scholarly journals MATHEMATICAL MODELS APPLICATION TO PREDICT HEAT AND CHEMICAL AIR POLLUTION IN WORKING AREARS

2021 ◽  
pp. 39-45
Author(s):  
V. BILIAIEVA
Keyword(s):  
Air Pollution ◽  
Mathematical Models ◽  
Numerical Integration ◽  
Laplace Equation ◽  
Energy Equation ◽  
Velocity Potential ◽  
Numerical Models ◽  
Hazardous Substances ◽  
Physical Factors ◽  
Hazardous Substance

Problem statement. The problem of prediction the level of air pollution in working areas is considered on the basis of mathematical models of aerodynamics and heat and mass transfer. The task is to calculate the concentration field of chemically hazardous substances and the temperature field in the working zones. The purpose of the article. Construction of numerical models that allow determine the distribution of temperature and concentration of chemically hazardous substances in work areas with a complex geometric shape. Methodology. For numerical modeling of the process of air pollution in working areas during the spread of chemically hazardous substances, G. Marchuk's equation is used, which takes into account the transfer of a chemically hazardous substance due to convection, as well as due to turbulent diffusion. The energy equation is used to model the thermal contamination of work areas. To simulate the wind speed field in the presence of various kinds of obstacles, the Laplace equation for the speed potential is used. The integration of the modeling equations is carried out on a rectangular grid. For the numerical integration of the equation describing the propagation of a chemically hazardous substance in the air of working areas, a finite-difference splitting scheme is used. For the numerical integration of the Laplace equation for the velocity potential, two splitting schemes are used. The unknown value of the velocity potential at each splitting step is calculated using an explicit formula. Numerical integration of the energy equation is carried out using an explicit difference scheme. Scientific novelty. The constructed numerical models that allow to calculate the zones of chemical and thermal pollution, taking into account a set of important physical factors. A feature of numerical models is the speed of calculation, which is important when serial calculations are carrying out in practice. Practical significance. A complex of applied programs was created on the basis of the developed numerical models. This complex of programs allows to analyze and predict the intensity and size of zones of thermal or chemical pollution. This set of programs can be useful in determining the affected areas in case of extreme situations at chemically hazardous facilities. Conclusions. Numerical models have been developed. On the basis of these models a complex of applied programs has been created that allow to study multiparameter processes of chemical and thermal air pollution of working areas using the method of computer modeling. The complex of programs can be implemented on computers of low and medium power. The results of a computational experiment are presented.

scholarly journals A global association between Covid-19 cases and airborne particulate matter at regional level

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Angelo Solimini ◽  
F. Filipponi ◽  
D. Alunni Fegatelli ◽  
B. Caputo ◽  
C. M. De Marco ◽  
...  
Keyword(s):  
Air Pollution ◽  
Particulate Matter ◽  
Negative Binomial ◽  
Numerical Models ◽  
Regional Level ◽  
Pollution Level ◽  
Observation Data ◽  
Cumulative Number ◽  
Mixed Effect

AbstractEvidences of an association between air pollution and Covid-19 infections are mixed and inconclusive. We conducted an ecological analysis at regional scale of long-term exposure to air-borne particle matter and spread of Covid-19 cases during the first wave of epidemics. Global air pollution and climate data were calculated from satellite earth observation data assimilated into numerical models at 10 km resolution. Main outcome was defined as the cumulative number of cases of Covid-19 in the 14 days following the date when > 10 cumulative cases were reported. Negative binomial mixed effect models were applied to estimate the associations between the outcome and long-term exposure to air pollution at the regional level (PM10, PM2.5), after adjusting for relevant regional and country level covariates and spatial correlation. In total we collected 237,749 Covid-19 cases from 730 regions, 63 countries and 5 continents at May 30, 2020. A 10 μg/m3 increase of pollution level was associated with 8.1% (95% CI 5.4%, 10.5%) and 11.5% (95% CI 7.8%, 14.9%) increases in the number of cases in a 14 days window, for PM2.5 and PM10 respectively. We found an association between Covid-19 cases and air pollution suggestive of a possible causal link among particulate matter levels and incidence of COVID-19.

scholarly journals History, observation and mathematical models in the seismic analysis of the Valadier abutment area in the Colosseum

1995 ◽  
Vol 38 (5-6) ◽  
Author(s):  
G. Croci ◽  
D. D'Ayala ◽  
R. Liburdi
Keyword(s):  
Mathematical Models ◽  
Seismic Analysis ◽  
Numerical Models ◽  
Time History ◽  
Historical Records ◽  
Direct Integration ◽  
Structural Behaviour ◽  
Seismic Behaviour ◽  
Before And After ◽  
Xix Century

The present work aimed to outline the need to investigate different fields of research to interpret the structural behaviour of a monument as complex as the Colosseum. It is shown how defining the numerical models first. then refining them, followed by interpretation of results. is strictly linked with the inforination gathered from historical records and observation of the ~nonumenta s it is today. The study is confined to the area of the Valadier abutment. analysing its state and its seismic behaviour before and after the XIX century restoration using different ilumerical tools, from the elastic modal analysis to the non linear step by step time history direct integration. The procedure comparati\ely evaluates the reliability in the interpretation of the results and identifies future lines or research.

