844 research outputs found
Thermochemical Conversion Processes for Solid Fuels and Renewable Energies: Volume II
No full textThe increasing share of renewable energy sources is drawing attention to a critical challenge. The availability of wind turbines and photovoltaic solar cells is limited and difficult to predict. They usually provide a fluctuating feed-in to the grid, so energy reserves, e.g., conventional thermal power plants or energy storage systems, are necessary to establish a balance between electricity supply and demand. Various solutions can be adopted to maintain the security of supply and improve the flexibility of the future power system, such as improving the efficiency of technical processes in areas such as thermal power plants, cement and metallurgy industries, the use of advanced thermochemical conversion technologies such as gasification, the expansion of high-voltage transmission infrastructure, the promoting of renewable energy sources, the employment of large-scale energy storage systems, and the use of highly flexible power generation units with carbon capture and utilisation, such as combined-cycle power plants. Given this background, this Special Issue contains fundamental scientific studies on the latest research progress in the development and optimisation of gasification processes, renewable energy source “solar energy”, synthesis of new hybrid nanocomposites and nanofluids, carbon capture, and energy storage systems. Special Issue Editors Falah Alobaid Jochen Ströhl
Gene loss and lineage specific restriction-modification systems associated with niche differentiation in the Campylobacter jejuni Sequence Type 403 clonal complex
No full textCampylobacter jejuni is a highly diverse species of bacteria commonly associated with infectious intestinal disease of humans and zoonotic carriage in poultry, cattle, pigs, and other animals. The species contains a large number of distinct clonal complexes that vary from host generalist lineages commonly found in poultry, livestock, and human disease cases to host-adapted specialized lineages primarily associated with livestock or poultry. Here, we present novel data on the ST403 clonal complex of C. jejuni, a lineage that has not been reported in avian hosts. Our data show that the lineage exhibits a distinctive pattern of intralineage recombination that is accompanied by the presence of lineage-specific restriction-modification systems. Furthermore, we show that the ST403 complex has undergone gene decay at a number of loci. Our data provide a putative link between the lack of association with avian hosts of C. jejuni ST403 and both gene gain and gene loss through nonsense mutations in coding sequences of genes, resulting in pseudogene formation
Die Römische Republik /
No full textWer sich für antike Geschichte interessiert, greift zu dieser knappen und gut lesbaren Geschichte der Römischen Republik, geschrieben von einem der bekanntesten Althistoriker Deutschlands. Jochen Bleicken (1926-2005) führt den Leser von der Zeit der Etrusker bis zum Ende der Republik, das die Herrschaft Caesars besiegelte. Alle wichtigen Phasen der republikanischen Geschichte entfalten sich: die Ständekämpfe, Aufstieg Roms zur Weltherrschaft - und die zugehörigen ungeheuren kriegerischen Auseinandersetzungen -, Ursachen und Beginn der inneren Krise seit den Gracchen, die Restauration unter Sulla und schließlich: die Auflösung der Republik und die Begründung der Monarchie. Aloys Winterling Jochen Bleicken, 1926-2005, war Professor für Alte Geschichte an der Universität Göttingen und u.a. Mitherausgeber von "Oldenbourg Grundriss der Geschichte" und der HISTORISCHEN ZEITSCHRIFT.Wer sich für antike Geschichte interessiert, greift zu dieser knappen und gut lesbaren Geschichte der Römischen Republik, geschrieben von einem der bekanntesten Althistoriker Deutschlands. Jochen Bleicken (1926-2005) führt den Leser von der Zeit der Etrusker bis zum Ende der Republik, das die Herrschaft Caesars besiegelte. Alle wichtigen Phasen der republikanischen Geschichte entfalten sich: die Ständekämpfe, Aufstieg Roms zur Weltherrschaft - und die zugehörigen ungeheuren kriegerischen Auseinandersetzungen -, Ursachen und Beginn der inneren Krise seit den Gracchen, die Restauration unter Sulla und schließlich: die Auflösung der Republik und die Begründung der Monarchie. Aloys Winterling Jochen Bleicken, 1926-2005, war Professor für Alte Geschichte an der Universität Göttingen und u.a. Mitherausgeber von "Oldenbourg Grundriss der Geschichte" und der HISTORISCHEN ZEITSCHRIFT.Mode of access: Internet via World Wide Web.Description based on online resource; title from PDF title page (publisher's Web site, viewed 08. Jul 2019
Wide band correlated-k approaches for non-grey radiation modelling in oxy-fuel combustion with dry recycling
No full textIncreased CO2 and H2O concentrations in oxy-fuel combustion promote radiation compared to conventional air based technologies. Spectral radiation models are necessary to calculate the radiative properties of CO2 and H2O. In the present study, the wide band correlated-k method (WBCK) is evaluated for non-grey radiative transfer calculations in oxy-fuel combustion. Several WBCK formulations are presented and applied to virtual gas turbine combustors for both air and oxy-fuel combustion with dry recycling involving strongly varying H2O/CO2 ratios. The spectral formulation of the WBCK is the most exact approach, but leads to excessive computational times. The multiple gases formulation using three optimised absorption coefficient is found to be the optimum choice regarding accuracy and computational efficiency. The results of a standard weighted-sum-of-grey-gases method strongly deviate from those of the WBCK
Essentials of services marketing / Jochen Wirtz, Christopher Lovelock.
