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Search Results: 1 - 10 of 305777 matches for " F. G. Schmitt "
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Scaling properties of pH fluctuations in coastal waters of the English Channel: pH as a turbulent active scalar
S. B. Zongo,F. G. Schmitt
Nonlinear Processes in Geophysics (NPG) , 2011,
Abstract: We consider here pH and temperature fluctuations in marine waters, recorded at fixed points using high resolution automatic devices. We analyze time series coming from 4 monitoring stations located along French coast: one station is situated in the coastal area off Boulogne-sur-mer (Eastern English Channel) and 3 stations in the Bay of Seine. All these pH time series reveal large fluctuations at all scales similar to turbulent temperature fluctuations. We compare the pH and temperature time series through Fourier spectral analysis methods: spectra, compensated spectra, cospectra. We find good scaling properties of pH fluctuations, with power spectral slopes close to 1.5 for marine stations and 1.2 for the estuarine station. These analyses show that pH fluctuations in marine waters are strongly influenced by turbulent hydrodynamical transport, and may be considered as a turbulent active scalar.
Effect of variable winds on current structure and Reynolds stresses in a tidal flow: analysis of experimental data in the Eastern English Channel
K. A. Korotenko,A. V. Sentchev,F. G. Schmitt
Ocean Science Discussions (OSD) , 2012, DOI: 10.5194/osd-9-2215-2012
Abstract: Wind and wave effects on tidal current structure and turbulence throughout the water column are examined using an upward-looking acoustic Doppler current profiler (ADCP). The instrument has been deployed on the seafloor of 20-m depth, off the North-Eastern French coast in the Eastern English Channel over 12 tidal cycles and covered the period of the transition from mean spring to neap tide and forcing regimes varied from calm to moderate storm conditions. During storms, we observed gusty winds with magnitude reached 15 m s 1 and wave height reached up to 1.3 m. Analysis of velocity spectra revealed a noticeable contribution of wind-induced waves to spectral structure of velocity fluctuations within the upper 10-m layer. Near the surface, stormy winds and waves produced a significant intensification of velocity fluctuations, particularly when the sustained wind blew against the ebb tide flow. As during wavy periods the variance-derived Reynolds stress estimates might include a wave-induced contamination, we applied the Variance Fit method to obtain unbiased stresses and other turbulent quantities. Over calm periods, the turbulent quantities usually decreased with height above the seabed. The stresses were found to vary regularly with the predominantly semidiurnal tidal flow, with the along-shore stress being generally greater during the flood flow (~2.7 Pa) than during the ebb flow (~ 0.6 Pa). The turbulent kinetic energy production rate, P, and eddy viscosity, Az}, followed a nearly regular cycle with close to a quarter-diurnal period. As for the stresses, near the seabed, we found the maximum values of estimated quantities of P and Az to be 0.1 W m 3 and 0.5 m2 s 1, respectively, during the flood flow. Over the storm periods, we found the highest stress values (~ 2 Pa) during ebb when tidal currents were opposite to the southwesterly winds while, during the flood, the surface stresses slightly exceeded those estimated for a calm period.
