Concentration Of Harmful Gases Research Articles

Rapid CO detection using MWCNTs/SnO2 hierarchical structure: synthesis, characterization, and RT gas sensing features

Industrialization, modernization, and heavy car populations cause an extensive release of hazardous gases which impact the environment and human health. In this respect, employing gas sensors for detecting different concentrations of carbon oxides, nitrogen oxides, and other harmful gases is being advanced with much interest and necessity. In our current work, we have feasibly synthesized MWCNTs/SnO2 hierarchical structure through a hydrothermal process. The attained XRD diffraction pattern reflects the crystallinity with a crystallite size <10 nm. The FTIR results signify the presence of the functional group which verifies the successful interaction and connection for the composite network. Morphological features using SEM, HRTEM depict the hierarchical structure persistence. The adsorption/desorption curves are investigated using BET analysis acquiring a surface area of 189 cc/g. Numerous gases were included in the gas sensing study such as ethanol, methanol, acetone, ammonia, CO, and CO2. The sensing performance displays a remarkable result for carbon monoxide (CO) detection. The response time for CO detection was 5 s, while the recovery was 7s for 300 ppm at RT. The improved selectivity of CO amongst ethanol, CO2 and other gases is demonstrated. The proposed CO sensing structure combines feasible approach, low-cost, room temperature operation, and fast response/recovery times. The structure is promising for CO gas detection for versatile industrial applications.

Design of Environmental Monitoring and Alarm System Based on Microcontroller

With the development of society, the improvement of science and technology, and the continuous optimization of production and life, people's living standards are also constantly improving. Therefore, people are starting to pay more and more attention to the comfort level of indoor environment. Housing is not only a place for family reunion and living, but also an important material guarantee for people's lives. However, with the rampant use of decoration materials and the increasing popularity of daily necessities, the hidden dangers of the living environment have greatly increased. Indoor environmental pollution has become one of the serious killers affecting modern human health, seriously affecting people's production and life. Therefore, it is particularly important to monitor the indoor environment, which not only needs to sensitively detect the concentration of various harmful gases, but also has an alarm function to constantly remind of dangers. The main functions of this design include: Connecting the microcontroller with temperature, humidity, and gas sensors to achieve real-time collection and reading of indoor temperature and humidity values, as well as monitoring gas concentration, and achieving the expected results. The display circuit was designed using LCD. The buzzer alarm function was used to automatically alarm when the gas concentration and temperature/humidity values exceeded the set standard values. When the temperature and humidity exceed the limit, the LCD display can immediately prompt and combine with LED alarm. When the gas concentration exceeds the limit, LED alarm is used.

Characterization of harmful gases and bioaerosols of pig farms: a review of the existing literature

From the ecological and economic point of view, intensive pig farming is drawing more and more attention due to the appearance of harmful substances, which significantly increases the risks of air, water and soil pollution. In addition, the optimal criteria for the content of harmful gases, dust and microorganisms in the environment of pig farms are currently not clearly defined. In order to better understand the interaction of harmful emissions and aerosols, the article reviews data from the literature on their main components, concentrations, and interactions. The results showed that the main pollutants in pig farming are harmful gases (ammonia (NH3), carbon dioxide (CO2), methane (CH4), nitrogen oxide (N2O), hydrogen sulfide (H2S), which are released from manure. The presence of even small concentrations of harmful gases in farm air can cause respiratory and cardiovascular system disorders not only in animals, but also in humans. Along with harmful gases, it is important to control the emission of solid particles and dust from livestock premises, which can form aerosols. Microbial aerosols in pig houses contain bacteria, fungi, viruses, which mainly come from the animals themselves, manure or service personnel. The bioaerosol includes the Firmicutes and Bacteroidetes bacterial divisions and their derivatives. In addition, the content of potentially dangerous bacteria in the bioaerosol can reach up to 40 %. A major concern causes the presence of a large number of antibiotic-resistant microorganisms in the air of these farms (including MRSA). The existing strategies and methods to combat these problems are still imperfect and need to be refined. Currently, the interaction of harmful gases, dust, solid particles and microorganisms is not taken into account, which can increase the toxic effect of each other on the animal's body. Therefore, there is a need for a better understanding of these interactions in order to improve the strategy for improving the microclimate conditions by correcting the microbiota, finding and developing biological preparations that contain natural bacteria capable of neutralizing odors and disinfecting livestock premises.

