Vibration A Rock
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. 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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2. 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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3. Modelo de aferiÃÃo da velocidade de partÃculas atravÃs de parÃmetro energÃtico
A vibraÃÃo Ã, sem dÃvida, o efeito que causa maiores danos nas operaÃÃes de desmonte com uso de explosivos, apesar de o ruÃdo produzido pela detonaÃÃo ser o efeito mais perceptÃvel pelo ser humano. O objetivo principal dessa Tese à estudar a vibraÃÃo resultante do desmonte de rochas com explosivos em minas a cÃu aberto, estudando os critÃrios
Publicado em: 2008
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4. DEVELOPMENT OF A VIBROIMPACT DEVICE / DESENVOLVIMENTO DE UM DISPOSITIVO GERADOR DE VIBROIMPACTO
Hard rock drilling is still a great challenge for oil companies. One current line of research involves combining the two existing drilling techniques in order to enhance the rate of penetration. This new technique is called Resonance Hammer Drilling. This dissertation proposes the design and development of the first prototype that will operate in resonance,
Publicado em: 2006
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5. Influencia da vibração na permeabilidade absoluta de meios porosos saturados com agua / Influence of the vibration on the absolute permeability of porous media satured with water
This work verifies experimentally the effects of the mechanical vibration on the absolute permeability of saturated porous media upon which a uniform flow is simultaneously imposed. After finding a driving range within which indirect effects of the vibration are excluded, such as those resulting from ultrasonic heating and mechanical disintegration of the ro
Publicado em: 2004
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6. Exploratory electromyography in the study of vibration-induced white finger in rock drillers.
Electrophysiological observations made in the hands of a group of 16 rock-drillers were compared with 15 controls. Motor and sensory conduction velocities in the median and ulnar nerves together with the latency, duration, and amplitude of the evoked action potentials were measured. The differences between the groups were statistically significant mainly in
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7. Comparative study of vibration disease among operators of vibrating tools by factor analysis.
Principal component analysis was carried out to determine the interrelationships between subjective symptoms experienced by workers using various types of vibrating tools (brush saws (41), rock drills (39), chipping hammers (42) and chain saws (49)) and control groups (clerks (44), farmers (42)). The characteristics of the patterns of common factors extracte
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8. Aesthesiometric threshold changes over the course of a workshift in miners exposed to hand-arm vibration.
The objective of this study was to investigate whether aesthesiometric threshold changes occur over the course of a workshift in vibration exposed hard rock miners relative to workers unexposed to vibration during the shift. The subjects were 99 miners and 40 smelter workers; four subjects declined to participate and nine were excluded from the analysis beca
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9. Radiographic osteoarthrosis in the acromioclavicular joint resulting from manual work or exposure to vibration.
The hypothesis that manual work and exposure to vibration are antecedents to the development of osteoarthrosis was assessed employing a cross sectional study design. The frequency of osteoarthrosis in the acromioclavicular joint was studied in three groups of workers in the construction industry. Two groups were manual workers (54 bricklayers and 55 rock bla
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10. Vibrotactile sense and hand symptoms in blue collar workers in a manufacturing industry.
OBJECTIVES: To study whether vibrotactile sense combined with questionnaires (subjective complaints) and a clinical examination (including scoring of the Stockholm workshop scale (sensorineural staging)) could serve as a screening procedure, in the health care service, for sensorineural symptoms. A group of blue collar workers exposed to vibration in a manuf
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11. Hand-arm vibration syndrome among travertine workers: a follow up study.
In a six year follow up study of the handarm vibration syndrome, 62 stoneworkers operating hand held vibrating tools in 10 travertine quarries and mills were first investigated in 1985 and then in 1991. The frequency weighted acceleration of vibration from the rock drills and stone hammers used by the travertine workers exceeded 20 m/s2, indicating a hazardo