Статті в журналах: "Reaction mass-transfer processes"

1

Tripathi, R., S. Sodaye, K. Ramachandran, S. K. Sharma, and P. K. Pujari. "Incomplete mass transfer processes in 28Si +93Nb reaction." International Journal of Modern Physics E 27, no. 02 (February 2018): 1850010. http://dx.doi.org/10.1142/s0218301318500106.

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Cross sections of reaction products were measured in [Formula: see text]Si[Formula: see text]Nb reaction using recoil catcher technique involving by off-line gamma-ray spectrometry at beam energies of 105 and 155[Formula: see text]MeV. At [Formula: see text][Formula: see text]MeV, the contribution from different incomplete mass transfer processes is investigated. Results of the present studies show the contribution from deep inelastic collision (DIC), massive transfer or incomplete fusion (ICF) and quasi-elastic transfer (QET). The contribution from massive transfer reactions was confirmed from the fractional yield of the reaction products in the forward catcher foil. The present results are different from those from the reactions with comparatively higher entrance channel mass asymmetry with lighter projectiles, for which dominant transfer processes are ICF and QET which involve mass transfer predominantly from projectile to target. The [Formula: see text] values of the products close to the target mass were observed to be in a wide range, starting from [Formula: see text] of the target ([Formula: see text]Nb) and extending slightly below the [Formula: see text] of the composite system, consistent with the contribution from DIC and QET reactions. At [Formula: see text][Formula: see text]MeV, a small contribution from QET was observed in addition to complete fusion.

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2

Prytula, A., V. Fedirko, Y. M. Pohreliuk, and Ya Matychak. "Surface Chemical Reactions in Processes of Diffusion Mass Transfer." Defect and Diffusion Forum 237-240 (April 2005): 1312–0. http://dx.doi.org/10.4028/www.scientific.net/ddf.237-240.1312.

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The phenomenological theory for describing high-temperature interaction between metal and diluted gaseous medium has been developed. The theory is based on the assumption of duplex contact layer existence in the vicinity of interface (with relative thickness 2 d), where chemical reactions and processes of gas component migration occur. The non-stationary conditions of mass transfer at the interface are described involving effective average parameters. These conditions allow considering a wide spectrum of boundary diffusion phenomena (in a short and prolonged time ranges), in order to describe the kinetics of accumulation of diffusing component close to the interface. The description of the kinetic of gaseous saturation of metal (nitriding and borating) in the diluted medium becomes a partial proof of the suggested models. In order to approach the diffusion phenomena, boundary conditions, which contain, besides the coordinate derivative of concentration function, also the time derivative, were suggested. The derived equations describe the time dependence of change of surface concentration of gaseous component, the kinetics of its accumulation owing to chemical reaction, the specimen mass change owing to both, the diffusive addition dissolution in metal and its chemical interaction. The role of temperature is also discussed.

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3

Gancarczyk, Anna, Katarzyna Sindera, Marzena Iwaniszyn, Marcin Piątek, Wojciech Macek, Przemysław J. Jodłowski, Sebastian Wroński, Maciej Sitarz, Joanna Łojewska, and Andrzej Kołodziej. "Metal Foams as Novel Catalyst Support in Environmental Processes." Catalysts 9, no. 7 (July 5, 2019): 587. http://dx.doi.org/10.3390/catal9070587.

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Metal foams are considered as promising catalyst carriers due to their high porosity, large specific surface area, and satisfactory thermal and mechanical stability. The study presents heat transfer and pressure drop experiments performed for seven foams of different pore densities made from diverse metals. Mass transfer characteristics are derived using the Chilton–Colburn analogy. It was found that the foams display much more intense heat/mass transfer than a monolith, comparable to packed bed. Next, the foams’ efficiencies have been compared, using 1D reactor modeling, in catalytic reactions displaying either slower (selective catalytic reduction of NOx) or faster kinetics (catalytic methane combustion). For the slow kinetics, the influence of carrier specific surface area at which catalyst can be deposited (i.e., catalyst amount) was decisive to achieve high process conversion and short reactor. For this case, monolith appears as the best choice assuming it’s the lowest pressure drop. For the fast reaction, the mass transfer becomes the limiting parameter, thus solid foams are the best solution.

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4

Nagy, Endre, and Márta Vitai. "Analysis of Mass Transport through Anisotropic, Catalytic/Bio-Catalytic Membrane Reactors." Catalysts 9, no. 4 (April 13, 2019): 358. http://dx.doi.org/10.3390/catal9040358.

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This paper investigated the steady-state mass transport process through anisotropic, composite membrane layers with variable mass transport coefficients, such as the diffusion coefficient, convective velocity, or chemical/biochemical reaction rate constant. The transfer processes can be a solution-diffusion model or diffusive plus convective process. In the theoretical part, the concentration distribution as well as the inlet and outlet mass transfer rates’ expressions are defined for physical transport processes with variable diffusion or solubility coefficients and then that for transport processes accompanied by first- and zero-order reactions, in the presence of diffusive and convective flow, with constant and variable parameters. The variation of the transport parameters as a function of the local coordinate was defined by linear equations. It was shown that the increasing diffusion coefficient or convective flow induces much lower concentrations across the membrane layer than transport processes, with their decreasing values a function of the space coordinate. Accordingly, this can strongly affect the effect of the concentration dependent chemical/biochemical reaction. The inlet mass transfer rate can also be mostly higher when the transport parameter decreases across the anisotropic membrane layer.

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5

Bhattacharya, S., J. D. Belgrave, D. G. Mallory, R. G. Moore, M. G. Ursenbach, and S. A. Mehta. "Investigation of Thermal Fingerprint in Accelerating-Rate Calorimetry for Air-Injection Enhanced-Oil-Recovery Processes." SPE Journal 22, no. 02 (October 10, 2016): 548–61. http://dx.doi.org/10.2118/178095-pa.

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Summary The accelerating-rate calorimeter (ARC) is unique for its exceptional adiabaticity, its sensitivity, and its sample universality. Accelerating Rate Calorimetry is one of the screening tests used to determine the suitability for air-injection enhanced oil recovery (EOR). These tests show oil reactivity and exothermicity over a broad range of temperatures: low-temperature range (LTR), negative-temperature-gradient region (NTGR), and high-temperature range (HTR). An experimental and simulation study was carried out to expand understanding and interpretation of the data derived from high-pressure closed-ARC tests. Athabasca bitumen was used for the experimental study in a closed ARC at 13.89 MPag (2000 psig) to identify the temperature ranges over which the oil reacts with oxygen in the injected air. Self-heat rate from accelerating-rate calorimetry and mass-loss rates from the differential thermogravimetric analysis show the influence of mass transfer of oxygen within bitumen in the LTR and HTR. A numerical model was developed to integrate the concept of mass transfer with a reaction-kinetic model. The model incorporates solubility of oxygen with partition equilibrium coefficient (K-value) as a medium to introduce oxygen into the bitumen layer, which later transfers throughout oil layer by diffusion. This model considers both low- and high-temperature oxidation (LTO and HTO), and thermal-cracking reactions, as described in traditional reaction-kinetic models of in-situ-combustion (ISC) processes. Results show that formation of an asphaltenes film in the LTR caused by oxidation of maltenes obstructs oxygen (mass-transfer restriction) penetration into the bitumen layer. The simulated result shows that, by integrating mass transfer with the kinetic model, it is possible to predict the NTGR. Viscosity and temperature dependence on the mass transfer of oxygen is linear. As time passes and chemical reaction becomes more important with increasing temperature, the relationship deviates from linearity. With increasing temperature, the influence of chemical interaction on the oxygen distribution becomes greater, and this results in a shorter initial stage of mass transfer of oxygen within the bitumen film at low temperatures. This implies that the ARC can be a useful tool for understanding the effect of mass transfer on the oxidation characteristic for predicting LTR, NTGR, and HTR.

