scholarly journals Research on the Computed Tomography Pebble Flow Detecting System for HTR-PM

2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Xin Wan ◽  
Ximing Liu ◽  
Jichen Miao ◽  
Peng Cong ◽  
Yuai Zhang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Helical Ct ◽  
Design Parameters ◽  
Three Dimensional Model ◽  
Safe Operation ◽  
Cross Sectional ◽  
Ct System ◽  
Near Future ◽  
Pebble Flow

Pebble dynamics is important for the safe operation of pebble-bed high temperature gas-cooled reactors and is a complicated problem of great concern. To investigate it more authentically, a computed tomography pebble flow detecting (CT-PFD) system has been constructed, in which a three-dimensional model is simulated according to the ratio of 1 : 5 with the core of HTR-PM. A multislice helical CT is utilized to acquire the reconstructed cross-sectional images of simulated pebbles, among which special tracer pebbles are designed to indicate pebble flow. Tracer pebbles can be recognized from many other background pebbles because of their heavy kernels that can be resolved in CT images. The detecting principle and design parameters of the system were demonstrated by a verification experiment on an existing CT system in this paper. Algorithms to automatically locate the three-dimensional coordinates of tracer pebbles and to rebuild the trajectory of each tracer pebble were presented and verified. The proposed pebble-detecting and tracking technique described in this paper will be implemented in the near future.

scholarly journals Accuracy and Reproducibility of Facial Measurements of Digital Photographs and Wrapped Cone Beam Computed Tomography (CBCT) Photographs

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 757
Author(s):  
Maged Sultan Alhammadi ◽  
Abeer Abdulkareem Al-mashraqi ◽  
Rayid Hussain Alnami ◽  
Nawaf Mohammad Ashqar ◽  
Omar Hassan Alamir ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Soft Tissue ◽  
Cone Beam Computed Tomography ◽  
High Reliability ◽  
Three Dimensional ◽  
Cone Beam ◽  
Cross Sectional ◽  
Facial Profile ◽  
Digital Photographs ◽  
Gonial Angle

The study sought to assess whether the soft tissue facial profile measurements of direct Cone Beam Computed Tomography (CBCT) and wrapped CBCT images of non-standardized facial photographs are accurate compared to the standardized digital photographs. In this cross-sectional study, 60 patients with an age range of 18–30 years, who were indicated for CBCT, were enrolled. Two facial photographs were taken per patient: standardized and random (non-standardized). The non-standardized ones were wrapped with the CBCT images. The most used soft tissue facial profile landmarks/parameters (linear and angular) were measured on direct soft tissue three-dimensional (3D) images and on the photographs wrapped over the 3D-CBCT images, and then compared to the standardized photographs. The reliability analysis was performed using concordance correlation coefficients (CCC) and depicted graphically using Bland–Altman plots. Most of the linear and angular measurements showed high reliability (0.91 to 0.998). Nevertheless, four soft tissue measurements were unreliable; namely, posterior gonial angle (0.085 and 0.11 for wrapped and direct CBCT soft tissue, respectively), mandibular plane angle (0.006 and 0.0016 for wrapped and direct CBCT soft tissue, respectively), posterior facial height (0.63 and 0.62 for wrapped and direct CBCT soft tissue, respectively) and total soft tissue facial convexity (0.52 for both wrapped and direct CBCT soft tissue, respectively). The soft tissue facial profile measurements from either the direct 3D-CBCT images or the wrapped CBCT images of non-standardized frontal photographs were accurate, and can be used to analyze most of the soft tissue facial profile measurements.

Clinical experience of using virtual 3D modelling for pre and intraoperative guidance during robotic-assisted partial nephrectomy

2021 ◽  
pp. 205141582110002
Author(s):  
Lorenz Berger ◽  
Aziz Gulamhusein ◽  
Eoin Hyde ◽  
Matt Gibb ◽  
Teele Kuusk ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Partial Nephrectomy ◽  
Surgical Outcome ◽  
Prospective Cohort ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Robotic Assisted ◽  
Robotic Assisted Partial Nephrectomy

