Concreto celular polimérico: influência na adição de resíduo de poliéster insaturado termofixo

This work addresses the production of lightweight concrete building elements, such as plates, prefabricated slabs for pre-molded and panels of fencing, presenting a singular concrete: the Lightweight Concrete, with special properties such low density and good strength, by means of the joint use of industrial waste of thermosetting unsaturated polyesters and biodegradable foaming agent, named Polymeric Lightweight Concrete. This study covered various features of the materials used in the composition of the Polymeric Lightweight Concrete, using a planning of factorial design 23, aiming at studying of the strength, production, dosage processes, characterization of mechanical properties and microstructural analysis of the transition zone between the light artificial aggregate and the matrix of cement. The results of the mechanical strength tests were analyzed using a computational statistics tool (Statistica software) to understand the behavior and obtain the ideal quantity of each material used in the formula of the Polymeric Lightweight Concrete. The definition of the ideal formula has the purpose of obtaining a material with the lowest possible dry density and resistance to compression in accordance with NBR 12.646/92 (≥ 2.5 MPa after 28 days). In the microstructural characterization by scanning electron microscopy it was observed an influence of the materials in the process of cement hydration, showing good interaction between the wrinkled face of the residue of unsaturated polyesters thermosetting and putty and, consequently, the final strength. The attaining of an ideal formula, given the Brazilian standards, the experimental results obtained in the characterization and comparison of these results with conventional materials, confirmed that the developed Polymeric Lightweight Concrete is suitable for the production of building elements that are advantageous for construction

Síntese, aplicação e avaliação do efeito do teor de fósforo da celulose fosfatada em argamassa de alvenaria com aditivo comercial a base de hidroxi-etil-metil celulose (HEMC)

Generally, cellulose ethers improves mortar properties such as water retention, workability and setting time, along with adherence to the substrate. However, a major disadvantage of the addition of cellulose ethers in mortars is the delay in hydration of the cement. In this paper a cellulose phosphate (Cp) was synthesized water soluble and has been evaluated the effect of their incorporation into mortar based on Portland cement. Cellulose phosphate obtained was characterized by spectrophotometry Fourier transform infrared (FTIR), X-ray diffraction (XRD), elemental analysis and scanning electron microscopy (SEM). Mortar compositions were formulated with varying phosphorus content in cellulose and cellulose phosphate concentrations, when used in partial or total replacement of the commercial additive based hydroxyethyl methyl cellulose (HEMC). The mortars formulated with additives were prepared and characterized by: testing in the fresh state (consistency index, water retention, bulk density and air content incorporated) and in the hardened state (absorption by capillarity, density, flexural and compression strength). In mixtures the proportion of sand:cement of 1:5 (v / v) and factor a / c = 1.31 and water were held constant. Overall, the results showed that the celluloses phosphates employed in mortars added acted significantly when partially substituting the commercial additive. With regard to consistency index, water retention and bulk density in the fresh state and absorption by capillarity and bulk density apparent in the hardened state, showed no appreciable differences as compared to the commercial additive. The incorporated air content in the fresh state reduced markedly, but did not affect other properties. The mortars with cellulose phosphate, partially replacing the commercial additive showed an improvement of the properties of flexural strength and compressive strength

Efeito da incorporação de diatomita na estabilidade e permeabilidade de compósitos cimentíceos espumados aplicados a poços de petróleo

