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Selected topics of inorganic mechanochemical synthesis are discussed. Variant mechanochemical syntheses are considered. The ex situ and in situ/operando methods to monitor the process are discussed. Methods for controlling the yield and kinetics of the mechanochemical synthesis are considered. The challenges and possible ways to address them are discussed. Thermal and mechanochemical syntheses are compared, with a special focus on mixing and milling processes. We consider the effects of various types of mechanical treatment on individual particles and on their mixtures. A special attention is paid to the macrokinetics of mechanochemical synthesis and its role in mixing and milling. The basic assumptions that render a mathematical model capable of describing the macrokinetics of mechanochemical synthesis in solid + reactive gas and solid + solid systems are written.

Speciated characterization of Volatile Organic Compounds (VOCs), including oxygenated VOCs (OVOCs), from construction machinery and river ships in China is currently lacking. In this regard, we conducted field measurement on speciated VOC (including OVOC) emissions from six construction machinery and five river ships in the Pearl River Delta (PRD) region to identify VOC emission characteristics. We noticed that OVOC emissions from construction machinery and ships accounted for more than 50% of the total VOC emissions, followed by alkenes, aromatics and alkanes. Formaldehyde and acetaldehyde were the most emission species, accounting for 61.8%-83.2% of OVOCs. For construction machinery, the fuel-based emission factors of roller, grader and pile driver were 3.12, 3.12 and 7.36 g/kg, respectively. With the rigorous restraint by the national emission standards, VOC emissions of construction machinery had decreased considerably, especially during stage Ⅲ. Ozone formation potential was also significantly reduced due to the significant decrease in emissions of OVOCs and alkenes with higher reactivity. For river ships, the fuel-based emission factors of cargo ships and speedboat were 1.46 and 0.44 g/kg, respectively. VOC emissions from construction machinery and river ships in Guangdong Province in 2017 were 8851.0 and 4361.0 ton, respectively. This study filled the knowledge gaps of reactive gas emissions from different kinds of non-road mobile sources over the PRD, and more importantly, highlighted the necessity in adding OVOC measurement to give a complete and accurate depiction of reactive gas emissions from non-road mobile sources.

To reveal the fuel ignition delay differences among diluent gases, non-reactive gas Ar, He, N2 and reactive gas CO2 four gases were selected to compare the ethylene ignition delay difference on a shock tube rig. The tested condition temperature and pressure range is 1074–1832 K and 2 atm. Comparison results show that the ethylene ignition delay discrepancy was not pronounced among Ar, He and N2 these non-reactive dilution gases. In terms of CO2 dilution, a critical CO2 concentration was observed. When the CO2 concentration was lower than this critical value, no distinguished ignition delay difference was found. Conversely, the ignition delay difference was pronounced once the CO2 concentration was above this critical value. Particularly, the difference was specially apparent in low temperature conditions. Reaction dynamic analysis shows that the heat effect is predominant in low temperature while the chemical effect is predominant in high temperature in the reaction of CO2 participation. Additionally, the CH* and OH* radical emission signal intensity turns smaller and profile curve turns irregular as the CO2 ratio increases. The CO2 shows a strong inhibition effect which is closely related with H radical consumption reaction CO2+H CO + OH.

Combustion and ignition processes are considered from the standpoint of the theory of thermal ignition and reaction kinetics. An analytical solution to the problem of thermal hotspot ignition is obtained to describe the ignition of reactive gas mixtures. As a result of this solution, the critical ignition conditions and induction time were determined. A solution to the problem of ignition of a methane–air mixture characteristic of mine working conditions.

Introduction. The article deals with mathematical modeling of the subsonic flow of a multicomponent reactive mixture in a flowing chemical reactor. The numerical algorithm is based on the finite volume method; the calculation is performed on unstructured triangular grids using the Message Passing Interface parallel computing technology. Materials and Methods. To describe the flows under studying, the Navier–Stokes equations are used in the approximation for low Mach numbers. To solve these equations, the finite volume method on unstructured triangular grids is used. The study uses a splitting scheme for physical processes, namely, the chemical kinetics equations responsible for the transformations of substances are first solved, and then the equations describing the conservation laws of momentum and energy for each component of the gas mixture are solved. To find numerical flows through the edges of the grid elements, the Lax–Friedrichs–Rusanov scheme is used. To solve the equations of chemical kinetics, a compact algorithm proposed by the team led by N.N. Kalitkin is used. The METIS library is used to divide the grid into connected subdomains with an approximately equal number of cells. To organize parallel computing, Message Passing Interface technology is used. Results. The article presents a numerical algorithm for studying multicomponent gas flows on unstructured triangular grids taking into account viscosity, diffusion, thermal conductivity, and chemical reactions. As a result of the study, a numerical simulation of the flow of a subsonic multicomponent gas in a flowing chemical reactor was carried out using ethane pyrolysis as an example. Computational, known numerical solutions and experimental data of ethane pyrolysis in a flowing reactor are compared. Discussion and Conclusion. The numerical results on the conversion of the initial gas mixture are in good agreement with the known experimental data. The presented distribution patterns of the main components of the mixture and gas-dynamic parameters correspond to the flow pattern observed experimentally. Further work in this direction involves the modeling of subsonic gas flows on unstructured tetrahedral meshes using algorithms of higher accuracy for a more accurate study of ongoing processes.

