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Voss, R. "Radioactive and kinematic tracers of feedback from massive stars". EPJ Web of Conferences 19 (2012): 10004. http://dx.doi.org/10.1051/epjconf/20121910004.
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Iwata, Ren, Shigeki Yamazaki y Tatsuo Ido. "Automated injection of a radioactive sample for preparative HPLC with feedback control". International Journal of Radiation Applications and Instrumentation. Part A. Applied Radiation and Isotopes 41, n.º 12 (enero de 1990): 1225–27. http://dx.doi.org/10.1016/0883-2889(90)90211-x.
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Pysklywec, Russell N. y Christopher Beaumont. "Intraplate tectonics: feedback between radioactive thermal weakening and crustal deformation driven by mantle lithosphere instabilities". Earth and Planetary Science Letters 221, n.º 1-4 (30 de abril de 2004): 275–92. http://dx.doi.org/10.1016/s0012-821x(04)00098-6.
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Peng, Tianlin, Dewen Tang y Jianing Wu. "Design of an autonomous navigation system for emergency disposal robots at radioactive waste sites under extreme climatic conditions". Journal of Physics: Conference Series 2419, n.º 1 (1 de enero de 2023): 012088. http://dx.doi.org/10.1088/1742-6596/2419/1/012088.
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Abstract There are many factors of environmental hazards that endanger the lives of personnel at radioactive waste sites after sudden extreme weather disasters, and the use of robotic substitutes can effectively safeguard the lives of personnel. For the situation where the environmental information of radioactive waste sites is unknown and there are many variables, an autonomous navigation system of emergency disposal robots with strong resilience and stability is designed. First, an algorithm based on the Rao-Blackwellized particle filtering theory is used in the autonomous navigation system to achieve more accurate robot positioning and map building through four processes: prediction, correction, resampling, and map building. Second, the traditional path planning algorithm combined with road information is added to Hopfield neural network to achieve deep analysis of complex road conditions. Finally, the intelligent voice interaction function is added to the navigation system to realize the robot’s interaction and real-time monitoring and feedback. The experimental results show that the emergency disposal robot has high accuracy in positioning, navigation, obstacle avoidance, etc., can respond quickly in unexpected situations and can carry out effective voice interaction.
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Huang, Hanzhi. "Current status and applications of time-to-digital converters". Applied and Computational Engineering 53, n.º 1 (28 de marzo de 2024): 79–83. http://dx.doi.org/10.54254/2755-2721/53/20241275.
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Time-to-Digital Converter (TDC) is widely used to realize time interval measurement. The high-precision time measurement technique has important applications in the fields of laser ranging, particle identification, and radioactive nuclear medicine engineering. Based on the existing literature research and data, this paper studies the application areas of TDC in the present development and analyzes the future prospects of TDC applications. The research results showed that: TDC, based on signal screening, realizes time interval measurement as the ultimate purpose of building the system and, at the same time, completes the function of multi-pulse time interval measurement, which can meet the needs of more diversified measurements in the experiments. In the circuit structure, it can identify the feedback output in the all-digital phase-locked loop (ADPLL) and the reference clock phase and frequency information between the feedback output and the reference clock in an ADPLL. It is also promising for use in other areas of high-precision time measurement and processing of circuit signals.
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Lin, Xiaofeng, Shoujun Zhou, Tiexiang Wen, Shenghao Jiang, Cheng Wang y Jingtao Chen. "A novel multi-DoF surgical robotic system for brachytherapy on liver tumor: Design and control". International Journal of Computer Assisted Radiology and Surgery 16, n.º 6 (1 de mayo de 2021): 1003–14. http://dx.doi.org/10.1007/s11548-021-02380-7.
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Abstract Purpose Radioactive seed implantation is an effective invasive treatment method for malignant liver tumors in hepatocellular carcinomas. However, challenges of the manual procedure may degrade the efficacy of the technique, such as the high accuracy requirement and radiation exposure to the surgeons. This paper aims to develop a robotic system and its control methods for assisting surgeons on the treatment. Method We present an interventional robotic system, which consists of a 5 Degree-of-Freedom (DoF) positioning robotic arm (a 3-DoF translational joint and a 2-DoF revolute joint) and a needle actuator used for needle insertion and radioactive seeds implantation. Control strategy is designed for the system to ensure the safety of the motion. In the designed framework, an artificial potential field (APF)-based motion planning and an ultrasound (US) image-based contacting methods are proposed for the control. Result Experiments were performed to evaluate position and orientation accuracy as well as validate the motion planning procedure of the system. The mean and standard deviation of targeting error is 0.69 mm and 0.33 mm, respectively. Needle placement accuracy is 1.10 mm by mean. The feasibility of the control strategy, including path planning and the contacting methods, is demonstrated by simulation and experiments based on an abdominal phantom. Conclusion This paper presents a robotic system with force and US image feedback in assisting surgeons performing brachytherapy on liver tumors. The proposed robotic system is capable of executing an accurate needle insertion task with by optical tracking. The proposed methods improve the safety of the robot’s motion and automate the process of US probe contacting under the feedback of US-image.
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Pan, Lung-Fa, Chao-Yu Chiang, Chao-Chun Huang, Hua-Tsan Kao, Chih-Feng Chen, Bing-Ru Peng y Lung-Kwang Pan. "Thyroid Biokinetics for Radioactive I-131 in Twelve Thyroid Cancer Patients via the Refined Nine-Compartmental Model". Applied Sciences 12, n.º 11 (30 de mayo de 2022): 5538. http://dx.doi.org/10.3390/app12115538.
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The thyroid biokinetic model of radioactive I-131 was re-evaluated using a refined nine-compartmental model and applied to twelve thyroid cancer patients. In contrast to the simplified four-compartmental model regulated by the ICRP-56 report, the revised model included nine compartments specified in the ICRP-128 report, namely, oral, stomach, body fluid, thyroid, whole body, liver, kidney, bladder, and remainder (i.e., the whole body minus kidney and bladder). A self-developed program run in MATLAB was designed to solve the nine first-order simultaneous linear differential equations. The model was realized in standard and simplified versions. The latter neglected two feedback paths (body fluid to oral, i31, and kidney to the whole body, i87) to reduce computations. Accordingly, the biological half-lives for the major compartments (thyroid and body fluid + whole body) were 36.00 ± 15.01, 15.04 ± 5.63, 34.33 ± 15.42, and 14.83 ± 5.91 of standard and simplified version. The correlations between theoretical and empirical data for each patient were quantified by the dimensionless AT (agreement) index and, the ATtot index integrated each individual AT of a specific organ of one patient. Since small AT values indicated a closer correlation, the obtained range of ATtot (0.048 ± 0.019) proved the standard model’s reliability and high accuracy, while the simplified one yielded slightly higher ATtot (0.058 ± 0.023). The detailed outcomes among various compartments of twelve patients were calculated and compared with other researchers’ work. The correlation results on radioactive I-131 evolution in thyroid cancer patients’ bodies are instrumental in viewpoint of radioactive protection of patients and radiological personnel.
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Wissmeier, Laurin y Joachim Poppei. "Simulating the feedback between corrosive gas generation and water availability for the evaluation of radionuclide mobility in the context of radioactive waste disposal". Safety of Nuclear Waste Disposal 1 (10 de noviembre de 2021): 109–10. http://dx.doi.org/10.5194/sand-1-109-2021.
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Abstract. It has been recently recognized that the availability of liquid water may be a controlling factor in the feedback between the physical processes of variably saturated liquid and gas flow on the one hand, and various chemical processes such as metal corrosion in an underground storage facility for radioactive waste on the other hand (e.g., Huang et al., 2021, and reference therein). Iron corrosion in anoxic conditions produces hydrogen gas and consumes water, as expressed by the following stylized chemical equation (e.g., Diercks and Kassner, 1988; Senior et al., 2021): 3Fe+4H2O⟶Fe3O4+4H2 Since water is an educt the corrosion reaction may be suspended or suppressed by the scarcity of water near the corroding surfaces. At the same time, gas pressure build-up through hydrogen generation may limit further water ingress. We developed a model that focuses on the close coupling between gas generation through iron corrosion and water availability. The feedback between iron corrosion, gas generation and liquid phase flow is considered by implementing the corrosion reaction in the subsurface flow and transport simulator PFLOTRAN (Hammond et al., 2012; Lichtner et al., 2015, 2020) making use of its coding provisions to implement source/sink terms for water and gas. These source/sink terms reflect the kinetics of the iron corrosion and its dependence on the educts, where the availability of water is approximated by the local liquid saturation. The model was applied to evaluate the mobility of radionuclides in, and their release from a hypothetical geological storage facility for radioactive waste. The radionuclides are traced through the emplacement chambers and drift by means of advective and diffusive transport. Parameter variations illustrate the influence of crucial modelling parameters on the simulation results.
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Васин, М., M. Vasin, В. Соловьев, V. Solov'ev, В. Мальцев, V. Maltsev, И. Андрианова, I. Andrianova, С. Лукьянова y S. Luk'yanova. "Primary Radiation Stress, Inflammatory Reaction and the Mechanism of Early Postradiation Reparative Processes in Irradiated Tissues". Medical Radiology and radiation safety 63, n.º 6 (12 de noviembre de 2018): 71–81. http://dx.doi.org/10.12737/article_5c0eb50d2316f4.12478307.
