297 research outputs found

    UV DISINFECTION - A METHOD OF PURIFYING WASTEWATER FROM FARMS – A REVIEW

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    The livestock industry increased significantly globally due to increasing demand for animal products. There are however, growing concerns on the environmental risks, associated with the disposal of untreated livestock wastewater into streams and rivers. Disinfection is considered to be the primary mechanism for the inactivation/ destruction of pathogenic organisms to prevent the spread of waterbornediseases to downstream users and the environment.Water disinfection using ultraviolet light is a newer process that currently has a limited use area [5].The purpose of this paper is to present the ultraviolet disinfection process used for the treatment of waste water

    Materiales activados alcalinamente a base de residuos de vidrio y escoria para aislamiento térmico y acústico

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    Porous alkali activated materials (AAM), can be obtained from waste glass powder and slag mixtures by alkali activation with NaOH solution. To obtain an adequate porous microstructure, the hardened AAM pastes were thermally treated at temperatures ranging between 900°C and 1000°C, for 60 or 30 minutes. Due to the intumescent behaviour specific for this type of materials, an important increase of the volume and porosity occurs during the thermal treatment. The partial substitution of waste glass powder with slag, determines the increase of compressive strength assessed before (up to 37 MPa) and after (around 10 MPa) thermal treatment; the increase of slag dosage also determines the increase of the activation temperature of the intumescent process (above 950°C). The high porosity and the specific microstructure (closed pores with various shapes and sizes) of these materials recommend them to be utilised as thermal and acoustical insulation materials.Los materiales activados alcalinamente porosos (AAM) se pueden obtener a base de polvo de residuos de vidrio y mezclas de escoria mediante activación alcalina con una solución de hidróxido de sodio (NaOH). Para obtener una microestructura porosa adecuada, las pastas de AAM endurecidas se trataron térmicamente a temperaturas que oscilan entre 900°C y 1000°C durante 60 o 30 minutos. Debido al comportamiento intumescente específico de este tipo de material, se produce un aumento significativo en el volumen y la porosidad durante el tratamiento térmico. La sustitución parcial del polvo de residuos de vidrio por escoria conlleva un aumento en las resistencias a compresión previamente evaluadas (hasta 37 MPa) y después (aproximadamente 10 MPa) del tratamiento térmico; el aumento de la dosis de escoria también determina el aumento de la temperatura de activación del proceso intumescente (por encima de 950°C). La alta porosidad y la microestructura específica de estos materiales recomiendan que se utilicen como materiales de aislamiento térmico y acústico

    ADVANCED TECHNOLOGIES FOR WASTEWATER TREATMENT BY UV – A REVIEW–

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    Reclamation and reuse ofwastewater is one of the most effectiveways to alleviatewater resource scarcity.Disinfection plays a key role in reuse of wastewater for eliminatinginfectious diseases.Water disinfection using ultraviolet light is a newer process that currently has a limited use area. Ultraviolet(UV) disinfection is now widely implemented as a tertiary treatment forwastewater reclamation. The purpose of this paper is to present the most representative studies on the use of ultraviolet in wastewater treatment

    INFLUENCE OF THE NUMBER OF PASSES OF AGRICULTURAL MACHINERY ON PENETRATION RESISTANCE AND THE DEGREE OF SOIL COMPACTION

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    In the context of the ongoing development of mechanized agriculture, which implies the use of heavy agricultural machinery, often on soils with high moisture content, it increased significantly the risk of soil compaction. Compaction has become a problem of major proportions especially to farmers, because this phenomenon causes environmental damage, and affects soil quality and crop production. Penetration resistance is a valuable and easy to determine indicator of the degree of compaction of agricultural soil. In this paper are presented the results of some experimental research conducted to determine the penetration resistance of a plot of clover, under the influence of the number of passes of a tractor, in order to assess, from an qualitative point of view, the degree of soil compaction

    Geometrical Models of the Locally Anisotropic Space-Time

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    Along with the construction of non-Lorentz-invariant effective field theories, recent studies which are based on geometric models of Finsler space-time become more and more popular. In this respect, the Finslerian approach to the problem of Lorentz symmetry violation is characterized by the fact that the violation of Lorentz symmetry is not accompanied by a violation of relativistic symmetry. That means, in particular, that preservation of relativistic symmetry can be considered as a rigorous criterion of the viability for any non-Lorentz-invariant effective field theory. Although this paper has a review character, it contains (with few exceptions) only those results on Finsler extensions of relativity theory, that were obtained by the authors.Comment: 35 pages, 5 figures, to appear in the Russian journal Hypercompl. Numb. Geom. Phys; submit/0362894 (George Bogoslovsky

    EXPERIMENTAL STUDY OF THE SEDIMENTATION OF SOLID PARTICLES IN WASTEWATER

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