Testing Generative Pre-trained Transformer for Knowledge Abstraction and Reasoning for Nuclear Reactor Design and Safety Applications

The decision regarding the adequacy of a Modeling and Simulation (M & S) tool is governed by different challenging factors. The M & S tools significantly vary in fidelity and scale of the simulation. Moreover, representative data for validating the adequacy of the code is scarce and limited. Therefore, standard procedures and methodologies, like, Code Scaling Applicability and Uncertainty (CSAU) and Evaluation Model Development and Assessment Process (EMDAP) have been developed by the United States Nuclear Regulatory Commission (US NRC) to guide the development and assessment of modeling and simulation tools. Though comprehensive in scope, different elements of these methodologies are governed by expert input and insight. Phenomena Identification and Ranking Table (PIRT), in particular, is based on expert input/opinion regarding the importance and knowledge level of different phenomena with respect to the figures of merit. The quality of PIRT depends on the domain knowledge and expertise of the participating group of experts. Knowledge abstraction and reasoning are important for PIRT formulation and understanding relationships and dependencies between different phenomena. The decision of adequacy of an M & S tool for an intended use also requires information retrieval, context-based knowledge abstraction, and reasoning to provide adequate evidential support. The risk assessment for nuclear reactor applications is based on probabilistic analysis and requires an estimation of the safety margin while considering different heterogeneous factors related to verification, validation, and uncertainty quantification of M & S tools. This process of knowledge abstraction and reasoning can be quite time-consuming, costly, and resource incentive. In this work, we explore and test the capabilities of Artificial intelligence-based large language models called Generative Pre-trained Transformers in information retrieval, knowledge abstraction, and reasoning to support evidence-based adequacy analysis of M & S tools. In particular, we analyze the ability and efficiency of GPT in replacing the expert-driven elements in adequacy analysis of M & S tools for an intended application (e.g., formulation of PIRT, understanding relationship and interdependencies between different phenomena. The main objective of this paper is to test the domain knowledge of GPT and identify its strengths, weaknesses, and challenges for their application in the nuclear engineering domain.Federal Research and Development Fundin

RESENHA - VILLEN, Patrícia. Amílcar Cabral e a crítica ao colonialismo

Resenha da obra: VILLEN, Patrícia. Amílcar Cabral e a crítica ao colonialismo: entre harmonia e contradição. 1ª Ed. São Paulo: Expressão Popular, 2013

A Meta-Analysis Approach on Medical, Surgical and Expectant Management on Abortion of First Trimester

An increase in miscarriage in the first trimester of gestation and its associated complication is burden-some on the quality of life of a woman. Medical, surgical, and expectant care are carried out after the miscarriage to remove any remaining tissues in the uterus. Understanding the efficacy and safety of these interventions will raise awareness and be a deciding factor to choose an appropriate treatment plan. Present review aims to determine the efficacy and safety of medical, surgical, and expectant care of various medical and surgical methods for first-trimester miscarriage. This review included studies that allocated women to medical, surgical or expectant management in the first trimester. PubMed, Cochrane Library, MEDLINE, and Embase Library were searched for the literature. The primary outcome was the complete evacuation of products of conception. Data were independently reviewed, graded for evidence quality, and assessed for risk bias by using the guidelines of PRISMA (Preferred Report Items for Systematic Review and Meta-Analysis). 21 eligible articles were included in this systematic review, comprising of 7931 patients undergoing medical, surgical or expectant-management for early spontaneous-miscarriage. The success rate in surgical intervention was higher when compared with medical intervention (OR: 16.12 [9.11, 28.52]) and expectant management (OR: 2.78 [2.13, 3.61]). Whereas medical intervention had a high success rate when compared with expectant-management (OR: 4.29 [2.31, 7.97]). The review determines the effect of medical, surgical, and expectant-management procedures on women who have had spontaneous-miscarriages in their first-trimester. PROSPERO-International prospective register of systematic reviews–CRD42020154395

