Co-pyrolysis of Sewage Sludge with Distillation Residue: Kinetics Analysis via Iso-conversional Methods

This study explored the synergistic interaction of sewage sludge(SS)and distillation residue(DR)during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems,utilizing thermogravimetric analysis(TGA)and thermogravimetric analysis with mass spectrometry(TGA-MS).The results reveal the coexisting synergistic and antagonistic effects in the co-pyrolysis of SS/DR.The synergistic effect arises from hydrogen free radicals in SS and catalytic components in ash fractions,while the antagonistic effect is mainly due to the melting of DR on the surface of SS particles during pyrolysis and the reaction of SS ash with alkali metals to form inert substances.SS/DR co-pyrolysis reduces the yielding of coke and gas while increasing tar production.This study will promote the reduction,recycling,and harmless treatment of hazardous solid waste.

Biomass Carbon Improves the Adsorption Performance of Gangue-Based Ceramsites:Adsorption Kinetics and Mechanism Analysis

The large accumulation of coal gangue,a common industrial solid waste,causes severe environmental problems,and green development strategies are required to transform this waste into high-value-added products.In this study,low-cost ceramsites adsorbents were prepared from waste gangue,silt coal,and peanut shells and applied to remove the organic dye methylene blue from wastewater.We investigated the microstructure of ceramsites and the effects of the sintering atmosphere,sintering temperature,and solution pH on their adsorption performance.The ceramsites sintered at 800℃under a nitrogen atmosphere exhibited the largest three-dimensional-interconnected hierarchical porous structure among the prepared ceramsites;further,it exhibited the highest methylene blue adsorption performance,with an adsorption capacity of 0.954 mg·g^(−1),adsorption efficiency of over 95%,and adsorption equilibrium time of 1 h at a solution pH of 9.The removal efficiency remained greater than 75%after five adsorption cycles.The adsorption kinetics data were analyzed using various models,including the pseudosecond-order kinetic model and Langmuir equation,and the adsorption was attributed to electrostatic interactions between the dyes and ceramsites,n-interactions,and hydrogen bonds.The prepared coal gangue ceramsites exhibited excellent adsorption capacities,removal rates,and cyclic stabilities,demonstrating their promising application prospects for the comprehensive utilization of solid waste and for wastewater treatment.

Kinetics analysis of decomposition of vanadium slag by KOH sub-molten salt method

A novel process was developed for the decomposition of vanadium slag using KOH sub-molten salt under ambient pressure, and the effects of reaction temperature, alkali-to-ore mass ratios, particle size, and stirring speed on vanadium and chromium extraction were studied. The results suggest that the reaction temperature and KOH-to-ore mass ratio are more influential factors for the extraction of vanadium and chromium. Under the optimal reaction conditions （temperature 180 °C, initial KOH-to-ore mass ratio 4：1, stirring speed 700 r/min, gas flow 1 L/min, and reaction time 300 min）, vanadium and chromium extraction rates can reach up to 95% and 90%, respectively. Kinetics analysis results show that the decomposing process of vanadium slag in KOH sub-molten salt can be well interpreted by the shrinking core model under internal diffusion control. The apparent activation energies for vanadium and chromium are 40.54 and 50.27 kJ/mol, respectively.

Dual-single-atoms of Pt-Co boost sulfur redox kinetics for ultrafast Li-S batteries

Applications of lithium-sulfur(Li-S)batteries are still limited by the sluggish conversion kinetics from polysulfide to Li_(2)S.Although various single-atom catalysts are available for improving the conversion kinetics,the sulfur redox kinetics for Li-S batteries is still not ultrafast.Herein,in this work,a catalyst with dual-single-atom Pt-Co embedded in N-doped carbon nanotubes(Pt&Co@NCNT)was proposed by the atomic layer deposition method to suppress the shuttle effect and synergistically improve the interconversion kinetics from polysulfides to Li_(2)S.The X-ray absorption near edge curves indicated the reversible conversion of Li_(2)Sx on the S/Pt&Co@NCNT electrode.Meanwhile,density functional theory demonstrated that the Pt&Co@NCNT promoted the free energy of the phase transition of sulfur species and reduced the oxidative decomposition energy of Li_(2)S.As a result,the batteries assembled with S/Pt&Co@NCNT electrodes exhibited a high capacity retention of 80%at 100 cycles at a current density of 1.3 mA cm^(−2)(S loading:2.5 mg cm^(−2)).More importantly,an excellent rate performance was achieved with a high capacity of 822.1 mAh g^(−1) at a high current density of 12.7 mA cm^(−2).This work opens a new direction to boost the sulfur redox kinetics for ultrafast Li-S batteries.

