STUDY OF THE OXIDATION PROCESS OF NITROGEN OXIDES BY OZONE

The need to reduce emissions of pollutants, in particular nitrogen oxides, as required by regulations in Ukraine, requires the use of modern technologies and methods for waste gas treatment at industrial enterprises. This is especially true of thermal power plants, which are powerful sources of nitrogen oxide emissions. The technological part of the wet or semi-dry method of purification is the area for the oxidation of nitrogen oxides to obtain easily soluble compounds. The paper presents the results of a study of the process of ozone oxidation of nitrogen oxides in a chemical reactor. Data for the analysis of the process were obtained by performing physical experiments on a laboratory installation and related calculations on a mathematical model. Studies of the oxidation process have shown that the required amount of ozone depends not only on the content of nitrogen monoxide, but also on the content of nitrogen dioxide. The process of conversion of nitrogen monoxide to a satisfactory level occurs at the initial value of the molar ratio of ozone to nitrogen monoxide in the range of 1.5…2. The conversion efficiency of nitrogen monoxide reaches 90% at a gas temperature less than 100 °C. To achieve high conversion efficiency at gas temperatures above 100 °C, it is necessary to increase the initial ozone content when the molar ratio exceeds 2. The analysis shows that the conversion efficiency of nitric oxide largely depends on the residence time of the gas mixture in the reaction zone. Due to lack of time under certain conditions, the efficiency decreases by approximately 46%. To increase it, it is necessary to accelerate the rate of oxidation reactions due to better mixing of gases by turbulence of the flow in the oxidizing reactor. Bibl. 6, Fig. 6, Tab. 3.

Nitro Fatty Acids (NO2-FAs): An Emerging Class of Bioactive Fatty Acids

Unsaturated nitro fatty acids (NO2-FAs) constitute a category of molecules that may be formed endogenously by the reaction of unsaturated fatty acids (UFAs) with secondary species of nitrogen monoxide and nitrite anions. The warhead of NO2-FAs is a nitroalkene moiety, which is a potent Michael acceptor and can undergo nucleophilic attack from thiol groups of biologically relevant proteins, showcasing the value of these molecules regarding their therapeutic potential against many diseases. In general, NO2-FAs inhibit nuclear factorκ-B (NF-κB), and simultaneously they activate nuclear factor (erythroid derived)-like 2 (Nrf2), which activates an antioxidant signaling pathway. NO2-FAs can be synthesized not only endogenously in the organism, but in a synthetic laboratory as well, either by a step-by-step synthesis or by a direct nitration of UFAs. The step-by-step synthesis requires specific precursor compounds and is in position to afford the desired NO2-FAs with a certain position of the nitro group. On the contrary, the direct nitration of UFAs is not a selective methodology; thus, it affords a mixture of all possible nitro isomers.

Analysis of the content of nitric oxide (II) metabolites rats of different ages

Nitrogen monoxide is a gas transmitter that is an important intermediary in many organ systems, especially in the central nervous system. Nitrogen monoxide is involved in the relaxation of smooth vascular muscles, activation of neurons and responsible for the cytotoxicity of macrophages. The study of change nitrogen oxide metabolite concentration helps to determine its effects on human and animal organs. The study was carried out on laboratory animals of different ages. We used a spectrophotometric method to determine the level of metabolites based on the reaction of nitrites to the Griss reagent. We noted that the maximum level of metabolites NO was observed in newborn animals at the age of 4 days. In addition, metabolite concentrations decreased gradually by 14-15 days of life, reaching a minimum of 30 days Key words: nitrogen monoxide, rats, age, metabolites of nitrogen monoxide, spectrophotometry.

Kupffer cells in the regulation of the cholesterol content in the liver and the blood lipoproteins, the level of iodine-containing thyroid hormones in the blood and the body temperature in rats with experimental peritonitis

Despite the modern surgery progress and success, the achievements of asepsis and antisepsis, as well as rather broad possibilities of antibacterial, infusion and detoxification therapy, the incidence of peritonitis and mortality from it remain at a high level.The aim of the study was to clarify the significance of the activity of Kupffer cells in the regulation of total cholesterol in the liver and blood lipoproteins, the level of iodine-containing thyroid hormones in the blood and the body temperature in rats with experimental peritonitis.It was found that in the conditions of experimental peritonitis in rats, secondary atherogenic dyslipoproteinemia develops and the level of iodine-containing thyroid hormones in the blood decreases. Kupffer cells and nitrogen monoxide are involved in the changes in the content of total cholesterol, lipoproteins, the level of iodine-containing hormones in the blood plasma and the body temperature during peritonitis. A decrease in the activity of Kupffer cells in peritonitis, apparently, plays a compensatory role and prevents the development of secondary dyslipoproteinemia.

FTIR Investigation of Nitrogen Monoxide and Carbon Monoxide Influence on Human Blood Coagulation

The formation of fibrin clots determines the characteristics of blood plasma coagulation. It is known that small molecules like nitrogen and carbon monoxides have a toxic effect at high concentrations due to the competitive binding to hemoglobin, preventing further oxygen transfer. The mechanisms of intoxication with these gases have been extensively studied in the literature, but there is little information on their effects on other vital processes. In particular, blood coagulation parameters have not been studied, although prolonged exposure to relatively low concentrations of gases can cause significant pathological changes. In this paper, the characteristics of the fibrin-polymer after coagulation of a blood plasma sample under conditions of pretreatment with gases were studied using FTIR-spectroscopy. The changes in the vibrations of individual bonds and fragments in the Amide I and Amide B regions are shown and analyzed. It was established that at concentrations of CO exceeding the endogenous levels, the connector α-helix unfolds and β-structures form, leading to the loss of part of the hydrate shell, the formation of a fibrin clot with a disordered structure of higher density due to an increase in its hydrophobicity. For cases where samples were treated with NO gas, the degree of aggregation of the fibrin clot from plasma incubated with nitroglycerin was one-quarter less than the original, the proportion of α-helices was not reduced, and there were no disordered structures in the clot. This may indicate a lower clot density and probably easier lysis of the one.

