Concrete deterioration due to sulfide-bearing aggregates

Dans la région de Trois-Rivières (Québec, Canada), plus de 1 000 bâtiments résidentiels et commerciaux montrent de graves problèmes de détérioration du béton. Les problèmes de détérioration sont liés à l’oxydation des sulfures de fer incorporés dans le granulat utilisé pour la confection du béton. Ce projet de doctorat vise à mieux comprendre les mécanismes responsables de la détérioration de béton incorporant des granulats contenant des sulfures de fer, et ce afin de développer une méthodologie pour évaluer efficacement la réactivité potentielle de ce type de granulats. Un examen pétrographique détaillé de carottes de béton extraites de fondations résidentielles montrant différents degré d’endommagement a été réalisé. Le granulat problématique contenant des sulfures de fer a été identifié comme un gabbro à hypersthène incorporant différentes proportions (selon les différentes localisations dans les deux carrières d’origine) de pyrrhotite, pyrite, chalcopyrite et pentlandite. Les produits de réaction secondaires observés dans les échantillons dégradés comprennent des formes minérales de "rouille", gypse, ettringite et thaumasite. Ces observations ont permis de déterminer qu’en présence d’eau et d’oxygène, la pyrrhotite s’oxyde pour former des oxyhydroxides de fer et de l’acide sulfurique qui provoquent une attaque aux sulfates dans le béton. Tout d’abord, la fiabilité de l’approche chimique proposée dans la norme européenne NF EN 12 620, qui consiste à mesurer la teneur en soufre total (ST,% en masse) dans le granulat pour détecter la présence (ou non) de sulfures de fer, a été évaluée de façon critique. Environ 50% (21/43) des granulats testés, représentant une variété de types de roches/lithologies, a montré une ST > 0,10%, montrant qu’une proportion importante de types de roches ne contient pas une quantité notable de sulfure, qui, pour la plupart d’entre eux, sont susceptibles d’être inoffensifs dans le béton. Ces types de roches/granulats nécessiteraient toutefois d’autres tests pour identifier la présence potentielle de pyrrhotite compte tenu de la limite de ST de 0,10 % proposée dans les normes européennes. Basé sur une revue exhaustive de la littérature et de nombreuses analyses de laboratoire, un test accéléré d’expansion sur barres de mortier divisé en deux phases a ensuite été développé pour reproduire, en laboratoire, les mécanismes de détérioration observés à Trois-Rivières. Le test consiste en un conditionnement de 90 jours à 80°C/80% RH, avec 2 cycles de mouillage de trois heures chacun, par semaine, dans une solution d’hypochlorite de sodium (eau de javel) à 6% (Phase I), suivi d’une période pouvant atteindre 90 jours de conditionnement à 4°C/100 % HR (Phase II). Les granulats ayant un potentiel d’oxydation ont présenté une expansion de 0,10 % au cours de la Phase I, tandis que la formation potentielle de thaumasite est détectée par le regain rapide de l’expansion suivi par la destruction des échantillons durant la Phase II. Un test de consommation d’oxygène a également été modifié à partir d’un test de Drainage Minier Acide, afin d’évaluer quantitativement le potentiel d’oxydation des sulfures de fer incorporés dans les granulats à béton. Cette technique mesure le taux de consommation d’oxygène dans la partie supérieure d’un cylindre fermé contenant une couche de matériau compacté afin de déterminer son potentiel d’oxydation. Des paramètres optimisés pour évaluer le potentiel d’oxydation des granulats comprennent une taille de particule inférieure à 150 μm, saturation à 40 %, un rapport de 10 cm d’épaisseur de granulat par 10 cm de dégagement et trois heures d’essai à 22ᵒC. Les résultats obtenus montrent que le test est capable de discriminer les granulats contenant des sulfures de fer des granulats de contrôle (sans sulfures de fer) avec un seuil limite fixé à 5% d’oxygène consommé. Finalement, un protocole d’évaluation capable d’estimer les effets néfastes potentiels des granulats à béton incorporant des sulfures de fer a été proposé. Le protocole est divisé en 3 grandes phases: (1) mesure de la teneur en soufre total, (2) évaluation de la consommation d’oxygène, et (3) un test accéléré d’expansion sur barres de mortier. Des limites provisoires sont proposées pour chaque phase du protocole, qui doivent être encore validées par la mise à l’essai d’un plus large éventail de granulats.

