Abstract Objective: To describe the profile of multidrug-resistance (MDR), extensively resistance (XDR) and pandrug-resistance (PDR) to antibacterial drugs in isolates from patient samples from a third level private hospital in the North of Mexico. Method: A retrospective study was carried out during the period from February 2016 to April 2019. From 156 clinical samples of urine, wounds, blood, expectoration and other fluids, 166 bacteria were isolated; 10 samples included two microorganisms. Isolated microorganisms were classified into MDR, XDR or PDR. Results: 78% of the Gram negative and 69% of the Gram positive isolates showed MDR, XDR or PDR. Staphylococcus epidermidis was the most frequently isolated MDR Gram positive bacteria. Escherichia coli and Klebsiella sp. were among the most frequent MDR Gram negative. In two cases, the clinical isolates of Pseudomonas aeruginosa from the neonatal intensive care unit showed PDR. Conclusions: The intensive care, surgery and neonatal intensive care unit services deserve special attention due to the high proportion of MDR isolates and the presence of PDR due to P. aeruginosa.

Resumen Objetivo: Describir el perfil de multirresistencia (MDR), resistencia extendida (XDR) y panresistencia (PDR) a antibacterianos en aislados de muestras de pacientes de un hospital privado de tercer nivel en el norte de México. Método: Se realizó un estudio retrospectivo durante el periodo comprendido de febrero de 2016 a abril de 2019. A partir de 156 muestras clínicas de orina, heridas, sangre, expectoración y otros fluidos se aislaron 166 bacterias; 10 de las muestras incluyeron dos microorganismos. Los microrganismos aislados se clasificaron en MDR, XDR o PDR. Resultados: El 78% de los aislados gramnegativos y el 69% de los aislados grampositivos mostraron MDR, XDR o PDR. Staphylococcus epidermidis fue la bacteria grampositiva con multirresistencia más frecuentemente aislada. Escherichia coli y Klebsiella sp. se encontraron entre los gramnegativos MDR más frecuentes. En dos casos, los aislados clínicos de Pseudomonas aeruginosa procedentes de la unidad de cuidados intensivos neonatales mostraron PDR. Conclusión: Los servicios de terapia intensiva, cirugía y unidad de cuidados intensivos neonatales merecen especial atención por la alta proporción de aislados MDR y la presencia de PDR a causa de P. aeruginosa.

Abstract The similarity between parasites communities’ decay with distance and its analysis may explain important ecological process such host dispersion. Patagonia is inhabited by two armadillo species, Chaetophractus villosus and Zaedyus pichiy. In this study we describe and analyze the variation on helminth fauna of these armadillos in Patagonia compared with northern localities described in previous studies. A total of 49 armadillos were collected in Patagonia. Quantitative descriptors of parasite ecology were calculated and community structure of helminths was analyzed following the central-satellite species hypothesis. The parasite richness in Patagonia decreases almost 50% in both armadillos. Zaedyus pichiy present the same central species in Patagonia as in northern localities. For C. villosus central-satellite species analysis could not be applied. The loss of some helminths in Z. pichiy could be the result of lower temperatures or the absence of intermediate arthropods hosts. But in C. villosus the absence of some helminths with Patagonian distribution could be explained by its recent dispersion in Patagonia. Trichohelix tuberculata still being the only helminth in C. villosus introduced population of Tierra del Fuego.

Armadillos are among the most common mammals in agroecosystems in Argentina. Their insectivorous/omnivorous food habits raise the question about their putative role as pest controllers. The aim of this study is to describe the prey items of five armadillo species and evaluate their possible role as natural pest controllers. The stomach contents of 12 Dasypus hybridus, 10 Chaetophractus vellerosus, 14 Chaetophractus villosus, 4 Tolypeutes matacus and 9 Zaedyus pichiy were analyzed. We described the diet and identified prey items to family level, whenever possible, and computed the frequency of occurrence (FO) and relative abundance of prey items. With these values, the Item Categorization Index (ICI) was calculated to classify the items in order of importance (primary, secondary and tertiary items). Shannon diversity index was also computed. The armadillos studied here consumed arthropod species belonging to families of phytosanitary importance such as Acrididae, Scarabaeidae, Tenebrionidae, Lepidoptera, Formicidae, and Termitidae. Only two armadillos showed primary items in their diet; Z. pichiy (ants and tenebrionids) and T. matacus (termites and scarabid larvae). Important pest arthropods had FO values close to or greater than 50% in the diet of all armadillos. Armadillos consumed arthropods that are important pests for agriculture, forestry, and wood construction. Even though this study was mainly focused on armadillos’ diet, we suggest that the presence of these native species could benefit the productivity and health of agroecosystems by reducing the need for harmful agrochemicals.

