Dangerous gas explosion accidents result in considerable amount of casualties and property damage.
Hence, an investigation on the generation of poisonous gases in gas explosions exerts important implications
for accident prevention and control and in the decision-making processes of fire rescue. Therefore, a gas
explosion piping test system is established in this paper. Experimental research on gas explosion is conducted by
selecting methane/air premixed gases with concentrations of 7%, 9%, 11%, 13%, and 15% in the gas explosive
range. This research aims to reveal the regularity of CO generation after gas explosion in pipelines.
Experimental results showed that when the gas concentration is small (< 9%), 1500–3000 ppm CO will be
produced. When the gas concentration is large (> 9%), the CO amount will reach 3000–40000 ppm. The
variation trend in CO concentration and the quantity of explosive gas are also obtained.
Buried Natural Gas Pipe Line Leakage – Quantifying Methane Release and Disper...CFD LAB
The methane into the soil from buried natural gas pipelines due to small leakages, changes the soil properties, posing potential risks to humans and the environment. It is essential to estimate the leakage rate and monitor the methane diffusion range outside the pipeline, which is challenging due to the presence of soil. The main contribution of this work is to bridge the gap between estimating the leakage rate of underground pipelines and predicting the diffusion behaviors through calculating the gas concentration in the soil. The quantified leakage rate estimation model for air was firstly established by experimental results and validated by the numerical results, which were further modified by the methane with the numerical simulations. The methane diffusion model in the soil was then performed, through which, the influencing factors were explained and validated. In addition, the methane release and dispersion results in the soil could be used as the boundary conditions of the gas diffusion model in the air. The results show that the quantifying estimation correlations can predict the leakage rate and dispersion range in the soil accurately with errors less than 7.2 % and 15 %, respectively. Moreover, the quantified relations have been validated by the full-field experiments. And, the dispersion behaviors in the air could be portrayed instead of being regarded as a jet flow.
Buried Natural Gas Pipe Line Leakage – Quantifying Methane Release and Disper...CFD LAB
The methane into the soil from buried natural gas pipelines due to small leakages, changes the soil properties, posing potential risks to humans and the environment. It is essential to estimate the leakage rate and monitor the methane diffusion range outside the pipeline, which is challenging due to the presence of soil. The main contribution of this work is to bridge the gap between estimating the leakage rate of underground pipelines and predicting the diffusion behaviors through calculating the gas concentration in the soil. The quantified leakage rate estimation model for air was firstly established by experimental results and validated by the numerical results, which were further modified by the methane with the numerical simulations. The methane diffusion model in the soil was then performed, through which, the influencing factors were explained and validated. In addition, the methane release and dispersion results in the soil could be used as the boundary conditions of the gas diffusion model in the air. The results show that the quantifying estimation correlations can predict the leakage rate and dispersion range in the soil accurately with errors less than 7.2 % and 15 %, respectively. Moreover, the quantified relations have been validated by the full-field experiments. And, the dispersion behaviors in the air could be portrayed instead of being regarded as a jet flow.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Practical Issues of Combustion Oxygen Measurement Specifically Related to NOx...Arjay Automation
Power plants concerned with lowering NOx emissions are making tremendous changes to accommodate EPA regulatory requirements. A substantial number of these changes include the expansion and upgrade of the plant combustion oxygen measurement equipment. There is a striking relationship between the number of NOx reductions projects and the sales quantity of insitu oxygen detectors. The reason is that power plant betterment groups, operators, boiler manufacturers and engineering firms understand the direct relationship between NOx and excess air in the combustion process.
An area of daily practical importance to boiler operators and I&C teams are the common problems with insitu oxygen measurements. This paper focuses on the practical issues of combustion oxygen measurement as they relate to specifically to fuel usage and NOx emissions.
Read the entire white paper, courtesy of Yokogawa Corporation of America here.
This is a lecture is a series on combustion chemical kinetics for engineers. The course topics are selections from thermodynamics and kinetics especially geared to the interests of engineers involved in combusition
Kivekäs acp 2014 ship contribution to particle number (1)www.thiiink.com
“The ships sailing along the main shipping lane at the west coast
of Jutland Are responsible for 5 to 8 % of the number of all
particles at western Jutland, and between 4 and 8 % of the
particle mass concentration. The estimate from this measurement study
is however a gross underestimation of the true influence of the
shipping activity in the North Sea, since with the current method
that we used, we were not able to register the influence of all ships
sailing in the North Sea. So, in reality, we expect a much higher number.
In other words: The 5-8 % and 4 to 8 % number has to be considered
as a lower estimate. Hence, shipping is contributing to nanoparticles
downwind of major shipping lanes, which have dangerous health effects.
Since, we were able to account for the pollution from only one shipping lane
in the North Sea in the above study, we continued with the next study during
2016, using a different method, where we could study the influence from multiple ship lanes:
The inventory EE in Indonesia is still very limited.
