Porosity
Mostrando 13-24 de 880 artigos, teses e dissertações.
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13. Silicon carbide hollow fiber membranes developed for the textile industry wastewater treatment
Abstract In order to reduce the impacts of the industrial effluent on the environment, silicon carbide hollow fiber membranes were prepared by the precipitation-immersion technique and sintered at 1450 and 1500 °C. The membranes were characterized by X-ray diffraction, their surface structure was characterized by scanning electron microscopy and atomic forc
Cerâmica. Publicado em: 2021-06
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14. Evaluation of the combined addition of aluminum lactate and calcium carbonate to alumina-based castables
Abstract Calcium aluminate cement (CAC) can induce the development of high green mechanical strength to refractory castables in a short period of time (24 h). However, the production of this hydraulic binder is energy-intensive and releases a large content of carbon dioxide (CO2), which adds to global warming. Thus, aiming to develop an alternative binding s
Cerâmica. Publicado em: 2021-06
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15. Microbial activity and studies on excavated megalithic micaceous potsherds from Peninsular India
Abstract The abundantly available mica flakes were added in raw materials to manufacture pottery in Central Peninsular India during the early Iron Age (700-300 BCE) for storage and glittering. The micaceous potsherds from the excavated megalithic site of Nagpur were studied for their composition, manufacturing techniques, microstructural features, microbial
Cerâmica. Publicado em: 2021-06
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16. Nanofibras eletrofiadas e suas aplicações: avanços na última década
In recent years there has been an increasing interest in the development of nanomaterials with improved properties compared to their counterparts at the micro- and macroscopic scale. In this context, nanofibers obtained by electrospinning technique are highly attractive due to the unique combination of high surface area/volume ratio, porosity, flexibility, m
Quím. Nova. Publicado em: 2021-06
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17. Porosity of CHA Zeolite Driving the Formation of Polyaromatic Coke Species in the Methanol to Olefins Reaction
The pore size of the chabazite structure is exceptionally suitable for the methanol to olefins (MTO) reaction. The reaction has an induction period required for the formation of a hydrocarbon pool (HP), usually composed of aromatic compounds of different sizes. HP is alkylated by methanol and afterward cracked, leading to the formation of olefins. Despite th
J. Braz. Chem. Soc.. Publicado em: 2021-05
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18. SPATIAL AUTOCORRELATION OF PHYSICAL ATTRIBUTES OF AN OXISOL
ABSTRACT Studies that seek to identify a smaller number of soil attributes that represent others can generate less expenditure of time and financial resources for monitoring cultivated areas. Thus, this study aimed to analyze the spatial distribution and spatial autocorrelation of physical attributes of an Oxisol (Latossolo Vermelho Amarelo, Brazilian Soil C
Eng. Agríc.. Publicado em: 2021-04
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19. Influence of sintering parameters on the microstructure and mechanical properties of nanosized 3Y-TZP ceramics
Abstract The fracture toughness of 3Y-TZP ceramics obtained from a nanocrystalline powder with an optimized microstructure and highly transformable tetragonal grains was investigated. Samples of ZrO2-3 mol% Y2O3 were sintered at temperatures between 1250 and 1400 °C, with isothermal holding times of up to 16 h. Samples sintered at 1250 °C exhibited relativ
Cerâmica. Publicado em: 2021-03
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20. Thermal decomposition and reaction sintering for synthesis of mullite-zirconia composite using kaolin, γ-alumina and zirconia
Abstract The refractory materials used in the wall of the furnaces for glass melting can be prepared from mullite-zirconia composite material. The composite of mullite/zirconia was synthesized from Iraqi kaolin, γ-alumina, and zirconia using thermal decomposition with reaction sintering at 1600 °C. Several batches were prepared with various ratios of kaoli
Cerâmica. Publicado em: 2021-03
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21. Cortical Bone Modifications after Radiotherapy: Cortex Porosity and Osteonal Changes Evaluated Over Time
Resumo Com o objetivo de avaliar a microarquitetura óssea cortical e a morfologia dos osteons após irradiação, foram utilizados doze coelhos machos da Nova Zelândia. Os animais foram divididos: grupo controle (sem radiação-NIr); e 3 grupos irradiados, sacrificados após: 7 (Ir7d); 14 (Ir14d) e 21 (Ir21d) dias. Foi utilizada uma dose única de radiaç�
Braz. Dent. J.. Publicado em: 2021-02
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22. Achados de fundoscopia de pacientes diabéticos e/ou hipertensos
ABSTRACT Soil compaction in agricultural areas has greatly increased in recent decades due to intensive farming practices, including short-cycle crops and machinery intensification. This study aimed to evaluate the impacts of management systems on the physical quality of a dystrophic Yellow Oxisol, in the Cerrado region of Brazil. Treatments consisted of fiv
Rev. bras.oftalmol.. Publicado em: 2020-10
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23. CHANGES IN PHYSICAL QUALITY OF OXISOLS UNDER DIFFERENT MANAGEMENT SYSTEMS IN THE BRAZILIAN CERRADO
ABSTRACT Soil compaction in agricultural areas has greatly increased in recent decades due to intensive farming practices, including short-cycle crops and machinery intensification. This study aimed to evaluate the impacts of management systems on the physical quality of a dystrophic Yellow Oxisol, in the Cerrado region of Brazil. Treatments consisted of fiv
Eng. Agríc.. Publicado em: 2020-10
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24. Maximization of the use of casting sand residue in the production of fired ceramic bricks
Abstract In this study, a red ceramic was developed with the addition of sand residue from deburring and finishing processing of cast iron molds, replacing a variable fraction of the clay. The formulated masses were shaped by pressing and firing at different temperatures (850, 900 and 1000 ºC) at a heating rate of 180 ºC/h and 2-hour level. The bodies were
REM, Int. Eng. J.. Publicado em: 2020-09