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6

Altabbakh, Dr Ban A. Ahmed, Sattar J. Hussen, and Saba A. Yosif. "Simultaneous Mass, Heat and Momentum Transfer in an Adiabatic Packed Bed Reactor." Journal of Petroleum Research and Studies 3, no. 1 (May 6, 2021): 1–25. http://dx.doi.org/10.52716/jprs.v3i1.61.

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Process modeling or computer simulation is one of the most important studies which gives the engineer a whole description about certain processes including all the mathematical relationships that are relating the process variables. Transport phenomena on fixed bed reactor was studied because of their importance and their effects on the catalyst performance in all chemical reactions. Simultaneous mass , heat and pressure drop were studied and all the process variables such as temperature, rate of reaction , pressure along length of the reactor were calculated and the data obtained from the mathematical package showed that with the increase the reaction temperature the process production , rate of reaction and pressure drop will increase.

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7

Samant, Ketan D., and Ka M. Ng. "Effect of kinetics and mass transfer on design of extractive reaction processes." AIChE Journal 44, no. 10 (October 1998): 2212–28. http://dx.doi.org/10.1002/aic.690441010.

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8

Berkemeier, T., A. J. Huisman, M. Ammann, M. Shiraiwa, T. Koop, and U. Pöschl. "Kinetic regimes and limiting cases of gas uptake and heterogeneous reactions in atmospheric aerosols and clouds: a general classification scheme." Atmospheric Chemistry and Physics Discussions 13, no. 1 (January 9, 2013): 983–1044. http://dx.doi.org/10.5194/acpd-13-983-2013.

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Abstract. Heterogeneous reactions are important to atmospheric chemistry and are therefore an area of intense research. In multiphase systems such as aerosols and clouds, chemical reactions are usually strongly coupled to a complex sequence of mass transport processes and results are often not easy to interpret. Here we present a systematic classification scheme for gas uptake by aerosol or cloud particles which distinguishes two major regimes: a reaction-diffusion regime and a mass-transfer regime. Each of these regimes includes four distinct limiting cases, characterized by a dominant reaction location (surface or bulk) and a single rate-limiting process: chemical reaction, bulk diffusion, gas-phase diffusion or mass accommodation. The conceptual framework enables efficient comparison of different studies and reaction systems, going beyond the scope of previous classification schemes by explicitly resolving interfacial transport processes and surface reactions limited by mass transfer from the gas phase. The use of kinetic multi-layer models instead of resistor model approaches increases the flexibility and enables a broader treatment of the subject, including cases which do not fit into the strict limiting cases typical of most resistor model formulations. The relative importance of different kinetic parameters such as diffusion, reaction rate and accommodation coefficients in this system is evaluated by a quantitative global sensitivity analysis. We outline the characteristic features of each limiting case and discuss the potential relevance of different regimes and limiting cases for various reaction systems. In particular, the classification scheme is applied to three different data sets for the benchmark system of oleic acid reacting with ozone. In light of these results, future directions of research needed to elucidate the multiphase chemical kinetics in this and other reaction systems are discussed.

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9

Berkemeier, T., A. J. Huisman, M. Ammann, M. Shiraiwa, T. Koop, and U. Pöschl. "Kinetic regimes and limiting cases of gas uptake and heterogeneous reactions in atmospheric aerosols and clouds: a general classification scheme." Atmospheric Chemistry and Physics 13, no. 14 (July 15, 2013): 6663–86. http://dx.doi.org/10.5194/acp-13-6663-2013.

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Abstract. Heterogeneous reactions are important to atmospheric chemistry and are therefore an area of intense research. In multiphase systems such as aerosols and clouds, chemical reactions are usually strongly coupled to a complex sequence of mass transport processes and results are often not easy to interpret. Here we present a systematic classification scheme for gas uptake by aerosol or cloud particles which distinguishes two major regimes: a reaction-diffusion regime and a mass transfer regime. Each of these regimes includes four distinct limiting cases, characterised by a dominant reaction location (surface or bulk) and a single rate-limiting process: chemical reaction, bulk diffusion, gas-phase diffusion or mass accommodation. The conceptual framework enables efficient comparison of different studies and reaction systems, going beyond the scope of previous classification schemes by explicitly resolving interfacial transport processes and surface reactions limited by mass transfer from the gas phase. The use of kinetic multi-layer models instead of resistor model approaches increases the flexibility and enables a broader treatment of the subject, including cases which do not fit into the strict limiting cases typical of most resistor model formulations. The relative importance of different kinetic parameters such as diffusion, reaction rate and accommodation coefficients in this system is evaluated by a quantitative global sensitivity analysis. We outline the characteristic features of each limiting case and discuss the potential relevance of different regimes and limiting cases for various reaction systems. In particular, the classification scheme is applied to three different datasets for the benchmark system of oleic acid reacting with ozone in order to demonstrate utility and highlight potential issues. In light of these results, future directions of research needed to elucidate the multiphase chemical kinetics in this and other reaction systems are discussed.

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10

Cheng, Huanbo, Jie Zhang, Haihong Huang, and Zhifeng Liu. "Mass transfer model of supercritical fluid degradation for carbon fiber composites." Journal of Composite Materials 51, no. 8 (July 17, 2016): 1073–85. http://dx.doi.org/10.1177/0021998316658944.

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It is critical to study the mass transfer of supercritical fluid degradation for carbon fiber composites to investigate their degradation mechanism, design the reactor, and develop recycling processes. The mass transfer process of supercritical fluid degradation was described from two aspects: mass diffusion from outside to inside, and from inside to outside. Mass transfer model of supercritical fluid degradation was established based on a proposed concentric cylindrical representative volume element. The reaction kinetic parameters were incorporated into the mass transfer equation, and the concentration distribution of supercritical fluid, mass transfer rate, reaction order, and reaction rate constant during the carbon fiber composites degradation process were calculated. Relaxation time was incorporated into the mass transfer process, and the supercritical fluid concentration calculation method considering non-Fick effect was proposed. Finally, two pretreatment methods were adopted to speed up the mass transfer process.

