Technische Universität Bergakademie Freiberg: Qucosa
Not a member yet
1431 research outputs found
Sort by
Fraktionale Modellierung und Parametrierung von technischen Spulen
Get PDFDie genaue Abbildung des Verhaltens von technischen Spulen über einen weiten Frequenzbereich ist für eine präzise Modellierung von technischen Maschinen notwendig. Technische Spulen mit einem ferromagnetischen Kern zeigen andere Eigenschaften als ideale Spulen [1, 2]. Dies ist auf die Wirbelstromverluste, Hystereseverluste und ab einem bestimmten Frequenzbereich auftretenden Skineffektverlusten zurückzuführen. In diesem Beitrag werden zwei Verfahren der Modellierung von technischen Spulen, das klassische Modell und das fraktionale Modell, miteinander verglichen. Für beide Modelle werden die Parameter anhand der Methode der kleinsten Fehlerquadrate (MKQ) identifiziert. Die gewonnenen Ergebnisse werden an Messungen validiert
A study of young firm performance in France between 2006 and 2009 using the process theory of organisation
Get PDFThis thesis studies the performance of a cohort of French firms between 2006 and 2009 using a theoretical framework developed for this purpose. This framework is based on the author’s entrepreneurial experience and conviction that firm performance is dependent on solving a managerial problem with two components: (i) an entrepreneurial component which focuses on creating market power with respect to customer wants, resources, means of production, and technology and (ii) an organisational component aiming to implement adequate labour division and coordination and motivation mechanisms in the firm. Solving both aspects of the managerial problem in firms is expected to increase frim performance over time. This book describes the origins of the managerial problem in the economic literature, studies its dual organisational and entrepreneurial aspect, and measures its effect on firm performance.:INTRODUCTION
PART I: LITERATURE REVIEW, RESEARCH QUESTION, AND RESEARCH PLAN
CHAPTER 1 : LITERATURE REVIEW
CHAPTER 2 : RESEARCH QUESTION
CHAPTER 3 : RESEARCH PLAN
PART II: THEORETICAL DEVELOPMENT
CHAPTER 4 : THE PROCESS THEORY OF ORGANISATION
CHAPTER 5 : A MODEL OF FIRM PERFORMANCE
CHAPTER 6 : LEVERAGES ON FIRM PERFORMANCE
CHAPTER 7 : THE MANAGERIAL PROBLEM
PART III: EMPIRICAL ANALYSIS
CHAPTER 8 : BUILDING A MODEL TO ASSESS FIRM PERFORMANCE
CHAPTER 9 : ENTREPRENEURIAL ABILITY AND ITS CHARACTERISTICS
CHAPTER 10 : ORGANISATIONAL ABILITY AND ITS CHARACTERISTICS
CHAPTER 11 : THE IMPACT OF MANAGEMENT ON FIRM PERFORMANCE
PART IV: OUTLOOK
APPENDIX A: THE AUSTRIAN SCHOOL OF THOUGHTS AND ITS EVOLUTION
APPENDIX B: A CALCULATED EXAMPLE OF FIRM PERFORMANCE WITH NESTED PROCESSES
APPENDIX C: ON STRUCTURING AND DRIVING THE FIRM
APPENDIX D: LANDMARKS TO UNDERSTANDING THE ENTREPRENEURIAL PROCESS
APPENDIX E: DESCRIPTIVE STATISTICS
APPENDIX F: MODEL SPECIFICATION
REFERENCE
Stratigraphie, Fazies und geothermisches Potenzial von fluvio-deltaischen Ablagerungsräumen der Oberen Trias und des Unteren Jura im östlichen Teil des Mitteleuropäischen Beckens
Get PDFDie vorliegende, aus insgesamt vier Einzelveröfffentlichungen bestehende Dissertation soll den Kenntnisstand über fazielle und biostratigraphische Entwicklungen und Gliederungsmöglichkeiten in der höheren Trias und dem Unteren Jura im östlichen Teil des Mitteleuropäischen Beckens (insbesondere des Norddeutschen Beckens) erweitern, und die bislang verfügbaren Daten in einem Kontext wiedergeben. Als wesentliche Punkte der Arbeit sollen genannt werden:
1. Verbesserung des stratigraphischen Gerüsts: Basierend auf hochauflösender Palynostratigraphie (in der Exter-Formation, Rhätkeuper) und der biostratigraphisch kontrollierten Definition von sequenzstratigraphischen Flutungs- und Regressionsflächen (im Unteren Jura) konnten konkrete Zeitscheiben ausgewiesen werden, auf deren Grundlage Untergrund-Fazieskarten erstellt worden sind. Durch Korrelation gleichalter Ablagerungen kann u. a. der Trias-Jura-Übergang im Norddeutschen Becken besser identifiziert werden.
