Kinetic Treatment Research Articles

Frequent flaws encountered in the manuscripts of kinetic papers.

In the manuscripts dealing with thermoanalytical kinetics, many flaws, mistakes, and misconceptions are encountered repeatedly. In this paper, frequent flaws encountered in manuscript of kinetic papers are reviewed, mainly those originating in the false interpretation of the general rate equation, improper employment of integral isoconversional methods, conclusions drawn from the values of a single kinetic parameter, absence of error estimation and application of single-heating rate methods. Assessment of the quality of kinetic treatment is also noticed. Some experimental imperfections that could lead to incorrect values of kinetic parameters are mentioned.

Results of kinetotherapy in the treatment of scapulohumeral periarthritis

Scapulohumeral periarthritis is the affection that raises some of the most serious problems of functional recovery, as it is found in about 80% of the illnesses of the shoulder. This condition causes pain and movement restriction. Scapulohumeral periarthritis means any medical condition characterized by pain from painful inflammation of the soft parts around the shoulder articulation. The aim is to evaluate the systematic application of physiotherapeutic methods and procedures to restore diminished or lost functional capacity in patients diagnosed with scapulohumeral periarthritis. The evaluation of patients with scapulohumeral periarthritis was carried on within a complex recovery program, individualized, depending on the stage of affection, the age and gender of the patient, theorizing and stage of evolution of the disease. The kinetic treatment aimed to repel pain, to gain joint mobility, to gain strength, ability and stability.

Revealing Kinetics Process of Fast Charge‐Storage Behavior Associated with Potential in 2D Polyaniline

Clarifying the electrode kinetics and thermodynamic processes of 2D materials in electrochemical energy‐storage system becomes an important topic, especially for the system with complex and interlaced electrochemical processes. One single analytical method can hardly describe the diffusion‐controlled and interface‐reaction‐controlled process. Hence, the tungstate‐linked polyaniline, a novel 2D conductive polymer with obvious Faradaic reaction, is introduced, as the research object. Based on the multi‐scan rate cyclic voltammetry data, the applicable rules of different electrochemical kinetic treatment methods are proved effectively: the rate fitting equation based on theoretical capacitance calibration is more suitable to describe the kinetic behavior of interface‐reaction‐controlled process, while the power–law relationship based on the b value is more reasonable to study the diffusion‐controlled process. Moreover, the higher capacitance of the electrode materials in acidic electrolyte is emphasized via in situ electrochemical testing techniques. Proton intercalation and participating in the redox reaction can obviously accelerate the electrode process. The developed multidimensional assessment method is superior in more accurate analysis of the kinetics of electrochemical energy‐storage devices.

A Shock-Tube and Chemical Kinetics Model Investigation Encompassing all Five Pentene Isomers

Kinetic treatment of the full group of C5 olefins is presented with new measurements on 1-pentene (1-C5H10), 2-pentene (2-C5H10), and 3-Methyl-1-Butene (3M1B) combined with recently published data obtained at similar conditions from our group on 2-Methyl-2-Butene (2M2B) and 2-Methyl-1-Butene (2M1B). This extensive experimental database contains carbon monoxide and water time-history profiles, along with their measured CO and H2O induction delay times. The oxidation of the five pentene isomers was carried out at three equivalence ratios (0.5, 1.0, and 2.0) in mixtures highly diluted in 99.5% Helium-Argon. The experiments were performed for temperatures ranging from 1400 to 1900 K at near-atmospheric pressure. A unique comparison of the complete set of pentene isomers permits the understanding of the C=C double bond position and branching impacts on combustion properties, using the chemical kinetics mechanism of both linear and branched structures. The impact of the C = C double bond location – either the 1–2 or 2–3 bond site – is described using the linear molecules 1-C5H10 and 2-C5H10. Species induction delay times were measured for the five isomers for each equivalence ratio investigated. Results showed noticeable differences between isomers, with the induction delay time results for 3M1B being the shortest, closely followed by 2-C5H10, 1-C5H10, and then after a large leap in decreasing reactivity, by 2M2B and 2M1B. Numerical predictions using up to 9 models available in the literature were performed. An error score function was used to evaluate the properties of the pentene isomer models in the current literature.

