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Phytotoxic air pollutants such as atmospheric nitrogen dioxide (NO2) are among the major stresses affecting tree photosynthesis in urban areas. We clarified the relationship between NO2 concentrations and photosynthetic function for three major urban trees, Prunus × yedoensis, Rhododendron pulchrum, and Ginkgo biloba, planted in Kyoto and surrounding cities, combining our published data and new data collected from 2020 to 2023. High NO2 increased long-term water use efficiency for all species. High NO2 decreased photosynthesis in P. yedoensis and R. pulchrum, while for G. biloba, NO2 imposed little effect on photosynthesis. We then focused on the decrease in NO2 due to (1) air pollution control measures from 2005 to 2023 and (2) the economic recession caused by the COVID-19 pandemic, and examined whether these factors improved photosynthesis in urban trees. The historic decrease in NO2 improved leaf photosynthesis for P. yedoensis and R. pulchrum, while the COVID-19 pandemic reduced NO2 by only 0.3 ppb and did not further improve photosynthesis in these tree species. This report shows that air pollution control measures improved photosynthesis in urban trees over several years in Japan, and is valuable because it demonstrates that air pollution control measures can increase CO2 uptake by urban trees. [ABSTRACT FROM AUTHOR]

Air pollution caused by gas emission dispersion leads to damage of the environment and is harmful to humans. In this article, we study and analyze the gas emissions of nitrogen oxide (NOX), sulfur oxide (SOX), and Total Petroleum Hydrocarbons (TPHs) in Al Rifaee City. The feedback and main source of pollution was due to the production of crude oil from the Gharraf oil field (GOF), located in the northwest direction of Al Rifaee City. The highest monthly total emission rate for all years was for TPHs (79499.8685 MMSCF); it was 6483.69, and 1560.73 tons) for NOX and SOX, respectively. The value of correlation factor R2 for NOX was equal to 0.190, which is higher than SOX and TPHs. In the second part of this article, the concentrations of the above pollutants were measured in the laboratory in September 2023, and the maximum value was for TPHs 610 µg/kg in the soil sample of the northwestern area of Al-Rifaee city center due to crude oil production from the Gharraf oil field (GOF). [ABSTRACT FROM AUTHOR]

This article presents a comprehensive examination of the combined catalytic conversion technology for nitrogen oxides (NOx) and volatile organic compounds (VOCs), which are the primary factors contributing to the formation of photochemical smog, ozone, and PM2.5. These pollutants present a significant threat to air quality and human health. The article examines the reaction mechanism and interaction between photocatalytic technology and NH3-SCR catalytic oxidation technology, highlighting the limitations of the existing techniques, including catalyst deactivation, selectivity issues, regeneration methods, and the environmental impacts of catalysts. Furthermore, the article anticipates prospective avenues for research, underscoring the necessity for the development of bifunctional catalysts capable of concurrently transforming NOx and VOCs across a broad temperature spectrum. The review encompasses a multitude of integrated catalytic techniques, including selective catalytic reduction (SCR), photocatalytic oxidation, low-temperature plasma catalytic technology, and biological purification technology. The article highlights the necessity for further research into catalyst design principles, structure–activity relationships, and performance evaluations in real industrial environments. This research is required to develop more efficient, economical, and environmentally friendly waste gas treatment technologies. The article concludes by outlining the importance of collaborative management strategies for VOC and NOx emissions and the potential of combined catalytic conversion technology in achieving these goals. [ABSTRACT FROM AUTHOR]

Asthma is a chronic respiratory disease characterized by variable airflow obstruction, bronchial hyperresponsiveness, and airway inflammation. Evidence suggests that air pollution has a negative impact on asthma outcomes in the population. Extrinsic asthma usually begins in childhood, and most patients have a prior history of allergic diseases such as rhinitis, conjunctivitis, and urticaria. This type of asthma is closely related to hypersensitivity to allergens such as house dust, pollen, molds, animal hair, and organic and chemical dust. Air pollution is a major environmental factor that can exacerbate asthma symptoms such as dyspnoea, cough, and wheezing and has been linked to an increased risk of developing asthma. This study aims to investigate the relationship between air pollution and extrinsic asthma, including how it can exacerbate asthma symptoms and the potential harmful effects on health. [ABSTRACT FROM AUTHOR]

