33 research outputs found
Towards a classification framework for approaches to enterprise architecture analysis
Analysis is an important part of the Enterprise Architecture Management Process. Prior to decisions regarding transformation of the Enterprise Architecture, the current situation and the outcomes of alternative action plans have to be analyzed. Many analysis approaches have been proposed by researchers and current Enterprise Architecture Management tools implement Analysis functionalities. However, few work has been done structuring and classifying Enterprise Architecture Analysis approaches. This paper collects and extends existing classification schemes, presenting a framework for Enterprise Architecture Analysis classification. For evaluation, a collection of Enterprise Architecture Analysis approaches has been classified based on this framework. As a result, the description of these approaches has been assessed, a common set of important categories for Enterprise Architecture Analysis classification has been derived and suggestions for further development are drawn
Finite element modeling for analysis of electroluminescence and infrared images of thin-film solar cells
Sheet resistance losses and local defects are challenges faced in solar module fabrication and upscaling processes. Commonly used investigation tools are non-invasive optical and thermal imaging techniques, such as electroluminescence, photoluminescence as well as illuminated and dark infrared imaging. Here, we investigate the potential of computationally efficient finite element simulation of solar cells and modules by considering planar electrodes coupled by a local current–voltage coupling law. Sheet resistances are determined by fitting current simulation results of an OPV solar cell to electroluminescence imaging data. Moreover, a thermal model is introduced that accounts for Joule heating due to an electrothermal coupling. A direct comparison of simulated temperature maps to measured infrared images is therefore possible. The electrothermal model is successfully validated by comparing measured and simulated temperature profiles across four interconnected organic solar cells of a mini-module. Furthermore, the influence of shunts on the thermal behavior of OPV modules is investigated by comparing electrothermal simulation results to dark lock-In IR thermography images
Comparative Indoor and Outdoor Degradation of Organic Photovoltaic Cells via Inter-laboratory Collaboration
DNA Methyltransferase Is Actively Retained in the Cytoplasm during Early Development
The overall DNA methylation level sharply decreases from the zygote to the blastocyst stage despite the presence of high levels of DNA methyltransferase (Dnmt1). Surprisingly, the enzyme is localized in the cytoplasm of early embryos despite the presence of several functional nuclear localization signals. We mapped a region in the NH2-terminal, regulatory domain of Dnmt1 that is necessary and sufficient for cytoplasmic retention during early development. Altogether, our results suggest that Dnmt1 is actively retained in the cytoplasm, which prevents binding to its DNA substrate in the nucleus and thereby contributes to the erasure of gamete-specific epigenetic information during early mammalian development
Comparative Indoor and Outdoor Degradation of Organic Photovoltaic Cells via Inter-laboratory Collaboration
We report on the degradation of organic photovoltaic (OPV) cells in both indoor and outdoor environments. Eight different research groups contributed state of the art OPV cells to be studied at Pomona College. Power conversion efficiency and fill factor were determined from IV curves collected at regular intervals over six to eight months. Similarly prepared devices were measured indoors, outdoors, and after dark storage. Device architectures are compared. Cells kept indoors performed better than outdoors due to the lack of temperature and humidity extremes. Encapsulated cells performed better due to the minimal oxidation. Some devices showed steady aging but many failed catastrophically due to corrosion of electrodes not active device layers. Degradation of cells kept in dark storage was minimal over periods up to one year
Dünnschichtsolarzellenanordnung sowie Verfahren zu deren Herstellung
The present invention relates to a method for producing a thin film solar cell arrangement, in which a plurality of individual thin film solar cells are applied to a substrate. The individual thin film solar cells are deposited one above the other in some regions in such a manner that an overlap region is formed from respective pairs of two individual thin film solar cells; a series connection of the two thin film solar cells forming the pair lies in this region. The thin film solar cell arrangement has a transition region, in which thin film solar cell applied to the first solar cell is transferred to a layer located beneath
PVT-Modul, Isolierverglasung und deren Verwendung
Die Erfindung betrifft ein PVT-Modul (1) mit zumindest einer photovoltaischen Zelle (10) und zumindest einem thermischen Solarkollektor (20), wobei die photovoltaische Zelle (10) und der thermische Solarkollektor (20) zumindest in einer Teilfläche (120) miteinander in Kontakt stehen, wobei die photovoltaische Zelle (10) eine organische Solarzelle ist oder eine solche enthält. Weiterhin betrifft die Erfindung die Verwendung eines solchen PVT-Moduls
Heat to Hydrogen by RED—Reviewing Membranes and Salts for the RED Heat Engine Concept
The Reverse electrodialysis heat engine (REDHE) combines a reverse electrodialysis stack for power generation with a thermal regeneration unit to restore the concentration difference of the salt solutions. Current approaches for converting low-temperature waste heat to electricity with REDHE have not yielded conversion efficiencies and profits that would allow for the industrialization of the technology. This review explores the concept of Heat-to-Hydrogen with REDHEs and maps crucial developments toward industrialization. We discuss current advances in membrane development that are vital for the breakthrough of the RED Heat Engine. In addition, the choice of salt is a crucial factor that has not received enough attention in the field. Based on ion properties relevant for both the transport through IEMs and the feasibility for regeneration, we pinpoint the most promising salts for use in REDHE, which we find to be KNO3, LiNO3, LiBr and LiCl. To further validate these results and compare the system performance with different salts, there is a demand for a comprehensive thermodynamic model of the REDHE that considers all its units. Guided by such a model, experimental studies can be designed to utilize the most favorable process conditions (e.g., salt solutions)
Heat to Hydrogen by RED—Reviewing Membranes and Salts for the RED Heat Engine Concept
The Reverse electrodialysis heat engine (REDHE) combines a reverse electrodialysis stack for power generation with a thermal regeneration unit to restore the concentration difference of the salt solutions. Current approaches for converting low-temperature waste heat to electricity with REDHE have not yielded conversion efficiencies and profits that would allow for the industrialization of the technology. This review explores the concept of Heat-to-Hydrogen with REDHEs and maps crucial developments toward industrialization. We discuss current advances in membrane development that are vital for the breakthrough of the RED Heat Engine. In addition, the choice of salt is a crucial factor that has not received enough attention in the field. Based on ion properties relevant for both the transport through IEMs and the feasibility for regeneration, we pinpoint the most promising salts for use in REDHE, which we find to be KNO3, LiNO3, LiBr and LiCl. To further validate these results and compare the system performance with different salts, there is a demand for a comprehensive thermodynamic model of the REDHE that considers all its units. Guided by such a model, experimental studies can be designed to utilize the most favorable process conditions (e.g., salt solutions)