976 resultados para Vertically rising aircraft


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Thesis (Master's)--University of Washington, 2016-06

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The automated transfer of flight logbook information from aircrafts into aircraft maintenance systems leads to reduced ground and maintenance time and is thus desirable from an economical point of view. Until recently, flight logbooks have not been managed electronically in aircrafts or at least the data transfer from aircraft to ground maintenance system has been executed manually. Latest aircraft types such as the Airbus A380 or the Boeing 787 do support an electronic logbook and thus make an automated transfer possible. A generic flight logbook transfer system must deal with different data formats on the input side – due to different aircraft makes and models – as well as different, distributed aircraft maintenance systems for different airlines as aircraft operators. This article contributes the concept and top level distributed system architecture of such a generic system for automated flight log data transfer. It has been developed within a joint industry and applied research project. The architecture has already been successfully evaluated in a prototypical implementation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract not available

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract not available

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract not available

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract not available

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The hydrodynamics and hydrochemistry of salt and fresh water from solid rock aquifer systems in the Pyrmont area are described and interpreted on the basis of recent investigations including geoelectrics, isotope hydrology, soil air analysis. Theories on the source of the springs in this area are developed, which explain the different compositions of the springs and make it possible to protect them. Data from new and re-interpretated drill holes, borehole logs and outcrops suggest a revision of the geological structure of the Pyrmont dome. Bad Pyrmont is situated on a wide dome of Triassic rocks in the southern part of the Lower Saxony uplands. Inversion of the relief has caused the development of an erosional basin surrounded by prominent ridges. Deep faults developed at the crest of the dome as this part of the structure was subjected to the strongest tectonic stress. Subrosion of the Zechstein salts in the western part of the dome has caused the main salt bed to wedge out below the western part of the dome along a N-S striking structure; this structure is refered to as the „Salzhang“ (salt slope). West of the „Salzhang“, where subrosion has removed the salt bed that prevents gas rising from below, carbon dioxide of deep volcanic origin can now rise to the surface. Hydraulic cross sections illustrate the presence of extensive and deep-seated groundwater flow within the entire Pyrmont dome. While groundwater flow is directed vertically downwards in the ridges surrounding the dome, centripetal horizontal flow predominates the intermediate area. In the central part of the dome, groundwater rises to join the River Emmer, which is the main receiving water course in the central part of the eroded basin. The depth of the saltwater/freshwater interface is determinated by the weight of the superimposed freshwater body. Hydrochemical cross sections show the shape and position of the interface and document a certain degree of hydrochemical zonation of the gently mineralized fresh water. Genetic relationships between the two main water types and the hydrochemical zones of the freshwater body are discussed. The knowledge of the hydrogeological relationship in the Bad Pyrmont aquifer systems permits a spatially narrow coexistence of wells withdrawing groundwater for different purposes (medicinal, mineral, drinking and industrial water).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Practical application of flow boiling to ground- and space-based thermal management systems hinges on the ability to predict the system’s heat removal capabilities under expected operating conditions. Research in this field has shown that the heat transfer coefficient within two-phase heat exchangers can be largely dependent on the experienced flow regime. This finding has inspired an effort to develop mechanistic heat transfer models for each flow pattern which are likely to outperform traditional empirical correlations. As a contribution to the effort, this work aimed to identify the heat transfer mechanisms for the slug flow regime through analysis of individual Taylor bubbles. An experimental apparatus was developed to inject single vapor Taylor bubbles into co-currently flowing liquid HFE 7100. The heat transfer was measured as the bubble rose through a 6 mm inner diameter heated tube using an infrared thermography technique. High-speed flow visualization was obtained and the bubble film thickness measured in an adiabatic section. Experiments were conducted at various liquid mass fluxes (43-200 kg/m2s) and gravity levels (0.01g-1.8g) to characterize the effect of bubble drift velocity on the heat transfer mechanisms. Variable gravity testing was conducted during a NASA parabolic flight campaign. Results from the experiments showed that the drift velocity strongly affects the hydrodynamics and heat transfer of single elongated bubbles. At low gravity levels, bubbles exhibited shapes characteristic of capillary flows and the heat transfer enhancement due to the bubble was dominated by conduction through the thin film. At moderate to high gravity, traditional Taylor bubbles provided small values of enhancement within the film, but large peaks in the wake heat transfer occurred due to turbulent vortices induced by the film plunging into the trailing liquid slug. Characteristics of the wake heat transfer profiles were analyzed and related to the predicted velocity field. Results were compared and shown to agree with numerical simulations of colleagues from EPFL, Switzerland. In addition, a preliminary study was completed on the effect of a Taylor bubble passing through nucleate flow boiling, showing that the thinning thermal boundary layer within the film suppressed nucleation, thereby decreasing the heat transfer coefficient.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Journal impact factors have become an important criterion to judge the quality of scientific publications over the years, influencing the evaluation of institutions and individual researchers worldwide. However, they are also subject to a number of criticisms. Here we point out that the calculation of a journal’s impact factor is mainly based on the date of publication of its articles in print form, despite the fact that most journals now make their articles available online before that date. We analyze 61 neuroscience journals and show that delays between online and print publication of articles increased steadily over the last decade. Importantly, such a practice varies widely among journals, as some of them have no delays, while for others this period is longer than a year. Using a modified impact factor based on online rather than print publication dates, we demonstrate that online-to-print delays can artificially raise a journal’s impact factor, and that this inflation is greater for longer publication lags. We also show that correcting the effect of publication delay on impact factors changes journal rankings based on this metric. We thus suggest that indexing of articles in citation databases and calculation of citation metrics should be based on the date of an article’s online appearance, rather than on that of its publication in print.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abiotic factors are fundamental drivers of the dynamics of wild marine fish populations. Identifying and quantifying their influence on species targeted by the fishing industry is difficult and very important for managing fisheries in a changing climate. Using multiple regression, we investigated the influence of both temperature and rainfall on the variability of recruitment of a tropical species, the brown tiger prawn (Penaeus esculentus), in Moreton Bay which is located near the southern limit of its distribution on the east coast of Australia. A step-wise selection between environmental variables identified that variations in recruitment from 1990 to 2014 were best explained by a combination of temperature and spawning stock biomass. Temperature explains 35% of recruitment variability and spawning stock biomass 33%. This analysis suggests that increasing temperatures have increased recruitment of brown tiger prawn in Moreton Bay.