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51.
52.
Der Begriff “Nullenergiehaus” ist in den letzten Jahren national und international zum Inbegriff für die konsequente Zusammenführung von Maßnahmen zur drastischen Energieeinsparung und optimierter dezentraler Nutzung erneuerbarer Energien geworden. Dabei geht es nicht um energieautarke Gebäude und die dabei große Herausforderung der saisonalen Energiespeicherung. Grundidee ist, dass die von einem Gebäude in ein Netz eingespeiste Energiemenge in der Jahresbilanz mindestens dem Energiebezug entspricht. Plusenergiehäuser erzielen eine positive Bilanz. Trotz Verankerung in zahlreichen energiepolitischen Positionspapieren existiert aber bisher keine Definition oder normative Beschreibung. Der Beitrag erläutert in einem internationalen Kontext die Hintergründe und diskutiert die Einflussgrößen bei der Bilanzierung. Nach Darstellung der normativen Berechnungszusammenhänge wird eine abgestimmte Terminologie und nationale Vorgehensweise vorgeschlagen. Diese berücksichtigt neben der Energiebilanz die Energieeffizienz und die Eigenbedarfsdeckung. From Low‐Energy to Zero‐Energy Building: Status and Perspectives. ”Net Zero Energy Building” has become a prominent wording to describe the synergy of energy efficient building and renewable energy utilization to reach a balanced energy budget over a yearly cycle. Taking into account the energy exchange with a grid infrastructure overcomes the limitations of energy autonomous buildings with the need for seasonal energy storage on‐site. Even though the wording ”Net Zero Energy Building” occurs in many energy policy documents a harmonized definition or a balancing method is still missing. The paper reports on the background and the various effects influencing the energy balance approach. After discussing the national energy code framework in Germany a harmonized terminology and balancing procedure is suggested. Besides the energy balance the procedure takes load energy efficiency and matching into account. 相似文献
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55.
Georg Zurhelle M. Petz Erika Müller-Seitz Eike Siewert 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1999,59(1):299-300
4-Epimers of tetracycline (TC) and chlortetracycline (CTC) were formed in vivo in laying hens and excreted in substantial amounts besides the residues of the administered parent compounds via the egg. The recent observation of isochlortetracycline (i-CTC) and its 4-epimer as being the principal metabolites in eggs after feeding CTC could be confirmed. The ratio of 4-epimer to parent compound of TC, CTC and i-CTC was lower in egg white and higher in yolk and did not change during medication with TC or CTC. Further, yet unidentified, in vivo formed metabolites were observed. 相似文献
56.
Juan A. Botía Blaya Isabelle Demeure Paolo Gianrossi Pedro Garcia Lopez Juan Antonio Martínez Navarro Eike Michael Meyer Patrizio Pelliccione Frédérique Tastet-Cherel 《Service Oriented Computing and Applications》2009,3(1):25-45
Next generation collaborative systems will offer mobile users seamless and natural collaboration amongst a diversity of agents,
within distributed, knowledge-rich and virtualized working environments. This ambitious goal faces numerous challenges from
the underlying communication infrastructure to the high level application services, with the aim to provide services with
the appropriate quality (such as persistence, synchronization, and security). Most currently available tools supporting collaboration
address either rather traditional and rigid intra-organizational collaboration scenarios or, at the opposite, completely free
and unstructured open communities’s interactions. Emerging dynamic, flexible and ad hoc collaboration schemes are hardly or
not supported at all. The POPEYE framework offers collaborative services for applications that aim to enable spontaneous collaboration
over P2P wireless ad hoc groups, where fixed infrastructure is not a prerequisite, where virtual communities can emerge spontaneously
and share data with the appropriate quality of service for business applications (persistence, synchronization, security,
etc.). 相似文献
57.
Eike Gegenmantel 《International Journal of Network Management》1994,4(1):34-47
Network Information Models make up the link between the technical realization of a network and its management. The structure and working principles of such an information model will be shown for telecommunications networks based on the technology of the Synchronous Digital Hierarchy (SDH) 相似文献
58.
