638 research outputs found
Towards subdiffraction imaging with wire array metamaterial hyperlenses at MIR frequencies
No full textWe describe the fabrication of metamaterial magnifying hyperlenses with subwavelength wire array structures for operation in the mid-infrared (around 3 µm). The metadevices are composed of approximately 500 tin wires embedded in soda-lime glass, where the metallic wires vary in diameter from 500 nm to 1.2 µm along the tapered structure. The modeling of the hyperlenses indicates that the expected overall losses for the high spatial frequency modes in such metadevices are between 20 dB to 45 dB, depending on the structural parameters selected, being promising candidates for far-field subdiffraction imaging in the mid-infrared. Initial far-field subdiffraction imaging attempts are described, and the problems encountered discussed.</p
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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Two-country stock-flow-consistent macroeconomics using a closed model within a dollar exchange regime
No full textAsylum policy and housing for asylum seekers in the EU – A look at Malta’s open centres for asylum seekers
No full textEffects of pressurization and surface tension on drawing Ge-Sb-Se chalcogenide glass suspended-core fiber
No full textDrawing chalcogenide glass microstructured optical fibers efficiently requires a good understanding of the different drawing conditions beforehand, due to the high cost of the chalcogenide glass materials. A simulation based on Stokes’ model that includes pressurization and glass surface tension is validated with respect to drawing a Ge28Sb12Se60 chalcogenide glass single hole capillary, as well as microstructured optical fiber with three holes, with different pressurizations. Suspended-core Ge28Sb12Se60 fibers with bridges just hundreds of nanometer wide are drawn using parameters predicted by the simulations. These fibers should be suitable for applications such as generating mid-infrared (MIR) supercontinuum based on chalcogenide glasses.Wu Shengling, Simon Fleming, Boris T. Kuhlmey, Heike Ebendorff-Heidepriem and Alessio Stefan
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
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