Biomechanical role and motion contribution of ligaments and bony constraints in the elbow stability: A preliminary study

In flexion-extension motion, the interaction of several ligaments and bones characterizes the elbow joint stability. The aim of this preliminary study was to quantify the relative motion of ulna respect to humerus in two human elbow specimens and to investigate the constraints role for maintaining the joint stability in different dissections condition. Two clusters of 4 markers were fixed respectively to ulna and humerus, and their trajectory was recorded by a motion capture system during orthopedic maneuver. Considering the medial ulnar collateral posterior bundle (pMUCL) and the coronoid, two dissection sequences were executed. The orthopedic maneuver of compression, pronation and varus force was repeated at 30°, 60°, 90° flexion for the functional investigation of constraints. Ulna deflection was compared to a baseline flexion condition. Respect to intact elbow, the coronoid osteotomy influences the elbow stability at 90° (deflection=11.49±17.39 mm), while small differences occur at 30° and 60°, due to ligaments constraint. The contemporary pMUCL dissection and coronoid osteotomy causes elbow instability, with large deflection at 30° (deflection=34.40±9.10 mm), 60° (deflection=45.41±18.47 mm) and 90° (deflection=52.16±21.92 mm). Surgeons may consider the pMUCL reconstruction in case of unfixable coronoid fracture

Penrose type inequalities for asymptotically hyperbolic graphs

In this paper we study asymptotically hyperbolic manifolds given as graphs of asymptotically constant functions over hyperbolic space \bH^n. The graphs are considered as subsets of \bH^{n+1} and carry the induced metric. For such manifolds the scalar curvature appears in the divergence of a 1-form involving the integrand for the asymptotically hyperbolic mass. Integrating this divergence we estimate the mass by an integral over an inner boundary. In case the inner boundary satisfies a convexity condition this can in turn be estimated in terms of the area of the inner boundary. The resulting estimates are similar to the conjectured Penrose inequality for asymptotically hyperbolic manifolds. The work presented here is inspired by Lam's article concerning the asymptotically Euclidean case.Comment: 29 pages, no figure, includes a proof of the equality cas

Ess target performance for different beam pulses

Last trends in the design of linear accelerators for high power spallation sources point to the use of ion beams of larger energies and shorter pulse lengths in order to enhance the reliability of the system. In this sense the recommendations for ESS are to increase the energy of the proton beam from 1.3GeV to 2-2.5GeV and to reduce the length of the beam pulse from 2ms to 1-1.5ms, keeping the source average power at 5MW. Different values for the repetition rate are also being discussed (16 2/3, 20, 25 Hz). ESS Bilbao is analyzing the impact of these modifications on the design of the target system. In this paper the effects of the different beam energies on the target disc thermohydraulics and the neutron performance of the source are discussed. Initial calculations were performed for a rotating target with ESS 2002 parameters. During the development of the work –that are being performed in collaboration with SNS– the decision was made to use the SNS-STS Target-Moderator-Reflector Assembly (TMRA) –slightly modified to accommodate the target design being studied for ESS– which presents a state of the art design with a cylindrical liquid para-hydrogen moderator in wing configuration aimed to enhance cold neutron productio

REMOVABLE SETS FOR LIPSCHITZ HARMONIC FUNCTIONS ON CARNOT GROUPS

Abstract. Let G be a Carnot group with homogeneous dimension Q ≥ 3 and let L be a sub-Laplacian on G. We prove that the critical dimension for removable sets of Lipschitz L-harmonic functions is (Q − 1). Moreover we construct self-similar sets with positive and finite H Q−1 measure which are removable. 1

Adaptation of the generic PDE's results to the notion of prevalence

Many generic results have been proved, especially concerning the qualitative behaviour of solutions of partial differential equations. Recently, a new notion of "almost always", the prevalence, has been developped for vectorial spaces. This notion is interesting since, for example, prevalence sets are equivalent to the full Lebesgue measure sets in finite dimensional spaces. The purpose of this article is to adapt the generic PDE's results to the notion of prevalence. In particular, we consider the cases where Sard-Smale theorems or arguments of analytic perturbations of the parameters are used

Search for charmed particles

We propose to use the CCM spectrometer to carry out a sensitive search for charmed particles produced in strong interactions at a nominal beam energy of 150 GeV/c. We limit ourselves to production in the beam diffraction region for reasons of acceptance and reconstruction. We present results of a test run undertaken in April 1975 to demonstrate the feasibility of K{sub S}{sup 0} trigger, which we incorporate in the present proposal. Results of the test are combined with new insights which increase our sensitivity to charmed particle production by a large factor. We request a total of 2 x 10{sup 11} negative pions at a rate of 10{sup 6} per pulse. With this illumination we estimate that we can measure a large number of hadronic decay modes. We make estimates of enhancements in mass spectra from charmed particle production and decay and calculate expected backgrounds using data from existing experiments. With conservative assumptions about the charmed particle model, we calculate effects corresponding to ten or more standard deviations in our most favorable channels

The Mars Environmental Dynamics Analyzer, MEDA. A Suite of Environmental Sensors for the Mars 2020 Mission

86 pags., 49 figs., 24 tabs.NASA’s Mars 2020 (M2020) rover mission includes a suite of sensors to monitor current environmental conditions near the surface of Mars and to constrain bulk aerosol properties from changes in atmospheric radiation at the surface. The Mars Environmental Dynamics Analyzer (MEDA) consists of a set of meteorological sensors including wind sensor, a barometer, a relative humidity sensor, a set of 5 thermocouples to measure atmospheric temperature at ∼1.5 m and ∼0.5 m above the surface, a set of thermopiles to characterize the thermal IR brightness temperatures of the surface and the lower atmosphere. MEDA adds a radiation and dust sensor to monitor the optical atmospheric properties that can be used to infer bulk aerosol physical properties such as particle size distribution, non-sphericity, and concentration. The MEDA package and its scientific purpose are described in this document as well as how it responded to the calibration tests and how it helps prepare for the human exploration of Mars. A comparison is also presented to previous environmental monitoring payloads landed on Mars on the Viking, Pathfinder, Phoenix, MSL, and InSight spacecraft.This work has been funded by the Spanish Ministry of Economy and Competitiveness, through the projects No. ESP2014-54256-C4-1-R (also -2-R, -3-R and -4-R) and AYA2015-65041-P; Ministry of Science, Innovation and Universities, projects No. ESP2016-79612-C3-1-R (also -2-R and -3-R), ESP2016-80320-C2-1-R, RTI2018-098728-B-C31 (also -C32 and -C33) and RTI2018-099825-B-C31; Instituto Nacional de Técnica Aeroespacial; Ministry of Science and Innovation’s Centre for the Development of Industrial Technology; Grupos Gobierno Vasco IT1366-19; and European Research Council Consolidator Grant no 818602. The US co-authors performed their work under sponsorship from NASA’s Mars 2020 project, from the Game Changing Development program within the Space Technology Mission Directorate and from the Human Exploration and Operations Directorate