Se presenta información sobre la geología, litoestratigrafia y la composición de los carbones encontrados en la etapa de exploración en el área del contrato FJS-112 de la Mina NATAGAYMAS, municipio de El Espino-Boyacá, Colombia. Se realizó la recopilación y revisión bibliográfica de estudios geológico - mineros para el área carbonífera del Municipio El Espino, y visitas preliminares de reconocimiento de la zona de estudio, localizando afloramientos de carbón de la Formación Guaduas (Ktg). En el trabajo de campo se recolectó información regional y local. El muestreo de los mantos de interés se realizó de acuerdo a las normas establecidas por ECOCARBON LTDA. Se elaboró la cartografía geológica con sus perfiles geológicos en los cuales se ubicó la traza de los mantos de carbón encontrados. Se calcularon los recursos siguiendo las normas establecidas por ECOCARBON.

Presents information about geology, lithostratigraphy and the composition of the coal found in the stage of exploration in the area of contract FJS-112 of mine NATAGAYMAS, municipality of El Espino-Boyacá, Colombia. There was recopilation and bibliographical review for geological - mining studies for coal mining area of the municipality of El Espino, and preliminary recognition of the zone of study visits, the collection and review of geological studies - locating outcrops of coal of the Guaduas formation (Ktg). Regional and local information was collected in the field. Sampling of the robes of interest was conducted according to the norms established by ECOCARBON Ltda. Geological mapping with its geological profiles in which the trace of the robes of coal found was developed. Calculate of the resources was according to the ECOCARBON norms

The bauxite residue (BR) is the solid waste of largest generation by the aluminum industry, with a generation estimated in 10 million ton/year in Brazil. Its high alkalinity demands elevated costs to store it safely. Due to the high content of Al2O3 and Fe2O3 in BR, the present study evaluated its application for the synthesis of iron rich sulfobelite clinkers. Because of its composition, the cement made with this clinker presents environmental (30% to 62% reduction of CO2-equivalent emission), economic and even technical advantages over Portland cements. Formulations containing: limestone, gypsum, BR and clay, were fired at 1230°C to synthesize the clinkers. Variations in BR and clay content were studied to obtain three formulations, F-15, F-18 and F-21, of different Al2O3/Fe2O3 ratio values. Cements containing more than 10.5 wt-% of BR achieved mechanical resistance comparable to Portland cements (CP-II-Z32 and CP-V-ARI) for 7 and 28 days of curing age.

Este paper revisa la literatura de la teoría del conflicto armado y examina su aplicación a la lucha de los insurgentes con el Estado por el control territorial y político en Colombia durante 1999-2010. El análisis examina tres sub-periodos durante este tiempo y varias regiones geográficas, con el fin de analizar el efecto de los diferentes niveles de capacidad de los participantes en las dinámicas del conflicto, medido por la intensidad del conflicto a través del tiempo. Concluimos que mientras haya asimetrías entre el Estado y la insurgencia, es muy probable que la confrontación armada continúe.

This paper reviews the literature on the theory of armed conflict and examines its application to the insurgents´ struggle with the State for political and territorial control in Colombia during 1999-2010. The analysis examines three sub-periods during this period and several geographic regions to analyze the effect of varying levels of participant capability on the dynamics of the conflict, as measured by the intensity of the conflict over time. We conclude that as long as there are asymmetries between the State and the insurgency, armed confrontation is likely to continue.

The home range of the screaming hairy armadillo Chaetophractus vellerosus was estimated and its spatial pattern described under different degrees of land use pressure. Fieldwork was performed between 2006 and 2011 on a cattle ranch in Magdalena (Buenos Aires , Argentina), in two paddocks of similar size but with different intensities of use (North: low; South: high). A total of 213 individuals were captured (102 males and 111 females). Data from 30 adult individuals (12 males and 18 females) were analyzed in order to determine the home range using the minimum convex polygon method. The spatial pattern was described based on 85 captures and the nearest neighbor method. No significant differences in home range size were observed between sexes and seasons (fall-winter: males 0.23 ha, females 0.27 ha; spring-summer: males 0.75 ha, females 0.13 ha). The spatial distribution of armadillos was aggregated in both paddocks in fall-winter, being higher in the paddock with low intensity of use. An aggregated distribution was also observed during spring-summer in the southern paddock, while a random arrangement was found in the northern paddock. The home range of C. vellerosus is not affected by sex or season. The spatial arrangement of individuals is influenced by the intensity of land use.

