102,281 research outputs found
Design Features of Product-Integrated PV: An Evaluation of Various Factors under Indoor Irradiance Conditions
No full textThis thesis explores the field of product-integrated photovoltaics (PIPV), a term which is used for all types of products that contain solar cells in one or more of their surfaces, aiming at providing power during the product’s use. Product-integrated photovoltaics (PIPV) began to be widely introduced around 2000, although the use of PV systems in products dates back to the 70s. PIPV includes products such as PV-powered boats, aircrafts, cars, bicycles, camping tents, street lights, recycling bins, decorative lights, PV-powered watches, calculators, PV-powered lamps, sensors, chargers, toys, low-powered kitchen appliances, entertainment appliances or PV-powered art objects. The incorporation of PV systems in products could offer various benefits, such as enhanced functionality of the product as a result of energy autonomy, and independence and freedom of use due to the absence of a connection to the electricity grid, as well as the opportunity to reduce the capacity of batteries in portable products and therefore making them more sustainable. Furthermore, photovoltaic products represent a very reliable solution for the supply of electricity in areas, which lack access to an electricity grid.This thesis is oriented towards the development of scientific and technological knowledge about product-integrated PV (PIPV), as it focuses on the aspects that designers need to take into consideration when designing PV products. This research is interdisciplinary by nature due to its embedding in the field of industrial design engineering, regarding the technological aspects of PV technologies in products and user interaction with PV products. It combines the technical knowledge of PV technologies, indoor irradiance conditions and performance of PV cells and PV products in environments with low irradiance together with the typical behavior of users with these products and the way this behavior influences the performance of the products themselves. Besides being directed towards researchers, results of this study are useful for industrial designers who are developing PV products.<br/
Train-induced vibrations on urban metro and tram turnouts
No full textIn contrast to standard track, where train-induced vibrations are mainly related to track irregularities, the dynamic response of turnouts is dominated by the nonuniform geometry of wheel-rail contact and variations in track flexibility. Such peculiarities are responsible for the development of strong vibrations during train passage. At the point of rail intersection (heart), where a gap is unavoidable to provide the necessary wheel flange clearance, the system is subjected to severe impact loading, critical for the design and maintenance of railway tracks. Especially in the case of urban turnouts, the vibration levels are also directly related to the exerted noise nuisance. This paper presents two analysis methods to simulate train-turnout interaction. The first is based on a multibody model of the trainset and of wheel-rail contact, utilizing a simplified finite element model for the turnout. The second focuses on the details of the turnout, which is modeled with three-dimensional finite elements, utilizing a simplified model to compute impact loading due to wheel passage over the flange-way gap. The two models are validated against line measurements on three different urban metro and tram networks. A parametric analysis is conducted to investigate the role of soil-structure interaction, which is shown be important for the dynamic response of the system
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
No full textDieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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3346: Samuel G. Freedman, author, 2013
No full textPhotograph of author Samuel G. Freedman, at NT Daily Slash meeting in the Mayborn School of Journalism at UNT
A comparison of design features of 80 pv-powered products
No full textIn this paper 80 commercially available PV products have been analysed. The data set comprises 46 low power PV products in the range of 0 to 17 Wp and 34 PV products with a power of 17 Wp up to 27 kWp. The goal of our study is to investigate and evaluate features of PV products that are available on the market now and to present features that are important for manufacturers, industrial designers and users. Finally this survey is meant to identify topics relevant for research on products with integrated PV systems. In our study we analysed (1) the energy technologies applied in this set of products, (2) financial aspects and (3) several human factors. The data have been collected with a questionnaire by about 100 master students. Various features of these PV products were analysed and compared such as PV technology of the products, battery type and capacity, operational voltage, costs and number of simultaneous users. Because of the limited number of PV products analysed we cannot have a spherical picture of PV products’ design features. However through this study, valuable information about several features of products has been collected.Design EngineeringIndustrial Design Engineerin
A rationale basis for airways conditioning: too wet or not too wet?
No full textMedical gases conditioning during mechanical invasive ventilation is nowadays a problem. In fact, in spite of conditioning guidelines, absolute humidity (AH) into 25-35 mg/l, clinical evaluation of the optimal level of airway humidification has not yet been established with certainty. Physiologically, during spontaneous respiration the airway hydric balance, inspiratory AH expiratory AH, is negative of 27 mg/l about. Usually the patients on mechanical ventilation have an expiratory AH of 32-33 mg/l. An overhumidification of inspired gases, positive airway hydric balance, gives anatomic-physiological alterations of airways and lung parenchyma. During invasive mechanical ventilation, the practice of active hot humidifiers has a positive or level airway hydric balance. We think that inspired AH must be equal to expired AH to maintain an airway hydric balance at least level. At last, the temperature of inspired gases, with active hot humidifiers, shouldn't exceed 32-34 degrees C
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