The power needs of society and industry is increasing every year. Fossil energy sources are a major source of power generation tend to decrease dramatically and environmental impacts. The potential of RH and the PB in Indonesia is quite large which is produced every year. Based on previous studies, Indonesia has the potential of RH around 13.81×106 tons.The potential of PSW an average of about 252,945 tons/year generated from the year 2008-2010,
This potential can be exploited as a source of EE as well as the results of previous studies, in Thailand and in India
Contents of the lecture
What is combustion
Objectives of combustion
Stoichiometric amount of air
Air/fuel ratio and relation with POC
Combustion efficiency
The Expander Gas and Ammonia Ratio Influence on the Calcium Cyanamide YieldYogeshIJTSRD
For the first time, thermodynamic calculations based on relatively new physicochemical constants clarified the onset temperature of thermal ammonia decomposition, as well as the side chemical reactions probability between ammonia and carbon dioxide. The influence of the main technological parameters on the calcium cyanamide synthesis is investigated. The exhaust gases composition from the reactor for the calcium cyanamide synthesis was studied depending on the temperature. Kinetic studies of the calcium cyanamide synthesis determined the chemical reaction orders with respect to ammonia and carbon dioxide, and it was proved that the limiting stage of calcium cyanamide synthesis is the initial gas components diffusion through the product layer. O. Kh. Panzhiev | A. Kh. Panzhiev | N. Umarov | O. Azimov "The Expander Gas and Ammonia Ratio Influence on the Calcium Cyanamide Yield" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Special Issue | International Research Development and Scientific Excellence in Academic Life , March 2021, URL: https://www.ijtsrd.com/papers/ijtsrd38440.pdf Paper Url: https://www.ijtsrd.com/engineering/other/38440/the-expander-gas-and-ammonia-ratio-influence-on-the-calcium-cyanamide-yield/o-kh-panzhiev
“In southern Baltic Sea, we were able to measure the influence from
many shipping lanes on the coastal air quality. The measurements
Showed that ship traffic contributes to almost half of all nanoparticles
In southern Baltic Sea coastal areas when winds were blowing from shipping lanes
Towards the Baltic coast. In other words, shipping is significantly contributing
To severe health effects at coastal areas.”
Gasification of solid refuse fuel in a fixed bed reactorMd Tanvir Alam
The global energy demand is increasing rapidly with increasing human population, urbanization and modernization [1]. The world heavily relies on fossil fuel to meet its energy demand; in order to reduce the dependency on fossil fuels, diversify the use of new and alternative fuels and to secure energy production routes, energy production from waste is inevitable [2]. Solid refuse fuel (SRF) is a well-known alternative fuel produced from the combustibles in MSW [3]. In this study an effort was endeavored to gasify SRF in a fixed bed reactor at various equivalence ratio (ER) to find out the optimum condition.
Spatio-Temporal Trend Analysis of Projected Temperature over Rwandaiosrjce
IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) multidisciplinary peer-reviewed Journal with reputable academics and experts as board member. IOSR-JESTFT is designed for the prompt publication of peer-reviewed articles in all areas of subject. The journal articles will be accessed freely online
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Practical Issues of Combustion Oxygen Measurement Specifically Related to NOx...Arjay Automation
Power plants concerned with lowering NOx emissions are making tremendous changes to accommodate EPA regulatory requirements. A substantial number of these changes include the expansion and upgrade of the plant combustion oxygen measurement equipment. There is a striking relationship between the number of NOx reductions projects and the sales quantity of insitu oxygen detectors. The reason is that power plant betterment groups, operators, boiler manufacturers and engineering firms understand the direct relationship between NOx and excess air in the combustion process.
An area of daily practical importance to boiler operators and I&C teams are the common problems with insitu oxygen measurements. This paper focuses on the practical issues of combustion oxygen measurement as they relate to specifically to fuel usage and NOx emissions.
Read the entire white paper, courtesy of Yokogawa Corporation of America here.
This is a lecture is a series on combustion chemical kinetics for engineers. The course topics are selections from thermodynamics and kinetics especially geared to the interests of engineers involved in combusition
Kivekäs acp 2014 ship contribution to particle number (1)www.thiiink.com
“The ships sailing along the main shipping lane at the west coast
of Jutland Are responsible for 5 to 8 % of the number of all
particles at western Jutland, and between 4 and 8 % of the
particle mass concentration. The estimate from this measurement study
is however a gross underestimation of the true influence of the
shipping activity in the North Sea, since with the current method
that we used, we were not able to register the influence of all ships
sailing in the North Sea. So, in reality, we expect a much higher number.
In other words: The 5-8 % and 4 to 8 % number has to be considered
as a lower estimate. Hence, shipping is contributing to nanoparticles
downwind of major shipping lanes, which have dangerous health effects.
Since, we were able to account for the pollution from only one shipping lane
in the North Sea in the above study, we continued with the next study during
2016, using a different method, where we could study the influence from multiple ship lanes:
The inventory EE in Indonesia is still very limited.
The power needs of society and industry is increasing every year. Fossil energy sources are a major source of power generation tend to decrease dramatically and environmental impacts. The potential of RH and the PB in Indonesia is quite large which is produced every year. Based on previous studies, Indonesia has the potential of RH around 13.81×106 tons.The potential of PSW an average of about 252,945 tons/year generated from the year 2008-2010,
This potential can be exploited as a source of EE as well as the results of previous studies, in Thailand and in India
Contents of the lecture
What is combustion
Objectives of combustion
Stoichiometric amount of air
Air/fuel ratio and relation with POC
Combustion efficiency
The Expander Gas and Ammonia Ratio Influence on the Calcium Cyanamide YieldYogeshIJTSRD
For the first time, thermodynamic calculations based on relatively new physicochemical constants clarified the onset temperature of thermal ammonia decomposition, as well as the side chemical reactions probability between ammonia and carbon dioxide. The influence of the main technological parameters on the calcium cyanamide synthesis is investigated. The exhaust gases composition from the reactor for the calcium cyanamide synthesis was studied depending on the temperature. Kinetic studies of the calcium cyanamide synthesis determined the chemical reaction orders with respect to ammonia and carbon dioxide, and it was proved that the limiting stage of calcium cyanamide synthesis is the initial gas components diffusion through the product layer. O. Kh. Panzhiev | A. Kh. Panzhiev | N. Umarov | O. Azimov "The Expander Gas and Ammonia Ratio Influence on the Calcium Cyanamide Yield" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Special Issue | International Research Development and Scientific Excellence in Academic Life , March 2021, URL: https://www.ijtsrd.com/papers/ijtsrd38440.pdf Paper Url: https://www.ijtsrd.com/engineering/other/38440/the-expander-gas-and-ammonia-ratio-influence-on-the-calcium-cyanamide-yield/o-kh-panzhiev
“In southern Baltic Sea, we were able to measure the influence from
many shipping lanes on the coastal air quality. The measurements
Showed that ship traffic contributes to almost half of all nanoparticles
In southern Baltic Sea coastal areas when winds were blowing from shipping lanes
Towards the Baltic coast. In other words, shipping is significantly contributing
To severe health effects at coastal areas.”