Nitrogen oxides (NOx) are posing significant environmental risks. A nonmetallic 9-cyano quinacridone-porphyrin-based sensor is designed for their detection. This sensor demonstrates commendable sensitivity towards all forms of NOx. Nudged elastic band (Bouzineb et al. (2023) J Mol Model 29:365) method Transit/ Quadratic Synchronous Transit (QST) method / Linear Synchronous Transit QST method (LST) is applied to study the activation energy barrier for sensor to sense NOx. Optimal distances between NOx molecules and the porphyrin sensor are determined. Assessment of activation energy and adsorption energy values provide crucial insights into the sensor's aptitude for sensitivity. Remarkably, adsorption energy (Ead) values for NO, NO2, N2O3, N2O4, N2O5 are found to be − 0.01, − 0.78, − 7.29, − 2.75, − 3.02 eV, respectively. Non-covalent interactions (NCI) analysis presents weak attraction in the blue region and van der Waals interaction in the green region. The sensor's swift recovery time (τ) within the range of 10−12 further underscores its potential for prompt response. An exploration of the sensor's energy gap, recovery time, and adsorption energy values elucidates its sensitivity towards different NOx species. These are crucial factors in environmental monitoring. Furthermore, a detailed exploration of the sensing mechanism enhances comprehension of molecular interactions, showcasing the sensor's potential as an effective tool for environmental monitoring and remediation. It will be used in wrist watches, and automobiles to sense nitrogen oxides (NOx). [ABSTRACT FROM AUTHOR]

Catalytic converters are used to convert harmful gases such as carbon monoxide (CO), nitrogen oxides (NOₓ), and unburned hydrocarbons (HC) into less harmful or harmless gas emissions like carbon dioxide (CO₂), nitrogen (N₂), and water vapor (H₂O). In this study, supported catalysts for use of these CO and NO were developed by deposition of noble metals on cordierite (Cor) support with impregnation (IMP) in aqueous media. Effects of catalysts and washcoating for cordierite support were evaluated for carbon monoxide and nitrogen oxide activity in a batch reactor. They were characterized using XRD, BET, Raman, FTIR, and SEM–EDS. All catalysts were found to be effective in carbon monoxide conversion. The washcoating of catalyst support with cerium, lanthanum, zirconium, and yttrium changed the activity of the catalyst. The catalytic activity increased 20% with the washcoating. The coating enhanced catalytic activity by using cerium and zirconium oxides which improved thermal stability, while rare earth elements like lanthanum and yttrium helped stabilize the catalyst and optimize carbon monoxide conversion although some combinations had a negative impact on performance. It was observed that the C-Cor-Rh catalyst (99.96%) and C-Cor-Pd converted almost all (99.94%) harmful NO gas. The results showed that these catalysts had high efficiency for converting harmful NOx gaseous to different components. This study shown that innovative, cost-effective and highly efficient catalytic converters can be obtained by shaping the quality and quantity of the precious metals to be dopped to the support material through effective washcoating modeling. [ABSTRACT FROM AUTHOR]

Zn‐based catalytic batteries, recognized as eco‐friendly alternatives, are attracting significant research interest for their applications in energy storage, conversion, pollutant degradation, and ammonia synthesis. This review compiles the latest developments in Zn‐nitrogen oxides (NOx) batteries, covering various types including Zn‐nitrate, Zn‐nitric oxide, and Zn‐nitrite batteries. This study explores the electrode reactions and structural evolutions of these batteries, emphasizing the different challenges posed by cathodic reactions. Advanced design strategies for cathode materials, such as inhibiting hydrogen production, utilizing tandem sites, and enhancing reactant enrichment, are presented and evaluated. These strategies have markedly improved NOx reduction performance and have driven significant progress in Zn‐NOx battery. The future directions for research are outlined, highlighting the need for more efficient NOx reduction catalysts, optimization of Zn anodes, development of alternative metal anodes, battery structure improvements, and exploration of charging reactions. Addressing these challenges is crucial for advancing the development of eco‐friendly and high‐energy‐density Zn‐NOx batteries. [ABSTRACT FROM AUTHOR]