2. Sedimentologische und biofazielle Untersuchungen an gekernten Bohrungen und Übertageaufschlüssen ermöglichen die Rekonstruktion von hochauflösenden Untergrund-Fazieskarten innerhalb der konkretisierten Zeitscheiben, die Ablagerungsmodelle und biofazielle Zonierungen (Rhätkeuper bis Toarc) wiedergeben. Diese Ergebnisse können mittels Korrelation geophysikalischer Bohrlochmessungen auf Profile übertragen werden, von denen keine Festgesteinsprobe (mehr) vorliegt. Zusätzlich wird ein Vergleich mit rezenten Ablagerungssystemen möglich.
3. Bezugnahme der Ergebnisse auf die angewandte Forschung, insbesondere die Erkundung des geologischen Untergrundes und die Abschätzung der Reservoirqualität (mithilfe von geohydraulischen Messwerten [Porosität, Permeabilität] sowie hochauflösender Reservoirqualitätskarten, die aus den Untergrund-Fazieskarten abgeleitet worden sind). In Vorbereitung geothermischer Projekte ermöglichen diese Karten eine verbesserte standortbezogene Reservoirprognose, als dies bisher im östlichen Norddeutschen Becken möglich ist
Domain filling circle packings
Get PDFVerallgemeinerungen bekannter Existenz- und Eindeutigkeitsaussagen für gebietsfüllende Kreispackungen. Für jedes beschränkte, einfach zusammenhängende Gebiet und für jeden zulässigen Komplex existiert eine gebietsfüllende, verallgemeinerte Kreispackung, die einer beliebigen der folgenden Normalisierungen genügt.
alpha-beta-gamma: drei Randkreise sind je einem Randpunkt (Primende) zugeordnet
alpha-gamma: ein Kreis mit fixem Mittelpunkt und ein Randkreis mit zugeordnetem Primende
alpha-beta: zwei Kreise mit fixen Mittelpunkten
Bedingungen werden angegeben, unter welchen die aufgeführten Normalisierungen eindeutige Lösungen implizieren, welche zudem stetig von den Normalisierungsparametern abhängen. Ist der Alpha-Kreis ein innerer Kreis, dann wird gezeigt, dass die alpha-beta Normalisierung im Allg. keine Eindeutigkeit liefert. Bedingungen werden aufgeführt, die nicht-entartete Lösungen (klassische Kreispackungen) garantieren. Alle Beweise sind möglichst elementar und unabhängig von existierenden Kreispackungs-Ergebnissen.Existing existence and uniqueness results in the field of domain filling circle packings are generalized.
For every bounded, simply connected domain, for every admissible complex, and under any of the following normalizations it is shown that there is a domain filling generalized circle packing.
alpha-beta-gamma: three boundary disks are each associated with a boundary point (prime end)
alpha-gamma: one disk with fixed center and one boundary disk with associated prime end
alpha-beta: two disks with fixed centers
Conditions are given under which the stated normalizations yield unique solutions, which then depend continuous on some normalization parameters. For the special case of an interior alpha disk it is shown that the alpha-beta normalization does not yield uniqueness in general.
Several conditions are stated that guarantee non-degenerate solutions (classical circle packings).
