Engineering Commons^™

Pipeline Risk Analysis Optimization With Monte Carlo Method Using Gamma Distribution, Farhan Rama Digita, Jaka Fajar Fatriansyah, Abdul Rahim Ridzuan, Hanna Ovelia, Imam Abdillah Mas'ud, Irma Hartia Tihara, Baiq Diffa Pakarti Linuwih

Journal of Materials Exploration and Findings

The inspection process of piping components in the oil and gas industry is one of the most crucial things, given the high risk posed by pipeline system failures, which have a huge impact on losses, both from environmental and financial aspects. Risk-based inspection with the Monte Carlo method is one of the efforts that can be made to minimize failures in piping systems, by involving data distribution to calculate the probability of component failure. Although the normal distribution is commonly used for generating random variables, its use in corrosion rate calculation can lead to overestimation due to negative corrosion rate …

Gamma And Neutron Irradiation Effect On Ga-Polar And N-Polar Gan Based Diodes, Farnood Mirkhosravi

Optical Science and Engineering ETDs

III-nitride material (GaN) shows a lot of potential for next-generation power electronics. This material is advantageous due to its wide bandgap, high electron mobility, high thermal and mechanical stability, small form factor, and higher radiation tolerance. The higher radiation tolerance makes the GaN-based devices more attractive for harsh-environment applications, like aerospace, nuclear reactor, and fusion facilities, particle accelerators, and post-detonation environments applications.

GaN due to its unique crystal structure can be grown in different orientations and can provide specific advantages in electronic and optoelectronic devices. While the Ga-polar orientation of GaN has been widely investigated for its proprieties, there are …

An Improvement Of Cross Entropy Thresholding For Skin Cancer, Nancy Aref Zreika N, A. Zreika, Ali El Zaart, Abdallah Al Shakik

BAU Journal - Science and Technology

Image processing procedures in medical diagnosis are used to improve diagnosis accuracy. An example of this is skin cancer detection using the thresholding approach. Thus, research studies involved in identification of inherited mutations predisposing family members to malignant melanoma have been performed in the Cancer Genetics field. Melanoma is one of the deadliest cancers, but could be cured when diagnosed early. A fundamental step in image processing is segmentation that includes thresholding, among others. Thresholding is based on finding the optimal thresholds value that partitions the image into multiple classes to be able to distinguish the objects from the background. …

Changes In Neural Network Connectivity Of Normal Young Adults In Response To Power Wheelchair Trainer Using Eeg Coherence, Ruby Phung

Masters Theses

The ability to move and explore their surrounding environment plays a critical role in the development of cognitive function in children, especially during early childhood. The lack of independent and autonomous mobility is, therefore, a clear disadvantage for the overall development of children with multiple, severe disabilities. Limited number of studies have been conducted on the impact of power mobility device on this specific population. Previous exploratory and pilot studies showed promising results regarding quantifiable and consistent changes in the electroencephalogram (EEG) of children with multiple, severe disabilities when provided with power mobility training. This study aimed to further extend …

A Bayesian Approach To Aerial Localization Of Radioactive Sources, Robert Blake Wilkerson

Masters Theses

Securing nuclear material has become an important area for the safety of the U.S. and other countries. Within nuclear security, there is a potential to use orphaned or stolen radioactive sources to cause harm. As the amount of radioisotopes used by government and commercial businesses increases, the need to secure these sources becomes exponentially more difficult. It is well known that there have been several cases of lost, orphaned or stolen nuclear sources across the globe. There is a need for state-of-the-art radiation search methods to search for these potentially dangerous radioactive sources that could be misplaced. While there are …

The Effects Of Ionizing Radiation And Oxidizing Species On Strains Of Deinococcus Radiodurans Lacking Endogenous Oxidative Protection Methods, Dylan L. Klawuhn

Theses and Dissertations

Multiple strains of Deinococcus radiodurans were transformed, creating knockout mutations in genes responsible for manganese ion transport, manganese and copper/zinc super-oxide dismutase, and bacillithiol synthesis. These mutated strains were then irradiated with ~20,000 Gys. The results showed that the mutated strains had a higher sensitivity to ionizing radiation, those responsible for bacillithiol synthesis having an increase in sensitivity 3000 times more than wild type Deinococcus radiodurans. In addition to radiation the mutated strains were also exposed to paraquat, an oxidizing herbicide. Strains missing manganese super-oxide dismutase showed increased sensitivity.