Growth kinetics of titanium carbide coating by molten salt synthesis process on graphite sheet surface

The synthesis of carbide coatings on graphite substrates using molten salt synthesis(MSS),has garnered significant interest due to its cost-effective nature.This study investigates the reaction process and growth kinetics involved in MSS,shedding light on key aspects of the process.The involvement of Ti powder through liquid-phase mass transfer is revealed,where the diffusion distance and quantity of Ti powder play a crucial role in determining the reaction rate by influencing the C content gradient on both sides of the carbide.Furthermore,the growth kinetics of the carbide coating are predominantly governed by the diffusion behavior of C within the carbide layer,rather than the chemical reaction rate.To analyze the kinetics,the thickness of the carbide layer is measured with respect to heat treatment time and temperature,unveiling a parabolic relationship within the temperature range of 700-1300℃.The estimated activation energy for the reaction is determined to be 179283 J·mol^(-1).These findings offer valuable insights into the synthesis of carbide coatings via MSS,facilitating their optimization and enhancing our understanding of their growth mechanisms and properties for various applications.

A comparative study on kinetics and dynamics of two dump truck lifting mechanisms using MATLAB simscape

In this paper,two lifting mechanism models with opposing placements,which use the same hydraulic hoist model and have the same angle of 50°,have been developed.The mechanical and hydraulic simulation models are established using MATLAB Simscape to analyze their kinetics and dynamics in the lifting and holding stages.The simulation findings are compared to the analytical calculation results in the steady state,and both methods show good agreement.In the early lifting stage,Model 1 produces greater force and discharges goods in the container faster than Model 2.Meanwhile,Model 2 reaches a higher force and ejects goods from the container cleaner than its counterpart at the end lifting stage.The established simulation models can consider the effects of dynamic loads due to inertial moments and forces generated during the system operation.It is crucial in studying,designing,and optimizing the structure of hydraulic-mechanical systems.

Capparis spinosa L waste activated carbon as an efficient adsorbent for crystal violet toxic dye removal: Modeling, optimization by experimental design, and ecological analysis

Textile dyes are dramatic sources of pollution and non-aesthetic disturbance of aquatic life and therefore represent a potential risk of bioaccumulation that can affect living species.It is imperative to reduce or eliminate these dyes from liquid effluents with innovative biomaterials and methods.Therefore,this research aims to highlight the performance of Capparis spinosa L waste-activated carbon(CSLW-AC)adsorbent to remove crystal violet(CV)from an aqueous solution.The mechanism of CV adsorption on CSLW-AC was evaluated based on the coupling of experimental data and different characterization techniques.The efficiency of the CSLW-AC material reflected by the equilibrium adsorption capacity of CV could reach more than 195.671 mg·g^(–1) when 0.5 g·L^(–1) of CSLW-AC(Particle size≤250μm)is introduced into the CV of initial concentration of 100 mg·L^(–1) at pH 6 and temperature 65℃ and in the presence of potassium ions after 60 min of contact time according to the one parameter at a time studies.The adsorption behavior of CV on CSLW-AC was found to be consistent with the pseudo-second-order kinetic model and Frumkin's linear isothermal model.The thermodynamic aspects indicate that the process is physical,spontaneous,and endothermic.The optimization of the process by the Box Behnken design of experiments resulted in an adsorption capacity approaching 183.544 mg·g^(–1)([CV]=100 mg·L^(–1) and[CSLW-AC]=0.5 g·L^(–1) at 35 min).The results of the Lactuca sativa seeds germination in treated CV(70%),adsorbent solvent and thermal regeneration(more than 5 cycles),and process cost analysis(1.0484 USD·L^(–1))tests are encouraging and promising for future exploitations of the CSLW-AC material in different industrial fields.

