Abstract A new species of coccidia (Protozoa: Apicomplexa: Eimeriidae) is described from the saffron finch, Sicalis flaveola, is reported from Brazil. Sporulated oocysts of Isospora bertoi n. sp. are spherical to subspherical; 23.6 (21.1-26.5) x 22.0 (19.4-24.6) µm; shape Index (L/W ratio) 1.1 (1.0-1.2) µm; with bilayer smooth walls, ~1.1 μm. Micropyle and oocyst residuum are absent, but polar granules are present. Sporocysts are elongated ellipsoidal, 16.2 (13.6-17.9) x 10.1 (8.9-12.4) µm. Stieda body is button-shaped and Sub-Stieda and Para-Stieda body are absent. Sporocyst residuum is compact and composed of hundreds of granules scattered among the sporozoites. The sporozoite is claviform with an elongated posterior refractile body and nucleus.

Resumo Uma nova espécie de coccídio (Protozoa: Apicomplexa: Eimeriidae) do canário-da-terra, Sicalis flaveola, é relatada no Brasil. Oocistos esporulados de Isospora bertoi n. sp. são esféricos a subesféricos; 23,6 (21,1-26,5) x 22,0 (19,4-24,6) µm com índice morfométrico (L/W) de 1,1 (1,0-1,2); com parede lisa constituída por duas camadas com ~1,1 μm. Micrópila e resíduo de oocisto estão ausentes, mas grânulos polares estão presentes. Os esporocistos são elipsoidais alongados, 16,2 (13,6-17,9) x 10,1 (8,9-12,4) µm;. O corpo Stieda é em forma de botão, enquanto que os corpos de Sub-Stieda e Para-Stieda estão ausentes. O resíduo do esporocisto é compacto e constituido por centenas de grânulos espalhados entre os esporozoítos. O esporozoíto é claviforme com corpo e núcleo refráteis posteriores alongados.

Abstract Bruises threaten the welfare of cattle because they cause pain, suffering, and stress during the pre-slaughter stage. Thus, we used meta-analyses to estimate the prevalence of carcass bruising in cattle from the American continent, determined the characteristics of the bruises, and calculated the odds ratio (OR) of risk factor categories associated with bruising. We searched electronic databases to retrieve primary studies conducted in the American continent, which reported cattle carcass bruising, analyzed the size, location, shape, and age of the bruises, and assessed risk factors for bruising. We included 46 studies from nine countries comprising 928 447 cattle carcasses with an overall prevalence of 59.5 % (95 % CI: 51.9-66-9) and 2.9 (range 3.4-7.4) bruises per carcass in average. The prevalence doubled from 30.7 % during 1991-2000 to 64.2 °/o during 2011-2020. Fresh, small-sized bruises of the lowest severity and located mainly in the hindquarter were highly prevalent (37.5-66.4 %). The removed meat due to bruising ranged 0.11-1.12 kg/carcass with an accumulated weight of condemned meat between 15.6-647 kg. Among intrinsic factors, older cattle, dairy cattle, and female cattle had greater odds of bruising (OR= 1.57-1.98). For extrinsic factors, the odds for bruising increased 1.4-2.2 in cattle sourced from auction markets and exposed to poor handling, suboptimal transportation conditions, and deficient facilities. In cattle from America, bruises are a concern because their prevalence is growing and 60 % of cattle assessed in the studies suffered a bruise. Improving facilities and transportation conditions together with proper training of the personnel during the handling and transportation of the cattle will reduce bruising incidence.

Resumen Se evaluó el contenido de catequina en cortezas de las especies forestales Pinus patula, Pinus oocarpa y Eucaliptus grandis, cultivadas en el Departamento del Cauca-Colombia. Los extractos eceetanólicos se obtuvieron evaluando las mejores condiciones de tamaño de partícula, tiempo de agitación, relación disolvente-corteza, temperatura y agitación. El contenido de catequina se determinó usando cromatografía líquida de alta resolución (HPLC) con detector ultravioleta y empleando extracción en fase sólida (SPE) para la limpieza de las muestras. Se encontró un contenido de catequina de 2.00±0.03%, 2.96±0.02% y 0.18±0.03% en cortezas de P. patula, P. oocarpa y E. grandis respectivamente. Este contenido de catequina indica el gran potencial en aplicaciones industriales y medicinales para un recurso renovable como la corteza, abundante en la región y cuya disposición en campo afecta ambientalmente las zonas forestales.

