Carbon Monoxide Concentrations Research Articles

Performance of a Small PEMFC Stack Operated with CO/H2 Mixtures

Hydrogen produced by reforming processes may include sulfur (S),carbon monoxide (CO) and other impurities.. Presence of ppm level impurities in hydrogen may adsorp onto Pt catalyst and lower performance and lifetime. There are efforts to overcome cost and performance issues by reducing Pt amount and utilizing new catalyst and support materials, more tolerant to CO. Ru catalyst are often added to oxidize CO before poisoning Pt. Ti0.7Mo0.3O2 was investigated as an alternative support material for anode catalyst. It has been shown that the stoichiometric ratio between Ti and Mo have significant impact on the CO tolerance. Ti0.8Mo0.2O2 was synthesized and used as anode electrode in PEM fuel cell testing. In this paper, titanium/molybdenum alloy on carbon (Ti0.8Mo0.2O2-C) is evaluated as catalyst support to prevent performance decay by CO poisoning. 3-cell stack was developed and tested for performance and degradation issues. Cell hardware with 15 cm2 active area was used for fuel cell measurements. Cathode was loaded with 0.6 mgPt/cm2 (20 wt.% Pt/C) and anode with 0.5 mgPt/cm2 (40 wt.% Pt/Ti0.8Mo0.2O2-C) onto Sigracet 29BC GDL by painting. Bipolar plates for single cell and stack were designed using Solid Works. End plates, anode bipolar plate and cathode bipolar plate with cooling channels on the other surfaces were designed and produced from graphite composite in-house. Seals from silicon was also designed and produced in-house. MEA had active area of 15 cm2. Figure 1 shows stack formation with all components put together in order. Stack was conditioned under 100% humidified hydrogen. There was no effect of stack orientation on performance. Performance for 2-cell stack was better going from atmospheric pressure to 2 bar. When polarization was 0.6V, pressurized operation provided improvement in current density going from 1300 mA/cm2 (no pressure) to 2000 mA/cm2 (15 psig). When this 2-cell stack was subjected to different concentrations of CO, polarization values of Figure 2 was obtained. Increasing concentration of CO caused decrease in current densities. Utilizing a DC/DC converter, stack has provided power to charge a cell phone. More details will be shared for 2, 3 cell stack operation under CO conditions. Figure 1

Development of Durable Large-Sized CO2 Electrolysis Cells for Industrial Applications

Utilization of carbon dioxide (CO2) as a feedstock of valuable chemicals is necessary to achieve carbon neutrality. Toshiba is developing the low-temperature zero-gap type CO2 electrolysis cells to produce carbon monoxide (CO) [1,2]. CO can further be converted into various chemicals and fuels by catalytic reactions with hydrogen. To make the CO2 electrolysis technology industrially feasible, it is necessary to establish high-throughput system by expanding the electrode area and stacking the cells. Large-sized cells and stacks often suffer from low Faradaic efficiency for the CO production, which is related to insufficient and nonuniform supply of reactant CO2 gas to the cathode reaction sites. This time we focused on the development of large-sized single cells and fabricated an electrolysis cell with 400 cm2 electrodes. With properly designed gas flow plates and gaskets, the cell voltage and the CO Faradaic efficiency of the fabricated cell at a current density of 400 mA cm-2 were comparable to those of the previously developed smaller cells with 4 cm2 electrodes. The CO concentration in the cathode outlet gas reached ca. 80% by controlling the inlet CO2 flow rate. Stability is another essential property of CO2 electrolysis cells required for the industrial application. Cathode flooding and salt precipitation are major stability issues characteristic of relatively short-term operations, whose detailed mechanism is still in debate [3]. To mitigate those stability issues, we focused on the cathode inlet humidity and the pressure difference between the cathode and the anode. The former is related to the salt concentration in electrolyte solution around the cathode reaction sites, and the latter is related to the convection of electrolyte from the anode side to the cathode side. By controlling those parameters, stable performance over 100 h was achieved.Part of this work was commissioned by Ministry of the Environment, Government of Japan.[1] Y. Kofuji, A. Ono, Y. Sugano, A. Motoshige, Y. Kudo, M. Yamagiwa, J. Tamura, S. Mikoshiba, and R. Kitagawa, Chem. Lett., 50, 482-484 (2021).[2] Y. Kiyota, Y. Kofuji, A. Ono, S. Mikoshiba, and R. Kitagawa, 242nd ECS Meeting, I05-1942 (2022).[3] M. Sassenburg, M. Kelly, S. Subramanian, W. A. Smith, and T. Burdyny, ACS Energy Lett., 8, 321-331 (2023).