NH3 selective catalytic reduction (NH3-SCR) is the most prevalent and effective method for removing nitrogen oxides. Over the past few decades, manganese (Mn)-based catalysts have demonstrated strong catalytic activity and have been extensively studied for low-temperature NH3-SCR reactions. This paper provides an in-depth introduction to four forms of Mn-based catalysts: single manganese oxide-based catalysts, binary Mn-based metal oxide catalysts, ternary and multivariate Mn-based metal oxide catalysts, and nano-Mn-based catalysts. Advances have been made in enhancing Mn-based catalysts' redox performance and acidity, increasing the active component's dispersion, lowering binding energy, enlarging specific surface area, raising the Mn4+/Mn3+ ratio, and enriching surface adsorbed oxygen by optimizing preparation methods, altering the oxidation state of active components, modifying crystal phases, and adjusting morphology and dispersion, along with various metal modifications. The mechanism of low-temperature NH3-SCR reactions has been elucidated using various characterization techniques. Finally, the research directions and future prospects of Mn-based catalysts for low-temperature NH3-SCR reactions are discussed, aiming to accelerate the commercial application of new Mn-based catalysts. [ABSTRACT FROM AUTHOR]

For a rapid transition to a carbon-neutral transport sector, hydrogen internal combustion engines could be one measure. To support the development, suitable simulation models are needed. This paper provides enhancements to an existing combustion modeling approach for lean homogeneous hydrogen–air mixtures with online reaction kinetics and combines swirl charge motion with a spark ignited combustion process. These include a real gas equation of state, a wall heat loss model that is suitable for hydrogen and a flow model. The model is implemented in Python using Cantera with a custom solver interface. The model was successfully validated through experimental measurement data from an engine test bench. Additionally, some insights into the validity of the model assumptions are given by comparing model results to three-dimensional computational fluid dynamics simulation data. • Model for a spark-ignited combustion process and swirl-based charge motion. • Solver interface for connection of thermodynamics handled by Cantera and flow model. • Successful model validation using experimental data. • Analysis of flame sphericity with 3D CFD simulation results. [ABSTRACT FROM AUTHOR]

A technique for the Monte Carlo simulation of the radiation in the carbon dioxide and nitrogen dissociation products in a shock wave is described: the rates of chemical reactions, as well as the excitation of electronic, vibration, and rotation levels of atoms and molecules of CO, CN, O2, and C2. A comparison of the results of numerical simulation and the experimental data obtained on shock tubes of the Institute of Mechanics of Moscow State University is presented. [ABSTRACT FROM AUTHOR]

A analysis method for simultaneous determination of 7 pyrrolizidine alkaloids and their nitrogen oxides (monocrotaline, monocrotaline N- oxide, lycopsamine, lycopsamine-N-oxide, heliosinine, heliosinine-N-oxide, senecionine) in herbal tea was established by solid phase extraction-ultra high performance liquid chromatography tandem mass spectrometry (SPE-UPLC-MS/MS). The samples were extracted by 0.1 mol/L hydrochloric acid solution and purified by MCX solid phase extraction column, separated by Poroshell 120 EC-C18 chromatographic column (150 mm×3.0 mm, 2.7 μm), and detected by electrospray positive ionization multiple reaction monitoring (MRM) mode. The results showed that the 7 pyrrolizidine alkaloids and their nitrogen oxides showed good linear relationships in the linear range of 1.0-50 μg/L, and the correlation coefficients (R2) were both greater than 0.998. The limits of detection (LOD) and limits of quantitation (LOQ) were 0.3 μg/kg and 1.0 μg/kg, respectively. Average spiked recovery rates were 81.8%-98.8%, and the relative standard deviations (RSD) of precision experiment results were 1.98%-7.08%. The results of 20 herbal tea samples tested were found that 2 samples were detected with senecionine, which were 18.2 μg/kg and 33.5 μg/kg, respectively. The method was rapid, accurate, accurate and suitable for simultaneous determination of pyrrolizidine alkaloids and their nitrogen oxides in herbal tea.