Abstract The catechin content in barks of the forest species Pinus patula, Pinus oocarpa and Eucaliptus grandis, cultivated in the Department of Cauca-Colombia, was evaluated. The ethanol extracts were obtained by evaluating the best conditions of particle size, agitation time, solvent-bark ratio and temperature. The catechin content was determined using high performance liquid chromatography (HPLC) with ultraviolet detector and using solid phase extraction (SPE) for sample cleaning. A catechin content of 2.00 ± 0.03%, 2.96 ± 0.02% and 0.18 ± 0.03% was found in barks of P. patula, P. oocarpa and E. grandis respectively. Catechin content indicates the great potential in industrial and medicinal applications for a renewable resource such as bark, abundant in the region and whose field disposition environmentally affects forest areas.

Resumen: Los sistemas de producción industrial actuales usan metales pesados para la extracción de un material o como elemento en la refinación de un producto en particular lo que en principio resulta en la obtención del producto deseado con relativos bajos costos de producción. Sin embargo, usar estos metales presenta un grave problema a nivel ambiental debido a sus altos niveles de toxicidad para los organismos con los que interactúen una vez son descargados. Por tanto, se han desarrollado diversos métodos para tratar con estos metales una vez están en el agua y los métodos para analizarlos. Se realizó una búsqueda amplia y actualizada de las fuentes, efectos y toxicidad en los seres vivos, métodos de análisis y las diversas técnicas de tratamiento existentes para metales pesados. Como resultado el investigador estará más preparado al tener información actual sobre los tratamientos a tener en cuenta en la manipulación de metales pesados.

Abstract: Current industrial production systems nowadays use heavy metals for the extraction of a material or as an element in the refining of a particular product which in principle results in obtaining the desired product with relatively low production cost. However, using these metals presents a serious environmental problem due to their high levels of toxicity for the organisms which they interact once they are discharged. Therefore, various methods have been developed to deal with these metals once they are in the water and the methods to analyze them. A comprehensive and update search was made of the sources, effects and toxicity in the living beings, analysis methods and the various techniques of heavy metal treatment. As a result, the researcher will be more prepared to have current information on the treatments to be taken into account in the handling of heavy metals.

Abstract Emus are large flightless birds in the ratite group and are native to Australia. Since the mid-1980s, there has been increased interest in the captive breeding of emus for the production of leather, meat and oil. The aim of this study was to identify gastrointestinal parasites in the feces of emus Dromaius novaehollandiae from a South American scientific breeding. Fecal samples collected from 13 birds were examined by direct smears, both with and without centrifugation, as well as by the fecal flotation technique using Sheather’s sugar solution. Trophozoites, cysts and oocysts of protozoa and nematode eggs were morphologically and morphometrically evaluated. Molecular analysis using PCR assays with specific primers for the genera Entamoeba, Giardia and Cryptosporidium were performed. Trophozoites and cysts of Entamoeba spp. and Giardia spp., oocysts of Eimeria spp. and Isospora dromaii, as well as eggs belonging to the Ascaridida order were found in the feces. Three animals were diagnosed with Giardia spp., and three were positive for Entamoeba spp. based on PCR techniques. After analyzing the data, we concluded that emus were infected enzootically by nematode and protozoan species.