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The products of radiolysis released from cellular compartment under the influence of ionizing radiation: highly mobile groups of proteins, damaged nuclear and mitochondrial DNA, extracellular ATP and oxidized low density lipoproteins, cause stress activation in irradiated tissues through a pattern of the receptors with start of the cascade r53 and NF-κB of pro-inflammatory ways conducting to an expression of pro-inflammatory genes stimulating synthesis of cytokines of the IL-1 family. Excessive activation of pro-inflammatory way under the influence of a radioactive stress is limited to synthesis, anti-inflammatory cytokines: IL-4, IL-10, IL-11, IL-13 and also antagonists of IL-1 receptor and TGF-β. G-CSF and MG-CSF induced by action of pro-inflammatory cytokines have anti-inflammatory and anti-apoptotic properties decreasing level of pro-inflammatory cytokines IL-6 and TNF. Glucocorticoids participate in regulation of primary radioactive stress, suppressing an excessive expression of genes of pro-inflammatory cytokines. Increased IL-1 level stimulates secretion of corticosteroids through mechanism of feedback. Adrenergic stimulation is capable to raise a gene IL-1β expression. The mechanism of radiation apoptosis of stem cells is implemented through p53-Puma way which blocks interaction anti-apoptotic proteins of Bcl-2 with pro-apoptotic proteins of Bax and Bak. After release from mitochondrion of cytochrome C and apoptosis-inducing factor there is an activation of effector caspases: caspases 3, 6 and 7 through caspase 9, and final cell destruction. Wnt way is crucial for post-radiation repair. Potential of the regenerative response of hemopoietic tissue to radiation injury depends on catenin and ability of Wnt way to stimulate post-radiation bone marrow reparation. Mesenchymal stem cells of bone marrow play a large role in post-radiation regeneration of hemopoietic tissue. Their main action is carried out through TLR2 and TLR4 receptors. Mobilization of hemopoietic stem cells is bound to release proteases from bone marrow, including neutrophil elastase and cathepsin G, and a matrix metalproteinase-9. Radioprotective properties of exogenous IL-1 aren’t limited only by induction of raised G-CSF and GM-CSF production. The larger role in radiation protection is played by the reaction induced by IL-1 in the form of feedback with production anti-apoptotic and anti-inflammatory factors. Primary radioactive stress limits time of radiomitigable effect of IL-1 by 1-2 h after its application after radiation.
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Stevanović, Jelenka Savković. "Ecosystem Energy Changes". International Journal of Research and Scientific Innovation X, n.º XII (2024): 267–75. http://dx.doi.org/10.51244/ijrsi.2023.1012022.
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In this paper energy in ecosystem was studied. Energy balance equations of ecosystem were derived. Most of the energy in the Earth’s system comes from just a few sources: solar energy, gravity, radioactive decay, and the rotation of the earth. Earth is constantly changing as energy flows through the system. Earth’s weather and climate are mostly driven by energy from the Sun. The Sun provides the energy that drives the water cycle on Earth. In this paper different forms of energy, specific types, using and energy conservation were studied. Environments are highly complex systems whose evolution is determined by complicated networks of positive and negative feedback loops. In this paper macroscopic and microscopic approaches to energy flow through the ecosystem have been used.
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Pauwels, H., P. Daures, Y. J. Stockmann y J. Végh. "Cooperation between SSTC NRS and the EU in the Area of Nuclear Safety". Nuclear and Radiation Safety, n.º 2(74) (22 de mayo de 2017): 3–8. http://dx.doi.org/10.32918/nrs.2017.2(74).01.
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The paper first briefly outlines the main characteristics of the EU assistance programs aimed to enhance nuclear safety in the Beneficiary countries. Then EU assistance provided to the Ukrainian regulator (SNRIU) is detailed, with specific emphasis on projects enhancing the capabilities of SSTC NRS as technical support organisation (TSO) to SNRIU, including training and tutoring (T&T) activities. The changing role of SSTC NRS in the cooperation activities is described as well. The broad range of cooperation is then illustrated by some selected projects focusing on various technical areas (e.g. severe accident management and mitigation, radioactive waste and spent fuel management, NPP service time extension, plant performance monitoring and operating experience feedback).
Finally, the paper briefly discusses the future perspectives of the nuclear safety cooperation between the EU and Ukraine.
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Regal, Georg, Daniele Pretolesi, Helmut Schrom-Feiertag, Jaison Puthenkalam, Massimo Migliorini, Elios De Maio, Francesca Scarrone et al. "Challenges in Virtual Reality Training for CBRN Events". Multimodal Technologies and Interaction 7, n.º 9 (11 de septiembre de 2023): 88. http://dx.doi.org/10.3390/mti7090088.
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The contemporary geopolitical environment and strategic uncertainty shaped by asymmetric and hybrid threats urge the future development of hands-on training in realistic environments. Training in immersive, virtual environments is a promising approach. Immersive training can support training for contexts that are otherwise hard to access, dangerous, or have high costs. This paper discusses the challenges for virtual reality training in the CBRN (chemical, biological, radioactive, nuclear) domain. Based on initial considerations and a literature review, we conducted a survey and three workshops to gather requirements for CBRN training in virtual environments. We structured the gathered insights into four overarching themes—the future of CBRN training, ethical and safety requirements, evaluation and feedback, and tangible objects and tools. We provide insights on these four themes and discuss recommendations.
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Wei, X., P. Wang y F. Zhao. "Optimal operation strategy of LWR based on the PCI online prognosis model". Kerntechnik 85, n.º 2 (1 de diciembre de 2020): 98–104. http://dx.doi.org/10.1515/kern-2020-850206.
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Abstract The pellet-cladding interaction (PCI) is one of the major issues in fuel rod during the power change operation in light water reactors (LWR). The frequent power transient will lead to the PCI failure, which results in the radioactive leakage. Unfortunately, the failure cannot be detected on time during operation. For solving this problem, the PCI results is calculated and predicted before the power transient, and the results is used for optimizing the operation strategy. As everyone knows, the calculation of the fuel is a cumbersome work, which is not fit for online evaluation. At first, we present a PCI online prognosis model in this paper by the method of radial basis function neural network (RBFNN). Based on this online model, an optimal operation strategy is present then. The PCI evaluation results is treated as the feedback of the strategy, which will go to the power control system to decide to carry out the power plan or to modify it. The presented operation strategy used the fast online prognosis model to predict the PCI status, which is used as a feedback signal to the power control system. The optimal operation strategy is tested by the experimental data from the references, and the results demonstrate its effectiveness.
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Krause, Martin G. H., Donna Rodgers-Lee, James E. Dale, Roland Diehl y Chiaki Kobayashi. "Galactic 26Al traces metal loss through hot chimneys". Monthly Notices of the Royal Astronomical Society 501, n.º 1 (24 de noviembre de 2020): 210–18. http://dx.doi.org/10.1093/mnras/staa3612.
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ABSTRACT Radioactive 26Al is an excellent tracer for metal ejection in the Milky Way, and can provide a direct constraint on the modelling of supernova feedback in galaxy evolution. Gamma-ray observations of the 26Al decay line have found high velocities and hence require a significant fraction of the Galactic 26Al in the hot component. At the same time, meteoritic data combined with simulation results suggest that a significant amount of 26Al makes its way into stars before decay. We investigated the distribution into hot and cold channels with a simulation of a Milky-Way-like galaxy with massive-star feedback in superbubbles and with ejecta traced by 26Al. About 30–40 per cent of the ejecta remain hot, with typical cooling times of the order Gyr. 26Al traces the footpoints of a chimney-fed outflow that mixes metals turbulently into the halo of the model galaxy on a scale of at least 50 kpc. The rest diffuses into cold gas ≲ 104 K, and may therefore be quickly available for star formation. We discuss the robustness of the result by comparison to a simulation with a different global flow pattern. The branching ratio into hot and cold components is comparable to that of longer term average results from chemical evolution modelling of galaxies, clusters, and the intracluster medium.
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Ormai, Peter, Bálint Nős, Jiří Faltejsek, Jitka Mikšová, Nadja Železnik, Irena Mele, Kateryna Fuzik, Paul Carbol, Anthony Banford y Erika Holt. "Development of guidance documents in the EURAD and PREDIS projects". EPJ Nuclear Sciences & Technologies 8 (2022): 39. http://dx.doi.org/10.1051/epjn/2022035.
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Particular emphasis is dedicated to Knowledge Management activities within the EURAD (European Joint Programme on Radioactive Waste Management) and PREDIS (Pre-disposal management of radioactive waste) projects to ensure the capture of existing knowledge, transfer of knowledge between Members States and management of the knowledge for future generations. The EURAD project has three work packages dedicated to knowledge management. One of them, the EURAD Guidance work package (WP12) is developing a comprehensive suite of specific guidance documents that can be used by Members States with radioactive waste management (RWM) programmes that are at an early stage of development but can be beneficial also to more advanced programmes. The PREDIS project does not have a specifically allocated work package for guidance development. Rather, such activities are integrated within deliverables produced as part of the Strategic Implementation and State of Knowledge actions of the Roadmap contributions on predisposal waste management. The EURAD guidance work is based on the existing PLANDIS guide on RD&D planning, developed by the Implementing Geological Disposal of Radioactive Waste Technology Platform (IGD-TP). The guidance documents complement other documents prepared in parallel knowledge management activities inside EURAD project: the State of Knowledge documents. The differentiation is that guidance documents explain in more detail how the process can be established and performed, including illustrative examples. The guides are self-standing documents and integrated with the EURAD Roadmap. The target end users of the guidance are primarily programme owners and managers (i.e., governments/administrations, Waste Management Organisations, Research Entities and Technical Support Organisations) responsible for planning and implementing the RWM programme and the supporting RD&D activities at a national level, even though they might also be of use and interest to other interested stakeholders, such as representatives of civil society. To produce a first list of prioritised topics for guidance documents with the aim to select a topic for a pilot guide, the Guidance WP has developed a screening process that includes review by experts and end users. Based on the priority list, the first pilot guide was developed with the title “Cost Assessment and Financing Schemes of Radioactive Waste Management Programmes”. Experience gained during the selection of topics for the pilot guide and during its production are being incorporated into the procedure for identification of new topics for which guides will be developed. First, the degree of coverage of the EURAD Roadmap themes by suitable guide documents will be analysed by the WP 12 team. The analysis will be combined with feedback from experts verifying the needs for missing guides. Finally, the potential end user community representatives will be given the opportunity to comment on the prioritisation of selected guidance documents and make additional suggestions. The potential end users stay involved also during the production of the guides. This procedure aims to optimise the scarce expert resources in relation to the identified needs of guidance documents. This article explains the approach for selecting topics for guidance documents and the results obtained both in EURAD and PREDIS.
