X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope

X-shooter is the first 2nd generation instrument of the ESO Very Large Telescope(VLT). It is a very efficient, single-target, intermediate-resolution spectrograph that was installed at the Cassegrain focus of UT2 in 2009. The instrument covers, in a single exposure, the spectral range from 300 to 2500 nm. It is designed to maximize the sensitivity in this spectral range through dichroic splitting in three arms with optimized optics, coatings, dispersive elements and detectors. It operates at intermediate spectral resolution (R~4,000 - 17,000, depending on wavelength and slit width) with fixed echelle spectral format (prism cross-dispersers) in the three arms. It includes a 1.8"x4" Integral Field Unit as an alternative to the 11" long slits. A dedicated data reduction package delivers fully calibrated two-dimensional and extracted spectra over the full wavelength range. We describe the main characteristics of the instrument and present its performance as measured during commissioning, science verification and the first months of science operations.Comment: accepted for publication in A&

A shear cell for aligning and measuring birefringence of bow-shaped (banana) liquid crystals

Contains fulltext : 92635.pdf (publisher's version ) (Closed access

Experiences from Test-Driven Development for Prototyping Software in Commercial Vehicles Industry

This master’s thesis, carried out at MAN Truck & Bus AG, presents a self-observational case study of the software  development  methodology  Test-driven  development  (TDD)  in  the  context  of  developing  a framework  for  human-machine  interface  concepts  in  commercial  vehicles.  Software  developers  are constantly looking for ways to improve productivity and the quality of their code. TDD has been said to do precisely this, but not many experience reports from new practitioners can be found, making it difficult to know what to expect when using it for the first time. This thesis focuses on the experiences of a beginner to the TDD practice and follows the development of the framework and the changes made to the design over time. The framework, consisting of a C++ server application and an Android client, was developed using TDD. Decisions, obstacles and general experiences from the development process are documented in this report with the aim of finding out how TDD works in practice for a beginner and how well the practice is suited for this particular kind of project. It was concluded that TDD seems to have both benefits and drawbacks, as it appears to facilitate lower coupling of the code and a more structured design, but also complicates the changing of public interfaces since the changes often also affect the test code. Subjectively perceived effects of the practice included that developer  focus  improved,  that  testing  actually  occurred  and  that  the  continuous  passing  of  tests  gave confidence and a sense of accomplishment to the developer. Furthermore it was concluded that experienced developers may reap more benefits from TDD whereas developers with little experience might have a harder time  adjusting  to  the  practice  and  may  not  see  any  notable  improvement  on  the  design.  The  observed developer in this study also found that TDD was difficult to get used to and that it would have been helpful to initially pair up with an experienced TDD practitioner to be properly guided through the first steps and to form good habits. Some  parts  of  the  framework  developed  were  left  out  of  the  TDD  because  of  complexity  and  time reasons, leading the suitability of the practice for similar frameworks to be judged as moderate. The areas that  induced  problematic  situations  were  multithreading,  networking  and  graphical  user  interfaces  which were all considered difficult to handle with TDD

Progress in the Development of the HFML 45 T Hybrid Magnet

Contains fulltext : 166143.pdf (publisher's version ) (Closed access

X-shooter near infra-red spectrograph cryogenic design

Item does not contain fulltextSPIE ASTRONOMICAL TELESCOPES + INSTRUMENTATIO

Fabrication and Testing of the 20 kA Binary Current Leads for the NHMFL Series-Connected Hybrid Magnet

Contains fulltext : 166094.pdf (publisher's version ) (Closed access)4 p