rubber Testing. Progress Report of the Physical Testing Commitee, Rubber Division, A.C.S. (Dated Dec. 8, 1927)

1928 ◽  
Vol 1 (1) ◽  
pp. 182-191
Author(s):  
J. E. Partenheimer ◽  
E. R. Bridgwater ◽  
D. F. Cranor ◽  
E. B. Curtis ◽  
J. W. Schade ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Absolute Humidity ◽  
Rubber Compounds ◽  
Physical Testing ◽  
Temperature And Humidity ◽  
Cent Relative Humidity ◽  
Physical Tests ◽  
A Minor ◽  
Mixed Stock ◽  
Testing Room

Abstract The purpose of the work which this committee has undertaken is to determine the effect of the variables which influence the results of physical tests on rubber. The investigation has proven that variations in temperature which may occur from day to day in an uncontrolled testing room may affect the physical tests to as great a degree as a 25 to 40 per cent change in the time of cure, while relative humidity affects the results to only a minor degree. Furthermore, variations in the absolute humidity of the room in which the unvulcanized rubber is stored between the time of mixing and the time of curing may affect the tensile strength and modulus of rubber compounds to as great a degree as does the temperature after curing. It is, therefore, apparent that laboratory tests which are conducted under uncontrolled conditions of temperature and humidity may give highly erroneous results and may even give misinformation which is worse than no information at all. The committee, therefore, recommends that mixed stock prior to curing and cured stock prior to testing be conditioned for not less than twenty-four nor more than twenty-eight hours at 82 deg. F. ± 2 deg. and 45 per cent relative humidity ± 3 per cent and that the testing room be maintained at 82 deg. F. ± 2 deg. If a temperature of 82 deg. F. cannot be maintained for conditioning the mixed stock prior to curing, the committee recommends a relative humidity corresponding to the temperature used which gives an absolute humidity equal to that obtained under the former conditions. The temperature of the testing room should be controlled within the above stated limits, but it is not necessary to control the humidity of the entire room. A small conditioning cabinet in which the standard humidity is maintained has been found to be sufficient.

scholarly journals Optical fibre Sensor for Simultaneous Temperature and Relative Humidity Measurement: Towards Absolute Humidity Evaluation

2021 ◽  
pp. 130154
Author(s):  
Chenyang He ◽  
Serhiy Korposh ◽  
Ricardo Correia ◽  
Liangliang Liu ◽  
Barrie R. Hayes-Gill ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Optical Fibre ◽  
Absolute Humidity ◽  
Humidity Measurement ◽  
Optical Fibre Sensor ◽  
Fibre Sensor

Multi-lamellar organization of fully deuterated lipid extracts of yeast membranes

2014 ◽  
Vol 70 (12) ◽  
pp. 3167-3176 ◽  
Author(s):  
Yuri Gerelli ◽  
Alexis de Ghellinck ◽  
Juliette Jouhet ◽  
Valérie Laux ◽  
Michael Haertlein ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Neutron Diffraction ◽  
Structural Complexity ◽  
Structural Features ◽  
Metabolic Effects ◽  
Growth Media ◽  
Small Momentum Transfer ◽  
Lipid Species ◽  
Two Samples ◽  
Temperature And Humidity

Neutron scattering studies on mimetic biomembranes are currently limited by the low availability of deuterated unsaturated lipid species. In the present work, results from the first neutron diffraction experiments on fully deuterated lipid extracts from the yeastPichia pastorisare presented. The structural features of these fully deuterated lipid stacks are compared with those of their hydrogenous analogues and with other similar synthetic systems. The influence of temperature and humidity on the samples has been investigated by means of small momentum-transfer neutron diffraction. All of the lipid extracts investigated self-assemble into multi-lamellar stacks having different structural periodicities; the stacking distances are affected by temperature and humidity without altering the basic underlying arrangement. At high relative humidity the deuterated and hydrogenous samples are similar in their multi-lamellar arrangement, being characterized by two main periodicities of ∼75 and ∼110 Å reflecting the presence of a large number of polar phospholipid molecules. Larger differences are found at lower relative humidity, where hydrogenous lipids are characterized by a larger single lamellar structure than that observed in the deuterated samples. In both cases the heterogeneity in composition is reflected in a wide structural complexity. The different behaviour upon dehydration can be related to compositional differences in the molecular composition of the two samples, which is attributed to metabolic effects related to the use of perdeuterated growth media.