Effect of trace calcium on melting behavior of Ag-Cu-Zn brazing alloy by thermal analysis kinetics

The purity of the brazing alloys applied is necessary to be improved with the increasing cleanness of steel. Calcium is easily brought into the widely ased brazing alloy, Ag-Cu-Zn, during the producing process. This paper aims at revealing the effect of calcium on the melting behavior of the brazing alloy. The thermal analysis kinetics of silver alloy with trace calcium was studied by using differential scanning calorimetry （ DSC ） , and the enthalpy peaks were analyzed by differential methods. The rate constant of phase transformation in the probable brazing temperature range goes up with increasing calcium content, according to the values of the apparent activation energy, E, and the frequeney constant, A. It is concluded that the calcium addition could improve the melting performance of Ag-Cu-Zn brazing alloy.

Pyrolysis and combustion kinetics of lycopodium particles in thermogravimetric analysis

Biomass is a kind of renewable energy which is used increasingly in different types of combustion systems or in the production of fuels like bio-oil. Lycopodium is a cellulosic particle, with good combustion properties, of which microscopic images show that these particles have spherical shapes with identical diameters of 31 μm. The measured density of these particles is 1.0779 g/cm2. Lycopodium particles contain 64.06% carbon, 25.56% oxygen, 8.55% hydrogen and 1.83% nitrogen, and no sulfur. Thermogravimetric analysis in the nitrogen environment indicates that the maximum of particle mass reduction occurs in the temperature range of 250-550 ℃ where the maximum mass reduction in the DTG diagrams also occurs in. In the oxygen environment, an additional peak can also be observed in the temperature range of 500-600 ℃, which points to solid phase combustion and ignition temperature of lycopodium particles. The kinetics of reactions is determined by curve fitting and minimization of error.

Kinetics Analysis for the Parallel Reaction of Binary Rare Earth with Tribromoarsenazo

The overall reaction was determined on the basis of the dissociation constant of TBA and the ratio of the ligand to the rare earth ion in the complex.The rate law,rate constants and acitivition energies for the reaction of La^(3+),Gd^(3+)and Ho^(3+)with TBA were studied.It is shown in the study that prerequisites for performing differential rate analysis for binary rare earths with TBA are that the pseudo-first-order parallel reaction mechanism should be conformed with,no multinuclear complex would be formed and the co-coloration effects could be neglected.

Preliminary analysis of reactivity reconstruction capability based on inverse kinetics method under different initial reactivity states

Online reactivity monitoring plays an important role in operation and safety analyses of fission reactor systems. The inverse kinetics method, which is based on a point kinetics model, is the most widely used method for reactivity reconstruction of critical water reactors. However, this method is seldom applied to the reactivity reconstruction of subcritical reactors. In this study, an inverse kinetics method was employed for the reactivity reconstruction of a lead-based reactor under different initial reactivity states(ρ_0= 0,-2786,-5486,-8367, and-12,371 pcm). The results showed that the deviation in the reactivity of the lead-based subcritical reactor was greater when ρ_0 became smaller. The reactivity reconstructed using the inverse kinetics method was globally underestimated. At a given reactivity perturbation, the relative and absolute errors increased with the decrease in the initial reactivity. At a given initial reactivity, with the increase in the reactivity perturbation, the absolute error increased, whereas the relative error remained the same.This deviation is due to the variation in the external neutron source, spatial-spectral effects, and sub-diffusive effects, which require further study.

