The design concept of the 6-degree-of-freedom hydraulic shaker at ESTEC

The European Space Agency (ESA) has decided to extend its test facilities at the European Space and Technology Center (ESTEC) at Noordwijk, The Netherlands, by implementing a 6-degree-of-freedom hydraulic shaker. This shaker will permit vibration testing of large payloads in the frequency range from 0.1 Hz to 100 Hz. Conventional single axis sine and random vibration modes can be applied without the need for a configuration change of the test set-up for vertical and lateral excitations. Transients occurring during launch and/or landing of space vehicles can be accurately simulated in 6-degrees-of-freedom. The performance requirements of the shaker are outlined and the results of the various trade-offs, which are investigated during the initial phase of the design and engineering program are provided. Finally, the resulting baseline concept and the anticipated implementation plan of the new test facility are presented

Thermodynamics of an incommensurate quantum crystal

We present a simple theory of the thermodynamics of an incommensurate quantum solid. The ground state of the solid is assumed to be an incommensurate crystal, with quantum zero-point vacancies and interstitials and thus a non-integer number of atoms per unit cell. We show that the low temperature variation of the net vacancy concentration should be as $T^4$, and that the first correction to the specific heat due to this varies as $T^7$; these are quite consistent with experiments on solid $^4$He. We also make some observations about the recent experimental reports of ``supersolidity'' in solid $^4$He that motivate a renewed interest in quantum crystals.Comment: revised, new title, somewhat expande

COPTRAN - A method of optimum communication systems design

Single set of mathematical expressions describes system cost and probability of error of data transmission in terms of four basic parameters in the link equation. A Lagrange multiplier sets up equations whose solutions yield the optimum values for system design considerations and weight and cost values

Marine Protected Areas and commercial fisheries: the existing fishery in potential protected areas, and a modelling study of the impact of protected areas on North Sea Plaice

Dit rapport presenteert resultaten van onderzoek, dat in 2005/2006 is uitgevoerd. In het kader van de Europese Vogel en Habitat Richtlijnen dienen lidstaten te beschermen gebieden op zee aan te wijzen, wat mogelijk zou leiden tot beperkingen van visserijactiviteiten in deze gebieden. De vraag was, welke invloed dit zou hebben op de vis en visserij. In dit onderzoek is enerzijds een statische beschrijving opgesteld van de visserijinspanning en de vangsten in de voorgestelde gebieden, en is anderzijds een eerste analyse (simulatie-model) opgezet van het lange-termijn effect op migrerende vis (schol). Dit onderzoek werd eind 2006 afgerond met een concept-rapport

Preferential adsorption of high density lipoprotein (HDL) in blood plasma/polymer interaction

A few studies on the adsorption of plasma proteins to polymeric surfaces show that major plasma proteins: albumin (Alb), fibrinogen (Fb) and immunoglobulin (IgG) are adsorbed in much smaller quantities from plasma than from protein solutions (1,2). Present results show that this difference in adsorption is due to the preferential adsorption of high density lipoprotein from plasma onto the material surfaces studied (PVC and PS)

On the Use and Development of the Pentatonic Scale Through the Works of Antonín Dvořák

Concepts related to style change have been discussed thoroughly by theorists such as Leonard Meyer and others. In the case of Czech scholar, Antonín Dvořák, this change relates directly to his pentatonic style. While many musicologists suggest that the composer\u27s travels to the United States in the early 1890\u27s had a profound effect on the birth of his pentatonic style, this thesis posits that Dvořák\u27s pentatonicism is apparent from even his earliest works. In examining evidence of this pentatonicism it becomes clear that, for Dvořák, there are two types: thematic and cadential. Thematic pentatonicism arises from themes of works or movements which only include pitches found within the traditional Western pentatonic scale (scale degrees 1, 2, 3, 5, and 6). Cadential pentatonicism is more abstract in that it only makes an appearance during the close of phrases, sections, or melodic gestures. In these moments, often a rising or falling pentatonic scale will be heard in one or more melody instruments with a harmonic accompaniment that moves towards a tonic structure. In order to better understand and find these two factors, a corpus study was used along with various statistical and programming tools. The use of these tools allowed for a quicker and more thorough examination of various themes and figures for elements of pentatonicism. The results of this corpus study hint towards further research into the fields of pentatonic structure, Czech folk music, and the composer himself, Antonín Dvořá

Study and development of a mathematical analysis for the performance assessment of space communication system parameters

Electronic computer program user manual for optimum design of space communication syste

User's manual for COPTRAN, a method of optimum communication system design

User manual for COPTRAN /communication system optimization program translator

Generalization of Gutzwiller Approximation

We derive expressions required in generalizing the Gutzwiller approximation to models comprising arbitrarily degenerate localized orbitals.Comment: 6 pages, 1 figure, to appear in J.Phys.Soc.Jpn. vol.6