Indium tin oxide (ITO), alumina doped zinc oxide (ZnO) and NiCrCoAlY/alumina nanocomposites were systematically investigated as thermoelements. These ceramic thermoelements were initially tested relative to a platinum reference electrode and the resulting thermoelectric properties were evaluated. Bi-ceramic junctions comprised of the most stable and responsive ceramic thermoelements, i.e. those thermoelements with the largest and most stable Seebeck coefficients relative to platinum, were fabricated and tested. A bi-ceramic junction based on nitrogen-doped ITO:oxygen-doped ITO exhibited excellent high temperature stability and reproducibility, however, this thermocouple pair had a relatively low Seebeck coefficient (6 μV/°C). Alumina doped ZnO:ITO thermocouples generated a very large electromotive force at low temperatures but lacked high temperature stability. When nitrogen-doped ITO was combined with a NiCoCrAlY/alumina nanocomposite, a very large and stable Seebeck coefficient (375 μV/°C) was realized. Ceramic thermocouples based on several candidate materials were demonstrated at temperatures up to 1200 °C and the potential of using these materials in other thermoelectric devices including those for energy harvesting is discussed. 相似文献
59.
Eike Best Wojciech Frączak Richard P. Hopkins Hanna Klaudel Elisabeth Pelz 《Acta Informatica》1998,35(10):813-857
This paper describes a high-level Petri net model called M-nets (for modular multilabelled nets). A distinctive feature of
this model is that it allows both: unfolding, as do most other high-level net models; and composition – in particular, synchronisation
– in a process algebraic style, turning the set of M-nets into an algebraic domain. It turns out that the composition operations
of this domain have various algebraic properties. Moreover, the model is such that composition operations are coherent with
unfolding, in the sense that the unfolding of a composite high-level net is the composition of the unfoldings of its components.
One of the motivations for M-nets is that they be a vehicle for giving semantics of concurrent programming languages. To illustrate
their capability for that, the compositional semantics of – a simple, expressive concurrent programming language – is given. An associated low-level net semantics is described, and
the coherence of these high-level and low-level semantics is proved.
Received: 20 November 1996 / 13 January 1998 相似文献
60.
Botnar R Nagel E Scheidegger MB Pedersen EM Hess O Boesiger P 《Magma (New York, N.Y.)》2000,10(1):18-26
Objectives Magnetic resonance (MRI) velocity mapping was used to evaluate non-invasively the flow profiles of the ascending aorta in
normal volunteers and in patients with an aortic (mechanical) valve prosthesis.
Background In patients with artificial aortic valves the flow profile in the ascending aorta is severely altered. These changes have
been associated with an increased risk of thrombus formation and mechanical hemolysis.
Methods Velocity profiles were determined 30 mm distal to the aortic valve in six healthy volunteers and seven patients with aortic
valve replacement (replacement within the last 2 years) using ECG triggered phase contrast MRI. Peak flow, mean flow and mean
reverse flow were measured in intervals of 25 ms during the entire heart cycle. Systolic reverse flow, end-systolic closing
and diastolic leakage volume were calculated for all subjects.
Results Peak flow velocity during mid-systole was significantly higher in patients with valvular prosthesis than in normals (mean±SD,
1.9±0.4 m/s vs. 1.2±0.03 m/s,P<0.001) with a double peak and a zone of reversed flow close to the inner (left lateral) wall of the ascending aorta of the
patients. Closing volume was significantly larger in patients than in controls (−3.3±1.2 ml/beat vs. −0.9±0.5 ml/beat;P<0.001). There was reverse flow during systole in valvular patients amounting to 15.7±6.7% of total cardiac output compared
to 2.3±1.2% in controls (P<0.001). Diastolic mean flow was negative in patients after valve replacement but not in controls (−11.0±15.2 ml/beat vs.
6.8±3.2 ml/beat;P<0.01).
Conclusions The following three major quantitative observations have been made in the present study: (1) Mechanical valve prostheses have
an increased peak flow velocity with a systolic reverse flow at the inner (left lateral) wall of the ascending aorta. (2)
A double peak flow velocity pattern can be observed in patients with bileaflet (mechanical) prosthesis. (3) The blood volume
required for leaflet closure and the diastolic leakage blood volume are significantly higher for the examined bileaflet valve
than for native heart valves. 相似文献