Integrated Capture and Electrochemical Conversion of CO2 into CO

The capture and electrochemical conversion of CO2, powered by renewable electricity, is an attractive method of sustainably producing valuable chemicals and fuels (e.g. carbon monoxide (CO)), reducing atmospheric CO2, and storing intermittent renewable energy. Integrated capture and conversion (reactive capture) of CO2 presents a CO2-to-CO electrolysis pathway that eliminates most of the upstream capital and energy costs by releasing CO2 directly inside the electrolyzer using an internal pH-swing. The reactive capture system readily allows for the collection of produced gas products via phase separation, thus minimizing downstream separation costs.Industrial-scale integration of reactive capture systems with upgrading processes require a pure and consistent product stream. Previous studies using bicarbonate electrolytes have demonstrated high selectivity towards CO. However, the limited CO2 capture capacity of bicarbonate electrolytes dilute the cathode product gas stream with excess CO2. This mandates a secondary CO2 capture unit and increases the cost of downstream separation. Other studies using carbonate or carbamate electrolyte as the inlet feed did not simultaneously achieve high CO selectivity and long-term stability.This study sought to improve the Faradaic efficiency (FE) toward CO in our carbonate electrolysis system by engineering a novel membrane electrode assembly structure. We designed a composite CO2 diffusion layer (CDL) between the cathode and the membrane that attains high CO selectivity by simultaneously achieving high alkalinity and sufficient CO2 availability at the cathode. We determined that the thickness, wettability, and permeability of the CDL affected species transport and were important optimization parameters. Applying this strategy, we produced syngas, a mixture of CO and hydrogen (H2), with an industrial H2/CO ratio of 1.16 at 200 mA cm-2. This corresponded to a CO Faradaic efficiency (FE) of 46% and energy intensity of 52 GJ tsyngas-1. The syngas produced in this system was not diluted by CO2 and contained sufficient CO content to meet industrial standards. We further increased the FE towards CO by exploring different capture solutions and designing selective catalysts for energy efficient CO production. System parameters such as temperature and pressure effects were also investigated to improve the CO2 concentration at the cathode. This study illustrated the potential for the industrial implementation of an energy efficient and capital cost effective CO2-to-CO pathway via reactive capture.

Features of the coefficient of variation of parameters of the gas environment in fire in the premises

The object of the study is the selective coefficient of variation of dangerous parameters of the gas environment during the ignition of materials. The measure of the sample coefficient of variation of an arbitrary hazardous parameter of the gas environment observed at an arbitrary time interval is substantiated. The representativeness error of the measure of the sampling coefficient of variation, which depends on the value of the measure and the sample size, was determined. The measure allows you to numerically determine its value for an arbitrary observation interval. The difference in the measure at the intervals corresponding to the reliable absence and occurrence of ignition allows to detect the occurrence of ignition of the material. According to the results of laboratory studies, the measures of the sample coefficient of variation for carbon monoxide concentration, smoke density, and temperature of the gas medium in the laboratory chamber at intervals of absence and appearance of ignition of alcohol, paper, wood, and textiles were determined. It was established that the dangerous parameters of the gas environment at the intervals of absence and presence of ignition are characterized by different values of the increase in the measure of the sample coefficient of variation. For example, it is determined that the ignition of alcohol causes the maximum increase in the measure for carbon monoxide concentration from 0.135 to 0.441, for smoke density from 0.629 to 0.805, and for temperature from 0.001 to 0.115. When paper catches fire, the measure for carbon monoxide concentration and temperature increases from 0.0026 to 0.140 and from 0.0019 to 0.05, respectively. When burning wood, the measure for carbon monoxide concentration and temperature increases from 0.0072 to 0.177 and from 0.0067 to 0.016, respectively. The obtained results, provided that the hazardous parameters of the gas environment in the premises are measured and the sample coefficient of variation is calculated in practice, make it possible to use them in the creation of early fire detection systems

