Füllstand- und Durchflußmessung in verfahrenstechnischen Anlagen

Measurement of Level and Flow in Processing Plants The author reviews the processes and systems for the measurement of level. The devices are described for indicating the states ?Full”? and ?Empty”? in the automatic charging and discharging, for continuous measurement in the monitoring of the stores and processes, for measuring systems based on specific properties, such as conductivity and capacity, for electromechanical systems, for non-contact measuring procedures based on sonic and ultrasonic echometry as well as radioactivity, for microwave systems, and for the measurement of aggressive products and substances under high pressures and temperatures, and, in explosion-proof plants. In the measurement of flow, inductive flowmeters of high precision and reliability are used for conducting liquids; corrosion-resistant turbines are used for all products with low viscosity; tooth wheel flowmeter are used for highly viscous materials. The processes for the measurement of level and flow are described in an example for the treatment of waste water.     

国内甲醇消费市场状况

我国甲醇主要用于甲醛、对苯二甲酸二甲酯、农药、甲基叔丁基醚、醋酸的生产,我国甲醇消费量增长最快的领域将是燃料甲醇、醋酸和甲醛。预计 2005年甲醛对甲醇的需求量为 175万t左右,聚甲醛对甲醇的需求量为 40万t,醋酸需求甲醇为 62万t,甲基叔丁基醚为 46万t左右,甲胺为 30万t,碳酸二甲酯为 11万t,甲烷氯化物为 10万t,甲醇燃料为 80万t,农药为 22万t,对苯二甲酸二甲酯 3 0万t,其他衍生物 27万t。     

光固化医用胶粘剂研究进展

介绍了目前光固化医用胶粘剂的几个应用领域,包括软组织用胶粘剂、齿科用胶粘剂、骨科用胶粘剂以及医疗器械用胶粘剂等,并对其未来发展进行了展望。     

少烟三元乙丙橡胶材料研制

以三元乙丙橡胶(EPDM)为基体材料，三氧化二锑、十溴苯醚为阻燃剂制备了材料配方，试验了三氧化二锑(Sb22O3)、十溴苯醚(DBDPO))配比对材料烟雾和力学性能的影响，测试了材料的氧指数，可见光的透过率，自熄性等。结果表明，DBDPO与EPDM的相容性比较好，Sb2O3的相容性则相对比较差，两者都可以提高材料的阻燃性能。以4045EPDM橡胶为基体材料，当EPDM100g，白炭黑10g，二硫化四甲基秋兰姆(TMTD)2g，ZnO5g，促进剂M1g，硬脂酸2g，硫磺3g，Sb2O3和DBDPO质量比为20．0／40．0，可以获得具有较好力学性能的少烟EPDM橡胶材料。     

Preconcentration of trace elements by adsorption onto a niobium wire for electrothermal atomization atomic absorption spectrometry with a tungsten tube atomizer

In the present work, a new preconcentration method of trace elements by adsorption onto a niobium wire has been developed for electrothermal atomization atomic absorption spectrometry (ETAAS) with a tungsten tube atomizer. Detection limits (pg·mL^–1) by this method combined with ETAAS were 45 for bismuth, 7.0 for cadmium, 20 for copper, 1.3 for gold, 36 for lead, 65 for manganese, 9.5 for rhodium and 19 for silver.     

An overview of rheology in the computer industry

The rheological characterization of a wide variety of materials used in computer hardware is described. The materials and applications presented include liquid crystal polymers for components, solder paste for surface mounting of integrated circuits, screen printable polyimide for dielectric patterns, new photosensitive polyimide to reduce processing steps, hot-melt adhesive for temporary bonding, pressure-sensitive adhesive for permanent bonding of potical recording disks, bearing grease for magnetic recording disk drive spindles, fluoropolymer lubricants for magnetic recording disks, magnetic particle suspensions for magnetic tape and disks, toner for laser printing, thermoplastic polymer for rapid prototyping, and cathode paste for rechargeable lithium batteries. Rheological tests appropriate for each of the materials were designed to provide key information about its performance in the intended application. This overview provides insight into the relation between interpretation of rheological test data and materials performance in engineering applications as well as for process control. Rheology is essential to the development of computer hardware and peripheral devices. © 1996 John Wiley & Sons, Inc.     

Extraction of rapeseed,linseed, safflowerseed and tobaccoseed with a new laboratory extractor

In this study, extractions of rapeseed, linseed, safflowerseed and tobaccoseed have been conducted with a new extractor which has been developed for the extraction of vegetable tannins and which was later applied to sugar beets and sugar cane. Using the optimal conditions of the new extractor for oilseeds, that is, 315μ particle size and 62 C temperature, technical hexane has been employed, and the variations of the rate and distribution of oil extraction from solid materials have been determined. Optimal extraction periods with the new extractor were found to be 88 min for rapeseed, 90 min for linseed, 118 min for safflowerseed and 90 min for tobaccoseed. The same seeds have been extracted with the Soxhlet extractor for a period of 10 hr. Soxhlet extractor yields compared to Gülbaran yields with the new extractor were found to be only 98.18% for rapeseed, 98.15% for linseed, 97.79% for safflowerseed and 97.39% for tobaccoseed.     

