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Designing a power plant with highest efficiency:results from SFB 561

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航空动力学报 2009年第4期24卷 717-728页

作者： dieter Bohn Institute of Steam and Gas Turbines RWTH Aachen University

The goal of Collaborative Research Centre(SFB) 561 "thermally highly loaded,porous and cooled multi-layer systems for combined cycle power plants" is to expand the current technological and scientific knowledge on power plants in order to achieve total efficiencies of 65% in a combined cycle power plant in the year ***,the aero-thermomechanical,structural-mechanical,materials' scientific and production fundamentals for the development of steam and gas turbine components that are able to withstand highest thermal loads are being worked out within this *** means for the gas turbine that combustion chamber outlet temperatures of 1520℃ at 1.7MPa are to be *** order to control these high temperatures,it is not only required to develop new materials' solutions,including thermal barrier coatings,but also to apply improved cooling techniques,as for example effusion *** novel cooling concept is to be realised through open-porous *** structures can consist of drilled open-porous multi-layer systems or open-porous metallic *** development of graded multi-layer systems is also extremely important,as the grading will enable the use of coolant in dependence of the *** live steam parameters in the high pressure turbine are expected to be increased up to approximately 700℃ with pressure of *** elevated steam parameters can be encountered with Ni-base alloys,but this is a costly alternative,associated with many manufacturing ***,the SFB proposes cooling the highly loaded turbines instead,as this would necessitate the application of far less Ni-base *** protect the thermally highly loaded casing,a sandwich material consisting of two thin face sheets with a core of a woven wire mesh is used to cover the walls of the steam turbine *** current state of the research shows that by utilising innovative cooling technologies a total efficiency of 65% can be reached without exceeding the m

关键词： gas turbine steam turbine cooling novel materials process calculation

Hybrid system-a promising way solving future energy problems

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航空动力学报 2007年第4期22卷 565-576页

作者： dieter Bohn Institute of Steam and Gas Turbines RWTH Aachen University

With the increasing demand for electricity,an efficiency improvement and thereby reduced CO2 emissions of the power plants are expected in order to reach the goals set in the Kyoto *** comparison to conventional systems,the hybrid-systems with the use of synergetic effects offer the possibility to provide a substantial contribution to spare our natural resources and protect our *** Cycle Power Plants belongs innately hybrid system in the centralized energy *** can provide large amounts of power and have a quick start-up *** MGT/FC hybrid system is quite promising in the decentralized energy *** is widely used in stand-alone ***,the combination of fossil and renewable power plant technologies contains a large synergy potential to increase the efficiency of processes for power *** materials,innovative cooling technology,new combustion concepts and optimized production methods are needed to make the potential of these new technologies accessible for a quantum leap in the *** this it needs considerable research work and good coordinated research projects between the state,industry,research laboratories and universities.

关键词：航空推进系统混合燃料涡轮机能源

The Vγ4/butyrophilin conspiracy: novel role of intraepithelial γδ T cells in chronic inflammatory bowel disease

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Signal Transduction and Targeted Therapy 2023年第12期8卷 5575-5577页

作者： dieter Kabelitz Institute of Immunology Christian-Albrechts University Kiel and University Hospital Schleswig-Holstein Campus KielKielGermany

In a recent article published in Science,Dart and colleagues reported that colonic T cells expressing the Vγ4 T-cell receptor(TCR)interact with epithelial butyrophilin-like(BTNL)proteins BTNL3 and BTNL8 in healthy individuals,and they observed a depletion of Vγ4 T cells in inflammatory bowel diseases with renormalization associated with disease remission.1 This paper identifies the BTNL/Vγ4 axis as a new disease modifier in IBD.

