Module design and fault diagnosis in electric vehicle batteries

Systems integration issues, such as electrical and thermal design and management of full battery packs - often containing hundreds of cells - have been rarely explored in the academic literature. In this paper we discuss the design and construction of a 9 kWh battery pack for a motorsports application. The pack contained 504 lithium cells arranged into 2 sidepods, each containing 3 modules, with each module in a 12P7S configuration. This paper focuses particularly on testing the full battery pack and diagnosing subsequent problems related to cells being connected in parallel. We demonstrate how a full vehicle test can be used to identify malfunctioning strings of cells for further investigation. After individual cell testing it was concluded that a single high inter-cell contact resistance was causing currents to flow unevenly within the pack, leading to cells being unequally worked. This is supported by a Matlab/Simulink model of one battery module, including contact resistances. Over time the unequal current flowing through cells can lead to significant differences in cells' state of charge and open circuit voltages, large currents flowing between cells even when the load is disconnected, cells discharging and aging more quickly than others, and jeopardise capacity and lifetime of the pack

Selecting information technology for physicians' practices: a cross-sectional study

BACKGROUND: Many physicians are transitioning from paper to electronic formats for billing, scheduling, medical charts, communications, etc. The primary objective of this research was to identify the relationship (if any) between the software selection process and the office staff's perceptions of the software's impact on practice activities. METHODS: A telephone survey was conducted with office representatives of 407 physician practices in Oregon who had purchased information technology. The respondents, usually office managers, answered scripted questions about their selection process and their perceptions of the software after implementation. RESULTS: Multiple logistic regression revealed that software type, selection steps, and certain factors influencing the purchase were related to whether the respondents felt the software improved the scheduling and financial analysis practice activities. Specifically, practices that selected electronic medical record or practice management software, that made software comparisons, or that considered prior user testimony as important were more likely to have perceived improvements in the scheduling process than were other practices. Practices that considered value important, that did not consider compatibility important, that selected managed care software, that spent less than $10,000, or that provided learning time (most dramatic increase in odds ratio, 8.2) during implementation were more likely to perceive that the software had improved the financial analysis process than were other practices. CONCLUSION: Perhaps one of the most important predictors of improvement was providing learning time during implementation, particularly when the software involves several practice activities. Despite this importance, less than half of the practices reported performing this step

Das Zusammenspiel von Tradition und Innovation bei der Entwicklung neuer Fahrzeuge am Beispiel der Dr. Ing. h. c. F. Porsche AG

Diese Abschlussarbeit, von Franziska Remmlinger, ist im Jahr 2014 erschienen und beschreibt das Zusammenspiel von Tradition und Innovation bei der Entwicklung neuer Fahrzeuge am Beispiel der Dr. Ing. h. c. F. Porsche AG. Es handelt sich um eine Bachelorarbeit mit insgesamt 57 Seiten für die Hochschule Mittweida. Der Hauptteil der Arbeit besteht aus drei Teilen, wobei zunächst Tradition und Innovation in Bezug auf die deutsche Automobilbranche erläutert werden. Dann wird, im zweiten Teil das Wichtigste über das Beispielunternehmen Porsche dargelegt. Dies betrifftden Gründer des Unternehmens, eine chronologische Aufzählung der Modelle und den Zusammenschluss mit dem Automobilunternehmen Volkswagen. Im dritten Teil der Arbeit wird analysiert, inwiefern Tradition und Innovation beim Beispielunternehmen Porsche auftreten und Empfehlungen werden dargelegt. Es folgt das Fazit mit Zukunftsvisionen bezogen auf die Automobilbranche

Die Vorhersage der Filmkuehlwirkung bei Gasturbinenschaufeln aus Messungen in einem Heisswindkanal mit Triebwerksaehnlichkeit unter Beruecksichtigung des Einflusses variabler Stoffwerte

Available from the library of Darmstadt Technische Hochschule (DE) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman