2,4(5)-Dinitroimidazole(2,4(5)-DNI)is an important organic intermediate,and itself can also be used for energetic material.In this work,the solubility of 2,4(5)-DNI in(methanol+water,acetonitrile+water,acetone+water)b...2,4(5)-Dinitroimidazole(2,4(5)-DNI)is an important organic intermediate,and itself can also be used for energetic material.In this work,the solubility of 2,4(5)-DNI in(methanol+water,acetonitrile+water,acetone+water)binary solvents were measured by using a dynamic test method from 278.15 K to 323.15 K under 101.1 k Pa.The Jouyban–Acree model,van't Hoff–Jouyban–Acree model,Apelblat–Jouyb an–Acree model,Ma model,and Sun model were used to correlate the experimental data.The values of relative average deviation(RAD)and root-mean-square deviation(RMSD)were very small,indicating that the error between the experimental value and the correlated value was very small.The thermodynamic parameters such as dissolution enthalpy,dissolution entropy and Gibbs energy were calculated based on solubility data.High-purity of 2,4(5)-DNI was efficiently obtained by using cooling and dilution crystallization method.展开更多
Herein,iron oxide/hydroxides deposits(gossans)were utilized,for the first time,in the fabrication of magnetite nanoparticles(MNPs)to load modified coal(MC).The as-synthesized MNPs@MC composite was characterized via di...Herein,iron oxide/hydroxides deposits(gossans)were utilized,for the first time,in the fabrication of magnetite nanoparticles(MNPs)to load modified coal(MC).The as-synthesized MNPs@MC composite was characterized via different techniques and utilized for the Cr(Ⅵ)remediation.Experimental studies supported by theoretical treatment were applied to offer a new overview of the Cr(Ⅵ)adsorption geometry and mechanism at 25-45℃.Experimental results suggested that the Cr(Ⅵ)uptake was mainly governed by adsorption-reduction coupled mechanism.The Langmuir model fitted well the Cr(Ⅵ)adsorption data with maximum adsorption capacities extended from 115.24 to 129.63 mg·g^(-1).Theoretical calculations indicated that Cr(Ⅵ)ions were adsorbed on the MNPs@MC following the theory of the advanced monolayer statistical model.The number of ions removed per site ranged from 1.88 to1.23 suggesting the involvement of vertical geometry and multi-ionic mechanism at all temperatures.The increment of the active sites density and the adsorption capacity at saturation with improving temperature reflected an endothermic process.Energetically,the Cr(Ⅵ)adsorption was controlled by physical forces as the adsorption energies were less than 40 kJ·mol^(-1).The calculated free enthalpy,entropy.and internal energy explained the spontaneous nature and the viability of Cr(Ⅵ)adsorption on the MNPs@MC adsorbent.These results offer a new approach in utilizing the iron-rich deposits as gossans in the preparation of magnetic and low-cost adsorbents for wastewater remediation.展开更多
A rotary-concentrating device for thermal conduction is constructed to control and guide thermal energy transmitting in elastic plates.The designed device has the ability of concentrating for thermal conduction and co...A rotary-concentrating device for thermal conduction is constructed to control and guide thermal energy transmitting in elastic plates.The designed device has the ability of concentrating for thermal conduction and controlling the processes of thermal diffusion in a plate.The multilayered isotropic material properties of the rotary-concentrating device are derived based on the transformation and rotary medium method and a rotation parameter to control the thermal diffusion process is introduced.The efficiency of the rotary-concentrating device for thermal conduction is verified.Stability of temperature fields in a plate with the rotary-concentrating device is analyzed to study the performance of rotary-concentrating.Numerical examples show that the constructed rotary-concentrating device for thermal conduction can effectively rotate and focus on the thermal energy into the device for a wide range of diffusion temperatures,which can enhance the thermal conduction.Therefore,this study can provide a theoretical support for potential applications in fields of energy harvesting and thermal conduction control.展开更多
2,4(5)-Dinitroimidazole(2,4(5)-DNI) is an important energetic material, and it is also an important precursor for the preparation of drugs and energetic materials. In this study, the solubility of 2,4(5)-DNI in eleven...2,4(5)-Dinitroimidazole(2,4(5)-DNI) is an important energetic material, and it is also an important precursor for the preparation of drugs and energetic materials. In this study, the solubility of 2,4(5)-DNI in eleven pure solvents(chlorobenzene, benzene, 1,2-dichloroethane, toluene, water, isopropyl alcohol,ethyl acetate, acetonitrile, methanol, 1,4-dioxane and acetone) were measured by using a dynamic test method from 278.15 K to 323.15 K under 101.1 kPa. Four solubility models were used to fit the experimental data, which were ideal model, modified Apelblat equation, polynomial empirical equation, and λh equation. Meanwhile, the relative average deviation and root-mean-square deviation between the experimental data and the fitted data were also calculated. Furthermore, the three thermodynamic parameters,i.e., dissolution enthalpy, dissolution entropy and Gibbs energy were obtained based on solubility data.Finally, the crude product of 2,4(5)-DNI was crystallized with acetone as solvent, and the purity of the crystalline product was greater than 99.5%.展开更多
The kinetics of Cu ion exchange on Na-montmorillonite clay mineral has been investigated at three temperatures, in three solvents: H2O, ethylene glycol and glycerol. Solvent effects on the reaction rate have been disc...The kinetics of Cu ion exchange on Na-montmorillonite clay mineral has been investigated at three temperatures, in three solvents: H2O, ethylene glycol and glycerol. Solvent effects on the reaction rate have been discussed. The thermodynamic activation parameters were calculated and discussed in terms of solvation effects. The determined isokinetic temperature indicates that the reaction is enthalpy controlled where the interaction between solvent and clay surface plays an important role. A reaction mechanism which describes the solvent effect on the rate of Cu ion exchange is proposed.展开更多
Schiff<sup> </sup>base synthesis is usually acid catalyzed and it usually requires refluxing the mixture of aldehydes and amine in ethanolic solution. Synthesis and characterization of Schiff base ligands ...Schiff<sup> </sup>base synthesis is usually acid catalyzed and it usually requires refluxing the mixture of aldehydes and amine in ethanolic solution. Synthesis and characterization of Schiff base ligands derived from substituted amine and salicylaldehyde and their complexes (Cu<sup>2+</sup>, Co<sup>2+</sup>) are reported. The ligands and ligand-complexes were characterized by melting point, FTIR, CHN-elemental analysis and UV-Visible analysis. The UV-Visible and elemental analysis of complexes established (1:2) mole ratio (M:L). The stability constant and thermodynamic parameters (K, ΔG, ΔH, ΔS) were determined at different temperature (30 - 40)°C which established that the metal-complexes were very stable. The review describes the promising biological<sup> </sup>activities of Schiff base and their metal complexes.展开更多
