Search results for "Dynamics"
showing 10 items of 9782 documents
Knee joint loading in the open and square stance tennis forehands
2013
Sandamas, Paul 2013. Knee joint loading in the open and square stance tennis forehands. Department of Biology of Physical Activity, University of Jyväskylä. Master's Thesis in Biomechanics. 80 pages. The aim of this study was to calculate and compare the resultant forces and moments in the knee joint of the open and square stance tennis forehands. An additional aim was to incorporate the ground reaction forces to shed light on the role of the lower body in aiding pelvic rotation in these two different forehands. The two types of forehand strokes hit by 7 right-handed university team level tennis players were filmed and the ground reaction forces on each foot were measured simultaneously. A …
Free-volume Study in GeS2-Ga2S3-CsCl Chalcohalide Glasses Using Positron Annihilation Technique
2015
Abstract Positron annihilation lifetime spectroscopy combined with Doppler broadening of annihilation radiation was applied to study free-volume entities in Ge-Ga-S glasses having different amount of CsCl additives. It is shown that the structural changes caused by CsCl additives can be adequately described by positron trapping modes determined within two-state model. The results testify in a favor of rather unchanged nature of corresponding free-volume voids responsible for positron trapping in the studied glasses, when mainly concentration of these traps is a subject to most significant changes with composition.
Approche d'un territoire de montagne : occupations humaines et contexte pédo-sédimentaire des versants du col du Petit-Saint-Bernard, de la Préhistoi…
2014
As part of a multi-year programme, survey campaigns have been carried out on both slopes of the Petit-Saint-Bernard pass (2188 m, western Alps), at an altitude of between 750 and 3000 m. The method employed abandons ground-based surveying in favour of multiple manual surveys carried out on selected topographic contexts down to the base of the Holocene fill. The results obtained document the longterm development of the pedo-sedimentary dynamic and the occupation of the different altitude stages. The significance of the archaeological data collected is discussed in relation to the state of knowledge in a comparison area including the neighbouring valleys of the western Alps, to existing settl…
High-energy monitoring of NGC 4593 II. Broad-band spectral analysis: testing the two-corona model
2019
It is widely believed that the primary X-ray emission of AGN is due to the Comptonisation of optical-UV photons from a hot electron corona, while the origin of the 'soft-excess' is still uncertain and matter of debate. A second Comptonisation component, called warm corona, was therefore proposed to account for the soft-excess, and found in agreement with the optical-UV to X-ray emission of a sample of Seyfert galaxies. In this context, we exploit the broadband XMM-Newton and NuSTAR simultaneous observations of the Seyfert galaxy NGC 4593 to further test the so called "two corona model". The NGC 4593 spectra are well reproduced by the model, from the optical/UV to the hard X-rays. Moreover, …
Cosmological hydrodynamical simulations of galaxy clusters: X-ray scaling relations and their evolution
2018
We analyse cosmological hydrodynamical simulations of galaxy clusters to study the X-ray scaling relations between total masses and observable quantities such as X-ray luminosity, gas mass, X-ray temperature, and $Y_{X}$. Three sets of simulations are performed with an improved version of the smoothed particle hydrodynamics GADGET-3 code. These consider the following: non-radiative gas, star formation and stellar feedback, and the addition of feedback by active galactic nuclei (AGN). We select clusters with $M_{500} > 10^{14} M_{\odot} E(z)^{-1}$, mimicking the typical selection of Sunyaev-Zeldovich samples. This permits to have a mass range large enough to enable robust fitting of the r…
Unveiling the environment and faint features of the isolated galaxy CIG 96 with deep optical and HI observations
2018
Context. Asymmetries in atomic hydrogen (HI) in galaxies are often caused by the interaction with close companions, making isolated galaxies an ideal framework to study secular evolution. The AMIGA project has demonstrated that isolated galaxies show the lowest level of asymmetry in their HI integrated profiles compared to even field galaxies, yet some present significant asymmetries. CIG 96 (NGC 864) is a representative case reaching a 16% level. Aims. Our aim is to investigate the HI asymmetries of the spiral galaxy CIG 96 and what processes have triggered the star-forming regions observed in the XUV pseudo-ring. Methods. We performed deep optical observations at CAHA1.23m, CAHA2.2m and V…
Charge fluctuations and electric mass in a hot meson gas
2006
Net-Charge fluctuations in a hadron gas are studied using an effective hadronic interaction. The emphasis of this work is to investigate the corrections of hadronic interactions to the charge fluctuations of a non-interacting resonance gas. Several methods, such as loop, density and virial expansions are employed. The calculations are also extended to SU(3) and some resummation schemes are considered. Although the various corrections are sizable individually, they cancel to a large extent. As a consequence we find that charge fluctuations are rather well described by the free resonance gas.
Electroweak Gauge-Boson and Higgs Production at Small qT: Infrared Safety from the Collinear Anomaly
2012
We study the differential cross sections for electroweak gauge-boson and Higgs production at small and very small transverse-momentum $q_T$. Large logarithms are resummed using soft-collinear effective theory. The collinear anomaly generates a non-perturbative scale $q_*$, which protects the processes from receiving large long-distance hadronic contributions. A numerical comparison of our predictions with data on the transverse-momentum distribution in Z-boson production at the Tevatron and LHC is given.
¿Cabe hablar de una «generación de la crisis»? Discusión en torno a una noción sobreexplotada
2018
This article states that nowadays there is an overuse (or a misuse) of the «Generation» idea. The discussion among many authors over the «Generation of crisis» concept suggests that it is useful to outline the characteristics of the target of population of the collective of youth who are mainly affected by the economic and social crisis over the past years. Nevertheless, through analyzing the meanings of the «Generation of Crisis» made by Mannheim, Ortega and other classic authors, it is clear that the social class approach together with the generational one are needed to define this concrete concept. The conclusion of the articleis that both approaches are seen as underpinning their utilit…
Evoked local field potentials can explain temporal variation in blood oxygenation level-dependent responses in rat somatosensory cortex
2010
The aim of this study was to explain the temporal variations between subjects in the blood oxygenation level-dependent (BOLD) response. Somatosensory responses were elicited with the electrical forepaw stimulus at a frequency of 10 Hz in urethane-anesthetized rats, and functional magnetic resonance imaging (fMRI) with BOLD contrast and local field potential (LFP) measurements were performed simultaneously. BOLD fMRI activation was evaluated by two different models, one based on the stimulus paradigm (the block model) and the other on the simultaneously measured evoked LFP responses. In the initial analysis, the LFP model captured the BOLD activation in the primary somatosensory cortex in al…