Effect of catch cup geometry on 3D boundary layer flow over the wafer surface in a spin coating

Recently, development of high technology has been required for the formation of thin uniform film in manufacturing processes of semiconductor as the semiconductor instruments become more sophisticated. Spin coating is usually used for spreading photoresist on a wafer surface. However, since rotating speed of the disk is very high in spin coating, the dropped photoresist scarers outward and reattaches on the film surface. A catch cup is set up outside the wafer in spin coating, and scattered photoresist mist is removed from the wafer edge by the exhaust flow generated at the gap between the wafer edge and the catch cup. In the dry process of a spin coating, it is a serious concern that the film thickness increases near the wafer edge in the case of low rotating speed. The purpose of this study is to make clear the effect of the catch cup geometry on the 3D boundary layer flow over the wafer surface and the drying rate of liquid film.     

Design and simulation of antireflection coating for application to silicon solar cells

Phosphorous silicate glass (PSG) was formed at the temperature range 800–900°C during diffusion of phosphorous (P) into Si wafers from liquid POCl₃ source in ambient atmosphere of N₂ and O₂. The thickness and refractive indices were measured by an ellipsometer. The refractive index increased with the temperature of formation upto 875°C and then became constant at which point PSG is saturated with P. From the growth rate data at different temperatures, the linear and parabolic activation energies were determined as 0.79 and 1.43 eV for parabolic and linear rate constants, respectively. Therefore, growth rate of PSG is higher than thermal SiO₂. The PSG films were found to have refractive indices 1.85, 1.78, 1.74 and 1.71 for forming temperature 800°C, 825°C, 850°C and 875°C, respectively. Reflectivity varied from 2.5% to 7.5% in the wavelength range 450–700 nm. SIMS depth profiling suggests that there has been a pile up of P on the Si side at the Si/SiO₂ (PSG) interface.     

Development of a mixed integer programming model for technology development strategy and its application to IGCC technologies

The cost effective R&D strategy is required especially for large-scale technologies because their development demands a large amount of investment in general. A mixed integer programming model was developed for the optimum technology development strategy in the field of energy systems. The module of the technology development process in the model is based on GERT (Graphical Evaluation and Review Technique). In the module, a target technology is broken down into many elemental technologies. Usually several target technologies are involved for the evaluation of technology development strategy of one field and some of the elemental technologies are used common to a number of target technologies. Since elemental technologies are explicitly modeled, their spillover effects are necessarily evaluated in this model analysis. The proposed method was applied to the evaluation of the development strategy of four types of IGCC (Integrated coal Gasification Combined Cycle) technologies which have different levels of thermal efficiencies. The total investment on both their R&D and practical use is optimized under the constraint of meeting a certain exogenous scenario of electricity demand. The evaluation results include the optimum additional investment allocation among the developments of various elemental technologies; developments of integration technology for IGCC-43%, IGCC-55% and IGCC-48%, coal gasification technology, oxide dispersion strengthened superalloy technology for the gas turbine blade and vane, ceramic matrix composite technology for the gas turbine blade, dry sulfur-removal technology, etc. are cost-effective.     

Online simulation model of the slab-reheating process in a pusher-type furnace

This paper presents an online simulation model of the slab-reheating process in a pusher-type furnace in Acroni d.o.o. in Slovenia. The simulation model is connected to the information system of a hot-processing plant that provides online measuring and charging data of the furnace. The simulation model considers the exact geometry of the furnace enclosure, including the geometry of the slabs inside the furnace. A view-factor matrix of the furnace enclosure was determined using the Monte Carlo method. The heat exchange between the furnace gas, the furnace wall and the slab’s surface is calculated using a three-temperature model. The heat conduction in the slabs is calculated using the 3D finite-difference method. The model was validated using measurements from trailing thermocouples positioned in the test slabs during the reheating process in the furnace.A graphical user interface (GUI) was developed to ensure a user-friendly presentation of the simulation-model results.     

Development of a 20 kW wind turbine simulator with similarities to a 3 MW wind turbine

As the use of wind power has steadily increased, the importance of a condition monitoring and fault diagnosis system is being emphasized to maximize the availability and reliability of wind turbines. To develop novel algorithms for fault detection and lifespan estimation, a wind turbine simulator is indispensible for verification of the proposed algorithms before introducing them into a health monitoring and integrity diagnosis system. In this paper, a new type of simulator is proposed to develop and verify advanced diagnosis algorithms. The simulator adopts a torque control method for a motor and inverter to realize variable speed-variable pitch control strategies. Unlike conventional motor–generator configurations, the simulator includes several kinds of components and a variety of sensors. Specifically, it has similarity to a 3 MW wind turbine, thereby being able to acquire a state of operation that closely resembles that of the actual 3 MW wind turbine operated at various wind conditions. This paper presents the design method for the simulator and its control logic. The experimental comparison between the behavior of the simulator and that of a wind turbine shows that the proposed control logic performs successfully and the dynamic behaviors of the simulator have similar trends as those of the wind turbine.     