Спосіб отримання нітридних та/або карбонітридних зносо- та корозостійких покриттів включає розміщення у вакуумну камеру зразка, попередній розігрів зразка, напуск реактивного газу, створення газового розряду в газовій суміші для доставки реактивного газу на зразок, охолодження зразка. Як реактивний газ використовують азот, азотоводневу або карбідоазотну суміш. Створення газового розряду забезпечується поступовим збільшенням негативного потенціалу на зразку в межах від -3,5 кВ до -30 кВ протягом 20-30 хв. для забезпечення контрольованого подальшого розігріву зразка у межах від 300 до 570 °C.

In this work, we consider the unsteady one- dimensional flow of a viscous micropolar and heatconducting real gas. In addition to the usual variables of the micropolar fluid model, a new variable describing the amount of unburned fuel and an equation describing the chemical reaction were added to this model. The mathematical model is derived in the Lagrangian description. For the corresponding initial boundary problem with homogeneous boundary conditions as well as with sufficiently smooth initial conditions, we introduce a system of approximate equations using the Faedo-Galerkin method and construct its solutions. We describe the results of numerical tests on a number of examples, presenting the computed solutions, and test convergence and stabilization.

The ability to produce cold plasma at atmospheric pressure conditions was the basis for the rapid growth of plasma-related application areas in biomedicine. Plasma comprises a multitude of active components such as charged particles, electric current, UV radiation, and reactive gas species which can act synergistically. Anti-itch, antimicrobial, anti-inflammatory, tissue-stimulating, blood flow-enhancing, and proapoptotic effects were demonstrated in in vivo and in vitro experiments, and until now, no resistance of pathogens against plasma treatment was observed. The combination of the different active agents and their broad range of positive effects on various diseases, especially easily accessible skin diseases, renders plasma quite attractive for applications in medicine. For medical applications, two different types of cold plasma appear suitable: indirect (plasma jet) and direct (dielectric barrier discharge—DBD) plasma sources. The DBD device PlasmaDerm® VU-2010 (CINOGY Technologies GmbH), the atmospheric pressure plasma jet (APPJ) kINPen® MED (INP Greifswald/neoplas tools GmbH), and the SteriPlas (Adtec Ltd., London, United Kingdom) are CE-certified as a medical product to treat chronic wounds in humans and showed efficacy and a good tolerability. Recently, the use of plasma in cancer research and oncology is of particular interest. Plasma has been shown to induce proapoptotic effects more efficiently in tumor cells compared with the benign counterparts, leads to cellular senescence, and—as shown in vivo—reduces skin tumors. To this end, a world-wide first Leibniz professorship for plasmabiotechnology in dermatology has been introduced to establish a scientific network for the investigation of the efficacy and safety of cold atmospheric plasma in dermatooncology. Hence, plasma medicine especially in dermatology holds great promise.

In this work, we thoroughly examined the structure of the Co3O4 (111) surface under oxidative and reductive conditions, i.e. in equilibrium with realistic pressures of O2/H2O and H2/H2O, using dens...

We consider the equations for a viscous, compressible, radiative and reactive gas (pressure P = R ρ θ + a θ 4 / 3 , internal energy e = c v θ + a θ 4 / ρ ) over an unbounded exterior domain in R n , where n ≥ 2 is the space dimension. The existence, uniqueness, and large-time behavior of global spherically symmetric solutions are established for large initial data. The key point in the analysis is to deduce certain uniform a priori estimates on the solutions, especially on lower and upper bounds of the specific volume and temperature.

This chapter describes atmospheric pressure non-thermal plasma (APNTP) in the area of food processing. Various applications of APNTP are discussed including surface decontamination of food and water, transformation of packaging materials and improvement in the functionality of food ingredients. As well as benefitting the food industry, cold plasma treatment will conserve the environment as it is a ‘dry process’ using much less water. APNTP is cost-efficient because the reactive gas is produced using only electricity and air.