Gasification of solid refuse fuel in a fixed bed reactorMd Tanvir Alam
The global energy demand is increasing rapidly with increasing human population, urbanization and modernization [1]. The world heavily relies on fossil fuel to meet its energy demand; in order to reduce the dependency on fossil fuels, diversify the use of new and alternative fuels and to secure energy production routes, energy production from waste is inevitable [2]. Solid refuse fuel (SRF) is a well-known alternative fuel produced from the combustibles in MSW [3]. In this study an effort was endeavored to gasify SRF in a fixed bed reactor at various equivalence ratio (ER) to find out the optimum condition.
Spatio-Temporal Trend Analysis of Projected Temperature over Rwandaiosrjce
IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) multidisciplinary peer-reviewed Journal with reputable academics and experts as board member. IOSR-JESTFT is designed for the prompt publication of peer-reviewed articles in all areas of subject. The journal articles will be accessed freely online
Gasping for Breath: A (bogus) analysis of the health effects from ozone pollu...Marcellus Drilling News
A piece of nonsense/garbage issued by two virulently anti-fossil fuel groups in Ohio that attempts to make a connection between oil and gas development (i.e. fracking) in Ohio and asthma attacks in children. It is completely bogus and a sham.
Burner rim geometry effect on flame stabilityJameel Tawfiq
We studied a swirl burner in atmospheric pressure combustion system with different burner lengths to
burner rim diameter ratios (L/D). Three ratios, of L/D 1, 2 and 3, were used to investigate the effect of the
burner’s geometry on the stability window. The results show that the position of the flame front stabilization
changes with L/D ratio. The flame front stabilizes closer to the burner rim as the length of the burner is
increased. The equivalence ratio of the mixture was taken as constant for the comparison’s sake. The flame
stabilizes closer to the rim with an increase of the rim length
Commentary Refuting a Cornell Study on the Greenhouse Gas Footprint of Natura...Marcellus Drilling News
Cornell professors Lawrence Cathles, Larry Brown and Andrew Hunter, along with Milton Taam, respond with their own analysis of natural gas vs. coal and refute earlier claims by another group of Cornell professors (Howarth, Santoro and Ingraffea) that burning coal is actually better for the environment than burning natural gas.
Power Generation in Future by Using Landfill GasesIJARIIT
this paper describes an approach to power generation in future by using landfill gases. The present day methods of power generation are not much efficient & it may not be sufficient or suitable to keep pace with ever increasing demand. The recent severe energy crisis has forced the world to rethink & develop the landfill gas type power generation which remained unthinkable for several years after its discovery. Generation of electricity by using landfill gases is unique and highly efficient with nearly zero pollution. Landfill gas utilization is a process of gathering, processing, and treating the methane gas emitted from decomposing garbage to produce electricity. In advanced countries this technique is already in use but in developing countries it’s still under construction. The efficiency is also better than other non-conventional energy sources. These projects are popular because they control energy costs and reduce greenhouse gas emissions. These projects collect the methane gas and treat it, so it can be used for electricity or upgraded to pipeline-grade gas. These projects power homes, buildings, and vehicles. Keywords-landfill gas process, LFG collection system, flaring, LFG gas treatment, gas turbine, and micro turbine.
Study of Methane Emissions in the Marcellus, Haynesville and Fayetteville Sha...Marcellus Drilling News
A new study by researchers at the University of Colorado’s Cooperative Institute for Research in Environmental Sciences and the National Oceanic and Atmospheric Administration (NOAA). Titled "Quantifying atmospheric methane emissions from the Haynesville, Fayetteville, and northeastern Marcellus shale gas production regions," the new study finds very little methane leakage in the Marcellus Shale region--less than 1/2 of 1%.
Recent Trends in NOx Reduction Techniques from Gas Turbine Combustionijsrd.com
Fossil fuels are non-renewable energy resources and its rapid depletion is of widespread concern whereas at the same time global warming has prompted researchers to develop technologies to increase the combustor performance without any harmful impact on our environment.NOx Formation mechanisms have been discussed. Classification of NOx reduction techniques has been done. Important works related with swirling air injection into the combustion chamber for distributed combustion reactions have been discussed.
DESIGN CRITERIA FOR OPTIMIZATION OF THE CROSS IGNITION PROCESS IN GASTURBINE-...ijscmcjournal
Reducing of pollutants with simultaneous increase of the gas turbine power, is always a fundamental aim
of the Turbine technology. New developed structures and operating systems in the turbine production have
been established. In the meanwhile, burning instabilities are still appearing in these systems during a
Cross-ignition process (CI), creating pollutants due to high flame temperatures, and are not yet completely
investigated.
The phenomena of a CI is taking place during operation of malty-burner combustion chambers, when one
burner is extinguished and a particular volume of combustible mixture is formed in the distance between
this burner and the adjacent lightened one, which considered to be as an ignition path.