Development of China TIMES-30P model and its application to model China's provincial low carbon transformation

To explore the provincial energy system transformation till 2050 under the carbon emission constraints from a bottom-up perspective, this research develops the China TIMES-30P model with detailed characterization of China's provincial energy system and applies it to low carbon scenarios analysis. A set of methodology is developed to project the key provincial socio-economic parameters and the provincial energy service demand, which is the major driving force of the China TIMES-30P model. Results show that compared with the value in 2015, the provincial intensity of final energy consumption will decrease by 65%–90% under different scenarios in 2050. The intensities of primary energy consumption in most of the provinces will be lower than 0.2 tce/1000 dollars under different scenarios in 2050. In the WBD2 scenario, the national CO₂ emission can reach the peak value of 9.3 billion tons in 2020 and the provincial CO₂ emission intensity in 2050 will decrease by 85%–100%, compared with the value in 2015.     

Comparison of a Reaction Front Model and a Finite Difference Model for the Simulation of Solid Absorption Process

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Development of a simulation tool to enable optimisation of the energy consumption of the industrial timber-drying process

Reducing the liquid content of green products is an important step in the manufacture of many products. Process conditions in the drying phase have significant influences on the quality of the end product and on energy consumption and required manufacturing time. Effective optimisation of the drying process requires accurate representation of the drying product and its interaction with its environment. The development of a computer simulation tool to analyse the industrial batch timber drying process is outlined. A detailed finite difference product model describing the heat and mass transfers within a plank during drying is described. It is integrated with a customised CFD code characterising the process conditions within the drying chamber. Simulation output from the integrated model is used to generate a macroscopic representation of the product in its drying environment. This representation is included as a component in a modular industrial installation simulation environment. Analysis with this global model can lead to optimisation of energy consumption of the industrial timber drying process whilst maintaining product quality and acceptable drying duration.     

Modification of commercial briquetting machine to produce 35 mm diameter briquettes suitable for gasification and combustion

This paper describes an experience on producing 35 mm dia briquettes with a modified commercial briquetting machine and the results of studies on the combustion and gasification behavior of briquettes. Study reveals that at 12% (w.b.) moisture content of groundnut shell powder (1180–150 μm), good quality briquettes can be made, but it reduces the production rate and increases the power requirement. Combustion as well as gasification studies revealed that biomass briquettes of 35 mm diameter do not crumble or disintegrate during the conversion process, therefore these are suitable as feedstock for gasifiers.     

内燃机车新型预热燃油箱的研制与应用

介绍了新型预热燃油箱的研制和应用试验情况。指出将柴油机高温冷却水通过散热管引入燃油箱对燃油进行预热,可使机车在0℃以下的外温条件下使用0号柴油,实现"燃油低烧一号"工程,达到节资降耗的目的。     

纳米材料/技术及其在医学中的应用

【摘要】 为了使临床医师,特别是介入放射学和肿瘤学等专科医师,对纳米材料和纳米技术给予更多的关注,并进一步开展与此先进技术相关的临床或实验性研究,该文对纳米材料/技术的基础知识（包括定义、结构、分类和特性等）以及其在医学领域中的应用,以图文相结合的方式进行了综合性阐述,以使其内容更易理解。
     

Novel process to evaporate liquid fuels and its application to the catalytic partial oxidation of diesel

A novel process for evaporation of liquid hydrocarbons, like gasoline, diesel or kerosene, has been developed and tested. It allows to directly transfer a liquid hydrocarbon mixture into the gaseous phase avoiding all problems related to residue and carbon formation due to contact of the fuel with hot heat exchanger surfaces.     

A process simulation model for a 2 ton h−1 incinerator (a combined bed combustion and furnace heat transfer model)

A process simulation model was constructed for a 2 ton h⁻¹ incinerator. The simulation model was designed to provide system performance parameters according to various operating conditions. In accommodating the wide variation of quality and composition of input wastes, the plant operating parameters such as amount of excess air, preheated air temperature, waste feed rate and primary air distribution over the stoker, etc. must be carefully controlled. The proposed model calculates operating variables of each submodule, by employing steady-state thermal and material balance equations. Combustion of waste bed, and its radiative heat transfer in the combusion chamber are considered. The calculated results of the combustion chamber performance are evaluated, in terms of temperature, locations and width of the flame band, and mean residence time in the secondary combustion chamber. These results are compared with a limited set of field test measurements for verification of the model. © 1998 John Wiley & Sons, Ltd.     