Reactive gases (O3, CO, NO2, and SO2) were collected hourly at the Akedala regional background station in northwestern China during September 2017 to August 2018. Wind rose, cluster analysis, potential source contribution function (PSCF), and concentration-weighted trajectory (CWT) methods were adopted for identifying the transport pathways and potential source regions of these atmosphere components at Akedala. The average O3, CO, NO2, and SO2 mixing ratios detected were 29.65 ± 11.44 ppb, 123.78 ± 73.35 ppb, 3.79 ± 0.98 ppb, and 4.59 ± 0.88 ppb during the observation period, and the statistical results of the monthly mean values revealed that there were differences during the highest pollution period, with O3 and CO mainly peaking in February, with mixing ratios of 38.03 ± 7.10 ppb and 208.50 ± 106.50 ppb, respectively. Meanwhile, NO2 peaked in March (4.51 ± 0.54 ppb) and SO2 in January (5.70 ± 1.92 ppb). The most obvious diurnal variation of CO and SO2 was observed in the winter, with maximum levels reaching between 13 : 00 and 14 : 00. The diurnal variations of O3 exhibited low values during the night and maximum values in the afternoon (16 : 00–18 : 00). Diurnal variation was not significant in the case of NO2. Cluster analysis showed that six main paths affected the Akedala atmosphere. In turn, the PSCF and CWT analysis results indicated that the Akedala reactive gas was affected by both local and foreign sources. The high PSCF value of the reactive gas potential source areas appeared in eastern Kazakhstan, northern Xinjiang, Western Mongolia, and Southern Russia. The WCWT (weighted concentration-weight trajectory) values of CO and SO2 in winter were the highest, totaling 180–240 ppb and 5–6.5 ppb, respectively. The WCWT value of O3 in the spring and summer was higher than that in the autumn and winter. The main source area of O3 was about 32–36 ppb in the spring and summer, and the main source area of NO2 in the summer had a low WCWT value of 3–3.5 ppb, whereas the NO2 WCWT value was concentrated at 4–4.5 ppb in the other seasons.

To complement gaseous certified reference material (CRM) used as calibration gas mixtures, we report on dTDLAS-based Optical Gas Standards (‘OGS’) for absolute (“calibration free”) concentration measurement of gas species like, e.g., H2O, CO, HCl, NO2, reporting excellent agreements between dTDLAS results and CRM values.

The zirconium oxynitride (ZrNxOy) thin films were deposited on the SiO2/Si substrate via direct current reactive magnetron sputtering, by tuning the reactive gas ratio r (the volume ratio between 1% O2+99% N2 and Ar) from 5.0% to 20.0%. The temperature dependence of resistivity reveals that the ZrNxOy films for r 15.0%. The metal-insulator transition is thus observed in the ZrNxOy films by tuning r. This result provides insight into the design and control of the electrical properties in ZrNxOy-based devices.

This study discusses the mechanical and tribological properties of a series of carbon nitride coatings deposited by unbalanced DC magnetron sputtering using nitrogen-argon mixture gas and graphite targets. The carbon nitride coatings were with varying carbon/nitrogen ratio by varying the gas flow rate ratio of nitrogen gas/argon while kept the overall gas flow rate at constant. The carbon nitride coatings with C/N ratios from 2.01 to 3.27 were obtained. The coatings were characterized and studied by nanohardness, scratching, and wear testers. It was found that the carbon nitride coatings with C/N ratio=2.36 showed the best performance of all the evaluated properties.

Ozone is a reactive gas that can have negative health effects on human. Building materials can be significant sinks for indoor ozone, owing to the irreversible heterogeneous reactions between ozone and material surfaces. Therefore, the ozone removal on material surfaces is crucial for evaluating indoor ozone concentrations and human exposure. This paper presents a review of previous investigations on ozone removal on building materials. The reaction probabilities of common indoor building materials range from 10−8 to 10−4, and depend on the material chemical compounds and surface characteristics. The surface-treated materials are probably more important than the underlying material substrate in determining ozone deposition velocities. Ozone removal on material surface is also associated with the fluid mechanics near the surface. Reactions between ozone and unsaturated organic compounds that constituting or adsorbed on material surfaces may result in oxidized by-products yields, while inorganic materials usually exhibit negligible by-products yields. Besides, the ozone surface removal on building materials under various conditions, i.e. ozone concentrations, air flow conditions, relative humidity and temperature, are discussed. Ozone removal on building materials after short-term and long-term exposure is presented.