No full textIncludes bibliographical references and indexes.(xxxii, 670 pages) :Essentials of Services Marketing, 3e, is meant for courses directed at undergraduate and polytechnic students, especially those heading for a career in the service sector, whether at the executive or management level. It delivers streamlined coverage of services marketing topics with an exciting global outlook with visual learning aids and clear language. It has been designed so that instructors can make selective use of chapters and cases to teach courses of different lengths and formats in either services marketing or services management
Analysis, interpretation, and the local dimension of economic transformation: What went wrong and why?
No full textTransformation has been put in motion by a variety of both endogenous and exogenous forces. Although not any process was under the control of those countries, their choice of goals and instruments was anyway particularly great, at least theoretically. However, transformation was implemented as a rather narrowly defined and technically circumscribed problem-solving process aiming at applying sound general principles of economics and management to reach well-defined goals. It turned out to generate new problems and resulted in different outcomes in different countries and, within individual countries, in different territories. This paper treats transformation as innovation and considers that it had to deal with different dimensions, including both general principles and local features, opportunities, and constraints, and both analysis based on problem-solving, and interpretation of the new situation. These dimensions should have been managed simultaneously, but failed to do so. The paper provides a general explanation for the failure in managing simultaneously the various components of transformation and considers what the 2008 international crisis has revealed of the implementation of 20 years of transformation.Transformation, Local development, Reform, Analysis, Interpretation, Crisis, Washington Consensus, Innovation
Jochen Gerz // Jean Louis Garnell
No full textAlbertini's brief descriptions of Garnell's and Gerz's photo and text based works focus on the temporal and spatial limitations of language and image. Includes short texts by both artists
Materialist pedagogics – Hans-Jochen Gamm’s pedagogical approach to critical-humanist materialism
No full textDer Beitrag beschäftigt sich mit dem Ansatz des 2011 verstorbenen Erziehungswissenschaftlers Hans-Jochen Gamm. Kern dieses Ansatzes ist die materialistische Lesart der Gesellschaft und der in ihren Grundbedingungen aufgeworfenen Erziehungs- und Bildungsfragen. Rekonstruiert werden neben der spezifischen Materialismus-Interpretation Gamms auch die Anlage einer Erziehungs- und Bildungstheorie, die sich als Folge der Anwendung des materialistischen Erkenntnisverfahrens im pädagogischen Handlungsfeld konstituiert. Aus dieser Skizze ergeben sich Hinweise auf Anschlussmöglichkeiten, Theorieprobleme und Desiderata einer materialistischen Pädagogik. (DIPF/Orig.)The paper discusses the approach developed by the educational scientist Hans-Jochen Gamm, who died in 2011. The core of this approach is the materialist reading of society and of the educational issues explored with regard to their basic conditions. In addition to Gamm\u27s specific interpretation of materialism, the author reconstructs the outline of a theory of education which results from the application of a materialist method of cognition to the pedagogical field of action. Based on this outline, the author formulates possibilities of drawing on this approach as well as theoretical problems and desiderata of a materialist pedagogy. (DIPF/Orig.
A new stable splitting for singularly perturbed ODEs
No full textIn this publication, we consider IMEX methods applied to singularly perturbed ordinary differential equations. We introduce a new splitting into stiff and non-stiff parts that has a direct extension to systems of conservation laws and investigate its performance analytically and numerically. We show that this splitting can in some cases improve the order of convergence, demonstrating that the phenomenon of order reduction is not only a consequence of the method but also of the splitting.The authors would like to thank Sebastian Noelle for fruitful discussions. Furthermore, we would like to thank the anonymous referee for suggestions that helped improving the paper substantially. The second author has been partially supported by DFG project NO 361/3-3 (German Science Foundation)
Assessment of the re-ordered wide band model for non-grey radiative transfer calculations in 3D enclosures
No full textThe objective of the present study is to evaluate variations of the re-ordered wide band model for non-grey radiative transfer calculations in 3D enclosures using the discrete ordinates method. First, the performance of various angular and spatial discretisation schemes of the discrete ordinates method is investigated. Then, several formulations, averaging procedures, and scaling methods of the re-ordered wide band model are tested, and the results are validated against those of a statistical narrow band model. The grey gases formulation using three optimised absorption coefficient is found to be the most efficient method
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