977 resultados para Polar Configuration
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Helsingfors : A.W. Gröndahl & A.C. Öhman 1845 : Dresden, Adler u. Dietze
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The University of Barcelona is developing a pilot-scale hot wire chemical vapor deposition (HW-CVD) set up for the deposition of nano-crystalline silicon (nc-Si:H) on 10 cm × 10 cm glass substrate at high deposition rate. The system manages 12 thin wires of 0.15-0.2 mm diameter in a very dense configuration. This permits depositing very uniform films, with inhomogeneities lower than 2.5%, at high deposition rate (1.5-3 nm/s), and maintaining the substrate temperature relatively low (250 °C). The wire configuration design, based on radicals' diffusion simulation, is exposed and the predicted homogeneity is validated with optical transmission scanning measurements of the deposited samples. Different deposition series were carried out by varying the substrate temperature, the silane to hydrogen dilution and the deposition pressure. By means of Fourier transform infrared spectroscopy (FTIR), the evolution in time of the nc-Si:H vibrational modes was monitored. Particular importance has been given to the study of the material stability against post-deposition oxidation.
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The competitiveness of tourism destinations is a relevant issue for tourism studies, moreso, is a key element on the daily basis of tourism destinations. In this sense, the management of tourism destinations is essential to maintain competitive advantages. In this article tourism destination is considered as a relational network, where interaction and cooperation is needed among tourist agents, to achieve major levels of competitive advantage and a more effective destination management system. In addition, the perceptions of tourists are obtained from two main sources. The first one is the social construction of a tourism destination previous to the visit and the second one is obtained from the interaction between tourists and tourism destination agents during the visit. In this sense, the management of tourism destination to emit a homogenous and collective image is a factor that can reduce the gap if dissatisfaction from the previous and real tourist perception. The discussion is centered on the relationship within a destination, between the supply network and the targeted demand, considering these two approaches jointly, to benefit destination management. The main result is a conceptual model that shows how tourism agents and tourists in the tourism destination interact to improve the destination competitiveness
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One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring the high-end region of a pulsar's spectrum would shed light on this question. By developing a new electronic trigger, we lowered the threshold of the Major Atmospheric γ-ray Imaging Cherenkov (MAGIC) telescope to 25 giga-electron volts. In this configuration, we detected pulsed γ-rays from the Crab pulsar that were greater than 25 giga-electron volts, revealing a relatively high cutoff energy in the phase-averaged spectrum. This indicates that the emission occurs far out in the magnetosphere, hence excluding the polar-cap scenario as a possible explanation of our measurement. The high cutoff energy also challenges the slot-gap scenario.
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Local trajectories and arrangements play a significant role because the development of a research field, such as nanoscience and nanotechnology, requires substantial investments in human and instrumental resources. But why are there often concentrated in a limited number of places? What dynamics lead to such concentration? The hypothesis is that there is an assemblage of heterogeneous resources through the action of local actors. The chapter will explore, from an Actor Network Theory (ANT) perspective, how the local emergence of research dynamics from: the revival of local traditions, the local and national action of institutional entrepreneurs, controversial dynamics, and researchers' arrangements to involve other actors. It will examine how they connect up with each other and mutually commit themselves to the development of new technologies. It will focus on the role of narratives in this assembling: how were the local narratives of the past mobilized and to what effect.
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Peer-reviewed
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Keeping track of software assets and managing software installations in IT environments can be a hard endeavor, especially when the size and diversity of the environment grows. How to install and uninstall software efficiently and cost effectively? Are there too few or too many software licenses purchased? If installed, is the software actually in use? Software Asset Management (SAM) is a process that involves managing and optimizing the purchase, deployment, maintenance, utilization, and disposal of software applications within an organization. This master’s thesis describes a special Software Lifecycle Management Framework to provide solutions to the multitude of challenges within SAM. The main objectives when designing the framework was to provide a set of tools to control the software assets during their entire lifecycle while trying to minimize the costs related to owning and managing them.
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Monitoring of sewage sludge has proved the presence of many polar anthropogenic pollutants since LC/MS techniques came into routine use. While advanced techniques may improve characterizations, flawed sample processing procedures, however, may disturb or disguise the presence and fate of many target compounds present in this type of complex matrix before analytical process starts. Freeze-drying or oven-drying, in combination with centrifugation or filtration as sample processing techniques were performed followed by visual pattern recognition of target compounds for assessment of pretreatment processes. The results shown that oven-drying affected the sludge characterization, while freeze-drying led to less analytical misinterpretations.
