219 research outputs found
HARDWARE RESILIENCE: A WAY TO ACHIEVE RELIABILITY AND SAFETY IN NEW NUCLEAR REACTORS I&C SYSTEMS
The idea that systems have a property called ‘resilience’ has emerged in the last decade [1]. In this paper we intend to bring the idea of resilient systems for the hardware applied in safety-critical systems, such as the new nuclear reactor instrumentation and control (I&C) systems. The new systems (based in hardware description language (HDL) programmable devices) have been developed in response to the obsolescence of old analog technologies and current microprocessor-based digital technologies. Although HDL programmable devices have been widely used in various other industries for decades, they are still very new in nuclear reactors systems, which can be seen as a challenge and risk in the safety analyses and licensing efforts for utilities and designers. The goal of this work is to develop and test hardware architectures to tolerate the occurrence of faults, including multiple faults, minimizing the impact of the recovery process on system availability. Basic concepts of resilience in complex systems, as “return to equilibrium”, “robustness” and “extra adaptive capacity” were analyzed from the point of view of hardware architectures, leading to linkages between concepts and methods for resilience using an approach that increases reliability and simplifies the licensing process of systems based in HDL programmable devices in nuclear
plants
Designing for patient risk assessment in primary health care: a case study for ergonomic work analysis
In this paper, we study the importance of a consistent description of real work in patient risk assessment in the primary healthcare domain. Through a case study in the context of primary health care, we address the research problem of finding ways to build consistent real work descriptions of the patient risk assessment system in the primary healthcare domain, in order to foster the design of improved work situations and support devices. This is a qualitative field study based on ethnographic observation and semi-structured interviews carried out among professionals involved in the risk assessment process in a primary healthcare facility. The objects of ergonomic work analysis were work places and work situations with focus on human activity, as well as surrounding aspects. The analysis identified elements in the work domain with high cognitive demand and operations that could increase mental workload, providing elements for the earlier stages of the design of work situations and support devices to improve the risk assessment in primary health care. This paper shows the usefulness of real work descriptions in the design for complex situations like the risk assessment in health care, as well the impact of poor descriptions in generating harmful situations for both the patient and healthcare practitioners in the explored domain
Assessment Team Decision-Making: One Way to Assess the Multi-Criteria Decision-Making Based on Observation.
Decision-making has been a subject actively investigated in several areas of knowledge such as Philosophy,
Economics, Psychology, Computer Science, among others. This paper explores the potential opportunities
offered by two methodologies to assess the team decision-making at the end of a simulated exercise (training). We present a case study showing how to measure the team decision-making combining both methodologies to assess a team of three experienced Officers from the Military Fire Brigade of the State of Rio de Janeiro. The simulated exercise was carried out within the Integrated Center of Command and Control of Rio de Janeiro. We intend this study provide a pathway that can be helpful in reducing the subjectivity generated during the observation of the team decision-making in Emergency Management environments
Frailty and risk of complications in head and neck oncologic surgery. Systematic review and dose-response meta-analysis
There is emerging evidence that frail individuals present a decreased physiological reserve, decreased ability to maintain homeostasis, and increased vulnerability to stressors. The concept of frailty has become increasingly recognized as a valuable measure in oncological surgical patients, including those with head and neck cancer. Preoperative screening for frailty may provide an individualized risk assessment that can be used by an interdisciplinary team for preoperative counseling and to improve outcomes. The aim of this meta-analysis was to evaluate the relationship between frailty and the risk of major postoperative complications in frail individuals submitted to head and neck oncologic surgery. PubMed, SCOPUS, Web