Blasting
Mostrando 13-24 de 47 artigos, teses e dissertações.
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13. Achieving effective confinement through utilization of non-Newtonian fluid mixture as stemming structure
Abstract The economics of a mining operation is directly influenced by blasting outcomes, where blasting aims to comminute the rock mass in order to attain smaller grain sizes to be loaded and hauled at a minimum cost for its first processing stage. In order to promote adequate rock breakage, the stemming structure needs to provide proper confinement for the
REM, Int. Eng. J.. Publicado em: 2017-03
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14. Estimating extent and properties of blast-damaged zone around underground excavations
Abstract A common technique in hard rock tunneling, and underground excavation in general, is drilling and blasting. This method of excavation assumes that damage will be done to the surrounding rock mass depending on its quality. Herein is a proposal for how to estimate blast-damaged zone extent and shape, and how to quantify rock mass properties in this zo
Rem: Rev. Esc. Minas. Publicado em: 2015-12
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15. Effects of air abrasion with alumina or glass beads on surface characteristics of CAD/CAM composite materials and the bond strength of resin cements
ABSTRACT Objective The study aimed to evaluate effects of air abrasion with alumina or glass beads on bond strengths of resin cements to CAD/CAM composite materials. Material and Methods CAD/CAM composite block materials [Cerasmart (CS) and Block HC (BHC)] were pretreated as follows: (a) no treatment (None), (b) application of a ceramic primer (CP), (c)
J. Appl. Oral Sci.. Publicado em: 2015-12
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16. Evidences of the influence of the detonation sequence in rock fragmentation by blasting – Part II
Abstract This paper shows the work conducted at the Experimental Mine of the Research Center of Responsible Mining of the University of São Paulo, taking into account the theoretical issues presented in the first part of the article. The research was performed without changing the production cycle and without resorting to investments in new types of equipme
Rem: Rev. Esc. Minas. Publicado em: 2015-12
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17. Iso-velocity maps. A vibration control tool in quarries
Urban growth around mining areas has brought problems such as neighborhood's discomfort due to blasting vibrations, which can cause structural damage to the houses, dust and atmospheric overpressure. In Brazil, environmental restrictions are increasingly rigorous and seismic monitoring is required as an environmental control measure. This study aims to analy
Rem: Rev. Esc. Minas. Publicado em: 2015-09
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18. Evidences of the influence of the detonation sequence in rock fragmentation by blasting – Part I
Drilling and blasting are fundamental operations in the mining cycle and consti tute an important component of the mining costs. Rock fragmentation can in principle be managed by means of two options: by increasing or reducing the specific consumption of explosives, or by modifying the drilling pattern. The choice of one or other type of control depends on t
Rem: Rev. Esc. Minas. Publicado em: 2015-09
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19. Testing electrode suitability for field stimulation of high-threshold biological preparations
IntroductionA problem posed by electrical field (E) stimulation of biological preparations with high excitation threshold is that the E intensity required for excitation is likely to induce water electrolysis at the electrode surface, which can alter the extracellular medium and cause deleterious effects on the cells. In this study, different electrode mater
Res. Biomed. Eng.. Publicado em: 2015-09
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20. Surface Finishes for Ti-6Al-4V Alloy Produced by Direct Metal Laser Sintering
The implant’s surface is responsible for direct interaction with the human body. For cases where osseointegration must be favored and the risk of bacteria proliferation is lower, rough surfaces are more suitable, while for implants where the risks are higher, a reduced surface roughness is required. This study aimed to analyze and produce different surface
Mat. Res.. Publicado em: 2015-08
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21. Shear bond strength of ceramic brackets after different pre-treatments in porcelain surface
AIM: To evaluate the bond strength of brackets bonded after different surface treatments on two dental ceramics. METHODS: One hundred and twenty discs 5 mm thick and 7 mm diameter of two ceramic types were made and randomly divided in 8 groups. Groups 1, 3, 5, and 7 used Eris ceramic and groups 2, 4, 6, and 8 used d.Sign ceramic. The ceramic surfaces were t
Braz. J. Oral Sci.. Publicado em: 2015-03
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22. Abrasive blasting contamination in Super Duplex and carbon steels - a quantification approach by rietveld analysis
A methodology for quantifying the contamination after abrasive blasting by Aluminum Oxide and Martensitic Carbon Steel particles in Super Duplex and Carbon Steel substrates has been developed. The method consisted of performing x-ray diffraction in the blasted steel substrates and calculating the particle contamination using Rietveld Quantitative Method. In
Mat. Res.. Publicado em: 2014-10
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23. Effect of aluminum oxide blasting and use of industrial sealant on the outer abutment surface of the prosthetic morse taper system connection on the untightening torque / Efeito do jateamento de óxido de alumínio e uso de selante industrial, na superfície de pilares protéticos Cone Morse, de restaurações implanto suportadas sobre a resistência ao contratorque
Problemas com desenho de conexões protéticas sobre implantes, microfendas, afrouxamento e, consequentemente, perdas das estruturas protéticas reabilitadoras são tópicos frequentes do estudo odontológico. Conexões do tipo Cone Morse, devido às suas características, diminuíram o índice desses problemas, abrindo uma nova perspectiva para o sucesso da
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 18/06/2012
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24. The influence of surface treatment on the implant roughness pattern
An important parameter for the clinical success of dental implants is the formation of direct contact between the implant and surrounding bone, whose quality is directly influenced by the implant surface roughness. A screw-shaped design and a surface with an average roughness of Sa of 1-2 µm showed a better result. The combination of blasting and etching ha
J. Appl. Oral Sci.. Publicado em: 2012-10