Silk fibroin: a promising bio-material for the treatment of heavy metal-contaminated water, adsorption isotherms, kinetics, and mechanism.

Silk is the strongest natural biopolymer produced by silk worms possessing superior adsorbent properties and thus extensively used in various applications. The present study involved the preparation of powder form of a silk fibroin materials and their application in adsorption of heavy metals, particularly, iron from aqueous solution. The morphological and structural characteristic properties of this promising materialswere examined by using different analytical techniques. Batch experiments were conducted within feasible parametric ranges to understand the effect of dose, time, concentration, pH, and reusability. Silk fibroin was effective for iron adsorption over a wide range of pH 6 to 10. The adsorption removal efficiency of 98% was attained for removal of iron from contaminated water at moderate dose of 0.25g and contact time of 60min, which is unprecedented by considering the environment benign nature of the material. The data was examined in different isotherm models wherein it fitted best in Langmuir adsorption model. Similarly, Langmuir isotherm model, with R2 value of 0.984 and KL 0.412 and maximum adsorption capacity as 12.82mgg-1, suggests monolayer adsorption. Kinetic study with better R2 value of 0.941 represented the pseudo-second order kinetics governed by the chemisorption reaction. To understand the practical applicability of silk fibroin, the repeatability study up to 5 cycles were performed. The findings are very encouraging which confirmed the usage of silk fibroin as adsorbent for multiple cycles with marginal decrease in adsorption efficiency. Eventually, the material was tested for iron removal in real contaminated water which revealed its potential and selectivity for removal of iron in different matrix.

Kinetic and thermodynamic examinations for the unsteady couette flow problem of a plasma using the BGK cylindrical model

We aim to investigate the kinetic and irreversible thermodynamic treatment of the Couette flow of gaseous plasma (GP) confined between two coaxial rotating circular rigid cylinders. The Bhatnagar-Gross-Krook (BGK) model of the Boltzmann kinetic equation (BKE) is solved by applying the perturbation method coupled with the moments' approach with a two-stream Maxwellian distribution function (MDF). Nonlinear partial differential equations are precisely solved. As an actual application, we are considering the laboratory Argon GP. An interesting comparison between the non-equilibrium electron velocity distribution function (EVDF) and the equilibrium EVDF is made carefully with 3-Dimensional graphics in various time values. We found that the system goes to an equilibrium state (ES) with time compatible with Le Chatelier's principles. Moreover, we determined with very high precision the value of the system equilibrium time, which is tequ.≅2.4. That great advantage cannot be reached by solving other macroscopic magnetohydrodynamic models. The relations between the various macroscopic variables of the GP are studied. The irreversible non-equilibrium thermodynamics (NT) properties of the system are presented. We present the extended Gibbs equation (EGE) for the internal energy variation (IEV) in cylindrical geometry for GP for the first time, to the best of our knowledge. We have shown that our model is compatible with the H-theorem of Boltzmann and the Onsager-Casimir relations. The various participations in IEV are introduced. The significance of this search is due to its vast implementations in various fields, such as in GP physics, electrical engineering, medicine, biological systems, and numerous commercial and industrial deployments.

