1,030 research outputs found
The IPHAS catalogue of H alpha emission-line sources in the northern Galactic plane
No full textWe present a catalogue of point-source H alpha emission-line objects selected from the INT/WFC Photometric Ha Survey (IPHAS) of the northern Galactic plane. The catalogue covers the magnitude range 13 <= r' <= 19.5 and includes Northern hemisphere sources in the Galactic latitude range -5 degrees < b < 5 degrees. It is derived from similar to 1500 deg(2) worth of imaging data, which represents 80 per cent of the final IPHAS survey area. The electronic version of the catalogue will be updated once the full survey data become available. In total, the present catalogue contains 4853 point sources that exhibit strong photometric evidence for Ha emission. We have so far analysed spectra for similar to 300 of these sources, confirming more than 95 per cent of them as genuine emission-line stars. A wide range of stellar populations are represented in the catalogue, including early-type emission-line stars, active late-type stars, interacting binaries, young stellar objects and compact nebulae.
The spatial distribution of catalogue objects shows overdensities near sites of recent or current star formation, as well as possible evidence for the warp of the Galactic plane. Photometrically, the incidence of Ha emission is bimodally distributed in (r' - i'). The blue peak is made up mostly of early-type emission-line stars, whereas the red peak may signal an increasing contribution from other objects, such as young/active low-mass stars. We have cross-matched our H alpha-excess catalogue against the emission-line star catalogue of Kohoutek & Wehmeyer, as well as against sources in SIMBAD. We find that fewer than 10 per cent of our sources can be matched to known objects of any type. Thus IPHAS is uncovering an order of magnitude more faint (r' > 13) emission-line objects than were previously known in the Milky Way
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Search for fractionally charged quarks at ISABELLE
No full textA relatively simple experiment is proposed which is sensitive to conventional quarks of charge 1/3 or 2/3e and mass less than 200 GeV. The experiment uses a modest amount of conventional equipment, no magnetic momentum analysis, and in a period of one week will achieve a sensitivity of 10cm to isotropic quark production. Despite the experimental simplicity, the signature provided by a fractionally charged quark should be unambiguous. The method and apparatus are described, background and counting rates are discussed, and finally a cost estimate is given for this experiment. (JFP
Asylum policy and housing for asylum seekers in the EU – A look at Malta’s open centres for asylum seekers
No full textThe landscape ecology of butterflies in traditionally managed Norwegian farmland
No full textThe modernisation of agriculture has lead to changes in Norwegian farming landscapes that have consequences for butterfly distribution and abundance. Particularly important is the abandonment of traditionally managed grasslands and the consequent increase in potential barriers of scrub and trees in the landscape. In this thesis I use a landscape ecological perspective to explore the effects of abandonment on butterfly dispersal. I demonstrate that landscape elements influence butterfly movement behaviour: tall structures were significant barriers for a range of species and even low features, such as roads, elicited significant behavioural responses which shaped the movement patterns of butterflies. Behavioural differences between species were related to ecological and physiological characteristics. Movement patterns of Scarce Coppers (Lyceana virgaureae) were recorded by mark-release- recapture (MRR) techniques. Of 1711 recorded displacements, over 90 % were under 150 m. Exchange rates between meadows were dependent upon distance and the structure of intervening vegetation. A simple spatial model, parameterised with data from the behavioural experiments, was validated using MRR observations. This confirmed that the behaviour of individuals responding to single landscape elements has consequences at the level of populations and entire landscapes. The life history and movement behaviour of the endangered Apollo (Parnassius apollo), were examined using MRR. The butterfly is well adapted to a mosaic landscape structure; however, inter-meadow movement declined exponentially with increasing distance between meadows. Abandonment of hay meadows on steep slopes, with consequent forest succession, will adversely affect the Apollo by increasing the distances between open habitat. Genetic analyses support the findings of MMR studies and add a wider spatial and temporal perspective. As a conservation management priority, I recommend population mapping to identify key sites in regional networks of populations. Finally, I consider the links between empirical studies, modelling and the practical application of theory, and discuss the implications of landscape change for the butterflies of Norwegian farmland
The new port infrastructure: strategic design of a container data platform for Port of Rotterdam
No full textSea ports are undergoing a digital transformation, which can offer benefits for many involved stakeholders in the logistic chain. In order to stay relevant, Port of Rotterdam (PoR) should invest in developing new port infrastructure; digital connections that facilitate data exchange between logistic chain stakeholders. A strategic digital opportunity was found for PoR, design a platform that is focused on container data, which contributes to the competitive position of the port of Rotterdam and the business model of PoR. The thesis explores the design of the platform Cadex, a data platform that facilitates cargo data exchange between data suppliers, e.g. terminals and data demanders, shippers. Cadex offers shippers real-time data about their containers that enables shippers to act upon containers that deviate from the planned schedule. By making cargo data easy accessible it could save shippers significant costs that come with transport, the deprecation of their goods, the management of their logistics and their inventory. Especially in time sensitive trade, like fresh goods or factory parts this data is valuable. In addition, it could also contribute to a lower carbon footprint of shipments. The platform enables users to get data directly from the data owners (data supplies) like sea-port terminals and hinterland terminals and can therefore be labeled as reliable data. The data suppliers benefit from the revenue model the platform offers for their data and they are allowed to set their own asking price for this data, furthermore they benefit from the data they receive about their clients. PoR would directly benefit from the data exchange by charging a percentage of the price. In addition, PoR receives historical data about its clients, which improves their knowledge about the clients they serve and could be input for improvements in the port of Rotterdam. Moreover, a better customer service is offered to shippers that make use of the port of Rotterdam. The new port infrastructure Cadex offers, could improve the score of the port Rotterdam on the selection criteria and therefore, contribute to a higher competitive position. Developing this new port infrastructure is a long-term investment since the connections hold value. Once built, the infrastructure can be reused by other parties or other digital purposes with some adjustments. This makes PoR a relevant party in the digital transition. Without this new port infrastructure, PoR is more likely to be bypassed by other competing players who will reap the benefits of the digital transformation in sea-ports.Strategic Product Desig