This study aims to investigate the NOx/CO reduction characteristics of harmful gases according to the loading amount of active Ag, which plays the most important role in H2-SCR, and the type of support. H2-SCR with Ag loaded on support of TiO2 was reduced to Ag+ at about 140 °C in AgO oxide, and H2-SCR with Ag loaded on support of Al2O3 was reduced to Ag clusters (Agnδ+) at about 260 °C in AgO oxide. Because it is more unstable than AgO oxide, it promoted the chemical reaction of Ag. 0.5Ag/TiO2 H2-SCR showed the highest NOx conversion rate of about 18% at 200 °C, and the window width was also widened. 2Ag/Al2O3 H2-SCR improved the low-temperature activity of the catalyst due to its large specific surface area and the loading amount of active catalyst Ag. Although the harmful gas reduction performance has decreased significantly compared to the active material Pt used in the H2-SCR, research on active materials considering the performance the improvement and economic feasibility must be continued. [ABSTRACT FROM AUTHOR]

In the present study, the effect of biofuel and nano biofuel on the performance of a domestic boiler was investigated and compared with the pollutants emitted during the burning of diesel fuel. The biofuel was produced from waste cooking oil using potassium hydroxide (KOH) as a catalyst. Carbon nanotubes (CNT) with different concentrations of 0.05%/L, 0.1%/L, 0.15%/L, 0.2%/L, and 0.25%/L were added to the produced biodiesel to form a nano biofuel that was used to power a domestic boiler for demonstration purposes. The obtained performance results were compared using the same boiler when operating with biofuel and nano biofuel, respectively. When operated with different CNT concentrations, the emitted species from the boiler were also investigated by sampling the exhaust gases in each studied case. This study revealed that the performance of the boiler when operated with CNT was enhanced by decreasing the toxic emitted gasses and increasing the outlet water temperature compared to the case of the boiler with the biofuel alone. It increased the outlet water temperature and decreased the NOx (ppm) emissions. [ABSTRACT FROM AUTHOR]

Oxime ethers are attractive compounds in medicinal scaffolds due to the biological and pharmaceutical properties, however, the crucial and widespread step of industrial oxime formation using explosive hydroxylamine (NH2OH) is insecure and troublesome. Herein, we present a convenient method of oxime ether synthesis in a one‐pot tandem electrochemical system using magnesium based metal‐organic framework‐derived magnesium oxide anchoring in self‐supporting carbon nanofiber membrane catalyst (MgO‐SCM), the in situ produced NH2OH from nitrogen oxides electrocatalytic reduction coupled with aldehyde to produce 4‐cyanobenzaldoxime with a selectivity of 93 % and Faraday efficiency up to 65.1 %, which further reacted with benzyl bromide to directly give oxime ether precipitate with a purity of 97 % by convenient filtering separation. The high efficiency was attributed to the ultrafine MgO nanoparticles in MgO‐SCM, effectively inhibiting hydrogen evolution reaction and accelerating the production of NH2OH, which rapidly attacked carbonyl of aldehydes to form oximes, but hardly crossed the hydrogenation barrier of forming amines, thus leading to a high yield of oxime ether when coupling benzyl bromide nucleophilic reaction. This work highlights the importance of kinetic control in complex electrosynthetic organonitrogen system and demonstrates a green and safe alternative method for synthesis of organic nitrogen drug molecules. [ABSTRACT FROM AUTHOR]

Research on engines using different combustion principles has been spurred up by widespread worries about dangerous pollutants, stringent emission restrictions, and global warming. Low Temperature Combustion (LTC) is a cutting-edge idea for internal combustion engines that will be able to replace the standard modes of combustion and have the benefit of using both conventional and renewable fuels. In this sense, LTC has garnered interest on a worldwide scale recently, particularly the Homogeneous Charge Compression Ignition (HCCI) mode. The absence of flame propagation or diffusive flame distinguishes this combustion mechanism from spark ignition and compression ignition. On the contrary, chemical kinetics controls HCCI combustion. When the mixture approaches chemical activation in HCCI engines, which employ much diluted homogenous charge, auto ignition occurs simultaneously in several locations. In comparison to diesel engines, HCCI technology enables high efficiency operating with little nitrogen oxide, soot, and particulate matter emissions. The primary obstacles to be addressed are, however, the regulation of ignition timing, the impossibility of the high load operation, as well as increasing emissions of carbon monoxide and unburned hydrocarbons. The past and current work across the globe has revealed that engine working on HCCI module can be fuelled with different fuels with little emissions and high efficiencies. All the past work has been mentioned and explained in this current work. [ABSTRACT FROM AUTHOR]

