scholarly journals Thermodynamic analysis of the gas parameters distribution under leakage from a closed volume with rigid walls

2019 ◽  
Vol 109 ◽  
pp. 00071
Author(s):  
Serhii Ponomarenko ◽  
Oleksandr Zhevzhyk ◽  
Alex Vuginshteyn ◽  
Oleksandr Lutai
Keyword(s):  
Thermodynamic Analysis ◽  
Thermodynamic System ◽  
Effect Of Temperature ◽  
Closed Volume ◽  
Excessive Pressure ◽  
Gas Leakage ◽  
Parallel Processes ◽  
Average Temperature ◽  
Leakage Coefficient ◽  
Rigid Walls

The work deals with the thermodynamic analysis of the parameters of the gas in a closed volume with rigid walls, during its leakage and heat exchange with the environment. Based on the first law of thermodynamics, the law of Fick and the equation of the gas state, we obtained an equation that characterizes the effect of temperature gradient on the mass gas leakage in parallel processes of leakage and heat transfer. The regularity of the leakage coefficient change, determined by the diffusion coefficient, depending on the mass-average temperature in a closed thermodynamic system, is established. The variation of the leakage coefficient for the corresponding ranges of temperature gradients are shown. The research results can be implemented in the development of techniques and technologies for monitoring the tightness of hollow products under excessive pressure of the gas medium.

Effect of temperature on the equilibrium solubility of dimethylolpropionic acid: Measurement, correlation, thermodynamic analysis and solvent selection

2021 ◽  
Vol 328 ◽  
pp. 115462
Author(s):  
Vanee Mohdee ◽  
Katarína Fulajtárová ◽  
Tomáš Soták ◽  
Milan Hronec ◽  
Suphot Phatanasri ◽  
...  
Keyword(s):  
Thermodynamic Analysis ◽  
Effect Of Temperature ◽  
Equilibrium Solubility ◽  
Solvent Selection

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.

Effect of temperature and relative humidity on the milk production of dairy cows

2021 ◽  
Vol 13 (2) ◽  
pp. 22-27
Author(s):  
Ivan Imrich ◽  
Róbert Toman ◽  
Martina Pšenková ◽  
Eva Mlyneková ◽  
Tomáš Kanka ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Yield ◽  
Effect Of Temperature ◽  
Winter Period ◽  
Summer Period ◽  
Average Temperature ◽  
Holstein Friesian ◽  
Humidity Index ◽  
Index Value

The aim of this study was to evaluate the influence of environmental housing conditions on the milk yield of dairy cows. Measurements were taken in the summer period from June to September 2020 and in the winter period during January 2021 on a large-capacity farm of Holstein Friesian cattle. Cows were housed in free stall barn with the lying boxes and selected during the second or third lactations, in the summer period from the 51st day to the 135th day and in the winter period from the 64th day to the 120th day of lactation. The average temperature in the housing was 23 °C in summer, and 7.05 °C in winter. The average THI (thermal humidity index) value in summer was 70.43, but during the day the THI values sometimes reached 75. The dairy cows were therefore exposed to heat stress during summer. Increasing THI and temperature values negatively affected the milk yield, as there was a negative correlation between both THI and milk yield (r = -0.641; p <0.01) and temperature and milk yield (r = -0.637; p <0.01). Milk production in winter was at 58.77 kg per day and in summer at 49.55 kg per day. In the summer, the milk had a significantly lower content of fat (p <0.05), proteins (p <0.001), lactose (p <0.001), minerals (p <0.001) and conversely, a higher number of somatic cells (p <0.01). These results show that worse environmental conditions during the summer negatively affected the level of milk yield and the composition of the cows’ milk.

scholarly journals Effects of Climate on Incidence of Campylobacter spp. in Humans and Prevalence in Broiler Flocks in Denmark

2004 ◽  
Vol 70 (12) ◽  
pp. 7474-7480 ◽  
Author(s):  
Mary Evans Patrick ◽  
Lasse Engbo Christiansen ◽  
Michael Wainø ◽  
Steen Ethelberg ◽  
Henrik Madsen ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Linear Models ◽  
Public Health Problem ◽  
Effect Of Temperature ◽  
Maximum Temperature ◽  
Future Research ◽  
Combined Effects ◽  
Average Temperature ◽  
Effects Of Temperature ◽  
Single Predictor

