نتایج جستجو برای: ultrasonic velocity measurement

تعداد نتایج: 596055  

2004
Joseph N. Zalameda Mark K. Hinders

In a composite the matrix distributes the load onto and between the fibers. It is therefore important to know the volume fraction of fibers to ensure proper load distribution and predicted structural performance. The most common method of determining composite fiber volume fraction (FVF) involves removal of the matrix by burn off or acid digestion. While estimates of the fiber, matrix and void ...

Journal: :Ultrasonics 2013
J Pierre F Elias V Leroy

We describe an experimental setup specifically designed for measuring the ultrasonic transmission through liquid foams, over a broad range of frequencies (60-600kHz). The question of determining the ultrasonic properties of the foam (density, phase velocity and attenuation) from the transmission measurements is addressed. An inversion method is proposed, tested on synthetic data, and applied to...

1997
J. Dorighi S. Krishnaswamy J. Achenbach

A fiber optic ultrasonic system is described which monitors the cure of an epoxy resin. Ultrasound is generated using a high-power optical fiber to deliver high-energy pulses of light to the prepared surface of an aluminum mold that contains the curing epoxy resin. The generated ultrasound is detected using a local fiber optic ultrasound sensor embedded in the curing epoxy resin. The system was...

Low transmission of heat is one of the major problems for heat exchanger fluids in many industrial and scientific applications. This includes cooling of the engines, high power transformers to heat exchangers in solar hot water panels or in refrigeration systems. In order to tackle these problems in thermal industries, nanofluids could play a significant role as excellent heat exchanger materia...

Nowadays, the better performance of lightweight structures during earthquake has resulted in using lightweight concrete more than ever. However, determining the compressive strength of concrete used in these structures during their service through a none-destructive test is a popular and useful method.  One of the main methods of non-destructive testing in the assessment of compressive strength...

2009
J. B. Santos M. G. Rasteiro Fernando A. P. Garcia P. M. Faia R. Silva A. R. Ferreira

This work aimed to contribute to the modelling of slurry flows in horizontal pipes supported by experimental data gathered in a well instruments pilot rig. An ultrasonic sensor system was inserted in the pipe in order to calculate the slurry velocity profiles using a time domain correlation method. Effects of particles concentrations and slurry flow rates were investigated. A comparison of the ...

Flavonoids, are a large class of polyphenols, with more than 4000 combinations. They have an antioxidant role in plant photosynthesis and in the human body they optimally act as an antioxidant, anti-inflammatory, anticancer and protector of the heart. Quercetin is in the flavonol group that is used to fight protection specifically against viruses and cancer cells. In this study, Comparison of e...

دهقان منشادی, فریده, فقیه زاده گرجی, ایمان, میکائیلی, سعید,

Background and purpose: Middle Trapezius Muscle (MTM) is a key muscle in maintaining postural stability of the shoulder but it has received less attention in research. This study aimed to measure the ultrasonic thickness of the MTM in non-athlete healthy young men. Also, inter-rater repeatability in measuring ultrasonic thickness of this muscle was calculated. Materials and methods: A fundam...

2003
T. A. Andreeva

The paper is devoted to the experimental investigation of the statistical characteristics of the grid-generated turbulence produced in a wind tunnel. Ultrasonic time-of-flight method using dual transducers is utilized to develop a methodology for determination of the correlation functions of turbulent velocity and sound speed fluctuations. The ultrasonic flowmeter equation is considered in the ...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید