Testing of metrological parameters of analyzers of explosive gases in laboratory conditions

2021 ◽  
Vol 92 ◽  
pp. 47-56
Author(s):  
A. N. Chlenov ◽  
◽  
A. V. Kochegarov ◽  
A. M. Aleshkov ◽  
◽  
...  
Keyword(s):  
System Analysis ◽  
Fire Hazard ◽  
Test Chamber ◽  
Gas Analysis ◽  
Metrological Characteristics ◽  
Main Element ◽  
Volumetric Concentration ◽  
Current Standard ◽  
Flammable Liquids ◽  
Laboratory Facility

Introduction. When training fire safety specialists, it is practically important to acquire skills in assessing the fire hazard of accidents with the release of flammable gases (GG) and vapors of flammable liquids (FL). The task of detecting hazardous concentrations of these substances is performed by gas analysis systems, the main element of which is gas analyzers. Goals and objectives. The aim of the study is to create a gas analysis installation for determining the main metrological characteristics of gas analyzers in a training laboratory. The tasks include the analysis of an existing installation that complies with the current standard, consideration of the design of the test chamber and the methodology for its application for the study of gas analyzers with a diffusion supply of the analyzed medium. The methods include system analysis and mathematical assessment of physical processes occurring in the test chamber during the preparation and conduct of research. Results and discussion. The article proposes and substantiates the design of a laboratory facility, in which a given volumetric concentration of the explosive substance under investigation is created in a special chamber with the help of a dispenser. Mathematical expressions have been obtained to determine the required amount of flammable liquids. The method of preparation of the installation and options for its use for laboratory work are considered. This technique is simple and ensures the safety of industrial gas analyzers research. Conclusions. The article substantiates the design of the gas analysis unit using a special chamber as a source of the gas mixture (GM). A mathematical model of the formation of HMs with a given volumetric concentration of flammable liquids vapors is obtained, based on the Mendeleev-Cliperon equation. The technique of preparing a chamber for determining the metrological characteristics of gas analyzers in a training laboratory is considered. Keywords: explosive gas, gas analyzer, laboratory facility, ideal gas equation, test chamber

Residential fire risk assessment and management

2021 ◽  
Vol 92 ◽  
pp. 128-141
Author(s):  
A. A. Tanygina ◽  
Keyword(s):  
Risk Assessment ◽  
Russian Federation ◽  
System Analysis ◽  
Fire Hazard ◽  
Fire Risk ◽  
Economic Indicator ◽  
Federal State ◽  
Residential Sector ◽  
The Russian Federation ◽  
Hazard Levels

Introduction. The article analyzes statistical data for the period of 2006-2018 and presents an assessment of fire hazard levels in residential sectors of the constituent entities of the Russian Federation, which were determined on the basis of an integral socio-economic indicator of fire risk. It also considers the problems of assessing fire hazard in the residential sector as in a complex social and economic systems. The purpose of the study is to determine the levels of fire hazard and build a model for managing fire risks in residential sectors of the constituent entities of the Russian Federation. Research methods. To solve the research problems, the methods of system analysis, statistical analysis, mathematical statistics, etc. were used. Research results. A number of statistical dependencies of the fire situation in the Russian Federation have been analyzed and obtained. The indicators with the most fire hazardous level in the residential sectors of the constituent entities of the Russian Federation were determined by calculation. A block diagram of a model for managing fire risks in the residential sector using the integral socio-economic indicator of fire risk (ISEPPR) is built. Conclusion. The values of the fire hazard levels obtained in the work and the model of fire risk management in residential sectors of the constituent entities of the Russian Federation make it possible to improve management decisions in the field of supervisory activities and preventive work of the Federal State Fire Supervision Authorities. Keywords: residential sector, integral socio-economic indicator of fire risk, risk assessment, level of fire hazard

scholarly journals Ex Vivo Normothermic Perfusion, a Novel Method to Assess Pancreases after Preservation

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Julien Branchereau ◽  
Etohan Ogbemudia ◽  
Et al.
Keyword(s):  
Ex Vivo ◽  
Graft Function ◽  
Resistance Index ◽  
Gas Analysis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Current Standard ◽  
Extensive Experience ◽  
Macroscopic Appearance ◽  
Cold Preservation ◽  
Normothermic Perfusion