Effect of variable winds on current structure and Reynolds stresses in a tidal flow: analysis of experimental data in the eastern English Channel
K. A. Korotenko,A. V. Sentchev,F. G. Schmitt
Ocean Science (OS) & Discussions (OSD) , 2012, DOI: 10.5194/os-8-1025-2012
Abstract: Wind and wave effects on tidal current structure and turbulence throughout the water column are examined using an upward-looking acoustic Doppler current profiler (ADCP). The instrument has been deployed on the seafloor of 18-m mean depth, off the north-eastern French coast in the eastern English Channel, over 12 tidal cycles, and covered the period of the transition from mean spring to neap tide, and forcing regimes varied from calm to moderate storm conditions. During storms, we observed gusty winds with magnitudes reaching 15 m s 1 and wave heights reaching up to 1.3 m. Analysis of velocity spectra revealed a noticeable contribution of wind-induced waves to spectral structure of velocity fluctuations within the subsurface layer. Near the surface, stormy winds and waves produced a significant intensification of velocity fluctuations, particularly when the sustained wind blew against the ebb tide flow. As during wavy periods, the variance-derived Reynolds stress estimates might include a wave-induced contamination, we applied the Variance Fit method to obtain unbiased stresses and other turbulent quantities. Over calm periods, the turbulent quantities usually decreased with height above the seabed. The stresses were found to vary regularly with the predominantly semidiurnal tidal flow. The along-shore stress being generally greater during the flood flow (~2.7 Pa) than during the ebb flow (~ 0.6 Pa). The turbulent kinetic energy production rate, P, and eddy viscosity, Az, followed a nearly regular cycle with close to a quarter-diurnal period. As for the stresses, near the seabed, we found the maximum values of estimated quantities of P and Az to be 0.1 Wm 3 and 0.5 m2 s 1, respectively, during the flood flow. Over the storm periods, we found the highest unbiased stress values (~ 2.6 Pa) during ebb when tidal currents were opposite to the southwesterly winds while, during the flood, the surface stresses slightly exceeded those estimated for a calm period. A comparison of obtained results gives a good agreement with those of other researchers working on direct measurements of turbulence in tidal flows.
Invasive micropapillary carcinoma of the dog mammary gland: a case report
Cassali, G.D.;Serakides, R.;G?rtner, F.;Schmitt, F.C.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2002, DOI: 10.1590/S0102-09352002000400006
Abstract: this report describes the morphological and immunohistochemical findings of two cases of breast invasive micropapillary carcinoma occurring in dogs. histologically, the tumors are characterized by the presence of numerous irregular cystic formations filled out with nests of epithelial cells that exhibit a micropapillary pattern. these morphological features are characteristic of invasive micropapillary carcinoma in woman, a breast tumor not previously described in dogs.
Pleomorphic lobular carcinoma of the canine mammary gland: histopathologic and immunohistochemical features
Cassali, G.D.;G?rtner, F.;Schmitt, F.C.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2002, DOI: 10.1590/S0102-09352002000600006
Abstract: this report describes the morphological and immunohistochemical findings of a case of mammary gland pleomorphic lobular carcinoma occurring in the canine species. histologically, it was characterized by the presence of tumor cells loosely dispersed in the stroma or arranged in a linear pattern showing relatively abundant eosinophilic cytoplasm with an eccentric nuclei. these morphological features, characteristic of pleomorphic mammary gland lobular carcinoma in woman, were not previously described in dogs.
Pleomorphic lobular carcinoma of the canine mammary gland: histopathologic and immunohistochemical features
Cassali G.D.,G?rtner F.,Schmitt F.C.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2002,
Abstract: This report describes the morphological and immunohistochemical findings of a case of mammary gland pleomorphic lobular carcinoma occurring in the canine species. Histologically, it was characterized by the presence of tumor cells loosely dispersed in the stroma or arranged in a linear pattern showing relatively abundant eosinophilic cytoplasm with an eccentric nuclei. These morphological features, characteristic of pleomorphic mammary gland lobular carcinoma in woman, were not previously described in dogs.
Invasive micropapillary carcinoma of the dog mammary gland: a case report
Cassali G.D.,Serakides R.,G?rtner F.,Schmitt F.C.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2002,
Abstract: This report describes the morphological and immunohistochemical findings of two cases of breast invasive micropapillary carcinoma occurring in dogs. Histologically, the tumors are characterized by the presence of numerous irregular cystic formations filled out with nests of epithelial cells that exhibit a micropapillary pattern. These morphological features are characteristic of invasive micropapillary carcinoma in woman, a breast tumor not previously described in dogs.
