Introduccion y objetivos Aunque los bloqueos de rama (BR) se consideran hallazgos frecuentes, la informacion sobre su prevalencia real en la poblacion general es escasa, y es inexistente en los pacientes en dialisis. El objetivo es establecer la prevalencia del BR completo en la poblacion que inicia dialisis y los factores relacionados con su aparicion. Como analisis adicional, se explora su asociacion con la mortalidad y con la aparicion de un evento cardiovascular. Metodos Se incluyo a los pacientes que iniciaron dialisis en nuestro centro entre el 1 de noviembre de 2003 y el 31 de diciembre de 2006. Todos fueron sometidos a valoracion cardiologica al inicio de dialisis. Determinamos el BR y su relacion con factores clinicos y parametros ecocardiograficos y bioquimicos. Los pacientes fue...
Introduccion y objetivos La enfermedad renal oculta (ERO) es una entidad que define los estadios mas iniciales de insuficiencia renal y no se detecta con los metodos usados habitualmente. El objetivo es determinar la prevalencia de ERO en los pacientes hipertensos en consultas de cardiologia y su relacion con los distintos factores de riesgo y tratamientos cardiovasculares. Metodos. Estudio observacional, transversal, retrospectivo y multicentrico que se llevo a cabo en 1.214 hipertensos de consultas de cardiologia. Resultados . Se analizo a 1.190 pacientes (98%). El filtrado glomerular (FG) fue calculado (MDRD) por el cardiologo responsable en el 11% de los pacientes. Tras su determinacion a posteriori, el 9,5% presentaba ERO, mas probablemente mujeres, con mas edad, mas antecedents de di...
BackgroundPresumptive treatment of all febrile patients with anti-malarials leads to massive over-treatment. The aim was to assess the effect of implementing malaria rapid diagnostic...Full Text Available
BackgroundThe aim of the study was to compare the prevalence and types of HIV-related oral lesions between children and adult Tanzanian patients on HAART with those not on HAART...Full Text Available
Feb 23, 2001 ... Florida, as an F-16 weapons separation engineer with .... new era of space-based research aboard the International Space. Station. ..... the Web at: http://www. aiaa.org/calen- dar/index.hfm?cal=1&cfp=1 ...
A cross sectional population based epidemiological survey of 899 adults aged between 15 and 59 was undertaken in two urban areas of demographic surveillance sites in Dar es Salaam, Tanzania, using the...Full Text Available
Digital topographic models are the foundation of more advanced modeling applications and ultimately inform planning and decision making in many fields. Despite this, the error associated with these models and derived attributes is commonly overlooked. Little attention has been given in the scientific literature to the benefits gained from having less error in a model or to the corresponding cost associated with reducing model error by choosing one product over another. To address these gaps in knowledge we evaluated the error associated with five digital elevation models (DEMs) and derived attributes of slope and aspect relative to the same attributes derived from LiDAR data. We also estimated the acquisition and processing costs per square kilometer of the five test models and the LiDAR m...
Norad commissioned Econ Poeyry to map teaching and research activities and capacity related to clean energy in selected Ethiopian universities. The mapping identified challenges and opportunities with the aim of facilitating future intervention by the Ethiopian Government and donors to help improve the energy sector development of the country. The report covered the government-owned universities of Bahir Dar, Mekelle, Jimma, Arba Minch and Addis Ababa. The mapping was based on a questionnaire and on interviews at each university. (Author)
Objetivo Estudiar la evolucion de un grupo de neumonias extrahospitalarias causadas por germenes atipicos (Mycoplasma pneumoniae, Legionella spp., Coxiella burnetii y Chlamydophila pneumoniae) en funcion del tratamiento empirico recibido. Pacientes y metodos Entre enero de 1996 y febrero de 2001 ingresaron en nuestra unidad 390 casos de neumonia, de los que 89 estaban causados por germenes atipicos. Los pacientes se dividieron retrospectivamente en 2 grupos segun el tratamiento empirico pautado: grupo A, al que se habia proporcionado cobertura frente a germenes atipicos (quinolonas o macrolidos), y grupo B, al que no se habia proporcionado dicha cobertura. Se estudio la evolucion segun las diferencias entre ambos grupos en la estancia hospitalaria, la resolucion radiologica, el reingreso e...
