337 research outputs found
ASPECTS REGARDING BIOMASS FROM ENERGEIC PLANTS (ENERGETIC WILLOW – SALIX MINIMALIS) GRINDING PROCESS FOR PELLETIZATION
         Using energetic plants like energetic willow in the process of developing renewable energy processes, is under heavy research and development by scientists. Energetic crops are subjected to a technological process mainly for easy maneuverability purposes. An important processing phase is energetic plant grinding. The present paper describes researches regarding the grinding process of ha hammer mill using energetic willow as feeding material. 4 types of hammers and 5 grinding speeds were used. Starting from this data the necessary energy consumption for a 5 mm sieve was calculated
ASPECTS REGARDING BIOMASS FROM ENERGEIC PLANTS (ENERGETIC WILLOW – SALIX MINIMALIS) GRINDING PROCESS FOR PELLETIZATION
         Using energetic plants like energetic willow in the process of developing renewable energy processes, is under heavy research and development by scientists. Energetic crops are subjected to a technological process mainly for easy maneuverability purposes. An important processing phase is energetic plant grinding. The present paper describes researches regarding the grinding process of ha hammer mill using energetic willow as feeding material. 4 types of hammers and 5 grinding speeds were used. Starting from this data the necessary energy consumption for a 5 mm sieve was calculated
Materiales activados alcalinamente a base de residuos de vidrio y escoria para aislamiento térmico y acústico
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 especÃfico 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 especÃfica de estos materiales recomiendan que se utilicen como materiales de aislamiento térmico y acústico
Geometrical Models of the Locally Anisotropic Space-Time
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
ADVANCED TECHNOLOGIES FOR WASTEWATER TREATMENT BY UV – A REVIEW–
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
Progress in hydroxyapatite-starch based sustainable biomaterials for biomedical bone substitution applications
Hydroxyapatite is a calcium phosphate intensively proposed as a bone substitution material because of its resemblance to the constituents of minerals present in natural bone. Since hydroxyapatite’s properties are mainly adequate for nonload bearing applications, different solutions are being tested for improving these properties and upgrading them near the target values of natural bone. On the other hand, starch (a natural and biodegradable polymer) and its blends with other polymers have been proposed as constituents in hydroxyapatite mixtures due to the adhesive, gelling, and swelling abilities of starch particles, useful in preparing well dispersed suspensions and consolidated ceramic bodies. This article presents the perspectives of incorporating starch and starch blends in hydroxyapatite materials. Based on the role of starch within the materials, the review covers its use as (i) a polymeric matrix in hydroxyapatite composites used as adhesives, bone cements, bone waxes, drug delivery devices or scaffolds and (ii) a sacrificial binder for fabrication of porous hydroxyapatite scaffolds. The suitability of these materials for bone reconstruction has becomes a reachable aim considering the recent advancements in ceramic fabrication and the current possibilities of controlling the processing parameters
Synthesis and characterization of ZnO nanopowder by non-basic
Nanocrystalline ZnO particles were prepared from methanolic solutions of zinc acetate dihydrate without using base such as NaOH or LiOH through a colloid process carried out at a low temperature of 60 o C. The precipitate obtained after 12-72h contained ZnO, covered with polymeric species of zinc hydroxo acetate. The reaction course was studied by mass spectrometry means. To complete the hydrolysis process, up to pure ZnO, it was necessarily to reflux the white precipitate separate from methanolic solution, in water at 80 o C. We found that reaction time in the presence of methanol primarily influenced the size of the particles, while the reaction time in the presence of water mainly influenced the ZnO purity
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