Resumo Emus são aves grandes que não voam pertencentes ao grupo das ratitas e são originários da Austrália. Desde meados da década de 1980, aumentou o interesse pela criação de emus em cativeiro para a produção de couro, carne e óleo. O objetivo deste estudo foi identificar parasitas gastrointestinais nas fezes de emus Dromaius novaehollandiae de um criatório científico da América do Sul. Amostras de fezes coletadas de 13 aves foram examinadas por esfregaços diretos, tanto com e sem centrifugação, quanto com a técnica de flutuação fecal utilizando solução de açúcar de Sheather. Trofozoítos, cistos e oocistos de protozoários e ovos de nematóides foram avaliados morfologicamente e morfometricamente. Foram realizadas análises moleculares utilizando ensaios de PCR com primers específicos para os gêneros Entamoeba, Giardia e Cryptosporidium. Trofozoítos e cistos de Entamoeba spp. e Giardia spp., oocistos de Eimeria spp. e Isospora dromaii, bem como ovos pertencentes à ordem Ascaridida foram encontrados nas fezes. Três animais foram diagnosticados com Giardia spp., e três foram positivos para Entamoeba spp. com base em técnicas de PCR. Depois de analisar os dados, concluímos que os emus estavam infectados enzooticamente por espécies de nematóides e protozoários.

A review is presented of the radiological findings (computed tomography -CT- and magnetic resonance imaging -MRI-) of headache, according to our experience. According to MESH database this entity is a skull based pain that can have a benign cause or be an expression of a wide spectrum of disorders. Headaches can be classified according to their temporal evolution (acute or chronic), presentation (blow up, aura, rapidly evolutionary, etc.), or according to associated symptoms, such as seizures or focal deficits. They could also be classified into primary or secondary, depending on the presence or absence of demonstrable disease. The primary headaches can have known symptoms (i.e. migraine), but in secondary ones certain symptoms and signs should alert on the existence of structural disease. At this point imaging methods have an outstanding role, as they allow detecting and identifying structural causes in patients with headache. Our findings corresponded to primary headaches (i.e.: migraine infarction) and organic aetiologies, such as vascular causes (venous thrombosis, vasospasm and posterior reversible leukoencephalopathy); intracerebral and extra-axial haemorrhage; post-surgical and post- traumatic headaches; and those due to infections and tumours (pituitary apoplexy or intracranial hypertension). Malformations, such as Arnold-Chiari's, and intracranial hypotension have also been found. In some cases a CT is initially performed and then an MR, whilst in others MR is the method of choice. Neuroimaging facilitates the study of headache, helping to characterise them into primary or secondary. In the latter case, the imaging also enables the findings to be classified.

Se revisa la iconografía de los hallazgos por tomografía computada (TC) y resonancia magnética (RM) de la cefalea, según nuestra experiencia. De acuerdo con la base MESH, esta entidad se define como un dolor craneano, que puede ser de ocurrencia benigna o la manifestación de una amplia gama de desórdenes. Las cefaleas se clasifican por su evolución temporal (aguda o crónica), presentación (en estallido, gravativa, etc.) o coexistencia de síntomas asociados, como auras, convulsiones o déficits focales. También se dividen en primarias o secundarias, según la existencia o no de una patología subyacente. Las primarias pueden tener manifestaciones clínicas definidas, pero en las secundarias ciertos signos y síntomas deben alertar sobre la presencia de una patología estructural. En este caso, las neuroimágenes tienen un rol esencial al detectar las causantes del cuadro. Nuestros hallazgos correspondieron a cefaleas primarias (p. ej: infarto migrañoso) y a etiologías orgánicas, entre las que se destacaron causas vasculares, como patología venosa (trombosis), vasoespasmo y leucoencefalopatía posterior reversible; hemorragias intraparen-quimatosas y extraaxiales; cefaleas postraumáticas y posquirúrgicas; y causas infecciosas y tumorales (apoplejía hipofisaria e hipertensión endocraneana). Además, hubo malformaciones (Arnold-Chiari, p.ej.) y otras como hipotensión endocraneana. En algunos casos inicialmente se realizó una TC y luego una RM, mientras que en otros la RM fue el método de elección. Las neuroimágenes facilitan el estudio de la cefalea, caracterizando la afección en primaria o secundaria. En el segundo caso permiten, a su vez, clasificar los hallazgos.