of Science, Google Scholar and OpenThesis were systematically searched to identify studies that evaluated the risk of major postoperative complications in frail individuals undergoing head and neck oncologic surgery. The search was performed on August 31, 2020, without language or date restrictions. Two independent investigators screened the searched studies based on each paper?s title and abstract. Relevant studies were read in full and selected according to the eligibility criteria. Frailty was assessed by modified Frailty Index (mFI-11) and major postoperative complications were measured by the Clavien-Dindo classification. We performed a categorical and dose-response meta-analysis using a random-effects model to evaluate the association between frailty and the risk of major postoperative complications in patients submitted to head and neck oncologic surgery. The results of the meta-analysis were expressed as relative risk (RR) and 95% confidence interval (95% CI). The risk of bias was assessed using the Newcastle-Ottawa Scale (NOS). Four studies (9,947 patients) were included in this systematic review and meta-analysis. Frail patients presented an increased risk of life-threatening complications requiring intensive care unit (ICU) admission (RR = 4.67; 95% CI 1.54?14.10) and 30-day mortality (RR = 8.10; 95% CI 2.30?28.57) compared to non-frail patients. We found evidence of dose-response trend between mFI-11 and major postoperative complications. Higher frailty scores are associated with a significant increase in ICU-level complications and 30-day mortality after head and neck oncologic surgery
VIRTUAL REALITY TECHNIQUES IN THE AID TO POPULATION AWARENESS AROUND A NUCLEAR WASTE
Nuclear energy has proved to be an extremely important source of energy for today's society. However, these achievements, even present in people's daily lives, often go unnoticed and suffer rejection by the same society that enjoys such contributions. Rejection, mainly due to the lack of information. In this context, this work used Virtual Reality technology to inform and make the population aware of the benefits and disadvantages of nuclear energy. For this purpose, an interactive virtual environment was produced that allowed the exploration of a nuclear waste repository. Subsequently, an educational video was developed to provide end-user information support. Finally, an educational game was also created with the aim of raising public awareness and demystifying the nuclear area by bringing knowledge, in a clear and engaging way, to the population around a nuclear repository. The developed environment allowed the user to walk through the virtual representation of the reject repository, and also enabled the creation of a video capable of transmitting the initial information and improving the spatial comprehension of the model as a whole. In conclusion, the tool developed in the present work has the capacity to assist in the production of nuclear projects before even entering the construction phase. In addition, it is possible to apply this technique to inform the population about the nuclear practices that will be applied, providing a greater involvement of the people and, consequently, a better assimilation of knowledge about nuclear energy
A COLLABORATIVE VIRTUAL ENVIRONMENT FOR TRAINING OF SECURITY AGENTS IN NUCLEAR EMERGENCIES
In face the recently observed security menaces related to terrorist actions and natural disasters, there is a need
for a major qualification and training of the agents responsible for avoid any problems regarding to abnormal
conditions. In the conventional training procedures, however, field simulations are associated to logistical and
operational constraints regarded to the execution of the tests which can expose the user to risk.
On the other hand, the use of virtual simulations provides an alternative to such limitations besides of promote
the qualifying of professionals with a great reliability. For this reason, this paper proposes the development of a
collaborative virtual environment that will be used to prepare the security agents on identifying individuals
suspected of carrying radioactive materials. The development of the virtual environment consisted on modeling using Autodesk 3ds Max, where the scene itself and the scene objects were modeled besides the terrain creation and basic features programming using the Game Engine Unity 3D. In the Engine Game were included radiation detectors and avatars. The security agents were able to communicate to each other by means of auxiliary external tools like a headset software that makes possible the communication, coordination and cooperation required for an effective collaboration.