两用车底炉的设计及应用

本文介绍某厂设计制造的两用式车底炉。该炉可作淬火加热或冲压件加热之用。文中详细阐述了炉子结构及烧嘴。通过运行和测试,炉温均匀,热效率高。     

A thermodynamics model for the compression and expansion process during the engine’s motoring and a new method for the determination of TDC with simulation technique

In this paper, a thermodynamics model describes the pressure change during the motoring process of the internal combustion engine was given based on the mass conservation, energy conservation law and the state equation of perfect gas. The factors that affect the maximal pressure point position relative to the minimal volume point (top dead center) were analysed with the thermodynamics model. The one to one correspondence between the geometrical characteristics of the pressure diagram and the maximum pressure point position relative to the top dead center (TDC) was proven. Based on the model described, a new method for the determination of the TDC of the internal combustion engine was given. The simulation and experimental results indicate that the new method could determine the top dead center with an error smaller than 0.05 crank angle.     

Development of a simulation model for a three-dimensional wind velocity field using Ténès Algeria as a case study

A mathematical simulation model was developed that can determine the three-dimensional wind velocity field over a complex terrain. The Ténès area in the Valley of Cheliff in Algeria was used as a case study. This region is exposed to south-west circulation that makes it favorable to the use of wind energy. Knowledge of wind fields is crucial for predicting the dispersion of pollutants, for forecasting meteorological weather, for fire spread prediction and in the design and implementation of wind turbines. By means of a mass consistent model, an in-house program was developed to calculate the three-dimensional wind velocity field in the study region. The model was supported by a numerical box in which flow through is allowed for in the upper and lateral boundaries. The bottom boundary through which no flow through occurs was determined by the topographic relief at the surface. From measured wind velocities, observed values were calculated by interpolation-extrapolation. Using an optimization method, the adjusted velocities were obtained from constraints, observed velocities and the continuity equation. The model was verified with wind point data, the relative error did not exceed 6%.     

A new approach to optimize the performance of a hydrogen reservoir using activated carbon as the storing material

We have developed a new approach in order to compute the optimal way of filling as efficiently as possible an hydrogen reservoir using activated carbon as the storing material. Our approach combines finite element computation with multi objective optimization techniques based on the Fast Pareto Genetic Algorithm (FPGA) to find an ensemble of optimal solutions known as the Pareto front. We have illustrated our method by studying a small cylindrical reservoir. We were able to find a 7-point filling function (i.e. the input flow as a function of time) giving the shortest filling time to reach a stored hydrogen mass for a given heat transfer coefficient while keeping the reservoir internal temperature and pressure under their maximal safe values.     

Development and performances of a 0.5 kW high-pressure alkaline water electrolyser

The purpose of this research paper is to describe the characteristics and electrochemical performances of a pressurized alkaline water electrolysis short stack (5-cells, 0.5 kW) operated at 80 °C, from atmospheric pressure up to 100 bars. Expanded grids of metallic nickel covered with specific porous catalytic structures have been used as working electrodes. A polysulfone-based diaphragm with a high ionic conductivity has been specifically designed for operation in pressurized alkaline water electrolysis cells. I–V polarization curves have been recorded at current densities up to 1000 mA/cm², at temperatures up to 80 °C and under pressures up to 100 bars. The water electrolysis efficiency of this short-stack has been determined. A specific energy consumption of ca. 4.4–4.5 kWh/Nm³ has been obtained in the high current density range. Durability tests have been performed on the short stack over 1000 h. A limited degradation rate <5 μV/h has been recorded over that period of test.     

Development of a gas turbine performance analysis program and its application

A general-purpose performance prediction program, which can simulate various types of gas turbine such as simple, recuperative, and reheat cycle engines, has been developed. A stage-stacking method has been adopted for the compressor, and a stage-by-stage model including blade cooling has been used for the turbine. The combustor model has the capability of dealing with various types of gaseous fuels. The program has been validated through simulation of various commercial gas turbines. The simulated design performance has been in good agreement with reference data for all of the gas turbines. The average deviations of the predicted performance parameters (power output, thermal efficiency, and turbine exhaust temperature) were less than 0.5% in the design simulations. The accuracy of the simulation of off-design operation was also good. The maximum root mean square deviations of the predicted off-design performance parameters from the reference data were 0.22% and 0.44% for the two simple cycle engines, 0.22% for the recuperative cycle engine, and 0.21% for the reheat cycle engine. Both the design and off-design simulations confirmed that the component models and the program structure are quite reliable for the performance prediction of various types of gas turbine cycle over a wide range of operations.