Profiling microbial communities in an extremely acidic environment influenced by a cold natural carbon dioxide spring: A study of the Mefite in Ansanto Valley, Southern Italy.

The Ansanto Valley's Mefite, one of the Earth's largest non-volcanic CO2 gas emissions, is distinguished by its cold natural carbon dioxide springs. These emissions originate from the intricate tectonics and geodynamics of the southern Apennines in Italy. Known for over two millennia for its lethal concentration of CO2 and other harmful gases, the Mefite has a reputation for being toxic and dangerous. Despite its historical significance and unique geological features, there is a lack of information on the microbial diversity associated with the Mefite's gas emissions. This study presents an integrated exploration of the microbial diversity in the mud soil, using high-throughput sequencing of 16S rRNA (Prokaryotes) and ITS2 (Fungi), alongside a geochemical site characterisation. Our findings reveal that the Mefite's unique environment imposes a significant bottleneck on microbial diversity, favouring a select few microbial groups such as Actinobacteria and Firmicutes for Prokaryotes, and Basidiomycota for Fungi.

The effectiveness of the protective action of mineral adaptogen in respiratory diseases of broilers

There has been unrelenting interest of poultry farmers in feed additives that help to increase the viability of poultry, reduce mortality, and increase the absorption of feed. Adaptogens are such feed additives. Adaptogens increase nonspecific resistance, which has led to their use in poultry farming. However, their use in broiler feeding is limited. The reasons for the mortality of young animals are not only infections and violations in the technology of breeding, but also an increased concentration of harmful gases that can take the life of many chickens. Therefore, the search for new and effective means of protecting broilers is urgent. The aim of the study was: to determine the effectiveness of the pulmo-protective action of adaptogens in broiler feeding. Studies were carried out on arbor acres broilers to determine the effectiveness of the adaptogen as a protective drug, and to determine the efficiency of feeding and the safety of the broiler population when feeding the adaptogen. Micromorphological studies of the respiratory organs were carried out, features of the microstructure of the lungs were revealed with and without adaptogens. For the first time, the pulmo-protective effect of the fodder adaptogen against the background of disturbed microclimate parameters in the poultry house was histologically confirmed.

Controlling toxic and harmful gas in blasting with an inhibitor.

In engineering blasting, while efficiently breaking rocks with explosives, a large amount of toxic and harmful gases are generated, which not only pollutes the production environment but also easily leads to explosion smoke poisoning accidents. It must be highly valued by engineering technicians and management personnel. To effectively control the production of harmful gases during explosive blasting, an environmentally friendly and efficient harmful gas inhibitor has been developed, and its mechanism of action has been analyzed and revealed. Through model and on-site experiments, the appropriate addition ratio and charging structure scheme were determined, and good control effects were achieved. The research results indicate that the environment in which explosives are used has a significant impact on the composition of harmful gases produced during blasting. CO, NO, and NO2 are mainly produced in natural air environments, while NH3, CO, and NO are mainly produced in underground blasting environments. As the proportion of inhibitors added increases (2%, 4%, 6%), the decrease in the concentration of harmful gases during blasting first increases and then decreases. Compared with the control experiment, the total reduction rate of harmful gas concentration is 39.23%, 68.20%, and 59.69%, respectively, and the best control effect is achieved when 4% is added. When using the developed inhibitor adding device for the full hole addition scheme, the control effect of harmful gas concentration in blasting is the best, and the decrease in harmful gas concentration reaches 62.79%~84.73% at a distance of 30m~120m. The use of harmful gas inhibitors for blasting combined with other control measures can significantly improve the blasting operation environment, enhance the safety level of production operations, and have good promotion and application value.

