The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
R. L. Wang - One of the best experts on this subject based on the ideXlab platform.
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A new kinematics for ultra precision grinding of Conical Surfaces using a rotary table and a cup wheel
International Journal of Machine Tools & Manufacture, 2012Co-Authors: G. Feng, Renke Kang, R. L. WangAbstract:Abstract This paper reports a new kinematics for ultra precision grinding of Conical Surfaces. It uses a rotary table and a cup wheel to perform an infeed grinding. Its principle is that the generating curve of the grinding wheel is locally flat and the locally flat portion can be approximated by a sloping line segment if the machine configuration parameters such as the wheel radius, the center distance between the rotary table and the wheel, the wheel inclination angle and the rotary table direction angle are properly selected. A model for the conicity error of the generated Surface was developed. An algorithm for the selection of the desired values of the machine configuration parameters to grind Conical Surfaces was proposed. It was found that the minimum theoretical conicity error is extremely small for narrow Conical Surface or Conical Surface with shallow radial inclination angle. It is expected to be an efficient method to manufacture the Conical Surfaces of machine parts, mechanical sealing components and optical devices with high form accuracy, low Surface roughness and low subSurface damage.
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A new kinematics for ultra precision grinding of Conical Surfaces using a rotary table and a cup wheel
International Journal of Machine Tools and Manufacture, 2012Co-Authors: F. W. Huo, R.-K. Kang, D. M. Guo, G. Feng, R. L. WangAbstract:This paper reports a new kinematics for ultra precision grinding of Conical Surfaces. It uses a rotary table and a cup wheel to perform an infeed grinding. Its principle is that the generating curve of the grinding wheel is locally flat and the locally flat portion can be approximated by a sloping line segment if the machine configuration parameters such as the wheel radius, the center distance between the rotary table and the wheel, the wheel inclination angle and the rotary table direction angle are properly selected. A model for the conicity error of the generated Surface was developed. An algorithm for the selection of the desired values of the machine configuration parameters to grind Conical Surfaces was proposed. It was found that the minimum theoretical conicity error is extremely small for narrow Conical Surface or Conical Surface with shallow radial inclination angle. It is expected to be an efficient method to manufacture the Conical Surfaces of machine parts, mechanical sealing components and optical devices with high form accuracy, low Surface roughness and low subSurface damage. © 2012 Elsevier Ltd. All rights reserved.
Ludwig Plasswilm - One of the best experts on this subject based on the ideXlab platform.
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Surface dose characterisation of the Varian Ir-192 HDR Conical Surface applicator set with a vertically orientated source
Strahlentherapie und Onkologie, 2014Co-Authors: Konrad Buchauer, Guido Henke, H. Schiefer, Ludwig PlasswilmAbstract:Background Conical Surface applicators with an Ir-192 high-dose-rate brachytherapy source are a common modality for the treatment of non-melanomatous skin cancer with high tumour control rates. Surface dose characterisation of the Varian Varisource GammaMed+ IX afterloader vertical type Surface applicators is performed two dimensionally using high-resolution film dosimetry. Aim The focus of this study was to determine if Varian Surface applicators with a vertical source suffer from the dose distribution irregularities reported for comparable applicators. Our goal was to evaluate if the irregularities found affected