Thermal Behaviors of Work Roll in Finishing Trains of Hot Rolling

In order to analyze the thermal field and thermal contour of work roll in finishing trains of hot rolling in rolling process, a quasi two-dimension implicit finite difference model is developed. To improve the calculating speed and precision, some special solutions are introduced, including the development of this model, the simplification of boundary conditions and the computation of heat transfer coefficients. The results show that these solutions of thermal behaviors of work roll are very much efficient and the model can be used as an on-line profile and fatness control model of large industrial mills.

Thermal behaviors and heavy metal vaporization of phosphatized tannery sludge in incineration process

The high concentration of heavy metal (Cu, Cr, Zn, Pb) in tannery sludge causes severe heavy metal emissions in the process of incineration. In the present investigation, the tannery sludge was treated with 85% phosphoric acid before the incineration process in the tube furnace to control the heavy metal emissions. The thermal behavior and heavy metal vaporization of pre-treated tannery sludge were investigated, and X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis were also implemente...

Synthesis, Structure and Thermal Behaviors of a Magnesium(Ⅱ) Complex with Tetrazole-1-acetic Acid

A new complex of magnesium with tetrazole-l-acetic acid （tza） has been synthe- sized and characterized by elemental analysis and FT-IR spectrum. Single-crystal X-ray diffraction analysis determined the molecular formula as Mg（tza）2（H20）4. The crystal belongs to the triclinic system with Pi space group, and a = 6.133（2）, b = 6.488（2）, c = 10.0127（7） A, a = 77.282（10）, fl = 91.558（1）, ）, = 76.002（8）°, Y = 349.0（2）A3, Z = 1, C6HI4MgNsOs, Mr = 350.56, Dc = 1.668 g.cm-3, F（000） = 182,μ = 0.189, S = 1.000, the final R = 0.0294 and wR = 0.0785 for 1128 observed reflections with I 〉 20-（I）. In this molecule, the tza ion exhibits an infrequent monodentate coordination mode. The magnesium center is hexa-coordinated to a slightly distorted octahedral configuration by six oxygen atoms from two tza ligands and four coordinated water molecules. DSC and TG-DTG analyses were applied to assess the thermal decomposition behavior. The kinetic parameters of the exothermal peak were calculated by non-isothermal reaction kinetics. The values of critical temperature of thermal explosion, △S≠, △H≠ and △G^≠, were obtained as 596 K, -42.25 J mo1^-1 K^-1, 296.43 kJ mol^-1 and 323.53 kJ mol1, respectively.

Effects of rare earth oxide additives on the thermal behaviors of aluminum nitride ceramics

The effects of Y2O3 and Er2O3 on the sintering behaviors, thermal properties and microstructure of A1N ceramics were investigated. The experimental results show that the sintering temperature can be decreased; the relative density and thermal behavior can be improved by adding rare earth oxide in A1N ceramics. For A1N ceramics with 3 wt.% Er2O3 additive, the relative density is 98.8%, and the thermal conductivity reaches 106 W.m^-1.K^-1. The microstructure research found that no obvious aluminum erbium oxide was found in A1N ceramics doped with 3 wt.% Er203, which favored the improvement of the thermal conductivity of A1N ceramics.

Preparation,Structures,Thermal Properties and Sintering Behaviors of B_2O_3-SiO_2-ZnO-BaO-Al_2O_3 Glass

B_2O_3-SiO_2-ZnO-BaO-Al_2O_3 glass with different Al_2O_3 contents（1mol%, 3mol%, 5mol%, and 7mol%） was prepared, and it was intended to be used as lead-free and low-melting glass sealants for solid oxide fuel cells. The effects of Al_2O_3 content on the structures, thermal properties, and sintering behaviors of the B_2O_3-SiO_2-ZnO-BaO-Al_2O_3 glass were investigated in detail. The Al_2O_3 content largely influenced the structures and thermal properties of the glass. When the Al_2O_3 content 5mol%, the transition temperature of the glass decreased with the Al_2O_3 content, while the crystallization temperature increased with the Al_2O_3 content. However, higher Al_2O_3 content degraded the stability of the glass. The B_2O_3-SiO_2-ZnO-BaO-Al_2O_3 glass with 5 mol% Al_2O_3 content exhibits the optimal sintering densification characteristics and can be used as glass sealants for solid oxide fuel cells.