Experimental tests of the virtual simulations were performed with the participation of CNEN radiological
protection agents and collaborators. The tests have shown that the proposed method can contribute to improve the training results of the basic collaborative skills required for a CNEN agent in an emergency situation without the need to espose him to any kind of risk. In face of that, we hope that it can contribute to minimize the demand for qualified security professionals
Basin-wide variation in tree hydraulic safety margins predicts the carbon balance of Amazon forests
Funding: Data collection was largely funded by the UK Natural Environment Research Council (NERC) project TREMOR (NE/N004655/1) to D.G., E.G. and O.P., with further funds from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES, finance code 001) to J.V.T. and a University of Leeds Climate Research Bursary Fund to J.V.T. D.G., E.G. and O.P. acknowledge further support from a NERC-funded consortium award (ARBOLES, NE/S011811/1). This paper is an outcome of J.V.T.’s doctoral thesis, which was sponsored by CAPES (GDE 99999.001293/2015-00). J.V.T. was previously supported by the NERC-funded ARBOLES project (NE/S011811/1) and is supported at present by the Swedish Research Council Vetenskapsrådet (grant no. 2019-03758 to R.M.). E.G., O.P. and D.G. acknowledge support from NERC-funded BIORED grant (NE/N012542/1). O.P. acknowledges support from an ERC Advanced Grant and a Royal Society Wolfson Research Merit Award. R.S.O. was supported by a CNPq productivity scholarship, the São Paulo Research Foundation (FAPESP-Microsoft 11/52072-0) and the US Department of Energy, project GoAmazon (FAPESP 2013/50531-2). M.M. acknowledges support from MINECO FUN2FUN (CGL2013-46808-R) and DRESS (CGL2017-89149-C2-1-R). C.S.-M., F.B.V. and P.R.L.B. were financed by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES, finance code 001). C.S.-M. received a scholarship from the Brazilian National Council for Scientific and Technological Development (CNPq 140353/2017-8) and CAPES (science without borders 88881.135316/2016-01). Y.M. acknowledges the Gordon and Betty Moore Foundation and ERC Advanced Investigator Grant (GEM-TRAITS, 321131) for supporting the Global Ecosystems Monitoring (GEM) network (gem.tropicalforests.ox.ac.uk), within which some of the field sites (KEN, TAM and ALP) are nested. The authors thank Brazil–USA Collaborative Research GoAmazon DOE-FAPESP-FAPEAM (FAPESP 2013/50533-5 to L.A.) and National Science Foundation (award DEB-1753973 to L. Alves). They thank Serrapilheira Serra-1709-18983 (to M.H.) and CNPq-PELD/POPA-441443/2016-8 (to L.G.) (P.I. Albertina Lima). They thank all the colleagues and grants mentioned elsewhere [8,36] that established, identified and measured the Amazon forest plots in the RAINFOR network analysed here. The authors particularly thank J. Lyod, S. Almeida, F. Brown, B. Vicenti, N. Silva and L. Alves. This work is an outcome approved Research Project no. 19 from ForestPlots.net, a collaborative initiative developed at the University of Leeds that unites researchers and the monitoring of their permanent plots from the world’s tropical forests [61]. The authros thank A. Levesley, K. Melgaço Ladvocat and G. Pickavance for ForestPlots.net management. They thank Y. Wang and J. Baker, respectively, for their help with the map and with the climatic data. The authors acknowledge the invaluable help of M. Brum for kindly providing the comparison of vulnerability curves based on PAD and on PLC shown in this manuscript. They thank J. Martinez-Vilalta for his comments on an early version of this manuscript. The authors also thank V. Hilares and the Asociación para la Investigación y Desarrollo Integral (AIDER, Puerto Maldonado, Peru); V. Saldaña and Instituto de Investigaciones de la Amazonía Peruana (IIAP) for local field campaign support in Peru; E. Chavez and Noel Kempff Natural History Museum for local field campaign support in Bolivia; ICMBio, INPA/NAPPA/LBA COOMFLONA (Cooperativa mista da Flona Tapajós) and T. I. Bragança-Marituba for the research support.Tropical forests face increasing climate risk1,2, yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for example, Ψ50) and hydraulic safety margins (for example, HSM50) are important predictors of drought-induced mortality risk3-5, little is known about how these vary across Earth's largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters Ψ50 and HSM50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both Ψ50 and HSM50 influence the biogeographical distribution of Amazon tree species. However, HSM50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM50 are gaining more biomass than are low HSM50 forests. We propose that this may be associated with a growth-mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM50 in the Amazon6,7, with strong implications for the Amazon carbon sink.Publisher PDFPeer reviewe
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