Objetivo La generacion local de citocinas es un factor patogenico en el dano por isquemia-reperfusion en la disfuncion precoz del injerto. Este estudio analiza la expresion en tejido pulmonar de ARN mensajero de interleucina-8 (ARNm de IL-8) y su relacion con los cambios intersticiales pulmonares en un modelo experimental de isquemia-reperfusion pulmonar normotermica. MATERIAL Y METODOS Se estudiaron 16 conejos de la raza Nueva Zelanda en 3 grupos de estudio: a) basal; b) isquemia (lobulo inferior derecho tras isquemia de 1, 2 o 3 h), y c) reperfusion (lobulos superior y medio derechos tras 1 h de isquemia y 1, 2 o 3 h de reperfusion). Se deter- mino la expresion del ARNm de IL-8 mediante transcripcion inversa y reaccion en cadena de la polimerasa y estudio la infiltracion intersticial por...
ZusammenfassungUbelkeit und Erbrechen stellen zwei Symptome dar, die grundlich untersucht worden sind und bei Krebspatienten haufig auftreten. Die meisten Studien haben sich bislang mit Haufigkeit und Management dieser beiden Symptome befasst. Das Ziel dieser Studie bestand darin, ein besseres Verstandnis dafur zu entwickeln, wie Krebspatienten ihre Symptome erleben-insbesondere Ubelkeit und Erbrechen nach Chemotherapie-und welche Auswirkungen diese Symptome auf den Tagesablauf der Patienten haben. Neun Frauen mit unterschiedlichen Krebsleiden und Chemotherapie Regimes wurden zwecks Chemotherapie stationar aufgenommen und nahmen an der Studie teil. Es wurden halbstrukturierte Interviews einschliesslich einer Inhaltsanalyse in Anlehnung an Kvale durchgefuhrt (Klarung und Entwicklung neuer B...
This paper has two key objectives. Firstly, using the findings from case study research undertaken in Colombo (Sri Lanka), Faisalabad (Pakistan) and Dar es Salaam (Tanzania), the paper seeks to demonstrate the importance of an appropriate regulatory framework and effective mechanisms of enforcement for sustainable urban transport systems in developing countries. Secondly, the paper highlights the critical importance of communication and co-ordination between stakeholders (defined here as transport users, providers and regulators) if regulation is to be effective. The views of poor and disadvantaged passenger groups-women, children, the elderly and disabled-are used in the paper to illustrate the importance of transport systems to their livelihoods, such as work, education, health and socia...
In this article I explore the political event of the Tanzanian government's interdiction of a prominent educational civil society organization in order to theorize the emerging policy heterarchy in Tanzania. In the context of the ensuing public debate about the interdiction, I ask two questions: (1) what tensions are emerging from the democratization reforms embedded in national iterations of international EFA policies and (2) to what end are such reforms taking place? I address these questions with ethnographic, documentary and interview data collected as part of a broader study of participation in development between 2004 and 2007 in Dar es Salaam and the Singida region of central Tanzania. My analysis draws on critical, anthropological and postcolonial theories to explore the tensions o...
Already, MR Imaging is superior in diagnostic imaging of joints in many cases; however, there have been recent developments, which are the subjects of this paper. With gradient-echo sequences acquired in 3D technique, it is possible to produce high-resolution images of joints in acceptable scantime, because gradient-echo sequences are less time-consuming than convential SE sequences. With the acquisition of two echoes, phase difference between water and fat protons have to be considered. 3D Imaging is capable of displaying complex pathology in a superior way, which should be useful in preoperative planning. Tissue contrast is altered by fat saturation or magnetization transfer in order to achieve better conspicuity of lesions. Although diagnostic value of some of these options is not yet clear and further clinical studies are needed, they are a promising possibility for improving MR Imaging of the joints. (orig.) [Deutsch] In der Gelenkdiagnostik gibt es einige neuere Entwicklungen in ...