ABSTRACT Campylobacter infections are increasing and pose a serious public health problem in Denmark. Infections in humans and broiler flocks show similar seasonality, suggesting that climate may play a role in infection. We examined the effects of temperature, precipitation, relative humidity, and hours of sunlight on Campylobacter incidence in humans and broiler flocks by using lag dependence functions, locally fitted linear models, and cross validation methods. For humans, the best model included average temperature and sunlight 4 weeks prior to infection; the maximum temperature lagged at 4 weeks was the best single predictor. For broilers, the average and maximum temperatures 3 weeks prior to slaughter gave the best estimate; the average temperature lagged at 3 weeks was the best single predictor. The combined effects of temperature and sunlight or the combined effects of temperature and relative humidity predicted the incidence in humans equally well. For broiler flock incidence these factors explained considerably less. Future research should focus on elements within the broiler environment that may be affected by climate, as well as the interaction of microclimatic factors on and around broiler farms. There is a need to quantify the contribution of broilers as a source of campylobacteriosis in humans and to further examine the effect of temperature on human incidence after this contribution is accounted for. Investigations should be conducted into food consumption and preparation practices and poultry sales that may vary by season.

scholarly journals Influence of Heat Units on Defoliation, Physiology and Yield of Cotton during Defoliants Application

2020 ◽  
pp. 77-84
Author(s):  
P. Chandrasekaran ◽  
V. Ravichandran ◽  
T. Sivakumar ◽  
A. Senthil ◽  
L. Mahalingam ◽  
...  
Keyword(s):  
Tamil Nadu ◽  
Weather Condition ◽  
Sodium Chlorate ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Heat Units ◽  
Main Plot ◽  
Maximum Temperatures ◽  
Index Value ◽  
Favorable Weather

Aims: A study was conducted to determine the effect of temperature on defoliation process, physiology and yield of cotton during defoliants application. Study Design: The experiment was laid out in split-plot design with four replications. Place and Duration of Study: Field experiment was conducted at Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore during 2018 to 2019. Methodology: The main plot comprised of three stage of defoliants spray (120 DAS, 127 DAS and 134 DAS) and the sub-plots were seven defoliant treatments (Control, 2, 4 D (0.5%), Ethephon (0.5%), Ethephon (0.5%) + Triiodbenzoic acid (TIBA) (450 ppm), Sodium chlorate (0.9%), 6 benzylaminopurine (BAP) (0.1%), Thidiazuron + Diuron (0.03%). Results: After 15 days of defoliants spray, Thidiazuron + Diuron (0.03 %) recorded highest defoliation percentage (99.3, 98.1 and 96.8%) followed by Sodium chlorate (0.9 %) (91.9, 94.6 and 93.6%) at three different stage of defoliants spray. Although a significant effect was observed on chlorophyll index value (SPAD) due to the favorable weather condition like minimum temperature of 14.3, 16.9 and 19.3°C and maximum average temperature of 30.8, 31.8 and 33.23°C (120, 127 and 134 DAS respectively) during defoliants spray to 15 days after defoliants spray. Sodium chlorate (0.9%) and 6-BAP (0.1%) recorded higher (95.8 and 95.4) per cent boll opening at 120 DAS when comparing to 127 DAS and 134 DAS. Heat units accumulated during defoliants spray to 15 days after defoliants spray was 113.54, 140.52 and 169.57°C days (120, 127 and 134 DAS respectively). Conclusion: Therefore, the minimum and maximum temperatures of 14.3 and 33.3°C, respectively conducive for inducing defoliation process and boll opening in cotton.

scholarly journals IoT Utilized Gas-Leakage Monitoring System with Adaptive Controls Applicable to Dual Fuel Powered Naval Vessels/Ships: Development & Implementation

2020 ◽  
Vol 20 (1) ◽  
pp. 138-155
Author(s):  
Avijit Mallik ◽  
Sharif Ahmed ◽  
G. M. M. Hossain ◽  
M. R. Rahman
Keyword(s):  
Environmental Changes ◽  
Signal Transmission ◽  
Dual Fuel ◽  
Closed Volume ◽  
Liquefied Petroleum Gas ◽  
Gas Leakage ◽  
Adaptive Controls ◽  
Auto Ignition ◽  
Leakage Monitoring ◽  
Marine Vessels

AbstractLeakage of Liquefied Petroleum Gas and Liquified Natural Gas (LPG/LNG) produces hazardous and toxic impact on humans and other living creatures. The authors developed a system to monitor and control the gas leakage concentration. MQ-6 gas sensor is used for sensing the level of gas concentration in a closed volume. To monitor the consequences of environmental changes an IoT platform hosted by “Thingspeak” platform has been introduced. Both robust and cloud-forwarded controls have been applied to prevent uncontrolled leakage of those gases and auto-ignition. This type of system can be directly applied to the engine chamber/ fuel chamber of the modern marine vessels using dual fuel power cycle with LPG/LNG as secondary fuel-flamer. The results from the experiments clearly indicate satisfactory actuation speed and accuracy. The trials performed by the authors showed about 99% efficiency of signal transmission and actuation.

scholarly journals Modeling of wildfire occurrence by using climate data and effect of temperature increments