Objective: Surgical planning for robotic-assisted partial nephrectomy is widely performed using two-dimensional computed tomography images. It is unclear to what extent two-dimensional images fully simulate surgical anatomy and case complexity. To overcome these limitations, software has been developed to reconstruct three-dimensional models from computed tomography data. We present the results of a feasibility study, to explore the role and practicality of virtual three-dimensional modelling (by Innersight Labs) in the context of surgical utility for preoperative and intraoperative use, as well as improving patient involvement. Methods: A prospective study was conducted on patients undergoing robotic-assisted partial nephrectomy at our high volume kidney cancer centre. Approval from a research ethics committee was obtained. Patient demographics and tumour characteristics were collected. Surgical outcome measures were recorded. The value of the three-dimensional model to the surgeon and patient was assessed using a survey. The prospective cohort was compared against a retrospective cohort and cases were individually matched using RENAL (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, location relative to polar lines) scores. Results: This study included 22 patients. Three-dimensional modelling was found to be safe for this prospective cohort and resulted in good surgical outcome measures. The mean (standard deviation) console time was 158.6 (35) min and warm ischaemia time was 17.3 (6.3) min. The median (interquartile range) estimated blood loss was 125 (50–237.5) ml. Two procedures were converted to radical nephrectomy due to the risk of positive margins during resection. The median (interquartile range) length of stay was 2 (2–3) days. No postoperative complications were noted and all patients had negative surgical margins. Patients reported improved understanding of their procedure using the three-dimensional model. Conclusion: This study shows the potential benefit of three-dimensional modelling technology with positive uptake from surgeons and patients. Benefits are improved perception of vascular anatomy and resection approach, and procedure understanding by patients. A randomised controlled trial is needed to evaluate the technology further. Level of evidence: 2b

The Hyoid Bone in Malay Infants with Cleft Lip and Palate

2006 ◽  
Vol 43 (5) ◽  
pp. 532-538 ◽  
Author(s):  
Zainul A. Rajion ◽  
Grant C. Townsend ◽  
David J. Netherway ◽  
Peter J. Anderson ◽  
Toby Hughes ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cervical Spine ◽  
Software Package ◽  
Hyoid Bone ◽  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Three Dimensional ◽  
Cross Sectional ◽  
Computed Tomography Scans ◽  
Age Range

Objective: To compare morphological and positional variations of the hyoid bone in unoperated infants with cleft lip and palate (CL/P) with those in noncleft infants. Design: Retrospective, cross sectional. Patients and Methods: Three-dimensional computed tomography scans were obtained from 29 unoperated CL/P infants of Malay origin aged between 0 and 12 months and from 12 noncleft infants in the same age range. Observations were made and measurements were obtained with a software package developed at the Australian Craniofacial Unit. The sizes of the hyoid bones and the position of the hyoid body and epiglottis in relation to the cervical spine were measured. Anatomical anomalies of the hyoid and prevalence of aspiration pneumonia were also documented. Results: The hyoid bones and epiglottis were found to be located more inferiorly in CL/P infants compared with the noncleft infants. Also, 17% (5/29) of the CL/P infants had nonossified hyoid bodies. Conclusion: The results suggest that there are differences in the location and genesis of the hyoid bone in infants with CL/P that warrant further investigation.

Use of computed tomography data for forensic identification of an individual

2020 ◽  
Vol 6 (4) ◽  
pp. 41-45
Author(s):  
Sergey V. Leonov ◽  
Julia P. Shakiryanova
Keyword(s):  
Computed Tomography ◽  
Computer Tomography ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Reference Points ◽  
Forensic Identification ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
The Face ◽  
Tomography Data

Background: The article presents our own experience of using computer tomography for identification of individuals with known results. Aims: The aim of the study was to verify the possibility of performing an identification study using a three-dimensional model obtained from computed tomography of the head. Identification was performed using a three-dimensional model of the head, based on computer tomography sections made in various projections, with a step of 1.231.25 mm. Two-dimensional images of the face (photos) were used for comparison. All comparative studies were conducted using approved methods of craniofacial and portrait identification: by reference points and contours. The experiment used a computer program that allows you to export DICOM-files of computed tomography results to other formats (InVesalius), as well as computer programs that directly work with the research objects (Autodesk 3ds Max, alternative programs Adobe Photoshop, Smith Micro Poser Pro). Results: In the course of research, it was found that, having computer tomography data of the head, it is possible to conduct identification studies on the following parameters: on the reconstructed three-dimensional model of the soft tissues of the face, on the three-dimensional model of the skull (craniofacial identification), on the features of the structure of the ear. Conclusion: Positive results were obtained when comparing objects, which makes it advisable to use them in practical and scientific activities.

