In this work, a parametric study the gasification of the Mexican petroleum coke from the refineries of Cd Madero (CRM) and Cadereyta, Nuevo León (CRC) is performed. It is evaluates the energy behavior of the gasification process with objective to research which feedstock of petroleum coke has a better yield of energy. Effect feed petroleum coke on energy characteristics of the clear synthetic gas (gasl): molar composition of CO and H2, High Heating Value (HHVgasl), energy power (Ωgasl),Cold Gas Efficiency (CGEgasl) and thermal efficiency of gasification (ηtg) is realized. The parametric study has been realized for 0.64 < oxygen/coke < 1.11 ratio with the flow of oxygen (6036.388 kg/h) and steam/oxygen of 23% both constant. It is observed that in oxygen/coke 0.77 and 0.94 ratio it is present the best energy characteristics of the gasl from CRM and CRC, respectively. The best energy characteristics relationship of the gasl fined are: molar composition CO (65.6, 68.5), H2 (32.29, 29.13), HHVgasl (14054.6 kJ/kg gasl, 13438.76 kJ/kg gJ, Ωgasl (204.86 GJ/h, 178.02 GJ/h), CGEgasl (74.43%, 71.14%), ηtg (86.2%, 83.22%). The gasification of petroleum coke CRM produced energy with 26.20 MJ/kg coque rates whereas that gasification of the petroleum coke CRC produced 27.74 MJ/kg coque rates.

En este trabajo se realiza un estudio paramétrico de la gasificación del coque de petróleo mexicano de las refinerías de Cd. Madero, Tamaulipas denominado CRM y Cadereyta, Nuevo, León denominado CRC. Se evalúa el comportamiento energético del proceso de gasificación, con la finalidad de encontrar una alimentación de coque de petróleo de máximo provecho energético. Se analiza el efecto que tiene la alimentación de coque de petróleo sobre las características energéticas del gassin limpio (gasl): la composición molar de CO e H2, el poder calorífico superior (PCSgasl), la potencia energética (Ωgasl), la eficiencia de gas frío (EGFgasl) y la eficiencia térmica de gasificación (ηtg). El estudio paramétrico se realiza para una relación 0.64 < oxigeno/ coque < 1.11 manteniéndose constante el flujo de oxígeno (6036.388 kg/h) y una relación vapor de agua/oxígeno de 23%. Se observó que en la relación oxígeno/coque de 0.77 y 0.94 se presentan las mejores características energéticas del gasl del CRM y CRC, respectivamente. Las mejores características energéticas del gasl correspondientes al CRM y al CRC son: composición molar de CO (65.6, 68.5), H2 (32.29, 29.13), PCSgasl (14054.6 kJ/kg gasl, 13438.76 kJ/kg gasl), Ωgasl (204.86 GJ/h, 178.02 GJ/h), EGFgasl (74.43%, 71.14%), ηtg (86.2%, 83.22%). Al gasificar el coque de petróleo CRM la energía producida es a razón de 26.20 MJ/kg coque, mientras que al gasificar el coque de petróleo CRC se producen a razón de 27.74 MJ/kg coque.

This review provides examples of the fact that different procedures for the measurement of atherosclerosis in mice may lead to interpretation of the extent of atherosclerosis having markedly different biological and clinical significance for humans: 1) aortic cholesterol measurement is highly sensitive for the detection of early and advanced atherosclerosis lesions, but misses the identification of the location and complexity of these lesions that are so critical for humans; 2) the histological analysis of the aortic root lesions in simvastatin-treated and control mice reveals similar lesion morphology in spite of the remarkable simvastatin-induced reduction of the aortic cholesteryl ester content; 3) in histological analyses, chemical fixation and inclusion may extract the tissue fat and also shrink and distort tissue structures. Thus, the method may be less sensitive for the detection of slight differences among the experimental groups, unless a more suitable procedure employing physical fixation with histological sample freezing using optimal cutting temperature and liquid nitrogen is employed. Thus, when measuring experimental atherosclerosis in mice, investigators should be aware of several previously unreported pitfalls regarding the extent, location and complexity of the arterial lesion that may not be suitable for extrapolation to human pathology.

This paper evaluates in terms of energy the gasification of the petroleum coke from the refineries of Cd Madero and Cadereyta in Mexico. The energy evaluation of the synthetic gas (syngas) focuses mainly on the chemical composition of the clean syngas (gasl) and its energy characteristics: heating value, the energy power, the cold gas efficiency and the thermal efficiency of gasification. The results of the simulation indicate that the gasification of the petroleum coke from Cadereyta called CRC, produces a gasl with better performance and energy characteristics than those obtained when gasifying the coke of petroleum from Cd. Madero, called CRM. When the CRC is gasified, the rate of production of gasl obtained is of 2.07 kg gas l/kg coque, while the rate of production of gasl for the CRM is 1.89 kg gas l/kg coque. The HHV of the gasl of the CRC is 12 729.56 kJ/kg gasl while for the CRM is 11 639.13 kJ/kg gasl. The energy power of the gasl of the CRC is greater, with a difference of 25.87 GJ/h, with regard to the energy power of the gasl of the CRM. Under the specified conditions of operation, energy is generated ata rate of 26.46 MJ/kg coque coke in the gasification of the CRC coke of petroleum, while when gasifying the CRM coke of petroleum 22.09 MJ/kg coque are generated. Currently, the petroleum coke produced in the refinery of Madero is consumed in the power plants of Tamuín, San Luis Potosí, Mexico, while the petroleum coke produced by the refinery of Cadereyta is used in the cement industry.