TENSOMAX enables on-line monitoring of the thermal stress of the shaft to be performed in steam turbines, for which the TURBOMAX probe cannot be installed near the critical area of the shaft. TENSOMAX provides an alternative to the TURBOMAX with a slightly reduced accuracy of the simulation of the temperature distribution in the shaft. The high value placed on the operational performance of TENSOMAX remains, viz. that even with older turbines, and particularly in the case of turbines rehabilitated with a new shaft, careful and transparent operation is assured. (orig.) [German] Die Einrichtung TENSOMAX ermoeglicht eine Ueberwachung der thermischen Beanspruchung der Welle bei Dampfturbinen, bei denen die TURBOMAX-Sonde in der Turbine nahe der kritischen Stelle der Welle nicht einsetzbar ist. Daher stellt der TENSOMAX unter Beruecksichtigung minimaler Ungenauigkeit aufgrund der Nachbildung der Waermeuebergangszahl eine vorteilhafte Alternative zum TURBOMAX dar. Der ...
Within the context of practice-oriented constraints the speed and output power control of power plant turbines represents a big challenge for engineers for designing low order controllers with only a few parameter settings and in order to meet the requirements of the Deutsche Verbundgesellschaft. The results of a detailed study of the current standard and an improvement of the speed dynamic for load rejections are shown. (orig.) [German] Die Regelung der Drehzahl und die Leistung von Kraftwerksturbinen stellt im Rahmen von praxisorientierten Nebenbedingungen, wie z.B. dem Einsatz von Reglern geringer Ordnung mit wenigen Einstellparametern und den Vorgaben der Deutschen Verbundgesellschaft, eine grosse Herausforderung fuer den Entwicklungsingenieur dar. Die Ergebnisse einer ausfuehrlichen Untersuchung des bisherigen Standards und einer Verbesserung der Drehzahldynamik bei sogenannten Abfangpruefungen werden vorgestellt. (orig.)
Une enfant drepanocytaire homozygote SS de 14 ans (sans deficit en G6PD), non transfusee anterieurement, a une cholecystectomie pour lithiase decouverte a un bilan systematique. L'intervention est encadree de 2 transfusions de concentres erythrocytaires (CGR) phenotypes ABO Rh Kell, compatibilises. Quinze jours apres, elle presente une hemolyse aigue associant fievre, ictere, insuffisance renale tubulaire, hemoglobinurie et anemie profonde (Hb 3,6 g/dL). Les RAI deviennent positives avec, entre autres, un auto anticorps anti D suspecte, le test de Coombs direct est positif de type mixte. L'enfant n'est pas retransfusee, mais recoit 1 mg/kg/j de corticoides IV pendant 10 jours. L'hemoglobine retrouve sa valeur de base (9 g/dL) apres 15 jours. Un antigene RH1(D) partiel de type DAR est ulter...
Meltdown and gasification of waste in an oxygen atmosphere ('2sv' process) is an economically efficient alternative to energetic and thermal utilisation of biomass. Organic pollutants are split at temperatures up to 2000 C in a reducing atmosphere. The process uses elements of the oxygen cupola furnace for melting and gasification of many different waste fractions, e.g. polluted waste wood, household refuse and bulk waste, old tyres, light shredder fractions, sewage sludge, etc. [German] Die Sauerstoff-Schmelz-Vergasung ('2sv') stellt eine wirtschaftliche Alternative zur energetischen Nutzung von Biomassen wie auch zur thermischen Abfallverwertung dar. Organische Schadstoffe werden bei diesem neuen Verfahren bei Temperaturen bis zu 2000 C unter reduzierenden Bedingungen aufgespalten. Das Verfahren nutzt Elemente des Sauerstoff-Kupolofens fuer die Schmelzvergasung und eignet sich fuer zahlreiche Abfallarten wie z.B. belastetes ...
