1,933 research outputs found
ESTIMATION OF KNEE EXTENSION MOMENT CONSIDERING VELOCITY EFFECT AND MUSCLE ACTIVATION USING TENDON SLACK LENGTH OPTIMIZATION
This study presents a model to estimate knee extension moment considering muscle velocity effect and muscle activation. The muscle tendon force is very sensitive to the tendon slack length. To predict tendon slack length, exact muscle parameters of a human are needed. But it is difficult to measure all of the muscle parameters from human body. So we propose the algorithm which finds the tendon slack length of quadriceps for more accurate estimation of knee extension moment. Finally considering muscle velocity effect and muscle activation, knee extension moment is estimated. Algorithm was embodied by MATLAB optimization toolbox. And it is evaluated by using an experimental data
Managing Climatic Risks to Combat Land Degradation and Enhance Food security: Key Information Needs
This paper discusses the key information needs to reduce the negative impacts of weather variability and climate change on land degradation and food security, and identifies the opportunities and barriers between the information and services needed. It suggests that vulnerability assessments based on a livelihood concept that includes climate information and key socio-economic variables can overcome the narrow focus of common one-dimensional vulnerability studies. Both current and future climatic risks can be managed better if there is appropriate policy and institutional support together with technological interventions to address the complexities of multiple risks that agriculture has to face. This would require effective partnerships among agencies dealing with meteorological and hydrological services, agricultural research, land degradation and food security issues. In addition a state-of-the-art infrastructure to measure, record, store and disseminate data on weather variables, and access to weather and seasonal climate forecasts at desired spatial and temporal scales would be needed
Attempts to synthesise quaternary MAX phases (Zr,M)2AlC and Zr2(Al,A)C as a way to approach Zr2AlC
Despite having never been synthesized, the MAX phase Zr2AlC attracts a lot of interest owing to its foreseen properties. A possible way to circumvent this obstacle is to stabilize Zr2AlC by partially substituting one of its constituting elements. Here we report on attempts to synthesise quaternary MAX phases (Zr,M)2AlC and Zr2(Al,A)C where M = Cr, Ti or Mo and A = S, As, Sn, Sb and Pb. We were notably able to produce Zr2(Al0.2Sn0.8)C, Zr2(Al0.35Pb0.65)C, and Zr2(Al0.3Sb0.7)C, with the latter representing the first antimony-based MAX phase ever reported
Visual Environmental Data on Soils and Land Use
End of Project ReportThis project was established to develop a computer based system to
view, manipulate and store data on soils, environment and land use
in electronic map form for environmental decision support. It was
designed to produce new information, charts and maps by
combining features from the captured data, and to develop
networking systems to allow exchange of data with other Teagasc
centres, local and national government and the EU. The current
report presents maps and tabular data of particular relevance to the
environment. It includes information and maps on the total
stocking density of livestock in different parts of Ireland. This is
relevant to the nutrient loadings that soils and the environment are
subject to from normal farming operations. It also includes maps
and tabular information on phosphorus and potassium levels in
soils and the recommended manure and fertiliser application given
by Teagasc for grassland and cropping on these soils.
In addition, it also describes and illustrates with tables and maps, a
computerised programming approach for mapping phosphorus and
potassium levels in soils at a detailed level by using the farmer’s address to locate samples at townland or DED level.European Union Structural Funding (EAGGF
Comparison of the Electronic Structures of Two Non-cuprate Layered Transition Metal Oxide Superconductors
Comparison is made of the electronic structure of the little-studied layered
transition metal oxide LiNbO with that of NaCoO, which has
attracted tremendous interest since superconductivity was discovered in its
hydrate. Although the active transition metal states are quite different
due to different crystal fields and band filling, both systems show a strong
change of electronic structure with changes in the distance between the
transition metal ion layer and the oxygen layers. The niobate is unusual in
having a large second-neighbor hopping amplitude, and a nearest neighbor
hopping amplitude that is sensitive to the Nb-O separation. LiNbO also
presents the attractive simplicity of a single band triangular lattice system
with variable carrier concentration that is superconducting.Comment: 5 pages, 3 embedded figures (Proceedings in third Hiroshima
international workshop
Preliminary Surface Study of Short Term Dissolution of UK High Level Waste Glass
AbstractA simulated Magnox glass which is Mg- and Al- rich was subjected to aqueous corrosion in static mode with deionised water at 90°C for 7 days and assessed using Cameca and Ion-ToF Secondary Ion Mass Spectrometry (SIMS). Depth profiling and ion imaging were done for both unleached and leached samples to reveal elemental distributions from the glass surface into the bulk. All the elements were distributed evenly for unleached glass. After leaching, depletion of alkali ions i.e. Na and Li was observed indicating the interdiffusion (ion exchange) process of the initial stage of leaching. Enrichment of Mg near the surface layer indicated precipitation of Mg-rich crystals at the near surface region
Water vapour corrosion of rare earth monosilicates for environmental barrier coatings application
Water vapour corrosion resistance of five rare earth monosilicates Y2SiO5, Gd2SiO5, Er2SiO5, Yb2SiO5, and Lu2SiO5 was investigated during testing at 1350 ˚C for up to 166 h in static air with 90% water vapour. Four of the RE-silicates showed little weight gain (0.859 mg cm-2) after 166 h of exposure. Prior to testing the microstrucre consists of equiaxed grains of 4- 7 ± 0.4 µm. XRD analysis showed that after 50 h exposure to water vapour corrosion Y, Er, Yb and Lu-silicates had both mono and disilicates present on their surfaces as a result of the reaction between monosilicate and water vapour to form disilicate, while Gd-silicate has converted completely to G4.67Si3O13 making it less stable for environmental barrier coatings application. The microstructures of corroded Y, Er, Yb and Lu-silicates contain ridges and cracks, while that of Gd-silicate contains rounded grains suggesting melting along with striped contract grains
Density Functional Theory of Magnetic Systems Revisited
The Hohenberg-Kohn theorem of density functional theory (DFT) for the case of
electrons interacting with an external magnetic field (that couples to spin
only) is examined in more detail than previously. A unexpected generalization
is obtained: in certain cases (which include half metallic ferromagnets and
magnetic insulators) the ground state, and hence the spin density matrix, is
invariant for some non-zero range of a shift in uniform magnetic field. In such
cases the ground state energy is not a functional of the spin density matrix
alone. The energy gap in an insulator or a half metal is shown to be a ground
state property of the N-electron system in magnetic DFT.Comment: Four pages, one figure. Submitted for publication, April 13, 2000
Revised, Sept 27, 200
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