scholarly journals Impact of the water dimer on the atmospheric reactivity of carbonyl oxides

2016 ◽  
Vol 18 (26) ◽  
pp. 17698-17712 ◽  
Author(s):  
Josep M. Anglada ◽  
Albert Solé
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Water Dimer ◽  
Carbonyl Oxide ◽  
Carbonyl Oxides ◽  
Atmospheric Reactivity

The atmospheric reactivity of carbonyl oxides with water vapor depends on the nature of the carbonyl oxide, on the temperature and on the relative humidity as well.

scholarly journals HGPT2: An ERA5-Based Global Model to Estimate Relative Humidity

2021 ◽  
Vol 13 (11) ◽  
pp. 2179
Author(s):  
Pedro Mateus ◽  
Virgílio B. Mendes ◽  
Sandra M. Plecha
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Real Time ◽  
Prediction Models ◽  
Weather Prediction ◽  
Precipitable Water ◽  
Precipitable Water Vapor ◽  
Global Navigation Satellite Systems ◽  
International Gnss Service ◽  
Weighted Mean Temperature

The neutral atmospheric delay is one of the major error sources in Space Geodesy techniques such as Global Navigation Satellite Systems (GNSS), and its modeling for high accuracy applications can be challenging. Improving the modeling of the atmospheric delays (hydrostatic and non-hydrostatic) also leads to a more accurate and precise precipitable water vapor estimation (PWV), mostly in real-time applications, where models play an important role, since numerical weather prediction models cannot be used for real-time processing or forecasting. This study developed an improved version of the Hourly Global Pressure and Temperature (HGPT) model, the HGPT2. It is based on 20 years of ERA5 reanalysis data at full spatial (0.25° × 0.25°) and temporal resolution (1-h). Apart from surface air temperature, surface pressure, zenith hydrostatic delay, and weighted mean temperature, the updated model also provides information regarding the relative humidity, zenith non-hydrostatic delay, and precipitable water vapor. The HGPT2 is based on the time-segmentation concept and uses the annual, semi-annual, and quarterly periodicities to calculate the relative humidity anywhere on the Earth’s surface. Data from 282 moisture sensors located close to GNSS stations during 1 year (2020) were used to assess the model coefficients. The HGPT2 meteorological parameters were used to process 35 GNSS sites belonging to the International GNSS Service (IGS) using the GAMIT/GLOBK software package. Results show a decreased root-mean-square error (RMSE) and bias values relative to the most used zenith delay models, with a significant impact on the height component. The HGPT2 was developed to be applied in the most diverse areas that can significantly benefit from an ERA5 full-resolution model.

scholarly journals Deuterium excess in marine water vapor: Dependency on relative humidity and surface wind speed during evaporation

2014 ◽  
Vol 119 (2) ◽  
pp. 584-593 ◽  
Author(s):  
Marion Benetti ◽  
Gilles Reverdin ◽  
Catherine Pierre ◽  
Liliane Merlivat ◽  
Camille Risi ◽  
...  
Keyword(s):  
Water Vapor ◽  
Wind Speed ◽  
Relative Humidity ◽  
Surface Wind ◽  
Surface Wind Speed ◽  
Marine Water ◽  
Deuterium Excess

Influence of Temperature and Relative Humidity on Perm-Selectivity of PET Packaging Film

2011 ◽  
Vol 295-297 ◽  
pp. 1206-1210
Author(s):  
Yan Feng Guo ◽  
Xian Ping Ma ◽  
Yu Yan ◽  
Yun Gang Fu
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Experimental Studies ◽  
Thermodynamic Temperature ◽  
Packaging Film ◽  
Influence Of Temperature ◽  
Carbon Dioxide Gas ◽  
Pet Film ◽  
Pet Films ◽  
Temperature Water

The main feature of this article is the investigation on the influence of temperature, relative humidity, film thickness on permeability of PET packaging film, the analysis of perm-selectivity of the packaging films for oxygen gas and carbon dioxide gas, and the evaluation on experimental formulas of water vapor, O2 and CO2 gas permeating rates on the basis of gas molecular osmotic reaction kinetics and regression analysis. The comparison between experimental studies and calculation indicates that: (1) with increment of ambient temperature water vapor, O2 and CO2 permeating rate of PET films and PET/Al film also rise, and the logarithm of water vapor, O2 and CO2 gas permeating rates has linear relation with the reciprocal of thermodynamic temperature, and (2) the influence of relative humidity on water vapor permeating rate of PET film with thickness 12µm is the least, and that of PET film with thickness 20µm and PET/Al film with thickness 18µm is a little obvious. (3) The PET films hold remarkable perm-selectivity for O2 and CO2 gas, and CO2 gas permeating rate is about two times of O2 gas, yet O2 and CO2 gas permeating rates of PET/Al film are both very low and have small difference, so the PET/Al film has better barrier performance than the PET film.

scholarly journals Water Vapor Pressure Deficit in Portugal and Implications for the Development of the Invasive African Citrus Psyllid Trioza erytreae

Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 229 ◽  
Author(s):  
Paulo Eduardo Branco Paiva ◽  
Tânia Cota ◽  
Luís Neto ◽  
Celestino Soares ◽  
José Carlos Tomás ◽  
...  
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Vapor Pressure ◽  
Vapor Pressure Deficit ◽  
Water Vapor Pressure ◽  
Control Measures ◽  
Effective Control ◽  
First Instar ◽  
Trioza Erytreae ◽  
Water Vapor Pressure Deficit

