The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform
Günter K. Krieglstein - One of the best experts on this subject based on the ideXlab platform.
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The normalised rim/disc Area Ratio line.
International ophthalmology, 1996Co-Authors: Karl Ulrich Bartz-schmidt, Christian P. Jonescu-cuypers, Gabriele Thumann, Juliane Frucht, Andrea Sengersdorf, Ralf-dieter Hilgers, Günter K. KrieglsteinAbstract:The assessment of the cup of the optic disc depends, among other criteria, on the disc Area. A small cup in a small optic disc can indicate an advanced glaucomatous lesion, on the other hand a large cup in a large optic disc can be normal. Therefore, an individual normalised rim/disc Area Ratio line together with the curves of 50th percentile and the 95th percentile of normal could help to better distinguish between glaucomatous and normal optic cups. The aim of our study was to calculate and to evaluate such a normalised rim/disc Area Ratio line. Heidelberg Retina Tomograph examinations of the optic nerve head of 100 randomly selected eyes of 100 normal subjects were evaluated. We calculated the disc Area adjusted rim/disc Area Ratio in sectors of 10 degree. The 95th percentile and the 50th percentile of each of the 36 sectors were calculated. Based on these normal percentile lines it was possible to display an individual normalised rim/disc Area Ratio line in the topographic images of an individual optic disc examination. Here we demonstrated examples of a normal optic disc, optic nerve heads with moderate and advanced lesions and a small optic disc with glaucomatous damage. We present a new display mode of the results of Heidelberg Retina Tomograph optic nerve head examination, which may be helpful for an easy and reliable assessment of glaucomatous optic nerve head damage only looking at topographic images.
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The cumulative normalised rim/disc Area Ratio curve
Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie, 1996Co-Authors: Karl Ulrich Bartz-schmidt, Andrea Sengersdorf, Ralf-dieter Hilgers, Peter Esser, Peter Walter, Günter K. KrieglsteinAbstract:The assessment of the cup of the optic disc depends, among other criteria, on the disc Area. A small cup in a small optic disc can indicate an advanced glaucomatous lesion, while on the other hand a large cup in a large optic disc can be normal. Therefore, a cumulative normalised rim/disc Area Ratio curve could help to distinguish between glaucomatous and normal optic cups. The aim of our study was to calculate normalised rim/disc Area Ratio curve. Heidelberg Retina Tomograph examinations of the optic nerve head of 100 randomly selected eyes of 100 normal subjects were evaluated. We calculated the disc Area-adjusted normalised rim/disc Area Ratio in sectors of 10 degrees. The 95th, 90th and 50th percentiles of each of the 36 sectors were displayed in descending order. In relation to the normal percentile curves, it is possible to display an individual normalised rim/disc Area Ratio curve. We obtained such curves for a normal optic disc, optic nerve heads with moderate and advanced lesions and a small optic disc with glaucomatous damage. We present a new display mode for the results of Heidelberg Retina Tomograph optic nerve head examination, which may be helpful for easy and reliable assessment of the local, diffuse and combined components of glaucomatous optic nerve head damage depending on optic disc size.
S. A. Kha - One of the best experts on this subject based on the ideXlab platform.
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optimization of Area Ratio and thrust in suddenly expanded flow at supersonic mach numbers
Case Studies in Thermal Engineering, 2018Co-Authors: K. A. Patha, P. S. Dabee, S. A. KhaAbstract:Abstract In this investigation the flow field has been computed by the numerical approach using Computational Fluid Dynamics (CFD) Analysis to investigate the efficacy of the supersonic Mach numbers due to the flow from supersonic nozzle exhausted in a larger circular duct and the corresponding thrust force created due assess the flow development in the circular pipe, its measurement and the magnitude. For this study the nozzles were modeled using academic licensed ANSYS Workbench software. The nozzles were modeled for the Mach numbers 1.5, 2.0 and 2.5. The flow from the nozzles was numerically simulated for nozzle pressure Ratios (NPRs) in the range from 2 to 8, and the Area Ratios of the study were 2, 4, 6, 8 and 10. The simulation results were compared for geometrical and the kinematical parameters. The results indicate that the pressure in the base corner of enlarged duct is influenced by the level of expansion (i.e. Nozzle pressure Ratio), inertia level (i.e. Mach number) at the nozzle exit and the relief available (i.e. Area Ratio) to the shear layer. If the maximum thrust is the aim then the optimum Area Ratios should be considered. Lower Area Ratio is not suitable for higher NPR and higher Area Ratio is not suitable for lower NPR. The higher Area Ratio provides more space to expand compressed air. Also, the lower Area Ratio will offer minimum base drag. The base drag is strongly influenced by the Area Ratio up to certain limit. If the Area Ratio is again increases then there is no effect of increase in the Area Ratio on the base drag and Thrust. As the Mach number increases for the same Nozzle pressure Ratio and the Area Ratio, the net thrust force also increases. From the obtained results the optimum Area Ratio can be selected to maximize thrust for a given Nozzle pressure Ratio and Mach number.