Toughness Effect of Graphene Oxide-Nano Silica on Thermal-Mechanical Performance of Epoxy Resin

A graphene oxide/nano-silica(GOS)hybrid was rapidly and easily synthesized using graphene oxide(GO)and nano-silica(nano-SiO_(2))as raw materials,and the synthesized GOS was used to improve the mechanical properties of epoxy resin(EP).The modified EP with different mass fractions of GOS(0,0.1%,0.2%,0.3%and 0.4%)were prepared and studied.The structure,thermal stability,mechanical properties,fracture toughness and failure morphology of the modified EP were analyzed.The results showed that the tensile strength of GOS modified EP increased from 40.6 MPa to 80.2 MPa compared with EP,the critical stress intensity factor of GOS modified EP increased by 65.9%from 0.82 MPa·m^(1/2)to 1.36 MPa·m^(1/2),indicating a significant enhancement in fracture toughness.In addition,failure morphology was observed by scanning electron microscopy(SEM)observation.The toughness mechanism of the modified EP was also discussed.Finally,the thermal stability of the modified EP was improved by the addition of GOS.Compared with neat EP,the initial thermal degradation temperature and glass transition temperature of GOS modified EP increased by 4.5℃and 10.3℃,respectively.

Investigation of the Thermal Decomposition Behavior of Oleuropein with Many Pharmacological Activities from Olive by Thermogravimetry

Due to the existence of poly-hydroxyl structures,the temperature may have an effect on the thermal stability of oleuropein for its applications.In the current study,the thermal decomposition process and kinetics behavior of oleuropein from the olive resource were researched by thermogravimetric theoretical analysis methods and non-isothermal kinetics simulation.The results of thermogravimetry analysis showed the whole thermal decomposi-tion process of oleuropein involved two stages,with 21.22%of residue.It was also revealed that high heating rates of more than 20 K min^(-1) led to significant thermal hysteresis and inhibited the whole thermal decomposition behavior of oleuropein.Moreover,an investigation of the thermal decomposition kinetics indicated that the non-isothermal decomposition behavior followed a D3 model during thefirst stage(three-dimensional diffusion,Jander equation)and a D1 model in the second stage(one-dimensional diffusion).For thefirst and second ther-mal decomposition stages,the Kissinger,Friedman,Flynn-Wall-Ozawa,and Coats–Redfern four methods were applied to determine the activation energy(E=143.72 and 247.01 kJ mol^(-1))and Arrhenius preexponential factor(ln A=26.34 and 42.45 min^(-1)),respectively.Therefore,the study will provide good theoretical guidance for ther-mal stability and thermal transformation application of oleuropein.It will be suitable for low-temperature appli-cations in the cosmetic,food supplement and pharmaceutical industries.

Thermal Analysis of Sclerotium of Pleurotus tuber-regium (osu) for Effective Drying

Thermal drying could lead to the deterioration of substance which affect its nutraceutical and chemical properties. Hence, thermal stability of substance is necessary in course of its drying to acertain the degree of temperature it will be subjected to. In this research, sclerotium of Pleurotus tuberregium is subjected to thermogravimetric analysis, differential thermal analysis and differential scanning calorimetry. Both thermogravimetric analysis and differential thermal analysis were conducted from ambient temperature to 1000°C at a rate of 20°C/min constant heating rate, while differential scanning calorimetry was conducted from ambient temperature to 400°C at a rate of 10°C/min constant heating rate. Besides, the oxides contents of sclerotium of Pleurotus tuberregium were determined using x-ray fluorescence analysis and the mircostruture was determined with scanning electron microscopy. It was discovered that complete dehydration of the sample ended at about 110.38°C and oxidation reaction occurred between 233.42°C to 373.82°C with release of heat by the sample. Sclerotium of Pleurotus tuber-regium is thermal stable up to 233.42°C with decompostion of steroid which is its second major component at about 400°C to 480°C. The x-ray fluorescence analysis of sclerotium of Pleurotus tuber-regium revealed that Na2O, MgO, SiO2, Al2O3, and Fe2O3 are the major compound and SEM analysis showed that it is a solid with amorphous structure having some fibrous skeleton. This study revealed that sclerotium of Pleurotus tuberregium could be dried to minimal moisture content without the deterioration of its nutritional and medinicnal properties.