35 patients with ankle sprain were examined by MRI and stress radiographs. 13 were operated afterwards, 22 patients underwent a functional conservative therapy and were examined by MRI and stress radiographs and second time after three months. MRI reports were correct in 12 of 13 operated cases. After conservative therapy we did not find any disrupted ankle ligament. MRI showed intact ligaments thickened by scar. (orig./MG) [Deutsch] 35 Patienten mit klinischem Verdacht auf Aussenbandruptur wurden mit der MRT untersucht. 13 Patienten wurden operiert, 22 konzervativ therapiert. Letztere wurden nach drei Monaten erneut mit MRT und gehaltenen Aufnahmen untersucht. Die MRT-Befunde stimmten in 12 von 13 Faellen mit den operativ erhobenen Befunden ueberein. Nach dreimonatiger konzervativer Therapie waren alle 22 Sprunggelenke stabil. Die rupturierten Baender stellten sich verdickt und durchgaengig dar. (orig./MG)
The second volume contains a comprehensive presentation of inflammatory bone diseases, including seldom primary chronic osteomyelitis and morbus Paget. Substantial chapters on bone tumors and tumor-like lesions of bone joints are covering the state-of-the-art of diagnostic techniques of these seldom but important diseases. Besides the importance of projection radiography the contribution of MRI within differential diagnosis und staging of these diseases is emphasized. [German] Der zweite Band des Muskuloskelettalen Systems befasst sich mit der umfassenden Darstellung zur Diagnostik entzuendlicher Knochenerkrankungen und beinhaltet neben den klassischen infektioesen auch die seltenen, primaer chronischen Osteomyelitiden und den Morbus Paget. Umfangreiche Kapitel ueber die Knochentumoren und tumoraehnlichen Laesionen der Gelenke stellen in modernster Weise den aktuellen Stand des Wissens und der Diagnostik dieser seltenen, aber aus differenzialdiagnostischer Sicht sehr wichtigen ...
By joining the `climate association of European cities`, Frankfurt has agreed to reduce its CO{sub 2}-emissions by 50% by the year 2010. The so-called `climate offense 1991` was the first regulatory paper to be set up by a community to reach this goal over a long term. This report now represents the present level of the project. Main points are the development of houses with low entropy, the retrofitting of heating systems, water saving measures and energy management. (BWI) [Deutsch] Durch den Beitritt zum `Klima-Buendnis der Europaeischen Staedte` hat sich die Stadt Frankfurt/M. verpflichtet, die CO{sub 2}-Emissionen bis zum Jahr 2010 um 50% zu senken. Mit der sog. `Klimaoffensive 1991` wurde dann erstmals von einer Kommune in Deutschland ein detailliertes Regelwerk aufgestellt, um dieses Ziel langfristig erreichen zu koennen. Der vorliegende Bericht stellt den aktuellen Stand des Projektes dar. Kernpunkte sind die Entwicklung von Niedrigentropiehaeusern, die ...
Endoluminal vascular prostheses that can be implanted by percutaneous routes represent the most recent development in vascular interventional radiology. Various commercially available types of prosthesis are presented and the construction principles and applications are described. At present secure indications for the implantation of endoluminal prostheses are limited to the elimination of aneurysms and arteriovenous fistulae of the large vessels near the trunk in sections that do not cross a joint. The wide use in peripheral occlusive diseases cannot yet be recommended because confirmed data are not available. (orig.) [German] Endoluminale Gefaessprothesen, die perkutan implantierbar sind, stellen die juengste Entwicklung in der vaskulaeren interventionellen Radiologie dar. Verschiedene kommerziell erhaeltliche Prothesentypen werden vorgestellt, ihr Konstruktionsprinzip und ihre Applikation erlaeutert. Die gesicherten Indikationen zur endoluminalen ...