Objective: To determine the usefulness of the association between the resistance index (RI) values in renal arcuate arteries and creatinine clearance (Cr Cl) levels in order to predict or detect acute rejection in a kidney transplant patient. Materials and methods: A prospective study was conducted on a cohort of 87 patients who were subjected to a kidney biopsy due to clinical changes in renal function. The RI was measured, and Cr Cl levels determined using the modification of diet in renal disease formula. Results: The sensitivity of an RI association higher than 0.7 and a Cr Cl 0-30 was 53.3% (95% confidence interval [CI]: 34.3-71.7%), with a specificity of 98.2% (95% CI: 90.4-100%). The area under the curve was 0.758 (95% CI: 0.665-0.85), the positive and negative likelihood ratio was 22.9 (95% CI: 4.16-214) and 0.475 (95% CI: 0.324-0.685), respectively. The odds ratio was 62.9, and the positive and negative predicted value was 94.1% (95% CI: 71.3-99.9%) and 79.1% (95% CI: 68.3-88.4%), respectively. Conclusion: The RI association higher than 0.7- Cr Cl 0-30 showed to be useful to detect the possibility of acute renal rejection, with its good specificity (98.2%), although with a low sensitivity (53%).

Objetivo: Analizar la utilidad de la asociación del índice de resistencia (IR) en las arterias arcuatas renales con el aclaramiento de creatinina (Cl Cr) para predecir el rechazo agudo del riñón trasplantado. Materiales y métodos: Se realizó un estudio prospectivo de una cohorte de 87 pacientes que fueron sometidos a una biopsia renal por alteraciones clínicas de la función renal. Se les midió el IR junto con el Cl Cr mediante el método de modificación de la dieta en la enfermedad renal. Resultados: La sensibilidad de la asociación IR mayor de 0,7 y Cl Cr 0-30 fue del 53,3% (intervalo de confianza [IC] de 95%: 34,3-71,7%) y la especificidad del 98,2% (95% IC: 90,4-100%). El área bajo la curva fue de 0,758 (95% IC: 0,665-0,85), el likelihood ratio positivo de 22,9 (95% IC: 4,16-214), el likelihood ratio negativo de 0,475 (95% IC: 0,324- 0,685), el odds ratio de 62,9, el valor predictivo positivo de 94,1% (95% IC: 71,3- 99,9%) y el valor predictivo negativo de 79,1% (95% IC: 68,3-88,4%). Conclusión: La asociación IR mayor de 0,7 y Cl Cr 0-30 demostró ser útil para confirmar la posibilidad de rechazo renal agudo, al tener una buena especificidad (98,2%) a pesar de su baja sensibilidad (53%).

The treatment for the correction of prominent or valgus ears, is to create a normal distance (17-21 mm) between the mastoid and the helix and a normal appearance of the anterior auricular folds. From late 1800 to the present, many surgical techniques for correcting prominent or valgus ears have been described, each one with its own characteristics. We describe a technique to stabilize the result and prevent recurrence. This technique stabilizes the correction of the ear fixing it to the mastoid fascia using a dermalfat-perichondrium flap of simple design, useful, safe and easily reproducible. We have used it over 15 years, and that makes us believe that has stood the test of time.

El tratamiento quirúrgico para la corrección de las orejas prominentes o valgas se basa en crear una distancia de entre 17-21 mm entre el hélix y la mastoides, así como recrear unos pliegues auriculares anteriores bien definidos. Desde finales de 1800 hasta la actualidad se han descrito muchas técnicas para corregir las orejas despegadas, prominentes o valgas, cada una de ellas con sus propias características. En el presente trabajo describimos una técnica para estabilizar el resultado quirúrgico cuando se corrige esta entidad y evitar su recidiva. Se trata de un procedimiento de fijación mastoidea de la oreja mediante un colgajo dermo-graso-pericóndrico de sencillo diseño, útil, seguro y fácilmente reproducible. Hemos empleado esta técnica durante más de 15 años y creemos que ha resistido la prueba del tiempo.