The adsorption behavior of eosin yellow (EY) from aqueous solution onto γ-Al<sub>2</sub>O<sub>3</sub> nanoparticles in batch technique was studied. γ-Al<sub>2</sub>O<sub>3&l...The adsorption behavior of eosin yellow (EY) from aqueous solution onto γ-Al<sub>2</sub>O<sub>3</sub> nanoparticles in batch technique was studied. γ-Al<sub>2</sub>O<sub>3</sub> NPs was prepared and characterized by SEM, TEM, XRD and FTIR analysis. The effect of pH, dosage of adsorbent, contact time, temperature, and the initial concentration of dye was investigated. The maximum amount of dye removal found about 99.36% at pH4, the adsorption dose 1g/L, with the initial dye concentration of 100 mg/L, and the temperature of 25°C, with contact time 120 min. The adsorption behavior of the eosin yellow dye is applicable to Langmuir isotherm model, with the maximum sorption capacity of 47.78 mg/g of γ-Al<sub>2</sub>O<sub>3</sub>. The kinetic data also described by the pseudo-second-order model with a correlation coefficient (0.9999), and the mechanism of the process showed a multi-linear steps and the intra-particle diffusion was not only rate controlling step. The adsorption process was endothermic with positive enthalpy of 121.8 kJ/mol, and showed spontaneous process with a mean free energy -5.19 kJ/mol, and increase randomness, 369.77 J/mol. k, at the adsorbent solution interface. The adsorption process was chemisorption in nature The activation energy estimated from Arrhenius and modified Arrhenius is 40.9 kJ/mol, 106.37 kJ/mol respectively. The sticking probability of EY onto Al<sub>2</sub>O<sub>3</sub> NPs very high estimated from the value of S* < 1, (4.82E-19).展开更多
Dissolution and nucleation are two essential processes for industrial crystallization.This paper in-vestigates the effect of ethylene glycol addition on the crystallization behavior of dimethyl terephthalate(DMT)in so...Dissolution and nucleation are two essential processes for industrial crystallization.This paper in-vestigates the effect of ethylene glycol addition on the crystallization behavior of dimethyl terephthalate(DMT)in solution.The DMT solubility in mixed solvent system(methanol-ethylene glycol)was deter-mined by isothermal satiation approach,and the solubility was associated using seven models.The model fitting results were consistent with the experimental values.Based on the results,the metastable zone width(MSZW)of DMT was detected by the polythermal approach;the modified Sangwal's theory was used to investigate the nucleation behavior,which can provide a new way of thought for better analysis of the crystallization behavior.The results demonstrated that MSZW was associated with various elements,such as cooling rate,saturation temperature and mass fraction of ethylene glycol.The addition of ethylene glycol slowed down the nucleation rate as shown by the broadening of MSZW.We derive the solid-liquid interface energy,the nucleation driving force,the critical nucleation size and the critical Gibbs free energy according to the classical nucleation theory.It is demonstrated that the nucleation driving force and the solid-liquid interface energy are dependent and jointly influence the MSZW.展开更多
Chemically modified clay(CMC) was used as an adsorbent for the removal of Astrazon Golden Yellow 7GL(AGY-7GL), which is a basic dye from wastewater. For this purpose, the chemically modified clay was first characteriz...Chemically modified clay(CMC) was used as an adsorbent for the removal of Astrazon Golden Yellow 7GL(AGY-7GL), which is a basic dye from wastewater. For this purpose, the chemically modified clay was first characterized by determining zero point of charge(p Hzpc), and using BET, SEM and FTIR. Then effects of operational parameters on adsorption of AGY-7GL were studied in a batch system. The effect of various parameters such as contact time(0-180 min), pH(2-8), temperature(293-323 K), CMC concentration(0.075-0.5 mg/L) and initial AGY-7GL concentration(75-250 mg/L) were investigated on the adsorption efficiency and capacity adsorption of CMC for the removal of AGY-7GL. Thermodynamic and kinetic parameters were calculated from the results of the adsorption experiment. The evaluation of kinetic models shows that this data best fits the pseudo-second-order model. It is determined that the adsorption equilibrium data works very well with the nonlinear Freundlich isotherm model. Thermodynamic parameters such as ?H^0(19.0 k J/mol), ?G^0(-28.8 k J/mol) and ?S^0(0.148 k J/mol) were also determined. According to the experimental results, it is concluded that CMC could be used as an alternative low cost potential adsorbent for the removal of AGY-7GL from wastewater.展开更多
Based on prior investigation,this work defined a new thermodynamic shear advection parameter,which combines the vertical component of convective vorticity vector,horizontal divergence,and vertical gradient of generali...Based on prior investigation,this work defined a new thermodynamic shear advection parameter,which combines the vertical component of convective vorticity vector,horizontal divergence,and vertical gradient of generalized potential temperature.The interaction between waves and fundamental states was computed for the heavyrainfall event generated by landfalling typhoon“Morakot”.The analysis data was produced by ADAS[ARPS(Advanced Regional Prediction System)Data Analysis System]combined with the NCEP/NCAR final analysis data(1°×1°,26 vertical pressure levels and 6-hour interval)with the routine observations of surface and sounding.Because it may describe the typical vertical structure of dynamical and thermodynamic fields,the result indicates that the parameter is intimately related to precipitation systems.The parameter’s positive high-value area closely matches the reported 6-hour accumulated surface rainfall.And the statistical analysis reveals a certain correspondence between the thermodynamic shear advection parameter and the observed 6-hour accumulated surface rainfall in the summer of 2009.This implies that the parameter can predict and indicate the rainfall area,as well as the initiation and evolution of precipitation systems.展开更多
Kinetic analyses are important means for understanding the complicated coal pyrolysis process.This work conducted non-isothermal pyrolysis of four low-medium rank coals with thermogravimetric analyzer at different hea...Kinetic analyses are important means for understanding the complicated coal pyrolysis process.This work conducted non-isothermal pyrolysis of four low-medium rank coals with thermogravimetric analyzer at different heating rates(5,10 and 20 K/min).Four model-free fitting approaches including KAS,OFW,Starink and Friedman methods were used to analyze pyrolysis kinetics of the coals.Thermodynamic parameters including enthalpy(ΔH)Gibbs free energy(ΔG)and entropy(ΔS)were calculated with the activation values(E)obtained with KAS method.For the kinetic analysis,the KAS,OFW and Starink methods give close E values over the whole conversion range,but the Friedman method shows more deviant results.The thermodynamic favorability of coal pyrolysis is discussed,bothΔH andΔG increase with conversion consistently with the variation of E,revealing that pyrolysis is endothermic and thermodynamic favorability is reduced with conversion rises.The minusΔS implies that coal structures evolve from disordered to organized ones as universally accepted.These results are expected to deepen our understanding and to optimize the conditions of coal pyrolysis.展开更多
