The dynamics of Fast gas heating in a high power microwave discharge in air, is investigated in the framework of FDTD simulations of the Maxwell equations coupled with the fluid simulations of the plasma. It is shown that, an ultra-Fast gas heating of the order of several 100 Kelvins occurs in less than 100 ns. The main role in the heating is played by the electron impact dissociation of 2 O, dissociation via quenching of metastable states of 2 N, as well as, ( ) 1 O D quenching by nitrogen molecules. Among the electronically excited metastable states, ( ) 2 N B, C, a are the most important species. Slow heating of the gas above 1 μ s is attributed to the vibrational relaxation processes of 2 N, among them vibrationaltranslational relaxation of 2 N demonstrates the highest heating rate. The heating rate and thus the gas temperature are significantly increased with increasing of the microwave pulse amplitude, pulse width, and the gas pressure. In all cases, enhanced 2 O dissociation is the main factor behind the enhanced gas heating. The same effects are observed for increasing of the initial gas temperature, and 2 O percentage in a 2 2 N-O mixture.

In the present paper, a gas turbine (GT) unit with nominal capacity of 26.8 MWe, which is used for continuous production of electricity in Ilam gas Refinery Company, has been investigated for combined production of cooling, heating, power and process (CCHPP). Critical parameters are measured and the potentials of transforming the GT unit to CCHPP are investigated from technical, economic, and environmental points of view. A heat recovery steam generator (HRSG) converts the exhaust energy to steam that can be used for three purposes of cooling, heating and process. The cycle is first evaluated thermodynamically, and to be assured regarding HRSG, its operation is studied by using the pinch technology. Economical evaluation is carried out by calculating initial investment, payback period, net present value (NPV) and internal rate of return. In addition, the impact of using CCHPP on reduction of environment pollutant gases such as CO, CO2, and NOx is studied. The results reveal that, the fuel energy saving ratio of 36% is achieved for the minimum pinch point temperature of 19 C in the HRSG unit. The payback period is only 5.2 years, and the NPV during the project lifetime is 1.87 M$.Moreover the CO2, CO, and NOx reduction is about 32000, 22 and 27 tons/year respectively.