Effectiveness in the Removal of Organic Compounds from Municipal Landfill Leachate in Integrated Membrane Systems: Coagulation – NF/RO

The article presents the results of studies concerning the hydraulic permeability of integrated membrane systems during the treatment of municipal landfill leachate. The laboratory-scale experiments were conducted to determine the effectiveness of coagulation as a pretreatment option for treating stabilized landfill leachate and effectiveness of nanofiltration (NF) and reverse osmosis (RO) processes. The municipal landfill leachates were analyzed for the concentration of the following: polycyclic aromatic hydrocarbons (PAHs), nitrate nitrogen, ammonium nitrogen, chemical oxygen demand (COD), total organic carbon (TOC), total carbon (TC), suspended soils (SS), turbidity, pH. The commercially available coagulant – aluminum sulfate Al₂(SO₄)₃·18H₂O (alum) was used as a coagulant. The NF process was carried out at the transmembrane pressure of 1.5 MPa. The membrane separation process was based on a thin film membrane (DK). The transmembrane pressure of the RO stood at 2 MPa and for this process one polyamide membrane (AG) was used. The level of leachate treatment was defined for raw and cleaned wastewater indicators. Both NF and RO membranes allowed obtaining the high level of pollutants removal. In the coagulation–NF system, the removal efficiency was equal to 77% for PAHs, 88% for COD, 72% for ammonium nitrogen, 80% for nitrate nitrogen, 67% for TOC, 80% for TC, 96% for SS and during the RO – 86% for PAHs, 98% for COD, 93% for ammonium nitrogen, 87% for nitrate nitrogen, 89% for TOC, 100% for TC, 98% for SS. The calculations based on the assumptions of the mathematical filtration model (relaxation) made it possible to predict the efficiency of commercial filtration membranes used for leachate treatment.     

Chemical Analysis of Soda-Lime-Silica Glasses for Trace Quantities of Several Colorants

Methods for the analysis of soda-lime-silica glasses for trace amounts of CrzO3, COO, NiO, CuO, and selenium are described; the determination of sulfide sulfur in amber glass bottles is also described. The applicable range of these methods is as follows: for Cr₂O₃, 2 to 600 pgm.; for COO, 2 to 20 pgm.; for NiO, 5 to 100 pgm.; for CuO, 5 to 80 pgrn.; for selenium, 5 pgm. (approximate minimum); for sulfide sulfur, 0.005 to 0.10%.     

Mathematical Modeling and Simulation of Drying Using Two Industrial Concurrent and Countercurrent Rotary Dryers for Ammonium Nitrate

Drying of ammonium nitrate (AN) is accomplished in the Shiraz Petrochemical Complex (SPC) using a concurrent rotary dryer following a countercurrent rotary dryer. A mathematical model for these rotary dryers including heat and mass transfer was developed. The model was checked against industrial-scale data, which showed a good agreement. The average absolute deviation of the simulation results compared to the industrial data for the concurrent dryer was 4.0% for solids moisture, 1.3% for solids temperature, and 1.8% for air temperature and for the countercurrent dryer it was 9.0% for the solids moisture, 2.0% for solids temperature, and 4.6% for air temperature. These simulation results reveal that for outlet solid moisture, inlet AN moisture, and air temperature as well as the outlet temperature of product, the inlet solid and air temperature have major effects for both concurrent and countercurrent flow.     

汽车工业用粘接材料的现状与展望

本文按照汽车制造工序介绍国外汽车工业折边用胶粘剂、点焊胶接用胶粘剂、车身密封胶、车身底涂料、窗玻璃用单组份湿气固化型聚氨酯胶粘剂以及纤维增强树脂用结构胶粘剂等主要胶种的最新技术发展动向。讨论了我国汽车工业用胶粘剂的现状和差距，提出几点建议。     

Determination of Several Valences of Iron, Arsenic and Antimony, and Selenium in Glass

Methods for the analysis of silicate glasses are described for ferrous iron, for tri- and pentavalent arsenic and antimony when present together, and for selenium as Se^2-, Se°, Se⁴⁺, and Se⁶⁺. Analytical results are presented for FeO in the range 0 to 0.25%; for total As and Sb as tri-oxide, 0.1 to 1.25%; and for total Se, 0.05 to 0.25%. Apparatus for the determination of FeO is described, and a comparison is made of analytical data for FeO versus light transmittance at 1000 and at 1050 mμ for the same glass.     