Experimental Study on Hygroscopicity of Rapeseed (Brassica Napus)

2012 ◽  
Vol 479-481 ◽  
pp. 2275-2278
Author(s):  
Ming Jin Yang ◽  
Wu Ming Xu ◽  
Tian Tang ◽  
Ling Yang ◽  
Feng Liu
Keyword(s):  
Experimental Study ◽  
Brassica Napus ◽  
Relative Humidity ◽  
Moisture Absorption ◽  
Early Period ◽  
Critical Relative Humidity ◽  
Temperature And Humidity ◽  
Higher Temperature

The hygroscopicity property of the rapeseed at different temperature and humidity was experimental studied in this paper. Tested results show that: the moisture absorption rates increase with the increase of relative humidity at the early period of absorption, and higher temperature leads to earlier reach of moisture equilibrium; the critical relative humidity(CRH) increases with the increase of temperature; the optional relative humidity for safety storage of rapeseed should be controlled less than 60%.

scholarly journals The effect of some seasonal conditions on oestrus occurrence in cows

2009 ◽  
Vol 52 (5) ◽  
pp. 459-465
Author(s):  
B. Bülbül ◽  
M. B. Ataman
Keyword(s):  
Seasonal Variation ◽  
Relative Humidity ◽  
Environmental Temperature ◽  
Suppressive Effect ◽  
Climatic Conditions ◽  
Holstein Cows ◽  
Ovarian Activity ◽  
Environment Temperature ◽  
Humidity Index ◽  
Annual Distribution

Abstract. In this study, the effect of climatic conditions on oestrus occurrence was investigated by using 9 972 oestrus records of cows recorded between 1995 and 2003. A distinct seasonal variation in the oestrus occurrence was determined. Oestrus occurrence observed in January, March, November and December was less than that in June and September (P<0.05). Annual distribution of the oestrus occurrence was positively correlated with environment temperature and insulation duration, but it was negatively correlated with rainfall (P<0.01). However, there was no relationship between oestrus occurrence and relative humidity. In addition to these, there was a slight decrease in the oestrus response when the temperature-humidity index (THI) was above 72; nevertheless, this decrease was not significant (P >0.05). The data presented in this study demonstrated that the increase in the environmental temperature up to 23 °C did not cause a suppressive effect on the ovarian activity. In conclusion, annual distribution of the oestrus occurrence is positively correlated with environment temperature and insulation duration whereas it is negatively correlated with rainfall in Holstein cows, in this study.

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

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.

scholarly journals A new temperature- and humidity-dependent surface site density approach for deposition ice nucleation

2015 ◽  
Vol 15 (7) ◽  
pp. 3703-3717 ◽  
Author(s):  
I. Steinke ◽  
C. Hoose ◽  
O. Möhler ◽  
P. Connolly ◽  
T. Leisner
Keyword(s):  
Contact Angle ◽  
Relative Humidity ◽  
Active Surface ◽  
Ice Nucleation ◽  
Nucleation Theory ◽  
Classical Nucleation Theory ◽  
Aerosol Size Distribution ◽  
Surface Site ◽  
Linear Behavior ◽  
Temperature And Humidity

Abstract. Deposition nucleation experiments with Arizona Test Dust (ATD) as a surrogate for mineral dusts were conducted at the AIDA cloud chamber at temperatures between 220 and 250 K. The influence of the aerosol size distribution and the cooling rate on the ice nucleation efficiencies was investigated. Ice nucleation active surface site (INAS) densities were calculated to quantify the ice nucleation efficiency as a function of temperature, humidity and the aerosol surface area concentration. Additionally, a contact angle parameterization according to classical nucleation theory was fitted to the experimental data in order to relate the ice nucleation efficiencies to contact angle distributions. From this study it can be concluded that the INAS density formulation is a very useful tool to describe the temperature- and humidity-dependent ice nucleation efficiency of ATD particles. Deposition nucleation on ATD particles can be described by a temperature- and relative-humidity-dependent INAS density function ns(T, Sice) with ns(xtherm) = 1.88 ×105 · exp(0.2659 · xtherm) [m−2] , (1) where the temperature- and saturation-dependent function xtherm is defined as xtherm = −(T−273.2)+(Sice−1) ×100, (2) with the saturation ratio with respect to ice Sice >1 and within a temperature range between 226 and 250 K. For lower temperatures, xtherm deviates from a linear behavior with temperature and relative humidity over ice. Also, two different approaches for describing the time dependence of deposition nucleation initiated by ATD particles are proposed. Box model estimates suggest that the time-dependent contribution is only relevant for small cooling rates and low number fractions of ice-active particles.