Benchmarking The Gamma Pass Score Using Arccheck For Routine Dosimetric Qa Of Vmat Plans, Sankar Arumugam, Tony Young, Aitang Xing, David Thwaites, Lois C. Holloway

Faculty of Engineering and Information Sciences - Papers: Part A

A minimum expected gamma (gamma) pass rate for VMAT plan verification using ArcCHECK was established based on the RTTQA, TG119 test cases and 10 clinical plans with varying levels of complexity. The impact of the 'Measurement Uncertainty' parameter as available in the ArcCHECK software on gamma pass rate was studied for both global and local gamma analysis. Our results show that excluding measurement uncertainty adds tighter tolerance in local gamma comparison. From the verification of our benchmark cases we established minimum expected gamma pass rates of 85% and 88% for 2%/2mm global and 3%/3mm local tolerance criteria.

Evaluation Of 3d Gamma Index Calculation Implemented In Two Commercial Dosimetry Systems, Aitang Xing, Sankar Arumugam, Shrikant Deshpande, Armia George, Philip J. Vial, Lois C. Holloway, Gary Goozee

Faculty of Engineering and Information Sciences - Papers: Part A

3D Gamma index is one of the metrics which have been widely used for clinical routine patient specific quality assurance for IMRT, Tomotherapy and VMAT. The algorithms for calculating the 3D Gamma index using global and local methods implemented in two software tools: PTW-VeriSoft (R) r as a part of OCTIVIUS 4D dosimeter systems and 3DVH (TM) from Sun Nuclear were assessed. The Gamma index calculated by the two systems was compared with manual calculated for one data set. The Gamma pass rate calculated by the two systems was compared using 3%/3mm, 2%/2mm, 3%/2mm and 2%/3mm for two additional data …

The Effects Of Shielding On Non-Destructive Analysis (Nda) And The Use Of Small-Angle Compton Scattering To Overcome Those Effects, Cory Jake Hudson

Masters Theses

The use of passive Non-Destructive Analysis (NDA) equipment and techniques are very beneficial tools in the nuclear industry that have a plethora of applications and advantages over destructive or more invasive measurement methods. Of course, NDA techniques also have many limitations including dealing with many unknown parameters, overcoming the effects of gamma ray shielding, and the reliance on making many gross assumptions in the analysis of non-destructively acquired data. These limitations can lead to biased results or extremely difficult analysis which often introduces inaccurate conclusions and/or high levels of uncertainty.

This thesis paper will focus on specific NDA equipment and …

Neutron-Gamma Pulse Shape Discrimination Using Organic Scintillators With Silicon Photomultiplier Readout, Rhys M. Preston, John Eberhardt, James Tickner

Faculty of Engineering and Information Sciences - Papers: Part A

Neutron/Gamma pulse shape discrimination (PSD) was measured using stilbene and EJ-299-34 plastic scintillators with readout by silicon photomultipliers (SiPMs). The SiPM pulses were digitized and processed for energy and pulse shape information using a digital technique performing numerical weighted integrations on each pulse. A genetic algorithm (GA) was developed to optimize the weighting vectors used for the pulse shape discrimination. Efficient PSD was obtained down to an electron-equivalent energy of 127 keV with stilbene and 391 keV with the EJ-299-34 PSD plastic. Separation at lower energies was possible at reduced detection efficiency, down to 78 keV and 186 keV at …

Relating Microstructure To Process Variables In Beam-Based Additive Manufacturing Of Inconel 718, John Ryan Thompson

Browse all Theses and Dissertations

The advancement of laser or electron beam-based additive manufacturing requires the ability to control solidification microstructure. Previous work combined analytical point source solutions and nonlinear thermal finite element analysis (FEA) to explore the effects of deposition process variables on Ti-6Al-4V solidification microstructure. The current work seeks to extend the approach to Inconel 718, with the addition of Cellular Automaton-Finite Element (CAFE) models. Numerical data from finite element results are extracted in order to calculate accurate melt pool geometry, thus leading to corresponding cooling rates and thermal gradients. The CAFE models are used to simulate grain grown and nucleation, providing a …

A Dual Scintillator - Dual Silicon Photodiode Detector Module For Intraoperative Gamma\Beta Probe And Portable Anti-Compton Spectrometer, Anatoly B. Rosenfeld, Michael Lf Lerch, M. Chan, Dean Inwood, George J. Takacs, Bong Soo Lee, A F. Gektin, V L Perevertaylo

