Brazilian Nuclear Engineering Institute (IEN)


Brazilian Nuclear Engineering Institute (IEN)

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Sa L.T.M.,Pontifical Catholic University of Rio de Janeiro | Simmons S.,Open University Milton Keynes | Missailidis S.,Instituto Oswaldo Cruz IOC | Silva M.I.P.D.,Pontifical Catholic University of Rio de Janeiro | Santos-Oliveira R.,Brazilian Nuclear Engineering Institute (IEN)
Journal of Drug Targeting | Year: 2013

Background: The use of mesoporous silica for cancer targeting is increasing rapidly. The association between rigid model of nanoparticles such as mesoporous silica and biological compounds with affinity for oncological diseases is a very promising drug targeting system nowadays. Methods: In this study, we used the mesoporous silica (SBA-15) associated with aptamer (functionalized for the tumor marker MUC-1). Results: The results obtained in the characterization were quite interesting and demonstrated that the silica produced were very uniform and with a size range of 50-100nm. Thus, the results of cytotoxicity demonstrated that there is no cytotoxicity related to the nanoparticle. Conclusion: We conclude that although further studies are required, the nanoparticle mesoporous silica model loaded with aptamer is very functional and its use can be widespread for other application especially in nuclear medicine. © 2013 Informa UK Ltd. All rights reserved: reproduction in whole or part not permitted.

Santos-Oliveira R.,Brazilian Nuclear Engineering Institute (IEN) | Purdy C.,AHRM | Da Silva M.P.,University of Pernambuco | Dos Anjos Carneiro-Leao A.M.,University of Pernambuco | And 2 more authors.
Diabetologia | Year: 2011

Aims/hypothesis: The aim of this meta-analysis was to determine the relationship between HbA 1c levels and subsequent cardiovascular outcomes in individuals without diabetes. Methods: We searched Medline, Embase and Scopus from initiation of the study until the end of 2009. One reviewer searched and another verified findings. Data were extracted by one reviewer and verified by another. We accepted prospective studies in any language reporting three or more quartiles for HbA 1c levels. Within quartiles, authors must have presented both numbers of patient-years at risk and cardiovascular outcomes. Outcomes per person-time at risk were regressed on average HbA 1c values using Poisson regression. We pooled β coefficients using Cochran's semiweighted (inverse variance) random-effects model. Study quality was assessed using the Downs-Black scale. Results: We investigated 16 datasets (nine for total cardiovascular events and seven for death) from five papers with 44,158 patients (44% men) over 404,899 patient-years of follow-up. There were 1,366 cardiovascular deaths (3.1%; 3.37/1,000 person-years) and 2,142 cardiovascular events (4.9%; 5.29/1,000 person-years). The overall meta-analytic β coefficients were 0.720 (95% CI 0.307-1.133) and 0.757 (95% CI 0.382-1.132) for cardiac death and events, respectively. Compared with the baseline value of 0.0427, an HbA 1c level of 0.05 was associated with a relative risk for cardiovascular death of 1.13 (95% CI 1.05-1.21), a 0.06 value with 1.34 (95% CI 1.13-1.58), and a 0.07 HbA 1cwith relative risk 1.58 (95% CI 1.22-2.06). Results for total cardiovascular events were similar. The average study quality was 0.7 (70%). Conclusions/interpretation: We conclude that HbA 1c was significantly associated with cardiovascular events and deaths in persons without diabetes. © Springer-Verlag 2011.

Marinho R.S.,Federal University of Rio de Janeiro | Silva C.N.D.,Federal University of Rio de Janeiro | Afonso J.C.,Federal University of Rio de Janeiro | Cunha J.W.S.D.D.,Brazilian Nuclear Engineering Institute (IEN)
Journal of Hazardous Materials | Year: 2011

This work describes a route for platinum recovery from spent commercial Pt and PtSnIn/Al 2O 3 catalysts using strong basic mesoporous and macroporous anion exchange resins (Cl - form). The catalysts were leached with aqua regia (75°C, 20-25min). Platinum adsorption was influenced by the presence of other metals which form chlorocomplexes (tin, indium) and also base metals (aluminum). However, it was possible to overcome this fact by a sequential desorption procedure. Aluminum was selectively removed from the resins by elution with 3molL -1 HCl. Platinum was desorbed passing 1molL -1 Na 2S 2O 3 (pH 9). Tin was removed by elution with 0.1molL -1 ascorbic acid. Indium was removed using 0.1molL -1 EDTA as eluent. Desorption efficiency exceeded 99% for all metals. Metals were recovered in high yields (>98wt%). © 2011 Elsevier B.V.

