Characterization of CuInS2 thin films for solar cells prepared by spray pyrolysis

We have made a study of the chemical composition, the electrical, the optical and the structural properties of polycrystalline CuInS₂ thin films prepared by spray pyrolysis to be used for thin film solar cells. These films were deposited starting from aqueous solutions with different chemical compositions ([Cu]/[In] and [S]/[Cu] ratios) and at different substrate temperatures. In all cases, the material is p-type with grains preferentially oriented in the (112) direction of the sphalerite structure. The electro-optical properties show a very strong dependence on the [Cu]/[In] ratio in the solution. Films with copper excess have smaller resistivity and better crystallinity than those which are stoichiometric or have indium excess. The results obtained in this work show the possibility of having CuInS₂ thin films with a wide range of resistivity, a fact that could be important for making solar cells based on this material.     

喷射成形高温合金沉积态组织的形成与演变

对喷射成形高温合金的组织形成及其从雾化过程的树枝晶向等轴晶组织的演变过程进行了分析，结果表明，半液态层中发生的枝晶破碎，重熔所造成的核心增殖作用为等轴晶组织的形成提供了大量结晶核心，在此基础上枝晶臂的合并，粗化以及未严重固相枝晶的粗化和均匀化产生了喷射成形材料所持有的非枝非等轴晶组织。     

记第二届环太平洋先进材料及工艺国际会议

介绍第二届环太平洋先进材料及工艺国际会议情况，重点报导韩国钢铁工业、早期凝固过程研究、喷射成形、非晶合金、纳米材料和第三代单晶铸造高温合金等内容。     

常减压蒸馏装置高温部位的腐蚀与防护

阐述了常减压蒸馏装置高温部位的腐蚀机理，介绍了高温防腐蚀的三种方法：正确选材、高温缓蚀剂技术及喷涂渗铝技术，建议在类似的石化装置推广使用。     

高炉风口表面处理技术

介绍近代高炉风口采取等离子喷涂、各种金属渗镀和堆焊高温耐磨合金3种方法进行表面处理的情况。我国中小高炉多趋向发展多元金属渗镀,前苏联和日本风口经堆焊后抗磨性能有明显改善,采用上述3种处理后风口寿命均有数倍的提高。     

喷射成形技术在钢铁材料中的应用

本文简要介绍了喷射成形技术的原理、特点及其在钢铁材料中的应用概况 ,综述了各种喷射成形钢铁材料的研究现状及其产品发展状况     

Reply to the Comment by K. Jorgensen et al. to “Analysis of constant rate period of spray drying of slurry”

Previously developed model for spray drying of slurry droplets with high solid content (Liang, 2001) was revised to describe correctly a boundary condition on the outer surface of droplet on basis of the rate of liquid evaporation.     

Spray drying conditions and encapsulating composition effects on formation and properties of sodium diclofenac microparticles

This paper reports the preparation and characterization of sustained release sodium diclofenac microparticles by spray drying. Aqueous dispersions of ethyl cellulose (Surelease®) and Eudragit RS 30 D® were evaluated as controlled release polymers. The product properties (product moisture, size distribution, particle morphology, flow properties, total drug load, in-vitro dissolution studies, and encapsulating efficiency) were determined as a function of inlet temperature of the spray drying, the feed flow rate and composition of the microencapsulating formulation. In general, lower values of the product moisture content were observed at higher drying temperatures. The spray-dried product was composed mainly by rounded-shape and multi-size particles. The mean particle diameters of the Eudragit based microparticles tended to be slight bigger than the Surelease based microparticles. The spray dried microparticles showed delayed drug dissolution rates, sustaining the drug release for several hours. These findings confirm the feasibility of the spray drying for preparation of microparticles with sustained release properties. The physical and chemical properties of the microparticles can be changed by varying the spray drying parameters as well as the microencapsulating formulation.     

A MECHANISTICALLY BASED MATHEMATICAL MODEL OF SULFUR DIOXIDE ABSORPTION INTO A CALCIUM HYDROXIDE SLURRY IN A SPRAY DRYER

A mathematical model has been developed to predict So₂ absorption and removal during the constant rate drying period of a spray dryer. The model, based on film theory, treats the atomized slurry droplets as spheres containing discrete sorbent particles of slaked lime with the fluid uniformly distributed around the individual particles. The model includes gas and liquid phase mass transfer coefficients as well as resistance to Ca(OH)₂ dissolution. A sensitivity analysis has been conducted and a comparison was made between pilot-scale experimental data and model-predicted values of S0₂ removal efficiency.     

ALKYD PAINT WASTE CHARACTERIZATION AND DISTILLATION

In the present study the characterization and distillation of alkyd paint waste have been carried out in order to establish the technical viability of organic solvents recovery and to decide upon the best environmental management for the waste stream from a paint spray-booth application in an automotive component factory. The paint is a black primer based on an alkyd resin with toluene and xylene as solvents, black carbon as pigment, fillers, and other minor components.

The paint, paint wastes, and distillation wastes have been characterized by determination of the physicochemical properties of the solid (solvents content and flash point) and determination of ecotoxicity (EC₅₀), total organic carbon (TOC), and metals concentration of the leachates. The highly volatile matter (HVM) content, determined by the weight loss at 200°C, has been used as a parameter to relate with the hazardous wastes regulations based on the characterization parameters EC₅₀, TOC, and flash point.

Distillation experiments have been performed in a simple batch mode with mixtures of paint waste, water, and additives in order to obtain high efficiencies in the recovery of volatile organic compounds and to obtain a final solid with nonhazardous behavior and good manageability qualities. A fractional factorial design (2^3-1) of experiments was carried out in order to study the influence of the distillation variables: water/paint waste ratio (2/1-3/1 (g/g)), temperature (110°-145°C), alkaline additives (Na(OH),CaO, Ca(OH)₂), and amount of other additives (wt.% of bentonite, cement, and Ca(OH)₂) on the solvent recovery, [% VOCs]_Recovery, on the residual volatile organic compounds, [% VOCs]_{Distillation Waste}, and on the total organic content (TOC) of the waste leachates. The present work shows the quantitative results of the alkyd paint waste distillation process under optimum conditions.