Histamine derived dimer of µ-Chlorido-µ-Phenoxido Dicopper(II) complex as a potential enzyme mimic with catecholase activity

A new copper(II) complex, [Cu2(L1)(µ-Cl)2]2 (C1), of the binucleating 2,6-bis((2-(4′-imidazolyl)ethyl)aminomethylidene)-4-methylphenol (HL1) with N4O binding sites, has been synthesized to investigate as potential structural and functional model for catecholase activity of the dicopper(II) site. It has been characterized by spectroscopic techniques and X-ray crystallography. The complex C1 exists as chlorido bridged dimer of binuclear copper(II) units, each possessing one end-off compartmental ligand (L1) with endogenous µ-phenoxido and exogenous µ-chlorido groups leading to intermetallic distance Cu1···Cu2 of 3.129 Å and Cu1-O1(phenoxo)-Cu2 angle of 107.67(10)o. Each copper(II) center has distorted octahedral geometry with bridging by chlorides in the tetranuclear dimer. The crystal system is monoclinc with space group P21/c. Magnetic measurements reveal that C1 is strongly antiferromagnetically coupled with J = − 115.663 ± 0.82547 cm−1. The catecholase activity of the complex has been evaluated by oxidation of 3,5-di(tert-butyl)catechol and 4-methyl catechol to the corresponding quinones under aerobic conditions. A kinetic treatment on the basis of the Michaelis-Menten model has been applied for the kinetic study. The complex is found to be selective for the substrates with higher Vmax = 8.2726x10−8 M s−1 and Km = 0.0107 M for 3,5-DTBC at 30 °C as compared to Vmax = 5.0371x10−8 M s−1 and Km = 0.027 M for 4-methyl catechol at 50 °C while it is found to be practically inactive for dopamine, 2,3-dihydroxy naphthalene and pyrocatechol oxidation.

On Kinetic and Irreversible Thermodynamic Treatments of a Rarefied Gaseous Plasma Bounded by a Moving Plate.

On Kinetic and Irreversible Thermodynamic Treatments of a Rarefied Gaseous Plasma Bounded by a Moving Plate.

Advanced spatially hybrid fluid‐kinetic modelling of plasma‐edge neutrals and application to ITER case using SOLPS‐ITER

AbstractA spatially hybrid fluid‐kinetic approach for the efficient simulation of plasma‐edge neutrals is extended with a kinetic‐fluid condensation process and an automated approach to select a fluid or kinetic treatment at each point along the divertor targets. With the proposed hybrid fluid‐kinetic methods, the dominant charge–exchange reaction can be largely removed from the kinetic neutral simulation. The hybrid methods achieve quantitative agreement with the standard kinetic approach, with relative errors on the peak target plasma density and peak target ion flux density of 5–30%, while the Central Processing Unit (CPU) time for the kinetic neutral solver is reduced by a factor 3–6.

Kinetic simulations of collision-less plasmas in open magnetic geometries *

Laboratory plasmas in open magnetic geometries can be found in many different applications such as (a) scrape-of-layer (SOL) and divertor regions in toroidal confinement fusion devices, (b) linear divertor simulators, (c) plasma-based thrusters and (d) magnetic mirrors etc. A common feature of these plasma systems is the need to resolve, in addition to velocity space, at least one physical dimension (e.g. along flux lines) to capture the relevant physics. In general, this requires a kinetic treatment. Fully kinetic particle-in-cell (PIC) simulations can be applied but at the expense of large computational effort. A common way to resolve this is to use a hybrid approach: kinetic ions and fluid electrons. In the present work, the development of a hybrid PIC computational tool suitable for open magnetic geometries is described which includes (a) the effect of non-uniform magnetic fields, (b) finite fully-absorbing boundaries for the particles and (c) volumetric particle sources. Analytical expressions for the momentum transport in the paraxial limit are presented with their underlying assumptions and are used to validate the results from the PIC simulations. A general method is described to construct discrete particle distribution functions in a state of mirror-equilibrium. This method is used to obtain the initial state for the PIC simulation. Collisionless simulations in a mirror geometry are performed. The results show that the effect of magnetic compression is correctly described and momentum is conserved. The self-consistent electric field is calculated and is shown to modify the ion velocity distribution function in a manner consistent with analytic theory. Based on this analysis, the ion distribution function is understood in terms of a loss-cone distribution and an isotropic Maxwell-Boltzmann distribution driven by a volumetric plasma source. Finally, the inclusion of a Monte Carlo based Fokker-Planck collision operator is discussed in the context of future work.