2020 ◽  
Author(s):  
Amir Hossein Sadat Razavi ◽  
Majid Shafiepour Motlagh ◽  
Alireza Noorpoor ◽  
Amir Houshang Ehsani
Keyword(s):  
Forest Fires ◽  
Boreal Forests ◽  
Environmental Variables ◽  
Temperate Forests ◽  
Forest Type ◽  
Effect Of Temperature ◽  
Transient Temperature ◽  
Fire Occurrence ◽  
Model Output ◽  
Average Temperature

Abstract. Forest fires are assumed as one of the key natural hazards in the globe since it causes great losses in ecology, economy, and human lives; recent fire cases in US and their vast damages are vivid reasons to study the wildfires more deeply One of the basic requirements to manage the threats and protect wildlife is the ability to predict wildfire spots which is necessary to prioritize forest management. In this study, a 25-year period natural wildfire database and a wide array of environmental variables are used to develop an artificial neural network model with the aim of predicting potential fire spots. This study focuses on non-human reasons of wildfires (natural) to compute global warming effects on wildfires. Among the environmental variables, this study shows the significance of temperature for predicting wildfire cases while other parameters are presented in the next study. The study area of this study includes all forest fire cases in united states from 1992 to 2015 excluding tropical forests. The data of eight days including the day fire occurred and 7 previous days are used as input to the model to forecast fire occurrence probability of that day. The climatic inputs are extracted from ECMWF. The inputs of the model are temperature at 2 meter above surface, relative humidity, Total pressure, evaporation, volumetric soil water layer 1, snow melt, Keetch–Byram drought index, total precipitation, wind speed (along U and V direction), and NDVI. The results show there is a transient temperature span for each forest type which acts like a threshold to predict fire occurrence. In Temperate forests, A 0.1-degree Celsius increase in temperature relative to 7-day average temperature before a fire occurrence results in prediction model output of greater than 0.8 for 4.75 % of fire forest cases. In Boreal forests, the model output for temperature increase of less than 1 degree relative to past 7-day average temperature represents no chance of wildfire. But the non-zero fire forest starts at 2 degrees increase of temperature which ends to 2.62 % of fire forest cases with model output of larger than 0.8. It is concluded that other variables except temperature are more determinant to predict wildfires in temperate forests rather than in boreal forests.

Experimental Evaluation of Abradable Seal Performance at High Temperature

2008 ◽  
Author(s):  
A. Dadouche ◽  
M. J. Conlon ◽  
W. Dmochowski ◽  
B. Liko ◽  
J.-P. Bedard
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Gas Turbines ◽  
Operating Temperature ◽  
Microstructural Analysis ◽  
Operating Conditions ◽  
Effect Of Temperature ◽  
Gas Leakage ◽  
Series Of Experiments ◽  
Aero Engines

Abradable seals have been used in aero-engines and land-based gas turbines for more than three decades. They are applied to various sections of the engine in order to reduce gas leakage by optimizing the gap between rotating and stationary parts. This optimization represents a significant increase in efficiency and decrease in fuel consumption. Performance evaluation of any abradable seal includes measurement of its mechanical properties, abradability tests and (ultimately) tests in engines. The aim of this paper is to study the effect of temperature on the rub performance of abradable seals. A series of experiments has been carried out in order to evaluate a commercially available seal material at different operating conditions. The effect of operating temperature on contact force, abrasion scar appearance and blade wear is examined and analyzed. A microstructural analysis of the rub scar has also been performed.

scholarly journals Climatic factors associated with hospitalizations for rotavirus diarrhoea in children under 5 years of age

2007 ◽  
Vol 136 (1) ◽  
pp. 56-64 ◽  
Author(s):  
R. M. D'SOUZA ◽  
G. HALL ◽  
N. G. BECKER
Keyword(s):  
Hospital Admissions ◽  
Climatic Factors ◽  
Seasonal Effects ◽  
Effect Of Temperature ◽  
Factors Associated ◽  
Average Temperature ◽  
Temperature And Humidity ◽  
Higher Temperature ◽  
Log Linear ◽  
Children Under 5

SUMMARYThis study compares the seasonality of rotavirus diarrhoeal hospital admissions and its relationship to climatic factors across three Australian cities. Weekly admission of rotavirus diarrhoea (1993–2003) in children aged <5 years and weekly average temperature and relative humidity for each city were modelled using a log-linear model with a cubic trend and season. Interactions were included to test for differences in the effect of temperature and humidity between seasons and between cities. Admissions of rotavirus diarrhoea peaked in winter and spring and were lowest in summer. Higher temperature and humidity in the previous week were associated with a decrease in rotavirus diarrhoeal admissions in three cities. The effects of both temperature and humidity on rotavirus admissions in Brisbane differed across seasons. Strategies to combat outbreaks of rotavirus diarrhoea should take climatic factors and seasonal effects into consideration to plan for the excess seasonal hospital admissions.

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