scholarly journals Thermodynamic Study of Adsorption Capacity between Metal Film and Optical Crystal: Adsorption Energy of Ni Films on LiNbO3 Substrates

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1273
Author(s):  
Yuhang Xu ◽  
Fei Lu ◽  
Kaijing Liu ◽  
Changdong Ma
Keyword(s):  
Adsorption Energy ◽  
Metal Film ◽  
Substrate Material ◽  
Practical Significance ◽  
High Adsorption ◽  
Structural Differences ◽  
Different Temperatures ◽  
Growth Method ◽  
Full Annealing ◽  
Two Temperature

The growth of large areas of two-dimensional homogeneous graphene depends on the bond between the metal film, which acts as a catalyst, and the substrate material. The structural differences between the metal and the various anisotropic crystals make this growth method a challenge for the feasibility of growing graphene on optical crystals. In this paper, the evolution of the adsorption energy between nickel (Ni) films and Lithium Niobate (LiNbO3, LN) crystals is modelled under different thermal treatment environments by constructing a physical model of the temperature dependence of the adsorption energy between the two materials. With the aid of a series of simulated full annealing processes, the changes in adsorption energy at different temperatures were calculated. The results show that there are two “temperature windows” with target annealing temperatures of 700–800 K and 950–1050 K that prove to have high adsorption energies. This is of great guiding and practical significance for the direct transfer-free synthesis of graphene on LiNbO3 substrates.

Self-Toughness Porous Sodium Titanate Bioceramics Prepared via In Situ Grown Na2Ti6O13 Rods

2017 ◽  
Vol 727 ◽  
pp. 806-814 ◽  
Author(s):  
Xiao Wei Ma ◽  
Jian Xing Shen ◽  
Ke Chang Zhang ◽  
Ling Kai Kong ◽  
Jia Le Sun ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Sodium Titanate ◽  
The Novel ◽  
Ceramic Samples ◽  
Porous Bioceramic ◽  
Different Temperatures ◽  
Growth Method ◽  
Titanate Ceramics

Here in, we report the porous bioceramic with Na2Ti6O13 rods prepared by in‒situ growth method. The samples were prepared using cold uniaxial pressing (40 MPa) technique and further sintered at different temperatures. The structure and morphology were characterized by XRD and SEM. The porosity, compressive strength and fracture toughness were also investigated. The bone-like apatite deposition ability of the fabricated ceramic samples was evaluated by Kokubo simulated body fluid (SBF) soaking method. The results indicated that the Na2Ti6O13 rods with about 1‒3 μm in diameter are uniformly distributed in the self‒toughness porous sodium titanate ceramics (SPSTC). The SPSTC with a porosity of 61.10±1.12 % exhibits good compressive strength (43.36±2.43 MPa) and fracture toughness (3.47±0.21 MPa·m1/2). The results indicate that the novel SPSTC scaffolds are promising for bone tissue engineering applications.

scholarly journals Modified Dual-Site Langmuir Adsorption Equilibrium Models from A GCMC Molecular Simulation

2020 ◽  
Vol 10 (4) ◽  
pp. 1311
Author(s):  
Junchao Wang ◽  
Yongjie Wei ◽  
Zhengfei Ma
Keyword(s):  
Molecular Simulation ◽  
Adsorption Energy ◽  
Pressure Swing Adsorption ◽  
Adsorption Equilibrium ◽  
Equilibrium Data ◽  
Different Temperatures ◽  
Adsorption Energies ◽  
Pressure Swing ◽  
Adsorption Equilibrium Data ◽  
Dual Site

In the modern industrial separation process, the pressure swing adsorption technology is widely used to separate and purify gases due to its low energy consumption, low cost, convenience, reliability, and environmental benignity. The basic elements of the design and application of the pressure swing adsorption process are adsorption isotherms at different temperatures for adsorbents. The dual-site Langmuir (DSL) adsorption equilibrium model is the mostly used model; however, this model is based on the assumption that the adsorption energy on the surface of an adsorbent is uniform and remains unchanged. Here, a grand canonical Monte Carlo (GCMC) molecular simulation was used to calculate the CO2 adsorption equilibrium on MIL-101 (Cr) at 298 K. MIL-101 (Cr) was chosen, as it has more a general pore structure with three different pores. The calculation results showed that the adsorption energies with different adsorption pressures fitted a normal distribution and the relationship of the average adsorption energies, E with pressures had a linear form described as: E = aP + c. With this relationship, the parameter b = k·exp(E/RT) in the DSL model was modified to b = k·exp((aP + c)/RT), and the modified DSL model (M-DSL) was used to correlate the adsorption equilibrium data on CO2-MIL-101 (Cr), C2H4-HHPAC, CH4-BPL, and CO2-H-Mordenite, showing better correlations than those of the DSL model. We also extended the parameter qm in the M-DSL model with the equation qm = k1 + k2T to adsorption equilibrium data for different temperatures. The obtained model (M-TDSL) was checked with the abovementioned adsorption equilibrium systems. The fitting results also indicated that the M-TDSL model could be used to improve the correlation of adsorption equilibrium data for different temperatures. The linear relationship between the average adsorption energy and adsorption pressure could be further tested in other adsorption equilibrium models to determine its universality.