Functional Magnetic Resonance Imaging Neurofeedback and Motor training for Parkinson’s Disease: Randomised Trial

Objective: Real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback (NF) uses feedback of the patient’s own brain activity to self-regulate brain networks which in turn could lead to a change in behaviour and clinical symptoms. The objective was to determine the effect of neurofeedback and motor training and motor training (MOT) alone on motor and non-motor functions in Parkinson’s disease (PD) in a 10-week small Phase I randomised controlled trial. Methods: 30 patients with PD (Hoehn & Yahr I-III) and no significant comorbidity took part in the trial with random allocation to two groups. Group 1 (NF: 15 patients) received rt-fMRI-NF with motor training. Group 2 (MOT: 15 patients) received motor training alone. The primary outcome measure was the Movement Disorder Society – Unified Parkinson’s Disease Rating Scale-Motor scale (MDS-UPDRS-MS), administered pre- and post-intervention ‘off-medication’. The secondary outcome measures were the ‘on-medication’ MDS-UPDRS, the Parkinson’s disease Questionnaire-39, and quantitative motor assessments after 4 and 10 weeks. Results: Patients in the NF group were able to upregulate activity in the supplementary motor area by using motor imagery. They improved by an average of 4.5 points on the MDS-UPDRS-MS in the ‘off-medication’ state (95% confidence interval: -2.5 to -6.6), whereas the MOT group improved only by 1.9 points (95% confidence interval +3.2 to -6.8). However, the improvement did not differ significantly between the groups. No adverse events were reported in either group. Interpretation: This Phase I study suggests that NF combined with motor training is safe and improves motor symptoms immediately after treatment, but larger trials are needed to explore its superiority over active control conditions. Clinical Trial website : Unique Identifier: NCT01867827 URL: https://clinicaltrials.gov/ct2/show/NCT01867827?term=NCT01867827&rank=1

Curricular internship report in medical writing at Blueclinical, Portugal

The contents of this report are a summary of the activities carried out during the 8-month internship as an Associate Medical Writer at Blueclinical Ltd, Matosinhos, Portugal. Mainly my activities were related to medical writing, particularly writing the clinical research protocols, clinical study reports, writing manuscript and preparing poster presentations. In addition to these activities, I also participated in performance of a clinical trial from beginning to end. During the period of its realization, I was able to familiarize myself with all the steps of the Phase I clinical trial.

Étude du comportement de la chromatine, de la régulation de la transcription et réparation des gènes de l’ARNr avant la réplication de l’ADN et assemblage de la réparation par excision de nucléotides chez Saccharomyces cerevisiae

Résumé : Le nucléole est considéré comme étant une « usine » à produire des ribosomes. Cette production est la fonction la plus énergivore de la cellule. Elle met en jeu les trois ARN polymérases et représente 80% de l’activité de transcription au sein d’une cellule. Les trois quarts de cette activité de transcription correspondent à la synthèse des ARNr par l’ARN polymérase I (ARNPI). Ainsi mieux comprendre les mécanismes cellulaires se déroulant à l’intérieur de ce compartiment permettra le développement de nouveaux traitements contre le cancer. La synthèse d’ARNr par l’ARNPI est régulée à trois niveaux : l’initiation de la transcription, l’élongation et le nombre de gènes de l’ARNr en transcription. La plupart des travaux qui se sont intéressés à ces niveaux de régulation ont été réalisés avec des cellules en phase exponentielle de croissance. Au cours de mes travaux, je me suis attardé sur la régulation de la transcription par l’ARNPI au cours de la phase G1 du cycle cellulaire et au début de la phase S. Ainsi mes résultats ont montré que si la chromatine des gènes de l’ARNr est essentiellement dépourvue de nucléosomes, la régulation de l’ARNPI diffère dans des cellules en G1 et au début de la phase S. J’ai pu de ce fait observer qu’en G1, la transcription de l’ARNPI se concentre sur un nombre réduit de gènes en transcription. Dans des cellules arrêtées au début de la phase S avec de l’hydroxyurée, la transcription de l’ARNPI est perturbée par un défaut de maturation de l’ARNR. Fort de ces résultats sur la nature des gènes ribosomaux en phase G1, je me suis attardé à la réparation de ces gènes lors de cette phase. Alors que dans des cellules en phase exponentielle de croissance irradiées avec des UVC, la chromatine des gènes de l’ARNr se ferme ; je n’ai pas observé la formation de nucléosomes suite à l’irradiation de cellules synchronisée en G1. Mes résultats montrent également que la réparation est plus efficace. Parallèlement, j’ai exploré l’assemblage du complexe de réparation par excision de nucléotides. Toutefois, les résultats obtenus sont peu concluants.