This study investigated efficiency of tetramethyl ammonium hydroxide pentahydrate(TMAH)in removal of heavy metal ions from heavy oils obtained from Nigerian oil sands by Soxhlet-extraction technique.Metals were remove...This study investigated efficiency of tetramethyl ammonium hydroxide pentahydrate(TMAH)in removal of heavy metal ions from heavy oils obtained from Nigerian oil sands by Soxhlet-extraction technique.Metals were removed from the heavy oils at variable temperatures using TMAH.Elemental analysis was done using Atomic absorption spectrophotometry(AAS).Percentage recovery was≥92.85%,confirming reliability of results.Total metal concentrations followed order:Ni>Pb>Mn>Cu>Cr>Cd.Analysis of variance results showed that F<F_(critical)(0.01<3.68),indicating acceptance of null hypothesis.Cluster analysis result indicated three major inter-elemental clustering groups,indicating chemical affinity and/or similar sources,while T-test result indicated significant differences.Metal removal efficiency decreased with increased temperature,indicating exothermic process.Thermodynamic parameter values were negative,confirming exothermic reactions.Also,negative△DS°values indicated decreased randomness at solid/liquid interface during the extraction.△DG°negative values indicated feasible and spontaneous extraction.Conclusively,the distribution of metals in the analyzed heavy oils followed similar trend,due to similarity in their geological activity,source rock type,maturation and depositional environment.Thermodynamics parameters values showed the extraction process was exothermic,feasible and spontaneous thus,proving metal extraction using TMAH to be efficient.展开更多
The traditional qualitative analysis of the individual factors on the kinetic and thermodynamic parameters cannot sufficiently reveal the mechanism underlying ammonia volatilization in soil.This study aimed to determi...The traditional qualitative analysis of the individual factors on the kinetic and thermodynamic parameters cannot sufficiently reveal the mechanism underlying ammonia volatilization in soil.This study aimed to determine the effects of temperature,moisture content,and their interaction on the kinetic and thermodynamic parameters,which revealed the key control mechanism underlying ammonia volatilization,modified the traditional Arrhenius model,and established a quantitative prediction model of cumulative NH_(3)-N loss(CNL).Laboratory culture experiments were conducted under different temperatures(T)(15℃,20℃,25℃and 35℃)and moisture contents(θ)(60%,80%,and 100%field capacities).Soil ammonia volatilization was also measured every 2 d.Results showed that the effects of individual factors and their interaction on the values of reaction rate(K_(N)),Activation free energy(ΔG),and activation entropy(ΔS)followed the descending order of T>θ>T·θ,whereas those of activation enthalpy(ΔH)and activation degree(lgN)followed the descending order ofθ>T>T·θ.The interaction showed significant effect on K_(N)value and insignificant effect on all the thermodynamic parameters.The effects of water and temperature were mainly observed during the preparatory stage and the most critical transition state stage of the chemical reaction,respectively.Given thatΔH>0,ΔG>0,andΔS>0,ammonia volatilization is found to be an endothermic reaction controlled by enthalpy.The new K_(N)(T)-2 model with the determination coefficient(R^(2))of 0.999 was more accurate than the traditional Arrhenius model with the R^(2)of 0.936.The new NH_(3)(T,θ)model with the mean absolute percentage error(MAPE)of 4.17%was more accurate than the traditional NH_(3)(T)model with the MAPE of 7.11%.These results supplemented the control mechanism underlying ammonia volatilization in soil fertilized with urea and improved the prediction accuracy of CNL.展开更多
Precipitation of heavy hydrocarbon components such as Wax and Asphaltenes are one of the most challenging issues in oil production processes.The associated complications extend from the reservoir to refineries and pet...Precipitation of heavy hydrocarbon components such as Wax and Asphaltenes are one of the most challenging issues in oil production processes.The associated complications extend from the reservoir to refineries and petrochemical plants.Precipitation is most destructive when the affected areas are hard to reach,for example the wellbore of producing wells.This work demonstrates the effect of adjusting choke valve sizes on thermodynamic parameters of fluid flowing in a vertical well.Our simulation results revealed optimum choke valve sizes that could keep producing vertical wells away from Asphaltene precipitation.The results of this study were implemented on a well in Darquin Reservoir that had been experiencing asphaltene precipitation.Experimental analysis of reservoir fluid,Asphaltene tests and thermodynamic simulations of well column were carried out and the most appropriate size of choke valve was determined.After replacing the well's original choke valve with the suggested choke valve,the Asphaltene precipitation problem diminished.展开更多
The widespread use of sodium p-perfluorous nonenoxybenzene sulfonate(OBS), a typical alternative to perfluorooctane sulfonate, has resulted in potential threats to the environment, but the adsorption behavior of OBS i...The widespread use of sodium p-perfluorous nonenoxybenzene sulfonate(OBS), a typical alternative to perfluorooctane sulfonate, has resulted in potential threats to the environment, but the adsorption behavior of OBS in soils has not yet been reported. In this study, the adsorption behaviors of OBS on five soils with different physicochemical properties were investigated. The rate of OBS adsorption was fast, and most of the OBS uptake was completed within 12 h. The good model fit of OBS adsorption to the pseudo-second-order and Elovich models indicated the occurrence of chemical adsorption. The adsorption isotherms of OBS on the soils were better described by the Freundlich model than by the Langmuir model, suggesting that the OBS adsorption sites on the soils were heterogeneous. This is possibly associated with various adsorption mechanisms including hydrophobic, π-π, hydrogen bonding, and electrostatic interactions,further confirmed by the good model fit to the D-R isotherm. Adsorption of OBS occurred on the soils, and the adsorption process was spontaneous and endothermic. In addition, the soils were more suitable for OBS adsorption at lower pH values due to the stronger electrostatic adsorption. The OBS adsorption on the soils decreased with the increase of soil depth from 0 to 30 cm. Moreover, the presence of organic matter and ammonia nitrogen in the soils was favorable for OBS adsorption, and these parameters decreased with increasing soil depth, making OBS adsorption less prominent in the deeper soil. This study indicates that OBS is easily enriched in surface soils, and that soil organic matter and ammonia nitrogen significantly affect OBS migration in soil.展开更多