The current research investigates the impact of a split fueling strategy combined with several flow rates of exhaust gas recirculation (EGR) on the combustion and emission characteristics of a diesel engine running on B20 waste cooking oil (WCO) biodiesel. A four‐stroke single‐cylinder common rail direct injection engine was employed for experiments. It operates with a B20 blend of WCO biodiesel at 600 bar pressure for varying pilot fueling conditions of 10%, 20%, and 30%. The B20 blend with 30% pilot fuel injection (B20P30) showed excellent performance and emission characteristics compared with B20 blend with 10% pilot fuel injection (B20P10) and B20 with 20% pilot fuel injection (B20P20). However, B20P30 had greater levels of nitrogen oxide (NOx) emissions than those by diesel. EGR discharge levels in 5% increments, ranging from 0% to 15% were introduced to address this issue. The experimental findings revealed that both cylinder peak pressure and heat release rate showed a reduction when the EGR flow rate was enhanced. The recirculation of exhaust gas into the combustion chamber led to a slight increase in the emission levels of hydrocarbon (HC), carbon monoxide (CO), and smoke, as well as a decrease in carbon dioxide (CO2). Nevertheless, the introduction of EGR significantly decreased NOx emissions by 22.94%, 35.05%, and 47.96% for EGR flow rates of 5%, 10%, and 15%, respectively, when compared with the engine operating without EGR. Overall, the two‐stage fueling strategy, B20P30 blended with 10% EGR corroborated to be beneficial in reducing NOx emissions with minimal performance penalties. Although there was a slight uptick in certain emissions, the overall trade‐off between emission reduction and performance was favorable. The culmination of this study is targeting the objectives of sustainable development goal 7 (clean energy) and goal 13 (climate action) to be achieved by 2030. [ABSTRACT FROM AUTHOR]

Ammonia have been attractive as one of the alternative fuels for reducing greenhouse gas (GHG) emissions. However, ammonia combustion has lower combustion performance than common hydrocarbon fuels. Furthermore, it may emit nitrous oxide (N 2 O), which is one of the GHGs. This paper presents the experimental investigations of plasma-assisted ammonia combustion (PAAC) using a rod-electrode-type microwave plasma source (MPS) at atmospheric pressure. The equivalence ratios of premixed ammonia/dry air (NH 3 /Air) gas are set below the stoichiometric combustion of NH 3 to reduce toxic NH 3 in the combustion gas. Under the condition of the equivalence ratios, the experiments are focused on reducing the unburned NH 3 and produced N 2 O concentrations in the combustion gas. In the experiments, the unburned NH 3 , nitrogen oxide (NO x) (the sum of nitric oxide (NO) and nitrogen dioxide (NO 2)), and N 2 O concentrations in the combustion gas are investigated in terms of the flow velocity of premixed NH 3 /Air gas inside the rod-electrode-type MPS and the transmission power to the rod-electrode-type MPS. In conclusion, the rod-electrode-type MPS is identified to be useful for PAAC. The NH 3 and N 2 O concentrations in the combustion gas reach approximately 25 and 4 parts per million (ppm), respectively, under the conditions of the equivalence ratio of 1.0, flow velocity of approximately 0.167 m/s, and transmission power of about 84 W. At that time, the NO x concentration is approximately 4300 ppm, and the power transmission efficiency is approximately 68 %. • Plasma-assisted ammonia combustion (PAAC) was conducted using microwave discharge. • The microwave discharge was generated using a rod-electrode-type microwave plasma source (MPS). • The experiments were conducted without a swirler and below the stoichiometric combustion. • The minimum concentrations of NH 3 and N 2 O in the combustion gas reached 25 and 4 ppm. • The rod-electrode-type MPS was identified to be useful for PAAC. [ABSTRACT FROM AUTHOR]