Anatoly Rozenfeld

A new approach has been investigated for the miniaturization and simplification of intraoperative gamma and beta probes that have recently found application in radioguided surgery and sentinel lymph node biopsy. The probe design that is based on dual annular scintillators coupled to specially designed silicon concentric dual photodiode (CDPD). This approach allows us to avoid fiber optics coupling and PMTs. Two channels readout front-end electronics including shaper amplifier attached directly to the back of the detector module has been proposed. Two geometries of Si dual photodiodes coupled to CsI(Tl) annular scintillators with light masking between them were fabricated and investigated. …

Brachyview: Proof-Of-Principle Of A Novel In-Body Gamma Camera For Low Dose-Rate Prostate Brachytherapy, M Petasecca, K J. Loo, M Safavi-Naeini, Z Han, P E. Metcalfe, S Meikle, S Pospisil, J Jakubek, Joseph Bucci, Marco Zaider, M L. F Lerch, Y Qi, Anatoly B. Rosenfeld

Faculty of Engineering and Information Sciences - Papers: Part A

Purpose: The conformity of the achieved dose distribution to the treatment plan strongly correlates with the accuracy of seed implantation in a prostate brachytherapy treatment procedure. Incorrect seed placement leads to both short and long term complications, including urethral and rectal toxicity. The authors present BrachyView, a novel concept of a fast intraoperative treatment planning system, to provide real-time seed placement information based on in-body gamma camera data. BrachyView combines the high spatial resolution of a pixellated silicon detector (Medipix2) with the volumetric information acquired by a transrectal ultrasound (TRUS). The two systems will be embedded in the same probe …

A Dual Scintillator - Dual Silicon Photodiode Detector Module For Intraoperative Gamma\Beta Probe And Portable Anti-Compton Spectrometer, Anatoly B. Rosenfeld, Michael Lf Lerch, M. Chan, Dean Inwood, George J. Takacs, Bong Soo Lee, A F. Gektin, V L Perevertaylo

George Takacs

A new approach has been investigated for the miniaturization and simplification of intraoperative gamma and beta probes that have recently found application in radioguided surgery and sentinel lymph node biopsy. The probe design that is based on dual annular scintillators coupled to specially designed silicon concentric dual photodiode (CDPD). This approach allows us to avoid fiber optics coupling and PMTs. Two channels readout front-end electronics including shaper amplifier attached directly to the back of the detector module has been proposed. Two geometries of Si dual photodiodes coupled to CsI(Tl) annular scintillators with light masking between them were fabricated and investigated. …

Investigation Of High Resolution Compact Gamma Camera Module Based On A Continuous Scintillation Crystal Using A Novel Charge Division Readout Method, Qiu-Sheng Dai, Cui-Lan Zhao, Hualin Zhang, Yujin Qi

Faculty of Engineering and Information Sciences - Papers: Part A

The objective of this study is to investigate a high performance and lower cost compact gamma camera module for a multi-head small animal SPECT system. A compact camera module was developed using a thin Lutetium Oxyorthosilicate (LSO) scintillation crystal slice coupled to a Hamamatsu H8500 position sensitive photomultiplier tube (PSPMT). A two-stage charge division readout board based on a novel sub-tractive resistive readout with a truncated center-of-gravity (TCOG) positioning method was developed for the camera. The performance of the camera was evaluated using a flood 99mTc source with a four-quadrant bar-mask phantom. The preliminary experimental results show that the image …

Development Of A Simplified Readout For A Compact Gamma Camera Based On 2×2 H8500 Multi-Anode Pspmt Array, Yujin Qi, Meng Liu, Xuezhu Zhang, Cuilan Zhao, Jian Song, Hualin Zhang

Faculty of Engineering and Information Sciences - Papers: Part A

The aim of this study was to develop a highperformance simplified readout electronic for a compact gamma camera to achieve a maximized performance in its intrinsic spatial resolution. This compact camera is based on a pixellated NaI(Tl) crystal with 1.2 mm×1.2 mm×5 mm pixel element and 1.4 mm pixel pitch coupled to a 2×2 Hamamatsu H8500 multi-anode position sensitive photomultiplier tube (PSPMT) array. The design of the simplified readout is based on novel two-stage charge divisions with Truncated Center-of-Gravity (TCOG) positioning method to maximize the detector performance. The performance of the compact camera with the novel simplified readout was evaluated …