A B S T R A C T Temperature is one of the climate elements that has fluctuated a lot over time. When these fluctuations increase and decrease more than normal and are placed in the upper and lower regions of the statistical distribution, if continued, it can lead to the creation of heating and cooling waves. The purpose of this study is to analyze the temporal and spatial changes in heating and cooling waves in Iran during a period of 50 years. For this purpose, the temperature of 663 synoptic stations from 1962 to 2004 was obtained from the Esfazari database. Then, in order to complete this database, the daily temperature from 2004 to 2011 was obtained from the Meteorological Organization of the country and added to the aforementioned database. In order to perform calculations and draw maps, Matlab, grads and Surfer software have been used. The results of this study showed that the index of cooling waves and heating waves, while having a direct effect on each other, had an increasing trend in most of the area of Iran. The statistical distribution of the index of cooling waves is more heterogeneous than that of the index of heating waves. So that the spatial variation coefficient for cold waves is 84.22%. Also, the index of cooling waves has more spatial variability. The highest common diffraction of the index of heating and cooling waves has been seen in the northwest, east and along the Zagros mountains. Analysis of the indexes trends show that heat waves have intensified in 65.8% of Iran and the intensity of cold waves has decreased in 48.5% of Iran Extended Abstract Introduction Temperature is one of the major climatic variables, which it has a direct impact on different aspects of human life. It plays an essential role in the growth of crops and is considered a key driver of the biological system(Reicosky et al, 1988). It is associated with several types of extremes, for example, heat and cold waves which caused human societies maximum damage. Past occurrences of heat waves hitherto had significant impacts on several aspects of society. Have increased Mortality and morbidity. Ecosystems can be affected, as well as increased pressure on infrastructures that support society, such as water, transportation, and energy(Dewce, 2016). The long-term change of extreme temperatures has a key role in climatic change. The form of statistical distribution and the variability of mean values and also extreme event indicate a change in the region. It can be a small relative change in the mean as a result of a large change in the probability of extreme occurrence. Also, the variation in temperature data variance is significantly more important than the mean, for assessing the extreme occurrence of climate(Toreti and Desiato, 2008). The average surface temperature has increased the world between 0.56 and 0.92 ° C over the past 100 years(IPCC, 2007). Meanwhile, it was in the Middle East, the average daily temperature increased by 0.4-0.5 ° C in decades(Kostopoulou et al, 2014; Tanarhte et al, 2012). Considering that not many studies have been done in the field of spatio-temporal Variations of the heating and cooling waves thresholds in Iran, in this study, the spatio-temporal Variations of the heating and cooling waves thresholds in Iran during 50 years were examined and analyzed.   Methodology The daily temperature from the beginning of the year 21/03/1967 to 19/05/2005 was obtained from the Esfazari database prepared by Dr. Masoudian at the University of Isfahan. In order to increase the time resolution of the mentioned database, the daily temperature of observations from 05/21/2005 to 05/12/2012 has been added to the mentioned database using the same method, and the exact spatial resolution (15 x 15 km) is used as a database. Threshold indices of heating waves are the average numbers between the 95th and 99th percentiles, that is, the extreme hot threshold to the limit of excessively extreme hot. For extreme cool, from the 5th percentile down to zero is used. Of course, a condition was added to these thresholds, which is that these thresholds must be repeated two days in a row. These thresholds were extracted for each day in the 50 years of the study period and used as the original database. In order to analyze the relationship between cooling and heating waves, Pearson's correlation coefficient was used and regression was used to analyze the trend.   Results and discussion The average of cold waves was 5.26 ° C and for the heat waves is 30.20° C. Generally, if the temperature is upper or lower than this threshold, it is considered as hot or cold temperatures. A comparison of the median, mode, and average of cold waves with heat waves shows that the distribution is more heterogeneous for cold waves and its CV is 84.22%. In southern Iran, the average threshold heat waves are higher. This situation can be caused by the effects of subtropical high-pressure radiation, low latitude, and proximity to the sea. Though the threshold is higher in these areas, fewer fluctuations and changes are seen in the area. Heights moderate the temperature so they pose a minimum threshold for heat waves i.e. an iso-threshold of 25 ° C is consistent along the Zagros mountain chains, but in the west and east of Zagros Mountains, the threshold of heat waves is increased. Heat waves have increased in most areas of the country. So nearly 85 percent of the Iran has been an increasing trend, of which 65.8 percent is statistically significant at the 95% confidence level. Still, more areas of the country (60 percent) have a trend between 0.00828 and 0.00161. As can be seen, only 15% of the land area (including the southwest and northwest of the Country) had decreased heat waves. Cold waves, in most parts of the country, have a Positive Trend. However, about 25 percent of the study area's cold waves have a negative trend. they are located in areas higher than Latitude 30°. The largest decline of the wave's trend along the country is highlands. Nowadays, most of the country, has a trend between 0.01494 and 0.00828 ° C, respectively. Conclusion Common changes and effects of heat and cold waves had a direct relationship in many parts of the country. It is remarkable common variance in the East reached 55 percent, according to statistical significance. In some areas of the northwest and southwest, which have been impressive heights, the common variance is 40 percent. This common variance in mountains area has been high values. Investigation of heat waves trend shows that 65.8% of Iran significant positive trend and 7.1% significant negative trend. Also, the cold waves trend has indicated a 48.5% significant positive trend and a 10.8% significant negative trend. Climate change and global warming have changed the frequency and severity of temperature extremes. The present study, by examining the number of warm waves, concluded that the warm waves have increased in magnitude in 65.8% of the Iran zone. Also, the study of the cold waves trend showed that 48.5 percent of Iran had a positive trend, which means that the amount of temperature in the cold waves increased In other words, the severity of the cold has been reduced And only 10.8 percent of Iran had a negative cold wave trend And it shows the intensity of these waves is reduced.   Funding There is no funding support.   Authors’ Contribution The authors contributed equally to the conceptualization and writing of the article. All of the authors approthe contenttent of the manuscript and agreed on all aspects of the work declaration of competing interest none.   Conflict of Interest The authors declared no conflict of interest.   Acknowledgments  We are grateful to all the scientific consultants of this paper.

Baking powder is the most important chemical leavening agent that is used for aeration in bakery products; and lead to better preparation of dough and makes it tender and porous. This study was conducted to evaluate gas production ability of several samples baking powders that is determined by Fast laboratory volumetric method (using the Chittick apparatus). Moreover, dough properties (including specific gravity) and physical properties of produced cake (volume, apparent density) were assessed. Correlation of volumetric methods and cake voluminal properties was studied concerning significantly strong relation among Chittick test results and the baked cake physical properties; it can be used to predict the volumetric properties of different samples of baking powders without the need for the baking trial.