Implementation and evaluation of updated photolysis rates in the EMEP MSC-W chemistry-transport model using Cloud-J v7.3e

Abstract. The present work describes the implementation of the state of the art Cloud-J v7.3 photolysis rate calculation code in the EMEP MSC-W chemistry-transport model. Cloud-J calculates photolysis rates and accounts for cloud and aerosol optical properties at model run time, replacing the old system based on tabulated values. The performance of Cloud-J is evaluated against aerial photolysis rate observations made over the Pacific Ocean and against surface observations from three measurement sites in Europe. Numerical experiments are performed to investigate the sensitivity of the calculated photolysis rates to the spatial and temporal model resolution, input meteorology model, simulated ozone column, and cloud effect parameterization. These experiments indicate that the calculated photolysis rates are most sensitive to the choice of input meteorology model and cloud effect parameterization while also showing that surface ozone photolysis rates can vary by up to 20 % due to daily variations in total ozone column. Further analysis investigates the impact of Cloud-J on the oxidizing capacity of the troposphere, aerosol–photolysis interactions, and surface air quality predictions. Results find that the annual mean mass-weighted tropospheric hydroxyl concentration is increased by 26 %, while the photolytic impact of aerosols is mostly limited to large tropical biomass-burning regions. Overall, Cloud-J represents a major improvement over the tabulated system, leading to improved model performance for predicting carbon monoxide and daily maximum ozone surface concentrations.

Experimental Investigation of the Effect of Superheated Liquid Fuel Injection on the Combustion Characteristics of Lean Premixed Flames

Abstract The effect of superheated liquid fuel injection on the performance and emissions of a single nozzle combustor was investigated. Combustion of the lean premixed flames was achieved using a combination of jet and swirl as a stabilization method. In a nonreactive setup, the optimum transition temperature of Jet A-1 fuel from liquid to superheated vaporized state was analyzed. In a subsequent reactive setup, a series of tests were conducted with the liquid fuel at low and elevated temperatures. The experiments were conducted at ambient pressure and various air and fuel preheat temperatures, axial swirlers, thermal powers, adiabatic flame temperatures, and flame tube diameters. Concentrations of nitric oxide (NOx) and carbon monoxide (CO) in the flue gas were measured. The operating conditions were systematically selected according to the design of experiments (DOE) method. The results showed that the adiabatic flame temperature caused the most significant change in combustion emissions and the position and shape of the reaction zone, while the superheated fuel injection had only a minor effect because the liquid fuel droplets were largely vaporized before entering the reaction zone through the integration of a swirler and a prefilmer. The use of the axial swirler and prefilmer allowed the combustor to operate in both spray and fully vaporized fuel conditions. As a result, very low emission concentrations of NOx (≈5 ppm) and CO (≈6 ppm) were achieved. The median flame length and height above the burner of the characterized flames showed competitive values of 32 mm and 50 mm, respectively. Lean blowout limits of less than 1500 K were achieved. Two different flame modes were observed during the experiments. By increasing the bulk velocity of the combustor, its hysteresis was resolved, resulting in stable and reliable flames with a wide low-NOx operating range.