Adsorptive polyethesulfone(PES)membranes were prepared by intercalation of powder activated carbon(PAC)with and without functionalization.Accordingly,PAC was aminated with 1,5-diamino-2-methylpentane,and the physicoch...Adsorptive polyethesulfone(PES)membranes were prepared by intercalation of powder activated carbon(PAC)with and without functionalization.Accordingly,PAC was aminated with 1,5-diamino-2-methylpentane,and the physicochemical properties of the functionalized PAC were analyzed.Intercalation of PAC within the PES scaffold changed the porosity and mean pore size of the aminated membrane(AC-NH2)from 52.6%to 92.5%and from 22.6 nm to 3.5 nm,respectively.The effect of temperature on the performance of the modified mem-branes was monitored by the flux and chemical oxygen demand(COD)removal of leachate.At ambient tempera-ture,the COD removal of the neat,AC-containing,and AC-NH2 membranes was 47%,52%,and 58.5%,respec-tively.A similar increment was obtained for the membrane flux,which was due to the synergistic effect of the high porosity and large number of hydrophilic functional groups.The experimental leachate adsorption data were analyzed by Langmuir,Freundlich,and Dubinin-Radushkevich isotherm models.For all membranes,the significant thermodynamic parameters(ΔH,ΔS,and ΔG)were calculated and compared.The isosteric heat of adsorption was lower than 80 kJ·mol^-1,indicating that the interaction between the membranes and the leachate is mainly physical,involving weak van der Waals forces.展开更多
The study of complex properties in a binary mixture of 1,2-dichloroethane(DE)and n-methylformamide(NMF)polar liquids has been carried out in the frequency range of 10 MHz to 30 GHz for 11 different concentrations usin...The study of complex properties in a binary mixture of 1,2-dichloroethane(DE)and n-methylformamide(NMF)polar liquids has been carried out in the frequency range of 10 MHz to 30 GHz for 11 different concentrations using time domain reflectometry technique at 283,288,293 and 298 K temperatures.Complex property of binary liquids indicates the type of distribution of the dielectric relaxation time.The Bruggeman parameter gives the information about molecular interactions within binary polar liquids.Thermodynamic parameter deals with the passing of a dipole across a potential barrier which separates the minima of energy.展开更多
The stability of the Fe_(23)Zr_(6)phase in Fe–Zr system was studied,and the partial Fe–Zr phase diagram was revised by means of X-ray diffraction,electron probe microanalysis and differential thermal analysis method...The stability of the Fe_(23)Zr_(6)phase in Fe–Zr system was studied,and the partial Fe–Zr phase diagram was revised by means of X-ray diffraction,electron probe microanalysis and differential thermal analysis methods.On the basis of the experimental results in the present work and literature,the Fe–Zr system was reassessed using CALculation of PHAse Diagram(CALPHAD)method.Solution phases,liquid,fcc,bcc and hcp,are modeled as the substitutional solution.The intermetallic compounds,hex.-Fe_(2)Zr,Fe_(2)Zr,FeZr_(2)and FeZr3 phases,are treated as Fe_(2)(Fe,Zr)1,(Fe,Zr)2(Fe,Zr)1,(Fe,Zr)1Zr_(2)and(Fe,Zr)1(Fe,Zr)3 by a two-sublattice model,respectively.The Fe_(23)Zr_(6)phase is treated as stoichiometric compound.A set of self-consistent thermodynamic parameters of the Fe–Zr system was obtained.The results confirm the stability of Fe_(23)Zr_(6)phase,improve the phase diagram of the Fe–Zr system and provide a theoretical reference for the development of Zr alloys.展开更多
Dielectric permittivity and relaxation dynamics of binary and ternary mixture of stearic acid on various concentration and their thermodynamic effects are studied.The static dielectric constant(ε_(0)),dielectric perm...Dielectric permittivity and relaxation dynamics of binary and ternary mixture of stearic acid on various concentration and their thermodynamic effects are studied.The static dielectric constant(ε_(0)),dielectric permittivity(ε′)and dielectric loss(ε″)are found by bilinear calibration.The relaxation time(τ),dielectric strength(Δε)and the excess permittivity(ε^(E))are found.The thermodynamic parameters such as enthalpy(ΔH),entropy(ΔS)and Gibb's free energy(ΔG)are evolved.The significant changes in dielectric parameters are due to the intramolecular and intermolecular interactions in response to the applied frequency.The permittivity spectra of stearic acid–alcohol in the frequency range of 10MHz to 30 GHz have been measured using picoseconds Time Domain Reflectometry(TDR).The dielectric parameters(ε_(0),ε′,ε″)are found by bilinear calibration method.Influence of temperature in intermolecular interaction and the relaxation process are also studied.The FT-IR spectral analysis reveals that the conformation of functional groups and formation for hydrogen bonding are present in both binary and ternary mixtures of stearic acid.展开更多
The Complex permittivity spectra of glycol ether(GE)compounds such as ethylene glycol mono-methyl ether(EGME)with water mixture over entire concentration range and in temperature range of 10-25℃ have been determined ...The Complex permittivity spectra of glycol ether(GE)compounds such as ethylene glycol mono-methyl ether(EGME)with water mixture over entire concentration range and in temperature range of 10-25℃ have been determined using Time Domain Reflectometry(TDR)technique in the frequency range 10MHz to 50 GHz.The complex permittivity spectra for EGME-water were fitted in the Cole-Davidson model.The Static dielectric constant(ε_(0)^(E)),Relaxation time(τ),effective Kirkwood correlation factor(g_(eff)),excess permittivity(ε_(0)),thermodynamic parameters(activation enthalpy and activation entropy)and Bruggeman factor(f_(B))have been calculated by the nonlinear least square fit method.The intermolecular interactions between EGME-water binary mixtures suggest the nonlinear behavior of dielectric parameters.The contribution of hydrogen bonding interactions among the solute-solvent mixtures is confirmed by Excess properties and Bruggeman factor.展开更多
文摘2,4(5)-Dinitroimidazole(2,4(5)-DNI)is an important organic intermediate,and itself can also be used for energetic material.In this work,the solubility of 2,4(5)-DNI in(methanol+water,acetonitrile+water,acetone+water)binary solvents were measured by using a dynamic test method from 278.15 K to 323.15 K under 101.1 k Pa.The Jouyban–Acree model,van't Hoff–Jouyban–Acree model,Apelblat–Jouyb an–Acree model,Ma model,and Sun model were used to correlate the experimental data.The values of relative average deviation(RAD)and root-mean-square deviation(RMSD)were very small,indicating that the error between the experimental value and the correlated value was very small.The thermodynamic parameters such as dissolution enthalpy,dissolution entropy and Gibbs energy were calculated based on solubility data.High-purity of 2,4(5)-DNI was efficiently obtained by using cooling and dilution crystallization method.