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Pleintinger, Moritz M. M., Thomas Siegert, Roland Diehl, Yusuke Fujimoto, Jochen Greiner, Martin G. H. Krause y Mark R. Krumholz. "Comparing simulated 26Al maps to gamma-ray measurements". Astronomy & Astrophysics 632 (diciembre de 2019): A73. http://dx.doi.org/10.1051/0004-6361/201935911.
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Context. The diffuse gamma-ray emission of 26Al at 1.8 MeV reflects ongoing nucleosynthesis in the Milky Way and traces massive-star feedback in the interstellar medium due to its 1 Myr radioactive lifetime. The morphology and dynamics of the interstellar medium are investigated in astrophysics through 3D hydrodynamic simulations in fine detail as there are few suitable astronomical probes available. Aims. We aim to compare a galactic-scale hydrodynamic simulation of the Galaxy’s interstellar medium, including feedback and nucleosynthesis, with gamma-ray data on 26Al emission in the Milky Way, extracting constraints that are only weakly dependent on the particular realisation of the simulation or Galaxy structure. Methods. Due to constraints and biases in both the simulations and the gamma-ray observations, such comparisons are not straightforward. For a direct comparison, we performed maximum likelihood fits of both simulated sky maps and observation-based maximum entropy maps to measurements using INTEGRAL/SPI. In order to study general morphological properties, we compare the scale heights of 26Al emission produced by the simulation to INTEGRAL/SPI measurements. Results. The direct comparison shows that the simulation describes the observed inner Galaxy well, however it differs significantly from the observed full-sky emission morphology. Comparing the scale height distribution, we see similarities for small-scale height features and a mismatch at larger-scale heights. We attribute this to prominent foreground emission sites which are not captured by the simulation.
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Benbow, Steven, James Wilson, Richard Metcalfe y Jarmo Lehikoinen. "Avoiding unrealistic behaviour in coupled reactive-transport simulations of cation exchange and mineral kinetics in clays". Clay Minerals 54, n.º 1 (14 de febrero de 2019): 83–93. http://dx.doi.org/10.1180/clm.2019.7.
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AbstractBentonite clay is often included as a buffer, backfill and/or sealing material in designs for deep geological repositories for radioactive wastes. It is expected that bentonite materials may undergo some mineralogical alteration as they interact with in situ groundwaters over long timescales on the order of thousands to millions of years. Long-term modelling of these materials is therefore important in order to demonstrate confidence that the engineered designs will continue to perform as required over their intended lifetimes (required assessment timescales can be up to 1 million years). The key geochemical processes that must be considered in such modelling are mineral dissolution and precipitation and cation exchange. These processes are expected to occur simultaneously and so modelling of their coupled effects and their rates (kinetics) is necessary. Illustrative reactive-transport models of the geochemical alteration of montmorillonite (the primary mineral in bentonite exhibiting cation exchange) are presented which demonstrate that one possible approach to fully coupling cation exchange and clay mineral dissolution kinetics, referred to here as the ‘all-component coupling’ approach, may lead to unrealistic behaviour due to feedback that may occur in the formulation. This feedback can be avoided if a ‘common-component’ conceptual model for the dissolution of exchanger end members is adopted, where only the saturation of the exchanger ‘structural unit’ is considered when evaluating the potential for dissolution of the mineral. Such considerations have been proposed historically in stability analyses for montmorillonite, but have not been explored widely in the modelling literature.
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Wang, Yuan Ming, Yong Ming Zhang, Heng Ze Zhao y Lan Ming Zhao. "Experimental Investigation of Downward Flame Spread over RPU Samples". Applied Mechanics and Materials 328 (junio de 2013): 921–25. http://dx.doi.org/10.4028/www.scientific.net/amm.328.921.
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The combustion process of polymer is a complex coupling of energy feedback from flame to fuel surface with degradation of polymer. In this paper, a series of comparative laboratory-scale experiments were carried out to study the effect of sample width on downward flame spread over the rigid polyurethane (RPU) foam, a typical thermal insulation material. The variations of some important parameters such as flame height, pulsation frequency and flame spread rate were measured and analyzed. Results show that if the width fixed, the parameters mentioned above independent with time. If the width less than 25cm, the sample can not burn completely. With the expand of width, average flame height and flame spread rate present the same chang trend that increase first and then decrease and finally reach a steady state, flame pulsation frequency increases first and then decreases since sample width more than 20cm. The heat transfer from flame and pyrolysis zone to virgin region is proportional to the height of flame, and mainly dominated by radioactive regime.
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Diehl, Roland, Jochen Greiner, Martin G. H. Krause, Moritz M. M. Pleintinger y Thomas Siegert. "Gamma-ray spectroscopy of galactic nucleosynthesis". EPJ Web of Conferences 279 (2023): 02001. http://dx.doi.org/10.1051/epjconf/202327902001.
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Diffuse gamma-ray emission from the decay of radioactive 26Al is a messenger from the nucleosynthesis activity in our current-day galaxy. Because this material is attributed to ejections from massive stars and their supernovae, the gamma-ray signal includes information about nucleosynthesis in massive star interiors as it varies with evolutionary stages, and about their feedback on the surrounding interstellar medium. Our method of population synthesis of massive-star groups has been refined as a diagnostic tool for this purpose. It allows to build a bottom-up prediction of the diffuse gamma-ray sky when known massive star group distributions and theoretical models of stellar evolution and core-collapse supernova explosions are employed. We find general consistency of an origin in such massive-star groups, in particular we also find support for the clumpy distribution of such source regions across the Galaxy, and characteristics of large cavities around these. A discrepancy in the integrated 26Al gamma-ray flux is interpreted as an indication for excess 26Al emission from nearby, distributed in cavities that extend over major regions of the sky.
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Li, XianLing, DongJiang Han, XinFa Dai, ShuYu Lv, Mo Tao, Wei Zheng y YiBin Tang. "Fault Diagnosis to Nuclear Power Plant System Based on Time-Series Convolution Neural Network". Wireless Communications and Mobile Computing 2022 (5 de septiembre de 2022): 1–14. http://dx.doi.org/10.1155/2022/3323239.
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Nuclear power plant (NPP) is a highly complex engineering system which has typical internal feedback and strong component coupling. With these features, most NPP systems have high risk of radioactive release, which makes it essential to perform fault detection (FD) to the NPP systems. To address this challenge, this paper proposes a FD mechanism named characteristic time-series convolutional neural network (CT-CNN) based on principal component analysis (PCA), time-series analysis, and convolutional neural network (CNN) mechanisms. First, the models of NPP FD system are formulated. Then, the PCA mechanism is applied to extract the features of the NPP system. Next, the time-series analysis and CNN approaches are applied to realize FD to the NPP system. With the above mechanisms, the proposed approach has not only shown strong stability and become adaptive to different data set, but also preserves both time and state characteristics of the NPP system. In experiment, it shows the proposed approach can achieve better performance in both detection accuracy and variance than the classic back propagation, LSTM method, and standard CNN algorithms. More significantly, its optimal accuracy can be as high as 99.8%.
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Medeckytė, Kamilė y Daiva Tamulevičienė. "Development of environmental management accounting system: a conceptual approach". Buhalterinės apskaitos teorija ir praktika, n.º 27 (2 de mayo de 2023): 2. http://dx.doi.org/10.15388/batp.2023.51.
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With the rise of environmental problems caused by human activities, such as misuse of natural resources, rapid deforestation, and discharge of radioactive and other chemical waste into water bodies, soil and the atmosphere, environmental management accounting has emerged as a tool for promoting sustainable development and reducing negative environmental impacts in businesses. This area of accounting provides a means for analyzing, assessing, controlling, and managing the environmental performance of companies. However, there is a dearth of studies in the scientific literature that systematically assess the potential for introducing and developing environmental management accounting in an enterprise. Therefore, this study aims to identify the areas, instruments, outcome, impact measures, and other elements of environmental management accounting, and integrate them in a targeted manner to develop a conceptualized environmental management accounting system. The results of the literature review and systematic analysis are summarized to provide a conceptual framework for an environmental management accounting system consisting of the following elements: 1) objectives; 2) inputs; 3) processes; 4) outputs/outcomes; 5) feedback; and 6) external environmental conditions. The introduction of such a system would improve the development of environmental management accounting for the long-term sustainability and eco-efficiency of companies.
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Tatomir, Alexandru, Milena Schönhofen-Romer, Astrid Göbel, Dinara Abbasova, Thuro Arnold, Vinzenz Brendler y Kateryna Fuzik. "Procedures to involve knowledge providers for capturing the state of knowledge in radioactive waste management: insights from the European Joint Programme on Radioactive Waste Management". Safety of Nuclear Waste Disposal 2 (6 de septiembre de 2023): 225–26. http://dx.doi.org/10.5194/sand-2-225-2023.