Mini-review of waste-to-energy related air pollution and their limit value regulations in an international comparison

2021 ◽  
pp. 0734242X2110606
Author(s):  
Isla Hodgkinson ◽  
Roman Maletz ◽  
Franz-Georg Simon ◽  
Christina Dornack
Keyword(s):  
Air Pollution ◽  
Environmental Impact ◽  
Waste Incineration ◽  
Waste To Energy ◽  
Hazardous Substances ◽  
Environmental Pressures ◽  
Best Available Technologies ◽  
Limit Value ◽  
Anthropogenic Processes ◽  
India And China

The concept of circular economy supports mitigation of climate change and other environmental pressures to the planet. Circulating materials in anthropogenic processes come with the risk of accumulating hazardous substances and compounds. In this concept, waste incineration or waste-to-energy (WtE) is a necessary technology to remove these compounds from the life cycle. In this mini-review, contaminants of major importance in the flue gas from waste incineration plants and their environmental impact are discussed. Air pollution of WtE is often seen as the most relevant environmental impact of this treatment option. The emission values parameter set for different countries is presented and compared. The most stringent legally set of emission values could be found in parts of Europe and South Korea. Japan also permits similar strict values when authorising individual incineration plants. In North America, the values are partially less strict as the best available technologies in Europe suggest being possible. Emerging economies, such as India and China, have shown efforts to improve their environmental protection standards but still have room to improve. This could be set in relation to other industrial emitting processes and therefore could be used to assess the relevance of this industry sector to the national emission inventories.

scholarly journals A Facility Location Model for Air Pollution Detection

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
G. Lancia ◽  
F. Rinaldi ◽  
P. Serafini
Keyword(s):  
Genetic Algorithm ◽  
Air Pollution ◽  
Air Quality ◽  
Mathematical Models ◽  
Facility Location ◽  
Large City ◽  
Location Model ◽  
Practical Algorithms ◽  
Pollution Detection ◽  
The City

We describe mathematical models and practical algorithms for a problem concerned with monitoring the air pollution in a large city. We have worked on this problem within a project for assessing the air quality in the city of Rome by placing a certain number of sensors on some of the city buses. We cast the problem as a facility location model. By reducing the large number of data variables and constraints, we were able to solve to optimality the resulting MILP model within minutes. Furthermore, we designed a genetic algorithm whose solutions were on average very close to the optimal ones. In our computational experiments we studied the placement of sensors on 187 candidate bus routes. We considered the coverage provided by 10 up to 60 sensors.

Development and Implementation of Guidelines for Federal On-Scene Coordinators for Protecting Historic Properties

1999 ◽  
Vol 1999 (1) ◽  
pp. 363-366 ◽  
Author(s):  
Jan C. Thorman ◽  
Pamela Bergmann
Keyword(s):  
United States ◽  
Historic Preservation ◽  
Emergency Response ◽  
The United States ◽  
Hazardous Substances ◽  
Advisory Council ◽  
Hazardous Substance ◽  
Contingency Plan ◽  
National Response ◽  
Response Team

ABSTRACT In 1997, the National Response Team completed a Programmatic Agreement on Protection of Historic Properties during Emergency Response under the National Oil and Hazardous Substances Pollution Contingency Plan. This agreement, which was drafted by a National Response Team ad hoc committee consisting of representatives of National Response Team member agencies, the Advisory Council on Historic Preservation, and the National Conference of State Historic Preservation Officers, has important ramifications for federal On-Scene Coordinators and responsible parties conducting spill response in the United States. The purpose of the Programmatic Agreement is to ensure that historic properties are appropriately taken into account in planning for and conducting emergency response to oil spills and hazardous substance releases under the National Oil and Hazardous Substances Pollution Contingency Plan. The agreement provides a uniform, nationwide approach to considering and protecting historic properties before and during an emergency response. Signatories, which include the U.S. Coast Guard and the Environmental Protection Agency, agree to implement this Programmatic Agreement or to develop and then implement regional Programmatic Agreements that are consistent with the nationwide Programmatic Agreement and the National Historic Preservation Act. As of September 1998, implementation of the nationwide Programmatic Agreement and development of regional Programmatic Agreements were just beginning by Regional Response Teams and federal On-Scene Coordinators throughout the United States. The Alaska Regional Response Team, whose development of regional cultural resources guidelines in the early 1990s led to the development of the nationwide Programmatic Agreement, had begun preparing a document on implementation of the nationwide Programmatic Agreement in Alaska. The emergency response provisions of the nationwide Programmatic Agreement were implemented for the first time in the November 1997, M/V Kuroshima spill near Dutch Harbor, Alaska. The major lesson learned from this incident with regard to the nationwide Programmatic Agreement is that its provisions are workable and can contribute to the overall success of the response.