Examining the spatial and temporal variations in the indoor gaseous, PM2.5, BC concentrations in urban homes in India

Given that people spend the majority of their time indoors, accurate measurement of pollutants in indoor environment settings is critical especially when the levels of air pollution often surpass those of outdoor environments. While extensive studies have been focussed on outdoor air quality, limited studies have examined indoor air quality in a residential setting. We measured gaseous and particulate pollutants using portable real-time monitors for ∼24 h in indoor living spaces in dwellings, in urban slums in three metropolitan cities of India: Mumbai, Bangalore, and Delhi, and captured the pollutant levels from the domestic activities, which varied according to magnitudes and durations. The mean (±SD) of indoor total volatile organic compounds (TVOCs) and carbon monoxide (CO) were 720.1 (±86.5) μg/m3 and 1.2 (±0.3) ppm, respectively, for Mumbai; 626.1 (±169.9) and 0.9 (±0.5), respectively, for Bangalore; and 682.6 (±251.8) and 1.7 (±0.8), respectively, for Delhi. Particulate matter (PM2.5) and black carbon (BC) levels were 62.6 (±16.9) and 3.2 (±3.6), respectively, for Bangalore, and 187.7 (±72.1) μg/m3 and 10.5 (±3.3) μg/m3, respectively, for Delhi. Corresponding PM2.5 level in Mumbai were 111.2 (±20.1) μg/m3. While high indoor levels of CO were associated with cooking, the use of incense and candles elevated CO and BC, cleaning activities increased TVOC and sweeping activities increased PM2.5. These levels are further affected by factors such as chimneys in homes (Mumbai-∼ 0.03%, Bangalore-∼15% and Delhi-∼ 37%), operating exhaust fans (Mumbai-∼35%, Bangalore-∼40% and Delhi-∼78%) and cross-ventilation characteristics (Mumbai-∼65%, Bangalore∼62% and Delhi-∼75%). Indoor concentrations excluding indoor activities, and outdoor concentration of CO (PM2.5) were found to be significantly correlated, ∼0.51(0.40), 0.43(0.46) and 0.74 (0.68) for three cities respectively, which implies that outdoor air pollution is an important variable to consider when studying indoor air quality, especially during winter season where higher levels are observed in ambient environment.

Computational design of a smoke detector with high sensitivity considering three-dimensional flow characteristics

Early fire detection is essential for preventing catastrophic events, and fire detectors play a critical role in ensuring fire safety. Among the various types of fire detectors, photoelectric smoke detectors are widely used because of their ability to detect smoke at an early stage. The present study investigates the effects of changes in flow directions and inlet size on the smoke detection ability of a photoelectric smoke detector by conducting computational fluid dynamics (CFD) simulations. The results indicated that when the flow direction changes, the components in the optical chamber may hinder the smoke inflow and increase the detector activation time. Moreover, the smoke inlet size was found to affect the carbon monoxide concentration inside the chamber. The velocity magnitude distributions confirmed the correlation between the smoke velocity in the labyrinth structures entering the optical chamber and the detection ability of the smoke detector. These findings suggested that when optimizing the performance of a smoke detector, flow direction, inlet size, and amount of smoke introduced into the optical chamber should be considered. The current study suggested the modified design of the smoke detector to have superior detection ability in both directions compared to the base case in terms of activation time.

Vehicular Volume and Concentration of Gaseous Atmospheric Pollutants and Particulate Matter at Selected Road Junctions in Port Harcourt, Nigeria

The increase in industrial and vehicular activities has led to the proliferation of atmospheric pollutants in cities globally. The Niger Delta region is an industrial hub and serves as the nation's resource base by exploring crude oil. This work postulated that there would be high pollutants and particulate matter at road junctions due to the multiplicity of several vehicles owned by the surging human population. The number of vehicles at each junction were counted. A multi-parameter gas monitor (A multi–RAE PLUS (PGM-50) was used to collect air samples at different junctions (n = 5). The concentration of nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), particulate matter (PM2.5, PM10), temperature, relative humidity, and wind were analyzed. The result revealed that the volume of the vehicles at road traffic junctions follows the order Rumuola>Mile 3/UST Roundabout>Choba Junction>Garrison>Lagos Bus Stop. Choba Junction had the highest concentration of pollutants. The highest concentration of vehicular pollutants was observed in the morning. Carbon monoxide (CO) had the highest concentration, followed by SO2 and NO2. While for particulate matter, PM2.5 had a higher concentration than PM10. The result implies that the number of vehicular traffic does not necessarily determine the concentration of pollutants because other anthropogenic activities are causing a spike in atmospheric pollutants within the city.