基金supported by Researchers Supporting Project number(RSP2023R455),King Saud University,Riyadh,Saudi Arabia。
文摘Herein,iron oxide/hydroxides deposits(gossans)were utilized,for the first time,in the fabrication of magnetite nanoparticles(MNPs)to load modified coal(MC).The as-synthesized MNPs@MC composite was characterized via different techniques and utilized for the Cr(Ⅵ)remediation.Experimental studies supported by theoretical treatment were applied to offer a new overview of the Cr(Ⅵ)adsorption geometry and mechanism at 25-45℃.Experimental results suggested that the Cr(Ⅵ)uptake was mainly governed by adsorption-reduction coupled mechanism.The Langmuir model fitted well the Cr(Ⅵ)adsorption data with maximum adsorption capacities extended from 115.24 to 129.63 mg·g^(-1).Theoretical calculations indicated that Cr(Ⅵ)ions were adsorbed on the MNPs@MC following the theory of the advanced monolayer statistical model.The number of ions removed per site ranged from 1.88 to1.23 suggesting the involvement of vertical geometry and multi-ionic mechanism at all temperatures.The increment of the active sites density and the adsorption capacity at saturation with improving temperature reflected an endothermic process.Energetically,the Cr(Ⅵ)adsorption was controlled by physical forces as the adsorption energies were less than 40 kJ·mol^(-1).The calculated free enthalpy,entropy.and internal energy explained the spontaneous nature and the viability of Cr(Ⅵ)adsorption on the MNPs@MC adsorbent.These results offer a new approach in utilizing the iron-rich deposits as gossans in the preparation of magnetic and low-cost adsorbents for wastewater remediation.
基金Project supported by the National Natural Science Foundation of China(Grant No.12102150)the Natural Science Foundation of Jiangsu Province+3 种基金China(Grant Nos.BK20200884 and BK20201414)the Natural Science Foundation of Colleges and Universities in Jiangsu Province,China(Grant No.20KJB130004)China Postdoctoral Science Foundation(Grant No.2021M702444)the Jiangsu’s Mass Entrepreneurship and Innovation Program of Jiangsu Province。
文摘A rotary-concentrating device for thermal conduction is constructed to control and guide thermal energy transmitting in elastic plates.The designed device has the ability of concentrating for thermal conduction and controlling the processes of thermal diffusion in a plate.The multilayered isotropic material properties of the rotary-concentrating device are derived based on the transformation and rotary medium method and a rotation parameter to control the thermal diffusion process is introduced.The efficiency of the rotary-concentrating device for thermal conduction is verified.Stability of temperature fields in a plate with the rotary-concentrating device is analyzed to study the performance of rotary-concentrating.Numerical examples show that the constructed rotary-concentrating device for thermal conduction can effectively rotate and focus on the thermal energy into the device for a wide range of diffusion temperatures,which can enhance the thermal conduction.Therefore,this study can provide a theoretical support for potential applications in fields of energy harvesting and thermal conduction control.
文摘2,4(5)-Dinitroimidazole(2,4(5)-DNI) is an important energetic material, and it is also an important precursor for the preparation of drugs and energetic materials. In this study, the solubility of 2,4(5)-DNI in eleven pure solvents(chlorobenzene, benzene, 1,2-dichloroethane, toluene, water, isopropyl alcohol,ethyl acetate, acetonitrile, methanol, 1,4-dioxane and acetone) were measured by using a dynamic test method from 278.15 K to 323.15 K under 101.1 kPa. Four solubility models were used to fit the experimental data, which were ideal model, modified Apelblat equation, polynomial empirical equation, and λh equation. Meanwhile, the relative average deviation and root-mean-square deviation between the experimental data and the fitted data were also calculated. Furthermore, the three thermodynamic parameters,i.e., dissolution enthalpy, dissolution entropy and Gibbs energy were obtained based on solubility data.Finally, the crude product of 2,4(5)-DNI was crystallized with acetone as solvent, and the purity of the crystalline product was greater than 99.5%.
文摘The kinetics of Cu ion exchange on Na-montmorillonite clay mineral has been investigated at three temperatures, in three solvents: H2O, ethylene glycol and glycerol. Solvent effects on the reaction rate have been discussed. The thermodynamic activation parameters were calculated and discussed in terms of solvation effects. The determined isokinetic temperature indicates that the reaction is enthalpy controlled where the interaction between solvent and clay surface plays an important role. A reaction mechanism which describes the solvent effect on the rate of Cu ion exchange is proposed.