Propuesta metodológica para la renovación de los sistemas y procesos de administración de los mercados eléctricos: el caso colombiano

El mercado eléctrico ha evolucionado en Colombia desde 1995, fortaleciéndose institucionalmente, dinamizando su desarrollo, y enfrentando grandes desafíos. Los sistemas de administración, que soportan el funcionamiento del mercado, han evolucionado a la par, aunque algunos se encuentran aislados entre sí o han sido desarrollados en plataformas diferentes, lo que dificulta la sostenibilidad y el mantenimiento, y reducen la facilidad de incorporar cambios. Al referenciarse con otros mercados en el mundo, se observa gran dinámica en la incorporación de tecnologías en información y comunicaciones, avances regulatorios o requerimientos de clientes. Se requiere una renovación tecnológica que conserve el conocimiento adquirido, y permita incorporar fácilmente las tendencias del mercado. Este artículo presenta los resultados de la propuesta metodológica para la renovación tecnológica enmarcada en el proyecto Colciencias CNBT 833559938649 de investigación tecnológica, Sistema para la administración del mercado de energía eléctrica en Colombia, Fase I.

Investigating a Hybrid Metaheuristic For Job Shop Rescheduling

Previous research has shown that artificial immune systems can be used to produce robust schedules in a manufacturing environment. The main goal is to develop building blocks (antibodies) of partial schedules that can be used to construct backup solutions (antigens) when disturbances occur during production. The building blocks are created based upon underpinning ideas from artificial immune systems and evolved using a genetic algorithm (Phase I). Each partial schedule (antibody) is assigned a fitness value and the best partial schedules are selected to be converted into complete schedules (antigens). We further investigate whether simulated annealing and the great deluge algorithm can improve the results when hybridised with our artificial immune system (Phase II). We use ten fixed solutions as our target and measure how well we cover these specific scenarios.

A altura de dossel e a adubação nitrogenada da pastagem podem afetar a nutrição nitrogenada do milho, num sistema de integração lavoura pecuária?

We conducted a field experiment near Abelardo Luz, Santa Catarina, from October 2012 to April 2014, to evaluate the effect interaction of nitrogen fertilization and height of canopy over the N nutrition of corn subsequently grown to pasture. The data belonging to this thesis are related to the first two production cycles obtained in sorghum pasture (2012/2013), oat (2013) and corn crop (2013/2014). In the evaluation of forage sorghum and oat it was used the same experimental design, consisting of randomized complete block in a factorial arrangement (2 x 2) with three replications. The first factor was considered canopy height (Low and High) and the second factor was the fertilization of cover crop pasture (0 and 200 kg N.ha-1). In phase I and II, the combination of factors evaluators were prepared in the same experimental unit. For corn crop the design was a randomized complete block in a factorial design (2X2X4X6) with three replications. Factors considered in corn were: canopy height of pasture (Low and High), nitrogen application times (NG - nitrogen in the grains and NP - nitrogen in pasture), nitrogen fertilization in corn (0, 100, 200 and 300 kg N.ha-1) and time (46, 53, 60, 67, 76 and 103 days after sowing the maize). In phases I and II, in general the use of N in the pasture increased the productive potential of the pasture and animal management and canopy height has changed the dynamics of structural components and botanical pasture. In cold conditions for long periods and not acclimatized plants the adoption of high nitrogen fertilization and height high grazing pasture leave vulnerable to damage caused by the freezing of plants. The anticipation of nitrogen fertilization on pasture positively affects the corn crop by increasing the accumulated dry matter and N content in the plant. Nitrogen nutritional content of corn with the anticipation of fertilization in pasture is suitable for obtaining high crop production in integrated crop-livestock system. When used nitrogen only coverage in corn sufficiency level in the nitrogen nutrition is achieved with the use of 100 kg N.ha-1. With the use of 200 kg N ha -1 NG and NP no difference in nitrogen content and nitrogen nutrition index.