Lightweight oilwell cement slurries have been recently studied as a mean to improve zonal isolation and sheath-porous formation adherence. Foamed slurries consisting of Portland cement and air-entraining admixtures have become an interesting option for this application. The loss in hydrostatic pressure as a consequence of cement hydration results in the expansion of the air bubbles entrapped in the cement matrix, thus improving the sheath-porous formation contact. Consequently, slurries are able to better retain their water to complete the hydration process. The main objective of the present study was to evaluate the effect of the addition of an air-entraining admixture on the density, stability and permeability of composite slurries containing Portland cement and diatomite as light mineral load. Successful formulations are potential cementing materials for low fracture gradient oilwells. The experimental procedures used for slurry preparation and characterization were based on the American Petroleum Institute and ABNT guidelines Slurries containing a pre-established concentration of the air-entraining admixture and different contents of diatomite were prepared aiming at final densities of 13 to 15 lb/gal. The results revealed that the reduction of 15 to 25% of the density of the slurries did not significantly affect their strength. The addition of both diatomite and the air-entraining admixture increased the viscosity of the slurry providing better air-bubble retention in the volume of the slurry. Stable slurries depicted bottom to top density variation of less than 1.0 lb/gal and length reduction of the stability sample of 5.86 mm. Finally, permeability coefficient values between 0.617 and 0.406 mD were obtained. Therefore, lightweight oilwell cement slurries depicting a satisfactory set of physicochemical and mechanical properties can be formulated using a combination of diatomite and air-entraining admixtures for low fracture gradient oilwells

Factores preditivos de linfoma no síndrome de Sjögren : a propósito de um caso clínico

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

Desenvolvimento de um sistema misto de pasta à base de geopolímero e cimento portland para correção de perda de circulação

The materials engineering includes processes and products involving several areas of engineering, allowing them to prepare materials that fulfill the needs of various new products. In this case, this work aims to study a system composed of cement paste and geopolymers, which can contribute to solving an engineering problem that directly involves the exploitation of oil wells subject to loss of circulation. To correct it, has been already proposed the use of granular materials, fibers, reducing the drilling fluid or cement paste density and even surface and downhole mixed systems. In this work, we proposed the development of a slurry mixed system, the first was a cement-based slurry and the second a geopolymer-based slurry. The cement-based slurry was formulated with low density and extenders, 12.0 ppg (1.438 g/cm ³), showing great thixotropic characteristics. It was added nano silica at concentrations of 0.5, 1.0 and 1.5 gps (66.88, 133.76 and 200.64 L/m3) and CaCl2 at concentrations of 0.5, 1, 0 and 1.5%. The second system is a geopolymer-based paste formulated from molar ratios of 3.5 (nSiO2/nAl2O3), 0.27 (nK2O/nSiO2), 1.07 (nK2O/nAl2O3) and 13.99 (nH2O/nK2O). Finally, we performed a mixture of these two systems, for their application for correction of circulation lost. To characterize the raw materials, XRD, XRF, FTIR analysis and titration were performed. The both systems were characterized in tests based on API RP10B. Compressive strength tests were conducted after curing for 24 hours, 7 and 28 days at 58 °C on the cement-based system and the geopolymer-based system. From the mixtures have been performed mixability tests and micro structural characterizations (XRD, SEM and TG). The results showed that the nano silica, when combined with CaCl2 modified the rheological properties of the cement slurry and from the concentration of 1.5 gpc (200.64 L / m³) it was possible to obtain stable systems. The system mixture caused a change in the microstructure of the material by favoring the rate of geopolymer formation to hinder the C3S phase hydration, thus, the production of CSH phases and Portlandite were harmed. Through the mixability tests it can be concluded that the system, due to reduced setting time of the mixture, can be applied to plug lost circulation zones when mixed downhole

Hydration status using free water reserve in Portuguese adolescents

Introduction: Few data is available about the hydration status of active adolescents in free living conditions. Cell dehydration may be prevalent in healthy, free-living children at school and they could be in a state of chronic voluntary dehydration. Objective: This study aims to describe hydration status assessed by Free Water Reserve (FWR) in adolescents. Method: Two hundred participants (118 girls), aged 13-18 years completed the study. Urinary volume (ml/d) and urinary osmolality (mosm/kg) were measured by one 24h urinary collection, and coefficient of creatinine was used to validate completeness of urine collections. FWR (measured urine volume minus the obligatory urine volume) was used for characterization of hydration status. Positive values of FWR indicate euhydration, negative values the risk of hypo-hydration. Results: Median urinary volume excretion was 1100.0 ml/d for boys and 1025.0 ml/d for girls (p=0.923). Mean urinary osmolality was 715.7±172.3 mosm/kg for boys and 597.42±193.1 mosm/kg for girls (p=0.247). Median FWR (ml/24h) was positive in both sex groups (173.2 ml/d in boys and 373.2 ml/d in girls); however, 40.2% of boys and 31.4% of girls (p=0.195) were at risk of hypo-hydration status. Conclusions: In this sample of adolescents approximately one third was classified as at risk of hypo-hydration status. Preventive measures to increase the level of total water intake should be considered.

