In einem Interview präsentiert Dr. Gernot Erler (SPD, Staatsminister im Auswärtigen Amt)sein neuestes Buch „Mission Weltfrieden: Deutschlands neue Rolle in der Weltpolitik“ und gibt damit Einblicke in die Außenpolitik der Großen Koalition und der unter Gerhard Schröder.

La nouvelle technique d'hyperdéformation nommée High Pressure Tube Twisting (HPTT), est un procédé continu d'affinement du grain pour les matériaux métalliques avec la géométrie tubulaire. Il consiste à placer un mandrin dans le tube avant d'appliquer une compression axiale directement sur le tube confiné des deux côtés pour produire une pression hydrostatique importante. Le tube est ensuite cisaillé par un couple externe à l'aide de la force de frottement généré par la pression hydrostatique. Les structures ultrafines produit avec HPTT ont été confirmés par MET et leur propriétés mécaniques ont été évaluées. La limite d'élasticité est augmentée de façon monotone avec la déformation imposée par HPTT. L'évolution de la microstructure est étudiée par la technique EBSD et les mesures de texture ont été réalisées avec des rayons X. Les échantillons déformés ont la texture de cisaillement simple, avec des intensités relativement faibles et l'effet de la texture initiale sur la texture finale persiste jusqu'à un cisaillement de 6. La distribution des désorientations entre les grains est bimodale et le second pic augmente avec la déformation. Application industrielle de cette nouvelle technique SPD exige la modélisation avancée en termes d'évolution de texture et le processus de fragmentation des grains. Dans ce but, le nouveau modèle de fragmentation du grain proposé par Toth et al. a été utilisée. L'affinement du grain améliore les résultats de simulation texture de façon significative et donne des informations complémentaires sur la distribution et la taille moyenne des grains, et la distribution de désorientation qui peut être directement comparés aux résultats expérimentaux / The new severe plastic deformation (SPD) technique, designated as high pressure tube twisting (HPTT), is a continuous process for grain refinement in bulk metallic materials with tubular geometry. It consists of placing a mandrel into the tube before applying an axial compression directly on the tube confined on both sides to produce high hydrostatic pressure. The tube is then twisted by an external torque with the help of the friction force genrated by the hydrostatic pressure. The ultra-fine grained structures produced with HPTT were confirmed using transmission electron microscopy and their microstructure and mechanical properties were evaluated. The value of yield stress is increased monotonically with the deformation imposed by HPTT. Meanwhile, the inverse deformation path is proved to be less advantageous. Microstructural evolution is studied by EBSD technique and texture measurements were carried out using X-ray. Deformed samples have simple shear texture with relatively low intensities and the effect of the initial texture on the final texture persists up to shear strain of nearly 6. Grain-to-grain misorientation distribution functions are bimodal and the second pick become higher with increasing strain. Industrial application of this new SPD technique requires advanced modelling in terms of texture evolution and grain fragmentation process. For this purpose, the new grain refinement model proposed by Toth and al. was used. Grain refinement improves the texture simulation results significantly and gives information on the average grain size, grain size distribution and misorientation distribution function that can be directly compared to experimental results

No description available.

The purpose of this work was to study learn about grain refinement mechanisms and texture development in cast n-type Bi90Sb10 alloy caused by severe plastic deformation. The practical objective is to produce a fine grained and textured microstructure in Bi90Sb10 alloy with enhanced thermoelectric performance and mechanical strength. In the study, twelve millimeter diameter cast bars of Bi90Sb10 alloy were encapsulated in square cross section aluminum 6061 alloy containers. The composite bars were equal channel angular (ECAE) extruded through a 90 degree angle die at high homologous temperature. Various extrusion conditions were studied including punch speed (0.1, 0.3 and 0.6 in/min), extrusion temperature (220, 235 and 250oC), number of extrusion passes (1, 2 and 4), route (A, BC and C), and exit channel area reduction ratio (half and quarter area of inlet channel). The affect of an intermediate long term heat treatment (for 100 hours at 250oC under 10-3 torr vacuum) was explored. Processed materials were characterized by optical microscopy, x-ray diffraction, energy dispersive spectroscopy, wavelength dispersive spectroscopy and scanning electron microscopy. Texture was analyzed using the {006} reflection plane to identify the orientation of the basal poles in processed materials. The cast grains were irregularly shaped, had a grain size of hundreds-of-microns to millimeters, and showed inhomogeneous chemical composition. Severe plastic deformation refines the cast grains through dynamic recrystallization and causes the development of a bimodal microstructure consisting of fine grains (5-30 micron) and coarse grains (50-300 micron). ECAE processing of homogenizied Bi-Sb alloy causes grain refinement and produces a more uniform microstructure. Texture results show that ECAE route C processing gives a similar or slightly stronger texture than ECAE route A processing. In both cases, the basal-plane poles become aligned with the shear direction. Reduction area exit channel extrusion is more effective for both grain refinement and texture enhancement than simple ECAE processing.

