1,572 research outputs found
Expansion coefficient of the pseudo-scalar density using the gradient flow in lattice QCD
We use the Yang-Mills gradient flow to calculate the pseudo-scalar expansion
coefficient . This quantity is a key ingredient to obtaining the
chiral condensate and strange quark content of the nucleon using the Lattice
QCD formulation, which can ultimately determine the spin independent (SI)
elastic cross section of dark matter models involving WIMP-nucleon
interactions. The goal, using the gradient flow, is to renormalize the chiral
condensate and the strange content of the nucleon without a power divergent
subtraction. Using Chiral symmetry and the small flow time expansion of the
gradient flow, the scalar density at zero flow time can be related to the
pseudo-scalar density at non zero flow time. By computing the flow time
dependance of the pseudo-scalar density over multiple lattices box sizes,
lattice spacings and pion masses, we can obtain the scalar density of the
nucleon. Our lattice ensembles are , PCAC-CS gauge field
configurations, varying over ~MeV at
~fm, with additional ensembles that vary ~fm at ~MeV
Atlantic shelf sand ridge study : physical oceanography and sediment dynamics data report
This report describes and presents the hydrodynamic meaurements made during the Atlantic Shelf Sand Ridge Study at and
near Peahala Ridge, offshore of Long Beach Island, New Jersey, in Spring 1985. The intent of this phase of the study was to
examine the physical oceanographic and fluid mechanical processes in the vicinity of Peahala Ridge, one of the large shore-oblique
sand ridges common in the area, and from this to identify those processes responsible for sand transport near the ridge with particular
reference to its generation, maintenance and migration. The field measurement program was carried out from March to May
1985 by scientists and staff of the Woods Hole Oceanographic Institution. It included measurements of currents, temperature, waves,
pressure and near-bed velocity profiles. This phase was part of a larger oil industry study that included extensive geological and
geophysical measurements of Peahala Ridge and other ridge-and-swale areas of the mid-Atlantic continental shelf.Funding was provided by the Cities Services Oil and Gas Corporation under agreement as of April 25, 1985 and the Woods Hole Oceanographic Institution Coastal Research Center
Nonlinear Near-Field Microwave Microscope For RF Defect Localization in Superconductors
Niobium-based Superconducting Radio Frequency (SRF) cavity performance is
sensitive to localized defects that give rise to quenches at high accelerating
gradients. In order to identify these material defects on bulk Nb surfaces at
their operating frequency and temperature, it is important to develop a new
kind of wide bandwidth microwave microscopy with localized and strong RF
magnetic fields. By taking advantage of write head technology widely used in
the magnetic recording industry, one can obtain ~200 mT RF magnetic fields,
which is on the order of the thermodynamic critical field of Nb, on submicron
length scales on the surface of the superconductor. We have successfully
induced the nonlinear Meissner effect via this magnetic write head probe on a
variety of superconductors. This design should have a high spatial resolution
and is a promising candidate to find localized defects on bulk Nb surfaces and
thin film coatings of interest for accelerator applications.Comment: 4 pages, 6 figures Journal-ref: 2010 Applied Superconductivity
Conferenc
Pheochromocytoma – clinical manifestations, diagnosis and current perioperative management
Pheochromocytoma is a neuroendocrine tumor characterized by the excessive production of catecholamines (epinephrine, norepinephrine, and dopamine). The diagnosis is suspected due to hypertensive paroxysms, associated with vegetative phenomena, due to the catecholaminergic hypersecretion. Diagnosis involves biochemical tests that reveal elevated levels of catecholamine metabolites (metanephrine and normetanephrine). Functional imaging, such as 123I-metaiodobenzylguanidine scintigraphy (123I-MIBG), has increased specificity in identifying the catecholamine-producing tumor and its metastases. The gold-standard treatment for patients with pheochromocytoma is represented by the surgical removal of the tumor. Before surgical resection, it is important to optimize blood pressure and intravascular volume in order to avoid negative hemodynamic events
CAD, CAE and rapid prototyping methods applied in long bones orthopaedics
U radu su prikazane metode za analizu ljudskih koštanih zglobova. Prvo, upotrebom CT slika, definisani su 'čvrsti' delovi kao glavne komponente kosti i 'meki' delovi kao što su ligamenti ili meniskusi. Ove komponente uvoze se u modul za montažu parametrizovanog okruženja i dobija se biomehanički model ljudskog hoda, koji se izvozi u kinematsko simulaciono okruženje i koristi za analizu konačnim elementima, gde se prvo definišu kinematski parametri. Sa ovako definisanim parametrima može se izvršiti zamena kinematskih i dinamičkih simulacija podsistema klasičnim, normalnim kretanjem. Nakon interpretacije rezultata, mogu se modifikovati početni parametri biomehaničkih podsistema. U sledećoj fazi, komponente podsistema su podeljene sukcesivno i dobijena je struktura konačnih elemenata za ceo biomehanički sistem spojeva koji učestvuju u ljudskoj lokomociji.The