文摘Schiff<sup> </sup>base synthesis is usually acid catalyzed and it usually requires refluxing the mixture of aldehydes and amine in ethanolic solution. Synthesis and characterization of Schiff base ligands derived from substituted amine and salicylaldehyde and their complexes (Cu<sup>2+</sup>, Co<sup>2+</sup>) are reported. The ligands and ligand-complexes were characterized by melting point, FTIR, CHN-elemental analysis and UV-Visible analysis. The UV-Visible and elemental analysis of complexes established (1:2) mole ratio (M:L). The stability constant and thermodynamic parameters (K, ΔG, ΔH, ΔS) were determined at different temperature (30 - 40)°C which established that the metal-complexes were very stable. The review describes the promising biological<sup> </sup>activities of Schiff base and their metal complexes.
文摘The adsorption behavior of eosin yellow (EY) from aqueous solution onto γ-Al<sub>2</sub>O<sub>3</sub> nanoparticles in batch technique was studied. γ-Al<sub>2</sub>O<sub>3</sub> NPs was prepared and characterized by SEM, TEM, XRD and FTIR analysis. The effect of pH, dosage of adsorbent, contact time, temperature, and the initial concentration of dye was investigated. The maximum amount of dye removal found about 99.36% at pH4, the adsorption dose 1g/L, with the initial dye concentration of 100 mg/L, and the temperature of 25°C, with contact time 120 min. The adsorption behavior of the eosin yellow dye is applicable to Langmuir isotherm model, with the maximum sorption capacity of 47.78 mg/g of γ-Al<sub>2</sub>O<sub>3</sub>. The kinetic data also described by the pseudo-second-order model with a correlation coefficient (0.9999), and the mechanism of the process showed a multi-linear steps and the intra-particle diffusion was not only rate controlling step. The adsorption process was endothermic with positive enthalpy of 121.8 kJ/mol, and showed spontaneous process with a mean free energy -5.19 kJ/mol, and increase randomness, 369.77 J/mol. k, at the adsorbent solution interface. The adsorption process was chemisorption in nature The activation energy estimated from Arrhenius and modified Arrhenius is 40.9 kJ/mol, 106.37 kJ/mol respectively. The sticking probability of EY onto Al<sub>2</sub>O<sub>3</sub> NPs very high estimated from the value of S* < 1, (4.82E-19).
基金supported by the National Key Research and Development Program of China(grant No.2019YFC1908201)the Key Program of National Natural Scientific Fund of China(grant No.22238011)+1 种基金the National Natural Science Foundation of China(grant Nos.22178364,21978291)the Natural Science Foundation of Liaoning Province(China)(grant No.2019-ZD-0083).
文摘Dissolution and nucleation are two essential processes for industrial crystallization.This paper in-vestigates the effect of ethylene glycol addition on the crystallization behavior of dimethyl terephthalate(DMT)in solution.The DMT solubility in mixed solvent system(methanol-ethylene glycol)was deter-mined by isothermal satiation approach,and the solubility was associated using seven models.The model fitting results were consistent with the experimental values.Based on the results,the metastable zone width(MSZW)of DMT was detected by the polythermal approach;the modified Sangwal's theory was used to investigate the nucleation behavior,which can provide a new way of thought for better analysis of the crystallization behavior.The results demonstrated that MSZW was associated with various elements,such as cooling rate,saturation temperature and mass fraction of ethylene glycol.The addition of ethylene glycol slowed down the nucleation rate as shown by the broadening of MSZW.We derive the solid-liquid interface energy,the nucleation driving force,the critical nucleation size and the critical Gibbs free energy according to the classical nucleation theory.It is demonstrated that the nucleation driving force and the solid-liquid interface energy are dependent and jointly influence the MSZW.
文摘Chemically modified clay(CMC) was used as an adsorbent for the removal of Astrazon Golden Yellow 7GL(AGY-7GL), which is a basic dye from wastewater. For this purpose, the chemically modified clay was first characterized by determining zero point of charge(p Hzpc), and using BET, SEM and FTIR. Then effects of operational parameters on adsorption of AGY-7GL were studied in a batch system. The effect of various parameters such as contact time(0-180 min), pH(2-8), temperature(293-323 K), CMC concentration(0.075-0.5 mg/L) and initial AGY-7GL concentration(75-250 mg/L) were investigated on the adsorption efficiency and capacity adsorption of CMC for the removal of AGY-7GL. Thermodynamic and kinetic parameters were calculated from the results of the adsorption experiment. The evaluation of kinetic models shows that this data best fits the pseudo-second-order model. It is determined that the adsorption equilibrium data works very well with the nonlinear Freundlich isotherm model. Thermodynamic parameters such as ?H^0(19.0 k J/mol), ?G^0(-28.8 k J/mol) and ?S^0(0.148 k J/mol) were also determined. According to the experimental results, it is concluded that CMC could be used as an alternative low cost potential adsorbent for the removal of AGY-7GL from wastewater.
基金National Key R&D Program of China(2017YFC1501604)Key Laboratory of South China Sea Meteorological Disaster Prevention and Mitigation of Hainan Province(SCSF202101)+1 种基金Open Grants of the State Key Laboratory of Severe Weather(2022LASW-B09)National Natural Science Foundation of China(41405049)。
文摘Based on prior investigation,this work defined a new thermodynamic shear advection parameter,which combines the vertical component of convective vorticity vector,horizontal divergence,and vertical gradient of generalized potential temperature.The interaction between waves and fundamental states was computed for the heavyrainfall event generated by landfalling typhoon“Morakot”.The analysis data was produced by ADAS[ARPS(Advanced Regional Prediction System)Data Analysis System]combined with the NCEP/NCAR final analysis data(1°×1°,26 vertical pressure levels and 6-hour interval)with the routine observations of surface and sounding.Because it may describe the typical vertical structure of dynamical and thermodynamic fields,the result indicates that the parameter is intimately related to precipitation systems.The parameter’s positive high-value area closely matches the reported 6-hour accumulated surface rainfall.And the statistical analysis reveals a certain correspondence between the thermodynamic shear advection parameter and the observed 6-hour accumulated surface rainfall in the summer of 2009.This implies that the parameter can predict and indicate the rainfall area,as well as the initiation and evolution of precipitation systems.
基金the National Key Research and Development Program of China(Grant 2018YFB0604600)the National Natural Science Foundation of China(Grants 21808002,U1710114,21878001 and 22078002 and 21978003).