Host-guest system of 4-nerolidylcatechol in 2-hydroxypropyl-beta-cyclodextrin: preparation, characterization and molecular modeling

The interaction of 4-nerolidylcatechol (4-NRC), a potent antioxidant agent, and 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was investigated by the solubility method using Fourier transform infrared (FTIR) methods in addition to UV-Vis, (1)H-nuclear magnetic resonance (NMR) spectroscopy and molecular modeling. The inclusion complexes were prepared using grinding, kneading and freeze-drying methods. According to phase solubility studies in water a B(S)-type diagram was found, displaying a stoichiometry complexation of 2:1 (drug:host) and stability constant of 6494 +/- A 837 M(-1). Stoichiometry was established by the UV spectrophotometer using Job's plot method and, also confirmed by molecular modeling. Data from (1)H-NMR, and FTIR, experiments also provided formation evidence of an inclusion complex between 4-NRC and HP-beta-CD. 4-NRC complexation indeed led to higher drug solubility and stability which could probably be useful to improve its biological properties and make it available to oral administration and topical formulations.

L1 track finding for a time multiplexed trigger

At the HL-LHC, proton bunches will cross each other every 25. ns, producing an average of 140 pp-collisions per bunch crossing. To operate in such an environment, the CMS experiment will need a L1 hardware trigger able to identify interesting events within a latency of 12.5. μs. The future L1 trigger will make use also of data coming from the silicon tracker to control the trigger rate. The architecture that will be used in future to process tracker data is still under discussion. One interesting proposal makes use of the Time Multiplexed Trigger concept, already implemented in the CMS calorimeter trigger for the Phase I trigger upgrade. The proposed track finding algorithm is based on the Hough Transform method. The algorithm has been tested using simulated pp-collision data. Results show a very good tracking efficiency. The algorithm will be demonstrated in hardware in the coming months using the MP7, which is a μTCA board with a powerful FPGA capable of handling data rates approaching 1. Tb/s.

Reproductive performance as affected by lactation status and body fat in beef cows.

Seventy-one mature Brangus cows, 38 nonlactating (NL) and 33 in late stage of lactation (L) were fed for 192 days (Phase I) a low energy diet (L). During Phase II (65 days) 19 NL and 17 L cows were fed a high energy diet (H). The other nonlactating (19) and lactating (16) cows remained on the low energy diet. Energy restriction during Phase I did not affect (P> 0.05) cyclic ovarian activity although losses in body weight and condition were substantial. Rapid changes in body weight, condition, and percent empty body lipe (EBLP) during Phase II did not substantially influencefertility, although a five-fold difference in EBLP was observed (NL0H vs. L-L). Treatment groups did not differ (P> 0.05) in conception rate, days from the beginning of the breeding season to breeding and to conception, conception at first service, and number of services per conception. Values observed for these parameters for NL-H, L-H, NL-L, and L-L groups were respectively: 68,4%, `3,.2, 23.3, 36.8% and 1.68; 82,4% 12.7, 19.5, 58.8% and 1.29; 68.4%, 10.2, 17.4, 47.4%, and 1.41; 68.8%, 12.4, 19.5, 43.7%, and 1.50.

Biologia reprodutiva da Tainha, Mugil curema valenciennes, 1836 (osteichthyes: mugilidade) nas águas costeiras do Rio Grande do Norte

The marine fish white mullet, Mugil curema Valenciennes, 1836 (Osteichthyes: Mugilidae) exhibits a wide geographical distribution, being common in the Brazilian coast and is an important component of the artisanal fisheries. The objective of this study was to investigate the reproductive biology of M. curema in the coastal waters of Rio Grande do Norte. Fish samples were captured on a monthly basis during August, 2008 to July, 2009. The fish specimens were numbered, weighed, measured, dissected and their gonads were removed, weighed, their sex and gonadal development were identified. The length-weight relationship was determined for males and females. The sex ratio, the size at first gonadal maturation and gonadosomatic index (GSI) were calculated and ovarian development was investigated using macroscopic and histological techniques. The fecundity, spawning type and the reproductive period of the species were determined. A total of 366 specimens (186 males and 180 females) were captured. The sex ratio was 1:1 and the females were heavier than males. The estimated values of the angular coefficient for both sexes suggest that the species has isometric growth. The size at which 50% of the population began the process of maturation was 25.9 cm of total length for grouped sex. The macroscopic characteristics of the ovaries showed four stages of development: immature, maturing, mature and spent. However, the microscopic characteristics of the ovaries showed five stages of development: immature, early maturing, late maturing, mature and spent. The development of oocytes indicated five phases: Chromatin-nucleolus (phase I), initial perinucleolar (phase II), final perinuclear (phase II), formation of vitelline vesicle or yolk (phase III), vitellogenic (phase IV) and complete vitellogenesis (phase V). The species has a prolonged spawning period, with two peaks coinciding with the rainy season.