Karl Ulrich Bartz-schmidt - One of the best experts on this subject based on the ideXlab platform.
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The normalised rim/disc Area Ratio line.
International ophthalmology, 1996Co-Authors: Karl Ulrich Bartz-schmidt, Christian P. Jonescu-cuypers, Gabriele Thumann, Juliane Frucht, Andrea Sengersdorf, Ralf-dieter Hilgers, Günter K. KrieglsteinAbstract:The assessment of the cup of the optic disc depends, among other criteria, on the disc Area. A small cup in a small optic disc can indicate an advanced glaucomatous lesion, on the other hand a large cup in a large optic disc can be normal. Therefore, an individual normalised rim/disc Area Ratio line together with the curves of 50th percentile and the 95th percentile of normal could help to better distinguish between glaucomatous and normal optic cups. The aim of our study was to calculate and to evaluate such a normalised rim/disc Area Ratio line. Heidelberg Retina Tomograph examinations of the optic nerve head of 100 randomly selected eyes of 100 normal subjects were evaluated. We calculated the disc Area adjusted rim/disc Area Ratio in sectors of 10 degree. The 95th percentile and the 50th percentile of each of the 36 sectors were calculated. Based on these normal percentile lines it was possible to display an individual normalised rim/disc Area Ratio line in the topographic images of an individual optic disc examination. Here we demonstrated examples of a normal optic disc, optic nerve heads with moderate and advanced lesions and a small optic disc with glaucomatous damage. We present a new display mode of the results of Heidelberg Retina Tomograph optic nerve head examination, which may be helpful for an easy and reliable assessment of glaucomatous optic nerve head damage only looking at topographic images.
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The cumulative normalised rim/disc Area Ratio curve
Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie, 1996Co-Authors: Karl Ulrich Bartz-schmidt, Andrea Sengersdorf, Ralf-dieter Hilgers, Peter Esser, Peter Walter, Günter K. KrieglsteinAbstract:The assessment of the cup of the optic disc depends, among other criteria, on the disc Area. A small cup in a small optic disc can indicate an advanced glaucomatous lesion, while on the other hand a large cup in a large optic disc can be normal. Therefore, a cumulative normalised rim/disc Area Ratio curve could help to distinguish between glaucomatous and normal optic cups. The aim of our study was to calculate normalised rim/disc Area Ratio curve. Heidelberg Retina Tomograph examinations of the optic nerve head of 100 randomly selected eyes of 100 normal subjects were evaluated. We calculated the disc Area-adjusted normalised rim/disc Area Ratio in sectors of 10 degrees. The 95th, 90th and 50th percentiles of each of the 36 sectors were displayed in descending order. In relation to the normal percentile curves, it is possible to display an individual normalised rim/disc Area Ratio curve. We obtained such curves for a normal optic disc, optic nerve heads with moderate and advanced lesions and a small optic disc with glaucomatous damage. We present a new display mode for the results of Heidelberg Retina Tomograph optic nerve head examination, which may be helpful for easy and reliable assessment of the local, diffuse and combined components of glaucomatous optic nerve head damage depending on optic disc size.