О влиянии роста давления воздуха с глубиной на расчет требуемого количества воздуха в глубоких рудниках

The effect of increasing air pressure with the depth on the calculation of the required amount of air in the deep mines is analyzed in the work. It is established that with an increase in air pressure, the values of the volumetric maximum permissible concentrations of toxic and explosive gases in it decrease, while their maximum permissible mass concentrations remain unchanged. Failure to consider the decrease in volumetric maximum allowable concentrations of toxic and explosive gases with depth when calculating the required amount of air in the mines in some cases can lead to an underestimation of air flow rates in working areas and, as a result, to an excess of maximum allowable concentrations of harmful gases. To move the same volume of air, local ventilation fans at great depths need to expend more power than at the surface. Therefore, when working at depth, it is required to use local ventilation fans with electric motors of greater power. When air is supplied to a greater depth, it is compressed and the volume flow decreases. Therefore, in order to maintain the required volumes of air at depth, it is required to increase its flow rate at the main fan installation. This should be considered when calculating the required amount of air in deep mines. The results obtained in the work can be applied in the design of deep mines and the development of methods for calculating the required amount of air for them. Based on the conducted research, the method was adjusted for calculating the amount of air used at the Glubokaya mine of the Skalisty mine of the Polar Branch of PJSC MMC Norilsk Nickel.

Analysis of experimental data on the gas composition of air on a livestock farm

The article presents studies on the concentration of harmful gases and the movement of air flows in the livestock room. Due to the fact that hydrogen sulfide is extremely volatile, it is well susceptible to removal by ventilation, because of this, maximum peaks of its concentration can be observed in the exhaust area. For a height of 0.5 m, it was 1.66 mg/m3, for 1.5 m — 1.92 mg/m³, and at a height of 2 m, the concentration reached 1.8 mg/m3. The largest amount of carbon dioxide is localized in the feed passage. This is due to the fact that animals most of the time are located in the direction in his direction, and since cattle are the main source of carbon dioxide, since a larger amount is released during respiration, then the main localization of the gas will be directly in the feed passage. In the area of ventilation, CO2 concentrations are equal to 1054 ppm, and in the area without ventilation — 1178 ppm. The maximum peaks of ammonia localization have been established, most of them are located in the area of the room in which the ventilation system is located. For a height of 0.5 m, it was 45.4 mg/m3, for 1.5 m — 43.6 mg/m3, and at a height of 2 m, the concentration reached 44.4 mg/m3. Ammonia concentrations equal to 27.3 mg/m3, 24.8 mg/m3 and 28.6 mg/m3, respectively, were detected at the aft passage, which is closer to the hood, at heights of 0.5 m, 1.5 m and 2 m. Above the feed table, which is located in the part of the cowshed without ventilation, indicators equal to 41.2 mg/m3, 48.7 mg/m3, 22 mg/m3 were found for a height of 0.5 m, 1.5 m and 2 m, respectively. Studies have shown that the peak values of gases are in the area of the cowshed, in which the ventilation system is located. It also depends on the properties of gases (lighter will reach ventilation faster).

Research and Design of Arc Welding Parameters Control and Environment Monitoring System Based on DSP

In the process of the welding operation, a large number of welding smoke, toxic gas, and other pollutants will be produced, which can cause a variety of respiratory diseases. Therefore, the welder’s health is affected and the atmospheric environment is polluted. To monitor the detrimental soot substances produced in the arc welding process, an arc welding parameters control and environmental monitoring system was built by taking high-performance DSP (Digital Signal Processor) TMS320F2812 as the control core, which uses wireless communication technology. Multi-information sensing and welding parameters control can be carried out through the system in the arc welding process. The concentration of welding smoke, harmful gas, and other substances in the arc welding environment can be monitored in real time and the real-time environmental conditions are displayed visually. The functions of audible and visual alarms, automatic ventilation, and telecommunication are provided by the system. A lot of experimental verification and debugging results show that parameters control in the arc welding process and the monitor welding environment in real time could be realized by the built system and is running well.

Study on the Cause of Hypoxia in the Corner of Return Air of Shallow Buried Flammable Coal Seam Group Mining Face and the Coordinated Prevention and Control of Coal Spontaneous Combustion