Wie stabil ist die Außenpolitik der Großen Koalition? Aufgrund ihrer Position als stellvertretende außenpolitische Sprecherin der SPD ist es der Autorin möglich, neben den Gemeinsamkeiten auch die entscheidenden Unterschiede zu beleuchten. Vor dem Hintergrund mehrerer Beispiele, wie dem EU-Beitritt der Türkei, stellt sie den Konsens zwischen CDU/ CSU und SPD als fragil heraus.

Målet med detta examensarbete är att minska risken för olyckor där grävmaskiner, med borr- eller pålmast monterad, är inblandade. För att kunna uppnå detta mål, har ett beräkningsprogram skapats som definierar ett säkert arbetsområde innan ostabilitet inträffar. Detta har gjorts genom att studera tidigare forskningsarbeten inom området samt verifiering av beräkningsprogrammet med hjälp av en fallstudie och data om maximal lyftkapacitet för grävmaskinen.

Thesis (doctoral)--Freie Universität, 1983. / Title from label on t.p. Vita. Includes bibliographical references (p. 266-274).

No description available.

Methods designed for incorporation into multiscale modeling polycrystals are presented in this work in two tasks. This work contains mesoscale methods for capturing the effects of both the interactions of slip dislocations encountering twin grain boundaries and the simultaneous growth of multiple twin grain volume fractions on mechanical hardening and texture evolution. These are implemented in a crystal plasticity framework using the Los Alamos visco-plastic self consistent code, VPSC-7. Presented here, the effects of simultaneous growth in multiple twin variants on textural evolution is tracked using a Kalidindi-type twin volume transfer scheme. In Task 1, the implementation of this scheme in order to simulate the texture of Twinning Induced Plasticity steels (TWIP) subjected to Equal Channel Angular Pressing (ECAP) are summarized. In Task 2, the hardening effects of two types of interactions between slip dislocations and encountered twin grain boundaries, namely dislocation transmutation and dissociation, are captured by way of modifying the dislocation density based hardening model of [14]. Interactions of the first type are presented in a constitutive relation calculating the amount of dislocation density apportioned to a given slip system contained within the encountered twin volume fraction from each interacting slip system in the parent volume fraction. The amount transmuted from each interacting slip system described using the Correspondence Method, an onto mapping of slip systems in a parent grain to slip systems in considered twin grains. Interactions of the second type are then introduced into this constitutive relation as a disassociation parameter, the value of which is established by observations gleaned from the results of the molecular dynamics simulations of [11] and [36]. These methods are implanted to simulate the anisotropic hardening behavior of HCP magnesium under multiple load paths.

