6,773 research outputs found
VESTA Project: Phase 0 report
This report presents the results of technical studies conducted at CNES/PMF/APS between October 1984 and September 1985 on the VESTA project. These preliminary studies were conducted to establish mission feasibility in terms ofthe trajectory and the scientific objectives, and to determine the type of interfaces which will be required with the Soviets and to measure the magnitude of French participation. A joint French-Soviet report recommends that the project enter phase A, and was approved by CNES and INTERCOSMOS in September, 1985. The mission analysis is made for a mid-1991 launch, and a development schedule for an end-1992 launch is suggested. The decision to postpone the mission was made during the course of the study
Selective gas phase hydrogenation of nitroarenes over Mo2C-supported Au–Pd
Open Access via RSC Gold 4 Gold Financial support to Dr. X. Wang through the Overseas Research Students Award Scheme (ORSAS) is acknowledged. Dr. N. Perret also acknowledges financial support from COST Action MP0903 Nanoalloys.Peer reviewedPublisher PD
Bosonic Quartic Couplings at LEP2
We list the set of C and P conserving anomalous quartic vector bosons
self-couplings which can be tested at LEP2 through triple vector boson
production. We show how this set can be embedded in manifestly SU(2)xU(1) gauge
invariant operators exhibiting an SU(2)_c global symmetry. We derive bounds on
these various couplings and show the most relevant distributions that can
enhance their contribution. We also find that an e+e- collider running at 500
GeV can improve the LEP2 limits by as much as three orders of magnitude.Comment: 21 pages, 7 figure
Effect of detraining on bone and muscle tissue in subjects with chronic spinal cord injury after a period of electrically-stimulated cycling: a small cohort study
Objective: To investigate adaptive changes in bone and muscle parameters in the paralysed limbs after de-training or reduced functional electrical stimulation (FES) induced cycling following high-volume FES-cycling in chronic spinal cord injury (SCI).
Subjects: Five subjects with motor-sensory complete SCI (age 38.6 years, lesion duration 11.4 years) were included. Four subjects stopped FES-cycling completely after the training phase whereas one continued reduced FES-cycling (2-3 times/week, for 30min).
Methods: Bone and muscle parameters were assessed in the legs using peripheral quantitative computed tomography at six and twelve months after cessation of high-volume FES-cycling.
Results: Gains achieved in the distal femur by high-volume FES-cycling were partly maintained at one year of detraining: 73.0% in trabecular bone mineral density (BMD), 63.8% in total BMD, 59.4% in bone mineral content and 22.1% in muscle cross-sectional area (CSAmuscle) in the thigh. The subject who continued reduced FES-cycling maintained 96.2% and 95.0% of the previous gain in total and trabecu-lar BMD, and 98.5% in CSAmuscle.
Conclusion: Bone and muscle benefits achieved by one year of high-volume FES-cycling are partly preserved after 12 months of detraining whereas reduced cycling maintains bone and muscle mass gained. This suggests that high-volume FES-cycling has clinical relevance for at least 1y after detraining
Design concepts and performance of NASA X-band (7162 MHz/8415 MHz) transponder for deep-space spacecraft applications
The design concepts and measured performance characteristics are summarized of an X band (7162 MHz/8415 MHz) breadboard deep space transponder (DSP) for future spacecraft applications, with the first use scheduled for the Comet Rendezvous Asteroid Flyby (CRAF) and Cassini missions in 1995 and 1996, respectively. The DST consists of a double conversion, superheterodyne, automatic phase tracking receiver, and an X band (8415 MHz) exciter to drive redundant downlink power amplifiers. The receiver acquires and coherently phase tracks the modulated or unmodulated X band (7162 MHz) uplink carrier signal. The exciter phase modulates the X band (8415 MHz) downlink signal with composite telemetry and ranging signals. The receiver measured tracking threshold, automatic gain control, static phase error, and phase jitter characteristics of the breadboard DST are in good agreement with the expected performance. The measured results show a receiver tracking threshold of -158 dBm and a dynamic signal range of 88 dB
Development and structuring of the sector of full field organic vegetables in cereal zones
The organic vegetable consumption shows a progress that proved to be steady over years. Nevertheless, the offer of organic vegetables remains insufficient. The CasDar program dedicated to organic field vegetables, 2010-2013, aimed at studying the conditions for the development of large-scale production, by technical answers, and by contributing to the organization of the sector. This action, that concerned six regions of the North and the Central France, was led by players of the sector, producers, wholesalers, transformers, distributors. This favored a shared analysis of strengths and weaknesses of the sector. In a second step, the partners developed tools, to meet the identified stakes, that can be used in the zones of production of full field vegetables in cereal regions and available to the actors of the sector