Marinho R.S.,Federal University of Rio de Janeiro | Afonso J.C.,Federal University of Rio de Janeiro | da Cunha J.W.S.D.,Brazilian Nuclear Engineering Institute (IEN)
Journal of Hazardous Materials | Year: 2010

This work examines a hydrometallurgical route for processing spent commercial catalysts (Pt and PtSnIn/A2O3) used in Brazilian refineries for recovery of the noble metal with less final wastes generation. Samples were initially pre-oxidized (500°C, 5h) in order to eliminate coke. The basis of the present route is the partial dissolution of the pre-oxidized catalyst in aqua-regia. Temperature and time necessary to dissolve all platinum were optimized in order to reduce the operation severity and aluminum solubilization. All platinum and 16-18wt.% of aluminum were dissolved at 75°C in 20-25min. Separation of platinum from the acidic solution was accomplished by solvent extraction. The best extractant (>99wt.%) was Aliquat 336 (a quaternary ammonium salt) in one stage (A/O phase ratio=1, v/v). Platinum was stripped (>99.9wt.%) in one stage (A/O phase ratio=1, v/v) with aqueous sodium thiosulfate (≥0.75molL-1). Black platinum was obtained from this solution via reduction with magnesium or ascorbic acid. © 2010 Elsevier B.V.

Costa S.D.,Brazilian Nuclear Engineering Institute (IEN)
Safety and Reliability of Complex Engineered Systems - Proceedings of the 25th European Safety and Reliability Conference, ESREL 2015 | Year: 2015

The Angra Nuclear Power Plant is located in Rio de Janeiro, Brazil. It comprises 2 units in operation and a third one under construction. They are licensed to operate for 40 years with an extendable lifetime possibility for 20 more years. To obtain the Brazilian regulatory body agreement the owner has to prove that the systems, equipment and structures are reliable. This report presents the methodology, based on Electric Power Research Institute guidelines, applied to ensure that the safety electronic systems reliability is consistent, provide maximum lifetime extension and a reduction in changes and upgrades. The Safety Electronic Systems Reliability Monitoring Program purpose is to monitor their performance during the plant operation and shutdown periods by running tests to predict faults, enhancing safety and supporting the company´s investment policy in exchanging or modernization of these systems as well as a tool to improve the maintenance program and operation strategies. © 2015 Taylor & Francis Group, London.

Gonalves Filho O.J.A.,Brazilian Nuclear Engineering Institute (IEN)
Nuclear Engineering and Design | Year: 2011

This paper presents the results of the economic assessment of the International Reactor Innovative and Secure (IRIS) for deployment in Brazil using the assessment methodology developed under the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO), co-ordinated by the International Atomic Energy Agency (IAEA). INPRO initiated in 2001 and has the main objective of helping to ensure that nuclear energy will be available to contribute in a sustainable manner to the energy needs of the 21st century. Among its missions is the development of a methodology to assess innovative nuclear energy systems (INSs) on a global, regional and national basis. In 2005, Brazil submitted a proposal for the assessment of two small-size reactors as components of an INS, completed with a conventional open nuclear fuel cycle based on enriched uranium. One of the reactors assessed was IRIS, a small-size, modular, integral-type PWR reactor. IRIS was evaluated with regard to the areas of reactor safety and economics only. This paper outlines the rationale for the study and summarizes the results of the economic assessment. The study concluded that the reference design of IRIS complies with most of INPRO economics criteria and has potential to comply with the remaining ones. © 2011 Elsevier B.V. All rights reserved.

De Carvalho P.V.R.,Brazilian Nuclear Engineering Institute (IEN)
Reliability Engineering and System Safety | Year: 2011

The Functional Resonance Analysis Model (FRAM) defines a systemic framework to model complex systems for accident analysis purposes. We use FRAM in the mid-air collision between flight GLO1907, a commercial aircraft Boeing 737-800, and flight N600XL, an executive jet EMBRAER E-145, to investigate key resilience characteristics of the Air Traffic Management System (ATM). This ATM system related accident occurred at 16:56 Brazilian time on September 29, 2006 in the Amazonian sky. FRAM analysis of flight monitoring functions showed system constraints (equipment, training, time, and supervision) that produce variability in system behavior, creating demand resources mismatches in an attempt to perceive and control the developing situation. This variability also included control and coordination breakdowns and automation surprises (TCAS functioning). The analysis showed that under normal variability conditions (without catastrophic failures) the ATM system (pilots, controllers, supervisors, and equipment) was not able to close the control loops of the flight monitoring functions using feedback or feedforward strategies to achieve an adequate control of an aircraft flying in the controlled air space. Our findings shed some light on the resilience of Brazilian ATM system operation and indicated that there is a need of a deeper understanding on how the system is actually functioning. © 2011 Elsevier Ltd. All rights reserved.