Satellite-based assessment of national carbon monoxide concentrations for air quality reporting in Finland

Carbon monoxide (CO) has negative health effects, especially on the respiratory system, when present in large concentrations in ambient air. Therefore, it is one of the 12 air pollutants with monitoring and assessment obligations set by the European Union Ambient Air Quality Directives. With low CO concentrations in Finland, continuous surface measurements are not compulsory but the monitoring and assessment obligation remains. Currently, there are no air quality stations equipped with CO measurements in Finland, and the assessment can only be based on emission estimates.In this work, we demonstrate the use of satellite-based CO measurements from the TROPOspheric Monitoring Instrument (TROPOMI) on-board Sentinel-5 Precursor satellite (S5P) to strengthen the assessment with actual measurements. Averaging satellite measurements over several years reveals the spatial distribution of CO with nationwide coverage in city-scale resolution. Individual satellite measurements, in turn, are used to estimate the surface concentrations and their annual variability in different regions in Finland.For the surface estimates, we used a simple and robust linear model between the satellite measurements and ground-level in-situ measurements. We found that the linear model produces reasonable surface concentration estimates to be used in air quality assessments where the objective is to evaluate whether the monitoring threshold set by the EU is exceeded on a yearly scale. It is noted that cloudiness can cause local data gaps of several days and the low solar elevation angles prevent satellite measurements from 9 to 18 weeks during the winter time in Finland.In Finland, the average total columns show low spatial variability, with only a few high-concentration areas identified. For the last three years, the estimated surface concentrations have stayed well below the lower assessment threshold set by the Air Quality Directive.

Optical Characteristics of Aerosol and Carbon Monoxide Content in the Atmosphere over Irkutsk Oblast and Buryatia in 2010–2021

Optical Characteristics of Aerosol and Carbon Monoxide Content in the Atmosphere over Irkutsk Oblast and Buryatia in 2010–2021

Cryogenic Air Supply Feasibility for a Confined Space: Underground Refuge Alternative Case Study.

A breathable air source is required for a confined space such as an underground refuge alternative (RA) when it is occupied. To minimize the risk of suffocation, federal regulations require that mechanisms be provided and procedures be included so that, within the refuge alternative, the oxygen concentration is maintained at levels between 18.5% and 23% for 96 h. The regulation also requires that, during use of the RA, the concentration of carbon dioxide should not exceed 1%, and the concentration of carbon monoxide should not exceed 25 ppm. The National Institute for Occupational Safety and Health (NIOSH) evaluated the cryogenic air supply's ability to provide breathable air for a refuge alternative. A propane smoker was used to simulate human breathing by burning propane gas which will consume O2 and generate CO2 and H2O. The rate of propane burned at the smoker was controlled to represent the O2 consumption rate for the breathing of a certain number of people. Two 96-h tests were conducted in a sealed shipping container, which was used as a surrogate for a refuge alternative. While burning propane gas to simulate human oxygen consumption, cryogenic air was provided to the shipping container to determine if the cryogenic air supply would keep the O2 level above 18.5% and CO2 level below 1% inside the shipping container as required by the federal regulations pertaining to refuge alternatives. Both of the 96-h tests simulated the breathing of 21 persons. The first test used the oxygen consumption rate (1.32 cu ft of pure oxygen per hour per person) specified in federal regulations, while the second test used the oxygen consumption rate specified by (Bernard et al. 2018, "Estimation of Metabolic Heat Input for Refuge Alternative Thermal Testing and Simulation," Min. Eng., 70(8), pp. 50-54) (0.67 cu ft of pure oxygen per hour per person). The test data shows that during both 96-h tests, the oxygen level was maintained within a 21-23% range, and the CO2 level was maintained below 1% (0.2-0.45%). The information in this paper could be useful when applying a cryogenic air supply as a breathable air source for an underground refuge alternative or other confined space. [DOI: 10.1115/1.4064062].