Cross ignition process should be performed along the ignition path in a particularly controlled small time.
So that, no excessive quantities of combustible mixtures will be injected during this time in the combustion
chamber. Otherwise, burning instabilities and mechanical wear will be occurred.
Depending on this illustration, the Cross Ignition Time (CIT) of an extinguished burner, that will be
considered as the evaluation measure for the entire cross-ignition process, should be Possibly as low as its
normal ignition time.
The main objective of this project is to reproduce constructive criteria for controlling of cross ignition
process by influencing the mixing process and heat flux in a defined mixing zone existing along the ignition
path.
Design Criteria for Optimization of the Cross Ignition Process in Gasturbine-...ijscmcj
Reducing of pollutants with simultaneous increase of the gas turbine power, is always a fundamental aim of the Turbine technology. New developed structures and operating systems in the turbine production have been established. In the meanwhile, burning instabilities are still appearing in these systems during a Cross-ignition process (CI), creating pollutants due to high flame temperatures, and are not yet completely investigated.The phenomena of a CI is taking place during operation of malty-burner combustion chambers, when one burner is extinguished and a particular volume of combustible mixture is formed in the distance between this burner and the adjacent lightened one, which considered to be as an ignition path. Cross ignition process should be performed along the ignition path in a particularly controlled small time.So that, no excessive quantities of combustible mixtures will be injected during this time in the combustion chamber. Otherwise, burning instabilities and mechanical wear will be occurred. Depending on this illustration, the Cross Ignition Time (CIT) of an extinguished burner, that will be considered as the evaluation measure for the entire cross-ignition process, should be Possibly as low as its normal ignition time.The main objective of this project is to reproduce constructive criteria for controlling of cross ignition process by influencing the mixing process and heat flux in a defined mixing zone existing along the ignition path.
A bridge to nowhere: methane emissions and the greenhouse gas footprint of na...Marcellus Drilling News
A so-called research paper by Cornell professor Robert Howarth who attempts to prop up his wild theories that methane is worse for the earth than burning coal by reviewing other people's research and issuing so-called reports in so-called "peer reviewed" (and obscure) online journals. The original is published here: http://onlinelibrary.wiley.com/doi/10.1002/ese3.35/full
International Journal of Engineering Research and Development (IJERD)IJERD Editor
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
Varying Effects of Temperature and Path-length on Ozone Absorption Cross-sectionTELKOMNIKA JOURNAL
Inconsistencies in the absorption cross section of ozone have been observed. Hence, for accurate measurement, we have reported the combined effects of varying optical path-length and temperature on the ozone gas absorption cross section (OACS) at 334.15nm. Adopting optical absorption spectroscopy, results of the (OACS) have been simulated using spectralcalc simulator with HITRAN 12 has the latest line list. OACS increased by 52.27% as the temperature increased from 100K to 350K while it was slightly affected by a 0.007% decrease varying the path-length from 0.75cm-130cm.
A new study from the Centre for Policy Studies that conters previous claims that a large amount of methane leaks during shale drilling and production. This study says that methane leakage from shale production is seriously over-estimated.
Similar to Experimental Study on Toxic Gas Produced during Pipeline Gas Explosions (20)
Efforts made in many countries to stop the COVID-19 pandemic include vaccinations. However,
public skepticism about vaccines is a pressing issue for health authorities. With the COVID-19 vaccine
available,
SARS-CoV-2, as the causative agent of COVID-19, has spread throughout the world after becoming
a pandemic in March 2020. In the midst of the ongoing COVID-19 pandemic, we are also faced with another
serious health problem
This paper discusses the construction and implementation of a system for the measurement of
electrical power parameters; amperage and voltage of the hybrid system photovoltaic solar-wind, to evaluate
the system parameters and performance. The basis of the development of the measuring apparatus is the use of
an Arduino Mega 2560 to provide the interface between the electrical circuits of the sensors and the dynamics
of the voltage-amperage as well as collect data in an analog format as well as development of functional
dependence relationships. The collected data is converted into digital format and stored it in an Excel format
through the "PLX-DAQ Spreadsheet" that connects the Arduino and the PC for display and analysis of the
system parameters. The proposed technique for power measurements of AC and DC proved to be reliable and
can predict the power amperage and voltage within relative error of 1.63 % for AC and 4.16% for DC,
respectively.
The optimum speed required for mass-size reduction of shells to produce most sizes that are small
comparable with kernel sizes; coupled with retention of kernel wholeness in cracked palm nut mixture under
repeated impact was investigated. This is to enhance whole kernel separation by dry method, reduce maintenance
and production cost of palm kernel oil (PK0); and lower the risk of oil rancidity associated with split kernel
production and wet method of separation. A static nut cracker and centrifugal nut cracker were used in this study as
Test Rigs while sieves were used to grade cracked shells and whole kernels. The data generated were evaluated. A
model was developed for energy via speed required to retain kernels wholeness following repeated impact in the
crackers. Technical analysis revealed that the maximum allowable speed to retain kernel wholeness is 27.93 m/s;
the minimum allowable average speed to fragment cracked shells is 24.95 m/s. Further analysis showed that the
optimum speed and energy required for cracked nut mixture under repeated impact to have kernel wholeness
retention and production of small sizes of cracked shells relative to kernel sizes are 25.71 m/s and 0.4 J,
respectively.
This review was written to provide a comprehensive summary of the suggested etiologies of Chronic Kidney
Disease of Unknown Etiology (CKDu) in Sri Lanka. In this review, Chronic Kidney Disease (CKD) is explained
in detail and its known etiologies are discussed. CKDu is defined and its epidemiology is discussed, with the
compilation of statistic from over 15 research papers through the years 2000 to present.