The use of reactive gas atmospheres is proposed here as a new tool to control the synthesis of MOFs. With the addition of Al to an Fe-fumarate synthesis medium (which produces the typical structure of MOF MIL-88A(Fe)), a hybrid Fe/Al-fumarate that exhibits the structure of MOF MIL-53(Al)-FA was obtained even though both metals could be identified in the resulting material by STEM-HAADF. The use of CO and O2 atmospheres (6 bar) in the synthesis of both MIL-88A(Fe) and MIL-53(Fe/Al)-FA might accelerate their synthesis and give rise to a highly crystalline solid and to core–shell nanoparticles (190 ± 42 nm) with an Fe-rich core surrounded by an Al-rich shell, i.e., with a controlled Fe/Al atomic distribution. After pyrolysis the MIL-53(Fe/Al)-FA particles exhibited superparamagnetism while keeping some texture (244 m2 g−1vs. 862 m2 g−1 of the as-made material)., The authors acknowledge financial support from the Spanish MINECO and FEDER (MAT2016-77290-R), Aragón Government (DGA, T05), Universidad de Zaragoza (2007/0016) and ERC Consolidator Grant program (ERC-2013-CoG-614715, NANOHEDONISM) and People Program (CIG-Marie Curie Actions, REA grant agreement no. 321642). CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008–2011 financed by the Instituto de Salud Carlos III with the assistance of the European Regional Development Fund.

In this work, we studied the effect of constant parameters of the sputtering system on the width of the hysteresis loop during reactive sputtering. The sticking coefficient of the reactive gas to the surface, the chamber pumping speed, the target area, etc. are taken as parameters. The comparative study was carried out by numerical solution of systems of algebraic equations describing the chemisorption and physicochemical models of metal target reactive sputtering in a single reactive gas. The calculations were performed for sputtering a tantalum target in an Ar + O2 mixture. The studied dependences were non-linear in all cases.

Combustible aqueous foams and foamed emulsions represent prospective energy carriers. This paper is devoted to the overview of model assumptions required for numerical simulations of combustion and detonation processes in aqueous foams. The basic mathematical model is proposed and used for the analysis of the combustion development in the wet aqueous foam containing bubbles filled with reactive gas. The numerical results agree with the recent experimental data on combustion and detonation in aqueous foams containing premixed hydrogen–oxygen. The obtained results allowed for distinguishing the mechanisms of flame acceleration, transition to detonation, detonation propagation, and decay.

In this paper, we study a free boundary problem for the 1D viscous radiative and reactive gas. We prove that for any large initial data, the problem admits a unique global generalized solution. Meanwhile, we obtain the time-asymptotic behavior of the global solutions. Our results improve and generalize the previous work.

The compression and inflammation of reactive gas bubbles in bubble detonation waves have been studied, and the considerable influence of the fluid (liquid or vapor) on the detonation parameters has been found. It has been shown numerically that the final values of the pressure and temperature significantly decrease if the temperature dependence of the adiabatic index is taken into account at the compression stage. The parameters of reactive gas combustion products in the bubble have been calculated in terms of an equilibrium model, and the influence of the fluid that remains in the bubble in the form of microdroplets and vapor on these parameters has been investigated.

Cold plasma technology offers several potential applications in the food and biomedical industries. This work aims at highlighting the potential applications of cold plasma in food industry highlighting the current research and trends in this area. The main applications of cold plasma for food industry could be grouped as food decontamination, food quality improvement, toxin degradation and surface modifications of packaging materials. Cold plasma has proven to be effective for inactivation of various pathogens and spoilage organisms without adversely affecting the food quality. It has also shown the potential for significant degradation of mycotoxins and pesticides present in the agricultural produce. Current plasma research is driven to analyze its effectiveness against various pathogens in different food products with a keen emphasis to gain insights on the inactivation mechanisms at a molecular level. Although, cold plasma technology has shown promising results, it requires further studies to understand the reactive gas chemistry, toxicological, ecological and economic impacts of this technology.

Leached Pt-Fe and Pt-Co catalysts were prepared by acid leaching the reduced catalysts in acid solution. Oxidation treatments of leached catalysts produced the structure of metal oxides decorating the surface of nanoparticles. The fully oxidized Fe2O3 and Co3O4 species on Pt nanoparticle surfaces result in the low performance of the CO complete oxidation (COOX) reaction. In contrast, unsaturated FeO and CoO surface species can be formed during exposure to the CO preferential oxidation (CO-PROX) reaction with an excess of H2, leading to a high O2 activation ability and enhancing the CO-PROX activity. The FeOx surface structures can be transformed between these two states by varying the reactive gas environments, exhibiting oscillating activity in these two reactions. Conversely, the CoO surface structure formed in the H2-rich atmosphere is stable when exposed to the COOX reaction and exhibits similar activity in these two reactions. It is hoped that this work may assist in understanding the important role of surface oxides in real reactions.