Structural hydrogeology in the Kenogami uplands, Quebec, Canada

La caractérisation du système de joints est un élément très important lors de la réalisation de levés sur les aquifères fracturés, puisque la porosité secondaire contrôle l'écoulement des eaux souterraines. Il est également important d'analyser les types d'interactions entre les joints. Par exemple, les types de terminaison des joints ainsi que la prédominance de certaines familles de joints représentent des informations qui permettant de comprendre les événements tectoniques responsables de la génération des systèmes de joints dans l'aquifère. En outre, le champ de contrainte actuel est habituellement le paramètre le plus important dans le contrôle de l'ouverture des joints, laquelle joue un rôle majeur dans l'écoulement des eaux souterraines. L'objectif principal de ce travail est de caractériser un aquifère dans des roches cristallines fracturées avec une lithologie relativement homogène, en définissant un modèle hydrogéologique de la zone d'étude. Ce modèle a été construit à l'aide de levés structuraux à différentes échelles et des analyses de données hydrogéologiques. Cette étude a été réalisée sur le seuil de Kénogami, dans le graben du Saguenay, au Québec. Elle visait à répondre aux questions suivantes: (1) est-ce que le système de joints dans le socle rocheux est structuré, c'est à dire, est-il possible d'identifier des orientations préférentielles de joints et des domaines structuraux? (2) Les systèmes de joints peuventils être définis à différentes échelles, par exemples aux échelles régionale et locale? Si oui, y a-t-il des relations entre les systèmes observés à différentes échelles? (3) Est-il possible d'identifier des corrélations entre le(s) système(s) de joints et les champs de contraintes passés et actuel? (4) Y a-t-il une relation entre les propriétés hydrogéologiques obtenues à partir de forages et le(s) système(s) de joints? Le levé structural a comporté trois phases principales. Premièrement, une caractérisation à l'échelle régionale du système de joints a été effectuée à partir de l'interprétation de photos aériennes, de l'analyse des linéaments, et d'un levé général de terrain sur des sites sélectionnés. Ce dernier type de levé implique l'étude de la distribution spatiale des principales familles de joints, et l'étude des âges relatifs des familles de joints et des champs de contrainte passés, menée sur des affleurements horizontaux. Deuxièmement, un levé détaillé sur des coupes de routes sélectionnées a été réalisé afin d'identifier et caractériser les familles de joints qui composent la fracturation dans la zone d'étude. Enfin, la réalisation de diagraphies géophysiques dans des forages a fourni des informations sur les joints en profondeur, notamment les familles de joints subhorizontaux. Ces étapes ont permis de répondre à la problématique proposée au début de cette recherche. Ce projet a permis la caractérisation d'un aquifère dans des roches cristallines fracturées, selon les aspects suivants: les systèmes de joints à différentes échelles, les champs de contraintes passés, les propriétés hydrauliques et les relations possibles entre ces paramètres. La méthodologie adoptée pourra être appliquée à d'autres études sur les aquifères rocheux fracturés. Enfin, un modèle conceptuel a été développé pour l'aquifère fracturé dans le seuil de Kénogami, en utilisant l'approche du bloc unitaire. Ce modèle peut être extrapolé à l'échelle régionale et il reflète la prédominance des joints subverticaux dans la zone d'étude. Les autres contributions de ce travail comprennent la mise en place de procédures : (1) pour appliquer la correction de Terzaghi sur ordinateur sans utilisation de logiciels spécialisés, et (2) pour l'analyse de l'orientation de la composante horizontale principale des champs de contraintes passés sur les affleurements horizontaux. Aussi, ce travail a mis en valeur l'intérêt de la caractérisation d'un milieu fracturé avec l'approche du bloc unitaire, par une discussion de sa relation avec les propriétés hydrauliques, suivie de leur incorporation dans les modèles numériques

A comprehensive dataset of environmentally contaminated sites in the state of São Paulo in Brazil