关键词： bowel inflammatory diseases

Welding mechanics for advanced component safety assessment

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Frontiers of Materials Science 2011年第2期5卷 224-235页

作者： dieter SIEGELE Fraunhofer Institute for Mechanics of Materials IWM WShlerstr. 11 79108 Freiburg Germany

Numerical methods are nowadays a useful tool for the calculation of distortion and residual stresses as a result from the welding process. Modern finite element codes not only allow for calculation of deformations and stresses due to the welding process but also take into account the change of microstructure due to different heating and cooling rates. As an extension to the pure welding simulation, the field of welding mechanics combines the mechanics and the material behaviour from the welding process with the assessment of service behaviour of welded components. In the paper, new results of experimental and numerical work in the field of welding mechanics are described. Through examples from automotive, nuclear and pipe-line applications it is demonstrated that an equilibrated treatment and a close interaction of ＂process＂, ＂properties＂ and ＂defects＂ are necessary to come up with an advanced fitness-forservice assessment of welded components.

关键词： welding simulation residual stress defect assessment fracture mechanics

Lab experiments on the innovative rapid thick strip casting process

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International Journal of Minerals,Metallurgy and Materials 2012年第5期19卷 391-398页

作者： Richard Nagy dieter Senk Department of Ferrous Metallurgy IEHK RWTH Aachen UniversityAachen 52056Germany

Rapid thick strip casting （RTSC） by Anton Hulek, Inventmetall, is an innovative concept for the production of hot strips with a final as-cast thickness of about 25 mm before rolling. The innovation of the mechanism consists in a vertical mould performing a caterpillar motion. This moving mould has an unconventional parallelogram-shaped cross-section. The conventional rectangular shape is formed in the shaping machine, which is placed straight below the mould. Further elements of the technology are state-of-the-art. For the investigation of this new casting system theoretical calculations were complemented with practical experiments. The investigation focused mainly on two key aspects： the characteristics of the mould and the shaping process. For the practical analysis a static mould with three pairs of elements in laboratory scale was developed and commissioned by the Dept. of Ferrous Metallurgy @ RWTH Aachen University. The shaping experiments were carried out in model scale with two different materials and in variable boundary conditions. The results of these experiments delivered important mechanical as well as thermal informations about the casting system.

关键词： continuous casting rapid solidification strip metal moulds near-net-shape casting

PET imaging in ischemic cerebrovascular disease:current status and future directions

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Neuroscience Bulletin 2014年第5期30卷 713-732页

作者： Wolf-dieter Heiss Max Planck Institute for Neurological Research

Cerebrovascular diseases are caused by interruption or significant impairment of the blood supply to the brain, which leads to a cascade of metabolic and molecular alterations resulting in functional disturbance and morphological damage. These pathophysiological changes can be assessed by positron emission tomography （PET）, which permits the regional measurement of physiological parameters and imaging of the distribution of molecular markers. PET has broadened our understanding of the flow and metabolic thresholds critical for the maintenance of brain function and morphology： in this application, PET has been essential in the transfer of the concept of the penumbra （tissue with perfusion below the functional threshold but above the threshold for the preservation of morphology） to clinical stroke and thereby has had great impact on developing treatment strategies. Radioligands for receptors can be used as early markers of irreversible neuronal damage and thereby can predict the size of the final infarcts; this is also important for decisions concerning invasive therapy in large （＂malignant＂） infarctions. With PET investigations, the reserve capacity of blood supply to the brain can be tested in obstructive arteriosclerosis of the supplying arteries, and this again is essential for planning interventions. The effect of a stroke on the surrounding and contralateral primarily unaffected tissue can be investigated, and these results help to understand the symptoms caused by disturbances in functional networks. Chronic cerebrovascular disease causes vascular cognitive disorders, including vascular dementia. PET permits the detection of the metabolic disturbances responsible for cognitive impairment and dementia, and can differentiate vascular dementia from degenerative diseases. It may also help to understand the importance of neuroinflammation after stroke and its interaction with amyloid deposition in the development of dementia. Although the clinical application of PET

