2,595 research outputs found

    Hydrocracking of long paraffins over Pt-Pd/WO3-ZrO2 in the presence of sulfur and aromatic impurities

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    The hydrocracking of long paraffins in the presence of sulfur and aromatic impurities using Pt–Pd/WO3–ZrO2 was assessed. The catalysts were tested for n-hexadecane hydrocraking in the presence and absence of several poisons, benzothiophene, quinolein, carbon disulfide, benzene, and naphthalene. At small impurity levels, aromatics are beneficial for the hydrocracking of long paraffins because they increase the liquid yield and reduce the cracking to light gases. Sulfur compounds were strong poisons of the activity. Benzothiophene was the strongest, producing the highest decline in activity and being more strongly chemisorbed than basic quinolein. Sulfur poisoning drastically affected the hydrocracking activity, indicating that acid isomerization cracking on WO3–ZrO2 follows a bifunctional mechanism with a big influence of the metal function. Incorporation of Pd to Pt/WO3–ZrO2 reduced the sulfur poisoning, with Pt–Pd (3:1)/WO3–ZrO2 being the best catalyst for stable hydrocracking of long paraffins in the presence of sulfur. This catalyst retained most of the activity of the Pt/WO3–ZrO2 parent material while being less affected by sulfur.Fil: Busto, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Grau, Javier Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Sepulveda, Jorge H.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Tsendra, Oksana. National Academy of Sciences. Chuiko Institute of Surface Chemistry; UcraniaFil: Vera, Carlos Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

    CHANGE OF CHOSEN SOIL PHYSICAL PROPERTIES OF CHERNOZEM AFTER SEVEN YEARS OF NO-TILL SOIL CULTIVATION

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    Soil physical properties were investigated in two types of growing systems - integrated no-till system and conventional system with ploughing, in 1999 – 2005 on chernozem in maize growing region. Bulk density decreased and total porosity increased during 7 years in both growing systems. In integrated system the improvement of soil physical properties could be explained by remaining of plant residues on soil surface. In conventional system the plant residues were incorporated into soil by ploughing. This led to the higher proportion of organic matter in soil. Soil cultivated conventionally had significantly higher value of reduced bulk density, significantly lower porosity and significantly higher values of soil moisture compared to soil in integrated no-till system. Maximum capillary water capacity was not significantly influenced by soil cultivation. Values of investigated soil physical properties in both systems were not markedly different from the typical values of cultivated chernozem

    The directions of increase the effectiveness of the use of proceeded sources energy

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    An exploration of learning styles used by social work students: a systematic review

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    Social work educators are faced with the challenge of ensuring that students from diverse backgrounds are fully equipped with the necessary knowledge and skills. However, to be effective social work educators, the educator is required to understand the learning style of the student. The aim of this systematic review was to explore the learning styles of social work students for the purpose of understanding how to adapt and refine teaching strategies in social work. To this end, a search for descriptive studies in databases, which included Ebscohost (Academic Premier, CINAHL, SOcIndex, Psycharticles, Medline), DOAJ and Pubmed, was conducted. Eight articles met the criteria for inclusion in this systematic review. The target population included both undergraduate and postgraduate students. The studies were mainly conducted in developed countries. The results suggest that the most common approach for social workers is the diverging learning style, which entails having an interest in people, being aware of emotion, and a tendency to be imaginative. This review recommends that if there is an improved understanding of students’ learning needs then educators could adapt their teaching strategies to accommodate and support students from diverse backgrounds, with diverse learning needs.DHE

    THE MEDIATION IN THE MEDICAL MALPRAXIS

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    The conflict has been defined over time in many forms. Dispute, disagreement, fight, litigation, divergence are common terms that we hear every day and that talk about the existence of conflict situations. When there is a clash of interests, concepts or egos of people, we are dealing with a conflict.            The medical malpraxis is a topic that throughout the last years has raised many controversies

    Integration of Solvent Extraction and Non-Catalytic Esterification for the Treatment of Acidic Feedstocks

