A LUNAR POWER PLANT

A concept of a nuclear power plant to be assembled on earth and operated on the moon is presented. The two principal design objectives are reliability and high specific power. Wherever there is an incompatibility between these two objectives, the decision favors reliability. The design is based on the premise that the power plant must be designed on the basis of current technology and with a minimum amount of research and development. The principal components consist of a fast reactor in a direct cycle with a mercury-vapor turbine. The high- frequency generator, hydrogen compressor for the generator cooling system, mercury-recirculating pump, and condensate pump are on an extension of the turbine shaft. Ths mercury vapor is condensed and the hydrogen cooled in wing radiators. The reactor is of a construction quite similar to EBR-I Mark IlI for which there is a large amount of operating experience. The radiator is a vertical tube-and-fin type built in concentric cylindrical sections of increseing diameter. The curved headers are connected by swivel joints so that, upon arrival, the radiator can be quickly unfolded from the compact cylindrical package it formed during transportation. (auth

Best packing of rods into boxes

AbstractWe determine the maximum number of 1 × 1 x … × 1 × n rods which will fit inside an arbitrary d-dimensional rectangular box, on condition that they be packed parallel to the edges of the box

The Fueling and Evolution of AGN: Internal and External Triggers

In this chapter, I review the fueling and evolution of active galactic nuclei (AGN) under the influence of internal and external triggers, namely intrinsic properties of host galaxies (morphological or Hubble type, color, presence of bars and other non-axisymmetric features, etc) and external factors such as environment and interactions. The most daunting challenge in fueling AGN is arguably the angular momentum problem as even matter located at a radius of a few hundred pc must lose more than 99.99 % of its specific angular momentum before it is fit for consumption by a BH. I review mass accretion rates, angular momentum requirements, the effectiveness of different fueling mechanisms, and the growth and mass density of black BHs at different epochs. I discuss connections between the nuclear and larger-scale properties of AGN, both locally and at intermediate redshifts, outlining some recent results from the GEMS and GOODS HST surveys.Comment: Invited Review Chapter to appear in LNP Volume on "AGN Physics on All Scales", Chapter 6, in press. 40 pages, 12 figures. Typo in Eq 5 correcte

We All Know How, Don’t We? On the Role of Scrum in IT-Offshoring

Part 2: Creating Value through Software DevelopmentInternational audienceOffshoring in the IT-industry involves dual interactions between a mother company and an external supplier, often viewed with an implicit perspective from the mother company. This article review general off shoring and IT offshoring literature, focusing on the proliferation of a globally available set of routines; Scrum and Agile. Two cases are studied; a small company and short process and a large mother company with a long process. The interactions of the set ups shows that global concepts like Scrum and Agile are far from a common platform. The “well known” concepts are locally shaped and the enterprises have mixed experiences

The upgrade of the ALICE TPC with GEMs and continuous readout

The upgrade of the ALICE TPC will allow the experiment to cope with the high interaction rates foreseen for the forthcoming Run 3 and Run 4 at the CERN LHC. In this article, we describe the design of new readout chambers and front-end electronics, which are driven by the goals of the experiment. Gas Electron Multiplier (GEM) detectors arranged in stacks containing four GEMs each, and continuous readout electronics based on the SAMPA chip, an ALICE development, are replacing the previous elements. The construction of these new elements, together with their associated quality control procedures, is explained in detail. Finally, the readout chamber and front-end electronics cards replacement, together with the commissioning of the detector prior to installation in the experimental cavern, are presented. After a nine-year period of R&D, construction, and assembly, the upgrade of the TPC was completed in 2020.publishedVersio

First-line treatment with infliximab versus conventional treatment in children with newly diagnosed moderate-to-severe Crohn's disease: An open-label multicentre randomised controlled trial

Objective: In newly diagnosed paediatric patients with moderate-to-severe Crohn's disease (CD), infliximab (IFX) is initiated once exclusive enteral nutrition (EEN), corticosteroid and immunomodulator therapies have failed. We aimed to investigate whether starting first-line IFX (FL-IFX) is more effective to achieve and maintain remission than conventional treatment. Design: In this multicentre open-label randomised controlled trial, untreated patients with a new diagnosis of CD (3-17 years old, weighted Paediatric CD Activity Index score (wPCDAI) >40) were assigned to groups that received five infusions of 5 mg/kg IFX at weeks 0, 2, 6, 14 and 22 (FL-IFX), or EEN or oral prednisolone (1 mg/kg, maximum 40 mg) (conventional). The primary outcome was clinical remission on azathioprine, defined as a wPCDAI <12.5 at week 52, without need for treatment escalation, using intention-to-treat analysis. Results: 100 patients were included, 50 in the FL-IFX group and 50 in the conventional group. Four patients did not receive treatment as per protocol. At week 10, a higher proportion of patients in the FL-IFX group than in the conventional group achieved clinical (59% vs 34%, respectively, p=0.021) and endoscopic remission (59% vs 17%, respectively, p=0.001). At week 52, the proportion of patients in clinical remission was no

MATISSE, the VLTI mid-infrared imaging spectro-interferometer

GalaxiesStars and planetary systemsInstrumentatio

The LHCb upgrade I

The LHCb upgrade represents a major change of the experiment. The detectors have been almost completely renewed to allow running at an instantaneous luminosity five times larger than that of the previous running periods. Readout of all detectors into an all-software trigger is central to the new design, facilitating the reconstruction of events at the maximum LHC interaction rate, and their selection in real time. The experiment's tracking system has been completely upgraded with a new pixel vertex detector, a silicon tracker upstream of the dipole magnet and three scintillating fibre tracking stations downstream of the magnet. The whole photon detection system of the RICH detectors has been renewed and the readout electronics of the calorimeter and muon systems have been fully overhauled. The first stage of the all-software trigger is implemented on a GPU farm. The output of the trigger provides a combination of totally reconstructed physics objects, such as tracks and vertices, ready for final analysis, and of entire events which need further offline reprocessing. This scheme required a complete revision of the computing model and rewriting of the experiment's software

Static and dynamic numerical simulations of a generic UCAV configuration with and without control devices

A contribution for the assessment of the static and dynamic aerodynamic behavior of a generic UCAV configuration with control devices using CFD methods is given. For the CFD simulations the unstructured grid based DLR TAU-Code and the structured grid based NLR solver ENSOLV are used. The numerical methods are verified by experimental wind tunnel data. The current investigations should provide a contribution to assess the prediction capability of control device effectiveness using CFD methods. The presented computational results for the assessment will be validated by dedicated experimental data. Furthermore, it should support the understanding of the flow physics around the trailing edge control devices of highly swept configurations with a vortex dominated flow field. Design requirements should be able draw by analyzing the interaction between the vortical flow and the control devices. The present work is part of the NATO STO/AVT Task Group AVT-201 on Stability and Control prediction method