In this article the methodology followed to diagnose the performance of the equipment where heat is transferred from the feed water, condensate and circulation water systems in fossil power plants (FPP). The data collection is made with the unit in normal operation, using local instrumentation without taking the equipment out of service for its installation. The equipment diagnosis is made through the analysis of the collected data in actual operation and the design data; for this purpose a thermal balance of the interested systems is performed to obtain all the conditions an operation data. Later on the performance indicative parameters (PIP) of actual operation and design are calculated and compared one against the other. Such a comparison reveals the performance deterioration and the possible equipment faults. The data obtained and the supplementary information are stored in a data base whose objective is that Comision Federal de Electricidad has on hand a prompt access to them in ...
This seminar on the subject of ``electrical smog`` welcomed participants from Bavarian environmental consultancy agencies, rural and urban district authorities, ministries, consume-consultancy agencies and public health authorities. Leading scientists from research and authorities gave papers on the sources, exposure and effects/actions of electromagnetic fields and present the current state of knowledge about the hazards and risk of this radiation for human health. The proceedings in hand provide the papers given on the following topics: electromagnetic fields - and introduction to relevant issues; low-frequency fields - sources and exposure; high-frequency fields - sources and exposure; biological actions and effects of low-frequency fields; biological actions and effects of high-frequency fields; low-frequency fields - helath risk assessment; high-frequency fields - health risk assessment. (Uhe) [Deutsch] Das Seminar zum Thema Elektrosmog wurde fuer Teilnehmer aus bayerischen ...
Osteonecrosis (ON) of the hip joint remains an unsolved therapeutical problem. Diagnosis of ON of the hip has been improved by the technical progress of imaging modalities and better understanding pathomorphology. Over a long period only plain radiographs have been available. Scintigraphy and computed tomography contributed to differential diagnosis and early detection of bone necrosis. Diagnosis in an early reversible stage is of importance. Understanding of pathophysiology, early diagnosis and therapeutical approach has been significantly improved by MR imaging. Using the ARCO system all imaging modalities and their diagnostic viability are described in the five ARCO stages. At the end a diagnostic algorithm will be proposed. (orig.) [German] Die Osteonekrose des Hueftgelenks (ON) stellt noch immer ein nicht geloestes therapeutisches Problem dar. Die diagnostischen Moeglichkeiten bei der ON wurden in den letzten Jahren durch technische Fortschritte bei den ...
Recurrent variceal bleeding due to liver cirrhosis led to treatment with a transjugular intrahepatic portosystemic shunt (TIPS) in a pregnant woman at 20 weeks` gestation. Fetal radiation exposure was estimated to be less than 10 mSv. The use of a graduated catheter allowed measurement of field size and reliable determination of the patient`s entrance dose. Radiation exposure of an approximated fetal dosage of 5.2 mSv did not justify abortion for medical reasons. Therefore, TIPS procedure is not generally contraindicated during pregnancy itself. TIPS placement may be a therapeutic option related to the severity of the underlying maternal disease, after radiation exposure of the fetus has been estimated. (orig.) [Deutsch] Bei rezidivierender Oesophagusvarizenblutung auf dem Boden einer Leberzirrhose wurde bei bestehender Schwangerschaft der 20. Woche ein transjugulaerer portosystemischer Stent-Shunt (TIPS) neu angelegt. Praeinterventionell wurde die zu erwartende Strahlenexposition fuer ...
