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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Herkunft, Aufgabe und Zukunft der Menschen- und Buergerrechte : Vorlesungen zur Mercator-Professur 2000

Limbach, Jutta 25 February 2003 (has links)
Mein Grund, das Thema Menschen- und Buergerrechte zu waehlen, ist ein aktueller: das Besorgnis erregende Wiederaufleben nationalistischen Ungeistes im vereinigten Deutschland. Die sich haeufenden antisemitischen Anschlaege und rassistischen Gewalttaten, sowie die dabei des Oefteren zu beobachtende Gleichgueltigkeit der Umwelt, lassen daran zweifeln, dass die Menschenrechte in der Bundesrepublik bereits zum Gemeingut aller Buerger und Buergerinnen geworden sind. Das ist umso bestuerzender als das Bekenntnis zur Unantastbarkeit der Menschenwuerde und zu den unverletzlichen Menschenrechten in unserem Grundgesetz eine Reaktion auf das menschenverachtende Regime der Nationalsozialisten gewesen ist. Glaubten wir doch, dass die Erinnerung an, die Reue ueber und die Verantwortung fuer Auschwitz zu einem Grundelement der politischen Kultur in der Bundesrepublik Deutschland geworden sei.
12

Was heisst: Eine Metapher verstehen? - Die Gewalt spricht nicht : Zum Verhaeltnis von Macht und Gewalt - Theorie der Moral nach Todorov und Luhmann. Vorlesungen anlaesslich der Mercator-Professur 1999

Reemtsma, Jan Philipp 25 February 2003 (has links)
Vorlesungen anlaesslich der Mercator-Professur 1999.
13

Integrierte Ansteuerschaltungen für mikromechanische Flächenlichtmodulatoren - Intergated Control Circuits for Micromechanic Spatial Light Modulators

Kirstein, Kay-Uwe 08 March 2002 (has links)
In this thesis a circuit technology is described, which enables an integrated controling of an active matrix of micromechanic spatial light modulators (SLM). Possible applications areas for micromechanic spatial light modulators are projection of still or moving images, maskless lithography and adaptive optics. Especially in the areas of lithography and adaptive optics typical requirements of light modulators are high optical resolutions, high accuracy of modulation and fast addressing in order to enable a fast image repetition rate. The developed circuits are optimised for use as a maskless litography system and provide a minimum pixel pitch of 16 <font face="Symbol">m</font><i>m</i>. Demonstrators with image areas of 256 x 256 pixels and a modulation resolution of 16 steps on each pixel enabled a minimum geometric lithographic resolution of less than 20 nm, using today available optics.
14

Probenahme und chemische Analytik korngrößenfraktionierten Immissions- und Emissionsaerosolen - Sampling and chemical analyses of size-fractionated aerosols in ambient air and emissions

John, Astrid Christiane 28 March 2002 (has links)
Within this thesis, instruments and methods were developed for sampling devices and chemical analysis of PM 10 and PM 2.5. These two particle size fractions are European standards for air quality monitoring since 1999. A specially designed "ambient air sampling system" for the direct collection of PM 10, PM 2.5 and PM 1 on TXRF-sample carriers for subsequent analysis by Total-Reflection X-Ray Fluorescence Analysis (TXRF) was constructed and calibrated in the laboratory. Additionally, a PM 1-Inlet for a High-Volume-Sampler was developed. As a result, the determination of mass concentrations as well as important chemical constituents (anions and cations, elemental and organic carbon, heavy metals, polycyclic aromatic hydrocarbons) is possible for the fine particle fraction PM 1. The newly developed instruments were used together with commercially available PM 10- and PM 2.5-samplers for a field campaign at a traffic-related measurement site. Data analyses showed good results concerning quality assurance and dem onstrated the complementarities of the different sampling systems. A detailed characterization of the ambient aerosols was obtained and a first source apportionment could be conducted. However, the results also showed that for an efficient air pollution reduction strategy, particle size fractionated emission measurements are necessary as well. Therefore, a PM 10/PM 2.5 in-stack cascade impactor was designed and calibrated. During measurements at various industrial plants, the newly developed instrument showed good results concerning reproducibility and plausible data in comparison with mass concentrations obtained with the plane filter device for the determination of total suspended particulates (TSP). A chemical characterization similar to the ambient air particles was conducted with TXRF for some of the samples. The results showed that size fractionated particle sampling together with multielemental analyses give characteristic patterns ("fingerprints") of emissions. In a next step, the information can be used for source apportionment by fingerprintmodelling and the quantification of the contribution of different sources to ambient air particle concentrations.
15

Beste einseitige <i>L</i><sup>1</sup>-Approximation mit Quasi-Blending-Funktionen / Best One-sided <i>L</i><sup>1</sup>-Approximation by Quasi-Blending Functions

Klinkhammer, John 17 April 2002 (has links)
Let $I^2:=[-1,1] imes[-1,1]$ be the unit square and let $U$ be a subspace of $C(I^2)$. If $f$ is a continuous function, then $u^{ast}in U$ is said to be a {it best one--sided $L^1$--approximation to f in $U$ from above} if $u^{ast}geq f$ and $|f-u^{ast}|_1leq |f-u|$ for every $u in U$ with $ugeq f$. In this paper we consider the problem of characterization of such best approximants for the case where $U$ consists of all (quasi--)blending--functions of order $(m,1)$.
16