Application of Ultrasonic Atomization on a Micro Jet Engine Using Biofuel for Improving Performance

Jet engines are commonly used in aeronautical applications, and are one of the types of gas turbine engines. The circulation of air releases heat energy to expand the volume of hot fluids and impact the turbine wheel to generate power of hot gases. The present study investigates the potential of using ultrasonic atomization technology to assist in the combustion process. An experimental rig was set up to determine the performance of jet engines using ultrasonic droplets. A gas analyzer was used to measure various greenhouse emissions of exhaust gas. The performance of the engine was tested under three load levels (high, medium, low), starting from 10 psi at a steady state, to the minimum value. A significant result was tested for a low value of nitrogen monoxide at the three levels of load, and a specific result was tested for an efficiency value of 2% at the three levels of load. Carbon dioxide was found to decrease at the low load level. The use of an ultrasonic atomization device to assist in the combustion process was useful in achieving engine efficiency of 1% and a reduction of 25% in carbon dioxide exhaust gas.

Light-off Investigation of Oxymethylene Ether (OME) Considering the Presence of the Exhaust Components Heptane, Carbon, and Nitrogen Monoxide

Synthetic fuels and fuel blends like OMEs can contribute to tank-to-wheel CO2 emission savings. At the same time, it is known that these fuels have a lower exhaust temperature compared to conventional diesel. This effect has major impact on the exhaust after-treatment system, particularly in cold start conditions. This paper investigates the light-off behavior of exhaust gases containing OMEs by temperature-programmed oxidation experiments using a state-of-the-art oxidation catalyst. The main side product of catalytic oxidation of OMEs between 100 °C and the oxidation temperature T50, which was around 160 °C, was shown to be formaldehyde. While alkane oxidation, in this case heptane, was little influenced by OME oxidation, the oxidation temperature T50 of CO increases by more than 10 °C by OME addition. Nitrogen monoxide impeded the oxidation of OME in a similar way to the other components investigated. Due to the amount of FA produced and its toxicity, it could be concluded that it is necessary to heat up exhaust after-treatment systems of OME diesel engines even faster than conventional diesel exhaust after-treatment systems. The relatively high reactivity of OME on oxidation catalyst can be used by active thermal management approaches.

Preparation, Antioxidant Properties and Ability to Increase Intracellular NO of a New Pyridoxine Derivative B6NO

In the case of various pathologies, an imbalance between ROS generation and the endogenous AOS can be observed, which leads to excessive ROS accumulation, intensification of LPO processes, and oxidative stress. For the prevention of diseases associated with oxidative stress, drugs with antioxidant activity can be used. The cytotoxic, antioxidant, and NO-donor properties of the new hybrid compound B6NO (di(3-hydroxy-4,5-bis(hydroxymethyl)-2-methylpyridinium) salt of 2-(nitrooxy)butanedioic acid) were studied. It was determined that B6NO chelates iron ions by 94%, which indicates B6NO’s ability to block the Fenton reaction. The hybrid compound B6NO inhibits the process of initiated lipid peroxidation more effectively than pyridoxine. It was shown that B6NO exhibits antioxidant properties by decreasing ROS concentration in normal cells during the oxidative stress induction by tert-Butyl peroxide. At the same time, the B6NO antioxidant activity on tumor cells was significantly lower. B6NO significantly increases the intracellular nitrogen monoxide accumulation and showed low cytotoxicity for normal cells (IC50 > 4 mM). Thus, the results indicate a high potential of the B6NO as an antioxidant compound.

Effect of COVID-19-Related Lockdown οn Hospital Admissions for Asthma and COPD Exacerbations: Associations with Air Pollution and Patient Characteristics

We conducted a retrospective observational study to assess the hospitalization rates for acute exacerbations of asthma and COPD (chronic obstructive pulmonary disease) during the first imposed lockdown in Athens, Greece. Patient characteristics and the concentration of eight air pollutants [namely, NO (nitrogen monoxide), NO2 (nitrogen dioxide), CO (carbon monoxide), PM2.5 (particulate matter 2.5), PM10 (particulate matter 10), O3 (ozone), SO2 (sulfur dioxide) and benzene] were considered. A total of 153 consecutive hospital admissions were studied. Reduced admissions occurred in the Lockdown period compared to the Pre-lockdown 2020 (p < 0.001) or the Control 2019 (p = 0.007) period. Furthermore, the concentration of 6/8 air pollutants positively correlated with weekly hospital admissions in 2020 and significantly decreased during the lockdown. Finally, admitted patients for asthma exacerbation during the lockdown were younger (p = 0.046) and less frequently presented respiratory failure (p = 0.038), whereas patients with COPD presented higher blood eosinophil percentage (p = 0.017) and count (p = 0.012). Overall, admissions for asthma and COPD exacerbations decreased during the lockdown. This might be partially explained by reduction of air pollution during this period while medical care avoidance behavior, especially among elderly patients cannot be excluded. Our findings aid in understanding the untold impact of the pandemic on diseases beyond COVID-19, focusing on patients with obstructive diseases.