The Stereodivergent Formation of 2,6-cis and 2,6-trans-Tetrahydropyrans: Experimental and Computational Investigation of the Mechanism of a Thioester Oxy-Michael Cyclization

The origins of the stereodivergence in the thioester oxy-Michael cyclization for the formation of 4-hydroxy-2,6-cis- or 2,6-trans-substituted tetrahydropyran rings under different conditions was investigated both computationally and experimentally. Synthetic studies showed that the 4-hydroxyl group was essential for stereodivergence. When the 4-hydroxyl group was present, TBAF-mediated conditions gave the 2,6-trans-tetrahydropyran and trifluoroacetic acid-mediated conditions gave the 2,6-cis-tetrahydropyran. This stereodivergence vanished when the hydroxyl group was removed or protected. Computational studies revealed that: (i) the trifluoroacetic acid catalysed formation of 2,6-cis-tetrahydropyrans was mediated by a trifluoroacetate-hydroxonium bridge and proceeded via a chair-like transition state; (ii) the TBAF-mediated formation of 2,6-trans-tetrahydropyrans proceeded via a boat-like transition state, where the 4-hydroxyl group formed a crucial hydrogen bond to the cyclizing alkoxide; (iii) both reactions are under kinetic control. The utility of this stereodivergent approach for the formation of 4-hydroxy-2,6-substituted tetrahydropyran rings has been demonstrated by the total syntheses of the anti-osteoporotic natural products diospongin A and

Assessing the Trustworthiness of a Digital Twin within the Nearly Autonomous Management and Control System

Digital Twins have the capability to automate certain tasks and thereby improve the economics of advanced nuclear reactor operation and maintenance (O&M) activities. A key blocker to the acceptance of these technologies is the absence of a comprehensive framework for assessing the trustworthiness of digital twins. Due to the data-driven nature of Digital Twins, it is possible to harness the methods developed in the fields of Artificial Intelligence (AI) Safety to assess certain aspects of trustworthiness. However, this poses additional challenges. In the NAMAC system the Digital Twin for Diagnosis is trained from system-level thermal-hydraulic simulation data to predict a safety significant factor - peak fuel centerline temperature - during a Loss-of-flow scenario. Unfortunately, conventional AI safety techniques like Adversarial Testing are focused almost entirely on classification models based on static data - the Digital Twins within the NAMAC system are regression models based on time-series data. Symbolic rule extraction techniques for explainability suffers from the same classification model restriction- with the added difficulty of these techniques often being applicable only to certain model architectures. This study documents the first attempts at adapting these methods to the task of assessing the trustworthiness of the NAMAC digital twin for Diagnosis