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Abstract. Capturing the state of knowledge (SoK) in radioactive waste management (RWM) is a very important activity for supporting member states with the implementation of their national programmes towards the safe and effective management of radioactive waste. This requires the involvement of experts (i.e. persons widely recognised to be a reliable source of knowledge or have techniques or skills) who can share their expertise and knowledge with the wider community through the production of knowledge management (KM) documents (i.e. of domain insight (DI) and SoK; Knuuti et al., 2022). During the past 3 years, the European Joint Programme on Radioactive Waste Management (EURAD) has gained valuable insights into the procedures of involving experts and knowledge sharing. These lessons can be useful for other organisations who want to engage knowledge providers in capturing the SoK in the field of RWM. The process of expert involvement for the KM document production (i.e. authorship and review) can be divided into the following three different steps: (1) identification and selection, (2) engagement, and (3) support. The major challenges identified when involving the knowledge providers (i.e., authors and reviewers of the KM documents) are the limited resources and the motivation of experts. Experts are in high demand and therefore often have limited resources available for taking on additional work. Thus, it is important to provide a clear description of the work that needs to be done and to outline any potential incentives for the expert to take part (e.g. providing a real benefit to end-users). Other factors are to stay flexible in the scheduling and in the processes, as experts may have limited availability, and then there is also financial compensation. Often, experts' employers cannot allow them to work without compensation. Building personal connections and trust over time can also help to encourage experts to participate. If the expert is asked to contribute to the EURAD KM programme by an esteemed colleague of many years, then this may lead to a greater commitment than from an open call for volunteers. Feedback on the process was collected through interviews with the experts and reviewers, workshops, conferences (e.g. annual events), personal communication, questionnaires, from the mid-term review of the KM programme, and from personal observations of the authors. Knowledge sharing encompasses various factors, including the organisational context, interpersonal and team characteristics, cultural and individual traits, and motivational factors (Wang and Noe, 2010). Identified motivational factors include recognition, building personal connections, building reputation, social obligation (e.g. request from a peer in the field, a friend, or a colleague), convenience (e.g. knowing the project), content of benefit (e.g. awareness), and social motivations (e.g. contributing to society). Moreover, experience has also shown that, regardless of the personal connection, face-to-face support for the experts is indispensable. Effective communication, openness, and a sense of collegiality, in addition to a climate of trust, are key elements for the creation of an engaging environment promoting tacit knowledge sharing. Furthermore, the engagement of experts can also be facilitated by providing high-quality examples of DI and SoK documents (e.g. see the EURAD Roadmap; Beattie et al., 2022). As the number of published documents increases, it is reasonable to assume that expert involvement will become easier. Overall, a good connection to experts is an important benefit for the EURAD KM programme. Strengthening the connection to the EURAD research work packages by establishing KM ambassadors facilitates the involvement of experts. Expert participation in upcoming initiatives should involve activities to promote and disseminate knowledge, in addition to updating the KM documents, as this is required as new knowledge emerges. By maintaining a high level of output from top experts, interested end-users will be attracted and trust in EURAD will be strengthened.
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Brito, H., R. Cazar, N. Moreno, J. Quintanilla, M. Inca, M. Guillen, D. Zavala y P. Robalino. "Manejo De Residuos Sólidos Hospitalarios En La Unidad Oncológica Solca-Chimborazo". European Scientific Journal, ESJ 12, n.º 8 (30 de marzo de 2016): 423. http://dx.doi.org/10.19044/esj.2016.v12n8p423.
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It was determined that the handling of the solid waste generated by the SOLCA – Chimborazo cancer hospital was not appropriate, both internally and externally. Because of that, the classification, transport, storage, deactivation, and intermediate disposition are inconvenient. Thus, it was realized that it is important to have the requirements and documents to follow and comply the objectives that are specified within the management, focusing on feedback and continuous improvement. To learn about the nature of the generated residuals, they were characterized in the hospital. Common, infectious, radioactive, organic and sharp residuals were found during the months of September, November and December. The common waste is comprised of cardboard, paper and plastic. The per-capita production of residuals was 0.76 kg/patient/day. The environmental impact caused by the generation of hospital solid waste was 56% severe impacts and 44% moderate impacts, which could elicit health problems in the population surrounding the hospital. For this reason, the appropriate management of solid waste allowed to obtain large environmental benefits and reduce the pollution generated by the hospital solid waste. It is recommended to SOLCA-Chimborazo and other health institutions the implementation of an adequate solid waste management, which will allow them to comply with all the requirements enforced by the environmental regulations.
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Papafotiou, Alexandros, Argha Namhata, Abhishek Singh, Mark Williams, Marius Jigmond y Paul Marschall. "A workflow for parametric sensitivity analysis of heat and gas release from a deep geological repository for SF/HLW". Geological Society, London, Special Publications 482, n.º 1 (7 de septiembre de 2018): 149–73. http://dx.doi.org/10.1144/sp482.2.
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AbstractA key component of the site comparison planned for the deep geological disposal of spent fuel and high-level waste (SF/HLW) in Switzerland is the assessment of the evolution of repository-induced perturbations in the repository nearfield associated with thermal effects from heat production due to radioactive decay of radionuclides, as well as gas pressures developing in the backfilled underground structures from the anaerobic corrosion of the steel waste canisters and tunnel support materials. The assessment of such effects is integrated in the site comparison through safety indicators used to evaluate repository performance. In this context, probabilistic assessments need to integrate the uncertainty of the entire ensemble of input parameters, and estimate the propagation to these indicators in a reliable and computationally efficient manner. This paper presents the development of a methodology for an indicator-based assessment of heat- and gas-induced effects in a SF/HLW repository in Opalinus Clay integrating a probabilistic treatment of parametric uncertainty. The workflow is demonstrated using preliminary data, repository configurations and indicators. Complementary simulations are presented to demonstrate the feedback to the optimization of repository design in order to mitigate repository-induced effects that can potentially compromise the safety function of the engineered and natural barriers.
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Ananyev, Sergey y Andrei Kukushkin. "Calculation of Consistent Plasma Parameters for DEMO-FNS Using Ionic Transport Equations and Simulation of the Tritium Fuel Cycle". Applied Sciences 13, n.º 14 (24 de julio de 2023): 8552. http://dx.doi.org/10.3390/app13148552.
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Modeling the D and T fluxes in Fusion Neutron Source based on a tokamak fuel cycle systems was performed consistently with the core and divertor plasma. An indirect integration of ASTRA, SOLPS4.3, and FC-FNS codes is used. The feedback coupling is realized between the pumping and puffing systems in the form of changes in the isotopic composition of the core and edge plasma. In the ASTRA code, instead of electrons, ions were used in the particle transport equations. This allows better estimates of the flows of the D/T components of the fuel that have to be provided by the gas puffing and processing systems. The particle flows into the plasma from pellets, required to maintain the target plasma density <ne> = (6–8) × 1019 m−3 are 1022 particles/s. In the majority of the working range of parameters, additional ELM stimulation is necessary (by ~1-mm3-size pellets from the low magnetic field side) in order to maintain the controlled energy losses at the level δWELM~0.5 MJ. For the starting load of the FC and steady-state operation of the facility, up to 500 g of tritium are required taking into account the radioactive decay losses.
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Tuck, Adrian F. "Anthropogenic Impacts in the Lower Stratosphere: Scale Invariant Analysis". Atmosphere 15, n.º 4 (9 de abril de 2024): 465. http://dx.doi.org/10.3390/atmos15040465.
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Aircraft and rockets entered the lower stratosphere on a regular basis during World War II and have done so in increasing numbers to the present. Atmospheric testing of nuclear weapons saw radioactive isotopes in the stratosphere. Rocket launches of orbiters are projected to increase substantially in the near future. The burnup of orbiters has left signatures in the aerosol. There are proposals to attenuate incoming solar radiation by deliberate injection of artificial aerosols into the stratosphere to “geoengineer” cooling trends in surface temperature, with the aim of countering the heating effects of infrared active gases. These gases are mainly carbon dioxide from fossil burning, with additional contributions from methane, chlorofluorocarbons, nitrous oxide and the accompanying positive feedback from increasing water vapor. Residence times as a function of altitude above the tropopause are critical. The analysis of in situ data is performed using statistical multifractal techniques and combined with remotely sensed and modeled results to examine the classical radiation–photochemistry–fluid mechanics interaction that determines the composition and dynamics of the lower stratosphere. It is critical in assessing anthropogenic effects. It is argued that progress in predictive ability is driven by the continued generation of new and quantitative observations in the laboratory and the atmosphere.
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Dal Bello, Federica, Enrica Mecarelli, Daniela Gastaldi, Francesco Savino y Claudio Medana. "Nano-HPLC-HRMS Analysis to Evaluate Leptin Level in Milk Samples: A Pilot Study". Applied Sciences 10, n.º 17 (3 de septiembre de 2020): 6135. http://dx.doi.org/10.3390/app10176135.
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Leptin is a 16 kDa lipophilic protein hormone secreted by adipocytes and its most significant function is to inform the brain with negative feedback that regulates food intake. Recently the protein found in human breast milk was related to breast feeding and onset of obesity, and the evidence of a low probability to develop pediatric obesity in children fed with breast milk was also confirmed. Since leptin could have a critical role, its quantitation both in human breast, bovine milk and in infant formula products is interesting. For this reason, we developed an analytical method based on immunoaffinity purification followed by an analysis with nano-High Pressure Liquid Chromatography coupled with High Resolution Mass Spectrometry analyzer (nano-HPLC-HRMS) to identify and quantify leptin in milk samples and performed a pilot study using samples of human breast milk, bovine milk and infant formulas. With an obtained lower limit of quantitation (LLOQ) of 100 ng mL−1 we quantified leptin in human breast milk finding an average of 6.70 ng mL−1. Our results show that leptin was under LLOQ both in bovine milk and in infant formula products. In conclusion, the developed analytical method here described was suitable to quantify leptin in milk samples with a good sensitivity and selectivity, and without the use of radioactive reagents.
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Štibinger, Petr, George Broughton, Filip Majer, Zdeněk Rozsypálek, Anthony Wang, Kshitij Jindal, Alex Zhou et al. "Towards new frontiers in mobile manipulation: Team CTU-UPenn-NYU at MBZIRC 2020". Field Robotics 2, n.º 1 (10 de marzo de 2022): 75–106. http://dx.doi.org/10.55417/fr.2022004.