African citrus psyllid (Trioza erytreae (Del Guercio)) is a vector insect of the bacterium Candidatus Liberibacter africanus, the putative causal agent of Huanglongbing, the most devastating citrus disease in the world. The insect was found on the island of Madeira in 1994 and in mainland Portugal in 2015. Present in the north and center of the country, it is a threat to Algarve, the main citrus-producing region. Trioza erytreae eggs and first instar nymphs are sensitive to the combination of high temperatures and low relative humidity. Daily maximum air temperature and minimum relative humidity data from 18 weather stations were used to calculate the water vapor pressure deficit (vpd) from 2004 to 2018 at various locations. Based on the mean vpd and the number of unfavorable days (vpd < 34.5 and vpd < 56 mbar) of two time periods (February to May and June to September), less favorable zones for T. erytreae were identified. The zones with thermal and water conditions like those observed in the Castelo Branco and Portalegre (Center), Beja (Alentejo), Alte, and Norinha (Algarve) stations showed climatic restrictions to the development of eggs and first instar nymphs of African citrus psyllid. Effective control measures, such as the introduction and mass release of Tamarixia dryi (Waterson), a specific parasitoid, and chemical control are necessary in favorable periods for T. erytreae development, such as in spring and in areas with limited or no climate restrictions.

Effect of Anthocyanin Preparations as Colorants on Hygroscopicity of Dry-Pack Foods

1979 ◽  
Vol 42 (3) ◽  
pp. 225-227 ◽  
Author(s):  
F. M. CLYDESDALE ◽  
J. H. MAIN ◽  
F. J. FRANCIS ◽  
K. M. HAYES
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Transmission Rate ◽  
Packaging Material ◽  
Physical Parameters ◽  
Water Vapor Transmission Rate ◽  
Natural Colorants ◽  
Water Vapor Transmission ◽  
Grape Skins ◽  
Equilibrium Relative Humidity

The equilibrium relative humidity isotherm of a cherry beverage base and a strawberry gelatin dessert mix colored with anthocyanins from grape skins, cranberries and roselle was evaluated versus a Red No. 2 control. As well, the water vapor transmission rate of the packaging material was evaluated to evaluate probable shelf-life. Results indicated that physical parameters, such as hygroscopicity, must be considered in estimating effects of the use of natural colorants in foods as well as the color and chemical stability normally investigated.

Role of the (H2O)n (n = 1–3) cluster in the HO2 + HO → 3O2 + H2O reaction: mechanistic and kinetic studies

2018 ◽  
Vol 20 (12) ◽  
pp. 8152-8165 ◽  
Author(s):  
Tianlei Zhang ◽  
Xinguang Lan ◽  
Zhangyu Qiao ◽  
Rui Wang ◽  
Xiaohu Yu ◽  
...  
Keyword(s):  
Water Vapor ◽  
Single Molecule ◽  
Kinetic Studies ◽  
Water Dimer ◽  
Water Trimer ◽  
Catalytic Effects

Upon incorporation of the catalyst (H2O)n (n = 1–3) into the reaction HO2 + HO → H2O + 3O2, the catalytic effects of water, water dimer, and water trimer mainly arise from the contribution of a single molecule of water vapor.

The Impact of the Gas Temperature and of the Relative Humidity on the Performance of Fans Operating in Drying Plants

2018 ◽  
Author(s):  
Manuel Fritsche ◽  
Philipp Epple ◽  
Antonio Delgado
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Second Step ◽  
Gas Temperature ◽  
Numerical Computations ◽  
Ansys Cfx ◽  
The Impact ◽  
Similarity Laws

In order to investigate the impact of the gas temperature and its relative humidity on the performance of fans, the similarity laws for fans were extended and verified and numerical computations with the commercial CFD solver ANSYS CFX were performed. First the accuracy of the original fan laws was verified for different operating conditions. In a second step the influence of the temperature on the fan characteristics was investigated. Finally, to include the effect of the relative humidity multiphase simulations with air and water vapor were performed. Therefore, the relative humidity was analyzed for different gas temperatures. In such a way the full influence of the temperature and of the relative humidity on the performance characteristics of radial fans operating in drying plants was obtained. These numerical results have been analyzed in detail and compared with the results predicted by the presented extended similarity laws for turbomachines.

Diffusion of water vapor through human skin in hot environment and with application of atropine

1959 ◽  
Vol 14 (2) ◽  
pp. 276-278 ◽  
Author(s):  
Konrad J. K. Buettner ◽  
Frederick F. Holmes
Keyword(s):  
Water Vapor ◽  
Relative Humidity ◽  
Human Skin ◽  
Liquid Water ◽  
Water Loss ◽  
Diffusion Resistance ◽  
Vapor Transfer ◽  
Hot Environment ◽  
Human Forearm ◽  
Very High

At room temperatures between 20° and 40°C, vapor transfer through skin of human forearm was tested with four small heated bottles containing air of humidities ranging from 2 to 100% relative humidity. Exposure times ranging from 30 to 120 minutes had no influence on results. Water loss or gain of skin were observed for the different bottles. At very high humidities, liquid water deposit on the skin was measured by weighing a blotter. Skin vapor loss decreases systematically when bottle moisture increases. This increase is enhanced at room temperatures above 24℃, where total loss into a dry bottle increases more than fivefold. This increase seems only partially caused by sweat and partially by a decrease of the skin diffusion resistance. Tourniquet and locally applied atropine did not affect vapor transfer in a cool room. In a hot room, the tourniquet lowered the vapor loss by only 20%, whereas atropine drastically curtailed vapor loss. Submitted on August 25, 1958

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