Ultrasonic Waves
Mostrando 1-12 de 50 artigos, teses e dissertações.
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1. Simulation of Current Pulses and Sound Waves Resulting from Partial Discharges in a Needle-Plane Geometry in Air
Abstract Partial discharges can occur in different types of electric equipment and cause progressive insulation deterioration, so there is interest in monitoring partial discharges for assessing the state of the isolation of an electric system and to predict failures. Techniques to detect partial discharges, such as detecting ultrasonic emission, have been p
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Dual-stage sugar substitution in Tommy Atkins mango
RESUMO A técnica de substituição de açúcar em dois estágios (D3S) foi utilizada para induzir a troca de açúcares na manga. Esta técnica envolve dois estágios, nos quais os açúcares de alto teor calórico são parcialmente removidos das amostras de frutas no primeiro estágio e, no segundo, açúcar de baixa caloria é incorporado à manga. Ondas
Rev. bras. eng. agríc. ambient.. Publicado em: 2019-01
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3. Peptidomic investigation of Neoponera villosa venom by high-resolution mass spectrometry: seasonal and nesting habitat variations
Abstract Background: Advancements in proteomics, including the technological improvement in instrumentation, have turned mass spectrometry into an indispensable tool in the study of venoms and toxins. In addition, the advance of nanoscale liquid chromatography coupled to nanoelectrospray mass spectrometry allows, due to its high sensitivity, the study of ve
J. Venom. Anim. Toxins incl. Trop. Dis. Publicado em: 26/03/2018
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4. Monitoring Heat Treatments in Steels by a Non Destructive Ultrasonic Method
In order to determine if heat treatments can be discerned by nondestructive ultrasonic testing, samples of SAE 1045 and SAE 4140 steels were subjected to the classical heat treatments of annealing, normalizing, quenching, and quenching and tempering, and their elastics constants, Young's, shear and Poisson's moduli, were monitored by ultrasound. Results show
Mat. Res.. Publicado em: 24/08/2017
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5. Ultrasonic method of microvibration detection: part II - additional processing method and applications
Abstract Introduction In the last 28 years, the scientific community has been using elastography to evaluate the mechanical properties of biological tissue. The aim of this work was the optimization of the UDmV method, presented in Part I of the series, by means of modifying the technique employed to generate the reference sine and cosine functions, used fo
Res. Biomed. Eng.. Publicado em: 17/08/2017
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6. Acoustic Birefringence and Poisson's Ratio Determined by Ultrasound: Tools to Follow-Up Deformation by Cold Rolling and Recrystallization
Poisson's ratio and birefringence, both measured by ultrasound, are used to follow the evolution of the anisotropy in ASTM A-36 steel plates cold-rolled between 5 and 50% deformation, and then subjected to recrystallization at 900 and 1000 ºC. Times of flight of longitudinal and shear waves along the thickness of the plates were measured. As orthotropy incr
Mat. Res.. Publicado em: 31/07/2017
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7. A magneto-motive ultrasound platform designed for pre-clinical and clinical applications
Abstract Introduction Magneto-motive ultrasound (MMUS) combines magnetism and ultrasound (US) to detect magnetic nanoparticles in soft tissues. One type of MMUS called shear-wave dispersion magneto-motive ultrasound (SDMMUS) analyzes magnetically induced shear waves (SW) to quantify the elasticity and viscosity of the medium. The lack of an established pres
Res. Biomed. Eng.. Publicado em: 12/01/2017
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8. Application of Ultrasound-Assisted Emulsification Microextraction Based on Applying Low Density Organic Solvents to the Extraction and Determination of Mononitrotoluenes in Water Samples
In this study, simple and efficient ultrasound-assisted emulsification microextraction (USAEME) based on applying low density organic solvents combined with gas chromatography-flame ionization detector (GC-FID) was developed for the preconcentration and determination of mononitrotoluenes (MNTs) in water samples. In this method, the fine droplets of toluen
J. Braz. Chem. Soc.. Publicado em: 2015-07
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9. Finite element simulation of laser generated ultrasound waves in aluminum plates
The Laser-Ultrasonic technique uses laser energy to generate ultrasound waves in various solids. This technique allows inspecting large structures. The generated ultrasound wave form is affected by features of laser pulse (wavelength, pulse duration, power density). The goal of this paper is to study the effects of laser parameters (rise time and beam radius
Lat. Am. j. solids struct.. Publicado em: 2014
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10. Preparation of refractory calcium aluminate cement using the sonochemical process
Calcium aluminate cements (CAC) were prepared using the sonochemical process, followed by heat treatment. A study was made of the action of ultrasonic waves and the influence of thermal treatment conditions on two initial molar compositions of 1:1 and 1:2 of calcia:alumina. The aqueous suspension containing the raw materials (A-50 alumina and CaO) was subjec
Mat. Res.. Publicado em: 22/03/2013
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11. Implementação de um algoritmo numérico para solução da equação de Christoffel generalizada em acustoelasticidade. / Implementation of a numerical algorithm for solution of the generalized Chistoffel equation in acoustoelasticity.
Extensive studies carried out in the last decades on the propagation of ultrasonic waves in solids led to the development of nondestructive techniques for the assessment of the safety and integrity of industrial structures and components. The interest in the application of ultrasound techniques for stress measurement for example comes from the measurable cha
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 31/08/2012
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12. Simulação da propagação de ondas ultrassônicas longitudinais em materiais estruturais aeroespaciais / Simulating the propagation of longitudinal ultrasonic waves in aerospace structural materials
The use of composite materials in the aerospace industry is increasing due to its low ratio between density and mechanical strength. To perform non-destructive testing using ultrasound, it is necessary to know the sound velocity in these materials. It is not always possible to manufacture physical prototypes during the development of a project because of tim
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/08/2012