K. A. Patha - One of the best experts on this subject based on the ideXlab platform.
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optimization of Area Ratio and thrust in suddenly expanded flow at supersonic mach numbers
Case Studies in Thermal Engineering, 2018Co-Authors: K. A. Patha, P. S. Dabee, S. A. KhaAbstract:Abstract In this investigation the flow field has been computed by the numerical approach using Computational Fluid Dynamics (CFD) Analysis to investigate the efficacy of the supersonic Mach numbers due to the flow from supersonic nozzle exhausted in a larger circular duct and the corresponding thrust force created due assess the flow development in the circular pipe, its measurement and the magnitude. For this study the nozzles were modeled using academic licensed ANSYS Workbench software. The nozzles were modeled for the Mach numbers 1.5, 2.0 and 2.5. The flow from the nozzles was numerically simulated for nozzle pressure Ratios (NPRs) in the range from 2 to 8, and the Area Ratios of the study were 2, 4, 6, 8 and 10. The simulation results were compared for geometrical and the kinematical parameters. The results indicate that the pressure in the base corner of enlarged duct is influenced by the level of expansion (i.e. Nozzle pressure Ratio), inertia level (i.e. Mach number) at the nozzle exit and the relief available (i.e. Area Ratio) to the shear layer. If the maximum thrust is the aim then the optimum Area Ratios should be considered. Lower Area Ratio is not suitable for higher NPR and higher Area Ratio is not suitable for lower NPR. The higher Area Ratio provides more space to expand compressed air. Also, the lower Area Ratio will offer minimum base drag. The base drag is strongly influenced by the Area Ratio up to certain limit. If the Area Ratio is again increases then there is no effect of increase in the Area Ratio on the base drag and Thrust. As the Mach number increases for the same Nozzle pressure Ratio and the Area Ratio, the net thrust force also increases. From the obtained results the optimum Area Ratio can be selected to maximize thrust for a given Nozzle pressure Ratio and Mach number.
Andrea Sengersdorf - One of the best experts on this subject based on the ideXlab platform.
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The normalised rim/disc Area Ratio line.
International ophthalmology, 1996Co-Authors: Karl Ulrich Bartz-schmidt, Christian P. Jonescu-cuypers, Gabriele Thumann, Juliane Frucht, Andrea Sengersdorf, Ralf-dieter Hilgers, Günter K. KrieglsteinAbstract:The assessment of the cup of the optic disc depends, among other criteria, on the disc Area. A small cup in a small optic disc can indicate an advanced glaucomatous lesion, on the other hand a large cup in a large optic disc can be normal. Therefore, an individual normalised rim/disc Area Ratio line together with the curves of 50th percentile and the 95th percentile of normal could help to better distinguish between glaucomatous and normal optic cups. The aim of our study was to calculate and to evaluate such a normalised rim/disc Area Ratio line. Heidelberg Retina Tomograph examinations of the optic nerve head of 100 randomly selected eyes of 100 normal subjects were evaluated. We calculated the disc Area adjusted rim/disc Area Ratio in sectors of 10 degree. The 95th percentile and the 50th percentile of each of the 36 sectors were calculated. Based on these normal percentile lines it was possible to display an individual normalised rim/disc Area Ratio line in the topographic images of an individual optic disc examination. Here we demonstrated examples of a normal optic disc, optic nerve heads with moderate and advanced lesions and a small optic disc with glaucomatous damage. We present a new display mode of the results of Heidelberg Retina Tomograph optic nerve head examination, which may be helpful for an easy and reliable assessment of glaucomatous optic nerve head damage only looking at topographic images.
-
The cumulative normalised rim/disc Area Ratio curve
Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie, 1996Co-Authors: Karl Ulrich Bartz-schmidt, Andrea Sengersdorf, Ralf-dieter Hilgers, Peter Esser, Peter Walter, Günter K. KrieglsteinAbstract:The assessment of the cup of the optic disc depends, among other criteria, on the disc Area. A small cup in a small optic disc can indicate an advanced glaucomatous lesion, while on the other hand a large cup in a large optic disc can be normal. Therefore, a cumulative normalised rim/disc Area Ratio curve could help to distinguish between glaucomatous and normal optic cups. The aim of our study was to calculate normalised rim/disc Area Ratio curve. Heidelberg Retina Tomograph examinations of the optic nerve head of 100 randomly selected eyes of 100 normal subjects were evaluated. We calculated the disc Area-adjusted normalised rim/disc Area Ratio in sectors of 10 degrees. The 95th, 90th and 50th percentiles of each of the 36 sectors were displayed in descending order. In relation to the normal percentile curves, it is possible to display an individual normalised rim/disc Area Ratio curve. We obtained such curves for a normal optic disc, optic nerve heads with moderate and advanced lesions and a small optic disc with glaucomatous damage. We present a new display mode for the results of Heidelberg Retina Tomograph optic nerve head examination, which may be helpful for easy and reliable assessment of the local, diffuse and combined components of glaucomatous optic nerve head damage depending on optic disc size.
