The effects of process conditions on the plasma characteristic in radio-frequency capacitively coupled SiH_4/NH_3/N_2 plasmas: Two-dimensional simulations

A two-dimensional （2D） fluid model is presented to study the behavior of silicon plasma mixed with SiH4 , N2 , and NH3 in a radio-frequency capacitively coupled plasma （CCP） reactor. The plasma–wall interaction （including the deposition） is modeled by using surface reaction coefficients. In the present paper we try to identify, by numerical simulations, the effect of variations of the process parameters on the plasma properties. It is found from our simulations that by increasing the gas pressure and the discharge gap, the electron density profile shape changes continuously from an edge-high to a center-high, thus the thin films become more uniform. Moreover, as the N2 /NH3 ratio increases from 6/13 to 10/9, the hydrogen content can be significantly decreased, without decreasing the electron density significantly.

Optimization of Generator Based on Gaussian Process Regression Model with Conditional Likelihood Lower Bound Search

The noise that comes from finite element simulation often causes the model to fall into the local optimal solution and over fitting during optimization of generator.Thus,this paper proposes a Gaussian Process Regression(GPR)model based on Conditional Likelihood Lower Bound Search(CLLBS)to optimize the design of the generator,which can filter the noise in the data and search for global optimization by combining the Conditional Likelihood Lower Bound Search method.Taking the efficiency optimization of 15 kW Permanent Magnet Synchronous Motor as an example.Firstly,this method uses the elementary effect analysis to choose the sensitive variables,combining the evolutionary algorithm to design the super Latin cube sampling plan;Then the generator-converter system is simulated by establishing a co-simulation platform to obtain data.A Gaussian process regression model combing the method of the conditional likelihood lower bound search is established,which combined the chi-square test to optimize the accuracy of the model globally.Secondly,after the model reaches the accuracy,the Pareto frontier is obtained through the NSGA-II algorithm by considering the maximum output torque as a constraint.Last,the constrained optimization is transformed into an unconstrained optimizing problem by introducing maximum constrained improvement expectation(CEI)optimization method based on the re-interpolation model,which cross-validated the optimization results of the Gaussian process regression model.The above method increase the efficiency of generator by 0.76%and 0.5%respectively;And this method can be used for rapid modeling and multi-objective optimization of generator systems.

Parallel Technologies with Image Processing Using Inverse Filter

Real-time capabilities and computational efficiency are provided by parallel image processing utilizing OpenMP. However, race conditions can affect the accuracy and reliability of the outcomes. This paper highlights the importance of addressing race conditions in parallel image processing, specifically focusing on color inverse filtering using OpenMP. We considered three solutions to solve race conditions, each with distinct characteristics: #pragma omp atomic: Protects individual memory operations for fine-grained control. #pragma omp critical: Protects entire code blocks for exclusive access. #pragma omp parallel sections reduction: Employs a reduction clause for safe aggregation of values across threads. Our findings show that the produced images were unaffected by race condition. However, it becomes evident that solving the race conditions in the code makes it significantly faster, especially when it is executed on multiple cores.

Extraction Conditions of Essential Oil from Eucalyptus Leaves by Distillation

[Objectives]To explore the extraction conditions of essential oil from eucalyptus leaves.[Methods]The essential oil of eucalyptus leaves was extracted by steam distillation,and the yields of essential oil from eucalyptus leaves under different extraction times,soaking times and different solid-liquid ratios were analyzed through orthogonal test with three factors and three variables.[Results]The effects of various factors on extraction results were:distillation time>solid-liquid ratio>soaking time.When the extraction time and soaking time were 1.5 and 2 h,and the solid-liquid ratio of eucalyptus leaves to distilled water was 1:10,the yield of essential oil was the highest(0.8%).The yield of essential oil increased with the increase of extraction and soaking time,but when reaching the optimal value,the yield decreased with the extension of time.Increasing the solid-liquid ratio can improve the yield of essential oil,but beyond a certain value the yield increased gradually while the cost performance decreased.[Conclusions]The results will provide some reference for the recovery and utilization of eucalyptus leaves.

Study on Processing Conditions of Aluminum Matrix Composites Reinforced with Boron Carbide Particles

Different pre-heating of boron carbide particles for reinforcement and different processing conditions were studied in this work. Being one of the most cost-effective industrial methods, conventional melt stir-casting route was utilized.Result showed that the boron carbide particles distributed well for a suitable pre-heating temperature and processed in air.No reaction product was found at the A1-B4C interfaces at the resolution limit of SEM used in that way.

Necessary Conditions for the Application of Moving Average Process of Order Three

Invertibility is one of the desirable properties of moving average processes. This study derives consequences of the invertibility condition on the parameters of a moving average process of order three. The study also establishes the intervals for the first three autocorrelation coefficients of the moving average process of order three for the purpose of distinguishing between the process and any other process (linear or nonlinear) with similar autocorrelation structure. For an invertible moving average process of order three, the intervals obtained are , -0.5ρ2ρ1<0.5.