Thermal Behavior,Nonisothermal Decomposition Reaction Kinetics of Mixed Ester Double-base Gun Propellants

The thermal decomposition behavior and nonisothermal reaction kinetics of the double-base gun propellants containing the mixed ester of triethyleneglycol dinitrate（TEGDN） and nitroglycerin（NG） were investigated by thermogravimetry（TG） and differential thermogravimetry（DTG）, and differential scanning calorimetry（DSC） under the high-pressure dynamic ambience. The results show that the thermal decomposition processes of the mixed nitric ester gun propellants have two mass-loss stages. Nitric ester evaporates and decomposes in the first stage, and nitrocellulose and centralite II（C2） decompose in the second stage. The mass loss, the DTG peak points, and the terminated temperatures of the two stages are changeable with the difference of the mass ratio of TEGDN to NG. There is only one obvious exothermic peak in the DSC curves under the different pressures. With the increase in the furnace pressure, the peak temperature decreases, and the decomposition heat increases. With the increase in the content of TEGDN, the decomposition heat decreases at 0.1 MPa and rises at high pressure. The variety of mass ratio of TEGDN to NG makes few effect on the exothermic peak temperatures in the DSC curves at different pressures. The kinetic equation of the main exothermal decomposition reaction of the gun propellant TG0601 was determined as： dα/dt=1021.59（1-α）3e-2.60×104/T. The reaction mechanism of the process can be classified as chemical reaction. The critical temperatures of the thermal explosion（Tbe and Tbp） obtained from the onset temperature（Te） and the peak temperature（Tp） are 456.46 and 473.40 K, respectively. ΔS≠, ΔH≠, and ΔG≠ of the decomposition reaction are 163.57 J·mol^-1·K^-1, 209.54 kJ·mol^-1, and 133.55 kJ·mol^-1, respectively.

Thermal decomposition of ammonium perchlorate catalyzed with CuO nanoparticles

Ammonium perchlorate(APC)is the most common oxidizer in use for solid rocket propulsion systems.However its initial thermal decomposition is an endothermic process that requires 102.5 J·g^-1.This manner involves high activation energy and could render high burning rate regime.This study reports on the sustainable fabrication of CuO nanoparticles as a novel catalyzing agent for APC oxidizer.Colloidal CuO nanoparticles with consistent product quality were fabricated by using hydrothermal processing.TEM micrographs demonstrated mono-dispersed particles of 15 nm particle size.XRD diffractogram demonstrated highly crystalline material.The synthesized colloidal CuO particles were effectively coated with APC particles via co-precipitation by using fast-crash solvent-antisolvent technique.The impact of copper oxide particles on APC thermal behavior has been investigated using DSC and TGA techniques.APC demonstrated an initial endothermic decomposition stage at 242℃ with subsequent two exothermic decomposition stages at 297,8℃ and 452.8℃ respectively.At 1 wt%,copper oxide offered decrease in initial endothermic decomposition stage by 30%.The main outcome of this study is that the two main exothermic decomposition peaks were merged into one single peak with an increase in total heat release by 53%.These novel features can inherit copper oxide particles unique catalyzing ability for advanced highly energetic systems.

3D FE Analysis of Thermal Behavior of Billet in Rod and Wire Hot Continuous Rolling Process

An FE model was developed to study thermal behavior during the rod and wire hot continuous rolling process. The FE code MSC. Marc was used in the simulation using implicit static arithmetic. The whole rolling process of 30 passes was separated and simulated with several continuous 3D elastic-plastic FE models. A rigid pushing body and a data transfer technique were introduced into this model. The on-line experiments were conducted on 304 stainless steel and GCr15 steel hot continuous rolling process to prove the results of simulation by implicit static FEM. The results show that the temperature results of finite element simulations are in good agreement with experiments, which indicate that the FE model developed in this study is effective and efficient.

Thermal Behavior in Relation to Different Bindings of Alumina Based Castables from 20 to 1000℃

Thermal behavior and physical properties of castables during curing and drying-out are associated with their binding system. In this work, five alumina based （ Al2O3 〉 87% ） castables with different combinations of binding materials, i. e. , （ 1 ） CA cement （CA） ＋ Reactive alumina （ RA ） ＋ H2O ; （ 2 ） high level addi- tion of CA ＋ Microsilica （MS） ＋ H2O ; （ 3 ） low level addition of CA ＋ MS ＋ H2O ; （4） MS ＋ Hydratable alumina ＋ H20 and （ 5 ） MS ＋ Magnesia ＋ H2O, respectively, have been investigated on the flowability and thermal behavior during curing at room temperature, drying at 110% and heating from 200℃ to 1000℃ at an interval of 100℃ , in terms of water addition, vibration flow value, porosity, dehydration, explosion resistance, cold and hot bending strengths. Differences in dehydrating behavior and the mentioned properties have been revealed and correlated to the binding system.