A tendência por unidades de produção mais sustentáveis vem obrigando a indústria de alumínio a adotar estratégias para reduzir o consumo de energia e minimizar a geração de resíduos. Procedimentos nesta direção têm sido implementados em fornos de cozimento de anodo, onde alguns aprimoramentos têm permitido a redução no consumo de energia. Entretanto, sabe-se que durante a etapa de queima do anodo, elevada quantidade de calor é ainda dissipada para o ambiente, aumentando os custos com energia. Desta forma, o presente trabalho tem por objetivo apresentar alternativas de redução do consumo de combustível do forno de cozimento de anodo considerando, para isto, o transporte de calor das câmaras de combustão desde as paredes refratárias até o bloco de carbono, passando pelo coque fluido. Os resultados aqui obtidos indicam que uma possível mudança da distribuição do tamanho de partículas do coque, bem como, a adição de uma manta isolante no topo do forno pode aperfeiçoar o desempenho do sistema quando o foco é sustentabilidade e otimização do processo.

The trend for sustainable production units induced the aluminum industry to adopt strategies of reducing the energy consumption and waste generation. In this sense, several procedures have been carried out in the anode baking furnace, reducing its energy consumption. However, during the carbon block thermal treatment, a great amount of heat is still released to the environment, increasing the energy cost. Therefore, the present work aims to show alternatives of reducing the anode furnace energy consumption considering the heat flow from the combustion chamber, via the flue wall and the fluid coke, till the anode. The results point out that a change in the fluid coke particle size distribution as well as placing an insulating blanket on the top of the furnace can optimize the anode furnace performance when the focus is sustainability and the process optimization.

Pyoderma Gangrenosum (PG) is a rare disease whose etiology is unknown, suspecting that could be due to autoimmune disorders. We present 2 cases of Granulomatous PG in mediate postoperatory (3-6 weeks) in patients undergoing mammoplasty (mastopexy with prosthesis). Both cases were solved by treatment with corticosteroids.

El Pioderma Gangrenoso (PG) es una rara enfermedad de etiología desconocida, sospechándose que pudiera ser debida a trastornos de autoinmunidad. Presentamos 2 casos de PG Granulomatoso en el postoperatorio mediato (3-6 semanas) en pacientes sometidas a mamoplastia (mastopexia con prótesis). Ambos casos se solucionaron mediante tratamiento con corticoesteroides.

A literatura indica diversos tipos de ensaios e diferentes métodos de avaliação de dano por choque térmico. Adicionalmente sabe-se que, em determinadas aplicações, esse tipo de dano é um dos principais responsáveis pela degradação do revestimento refratário. Neste contexto e buscando a melhor forma de reproduzir as condições em serviço do revestimento refratário, o presente trabalho foi realizado visando analisar qual tipo de ensaio de choque térmico e método de avaliação do dano são os mais adequados para avaliar o desempenho destes materiais. Essa análise foi baseada em uma revisão bibliográfica e resultados obtidos em laboratório, em que se comparou e avaliou as vantagens e desvantagens dos métodos mais relevantes encontrados na literatura. Por fim, com o auxilio da ferramenta SWOT foi possível verificar se o método adotado pelos autores desse trabalho é adequado para auxiliar na seleção do refratário para aplicação em calcinadores de leito fluidizado.

The literature shows different tests and techniques for evaluating the thermal shock damage. Additionally, it is known that, for certain applications, this type of wear mechanism is one of the main causes of fluid flash calciner refractory degradation. Within this context and in order to find the best way to reproduce the refractory lining service conditions, this work was carried out to point out which thermal shock test and damage assessment method are more suitable to evaluate these materials. This analysis was based on a literature review and laboratory experiments, comparing and evaluating the advantages and disadvantages of the most important methods available. Finally, with the support of the SWOT tool it was possible to evaluate whether the method adopted by the authors of this work is appropriated for helping the selection of the refractories for calciners application.