treatment and dose output verification procedures. Methods Ionisation chamber-based verification of applicator output was established according to guidelines provided by the manufacturer. For additional measurement of Surface dose Gafchromic EBT3 film dosimetry was used. The term “therapeutic dose” was defined as 85 % of the prescribed dose level. Results For the 10 different applicator inserts evaluated, cold spots were observed. Mean cold spot size was 2.0 mm × 3.6 mm (± 0.6 mm). The cold spots were dosimetrically well below 85 % of the prescribed dose. The cold spot was situated 2.2 mm (1.4–2.7 mm) unilaterally from the central axis and caused general asymmetry in the dose profiles intersecting the cold spot area. A source tilt of approximately 8° (± 1°) was determined for the source used for irradiation. Conclusions A central underdosed area exceeding 15 % of the prescribed dose has not been previously reported. Source tilt was observed and found to affect clinical use and possibly treatment outcome in applicators using a vertically arranged source. Surface applicators with a vertically orientated source were subject to dose irregularities that could impact on chamber-based applicator output verification procedures. We recommend film dosimetry-backed applicator commissioning to avoid systematic errors. Hintergrund Konische Oberflächenapplikatoren sind ein etabliertes Mittel um mit Ir-192 HDR-Brachytherapie nichtmelanomatöse Hautkrebserkrankungen mit hohen Tumorkontrollraten zu behandeln. In dieser Arbeit wird eine hochauflösende Analyse der Oberflächendosis eines Varian-Varisource-GammaMed+ IX-Afterloader-Konus-Applikatorsatzes des vertikalen Typs dargestellt. Ziel der Arbeit Analyse der Oberflächendosisverteilung des Applikatorsatzes im Hinblick auf Unregelmäßigkeiten, die für ähnliche Applikatoren bereits berichtet wurden. Weiterhin wird untersucht, ob Applikatoren des vertikalen Typs zusätzliche Verfahren als Ergänzung der aktuell vorgeschlagenen Methoden zur Verifikation des Dosisoutputs von konischen Oberflächenapplikatoren benötigen. Methoden Die Verifikation der absoluten Dosis wird nach Herstellerangaben durchgeführt. Die Dosisverteilung an der Oberfläche wird zusätzlich mit Gafchromic-EBT3-Filmdosimetrie bestimmt. Der Begriff „therapeutische Dosis“ ist in dieser Arbeit mit 85 % der verschriebenen Dosis definiert. Ergebnisse Zehn ausgewertete Applikatoren zeigen Unterdosierungen in der Applikatormitte, mit einer mittlere Größe von 2,0 mm × 3,6 mm (± 0,6 mm), dosimetrisch deutlich unter 85 % der verschriebenen Dosis. Die Unterdosierung liegt 2,2 mm (1,4–2,7 mm) seitlich der Zentralachse und verursacht eine generelle Asymmetrie in der Dosisverteilung. Ein Schiefstand von 8° (± 1°) wurde für die verwendete Quelle bestimmt. Schlussfolgerung Eine um mehr als 15 % reduzierte Dosis in der Applikatormitte wurde bei Oberflächenapplikatoren bislang nicht berichtet. Quellenschiefstand wurde als Parameter identifiziert, der die Handhabung dieser Oberflächenapplikatoren und möglicherweise den Therapieerfolg beeinflussen kann. Das beschriebene kleinräumige Dosisartefakt kann systematischen Einfluss auf kammerbasierte Dosisverifikationsverfahren haben. Wir empfehlen daher bei der Applikatorkommissionierung eine zusätzliche Absicherung mit Filmdosimetrie.
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Surface dose characterisation of the Varian Ir-192 HDR Conical Surface applicator set with a vertically orientated source
Strahlentherapie Und Onkologie, 2014Co-Authors: Konrad Buchauer, Guido Henke, H. Schiefer, Ludwig PlasswilmAbstract:Background Conical Surface applicators with an Ir-192 high-dose-rate brachytherapy source are a common modality for the treatment of non-melanomatous skin cancer with high tumour control rates. Surface dose characterisation of the Varian Varisource GammaMed+ IX afterloader vertical type Surface applicators is performed two dimensionally using high-resolution film dosimetry.