Essays on Emissions Trading Markets

This dissertation is a collection of three economics essays on different aspects of carbon emission trading markets. The first essay analyzes the dynamic optimal emission control strategies of two nations. With a potential to become the largest buyer under the Kyoto Protocol, the US is assumed to be a monopsony, whereas with a large number of tradable permits on hand Russia is assumed to be a monopoly. Optimal costs of emission control programs are estimated for both the countries under four different market scenarios: non-cooperative no trade, US monopsony, Russia monopoly, and cooperative trading. The US monopsony scenario is found to be the most Pareto cost efficient. The Pareto efficient outcome, however, would require the US to make side payments to Russia, which will even out the differences in the cost savings from cooperative behavior. The second essay analyzes the price dynamics of the Chicago Climate Exchange (CCX), a voluntary emissions trading market. By examining the volatility in market returns using AR-GARCH and Markov switching models, the study associates the market price fluctuations with two different political regimes of the US government. Further, the study also identifies a high volatility in the returns few months before the market collapse. Three possible regulatory and market-based forces are identified as probable causes of market volatility and its ultimate collapse. Organizers of other voluntary markets in the US and worldwide may closely watch for these regime switching forces in order to overcome emission market crashes. The third essay compares excess skewness and kurtosis in carbon prices between CCX and EU ETS (European Union Emission Trading Scheme) Phase I and II markets, by examining the tail behavior when market expectations exceed the threshold level. Dynamic extreme value theory is used to find out the mean price exceedence of the threshold levels and estimate the risk loss. The calculated risk measures suggest that CCX and EU ETS Phase I are extremely immature markets for a risk investor, whereas EU ETS Phase II is a more stable market that could develop as a mature carbon market in future years.

Geographical literacy, attitudes, and experiences of freshman students: A qualitative study at Florida International University

The purpose of the study was to explore the geography literacy, attitudes and experiences of Florida International University (FIU) freshman students scoring at the low and high ends of a geography literacy survey. The Geography Literacy and ABC Models formed the conceptual framework. Participants were freshman students enrolled in the Finite Math course at FIU. Since it is assumed that students who perform poorly on geography assessments do not have an interest in the subject, testing and interviewing students allowed the researcher to explore the assumption. ^ In Phase I, participants completed the Geography Literacy Survey (GLS) with items taken from the 2010 NAEP Geography Subject Area Assessment. The low 35% and high 20% performers were invited for Phase II, which consisted of semi-structured interviews. A total of 187 students participated in Phase I and 12 in Phase II. ^ The primary research question asked was what are the geography attitudes and experiences of freshman students scoring at the low and high ends of a geographical literacy survey? The students had positive attitudes regardless of how they performed on the GLS. ^ The study included a quantitative sub-question regarding the performance of the students on the GLS. The students’ performance on the GLS was equivalent to the performance of 12th grade students from the NAEP Assessment. There were three qualitative sub-questions from which the following themes were identified: the students’ definition of geography is limited, students recall more out of school experiences with geography, and students find geography valuable. In addition, there were five emergent themes: there is a concern regarding a lack of geographical knowledge, rote memorization of geographical content is overemphasized, geographical concepts are related to other subjects, taking the high school level AP Human Geography course is powerful, and there is a need for real-world applications of geographical knowledge. ^ The researcher offered as suggestions for practice to reposition geography in our schools to avoid misunderstandings, highlight its interconnectedness to other fields, connect the material to real world events/daily decision-making, make research projects meaningful, partner with local geographers, and offer a mandatory geography courses at all educational levels.^

Studies on the phase diagram of the surfactant/1-pentanol water ternary system I: The isotropic phases

The phase diagram of the dodecyl dimethyl ammonium hydroxyl propyl sulfonate(DDAHPS)/1-pentanol(C5H11OH)/water ternary system has been established. It contains two isotropic monophase regions (L-1 and L-2) and a liquid crystalline region (L.C.). The isotropic phase regions have been investigated by means of Raman spectroscopy and conductivity.