All proofs are kept as elementary as possible and independent of existing circle packing results
Оценка и снижение экологической опасности отвалов горного производства в Новороссийской промышленной агломерации
Get PDFAbandoned non-reclaimed marl mine dumps of the cement factory in the Novorossiysk industrial agglomeration (NW Caucasus, Russia) are hazardous because of fugitive dust emissions, erosion and possible occurrence of a debris-flow disaster. Having high sorption capacity, dust accumulates pollutants contained in the atmospheric air and subsequently precipitates on the topsoil. Soil and plant sampling and chemical analysis (> 200 specimens) revealed the geochemical anomalies of Pb, Zn, Cu, Ba and Sr. Land zoning based on accumulated environmental damage indicators and the debris-flow technical risk was performed to assess environmental threats. The designed mine dump reclamation includes soil stabilisation by application of geosynthetic cover, hydro-seeding of soil improvers and seeds of herbaceous plants on the slopes, and anti-erosion plantation of cades and smoke trees at subhorizontal surfaces
Neuer internationaler MSc-Studiengang „Geomatics for Mineral Resource Management“
Get PDFZum Wintersemester 2019/2020 wird an der TU Bergakademie Freiberg ein neuer MSc- Studiengang „Geomatics for Mineral Resource Management“ angeboten. Dieser ist Teil eines internationalen Programmes unter Beteiligung der Universitäten Técnico Lisboa in Portugal, Delft University of Technology in den Niederlanden, TU Bergakademie Freiberg in Deutschland, Montanuniversität Leoben in Österreich sowie Wroclaw University of Science and Technology in Polen. Es ist vorgesehen, ein europaweit sichtbares Programm anzubieten, dass den Studierenden ein flexibles internationales Studium an jeweils zwei der Hochschulen ermöglicht und sie auf Führungsaufgaben im Bereich der Geomatik in der Rohstoffwirtschaft vorbereitet. Der Beitrag fasst das Konzept des internationalen Programmes zusammen und stellt die Möglichkeiten an der TU Freiberg konkret dar.For the winter term 2019/2020, a new MSc program 'Geomatics for Mineral Resource Management' will be offered at the TU Bergakademie Freiberg. This is part of an international program involving the Universities of Técnico Lisboa in Portugal, Delft University of Technology in the Netherlands, TU Bergakademie Freiberg in Germany, Montanuniversität Leoben in Austria and Wroclaw University of Science and Technology in Poland. The ambition is to offer a Europe-wide visible program that enables students to study internationally flexibly at two of the universities being prepared for a leader role in geomatics for Mineral Resource Management. The article summarizes the concept of the international program and presents the possibilities at the TU Freiberg
Characterization and quantification of crystalline and amorphous phase assemblage in ternary binders during hydration
Get PDFThis dissertation aims to provide a comprehensive understanding of the evolution of solid phase composition with ongoing hydration in OPC‒rich and CAC‒CsHx rich ternary binders. The work is based on a multi‒method approach including XRD, TGA, MAS NMR spectroscopy, calorimetry, microscopy and thermodynamic calculations. From the combinations of results obtained from the different analytical methods, a schematic representation of the phase evolution with ongoing hydration in OPC and CAC‒CsHx rich combinations was achieved, along with plots showing the distributing hydrate phases in the ternary diagram OPC‒CAC‒CsHx. C‒S‒H, portlandite, ettringite and AFm phases stand as main hydration products in the OPC‒rich combinations. C‒S‒H accounts for ~70% of the X‒ray amorphous fraction. In the CAC‒CsHx rich combinations ettringite along with AH3, monosulphoaluminate, strätlingite and hydrogranet phases precipitate. The high portions of X‒ray amorphous fractions in such combinations were mainly attributed to AH3 gel and AFm phases. Additionally, comparison of QXRD results with stoichiometric calculations, thermal analysis and 27Al NMR revealed that a portion of the formed ettringite and portlandite are in an X‒ray amorphous state during hydration. The variation of CAC type and water content strongly influences the hydration mechanism and phase assemblage in the ternary binders, whereas differences in mixtures with different sulphate sources are mainly related to the different dissolution kinetics of the sulphate
Особенности структурно-механических свойств нефтяных дисперсных систем