The intermetallic phase NiAl is a potential material for high-temperature applications; however, its technical application was prevented so far by its high brittleness at room temperature. This problem may be solved by incorporating relatively high-ductility particles into the NiAl matrix. Controlled crack propagation experiments, tensile and pressure tests were carried out in order to analyze the toughness and deformation characteristics of NiAl composite materials containing niobium or molybdenum particles at room temperature and in ambient atmosphere. Both the niobium and the molybdenum particles increase the toughness as compared to the pure NiAl matrix, but no ductilisation was observed in the composite materials investigated. Model experiments in consideration of experimental data suggest, hovewer, that the toughness and ductility of NiAl may be enhanced by optimizing the microstructural and production parameters of the incorporated ductile particles. (orig.) [Deutsch] Die ...
The direct injection Diesel engine with its specific fuel consumption of about 200 g/kWh is one of the most efficient thermal engines. However in case of relatively low CH- und CO-emission the soot- and NO{sub x} concentration in the exhaust gas turns out to be a problem with respect to the legislation on emission limits. At the department of piston- and turbo-machines of the Trier University of Applied Sciences, a single-cylinder testing engine with two injection-systems (fuel and water) has been developed. This engine has been constructed to analyse the effect of stratified water-injection on the soot- and NO{sub x} emissions of exhaust gases of a Diesel engine. (orig.) [German] Der Dieselmotor mit Direkteinspritzung stellt mit spezifischen Kraftstoffverbraeuchen in der Groessenordnung von 200 g/kWh eine der wirtschaftlichsten thermischen Kraftmaschinen dar. Bei relativ niedrigen Kohlenwasserstoff- und Kohlenmonoxid-Emissionen erweist sich die Russ- und ...
Tanzania has recently developed a comprehensive environmental policy which has put high priority on several specific environmental issues. One of the issues is the quality of waste water. A special priority is given to the pollution from the sisal industry. The East-African agro-industries generate very large quantities of organic residues from production and processing of different crops. These residues form a major contribution to the pollution of air, soil and waterways, but, at the same time they constitute a large potential for production of bioenergy through anaerobic digestion as well as potential substrate for other biological fermentation processes. Generally, these residues are regarded as having no or very little value and the different disposal methods are mainly a matter of getting rid of the waste. The generation of residues are very often concentrated on few large units, which makes the exploitation of these resources feasible in large scale biogas systems. Typically the ...
Purpose: To evaluate the success rates of the implantation of stent grafts in the treatment of peripheral aneurysms. Materials and methods: in 13 patients with 15 aneurysms at the common iliac artery (n = 6), external iliac artery (n = 1), hypogastric artery (n = 2), femoral artery (n = 2) or popliteal artery (n = 4), implantation of dacron-covered nitinol stents was performed. The patients were followed up for three to 20 months (mean, 8.8 months) with intravenous digital subtraction angiography, CT or colour-coded Doppler sonography. Results: In all cases, the aneurysm was successfully occluded after stent implantation. In one case with a popliteal aneurysm, kinking of the vessel caused thrombosis of the stent. The stent was successfully reopened. The aneurysm however, had to be surgically treated 9 months later. The primary and secondary patency rates at 6 months were 93% and 100%, respectively. Conclusion: The method described might be an alternative therapy to surgery. There are ...
To test the assumption underlying every morphometric twin study that the brains of monozygotic twins are almost identical. Methods: High resolution MRI of the neurocranium of 26 monozygotic twin pairs were acquired and the volumes of 36 cerebral structures were measured. The same twins served as control group after rear-ranging them into non-related pairs of same sex and matching them for age, body height and body weight. Results: For most of the examined structures the correlations within the twins were significant (R = 0,97-0,59). Except for total forebrain volume the controls showed no significant similarity. Conclusions: For almost every measured cerebral structure the assumption, that significant similarities exist between healthy monozygotic twins is correct. Therefore discordant monozygotic twins represent an excellent sample when investigating cerebral correlates of neurologic and psychiatric disorders. (orig.) [German] Pruefung der Grundannahme hirnmorphologischer ...