Axillary lymphadenopathy associated with augmentation mammoplasty with silicone implants is a rare occurrence, not exceptional, and very worrying for patient and surgeon. We reviewed 1697 medical records of patients undergoing augmentation mammoplasty with silicone implants in order to study the relationship between implant rupture and axillary lymphadenopathy The 1697 patients were divided into groups having 1, 2, 3, 5 and 7 years after surgery. We reviewed the medical records and studied those who consulted for suspected implant rupture and axillary lymph nodes There were no implant rupture before 5 years after surgery. The percentage of rupture was 1.2% at 5 years and 2.3% at 7 years. Silicon lymphadenopathy occurred in 55% of the ruptures detected at 5 years and 61.6% of the ruptures detected at 7 years. Several studies have shown that breast implants will biodegrade over time leading in a more or less long time to rupture. In some cases rupture of the mammary implant filled with silicone gel, leads to the appearance of axillary lymphadenopathy. Sometimes the primary symptom of rupture, specially when they are filled with high cohesiveness gel, is the appearance of lymphadenopathy. Surgeons should think about keeping patients under periodic reviews and in an implants exchange program.

La aparición de adenopatías axilares asociadas a mamoplastia de aumento mediante prótesis de silicona es un hecho infrecuente, no excepcional, y muy preocupante para paciente y cirujano. Hemos hecho una revisión de 1697 historias clínicas de pacientes sometidas a mamoplastia de aumento mediante prótesis de silicona al objeto de estudiar la relación entre roturas protésicas y adenopatías axilares Las 1697 pacientes se dividieron en grupos que cumplían 1, 2, 3, 5 y 7 años de haber sido intervenidas. Revisamos sus historias clínicas y estudiamos las que con posterioridad a la cirugía habían consultado por sospecha de rotura protésica y adenopatías axilares. No encontramos roturas protésicas antes de los 5 años de haber efectuado el implante. El porcentaje de roturas fue de 1,2% en el 5º año y el 2,3% a los 7 años. La aparición de adenopatías siliconomatosas se produjo en el 55% de las roturas detectadas en el 5º año y en el 61,6% de las roturas detectadas en el 7º año. Diversos estudios han demostrado que los implantes mamarios se biodegradan con el paso del tiempo llevando, en un tiempo mas o menos largo, hacia su rotura. En algunos casos, la rotura de las prótesis mamarias rellenas de gel de silicona conduce a la aparición de adenopatías axilares. En ocasiones el síntoma primario de la rotura de la prótesis, especialmente cuando están rellenas de gel de alta cohesividad, es la aparición de adenopatías. Los cirujanos deberíamos pensar en mantener a nuestras pacientes bajo revisiones periódicas y en un programa de recambio de las prótesis.

When a patient consults a plastic surgeon for breast augmentation with mammary implants, most of the times, is difficult to know exactly what breast volume does she want. The method to value patient's breast volume and the one she would like to have is limited by technical problems and by the low accuracy in the psyco-social interpretation of measurements and calculation that can be done. The aim of this study was to find a way to relate patient's breast volume, the bra that she uses and the bra that she wants to use, with the volume of the breast implant needed to get the desired cup bra. We collected anthropomorphic thoracic and breast measures in 100 women between 18 and 32 years old candidates to a prosthetic breast augmentation and made an evaluation about the size of the bra they were wearing and the bra that they would like to use after surgery procedure. We studied the volume of the cup of the bras related to the calibration system of usual commercial measures. Patients were asked for two questions: ¿what volume of cup and contour bra does she use? and ¿what volume of cup and contour bra does she want to use?, and the responses were related to the previous measurements. We looked for that breast implant that, complementing the volume of the breast cup, could fill the cup of the desired bras. Knowing the commercial sizes of the bras, the bra size that the patients uses, which bra she would like to use, and knowing the measures of chest contour, breast contour (or thoracomammary contour), projection, diameter and mammary contour we can select the most adequate breast implant in every patient in order to get satisfactory results.

