Search results for "Mg"
showing 10 items of 492 documents
Physiological loading during normal daily life and exercise assessed with electromyography
2014
Acute incremental endurance performance and explosive strength training period : muscle activity, acid-base balance and hormonal responses
2015
Johdanto. Akuutin kestävyys- ja voimaharjoituksen fysiologiset vasteet ilmenevät luurankolihaksissa, hengitys- ja verenkiertoelimistössä, sekä endokriinisessa että immuunijärjestelmässä. Nämä vasteet voivat heikentää suorituskykyä, ja esimerkiksi happo-emästasapaino on tarkoin säädelty negatiivisten seurausten varalta. Lihasten toimintaa voidaan tutkia elektromyografialla (EMG), ja nykyään on myös mahdollista käyttää tekstiilielektrodeja, jotka mahdollistavat lihasryhmien sähköisen aktiivisuuden tallentamisen normaalin liikkumisen aikana. Tämän tutkimuksen tarkoituksena oli tutkia yhteyksiä etu- ja takareisien lihasaktiivisuuksien ja happo-emästasapainon välillä, vertailla lihasaktiivisuuks…
Water dissociation and water-gas shift energetics on MgO, MgO/Ag and Au/MgO/Ag surfaces
2011
Water dissociation and the energetics of the WGS reaction on a bulk MgO, an Ag supported MgO thin film and Au/MgO/Ag surfaces is studied based on the density functional theory. The literature results for water splitting on MgO and MgO/Ag surfaces with a step type defect are repeated and further analysis on the origin of the energetically favored dissociative water adsorption are made. The reactivity towards water dissociation on the stepped MgO and MgO/Ag surfaces is attributed to four contributing factors: 1. The change in the interlayer distance of the surface in dissociative adsorption is diminished on the stepped surfaces compared to the flat surfaces. On the flat surfaces the dissociat…
Up-conversion and Photoluminescence in Er3+ Single Crystal MgAl-spinel
2015
Abstract Traditional and up-conversion luminescence of MgAl 2 O 4 single crystal doped with erbium ions obtained by the Verneuil method has been investigated. The time resolved spectral measurements of the green and red up-conversion luminescence bands show that a build-up part is present in the up-conversion luminescence kinetics. This means that energy transfer process is involved in the creation of the luminescence. Considering rather small concentration of Er 3+ in the material (0.12 mass %), the expected up-conversion mechanism should be excited state absorption since the average distance between erbium ions is high. The above-mentioned considerations suggest that clustering of the act…
Sit-stand workstations : effects on occupational sitting time, potential health benefits, and acute postural physiology
2017
Given that a high amount of sedentary behavior is a global health issue, reducing sitting time is emerging as a novel intervention strategy and a workplace health priority. Sit-stand workstations have been introduced to the workplace, and can be used to rotate between sitting and standing postures at work. It is important to develop and evaluate sit-stand interventions that aim to induce behavioral changes and potential health benefits, in order to effectively implement them into practice. Therefore, this thesis examined whether and to what extent sit-stand workstations can reduce occupational sitting and improve health indexes in a real workplace. The thesis included four studies in field …
Surface canal, squelette et espace des sphères
2016
A canal surface is the envelope of a one-parameter familly of oriented spheres. With the knowledge of center an radius functions associated to it, it is easy to compute a parametrisation of the surface. In this article, we study the inverse operation, which is the search for the spheres in the canal surface. By selecting a point on the boundary and using the sphere space, we estimate the maximal sphere tangent with this point and a second point on the boundary. Furthermore, we estimate a second sphere, which allows to build the characteiristic circle of the canal surface. So this article consists in a new approach of the skeletonization of an object. Indeed, a skeleton is a shape representa…
Espace de Minkowski-Lorentz et des sphères : un état de l'art
2016
International audience; Dans cet article, nous faisons une présentation de l'espace de Minkowski-Lorentz généralisant, à Ê 5 l'espace utilisé dans la théorie de la relativité. Cet espace de dimension 5 contient un paraboloïde de dimension 3 et isométrique à l'espace affine euclidien usuel E 3 , l'ensembles des sphères et plans orientés de E 3 regroupés sur une pseudo-sphère unité de dimension 4. Une premier avantage de cet espace est l'écriture intuitive d'une sphère qui est caractérisée par un point, un vecteur normal en ce point et une courbure. Un deuxième avantage est la manipulation de surfaces canal qui sont représentées par des courbes. Un troisième avantage concernant la simplificat…
Quasiconformal geometry and removable sets for conformal mappings
2020
We study metric spaces defined via a conformal weight, or more generally a measurable Finsler structure, on a domain $\Omega \subset \mathbb{R}^2$ that vanishes on a compact set $E \subset \Omega$ and satisfies mild assumptions. Our main question is to determine when such a space is quasiconformally equivalent to a planar domain. We give a characterization in terms of the notion of planar sets that are removable for conformal mappings. We also study the question of when a quasiconformal mapping can be factored as a 1-quasiconformal mapping precomposed with a bi-Lipschitz map.
Quasisymmetric extension on the real line
2015
We give a geometric characterization of the sets $E\subset \mathbb{R}$ that satisfy the following property: every quasisymmetric embedding $f: E \to \mathbb{R}^n$ extends to a quasisymmetric embedding $f:\mathbb{R}\to\mathbb{R}^N$ for some $N\geq n$.
Transitions in European land-management regimes between 1800 and 2010
2015
Land use is a cornerstone of human civilization, but also intrinsically linked to many global sustainability challenges—from climate change to food security to the ongoing biodiversity crisis. Understanding the underlying technological, institutional and economic drivers of land-use change, and how they play out in different environmental, socio-economic and cultural contexts, is therefore important for identifying effective policies to successfully address these challenges. In this regard, much can be learned from studying long-term land-use change. We examined the evolution of European land management over the past 200 years with the aim of identifying (1) key episodes of changes in land …