This work contributes to the monitoring of water pollution of some selected Dams in Katsina
State, North western Nigeria by assessing the degree of heavy metal pollution in the Dams sediment samples.
The study was conducted in the year 2017 within some selected Dams in the State (Ajiwa, Zobe,
Sabke/Dannakola) that are beehives of fishing and Agricultural activities in Katsina State. Analysis for the
concentration of these heavy metals; Cr, Cd, Fe, Ni, Mn, Pb and Zn was conducted by the use of AAS (by
Atomic Absorption Spectrophotometry) method. Several indices were used to assess the metal contamination
levels in the sediment samples, namely; Geo-accumulation Index (Igeo), Enrichment Factor (EF),
Contamination Factor (CF), Degree of Contamination (Cd), Pollution Load Index (PLI) and Potential
Ecological Risk Index (PERI). The result of this study has shown that generally among the heavy metals
evaluated, the highest concentration was observed for Fe (range: 2.6718-4.2830 ppm), followed by Zn (range:
0.4265-0.7376 ppm), Cr (range: 0.1106-0.1836 ppm), Cd (range: 0.1333-0.1273 ppm) and Mn (range: 0.1136-
0.1271 ppm). While Pb has the lowest concentration (range: 0.0472-0.0598 ppm). For all the site sampled the
heavy metal Ni was below detection level (BDL). From the results of heavy metals I-geo values, according to
Muller’s classification, all the sediment samples from the selected dams were unpolluted (class 0). The result for
the enrichment factor has shown that for all the selected dam sediment samples the heavy metals show
deficiency to minimal enrichment. Also based on the contamination factors for all sediment samples the heavy
metal Cd has a CF values range of 0.5430-0.6665 (~1), indicating that the sediment samples are moderately
contaminated with Cd. In contrast, the rest of the heavy metals exhibit low contamination in general. The value
of PLI ranges from 0.2408 to 0.4935, indicating unpolluted to moderate pollution. The Eri values for all
samples are all < 40, presenting low ecological risk. The results suggest that the sediment samples from the
selected dams in Katsina state has low contamination by the heavy metals evaluated.
Using QR Decomposition to calculate the sum of squares of a model has a limitation that the number of rows,
which is also the number of observations or responses, has to be greater than the total number of parameters used in the
model. The main goal in the experimental design model, as a part of the Linear Model, is to analyze the estimable function
of the parameters used in the model. In order not to deal with generalized invers, partitioned design matrix may be used
instead. This partitioned design matrix method may be used to calculate the sum of squares of the models whenever the total
number of parameters is greater than the number of observations. It can also be used to find the degrees of freedom of each
source of variation components. This method is discussed in a Balanced Nested-Factorial Experimental Design.
Introduction:It has been proven twice that the Hambantota District has the highest life expectancy in male
population. This study focused to find and identify reasons for Hambantota District people to have high life
expectancy at birth.
Methodology: Research was carried out in both qualitative and quantitative phases in five MOH (Medical
Health Officer) divisions in HambantotaDistrict. Study focused on 3 age categories, 55-65 Years, 66-75 Years,
and above 76 Years. Main objectives and key information areas are Life Style and Social Behaviors, Food
Consumption and Diet, Familial Trait and Physical and Mental Health.
Findings: Majority of the male population have educated up to grade 5and most are engaged in the agriculture
while others engaged in fishery and self-employment etc. Almost everyone reachestheir workplaces by foot or by
bicycle. Many of them work less than six hours. They spend their free time with their family members and watch
TV. Most of them do not consume alcohol and smoke. Almost everyone take part in social activities. Majority eat
red rice for all three meals. Almost everyone eats fish every day. They have a high salt intake. Their parents and
ancestors have also have had a high life expectancy. Only a minority suffer from chronic illnesses. They all have
a good physical and mental health condition. They spend happy and relaxed lifestyle.
Conclusion: Healthy diet, low alcohols consumption and smoking, high iodine intake, physical activeness and
their social wellbeing effect for high life expectancy within the male population of selected five MOH divisions
in Hambantota District. They have a free and happy life. Genetics of these people also may contribute for high
life expectancy. Abundance of neem trees in this area also may effect on their high life expectancy.
A clay deposit in Chavakali of western Kenya was evaluated for its potential as refractory raw
material. The collected clay sample was crushed, sieved and the chemical composition determined in
percentage weight (wt %) of (SiO2, Al2O3, Fe2O3, etc) using Atomic Absorption Spectrophotometer (AAS). The
samples were moulded into rectangular shaped bricks of 40mm height, 40mm width and 80mm length, allowed
to dry and later fired up to a temperature of 10000C. Refractory properties like Compressive strength,
Hardness, Linear shrinkage on firing, Apparent porosity and Density were determined using standard
techniques. The result of chemical analysis indicated that the clay was composed of Silica (SiO2), 67.3%;
Alumina (Al2O3), 16.67%; Iron Oxide (Fe2O3), 3.87%; Calcium Oxide (CaO), 0.37%; Potassium Oxide (K2O),
2.30%; Sodium Oxide (Na2O), 1.39%; and other traces. The physical and mechanical tests show that the clay
has Cold Crushing Strength of 10.36MPa, Hardness of 40.080 GPa, Linear shrinkage of 6.17%, Apparent
Porosity of 32.71% and Bulk Density of 2.77g/cm3
. Chavakali clay can make better local refractory
Nihon University challenged world record of the human-powered aircraft flight based on the
regulation of Fédération Aérionautique Internationale in Kasumigaura Lake, Japan, 2014. The wing fell off in
midair immediately after take-off, the pilot landed to the lake for safety. So, the challenge failed. It guessed the
operational errors were correlated with the wing falling in midair, which had not happened in our experience.