Beverages intake and hydration status in adolescents

Introduction: Type and quantity of beverages intake among adolescents may influence their hydration status. Objective: To evaluate the association between hydration status assessed by Free Water Reserve (FWR) and consumption of 5 types of beverages (water, milk, soft drinks, fruit juices and hot beverages). Conclusions: In this sample of participants, euhydrated adolescents ingest more water and hot beverages than those at risk of hypo-hydration.

Eficacia de la nutrición parenteral domiciliaria de larga evolución con catéter de acceso periférico: a propósito de un caso

El uso de la nutrición parenteral domiciliaria (NPD) en pacientes que no pueden alcanzar sus requerimientos nutricionales por la vía enteral está aumentando en los últimos años, permitiendo la normalización del estilo de vida de los pacientes. Entre las patologías que más frecuentemente precisan de la NPD en España destacan la neoplasia y la isquemia mesentérica. Sin embargo, la NPD constituye uno de los pilares básicos del tratamiento de enfermedades mucho menos frecuentes como es el caso de la esclerosis peritoneal encapsulante. A continuación presentamos el caso de un paciente diagnosticado de esclerosis peritoneal encapsulante con soporte NPD de más de 7 años de NPD con un catéter central de inserción periférica (PICC) para la NPD sin complicaciones y pudiendo realizar su actividad laboral habitual. Dado lo excepcional del caso lo remitimos para su publicación.

Critical energy deficit and mortality in critically ill patients

Objective: We investigate the influence of caloric and protein deficit on mortality and length of hospital stay of critically ill patients. Methods: A cohort prospective study including 100 consecutive patients in a tertiary intensive care unit (ICU) receiving enteral or parenteral nutrition. The daily caloric and protein deficit were collected each day for a maximum of 30 days. Energy deficits were divided into critical caloric deficit (≥ 480 kcal/day) and non-critical caloric deficit (≤ 480 kcal/day); and in critical protein deficit (≥ 20 g/day) and non-critical protein deficit (≤ 20 g/day). The findings were correlated with hospital stay and mortality. Results: The mortality rate was 33%. Overall, the patients received 65.4% and 67.7% of the caloric and protein needs. Critical caloric deficit was found in 72% of cases and critical protein deficit in 70% of them. There was a significant correlation between length of stay and accumulated caloric deficit (R = 0.37; p < 0.001) and protein deficit (R = 0.28; p < 0.001). The survival analysis showed that mortality was greater in patients with both critical caloric (p < 0.001) and critical protein deficits (p < 0.01). The Cox regression analysis showed that critical protein deficit was associated with higher mortality (HR 0.25, 95% CI 0.07-0.93, p = 0.03). Conclusions: The incidence of caloric and protein deficit in the ICU is high. Both caloric and protein deficits increase the length of hospital stay, and protein deficit greater than 20 g/day is an independent factor for mortality in critical care unit.

Timing versus caloric goal in nutritional therapy for critically ill patients

Introduction: Enteral nutrition is an important therapy for severely critically ill patients. The timing and amount of energy have been highly debated. Objective: The aim of the present study was to directly compare the timing and the caloric targets in critically ill patients. Methods: Retrospective cohort study conducted at a single center, comparing timing and caloric goal for critically ill patients. Patients were stratified according to the start of nutritional therapy (24, 48, or more than 48 h) and the amount of energy delivered (target adequacy of previously calculated percentage in the first week). Statistical analysis was performed using parametric and non-parametric tests for independent samples and logistic regression. The results were expressed as mean ± standard deviation or incidence and percentage. Results and discussion: There were no differences in major clinical outcomes in relation to the achievement of percentage of caloric goal at the end of the first week of the study. The beginning of caloric intake on the first day of hospitalization was associated with reduced mortality in the intensive care unit, but not with hospital mortality. The strategy of an early and limited amount of calories seems to be associated with a better outcome. Prospective studies evaluating and comparing these strategies are recommended.

