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Showing 1 to 20 of 30 for “"Penumbra"”.
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Analysis of the penumbra formation in sunspots
The formation of the penumbra in sunspots is a physical process which involve the coupling between the plasma and the magnetic field in different layers of the solar atmosphere. Its study requires long time series of observations carried out with high temporal, spatial, and spectral resolution. …
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Highly Physical Solar Radiation Pressure Modeling During Penumbra Transitions
… space-based science instruments. During Earth penumbra transitions, sunlight is passing through Earth's lower atmosphere and, in the process, its path, intensity, spectral composition, and shape are significantly affected. This dissertation presents a new method for highly physical SRP modeling …
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Die Rolle von L-Arginin/Stickstoffmonoxid und Kohlendioxid bei der Regulation der Durchblutung in der Penumbra bei der experimentellen transienten fokalen zerebralen Ischämie
… als Vasodilatator in der Penumbra einer transienten fokalen zerebralen Ischämie bei der Ratte. Methode: Hierzu wurde bei narkotisierten, beatmeten Ratten der rCBF während und nach fokaler Ischämie und Reperfusion (Fadenmodell) mit der LDF-Methode simultan in beiden …
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fMRI assessment of ischemic stroke in humans
… are two major injury regions: the infarct and penumbra. Mostly, since the infarct regions became dead tissues rapidly after stroke, there is a tiny possibility to rescue them in time. But penumbra parts are different. Tissues there will be viable for hours after ischemia. Hence, both …
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Role of non-enhanced CT characteristics for differentiating reversible and irreversible brain tissue injury and estimating the tissue fate in acute ischaemic stroke
… between areas of salvageable tissue at risk (Penumbra), and irreversibly damaged tissue (infarct core) in patients with ischaemic stroke. It also seeks to predict the outcome of brain tissue fate - whether it will develop into infarct or show signs of recovery - within 24-48 hours after the …
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Producción de biomasa de nacedero (Trichanthera gigantea) en diferentes escenarios de sombra y frecuencias de cortes, en el Rancho Ebenezer, Niquinohomo, Masaya
… bajo tres escenarios de sombra (umbra, penumbra y a pleno sol) y cuatro frecuencias de corte (30, 60, 90 y 120 días) y su efecto sobre la producción de biomasa y contenido de proteína de nacedero. El estudio se ubicó en la comarca Hoja Chigüe #1 a una distancia de 4 Km al sur del …
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Image formation using geometrical theory of diffraction and its applications to lithography
… RAY FIELDS ARE SAMPLED ABOUT THE PENUMBRA REGIONS ABOVE SOME THRESHOLD</P><P>VALUE, 1D AND 2D IMAGE DISTURBANCES CAN BE CONSTRUCTED ENTIRELY FROM EDGE AND</P><P>VERTEX RAY CONTRIBUTIONS, RESPECTIVELY. BY REARRANGING THE MATHEMATICAL FORMULATION,</P><P>2D IMAGE DISTURBANCE CAN BE …
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A obra de Alves Redol para crianças
… de Alves Redol, uma área que se tem mantido na penumbra, no conjunto dos títulos escritos pelo romancista. O trabalho foi dividido em três partes: na primeira parte desenvolvemos a contextualização do escritor na sua época, com uma breve abordagem à temática do neo-realismo e às várias obras do …
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Monte Carlo simulations of the iThemba LABS neutron beam facility
… intensity throughout its diameter and a small penumbra. Secondary neutrons produced from the interactions of the primary charged particles with structural parts e.g. beampipes, shielding wall, target holder, etc. have been observed in the measured neutron fluence spectra. The Monte Carlo …
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Signal Transduction and Gene Regulation in Cerebral Arteries Following Ischemia
… for the survival of the neuronal tissue in the penumbra. Previous investigations have revealed upregulation of contractile receptors, a putative factor in the blood flow reduction following stroke that can could augment cell death. The major aim of the study is achieve a better understanding of …
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High resolution solar observations in the context of space weather prediction
… region presented. Formation of a rudimentary penumbra is studied. The effects of the change of the magnetic fields on the upper level atmosphere is discussed. Coronal Mass Ejections (CMEs) have a great impact on space weather. To study the relationship between CMEs and filament disappearance, …
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Aktive Regionen der Sonnenoberfläche und ihre zeitliche Variation in zweidimensionaler Spektro-Polarimetrie
… Power der Geschwindigkeit sind in einer dunklen, penumbralen Struktur sowie in der Lichtbrücke ausgeprägte Strukturen erkennbar, die sich mit einer Horizontalgeschwindigkeit von 5-8 km/s in die ruhige Sonne bewegen. Diese zeigen einen deutlichen Anstieg der Power, vor allem im 5-Minuten-Band, und …
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Application of adaptive optics to the spectroscopic investigation of small-scale solar structures
… with down-flowing plasma. Furthermore, we find penumbral grains that have penetrated the umbra and appear as brightenings. We study the velocity signature of penumbral grains and find strong up-flows of solar plasma associated with the inner, bright parts of penumbral grains, where as the …
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Counselling psychologists perspectives on professionalism
… a stable central core of ethical practice and a penumbra of professional legitimacy; and the identification of tensions between the perspectives of the participants and traditional forms of professionalism. The research concludes that ethical practice is the defining factor of participants' …
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Anatomical and Functional Organization of Domain-General Brain Regions
… interconnected regions, surrounded by a penumbra of 17 additional regions. MD activations were also identified in specific subcortical and cerebellar regions. Chapter 3 investigated the relation between the newly defined MD regions and previously identified sensory-biased cortical …
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Unraveling the Role of EphA4 in Immune-Mediated Arteriogenesis After Ischemic Stroke
… retrogradely re-supply blood to help salvage the penumbra following cerebral vascular occlusion. Their outward growth or remodeling (arteriogenesis) is essential for promoting cerebral reperfusion and preventing tissue damage after ischemic stroke. Increased fluid shear stress on collateral vessel …
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The Cross-Talk Between Neurons and Microglia Through Interleukin-4 After Ischemic Injury
… suggest that the viable neurons in the ischemic penumbra (location receiving less profound damage, as compare to ischemic core) produce and release a potent anti-inflammatory cytokine, interleukin(IL) -4. We propose that this neuronal response to sublethal ischemia is designed to guide …
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Design and Validation of a Prototype Collimation System with Reduced Applicator Weights for Elekta Electron Therapy Beams
… for calculating dose inside the field and its penumbra during trimmer weight optimization. In Aim 3, 1% electron ranges and out-of-field leakage doses were both computed using MC for copper, lead, and tungsten. At 20 MeV tungsten and lead had comparable ranges (g cm-2), both lower than copper. …
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The 3-D topology of magnetic fields in and around sunspots
… In this thesis, the properties of a sunspots' penumbra are derived from the observed spectra by means of an inversion, a forward modeling technique. A method for the construction of a 3-dimensional model of the field topology from the inversion results is presented. It offers the possibility to …
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