Julien Branchereau1,2* and Etohan Ogbemudia1*, Kaithlyn Rozenberg1, Fungai Dengu1, Gabriella Hakim1, Flavia Neri1, Georg Ebeling1, Letizia Lo Faro1, James Hunter1, Rutger Ploeg1* and Peter Friend1* * "Authors contributed equally to this work" 1-Nuffield Department of Surgical Sciences - University of Oxford 2-Nantes Hospital University - France Introduction Static cold storage (SCS) of pancreases remains the current standard method for preservation prior to transplantation. Pulsatile hypothermic machine perfusion (HMP) is an emerging method that could potentially improve the preservation of pancreases to enhance graft function. This is based on personal extensive experience with HMP of pancreases in human, porcine allotransplantation and large non-human primate models. All models consistently showed preservation of pancreatic parenchyma on histological assessment for up to 24hours. To provide reassurance of organ viability prior to transplantation further investigations are necessary. We propose that normothermic perfusion (NMP) of pancreases after cold preservation allows necessary functional and physiological assessments. Method Porcine pancreases (3) were retrieved from the slaughterhouse after 30 minutes of warm ischaemia and were flushed. After 3 hours of cold ischaemia two pancreases were perfused by HMP (Wave machine; Waters Medical Systems) for 6 hours followed by 1 hour of NMP. One pancreas after 3 hours of CIT was placed on NMP for 2.5hours, this was the first pancreas NMP to assess feasibility of this technique.NMP was achieved by modification of the kidney assist device. Oxygenation was with 21% oxygen. The pancreases were cannulat ed via the aorta with free drainage of perfusate from the portal vein. NMP parameters for all pancreases were a pressure of 40mmHg and temperature of 37C. Perfusate was composed of red blood cells, plasma to provide a haematocrit of 25%, with additives of co-amoxiclav and 25,000IU of heparin. During the perfusions we collected serial perfusate samples for blood gas analysis and for insulin enzyme-linked immunosorbent assay (ELISA). Results The macroscopic appearance of the pancreases and the attached duodenum at the end of NMP appeared viable. Average resistance index during NMP was 0.62 ru (range 0.30 to 0.90 ru). Average flow rate was 77mls/min (range 53 to 100 mls/min). Throughout, the duration of NMP in the two pancreases perfused for one-hour lactate remain stable with no increase from baseline. In the one pancreas perfused for 2.5hours lactate was also stable in the first hour then increased by 50% during the last 1.5hours of perfusion. ELISA confirmed the presence of insulin in the perfusate for all three perfusions. Conclusion Normothermic perfusion is a feasible method to allow physiological and functional assessment of pancreases after cold preservation techniques encouraging us to further develop this model.  

scholarly journals Critical Factors Determining the Onset of Backdraft Using Solid Fuels

2019 ◽  
Vol 56 (3) ◽  
pp. 937-957
Author(s):  
Chia Lung Wu ◽  
Simón Santamaria ◽  
Ricky Carvel
Keyword(s):  
Gas Analysis ◽  
Maximum Temperature ◽  
Critical Factors ◽  
Critical Temperatures ◽  
Fuel Gas ◽  
Fire Propagation ◽  
Flammable Liquids ◽  
Auto Ignition ◽  
Reduced Scale ◽  
Pyrolysis Gases

