scholarly journals The impact of oxidiser humidity on methane combustion in a gas burner

2020 ◽  
Vol 8 (2) ◽  
pp. 48-59
Author(s):  
Andrii Avramenko
Keyword(s):  
Combustion Process ◽  
Methane Combustion ◽  
Environmental Indicators ◽  
Hazardous Substances ◽  
Simulation Methods ◽  
Air Humidity ◽  
Topical Problem ◽  
Study Results ◽  
Numerical Simulation Methods ◽  
The Impact

The improvement of thermodynamic and environmental indicators of energy facilities is a vital and topical problem. Numerical simulation methods are used to investigate the processes of combustion and formation of hazardous substances by computation, and to work out recommendations on increasing the effectiveness of fuel combustion. The paper examines the impact of atmospheric air humidity on the process of combustion of a stoichiometric methane-air mixture in a burner. The combustion process is simulated in the 3D unsteady statement in Cartesian coordinates. In the investigation, the combustion of the methane-air mixture is considered in one stage. Air humidity is considered in the 0 to 100% range. The monoxide nitrogen formation process is described using the extended Zeldovich-Fenimore mechanism. A comparative study has found that increasing air humidity up to 100% reduces the mass emission of monoxide nitrogen by a factor of 1.27, as compared to dry air. The study results can be used for designing equipment that uses methane as fuel.

scholarly journals Study on effect CO2 diluent on fuel cоmbustion in methane-oxygen combustion chambers

Vestnik IGEU ◽  
2021 ◽  
pp. 14-22
Author(s):  
I.I. Komarov ◽  
D.M. Kharlamova ◽  
A.N. Vegera ◽  
V.Y. Naumov
Keyword(s):  
Carbon Dioxide ◽  
Combustion Chamber ◽  
Combustion Process ◽  
Methane Combustion ◽  
Flame Stabilization ◽  
Total Carbon ◽  
Working Fluid ◽  
Combustion Mechanism ◽  
Combustion Chambers ◽  
The Impact

Studying closed gas turbine cycles on supercritical carbon dioxide is currently a promising issue in the development of power energy sector in terms of increasing energy efficiency and minimizing greenhouse gas emissions into the atmosphere. Combustion of methane with oxygen in the combustion chamber occurs not in the nitrogen environment, but in the environment of carbon dioxide, that is the working fluid of the cycle, which is an inhibitor of chemical reactions. A large mass content of such a diluent of the reaction mixture in the volume of the chamber leads to the risks of significant chemical underburning, efficiency decrease of the combustion chamber and the cycle as a whole. The aim of the research is to study the kinetic parameters of the combustion of methane with oxygen in a supercritical CO2 diluent medium to ensure reliable and stable combustion of fuel by assessing the degree of the inhibitory effect of CO2 and determining its permissible amount in the active combustion zone of the combustion chamber. The research method is a numerical simulation of turbulent-kinetic processes of methane combustion in the combustion chamber using the reduced methane combustion mechanism. Ansys Fluent software package has been used. The authers have studied the impact of CO2 diluent on fuel cоmbustion in methane-oxygen combustion chambers. It is found that the combustor flame stabilization takes place if the content of СО2 diluent supplied to the mixture with oxidizer is 0,46–0,5 of mass fraction; additional СО2 diluent forms local low temperature zones which slow down the combustion process. When this happens, adding cooling СО2 into the flame stabilization zone should be eliminated. The study has found that no more than 20 % of the total carbon dioxide content should be supplied to the combustion chamber; to stabilize the flame and reduce its length, it is necessary to install blades to swirl the fuel and oxidizer mixed with CO2 at the inlet of the combustion chamber; CO2 supply for cooling should be carried out not less than 130 mm away from the burner mouth.

scholarly journals Impact of environmental indicators on the COVID-19 pandemic in Delhi, India

2020 ◽  
Author(s):  
Sherry Mangla ◽  
Ashok Kumar Pathak ◽  
Prafulla Kumar Sahoo
Keyword(s):  
Wind Speed ◽  
Air Pollutants ◽  
Meteorological Parameters ◽  
Correlation Method ◽  
Secondary Data ◽  
Quality Parameters ◽  
Environmental Indicators ◽  
Study Results ◽  
The Impact ◽  
Spearman’S Correlation

Abstract Currently there is a huge debate on whether meteorological and air quality parameters are playing a crucial role in the transmission of COVID-19 across the globe. On this background, this study aims to evaluate the impact of air pollutants (PM2.5, PM10, CO, NOx, SO2, AQI), and meteorological parameters (temperature, humidity, wind speed, and rainfall) on the spread, recoveries and mortality due to COVID-19 outbreak in Delhi. Spearman’s correlation method is employed on a secondary data collected from the Ministry of Environment, India and the COVID-19 data collected using daily government health bulletins for Delhi. Our result shows that the COVID-19 incidences are significantly positively correlated with temperature (r infections= 0.90, r recoveries= 0.84, r deaths= 0.83, p<0.05) and negatively correlated with humidity (r infections = -0.63, r recoveries = -0.58, r deaths = -0.56, p<0.05). This finding indicates that temperature and humidity play a significant role on the infections, recoveries and deaths due to the COVID-19. The study results may be useful for policymakers in managing the outbreak of COVID-19 in Delhi, India.

