This paper presents the design, assembly, and performance investigation of an optoelectronic readout system specifically designed to enhance the real-time readout capabilities of Superheated Drop ...Detectors (SDDs). SDDs as fast neutron detectors have been widely used in different areas such as homeland security, radiation protection, and personal dosimetry. In homeland security, SDDs showed the potential of detecting prompt fission neutrons from special nuclear materials in radiation portal monitor systems, possibly positioning them as a valuable alternative to He-3 detectors. In radiation protection and personal dosimetry, downsized SDDs may be employed to assess the level of exposure of workers in nuclear energy production facilities or as a tool to perform photoneutron contamination studies of medical and research accelerators. The proposed readout system utilizes lightemitting diodes to illuminate the detectors, while photodiodes are employed to record the integral value of scattered light resulting from bubbles’ formation, a consequence of neutron interaction. To validate the behavior of the system, comprehensive field testing was conducted after assembling and integrating it with custom-made 3D printed structures tailored for different SDD geometry, and the reader was utilized to examine the optical and detection characteristics of different SDD compositions under various ionizing radiation conditions. The potential to actively read out SDDs in real-time represents a significant advancement for this radiation detection technology, particularly in fields such as radiation protection and industrial applications, and it provides valuable insights for future enhancements in the field of neutron radiation detection.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Since the Fukushima Daiichi Nuclear Power Plant accident in March 2011, the technology available for unmanned aerial vehicles (UAVs) for radiation monitoring has improved greatly. Remote access to ...radiation-contaminated areas not only eliminates unnecessary exposure of civilians or military personnel, but also allows workers to explore inaccessible places. Hazardous levels of radioactive contamination can be expected as a result of accidents in the nuclear power industry or as a result of the intentional release of radioactive materials for terrorist purposes (dirty bombs, building contamination, etc.). The possibility to detect, identify, and characterize radiation and nuclear material using mobile and remote sensing platforms is a common requirement in the radiation sensing community. The technology has applications in homeland security and law enforcement, customs and border protection, nuclear power plant safety and security, nuclear waste monitoring, environmental recovery, and the military. In this work, the authors have developed, implemented, and characterized a gamma-ray detection and spectroscopy system capable of operating on a UAV. The system was mainly developed using open-source software and affordable hardware components to reduce development and maintenance costs and provide satisfactory performance as a detection instrument. The designed platform can be used to perform mapping or localization tasks to improve the risk assessment process for first responders during the management of radiological and nuclear incidents. First, the design process of the system is described; the result of the characterization of the platform is then presented together with the use of the prototype installed on a UAV in an exercise simulating a radiological and nuclear contamination scenario.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
This paper details the development of an inexpensive, power-efficient, and lightweight radiation detection system specifically designed for deployment on Unmanned Aerial Vehicles (UAVs). The system ...addresses the need for swift, remote radiation detection capabilities during radiological and nuclear emergencies, a demand emphasized by events such as the Fukushima accident in 2011. The design is based on readily accessible components, which lessens reliance on costly, specialized hardware like FieldProgrammable Gate Arrays (FPGAs) and ApplicationSpecific Integrated Circuits (ASICs). The proposed system comprises two types of detectors: inorganic scintillators, specifically CsI:tl and GAGG:ce, paired with Silicon Photomultipliers (SiPMs) for gamma-ray detection, and solid-state detectors provided with a
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Li converter for thermal neutron detection. These detectors operate independently, increasing redundancy and system reliability. The system’s performance, evaluated through extensive testing, has shown significant improvements in linearity and noise characteristics over previous iterations. Beyond its primary function in emergency response, the system could find applicability in diverse fields such as environmental radiation monitoring, geological surveys, industrial inspections, and scientific research.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Anatomical variations in the liver arterial supply are quite common and can affect the surgical strategy when performing a minimally invasive pancreaticoduodenectomy (MIPD). Their presence must be ...preemptively detected to avoid postoperative liver and biliary complications.
Following the PRISMA guidelines and the Cochrane protocol we conducted a systematic review on the management of an accessory or replaced right hepatic artery (RHA) arising from the superior mesenteric artery when performing an MIPD.
Five studies involving 118 patients were included. The most common reported management of the aberrant RHA was conservative (97.0%); however, patients undergoing aberrant RHA division without reconstruction did not develop liver or biliary complications. No differences in postoperative morbidity or long-term oncological related overall survival were reported in all the included studies when comparing MIPD in patients with standard anatomy to those with aberrant RHA.