文摘Kinetic analyses are important means for understanding the complicated coal pyrolysis process.This work conducted non-isothermal pyrolysis of four low-medium rank coals with thermogravimetric analyzer at different heating rates(5,10 and 20 K/min).Four model-free fitting approaches including KAS,OFW,Starink and Friedman methods were used to analyze pyrolysis kinetics of the coals.Thermodynamic parameters including enthalpy(ΔH)Gibbs free energy(ΔG)and entropy(ΔS)were calculated with the activation values(E)obtained with KAS method.For the kinetic analysis,the KAS,OFW and Starink methods give close E values over the whole conversion range,but the Friedman method shows more deviant results.The thermodynamic favorability of coal pyrolysis is discussed,bothΔH andΔG increase with conversion consistently with the variation of E,revealing that pyrolysis is endothermic and thermodynamic favorability is reduced with conversion rises.The minusΔS implies that coal structures evolve from disordered to organized ones as universally accepted.These results are expected to deepen our understanding and to optimize the conditions of coal pyrolysis.
文摘This study investigated efficiency of tetramethyl ammonium hydroxide pentahydrate(TMAH)in removal of heavy metal ions from heavy oils obtained from Nigerian oil sands by Soxhlet-extraction technique.Metals were removed from the heavy oils at variable temperatures using TMAH.Elemental analysis was done using Atomic absorption spectrophotometry(AAS).Percentage recovery was≥92.85%,confirming reliability of results.Total metal concentrations followed order:Ni>Pb>Mn>Cu>Cr>Cd.Analysis of variance results showed that F<F_(critical)(0.01<3.68),indicating acceptance of null hypothesis.Cluster analysis result indicated three major inter-elemental clustering groups,indicating chemical affinity and/or similar sources,while T-test result indicated significant differences.Metal removal efficiency decreased with increased temperature,indicating exothermic process.Thermodynamic parameter values were negative,confirming exothermic reactions.Also,negative△DS°values indicated decreased randomness at solid/liquid interface during the extraction.△DG°negative values indicated feasible and spontaneous extraction.Conclusively,the distribution of metals in the analyzed heavy oils followed similar trend,due to similarity in their geological activity,source rock type,maturation and depositional environment.Thermodynamics parameters values showed the extraction process was exothermic,feasible and spontaneous thus,proving metal extraction using TMAH to be efficient.
基金This study is supported by the National Natural Science Foundation of China(No.51579168,51249002)the Natural Science Foundation of Shanxi Province of China(No.201601D011053)+1 种基金the Graduate Education Innovation Program of Shanxi Province of China(No.2016BY064)the Scientific and Technological Project of Shanxi Province of China(No.20140311016-6).
文摘The traditional qualitative analysis of the individual factors on the kinetic and thermodynamic parameters cannot sufficiently reveal the mechanism underlying ammonia volatilization in soil.This study aimed to determine the effects of temperature,moisture content,and their interaction on the kinetic and thermodynamic parameters,which revealed the key control mechanism underlying ammonia volatilization,modified the traditional Arrhenius model,and established a quantitative prediction model of cumulative NH_(3)-N loss(CNL).Laboratory culture experiments were conducted under different temperatures(T)(15℃,20℃,25℃and 35℃)and moisture contents(θ)(60%,80%,and 100%field capacities).Soil ammonia volatilization was also measured every 2 d.Results showed that the effects of individual factors and their interaction on the values of reaction rate(K_(N)),Activation free energy(ΔG),and activation entropy(ΔS)followed the descending order of T>θ>T·θ,whereas those of activation enthalpy(ΔH)and activation degree(lgN)followed the descending order ofθ>T>T·θ.The interaction showed significant effect on K_(N)value and insignificant effect on all the thermodynamic parameters.The effects of water and temperature were mainly observed during the preparatory stage and the most critical transition state stage of the chemical reaction,respectively.Given thatΔH>0,ΔG>0,andΔS>0,ammonia volatilization is found to be an endothermic reaction controlled by enthalpy.The new K_(N)(T)-2 model with the determination coefficient(R^(2))of 0.999 was more accurate than the traditional Arrhenius model with the R^(2)of 0.936.The new NH_(3)(T,θ)model with the mean absolute percentage error(MAPE)of 4.17%was more accurate than the traditional NH_(3)(T)model with the MAPE of 7.11%.These results supplemented the control mechanism underlying ammonia volatilization in soil fertilized with urea and improved the prediction accuracy of CNL.
文摘Precipitation of heavy hydrocarbon components such as Wax and Asphaltenes are one of the most challenging issues in oil production processes.The associated complications extend from the reservoir to refineries and petrochemical plants.Precipitation is most destructive when the affected areas are hard to reach,for example the wellbore of producing wells.This work demonstrates the effect of adjusting choke valve sizes on thermodynamic parameters of fluid flowing in a vertical well.Our simulation results revealed optimum choke valve sizes that could keep producing vertical wells away from Asphaltene precipitation.The results of this study were implemented on a well in Darquin Reservoir that had been experiencing asphaltene precipitation.Experimental analysis of reservoir fluid,Asphaltene tests and thermodynamic simulations of well column were carried out and the most appropriate size of choke valve was determined.After replacing the well's original choke valve with the suggested choke valve,the Asphaltene precipitation problem diminished.
基金supported by the Fundamental Research Project of Qinghai Province (No.2019-ZJ-935Q),Chinathe Beijing Natural Science Foundation (No.8184079),China。
文摘The widespread use of sodium p-perfluorous nonenoxybenzene sulfonate(OBS), a typical alternative to perfluorooctane sulfonate, has resulted in potential threats to the environment, but the adsorption behavior of OBS in soils has not yet been reported. In this study, the adsorption behaviors of OBS on five soils with different physicochemical properties were investigated. The rate of OBS adsorption was fast, and most of the OBS uptake was completed within 12 h. The good model fit of OBS adsorption to the pseudo-second-order and Elovich models indicated the occurrence of chemical adsorption. The adsorption isotherms of OBS on the soils were better described by the Freundlich model than by the Langmuir model, suggesting that the OBS adsorption sites on the soils were heterogeneous. This is possibly associated with various adsorption mechanisms including hydrophobic, π-π, hydrogen bonding, and electrostatic interactions,further confirmed by the good model fit to the D-R isotherm. Adsorption of OBS occurred on the soils, and the adsorption process was spontaneous and endothermic. In addition, the soils were more suitable for OBS adsorption at lower pH values due to the stronger electrostatic adsorption. The OBS adsorption on the soils decreased with the increase of soil depth from 0 to 30 cm. Moreover, the presence of organic matter and ammonia nitrogen in the soils was favorable for OBS adsorption, and these parameters decreased with increasing soil depth, making OBS adsorption less prominent in the deeper soil. This study indicates that OBS is easily enriched in surface soils, and that soil organic matter and ammonia nitrogen significantly affect OBS migration in soil.