Blast load simulation using conical shock tube systems

2019 ◽  
Vol 11 (2) ◽  
pp. 135-158 ◽  
Author(s):  
Ahmed Ismail ◽  
Mohamed Ezzeldin ◽  
Wael El-Dakhakhni ◽  
Michael Tait
Keyword(s):  
Shock Tube ◽  
Three Dimensional ◽  
Design Parameters ◽  
Civil Infrastructure ◽  
Two Dimensional ◽  
Blast Loads ◽  
Dimensional Model ◽  
Tube System ◽  
Three Dimensional Model ◽  
Conical Shock

With the increased frequency of accidental and deliberate explosions, evaluating the response of civil infrastructure systems to blast loading has been attracting the interests of the research and regulatory communities. However, with the high cost and complex safety and logistical issues associated with field explosives testing, North American blast-resistant construction standards (e.g. ASCE 59-11 and CSA S850-12) recommend the use of shock tubes to simulate blast loads and evaluate relevant structural response. This study first aims at developing a simplified two-dimensional axisymmetric shock tube model, implemented in ANSYS Fluent, a computational fluid dynamics software, and then validating the model using the classical Sod’s shock tube problem solution, as well as available shock tube experimental test results. Subsequently, the developed model is compared to a more complex three-dimensional model and the results show that there is negligible difference between the two models for axisymmetric shock tube performance simulation; however, the three-dimensional model is necessary to simulate non-axisymmetric shock tubes. Following the model validation, extensive analyses are performed to evaluate the influences of shock tube design parameters (e.g. the driver section pressure and length and the expansion section length) on blast wave characteristics to facilitate a shock tube design that would generate shock waves similar to those experienced by civil infrastructure components under blast loads. The results show that the peak reflected pressure increases as the driver pressure increases, while a decrease in the expansion length increases the peak reflected pressure. In addition, the positive phase duration increases as both the driver length and expansion length are increased. Finally, the developed two-dimensional axisymmetric model is used to optimize the dimensions of a physical large-scale conical shock tube system constructed for civil infrastructure component blast response evaluation applications. The capabilities of such shock tube system are further investigated by correlating its design parameters to a range of explosion threats identified by different hemispherical TNT charge weight and distance scenarios.

A Numerical Investigation of Automobile Environment Through Cooling Period and Condensation

2009 ◽  
Author(s):  
Md. Faisal Kader ◽  
Kang Hyu Goo ◽  
Yong-Du Jun ◽  
Kum-Bae Lee
Keyword(s):  
Fluid Flow ◽  
Initial Period ◽  
Three Dimensional ◽  
Practical Significance ◽  
Scale Model ◽  
Design Parameters ◽  
Experimental Investigations ◽  
Three Dimensional Model ◽  
Cooling Period ◽  
Initial Stage

Understanding the fluid flow and heat transfer characteristics within a vehicle compartment is very important for controlling the effect of major design parameters. Also, adequate visibility through the vehicle windshield over the entire driving period is of paramount practical significance. The numerical solution was done by an operation friendly, fast and accurate CFD code — SC/Tetra with a full scale model of a SM3 car and turbulence was modeled by the standard k-ε equation. Numerical analysis of the three-dimensional model predicts a detailed description of fluid flow and temperature distribution in the passenger compartment and on the inside windshield screen. During the cooling period, the lowest temperature is observed in the lower part of the windshield and in the vicinity of the defroster griller. It was found that the temperature dropped down to a comfortable range almost linearly at the initial stage. The initial period to achieve this comfortable range is dependent on the inlet velocity. Experimental investigations are performed to determine the localized thermal comfort and further validation of the numerical results.

scholarly journals Simulation Technique of Kinematic Processes in the Vehicle Steering Linkage

2018 ◽  
Vol 7 (4.3) ◽  
pp. 120 ◽  
Author(s):  
Sergii Chernenko ◽  
Eduard Klimov ◽  
Andrii Chernish ◽  
Olexandr Pavlenko ◽  
Volodymyr Kukhar
Keyword(s):  
Three Dimensional ◽  
Simulation Technique ◽  
Design Parameters ◽  
Three Dimensional Model ◽  
Design Data ◽  
Power Characteristics ◽  
Left And Right ◽  
Turning Radius ◽  
The Impact ◽  
The Mathematical Model