The paper studies the thermal schemes and construction characteristics of gas turbine units. The pros and cons of the considered turbines are compared with steam turbine units. At the same time, the amount of nitrogen gas coming out of the gas turbine and a steam turbine of the same power is calculated and a comparative analysis is given. It is found that the amount of nitrogen gas coming out of the gas turbine is 4 times less than that of the steam turbine. [ABSTRACT FROM AUTHOR]

A series of novel Mn6Zr1-xCox denitrification catalysts were prepared by the co-precipitation method. The effect of co-modification of MnOx catalyst by zirconium and cobalt on the performance of NH3-SCR was studied by doping transition metal cobalt into the Mn6Zr1 catalyst. The ternary oxide catalyst Mn6Zr0.3Co0.7 can reach about 90% of NOx conversion in a reaction temperature range of 100-275°C, and the best NOx conversion can reach up to 99%. In addition, the sulfur resistance and water resistance of the Mn6Zr0.3Co0.7 catalyst were also tested. When the concentration of SO2 is 200ppm, the NOx conversion of catalyst Mn6Zr0.3Co0.7 is still above 90%. 5 Vol% H2O has little effect on catalyst NOx conversion. The results showed that the Mn6Zr0.3Co0.7 catalyst has excellent resistance to sulfur and water. Meanwhile, the catalyst was systematically characterized. The results showed that the addition of zirconium and cobalt changes the surface morphology of the catalyst. The specific surface area, pore size, and volume of the catalyst were increased, and the reduction temperature of the catalyst was decreased. In conclusion, the doping of zirconium and cobalt successfully improves the NH3-SCR activity of the catalyst. [ABSTRACT FROM AUTHOR]

In this work, a new composite photocatalyst was synthesized by flower-like Bi2O3 and two-dimensional multilayer V2C using a facile hydrothermal method. Compared with the pristine sample, the specific surface area of Bi2O3/V2C MXene composite is significantly increased, which is favourable to improve the photocatalytic efficiency. The analysis of the UV-vis absorption spectrum and band gap energy shows that the construction of heterojunction broadens the light response range, improves the light absorption capacity, and obtains a narrower band gap than any of the single component, which is beneficial to the utilization of light. PL, TPC and EIS analysis revealed that Bi2O3/V2C MXene composite had stronger carrier mobility, which further confirmed that the photocatalytic oxidation performance of the system was the dominant reason in the photocatalytic NO pollutant removal process. This study provides a new idea for better understanding the two-dimensional MXene material-based photocatalyst and improving the NO removal efficiency. [ABSTRACT FROM AUTHOR]

GLOBAL CLIMATE The dominant greenhouse gases released into Earth's atmosphere including carbon dioxide, methane, and nitrous oxide reached record highs in 2022. The annual global average carbon dioxide concentration at [...]

Yessy Novianti,1 Wahyu Hidayat,2 Desi Elvhira Rosa1 1Oral Medicine Residency Program, Faculty of Dentistry, Universitas Padjadjaran, Bandung, Indonesia; 2Department of Oral Medicine, Faculty of Dentistry, Universitas Padjadjaran, Bandung, IndonesiaCorrespondence: Yessy Novianti, Faculty of Dentistry, Universitas Padjadjaran, Sekeloa Selatan Street No. 1, Bandung, 40132, Indonesia, Tel +6281368429045, Email yessy21001@mail.unpad.ac.idIntroduction: Psoriasis is a complex autoimmune disease associated with chronic systemic keratinization and inflammation, which can affect the skin, joints, and oral cavity. Xerostomia is a subjective feeling of oral dryness that impairs patient comfort and lowers the quality of life. The aim of this case report is to describe the clinical mechanism of xerostomia in a psoriasis patient with multiple systemic diseases.Case Report: A 51-year-old inpatient man with psoriasis vulgaris was referred to the Oral Medicine Department with complaints of difficulty swallowing due to a sore throat and dry tongue since last week. The patient had psoriasis vulgaris 15 years ago, chronic adrenal insufficiency, psoriatic arthritis, acute circulatory collapse, anemia of inflammation, acute kidney injury, dehydration, gastritis, urinary tract infections, and malnutrition. A complete anamnesis and oral examination were done. The patient was diagnosed with severe xerostomia, a fissured tongue, exfoliative cheilitis, angular cheilitis, and gingivitis by the Oral Medicine Department.Case Management: The patient was treated with petroleum jelly, chlorine dioxide mouthwash, miconazole cream, and benzydamine HCl lozenges.Conclusion: Based on case reports and reviews, multiple systemic diseases may not only increase the risk of xerostomia but also aggravate its severity.Keywords: acute kidney injury, inflammation, nitrogen oxide, psoriasis arthritis, SXI-ID