paper presents some methods used to analyze human bone joints. First, there were defined the 'hard' parts as the main bone components and 'soft' parts as ligaments or menisci using CT images. These components are imported into a parameterized environment assembly module and a biomechanical model of human walking is being obtained, which is exported to a kinematic simulation environment and finite element analysis, where first the kinematic parameters are defined. With these defined parameters, the kinematic and dynamic simulation of the subsystems for classical, normal motion can be switched. Following the interpretation of the results, the initial parameters of the biomechanical subsystems may be modified. In the next phase, the components of the subsystems are divided successively and the finite element structure is obtained for the entire biomechanical system of the joints that participate in human locomotion
A multiscale framework for deconstructing the ecosystem physical template of high-altitude lakes
CAD, CAE and rapid prototyping methods applied in long bones orthopaedics
U radu su prikazane metode za analizu ljudskih koštanih zglobova. Prvo, upotrebom CT slika, definisani su 'čvrsti' delovi kao glavne komponente kosti i 'meki' delovi kao što su ligamenti ili meniskusi. Ove komponente uvoze se u modul za montažu parametrizovanog okruženja i dobija se biomehanički model ljudskog hoda, koji se izvozi u kinematsko simulaciono okruženje i koristi za analizu konačnim elementima, gde se prvo definišu kinematski parametri. Sa ovako definisanim parametrima može se izvršiti zamena kinematskih i dinamičkih simulacija podsistema klasičnim, normalnim kretanjem. Nakon interpretacije rezultata, mogu se modifikovati početni parametri biomehaničkih podsistema. U sledećoj fazi, komponente podsistema su podeljene sukcesivno i dobijena je struktura konačnih elemenata za ceo biomehanički sistem spojeva koji učestvuju u ljudskoj lokomociji.The paper presents some methods used to analyze human bone joints. First, there were defined the 'hard' parts as the main bone components and 'soft' parts as ligaments or menisci using CT images. These components are imported into a parameterized environment assembly module and a biomechanical model of human walking is being obtained, which is exported to a kinematic simulation environment and finite element analysis, where first the kinematic parameters are defined. With these defined parameters, the kinematic and dynamic simulation of the subsystems for classical, normal motion can be switched. Following the interpretation of the results, the initial parameters of the biomechanical subsystems may be modified. In the next phase, the components of the subsystems are divided successively and the finite element structure is obtained for the entire biomechanical system of the joints that participate in human locomotion
Climate change enhances the mobilisation of naturally occurring metals in high altitude environments
Manmade climate change has expressed a plethora of complex effects on Earth's biogeochemical compartments. Climate change may also affect the mobilisation of natural metal sources, with potential ecological consequences beyond mountains' geographical limits; however, this question has remained largely unexplored. We investigated this by analysing a number of key climatic factors in relationship with trace metal accumulation in the sediment core of a Pyrenean lake. The sediment metal contents showed increasing accumulation trend over time, and their levels varied in step with recent climate change. The findings further revealed that a rise in the elevation of freezing level, a general increase in the frequency of drier periods, changes in the frequency of winter freezing days and a reducing snow cover since the early 1980s, together are responsible for the observed variability and augmented accumulation of trace metals. Our results provide clear evidence of increased mobilisation of natural metal sources - an overlooked effect of climate change on the environment. With further alterations in climate equilibrium predicted over the ensuing decades, it is likely that mountain catchments in metamorphic areas may become significant sources of trace metals, with potentially harmful consequences for the wider environment
Evaluation of a User-Adapted Spoken Language Dialogue System: Measuring the Relevance of the Contextual Information Sources
We present an evaluation of a spoken language dialogue system with a module for the management of userrelated information, stored as user preferences and privileges. The flexibility of our dialogue management approach, based on Bayesian Networks (BN), together with a contextual information module, which performs different strategies for handling such information, allows us to include user information as a new level into the Context Manager hierarchy. We propose a set of objective and subjective metrics to measure the relevance of the different contextual information sources. The analysis of our evaluation scenarios shows that the relevance of the short-term information (i.e. the system status) remains pretty stable throughout the dialogue, whereas the dialogue history and the user profile (i.e. the middle-term and the long-term information, respectively) play a complementary role, evolving their usefulness as the dialogue evolves
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