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11

Dzevochko, O., M. Podustov, and A. Dzevochko. "RESEARCH OF THERMAL AND MASS-EXCHANGE PROCESSES IN GAS-LIQUID FILM ABSORBERS IN SURFACE-ACTIVE TECHNOLOGY." Integrated Technologies and Energy Saving, no. 3 (November 9, 2021): 3–16. http://dx.doi.org/10.20998/2078-5364.2021.3.01.

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The article states that surfactants have an asymmetrically constructed molecule that contains hydrophilic and hydrophobic groups. The main department of surfactant production is the process of sulfation of organic matter with gaseous sulfur trioxide. It is shown that the process of sulfation in gas-liquid film absorbers consists of the following stages: the process of mass transfer of sulfur trioxide from the gas stream to the liquid phase; the process of absorption of sulfur trioxide by organic matter with the passage of an exothermic chemical reaction; the process of heat exchange between the liquid phase and the gas stream; the process of heat exchange between the liquid phase and the flow of cooling water. Studies of heat and mass transfer processes at these stages make it possible to select the necessary equations for the calculation of heat transfer coefficients, heat transfer coefficients and mass transfer coefficient. It is recommended to calculate the heat transfer coefficient from liquid to gas by the equation when the diffusion and thermal Prandtl numbers are close to unity. The use of the classical equation to calculate the heat transfer coefficient from the liquid phase to the wall of the reaction tube did not give the desired result. Therefore, an equation was used that takes into account the properties of the gas-liquid flow as a whole. It is recommended to calculate the heat transfer coefficient from the reaction pipe wall to the cooling water flow according to the classical Nusselt equation. Experimental data processing data for calculating the density and dynamic viscosity of the reaction mass along the length of the reactor are presented. The equation for calculating the mass transfer coefficient was obtained by analyzing 6 equations of different authors who were engaged in the process of sulfation of organic substances. A mathematical description of the sulfation process in a film absorber was developed for analysis. During the development of the mathematical description, the balance equations of mass and heat transfer for the reaction tube were compiled. Based on the results of mathematical modeling, an equation was chosen that includes the tangential stress at the gas-liquid interface. The results of mathematical modeling were compared with Gutierrez's experimental data and the results of Dabir's mathematical modeling. The obtained results will be used in mathematical modeling of the sulfation process in a film absorber.

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12

Vakouftsi, E., G. Marnellos, C. Athanasiou, and Frank A. Coutelieris. "Modeling of Flow and Transport Processes Occurred in a Typical Polymer Electrolyte Membrane Fuel Cell (PEMFC)." Defect and Diffusion Forum 273-276 (February 2008): 87–92. http://dx.doi.org/10.4028/www.scientific.net/ddf.273-276.87.

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In the present work, a three dimensional model examining the fluid flow along with the fundamental transport phenomena occurring in a typical polymer electrolyte fuel cell (PEMFC), i.e. heat transfer, mass transport and charge transfer, has been developed. The flow field was simulated according to the well known Navier-Stokes equations, while the heat transfer was described by the typical conduction/convection equation and the mass transport by the convection/diffusion one. Furthermore, reaction kinetics were studied by the Butler-Volmer equation for the heterogeneous reactions occurring at the porous electrodes. The developed model was numerically solved by using the commercially available CFD package CFD-RC©, which is based on the multi-step finite volume method. The fuel cell performance in terms of velocity, temperature, mass fractions of active compounds and electric field has been investigated as well.

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13

Rachmanto, Tri, David Allanson, Christian Matthews, and Ian Jenkinson. "Measuring Mass Transfer on Biodiesel Process by Means of Impedance Measurement." Applied Mechanics and Materials 391 (September 2013): 467–72. http://dx.doi.org/10.4028/www.scientific.net/amm.391.467.

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Transesterification is commonly used to produce biodiesel from methylester. In order to control the conversion process is useful to employ process monitoring, in particular monitoring of the mass transfer processes that limits the initial rates of transesterification. Monitoring of these initial stages of the reaction may allow for process optimization. Many methods have been identified to monitor reaction progress. This paper proposes a method to monitor the initial stages of the biodiesel production process using impedance measurement. The impedance measurements presented show the expected sigmoid curves that are associated with mass transfer (mixing) processes taking place during the early stages of the transesterification process.

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14

Wu, Ai-xiang, Jin-zhi Liu, and Ling-yan Tang. "Simulation of coupled flowing-reaction-deformation with mass transfer in heap leaching processes." Applied Mathematics and Mechanics 28, no. 3 (March 2007): 327–35. http://dx.doi.org/10.1007/s10483-007-0306-1.

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15

Bojadjiev, Chr. "Nonlinear mass transfer and hydrodynamic stability in solubility phenomena." Pure and Applied Chemistry 74, no. 10 (January 1, 2002): 1801–10. http://dx.doi.org/10.1351/pac200274101801.

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The dissolution of gases, liquids,or solids in liquids is a heterogeneous reaction, and in many cases, the reaction rate is limited by a diffusive transfer of substance in the boundary layer at the face interphase. In modern industry, intensive interphase mass transfer processes are accomplished by large concentration gradients. This can result in a set of nonlinear effects and the difference between experimental data and predictions of the linear mass transfer theory. One of the main nonlinear effects is a result of the induction of a secondary flow at the interface boundary. This can lead to essential changes of the dissolution rate and the hydrodynamic stability of the system.

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16

Yang, Chao, Guo Gang Yang, Dan Ting Yue, and Jin Liang Yuan. "CFD Analysis of Elementary-Kinetic Chemical Reactions and Effects on Transport Processes in Anodes of Solid Oxide Fuel Cells." Applied Mechanics and Materials 190-191 (July 2012): 43–52. http://dx.doi.org/10.4028/www.scientific.net/amm.190-191.43.

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Solid oxide fuel cell (SOFC) is one of most promising types of fuel cells with advantages of high efficiencies, flexible fuel types. As a device directly converting the free energy of chemical reactant to electrical energy and heat, the performance of SOFC is strongly affected by the chemical and electro-chemical reactions occurring in the porous anode coupled with mass, momentum and heat transfer processes. A 3D CFD model has been developed by using in-house code to analyze the various processes coupled with elementary surface reactions occurring in SOFC’s anode, to identify the effects between transfer processes and some elementary reactions occurring in the anode. It shows that single step elementary reaction can affect the distribution of surface species, but not remarkable on global conditions such as temperature and gas distribution. On the other hand, global parameters including temperature, porous characteristics affect the surface species distribution and elementary reaction processes largely.

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17

Mandal, Gopinath, and Dulal Pal. "Entropy Generation Analysis of Radiated Magnetohydrodynamic Flow of Carbon Nanotubes Nanofluids with Variable Conductivity and Diffusivity Subjected to Chemical Reaction." Journal of Nanofluids 10, no. 4 (December 1, 2021): 491–505. http://dx.doi.org/10.1166/jon.2021.1812.