AbstractBackdraft is an explosive fire phenomenon which typically occurs during fire-fighting activities, occasionally leading to fire-fighter fatalities. Real backdraft incidents involve complex fuel gas mixtures consisting of the products of underventilated burning and pyrolysis following burnout. However, most experimental research into backdraft has used methane gas or flammable liquids as fuel. Some aspects of real backdraft behavior may have been overlooked as a consequence of this simplicity. A reduced scale series of compartment fire tests have been carried out to investigate the critical factors governing the onset of backdraft, using polypropylene and high density polyethylene samples as fuel. It is established that there are critical temperatures for auto-ignition of the pyrolysis gases leading to backdraft which vary with fuel properties. For polypropylene the highest temperature in the compartment must be above 350°C for auto-ignition of the fuel gases, while mixtures in the presence of a pilot source can be ignited down to about 320°C. Backdraft cannot occur when the compartment temperature is below 320°C. For polyethylene, the corresponding temperature for auto-ignition is 320°C. In parallel with these tests, a series of pyrolysis investigations have been carried out using the fire propagation apparatus, with FTIR gas analysis. The observed critical temperatures for backdraft correlate well with the evolved pyrolysis gases. Analysis shows that higher temperatures are required for backdraft when the CO/CO2 ratio is small, and that below the auto-ignition temperature, backdraft can only occur above a CO/CO2 ratio of about 35%. It is concluded that the crucial factors determining whether backdraft occurs or not are the maximum temperature and the CO/CO2 ratio in the compartment, prior to opening the door.

High Temperature Oxygen Index Instrument with Quantitative FT-IR Gas Analysis

1995 ◽  
Vol 13 (3) ◽  
pp. 197-213 ◽  
Author(s):  
Karen Kinsella ◽  
Chad M. Nelson ◽  
John R. Haigis ◽  
Martin D. Carangelo ◽  
Marie B. Ditaranto ◽  
...  
Keyword(s):  
Building Materials ◽  
Standardized Test ◽  
Oxygen Index ◽  
Fire Hazard ◽  
Gas Analysis ◽  
Exposure Temperature ◽  
Product Profile ◽  
On Line ◽  
Ft Ir ◽  
Fire Characteristics

A bench-scale instrument has been constructed which provides a fire hazard and combustion product profile of polymers and composites used in advanced construction. Novel to the instrument is that a standardized test of material flammability (oxygen index) can be measured as a function of sample exposure temperature up to 800°C. Sample mass loss is measured concur rently ; and Fourier transform infrared (FT-IR) spectroscopy is used for on-line quantification of evolved gas species during heating, burning, and smoldering of the sample. The instrument has applications for industrial quality control of the fire characteristics of processed materials, and research and development of new building materials. This article describes the instrument and presents measurement results for several materials.

scholarly journals ASSESSMENT OF THE FIRE RISK IN OIL PRODUCTS TRANSPORT DEPENDING ON THE AREA OF SPILL

2015 ◽  
pp. 132-136
Author(s):  
V. D. Khalikov ◽  
F. Sh. Hafizov
Keyword(s):  
Oil And Gas ◽  
Fire Hazard ◽  
Fire Risk ◽  
Oil And Gas Industry ◽  
Concrete Surface ◽  
Oil Products ◽  
Gas Industry ◽  
Flammable Liquids

The character of impact of the flammable liquids spill area in assessing the fire hazard of transport facilities in oil and gas industry was determined. The area of spill was defined for gasoline of trademark AI-92. The calculation of the spill area was made by three types of a surface (a prepared ground, not prepared ground and concrete surface).

On probabilistic-physical and entropy approaches to combustion processes and determination of fire hazard

2021 ◽  
pp. 36-51
Author(s):  
Valeriy V. Belozerov
Keyword(s):  
System Analysis ◽  
Fire Hazard ◽  
Fire Retardant ◽  
Problem Statement ◽  
Combustion Theory ◽  
Acoustic Methods ◽  
Combustion Processes ◽  
The Relationship ◽  
Empirical Approaches

Introduction. The article provides an overview of the existing approaches to solving the problem of combustion of substances and materials, for their adequacy in determining their fire hazard of products and objects. The relevance of the work is due to the need to move from latent forms in determining the fire hazard of materials and products made from them (degrees of fire resistance, flammability groups, groups of the effectiveness of fire retardant coatings, etc.) to analytical forms describing the processes in the combustion theory. Problem statement. The task of the research is to determine the relationship between the theory of combustion of substances and materials and to assess their fire hazard in natural and man-made systems. Theoretical part. The system analysis of solutions to the combustion theory problems is performed. Its results became the basis of probabilistic-physical and entropy approaches, as well as proposals for changing standards designed to provide protection from fires. Conclusions. The results of the study showed the need to revise empirical approaches in assessing the fire hazard of materials and products made from them, which includes using thermoanalytic and acoustic methods and means.

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