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In this paper we present an autonomous robotic system for picking, transporting, and precisely placing magnetically graspable objects. Such a system would be especially beneficial for construction tasks where human presence is not possible, e.g. due to chemical or radioactive pollution. The system comprises of two primary components – a wheeled, mobile platform and a manipulator arm. Both are interconnected through an onboard computer and utilize various onboard sensors for estimating the state of the robot and its surroundings. By using efficient processing algorithms, data from the onboard sensors can be used in a feedback loop during all critical operational sections, resulting in a robust system capable of operating on uneven terrain and in environments without access to satellite navigation. System functionality has been proven in Challenge II of the MBZIRC 2020 competition. The Challenge required a ground robot to build an L-shaped structure of colored bricks laid in a predefined pattern. Such a mission incorporates several demanding subchallenges, spanning multiple branches of computer science, cybernetics, and robotics. Moreover, all the subchallenges had to be performed flawlessly in rapid succession, in order to complete the Challenge successfully. The extreme difficulty of the task was highlighted in the MBZIRC 2020 finals, where our system was among the only two competitors (out of 32) that managed to complete the task in autonomous mode.
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Fujimoto, Yusuke, Mark R. Krumholz y Shu-ichiro Inutsuka. "Distribution and kinematics of 26Al in the Galactic disc". Monthly Notices of the Royal Astronomical Society 497, n.º 2 (24 de julio de 2020): 2442–54. http://dx.doi.org/10.1093/mnras/staa2125.
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ABSTRACT 26Al is a short-lived radioactive isotope thought to be injected into the interstellar medium (ISM) by massive stellar winds and supernovae (SNe). However, all-sky maps of 26Al emission show a distribution with a much larger scale height and faster rotation speed than either massive stars or the cold ISM. We investigate the origin of this discrepancy using an N-body + hydrodynamics simulation of a Milky-Way-like galaxy, self-consistently including self-gravity, star formation, stellar feedback, and 26Al production. We find no evidence that the Milky Way’s spiral structure explains the 26Al anomaly. Stars and the 26Al bubbles they produce form along spiral arms, but, because our simulation produces material arms that arise spontaneously rather than propagating arms forced by an external potential, star formation occurs at arm centres rather than leading edges. As a result, we find a scale height and rotation speed for 26Al similar to that of the cold ISM. However, we also show that a synthetic 26Al emission map produced for a possible Solar position at the edge of a large 26Al bubble recovers many of the major qualitative features of the observed 26Al sky. This suggests that the observed anomalous 26Al distribution is the product of foreground emission from the 26Al produced by a nearby, recent SN.
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Debie, Pieterjan, Noemi B. Declerck, Danny van Willigen, Celine M. Huygen, Bieke De Sloovere, Lukasz Mateusiak, Jessica Bridoux et al. "The Design and Preclinical Evaluation of a Single-Label Bimodal Nanobody Tracer for Image-Guided Surgery". Biomolecules 11, n.º 3 (26 de febrero de 2021): 360. http://dx.doi.org/10.3390/biom11030360.
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Intraoperative guidance using targeted fluorescent tracers can potentially provide surgeons with real-time feedback on the presence of tumor tissue in resection margins. To overcome the limited depth penetration of fluorescent light, combining fluorescence with SPECT/CT imaging and/or gamma-ray tracing has been proposed. Here, we describe the design and preclinical validation of a novel bimodal nanobody-tracer, labeled using a “multifunctional single attachment point” (MSAP) label, integrating a Cy5 fluorophore and a diethylenetriaminepentaacetic acid (DTPA) chelator into a single structure. After conjugation of the bimodal MSAP to primary amines of the anti-HER2 nanobody 2Rs15d and 111In-labeling of DTPA, the tracer’s characteristics were evaluated in vitro. Subsequently, its biodistribution and tumor targeting were assessed by SPECT/CT and fluorescence imaging over 24 h. Finally, the tracer’s ability to identify small, disseminated tumor lesions was investigated in mice bearing HER2-overexpressing SKOV3.IP1 peritoneal lesions. [111In]In-MSAP.2Rs15d retained its affinity following conjugation and remained stable for 24 h. In vivo SPECT/CT and fluorescence images showed specific uptake in HER2-overexpressing tumors with low background. High tumor-to-muscle ratios were obtained at 1h p.i. and remained 19-fold on SPECT/CT and 3-fold on fluorescence images over 24 h. In the intraperitoneally disseminated model, the tracer allowed detection of larger lesions via nuclear imaging, while fluorescence enabled accurate removal of submillimeter lesions. Bimodal nuclear/fluorescent nanobody-tracers can thus be conveniently designed by conjugation of a single-molecule MSAP-reagent carrying a fluorophore and chelator for radioactive labeling. Such tracers hold promise for clinical applications.
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Ma, Kun L., Zac Varghese, Yin Ku, Stephen H. Powis, Yaxi Chen, John F. Moorhead y Xiong Z. Ruan. "Sirolimus inhibits endogenous cholesterol synthesis induced by inflammatory stress in human vascular smooth muscle cells". American Journal of Physiology-Heart and Circulatory Physiology 298, n.º 6 (junio de 2010): H1646—H1651. http://dx.doi.org/10.1152/ajpheart.00492.2009.
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Inflammatory stress accelerates the progression of atherosclerosis. Sirolimus, a new immunosuppressive agent, has been shown to have pleiotropic antiatherosclerotic effects. In this study we hypothesized that sirolimus inhibits 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR)-mediated cholesterol synthesis in human vascular smooth muscle cells (VSMCs) under inflammatory stress. Using radioactive assay, we demonstrated that sirolimus inhibited the increase of interleukin-1β (IL-1β)-induced cholesterol synthesis in VSMCs. Further studies showed that sirolimus inhibited both the HMGR gene and protein expression in VSMCs treated with or without IL-1β. These effects were mediated by inhibiting the gene expression of sterol regulatory element-binding protein-2 (SREBP-2) and SREBP-2 cleavage-activating protein (SCAP) as checked by real-time PCR, Western blot analysis, and confocal microscopy for the observation of decreased protein translocation of the SCAP/SREBP-2 complex from the endoplasmic reticulum (ER) to the Golgi. Insulin-induced gene-1 (Insig-1) is a key ER protein controlling the feedback regulation of HMGR at transcriptional and posttranscriptional levels. We demonstrated that sirolimus increased Insig-1 expression which may bind to the SCAP, preventing the exit of SCAP-SREBP complexes from the ER. The increased Insig-1 also accelerated HMGR protein degradation in VSMCs as shown by pulse-chase analysis. In conclusion, sirolimus inhibits cholesterol synthesis induced by inflammatory stress through the downregulation of HMGR expression and the acceleration of HMGR protein degradation. These findings may improve our understanding of the molecular mechanisms of the antiatherosclerosis properties of sirolimus.
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KANDA, Reiko, Shin SAIGUSA, Tadaaki BAN-NAI, Isao KAWAGUCHI, Yusuke KOBA, Hideo TATSUZAKI y Fumiaki TAKAHASHI. "The Report of the ICRU Expert Workshop on Radiation Monitoring for Protection of the Public after Major Radioactive Release to the Environment: Feedback from the Accident at the Fukushima Daiichi NPS". Japanese Journal of Health Physics 52, n.º 1 (2017): 42–47. http://dx.doi.org/10.5453/jhps.52.42.
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Yuan, Yilong, Tianfu Xu, Fabrizio Gherardi y Hongwu Lei. "Thermo-Hydro-Mechanical Coupled Modeling of In-Situ Behavior of the Full-Scale Heating Test in the Callovo-Oxfordian Claystone". Energies 15, n.º 11 (2 de junio de 2022): 4089. http://dx.doi.org/10.3390/en15114089.
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Within the context for deep geological disposal (DGD) of high-level radioactive waste (HLW), thermo-hydro-mechanical (THM) coupled numerical modeling has become significantly important for studying the safe disposal of HLW. In this work, a 3D mechanical module is incorporated into the thermal–hydraulic (TH) coupled code TOUGH2, thus forming an integrated THM coupled simulator referred to as TOUGH2Biot. The Galerkin finite element method is used to discretize the space for rock mechanical calculation. The mechanical process is sequentially coupled with the fluid and heat flow processes, which further gives feedback to the flow through stress-dependent hydraulic properties (e.g., porosity and permeability). Based on the available geological data at the Meuse/Haute-Marne Underground Research Laboratory (MHM URL) in France, the improved simulator is used to analyze the coupled THM behaviors of the Callovo-Oxfordian claystone (COx) induced by thermal loading. The anisotropy of material parameters (e.g., permeability and thermal conductivity) caused by the bedding and of in-situ stresses are well considered in our model. The numerical simulation can reasonably reproduce the field observations, including changes in temperature and pore pressure at monitoring boreholes during the ALC1604 experiment. The modeling results indicate that the anisotropic effects are remarkable, and temperature, pore pressure, and effective stress along the bedding increase more rapidly than in the vertical direction. Insight into numerical results through the visual model is beneficial for helping us to interpret the field observations and to understand the complex THM problem in the COx claystone formation. The numerical method and the modeling results presented in this work can be effectively used in support of performance assessment studies of HLW disposal sites to build confidence in the safety of future applications of nuclear energy systems.
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Pinaroli, G., S. Herrmann, S. Miryala, V. Manthena, G. W. Deptuch, G. A. Carini, A. E. Bolotnikov et al. "Multi-channel front-end ASIC for a 3D position-sensitive detector". Journal of Instrumentation 17, n.º 02 (1 de febrero de 2022): C02011. http://dx.doi.org/10.1088/1748-0221/17/02/c02011.