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The purpose of this article is to analyze the entropy generation and heat and mass transfer of carbon nano-tubes (CNTs) nanofluid by considering the applied magnetic field under the influence of thermal radiation, variable thermal conductivity, variable mass diffusivity, and binary chemical reaction with activation energy over a linearly stretching cylinder. Convective boundary conditions on heat and mass transfer are considered. An isothermal model of homogeneous-heterogeneous reactions is used to regulate the solute concentration profile. It is assumed that the water-based nanofluid is composed of single and multi-walled carbon nanotubes. Employing a suitable set of similarity transformations, the system of partial differential equations is transformed into the system of nonlinear ordinary differential equations before being solved numerically. Through the implementation of the second law of thermodynamics, the total entropy generation is calculated. In addition, entropy generation for fluid friction, mass transfer, and heat transfer is discussed. This study is specially investigated for the impact of the chemical reaction, and activation energy with entropy generation subject to distinct flow parameters. It is found that the slip parameters greatly influence the flow characteristics. Fluid temperature is elevated with higher radiation parameters and thermal Biot number. Entropy and Bejan number are found to be an increasing function of solid volume fraction, magnetic field, and curvature parameters. Binary chemical reaction and activation energy on concentration profile have opposite effects.

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18

Jensen, NJ, and T. Sumpter. "Development of Experimental Methods for Study of Gas-Phase Charge-Reversal Charge Transfer Processes of Potential Interest in Smoke Chemistry." Beiträge zur Tabakforschung International/Contributions to Tobacco Research 16, no. 3 (July 1, 1995): 95–105. http://dx.doi.org/10.2478/cttr-2013-0636.

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AbstractGas phase reactions are of fundamental interest in smoke chemistry. Many types of reactions and decompositions have been characterized. However, one type of reaction, the charge transfer process, is very difficult to characterize by conventional means. Methods have been developed using a four sector tandem mass spectrometer for chemical characterization of charge-reversal charge transfer reaction products. This is accomplished by operating two of the sectors of the instrument in the negative ion mode and the other two sectors of the instrument in the positive ion mode with inert gas collision at the interface to facilitate charge transfer. For example if a negatively charged ion generated and selected in MS I is collisionally activated at the interface and the products are analysed with MS II in the positive ion mode, then only chemical species generated in charge-reversal charge transfer processes of the original parent anion are identified. This technique has been applied to fundamental studies of model compounds including fatty acids, solanesol, sugars and humectants.

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Liu, Zhen, Bin Zhang, and Xiong Bill Yu. "Multiphysics for Early Stage Cement Hydration: Theoretical Framework." Advanced Materials Research 255-260 (May 2011): 4247–50. http://dx.doi.org/10.4028/www.scientific.net/amr.255-260.4247.

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The chemical hydration involves complex multiphysical processes including mass and energy transfer, chemical reactions and consequently stress development and shrinkage. This paper proposed a multiphysics numerical model to predict the kinetics cement paste. The chemical reaction theory, heat transfer theory, diffusion theory, and continuum mechanics were coupled in the theoretical model. A comprehensive theoretical model is established with partial different equation system, auxiliary functions, and typical boundary conditions.

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Margi, Nikhil H., and Ganapati D. Yadav. "Design and Development of Novel Continuous Flow Stirred Multiphase Reactor: Liquid–Liquid–Liquid Phase Transfer Catalysed Synthesis of Guaiacol Glycidyl Ether." Processes 8, no. 10 (October 10, 2020): 1271. http://dx.doi.org/10.3390/pr8101271.

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Phase transfer catalysed (PTC) reactions are used in several pharmaceutical and fine chemical industrial processes. We have developed a novel stirred tank reactor (Yadav reactor) to conduct batch and continuous liquid–liquid–liquid (L-L-L) PTC reactions. The reactor had a provision of using three independent stirrers for each phase, thereby having complete control over the rate of mass transfer across the two interfaces. In the continuous mode of operation, the top and bottom phases were continuously fed into the reactor while the middle phase was used as a batch. All three stirrers were used independently, thereby having independent control of mass transfer resistances. The reactor in a batch mode showed higher conversion and selectivity compared to a conventional batch reactor. L-L-L PTC reaction in the continuous mode was successfully performed without loss of the middle catalyst phase and with steady conversion and selectivity. The reaction of guaiacol with epichlorohydrin was conducted as a model reaction, with a 76% conversion of epichlorohydrin, 85% selectivity of guaiacol glycidyl ether, and the middle catalyst phase was stable throughout the process.

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MAZZOCCO, MARCO. "REACTION DYNAMICS INDUCED FROM LIGHT WEAKLY-BOUND RADIOACTIVE ION BEAMS AT NEAR-BARRIER ENERGIES." International Journal of Modern Physics E 19, no. 05n06 (June 2010): 977–88. http://dx.doi.org/10.1142/s0218301310015424.

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This work presents an overview of the latest experiments performed to study the reaction dynamics induced from light weakly-bound Radioactive Ion Beams on medium-mass and heavy targets at near-barrier energies. Production reactions, secondary beam intensities and experimental results on elastic scattering, transfer, breakup and fusion processes are presented and discussed. A comparative analysis of fusion and reaction cross section data for different projectile-target combinations is finally given.

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Glushkov, Dmitrii O., and Pavel A. Strizhak. "Mathematical Modeling of Heat and Mass Transfer Processes with Chemical Reaction at Polymeric Material Ignition by Several Small-Size Hot Particles." Mathematical Problems in Engineering 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/614143.

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Numerical research of interconnected heat and mass transfer processes in the “two hot particles—polymeric material—air” system was executed. The joint effect of several local heat sources on the main integrated characteristic of ignition process (ignition delay time) was established. Two ignition models characterized by the relative positioning of hot particles on a polymeric material surface were revealed. Besides, there were established characteristics of local heat sources and the distance between them (700 K<Tp<1150 K andL>1.5orTp>1150 K and0.25<L<1.5)when regularities of heat and mass transfer processes in the “two hot particles—polymeric material—air” system are similar to regularities of heat and mass transfer processes in the “single hot particle—polymeric material—air” system.

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Yuguchi, Takashi, Takanobu Matsuki, Yuya Izumino, Eiji Sasao, and Tadao Nishiyama. "Mass transfer associated with chloritization in the hydrothermal alteration process of granitic pluton." American Mineralogist 106, no. 7 (July 1, 2021): 1128–42. http://dx.doi.org/10.2138/am-2020-7353.