Get PDFThe present-day challenge of oil industry is gradual decrease of conventional light crude reserves and increased consumption of hard-to-recover heavy crude. The goal of thesis is to establish change regularities of structural-mechanical properties and thermody-namic activation parameters for viscous flow in oil dispersed systems (ODS) of various composition (paraffin and naph-thene and aromatic bases) from Timan-Pechora petroleum region (Russia) in a broad range of temperatures and shear rates and under the exposure of external fields, and also to experimentally determine phase diagrams of binary hydrocarbon systems (nonadecane – decaline and nonadecane – naphthalene) modeling ODS mixture of completely opposite nature. Study results can be used for predicting and preventing structure formation during production, transport and storage of ODS's with various content of solid paraffins, resins and asphaltenes.:INTRODUCTION
CHAPTER 1. ANALYSIS OF THE MODERN CONDITION AND METHODS OF RESEARCH OF HEAVY OILS
1.1 The current state of hydrocarbon reserves
1.2 Oil classification
1.3 Oil chemical composition
1.4 Influence of components of oil dispersed systems on their low-temperature properties
1.5 Structuring in oil dispersed systems
1.6 Rheological models of oil dispersed systems
1.7 Evaluation of the thermodynamic characteristics of the activation of the viscous flow of oil dispersed systems
1.8 Chemical composition and structural-mechanical properties of the oils from Timan-Pechora province
1.9 Modern methods of influencing the structure and properties of oil dispersed systems
CONCLUSIONS TO CHAPTER 1
CHAPTER 2. OBJECTS AND METHODS OF RESEARCH
2.1 Objects of research
2.1.1 Physical and chemical properties of oils from Timan-Pechora province
2.1.2 Physical and chemical properties of high-boiling fractions from Timan-Pechora province
2.1.3 Physical and chemical properties of light distillate from heavy oil and individual hydrocarbons (nonadecane, decaline and naphthalene)
2.2 Research methods
2.2.1 Methods of conducting research on the physicochemical properties of oils
2.2.2 Methods of determining the group hydrocarbon composition of oil dispersed systems
2.2.3 Method for determination of low-temperature properties of binary systems
2.2.4 Methods for determining the structural and mechanical properties of oil dispersed systems from Timan-Pechora province
2.2.5 Characteristics of sources of external impact on oil
2.2.6. Methods of processing samples by external influence
CONCLUSIONS TO CHAPTER 2
CHAPTER 3. INVESTIGATION OF LOW-TEMPERATURE PROPERTIES OF BINARY AND OIL DISPERSED SYSTEMS
3.1 Justification of the computational models used to describe the phase diagrams of binary systems
3.2 Investigation of low-temperature properties on model binary systems of nonadecane-decaline and nonadecane-naphthalene
3.3 Investigation of the low-temperature properties of a light distillate mixture (NK-330 °C) of heavy naphthenic-aromatic Yarega oil and light paraffin haryaga oil
CONCLUSIONS TO CHAPTER 3
CHAPTER 4. INVESTIGATION OF CHANGES IN STRUCTURAL AND MECHANICAL PROPERTIES OF OILS AND THEIR HIGH-BOILING FRACTIONS UNDER EXTERNAL EXPOSURE
4.1 Determination of the type of liquid in oil dispersed systems at different temperatures
4.2 Determination of the dependence of the ultimate shear stress of oil dispersed systems on temperature
4.3 Investigation of the thixotropic properties of the oils from Timan-Pechora province
4.4 Impact of external fields on the rheological properties of heavy oil
4.5 Effects of external fields and diluents on the rheological properties of heavy oil
CONCLUSIONS TO CHAPTER 4
CHAPTER 5. RESEARCH OF THERMODYNAMIC CHARACTERISTICS OF THE ACTIVATION OF A VISCOUS FLOW OF OILS AND HIGH-BOILING FRACTIONS UNDER DIFFERENT CONDITIONS (TEMPERATURES AND SHEAR RATE)
5.1 Liquidus temperature and activation energy of viscous flow of oil dispersed systems
5.2 Thermodynamic characteristics of the activation of a viscous flow of oil dispersed systems
5.3 Investigations of the strength of intermolecular interaction in oil dispersed systems as a function of the frequency of molecule jumps
5.4 Change in the activation energy of viscous flow of oil dispersed systems with increasing shear rate
5.5 Changes in thermodynamic characteristics of the activation of a viscous flow of oil dispersed systems with increasing shear rate
5.6 Changes in the strength of intermolecular interaction in oil dispersed systems with increasing shear rate
CONCLUSIONS TO CHAPTER 5
CONCLUSION
LIST OF ACCEPTED REDUCTIONS
BIBLIOGRAPHY
ANNEX 1. Act of introduction of development in LLC LUKOIL-Ukhtaneftepererabotka
APPENDIX 2. Patent of the Russian Federation 'Method of preparation of heavy oil for refinin
Analysis and Optimization of Communication Networks with Flow Requirements
Get PDFIn this thesis, we will study the concept of k-edge connected and k-connected reliability.