CO-based early warning threshold for coal spontaneous combustion

Few studies have been involved in the CO-based early warning threshold, although carbon monoxide (CO) is a vital gas indicator for predicting coal spontaneous combustion. In this paper, based on the dependency relationship between CO concentration and coal temperature, a novel approach is proposed to determine the critical value of CO. Firstly, the low-temperature oxidation characteristics of coal samples were investigated through a temperature-programmed system, and the critical temperature of coal samples was analyzed. Furthermore, the functional relationship between CO emissions and coal temperature was investigated based on on-site measurements. Accordingly, the critical value of CO corresponding to the critical temperature was determined. Finally, the migration and generation behavior of CO was studied by combining with air seepage, component transport, thermal transfer, and exothermic reaction. The results show that when the coal temperature in goaf reaches the critical temperature of 53 °C, the CO concentration will reach 110.84 ppm. This concentration is the critical value of CO. The numerical simulation analysis of CO gas migration in goaf shows that when CO concentration reaches the critical value, the CO gas concentration in the corner of the upper corner, the return air flow, and extraction pipeline are 10.69 ppm, 7.91 ppm and 67.26 ppm, respectively. This concentration is the critical value of CO at the corresponding position. The approach established can meet the requirements of identification of spontaneous combustion potential of coal, and ensure the safety of mine production.

ANALYSIS OF CARBONMONICIDE (CO) AIR QUALITY IN DKI JAKARTA DUE TO LARGE-SCALE SOCIAL RESTRICTIONS (PSBB) POLICIES FIRST VOLUME USING CLOUD- BASED COMPUTING ON GOOGLE EARTH ENGINE

VThe corona virus first appeared in Wuhan, China and spread to Indonesia in 2020, causing the Indonesian government to implement Large-Scale Social Restrictions (PSBB) in several cities, one of which is DKI Jakarta. The government is implementing Large-Scale Social Restrictions (PSBB) which aims to stop the spread of the corona virus. During the Large-Scale Social Restrictions (PSBB) period, all community activities were mostly carried out at home, many public facilities were closed. With the implementation of the Large-Scale Social Restrictions (PSBB) policy which limits community activities in DKI Jakarta, it turns out it also has an impact on the concentration of carbon monoxide (CO) gas emissions in the air . This research uses a statistical analysis method for CO gas emissions from Sentinel-5P imagery which is extracted using cloud-based computing on Google Earth Engine. V isualization of the spatial distribution of CO gas emission content was carried out by interpolating CO data extracted using the kriging interpolation method. The results of the research show that in the first volume of the PSBB on April 10 - June 4 2020 , an unstable CO concentration pattern was seen and the average CO was obtained, namely, 0.03187 mol/m 2 . In the period a year after the first volume of PSBB 10 A April-4 June 2021, there was an increase in CO concentration by 10% to 0.0352 mol/m 2 , so this shows that the implementation of the first volume of PSBB in DKI Jakarta affected the concentration of carbon monoxide (CO) in the air

Investigation of co-gasification characteristics of coal with wood biomass and rubber seals in a fixed bed gasifier