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Abstract This study, along with our previous studies (Yuguchi et al. 2015, 2019a), reveals the hydrothermal alteration processes in a pluton, with a focus on the mass transfer between minerals and hydrothermal fluid. It also depicts the sequential variations in fluid chemistry as alteration progresses. Hydrothermal alteration of the Toki granite in Tono, Japan—the study area of this research—progressed through the successive processes of chloritization, plagioclase alteration, and precipitation of a carbonate. This paper describes the alteration processes of hornblende chloritization, K-feldspar chloritization, and the formation of fracture-filling chlorite through petrography and mineral chemistry. A set of singular value decomposition analyses was conducted to obtain reaction equations for the chloritization processes, which facilitates the quantitative assessment of mass transfer between the reactant and product minerals, and the inflow and outflow of components through the hydrothermal fluid. Several types of chloritization reactions (including biotite chloritization) can be characterized by their reaction with the inflow of Al3+, Fe2+, Mn2+, and Mg2+ and the outflow of H4SiO4, Ca2+, K+, and F–. The age and thermal conditions of hornblende chloritization (64–54 Ma and 330–190 °C), K-feldspar chloritization (68–53 Ma and 350–210 °C), and precipitation of fracture-filling chlorite (66 and 63 Ma, 340 and 320 °C) overlap with those of biotite chloritization (68–51 Ma and 350–180 °C). The chloritization reactions (this study and Yuguchi et al. 2015) and plagioclase alteration (Yuguchi et al. 2019a) represent sequential variations in fluid chemistry at temporal conditions from 68 to 51 Ma as the temperature decreased from 350 to 180 °C. As the alteration proceeds, the concentrations of aluminum, iron, manganese, and magnesium ions in the hydrothermal fluid decrease gradually, and those of calcium, hydrogen, and fluorine ions increase gradually. Hornblende chloritization is associated with formation of magnetite and ilmenite. The thermal conditions of the hydrothermal fluid yielding the formation of magnetite and ilmenite can be interpreted by the chemical characteristics of chlorite around their associated minerals. The formation temperature of magnetite was higher than that of ilmenite, implying a decrease in oxygen fugacity in the hydrothermal fluid with the decrease in temperature from 280–310 to 220–250 °C.

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24

Shadid, J. N., and E. R. G. Eckert. "The Mass Transfer Analogy to Heat Transfer in Fluids With Temperature-Dependent Properties." Journal of Turbomachinery 113, no. 1 (January 1, 1991): 27–33. http://dx.doi.org/10.1115/1.2927734.

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The analogy between heat transfer in a single-component fluid and isothermal mass transfer of a two-component fluid without chemical reaction is presented. The analogy is well established and frequently used for fluids with constant properties. However, in various applications such as in the cooling of hot components in gas turbines, the temperature varies widely, causing significant fluid property variations. The present paper reviews the constant-property situation and considers in detail the conditions necessary to ensure similarity of the two transport processes with temperature and concentration-dependent fluid properties. An application of the variable property analogy to mass transfer in binary mixtures is presented along with specific recommendations for the CO2–air and Freon-air systems. It is demonstrated that the essential similarity conditions of the analogy are very well fulfilled for film cooling, total coverage film cooling, and impingement cooling when the heat (mass) flux into the wall in the transport process is zero. The heat/mass transfer analogy can, therefore, be used with confidence for these processes.

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25

Salvitti, Chiara, Federico Pepi, Anna Troiani, and Giulia de Petris. "Intracluster Sulphur Dioxide Oxidation by Sodium Chlorite Anions: A Mass Spectrometric Study." Molecules 26, no. 23 (November 24, 2021): 7114. http://dx.doi.org/10.3390/molecules26237114.

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The reactivity of [NaL·ClO2]− cluster anions (L = ClOx−; x = 0–3) with sulphur dioxide has been investigated in the gas phase by ion–molecule reaction experiments (IMR) performed in an in-house modified Ion Trap mass spectrometer (IT-MS). The kinetic analysis revealed that SO2 is efficiently oxidised by oxygen-atom (OAT), oxygen-ion (OIT) and double oxygen transfer (DOT) reactions. The main difference from the previously investigated free reactive ClO2− is the occurrence of intracluster OIT and DOT processes, which are mediated by the different ligands of the chlorite anion. This gas-phase study highlights the importance of studying the intrinsic properties of simple reacting species, with the aim of elucidating the elementary steps of complex processes occurring in solution, such as the oxidation of sulphur dioxide.

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26

Boyadjiev, Christo, and Boyan Boyadjiev. "New Approach to Modeling and Simulation of Chemical and Mass Transfer Processes in Column Apparatuses." Recent Innovations in Chemical Engineering (Formerly Recent Patents on Chemical Engineering) 12, no. 1 (June 25, 2019): 79–95. http://dx.doi.org/10.2174/2405520411666181102161727.

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Objective: The classical mass transfer theory is not applicable for modeling the mass transfer of chemical, absorption, adsorption and catalytic processes in column apparatuses, where the velocity distributions and interphase boundaries are unknown. The modeling of these processes is related with the creation of new type of convection-diffusion models (for qualitative analysis) and average-concentration models (for quantitative analysis), where the surface reactions are replaced by equivalent volume reaction, while the velocity and concentration distributions are replaced by average velocity and concentrations. The effect of the radial non-uniformity of the velocity in the average-concentration models is introduced by model parameters, which must be obtained experimentally. Methods: The new convection-diffusion and average-concentration models are obtained in the cases of different processes in column apparatuses: simple and complicated chemical reactions, physical and chemical absorption, physical and chemical adsorption, heterogeneous catalytic processes (physical and chemical adsorption mechanism). These models are presented in the monograph Chr. Boyadjiev, M. Doichinova, B. Boyadjiev, P. Popova-Krumova, “Modeling of Column Apparatus Processes” (Second edition), Springer- Verlag, Berlin Heidelberg, 2018. Results: Two hydrodynamic situations are considered, when the radial velocity component is equal to zero, in the cases of an axial modification of the radial non-uniformity of the axial velocity component and when the radial velocity component is not equal to zero. Conclusion: The use of experimental data, for the average concentrations at the column end, for a concrete process and column, permits to obtain the model parameters, related with the radial non-uniformity of the velocity. These parameter values permit to use the averageconcentration models for modeling of different processes.

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27

Mitrovic, Bojan M., and Dimitrios V. Papavassiliou. "Effects of a first-order chemical reaction on turbulent mass transfer." International Journal of Heat and Mass Transfer 47, no. 1 (January 2004): 43–61. http://dx.doi.org/10.1016/s0017-9310(03)00380-6.

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28

Li, Ming Chun, Yu Sheng Wu, and Ying Tao Song. "The Coupled Heat and Mass Transfers in the Endothermic Chemical Reaction Packed Beds." Advanced Materials Research 402 (November 2011): 436–41. http://dx.doi.org/10.4028/www.scientific.net/amr.402.436.