Understanding Ir(III) Photocatalyst Structure-Activity Relationships: A Highly Parallelized Study of Light-Driven Metal Reduction Processes.

High-throughput synthesis and screening methods were used to measure the photochemical activity of 1440 distinct heteroleptic [Ir(C^N)2(N^N)]+ complexes for the photoreduction of Sn(II) and Zn(II) cations to their corresponding neutral metals. Kinetic data collection was carried out using home-built photoreactors and measured initial rates, obtained through an automated fitting algorithm, spanned between 0-120 μM/s for Sn(0) deposition and 0-90 μM/s for Zn(0) deposition. Photochemical reactivity was compared to photophysical properties previously measured such as deaerated excited state lifetime and emission spectral data for these same complexes; however, no clear correlations among these features were observed. A formal photochemical rate law was then developed to help elucidate the observed reactivity. Initial rates were found to be directly correlated to the product of incident photon flux with three reaction elementary efficiencies: (1) the fraction of light absorbed by the photocatalyst, (2) the fraction of excited state species that are quenched by the electron donor, and (3) the cage escape efficiency. The most active catalysts exhibit high efficiencies for all three steps, and catalyst engineering requirements to maximize these elementary efficiencies were postulated. The kinetic treatment provided the mechanistic information needed to decipher the observed structure/function trends in the high-throughput work.

Effectiveness of Kinetic Oscillation Stimulation Treatment in Patients with Non-Allergic Rhinitis Refractory to Conventional Medical Therapies

1.1. Introduction: Kinetic Oscillation Stimulation (KOS) is a new treatment for symptoms of non-allergic rhinitis (NAR). The aim of the study was to investigate effectiveness of KOS treatment in patients affected by NAR. 1.2. Methods: From December 2018 to July 2020, 39 patients, already refractory to conventional medical therapy, were treated with KOS. As control group, we considered a group of 41 patients treated with topical mometasone furoate, observed in the same period and number of days. During the ENT visit, objective examinations were performed to assess respiratory function. In addition, all the subjects filled out quality of life (QoL) questionnaires. All patients were reevaluated after 45 days. 1.3. Results: All the instrumental assessments and QoL questionnaires showed a significant improvement 45 days after KOS treatment. Sixteen patients (43%) reported an improvement across all tests. Active anterior rhinomanometry improved for Inspiratory Resistance in 26 patients (70%) and for Expiratory Resistance for 27 patients (73%). Moreover, we found that KOS group presented a better improvement statistically significant for the QoL questionnaries, respect the control group. 1.4. Conclusion: KOS treatment is a safe and mini-invasive procedure for the treatment of NAR symptoms, well accepted from patients and with a promising improvement of QoL, better than conventional medical therapies.

The role of preoperative kinetic physical treatment in patients with complete rupture of the anterior cruciate ligament

AbstractIntroductionThe present research has highlighted the role of preoperative kinetic physical therapy in patients with complete rupture of the anterior cruciate ligament.Material and methodThe study took place at theFizionovaMedical Recovery Center in Târgu Mureș, for 12 weeks, between November 2020 and March 2021, on a sample of 20 subjects, aged between 21 and 45 years. The inclusion criterion was the anterior cruciate ligament reconstruction surgery. The research methods were largely experimental. Statistical analysis included elements of descriptive statistics (mean, median, standard deviation) and elements of inferential statistics. The Shapiro-Wilk test was applied to determine the distribution of the analyzed data series. For the comparison of means, the t-Student test for unpaired data was applied. For the comparison of medians, the Mann-Whitney test was applied for unpaired data.ResultsThe experimental group regained its knee flexion degrees earlier than the control group following the preoperative kinetic physical treatment.ConclusionOur investigation concluded that immediate postoperative recovery has significant importance on the knee’s functionality, which is much more challenging to recover in case of prolonged immobilization.