TWO-TEMPERATURE NON-EQUILIBRIUM ISING MODELS

1996 ◽  
Vol 07 (03) ◽  
pp. 389-399 ◽  
Author(s):  
P. TAMAYO ◽  
R. GUPTA ◽  
F. J. ALEXANDER
Keyword(s):  
Ising Model ◽  
Computational Study ◽  
Heat Bath ◽  
Universality Class ◽  
Ising Models ◽  
Local Competition ◽  
Equilibrium Dynamics ◽  
Different Temperatures ◽  
Two Temperature ◽  
Non Equilibrium

We present results from a computational study of a class of 2D two-temperature non-equilibrium Ising models. In these systems the dynamics is a local competition of two equilibrium dynamics at different temperatures. We analyzed non-equilibrium versions of Metropolis, heat bath/Glauber and Swendsen-Wang dynamics and found strong evidence that some of these dynamics have the same critical exponents and belong to the same universality class as the equilibrium 2D Ising model.

scholarly journals Synthesis of a benzyl-grafted alginate derivative and its effect on the colloidal stability of nanosized titanium dioxide aqueous suspensions for Pickering emulsions

RSC Advances ◽  
2018 ◽  
Vol 8 (60) ◽  
pp. 34397-34407 ◽  
Author(s):  
Meixi Feng ◽  
Chuanhai Gu ◽  
Chaoling Bao ◽  
Xiuqiong Chen ◽  
Huiqiong Yan ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Adsorption Energy ◽  
Colloidal Stability ◽  
Pickering Emulsions ◽  
High Adsorption ◽  
Aqueous Suspensions ◽  
Nanosized Titanium Dioxide ◽  
Gravity Sedimentation ◽  
Spontaneous Aggregation

TiO2 nanoparticles (nano-TiO2) easily undergo spontaneous aggregation and gravity sedimentation ascribed to their high adsorption energy, which significantly restrict their actual applications.

scholarly journals A Thermal Damage Constitutive Model for Oil Shale Based on Weibull Statistical Theory

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Guijie Zhao ◽  
Chen Chen ◽  
Huan Yan
Keyword(s):  
High Temperature ◽  
Constitutive Model ◽  
Oil Shale ◽  
Thermal Damage ◽  
Triaxial Compression ◽  
Strain Curve ◽  
Practical Significance ◽  
Compression Tests ◽  
Different Temperatures ◽  
Damage Constitutive Model

In this work, we first studied the thermal damage to typical rocks, assuming that the strength of thermally damaged rock microelements obeys a Weibull distribution and considering the influence of temperature on rock mechanical parameters; under the condition that microelement failure conforms to the Drucker–Prager criterion, the statistical thermal damage constitutive model of rocks after high-temperature exposure was established. On this basis, conventional triaxial compression tests were carried out on oil shale specimens heated to different temperatures, and according to the results of these tests, the relationship between the temperature and parameters in the statistical thermal damage constitutive model was determined, and the thermal damage constitutive model for oil shale was established. The results show that the thermal damage in oil shale increases with the increase of temperature; the damage variable is largest at 700°C, reaching 0.636; from room temperature to 700°C, the elastic modulus and Poisson’s ratio decrease by 62.66% and 64.57%, respectively; the theoretical stress-strain curve obtained from the model is in good agreement with the measured curves; the maximum difference between the two curves before peak strength is only 5 × 10−4; the model accurately reflects the deformation characteristics of oil shale at high temperature. The research results are of practical significance to the underground in situ thermal processing of oil shale.

Gas Phase Phosphorus Heavily-Doped FZ Silicon Thermal Field Design and Growth Method

2012 ◽  
Vol 430-432 ◽  
pp. 929-932
Author(s):  
Xue Nan Zhang ◽  
Jian Hong Li ◽  
Yu Tian Wang ◽  
Chang Xu Zhang ◽  
Chun Geng Yang ◽  
...  
Keyword(s):  
Gas Phase ◽  
Thermal Field ◽  
Cooling System ◽  
Silicon Crystal ◽  
Substrate Material ◽  
Low Oxygen ◽  
Float Zone ◽  
Growth Method ◽  
Resistivity Variation ◽  
Heavily Doped

This paper introduces the fabrication method of a kind of gas phase phosphorus heavily-doped float zone (FZ) silicon, including thermal field design (electromagnetic copper coil with double water cooling system). This method solves the problems during the pulling process of heavily-doped FZ silicon crystal of phosphorus doped. The gas phase phosphorus heavily-doped FZ silicon crystal using this methods with low oxygen content (less than 0.2ppma),low radial resistivity variation (less than 10%), low resistivity (the minimum of 0.002 ohm.cm), and is good to meet the transient voltage suppressor (TVS) for silicon substrate material requirements.