Synthesis,Crystal Structure and Thermal Analysis of N-(2,3-Dimethyl-phenyl)-N'-(methoxyl formyl)thiourea

N-（2,3-Dimethyl-phenyl）-N＇-（methoxyl formyl）thiourea was synthesized by the reacting of 2,3-dimethylaniline,potassium thiocyanate（KSCN） and methyl chloroformate（ClCOOCH 3）.Single crystal was obtained by slowly evaporation solvent at room temperature.The structure was characterized by elemental analysis,IR and X-ray crystalography.The compound crystallized：a triclinic system with space group Pī,a=0.83440（12） nm,b=0.89113（13） nm,c=0.93015（13） nm,α=76.548（2） o,β=63.906（2） o,γ=82.538（2） o,V=0.60379（15） nm 3,Z=2,D c =1.311 mg/m 3,F（000）=252,μ=0.256 mm-1,R 1 =0.0379,wR 2 =0.0919.The specific heat capacity of the title compound was determined by a Micro-DSC method,and the specific heat capacity was 1.25 J·g-1 ·K-1 at 298.15 K.Thermodynamic functions,relative to those at the standard temperature of 298.15 K,were calculated via thermodynamic relationship.The thermal behavior of the title compound under a non-isothermal condition was studied by differential scanning calorimetry/thermogravimetric（DSC/TG） method.There was an obvious endothermic peak in the DSC curve,the peak temperature was 479.43 K.The compound mass loss was 89.94% observed from the TG curve.

Thermal Behavior, Non-isothermal Decomposition Reaction Kinetics of Copper(Ⅱ) Salt of 4-Hydroxy-3,5-dinitropyridine and Its Application in Propellant

The thermal behavior and kinetic parameters of the major exothermic decomposition reaction of the title compound in a temperature-programmed mode were studied by means of TG-DTG and DSC. The critical temperature of thermal explosion was calculated. The effect of the title compound on the combustion characteristic of composition modifier double base propellant containing RDX was explored with a strand burner. The results show that the kinetic model function in differential forms, the apparent activation energy(E a) and the pre-exponential factor(A) of the major exothermic decomposition reaction are 3(1-α)[-ln(1-α)] 2/3, 190.56 kJ/mol and 10 13.39 s -1, respectively. The critical temperature of thermal explosion of the compound is 353.08 ℃. The kinetic equation of the major exothermic decomposition process of the title compound at 0.1 MPa could be expressed as dα/dT=10 14.65(1-α)[-ln(1-α)] 2/3 e -2.2920×104/T. As an auxiliary catalyzer, the title compound can help the main catalyzer of lead salt of 4-hydroxy-3,5-dinitropyridine to accelerate the burning rate and reduce the pressure exponent of RDX-CMDB propellant.

A New Co(Ⅱ) Coordination Polymer Based on a Flexible 1,4-Cyclohexanedicarboxylic Acid: Synthesis, Structure and Thermal Behavior

A new Co(Ⅱ) coordination polymer, [Co(1,4-chdc)(L)(H2O)]n(1), was synthesized under hydrothermal condition(1,4-H2chdc = 1,4-cyclohexanedicarboxylic acid, L = 2-(4-fluoro-phenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline). Its crystal structure was determined by single-crystal X-ray diffraction. 1 crystallizes in triclinic, space group P1 with a = 8.790(5), b = 10.486(5), c = 13.305(5)A, α = 87.391(5), β = 82.925(5), γ = 81.841(5)°, V = 1204.2(10)A^3, Z = 2, C27H23FN4O5Co, Mr = 561.42, Dc = 1.548 g/cm^3, F(000) = 578, μ(Mo Ka) = 0.769 mm^-1, R = 0.0415 and wR = 0.1043. In 1, each 1,4-chdc anion bridges two neighboring Co(Ⅱ) atoms to give a chain structure. The L ligands are attached on one side of the chain through chelating the Co(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a double-chain structure. The double-chain structures are linked into a supramolecular layer structure through N–H…O hydrogen-bonding interactions between the adjacent double-chain structures. Moreover, the thermal behavior of 1 was also studied.

Thermal Behavior and Non-isothermal Kinetics of the Polyoxometalate of Ciprofloxacin with Tungstophosphoric Acid

The polyoxometalate （CPFX-HCl）3H3PW12O40·.8H2O was prepared and characterized by elemental analysis, IR spectra and TG-DTA-DTG. The thermal decomposition mechanism and non-isothermal kinetic parameters of the polyoxometalate were obtained from the analysis of TG-DTG data using the Achar equation, Coats-Redfern equation （CR）, Madhusudanan-Krishnan-Ninan equation （MKN） and Horowitz-Metzger equation （HM）. And their mathematical expressions of the kinetic compensation effect were also calculated.