En aquesta tesi es descriu l'electrònica i la gestió de la placa de control de l'SPD. SPD són les sigles corresponents a Scintillator Pad Detector, part del calorímetre d'LHCb de l'accelerador LHC.L'LHC és un accelerador orientat a estudiar els constituents de la matèria on LHCb n'és un dels detectors. El calorímetre és aquella part del detector destinada a mesurar l'energia de les partícules que el travessen. En el nostre cas l'SPD discrimina entre partícules carregades i no carregades contribuint així en les decisions del calorímetre.En l'electrònica de l'SPD trobareu diferenciades dues parts: l'electrònica en contacte directe amb el subdetector (Very Front End, VFE) i l'electrònica de gestió de l'SPD (la Control Board, CB). L'objectiu d'aquesta tesi és la descripció d'aquesta darrera així com la integració de l'SPD en el sistema de control del calorímetre. El VFE realitza un primer processat de les dades del detector determinant un nivell digital el qual indica si s'ha rebut una partícula carregada o no. La CB és l'encarregada en canvi de la monitorització i el control del sistema SPD: és capaç d'enviar dades de configuració als VFE i a la vegada en monitoritza el correcte funcionament.Veureu que el document es troba organitzat en 5 parts. A la primera part trobareu descrites les característiques principals del calorímetre, les seves funcions i la seva estructura. La part segona, tercera i quarta són dedicades integrament a la CB: a la part 2 tenim descrit el hardware, a la part 3 el sistema de control i a la quarta part hi trobarem comentats els diferents testos i proves realitzades tan sobre el hardware com amb el sistema de control. Finalment a la cinquena part hi trobarem resumits els objectius aconseguits amb el nostre disseny i les aportacions d'aquest en la globalitat de l'experiment. / En esta tesis se describe la electrónica y la gestión de la placa de control del SPD. SPD son las siglas correspondientes a Scintillator Pad Detector, parte del calorímetro de LHCb del acelerador LHC.LHC es un acelerador orientado al estudio de los constituyentes de la materia donde LHCb es uno de los detectores. El calorímetro es aquella parte del detector destinada a medir la energía de las partículas que lo traviesan. En nuestro caso el SPD discrimina entre partículas cargadas y neutras contribuyendo así a las decisiones del calorímetro.En la electrónica del SPD encontraréis diferenciadas dos partes: la electrónica en contacto directo con el detector (Very Front End, VFE) y la electrónica de gestión del SPD (la Control Board, CB). El objetivo de esta tesis es precisamente la descripción de esta última parte así como la integración del SPD en el sistema de control del calorímetro.El VFE realiza un primer procesado de los datos del detector determinando un nivel digital el cual indica si la partícula detectada está cargada o no. La CB es en cambio la encargada de la monitorización y el control del sistema SPD: es capaz de enviar datos de configuración a los VFE y a la vez monitorizar su correcto funcionamiento.Veréis que el documento se encuentra organizado en 5 partes. En la primera parte encontraréis descritas las características principales del calorímetro, sus funciones y su estructura. La segunda parte, la tercera y la cuarta están plenamente dedicadas a la CB: en la parte 2 tenemos descrito el hardware, en la parte 3 el sistema de control y en la cuarta encontraremos los diferentes tests y pruebas realizadas sobre el hardware y el sistema de control. Finalmente en la quinta parte tenemos resumidos los objetivos conseguidos con nuestro diseño y las aportaciones de este en la globalidad del experimento. / In this thesis you will have described the electronics and management of the SPD. SPD stands for Scintillator Pad Detector which is part of the LHCb calorimeter of the LHC accelerator.LHC is an accelerator oriented to study the matter constitution and LHCb is one of the detectors designed for this challenge. The LHCb part oriented to measure the particles energy is the calorimeter. The SPD is designed to discriminate between charged and neutral particles contributing in the calorimeter decisions.In the SPD electronics description we can distinguish between to parts: the electronics in contact with the subdetector (Very Front End, VFE) and the electronics in charge of the SPD management (the Control Board, CB). The goal of this thesis is the description of the last and also the integration of the SPD with the calorimeter control system.The VFE captures the data from the detector and makes a first digital decision depending on if the particle detected is charged or not. The CB is in charge of the monitoring and control of the SPD system: is able to send configuration data to the VFE and also monitors parameters to assure a proper behaviour.You will see that the document is divided in 5 parts. In the first, you will find described the calorimeter, its functionalities and its structure. Part 2, part 3 and part 4 are fully dedicated to the CB: in part 2 we will find the CB hardware, in part 3 the control system and finally in part 4 the different tests performed with the hardware and the control system. The document ends with part 5 where the main objectives of this work are summarized and also the contribution of the SPD design in the LHCb project.