Author(s): Umesh Goneppanavar (corresponding author) [1] Dear Editor, A 75-year-old male patient was undergoing lumbar discectomy under general endotracheal anaesthesia with pressure support ventilation (Drager Perseus A500 anaesthesia workstation, Draeger [...]

NH3 selective catalytic reduction (NH3-SCR) is the most prevalent and effective method for removing nitrogen oxides. Over the past few decades, manganese (Mn)-based catalysts have demonstrated strong catalytic activity and have been extensively studied for low-temperature NH3-SCR reactions. This paper provides an in-depth introduction to four forms of Mn-based catalysts: single manganese oxide-based catalysts, binary Mn-based metal oxide catalysts, ternary and multivariate Mn-based metal oxide catalysts, and nano-Mn-based catalysts. Advances have been made in enhancing Mn-based catalysts’ redox performance and acidity, increasing the active component’s dispersion, lowering binding energy, enlarging specific surface area, raising the Mn4+/Mn3+ ratio, and enriching surface adsorbed oxygen by optimizing preparation methods, altering the oxidation state of active components, modifying crystal phases, and adjusting morphology and dispersion, along with various metal modifications. The mechanism of low-temperature NH3-SCR reactions has been elucidated using various characterization techniques. Finally, the research directions and future prospects of Mn-based catalysts for low-temperature NH3-SCR reactions are discussed, aiming to accelerate the commercial application of new Mn-based catalysts.

Introduction. Copper ions (Cu2+) are structural elements of proteins such as cytochrome с oxidase (Complex IV), an enzyme that catalyzes the final step of electron transfer to oxygen during oxidative phosphorylation in the mitochondria. With Cu2+ homeostasis being of utmost importance, its disturbances in the central nervous system are involved in the mechanisms of many neurodegenerative and other brain disorders. This study aimed to assess the effects of non-toxic copper ion levels on death of cerebellar granule neurons associated with lipopolysaccharide (LPS; in vitro inflammation model) or azide sodium (NaN3; cytochrome с oxidase inhibitor). Materials and methods. LPS (10 μg/mL) or NaN3 (250 μM) was added on day 7 to 8 to the culture medium with rat cerebellar cells for 24 hours in vitro. Nitrite concentrations were measured in the culture medium by Griess assay; absorbance was recorded with a spectrophotometer at 540 nm, and morphologically intact cells were counted as survived neurons. Results. Added to the culture medium, LPS or NaN3 reduced neuron survival to 15 ± 2% or 20 ± 3% vs. control, respectively. Cu2+ (0.5 to 5.0 μM) increased neuron survival in a dose-dependent manner to 78 ± 4% with toxic levels of LPS and to 86 ± 6% with NaN3 with 5 μM Cu2+. The concentration of nitrites in the control culture medium was 2.0 ± 0.2 μM. Added to the cell cultures, LPS increased the concentration of nitrites to 8.5 ± 0.5 μM. Cu2+ 5 μM did not show any significant effects on nitrite accumulation in the culture medium. Conclusions. We showed that copper ions can exert protective effects on neurons against LPS-induced or NaN3-induced toxicity. This protection is likely to be associated rather with Cu2+ interaction with Complex IV of the electron transfer chain in the mitochondria than with inhibition of NO production. Effects of Cu2+ on apoptosis pathway proteins also cannot be ruled out.