Simulation-based Estimation of Thermal Behavior of Direct Feed Drive Mechanism with Updated Finite Element Model

Linear motors generate high heat and cause significant deformation in high speed direct feed drive mechanisms.It is relevant to estimate their deformation behavior to improve their application in precision machine tools.This paper describes a method to estimate its thermal deformation based on updated finite element（FE）model methods.Firstly,a FE model is established for a linear motor drive test rig that includes the correlation between temperature rise and its resulting deformation.The relationship between the input and output variables of the FE model is identified with a modified multivariate input/output least square support vector regression machine.Additionally,the temperature rise and displacements at some critical points on the mechanism are obtained experimentally by a system of thermocouples and an interferometer.The FE model is updated through intelligent comparison between the experimentally measured values and the results from the regression machine.The experiments for testing thermal behavior along with the updated FE model simulations is conducted on the test rig in reciprocating cycle drive conditions.The results show that the intelligently updated FE model can be implemented to analyze the temperature variation distribution of the mechanism and to estimate its thermal behavior.The accuracy of the thermal behavior estimation with the optimally updated method can be more than double that of the initial theoretical FE model.This paper provides a simulation method that is effective to estimate the thermal behavior of the direct feed drive mechanism with high accuracy.

Effect of the alidade thermal behavior on the pointing accuracy of a large radio telescope

The alidade’s non-uniform temperature field of a large radio telescope is very obvious under solar radiation.Estimating a radio telescope’s pointing errors,caused by the alidade deformation under solar radiation,is significant to improve the telescope’s pointing accuracy.To study the effect of the alidade thermal behavior on the pointing accuracy of a large radio telescope,a temperature experiment is first carried out in a 70-m radio telescope on a sunny day.According to the measured results,the temperature distribution rule of the alidade is summarized initially.In addition,the alidade’s temperature field is calculated by finite element thermal analysis.The simulated results are proved to be in good agreement with the experimental results.Finally,the alidade deformation under solar radiation is computed by finite element thermalstructure coupling analysis.The telescope’s pointing errors caused by alidade deformation are estimated via the alidade’s node displacements.The final results show that the effect of alidade thermal behavior on the telescope’s elevation pointing errorsΔε2+Δεr is much more than the effect on the telescope’s crosselevation pointing errorsΔε1.The maximum ofΔε2+Δεr is more than 45″,while the maximum ofΔε1 is less than 6″.This study can provide valuable references for improving the pointing accuracy of large radio telescopes.

Microstructural changes during heating of super duplex stainless steel and its thermal deformation behavior

Microstructural changes during heating of highly alloyed Cr26Ni7 type super duplex stainless steel （SDSS2607） and its thermal deformation behavior were investigated. At different heating rates, the mechanism of phase transition from y phase to 6 phase and growth modes of ~ phase differed. Variations in microstructures for as- cast SDSS2607 during heat preservation at 1 220 ~C indicated two kinds of transformations from y phase to 6 phase. In-situ observations of microstructural changes during the tensile process at 1 050 showed a mutual coordination between y and 6 phases. When the true strain increased, the mutual coordination between 7 and 6 phases was damaged. Subsequently, cracks nucleated at the ＂y/g interface. With the increase in temperature, the strength of as- cast SDSS2607 decreased while its plasticity increased. Its thermoplasticity was poor, and the reduction in area of tensile specimens was less than 80%. When the deformation strain of hot compression increased, the stable deformation zone in the heat processing maps enlarged gradually. Moreover, the unstable deformation zones were extended.

Synthesis,Crystal Structure and Thermal Behavior of a New 2D Barium(Ⅱ) Coordination Polymer with 1H-benzimi-dazole-5,6-dicarboxylate as the Single Ligand

The self-assembly of 1H-benzimidazole-5,6-dicarboxylic acid with barium chloride under hydrothermal conditions afforded a new 2D coordination polymer,[Ba2（L）（HL）Cl]n（1,L = 1H-benzimidazole-5,6-dicarboxylate）,which was characterized by elemental analysis,infrared spectroscopy,thermogravimetric analysis,and single-crystal X-ray diffraction.Compound 1 is of monoclinic system,space group P21/c with a = 10.0145（6）,b=25.6854（15）,c=7.3116（4） ？,β = 99.4980（10）°,V = 1854.95（19）3,C18H9Ba2ClN4O8,Z = 4,Mr=719.42,Dc = 2.576 g/cm3,μ（MoKα） = 4.427 mm-1,F（000） = 1352,the final R = 0.0202 and wR=0.0465 for 3051 observed reflections with I 2σ（I）.It exhibits an interesting two-dimensional network structure and high thermal stability（up to 420 ℃）.