Böcker utgivna av Cuvillier

"I find Prof Tagou's book refreshingly captivating, original and above all up-to-date. For the first time with no taboo and no bias, a Cameroonian, scholar hits head-on theories and practices of tribalism in Africa at large and specifically in Cameroon and Ivory Coast and handles them with serenity. The Rotation in High Office Democracy proposal questions in the most ridiculous way countries where the main obstacle to democracy is the mode of power transfer and retention for survival purposes. It is a pragmatic breath of fresh air for our nations bruised by colonialism and prejudice, then for new rulers and their wandering. It is both a solution to the Anglophone crisis and an answer to other ethno-regional problems facing Cameroon, Côte d'Ivoire and some African countries..."Haman Mana, Journalist and Editor in Chief of Le Jour"A piece of Bassa wisdom holds that each tree builds up from its roots. Metaphorically speaking, democracy should be like the earth, universally shared that feeds each tree according to the nature of its soil. Celestin Tagou, in an eloquently relevant style, demonstrates that democracy should benefit from an endogenous appraisal according to the historical, sociological and anthropological diversity of each people. For democracy, he puts forward a theoretically innovating model for diverse societies: Rotation in High Office Democracy."Dr. François Bingono Bingono, Journalist - Lecturer - Anthropologist

Organic electronics are getting more and more interest from industrial companies and research groups in the last years since they enable many new applications, which could not be realized by inorganic materials [1{7]. Flexible displays [1], large-area sensors [1], light-emitting large surfaces [8], printable radio-frequency identification tags (RFID) for packaging or logistic industry [2] and many other systems which require exible, large area and low-cost electronic devices are now developed for the near future or even already commercialized. Organic light-emitting-diode (OLED) displays, for example, are now implemented in portable devices and have higher performance than the traditional LCD displays [9]. OLED displays are self illuminating and do not need back lightening, therefore they have higher brightness, contrast and viewing angle in comparison to LCD displays [9]. Many electronic devices producers implemented OLED displays in their high-end smartphones and SLR cameras [10], and recently LG (a Korean company) introduced a 55-inch OLED television [11]. Large-area solar cells based on organic materials have also found their way to commercialization [12].All of these innovations were only possible after the introduction of organic conductors and semiconductors. Organic (semi)-conductors have the advantage of their low-cost processing technologies (e.g. printing or spray-coating). However, they have lower electrical conductivity, free charge carriers mobility [13] and packaging density than their inorganic counterparts. Therefore they are normally used in lowcost and low-performance applications, except in the case of OLED where they have clear advantages compared with other technologies.In order to produce fully exible devices, elementary devices for electronic circuits (e.g. transistors and diodes) need to be made with exible materials. The performance of these devices needs to be enhanced and their fabrication processes should be optimized to ensure their commercialization as switching elements in OLED displays or in other circuits. These tasks are principally a material issue, that means new materials with higher performance and easier processability are sought after. Most of the work done in this direction is devoted to synthesize new semiconducting materials with higher mobility and solution-processability. Parallel to these investigations, new dielectric materials with good dielectric properties even in thin films, solution-processability and good interface properties to the semiconductors should be developed. Cross-linked polymers are advantageous for organic field-effect transistors (OFETs) because of their electrical and chemical properties, specially their high volume resistivity and their stability towards solvents, acids and bases. This work shows that the application of cross-linked materials can also reduce or even eliminate the use of the volatile organic compounds (VOC), for which legal limitations are yearly augmented.

The stabilization of the carrier-envelope phase of ultrashort laser pulseswent through a rapid development from the first publication of a feasibleconcept in 1999 to being a mature tool for frequency metrology and attosecondscience now. Using this technique, stabilization of the timing between thecarrier wave and the envelope of a laser pulse with residual jitters of only 100attoseconds has become possible. Naturally, the questions arises whether andhow this can be further improved.The current work is devoted to determining the physical mechanisms whichgenerate jitter in carrier-envelope phase stabilization. Furthermore, it is investigatedwhether there is a fundamental limitation to the achievable accuracy.To this end, two methods for removal of technical noise contributions areinitially discussed. Different interferometer topologies are investigated andspurious interferometer noise is reduced by more than 40% using a commonpathlayout. A novel two-detector based carrier-envelope phase retrieval techniquefor amplified laser pulses is demonstrated enabling the circumvention ofthe shot-noise constraint of the conventional extraction method to the maximumextent possible. Next, a novel feed-forward stabilization concept isdeveloped that enables carrier-envelope phase stabilizations with only 20 attosecondresidual timing jitter between carrier and envelope of the laser pulse.This feed-forward method is unconditionally stable against drop-out and permitsthe generation of a train of pulses with identical electric field structurewith no additional measures. As the feed-forward concept widely avoids thetechnical noise sources of the conventional feedback stabilization, the resultingnoise spectra exhibit only two unavoidable residual noise mechanisms: a highfrequencywhite noise floor stemming from shot noise in the carrier-envelopephase detection and a drift-like contribution with 1/f noise characteristics.Finally, the drift-like residual noise mechanism is found to induce phasenoise below the level expected for the conversion of pump laser shot noise intocarrier-envelope phase jitter. A feedback based squeezing, a photon-numbersqueezing process and a quantum non-demolition like conversion are discussedas possible explanations for this striking finding. It is shown that either thefeedback squeezing or the quantum non-demolition process is the probableorigin for the observed sub-shot-noise signatures of the carrier-envelope phasejitter.