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Dipteryx odorata (Aubl.) Willd. is a tall arboreal species native to Central and Northern South America. This paper describes the chemical characterization and phytotoxic potential of polar and non-polar extracts from D. odorata seeds. Structural determinations were accomplished by chemical derivatization and analyzed by GC/MS. The chemical composition of the non-polar fraction (hexane and dichloromethane) presented fatty acids as major constituent. Medium polar and polar fractions (ethyl acetate and ethanol: water) contained carboxylic acid and high 6,7-Dyhidroxycoumarin-β-D-glucopyranoside content, not previously reported for seeds of D. odorata. Extracts showed a significant level of phytotoxic activity, correlated to the content of coumarin derivatives, predominantly in the polar fraction.
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In this thesis the main objective is to examine and model configuration system and related processes. When and where configuration information is created in product development process and how it is utilized in order-delivery process? These two processes are the essential part of the whole configuration system from the information point of view. Empirical part of the work was done as a constructive research inside a company that follows a mass customization approach. Data models and documentation are created for different development stages of the configuration system. A base data model already existed for new structures and relations between these structures. This model was used as the basis for the later data modeling work. Data models include different data structures, their key objects and attributes, and relations between. Representation of configuration rules for the to-be configuration system was defined as one of the key focus point. Further, it is examined how the customer needs and requirements information can be integrated into the product development process. Requirements hierarchy and classification system is presented. It is shown how individual requirement specifications can be connected for physical design structure via features by developing the existing base data model further.
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Digital reproduction, The National Library of Finland, Centre for Preservation and Digitisation, Mikkeli
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Green IT is a term that covers various tasks and concepts that are related to reducing the environmental impact of IT. At enterprise level, Green IT has significant potential to generate sustainable cost savings: the total amount of devices is growing and electricity prices are rising. The lifecycle of a computer can be made more environmentally sustainable using Green IT, e.g. by using energy efficient components and by implementing device power management. The challenge using power management at enterprise level is how to measure and follow-up the impact of power management policies? During the thesis a power management feature was developed to a configuration management system. The feature can be used to automatically power down and power on PCs using a pre-defined schedule and to estimate the total power usage of devices. Measurements indicate that using the feature the device power consumption can be monitored quite precisely and the power consumption can be reduced, which generates electricity cost savings and reduces the environmental impact of IT.
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Configuration management is often seen as an enabler for the main IT Service Management (ITSM) processes such as Incident and Problem management. A decent level of quality of IT configuration data is required in order to carry out routines of these processes. This case study examines the state of configuration management in a multinational organization and aims at identification of methods for its improvement. The author has stayed five months with this company in order to collect different sources of evidence and to make observations. The main source of data for this study is interviews with some of the key employees of the assigned organization who are involved into the ITSM processes. This study concludes the maturity level of the existing configuration management process to be repeatable but intuitive, and outlines the principal requirements for its improvement. A match between the requirements identified in the organization and the requirements stated in the ISO/IEC 20000 standard indicates the possibility of adopting ITIL guidelines as a method for configuration management process improvement. The outcome of the study presents a set of recommendations for improvement that considers the process, the information model and the information system for configuration management in the case organization.
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OBJETIVO: determinar a relação entre a morfologia do primeiro corpúsculo polar (CP) de oócitos humanos e as taxas de fertilização e clivagem e a qualidade embrionária em procedimentos de Injeção Intracitoplasmática de Espermatozóide (ICSI). MÉTODOS: estudo retrospectivo de 582 ciclos consecutivos de ICSI no período de julho de 2003 a julho de 2005. A morfologia do primeiro CP foi avaliada com revisão de 3.177 oócitos em metáfase II, imediatamente antes da realização da ICSI, sempre pelo mesmo observador. O CP foi classificado nas seguintes categorias: CP intacto e de tamanho normal, CP fragmentado ou CP de tamanho aumentado. Avaliamos as taxas de fertilização e de clivagem, o número e a proporção de embriões de boa qualidade em cada um dos três grupos avaliados 48 horas após a ICSI (D2). Foram considerados de boa qualidade os embriões com quatro células, sem fragmentação e com blastômeros simétricos em D2. RESULTADOS: as taxas de fertilização, clivagem e de formação de embriões de boa qualidade resultantes da inseminação de oócitos com o CP aumentado (20,7, 18,7 e 5%, respectivamente) foram significativamente menores que as de oócitos com o CP intacto e de tamanho normal (70,8, 62,5 e 19%, respectivamente) ou CP fragmentado (69,7, 60,5 e 17,1%, respectivamente). CONCLUSÕES: observamos que a presença do primeiro CP aumentado relaciona-se com piores taxas de fertilização, clivagem e de formação de embriões de má qualidade. Entretanto, a fragmentação no primeiro CP parece não interferir nos resultados da ICSI.