Study on the mechanism of isotope fractionation in soil water during the evaporation process under equilibrium condition

In this study, with the method of vacuum extraction, two evaporative processes of soil water and free water under equilibrium condition were simulated. For each sample,water vapor was condensed by liquid nitrogen and was collected in four time intervals. From the analysis of hydrogen and oxygen isotopic compositions of the water collected at different times, it was discovered that the isotope fractionation of soil water also follows the mode, which is just the same as the evaporative process of free water. The relationship between the stable hydrogen and oxygen isotopes in residual water showed that the simulative evaporation line was close to the global meteoric water line (GMWL) under the equilibrium condition at about 20℃. Comparison of the two types of evaporative processes indicated that the isotope fractionation and evaporation velocity of soil water were only slightly modified by the Van der Waals force.

Friction behaviors in the metal cutting process:state of the art and future perspectives

Material removal in the cutting process is regarded as a friction system with multiple input and output variables.The complexity of the cutting friction system is caused by the extreme conditions existing on the tool–chip and tool–workpiece interfaces.The critical issue is significant to use knowledge of cutting friction behaviors to guide researchers and industrial manufacturing engineers in designing rational cutting processes to reduce tool wear and improve surface quality.This review focuses on the state of the art of research on friction behaviors in cutting procedures as well as future perspectives.First,the cutting friction phenomena under extreme conditions,such as high temperature,large strain/strain rates,sticking–sliding contact states,and diverse cutting conditions are analyzed.Second,the theoretical models of cutting friction behaviors and the application of simulation technology are discussed.Third,the factors that affect friction behaviors are analyzed,including material matching,cutting parameters,lubrication/cooling conditions,micro/nano surface textures,and tool coatings.Then,the consequences of the cutting friction phenomena,including tool wear patterns,tool life,chip formation,and the machined surface are analyzed.Finally,the research limitations and future work for cutting friction behaviors are discussed.This review contributes to the understanding of cutting friction behaviors and the development of high-quality cutting technology.

Effects of Processing Conditions on Hydrothermal Synthesis of K_(0.5)Bi_(0.5)TiO_3 Nano-Powders

Potassium bismuth titanate nanosized powders were prepared by the hydrothermal method using Ti(C_4H_9O)_4 and Bi(NO_3)_3·5H_2O as raw materials in alkaline solution.The phase composition,particle size and morphology of the powders were studied by XRD and TEM analysis.The results showed that the powders were well crystallized and dispersed.The crystal phase of the powders was K_(0.5)Bi_(0.5)TiO_3 with the grain size of about 50 nm～100 nm.Hydrothermal temperature and alkaline concentrations had great effects on the phase composition and morphology of the resultant powders.Pure K_(0.5)Bi_(0.5)TiO_3 powders could be synthesized at 170℃～180℃with KOH concentration of 8 mol/L～12 mol/L.

Effect of Processing Conditions on the Compression Elasticity of Three Dimensional Crimp Staple

The multi-hollow three dimensional(3-D)crimp sta-ple were prepared by the non-symmetrical cooling spin-ning technology.The material properties,spinneret shape,drawing conditions,heat-setting conditions and silicon finishing conditions that influence the compression elasticity of the staple have been investigated.It is found that the compression elasticity of 3-D crimp PET staple is larger than that of 3-D crimp PP staple.The com-pression elasticity of the 5-hollow staple is much

Optimization of Screening Method for Feed Nutrition and Processing Conditions

On the basis of regressional relationship between nutritional indexes and technological conditions,when confronted with feed quality that contains multiple nutritional indexes,a comprehensive equation of evaluating feed quality was developed by using fuzzy mathematical method at first in this study,and then the optimum technological conditions were established by introduction of statistical frequency analysis method pursuant to the comprehensive evaluating equation mentioned above compared with conventional multi-aim nonlinear programming,this method can lead to easy solutions,and also can make adjustment of the importance of nutritional indexes to feed quality according to practical considerations.An example was given of soybean extruding to show how the method worked.

Occurrence Conditions and Process Analysis on Fluidization of Valley Type Landslide:Example of the Fluidization of Landslide in Qiongshan Ravine, Danba

A big debris flow which was arosed by landslide occurrence at night on July 11, 2003 in Qiongshan Ravine, Danba, Sichuan Province. According to the research, debris flow in Qiongshan Ravine is arosed by the fluidization of landslide. It had been rained about 70 days before debris flow occurred. That made the sediments in the gully to near to saturated or saturated in water. Being affect by the steep geography, the sediments occurrence peristalsis to transform, parts of soil bodies start disintegrate. All the sediments become transforming with water inleakaging to sediments, and than foreside slope flow to gully quickly after becoming fluidization. And the sediments come into being the debris flow with the water of the gully joining.

The Conditional Poisson Process and the Erlang and Negative Binomial Distributions

It is a well known fact that for the hierarchical model of a Poisson random variable Y?whose mean has an Erlang distribution, the unconditional distribution of Y is negative binomial. However, the proofs in the literature [1] [2] provide no intuitive understanding as to why this result should be true. It is the purpose of this manuscript to give a new proof of this result which provides such an understanding. The memoryless property of the exponential distribution allows one to conclude that the events in two independent Poisson processes may be regarded as Bernoulli trials, and this fact is used to achieve the research purpose. Another goal of this manuscript is to give another proof of this last fact which does not rely on the memoryless property.

Conditions,Mechanisms and Process within Self-organization Evolution

Business growth and development are similar to a selforganization evolution system. This paper intends to explore the context, drive and process within enterprise self-organization evolution from a conceptual perspective. And an enterprise evolution model can be applied on the basis of ecological logistic equations to approach the elementary process and the growth stage of organization. Moreover,the influence of diverse variable on the evolution of enterprise growth is discussed. At last, the study concludes that new structures and functions can emerge within organizations and enterprises,which contribute to transformation and upgrade during their self-organization evolution.

Magneto-Caloric Effect of Gd5Si2Ge2Compounds under Different Processing Conditions

The magneto-caloric effect of Gd5 Si2Ge2 compounds produced by various techniques is investigated in terms of their magnetization behaviors in the magnetic field from 0 to 2.0 T.The studied materials include arc-melted, annealed and sintered alloys.The results demonstrate that the Gd5Si2Ge2 alloys obtained under different processing conditions possess distinct magneto-caloric effect due to their various microstructures.Proper annealing treatment can enhance the magneto-caloric effect of the alloy remarkably.While the sintered alloy bears relatively lower value of magnetic entropy change ( △ SM) than arc-melted one.The magnetic entropy change of the annealed Gd5 Si2Ge2 alloy arrives the arrives the maximum value of - △SM = 15.29 J· kg-1· K-1 for magnetic field change under 2.0 T in the present work.

THE EXERGETIC EFFICIENCY OF MSF PROCESS AND THE CONDITIONS OF DESALINATION BY WASTE HEAT

The exergy losses and thermodynamic efficiency of MSF plant with brine recirculation are discussed bymeans of temperature difference functions proposed by the auther.In a MSF plant,the irreversible losses are found mainly in irreversible heat-transfer and flash evaporationprocesses.However,the basic variables are the temperature drop from stage to stage and the temperaturedifferences between flashed vapor and cooling water.In this paper,the flash temperature difference func-tion,the heat transfer temperature difference function and the total temperature difference function are sug-gested.The proposed temperature difference functions of MSF plant provide a convenient tool to analyse theirreversible behavior and evaluate the exergetic efficiency of this system,because without such improvement thecalculation of the exergetic efficiency of a MSF plant according to the classical formula will be not onlyinconvenient but also insignificant.As a result of present analysis,the reasonable parameters based on theenergy consumption are easily chosen.The above-mentioned principles are confirmed by commercial plants and a pilot plant in Tianjin.

Conditional Value-at-Risk for Random Immediate Reward Variables in Markov Decision Processes

We consider risk minimization problems for Markov decision processes. From a standpoint of making the risk of random reward variable at each time as small as possible, a risk measure is introduced using conditional value-at-risk for random immediate reward variables in Markov decision processes, under whose risk measure criteria the risk-optimal policies are characterized by the optimality equations for the discounted or average case. As an application, the inventory models are considered.

THE APPLICATION OF MICROELECTRODE TO THE STUDY OF MULTISTEP ELECTRODE PROCESSES UNDER STEADY STATE CONDITIONS PART I EE MECHANISM

Under steady-state conditions, the general currents of EE reactions at disk,hemispherical and spherical microelectrodes are derived.From these equations, some electrode reaction parameters can be very simply obtained.

Effect of Deformation Condition on Axial Compressive Precision Forming Process of Tube with Curling Die

The effect of the deformation condition on the axial compressive precision forming process of tube with curling die was investigated by using a rigid-plastic FEM. The results show that the forming accuracy depends mainly on geometric condition rp/d0, little on tube material properties and friction condition; the relative gap △/2rp of double-walled tubes obtained decreases with Increasing rp/d0, and there is a parameter k for a given to/do or rp/t0, when rp/d0 >k, △/2rp< 1, otherwise △/2rp>1.

Effect of Processing Conditions on the Interlaced Yarn

A new interlacer is used in this paper to investigate the effect of processing conditions on the properties of interlaced yarn.The experimental results show that number of tangles of interlaced yarn changes little with air pressure from 0.2 MPa to 0.5 MPa,and the number of tangles has a maximum value with yarn speed changing.For two yarn directions of entering and leaving yarn guide of interalcer,the yarn speed for the maximum number of tangles is 400 m/min and 600 m/min,respectively.The number of tangles changes with air pressure and yarn speed for two yarn directions is compared.