F. W. Huo - One of the best experts on this subject based on the ideXlab platform.
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A new kinematics for ultra precision grinding of Conical Surfaces using a rotary table and a cup wheel
International Journal of Machine Tools and Manufacture, 2012Co-Authors: F. W. Huo, R.-K. Kang, D. M. Guo, G. Feng, R. L. WangAbstract:This paper reports a new kinematics for ultra precision grinding of Conical Surfaces. It uses a rotary table and a cup wheel to perform an infeed grinding. Its principle is that the generating curve of the grinding wheel is locally flat and the locally flat portion can be approximated by a sloping line segment if the machine configuration parameters such as the wheel radius, the center distance between the rotary table and the wheel, the wheel inclination angle and the rotary table direction angle are properly selected. A model for the conicity error of the generated Surface was developed. An algorithm for the selection of the desired values of the machine configuration parameters to grind Conical Surfaces was proposed. It was found that the minimum theoretical conicity error is extremely small for narrow Conical Surface or Conical Surface with shallow radial inclination angle. It is expected to be an efficient method to manufacture the Conical Surfaces of machine parts, mechanical sealing components and optical devices with high form accuracy, low Surface roughness and low subSurface damage. © 2012 Elsevier Ltd. All rights reserved.
G. Feng - One of the best experts on this subject based on the ideXlab platform.
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A new kinematics for ultra precision grinding of Conical Surfaces using a rotary table and a cup wheel
International Journal of Machine Tools & Manufacture, 2012Co-Authors: G. Feng, Renke Kang, R. L. WangAbstract:Abstract This paper reports a new kinematics for ultra precision grinding of Conical Surfaces. It uses a rotary table and a cup wheel to perform an infeed grinding. Its principle is that the generating curve of the grinding wheel is locally flat and the locally flat portion can be approximated by a sloping line segment if the machine configuration parameters such as the wheel radius, the center distance between the rotary table and the wheel, the wheel inclination angle and the rotary table direction angle are properly selected. A model for the conicity error of the generated Surface was developed. An algorithm for the selection of the desired values of the machine configuration parameters to grind Conical Surfaces was proposed. It was found that the minimum theoretical conicity error is extremely small for narrow Conical Surface or Conical Surface with shallow radial inclination angle. It is expected to be an efficient method to manufacture the Conical Surfaces of machine parts, mechanical sealing components and optical devices with high form accuracy, low Surface roughness and low subSurface damage.
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A new kinematics for ultra precision grinding of Conical Surfaces using a rotary table and a cup wheel
International Journal of Machine Tools and Manufacture, 2012Co-Authors: F. W. Huo, R.-K. Kang, D. M. Guo, G. Feng, R. L. WangAbstract:This paper reports a new kinematics for ultra precision grinding of Conical Surfaces. It uses a rotary table and a cup wheel to perform an infeed grinding. Its principle is that the generating curve of the grinding wheel is locally flat and the locally flat portion can be approximated by a sloping line segment if the machine configuration parameters such as the wheel radius, the center distance between the rotary table and the wheel, the wheel inclination angle and the rotary table direction angle are properly selected. A model for the conicity error of the generated Surface was developed. An algorithm for the selection of the desired values of the machine configuration parameters to grind Conical Surfaces was proposed. It was found that the minimum theoretical conicity error is extremely small for narrow Conical Surface or Conical Surface with shallow radial inclination angle. It is expected to be an efficient method to manufacture the Conical Surfaces of machine parts, mechanical sealing components and optical devices with high form accuracy, low Surface roughness and low subSurface damage. © 2012 Elsevier Ltd. All rights reserved.
Konrad Buchauer - One of the best experts on this subject based on the ideXlab platform.