国际海事组织(IMO)涂层技术标准动态

详细介绍了国际海事组织(IMO)近年来制定的有关涂层的技术标准,即压载舱涂层性能标准、空舱涂层性能标准、涂层维护修理指南、永久检验通道(PMA)的涂层/防腐要求、油船货油舱涂层性能标准,为执行标准及制定防腐措施提供了依据。     

FULLY DEVELOPED LAMINAR FLOW IN A HELICALLY COILED TUBE OF FINITE PITCH

Solutions for steady, fully developed, laminar flow of an incompressible Newtonian fluid through a helically coiled tube of finite pitch were obtained by finite difference calculations. Prior theoretical solutions have apparently been limited to toroidal flow (with zero pitch). The computed results are consistent with those for this limiting case and with prior experimental data for finite pitch. The behavior for helical coils is intermediate between that for a straight pipe and a torus, and, for a moderate degree of pitch differs only slightly from that for a torus. A correlating equation was developed for the friction factor for all Reynolds numbers, all ratios of coil radius to lube radius and all ratios of pitch to coil radius for which the flow remains laminar.     

含NHD废水的回收处理

对NHD溶液污染的原因进行了分析,提出了防止污染可采取的措施,重点介绍了含NHD废水的回收工艺。多年来的实际应用情况表明：含NHD废水回收装置对污染严重的NHD溶液和过滤器反冲洗含NHD废水的回收有较理想的效果,且装置流程简单、操作方便、投资少、回收率高,经济和环保效益明显。     

皮内注射用卡介苗特异性鉴别试验多重PCR检测方法的建立及验证

目的建立皮内注射用卡介苗(Bacillus Calmette Guerin vaccine,BCG)特异性鉴别试验的多重PCR法,并进行验证。方法根据GenBank登录的Pasteur 1173P2株序列(AM408590. 1)设计并合成引物,以制备的BCG特异性鉴别试验国家参考品(简称BCG鉴别参考品)DNA为模板,多重PCR法扩增其特异性缺失区RD1,产物经3%琼脂糖凝胶电泳鉴定,验证方法的重复性、中间精密度、特异性、耐用性及灵敏度;采用该方法检测8批皮内注射用BCG供试品。结果 BCG鉴别参考品在重复检测6次、2名检测人员分别重复检测3 d、不同PCR退火温度及不同DNA聚合酶加量时均扩增出约200 bp的核酸片段;最低可检10 pg/mL的目的基因,仅对结核分枝杆菌H37Rv及皮内注射用BCG样品DNA扩增出特异性条带。经该方法检测,8批供试品PCR产物电泳均可见单一的目的条带,无RD1序列存在,大小与BCG鉴别参考品一致。结论多重PCR法的重复性、中间精密度、特异性、耐用性及灵敏度良好,可应用于皮内注射用BCG特异性鉴别试验。     

流感病毒在Vero细胞上的适应性

目的研究WHO指定流感疫苗生产用毒株在Vero细胞上的适应性,为用Vero细胞制备流感疫苗奠定基础。方法优化不同培养基、胰酶浓度、pH值等培养病毒的条件及收毒时间,将流感疫苗生产用毒株在Vero细胞上连续传代,并进行血凝效价检测及RT-PCR分析。结果在病毒维持液为F12+DMEM、pH为7.5、胰酶含量为1.5μg/ml、培养3 d收获病毒时,可获得较高的病毒血凝效价,连续传4代,病毒血凝效价降为0,RT-PCR检测结果为阴性。结论WHO推荐的流感疫苗生产用毒株在Vero细胞上连续传代,病毒血凝效价逐渐降低。     

抗生素含量测定方法在《中国药典》2010年版中的应用比较

文章主要结合《中华人民共和国药典》2010年版中收载的348个抗生素品种,对抗生素含量测定的方法进行了统计分析,其中有247个品种采用高效液相色谱法,86个品种采用微生物检定法,3个品种采用滴定分析法,12个品种采用紫外分光光度法。     

Shape normalization of catalyst pellet

A shape normalization, which is applicable in the entire range of Thiele modulus φ, is developed. A shape normalization established here for small φ and the shape normalization already established here for large φ are used in developing the normalization for all φ. This normalization brings the η - φ curves for all pellet shapes to a single curve corresponding to infinite slab geometry for all φ. The effectiveness factor for any shape of catalyst is simply the effectiveness factor for an infinite slab when the Thiele modulus for the slab is properly defined in terms of the characteristic pellet length and the reaction kinetics. The shape normalization is shown to give negligible error for any pellet configuration and first order reaction, and is postulated to hold for general kinetics and any pellet configuration, by proper definition of the Thiele modulus.     

Effect of soybean breakage on the quality of soybean oil: Preliminary study

Soybean samples were separated into 4 fractions (whole beans, halves, pieces, and fines) according to physical damage, and all fractions but the fines were analyzed for oil quality. Free fatty acids were found to increase from 0.65% for whole beans to 1.79% for halves, 3.04% for pieces, and 9.46% for fines (by differences). Neutral oil loss of hexane-extracted oil from these fractions was 4.5% for whole beans, 4.62% for halves, and 6.08% for pieces. The results give a measure of the decrease in quality of soybean oil with increasing soybean breakage.