关键词： stroke dementia PET brain metabolism brain ischemia

Natural water purification and water management by artificial groundwater recharge

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第3期9卷 221-226页

作者： Klaus-dieter BALKE Institute for Geosciences University of TübingenSigwartstr.10D-72076 TübingenGermany

Worldwide,several regions suffer from water scarcity and *** infiltration and subsurface storage of rain and river water can reduce water *** groundwater recharge,possibly combined with bank filtration,plant purification and/or the use of subsurface dams and artificial aquifers,is especially advantageous in areas where layers of gravel and sand exist below the earth's *** infiltration of surface water into the uppermost aquifer has qualitative and quantitative *** contamination of infiltrated river water will be reduced by natural *** minerals,iron hydroxide and humic matter as well as microorganisms located in the subsurface have high decontamination *** this,a final water treatment,if necessary,becomes much easier and *** quantitative effect concerns the seasonally changing river discharge that influences the possibility of water extraction for drinking water *** changes can be equalised by seasonally adapted infiltration/extraction of water in/out of the aquifer according to the river discharge and the water *** method enables a continuous water supply over the whole ***,artificially recharged groundwater is better protected against pollution than surface water,and the delimitation of water protection zones makes it even more save.

关键词： Artificial groundwater recharge Natural attenuation Water management

Recent advances in hepatitis B virus research:A German point of view

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World Journal of Gastroenterology 2007年第1期13卷 8-13页

作者： dieter Glebe Institute of Medical Virology Justus-Liebig University of Giessen Giessen Germany

More than 30 years after the discovery of human hepatitis B virus （HBV） this virus remains to be one of the major global health problems. In infected adolescents or adults, 5%-10% will lead to a chronic carrier state, whereas in infected neonates up to 90% develop chronicity. It is estimated that about 370 million people are chronic carriers of HBV worldwide. In many regions of the world, chronic HBV infection is still the major cause of liver cirrhosis and hepatocellular carcinoma. During the last 30 years, many steps of the viral life cycle have been unravelled, mainly due to cloning, sequencing and expression of the genomic DNA extracted from HBV virions. This has lead to the development of a safe and efficient vaccine and sensitive tests for HBV surface prol^in （HBsAg） allowing reliable diagnosis and screening of blood products. More recently, a growing number of reverse transcriptase inhibitors have been developed. However, together with these improvements new defidencies in prevention and cure of HBV infections are becoming apparent. Although HBV is a DNA virus, it is highly variable under immunity or drug induced selection pressure, resulting in vaccine-related escape mutants and drug resistance. To overcome these challenging problems new antivirals and optimised vaccines have to be developed.

关键词： Hepatitis B virus Molecular biology Viral life cycle Animal system Antiviral therapy

Eigenvalue sensitivity analysis based on the transfer matrix method

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International Journal of Mechanical System Dynamics 2021年第1期1卷 96-107页

作者： dieter Bestle Engineering Mechanics and Vehicle Dynamics Brandenburg University of Technology Cottbus‐SenftenbergCottbusGermany

For linear mechanical systems,the transfer matrix method is one of the most efficient modeling and analysis ***,in contrast to classical mod-eling strategies,the final eigenvalue problem is based on a matrix which is a highly nonlinear function of the ***,classical strategies for sensitivity analysis of eigenvalues *** parameters cannot be *** paper develops two specific strategies for this situation,a direct differentiation strategy and an adjoint variable method,where especially the latter is easy to use and applicable to arbitrarily complex chain or branched multibody *** the system analysis itself,it is able to break down the sensitivity analysis of the overall system to analytically determinable derivatives of element transfer matrices and recursive formula which can be applied along the transfer path of the topology *** examples of different complexity validate the proposed approach by comparing results to analytical calculations and numerical *** obtained procedure may support gradient‐based optimization and robust design by delivering exact sensitivities.

关键词： adjoint variable method direct differentiation sensitivity analysis transfer matrix method