There, vertices are modelled as fail-safe and edges fail stochastically independent. For a fixxed k, the network is then considered operational when each pair of vertices has k edge disjoint or internally disjoint paths, respectively, connecting them in the surviving subnetwork. Thus, the property of being operating covers the connectivity of the surviving graph together with some minimum bandwidth.
We study essential and irrelevant edges for those reliability measures. Further, we study a splitting approach to transform the reliability of the graph into the probability that subgraphs have a certain connectivity. We also extend an approximation algorithm of Karger from the All-Terminal Unreliability to k-edge connected Unreliability and study the k-edge connected Reliability for some special graph classes, namely graphs with restricted treewidth, edge-transitive graphs and the complete graph.:1 Introduction
2 Monotone Systems
2.1 Monotone Binary Systems
2.2 Monotone Multistate Systems
3 Graphs and Graph Operations
4 Higher Connectivity
4.1 Connectivity Number and Edge-Connectivity Number
4.2 Algorithms
5 Essential and Irrelevant Edges
6 Probabilistic Graphs and Reliability Measures
7 Reductions
8 Splitting
8.1 Some Special Cases for Small Separators/Cuts
8.2 Generalization to Arbitrary Separators
8.3 Constructing the Splitting Classes for 2-ec, 3-ec and 2-vc
8.4 Minimality
8.5 A Lattice-based Approach
9 An Approximation Scheme
9.1 Definition of Approximation Algorithms
9.2 The FPRAS for All-Terminal-Unreliability
9.3 Improved Bound for the Number of alpha-cuts
9.4 Extension to k-edge-connected Unreliability
10 Special Graph Classes
10.1 Graphs with Bounded Treewidth
10.2 Edge-Transitive Graphs
10.3 The Complete Graph
11 Future Research
12 Summar
Bergwerksplanung und interaktive Prozessüberwachung in der virtuellen Grubenwarte
Get PDFIm Rahmen des von der europäischen Kommission geförderten Forschungsvorhaben Real-Time Mining (Förderkennzeichen 641989) wurde eine Leitstand-Software entwickelt, mit der die heterogenen Daten der verschiedenen Partner in einer homogenen Benutzeroberfläche visualisiert und analysiert werden können. Das Visualisierungscockpit ist ein leistungsstarkes Modul, das die interaktive Darstellung von Lagerstättenmodellen, die 3DExtraktionsplanung, integrierte Daten des Positionierungssystems sowie die Visualisierung von Sensor- und Maschinenleistungsdaten beinhaltet. Neue Hardware-Technologien bieten heutzutage eine Vielzahl von Möglichkeiten für die innovative Umsetzung von Visualisierungslösungen. Der Einsatz von Virtual-Reality-Brillen ermöglicht eine immersive Erforschung der 3D-Daten. Dies ist noch intuitiver und komfortabler als eine 'klassische' 3D-Visualisierung und bietet große Möglichkeiten zur Unterstützung einer optimierten Entscheidungsfindung. Insbesondere in der Bergbauindustrie stehen sehr heterogene und komplexe Datensätze zur Verfügung. Um die Exploration dieser Daten besonders intuitiv zu gestalten, ist der Einsatz der VR-Technologie besonders naheliegend und daher wurde die Cockpit-Software als „VR-ready“ konzipiert. Die Implementierung basiert auf modernsten Technologien unter Berücksichtigung spezieller Softwareentwicklungsanforderungen wie Benutzerfreundlichkeit, Performance, Kompatibilität, Modularität und Erweiterbarkeit.As part of the research project funded by the European Commission (number 641989), a control station software was developed with which the heterogeneous data of the various partners can be visualized and analyzed in a homogeneous user interface. The visualization cockpit is a high-performance module that includes the visualization of deposit-model, 3D extraction planning, integrated data of the positioning-system as well as the visualization of sensor and machine performance data. New hardware technologies offer a variety of possibilities for innovative implementation of visualization solutions. The use of virtual reality glasses enables immersive exploration of the 3D data. This is even more intuitive and convenient than a “classic” 3D visualization and offer great opportunities to support optimized decision making. Especially in the mining industry very heterogeneous and complex data sets are available. To make the exploration of the data particularly intuitive, the use of VR technology is particularly obvious. The implementation of the cockpit software is carried out based on the latest technologies with respect to special software development requirements such as user-friendliness, performance, compatibility, modularity and expandability