The flight recording camera and the salvaged airplane were investigated. The fault tree analysis was conducted
for cause investigation. The wing falling was the result as the chain destruction starting from the coupling parts
being damaged in take-off. The defective take-off was caused by composite factors on only operational errors.
The risk that the ultralight airplane might disintegrate in midair by only operational error became apparent.
Due to the large-scale exploitation of mineral resources and the unreasonable human activities, the
geological disasters in Jiaozuo City have become increasingly prominent and the degree of harm increased. This
leds to a tremendous threat to human life and property safety. Jiaozuo City, the main types of geological
disasters, landslides, ground subsidence, debris flow and ground fissures. It has great significance to the
development of the city and the protection of people's life and property to explore the hidden dangers of
geological disasters and actively take preventive and control measures. The establishment of geological
hazard group measurement system of prevention and control to achieve the timely detection of geological
disasters, rapid early warning and effective avoidance.
To evaluate the influence of the entry speed to flow field above the water surface on an object
high-speed entering into water, the flow field was measured experimentally by using an optical visualization
method. The entry speed was ranging from 0.2 to 1.5 km/s. In case that the entry speed was higher than the
sound speed of gas above the water surface, the vertical velocity of the tip of a water splash was linear to the
vertical location of the tip. The ratio between the initial vertical velocity of a water splash and the entry speed
was independent from the entry speed and was constant.A shock wave was driven above the water surface by the
entry even thoughthe entry speed was lower than the sound speed of gas above the water surface.A scaling law
for the propagation of a shock wave driven by explosion of an explosive was applicable to the propagation of
the shock wave driven by the water entry by using the kinetic energy of the entry object instead of the explosive
energy.
Pingdingshan Coal Mine district is one of the six mining areas of Henan Province, which is a
large coal base in China. After 60 years of exploitation, it has brought great benefits, at the same time,
serious geological disasters have been occurred. It has seriously damaged the normal production of the
masses, life, restricting the development of Pingdingshan coal mine economy. In this paper, the
geological disasters such as ground collapse, ground fissures and ground subsidence in Pingdingshan coal
mine are analyzed, and the degree of geological disasters in the mining area is analyzed in combination
with the severely affected mining area. Finally, reasonable and feasible countermeasures have been put
forward.
Kelud volcano is located in East Java Province, Indonesia. According to Geochemical study of
Kelud Volcano, it could be divided into 3 periods which are Kelud I (older than 100 ky BP), Kelud II (40 – 100
ky BP), and Kelud III (younger than 40 ky BP). A specific petrogenesis of Kelud are dominatad by magma
mixing and fractional crystalization. New petrological data from Kelud volcano was taken through products of
the eruption in 1990 (Vulkanian type), 2007 (Lava plug forming) and 2014 (Plinian type). Petrographic study
on these rocks showed that reverse and oscilatory zoning on plagioclases, Shieve-like and corroded textures on
plagioclases and pyroxenes are common. However, normal zoning textures were also found on plagioclases and
pyroxenes. Whole rock study on these rocks showed all rocks were classified into Basalt to Andesite in
composition with calc-alkaline group. The study indicated that their magma origin derrived from slab with
fractional crystallization during in the magma reservoir, and magma mixing processes are dominant expecially
in magma pockets. Concequently, the magma origin and petrogenesis of Kelud magma after the 1966 eruption
are still the same as those of old magma of Kelud.
Black cotton soils are among a group of soils termed as problematic soils. These soils have
undesirable characteristics in relation to construction works and therefore need some form of improvement
when encountered in construction projects. Techniques for improvement of black cotton soils include
replacement, moisture control or adding a stabilizer. Cement and/or lime has been commonly used in soil
stabilization for ages. However, due to the associated cost, required quality control and the need to utilize waste
materials in construction, new stabilizing materials are emerging. This paper presents a study on application of
quarry dust for improving properties of black cotton soil in Mbeya region, Tanzania. The targeted improvement
was to achieve minimum acceptable characteristics for road subgrade as per Tanzania standards. It was
determined that 40% by weight of quarry dust added to the black cotton soil was able to improve the
characteristics by increasing CBR value from 3.8 to 15.7 and reducing PI from 32% to 15%. It will be worthy
studying the cost implication of the suggested improvement in relation to other techniques before application of
the study findings.
High intensity rain and morphometri in Padang city cause at Arau. Morphometri
geomorphologi that is related to wide of, river network, stream pattern and gradien of river. The form wide
of DAS will be by stream pattern and level.This will influence to the number of rain. Make an index to
closeness of stream depict closeness of river stream at one particular DAS. Speed of river stream influenced
by storey, level steepness of river. Steepness storey, level is comparison of difference height of river
downstream and upstream. Ever greater of steepness of river stream, excelsior speed of river stream that
way on the contrary. High to lower speed of river stream influence occurence of floods, more than anything
else if when influenced by debit big. By using rainfall from year 2005 to year 2015, and use Thiessen method
got a rainfall. Use the DEM IFSAR, analysed sofware ARGIS, and with from earth map, the result got DAS
in at condition of floods gristle and sedimentation. There are band evakuasi for resident which data in
floods area.