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Abstract Arrays of 3D position-sensitive detectors (3DPSD), operating at room temperature and using cadmium zinc telluride (CZT) and thallium bromide (TIBr) sensors, are suitable for gamma-ray spectrometry in many applications. One detector configuration, the 3D position-sensitive Virtual Frisch-Grid detector (VFG), is particularly advantageous for integrating into large area arrays. The signals generated inside each detector of the array are captured with the anode, cathode and four pads that enable the reconstruction of the position and energy of the ionizing interaction by measurements of amplitude and timing of the signals. For these applications, a low-noise front-end ASIC has been developed, capable of processing bipolar signals (needed because of AC-coupling of certain electrodes). The ASIC can be coupled to an ADC in order to form a compound “waveform digitizer” capable of post-processing the analog signals and determining amplitude and timing information. This paper describes a 32-channel front-end ASIC that is suitable for reading out a 3 × 3 or 4 × 4 element matrix in the VFG configuration. Each channel is composed of a low-noise charge amplifier with an adaptive continuous reset feedback circuit suitable for both positive and negative charge, a first order shaper and a single-to-differential converter output stage. Voltage and current references are all internally generated by 10-bit DACs and the chip is fully controllable with the I2C communication protocol. The readout channel response has been verified using the implemented injection circuit. Linear behavior up to ∼75 ke± with the gain of ∼80 mV/fC, and up to ∼200 ke± with the gain of ∼30 mV/fC was demonstrated. In conclusion, the first test result waveforms using a 137Cs radioactive source on a 5 × 5 × 12 mm3 TIBr crystal are reported.
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Hormann, Volker, Anna Kogiomtzidis y Clemens Walther. "Improvement by public participation? The case of the German calculation basis for the dose assessment for final disposal of high-level waste (HLW)". Safety of Nuclear Waste Disposal 2 (6 de septiembre de 2023): 247. http://dx.doi.org/10.5194/sand-2-247-2023.
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Abstract. In April 2022, the Federal Office for the Safety of Nuclear Waste Management (BASE) invited the public to comment on the previously issued draft of the “Berechnungsgrundlage für die Dosisabschätzung bei der Endlagerung von hochradioaktiven Abfällen” (Calculation basis for dose assessment of the final disposal of high-level radioactive waste); 360 comments and suggestions were submitted, especially concerning radioecological modelling. In a table that was made publicly available, many of the issues raised were commented on, but not all of them. At the end of June 2022, an expert workshop was held at BASE, where a subset of the comments was also discussed. In December 2022, BASE issued the final version of the “Berechnungsgrundlage”, unfortunately without any further feedback on why changes were made or not. In the present contribution we will analyse this participation process, taking into account both the aspect of implementation and the radioecological models used. Only a rather limited number of suggestions have been considered. To name a few, there has been no revision of the radioecological parameters that are being used in German administrative regulations and that have scarcely been updated within the past 40 years. Also, a proposed method for better estimating the retention times of radionuclides in soils with the help of distribution coefficients that have been tabulated by the IAEA but that can also be measured or calculated for special soils with the help of geochemical models was ignored. Still, the final version of the “Berechnungsgrundlage” assumes only three classes of retention times (10–8, 10–9, and 10–10 s) that do not appropriately reflect the behaviour of the individual radionuclides. On the other hand, the proposal to consider an additional contamination path, namely the capillary transport of radionuclides from groundwater into the root zone, has been included. In the workshop we would like to raise the question of whether and how this kind of process might be improved. Specifically, in view of the delay in site selection, the haste with which the project was completed should be discussed.
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Kodintseva, Е. А. y А. А. Akleyev. "Delayed correlated parameters of adaptive and innate immunity in chronically irradiated subjects". Russian Journal of Immunology 23, n.º 2 (15 de abril de 2020): 225–30. http://dx.doi.org/10.46235/1028-7221-399-dcp.
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Radiation-induced changes in the immune system develop quite early after the onset of radiation exposure and persist over a long time after it's removal. In case of chronic radiation exposure at dose rate lower than 0.1 Gy/year, the threshold of annual dose to suppress red bone marrow hemato- and immunopoiesis reaches 0.3-0.5 Gy. It was shown that adaptation mechanisms are triggered under the chronic impact of ionizing radiation in the hematopoietic system. In our study we quantitatively and qualitatively analyzed relationships between individual arms of the immune system which is important for understanding features of homeostasis and the adaptation capacity of immune system in chronically irradiated subjects at later time points. The main group included 376 persons exposed to chronic irradiation due to 1949-1960 industrial pollution with radioactive waste residing in Techa River basin. Average radiation dose for the red bone marrow in this group was 1.08±0.04 (0.08-4.46) Gy. The comparison group included 162 unexposed persons. The mean age of people in the main and comparison group was 70.3±0.3 (58-88) and 69.3±0.5 (58-90) years, respectively. The Kendall correlation analysis identified 82 statistically significant correlations (correlation coefficient higher than 0.3, p 0.05) between individual immune parameters versus 65 similar correlations found in the comparison group. The majority of identified correlation links in both groups ranged from 0.3 to 0.5 (main group – 57 correlations, comparison group – 41 correlations). There were found 16 and 14 correlations in the main and comparison group, respectively, with a coefficient ranged from 0.5 to 0.7. The correlation coefficient value higher than 0.7 was noted for 9 correlations in the main group and for 10 – in the comparison group. The χ-square analysis revealed no significant differences between total number of correlations and number of correlations of varying strength both in the main and comparison groups. The obtained data are consistent with previous studies and confirm that delayed changes in the immune system of subjects exposed to chronic low-rate irradiation were mild and evidenced about developed feedforward and feedback compensatory mechanisms.
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Göbel, Astrid, Tobias Knuuti, Carola Franzen, Dinara Abbasova, Thuro Arnold, Vinzenz Brendler, Kateryna Fuzik et al. "State-of-Knowledge and Guidance in EURAD Knowledge Management (Work Packages 11 State-of-Knowledge & 12 Guidance)". Safety of Nuclear Waste Disposal 1 (10 de noviembre de 2021): 249–50. http://dx.doi.org/10.5194/sand-1-249-2021.
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Abstract. EURAD, the European Joint Programme on Radioactive Waste Management (RWM), is the European Research Programme on RWM, aimed at supporting member states with the implementation of their national programmes. It brings together over 100 organisations from different backgrounds and countries, which work together in RD&D projects, Strategic Studies and Knowledge Management (KM). The importance of KM is recognised by EURAD and reflected in a number of activities. One essential activity is the capture of the current State-of-Knowledge in the field of RWM and its transfer to the implementation of the different national programmes. This is done by different types of Knowledge Documents that are made available through a dedicated IT tool (e.g. a Wiki). The development of the individual EURAD KM documents is performed by recognised experts. These experts will share their view on the most relevant knowledge on a specific topic, highlighting safety functions and operational aspects. Additionally, signposting to pre-existing documents is performed (State-of-the-Art Documents, Scientific Papers, etc.). The hierarchy of the works for the KM documents (Theme Overview, Domain Insight, State-of-Knowledge, Guidance) is closely linked to the generic EURAD Roadmap/GBS (Goals Breakdown Structure). It provides a hierarchical structure that facilitates definition, organisation and communication of topics. All of this allows knowledge to be captured and presented with the level of detail that is required by the end-user, from a broad overview down to an increasing level of detail (pyramid of knowledge). To ensure the quality and consistency of the documents with the overall EURAD KM approach, quality assurance and editorial procedures are applied. Collection of end-user feedback will aid the optimisation and further development of the KM activities. To facilitate the transfer of knowledge, the EURAD KM programme goes beyond documents and strives to facilitate exchange between people and signpost to other resources, such as Training and Mobility activities (also organised by EURAD Work Package 13 Training & Mobility) or Communities of Practice. All these activities will contribute to a useful and end-user-friendly EURAD KM programme that is designed to be operational well beyond the runtime of EURAD-1. This presentation will provide further insight into the approaches, status of work and an outlook on future activities that will support member states with the implementation of their national programmes.
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Kraan, G. P. B., T. E. Chapman, N. M. Drayer, B. Colenbrander y G. Buwalda. "Kinetic measurement of the urinary production rate of cortisol in male piglets: is the prerequisite 'collection until all label has disappeared' necessary?" Journal of Endocrinology 111, n.º 3 (diciembre de 1986): 439–48. http://dx.doi.org/10.1677/joe.0.1110439.
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ABSTRACT Urinary cortisol production rate (CPR) was calculated by two different methods in five male piglets (about 3 kg bodyweight) injected i.v. with 40–120 kBq tritiated cortisol ([3H]F). After administration of [3H]F, urine was obtained from four consecutive collections for the following 2 days, during which 80–100% of the label was recovered. Total radioactivity in the urine was measured and used to calculate the total rate constant of 0·115 ± 0·011 h−1 and, from this, the mean biological half-life (t½) of 6·0±0·6 h (s.d.; n = 4). It was found that the mass ratio of the two principal urinary cortisol metabolites tetrahydrocortisone (THE) and tetrahydrocortisol (THF) was strikingly less than 1·0 (0·4±0·1; n= 14), which is the reverse of that observed in older pigs, neonatal infants and man. To calculate CPR conventionally, the cumulative specific activities of THE and THF were calculated for the 2-day period of urine collection. The apparent mean CPR values on the basis of THE and THF were calculated as 11·5±1·6 (n = 5) and 12·8 ± 3·3 (n = 5) μmol/day respectively, and 12·1 ± 1·4 (n = 5) μmol/day for the average of THE and THF. The second method for calculating CPR consisted of determining the masses of THE and THF (μmol) per fraction of dose (m/fd) (fd refers to the ratio of radioactivity in the metabolite and dose) at different times after administration of [3H]F. The calculated m/fd values, which are synonymous with the dose divided by the specific activities of the metabolites, and the different times of urine collection were analysed by linear regression. The resulting slope is equal to the CPR. The CPR derived by this method for the average of THE and THF, 10·1±0·91 μmol/ day was significantly (P<0·014) lower than that derived conventionally, 12·1 ± 1·40 μmol/day. This second method may be used when CPR is determined in neonatal infants by means of non-radioactive, deuterated or 13C-enriched cortisol, where the extent of negative feedback by the relatively high dose of exogenous steroid on cortisol secretion must be kept as low as possible. This method also allows urine collections to be used at times when the tracer is still being excreted. J. Endocr. (1986) 111, 439–448
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Rozental, Jose de Julio. "Two decades of radiological accidents direct causes, roots causes and consequences". Brazilian Archives of Biology and Technology 45, spe (septiembre de 2002): 125–33. http://dx.doi.org/10.1590/s1516-89132002000500018.