ACROSS: An Observational Campaign to Improve Understanding of Photochemistry of Mixed Urban and Biogenic Air Masses

2020 ◽  
Author(s):  
Christopher Cantrell ◽  
Vincent Michoud ◽  
Paola Formenti ◽  
Jean-Francois Doussin ◽  
Aline Gratien ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Field Study ◽  
Organic Compounds ◽  
Numerical Models ◽  
Urban Air Pollution ◽  
Central Component ◽  
Urban Air ◽  
Oxides Of Nitrogen ◽  
Chemical Structures

<p>In recent decades, significant progress has been made in understanding the causes and impacts of urban air pollution, generally leading to improved air quality through enhanced knowledge and regulatory action. While a significant number of people still die prematurely each year from air pollution, progress continues to be made. Scientific investigation has exposed the processes by which primary pollutants, such as oxides of nitrogen and volatile organic compounds, are processed in the atmosphere, leading to their oxidation and ultimate removal, while at the same time producing secondary species such as ozone and organic aerosols.</p><p>Research has uncovered the complex chemistry of natural organic compounds released from trees and other plants. Because of the chemical structures of these compounds, they react somewhat differently than organic substances typically found in urban environments. The ACROSS (<strong>A</strong>tmospheric <strong>C</strong>hemist<strong>R</strong>y <strong>O</strong>f the <strong>S</strong>uburban fore<strong>S</strong>t) project focuses on scientific research to understand the detailed chemistry and physics of urban air mixed with biogenic emissions with the goals to increase detailed understanding of the chemical processes and to use this knowledge to improve the performance of air quality models. Enhanced knowledge and improved models will allow society to develop better strategies to improve air quality and save lives.</p><p>The central component of ACROSS is a comprehensive summertime field study with many instruments for the measurement of primary and secondary constituents. Measurements will be made from research aircraft, a tower located in a forest, tethered balloons and/or drones, and mobile platforms. Observations from the field study will be analyzed in a variety of ways involving statistical approaches and comparisons with different types of numerical models.</p><p>This presentation describes activities in preparation of the ACROSS measurement campaign and provides information for interested parties to become involved.</p>

scholarly journals The ignition of solid explosive media by hot wires

1949 ◽  
Vol 198 (1055) ◽  
pp. 523-539 ◽  
Keyword(s):  
Energy Equation ◽  
Critical Factor ◽  
Heat Losses ◽  
Heating Element ◽  
Heating Process ◽  
Physical Factors ◽  
Ignition Process ◽  
Chemical Action ◽  
Ignition System ◽  
The Moment

The present paper describes an investigation of the physical factors affecting the ignition of solid explosives by heated filaments embedded in the medium. The filaments were composed of fine resistance wire and were heated electrically, the critical thermal energy required to cause ignition being measured for wires of different geometrical, thermal and electrical characteristics and for different times of heating. Systematic variation of these factors enabled the energy equation for the ignition process to be formulated and its terms analyzed, the technique involving extrapolation to zero time of heating as a means of eliminating heat losses from the ignition system, and extrapolation to zero diameter of wire in order to eliminate terms involving the heating element; the former simulates the ideal case of a heat-insulated ignition system and the latter that of a line source of heat. The energy equation for ignition in these circumstances takes a simple form which implies that, at the moment of ignition, the heat supplied to the ignition system always equals the heat gained by the system plus the heat lost, the absence of any term representing heat generated by chemical action being very significant. For a given ignition system, the amount of heat absorbed up to the moment of ignition is shown to be independent of time, so that the increase in ignition energy with increasing time of ignition is wholly attributable to the heat losses sustained by the ignition system during the heating process. Further analysis shows that the critical factor governing ignition in systems of the type considered is the temperature, and that the geometry of the heating element probably determines the amount of explosive which must be raised to the critical temperature to ensure ignition.

scholarly journals GPU-Accelerated Laplace Equation Model Development Based on CUDA Fortran

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3435
Author(s):  
Boram Kim ◽  
Kwang Seok Yoon ◽  
Hyung-Jun Kim
Keyword(s):  
Analytical Solution ◽  
Laplace Equation ◽  
Large Scale ◽  
Numerical Models ◽  
Model Development ◽  
Computation Time ◽  
High Accuracy ◽  
Equation Model ◽  
Computational Time ◽  
Cuda Technology

In this study, a CUDA Fortran-based GPU-accelerated Laplace equation model was developed and applied to several cases. The Laplace equation is one of the equations that can physically analyze the groundwater flows, and is an equation that can provide analytical solutions. Such a numerical model requires a large amount of data to physically regenerate the flow with high accuracy, and requires computational time. These numerical models require a large amount of data to physically reproduce the flow with high accuracy and require computational time. As a way to shorten the computation time by applying CUDA technology, large-scale parallel computations were performed on the GPU, and a program was written to reduce the number of data transfers between the CPU and GPU. A GPU consists of many ALUs specialized in graphic processing, and can perform more concurrent computations than a CPU using multiple ALUs. The computation results of the GPU-accelerated model were compared with the analytical solution of the Laplace equation to verify the accuracy. The computation results of the GPU-accelerated Laplace equation model were in good agreement with the analytical solution. As the number of grids increased, the computational time of the GPU-accelerated model gradually reduced compared to the computational time of the CPU-based Laplace equation model. As a result, the computational time of the GPU-accelerated Laplace equation model was reduced by up to about 50 times.

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