Estudo do comportamento de pastas compósitas cimento/sílica/poliuretana para poços de petróleo HPHT

Os poços HPHT atravessam zonas anormalmente pressurizadas e com altos gradientes de temperatura. Esses poços apresentam elevadas concentrações de tensões produzidas pelas operações de perfuração e fraturamento hidráulico, flutuações da pressão e temperatura, forças dinâmicas geradas durante a perfuração, formações inconsolidadas, entre outros aspectos, podendo resultar em falhas mecânicas na bainha de cimento. Tais falhas comprometem a estabilidade mecânica do poço e o isolamento das zonas produtoras de óleos e/ou gás. Para que operações corretivas não se façam necessárias, é preciso adequar as pastas às condições de cada poço. Sistemas de pastas de cimento para poços HPHT requerem um bom controle de suas propriedades termo-mecânicas. Visto que a temperaturas superiores a 110 oC (230 oF) o cimento, após alcançar um valor máximo de resistência, inicia um processo de perda de resistência (retrogressão). Para prevenir esse efeito substitui-se parcialmente o cimento Portland por sílica com objetivo de incrementar a reação pozolânica. Esta reação modifica a trajetória do processo natural de hidratação do cimento, o gel de silicato de cálcio hidratado (C-S-H) se converte em várias outras fases com maior resistência. Polímeros também são adicionados para proporcionar maior flexibilidade e agir como barreira à propagação de trincas desenvolvidas sob tensão. O presente trabalho teve como objetivo estudar o comportamento do sistema cimento/sílica/polímero quando submetido às condições de alta temperatura e alta pressão. Foram formuladas pastas de cimento puro, pastas contendo 40 % BWOC de sílica flour e pastas com diferentes concentrações de poliuretana (5 % a 25 %) e 40 % BWOC de sílica flour. O peso específico das pastas foi fixado em 1,87 g/cm3 (15,6 lb/gal). Os resultados demonstram que as resistências da pasta contendo 40% de sílica e das com adição de polímero foram muito superiores a da pasta de cimento puro, não ocorrendo o efeito da retrogressão. As pastas com polímero apresentaram um crescente aumento da tenacidade com o aumento da concentração da mesma, sendo assim capaz de suportar as tensões. Além de se manterem estáveis termicamente acima de 180 ºC. O sistema também apresentou excelentes resultados de filtrado, reologia, água livre, estabilidade e permeabilidade. Sendo assim, o mesmo mostrou ser aplicável a poços HPHT

Caracterização reológica de pastas de cimento portland de alta resistência contendo diferentes tipos de polímeros superabsorventes pela técnica de reometria rotacional

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2016.

Incidencia de síndrome de abstinencia secundario a opioides y/o benzodiacepinas en dos unidades de cuidados intensivos pediátricos