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Practically all Countries utilize radioisotopes in medicine, industry, agriculture and research. The extent to which ionizing radiation practices are employed varies considerably, depending largely upon social and economic conditions and the level of technical skills available in the country. An overview of the majority of practices and the associated hazards will be found in the <A HREF="#tabela4">Table IV</A> to <A HREF="#tabela7">VII</A> of this document. The practices in normal and abnormal operating conditions should follow the basic principles of radiation protection and the Safety of Radiation Sources, considering the IAEA Radiation Protection and the Safety of Radiation Sources, Safety Series 120 and the IAEA Recommendation of the Basic Safety Standards for Radiation Protection, Safety Series Nº 115. The Standards themselves underline the necessity to be able to predict the radiological consequences of emergency conditions and the investigations that should need to be done. This paper describes the major accidents that had happened in the last two decades, provides a methodology for analyses and gives a collection of lessons learned. This will help the Regulatory Authority to review the reasons of vulnerabilities, and to start a Radiation safety and Security Programme to introduce measurescapable to avoid the recurrence of similar events. Although a number of accidents with fatalities have caught the attention of the public in recent year, a safety record has accompanied the widespread use of radiation sources. However, the fact that accidents are uncommon should not give grounds for complacency. No radiological accident is acceptable. From a radiation safety and security of the sources standpoint, accident investigation is necessary to determine what happened, why, when, where and how it occurred and who was (were) involved and responsible. The investigation conclusion is an important process toward alertness and feedback to avoid careless attitudes by improving the comprehension of Safety Performance and Safety Culture. Accident investigation is the first step toward avoiding future injures and financial losses, by prevention of recur recurrence. On the other hand, accident investigation is also essential for the establishment of the responsibilities and liability for the consequences. This document discuss the main accidents that have happened in the last two decades, in terms of causes, consequences, similarities and lessons learned when sealed sources have been damaged, lost, stolen and abandoned. In considerable majority death and serious injuries were resulted from failures in the safety system for radiation sources and for the security of radioactive materials.
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Kaushal, Nihal, Sudheer Patri, Ramesh Kumar Sharma y B. K. Sreedhar. "Lessons Learned from Failures and Design Improvements for Large Diameter Seals". Journal of Failure Analysis and Prevention, 22 de mayo de 2024. http://dx.doi.org/10.1007/s11668-024-01944-4.
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AbstractLarge diameter seals are used in Prototype Fast Breeder Reactor (PFBR) to prevent the escape of radioactive argon cover gas through wide annular gaps. The design of these seals shall address different challenges than normal seals. The large tolerances needed on the width of annulus, achievable tolerances on rubber, clearances in the seal holder, etc., influence the seal performance. The paper discusses analytical and experimental work done to develop robust large diameter seals. The contours of the present study are based on the feedback from the testing and qualification of small size model seals. Various permutations of geometry for seal and its holder are numerically investigated. The study mainly highlighted the influence of seal holder on the seal performance. Various sensitivity studies done on selected seal and seal holder demonstrated robustness of the design solutions. Graphical Abstract
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Zhu, Guangyu, Junxia Wu, Jia Yin, Yuan Wei, Peilin He, Ze Du, Liyao Ma, Zishuai Qiu, Zhaolong Zhang y Jiancheng Yang. "Stochastic cooling notch filter developments for the high-precision spectrometer ring in the high intensity heavy-ion accelerator facility project". Review of Scientific Instruments 94, n.º 9 (1 de septiembre de 2023). http://dx.doi.org/10.1063/5.0166975.
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Stochastic cooling of the high-precision spectrometer ring (SRing) at the High Intensity Heavy-Ion Accelerator Facility (HIAF) project in China, which is used mainly for experiments with radioactive fragment beams, is applied to speed up the cooling process of a stored ion beam. In this article, a new coaxial-type notch filter with an amplitude equalizer in the long branch and an optical-type notch filter with phase-stabilized optical fiber are discussed and evaluated for the SRing stochastic cooling system. Both prototypes of coaxial and optical notch filters are fabricated and tested. The minimum notch depth of coaxial and optical notch filters reaches to 26 and 40 dB, respectively. The performance of both coaxial notch filter and optical fiber notch filter is presented in this work. These developments will be used not only for the longitudinal stochastic cooling system but also have potential for the beam feedback system.
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Egres, Dorottya y Gábor Sarlós. "Nuclear perceptions from radioactive blue to sustainable green: The EU taxonomy as reflection of a divided public". Journal of Public Affairs, 23 de noviembre de 2023. http://dx.doi.org/10.1002/pa.2901.
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Following the Fukushima disaster, several European countries revisited their policies and decided to phase out nuclear energy production. More recently, however, the EU taxonomy proposed a classification system of environmentally sustainable economic activities and consequently reopened the debate regarding nuclear energy. This study analyses public comments about the inclusion or exclusion of nuclear energy as a response to climate change, in the conceptual frameworks of ecological modernization, sustainability and technological neutrality. The study highlights the challenge of shaping energy policies amid dynamic circumstances and diverse viewpoints. Proponents of nuclear energy emphasised its low‐carbon emissions and climate change mitigation potential, while opponents focused on issues of radioactive waste and environmental risks. The study reveals that sustainability emerges as a potential reconciling framework to match arguments to influence the EU's decision‐making, while it reflects the political primacy of this process. Finally, this research recommends improving feedback visibility and enhancing clear communication, and suggests further research directions to understand future EU nuclear energy policies.
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Geger, Emilia, Aleksandr Podvesovskii, Oksana Mikhaleva y Anton Korsakov. "Intelligent Analysis of the Ecological State of Environment with Application of Distributed Expertise (on the Example of Bryansk Region)". Proceedings of the 30th International Conference on Computer Graphics and Machine Vision (GraphiCon 2020). Part 2, 17 de diciembre de 2020, paper77–1—paper77–10. http://dx.doi.org/10.51130/graphicon-2020-2-3-77.
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The paper considers the problem of assessing the ecological state of the environment in the region. An approach to the intelligent analysis and estimation of anthropo-technogenic pollution of a territory with the application of integral indicators which take into account environmental pollution is proposed. To estimate the integral indicator parameters, distributed group expertise technology is used, supporting a mechanism for control of expert estimates consistency, taking into account experts’ competency in the relevant subject areas. Using the proposed approach, the problem of risk assessment of environmental impact of chemical air pollutants has been solved. Methods for control of expert estimates consistency based on the procedure of feedback with experts made it possible to increase the reliability of evaluation results and also to decrease the influence of a random expert error on the final assessment. The obtained aggregated risk estimates were used to construct, calculate and visualize the integral indicator of radioactive and chemical contamination of the districts of Bryansk region.
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Boucai, Laura, Mahesh Saqcena, Fengshen Kuo, Ravinder K. Grewal, Nicholas Socci, Jeffrey A. Knauf, Gnana P. Krishnamoorthy et al. "Genomic and transcriptomic characteristics of metastatic thyroid cancers with exceptional responses to radioactive iodine therapy." Clinical Cancer Research, 13 de febrero de 2023. http://dx.doi.org/10.1158/1078-0432.ccr-22-2882.
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Abstract Purpose: The determinants of response or resistance to radioiodine (RAI) are unknown. We aimed to identify genomic and transcriptomic factors associated with structural responses to RAI treatment of metastatic thyroid cancer, which occur infrequently, and to test whether high MAPK pathway output was associated with RAI refractoriness. Experimental Design: Exceptional response to RAI was defined as reduction of tumor volume based on RECIST v1.1. We performed a retrospective case-control study of genomic and transcriptomic characteristics of exceptional responders (ER) (n=8) vs non-responders (NR) (n=16) matched by histological type and stage at presentation on a 1:2 ratio. Results: ER are enriched for mutations which activate MAPK through RAF dimerization (RAS, class 2 BRAF, RTK fusions), whereas NR are associated with BRAFV600E, which signals as a monomer and is unresponsive to negative feedback. ER have a lower MAPK transcriptional output and a higher thyroid differentiation score (TDS) than NR (p<0.05). NR are enriched for 1q-gain (p<0.05) and mutations of genes regulating mRNA splicing and the PI3K pathway. BRAFV600E tumors with 1q-gain have a lower TDS than BRAFV600E/1q-quiet tumors and transcriptomic signatures associated with metastatic propensity. Conclusions: ER tumors have a lower MAPK output and higher TDS than NR, whereas NR have a high frequency of BRAFV600E and 1q-gain. Molecular profiling of thyroid cancers and further functional validation of the key findings discriminating ER from NR may help predict response to RAI therapy.
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Putero, Susetyo Hario, Mondjo Mondjo, Agus Budhie Wijatna, Sihana Sihana, Andang Widiharto, Nunung Prabaningrum, Anung Muharini et al. "Developing Nuclear Security Capacity of Indonesia’s Police and Security Officer: Lessons from Universitas Gadjah Mada’s Pilot Training". International Journal of Nuclear Security, 2022. http://dx.doi.org/10.7290/ijns07v97c.