A Dual Scintillator - Dual Silicon Photodiode Detector Module For Intraoperative Gamma\Beta Probe And Portable Anti-Compton Spectrometer, Anatoly B. Rosenfeld, Michael Lf Lerch, M. Chan, Dean Inwood, George J. Takacs, Bong Soo Lee, A F. Gektin, V L Perevertaylo

Faculty of Engineering - Papers (Archive)

A new approach has been investigated for the miniaturization and simplification of intraoperative gamma and beta probes that have recently found application in radioguided surgery and sentinel lymph node biopsy. The probe design that is based on dual annular scintillators coupled to specially designed silicon concentric dual photodiode (CDPD). This approach allows us to avoid fiber optics coupling and PMTs. Two channels readout front-end electronics including shaper amplifier attached directly to the back of the detector module has been proposed. Two geometries of Si dual photodiodes coupled to CsI(Tl) annular scintillators with light masking between them were fabricated and investigated. …

Phase Error Compensation For A 3-D Shape Measurement System Based On The Phase-Shifting Method, Song Zhang, Peisen S. Huang

Song Zhang

This paper describes a novel phase error compensation method for reducing the measurement error caused by nonsinusoidal waveforms in phase-shifting methods. For 3-D shape measurement systems using commercial video projectors, the nonsinusoidal waveform of the projected fringe patterns as a result of the nonlinear gamma of projectors causes significant phase measurement error and therefore shape measurement error. The proposed phase error compensation method is based on our finding that the phase error due to the nonsinusoidal waveform depends only on the nonlinearity of the projector’s gamma. Therefore, if the projector’s gamma is calibrated and the phase error due to the …

Performance Comparison Of Subtractive Resistive Readout With Conventional Resistive Readout For A High-Resolution Compact Gamma Camera, Y J. Qi, M J. Zhang, C L. Zhao, R F. Wojcik

Faculty of Engineering and Information Sciences - Papers: Part A

The purpose of this study was to investigate an optimal readout for a high-resolution compact gamma camera with maximum performance in crystal element identifications. The compact camera is based on a pixellated Nal(Tl) crystal with 1.2 mm pixel size coupled to a 5" Hamamatsu R3292 PSPMT. A conventional resistive-chain readout was initially developed for the camera. Then a novel subtractive resistive readout developed was utilized to optimize the performance of the camera. The performance of the camera was evaluated by raw flood images of a 137Cs source. The results show that the conventional resistive readout results in a significant shrinkage …

Generic Nonsinusoidal Phase Error Correction For 3d Shape Measurement Using A Digital Video Projector, Song Zhang, Shing-Tung Yau

Song Zhang

Structured light system using a digital video projector is increasingly used for a 3-D shape measurement because of its digital nature. However, the nonlinear gamma of the projector causes the projected fringe patterns to be non-sinusoidal, which results in phase error therefore shape measurement error. Previous work showed that, by using a small look-up-table (LUT), this type of phase error can be reduced significantly for a three-step phase-shifting algorithm. In this research, we prove that this type of phase error compensation method is not limited to a three-step phase-shifting algorithm. It is generic for any phase-shifting algorithm. The phase error …

Optimized Collimator Designs For Small Animal Spect Imaging With A Compact Gamma Camera, Yujin Qi

Faculty of Engineering and Information Sciences - Papers: Part A

The aim of this study to design optimized pinhole and parallel-hole collimators for the development of a high-resolution microSPECT system using a compact pixelleted scintillation detector. The detector has a field-of-view of 11 cm with pixellated crystal elements of 1.0 mm pixel size and 1.12 mm pixel pitch. The relative resolution and sensitivity advantages of pinhole and parallel-hole collimators for mice and rats imaging were investigated using analytic formulations and Monte Carlo simulations. The optimized collimator designs were obtained by maximizing the system detection efficiency for a given object resolution. The collimator designs were optimized for 140 keV incident gamma …

Radiation Effects On Pmos Devices, Camille G. Bates

Journal of the Microelectronic Engineering Conference

A Cesium—137 gamma radiation source was used to irradiate PMOS capacitors and transistors with doses of 7.50E4, 1.50E5, 3.0E5. The devices were tested for C-V and I-V data before and after irradiation. Results show that all doses created changes in the electrical characteristics, however comparison to literature was I inconclusive.