The thermochemical processing of waste in gasification to hydrogen-rich gas is considered to be a novel, promising technological option, complementing the currently employed hydrogen production methods and an effective and environment friendly way of waste utilization. The paper discusses the results of the experimental study on this novel technological option of co-gasification of coal with automotive rubber seals or wood chips in a fixed bed reactor with the application of oxygen and steam mixture as a gasification agent. The experiments were performed with the use of waste to coal blending ratio of 10:90, 15:85 and 20:80 (%w/w), and at the temperature range of 700–900 °C. The contents of carbon monoxide, carbon dioxide, hydrogen and methane in the gaseous product reported in the study were in the range of 35–36 %vol., 31–33 %vol., 29–31 %vol., and 0.10–0.16 %vol., respectively. The maximum values of the lower heating value and the total gas volume were reported for fuel blends of 10%w/w waste content at 900 °C. Hydrogen and carbon monoxide production increased with process temperature, and declined with waste fraction in a fuel blend. Gasification of fuel blends composed of coal and rubber resulted in higher hydrogen production than the gasification of coal-biomass fuel blends, which may be attributed principally to the higher fixed carbon content and higher alkali index of rubber when compared to the respective values of wood chips.

Effect of airport pollution on airport cities and air quality of the area (case study: Imam Khomeini international airport)

Airport pollution from increased air traffic affects regional air quality and health negatively. Previous research has mainly focused on modeling pollutant distribution near the airport in a short radius. Also, limited studies have been performed to create a general model of pollutant distribution for the future planning of urban development in a wide radius. In this research, the amount of gaseous pollutants and suspended particulate matter (SPM) produced by Imam Khomeini International Airport (IKIA) was estimated. The modeling of the distribution of pollutants was performed using AERMOD and ISCST3 software in a 50 km radius, taking into account the main meteorological and atmospheric parameters. The pollutants selected in this study were gaseous pollutants, including nitrogen oxides (NOx), carbon monoxide (CO) and sulfur dioxide (SO2) estimated by the simple approach method (option A) presented by the International Aviation Organization (ICAO), as well as SPM estimated by FOA.3 method provided by the Department of Federal Organization. IKIA produced 596 tons of NOx, 344 tons of CO, 19 tons of SO2 and about 3 tons of SPM from March 2021 to February 2022. Also, the maximum concentrations were in the 1-h time frame, and the results showed that the concentration of NOx, CO, SO2 and SPM was 162, 93.4, 5.14, and 0.77 μg/m3, respectively. The prevailing winds of the airport from the west and northwest caused the maximum impact of pollutants' distribution on the residential and industrial areas located in the east and southeast of the airport. Also, due to the east and southeast winds, most of the development phases of the airport city, which are located in the west and northwest of the airport, were affected by the distribution of pollutants. This research developed a pollutant distribution model to gain insight into mitigating airport pollution's impact on residential, industrial, and airport areas.

Monitoring and analysis of carbon monoxide and methane using Sensors and Remotely Piloted Aircraft Systems

INTRODUCTION: Air pollution in urban areas becomes a severe challenge to global health; exposure to polluting gases can lead to different diseases and even human mortality. In this sense, monitoring the concentration of polluting gases such as carbon monoxide and methane is important.
 OBJECTIVES: This document focuses on developing a Remotely Piloted Aircraft System (RPAS) to monitor the concentration of carbon monoxide and methane at different altitudes. 
 METHODS: This includes a Parrot AR Drone 2.0, where the measurement prototype was mounted. The data was transmitted and reception at a ground control station through an application programmed in LabVIEW 15.0.
 RESULTS: The experimental measurements showed that the concentration of carbon monoxide remains almost unchanged regardless of variations in altitude. In contrast, methane concentration reduces linearly with the increase in height with respect to ground level in Puerto Maldonado.
 CONCLUSION: We implemented an RPAS to monitor in real time, record data in a control station and analyze the concentration of carbon monoxide and methane in the South Eastern Peruvian Amazon.

Relationship between red blood cell lifespan and endogenous carbon monoxide in the common bottlenose dolphin and beluga.

