957 research outputs found

    The impact of ventilation cooling towers on plus energy houses in southern Europe

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    This is an Open Access Article. It is published by Taylor and Francis under the Creative Commons Attribution 4.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/4.0/Cooling homes is often important to maintain acceptable internal comfort. This can be achieved by both active and passive solutions. This research focused on passive systems and has examined one hypothesis: that evaporative cooling towers are an important element of plus-energy houses in southern Europe. Refinements to the design of the existing ventilation tower of a Solar Decathlon House developed by the Hochschule für Technik Stuttgart are proposed and tested in eight locations in Greece, Italy, Portugal and Spain using dynamic thermal and computational fluid dynamics simulations in order to predict energy consumption, mean and peak CO2 levels, temperatures, ventilation rates, cooling potential, fresh air distribution, indoor air quality and water consumption of the evaporative cooling system implemented within the tower. Results show that a 50% reduction of the annual energy demand for space cooling to be satisfied by other systems is achieved without compromising the internal comfort

    Magnetisierungsprozesse in Dysprosium

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    60 refs.Copy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

    Die Beruecksichtigung ungewisser Erwartungen bei Nutzen-Kosten-Untersuchungen im Verkehrswesen: Dargestellt am Beispiel der standardisierten Bewertung von Verkehrswegeinvestitionen der OePNV

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    Bibliothek Weltwirtschaft Kiel C 157616 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

    Softwarekonzepte zum Entwurf komplexer Systeme - Auswahl und Umsetzung am Beispiel eines Programmsystems zur Berechnung hypothetischer Kernschmelzunfaelle

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    Development and application of simulation systems for the analysis of complex processes require on the one hand and detailed engineering knowledge of the plant and the processes to be simulated and on the other hand a detailled knowledge about software engineering, numerics and data structures. The cooperation of specialists of both areas will become easier if it is possible to reduce the complexicity of the problems to be solved in a way that the analyses will not be disturbed and the communication between different disciplines will not become unnecessarily complicated. One solution to reduce the complexity is to consider computer science as an engineering discipline which provides mainly abstract elements and to allow engineers to build application systems based on these abstract elements. The principle of abstraction leads through the processes of modularisation and the solution of the interface problem to an almost problem independent system architecture where the elements of the system (modules, model components and models) operate only on those data assigned to them. In addition the development of abstract data types allows the formal description of the relations and interactions between system elements. This work describes how these ideas can be concretized to build complex systems which allow reliable and effective problem solutions. These ideas were applied successfully during the design, realization and application of the code system KESS, which allows the analysis of core melt down accidents in pressurized water reactors. (orig.)Entwicklung und Einsatz von Simulationssystemen zur Analyse komplexer Ablaeufe erfordern zum einen ein detailliertes Ingenieurwissen ueber die abzubildende Anlage und der dort ablaufenden Vorgaenge und zum anderen detaillierte Informatikkenntnisse ueber Software-Entwicklung, Numerik und Datenstrukturen. Das erfolgreiche Zusammenspiel von Spezialisten beider Bereiche wird erleichtert, wenn es gelingt, die Komplexitaet des zu loesenden Problems so weit zu reduzieren, dass zum einen die durchzufuehrenden Analysen nicht verfaelscht und zum anderen die Kommunikation zwischen verschiedenen Disziplinen nicht unnoetig erschwert wird. Eine Loesung dieser Problematik ergibt sich, wenn man die Informatik als Ingenieurwissenschaft betrachtet, deren Baumaterial im wesentlichen abstrakt ist und deren abstrakte Konstrukte von Ingenieuren in Anwendungen umzusetzen sind. Das Abstraktionsprinzips fuehrt ueber die Modularisierung und ueber die Loesung der Schnittstellenproblematik auf eine weitgehend problemunabhaengige Systemarchitektur, bei der die Bausteine des Systems, Anwendungsmodul, Modellkomponenten und Modelle, als Operatoren auf die ihnen zugeordneten Datenbestaende wirken. Darueber hinaus ermoeglicht der Entwurf geeigneter abstrakter Datentypen die formale Beschreibung der Beziehungen und Wechselwirkungen zwischen den einzelnen Systembausteine. Im Rahmen dieser Arbeit wird am Beispiel des Entwurfs, der Realisierung und der Anwendung des Programmsystems KESS zur Analyse schwerer Stoerfaelle in Druckwasserreaktoren gezeigt, wie sich diese Ideen konkret umsetzen lassen, wie es durch konsequente Anwendung dieser Ideen moeglich wird nichttriviale Systeme aufzubauen und wie dadurch zuverlaessige und effektive Problemloesungen moeglich werden. (orig.)SIGLEAvailable from TIB Hannover: RA 607(4-139) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

    On shear band localization phenomena of liquid-saturated granular elasto-plastic porous solid materials accounting for fluid viscosity and micropolar solid rotations

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    Elasto-plastic deformations of cohesive-frictional liquid-saturated granular solid materials can be described by use of a macroscopic continuum mechanical approach within the well-founded framework of the Theory of Porous Media (TPM). In the present contribution, the TPM formulation of the skeleton material is extended by micropolar degrees of freedom in the sense of the Cosserat brothers. Proceeding from two basic assumptions, material incompressibility of both constituents (skeleton material and pore-liquid) and geometrically linear solid deformations, the non-symmetric effective skeleton stress and the couple stress tensor are determined by linear elasticity laws. In the framework of the ideal plasticity concept, the plastic yield limit is governed by a smooth and closed single-surface yield function together with non-associated flow rules for both the plastic strain rate and the plastic rate of curvature tensor. Fluid viscosity is taken into account by the drag force. The inclusion of micropolar degrees of freedom, in contrast to the usual containuum mechanical approach to the TPM, allows, on the one hand, for the determination of the local average grain rotations and, on the other hand, additionally yields a regularization effect on the solution of the strongly coupled system of governing equations when shear banding occurs. However, in the framework of the original TPM formulation of fluid-saturated porous materials, the inclusion of the fluid viscosity alone also yields a certain regularization on shear band computations. The numerical examples are solved by use of finite element discretization techniques, where, in particular, the computation of shear band localization phenomena is carried out by the example of the well-known base failure problem of geotechnical engineering. (orig.)SIGLEAvailable from TIB Hannover: RR 6943(96/08) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

    Transientenspektroskopie an Haftstellen in sauerstoffreichem Silizium

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    With 117 refs.SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

    Temperatur-, Dehnungs- und Rissaufweitungsmessungen bei dem 1. Versuch zur Notkuehlsimulation Teilbericht fuer das Forschungsvorhaben FNK

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    TIB: AC 8915 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
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