scholarly journals Measuring OVOCs and VOCs by PTR-MS in an urban roadside microenvironment of Hong Kong: relative humidity and temperature dependence, and field intercomparisons

2016 ◽  
Vol 9 (12) ◽  
pp. 5763-5779 ◽  
Author(s):  
Long Cui ◽  
Zhou Zhang ◽  
Yu Huang ◽  
Shun Cheng Lee ◽  
Donald Ray Blake ◽  
...  
Keyword(s):  
Hong Kong ◽  
Organic Compound ◽  
Relative Humidity ◽  
Volatile Organic Compound ◽  
High Performance ◽  
Measurement Techniques ◽  
Absolute Humidity ◽  
Electron Capture Detection ◽  
Sampling Campaign ◽  
Volatile Organic

Abstract. Volatile organic compound (VOC) control is an important issue of air quality management in Hong Kong because ozone formation is generally VOC limited. Several oxygenated volatile organic compound (OVOC) and VOC measurement techniques – namely, (1) offline 2,4-dinitrophenylhydrazine (DNPH) cartridge sampling followed by high-performance liquid chromatography (HPLC) analysis; (2) online gas chromatography (GC) with flame ionization detection (FID); and (3) offline canister sampling followed by GC with mass spectrometer detection (MSD), FID, and electron capture detection (ECD) – were applied during this study. For the first time, the proton transfer reaction–mass spectrometry (PTR-MS) technique was also introduced to measured OVOCs and VOCs in an urban roadside area of Hong Kong. The integrated effect of ambient relative humidity (RH) and temperature (T) on formaldehyde measurements by PTR-MS was explored in this study. A Poly 2-D regression was found to be the best nonlinear surface simulation (r  =  0.97) of the experimental reaction rate coefficient ratio, ambient RH, and T for formaldehyde measurement. This correction method was found to be better than correcting formaldehyde concentrations directly via the absolute humidity of inlet sample, based on a 2-year field sampling campaign at Mong Kok (MK) in Hong Kong. For OVOC species, formaldehyde, acetaldehyde, acetone, and MEK showed good agreements between PTR-MS and DNPH-HPLC with slopes of 1.00, 1.10, 0.76, and 0.88, respectively, and correlation coefficients of 0.79, 0.75, 0.60, and 0.93, respectively. Overall, fair agreements were found between PTR-MS and online GC-FID for benzene (slope  =  1.23, r  =  0.95), toluene (slope  =  1.01, r  =  0.96) and C2-benzenes (slope  =  1.02, r  =  0.96) after correcting benzene and C2-benzenes levels which could be affected by fragments formed from ethylbenzene. For the intercomparisons between PTR-MS and offline canister measurements by GC-MSD/FID/ECD, benzene showed good agreement, with a slope of 1.05 (r  =  0.62), though PTR-MS had lower values for toluene and C2-benzenes with slopes of 0.78 (r  =  0.96) and 0.67 (r  =  0.92), respectively. All in all, the PTR-MS instrument is suitable for OVOC and VOC measurements in urban roadside areas.

scholarly journals Trends in continental temperature and humidity directly linked to ocean warming

2018 ◽  
Vol 115 (19) ◽  
pp. 4863-4868 ◽  
Author(s):  
Michael P. Byrne ◽  
Paul A. O’Gorman
Keyword(s):  
Relative Humidity ◽  
Land Surface ◽  
Moisture Transport ◽  
Climate Change Impacts ◽  
Atmospheric Dynamics ◽  
Specific Humidity ◽  
Climate Projections ◽  
Moist Static Energy ◽  
Temperature And Humidity ◽  
Static Energy

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.

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