Refine
Year of publication
Document Type
- Article (226)
- Announcement (104)
- Conference Proceeding (99)
- Part of a Book (43)
- Workingpaper / Report (24)
- Article trade magazine (21)
- Doctoral Thesis (4)
- Book (3)
- Collection (3)
- Course Material (3)
Keywords
- Amtliche Mitteilungen (101)
- Prüfungsrecht (77)
- Prüfungsordnung (66)
- Bachelor (41)
- Master (41)
- MV (31)
- Maschinenbau (30)
- Änderung (29)
- DOAJ (22)
- Satzung (21)
Department/institution
- Fachbereich - Maschinenbau und Verfahrenstechnik (539) (remove)
Wärme: Zuverlässige Kollektoren liefern hohe Solarerträge: Monitoring von Solarthermieanlagen
(2017)
There is a popular saying in German: Innovation is when the market shouts “Hooray!”. Thus, a new idea is only as good as its diffusion into the addressed social system. The question is what affects the adoption or rejection of a new idea. Carsten Deckert shares his experience on the main innovation resistances and on ways to increase the acceptance of new ideas. He talks about which perceived attributes of innovations are conducive to the rate of adoption of an innovation and which are characteristics of failed innovations.
Thermoelectric generators (TEGs) have the ability to convert waste heat into electrical energy under unfavorable conditions and are becoming increasingly popular in academia, but have not yet achieved a broad commercial success, due to the still comparably low efficiency. To increase the efficiency and economic viability of TEGs, research is performed on the materials on one hand and on the system connection on the other. In the latter case, the net output power of the cooling system plays a key role. At first glance, passive cooling seems preferable to active cooling because it does not affect the net electrical output power. However, as shown in the present review, the active cooling is to be preferred for net output power. The situation is similar in air and water-cooling. Even though air-cooling is easier to set up, the water-cooling should be preferred to achieve higher net output power. It is shown that microchannel cooling has similar hydraulic performance to conventional cooling and inserts increase the net output power of TEG. As the review reveals that active water-cooling should be the method of choice to achieve high net output power, it also shows that a careful optimization is necessary to exploit the potential.
Innovative thinking opens up new growth prospects in mechanical and plant engineering. Mechanical and plant engineering has been traditionally very important to the industrial location of Germany [1]. With an export share of 70%, it has a considerable direct influence on economic structure and job market. In addition, mechanical engineering is the “innovation engine” for other core industries in Germany – as supplier of production equipment for industries such as the car manufacture, plastics processing and electrical engineering sectors. Only through this production equipment can innovative products reach production readiness in the first place, and can “Made in Germany” continue to enjoy an excellent reputation all over the world.
Vitaler Wissensaustausch
(2008)
Schätzungen zufolge besitzen ein Viertel bis ein Drittel der Mitarbeiter eines Unternehmens unverzichtbares Experten-Know-how. Keine Organisation kann es sich heutzutage leisten, dieses Wissen nicht oder auch nur unvollständig zu nutzen. Darüber hinaus führt der demografische Wandel in Deutschland dazu, dass dieses Wissen den Unternehmen zunehmend verloren geht, wenn sie keinen vitalen Wissensaustausch betreiben.
Vergleichende Untersuchung von Kesseleinbindungen in solarthermischen Kombianlagen. Posterbeitrag
(2012)
In dieser Arbeit wird ein allgemeingültiges Verfahren zur Tragfähigkeitsberechnung von hochübersetzenden Epizykloidengetrieben entwickelt. Epizykloidengetriebe sind spezielle Umlaufrädergetriebe mit epizykloidaler Triebstockverzahnung. Die Grundlage des Verfahrens bilden die Berechnungs- und Anwendungsnormen der DIN 3990. Neben der Herleitung des Rechengangs wird beispielhaft der Tragfähigkeitsnachweis für die Anwendung in einem urbanen Elektrofahrzeug ausgeführt. Das dabei betrachtete Epizykloidengetriebe hat eine Übersetzung von -34 bei einer maximalen Eingangsdrehzahl von 20.000 min-1 und einer zu übertragenden Leistung von 27 kW. Der Rechengang teilt sich auf in den Nachweis der Flankentragfähigkeit, der Zahnfußtragfähigkeit und der Fresstragfähigkeit. Das Vorgehen je Nachweis ist dabei vergleichbar: Es werden zunächst individuelle Faktoren berechnet, die anschließend in den rechnerischen Festigkeitsnachweis einfließen. Bei der Entwicklung des Rechenverfahrens wird auf eine Allgemeingültigkeit der Gleichungen geachtet. Damit wird die erstellte Auslegungsgrundlage auch für ein breites Einsatzspektrum außerhalb der Elektromobilität nutzbar. Für zukünftige Untersuchungen zu Aspekten der Dimensionierung und Anwendung der Epizykloidengetriebe werden Hinweise und Ansätze basierend auf den erlangten Erkenntnissen bereitgestellt.
Computational models for the personalized analysis of human femurs contain uncertainties in bone material properties and loads, which affect the simulation results. To quantify the influence we developed a probabilistic framework based on polynomial chaos (PC) that propagates stochastic input variables through any computational model. We considered a stochastic E-ρ relationship and a stochastic hip contact force, representing realistic variability of experimental data. Their influence on the prediction of principal strains (ϵ1 and ϵ3) was quantified for one human proximal femur, including sensitivity and reliability analysis. Large variabilities in the principal strain predictions were found in the cortical shell of the femoral neck, with coefficients of variation of ≈40%. Between 60 and 80% of the variance in ϵ1 and ϵ3 are attributable to the uncertainty in the E-ρ relationship, while ≈10% are caused by the load magnitude and 5-30% by the load direction. Principal strain directions were unaffected by material and loading uncertainties. The antero-superior and medial inferior sides of the neck exhibited the largest probabilities for tensile and compression failure, however all were very small (pf<0.001). In summary, uncertainty quantification with PC has been demonstrated to efficiently and accurately describe the influence of very different stochastic inputs, which increases the credibility and explanatory power of personalized analyses of human proximal femurs.
The synthesis of Nb-doped TiO2 nanoparticles by spray drying: an efficient and scalable method
(2011)
A 3-stage model of a low pressure steam turbine has been equipped with extensive instrumentation to assess aerodynamic performance and for validation of numerical methods. Emphasis was placed on detailed measurements at the inlet and exit of the last stage guide vane. Two configurations were examined – the first used a guide vane with lean in the last stage and a the second used a guide vane combining both lean and sweep. The experimental results from the two configurations have been compared with data from various design methods, ranging from through-flow to 3D multistage viscous simulations with mixing planes. Despite the challenges in modelling complex rotating blades in a wet steam environment, good agreement between the numerical and experimental results was obtained, and the new stator vane combining lean and sweep achieved the desired increase in reaction at the hub section.