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Localization of hotspots via a lightweight system combining Compton imaging with a 3D lidar camera
Simons Mattias,De Schepper David,Demeester Eric,Schroeyers Wouter 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.8
Efficient and secure decommissioning of nuclear facilities demands advanced technologies. In this context, gamma-ray detection and imaging are crucial in identifying radioactive hotspots and monitoring radiation levels. Our study is dedicated to developing a gamma-ray detection system tailored for integration into robotic platforms for nuclear decommissioning, offering a safe and automated solution for this intricate task and ensuring the safety of human operators by mitigating radiation exposure and streamlining hotspot localization. Our approach integrates a Compton camera based 3D reconstruction algorithm with a single Timepix3 detector. This eliminates the need for a second detector and significantly reduces system weight and cost. Additionally, combining a 3D camera with the setup enhances hotspot visualization and interpretation, rendering it an ideal solution for practical nuclear decommissioning applications. In a proof-of-concept measurement utilizing a 137Cs source, our system accurately localized and visualized the source in 3D with an angular error of 1◦ and estimated the activity with a 3% relative error. This promising result underscores the system’s potential for deployment in real-world decommissioning settings. Future endeavors will expand the technology’s applications in authentic decommissioning scenarios and optimize its integration with robotic platforms. The outcomes of our study contribute to heightened safety and accuracy for nuclear decommissioning works through the advancement of cost-effective and efficient gamma-ray detection systems
Forensic Imaging for Causal Investigation of Death
David Simons,Alina Sassenberg,Heinz-Peter Schlemmer,Kathrin Yen 대한영상의학회 2014 Korean Journal of Radiology Vol.15 No.2
A 63-year-old man was found in the street after overrun by a car. Postmortem CT revealed multiple bone fractures, but surprisingly all without any relevant hemorrhage which would have been expected under such circumstances. A round radiopaque formation was found in the duodenum, which was reminiscent of ingested tablets. The toxicological analysisrevealed high concentrations of zopiclone and alcohol. By combining radiologic and forensic results, zopiclone and alcohol intoxication were concluded as the cause of death, followed by a postmortem overrun accident.
Marcel Simons,Tim Radel,Frank Vollertsen 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.22 No.8
The laser chemical process is a material-removing machining process in the micro range. The process is based on a laserassisted etching process between an electrolyte and a metallic workpiece. Local overheating causes a laser-induced electrolyte boiling process, which limits the laser chemical process window. In order to reduce the laser-induced electrolyte boiling process and thus expand the process window, the laser chemical process is carried out at different electrolyte start temperatures and thus different electrolyte viscosities and surface tensions. The experimental investigations were carried out on Titanium Grade 1 with the electrolytes phosphoric acid and sulfuric acid at different electrolyte temperatures and laser powers to determine the limits of the process window by evaluating the properties of the removal cavities. As a result, the process window is extended at lower electrolyte viscosities. Thereby, the electrolyte viscosities have no influence on the geometric shape of the removal. The extension of the process window is attributed to the fact that a reduction in electrolyte viscosity results in a less pronounced formation of the boiling process, the bubble diameters decrease, and the shielding effect of the bubbles is reduced.
Rudy Simons,Navneet Sonawane,Marian Verbruggen,Jayesh Chaudhary 한국식품영양과학회 2015 Journal of medicinal food Vol.18 No.2
This exploratory study was designed to assess the effectiveness of a lignan-rich extract of flaxseed hulls (LinumLife EXTRA®) in alleviating symptoms in subjects with benign prostatic hyperplasia (BPH) compared with placebo. Two dosages of extract were compared against placebo in a double-blinded, randomized, parallel, multicenter study. Newly diagnosed cases of BPH in patients aged 45–75 years with an American Urological Association Symptom Index (AUASI) score of ≥ 13 were included. Study treatment consisted of 500 or 1000 mg of extract containing 100 mg (low-dose active [LDA] group, n = 26) or 200 mg (high-dose active [HDA] group, n = 26) of secoisolariciresinol diglucoside (SDG), respectively. The placebo (P) group (n = 28) received matching maltodextrin capsules. Sixty subjects (LDA [n = 19], HDA [n = 20], and P [n = 21]) completed the study as per the protocol requirements. Change in the AUASI score within a period of 8 weeks, from baseline to end of treatment, was assessed. Significant improvement of obstructive symptoms and management of irritable BPH symptoms was achieved in all groups after treatment. Due to a strong placebo effect, there was no statistical difference between the groups that were treated with flaxseed hull extract as compared with the placebo group. Treatment with flaxseed hull extract did not lead to adverse effects compared with placebo. Supplementation with flaxseed hull extract was found to be safe and well-tolerated and may have improved the quality of life of individuals with BPH. The significant placebo effect as well as the number of subjects per treatment group and the relative short duration of the study may explain the lack of statistical significance between groups.
Keryn L. Simons,Susan M. Thomas,Peter A. Anderson 한국미생물학회 2010 The journal of microbiology Vol.48 No.5
Nucleotide excision repair (NER) rectifies a variety of chemically and structurally distinct DNA lesions. The current model of NER is based upon the enteric bacterium Escherichia coli and there is scarce information about how other bacterial species respond to, and correct, DNA damage. Here we report the isolation and functional analysis of the uvrA and uvrB genes from Vibrio natriegens, a naturally occurring marine bacterium. Genetic studies were completed to assess the repair capabilities of V. natriegens uvrA and uvrB in E. coli uvrA and uvrB mutants. In addition to the genetic studies, transcriptional fusions between the luciferase gene and the 5′ regulatory regions of uvrA and uvrB gene of V. natriegens and E. coli were constructed. Luminescent measurements from E. coli transformed with these constructs showed that whilst the response to UV irradiation of either E. coli or V. natriegens uvrA regulatory sequences was similar, both the rate and induction of luminescence detected from the uvrB regulatory regions differed.