Universal kinetics of imperfect reactions in confinement

Chemical reactions generically require that particles come into contact. In practice, reaction is often imperfect and can necessitate multiple random encounters between reactants. In confined geometries, despite notable recent advances, there is to date no general analytical treatment of such imperfect transport-limited reaction kinetics. Here, we determine the kinetics of imperfect reactions in confining domains for any diffusive or anomalously diffusive Markovian transport process, and for different models of imperfect reactivity. We show that the full distribution of reaction times is obtained in the large confining volume limit from the knowledge of the mean reaction time only, which we determine explicitly. This distribution for imperfect reactions is found to be identical to that of perfect reactions upon an appropriate rescaling of parameters, which highlights the robustness of our results. Strikingly, this holds true even in the regime of low reactivity where the mean reaction time is independent of the transport process, and can lead to large fluctuations of the reaction time - even in simple reaction schemes. We illustrate our results for normal diffusion in domains of generic shape, and for anomalous diffusion in complex environments, where our predictions are confirmed by numerical simulations.

Modelling electrocatalytic reactions with a concerted treatment of multistep electron transfer kinetics and local reaction conditions

A physicochemical model is developed for electrocatalytic reactions involving multiple electron transfer steps occurring in the electric double layer (EDL). The local reaction conditions are calculated using a mean-field EDL model, which is derived from a comprehensive grand potential that considers the steric effects, solvent polarization, and chemisorption-induced surface dipoles. Macroscopic mass transport in the so-called diffusion layer is controlled by the same set of controlling equations of the EDL model, without imposing the electroneutrality assumption as usual. The Gerischer’s formulation of electron transfer theory, corrected with local reaction conditions, is used to describe the kinetics of elementary steps. Multistep kinetics of the electrocatalytic reaction is treated using microkinetics modelling, without resorting to the usual rate-determining step approximation. In formal analysis of the model, we retrieve canonical models with additional assumptions. Self-consistent numerical implementation of the model is demonstrated for oxygen reduction reaction (ORR) at Pt(111) in acidic solution, and the aptness of the model is verified by comparison with experimental data. A comparative study of the full model and its simplified versions allows us to examine how the ORR is influenced by asymmetric steric effects, finite concentration of ions, solvent polarization, surface charge effects, and metal electronic structure effects. We find that the difference in terms of the overpotential between the full model and the simplest model can be up to ∼0.1 V at a current density of −6 mA .

Application of kinesiotherapy in knee meniscectomy

Rehabilitation of a patient with knee meniscectomy is a team effort, in which the kinesiotherapist has a special role, because exercise is the only therapeutic way to restore joint function. Kinetic treatment at the knee involves restoring the functionality of this segment, under conditions of muscle strength, stability and mobility controlled at this level, with the prevention of complications and increased quality of life. As a result, the treatment must be started early and performed according to the principle of its individualization. Kinesiotherapy through its specific means, methods and working techniques, offers us an excellent opportunity to improve joint function, reducing, reducing or eliminating pain and improving the patient's quality of life.

Situating the Vector Density Approach Among Contemporary Continuum Theories of Dislocation Dynamics

Abstract For the past century, dislocations have been understood to be the carriers of plastic deformation in crystalline solids. However, their collective behavior is still poorly understood. Progress in understanding the collective behavior of dislocations has primarily come in one of two modes: the simulation of systems of interacting discrete dislocations and the treatment of density measures of varying complexity that are considered as continuum fields. A summary of contemporary models of continuum dislocation dynamics is presented. These include, in order of complexity, the two-dimensional statistical theory of dislocations, the field dislocation mechanics treating the total Kröner–Nye tensor, vector density approaches that treat geometrically necessary dislocations on each slip system of a crystal, and high-order theories that examine the effect of dislocation curvature and distribution over orientation. Each of theories contain common themes, including statistical closure of the kinetic dislocation transport equations and treatment of dislocation reactions such as junction formation. An emphasis is placed on how these common themes rely on closure relations obtained by analysis of discrete dislocation dynamics experiments. The outlook of these various continuum theories of dislocation motion is then discussed.