In the Brazilian state of São Paulo, contaminated sites (CSs) constitute threats to health, environment and socioeconomic situation of populations. Over the past two decades, the Environmental Agency of São Paulo (CETESB) has monitored these known CSs. This paper discusses the produced dataset through digitising the CETESB reports and making them accessible to the public in English. The dataset reports on qualitative aspects of contamination within the registered sites (e.g., contamination type and spread) and their management status. The data was extracted from CETESB reports using a machine-learning computer vision algorithm. It comprises two components: an optical character recognition (OCR) engine for text extraction and a convolutional neural network (CNN) image classifier to identify checked boxes. The digitisation was followed by harmonisation and quality assurance processes to ensure the consistency and validity of the data. Making this dataset accessible will allow future work on predictive analysis and decision-making and will inform the required policy-making to improve the management of the CSs in Brazil

Peri-operative red blood cell transfusion in neonates and infants: NEonate and Children audiT of Anaesthesia pRactice IN Europe: A prospective European multicentre observational study

BACKGROUND: Little is known about current clinical practice concerning peri-operative red blood cell transfusion in neonates and small infants. Guidelines suggest transfusions based on haemoglobin thresholds ranging from 8.5 to 12 g dl-1, distinguishing between children from birth to day 7 (week 1), from day 8 to day 14 (week 2) or from day 15 (≥week 3) onwards. OBJECTIVE: To observe peri-operative red blood cell transfusion practice according to guidelines in relation to patient outcome. DESIGN: A multicentre observational study. SETTING: The NEonate-Children sTudy of Anaesthesia pRactice IN Europe (NECTARINE) trial recruited patients up to 60 weeks' postmenstrual age undergoing anaesthesia for surgical or diagnostic procedures from 165 centres in 31 European countries between March 2016 and January 2017. PATIENTS: The data included 5609 patients undergoing 6542 procedures. Inclusion criteria was a peri-operative red blood cell transfusion. MAIN OUTCOME MEASURES: The primary endpoint was the haemoglobin level triggering a transfusion for neonates in week 1, week 2 and week 3. Secondary endpoints were transfusion volumes, 'delta haemoglobin' (preprocedure - transfusion-triggering) and 30-day and 90-day morbidity and mortality. RESULTS: Peri-operative red blood cell transfusions were recorded during 447 procedures (6.9%). The median haemoglobin levels triggering a transfusion were 9.6 [IQR 8.7 to 10.9] g dl-1 for neonates in week 1, 9.6 [7.7 to 10.4] g dl-1 in week 2 and 8.0 [7.3 to 9.0] g dl-1 in week 3. The median transfusion volume was 17.1 [11.1 to 26.4] ml kg-1 with a median delta haemoglobin of 1.8 [0.0 to 3.6] g dl-1. Thirty-day morbidity was 47.8% with an overall mortality of 11.3%. CONCLUSIONS: Results indicate lower transfusion-triggering haemoglobin thresholds in clinical practice than suggested by current guidelines. The high morbidity and mortality of this NECTARINE sub-cohort calls for investigative action and evidence-based guidelines addressing peri-operative red blood cell transfusions strategies. TRIAL REGISTRATION: ClinicalTrials.gov, identifier: NCT02350348

Application of the Discrete Fracture Network method to define the hydrogeological conceptual model of the fractured aquifer in the Jurubatuba region, Sao Paulo, Brazil