• Introducción: El síndrome de abstinencia (SA) es el conjunto de síntomas y signos que se producen al suspender bruscamente la administración de un fármaco una vez se haya establecido dependencia física. • Objetivos: Caracterizar los pacientes que presentan SA secundario a opiodes (OP) y/o benzodiacepinas(BZ) durante la hospitalización en las unidades de cuidados intensivos pediátricos de la Clínica Infantil Colsubsidio (CIC) y Hospital del Niño de Panamá (HDN) del 1 de abril al 30 de septiembre del 2016. • Materiales y métodos: se realizó un estudio descriptivo, longitudinal, prospectivo. Incluimos 189 pacientes en la CIC y 144 pacientes en el HDN. Se utilizó la escala SOPHIA para el diagnóstico de SA, las escalas COMFORT para evaluar la sedación en pacientes ventilados no relajados y la escala FLACC para evaluar la analgesia. Se utilizó software StataV12® para el análisis estadístico. • Resultados: se reportó una incidencia global de SA de 6.1/100 días personas. La incidencia acumulada de SA fue de 56.08% y 29.86% para la CIC y el HDN respectivamente. En la CIC el 69.81% de los pacientes que requirieron infusión de OP y BZ desarrollaron SA. Se reportó una dosis acumulada de fentanyl de 530.34 ± 276.49 mcg/kg. Con respecto al HDN, de los pacientes que recibieron opioides y benzodiacepinas el 53.49 % desarrollaron SA. • Conclusión: El SA secundario a opioides y/o benzodiacepinas es frecuente en nuestras unidades con una incidencia variable, es mayor la presentación del SA al usar ambos fármacos, mayores dosis acumuladas y más días de infusión continua.

Delírium no doente crítico: fatores de risco modificáveis pelos enfermeiros

Enquadramento: O delírium está entre as doenças mentais mais prevalentes nos doentes hospitalizados por patologia aguda, e é um importante preditor independente de prognóstico negativo. Objetivos: Identi car os fatores de risco modi cáveis pelos enfermeiros, associados ao desenvolvimento de delírium nos doentes internados numa unidade de cuidados intensivos nível II de um hospital central. Metodologia: Realizou-se um estudo exploratório-descritivos, onde foi aplicada a escala Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) e recolhidos dados de cariz clínico e outros complementares de 57 doentes internados, selecionados de forma intencional. Resultados: Identi caram-se variáveis como fatores de risco potencialmente modi cáveis pelos enfermeiros, nomeadamente promoção da nutrição e hidratação, gestão de dispositivos clínicos, promoção da visita de familiares, favorecimento da utilização de próteses, gestão adequada da medicação prescrita; favorecimento de posicionamentos e oxigenoterapia adequados. Conclusão: A presença de delírium ainda é subvalorizada pelos enfermeiros. No entanto, estes podem advertir para a implementação de medidas que diminuam o delírium. Posto isto, deve-se sistematizar a avaliação do delírium nos doentes internados em unidades de cuidados intensivos.

Different levels of water deficit induces changes in growth pattern but not in chlorophyll fluorescence and water relations of Hancornia speciosa Gomes seedlings.

Hancornia speciosa Gomes é uma espécie conhecida popularmente no Brasil como mangabeira, cujo fruto apresenta alto valor nutricional. O conhecimento sobre a sua fisiologia é ainda escasso, principalmente no que se refere ao desenvolvimento inicial. Dessa forma, o objetivo do presente trabalho foi avaliar os efeitos de diferentes níveis de déficit hídrico sobre o padrão de crescimento, fluorescência de clorofila e relações hídricas em mudas de mangabeira. Foi utilizado um esquema fatorial (tratamentos x época de avaliação) com quatro tratamentos hídricos com base na capacidade de campo (CC) (80%, 60%, 40% e 20%), com cinco repetições. Foram avaliados a altura das plantas, número de folhas, diâmetro do caule, produção e partição de biomassa, eficiência quântica do fotossistema II (PSII), potencial hídrico (?w), teor relativo de água (TRA) e teor de carboidratos, proteínas e prolina. O déficit hídrico severo (20% CC) levou a uma redução no crescimento e alterou o padrão de partição de biomassa nas mudas. No entanto, as relações hídricas não foram significativamente afetadas, pois as mudas mantiveram altos valores de ?w e TRA, sem acúmulos significativos nos teores de solutos orgânicos quando cultivadas com 20%CC. Além do mais, a eficiência quântica do PSII não foi afetada pelos diferentes regimes hídricos, sugerindo que não houve fotoinibição devido ao estresse hídrico. A mudança no padrão de crescimento, com um incremento no aprofundamento das raízes e redução no crescimento da parte aérea parece ser a principal estratégia das mudas de H. speciosa para a manutenção da hidratação dos tecidos durante períodos de déficit hídrico.