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According to the assumption of local thermal non-equilibrium and the heat transfer controlled regime, a mathematical model describing the coupling between the heat and mass transfer processes in a porous packed bed with endothermic chemical reactions was established and solved by the alternate dimension implicit method. The calculated results showed that, the profiles of the temperature distributions of the two phases and the solid conversion ratio all decay near the radial boundary wall corresponding to the momentum boundary layer. However, the concentration of the product gas increases near the wall owing to the slower speed layer. The temperatures difference between the gas flow and solid pellets can not be ignored during the study of ore decomposition in the porous packed bed. The reaction features of the packed bed with endothermic reactions under different conditions can be analyzed by the established model.

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29

Yang, Chao, Guo Gang Yang, Dan Ting Yue, Xin Rong Lv, and Jin Liang Yuan. "Research on Catalytic Combustion of Low Concentration Methane in Combustion Channel of Compact Reformer." Advanced Materials Research 550-553 (July 2012): 411–15. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.411.

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The combustion channel of compact methane reformer includes fuel flow duct, porous layer and solid connector. There are heat transport and multi-component species diffusion/convection processes in porous structure. The transfer processes are coupled with methane catalytic combustion, and affect the performance and stability of reformer. A 3D in-house code has been developed to simulate the mass and heat transfer processes involving chemical reactions in the reformer channel in specific condition (mass fraction of CH4YCH4is less than 1% in the mixture of methane and air). It shows that, catalytic combustion reactions mainly tack place on the porous layer near inlet with a higher temperature area, the biggest heat flux region from the bottom wall is found near the higher temperature area. The reaction rate of methane, temperature of porous layer and heat flux increase with the increase of YCH4. In general, 0.4% is an adequate value for YCH4. The research has a benefit meaning to provide a guideline for the improvement and design for compact methane reformer.

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30

Zhdanova, Alena O., Genii V. Kuznetsov, and Pavel A. Strizhak. "Numerical Research of Heat and Mass Transfer Processes in Water Vapors and Gaseous Thermal Decomposition Products Mixture above the Combustible Wood on the Conditions of Chemical Reaction Termination in it." Advanced Materials Research 1040 (September 2014): 535–40. http://dx.doi.org/10.4028/www.scientific.net/amr.1040.535.

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The numerical analysis has been made of complex interrelated heat and mass transfer processes, chemical reactions and phase transformations under the thermal decomposition reaction suppression of typical combustible wood (needles of a pine, fir, fir-tree and larch, branches of a pine, fir, birch and larch, cones of a pine, leaves of aspen) by the “water slug” trace. Characteristic times have been calculated of the thermal decomposition reaction suppression of typical combustible wood at typical temperatures in “water slug” trace and the thickness of warmed material layers.

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31

Lema, J. M., R. Méndez, J. Iza, P. Garcia, and F. Fernández-Polanco. "Chemical Reactor Engineering Concepts in Design and Operation of Anaerobic Treatment Processes." Water Science and Technology 24, no. 8 (October 1, 1991): 79–86. http://dx.doi.org/10.2166/wst.1991.0219.

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As a prelude to the individual papers describing the various anaerobic treatment process configurations, the anaerobic treatment process is described in terms of chemical reaction engineering. These descriptions are made in terms of kinetics, stoichiometry, thermodynamics and mass transfer considerations. The implications of these concepts on design and operations are also discussed.

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32

Volk, A. M., A. I. Vilkotsky, and O. N. Pyzhcova. "Evaluation of the Efficiency of Transfer Processes in a Rotary Apparatus." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 64, no. 5 (October 8, 2021): 459–74. http://dx.doi.org/10.21122/1029-7448-2021-64-5-459-474.

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This paper considers the possibility of using vortex devices for interphase interaction while carrying out various physical and chemical processes in the chemical, food, gas production, construction and other industries. In the processes of mass transfer, one or several distributed components perform the transition from one phase to another through the active surface of their interface. To perform the implementation of these processes in absorbers, rectifiers, adsorbers, extractors effectively, the developed surface of the interacting phases acquire s a particular significance. Most of the chemical reactions in reaction devices and heterogeneous media occur when the initial distributed substances are supplied to the reaction zone and when the resulting products are removed from the chemical interaction zone through the phase interface. The processes under consideration are also used in solving environmental problems, viz. for sanitary cleaning of ventilation gases, wet cleaning of emissions. During evaporation, absorption, rectification, wet cleaning of gases and other processes, the problem of preventing the entrainment of liquid droplets with the gas flow is of great importance. One of the designs of a rotary multistage mass transfer apparatus is considered which makes it possible to achieve a finely dispersed liquid spray, uniform in height, with an ascending cross-flow of gas. The diagrams of installations for carrying out the experiment are given. On the basis of experimental studies, the dependence of the average diameter of dispersed liquid droplets on the geometric and hydrodynamic parameters has been obtained. The dispersed composition is described and dependences are given for determining the main characteristics used in physicochemical processes. The theoretical calculation of the movement of particles of the dispersed phase in the working volume of the apparatus at different flow rates of liquid and gas has been carried out. Theoretical and experimental methods were used to estimate the carryover of the liquid phase, an analysis of the process was carried out, and practical recommendations were given.

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33

Noworyta, Andrzej, and Anna Trusek-Holownia. "Enzymatic synthesis of hydrophobic compounds integrated with membrane separation." Chemical and Process Engineering 37, no. 1 (March 1, 2016): 15–27. http://dx.doi.org/10.1515/cpe-2016-0003.

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Abstract The enzymatic synthesis of a highly hydrophobic product (dipeptide precursor) in which the reaction is accompanied by the mass transfer of the reaction product to the organic phase and the substrates to the water phase is considered. Equations describing both continuous and batch processes are formulated. The range of variability in the operating parameters of such a bioreactor is specified, and the correlations reported in the literature to describe mass transfer in the membrane contactor are validated. The proposed process was verified experimentally, and good agreement between the determined and calculated concentrations was obtained in both phases.

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34

Ermakov, S. A., A. A. Ermakov, O. N. Chupakhin, and D. V. Vaissov. "Mass transfer with chemical reaction in conditions of spontaneous interfacial convection in processes of liquid extraction." Chemical Engineering Journal 84, no. 3 (December 2001): 321–24. http://dx.doi.org/10.1016/s1385-8947(00)00379-x.

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35

Lian, Boyue, Qi Jiang, Shikha Garg, Yuan Wang, Yuting Yuan, and T. David Waite. "Analysis of Ozonation Processes Using Coupled Modeling of Fluid Dynamics, Mass Transfer, and Chemical Reaction Kinetics." Environmental Science & Technology 56, no. 7 (March 23, 2022): 4377–85. http://dx.doi.org/10.1021/acs.est.1c07694.

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36

Awasthi, B. "Effects of Heat and Mass Flux on MHD Free Convection Flow Through a Porous Medium with Radiation and First Order Chemical Reaction." International Journal of Applied Mechanics and Engineering 23, no. 4 (November 1, 2018): 855–71. http://dx.doi.org/10.2478/ijame-2018-0047.

