Cycle basics of thermally driven heat pumps

Part of: Thermally driven heat pumps for heating and cooling. – Ed.: Annett Kühn – Berlin: Universitätsverlag der TU Berlin, 2013 ISBN 978-3-7983-2686-6 (print) ISBN 978-3-7983-2596-8 (online) urn:nbn:de:kobv:83-opus4-39458 [http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-39458]Thermally driven heat pumps (TDHP) work at three temperature levels. Driving heat Q2 is supplied at a high temperature level. Useful cold (cooling operation) or low temperature heat (heating operation) Q0 is supplied at a low temperature level. The sum of the heat supplied is released at a medium temperature level. Q1 is the useful heat in heating operation. In cooling operation, it is usually released to the environment. However, medium and low temperature heat can also be used simultaneously for heating and cooling purposes. (...

A 10 kW indirectly fired absorption heat pump : Concepts for a reversible operation

Part of: Thermally driven heat pumps for heating and cooling. – Ed.: Annett Kühn – Berlin: Universitätsverlag der TU Berlin, 2013 ISBN 978-3-7983-2686-6 (print) ISBN 978-3-7983-2596-8 (online) urn:nbn:de:kobv:83-opus4-39458 [http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-39458]In the last decade several small and medium sized solar or waste heat driven chillers have been developed and brought to market. Nevertheless, in Central Europe where many of these chillers are installed, the required cooling period of buildings is rather short. By using them as a heat pump during winter time their operating period can be extended in order to shorten the payback period and increase the cost effectiveness, and at the same time, the benefit to the environment is increased. From a thermodynamical point of view it is possible to run a chiller also as a heat pump, but in practice there are restrictions in application due to the dependency of the driving temperature and the temperatures of heat source and heat sink. Using the example of a 10 kW H2O/LiBr absorption chiller, constraints of and demands on different possible peripheral systems (heat sources and heat sinks) for the reversible operation have been investigated. In the paper we present combinations which are favorable, and others which should be avoided from a primary energy point of view

You Are What You Eat and So Is Our Planet: Identifying Dietary Groups Based on Personality and Environmentalism

Behavioral change interventions promoting the reduction of animal product consumption are valuable tools to improve ecological sustainability as well as public health and help the mitigation of climate change. Recent findings revealed improved efficacy of interventions targeted at barriers (e.g., self-efficacy) of three different types of meat consumers over non-targeted interventions (e.g., completion of unrelated surveys). However, such interventions have yet to factor in the role of individual differences in personality. Therefore, in a first step, we performed segmentation analysis on barriers and benefits of reducing animal product consumption (e.g., meat attachment, environmentalism) with the inclusion of personality. In an online sample of N=1135 participants, latent profile analysis revealed five distinct dietary groups: “plant-based eaters”, “meat-reducers”, “medium-hindrance meat eaters”, “medium strong-hindrance meat eaters, and “strong-hindrance meat eaters”, based on inhibitors and facilitators of meat reduction. Groups differed in terms of consumption of different animal products (η2=0.08 to η2=0.80) as well as the Big Five (η2=0.08 to η2=0.80) and Dark Triad (η2=0.08 to η2=0.80). Strong-hindrance meat eaters were characterized by low Conscientiousness, Agreeableness, and Openness as well as high dark trait expression, implying new targets for future intervention design.Medical School HamburgPeer Reviewe

Opportunities and challenges for digital morphology

Advances in digital data acquisition, analysis, and storage have revolutionized the work in many biological disciplines such as genomics, molecular phylogenetics, and structural biology, but have not yet found satisfactory acceptance in morphology. Improvements in non-invasive imaging and three-dimensional visualization techniques, however, permit high-throughput analyses also of whole biological specimens, including museum material. These developments pave the way towards a digital era in morphology. Using sea urchins (Echinodermata: Echinoidea), we provide examples illustrating the power of these techniques. However, remote visualization, the creation of a specialized database, and the implementation of standardized, world-wide accepted data deposition practices prior to publication are essential to cope with the foreseeable exponential increase in digital morphological data

Large fluctuations of the first detected quantum return time

How long does it take a quantum particle to return to its origin? As shown previously under repeated projective measurements aimed to detect the return, the closed cycle yields a geometrical phase which shows that the average first detected return time is quantized. For critical sampling times or when parameters of the Hamiltonian are tuned this winding number is modified. These discontinuous transitions exhibit gigantic fluctuations of the return time. While the general formalism of this problem was studied at length, the magnitude of the fluctuations, which is quantitatively essential, remains poorly characterized. Here, we derive explicit expressions for the variance of the return time, for quantum walks in finite Hilbert space. A classification scheme of the diverging variance is presented, for four different physical effects: the Zeno regime, when the overlap of an energy eigenstate and the detected state is small and when two or three phases of the problem merge. These scenarios present distinct physical effects which can be analyzed with the fluctuations of return times investigated here, leading to a topology-dependent time-energy uncertainty principle

Complex Langevin simulations and the QCD phase diagram: Recent developments

In this review we present the current state-of-the-art on complex Langevin simulations and their implications for the QCD phase diagram. After a short summary of the complex Langevin method, we present and discuss recent developments. Here we focus on the explicit computation of boundary terms, which provide an observable that can be used to check one of the criteria of correctness explicitly. We also present the method of Dynamic Stabilization and elaborate on recent results for fully dynamical QCD.Comment: 7 pages, 1 figure, 4 tables, to appear in EPJ