The chemical (extractives and lignin) content and histological property (microscopic structure)
of tissues of Ricinodendron heudelotii (Baill, Pierre ex Pax), an angiosperm, were investigated for its potential
as a fibrous raw material for pulp and paper production. Bolts of about 70 cm were cut from the felled trees at
three different merchantable height levels of 10%, 50%, and 90% to obtain: corewood, middlewood and
outerwood samples. The fiber characteristics of the selected trees viz: the fiber length, fibre diameter and lumen
diameter were measured while the cell wall thickness was derived from the measured fibre dimensions. The
average fiber length, cell wall thickness, and lumen width, were 1.40 mm, 4.6 µm, and 32.3 µm, respectively.
The extractive and lignin contents were determined. Klason lignin content was about 30%. Extractive content of
R. heudelotii ranged from 0.41 to 0.5%. Based on these findings R. heudelotii is suitable for pulp and paper
production.
The prolific Niger Delta Basin is a mature petroleum province. Therefore, further prospectivity in
the basin lies within deeper plays which are high pressure and high temperature (HPHT) targets. One of the
main characteristics of the Niger Delta is its unique diachronous tripartite stratigraphy. Its gross onshore and
shallow offshore lithostratigraphy consists of the deep-seated Akata Formation and is virtually exclusively
shale, the petroliferous paralic Agbada Formation in which sand/shale proportion systematically increases
upward, and at the top the Benin Formation composed almost exclusively of sand. This stratigraphic pattern is
not exactly replicated in the deep offshore part of the delta.
A low-carbon steel wire of AISI 1022 is used to easily fabricate into self-drilling tapping screws,
which are widely used for construction works. The majority of carbonitriding activity is performed to improve
the wear resistance without affecting the soft, tough interior of the screws in self-drilling operation. In this
study, Taguchi technique is used to obtain optimum carbonitriding conditions to improve the mechanical
properties of AISI 1022 self-drilling tapping screws. The carbonitriding qualities of self-drilling tapping screws
are affected by various factors, such as quenching temperature, carbonitriding time, atmosphere composition
(carbon potential and ammonia level), tempering temperature and tempering time. The quality characteristics of
carbonitrided tapping screws, such as case hardness and core hardness, are investigated, and so are their
process capabilities. It is experimentally revealed that the factors of carbonitriding time and tempering
temperature are significant for case hardness. The optimum mean case hardness is 649.2HV. For the case
hardness, the optimum process-capability ratio increases by about 200% compared to the original result. The
new carbonitriding parameter settings evidently improve the performance measures over their values at the
original settings. The strength of the carbonitrided AISI 1022 self-drilling tapping screws is effectively improved.
We consider a real-time multi-server system with identical servers (such as machine controllers,
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perform the worst case analysis of the system working under maximum load with preemptive priorities assigned
for servers of different activity type. We consider a system with separate queue to each channel. Two models
with ample maintenance teams and shortage of maintenance teams are treated. We provide analytical
approximations of steady state probabilities for these real-time systems and check their quality.
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Experimental Study on Toxic Gas Produced during Pipeline Gas Explosions
1. International Journal of Scientific and Technical Research in Engineering (IJSTRE)
www.ijstre.com Volume 3 Issue 1 ǁ January 2018.
Manuscript id. 214563900 www.ijstre.com Page 14
Experimental Study on Toxic Gas Produced during Pipeline Gas
Explosions
JIA Zhi-wei1,2
XU Sheng-ming1
(1.School of Safety Science and Engineering, Henan Polytechnic University, Jiaozuo, 454003, China
2.Central Plains Economic Zone Coal Methane cooperative innovation center in Henan Province,Jiaozuo, 454003, China)
Abstract: Dangerous gas explosion accidents result in considerable amount of casualties and property damage.
Hence, an investigation on the generation of poisonous gases in gas explosions exerts important implications
for accident prevention and control and in the decision-making processes of fire rescue. Therefore, a gas
explosion piping test system is established in this paper. Experimental research on gas explosion is conducted by
selecting methane/air premixed gases with concentrations of 7%, 9%, 11%, 13%, and 15% in the gas explosive
range. This research aims to reveal the regularity of CO generation after gas explosion in pipelines.
Experimental results showed that when the gas concentration is small (< 9%), 1500–3000 ppm CO will be
produced. When the gas concentration is large (> 9%), the CO amount will reach 3000–40000 ppm. The
variation trend in CO concentration and the quantity of explosive gas are also obtained.
Key Words: gas explosion, piping test system, gas concentration, CO concentration
I. Background and significance of the study
Approximately 95% of China’s coal is obtained through underground mining, which involves complex
geological conditions and relatively adverse working environments. In 2013, the average mining depth of large
and medium coal mines is 650 m; the mining depth of Pingdingshan coal mine in Henan Province is 1000 m,
which extends downward with an average annual rate of 10 m [1-3]
. With the increased coal mining depth, the gas
content and pressure in the coal and the gas emission quantity also increase, thereby causing increasingly severe
gas explosions and coal and gas outbursts. In recent years, with the gradual increase in the coal mine safety
management level and safety investment in China, the death rate per million ton coal decreases annually, and
gas disaster has been effectively controlled [4-5]
. Nevertheless, in 2013, the death rate per million tons of coal in
China remains 10 times that of the United States; additionally, the death rate from gas and coal dust explosions
still exceeds 100 each year [6-7]
. In the past 10 years, considerable local and international research has been
performed about the factors influencing the gas explosion generation and the effects of shape, size, angle, and
wall roughness of underground roadway on the generation of flame and wave during gas explosion [8-14]
.