In comparison to deterministic criteria, probabilistic reliability indices like interruption frequency and unavailability give a more differentiated insight into reliability in an electrical energy network. One possibility for network planning based on these indices is the definition of limits for customer nodes, another is the monetarisation of reliability in terms of interruption costs. Because of numerous disadvantages, interruption cost methods could not up to now win broad recognition in network planning in Western Europe. A more recent method for the monetarisation of reliability circumventing most of these disadvantages is the insurance system. In this system the customer selects a tariff class in an insurance system, and the utility reimburses its customers in the case of an interruption. In its first section, the paper describes a method for the flexible and realistic optimisation of MV networks. This method based on Genetic optimisation is able to integrate probabilistic ...
Surface structure analysis, i.e. metallographic analysis of component surfaces with the aid of replicas, is an established method of component monitoring and the only reliable non-destructive method for detecting and analyzing beginning creep damage in the form of creep pores. Creep pore development provides a basis for component condition analysis. It must be noted, however, that the modern martensitic 9-12 % Cr steels - like the established steels 10CrMo9-10 (P22) und X20CrMoV12-1 - have comparatively high creep fracture deformation rates in fatigue tests. This raises the question if these steels can be judged on the basis of data for established steels. The results so far suggest that even with low pore densities (single pores), a higher degree of damage and a shorter time until failure must be assumed. [German] Eine bewaehrte Methode der Bauteilueberwachung stellt die Oberflaechengefuegeuntersuchung, d. h. die metallografische Untersuchung der Bauteiloberflaeche mit Hilfe von ...
The paper presents fundamental studies on natural biosorption to algae of heavy metals. The investigations were carried out by TU Berlin University in a special research project (Sfb 193, 'Biologische Behandlung industrieller und gewerblicher Abwaesser'). The chlorophyceae C. vulgaris was used as reference alga, and 38 further algae were analzyed with regard to their sorption characteristics for lead, cadmium, nickel and zinc. The most effective algae were the chlorophyceae C. salina, the cyanophyceae S. hofmani and L. taylorii. The biosorption characteristics of C. salina and L. taylorii were investigated in detail. L. taylorii was found to be exploitable successfully in a technical process, so the investigations were extended to include copper. Knowledge about the chemical processes of biosorption is important for any attempt to modify the biosorption characteristics. Experiments on the incorporation of additional functional groups in the cell wall polysaccharides ...
Within its competence for energy research, the Bundesministerium fuer Wirtschaft und Arbeit (BMWA) (Federal Ministry of Economics and Technology) sponsors investigations into the safety of nuclear power plants. The objective of these investigations is to provide fundamental knowledge, procedures and methods to contribute to realistic safety assessments of nuclear installations, to the further development of safety technology and to make use of the potential of innovative safety-related approaches. The Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, by order to the BMWi, continuously issues information on the status of such investigations by publishing semi-annual and annual progress reports within the series of GRS-F-Fortschrittsberichte (GRS-F-Progress Reports). Each progress report represents a compilation of individual reports about the objectives, work performed, results achieved, next steps of the work etc. The individual reports are prepared in a standard form by the ...
The quantitative measurement of carbon concentration-distance curves serves as fundamental prerequisite for the evaluation of rim zone properties connected with decarburisation processes in material science. This was shown in part 1 of the present work with two samples from through-hardenable rolling bearing steel 100Cr6 (SAE 52100) austenitised in different oxidising atmospheres by position dependent determination of hardness, residual stresses, and X-ray line broadening ({l_brace}211{r_brace} {alpha}'-Fe diffraction line). In practice, it is important to predict carbon concentration-distance curves under prevailing heat treatment conditions or to conclude conversely from profile measurements. Based on a refined kinetics model of a diffusion-controlled process, part 2 therefore presents a simulation tool developed by means of the finite element method (FEM). Apart from the concentration dependence of the diffusion coefficient, it also considers the decarburisation induced ...