Cosmic “adiabatic” photon creation: Temperature law and blackbody spectrum

The temperature-redshift relation (cosmic thermometer) is rediscussed in the framework of gravitationally induced photon production in the expanding universe. It is found that the same extended temperature law can be derived based on three independent methods, namely: (i) through a simple heuristic approach, (ii) based on macroscopic irreversible thermodynamics with photon creation, and (iii) using a kinetic relativistic Boltzmann equation incorporating gravitational photon creation. All these methods yield the same answer. The modified kinetic treatment reveals not only that the Planckian blackbody spectrum endowed with the “adiabatic” creation is preserved in the course of the expansion but also that CMB anisotropies and distortions can be treated properly. The new cosmic thermometer suggests a crucial test to the standard cosmic concordance model in the thermal sector. It is also argued that the present results may open a new route for scrutinising the H0 Supernovae-CMB tension challenging the ΛCDM model.

Elevated-temperature Deformation Mechanisms in a CrMnFeCoNi High-Entropy Alloy

Stress reduction creep experiments were performed on a CrMnFeCoNi high-entropy alloy at 1073 K to characterize the steady-state and transient creep properties of this material. From measurements of constant-structure creep, the activation area for deformation of CrMnFeCoNi was determined to be ∼100 b2 and to decrease with increasing applied stress, indicating the presence of both concentrated solid solution and forest dislocation control of high temperature plastic deformation. With the aid of a recent solid solution theory for high entropy alloys, quantitative separation of the two mechanisms was carried out using a Haasen plot and the results show that creep in CrMnFeCoNi relies heavily on thermal activation with the majority of creep strength coming from solid solution hardening, especially at low applied stresses. The overall analysis conducted in this study reveals that steady-state creep deformation of CrMnFeCoNi at 1073 K can be adequately described by existing concentrated solid solution hardening models and forest dislocation hardening models. This observation suggests it may be possible to develop a unified treatment of the dislocation glide kinetics for this alloy from cryogenic to elevated temperatures.

Modeling and Experimental Study of the Electron Transfer Kinetics for Non-ideal Electrodes Using Variable-Frequency Square Wave Voltammetry.

The knowledge of nonequilibrium electron transfer rates is paramount for the design of modern hybrid electrocatalysts. Herein, we propose a general simulation-based approach to interpret variable-frequency square wave voltammetry (VF-SWV) for heterogeneous materials featuring reversible redox behavior. The resistive and capacitive corrections, inclusion of the frequency domain, and statistical treatment of the surface redox kinetics are used to account for the non-ideal nature of electrodes. This approach has been validated in our study of CoII/CoI redox transformation for Co tetraphenylporphyrin (CoTPP) immobilized on carbon cloth and multiwalled carbon nanotubes (CNTs) - one of the most active heterogeneous molecular catalysts in carbon dioxide (CO2) electroreduction. It is demonstrated that the modeling of experimental data furnishes the capacitance of the surface double layer C, uncompensated resistance Ru, symmetry coefficients α, kinetic constants k0, and equilibrium redox potentials E0 in one experiment. Moreover, the proposed method yields a stochastic map of the redox kinetics rather than a single value, thus exposing the inhomogeneous nature of the electrochemically active layer. The computed parameters are in excellent agreement with the results of the classic methods such as cyclic voltammetry and fall in line with the reported CoTPP catalytic activity. Thus, VF-SWV is suitable for the study of high-level composites such as covalent organic frameworks and organometallic-CNT mixtures. The resulting insights into the electron transfer mechanisms are especially useful for the rational development of the catalyst-support interfaces and immobilization methods.