Field Of Threads: Master’s Thesis on a tool for clarifying thread behavior
No full textMultithreaded programming is becoming increasingly important because of recent increase in the use of multiprocessor computing. Multithreaded or concurrent programming is inherently more complex than single threaded code, requiring the use of synchronization and causing possible problems like deadlock or dormancy. Dynamic analysis tools can aid in understanding the execution of concurrent programs and help with improving and debugging of these programs. Current tools express the complexity of concurrent programs with varying degrees of success. We have evaluated and analyzed the visualizations of these tools in relation to the inherent concurrency problems they were meant to solve and come up with an alternative approach to tracing, analyzing and visualizing program executions. By focusing on the use of shared fields we show memory based interaction between threads by use of sequence diagrams, structured in a novel way. This new approach is implemented in a Java based, Eclipse plugin, dynamic analysis tool called Field Of Thread (FOT). FOT provides a new low-level perspective to concurrency oriented dynamic analyses for visualizing shared memory based thread interaction.Computer and Information Science - Software EngineeringSoftware Engineering Research Group (SERG)Electrical Engineering, Mathematics and Computer Scienc
Calculation of Polymer-Solvent Phase Equilibria Using the SAFT Equation of State
No full textAt the Institute for Thermodynamics at the Technical University Berlin a program is under development for the calculation of phase equilibria. The program uses the SAFT equation of state without the association term. Interests lie especially in the calculation of equilibria of mixtures of non-associating polymers in solvents. The Institute faced huge numerical problems. A study after the causes of these problems was performed and the known problems with SAFT were solved…Applied SciencesScheikundige Technologie en der Materiaalkund
Projectontwikkeling door woningcorporaties, wat kost dat?
No full textEen onderzoek naar de specificatie van de proceskosten bij projectontwikkeling door woningcorporaties. In het onderzoek wordt ingegaan op de huidige methodiek die wordt toegepast door woningcorporaties, waarna wordt onderzocht hoe dit mogelijk verbeterd kan worden.HousingReal Estate & HousingArchitecture and The Built Environmen
The profitable influence of lease incentives for new office developments: A research on the phenomenon of office real estate developments (out)competing existing assets on effective rent levels without loss of quality
No full textDutch developers are thought to have been able to outcompete the owners of existing office space on rental pricing (the phenomenon). For tenants it was more inexpensive to move to newly proposed (not yet existent) office space than to remain where they are, or move to other existing office space. Three theoretical reasons were identified for the phenomenon to exist: 1) rent price lagging of existing assets to new market information, 2) lower production costs for the new development and 3) the creation of margin between development costs and asset selling price. Especially the latter has had influence on the phenomenon's existence. Three main aspects are identified for the creation of margin: 1) A period of Yield Compression (2004-2008) enabled great selling prices to be obtained. Thereby margin was created. It also led to a decrease in financing costs and allowed for the neglect of given lease incentives by developers, 2) the use of the normative residual land value method enabled margin to exist altogether and allowed for additional margin to be created, and 3) the use of Lease Incentives by the developer has shown to have an amplifying effect: Profit Sharing/the High-Low Method effectively lowers the rent level of the tenant by making maximum use of the created margin. Sources used: literature, expert interviews, key-actor interviews, dataset analysis and sensitivity analysis.Real Estate ManagementReal Estate & HousingArchitectur
Onderzoek naar de invloed van onvolkomen doorlassing op de vermoeiingssterkte van een lasverbinding
No full textDe achterassen van de DAF-vrachtwagens bestaan uit twee aslichaamhelften. Deze worden door een lasverbinding met elkaar verbonden. De lasverbinding heeft een doorlassingspercentage van ongeveer 80%. Het doel van dit onderzoek is de mogelijkheden na te gaan om verlaging van de doorlassingsgraad bij een vereiste vermoeiingssterkte van de lasverbinding. Ter bepaling van de vereiste vermoeiingssterkte moeten de optredende vermoeiingsbelastingen worden bepaald. Alleen de vermoeiingsbelastingen veroorzaakt door het torsiemoment en door de dwarskracht ten gevolge van het verticale moment blijken volgens de theorie schadelijk te zijn voor de lasverbinding. Deze kunnen een mode-3 scheurgroei vanuit de onvolkomen doorlassing veroorzaken. Met gegevens van wegmetingen is berekend dat het spanningstrajekt van deze vermoeiingsbelasting 36,3 N/mm^ bij 10® wisselingen bedraagt bij een spanningsverhouding van - 1. Er wordt door DAF geëist dat de lasverbinding deze vermoeiingsbelasting met een drie maal grotere levensduur kan weerstaan. De minimaal vereiste vermoeiingssterkte voor de lasverbinding is dus op een spanningstrajekt van 36,3 Wmnf bij een levensduur van 3x10® wisselingen gesteld. Voor de vermoeiingsexperimenten zijn proefstukken van de lasverbinding vervaardigd met verschillende doorlassingsgraad. Er zijn zowel mode-1 als mode-3 vermoeiingsexperimenten uitgevoerd. Op basis van de resultaten van deze experimenten kan geen uitspraak worden gedaan over de exacte minimaal toe te laten doorlassingsgraad van de lasverbinding. De resultaten hebben wel aangetoond dat een verlaging van het doorlassingspercentage tot een waarde van 70% zeer waarschijnlijk haalbaar is.Welding Technology and Non-destructive TestingTechnische MateriaalwetenschappenApplied Science
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