A tool model for predicting atmospheric chemical kinetics with sensitivity analysis

A package(a tool model) for program of predicting atmospheric chemical kinetics with sensitivity analysis is presented. The new direct method of calculating the first order sensitivity coefficients using sparse matrix technology to chemical kinetics is included in the tool model, it is only necessary to triangularize the matrix related to the Jacobian matrix of the model equation. The Gear type procedure is used to integrate a model equation and its coupled auxiliary sensitivity coefficient equations. The FORTRAN subroutines of the model equation, the sensitivity coefficient equations, and their Jacobian analytical expressions are generated automatically from a chemical mechanism. The kinetic representation for the model equation and its sensitivity coefficient equations, and their Jacobian matrix is presented. Various FORTRAN subroutines in packages, such as SLODE, modified MA28, Gear package, with which the program runs in conjunction are recommended. The photo\|oxidation of dimethyl disulfide is used for illustration.

The Use of Image Analysis to Simulate Growth Kinetics of Ferrite by Carbon Diffusion in SG Cast Iron

1.IntroductionThe use of the Quantimet 900 imageanalysis system to simulate the growth kine-tics of ferrite by carbon diffusion inspheroidal graphite(SG)cast iron has beendiscussed[1].The results obtained from theQ900 agreed qualitatively with experiment.

Study on Differential Rate Kinetics Analysis Based on the Substitution Reaction of Rare Earth-PHA with CyDTA

The kinetic behaviours of the substitution reaction of rare earth-PHA with CyDTA were studied systemati- cally.The relationship between the rate constant and atomic number was discussed.The rate differentiation val- ue R_d(R_d=lgk_(z+n)-lgk_z)was proposed to evaluate the possibility of differential kinetic analysis.The R_d value between the neighbouring lanthanide ions first increases and then decreases along with increasing atomic number, so that the middle and heavy rare earth mixture(such as Sm-Gd and Gd-Y)are ideal systems for the differential rate kinetic analysis.

A Chemical Kinetics Perspective on the High-Temperature Oxidation of Methane and Propane through Experiments and Kinetic Analysis

In the conversion of methane and propane under high temperature and pressure,the ignition delay time(IDT)is a key parameter to consider for designing an inherently safe process.In this study,the IDT characteristics of methane and propane(700–1000 K,10–20 bar)were studied experimentally and using kinetic modeling tools at stoichiometric fuel-tooxygen ratios.All the experiments were conducted through insentropic compression.The reliable experimental data were obtained by using the adiabatic core hypothesis,which can be used to generate and validate the detailed chemical kinetics model.The IDTs of methane and propane were recorded by a rapid compression machine(RCM)and compared to the predicted values obtained by the NUIGMech 3.0 mechanism.To test the applicability of NUIGMech 3.0 under different reaction conditions,the influence of temperature in the range of 700–1000 K(and the influence of pressure in the range of 10–20 bar)on the IDT was studied.The results showed that NUIGMech 3.0 could reasonably reproduce the experimentally determined IDT under the wide range of conditions studied.The constant volume chemical kinetics model was used to reveal the effect of temperature on the elementary reaction,and the negative temperature coefficient(NTC)behavior of propane was also observed at 20 bar.The experimental data can serve as a reference for the correction and application of kinetic data,as well as provide a theoretical basis for the safe conversion of low-carbon hydrocarbon chemicals.

Theoretical Analysis of the Kinetics Electron Transport at Solid/Solid Processes

The kinetics of electron transmission at solid/solid interface system are investigation and studied using a simple model that derives depending on the quantum consideration. A two quantum state for donor state ｜αn 〉 and acceptor state ｜αA 〉 are supposed. Marcus-Hush semi classical continuum levels theory adapted to evaluated the energies for orientation before transfer. The probability of transmission of electron is calculated to investigation the kinetics of transfer. Our result for calculation of rate constant of electron transfer shows a good agreement with experiment data.