Six-membered ring systems: with O and/or S atoms

A large variety of publications have emerged in 2012 involving O- and S-6- membered ring systems. The increasing number of reviews and other communica- tions dedicated to natural and synthetic derivatives and their biological significance highlights the importance of these heterocycles. Reviews on natural products involve biosynthesis and isolation of enantiomeric derivatives h12AGE4802i, biosynthesis, isolation, synthesis, and biological studies on the pederin family h12NPR980i and xanthones obtained from fungi, lichens, and bacteria h12CR3717i and on the potential chemotherapeutic value of phyto- chemical products and plant extracts as antidiabetic h12NPR580i, antimicrobial, and resistance-modifying agents h12NPR1007i. A more specific review covers a structure–activity relationship of endoperoxides from marine origin and their antitry- panosomal activity h12OBC7197i. New synthetic routes to naturally occurring, biologically active pyran derivatives have been the object of several papers. Different approaches have been discussed for the total synthesis of tetrahydropyran-containing natural products (")-zampanolide h12CEJ16868, 12EJO4130, 12OL3408i, (")-aspergillides A and B h12H(85)587, 12H(85)1255, 12TA252i, (þ)-neopeltolide h12JOC2225, 12JOC9840, 12H(85) 1255i, or their macrolactone core h12OBC3689, 12OL2346i. The total synthesis of bistramide A h12CEJ7452i and (þ)-kalihinol A h12CC901i and the stereoselec- tive synthesis of a fragment of bryostatin h12S3077, 12TL6163i have also been sur- veyed. Other papers relate the total synthesis of naturally occurring carbocyclic and heterocyclic-fused pyran compounds, such as (")-dysiherbaine h12CC6295i, penos- tatin B h12OL244i, Greek tobacco lactonic products, and analogues h12TL4293i and on the structurally intriguing limonoids andhraxylocarpins A–E h12CEJ14342i. The stereocontrolled synthesis of fused tetrahydropyrans was used in the preparation of blepharocalyxin D h12AGE3901i. Polyphenolic heterocyclic compounds have also received great attention in 2012. The biological activities and the chemistry of prenylated caged xanthones h12PCB78i, the occurrence of sesquiterpene coumarins h12PR77i, and the medicinal properties of the xanthone mangiferin h12MRME412i have been reviewed. An overview on the asymmetric syntheses of flavanones and chromanones h12EJO449i, on the synthesis and reactivity of flavones h12T8523i and xanthones h12COC2818i, on the synthesis and biosynthesis of biocoumarins h12T2553i, and on the synthesis and applications of flavylium compounds h12CSR869i has been discussed. The most recent developments in the synthesis and applications of sultones, a very important class of sulfur compounds, were reported h12CR5339i. A review on xanthene-based fluorescent probes for sensing cations, anions, bio- logical species, and enzyme activity has described the spiro-ring-opening approach with a focus on the major mechanisms controlling their luminescence behavior h12CR1910i. The design and synthesis of other derivatives to be used as sensors of gold species h12CC11229i and other specific metal cations h12PC823i have also been described. Recent advances related to coumarin-derived fluorescent chemosen- sors for metal ions h12COC2690i and to monitoring in vitro analysis and cellular imaging of monoamine oxidase activity h12CC6833i have been discussed. The study of various organic chromophores allowed the synthesis of novel dica- tionic phloroglucinol-type bisflavylium pigments h12SL2053i, and the optical and spectroscopic properties of several synthetic 6-aryldibenzo[b,d]pyrylium salts were explored h12TL6433i. Discussion of specific reactions leading to O- and S-membered heterocyclic compounds covers intramolecular radical cyclization h12S2475i and asymmetric enamine and dienamine catalysis h12EJO865i, oxa-Michael h12CSR988i and dom- ino Knoevenagel–hetero-Diels–Alder (hDA) reactions h12T5693i, and the versatility in cycloadditions as well as nucleophilic reactions using o-quinones h12CSR1050i. The use of specific reagents relevant to this chapter includes molecular iodine h12CEJ5460, 12COS561i, samarium diiodide–water for selective reductive transfor- mations h12CC330i, o-quinone methides as versatile intermediates h12CEJ9160i, InCl3 as catalyst h12T8683i, and gold and platinum p-acid mediated insertion of alkynes into carbon–heteroatom s-bonds h12S3401i. The remainder of this chapter discusses the most studied transformations on O- and S-6-membered heterocycles

Migração e desenvolvimento: uma análise do município de Barcarena-PA

Este artigo apresenta uma análise das principais mudanças enfrentadas pela cidade de Barcarena, uma vez que foi escolhida para sediar vários projetos industriais e portos para embarques de produtos industrializados e principalmente mercadorias para o Japão, Estados Unidos e vários países europeus. Analisamos o processo de migração, suas motivações, reflexos e, como se relacionam, sobretudo, com a chegada de empresas, que provocaram transformações demográficas e econômicas em Barcarena. Nesse sentido, o desenvolvimento econômico é discutido no contexto da fase de construção do porto e da operação das empresas Albras e Alunorte. Isso é particularmente discutido, dada a reorganização espacial e territorial, e a contradição observada desde a década de 1990, em relação a esse município como tendo um dos maiores PIB e PIB per capita do estado do Pará, apesar dos registros de baixos índices de desenvolvimento humano