基金the funding support of Babol Noshirvani University of Technology through Grant program No.BNUT/389026/97.
文摘Adsorptive polyethesulfone(PES)membranes were prepared by intercalation of powder activated carbon(PAC)with and without functionalization.Accordingly,PAC was aminated with 1,5-diamino-2-methylpentane,and the physicochemical properties of the functionalized PAC were analyzed.Intercalation of PAC within the PES scaffold changed the porosity and mean pore size of the aminated membrane(AC-NH2)from 52.6%to 92.5%and from 22.6 nm to 3.5 nm,respectively.The effect of temperature on the performance of the modified mem-branes was monitored by the flux and chemical oxygen demand(COD)removal of leachate.At ambient tempera-ture,the COD removal of the neat,AC-containing,and AC-NH2 membranes was 47%,52%,and 58.5%,respec-tively.A similar increment was obtained for the membrane flux,which was due to the synergistic effect of the high porosity and large number of hydrophilic functional groups.The experimental leachate adsorption data were analyzed by Langmuir,Freundlich,and Dubinin-Radushkevich isotherm models.For all membranes,the significant thermodynamic parameters(ΔH,ΔS,and ΔG)were calculated and compared.The isosteric heat of adsorption was lower than 80 kJ·mol^-1,indicating that the interaction between the membranes and the leachate is mainly physical,involving weak van der Waals forces.
基金The department of Science and Technology,New Delhi is gratefully acknowledged(Project No.SR/S2/LOP-25/2007)for its laboratory facility.
文摘The study of complex properties in a binary mixture of 1,2-dichloroethane(DE)and n-methylformamide(NMF)polar liquids has been carried out in the frequency range of 10 MHz to 30 GHz for 11 different concentrations using time domain reflectometry technique at 283,288,293 and 298 K temperatures.Complex property of binary liquids indicates the type of distribution of the dielectric relaxation time.The Bruggeman parameter gives the information about molecular interactions within binary polar liquids.Thermodynamic parameter deals with the passing of a dipole across a potential barrier which separates the minima of energy.
基金the major scientific and technological projects in Yunnan Province(Grant No.202002AB080001-1)National Natural Science Foundation of China(NSFC)(Grant No.51671025).
文摘The stability of the Fe_(23)Zr_(6)phase in Fe–Zr system was studied,and the partial Fe–Zr phase diagram was revised by means of X-ray diffraction,electron probe microanalysis and differential thermal analysis methods.On the basis of the experimental results in the present work and literature,the Fe–Zr system was reassessed using CALculation of PHAse Diagram(CALPHAD)method.Solution phases,liquid,fcc,bcc and hcp,are modeled as the substitutional solution.The intermetallic compounds,hex.-Fe_(2)Zr,Fe_(2)Zr,FeZr_(2)and FeZr3 phases,are treated as Fe_(2)(Fe,Zr)1,(Fe,Zr)2(Fe,Zr)1,(Fe,Zr)1Zr_(2)and(Fe,Zr)1(Fe,Zr)3 by a two-sublattice model,respectively.The Fe_(23)Zr_(6)phase is treated as stoichiometric compound.A set of self-consistent thermodynamic parameters of the Fe–Zr system was obtained.The results confirm the stability of Fe_(23)Zr_(6)phase,improve the phase diagram of the Fe–Zr system and provide a theoretical reference for the development of Zr alloys.
文摘Dielectric permittivity and relaxation dynamics of binary and ternary mixture of stearic acid on various concentration and their thermodynamic effects are studied.The static dielectric constant(ε_(0)),dielectric permittivity(ε′)and dielectric loss(ε″)are found by bilinear calibration.The relaxation time(τ),dielectric strength(Δε)and the excess permittivity(ε^(E))are found.The thermodynamic parameters such as enthalpy(ΔH),entropy(ΔS)and Gibb's free energy(ΔG)are evolved.The significant changes in dielectric parameters are due to the intramolecular and intermolecular interactions in response to the applied frequency.The permittivity spectra of stearic acid–alcohol in the frequency range of 10MHz to 30 GHz have been measured using picoseconds Time Domain Reflectometry(TDR).The dielectric parameters(ε_(0),ε′,ε″)are found by bilinear calibration method.Influence of temperature in intermolecular interaction and the relaxation process are also studied.The FT-IR spectral analysis reveals that the conformation of functional groups and formation for hydrogen bonding are present in both binary and ternary mixtures of stearic acid.
基金This work was supported by the Department of Science and Technology,New Delhi(Project No.DST PROJECTSB/S2/LOP-032/2013)as well as School of Physical Sciences,SRTM University,Nanded,India for providing necessary facilities。
文摘The Complex permittivity spectra of glycol ether(GE)compounds such as ethylene glycol mono-methyl ether(EGME)with water mixture over entire concentration range and in temperature range of 10-25℃ have been determined using Time Domain Reflectometry(TDR)technique in the frequency range 10MHz to 50 GHz.The complex permittivity spectra for EGME-water were fitted in the Cole-Davidson model.The Static dielectric constant(ε_(0)^(E)),Relaxation time(τ),effective Kirkwood correlation factor(g_(eff)),excess permittivity(ε_(0)),thermodynamic parameters(activation enthalpy and activation entropy)and Bruggeman factor(f_(B))have been calculated by the nonlinear least square fit method.The intermolecular interactions between EGME-water binary mixtures suggest the nonlinear behavior of dielectric parameters.The contribution of hydrogen bonding interactions among the solute-solvent mixtures is confirmed by Excess properties and Bruggeman factor.