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Surface dose characterisation of the Varian Ir-192 HDR Conical Surface applicator set with a vertically orientated source
Strahlentherapie und Onkologie, 2014Co-Authors: Konrad Buchauer, Guido Henke, H. Schiefer, Ludwig PlasswilmAbstract:Background Conical Surface applicators with an Ir-192 high-dose-rate brachytherapy source are a common modality for the treatment of non-melanomatous skin cancer with high tumour control rates. Surface dose characterisation of the Varian Varisource GammaMed+ IX afterloader vertical type Surface applicators is performed two dimensionally using high-resolution film dosimetry. Aim The focus of this study was to determine if Varian Surface applicators with a vertical source suffer from the dose distribution irregularities reported for comparable applicators. Our goal was to evaluate if the irregularities found affected treatment and dose output verification procedures. Methods Ionisation chamber-based verification of applicator output was established according to guidelines provided by the manufacturer. For additional measurement of Surface dose Gafchromic EBT3 film dosimetry was used. The term “therapeutic dose” was defined as 85 % of the prescribed dose level. Results For the 10 different applicator inserts evaluated, cold spots were observed. Mean cold spot size was 2.0 mm × 3.6 mm (± 0.6 mm). The cold spots were dosimetrically well below 85 % of the prescribed dose. The cold spot was situated 2.2 mm (1.4–2.7 mm) unilaterally from the central axis and caused general asymmetry in the dose profiles intersecting the cold spot area. A source tilt of approximately 8° (± 1°) was determined for the source used for irradiation. Conclusions A central underdosed area exceeding 15 % of the prescribed dose has not been previously reported. Source tilt was observed and found to affect clinical use and possibly treatment outcome in applicators using a vertically arranged source. Surface applicators with a vertically orientated source were subject to dose irregularities that could impact on chamber-based applicator output verification procedures. We recommend film dosimetry-backed applicator commissioning to avoid systematic errors. Hintergrund Konische Oberflächenapplikatoren sind ein etabliertes Mittel um mit Ir-192 HDR-Brachytherapie nichtmelanomatöse Hautkrebserkrankungen mit hohen Tumorkontrollraten zu behandeln. In dieser Arbeit wird eine hochauflösende Analyse der Oberflächendosis eines Varian-Varisource-GammaMed+ IX-Afterloader-Konus-Applikatorsatzes des vertikalen Typs dargestellt. Ziel der Arbeit Analyse der Oberflächendosisverteilung des Applikatorsatzes im Hinblick auf Unregelmäßigkeiten, die für ähnliche Applikatoren bereits berichtet wurden. Weiterhin wird untersucht, ob Applikatoren des vertikalen Typs zusätzliche Verfahren als Ergänzung der aktuell vorgeschlagenen Methoden zur Verifikation des Dosisoutputs von konischen Oberflächenapplikatoren benötigen. Methoden Die Verifikation der absoluten Dosis wird nach Herstellerangaben durchgeführt. Die Dosisverteilung an der Oberfläche wird zusätzlich mit Gafchromic-EBT3-Filmdosimetrie bestimmt. Der Begriff „therapeutische Dosis“ ist in dieser Arbeit mit 85 % der verschriebenen Dosis definiert. Ergebnisse Zehn ausgewertete Applikatoren zeigen Unterdosierungen in der Applikatormitte, mit einer mittlere Größe von 2,0 mm × 3,6 mm (± 0,6 mm), dosimetrisch deutlich unter 85 % der verschriebenen Dosis. Die Unterdosierung liegt 2,2 mm (1,4–2,7 mm) seitlich der Zentralachse und verursacht eine generelle Asymmetrie in der Dosisverteilung. Ein Schiefstand von 8° (± 1°) wurde für die verwendete Quelle bestimmt. Schlussfolgerung Eine um mehr als 15 % reduzierte Dosis in der Applikatormitte wurde bei Oberflächenapplikatoren bislang nicht berichtet. Quellenschiefstand wurde als Parameter identifiziert, der die Handhabung dieser Oberflächenapplikatoren und möglicherweise den Therapieerfolg beeinflussen kann. Das beschriebene kleinräumige Dosisartefakt kann systematischen Einfluss auf kammerbasierte Dosisverifikationsverfahren haben. Wir empfehlen daher bei der Applikatorkommissionierung eine zusätzliche Absicherung mit Filmdosimetrie.
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Surface dose characterisation of the Varian Ir-192 HDR Conical Surface applicator set with a vertically orientated source
Strahlentherapie Und Onkologie, 2014Co-Authors: Konrad Buchauer, Guido Henke, H. Schiefer, Ludwig PlasswilmAbstract:Background Conical Surface applicators with an Ir-192 high-dose-rate brachytherapy source are a common modality for the treatment of non-melanomatous skin cancer with high tumour control rates. Surface dose characterisation of the Varian Varisource GammaMed+ IX afterloader vertical type Surface applicators is performed two dimensionally using high-resolution film dosimetry.