scholarly journals Impact of Environmental Indicators on the COVID-19 Pandemic in Delhi, India

Pathogens ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1003
Author(s):  
Sherry Mangla ◽  
Ashok Kumar Pathak ◽  
Mohd. Arshad ◽  
Doyel Ghosh ◽  
Prafulla Kumar Sahoo ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Meteorological Parameters ◽  
Rank Correlation ◽  
Correlation Method ◽  
Secondary Data ◽  
Environmental Indicators ◽  
Ongoing Research ◽  
Study Results ◽  
Rank Correlation Method ◽  
The Impact

Currently, there is a massive debate on whether meteorological and air quality parameters play a crucial role in the transmission of COVID-19 across the globe. With this background, this study aims to evaluate the impact of air pollutants (PM2.5, PM10, CO, NO, NO2, and O3) and meteorological parameters (temperature, humidity, wind speed, and rainfall) on the spread and mortality due to the COVID-19 outbreak in Delhi from 14 Mar 2020 to 3 May 2021. The Spearman’s rank correlation method employed on secondary data shows a significant correlation between the COVID-19 incidences and the PM2.5, PM10, CO, NO, NO2, and O3 concentrations. Amongst the four meteorological parameters, temperature is strongly correlated with COVID-19 infections and deaths during the three phases, i.e., pre-lockdown (14 March 2020 to 24 March 2020) (r = 0.79), lockdown (25 March 2020 to 31 May 2020) (r = 0.87), and unlock (1 June 2020 to 3 May 2021) (r = −0.75), explaining the variability of about 20–30% in the lockdown period and 18–19% in the unlock period. NO2 explained the maximum variability of 10% and 7% in the total confirmed cases and deaths among the air pollutants, respectively. A generalized linear model could explain 80% and 71% of the variability in confirmed cases and deaths during the lockdown and 82% and 81% variability in the unlock phase, respectively. These findings suggest that these factors may contribute to the transmission of the COVID-19 and its associated deaths. The study results would enhance the ongoing research related to the influence of environmental factors. They would be helpful for policymakers in managing the outbreak of COVID-19 in Delhi, India.

Income Diversification and Bank Efficiency in Vietnam

2017 ◽  
pp. 52-67
Author(s):  
Sang Nguyen Minh
Keyword(s):  
Regression Model ◽  
Commercial Banks ◽  
Banking System ◽  
Operational Efficiency ◽  
Commercial Banking ◽  
Tobit Regression ◽  
Income Diversification ◽  
Positive Effects ◽  
Study Results ◽  
The Impact

This study uses the DEA (Data Envelopment Analysis) method to estimate the technical efficiency index of 34 Vietnamese commercial banks in the period 2007-2015, and then it analyzes the impact of income diversification on the operational efficiency of Vietnamese commercial banks through a censored regression model - the Tobit regression model. Research results indicate that income diversification has positive effects on the operational efficiency of Vietnamese commercial banks in the research period. Based on study results, in this research some recommendations forpolicy are given to enhance the operational efficiency of Vietnam’s commercial banking system.

Some reflections on social structure: Theoretical and practical aspects

2020 ◽  
Vol 18 (6) ◽  
pp. 1063-1078
Author(s):  
T.N. Skorobogatova ◽  
I.Yu. Marakhovskaya
Keyword(s):  
Service Industry ◽  
External Factors ◽  
Infrastructure Development ◽  
Social Infrastructure ◽  
Social Sphere ◽  
The Social ◽  
Study Results ◽  
The Republic ◽  
Internal And External Factors ◽  
The Impact

Subject. This article discusses the role of social infrastructure in the national economy and analyzes the relationship between the notions of Infrastructure, Service Industry and Non-Productive Sphere. Objectives. The article aims to outline a methodology for development of the social infrastructure of Russia's regions. Methods. For the study, we used the methods of statistical and comparative analyses. The Republic of Crimea and Rostov Oblast's social infrastructure development was considered as a case study. Results. The article finds that the level of social infrastructure is determined by a number of internal and external factors. By analyzing and assessing such factors, it is possible to develop promising areas for the social sphere advancement. Conclusions. Assessment and analysis of internal factors largely determined by the region's characteristics, as well as a comprehensive consideration of the impact of external factors will help ensure the competitiveness of the region's economy.