Se estimó el área de acción del armadillo Chaetophractus vellerosus y se describió su patrón espacial teniendo en cuenta la presión de uso del ambiente. Los muestreos se realizaron en un campo ganadero de Magdalena (Buenos Aires, Argentina), entre 2006 y 2011, en dos potreros de tamaño similar pero con distintas intensidades de uso (norte: baja; sur: alta). Se efectuaron 517 capturas de 213 individuos (102 machos y 111 hembras). Para determinar el área de acción se analizaron datos de 30 individuos adultos (12 machos y 18 hembras) mediante el método del mínimo polígono convexo. El patrón espacial se describió con 85 capturas y el método del vecino más cercano. No existieron diferencias significativas en el área de acción promedio entre sexos, ni entre estaciones (otoño-invierno: machos 0.23 ha, hembras 0.27 ha; primavera-verano: machos 0.75 ha, hembras 0.13 ha). Los individuos tuvieron una disposición agregada para ambos potreros en otoño-invierno, siendo mayor en el potrero de baja intensidad de uso. Durante primavera-verano en el potrero sur mantuvieron la misma distribución agregada, mientras que en el potrero norte presentaron una disposición al azar. El área de acción de C. vellerosus no se ve afectada por el sexo y las estaciones. La distribución espacial de los individuos es influenciada por la intensidad de uso del ambiente.

RESUMEN Objetivo. Investigar el efecto de la suplementación con jabones cálcicos protegidos, conteniendo ácidos grasos omega 3 ó 6 sobre la producción, composición de la leche y desempeño reproductivo. Materiales y métodos. Se utilizaron 24 vacas en un diseño mixto desde 20 días antes de la fecha prevista del parto hasta 105 días postparto, asignadas a los diferentes tratamientos; C: dieta control, O6: animales suplementados con grasas protegidas conteniendo omega 6 y O3: animales suplementados con grasas protegidas conteniendo omega 3. Se determinó la producción y la composición de la leche, así como la condición corporal (CC), el primer calor y primera ovulación posparto. Resultados. La suplementación con omega 3 ó 6 no afectó la producción láctea, ni los porcentajes de grasa, proteína, sólidos no grasos (SNG) y sólidos totales (ST). Sin embargo, hubo un efecto positivo a los 45 días posparto sobre la CC cuando los animales fueron suplementados con omega 6 (p<0.05) lo que se reflejó en una recuperación ovárica posparto más rápida (42.24±16.75 días a la primera ovulación posparto). Conclusiones. La utilización de la suplementación con omega 6 mejoró la condición corporal de los animales en el posparto temprano, disminuyendo los días a la primera ovulación y primer calor posparto, sin afectar la producción ni composición de la leche. La suplementación con omega 3 no influyó en ningún parámetro productivo en el posparto temprano.

ABSTRACT Objective. To investigate the effects of supplements with protected fat such as calcium soaps containing omega 3 or 6 milk production, composition and reproductive performance. Materials and methods. Twenty-four Holstein cows were used in a mixed model design. From 20 days before calving until 105 days postpartum, cows were assigned to different treatments; C: control diet, O6: animals supplemented with protected unsaturated fat including a higher amount of omega, 6 and O3: animals fed with protected unsaturated fat including higher amounts of omega 3. Milk volume and composition, and body condition score (CC) were determined, along with the first postpartum heat and ovulation. Results. Supplementation with omega 3 or 6 had no effect on milk volume, and fat percentages, protein, milk non-fat solids (SNF) and total solids (ST). However, there is a positive effect of omega 6 supplementation on the CC at 45 days postpartum (p<0.05). This was also reflected in a faster ovarian recovery (42.24±16.75 days to first postpartum ovulation). Conclusions. The use of omega 6 supplementation improves body condition score of animals during early postpartum, decreasing the days to the first ovulation and postpartum heat without affecting the volume or composition of the milk. Supplementation with omega 3 does not affect any productive parameters in the early postpartum.