The boiling line of diesel fuels is relevant for the combustion in modern engines. Biodiesel shows a boiling behavior that is very different to diesel fuel. To adapt the boiling line, metathesis reactions were carried out. Different products were obtained by varying the catalysts and the ratio of biodiesel to 1-hexene. As 20%-blends in diesel fuel some metathesis products were quite similar to the diesel fuel boiling line. The metathesis fuels were tested regarding interactions with other fuel components and engine oil. Additionally, the material compatibility was in focus. Corrosion effects on copper were within the specification for diesel fuel. Exhaust gas emissions from 20%-blends as well as mutagenicity showed no significant deviations versus diesel fuel.In the result, no significant disadvantages for metathesis fuels were found. However, there production occurs currently only in lab-scale.

Being organized into five chapters, this research detects the utilization of global and regional land use regimes by national bureaucracies. This research identifies domestic political background on utilizing international regimes within specific Indonesian land use change settings, a topic which has to date been neglected in this research field, with a few exceptions. Subsequently, the research poses several sub-questions to break down the main research question, which are as follows:1. What are the bureaucracies and their tasks as well as their legal options to pursue actual and potential interests in steering land use transformation systems in Indonesia?2. How did the domestic bureaucracy, together with international actors, use and adapt national instruments and international support to pursue their own (international and domestic) interests in several cases of land use transformation in Indonesia, such as (a) certification of palm oil and (b) Forest Management Units (FMU) and community forestry (CF)?3. How did the domestic bureaucracy utilize the Association of Southeast Asian Nations¿ (ASEAN) regional forest and environmental regime complex?4. How is the relevance of international and regional regimes used in domestic bureaucratic politics?

The present thesis aimed to investigate the effects of psychological stress on the microbicidal potential of human macrophages in order to shed more light on the mechanisms that underlie stress-induced delays in the progress of wound healing. For this purpose, two studies were conducted. In a first study, we implemented an in vitro assay to assess the microbicidal potential of human macrophages. In a second study, we set out to examine the influence of an acute psychological stressor on the microbicidal potential of human macrophages within a wound paradigm.STUDY IQuantitative and qualitative changes in circulating leukocytes are known to be linked to psychological states. However, there is little information regarding comparable results with leukocytes in peripheral tissues, such as associations between the microbicidal potential of macrophages and psychological states. In this study, we implemented an inexpensive, simple-to-use and valid in vitro method for measuring the microbicidal potential of ex vivo isolated human monocyte-derived macrophages (HMDM).The method was implemented and validated using 21 healthy male subjects (M = 35.0 yrs; SEM = 2.32). The assay principle is based on the reduction of 2-(4-Iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST-1) by superoxide anions (O2-.), the first in a series of pathogen-killing reactive oxygen species produced by activated macrophages. First, freshly-isolated human monocytes were chemically stimulated to differentiate into macrophages. Subsequently, the HMDM were activated with phorbol 12-myristate 13-acetate to induce a microbicidal or O2- response.The WST-1 macrophage assay induced O2- responses by HMDM in all of the subjects. Furthermore, the WST-1 reduction scores correlated closely with results obtained by a reference method. The findings suggest that the in vitro method implemented investigates the microbicidal potential of ex vivo isolated HMDM in a simple, cost-efficient and valid manner.STUDY IIAcute psychological stress induces changes in circulating blood leukocytes, but its effect on leukocytes in peripheral tissues is largely unknown. Activated tissue macrophages are important in early phases of wound healing, in particular by killing microbes. We hypothesized that (a) acute psychological stress reduces the microbicidal potential of HMDM, and (b) these reductions are related to stress hormone release.Forty-one healthy men (mean age 35 ± 1 yr) were randomized to either the stress (n = 24) or control group (n = 17). While the stress group underwent the Trier Social Stress Test (TSST; combination of mock job interview and mental arithmetic task), controls did not. Assessing the microbicidal potential, we investigated PMA-activated O2- production by ex vivo isolated HMDM immediately before and after stress, and during recovery up to 60 min after TSST / rest. Moreover, we repeatedly measured plasma norepinephrine and epinephrine levels as well as salivary cortisol.The groups differed significantly in their HMDM microbicidal potential (p =.01) in reaction to stress. Post hoc testing revealed that while HMDM of the control group displayed a significant increase in O2- production over time (p =.02), the cells of the stress group did not (p =.83). Immediately and 10 minutes after stress, O2- production by HMDM was lower in stressed subjects as compared to controls (p¿s