The heating value of natural gas is used to determine the quality of the gas sample, hence accurate prediction of heating value helps in controlling the issue of underbilling and overbilling between a gas aggregator and an off-taker. Moreover, the heating value of natural gas is not a fixed value and the accuracy of it in real-time is essential. This study was focused on the prediction of the Higher heating Value (HHV) of natural gas based on percentage gas compositions obtained from Ghana’s offshore oil fields using Artificial Neural Networks (ANN), Adaptive Boost (AdaBoost), Extreme Gradient Boost (XGBoost), Linear Regression (LR). These algorithms were modelled to determine the best predictive model using 2021 sample data on gas specifications. Eighty percent (80%) of the data was used for training and the remaining 20% was used for testing. The performance of each algorithm was evaluated using Root Mean Square Error (RMSE), Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), R2 and Adjusted R2. XGBoost performed better than all the other predictive models with an R2 and adjusted R2 of 91.18% and 90.93% respectively and RMSE, MAE, and MAPE of 1.7302, 0.5393 and 0.57% respectively. The incorporation of this method provides a diverse approach to the analysis of the pipeline dynamic results of the heating value of natural gas.

This paper proposed the effect of using a heat recovery system in the gas turbines of Semnan to Shahroud oil pumping station in energy conservation point of view. heating the transferred fl uids is one of the common approaches to reduce fl uids viscosity and energy consumption, respectively. Due to the low effi ciency of station turbines compared to modern turbines, it is expected that the use of heat recovery has a positive effect on improving station performance. By analyzing the combustion products of the gas turbine at the station, the heat extracted from the exhaust gas fl ow has been calculated, which is consumed in the recovery boiler. The pipeline application process, including recovery boiler and main equipment of Semnan and Shahroud pumping stations, have been modeled. By applying the model, it found that the amount of energy savings by gas-oil heating using a heat exchanger equals 395311 m3 natural gas annually. Therefore, optimal points of using combustion heat in the gas turbine output were obtained. In addition, the reduction of power consumption in the presented station has been calculated. Economic calculations were carried out for different countries, including Iran, Scandinavian countries, China, and the Europian Union average, based on their energy prices and bank interest rates.

The main process that occurs in the CNG refueling station is filling Fast process. The main objective of the present study is to apply a more accurate thermodynamic analysis of Fast filling process than previous works. By using the thermodynamic analysis, a CNG refueling station with the cascade system, has been simulated. Comparing real and ideal gas models, it can be realized that the temperature profiles are highly different and temperature rise is much more for ideal gas model. the lack of Joule-Thompson cooling effect is the most important factor for this different. The results indicated that there is a temperature rise in order 50 K for real gas and 80 K for the case of ideal gas. The results of the present work have been validated against the experimental data and previous studies. The AGA8 Equation of State has been used to calculate the thermodynamic properties of CNG. The results show that the energy consumed by the compressor for a cycle is equal to 55. 1 kWh and the average energy consumption is equal to 1. 6 kWh for a vehicle.

The aim of the present research is calculation and determination of the temperature distribution in the oxy-gas source line heating process for application in the steel plates. Analytical method was used to calculate the temperature distribution by solving mathematical equations. The temperature distribution was determined with numerical method using MATLAB software. A computerized numerical control line heating apparatus was used for carrying out the processes. ITI thermograph camera was used to measure the temperature. The effect of torch distance, gas flow and torch speed on the temperature distribution at the upper and lower surfaces of plate were evaluated. The changes of temperature distribution were achieved at torch speeds of 120, 200 and 300 mm/min, gas flow of 10, 9 and 8 lit/min and torch distances of 30, 40 and 50 mm. Calculated and measured maximum temperatures reached to 900, 810 and 720 K, and 885, 785, 690 K, at torch speeds of 120, 200, 300 mm/min, respectively. The calculated and measured maximum temperatures at gas flow of 10, 9, 8 lit/min are attained to be 900, 810 and 750 K, and 885, 795 and 740 K, respectively. Maximum calculated and measured temperatures at torch distance of 30, 40 and 50 mm are accomplished to be 900, 880 and 810 K and 885, 840 and 790 K, respectively.