Este estudo ilustra o impacto da calcinação de resíduo de bauxita (RB) nas propriedades de suspensões formuladas com cimento Portland, tanto no estado fresco como no endurecido. As suspensões foram avaliadas contendo uma razão constante de água-cimento e teor de resíduo variando de 5% a 20% em peso e em substituição ao cimento. As propriedades reológicas e a resistência mecânica foram alteradas em função do aumento do teor de RB, mas a calcinação não teve influência no resultado final obtido, seja no estado fresco ou no endurecido. Assim, pode-se afirmar que a utilização de resíduo de bauxita, natural ou calcinada, em formulações com cimento Portland pode reduzir o consumo de cimento, sendo uma alternativa para a utilização de uma grande quantidade deste tipo de resíduo.

This research work shows the impact of bauxite residue (BR) calcination on the rheological and hardened properties of Portland cement suspensions. These suspensions were evaluated with water-to-cement ratio of 0.5 and variations of residue content from 5% to 20% in partial substitution of cement. Both properties had influence of BR content, but had a negligible influence of calcination. Therefore, it can be inferred that the utilization of BR, in nature or calcinated, in formulations with Portland cement, may reduce the consumption of cement, being an alternative to use large amounts of this type of residue.

Para evaluar el efecto del consumo de un suplemento de grasa sobrepasante y del número de partos se evaluaron 31 cabras de alto mestizaje (5/8 a 3/4) ubicadas en Maracay, Venezuela. Se evaluó la producción de leche durante una lactancia, días en lactancia, características y componentes de la leche, los cambios de peso, condición corporal, triglicéridos y colesterol sanguíneos. Se utilizaron modelos estadísticos lineales aditivos con medidas repetidas en el tiempo mediante Proc GLM y una prueba de Tukey para detectar diferencias significativas. Se apreció un efecto altamente significativo (P<0,01) del tratamiento y número de partos sobre la producción total y una tendencia del tratamiento sobre la duración de la lactancia. Ni el tratamiento ni el número de partos afectaron las características físicas de la leche, pero el tratamiento tuvo un efecto significativo (P<0,01) aumentando todos los componentes de la leche en forma beneficiosa. El tratamiento no tuvo un efecto significativo sobre el peso, condición corporal y consumo voluntario. El número de partos tuvo un efecto significativo (P<0,01) sobre los componentes de la leche y el peso corporal aumentando hasta la cuarta lactancia. No hubo un efecto significativo ni del tratamiento ni del número de parto sobre los niveles de colesterol ni triglicéridos sanguíneos. Tampoco existió una correlación significativa entre ambos metabolitos entre si ni con la producción de leche, componentes de la leche, peso o condición corporal. Los resultados indican que la inclusión de un suplemento de grasa sobrepasante en la ración tiene un efecto beneficioso.

Effects of supplementation with protected fat and parity on goat milk production and composition were determined with 31 crossbreed Canarias goats located in Maracay, Venezuela. Also, effects on body weight changes, body condition, and blood triglycerides and cholesterol concentrations were evaluated. Additive linear statistical models with repeated measures of time with Proc GLM were used and Tukey test to detect significant differences. The treatment and the calving number had a highly significant effect (P<0.01) over the total production. Goat receiving diets with protected fat showed the longest lactation. Neither treatment nor parity affected milk physical characteristics, but the treatment did increase significantly (P<0.01) all milk components in a profitable way. Treatment had no significant effect on body weight, body condition or voluntary consumption. The calving number had a significant effect (P<0.01) on the milk components and body weight, all of them increased accordingly up to the 4th calving number. Neither treatment nor parity had a significant effect on blood cholesterol or triglyceride concentrations. There were not significant correlations between blood cholesterol and triglyceride levels or between milk production, milk component levels, body weight or body condition.

Introducción. La curva de lactancia de los mamíferos puede ser explicada por funciones matemáticas que permiten relacionar la producción de leche de una hembra a través del tiempo, teniendo en cuenta la fisiología de la hembra a lo largo de la lactancia. Objetivo. Identificar las funciones matemáticas que mejor expliquen la curva de producción de leche en Búfalas del corregimiento de la sierra, municipio de Puerto Nare, departamento de Antioquia-Colombia. Materiales y métodos. Fueron utilizadas 3580 lactancias las cuales fueron agrupadas de acuerdo al número de partos y época de parto de las búfalas. Se utilizaron 9 modelos matemáticos de curvas de lactancia entre lineales y no lineales. Los criterios de selección para el mejor modelo matemático, fue el que presentó el mayor porcentaje de curvas significativas y la media del coeficiente de determinación. Resultados. Los resultados mostraron que el modelo que mejor ajustó la curva de lactancia en búfalas fue el propuesto por Papajcsik y Bordero, en 1988, el cual ajusto un 100 % las curvas en todos los números de partos con todas las épocas de parto. Conclusión. La metodología para la obtención del tiempo al pico de producción y la producción máxima puede ser una herramienta útil para trabajos futuros.