Coal is the main energy source in China, and spontaneous combustion of coal is one of the main disasters in coal mines. Fully mechanized caving top coal mining technology is widely used in coal mines. Under the comprehensive action of multiple factors, gas generated by coal oxidation and low oxygen gas in goaf is easy to rush to working face, resulting in lower oxygen concentration in upper corner and exceeding harmful gas concentration. It seriously threatens the health of underground workers and the normal operation of production. If the oxygen concentration in the upper corner is changed, it is bound to cause the change of the oxygen concentration in the goaf and aggravate the threat of spontaneous combustion of coal in the goaf. In order to solve the double threat of low oxygen in upper corner and coal spontaneous combustion in goaf, based on Coulomb model, this paper uses command flow to conduct numerical simulation tests on the failure law of overlying strata, and obtains the influence of mining of the lower 1 coal seam and the lower 5 coal seam on the overlying strata subsidence and surface penetration. Based on the comprehensive consideration of atmospheric pressure, ore pressure activity, external air leakage and other factors, the mixed model of the source and emission of low oxygen gas in goaf was established, and the formation mechanism of low oxygen problem in the corner of return air of working face was defined. The use of pressure air belt to deal with low oxygen in return air corner is proposed creatively. The comprehensive fire prevention measures such as corner plugging, nitrogen injection and grouting are used to inhibit the oxidation of the left coal and the influx of low oxygen gas to the corner in the goaf, so as to achieve the goal of collaborative prevention and control of low oxygen in the corner of return air and coal spontaneous combustion. The research results have important reference significance for the mine with the risk of spontaneous combustion or the problem of low oxygen in the return air corner.

Poultry-Edge-AI-IoT System for Real-Time Monitoring and Predicting by Using Artificial Intelligence

Poultry farms have played a significant role throughout human history, in feeding the growing population. A good environment is a perfect condition for the growth of poultry, preventing disease, and effective production. The temperature higher and the humidity favor the growth of bacteria and hence the production of ammonia (NH3) by the decomposition of organic matter. Ammonia (NH3), carbon monoxide (CO), and carbon dioxide (CO2), Methane (CH4), hydrogen sulfide (H2S) are poisonous gases that can cause poultry diseases and mortality. The combination of Artificial Intelligence (AI), Internet of Things (IoT), and Edge Computing offer efficient and intelligent stand-alone systems of monitoring in real-time, predicting, and advanced automation. The paper aims to monitor in real-time and predict poultry barns' environmental conditions using an artificial intelligence algorithm. An intelligent system called Poultry-Edge-AI-IoT has been developed to gather, hash, store, pretreat, filter, knowledge extract, and transmit information from a heterogeneous wireless sensor network. The Poultry-Edge-AI-IoT system is based on IoT, AI, and Edge Computing for the detection of potential stress, the harmful gas concentration, and the prediction of poultry barns' environmental conditions. The system is modular and upgradeable.

Ammonium polyphosphate-melamine synergies in thermal degradation and smoke toxicity of flexible polyurethane foams

Polyurethane (PUR) foams can lead to fatal fires in the presence of an ignition and oxygen source. Obviously, the problem is not the mere loss of PUR foams properties but essentially, the smoke and toxic gases which are the main factors responsible for fire hazards. This paper reports on the main approaches taken to improve the smoke evolution and toxicity of isophorone diisocyanate (IPDI) based PUR foams which are the incorporation of ammonium polyphosphate (APP), melamine (M) and its combinations as additive flame retardants (FRs). In order to better understand the fire behavior, the influence of incorporated FR on the thermal degradation mechanism was also analyzed by means of thermogravimetry coupled to infrared spectroscopy (TGA-FTIR). In addition, foams were characterized in terms of smoke evolution and toxicity of released gases both asphyxiant and irritant using a smoke density chamber coupled to infrared spectroscopy (NBS-FTIR). Data showed that the mixture of APP and M in different amounts reduced the smoke generation and the concentration of harmful gases, underlying a synergetic effect for the combination of both flame-retardants.

Advanced perception and control method of harmful gas during construction period of coal tunnel based on DeepAR

Effective real-time treatment and control of harmful gases are key to ensuring the safety of tunnel construction workers. Currently, the monitoring ability of harmful gases is insufficient to match the processing needs, which poses significant risks to the safety of tunnel construction workers. This paper proposes an advanced perception and treatment method for harmful gases during tunnel construction, utilizing the DeepAR algorithm. Real-time monitoring of the concentration and diffusion of harmful gases is conducted, and a harmful gas concentration prediction model is established using the DeepAR algorithm, achieving advanced perception of harmful gases during tunnel construction. The harmful gas treatment plan is developed in advance, and the effectiveness of the proposed method is demonstrated by simulation testing under realistic field scenarios and comparing with other prediction models. The method was applied in a coal mine tunnel in Qinghai Province, achieving an accuracy rate of 94.3%, which is higher compared to those obtained using RNN and LSTM algorithms. Moreover, the computational time is less than 60 s. The method provides timely perception of the concentration distribution of harmful gases in the tunnel and proposes targeted treatment measures, verifying the effectiveness of the prediction model from the perspective of practical engineering application.