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Abstract The study of a magneto hydrodynamic (MHD) free convection flow of an incompressible viscous fluid flow past a vertical surface is analyzed by taking into account viscous dissipation under the influence of radiation effect and chemical reaction with constant heat and mass fluxes. The governing partial differential equations have been converted into a set of ordinary differential equations using non dimensional quantities. The perturbation technique has been applied to solve the system of partial differential equations. The velocity, temperature and concentration fields have been studied for the effect of the permeability parameter (α), Grashof number for heat transfer (Gr), Grashof number for mass transfer (Gm), Prandtl number (Pr), magnetic parameter (M), chemical reaction parameter (Kr), Schmidt number (Sc), Eckert number (E), radiation parameter (F) etc. The expressions for the skin-friction, rate of heat transfer and rate of mass transfer are also derived. It is observed that when the radiation parameter increases, the velocity increases near the vertical surface. It is also seen that the concentration decreases with an increase in the chemical reaction parameter (Kr).

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37

Jankowski, Mikolaj Jan, Raymond Olsen, Claus Jørgen Nielsen, Yngvar Thomassen, and Paal Molander. "Correction: The applicability of proton transfer reaction-mass spectrometry (PTR-MS) for determination of isocyanic acid (ICA) in work room atmospheres." Environmental Science: Processes & Impacts 20, no. 2 (2018): 415. http://dx.doi.org/10.1039/c8em90006j.

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Анотація:

Correction for ‘The applicability of proton transfer reaction-mass spectrometry (PTR-MS) for determination of isocyanic acid (ICA) in work room atmospheres’ by Mikolaj Jan Jankowski et al., Environ. Sci.: Processes Impacts, 2014, 16, 2423–2431.

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38

Chen, Richard, Mehmet Kerem Gokus, and Silvina Pagola. "Tetrathiafulvalene: A Gate to the Mechanochemical Mechanisms of Electron Transfer Reactions." Crystals 10, no. 6 (June 5, 2020): 482. http://dx.doi.org/10.3390/cryst10060482.

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This report describes aspects of our previous studies of the mechanochemical synthesis of charge transfer complexes of the electron donor tetrathiafulvalene, which are relevant to the use of laboratory X-ray powder diffraction for ex situ monitoring of mechanochemical reactions toward investigating their mechanisms. In particular, the reaction of tetrathiafulvalene and chloranil was studied under neat mechanochemical conditions and liquid-assisted grinding with diethyl ether (1 μL/mg). The product in both cases is the green tetrathiafulvalene chloranil polymorph and the mechanism of the redox reaction is presumably the same. However, while the kinetic profile of the neat mechanochemical synthesis was fitted with a second-order rate law, that of the overall faster liquid-assisted grinding reaction was fitted with the Ginstling-Brounshtein 3D diffusion-controlled model. Hence, the diffusional processes and mass transfer bringing the reactants together and separating them from products must be different. Diffraction measurements sensitive to crystalline phases and amorphous material, combined with in situ monitoring by spectroscopic techniques, will ultimately afford a better understanding of mechanochemical reaction mechanisms, a hot topic in mechanochemistry.

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39

Silverman, D. C. "Dimensionless Groups in the Modeling and Prediction of Corrosion Processes." Corrosion 41, no. 12 (December 1, 1985): 679–87. http://dx.doi.org/10.5006/1.3583003.

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Abstract Coupled differential equations that are difficult to solve, yet have predictive value, will arise when modeling a combination of general and localized corrosion in the presence of flow. These equations are impossible to solve if the flow is turbulent. By making the equations dimensionless, certain groups arise that can show the relative magnitudes of the processes involved. Three dimensionless groups arise from modeling the localized area. These show the ratios of the magnitudes of migration to diffusion, convective mass transport to diffusive mass transport, and surface reaction rate to mass transfer rate. The meanings of the groups are independent of geometry and flow conditions. These groups can provide a “back-of-the-envelope” type of guidance for experimental design and corrosion prediction even though the equations from which they are derived cannot be solved.

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40

Vlaev, Serafim D., and Jindřich Zahradník. "Energy effectiveness and working characteristics of different tower reactors for aerated slurry systems." Collection of Czechoslovak Chemical Communications 52, no. 11 (1987): 2624–39. http://dx.doi.org/10.1135/cccc19872624.

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Decisive hydrodynamic and mass transfer characteristics of different types of tower reactors (rotating disc reactor, single and multistage sieve-tray bubble columns, tower reactor with ejector gas distributor) as well as the energy effectiveness of their performance were compared with the purpose to establish a quantitative basis for the qualified choice of the proper reactor type according to demands of specific reaction processes. Selected design parameters included gas and solid phase holdup, kLaL, liquid phase residence time distribution, and axial distribution of the solid phase, the experiments were carried out in a wide range of solid phase concentration (0-20 wt. %) and particle sizes (2.3-280 μm). The experimental results proved that due to their favourable suspension characteristics and operation stability the rotating disc reactors can be advantageously used for slow reaction processes with low demands on the intensity of interfacial gas-liquid contact which can be carried out at low gas flow rates. On the other hand the multistage bubble column reactors proved to be superior devices for transport–controlled reaction processes regarding both the achievable rate of interfacial mass transfer and the overall energetic efficiency of phase contacting.

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41

Kalkal, S., S. Mandal, N. Madhavan, A. Jhingan, S. Nath, E. Prasad, Rohit Sandal, et al. "Ground state and excited state multinucleon transfer channels in interactions of 28Si with 90,94Zr in near barrier region." International Journal of Modern Physics E 30, no. 06 (June 2021): 2150053. http://dx.doi.org/10.1142/s0218301321500531.

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Multinucleon transfer reactions were measured in interactions of 28Si with 90,94Zr at a near barrier energy using recoil mass separator, Heavy Ion Reaction Analyzer (HIRA) at Inter University Accelerator Centre (IUAC), New Delhi. The effects of shell closure, positive Q-value transfer channels on the relative strengths of ground state and excited state transfer in multinucleon transfer processes were investigated. The kinematic coincidence technique was employed to reduce the background. The m/q ambiguity was resolved by time of flight (TOF) technique. Based on the Q-value considerations, it was observed that pickup channels were predominantly of neutron transfer, whereas, stripping channels were mainly of proton transfer. A 14-element BGO array was used to extract the relative strength of excited state transfer. In interactions of 28Si with 90Zr, it was observed that the ground state and excited states competes for populating all the transfer channels. In reactions of 28Si with 94Zr, nearly similar behavior was observed except for two-neutron pickup channel, where excited state transfer was dominant and four-neutron pickup channel where ground state transfer was dominant.

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42

Antoniotti, Paola, Lorenza Operti, Roberto Rabezzana, Francesca Turco, Stefano Borocci, and Felice Grandinetti. "Positive Ion Chemistry of SiH4/NF3 Gaseous Mixtures Studied by Ion Trap Mass Spectrometry." European Journal of Mass Spectrometry 15, no. 2 (April 2009): 209–20. http://dx.doi.org/10.1255/ejms.950.