Introduction.The lactation curve of mammals can be explained by mathematic functions which allow relating milk production of a female individual through time, taking into account her physiology throughout the lactation period. Objective. To identify the mathematic functions that can explain best the curve of milk production in a population of female buffalos from La Sierra, a village in the Puerto Nare town, Antioquia, Colombia. Materials and methods. 3850 lactations were used for the study, they were divided in groups according to their number and time of births the buffalos had. Nine mathematic models of lactation curves were used, both lineal and non-lineal. The selection criteria for choosing the best model were the highest percentage of significant curves and the media of the determination coefficient. Results. The model that best adjusted the lactation curve in female buffalos was that proposed by Papajcsik and Bordero, in 1988, which adjusted the curves in all the numbers of births with all the birth époques a 100%. Conclusion. The methodology to obtain the time at the peak of the production and the production at its maximum can be a useful tool for future works.

Introdução. A curva de latência dos mamíferos pode ser explicada por funções matemáticas que permitem relacionar a produção de leite de uma fêmea através do tempo, tendo em conta a fisiologia da fêmea ao longo da latência. Objetivo. Identificar as funções matemáticas que melhor expliquem a curva de produção de leite em Bufa-as da cidade da serra, município de Porto Nare, departamento de Antioquia- Colômbia. Materiais e métodos. Foram utilizadas 3580 latências as quais foram agrupadas de acordo ao número de partos e época de parto das bufa-as. Utilizaram-se 9 modelos matemáticos de curvas de lactância entre lineares e não lineares. Os critérios de seleção para o melhor modelo matemático foi o que apresentou a maior percentagem de curvas significativas e a média do coeficiente de determinação. Resultados. Os resultados mostraram que o modelo que melhor ajustou a curva de latência em bufaas foi o proposto por Papajcsik e Bordero, em 1988, o qual ajusto um 100 % as curvas em todos os números de partos com todas as épocas de parto. Conclusão. A metodologia para a obtenção do tempo ao bico de produção e a produção máxima pode ser uma ferramenta útil para trabalhos futuros.

OBJECTIVE: To evaluate the relationship that tiredness and sleepiness in bus drivers have to road accidents in Peru. Information from various countries indicates that driver sleepiness plays an important role in road accidents. However, there is only limited information on this subject in Peru. METHODS: Using a supervised, pretested survey, a cross-sectional observational and comparative study was carried out with 238 bus drivers who drive on the Northern Pan American Highway of Peru. To determine the relationship between variables the chi-square test was used, along with the Pearson correlation coefficient. The level of significance was set at P < 0.05. The variables analyzed were: tiredness, sleepiness, hours of driving per day, daily hours of sleep, body mass index, snoring, sleep apnea, and either having had or almost having had an accident while driving. RESULTS: Of the 238 drivers, all of them were men, 45% said they had had or nearly had had an accident while driving, 55% slept less than 6 hours per day, 31% had slept less than 6 hours in the 24 hours before answering the survey, and 80% were in the habit of driving more than 5 hours without stopping. Of the drivers, 56% of them reported being tired at least some of the time while driving; of this group, 65% of them reported being tired during the early morning. Seventy-six drivers (32%) said that while they were driving their eyes had fallen shut. In terms of where they slept, 194 of the drivers (81%) said they always slept in the lower luggage compartment of the bus while another driver was driving the bus or when the bus was parked in the bus terminal. The steps that drivers took to avoid falling asleep while driving included: wetting the face with water, eating fruit, opening the window of the driver's compartment, drinking coffee, listening to music, smoking, chewing coca leaves, and drinking alcohol mixed with coca leaves. In the opinion of 55% of the drivers, the leading cause of road accidents is tiredness. Accidents and near-accidents while driving occurred mainly between midnight and 6 a.m. Having an accident or a near-accident was strongly associated with tiredness and with having the eyes drop shut while driving (P < 0.0005). CONCLUSIONS: Tiredness and sleepiness while driving were common among the bus drivers, with various possible causes: acute and chronic sleep deprivation, irregular schedule changes, and sleep disorders due to the drivers' working conditions. Our results support the hypothesis that fatigue and sleepiness among bus drivers are related to road accidents.