Certain deep-diving marine mammals [i.e., northern elephant seal (Mirounga angustirostris), Weddell seal (Leptonychotes weddellii)] have blood carbon monoxide (CO) levels that are comparable with those of chronic cigarette smokers. Most CO produced in humans is a byproduct of heme degradation, which is released when red blood cells (RBCs) are destroyed. Elevated CO can occur in humans when RBC lifespan decreases. The contribution of RBC turnover to CO concentrations in marine mammals is unknown. Here, we report the first RBC lifespans in two healthy marine mammal species with different diving capacities and heme stores, the shallow-diving bottlenose dolphin (Tursiops truncatus) and deep-diving beluga whale (Delphinapterus leucas), and we relate the lifespans to the levels of CO in blood and breath. The belugas, with high blood heme stores, had the longest mean RBC lifespan compared with humans and bottlenose dolphins. Both cetacean species were found to have three times higher blood CO content compared with humans. The estimated CO production rate from heme degradation indicates some marine mammals may have additional mechanisms for CO production, or delay CO removal from the body, potentially from long-duration breath-holds.NEW & NOTEWORTHY This is the first study to determine the red blood cell lifespan in a marine mammal species. High concentrations of carbon monoxide (CO) were found in the blood of bottlenose dolphins and in the blood and breath of belugas compared with healthy humans. Red blood cell turnover accounted for these high levels in bottlenose dolphins, but there may be alternative mechanisms of endogenous CO production that are contributing to the CO concentrations observed in belugas.

Ni-MOF-74 film coated optical microfiber CO sensor cascaded with spiral fiber grating temperature compensator

Metal-organic framework (MOF) material is a good carbon monoxide (CO) storage material. This paper proposed a composite optical fiber structure based on spiral fiber grating (SFG) and tapered microfiber (TMF), which can realize the simultaneous sensing of CO concentration and temperature by coating different functional films. The refractive index (RI) of Ni-MOF-74 coated on tapered microfiber can be changed by absorbing CO molecules. The thermal expansion of Ultraviolet (UV) glue will change the period of the spiral fiber grating. Based on the above mechanism, the research shows that the CO sensitivity of the optical microfiber can reach 64.11 pm/ppm, and the temperature sensitivity is −30.1 pm/°C. The temperature sensitivity of the spiral fiber grating can reach 294 pm/°C, which can effectively compensate for the temperature sensitivity of the microfiber. This composite structure has a good application prospect in accurate CO gas concentration measurement.

Solvation Shell Anatomy of H2S and CO Dissolved in Reline and Ethaline Deep Eutectic Solvents.

Rising atmospheric concentrations of anthropogenic hydrogen sulfide (H2S) and carbon monoxide (CO) as a result of industrialization have encouraged researchers to explore innovative technologies for capturing these gases. Deep eutectic solvents (DESs) are an alternative media for mitigating H2S and CO emissions. Herein, we have employed ab initio molecular dynamics simulations to investigate the structures of the nearest-neighbor solvation shells surrounding H2S and CO when they are dissolved in reline and ethaline DESs. We aim to delineate the structural arrangement responsible for favorable H2S and CO capture by analyzing the key interactions between H2S and CO solutes with various components of the DESs. We observe that in the reline-H2S system, chloride and carbonyl oxygen of urea are found to have the closest distance interaction with hydrogen atoms of the H2S solute. The sulfur atom of H2S is found to be predominantly solvated by hydrogen and oxygen atoms of urea molecules and the hydroxyl hydrogen of choline cations. The chloride ions and ethylene glycol molecules predominantly govern the solvation of H2S in the ethaline-H2S system. In both the DESs, H2S is solvated by the hydroxyl group of the choline cations rather than by their ammonium group. In the reline-CO system, all the atoms of urea along with chloride dominate the immediate solvation shell around CO. In the ethaline-CO system, hydroxyl oxygen and hydrogen atoms of ethylene glycol are found in the nearest solvation structure around CO. Both the DESs exhibit a stronger solvent-solute charge-transfer tendency toward the H2S solute compared to CO.