The Impact of Bar Service Operation Practices on Organizational Performance in Indian Hotel Industry

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Mohinder C. Dhiman ◽  
Abhishek Ghai
Keyword(s):  
Organizational Performance ◽  
Hotel Industry ◽  
Demographic Variables ◽  
Study Results ◽  
Service Operation ◽  
Managerial Implications ◽  
Overall Performance ◽  
The Impact ◽  
The Relationship ◽  
Bivariate Test

The paper has a two fold purpose - examine the impact of bar service operation practices (BSOP) on organizational performance (OP) and study the relationship between organizational performance and demographic variables. Based on a survey of 362 bar managers perceptions on the impact of bar service operation practices on organizational performance were assessed by 59 practices and 6 demographic variables. Bivariate test and ANOVA were employed to test the working hypothesis in the study. Results indicated that there is a positive relationship between the bar service operation practices and organizational performance. Further, the results indicate some practical and managerial implications to improve organizational overall performance.

scholarly journals Environmental key performance indicators: the role of regulations and stakeholder influence

2021 ◽  
Author(s):  
Ewelina Zarzycka ◽  
Joanna Krasodomska
Keyword(s):  
Performance Indicators ◽  
Key Performance Indicators ◽  
Environmental Indicators ◽  
Business Strategies ◽  
Proactive Approach ◽  
Stakeholder Influence ◽  
Corporate Decisions ◽  
Study Results ◽  
Reporting Decisions

AbstractEnvironmental protection is of vital importance and needs to be considered in the context of business strategies, including companies’ reporting decisions. This paper aims to investigate the importance of stakeholders for environmental key performance indicators (KPIs) and the significance of different types of environmental KPIs to various stakeholders. The study is based on a content analysis of the disclosures provided by large public interest companies operating in Poland. The data were processed to produce descriptive statistics as well as classification and regression trees (C&RTs). According to the study results, the sample companies provide a variety of environmental indicators, with a total of 735 KPIs identified. The research confirms the importance of stakeholders interested in environmental issues for corporate decisions regarding environmental KPI disclosure. The study contributes to the extant literature by providing new insights into the importance of different stakeholder groups for the disclosure of environmental KPIs. It may serve as an incentive for standard setters and practitioners to take a proactive approach in further developing and improving environment-related reporting regulations.

scholarly journals Advances of 2nd Life Applications for Lithium Ion Batteries from Electric Vehicles Based on Energy Demand

2021 ◽  
Vol 13 (10) ◽  
pp. 5726
Author(s):  
Aleksandra Wewer ◽  
Pinar Bilge ◽  
Franz Dietrich
Keyword(s):  
Life Cycle ◽  
Lithium Ion Batteries ◽  
Electric Vehicles ◽  
Energy Demand ◽  
Lithium Ion ◽  
Life Cycles ◽  
Future Research ◽  
Research Areas ◽  
Study Results ◽  
The Impact

Electromobility is a new approach to the reduction of CO2 emissions and the deceleration of global warming. Its environmental impacts are often compared to traditional mobility solutions based on gasoline or diesel engines. The comparison pertains mostly to the single life cycle of a battery. The impact of multiple life cycles remains an important, and yet unanswered, question. The aim of this paper is to demonstrate advances of 2nd life applications for lithium ion batteries from electric vehicles based on their energy demand. Therefore, it highlights the limitations of a conventional life cycle analysis (LCA) and presents a supplementary method of analysis by providing the design and results of a meta study on the environmental impact of lithium ion batteries. The study focuses on energy demand, and investigates its total impact for different cases considering 2nd life applications such as (C1) material recycling, (C2) repurposing and (C3) reuse. Required reprocessing methods such as remanufacturing of batteries lie at the basis of these 2nd life applications. Batteries are used in their 2nd lives for stationary energy storage (C2, repurpose) and electric vehicles (C3, reuse). The study results confirm that both of these 2nd life applications require less energy than the recycling of batteries at the end of their first life and the production of new batteries. The paper concludes by identifying future research areas in order to generate precise forecasts for 2nd life applications and their industrial dissemination.

scholarly journals Robust Step Detection from Different Waist-Worn Sensor Positions: Implications for Clinical Studies

2020 ◽  
Vol 4 (1) ◽  
pp. 50-58
Author(s):  
Matthias  Tietsch ◽  
Amir Muaremi ◽  
Ieuan Clay ◽  
Felix Kluge ◽  
Holger Hoefling ◽  
...  
Keyword(s):  
Clinical Study ◽  
Clinical Studies ◽  
Neurological Diseases ◽  
Human Gait ◽  
Robust Solution ◽  
Step Detection ◽  
Study Protocols ◽  
Study Results ◽  
Wide Range ◽  
The Impact

Analyzing human gait with inertial sensors provides valuable insights into a wide range of health impairments, including many musculoskeletal and neurological diseases. A representative and reliable assessment of gait requires continuous monitoring over long periods and ideally takes place in the subjects’ habitual environment (real-world). An inconsistent sensor wearing position can affect gait characterization and influence clinical study results, thus clinical study protocols are typically highly proscriptive, instructing all participants to wear the sensor in a uniform manner. This restrictive approach improves data quality but reduces overall adherence. In this work, we analyze the impact of altering the sensor wearing position around the waist on sensor signal and step detection. We demonstrate that an asymmetrically worn sensor leads to additional odd-harmonic frequency components in the frequency spectrum. We propose a robust solution for step detection based on autocorrelation to overcome sensor position variation (sensitivity = 0.99, precision = 0.99). The proposed solution reduces the impact of inconsistent sensor positioning on gait characterization in clinical studies, thus providing more flexibility to protocol implementation and more freedom to participants to wear the sensor in the position most comfortable to them. This work is a first step towards truly position-agnostic gait assessment in clinical settings.

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