However, study on the mechanism and propagation law of gas explosion is still limited. In particular, research
on the generation and influencing factors of toxic gas during gas explosion lacks a system. Results cannot also
provide guidance on disaster relief decision for gas explosion accidents. Major coal dust explosion accidents
result in a substantial amount of casualties and property losses, a remarkable psychological trauma to the people,
and negative effects on the community. Therefore, research on the generation of shock wave, flame, and toxic
gas during gas explosion presents important guiding significance for accident control and disaster relief decision
[15]
. The generation and propagation of toxic gas, which causes considerable harm, should be investigated. The
2. Experimental Study on Toxic Gas Produced during Pipeline Gas Explosions
Manuscript id. 214563900 www.ijstre.com Page 15
obtained research results are largely important for estimating the diffusion range of toxic gas in underground
tunnel after gas explosion accidents.
II. Experimental study on carbon monoxide produced by gas explosion in pipelines
2.1 Establishment of experimental systems
In this experiment, we used the experimental system with a total length of 20.9 m. The explosion pipeline
showed a dimension of 80 mm × 80 mm. The gas explosion concentrations of 7%, 9%, 11%, 13%, and 15% of
methane/air premixed gas were selected to produce CO. We concluded that the CO amount in the gas explosion
accident is associated with the change in gas concentration. The schematic diagram of the gas explosion
experiment system is shown in Fig. 1.
1 2 3 4
5 6 7 8 9 10 11 12
1 - High Energy Ignition Device, 2 - Vacuum Flow Meter, 3 - Spherical Valve, 4 – Poison Gas Collection, 5–8
Front CO Detection Point, 9–12 Rear CO Detection Point
Figure 1 Gas explosion experiment system
Prior to the experiment, the spherical valve was opened. The vacuum pump was picked up at point 4, the
pipe was evacuated, the spherical valve was closed, and the gas with different concentrations was injected by the
vacuum flow meter. The gas explosion started at the ignition device and continued in the ball valve on the left
side of the pipeline. Points 5–8 were used to measure the gas explosion generated by the CO concentration. The
distance between points 5–8 and point 1 was 0.25, 1.35, 2.2, and 3.95 m, respectively. The physical model of the
experimental gas explosion system is shown in Figs. 2 and 3.
Figure 2 Cavity gas explosion experiment Figure 3 Gas explosion experimental
pipe system
2.2 Experimental data and treatment
Gas explosion with different gas concentrations (30 times) produced six groups of CO. Experimental results
are shown in Table 1。
3. Experimental Study on Toxic Gas Produced during Pipeline Gas Explosions
Manuscript id. 214563900 www.ijstre.com Page 16
Table 1 Relationship between each measuring point and the gas concentration
CH4 concentration
/%
CO concentration/ppm
Measuring point1 Measuring point2 Measuring point3 Measuring point4
7 1550 1600 1550 1400
9 2100 1900 1550 2200
11 16300 15200 17500 10700
13 26750 31050 28350 29500
15 39300 36900 32500 40300
7 1350 1400 1200 1750
9 2200 1350 1400 1700
11 11250 12000 11000 14550
13 27750 28050 29350 30500
15 33300 37000 31500 40500
7 1650 1750 1300 1400
9 2400 2200 2000 2150
11 13250 12050 13050 14550
13 28500 29150 29550 28700
15 39500 43200 44050 39500
7 1850 1300 1650 1400
9 2150 2150 2150 2150
11 11250 14050 11050 10050
13 31750 28350 29650 27850
15 39050 30500 32050 36500
7 1550 1350 2450 1050
9 2100 2050 1800 1350
11 13050 10500 11050 10300
13 31750 29000 30750 31550
15 35050 38050 40450 36750
7 1700 1350 1300 1650
9 2200 1700 1450 2050
11 13300 12500 13200 14300
13 28550 29350 31050 29850
15 33050 39500 27050 37050
The six groups of experimental results were averaged. The relationship between the gas concentration and
CO concentration was determined through the gas explosions with different concentrations, as shown in Fig. 4.
4. Experimental Study on Toxic Gas Produced during Pipeline Gas Explosions
Manuscript id. 214563900 www.ijstre.com Page 17
Figure 4 CO concentration with prefilled gas concentration
The relationship between CO and the amount of explosion gas involved in the enclosed confined space was
obtained using the following equations:
2 . 3 2 4 8
8 6 9 . 8 8xy ;
9359.02
R .
III. Data analysis and conclusion
The amount of CO produced after a gas explosion in the pipeline is related to the concentration of the gas
during explosion. Therefore, the gas concentration determines the peak density of CO. When the gas
concentration exceeds 9%, the CO concentration also increases evidently; high gas concentration results in a
large amount of CO produced. This result is attributed to that when the gas concentration is small (< 9%), the
amount of oxygen in contact with the gas is relatively abundant. Consequently, methane can be fully reacted.
Given that the gas density is less than that of air, a stratified phenomenon occurs in the pipeline mixing process:
the gas is in the upper part, and the air is in the lower part. A small amount of gas combustion during explosion
is insufficient, thereby producing a small amount of CO. When the gas concentration is relatively large (> 9%),
the reaction occurs when the critical point begins to react strongly with a highly representative reaction.
Furthermore, the oxygen cannot fully support all methane combustion, and the amount produced by the CO
increases rapidly with increased gas concentration.
Experimental data analysis resulted in the following conclusions:
(1) When the gas concentration is small (< 9%), the gas explosion will produce a small amount of CO
(1500–3000 ppm). By contrast, when the gas concentration is relatively large (> 9%), the gas explosion will
produce a large amount of CO (3000–40000 ppm).
(2) High gas concentration results in large amount of CO produced. The following relation is also
obtained: 2.3248
869.88xy .
IV. Acknowledgement
This study was supported by Program for National Natural Science Foundation of China (No.51774120).
5. Experimental Study on Toxic Gas Produced during Pipeline Gas Explosions
Manuscript id. 214563900 www.ijstre.com Page 18
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