Protocol for the anatomopathological examination of canine mammary tumors
Ferreira, E.;Bregunci, G.C.;Schmitt, F.C.;Cassali, G.D.;
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2003, DOI: 10.1590/S0102-09352003000100017
Abstract: foi elaborado um protocolo para exame anatomopatológico de tumores de mama em c?es, constituído de três partes: requisi??o, exame clínico e laudo histopatológico. o exame clínico contém dados sobre a descri??o macroscópica da les?o. o laudo histopatológico constituiu-se de campos para descri??o microscópica pormenorizada das les?es e classifica??o da principal les?o observada. a elabora??o do protocolo tem como objetivo estabelecer critérios para estudos e pesquisas sobre neoplasias mamárias em animais e auxiliar no diagnóstico e prognóstico de les?es mamárias.
Protocol for the anatomopathological examination of canine mammary tumors
Ferreira E.,Bregunci G.C.,Schmitt F.C.,Cassali G.D.
Arquivo Brasileiro de Medicina Veterinária e Zootecnia , 2003,
Abstract: Foi elaborado um protocolo para exame anatomopatológico de tumores de mama em c es, constituído de três partes: requisi o, exame clínico e laudo histopatológico. O exame clínico contém dados sobre a descri o macroscópica da les o. O laudo histopatológico constituiu-se de campos para descri o microscópica pormenorizada das les es e classifica o da principal les o observada. A elabora o do protocolo tem como objetivo estabelecer critérios para estudos e pesquisas sobre neoplasias mamárias em animais e auxiliar no diagnóstico e prognóstico de les es mamárias.
Spreading out Muscle Mass within a Hill-Type Model: A Computer Simulation Study
Michael Günther,Oliver R?hrle,Daniel F. B. Haeufle,Syn Schmitt
Computational and Mathematical Methods in Medicine , 2012, DOI: 10.1155/2012/848630
Abstract: It is state of the art that muscle contraction dynamics is adequately described by a hyperbolic relation between muscle force and contraction velocity (Hill relation), thereby neglecting muscle internal mass inertia (first-order dynamics). Accordingly, the vast majority of modelling approaches also neglect muscle internal inertia. Assuming that such first-order contraction dynamics yet interacts with muscle internal mass distribution, this study investigates two questions: (i) what is the time scale on which the muscle responds to a force step? (ii) How does this response scale with muscle design parameters? Thereto, we simulated accelerated contractions of alternating sequences of Hill-type contractile elements and point masses. We found that in a typical small muscle the force levels off after about 0.2?ms, contraction velocity after about 0.5?ms. In an upscaled version representing bigger mammals' muscles, the force levels off after about 20?ms, and the theoretically expected maximum contraction velocity is not reached. We conclude (i) that it may be indispensable to introduce second-order contributions into muscle models to understand high-frequency muscle responses, particularly in bigger muscles. Additionally, (ii) constructing more elaborate measuring devices seems to be worthwhile to distinguish viscoelastic and inertia properties in rapid contractile responses of muscles. 1. Introduction In case the force-velocity relation of a muscle (usually hyperbolic [1]: the Hill relation) is interpreted as a force law and coupled to inertia loads as, for example, in computer models of musculoskeletal multibody systems, it adds first-order dynamics to the systems’ mechanical equations of motion. Usually, the force-velocity relations of a specific isolated muscle preparation (according to [2–4]: earliest known experiments by Jan Swammerdam around 1663; later: e.g., [1, 5–19]) or lumped-muscle assemblies (e.g., [20–22]) are determined through isotonic (e.g., [10, 13, 18]) or isokinetic (e.g., [7, 10, 16, 17]) contractions or by accelerating external inertia loads (e.g., [20, 21]). In the isokinetic condition, a potential external inertia load would be nonaccelerated, whereas the muscle internal velocity distribution could not yet be guaranteed to have cancelled out (maybe internally and locally accelerated). Hypothesising that the muscle consists internally of just two parts arranged in series, the contractile element (CE) and the serial (visco-)elastic element (SEE), the isotonic condition is often chosen to separate an assumed subsequent steady-state
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