Kinetik der Kohlen-Pyrolyse als Grundlage für die Auslegung technischer Reaktoren

Kinetics of coal pyrolysis as a foundation for the design of technical reactors . The pyrolysis of coal is understood to mean its thermal decomposition at temperatures above 300°C, affording tar and char. It is the basic process underlying coking and the starting reaction of combustion, gasification, and hydrogenation. In addition, pyrolysis offers a means of converting coal into gases and liquids in a ?third way”? besides gasification and hydrogenation. In order to establish a basis for the design of relevant technical reactors, the kinetics of coal pyrolysis has been investigated as a function of temperature and rate of heating and recently of pressure under inert gases and hydrogen. In particular, the rates of formation and the yields of liquid and gaseous products and the alteration of the solid matter have been examined under pressures ranging from 1 to 100 bar and at rates of heating between 0.05 and 1 000 K/s. It is shown how product formation can be controlled by these parameters and how the experimental data can be applied to reactor design.     

Evaluation of the child with a bone or soft-tissue neoplasm

The prebiopsy evaluation of a child with a musculoskeletal neoplasm is the cornerstone for all subsequent treatment. A better understanding of the natural history of pediatric musculoskeletal tumors and an explosion in the development of sensitive new imaging modalities have significantly advanced the care of the child with a musculoskeletal pathologic condition. This article details the prebiopsy clinical and radiographic evaluation of the child or adolescent with a musculoskeletal neoplasm.     

Direct percutaneous transluminal coronary angioplasty in acute myocardial infarction. Predictors of short-term outcome and the impact of coronary stenting. Study Group of The Arbeitsgemeinschaft Leitender Kardiologischer Krankenhaus?rzte (ALKK)

BACKGROUND: Direct percutaneous transluminal coronary angioplasty (PTCA) is widely accepted in the treatment of acute myocardial infarction since excellent results had been reported from several small randomized trials. Less favourable results were observed in large-scale registries. In particular, the use of stents in acute myocardial infarction has become common practice without documented evidence of clinical efficacy. METHODS: Data were analysed from a registry of all consecutive percutaneous transluminal coronary angioplasty procedures from 62 centres in Germany, including 2331 direct percutaneous transluminal coronary angioplasty in acute myocardial infarction from July 1994 to April 1997. RESULTS: The overall angiographic success rate of percutaneous transluminal coronary angioplasty, defined as complete antegrade perfusion of the infarct vessel, was 87%. In-hospital mortality was 11.2%. The most important predictor of death was the presence of cardiogenic shock in 15% of patients, of whom 52% died. Mortality in patients without shock was 3.9%. Failed percutaneous transluminal coronary angioplasty was associated with a mortality of 36%. Further independent predictors of death were older age, multivessel disease, and anterior myocardial infarction. Stents were used in 4.1% of the procedures in 1994, increasing to 53% in 1997. However, this was not accompanied by improved clinical outcome. Mortality with coronary stenting was 9.9% vs 11.6% without stents (ns). CONCLUSIONS: Direct percutaneous transluminal coronary angioplasty is a valuable treatment strategy in acute myocardial infarction, although the results are less exceptional than reported from some highly specialized centres. Failed percutaneous transluminal coronary angioplasty seems to be harmful, thus outweighing much of the benefit from successful procedures. Stents did not improve the clinical outcome significantly, despite technically successful placement in 98%. Mortality from cardiogenic shock continues to be excessively high despite direct PTCA.     

Latent variable structure of the Brief Symptom Inventory in a sample of persons with spinal cord injuries.

Investigated the presence of underlying factors which may be helpful in understanding Brief Symptom Inventory (BSI) item responses with 215 inpatientsresponse with spinal cord injuries. BSI scores were analyzed with principal components and maximum-likelihood factor estimation, and 6 factors were retained: anxiety, depression, mental blocks, interpersonal sensitivity, spinal cord injury, and hostile suspiciousness. Examination of factor content indicated their relevance to aspects of the rehabilitation process. Evidence for construct validity was examined by comparing the factor scores of persons who were rehospitalized versus persons who were not rehospitalized in the first year following initial rehabilitation. The rehospitalized group had higher BSI depression, mental blocks, and spinal cord injury factor scores prior to discharge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Untersuchung von Rutschvorgängen beim Warmwalzen

Untersuchungen über Ursachen des Durchrutschens durch analytische und meßtechnische Methoden. Ermittlung der sich dabei einstellenden veränderten Reibungsverhältnisse zwischen Walze und Walzgut. Ein vereinfachtes mechanisches Ersatzmodell zur Lösungsfindung. Differentialgleichungen der einzelnen Bauelemente des mechanischen Ersatzsystems. Ermittlung des Gleitreibungskoeffizienten und maßgebliche Einflußgrößen auf dessen Verlauf.     

Zeitstandbruchverhalten einiger warmfester Stähle unter rechteckzyklisch veränderter Spannung oder Temperatur

Zeitstandversuche bis 10 000 h unter veränderlicher Spannung oder Temperatur an fünf ferritischen Stählen mit 0,10 bis 0,21% C, bis 12% Cr, 0,30 bis 1,1% Mo und bis 0,35% V sowie einem austenitischen Stahl mit 0,065% C, 1,62% Mn, 16,5% Cr, 2,16% Mo und 13,3% Ni. Zuverlässigkeit bekannter einfacher Regeln zur Vorhersage der Beanspruchungsdauer bis zum Bruch unter veränderlicher Spannung oder Temperatur und Unterschiede zwischen dem Verhalten verschiedener Stahlsorten.     

紧密纺纱线的预湿对织造性能的影响

描述了德国邓肯道夫纺织工艺研究所(ITV)将目前有关预湿的研究结果转移、拓展并试用于紧密纺和喷气纺纱线的研究过程.比较了紧密纺和环锭纺纱线的试验结果.紧密纺和涡流纺的经济优势和节约成本来自浆料消耗的减少和织造中与磨损相关的问题的减少.