Smoke exposure levels prediction following laboratory combustion of Pinus koraiensis plantation surface fuel

High concentrations of harmful gases released from forest fire will pose a short-term hazard to fire-fighters' cardiopulmonary function, even threaten their lives. In this study, laboratory experiments were conducted to examine the relationship between harmful gases concentrations and burning environment and fuel characteristics. In the experiments, fuel beds were created with controlled moisture contents and fuel loads; a wind tunnel device was used to conduct 144 trials, each with a specific wind speed. The easily predicted fire behavioral characteristics and the harmful gases concentrations such as CO, CO2, NOx, SO2 which were released during fuel combustion were measured and analyzed. The results showed that the influences of wind speed, fuel moisture content, and fuel load on the flame length are in accordance with the fundamental theory of forest combustion. The contributions by controled variables to the influence on the short-term exposure concentration of CO and CO2 can be ranked as fuel load > wind speed > fuel moisture. The R2 of the established linear model that was used to predict Mixed Exposure Ratio was 0.98. Our results can help protect the health and lives of forest fire-fighters and can be used by forest fire smoke management to guide fire suppression.

Ignition control and waste heat assessment of spontaneous combustion gangue hill by gravity heat pipe group: a case study in Shanxi Province, China.

Spontaneous combustion gangue hill has attracted great attention due to serious environmental pollution and terrible geological disasters. However, the rich thermal resources inside are often ignored. In order to control the spontaneous combustion of gangue hill and utilize the internal waste heat resources, this project studied the combined treatment effect of 821 gravity heat pipes, laid 47 sets of temperature monitoring devices, evaluated the storage of waste heat resources, and proposed different waste heat utilization methods. The results show that (1) the positions of spontaneous combustion are all located on the windward slope. The highest temperature is in the range of 6 ~ 12m underground, exceeding 700 ℃. (2) The single-tube experiment of gravity heat pipe shows that the effective temperature control radius is 2m. The cooling effect is obvious in the range of 3 ~ 5m underground. However, the temperature rises at the depth of 1m underground. (3) After 90days of treatment of the gravity heat pipe group, the temperature at the depths of 3m, 4m, 5m, and 6m in the high-temperature zone dropped by 56 ℃, 66 ℃, 63 ℃, and 42 ℃, respectively. The maximum temperature drop exceeds 160 ℃. The average temperature drop in the middle- and low-temperature areas is between 9 and 21°C. (4) The concentration of harmful gases (CO, SO2, and H2S) decreases by more than 90%. The hazard level is greatly reduced. (5) The amount of waste heat resources contained within 10m of the spontaneous combustion gangue hill is 7.83E13J. Waste heat resources can be used for indoor heating and greenhouse cultivation. And, under the temperature difference of 50°C, 100°C, and 150°C, the electric energy generated by the heat through the thermoelectric conversion device in the high-temperature zone of the gangue hill is 4056.8 kWh, 7468.2 kWh, and 10,603 kWh, respectively.

Experimental determination on cleaning the exhaust gas of an automobile muffler by an electric pulse

Nowadays, creating an environmentally reliable car by reducing the volume of harmful gases in it is a global problem of mankind. For this reason, one of the main areas of research is to improve the exhaust gas cleaning system of internal combustion engines. However, to date, there are no universal designs that would improve the performance of the purification system. In this regard, the development of new vehicle exhaust system designs based on an effective cleaning method is an urgent task. The article highlights the results of scientific and experimental research of the authors on the development of new designs of automobile exhaust muffler working on the basis of the method of electro-pulsed cleaning, designed to reduce the concentration of harmful exhaust gases. The developed experimental installation of the electric-pulse muffler performs gas purification by feeding an electric shock discharge to the electrodes installed in the muffler. The experimental data obtained show changes in the gas transparency depending on changes in the distance between the electrodes. Regression-correlation analysis established empirical dependences of gas transparency values on changes in the distance between the electrodes.

