Technical Note: Contrast solution density and cross section errors in inhomogeneity-corrected dose calculation for breast balloon brachytherapy

Abstract. For spatial explicit hydrological modelling an algorithm was needed which works as cellular automata on irregular meshes. From literature it was found that usual algorithms applied for this purpose do not route the water flow correctly to its adjacent cells. In this study the hydraulic linking between mesh cells is done by calculating the flow cross section between the mesh cells. The flow cross sections are positioned in the centre of the mesh edges and are perpendicular to the local gradient of the digital elevation model. The presented algorithm is simple in its implementation and efficient in computation. It is shown that the proposed algorithm works correctly for different synthesised hill slope shapes.

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Optimizing the Analytical Performance of Substrate-Integrated Hollow Waveguides: Experiment and Simulation

Applied Spectroscopy ◽

10.1177/0003702819867342 ◽

2019 ◽

Vol 73 (12) ◽

pp. 1451-1460

Author(s):

L. Tamina Hagemann ◽

Sonja Ehrle ◽

Boris Mizaikoff

Keyword(s):

Cross Section ◽

Limit Of Detection ◽

Signal To Noise Ratio ◽

Analytical Signal ◽

Technical Note ◽

Channel Cross Section ◽

Hollow Waveguides ◽

Ratio Limit ◽

Experiment And Simulation ◽

Inner Channel

The goal of this technical note was to compare experimentally and via simulation of eight substrate-integrated hollow waveguide (iHWG) designs, and to predict promising future iHWG structures in lieu of experiments. The iHWGs differed in their geometry (i.e., inlet funnel cross-section and inner channel cross-section), as well as in their material properties (i.e., type of metal, polish of inner channel). Experimentally, calibration functions of isobutane as a model analyte were determined, and the analytical figures of merit, i.e., signal-to-noise ratio, limit of detection, were evaluated for each iHWG. Evaluation of the amount of radiation incident at the real-world and simulated detector revealed that experiment and simulation were in excellent agreement. While material and quality of the inner channel wall did not have a significant influence on the performance, the iHWG geometry profoundly affected the performance in terms of light throughput: Increasing the inlet funnel dimensions and the inner channel cross-section benefits light throughout, and thus, the analytical signal. Based on these results, simulations of not yet fabricated iHWGs were performed and promising new iHWG structures were suggested.

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Technical Note: A fast and accurate analytical dose calculation algorithm for I‐125 seed‐loaded stent applications

Medical Physics ◽

10.1002/mp.15207 ◽

2021 ◽

Author(s):

Bo Liu ◽

Tianyu Xiong ◽

Jian Lu ◽

Shengwei Li ◽

Xiangzhi Bai ◽

...

Keyword(s):

Dose Calculation ◽

Technical Note ◽

Calculation Algorithm ◽

Dose Calculation Algorithm

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Technical note: An R program for automating bone cross section reconstruction

American Journal of Physical Anthropology ◽

10.1002/ajpa.21299 ◽

2010 ◽

Vol 142 (4) ◽

pp. 665-669 ◽

Cited By ~ 13

Author(s):

Adam D. Sylvester ◽

Evan Garofalo ◽

Christopher Ruff

Keyword(s):

Cross Section ◽

Technical Note ◽

R Program

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Technical Note: Flow velocity and discharge measurement in rivers using terrestrial and unmanned-aerial-vehicle imagery

Hydrology and Earth System Sciences ◽

10.5194/hess-24-1429-2020 ◽

2020 ◽

Vol 24 (3) ◽

pp. 1429-1445 ◽

Cited By ~ 6

Author(s):

Anette Eltner ◽

Hannes Sardemann ◽

Jens Grundmann

Keyword(s):

Flow Velocity ◽

Unmanned Aerial Vehicle ◽

Cross Section ◽

Flow Characteristics ◽

Technical Note ◽

Surface Flow ◽

Contactless Measurement ◽

Aerial Vehicle ◽

The Impact ◽

Flow Velocities

Abstract. An automatic workflow to measure surface flow velocities in rivers is introduced, including a Python tool. The method is based on particle-tracking velocimetry (PTV) and comprises an automatic definition of the search area for particles to track. Tracking is performed in the original images. Only the final tracks are geo-referenced, intersecting the image observations with water surface in object space. Detected particles and corresponding feature tracks are filtered considering particle and flow characteristics to mitigate the impact of sun glare and outliers. The method can be applied to different perspectives, including terrestrial and aerial (i.e. unmanned-aerial-vehicle; UAV) imagery. To account for camera movements images can be co-registered in an automatic approach. In addition to velocity estimates, discharge is calculated using the surface velocities and wetted cross section derived from surface models computed with structure-from-motion (SfM) and multi-media photogrammetry. The workflow is tested at two river reaches (paved and natural) in Germany. Reference data are provided by acoustic Doppler current profiler (ADCP) measurements. At the paved river reach, the highest deviations of flow velocity and discharge reach 4 % and 5 %, respectively. At the natural river highest deviations are larger (up to 31 %) due to the irregular cross-section shapes hindering the accurate contrasting of ADCP- and image-based results. The provided tool enables the measurement of surface flow velocities independently of the perspective from which images are acquired. With the contactless measurement, spatially distributed velocity fields can be estimated and river discharge in previously ungauged and unmeasured regions can be calculated, solely requiring some scaling information.

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