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Due to an increase in global nuclear security issues, there need to be improvements in human resources and security measures. The Republic of Indonesia is an archipelago country, which makes surveilling for nuclear security threats complicated. Recent radioactive material smuggling incidents proved that Indonesian police and security officers’ knowledge in nuclear security has been challenged and must be improved. In response, Universitas Gadjah Mada’s Nuclear Engineering Program composed a three-day pilot training program for local police and UGM's security officers in 2018. The objective of the training was to improve their capabilities in dealing with nuclear security issues around where they work and serve. Training materials were designed to introduce nuclear technology and provide the basic skills of handling nuclear security matters. The training was divided into 12 sessions, based on the needs stated by the Special Region of Yogyakarta's police chief. Lessons were delivered through traditional teaching, table-top exercises, exercises, and discussion. Fifteen-question pre-tests and post-tests were conducted to assess the officers’ knowledge of the training materials and the benefits of being trained. Based on the tests, we concluded that the participants’ understanding of nuclear security had improved. This increase in understanding was because the training materials fit their job needs, presented in various methods, and the participants’ awareness grew. It led to an increase in their awareness for securing the facilities utilizing radioactive sources in the Yogyakarta area. They said that the number of trainees in this event still does not meet the number of facilities that have to be secured. Therefore, the training should be carried out again and can be improved based on the participants' feedback. Furthermore, this training could be expanded and applied to the whole country.
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von Niederhäusern, Peter A., Carlo Seppi, Robin Sandkühler, Guillaume Nicolas, Stephan K. Haerle y Philippe C. Cattin. "Augmented reality for sentinel lymph node biopsy". International Journal of Computer Assisted Radiology and Surgery, 25 de septiembre de 2023. http://dx.doi.org/10.1007/s11548-023-03014-w.
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Abstract Introduction Sentinel lymph node biopsy for oral and oropharyngeal squamous cell carcinoma is a well-established staging method. One variation is to inject a radioactive tracer near the primary tumor of the patient. After a few minutes, audio feedback from an external hand-held $$\gamma $$ γ -detection probe can monitor the uptake into the lymphatic system. Such probes place a high cognitive load on the surgeon during the biopsy, as they require the simultaneous use of both hands and the skills necessary to correlate the audio signal with the location of tracer accumulation in the lymph nodes. Therefore, an augmented reality (AR) approach to directly visualize and thus discriminate nearby lymph nodes would greatly reduce the surgeons’ cognitive load. Materials and methods We present a proof of concept of an AR approach for sentinel lymph node biopsy by ex vivo experiments. The 3D position of the radioactive $$\gamma $$ γ -sources is reconstructed from a single $$\gamma $$ γ -image, acquired by a stationary table-attached multi-pinhole $$\gamma $$ γ -detector. The position of the sources is then visualized using Microsoft’s HoloLens. We further investigate the performance of our SLNF algorithm for a single source, two sources, and two sources with a hot background. Results In our ex vivo experiments, a single $$\gamma $$ γ -source and its AR representation show good correlation with known locations, with a maximum error of 4.47 mm. The SLNF algorithm performs well when only one source is reconstructed, with a maximum error of 7.77 mm. For the more challenging case to reconstruct two sources, the errors vary between 2.23 mm and 75.92 mm. Conclusion This proof of concept shows promising results in reconstructing and displaying one $$\gamma $$ γ -source. Two simultaneously recorded sources are more challenging and require further algorithmic optimization.
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Hossen, Muhammed Mufazzal y Mahmud Hossain. "SYSTEM DYNAMICS MODEL DEVELOPMENT BY ANALYZING CAUSES OF FUKUSHIMA DAIICHI NPP UNIT-1 ACCIDENT". International Journal of Engineering Applied Sciences and Technology 6, n.º 4 (1 de agosto de 2021). http://dx.doi.org/10.33564/ijeast.2021.v06i04.009.
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— Fukushima Daiichi NPP accident occurred on March 11, 2011. A system dynamics model is developed by analyzing the chronological progression and causes of the Fukushima Daiichi NPP unit-1 accident applying causeeffect relationship and qualitative causal loop and feedback loop. The accident progression demonstrates that the safety system of the NPP could not function properly, resulting in the loss of core cooling and confinement of radioactive materials functions, and a severe accident with hydrogen explosion occurred. The system dynamics model shows that earthquake, tsunami induced flooding, design failure of Tsunami height, loss of all AC power, loss of DC power, loss of ultimate heat sink, failure of HPCI system, failure of IC system, design complexity of isolation valves of IC and lack of training on IC operation, delayed water injection to reactor, delayed operation of containment venting, lacking of compressed air, high reactor pressure, and harsh radiological condition are the causes of this severe accident. High reactor pressure and harsh radiological condition were produced during the accident, which positively boost accident progression by demonstrating the effect of system dynamics. The conservative design to protect power sources from natural events and the loss of all power for an extended period must be considered during future design of NPP.
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Mufazzal Hossen, Muhammed y Mahmud Hossain. "SYSTEM DYNAMICS MODEL DEVELOPMENT BY ANALYZING CAUSES OF FUKUSHIMA DAIICHI NPP UNIT-1 ACCIDENT". International Journal of Engineering Applied Sciences and Technology 6, n.º 3 (1 de julio de 2021). http://dx.doi.org/10.33564/ijeast.2021.v06i03.004.
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Fukushima Daiichi NPP accident occurred on March 11, 2011. A system dynamics model is developed by analyzing the chronological progression and causes of the Fukushima Daiichi NPP unit-1 accident applying causeeffect relationship and qualitative causal loop and feedback loop. The accident progression demonstrates that the safety system of the NPP could not function properly, resulting in the loss of core cooling and confinement of radioactive materials functions, and a severe accident with hydrogen explosion occurred. The system dynamics model shows that earthquake, tsunami induced flooding, design failure of Tsunami height, loss of all AC power, loss of DC power, loss of ultimate heat sink, failure of HPCI system, failure of IC system, design complexity of isolation valves of IC and lack of training on IC operation, delayed water injection to reactor, delayed operation of containment venting, lacking of compressed air, high reactor pressure, and harsh radiological condition are the causes of this severe accident. High reactor pressure and harsh radiological condition were produced during the accident, which positively boost accident progression by demonstrating the effect of system dynamics. The conservative design to protect power sources from natural events and the loss of all power for an extended period must be considered during future design of NPP.
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Kumar, Ajay, Mauro Cacace y Magdalena Scheck-Wenderoth. "Thermodynamics of continental deformation". Scientific Reports 13, n.º 1 (14 de noviembre de 2023). http://dx.doi.org/10.1038/s41598-023-47054-3.
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AbstractContinental deformation is known to be controlled by the interplay between tectonic and gravitational forces modulated by thermal relaxation-controlled lithospheric strength leading to oscillations around an equilibrium state, or to runaway extension. Using data-driven thermomechanical modelling of the Alpine Himalayan Collision Zone, we demonstrate how deviations from an equilibrium between mantle dynamics, plate-boundary forces, and the thermochemical configuration of the lithosphere control continental deformation. We quantify such balance between the internal energy of the plate and tectonic forces in terms of a critical crustal thickness, that match the global average of present-day continental crust. It follows that thicker intraplate domains than the critical crust (orogens) must undergo weakening due to their increased internal energy, and, in doing so, they dissipate the acquired energy within a diffused zone of deformation, unlike the localized deformation seen along plate boundaries. This evolution is controlled by a dissipative thermodynamic feedback loop between thermal and mechanical relaxation of the driving energy in the orogenic lithosphere. Exponentially growing energy states, leading to runaway extension are efficiently dampened by enhanced dissipation from radioactive heat sources. This ultimately drives orogens with their thickened radiogenic crust towards a final equilibrium state. Our results suggest a genetic link between the thermochemical state of the crust and the tectonic evolution of silicate Earth-like planets.
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Sun, Yue, Xuesong Dai, Qihao Yin, Linfeng Ju, Miao Li y Xiaolan Tang. "Design and Control of Ultrasound Image-guided Prostatic Brachytherapy Robot". Recent Patents on Mechanical Engineering 16 (4 de diciembre de 2023). http://dx.doi.org/10.2174/0122127976272524231116192345.
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Background:: With the continuous development of medical robots, they have become a powerful tool for surgery and treatment. A prostate brachytherapy robot is a kind of robot widely used in prostate cancer treatment; its main function is to accurately implant radioactive seeds into prostate tissue to kill cancer cells. Using prostate brachytherapy robots for surgery can reduce damage to surrounding tissue during surgery, thereby reducing the risk of external electrolysis and metastasis of tumor cells. Objective:: This study aimed to design a prostate brachytherapy robot that is more in line with practical usage needs, based on the method of manually performing prostate brachytherapy surgery in clinical practice. Finally, its feasibility has been demonstrated through brachytherapy experiments. objective: This article aims to improve and design a prostate brachytherapy robot that is more in line with practical usage needs, based on the method of manually performing prostate brachytherapy surgery in clinical practice. Finally, its feasibility was demonstrated through brachytherapy experiments. Methods:: Firstly, the actual requirements for prostate particle implantation surgery have been analyzed, which has been followed by reviewing previous literature and patents to determine the design scheme of the robot. Finally, SOLIDWORKS software has been used for mechanical design of the robot, and the control system of the robot has been designed based on Arduino. Results:: A robotic arm type prostate particle implantation robot has been successfully designed. We have installed a visual module on the prostate particle implantation robot, which has enabled the robot system to have image transmission monitoring function to assist in the calibration of the puncture position before surgery. Finally, we have employed other sensors to complete the particle implantation experiment, and successfully confirmed its superiority through comparing errors. Conclusion:: This work has analyzed and studied the clinical process of prostate particle implantation surgery, and designed a prostate particle implantation robot, including the mechanical design and control system design of the robot. We have also simulated the scene of prostate particle implantation surgery in the human body through particle implantation experiments, and successfully and accurately implanted radioactive particles to the target. The experimental results have proven the feasibility of the robot. We have made improvements in execution efficiency by using a parallelogram-based robotic arm as the representation of the prostate particle implantation robot and equipped it with a visual module. The visual module collects a video stream of the puncture needle's perspective and provides feedback to the control end to assist in the calibration of the puncture position before surgery, greatly reducing the probability of secondary injury to patients.