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The positive ion chemistry occurring in silane/nitrogen trifluoride gaseous mixtures has been investigated by ion trap mass spectrometry. Reaction sequences and rate constants have been determined for the processes involving the primary ions SiH n+ ( n = 0–3) and NF x+ ( x = 1–3) and the secondary ions obtained from their reactions with SiH4 and NF3. The SiH n+ efficiently react with NF3 and undergo cascades of abstraction and scrambling reactions which form the fluorinated and perfluorinated cations SiHF m+ ( m = 1, 2), SiH2F+ and SiF x+ ( x = 1–3). Fluorinated Si2-clusters such as Si2H2F+, Si2H3F+ and Si2H5F+ were also observed. The reaction of both SiH3+ and SiH2F+ with NF3 produces the elusive fluoronitrenium ion NHF+. Any NF x+ reacts with SiH4 mainly by charge transfer. Additional ionic products are, however, observed which suggest intimate reaction complexes. Worth mentioning is the formation of SiNH2+ from the reaction of both NF+ and NHF+ with SiH4. The primary ions NF2+ and SiH3+ are also “sink” species in our observed chemistry.

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43

Pohorecki, Ryszard, E. Molga, and W. Moniuk. "Heat and Mass Transfer During Gas Absorption with Simultaneous Second-Order Chemical Reaction." Heat Transfer Research 38, no. 4 (2007): 339–49. http://dx.doi.org/10.1615/heattransres.v38.i4.50.

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44

Zhu, Chunying, Yutao Lu, Taotao Fu, Youguang Ma, and Huai Z. Li. "Experimental investigation on gas-liquid mass transfer with fast chemical reaction in microchannel." International Journal of Heat and Mass Transfer 114 (November 2017): 83–89. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2017.06.054.

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45

Sharma, Himanshu, Nadapana Vasu, and Sirshendu De. "Mass transfer during catalytic reaction in electroosmotically driven flow in a channel microreactor." Heat and Mass Transfer 47, no. 5 (December 14, 2010): 541–50. http://dx.doi.org/10.1007/s00231-010-0743-y.

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46

Sieniutycz, Stanisław. "Thermodynamic Structure of Nonlinear Macrokinetics in Reaction-Diffusion Systems." Open Systems & Information Dynamics 11, no. 02 (June 2004): 185–202. http://dx.doi.org/10.1023/b:opsy.0000034196.56929.71.

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Affinity picture — new for transport phenomena — and the traditional Onsagerian picture are shown to constitute two equivalent representations for kinetics of chemical reactions and transfer processes. Two competing directions in elementary chemical or transport steps are analyzed. Nonequilibrium systems are described by equations of nonlinear kinetics of Marcelin-Kohnstamm-de Donder type that contain terms exponential with respect to the Planck potentials and temperature reciprocal. Simultaneously these equations are analytical expressions characterizing the transport of the substance or energy through the energy barrier. We regard kinetics of this sort as potential representations of a generalized law of mass action that includes the effect of transfer phenomena and external fields. We also consider physical consequences of these kinetics closely and far from equilibrium, and show how diverse processes can be described. In these developments we point out the significance of nonlinear symmetries and generalized affinity. Correspondence with the Onsager's theory is shown in the vicinity of thermodynamic equilibrium. Yet, the theory shows that far from equilibrium the rates of transport processes and chemical reactions cannot be determined uniquely in terms of their affinities because these rates depend on all state coordinates of the system.

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47

Jankowski, Mikolaj Jan, Raymond Olsen, Yngvar Thomassen, and Paal Molander. "Correction: The stability and generation pattern of thermally formed isocyanic acid (ICA) in air – potential and limitations of proton transfer reaction-mass spectrometry (PTR-MS) for real-time workroom atmosphere measurements." Environmental Science: Processes & Impacts 20, no. 2 (2018): 416. http://dx.doi.org/10.1039/c8em90007h.

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Анотація:

Correction for ‘The stability and generation pattern of thermally formed isocyanic acid (ICA) in air – potential and limitations of proton transfer reaction-mass spectrometry (PTR-MS) for real-time workroom atmosphere measurements’ by Mikolaj Jan Jankowski et al., Environ. Sci.: Processes Impacts, 2016, 18, 810–818.

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48

Vlasenko, A., A. M. Macdonald, S. J. Sjostedt, and J. P. D. Abbatt. "Formaldehyde measurements by Proton transfer reaction – Mass Spectrometry (PTR-MS): correction for humidity effects." Atmospheric Measurement Techniques 3, no. 4 (August 17, 2010): 1055–62. http://dx.doi.org/10.5194/amt-3-1055-2010.

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Abstract. Formaldehyde measurements can provide useful information about photochemical activity in ambient air, given that HCHO is formed via numerous oxidation processes. Proton transfer reaction mass spectrometry (PTR-MS) is an online technique that allows measurement of VOCs at the sub-ppbv level with good time resolution. PTR-MS quantification of HCHO is hampered by the humidity dependence of the instrument sensitivity, with higher humidity leading to loss of PTR-MS signal. In this study we present an analytical, first principles approach to correct the PTR-MS HCHO signal according to the concentration of water vapor in sampled air. The results of the correction are validated by comparison of the PTR-MS results to those from a Hantzsch fluorescence monitor which does not have the same humidity dependence. Results are presented for an intercomparison made during a field campaign in rural Ontario at Environment Canada's Centre for Atmospheric Research Experiments.

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49

Vlasenko, A., A. M. Macdonald, S. J. Sjostedt, and J. P. D. Abbatt. "Formaldehyde measurements by Proton Transfer Reaction – Mass Spectrometry (PTR-MS): correction for humidity effects." Atmospheric Measurement Techniques Discussions 3, no. 2 (March 15, 2010): 965–88. http://dx.doi.org/10.5194/amtd-3-965-2010.

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Анотація:

Abstract. Formaldehyde measurements can provide useful information about photochemical activity in ambient air, given that HCHO is formed via numerous oxidation processes. Proton transfer reaction mass spectrometry (PTR-MS) is an online technique that allows measurement of VOCs at the sub-ppbv level with good time resolution. PTR-MS quantification of HCHO is hampered by the humidity dependence of the instrument sensitivity, with higher humidity leading to loss of PTR-MS signal. In this study we present an analytical, first principles approach to correct the PTR-MS HCHO signal according to the concentration of water vapor in sampled air. The results of the correction are validated by comparison of the PTR-MS results to those from a Hantzsch fluorescence monitor which does not have the same humidity dependence. Results are presented for an intercomparison made during a field campaign in rural Ontario at Environment Canada's Centre for Atmospheric Research Experiments.

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50

Juncu, Gh. "The influence of the Henry number on the conjugate mass transfer from a sphere: II - mass transfer accompanied by a first-order chemical reaction." Heat and Mass Transfer 38, no. 6 (June 1, 2002): 523–34. http://dx.doi.org/10.1007/s002310100256.

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