Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 67 for “"PTV"”.
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Geometrische und stochastische Modelle zur Optimierung der Leistungsfähigkeit des Strömungsmessverfahrens 3D-PTV
Die 3D Particle Tracking Velocimetry (3D PTV) ist eine Methode zur bildbasierten Bestimmung von Geschwindigkeitsfeldern in Gas- oder Flüssigkeitsströmungen. Dazu wird die Strömung mit Partikeln markiert und durch ein Mehrkamerasystem beobachtet. Das Ergebnis der Datenauswertung sind 3D Trajektorien …
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Fabrication of PtNi and PtV near-surface alloys as improved catalysts for proton exchange membrane hydrogen fuel cells
… of platinum nickel (PtNi) and platinum vanadium (PtV) near-surface alloys (NSAs) for use as improved catalysts in proton exchange membrane hydrogen fuel cells. The need for this study arose in order to further understand the principles behind the predicted catalytic properties of NSAs, to …
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Hubungan antara kecerdasan emosi dengan komitmen Guru Mata Pelajaran Teknik dan Vokasional di Daerah Batu Pahat
… pelajaran Pendidikan Teknikal dan Vokasional (PTV) di daerah Batu Pahat. Selain itu, kajian ini juga bertujuan untuk melihat hubungan antara kecerdasan emosi dan komitmen bagi guru mata pelajaran PTV. Bagi mencapai objektif dan matlamat kajian, kajian ini dijalankan dengan menggunakan tinjauan …
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Three-dimensional particle tracking velocimetry study of marine organism wake behavior
… particle tracking velocimetry (3D-PTV) is a flow measurement technique that tracks Lagrangian trajectories of passive tracer particles using stereoscopic imaging. The technique allows for detailed analysis of the velocities along particle trajectories in unsteady flows. The …
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Evaluation of target motion and determination optional treatment margins for prostate cancer treated with external beam radiotherapy on Halcyon
… target volume (CTV)-planning target volume (PTV) expansion margin was calculated. Patients and Methods Prostate motion was evaluated by comparing prostate position on the planning CT to cone-beam CT (CBCT) scans. Prostate position error in the medio-lateral (ML), antero-posterior (AP) and …
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Determination of an optimal treatment margin for intracranial tumours treated with radiotherapy at Groote Schuur Hospital
… obtaining above mentioned data the ideal CTV-PTV expansion margin was calculated using published CTV-PTV expansion margin recipes. Patients and methods The Electronic Portal Images (EPID) of 20 patients who met the inclusion criteria were compared to their Digitally Reconstructed Radiograph …
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An investigation of phase transformations in Pt-V coating systems
… been investigated. Five Pt- V ordered phases (PtV, PtV 3 , Pt 2 V, Pt 3 V and Pt 8 V) have been previously observed in bulk platinum-vanadium alloys. Phase formation in coatings is expected to be sequential and controlled by the lowest temperature eutectic (liquidus) composition; this allows …
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Investigations into the viral molecular determinants of lethality of Punta Toro virus (Bunyaviridae, phlebovirus) in the Syrian hamster.
Punta Toro virus (PTV) is transmitted by sandlfies (Lutzomyia spp.) in Panama and Northern Columbia and causes an acute febrile illness in humans lasting 2-5 days. Human seroprevalence in regions within Panama have been reported up to 34% in the most easterly region of Darien however little is …
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Development of A Beam-Specific Planning Target Volume and A Robust Plan Analysis to ol For Proton Therapy
… target volume (CTV) to a planning target volume (PTV). However, a PTV alone cannot adequately account for range uncertainties coupled to misaligned patient anatomy in the beam path since it does not account for the change in tissue density. In order to remedy this problem, we proposed a …
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3D particle tracking velocimetry using synthetic aperture imaging
… SA imaging to 3D Particle Tracking Velocimetry (PTV), adding the ability to conduct Lagrangian studies on flow fields over time. A new method has been developed to accurately locate seeding particles in volumes reconstructed using SA imaging, based on a proposed thresholding and average intensity …
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Evaluation of a Particle Sampling Probe to Measure Mass Concentration in Particle-Laden Flows
… are sampled using Particle Tracking Velocimetry (PTV), and to develop a method to physically measure particle mass concentration. To accomplish this, a free jet rig was used to create a particle-laden flow, and the probe was placed at the jet exit to sample particles. A laser and camera system …
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Integration des ruhenden Verkehrs in die Verkehrsangebots- und Verkehrsnachfragemodellierung
… Placed at program VISUM served from the PTV AG Karlsruhe for the traffic system modelling and rating, as well as the EVA demand model developed by LOHSE.
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DOSE-BASED EVALUATION OF A PROSTATE BED PROTOCOL
… impact of reducing the planning target volume (PTV) margin to five (IGRT-5) and eight (IGRT-8) mm isotropic was also evaluated.</p> <p>With the standard clinical PTV margin of ten/seven mm, the evaluated alternatives produced similar results. The minimum dose to the CTV was decreased by 1.6±1.0, …
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Δημιουργία, εκπαίδευση και εφαρμογή knowledge based planning (KBP) μοντέλων σε VMAT πλάνα ακτινοθεραπείας
… πλάνα, χρησιμοποιώντας δοσιμετρικούς δείκτες για PTV και OARs, καθώς και μέσω ανάλυσης γ-index (3%/2mm) στο πλαίσιο ελέγχων PSQA. Αποτελέσματα: Τα KBP μοντέλα παρήγαγαν πλάνα με συγκρίσιμα ή βελτιωμένα δοσιμετρικά αποτελέσματα σε σχέση με τα κλινικά πλάνα, διατηρώντας επαρκή κάλυψη του PTV και …
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Lagrangian dynamics of turbulence: Applications with 3D particle tracking velocimetry
… Particle Tracking Velocimetry (3D-PTV) to explore the Lagrangian dynamics of selected turbulent problems. 3D-PTV is a quantitative flow measurement technique that aims to track the Lagrangian paths of a set of particles in three dimensions using stereoscopic imaging. This …
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Three-dimensional particle tracking velocimetry for turbulence applications
… particle tracking velocimetry (3D-PTV) is a flow measure- ment technique that tracks the Lagrangian paths of a set of particles using photogrammetric principles. This technique allows to investigate complex fluid flows by measuring velocity and acceleration along particle …
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Volumetric modulated Arc Therapy versus 3D conformal radiotherapy in the treatment of locally advanced cervical cancer. A single institution, comparative dosimetric study
… higher conformity to the Planned Target Volume (PTV) and better sparing of organs at risk (OAR) when compared to 3D-CRT. This study focused on these principles as it applied to treatment and potential toxicity in the management of LACC. Aim: To compare dosimetric parameters between VMAT and …
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Robust Treatment Planning and Robustness Evaluation for Proton Therapy of Head and Neck Cancer
… plans robust against uncertainties compared to a PTV margin expansion approach. During radiation treatment, patients are prone to present anatomical variations during the treatment course, which can be random deviations in patient positioning, as well as treatment-induced tumor shrinkage and …
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Moving Phantom Study of Stereotactic Body Radiation Therapy for Lung Cancer
… in an underdosing (over 20%) in a portion of the PTV. In this underdosed volume, 1-2% of the PTV is underdosed by over 18 Gy, causing a 35-40% drop in the local control rate. We further observed that the discrepancy between the planned and measured dose distribution was due to the inaccurate …
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