Objectives The study was aimed to systematically understand the nitrogen budget from 2015 to 2019, and to determine the annual nitrogen balance in South Korea. Methods The nitrogen budget was calculated by classifying into agricultural and livestock, city, and forest areas. The nitrogen input was estimated from deposition, biological fixation, agricultural water, inorganic chemical fertilizer, compost, feedstuff, produced crops, imported grocery, and fuel consumption. The nitrogen output was estimated by considering denitrification, volatilization, ground water runoff, land and crop absorption, sewage disposal, drainage, forest uptake, and nitrogen oxide (NOx) emissions. Results and Discussion The annual nitrogen budget from 2015 to 2019 showed the input as 6,107,449 ton/yr, 6,144,666 ton/yr, 6,245,240 ton/yr, 6,281,552 ton/yr, 5,993,347 ton/yr and the output as 1,346,587 ton/yr, 1,369,119 ton/yr, 1,365,327 ton/yr, 1,378,940 ton/yr, 1,365,994 ton/yr, respectively. The NOx, highly contributing to change in the nitrogen budget, was caused by human activities such as vehicles, business places, and power plants. More than 32% of the total nitrogen budget was caused by NOx in every year. Conclusion The nitrogen budget continued to increase in the 2010s because of the increase in food and fuel consumption by urbanization. However, the nitrogen budget declined in 2019 due to the effort such as emission regulations and the use of alternatives as the awareness of environmental pollution gradually increased. Therefore, the appropriate institution should be established and actively implemented to reduce the nitrogen effectively.

Based on the results of a comprehensive experiment conducted in September 2020, the spatial distribution of the following trace gases over the seas of the Russian Arctic are analyzed: carbon monoxide (CO), ozone (O3), nitrogen oxide and dioxide (NO and NO2), and sulfur dioxide (SO2). It is shown that the gas concentrations in the surface air layer over the seas (at an altitude of 200 m) vary in the range 18–36 ppb for O3, 60–130 ppb for CO, 0.005–0.12 ppb for NO, 0.10–1.00 ppb for NO2, and 0.06–0.80 ppb for SO2. The distribution of the gases over the water area is heterogeneous over most seas, which most likely reflects differences in their uptake by the ocean and peculiarities of transport from the continent. [ABSTRACT FROM AUTHOR]

Pt/ZrP2O7 catalysts exhibiting high activity for catalytic NOx reduction by H2 in the presence of excess O2 were developed in this study. At a low temperature of 125 °C and a high space velocity of approximately 5 × 104 h–1, 0.4 wt % Pt/ZrP2O7 facilitated a higher NO conversion to N2 (51%) than 0.4 wt % Pt/ZrO2 (<5%) for a reaction mixture of 200 ppm NO, 5000 ppm H2, 10% O2, and He balance. However, N2O and NO2 production increased at temperatures lower than 100 °C and higher than 200 °C, thereby decreasing the N2 yield. High-resolution electron microscopy and X-ray photoelectron spectroscopy analyses of 0.4 wt % Pt/ZrP2O7 revealed the coexistence of large metallic Pt crystallites with sizes of ∼20 nm and highly dispersed Pt oxide nanoclusters. When Pt loading was decreased to 0.05 wt %, the large metallic Pt crystallites disappeared, and only the Pt oxide nanoclusters remained on ZrP2O7. Owing to this structural change, N2O/NO2 formation was significantly suppressed, enabling highly selective NO reduction to N2. Moreover, catalyst preparation by equilibrium adsorption instead of wet impregnation further improved the reaction, achieving >90% selective NO conversion to N2, which was nearly free of undesired byproducts (NH3, N2O, and NO2) at 175 °C. The Pt oxide nanocluster supported on ZrP2O7 was more tolerant to the presence of 10% water vapor in the exhaust gas than the metallic Pt particles. Therefore, the developed catalyst is suitable for applications in practical exhaust gas purification for H2-fueled internal combustion engines. [ABSTRACT FROM AUTHOR]