The Preliminary Aircraft Design and Optimisation tool, PrADO, is an in-house program of the Institute of Aircraft Design and Lightweight Structures, TU Braunschweig, Germany, which covers a wide range of aspects of aircraft preliminary design. An initial aircraft concept serves as a basis for various analysis modules. Each module is designated to fulfil one special task e.g. aerodynamic analysis, estimation of structural mass, etc. The available methods grouped within those modules range from statistical methods to physics based models. From an aircraft developer¿s point of view PrADO is used within both, the conceptual and the preliminary design phase.The aim of this thesis is to introduce methods and methodologies to aircraft conceptual and preliminary design, more precisely to PrADO, that allow to judge supersonic aircraft concepts. Therefore, the aerodynamic analysis module, the structural analysis module and the propulsion module are extended. An inviscid flow solver is integrated to obtain aerodynamic coefficients. The calculated data serves as input to other analysis modules of PrADO. While the aerodynamic analysis module solely uses the outer geometry of the aircraft, the structural analysis module uses its internal structural layout as additional input to a herein developed finite element model generator. The distribution of secondary mass, fuel loading and payload distributions as well as loads for ground cases and trimmed flight cases are taken from the PrADO database, whereas the aerodynamic forces are calculated by solving the inviscid Euler equations. The model serves as basis for structural sizing and consequently the estimation of structural mass. The purpose of the propulsion module is to size the engine, to calculate the engine performance map and to provide reliable mass data based on the thermodynamic cycle. PrADO provides various models for the analysis of turbojet, turbofan and turboprop engines. It is extended by a turbofan engine with mixed exhaust flow.The verification of the aerodynamic data is solely based on its expected qualitative distribution, since data from higher order methods was not available for the time being. The results compare well with the expected behaviour. The structural sizing process is verified based on an example from literature. The results of the developed sizing algorithm show extraordinary agreement with the reference data. The extended aircraft design process is finally applied to an aircraft from the European research project HISAC. The results compare well with global aircraft data. An excursion into the field of temperature effects in supersonic flight is provided, since no relevant literature is found on the topic with regard to conceptual and preliminary aircraft design. The results are translated into helpful information on thematerial selection process in the stage of aircraft pre-design.Eventually, the tool chain is applied to analyse a supersonic business jet and the results are presented. Based on the results of this basic design, a parameter study is conducted. A combination of cruise Mach number and design range is varied. Global design parameters show expected sensitivity to such variations.

Biofilms play a major role in material cycles and contribute to technical systems significantly. Despite their interference with the functionality of technical equipment or the product quality their ability to catabolize toxins and metabolize pharmaceutically relevant substances increases the interest in biofilm-based biotransformations. However, so far there is a lack of appropriate models that allow anticipating the mechanical stability of biofilms in particular during detachment processes.The main objective of this work was the development of a hydrogel based physico-chemical and growth independent biofilm imitate to investigate mechanical, primarily fluid dynamical stresses and their influence on growth and detachment effects of biofilms. Verification was achieved by comparison with real single culture biofilms. Single culture biofilms of Pseudomonas putida KT2440 were cultivated in a biofilm tube reactor and grown on different surfaces, e.g., tube walls, surface-modified object slides, plastic and iron nettings as well as membrane filters. The establishment of on-line analytics allowed the automatic measurement of dissolved oxygen, pH, temperature and planktonic cell growth by optical density in the cultivation broth. Image acquisition of the biofilm surface supported the observation of biofilm development in terms of growth and detachment.A hydrogel based on gellan was established as simplified artificial biofilm system, which behaves like a viscoelastic fluid. The degree of cross-linking at different gellan levels was modified by the addition of mono-and divalent ions (Na+, Mg2+) and the influence on the material constants in terms of storage (G¿) and loss (G¿¿) modulus was determined. Experiments and evaluation in the predefined design space were supported by Central Composite Design (CCD), an experimental design technique.The developed gellan-based hydrogel allows mimicking the mechanical properties of a biofilm excluding biological growth effects. It can now be used to validate further characterization methods or to test slowly growing biofilms where systematic errors are often smaller than the biological variances. Eventually this method enables a fast and reliable mechanical testing of biofilm systems.