Este trabalho consistiu em uma investigação de detalhe em um aquífero cristalino fraturado, com manto inconsolidado sobreposto a rochas cristalinas sãs do Complexo Embu com o objetivo de conhecer o arcabouço estrutural e hidráulico para investigação de uma área contaminada por solventes organoclorados na região do Canal Jurubatuba, São Paulo. Destaca-se que pela primeira vez foi aplicado com sucesso o método Discrete Fracture Network (DFN) em uma região tropical, envolvendo minuciosa coleta de informações estruturais em testemunhos de sondagem e perfilagens geofísicas, além da instrumentação empregada para a medição de transmissividade e cargas hidráulicas. Foi perfurado um poço com cerca de 60m de profundidade, com recuperação contínua de testemunhos, cuja descrição foi feita em campo. Foram realizadas perfilagens geofísicas: calibre, gama natural, imageamentos acústico, óptico, de temperatura (tipo ALS, trazido pela primeira vez ao Brasil), além de ensaios hidráulicos com sistemas de obturadores de pressão. Uma membrana flexível de poliuretano foi instalada no furo aberto para evitar contaminação cruzada, sendo retirada apenas no momento da instalação do sistema de monitoramento multinível. Foi instalado um sistema tipo Westbay, com 15 zonas de monitoramento, o primeiro deste tipo a ser instalado no Brasil. Em outra perfuração, foi instalado um sistema tipo CMT, com 7 zonas de monitoramento. Adicionalmente, em três poços preexistentes foram coletados dados estruturais em perfilagens acústica e de calibre, além de ensaios hidráulicos. Afloramentos próximos à sondagem realizada foram estudados para uma melhor compreensão das estruturas da área. Observou-se que materiais geológicos anteriormente considerados em contato abrupto na verdade apresentam contatos graduais, com importante alternância de materiais de distintas competências e porosidades duplas. Além disso, constatou-se a ocorrência de fluxo predominantemente descendente entre as camadas, e a perfilagem de temperatura e ensaios com obturadores indicaram continuidade de características hidráulicas entre diferentes materiais. A importância do fluxo descendente é suplantada pelo fluxo horizontal no intervalo de 9.5 a 14.6m, conforme sugerido pelas assinaturas isotópicas de oxigênio e deutério fortemente empobrecidas. Os trechos com transmissividade mais elevada estão relacionados ao gnaisse fino com as famílias de fraturas A (sub-horizontal) e B (N064/27, mergulho para SE), ou à intercalação de gnaisse fino, pegmatito e gnaisse bandado e combinação das famílias A e B, indicando que o fluxo não é necessariamente função de uma única orientação de estruturas, mas que seu potencial pode ser aumentado diante da associação de mais de uma família de fraturas. Algumas das famílias de fraturas aqui identificadas foram ainda relacionadas a estruturas descritas em trabalhos regionais.This work consisted of a detailed investigation of a fractured crystalline aquifer, with an unconsolidated overburden with a crystalline bedrock from the Embu Complex. The objective was knowing the structural and hydraulic framework for investigating an area contaminated by organochlorine solvents in the Jurubatuba Channel region, in Sao Paulo, Brazil. It is noteworthy that for the first time the Discrete Fracture Network (DFN) method was successfully applied in a tropical region, with detailed data from rock core and geophysical profiling, in addition to the instrumentation used for the measurement of transmissivity and hydraulic loads. . A borehole about 60m deep was drilled, with continuous rock core recovery, described in the field. Geophysical profiling was performed: caliper, natural gamma, acoustic and optical televiewer, temperature (ALS type, brought to Brazil for the first time), as well as hydraulic tests with packer systems. A flexible polyurethane membrane was installed in the open borehole in order to prevent cross-contamination, being removed only for installing the multilevel monitoring system. A Westbay system with 15 monitoring zones was installed, the first of its kind to be installed in Brazil. In another drilling, a CMT type system with 7 monitoring zones was installed. Additionally, in three pre-existing wells, structural data was collected in caliper and acoustic profiles, as well as in hydraulic tests. Outcrops near the boreholes were studied to better understand the fracture framework of the area. It was observed that geological materials previously considered in abrupt contact actually have gradual contacts, with important alternation of materials of different competences and double porosities. In addition, a predominantly downward flow between layers was found, and temperature profiling and packer tests indicated continuity of hydraulic characteristics between different materials. The importance of downward flow is supplanted by horizontal flow from 9.5 to 14.6m, as suggested by strongly depleted oxygen and deuterium isotopic signatures. The portions with higher transmissivities are related to fine gneiss with the fracture sets A (subhorizontal) and B (N064/27, dipping to SE), or the intercalation of fine gneiss, pegmatite and banded gneiss and combination of families A and B, indicating that the flow is not necessarily a function of a single fracture orientation, rather its potential can actually be increased by combining more than one fracture family. Finally, some of the fracture families identified here were also related to structures described in regional works