ANALYSIS AND DESIGN OF THE ACTUATION SYSTEM FOR THE LHC COLLIMATORS (PHASE I)
In order to cope with the highly destructive particle beam of the LHC, the cleaning and collimation system must fulfill very severe requirements. The actuation system of the LHC Collimators is a key element to meet the specifications, particularly in terms of precision and reliability. Each collimator jaw has to be moved with a very high accuracy to place the active surface at the required position with respect to the proton beam; at the same time the system must be adjustable and flexible to adapt to the uncertainties and variations in the beam tuning. In this note the general design of the actuation system for the various collimator designs is presented and particular emphasis is given to the analysis of the torque which the stepper motors must provide to move the jaws in and back and to the dynamical behaviour of the system in the event of malfunctioning when auto-retraction of the jaws is required. In the appendix, details are given on the estimated performances of the actuation system for different collimator types and orientations
Small-Angle X-ray and neutron scattering from diamond single crystals
Results of Small-Angle Scattering study of diamonds with various types of
point and extended defects and different degrees of annealing are presented. It
is shown that thermal annealing and/or mechanical deformation cause formation
of nanosized planar and threedimensional defects giving rise to Small-Angle
Scattering. The defects are often facetted by crystallographic planes 111, 100,
110, 311, 211 common for diamond. The scattering defects likely consist of
clusters of intrinsic and impurity-related defects; boundaries of mechanical
twins also contribute to the SAS signal. There is no clear correlation between
concentration of nitrogen impurity and intensity of the scattering.Comment: 6 pages, 5 figures; presented at SANS-YuMO User Meeting 2011, Dubna,
Russi
Large time zero temperature dynamics of the spherical p=2-spin glass model of finite size
18 pages, 3 figures. Published version18 pages, 3 figures. Published versionWe revisit the long time dynamics of the spherical fully connected -spin glass model when the number of spins is large but {\it finite}. At where the system is in a (trivial) spin-glass phase, and on long time scale we show that the behavior of physical observables, like the energy, correlation and response functions, is controlled by the density of near-extreme eigenvalues at the edge of the spectrum of the coupling matrix , and are thus non self-averaging. We show that the late time decay of these observables, once averaged over the disorder, is controlled by new universal exponents which we compute exactly
Long-term low-dose ketoconazole treatment in bilateral macronodular adrenal hyperplasia
Medical therapy for Cushing's syndrome due to bilateral macronodular adrenal hyperplasia (BMAH) is generally administered for a limited time before surgery. Aberrant receptors antagonists show inconsistent efficacy in the long run to prevent adrenalectomy. We present a patient with BMAH, treated for 10 years with low doses of ketoconazole to control cortisol secretion. A 48-year-old woman presented with headaches and hypertension. Investigations showed the following: no clinical signs of Cushing's syndrome; enlarged lobulated adrenals; normal creatinine, potassium, and aldosterone; normal urinary aldosterone and metanephrines; elevated urinary free cortisol and steroid metabolites; and suppressed plasma renin activity and ACTH. A screening protocol for aberrant adrenal receptors failed to show any illegitimate hormone dependence. Ketoconazole caused rapid normalisation of cortisol and ACTH that persists over 10 years on treatment, while adrenals show no change in shape or size. Ketoconazole decreases cortisol in patients with Cushing's syndrome, and may prevent adrenal overgrowth. Steroid secretion in BMAH is inefficient as compared with normal adrenals or secreting tumours and can be controlled with low, well-tolerated doses of ketoconazole, as an alternative to surgery.
LEARNING POINTS: Enlarged, macronodular adrenals are often incidentally found during the investigation of hypertension in patients harboring BMAH. Although laboratory findings include low ACTH and elevated cortisol, the majority of patients do not display cushingoid features.Bilateral adrenalectomy, followed by life-long steroid replacement, is the usual treatment of this benign condition, and alternative medical therapy is sought. Therapy based on aberrant adrenal receptors gives disappointing results, and inhibitors of steroidogenesis are not always well tolerated.However, ketoconazole at low, well-tolerated doses appeared appropriate to control adrenal steroid secretion indefinitely, while preventing adrenal overgrowth. This treatment probably constitutes the most convenient long-term alternative to surgery
- …