Cuando una paciente consulta al cirujano plástico con la intención de que éste le efectúe una mamoplastia de aumento es, en la mayoría de las ocasiones, difícil interpretar exactamente el volumen que desea. La determinación del volumen de la mama que posee la paciente y del volumen que quisiera tener se ve limitada por inconvenientes técnicos y por la poca precisión en la interpretación psicosocial de las mediciones y cálculos que se pueden hacer. El objetivo de este estudio ha sido desarrollar un sistema que partiendo de las medidas intrínsecas del sujetador permita relacionar el volumen de la mama de la paciente con el volumen de la copa del sujetador que desea y con la prótesis necesaria para conseguirlo. Tomamos medidas antropomórficas del tórax y de las mamas en 100 mujeres de entre 18 y 32 años de edad, candidatas a una mamoplastia de aumento y evaluamos la talla del sujetador que usaban y el que deseaban usar tras la cirugía. Estudiamos los volúmenes de las copas de los sujetadores en función del sistema de calibración comercial de tallas. Se plantearon a las pacientes dos preguntas en relación con la talla del sujetador: ¿qué contorno y copa de sujetador usa? y ¿qué contorno y copa de sujetador quiere usar? Las respuestas se relacionaron con sus medidas antropomórficas y se buscó implantar las prótesis mamarias que, complementando el volumen de su mama, consiguieran rellenar la copa del sujetador que deseaban. Conociendo el sistema de tallas de sujetadores, sabiendo el sujetador que usa la paciente y el que desea usar y tomando las medidas de contorno torácico, contorno mamario (o contorno tóraco-mamario), proyección, diámetro y contorno de la mama, podremos implantar en la paciente las prótesis mamarias del volumen adecuado para satisfacer sus expectativas.

Nos últimos anos a produção mundial de alumínio tem aumentado e para as empresas continuarem competitivas torna-se necessário que a média do custo de produção do metal seja reduzida. Uma das alternativas é aumentar a vida útil dos refratários usados em fornos de cozimento de anodo, bem como a sua capacidade de produção. Ambas estratégias podem resultar em maior qualidade do anodo e redução no custode manutenção do forno. O presente trabalho tem por objetivo apresentara caracterização termo-mecânica dos tijolos refratários utilizados em fornos de cozimento de anodo e a resistência destes materiais ao ataque químico. Os resultados indicam que a escolha da composição mais adequada depende de uma análise sistêmica das propriedades a alta temperatura, da resistência química e das práticas operacionais do forno.

In the latest years the worldwide production of aluminum is increasing and for the companies to keep their competitiveness it is necessary to reduce the average cost of the metal production. One of the alternatives is to increase the refractories working life used in anode baking furnaces and their production capacity. Both strategies may result in a higher anode quality and reduction of the furnace maintenance costs. This paper aims to present the thermo-mechanical characterization of the refractory bricks used in anode baking furnaces and their resistance to chemical attack. The results indicated that the selection of the most suitable composition depends on a systemic analysis involving the high temperature properties, chemical resistance and the operational practices of the furnace.

Nos últimos anos, a produção mundial de alumínio tem aumentado e para as empresas continuarem competitivas torna-se necessário que a média do custo de produção do metal seja reduzida. Uma das alternativas é aumentar a vida útil dos refratários usados em fornos de cozimento de anodo, bem como a sua capacidade de produção. Ambas estratégias podem resultar em maior qualidade do anodo e redução no custo de manutenção do forno. O presente trabalho tem por objetivo apresentar a caracterização termo-mecânica dos tijolos refratários utilizados em fornos de cozimento de anodo e a resistência destes materiais ao ataque químico. Os resultados indicam que a escolha da composição mais adequada depende de uma análise sistêmica das propriedades a alta temperatura, da resistência química e das práticas operacionais do forno.

In the latest years, the worldwide production of aluminum is increasing and for the companies to keep their competitiveness it is necessary to reduce the average cost of the metal production. One of the alternatives is to increase the refractories working life used in anode baking furnaces and their production capacity. Both strategies may result in a higher anode quality and reduction of the furnace maintenance costs. This paper aims to present the thermo-mechanical characterization of the refractory bricks used in anode baking furnaces and their resistance to chemical attack. The results indicated that the selection of the most suitable composition depends on a systemic analysis involving the high temperature properties, chemical resistance and the operational practices of the furnace.