Thermoviscoplasticity in Body-Centered Cubic Metals: A Two-Temperature Model With Grain Boundary Evolution

2020 ◽  
Vol 87 (11) ◽  
Author(s):  
Gurudas Kar ◽  
Debasish Roy ◽  
J. N. Reddy
Keyword(s):  
Plastic Deformation ◽  
Grain Boundary ◽  
Internal Variable ◽  
Dislocation Motion ◽  
Body Centered Cubic ◽  
Boundary Density ◽  
Different Temperatures ◽  
Growth Dislocation ◽  
Thermodynamics Modeling ◽  
Two Temperature

Abstract In this work, we develop a thermo-viscoplasticity model for body-centered cubic (BCC) metals based on a two-temperature theory of nonequilibrium thermodynamics. Modeling the plastic deformation here involves two subsystems, viz., a configurational subsystem related to grain growth, dislocation motion, and a kinetic vibrational subsystem describing the vibration of atoms. Due to a separation of the time scales, the two subsystems are described by two different temperatures. In this study, we introduce a grain boundary density, in addition to the mobile and forest dislocation densities, as an internal variable. The focus in this paper is on how large plastic deformation is affected by the evolving grain boundaries. In order to check the predictive quality of the model, numerical simulations are conducted and validated against available experimental evidence wherever possible.

Criteria Governing Electron Plasma Waves in a Two-Temperature Plasma

1987 ◽  
Vol 42 (10) ◽  
pp. 1175-1180 ◽  
Author(s):  
M. P. Dell ◽  
I. M. A. Gledhill ◽  
M. A. Hellberg
Keyword(s):  
Dielectric Function ◽  
Saddle Points ◽  
Plasma Waves ◽  
Electron Plasma ◽  
Temperature Plasma ◽  
Different Temperatures ◽  
Two Temperature

Using a technique based on the saddle-points of the dielectric function, criteria are found which govern the behaviour of electron plasma waves in plasmas with two electron populations having different temperatures.

Numerical study of the sheath in magnetized dusty plasma with two-temperature electrons

2014 ◽  
Vol 81 (1) ◽  
Author(s):  
I. Driouch ◽  
H. Chatei ◽  
M. El Bojaddaini
Keyword(s):  
Dusty Plasma ◽  
Numerical Study ◽  
Plasma Sheath ◽  
Hot Electrons ◽  
Dust Grains ◽  
Magnetized Dusty Plasma ◽  
Positive Ions ◽  
Different Temperatures ◽  
Dimensionless Variables ◽  
Two Temperature

Fluid simulations are used to investigate a multi-component magnetized dusty plasma sheath. The model consists of positive ions, dust grains, and two species of electron populations. These electrons are assumed to be a sum of two Maxwellian distributions with two different temperatures (cold and hot). According to multi-fluid equations and some dimensionless variables, the dimensionless equations are obtained and solved numerically. The effect of the presence of the hot electrons in the sheath is examined. A significant change is observed in the quantities characterizing the sheath with respect to one species electrons (cold) assumption.

Effect of Seed Treatments on Germination in Acacia

1977 ◽  
Vol 25 (3) ◽  
pp. 269 ◽  
Author(s):  
J Clemens ◽  
PG Jones ◽  
NH Gilbert
Keyword(s):  
Water Treatment ◽  
Germination Rate ◽  
Hot Water ◽  
Practical Significance ◽  
Hot Water Treatment ◽  
Percentage Germination ◽  
Single Treatment ◽  
Seed Mortality ◽  
Different Temperatures ◽  
Time Periods

The germination of seed of five Acacia spp. was studied following a manual chipping treatment or exposure to water held at different temperatures for discrete time periods. Response was evaluated on the basis of the final percentage germination, and estimates of rate of germination and time taken for germination to commence. There were differences in response of the species to hot water sufficiently large to be of practical significance. No single treatment gave optimum germination in all species. Increasing severity of treatment improved germination rate and percentage germination up to a point where seed mortality became apparent. Manual chipping of the seed gave larger improvements in germination rate, and the seeds began to germinate faster than those given any hot water treatment. However, in some species germination percentages were lower in chipped seeds than in those treated with hot water.

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