MIPD in patients with aberrant RHA is feasible without increase in morbidity and mortality. As preoperative strategy is crucial, we suggested planning an MIPD with an anomalous RHA focusing on preoperative vascular aberrancy assessment and different strategies to reduce the risk of liver ischemia.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The main purpose of engineering applications for fluid with natural and mixed convection is to control or enhance the flow motion and the heat transfer. In this paper, we use mathematical tools based ...on optimal control theory to show the possibility of systematically controlling natural and mixed convection flows. We consider different control mechanisms such as distributed, Dirichlet, and Neumann boundary controls. We introduce mathematical tools such as functional spaces and their norms together with bilinear and trilinear forms that are used to express the weak formulation of the partial differential equations. For each of the three different control mechanisms, we aim to study the optimal control problem from a mathematical and numerical point of view. To do so, we present the weak form of the boundary value problem in order to assure the existence of solutions. We state the optimization problem using the method of Lagrange multipliers. In this paper, we show and compare the numerical results obtained by considering these different control mechanisms with different objectives.
Bariatric surgery has shown to be effective in producing sustained weight loss and the resolution of obesity related medical problems. Recent research focused on the role of obesity and adipose ...tissue in tumorigenesis, finding a strong crosslink through different mechanisms and highlighting an increase in cancer incidence in individuals with obesity. The aim of this meta-analysis is to find if bariatric surgery reduces the incidence of colorectal cancer in patients with obesity. We performed a meta-analysis including 18 studies (PROSPERO ID: CRD4202235931). Bariatric surgery was found to be significantly protective toward colorectal cancer incidence in individuals with obesity (HR: 0.81,
= 0.0142). The protective effect persisted when considering women (RR: 0.54,
= 0.0014) and men (RR: 0.74,
= 0.2798) separately, although this was not significant for the latter. No difference was found when comparing Roux-en-Y gastric bypass and sleeve gastrectomy. Bariatric surgery reduces the incidence of colorectal cancer in individuals with obesity independently from gender and surgical procedure. Prospective large cohort studies are needed to confirm these findings.
This study addresses the optimization of the location of a radioactive-particle sensor on a drone. Based on the analysis of the physical process and of the boundary conditions introduced in the ...model, computational fluid dynamics simulations were performed to analyze how the turbulence caused by drone propellers may influence the response of the sensors. Our initial focus was the detection of a small amount of radioactivity, such as that associated with a release of medical waste. Drones equipped with selective low-cost sensors could be quickly sent to dangerous areas that first responders might not have access to and be able to assess the level of danger in a few seconds, providing details about the source terms to Radiological-Nuclear (RN) advisors and decision-makers. Our ultimate application is the simulation of complex scenarios where fluid-dynamic instabilities are combined with elevated levels of radioactivity, as was the case during the Chernobyl and Fukushima nuclear power plant accidents. In similar circumstances, accurate mapping of the radioactive plume would provide invaluable input-data for the mathematical models that can predict the dispersion of radioactivity in time and space. This information could be used as input for predictive models and decision support systems (DSS) to get a full situational awareness. In particular, these models may be used either to guide the safe intervention of first responders or the later need to evacuate affected regions.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Background: Roux-en-Y gastric bypass (RYGB) is currently one of the most performed bariatric procedures and it is associated with rapid weight loss. However, weight loss failure and weight regain ...after RYGB occurs in approximately 30% and 3−5% of patients, respectively, and represent a serious issue. RYGB pouch resizing is a surgical option that may be offered to selected patients with RYGB failure. The aim of this study is to assess long-term results of pouch resizing for RYGB failure. Materials and Methods: From February 2009 to November 2011, 20 consecutive patients underwent gastric pouch resizing for RYGB failure in our tertiary bariatric center. The primary outcome was the rate of failure (%EWL < 50% with at least one metabolic comorbidity) after at least 10 years from pouch resizing. Gastroesophageal Reflux Disease (GERD) was also assessed. Results: Twenty patients (18 women (90%)) were included and seventeen (85%) joined the study. The failure rate of pouch resizing was 47%. Mean %EWL and mean BMI were 47%, and 35.1 kg/m2, respectively. Some of the persistent co-morbidities further improved or resolved after pouch resizing. Seven patients (41%) presented GERD requiring daily PPI with a significantly lower GERD-HQRL questionnaire score after pouch resizing (p < 0.001). Conclusion: Pouch resizing after RYGB results in a failure rate of 47% at the 10-year follow-up while the resolution of comorbidities is maintained over time despite a significant weight regain.
Fluid-structure interaction (FSI) problems are of great interest, due to their applicability in science and engineering. However, the coupling between large fluid domains and small moving solid walls ...presents numerous numerical difficulties and, in some configurations, where the thickness of the solid wall can be neglected, one can consider membrane models, which are derived from the Koiter shell equations with a reduction of the computational cost of the algorithm. With this assumption, the FSI simulation is reduced to the fluid equations on a moving mesh together with a Robin boundary condition that is imposed on the moving solid surface. In this manuscript, we are interested in the study of inverse FSI problems that aim to achieve an objective by changing some design parameters, such as forces, boundary conditions, or geometrical domain shapes. We study the inverse FSI membrane model by using an optimal control approach that is based on Lagrange multipliers and adjoint variables. In particular, we propose a pressure boundary optimal control with the purpose to control the solid deformation by changing the pressure on a fluid boundary. We report the results of some numerical tests for two-dimensional domains to demonstrate the feasibility and robustness of our method.
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