Santos-Oliveira R.,Brazilian Nuclear Engineering Institute (IEN) | MacHado M.,University of Toronto
American Journal of the Medical Sciences | Year: 2011

Introduction: There is a considerable body of evidence describing that the pharmacokinetics and pharmacodynamics of radiopharmaceuticals may be changed by a variety of drugs, disease states and in some cases, surgical procedures. Objective: To systematically search the medical literature and review the published evidence on adverse reactions to radiopharmaceuticals. Methods: MEDLINE, EMBASE, International Pharmaceutical Abstracts and Science Citation Index were searched for studies reporting adverse reactions to radiopharmaceuticals. Controlled trials, cohort studies, case-control studies and case series published in major Western languages were considered for the review. Each study included in the present review was described in a narrative way, and major components of each study were reported (ie, research design, patient characteristics, types of drugs and radiopharmaceuticals, dosing information and adverse reactions). Results: The majority of adverse reactions to radiopharmaceuticals described in the literature required little or no treatment, and their negative effects were generally mild and self-limited. Large longitudinal greater than 5-year studies reported prevalence rates of adverse reactions due to radiopharmaceuticals ranging from 0 to 25 cases per 100,000 administrations. Case studies on the use of technetium reported mild adverse reactions; however, some led to potentially harmful complications. Similarly, studies involving fluorodeoxyglucose reported more severe adverse reactions. Conclusion: The literature on radiopharmaceuticals adverse effects is scarce, and just a few studies were conducted to investigate the association between radiopharmaceuticals and adverse reactions. Despite relatively mild and self-limited symptoms, the current widespread use of radiopharmaceuticals requires constant monitoring for adverse reactions. © 2011 Lippincott Williams & Wilkins.

Oliveira M.V.D.,Brazilian Nuclear Engineering Institute (IEN) | Almeida J.C.S.D.,Brazilian Nuclear Engineering Institute (IEN)
Progress in Nuclear Energy | Year: 2013

In pressurized water reactor (PWR) nuclear power plants (NPPs) pressure control in the primary loops is fundamental for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral-derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study is two-fold: first, to develop a pressurizer model based on artificial neural networks (ANNs); secondly, to develop fuzzy controllers for the PWR pressurizer modeled by the ANN and compare their performance with conventional ones. Data from a 2785 MWth Westinghouse 3-loop PWR simulator was used to test both the pressurizer ANN model and the fuzzy controllers. The simulation results show that the pressurizer ANN model responses agree reasonably well with those of the simulated power plant pressurizer, and that the fuzzy controllers have better performance compared with conventional ones. © 2012 Elsevier Ltd. All rights reserved.

Pinto L.N.,Brazilian Nuclear Engineering Institute (IEN) | Gonnelli E.,Brazilian Nuclear Engineering Institute (IEN) | Dos Santos A.,Brazilian Nuclear Engineering Institute (IEN)
AIP Conference Proceedings | Year: 2014

Researches that aim to improve the performance of neutron transport codes and quality of nuclear cross section databases are very important to increase the accuracy of simulations and the quality of the analysis and prediction of phenomena in the nuclear field. In this context, relevant experimental data such as reactivity worth measurements are needed. Control rods may be made of several neutron absorbing materials that are used to adjust the reactivity of the core. For the reactor operation, these experimental data are also extremely important: with them it is possible to estimate the reactivity worth by the movement of the control rod, understand the reactor response at each rod position and to operate the reactor safely. This work presents a temperature correction approach for the control rod calibration problem. It is shown the control rod calibration data of the IPEN/MB-01 reactor, the integral and differential reactivity curves and a theoretical analysis, performed by the MCNP-5 reactor physics code, developed and maintained by Los Alamos National Laboratory, using the ENDF/B-VII.0 nuclear data library. © 2014 AIP Publishing LLC.

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