Acoustic Emission
Mostrando 13-24 de 62 artigos, teses e dissertações.
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13. Cochlear function in ultra-high frequencies in parents of individuals with autosomal recessive hearing loss / Função coclear em frequências ultra-altas em pais de indivíduos com deficiência auditiva autossômica recessiva
INTRODUCTION: In nonsyndromic hearing loss of recessive autosomal heritage, caused by changes in the gene GJB2 (Gap Junction Bet-2 Protein), parents of individuals with hearing loss are heterozygous carriers of a recessive allele which causes deafness, however, are asymptomatic, but may present early and mild hearing changes. OBJECTIVE: Assessing the cochlea
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 14/12/2012
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14. Statistical analysis of acoustic emission signals generated during turning of a metal matrix composite
Acoustic emission technique (AET) has been used to monitor the progress of tool wear during turning of silicon carbide (20 wt.%) dispersed Al alloy metal matrix composite. Acoustic emission (AE) signals generated beyond a specific cutting distance increase abruptly. Statistical analysis based on assumed β distribution of AE energy showed that skewness and k
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2012-06
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15. Determination of the relative position between grinding wheel and a cylindrical workpiece on a 7 axis grinding machine by acoustic emission
The contact between grinding wheel and workpiece in the grinding process is recognized by acoustic emission (AE). Two acoustic emission monitoring systems (MS) were integrated into a 3 axis CNC grinding machine. A laptop allows the signal acquisition and visualization. The acquired AE RMS signals from the contact between tool and workpiece are analyzed permi
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2012-03
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16. Employment of acoustic field for pollutant emission reduction under lean combustion
Pulsating combustion is a technique that directly intervenes in combustion processes modifying pollutant emissions and increasing thermal efficiency by varying pressure and temperature in the flame region. The pulsations accelerate mixture rate between oxidant and fuel, resulting in a more intense combustion process, with low fuel waste and potential for low
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 13/07/2011
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17. MONITORING FLEXIBLE RISERS WITH OPTICAL FIBER SENSORS / MONITORAMENTO DE RISERS FLEXÍVEIS COM SENSORES A FIBRA ÓPTICA
The interest in structural health monitoring of flexible risers has grown significantly in recent years. For ducts that are already reaching their design life, monitoring systems can provide early warnings of potential failures and also assist the operator in scheduling downtime. Different techniques are being tested by operators of flexible pipes such as au
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/04/2011
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18. Aplicabilidad del monitoreo de emisiones del arco eléctrico para el control de calidad en el proceso MAG-S
Ensuring quality in welding is not a trivial task. For this purpose several quality control checks are performed, at the expense, costs and production times are increased. There are several automated welding systems and they are assisted by control systems based on monitoring of welding parameters. However, automated quality monitoring systems are limited an
Soldagem & Inspeção. Publicado em: 2011-12
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19. Uncooled detectors of continuum terahertz radiation
THz continuum spectral photometry has new and unique applications in different civil and military areas presenting a number of distinctive advantages on the well known microwaves or mid- to near-infrared technologies. THz sensing is essential to investigate the emission mechanisms by high energy particle acceleration processes. Technical challenges appear to
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2011-06
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20. Análise de criticidade de descontinuidade em um bocal de um vaso de pressão
Pressure vessels and pipes are essential equipment in the chemical, petrochemical, petroleum refining, among others. The safety operation of this equipment is an important aspect, since failures can vary from large financial losses to catastrophic consequences. Evaluation discontinuity found in inspections can be perfomed by fitness for service methodology w
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 2011
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21. Influence of optimized lubrication-cooling and minimum quantity lubrication on the cutting forces, on the geometric quality of the surfaces and on the micro-structural integrity of hardened steel parts
The is paper presents an analysis of the influence of minimum quantity lubrication (MQL), optimized and conventional cooling, using different cutting fluid volumes and flow rates, on the surface quality and integrity of hardened steel workpieces, in cylindrical plunge grinding with superabrasive CBN grinding wheels. The final quality of the workpieces were e
Matéria (Rio de Janeiro). Publicado em: 2011
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22. Padrões de emissão acústica em moscas-das-frutas do gênero Anastrepha (Diptera: Tephritidae) e suas implicações no isolamento reprodutivo pré-copulatório / Acoustic emission patterns in fruit flies of genus Anastrepha (Diptera: Tephritidae) and precopulatory reproductive isolation
Três tipos de sons de cortejo foram descritos para machos de tefritídeos: de chamada, na ausência de fêmeas; de aproximação, na proximidade de fêmeas; e de pré-cópula, após a monta das fêmeas pelos machos. Nas espécies do gênero Anastrepha em que foram registrados sons de acasalamento, somente dois tipos estão presentes: de chamada e de précó
Publicado em: 2011
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23. Entrenamiento del vibrato en cantantes
BACKGROUND: vocal vibrato is one of the most important acoustic, technical and stylistic features to characterize the voice quality in classical singers. Technically, vibrato is a pulsation of pitch, usually accompanied with synchronous pulsations with intensity and timbre. Vibrato can be described acoustically by the rate, extent and periodicity of frequenc
Revista CEFAC. Publicado em: 23/07/2010
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24. Analysis of forecasting capabilities of ground surfaces valuation using artificial neural networks
Industry worldwide has been marked by intense competition in recent years, placing companies under ever increasing pressure to improve the efficiency of their product processes. In addition to efficiency, precision is an extremely important factor, allowing companies to maintain standards and procedures aligned with international standards. One of the finish
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2010-06