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    The possibility of directly feeding the extract of a liquid-liquid extraction unit to a chemical reactor is analyzed. An example of extraction and noncatalytic esterification of naphthenic acids from acid petroleum crudes is used. Methanol is used both as a solvent and as a reactant. Separate tests of extraction and reaction are performed, and the performance of an integrated process is deduced by computer simulation. Thermodynamic and kinetic parameters for the extraction of naphthenic acids from an acid crude were determined. A partition coefficient of m = 0.66 at 60 °C between the alcoholic and petroleum phases was found. Three successive batch extractions with a 1:1 v/v ratio reduced the acidity from 4.3 to about 1.1 mgKOH g-1. Naphthenic acid concentrates were reacted with supercritical methanol in a batch reactor at high temperatures (280 °C), yielding naphthenic esters. Reaction of 1-2 h with methanol-to-oil molar ratios of 3-6 yielded 92-96% conversion because of a relatively low value of the equilibrium constant. Total conversion could, however, be achieved with the highly diluted extracts. Simulations were run using three countercurrent mixer-settlers and a noncatalytic reactor. The results indicated that extraction/supercritical esterification is a convenient pretreatment step of acidic feedstocks because of its simplicity, the good quality of the deacidified feedstock (acidity <0.5 mgKOH g-1), the total removal of the acids, and the good properties of the ester product as a fuel additive. Characterization of the methyl naphthenate product showed that it had a lower viscosity than the crude or the naphthenic acids; a high flash point; and total miscibility in gasoline, kerosene, and diesel. These and other properties showed that it could be sent to the diesel or fuel oil pools.Fil: Busto, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Torresi, Pablo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Manuale, Débora Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Yori, Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; ArgentinaFil: Vera, Carlos Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera". Universidad Nacional del Litoral. Instituto de Investigaciones en Catálisis y Petroquímica "Ing. José Miguel Parera"; Argentin

    The Integrative Nature of Interculturalism in Galicia at The Beginning of the 20th Century

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    The article outlines the main aspects of interculturalism in Galicia at the beginning of the 20th century. The interculturalism has been defined as the initial basis of communication, formed by a combination of social and educational environment. In modern society with many political and intercultural problems, the communicative competence and formation of tolerant attitudes towards people play a significant role. Linguistic education is one of the main tasks of educational pedagogy, linguistics, methodology, language rules, principles, and methods of teaching, ways of investigating education. The level of language culture of the personality in the mother tongue and foreign languages is evidence of the development of linguistic competence. The changes in the cultural sphere of society determine the need to investigate linguistic problems, focusing on improving language culture to achieve efficiency. The language problems have gone beyond the framework of philology and have become the general problems of society to regulate language culture in the process of social communication, social processes, the development of society as a whole system. In the political sphere, the culture of language promotes the emergence of mutual interest and respect between people of different nationalities and the stabilization of interethnic and international relations. The described innovative approach in the organization of social communication and interculturalism in Galicia space can be creatively and practically adapted in the conditions of any modern multicultural society

    Radio Frequency Magnetron Sputter Deposition as a Tool for Surface Modification of Medical Implants

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    The resent advances in radio frequency (RF)‐magnetron sputtering of hydroxyapatite films are reviewed and challenges posed. The principles underlying RF‐magnetron sputtering used to prepare calcium phosphate‐based, mainly hydroxyapatite coatings, are discussed in this chapter. The fundamental characteristic of the RF‐magnetron sputtering is an energy input into the growing film. In order to tailor the film properties, one has to adjust the energy input into the substrate depending on the desired film properties. The effect of different deposition control parameters, such as deposition time, substrate temperature, and substrate biasing on the hydroxyapatite (HA) film properties is discussed

    Multibiomarker responses and bioaccumulation of fipronil in Prochilodus lineatus exposed to spiked sediments: Oxidative stress and antioxidant defenses

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    Fipronil is a current use pesticide, widely used in many crops, commonly adsorbed to sediments of aquatic environments. The purpose of this study was to evaluate the biomarker responses and fipronil distribution pattern in different matrixes (fish, sediment and water) after juveniles P. lineatus exposure at two environmental concentrations (5.5 and 82 μg kg‐−1) of fipronil-spiked sediments. The levels of oxidized proteins (PO), lipid peroxidation (LPO), and enzymatic activity of superoxide dismutase (SOD), reduced glutathione content (GSH), antioxidant capacity against peroxyls (ACAP) and acetylcholinesterase (AChE) were evaluated in liver, gills and brain. Concentrations of fipronil and its metabolites (f. desulfinyl, f sulphpHide and f. sulfone) were quantified by GC-ECD. F. desulfinyl was the major metabolite found in all matrixes, followed by f. sulphide in sediments, while f. sulfone was mainly accumulated in fish. Fipronil promoted oxidative stress in P. lineatus, as evidenced by the increases in LPO and PO levels and the decrease brain AChE activity. Fish exposed at both concentrations showed significant decrease in antioxidant capacity. Alterations in the antioxidant defenses system was evidenced in all organs. These results suggest that the occurrence of fipronil in aquatic environments can generate oxidative stress at different levels in P. lineatus, showing that this species is highly sensitive to the deleterious effects of fipronil and metabolites.Fil: Santillán Deiú, Antonella. Universidad Nacional de Luján. Instituto de Ecología y Desarrollo Sustentable. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ecología y Desarrollo Sustentable; ArgentinaFil: Ondarza, Paola Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Miglioranza, Karina Silvia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: de la Torre, Fernando Roman. Universidad Nacional de Luján. Instituto de Ecología y Desarrollo Sustentable. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ecología y Desarrollo Sustentable; Argentin
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