OBJETIVO: Evaluar la relación del cansancio y la somnolencia en los conductores de ómnibus con los accidentes de carretera. La información obtenida de diversos países atribuye a la somnolencia del conductor una parte importante en la génesis de los accidentes de carretera. No obstante, la información al respecto es escasa en el caso del Perú. MÉTODOS: Se realizó un estudio transversal, de índole observacional y comparativa, basado en una encuesta prevalidada y de aplicación supervisada, entre 238 conductores de ómnibus que circulan por la carretera Panamericana Norte del Perú. Para determinar la relación entre variables se emplearon la prueba de ji al cuadrado y el índice de Pearson, con un valor de significación de P < 0,05. Variables de análisis:cansancio, somnolencia, horas de conducción por día, horas de sueño por día, índice de masa corporal, ronquido, pausas respiratorias y el antecedente de haber tenido o estar a punto de tener un accidente durante la conducción. RESULTADOS: De los 238 conductores, todos ellos varones, 45% refirieron haber estado a punto de tener un accidente o haberlo sufrido durante la conducción, 55% dormían menos de 6 horas al día, 31% habían dormido menos de 6 horas en las últimas 24, y 80% acostumbraban conducir más de 5 horas sin descanso. Señalaron cansancio durante la conducción 56% y, de estos, 65% lo experimentaban durante la madrugada. Setenta y seis (32%) conductores reconocieron que pestañeaban durante la conducción. Ciento noventa y cuatro (81%) siempre dormían en el maletero, estuviera el ómnibus en ruta o en la terminal. Maniobras para evitar dormirse: mojarse la cara con agua, comer fruta, abrir ventana de la cabina, beber café, escuchar música, fumar, masticar (chacchar) coca y beber alcohol con hoja de coca. En opinión de 55% de los conductores, la primera causa de accidentes de carretera es el cansancio. Los accidentes durante la conducción, virtuales o consumados, ocurrieron predominantemente entre las 00:00 y las 06:00 horas. Este antecedente mostró firme asociación (P< 0,0005) con el pestañeo y el cansancio. CONCLUSIONES: La somnolencia y el cansancio durante la conducción fueron frecuentes. Su origen puede ser multifactorial: privación aguda y crónica del sueño, rotación desordenada de horarios y trastornos del sueño de origen ambiental. Los resultados respaldan la hipótesis de que hay una relación entre la fatiga y somnolencia de los conductores y los accidentes en carreteras.

Foram desenvolvidas formulações vulcanizáveis com o elastômero SBR (copolímero de butadieno-estireno) para a obtenção de materiais com alto desempenho mecânico, resistência à inflamabilidade e baixo custo. Além dos aditivos convencionais para elastômeros diênicos, como óxido de zinco, ácido esteárico, enxofre, negro de fumo (NF) e o acelerador TBBS (N-t-butil-2benzotiazol-sulfenamida), o hidróxido de alumínio (ATH) foi utilizado como agente anti-chama e supressor de fumaça. Para atingir os objetivos propostos, foram usadas quantidades variadas da relação ATH/NF em formulações de SBR. Os diferentes compósitos foram caracterizados quanto aos seguintes ensaios: resistência à tração, resistência ao rasgamento, dureza, deformação permanente à compressão (DPC), resiliência, resistência à chama e índice limite de oxigênio (LOI). Os resultados obtidos permitiram concluir que, com base na formulação utilizada para SBR, os compósitos finais contendo negro de fumo na faixa de 25 a 50 phr (partes por cem partes de borracha), e o hidróxido de alumínio acima de 125 phr, caracterizaram-se como de alto desempenho mecânico, com resistência à chama e, como conseqüência da grande quantidade de carga incorporada, de baixo custo.

Vulcanizable SBR (butadiene-styrene copolymer) formulations were developed with the objective to obtain high mechanical performance materials with flame resistance and low cost. Aluminum hydroxide (ATH) was used as anti-flame and smoke suppressor agent in addition to the conventional additives used in diene elastomers like zinc oxide, stearic acid, sulfur, carbon black (NF) and TBBS (N-t-butyl-2-benzothiazole sulfenamide) accelerator. To reach the proposed goal, different amounts of ATH/NF ratio were used in these formulations. The resulting composites were characterized by the following tests: tensile strength, tear resistance, hardness, compression set, flame resistance and limiting oxygen index (LOI). Based upon the results obtained with the formulations used for SBR, it was possible to conclude that carbon black in the range of 25-50 phr and aluminum hydroxide in amounts higher than 125 phr, characterize the final composites as having high mechanical performance, flame resistance and low cost, as a consequence of the large quantity of incorporated filler.