Elektroabsorptionsmodulatoren für den Einsatz in einem faseroptischen E-Feld-Sensorsystem - Electroabsorption modulators for a fiberoptic E-field-sensorsystem

Schmidt, Manuel 18 April 2002 (has links)
This thesis reports on the development of waveguide electroabsorption modulators based on multiple quantum well structures. The requirements to the modulator are given by the application in a fiberoptic E-field sensor system. The theoretical calculation of a quantum well structure which is tailored to the application, of the waveguide and of the electrical structure of the device is treated first. Following the technological realization of the developed concept and the characterization of the fabricated devices is described. The achieved performance of the modulators is discussed regarding the influence on the sensorsystem. This results in a minimum detectable field of 20 mV/m, a dynamic range of 105 dB and a frequency range from 100 MHz up to 8 GHz. In a final comparison between the performance of the sensorsystem which is dominated by the modulator and that of commercially available products based on lithiumniobate modulators the advantages of the developed concept are described. In addition to a high sensitivity and a broad frequency range also the operation of the modulator in optical reflection and the low polarization dependence of the modulator which is necessary for the use of conventional non polarization maintaining fibers are worth mentioning.
17

Thermische und photochemische Charakterisierung der Produkte einer Photo-Diels-Alder-Reaktion - Thermal and Photochemical Characterisation of the Products of a Photo-Diels-Alder-reaction

Kruse, Claudia 25 April 2002 (has links)
During the irradiation of 1-acetylnaphthaline in the presence of c,d-substituted olefines with a cyclic amine as a donor different products were generated. The reaction pathways were monitored by NMR-spectroscopy and it was proved that the main products were generated by a Photo-Diels-Alder-reaction. The c,d-olefines are added head-to-tail with the donor substituent in endo-position to the remaining aromatic system. Their structures could unambiguously be proven by single crystal x-ray structure analysis. Furthermore their thermal and photochemical properties were investigated: the activation enthalpies and activation entropies for their thermal decompositions were investigated and during their irradiation in solution with light of 254 nm a Di-<font face="Symbol">p</font>-methane-rearrangement could be observed.
18

Automatische Bildfolgenanalyse mit statistischen Mustererkennungsverfahren - Automatic Analysis of Image Sequences Using Statistical Methods for Pattern Recognition

Eickeler, Stefan 07 May 2002 (has links)
In this thesis new methods for the automatic recognition of the content of image sequences are presented. Solutions to the following video sequences analysis tasks are developed: temporal decomposition of an image sequence into scenes and classification of the scenes, and the recognition of people and their movements in the image sequence. The temporal segmentation of a image sequence and the classification of the segments can be used for image sequences with a given content structure, like broadcast news. The image sequences have a defined chronology of scenes, which belong to certain content classes. The content classes and their chronology are represented by nested Hidden Markov models during the recognition. Another application of the Hidden Markov Modells are the classification of movements of objects in the image sequence. The recognition of human gestures for the application of human-computer-interaction is investigated. The recognition system is capable of recognizing a set of pre-defined gestures that are performed in the viewing area of a camera. The system is able to identify undefined movements and can distinguish them from the gestures. The final task is recognizing people visible in image sequences. The recognition of the people is done by recognizing their faces. The indexing of the faces is composed of the two sub-tasks: detection of the faces and recognition of the faces. It is shown that the face-based video indexing can be used to find known persons in the image sequence as well as to group the people in the sequence unsupervised.
19

Herstellung und Charakterisierung von polymeren Gateisolatoren zur Bestimmung von Referenz-Elektrolytpotentialen - Fabrication and Characterization of Polymeric Gate Insulators for Determination of Reference Electrolyte Potentials

Sorge, Stephan 10 May 2002 (has links)
This work describes the fabrication and usability of organic polymeric layers as gate insulators of field effect transistors (reference field effect transistors, REFET) that are dedicated to the determination of pH-reference potentials in electrolytic solutions. Based on the site binding model hydrophobe CF-polymers were investigated. Various techniques are able to generate polymeric layers that are characterized by low selective hydrogen ion sensitivity. Additional results indicate the necessity of reexamination the site binding model´s usability for polymers with low amount of dissociating sites. This work suggests a model assuming ion adsorption onto polymeric surfaces. This model describes results from CV-measurements as well as measurements on REFETs in a qualitative and quantitative way
20

Diastereoselektion in der Paternò-Büchi-Reaktion von 1,2-Dicarbonylverbindungen mit <font face="Symbol">a</font>-Cyanenaminen - Diastereoselection of the Paternò-Büchi-Reaction of 1,2-Dicarbonyl Compounds with <font face="Symbol">a</font>-Cyanenamines

Wolven, Christiane van 29 May 2002 (has links)
Reactions of photoexcited 1,2-dicarbonyl compounds with chirally labelled and unlabelled captodative alkenes have been investigated, with special emphasis on their diastereoselection in cycloadditions. Irradiation of methyl phenylglyoxylate in presence of unlabelled alkenes yields to the corresponding rel-(2R, 3R)-head-to-head-oxetanes. Using the chirally labelled (S)-(methoxymethylpiperidinyl)propenenitrile gives rise to two oxetanes, one of which was isolated and identified as (2R, 3R)-head-to-head-oxetane by X-ray cristallography. Additionally, the photoreduction product meso-dimethyl-2,3-diphenyltartrate of the ester was formed in all reactions. The photoreactions of benziles with chirally labelled c,d-alkenes give rise to oxetanes in low yields, in these cases the products of Norrish type I reactions become competitive.

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