The results of the investigation of the turning kinematics of the steerable wheels of the KrAZ-7634NE off-road vehicle with a wheel formula 8x8 and two front steer axles are given. The theoretical relations between the steer angles of the steerable wheels on the basis of the scheme of double-axle steering turning of the vehicle are shown. The mathematical model of flat four-bar vehicle steering linkage is developed, it determines the relation between the steering linkage left and right steering arms turning angles at any turning radius of the vehicle. KrAZ-7634HE steering three-dimensional model was created and simulation technique of its work was carried out using Creo software. It has been shown that the flat steering linkage model provides sufficient accuracy of calculations in analysis of turning kinematics. The design data can be used for any vehicles that have a similar steering linkage, they allow to analyze the impact of the vehicle design parameters on the turning kinematics and optimize them. Further study of the impact of the kingpin inclinations on the steering linkage kinematic and power characteristics are required.  

Research on Fatigue Life of the Casting Crane’s Girder

2011 ◽  
Vol 295-297 ◽  
pp. 598-602
Author(s):  
Zhi Cheng Huang
Keyword(s):  
Fatigue Life ◽  
Fracture Mechanics ◽  
Design Method ◽  
Three Dimensional ◽  
Data Access ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Safe Operation

Taken a certain type of casting crane’s girder as research object, established its three-dimensional model by using Pro/ENGINEER software, and then import it into the ANSYS program for analysis with ANSYS data access module (DDA), integrating the analysis results and the theory of fracture mechanics, the thesis comprehensively analyzed the fatigue life of the casting crane’s girder with damnification-limit design method. It provided some theory basis and reference for casting crane’s safe operation and fatigue lift design.

Colon dissection: a new three‐dimensional reconstruction tool for computed tomography colonography

2005 ◽  
Vol 46 (3) ◽  
pp. 222-226 ◽  
Author(s):  
R. Röttgen ◽  
F. Fischbach ◽  
M. Plotkin ◽  
H. Herzog ◽  
T. Freund ◽  
...  
Keyword(s):  
Computed Tomography ◽  
3D Reconstruction ◽  
Ct Colonography ◽  
Virtual Colonoscopy ◽  
Three Dimensional ◽  
Virtual Endoscopy ◽  
Helical Ct ◽  
Conventional Colonoscopy ◽  
Colon Polyps ◽  
The Difference

Purpose: To improve the sensitivity of computed tomography (CT) colonography in the detection of polyps by comparing the 3D reconstruction tool “colon dissection” and endoluminal view (virtual colonoscopy) with axial 2D reconstructions. Material and Methods: Forty‐eight patients (22 M, 26 F, mean age 57±21) were studied after intra‐anal air insufflation in the supine and prone positions using a 16‐slice helical CT (16×0.625 mm, pitch 1.7; detector rotation time 0.5 s; 160 mAs und 120 kV) and conventional colonoscopy. Two radiologists blinded to the results of the conventional colonoscopy analyzed the 3D reconstruction in virtual‐endoscopy mode, in colon‐dissection mode, and axial 2D slices. Results: Conventional colonoscopy revealed a total of 35 polyps in 15 patients; 33 polyps were disclosed by CT methods. Sensitivity and specificity for detecting colon polyps were 94% and 94%, respectively, when using the “colon dissection”, 89% and 94% when using “virtual endoscopy”, and 62% and 100% when using axial 2D reconstruction. Sensitivity in relation to the diameter of colon polyps with “colon dissection”, “virtual colonoscopy”, and axial 2D‐slices was: polyps with a diameter >5.0 mm, 100%, 100%, and 71%, respectively; polyps with a diameter of between 3 and 4.9 mm, 92%, 85%, and 46%; and polyps with a diameter <3 mm, 89%, 78%, and 56%. The difference between “virtual endoscopy” and “colon dissection” in diagnosing polyps up to 4.9 mm in diameter was statistically significant. Conclusion: 3D reconstruction software “colon dissection” improves sensitivity of CT colonography compared with the endoluminal view.

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