Non-isothermal kinetic analysis of thermal dehydration of La_2(CO_3)_3·3.4H_2O in air

The single phase La2（CO3）3·3.4H2 O was synthesized by hydrothermal method. The thermal decomposition and intermediates and final solid products of La2（CO3）3·3.4H2O from 30 to 1000 °C were characterized by XRD, FTIR and DTA-TG. The kinetics of dehydration of La2（CO3）3·3.4H2O in the temperature range of 30-366 °C was investigated under non-isothermal conditions. Flynn-Wall-Ozawa and Friedman isoconversion methods were used to calculate the activation energy and analyze the reaction steps; multivariate non-linear regression program was applied to determine the most probable mechanism and the kinetic parameters. The results show that the thermal dehydration of La2（CO3）3·3.4H2O is a kind of three-step competitive reaction, and controlled by an n-order initial reaction followed by n-order competitive reaction（FnFnFn model）. The activation energy matching with the most probable model is close to value obtained by Friedman method. The fitting curves match the original TG-DTG curves very well.

DISPLACEMENT CONTROL AND KINETIC ANALYSIS OF A NOVEL VARIABLE DISPLACEMENT COMPRESSOR FOR AUTOMOTIVE AIR CONDITIONER

A novel variable displacement compressor (VDC) for automotive air conditioner (AAC) is introduced, which inherits the advantages of common wobble plate type VDC. It has fewer parts and makes less noise, and instead of pneumatic valve the displacement is controlled by electronic control valve. In order to know the control mechanism well and get a good control effect, a mathematical model for the variable displacement mechanism is developed according to the geometrical and kinematical information of the compressor. Using the model, the effect of relevant parameters on variable displace control is estimated. It is helpful to make the optimum decision in the flow control of AAC. As the novel displacement control device, the structure and control rule of electronic control valve is introduced. It can get better effect than the conventional pneumatic valves. And by using this new electronic control device, the optimum systemic control of AAC is available.

Efficient Gait Analysis Using Deep Learning Techniques

Human Activity Recognition(HAR)has always been a difficult task to tackle.It is mainly used in security surveillance,human-computer interaction,and health care as an assistive or diagnostic technology in combination with other technologies such as the Internet of Things(IoT).Human Activity Recognition data can be recorded with the help of sensors,images,or smartphones.Recognizing daily routine-based human activities such as walking,standing,sitting,etc.,could be a difficult statistical task to classify into categories and hence 2-dimensional Convolutional Neural Network(2D CNN)MODEL,Long Short Term Memory(LSTM)Model,Bidirectional long short-term memory(Bi-LSTM)are used for the classification.It has been demonstrated that recognizing the daily routine-based on human activities can be extremely accurate,with almost all activities accurately getting recognized over 90%of the time.Furthermore,because all the examples are generated from only 20 s of data,these actions can be recognised fast.Apart from classification,the work extended to verify and investigate the need for wearable sensing devices in individually walking patients with Cerebral Palsy(CP)for the evaluation of chosen Spatio-temporal features based on 3D foot trajectory.Case-control research was conducted with 35 persons with CP ranging in weight from 25 to 65 kg.Optical Motion Capture(OMC)equipment was used as the referral method to assess the functionality and quality of the foot-worn device.The average accuracy±precision for stride length,cadence,and step length was 3.5±4.3,4.1±3.8,and 0.6±2.7 cm respectively.For cadence,stride length,swing,and step length,people with CP had considerably high inter-stride variables.Foot-worn sensing devices made it easier to examine Gait Spatio-temporal data even without a laboratory set up with high accuracy and precision about gait abnormalities in people who have CP during linear walking.

Kinetic Model and Simulation Analysis for Toluene Disproportionation and C9-Aromatics Transalkylation

A new kinetic model for commercial unit of toluene disproportionation and C9-armatiocs transalkylation is developed based on the reported reaction scheme.A time based catalyst deactivation function taking weight hourly space velocity(WHSV)into account is incorporated into the model,which reasonably accounts for the loss in activity because of coke deposition on the surface of catalyst during long-term operation.The kinetic parameters are benchmarked with several sets of balanced plant data and estimated by the differential variable metric optimiza- tion method.Sets of plant data at different operating conditions are applied to make sure validation of the model and the results show a good agreement between the model predictions and plant observations.The simulation analysis of key variables such as temperature and WHSV affecting process performance is discussed in detail,giv- ing the guidance to select suitable operating conditions.