En este trabajo se evalúa energéticamente la gasificación del coque de petróleo de las refinerías de Cd. Madero y Cadereyta de México. La evaluación energética del gas sintético (gassin) se centra principalmente en la composición química del gassin limpio (gasl) y sus características energéticas: el poder calorífico, la potencia energética, la eficiencia de gas frío y la eficiencia térmica de gasificación. Los resultados de la simulación indican que la gasificación del coque de Cadereyta denominado CRC, produce un gasl con mejor rendimiento y características energéticas que el gasl obtenido al gasificar el coque de petróleo de Cd. Madero, denominado CRM. Cuando se gasifica el CRC, la razón de producción de gasl obtenida es de 2.07 kg gas l/kg coque, mientras que la razón de producción de gasl para el CRM es de 1.89 kg gas l/kg coque.El poder calorífico del gasl del CRC es de 12 729.56 kJ/kg gasl mientras que para el CRM es de 11 639.13 kJ/kg gasl. La potencia energética del gasl del CRC es mayor con una diferencia de 25.87 GJ/h, con respecto a la potencia energética del gasl del CRM. Con las condiciones de operación especificadas, en la gasificación del coque de petróleo CRC se generan energía a razón de 26.46 MJ/kg coque, mientras que al gasificar el coque de petróleo CRM se generan 22.09 MJ/kg coque. Actualmente, el coque producido en la refinería de Cd. Madero se consume en las plantas de potencia de Tamuín, San Luis Potosí, México, mientras que el coque que produce la refinería de Cadereyta se usa en la industria cementera.

O estudo da transferência de umidade é importante para a caracterização do comportamento das argamassas notoriamente no que se refere à durabilidade, à estanqueidade, à degradação de aspecto e ao desempenho térmico. No entanto, as pesquisas que abordam propriedades relacionados aos mecanismos de transferência de umidade apresentam resultados válidos apenas para argamassas convencionais. Em contrapartida, o uso de resíduos sólidos industriais e o emprego de aditivos têm sido cada vez mais intenso na construção civil. O objetivo do presente trabalho foi realizar a avaliação das propriedades relacionadas com os mecanismos de transferência de umidade não somente de argamassas convencionais, mas também de argamassas confeccionadas com teores de 50 e 100%, em volume, de cinzas pesadas em substituição ao agregado natural, contendo ou não aditivo incorporador de ar. A escolha da cinza pesada advém da grande disponibilidade deste resíduo na região sul do Brasil e da sua característica peculiar de apresentar conteúdo de umidade de equilíbrio bastante superior ao da areia. O estudo também abordou o aditivo incorporador de ar, pelo fato de atuar na formação de alvéolos não interligados ao longo dos capilares e promover a redução na massa específica aparente. As propriedades avaliadas foram: massa específica, porosidade aberta, cinética de absorção de água por capilaridade, cinética de secagem, adsorção e ângulo de molhamento aparente. Os resultados mostraram que o teor de cinza pesada e o emprego de aditivo incorporador de ar são parâmetros que afetam significativamente as propriedades relacionadas com a transferência de umidade. O programa experimental permitiu evidenciar que a natureza da cinza determina o nível da fixação de umidade da argamassa e a sua dinâmica na fixação.

The study of moisture transfer has great importance for the characterization of mortars behavior, particularly in relation to durability, waterproofing, aesthetics degradation and the thermal performance. However, researches on properties related to moisture transfer mechanisms present applicable results only for conventional mortars. On the other hand, the use of industrial solid residues and admixtures are increasing in civil construction activities. The present work evaluated the properties related to moisture transfer mechanisms not only in conventional mortars, but also in mortars with 50% and 100% natural aggregate replaced by bottom ash, by volume, and with and without air-entraining agent. Bottom ash was chosen because it is a residue of great availability in southern Brazil, and its equilibrium moisture content is higher than that of sand, reflecting its porous nature. In relation to admixtures to cement-based materials, air-entraining agent deserves prominence because it increases the disconnection of the capillary network and decreases the specific gravity. The evaluated properties had been: specific gravity, porosity, water absorption by capillarity, air drying, water vapor sorption isotherms and apparent wetting angle. The results show that the bottom ash percentage and the air-entraining agent are parameters that significantly affect the properties related with the moisture transfer.

As substâncias húmicas aquáticas investigadas foram convencionalmente extraídas de amostra de água coletada no Rio Negro - AM, Brasil utilizando-se resina XAD 8. Investigações usando ressonância nuclear magnética de próton e carbono treze indicaram a presença de alta aromaticidade com pouca substituição, pequena quantidade carbono carboxílico e razão 1:1 de grupos alifáticos / aromáticos. A razão das absorbâncias E350/E450, na região do ultravioleta e do visível, sugere a presença de estruturas alifáticas em proporções relativamente grandes. A distribuição do peso molecular das substâncias húmicas aquáticas foi caracterizada utilizando-se um sistema de ultra filtração de 5 estágios. O fracionamento indicou que metais traço, originalmente complexados com as substâncias húmicas, apresentam diferentes distribuições.

The aquatic humic substances investigated in this study were conventionally isolated from Rio Negro waters - Amazonas State/Brazil by means of the collector XAD 8. Molecular spectroscopy investigations of these humic substances using ¹H-NMR and 13C-NMR indicated the presence of high aromaticity with few substituents, small amounts of carboxylic carbon, and an aliphatic/aromatic ratio of 1:1. The relatively high UV-VIS absorbance E350/E450 ratio suggested the presence of relatively large proportions of aliphatic structures. Moreover, using a five-stage tangential-flow ultrafiltration (UF) device, the molecular-size distribution of the isolated humic substances was characterized. The fractionation patterns showed that metal traces remaining in humic substances after their XAD 8 isolation have different size distributions. For instance, Mn, Cu, Cd and Ni quantified by ICP-AES were preferably found in the high molecular-weight fractions (10-100 kDa).