Effect of Controlling Light on Cashmere Growth and Harmful Gas Parameters in Shanbei White Cashmere Goats

The quality and yield of cashmere closely affect the economic benefits of cashmere goat farming. Studies have shown that controlling light can have an important impact on cashmere but can also affect the concentration of harmful gases. In order to explore the impact of a short photoperiod on the growth of cashmere and harmful gases in goat houses, 130 female (non-pregnant) Shanbei white cashmere goats, aged 4-5 years with similar body weights, were randomly divided into a control group and a treatment group, with 65 goats in each group. The dietary nutrition levels of the experimental goats were the same, and completely natural light was used in the control group; the light control group received light for 7 h every day (9:30-16:30), and the rest of the time (16:30-9:30 the next day) they did not receive light. The light control treatment was carried out in a control house, and the gas content was analyzed. It was found that a shortened period of light exposure could increase the annual average cashmere production by 34.5%. The content of each gas has a certain functional relationship with the measurement time period, but at the same time, we found that the content of NH3 also changes seasonally. In summary, the use of shortened light periods when raising cashmere goats can significantly increase cashmere production and quality, but at the same time, it will increase the concentration of harmful gases in the goat barn, and ventilation should be increased to ensure the health of the goats and the air quality in the barn.

An extreme environment drives local adaptation ofGenista tinctoria(Fabaceae) from the Mefite (Ansanto Valley, southern Italy)

AbstractThe Mefite in the Ansanto Valley is one of the largest and oldest cold natural carbon dioxide springs (CNCDS) known in the world. This site is characterized by toxic concentrations of CO2 and other harmful gases, and few plant species can survive in this environment. Among these plants, there is an aberrant Genista tinctoria population previously described as G. anxantica. This study aims to advance understanding of evolution over small geographical scales in an extreme environment using G. tinctoria populations from low and high CO2 environments. To investigate differentiation of the Mefite population, we analysed plastid sequences and microsatellite data for populations in the surrounding area. Considering the genetic results, it is evident that the population of the Mefite has an exclusive genetic pattern from both plastid and nuclear points of view with the presence of significant genetic barriers for both genomes analysed, which would point to the isolation of this population from neighbouring G. tinctoria populations. The population of G. tinctoria from the Mefite shows evidence of genetic differentiation from the nearby populations and the genetic indices show discrete variation. Recruitment was confirmed in the Mefite population, an indication that fitness is maintained despite the extreme local conditions. Our results indicate that the potent selection pressure imposed by the Mefite atmosphere has driven genetic differentiation of the local population from nearby G. tinctoria populations. A correct taxonomic rank evaluation and some conservation remarks are also proposed. Our study demonstrates that CO2 concentrations can influence population differentiation and adaptation in plants in a similar way to atmospheric sulphur, herbicides or edaphic conditions.

Development and Assessment of an Indoor Air Quality Control IoT-Based System

Good health and well-being are primary goals within the list of Sustainable Development Goals (SDGs) proposed by the United Nations (UN) in 2015. New technologies, such as Internet of Things (IoT) and Cloud Computing, can aid to achieve that goal by enabling people to improve their lifestyles and have a more healthy and comfortable life. Pollution monitoring is especially important in order to avoid exposure to fine particles and to control the impact of human activity on the natural environment. Some of the sources of hazardous gas emissions can be found indoors. For instance, carbon monoxide (CO), which is considered a silent killer because it can cause death, is emitted by water heaters and heaters that rely on fossil fuels. Existing solutions for indoor pollution monitoring suffer from some drawbacks that make their implementation impossible for households with limited financial resources. This paper presents the development of IdeAir, a low-cost IoT-based air quality monitoring system that aims to reduce the disadvantages of existing systems. IdeAir was designed as a proof of concept to capture and determine the concentrations of harmful gases in indoor environments and, depending on their concentration levels, issue alarms and notifications, turn on the fan, and/or open the door. It has been developed following the Test-Driven Development Methodology for IoT-based Systems (TDDM4IoTS), which, together with the tool (based on this methodology) used for the automation of the development of IoT-based systems, has facilitated the work of the developers. Preliminary results on the functioning of IdeAir show a high level of acceptance by potential users.

Visualization method for multidimentional random processes

The article proposes a method for visualizing multidimensional random process realizations using the example of the concentrations of harmful gases emitted into the atmosphere from a thermal power plant. The method is based on the transformation of gas concentration values in one point of multidimensional space at the same time into a two-dimensional curve, which is described by the sum of products of normalized concentrations by orthogonal Legendre functions of the corresponding order. The combination of such curves on a two-dimensional plane at discrete times creates a characteristic image that can be used to visually detect features of gas concentrations over time by a human operator.