Refine
Year of publication
- 2024 (2)
- 2023 (10)
- 2022 (29)
- 2021 (15)
- 2020 (25)
- 2019 (19)
- 2018 (15)
- 2017 (14)
- 2016 (9)
- 2015 (12)
- 2014 (22)
- 2013 (14)
- 2012 (3)
- 2011 (15)
- 2010 (21)
- 2009 (12)
- 2008 (16)
- 2007 (6)
- 2006 (12)
- 2005 (16)
- 2004 (22)
- 2003 (8)
- 2002 (16)
- 2001 (10)
- 2000 (13)
- 1999 (16)
- 1998 (17)
- 1997 (24)
- 1996 (23)
- 1995 (16)
- 1994 (15)
- 1993 (11)
- 1992 (8)
- 1991 (4)
- 1990 (3)
- 1989 (12)
- 1988 (11)
- 1987 (6)
- 1986 (7)
- 1985 (6)
- 1984 (4)
- 1983 (5)
- 1982 (3)
- 1981 (4)
- 1980 (3)
- 1979 (3)
- 1978 (2)
- 1977 (1)
- 1975 (2)
Institute
- Fachbereich Energietechnik (562) (remove)
Has Fulltext
- no (562) (remove)
Language
- English (562) (remove)
Document Type
- Article (351)
- Conference Proceeding (162)
- Part of a Book (25)
- Book (9)
- Conference: Meeting Abstract (7)
- Doctoral Thesis (2)
- Other (2)
- Talk (2)
- Master's Thesis (1)
- Report (1)
Keywords
- Earthquake (5)
- Diversity Management (4)
- Energy storage (4)
- Power plants (4)
- Seismic design (4)
- Associated liquids (3)
- Concentrated solar power (3)
- Hybrid energy system (3)
- Out-of-plane load (3)
- Seismic loading (3)
With proven impact of statistical fracture analysis on fracture classifications, it is desirable to minimize the manual work and to maximize repeatability of this approach. We address this with an algorithm that reduces the manual effort to segmentation, fragment identification and reduction. The fracture edge detection and heat map generation are performed automatically. With the same input, the algorithm always delivers the same output. The tool transforms one intact template consecutively onto each fractured specimen by linear least square optimization, detects the fragment edges in the template and then superimposes them to generate a fracture probability heat map.
We hypothesized that the algorithm runs faster than the manual evaluation and with low (< 5 mm) deviation. We tested the hypothesis in 10 fractured proximal humeri and found that it performs with good accuracy (2.5 mm ± 2.4 mm averaged Euclidean distance) and speed (23 times faster). When applied to a distal humerus, a tibia plateau, and a scaphoid fracture, the run times were low (1–2 min), and the detected edges correct by visual judgement. In the geometrically complex acetabulum, at a run time of 78 min some outliers were considered acceptable. An automatically generated fracture probability heat map based on 50 proximal humerus fractures matches the areas of high risk of fracture reported in medical literature.
Such automation of the fracture analysis method is advantageous and could be extended to reduce the manual effort even further.
The adsorption of fluor-carbon complexes on GaAs(110) studied by electron energy loss spectroscopy
(1986)
Textile reinforced concrete. Part I: Process model for collaborative research and development
(2003)
The Solar-Institute Jülich (SIJ) has initiated the construction of the first and only German solar tower power plant and is now involved in the accompanying research. The power plant for experimental and demonstration purposes in the town of Jülich started supplying electric energy in the beginning of 2008. The central receiver plant features as central innovation an open volumetric receiver, consisting of porous ceramic elements that simultaneously absorb the concentrated sunlight and transfer the heat to ambient air passing through the pores so that an average temperature of 680°C is reached. The subsequent steam cycle generates up to 1.5 MWe. A main field of research at the SIJ is the optimization of the absorber structures. To analyze the capability of new absorber specimens a special test facility was developed and set up in the laboratory. A high-performance near-infrared radiator offers for single test samples a variable and repeatable beam with a power of up to 320 kW/m² peak. The temperatures achieved on the absorber surface can reach more than 1000°C. To suck ambient air through the open absorber - like on the tower - it is mounted on a special blower system. An overview about the test facility and some recent results will be presented.
Technical assessment of Brayton cycle heat pumps for the integration in hybrid PV-CSP power plants
(2022)
The hybridization of Concentrated Solar Power (CSP) and Photovoltaics (PV) systems is a promising approach to reduce costs of solar power plants, while increasing dispatchability and flexibility of power generation. High temperature heat pumps (HT HP) can be utilized to boost the salt temperature in the thermal energy storage (TES) of a Parabolic Trough Collector (PTC) system from 385 °C up to 565 °C. A PV field can supply the power for the HT HP, thus effectively storing the PV power as thermal energy. Besides cost-efficiently storing energy from the PV field, the power block efficiency of the overall system is improved due to the higher steam parameters. This paper presents a technical assessment of Brayton cycle heat pumps to be integrated in hybrid PV-CSP power plants. As a first step, a theoretical analysis was carried out to find the most suitable working fluid. The analysis included the fluids Air, Argon (Ar), Nitrogen (N2) and Carbon dioxide (CO2). N2 has been chosen as the optimal working fluid for the system. After the selection of the ideal working medium, different concepts for the arrangement of a HT HP in a PV-CSP hybrid power plant were developed and simulated in EBSILON®Professional. The concepts were evaluated technically by comparing the number of components required, pressure losses and coefficient of performance (COP).
This paper describes two courses on
simulation methods for graduate students:
“Simulation Methods” and “Simulation and
Optimization in Virtual Engineering” The
courses were planned to teach young engineers
how to work with simulation software as well as
to understand the necessary mathematical background.
As simulation software COMSOL is
used. The main philosophy was to combine
theory and praxis in a way that motivates the
students. In addition “soft skills” should be
improved. This was achieved by project work as
final examination. As underlying didactical principle
the ideas of Bloom’s revised taxonomy
were followed. The paper basically focusses on
educational aspects, e.g. how to structure the
course, plan the exercises, organize the project
work and include practical COMSOL examples.