نتایج جستجو برای: ultrasonic velocity

تعداد نتایج: 167684  

Journal: :ماشین های کشاورزی 0
رسول معمار دستجردی سعید مینایی محمد هادی خوش تقاضا

development of ultrasound technique has not been progressing for evaluating the internal quality of fruits as fast as that of processed foods. in this research for quality assessment of pear fruit (shah miveh variety) an ultrasonic measurement system was constructed to transmit and receive the ultrasonic waves. the apparatus included a pulser-receiver, a pair of 75 khz ultrasonic transducers wi...

Journal: :iranian journal of radiation research 0
mokhtari-dizadji department of medical physics, tarbiat modarres university, tehran, iran m. vahed m. gity

background: ultrasound propagation velocity was measured experimentally in normal, fibroadenoma and ductal carcinoma breast tissues, in order to distinguish normal breast tissue from tumors. materials and methods: in quantitative measurements of ultrasound velocity, 403 breast tissue images were selected, comprising 130 normal breast tissue, 130 fibroadenoma, and 143 ductal carcinoma tumors. th...

Journal: :medical journal of islamic republic of iran 0
mb tavakoli from the department of medical physics and medical engineering, school of medicine, isfahan

currently available non-invasive clinical methods for diagnosing osteoporosis are mainly associated with ionizing radiation. ultrasonic assessment of bone disease is a more recent technology. a theoretical explanation for the relationship between ultrasonic parameters and bone structure is necessary. thus, two types of bone samples of perspex (hap) and perspex-glass beads were produced. each ty...

2014
Giovanna Concu Barbara De Nicolo Monica Valdes

The aim of this study was to evaluate ultrasonic P-wave velocity as a feature for predicting some physical and mechanical properties that describe the behavior of local building limestone. To this end, both ultrasonic testing and compressive tests were carried out on several limestone specimens and statistical correlation between ultrasonic velocity and density, compressive strength, and modulu...

MB TAVAKOLI,

Currently available non-invasive clinical methods for diagnosing osteoporosis are mainly associated with ionizing radiation. Ultrasonic assessment of bone disease is a more recent technology. A theoretical explanation for the relationship between ultrasonic parameters and bone structure is necessary. Thus, two types of bone samples of perspex (HAP) and perspex-glass beads were produced. Ea...

2012
Chunyu Yu Chao Guo Jia-yi Liang Tong Wang

According to the shortcomings of the existing ultrasonic wind velocity measurement device, for instance, complexity of circuit and difficulty of signal processing, a new ultrasonic wind velocity measurement is put forward based on phase discrimination and a new sensor configuration as well. Thus, a system model is built. Firstly, an equilateral triangle should be constituted by an ultrasonic em...

2014
Seunghee Park Junkyeong Kim

In this study, two kinds of nondestructive evaluation (NDE) techniques (rebound hardness and ultrasonic pulse velocity methods) are investigated for the effective maintenance of underwater concrete structures. A new methodology to estimate the underwater concrete strengths more effectively, named “artificial neural network (ANN) – based concrete strength estimation with the combination of rebou...

2004
Anish Kumar Baldev Raj

Ultrasonic measurements have been performed for comprehensive microstructural characterisation in 9 % Cr ferritic steels. The variation in grain size, the effect of solution annealing temperature on microstructure developed, the variation in microstructure of the weld joints, the effect of post weld heat treatment and precipitation behaviour during thermal ageing and creep testing have been suc...

2014
M Jiri Brozovsky

Modulus of elasticity is one of the important parameters of construction materials, which considerably influence their deformation properties and which can also be determined by means of non-destructive test methods like ultrasonic pulse method. However, measurement results of ultrasonic pulse methods are influenced by various factors, one of which is the natural frequency of the transducers. T...

2015
M A Amer

Ultrasonic properties of materials present a strong dependence on temperature and in turn the ultrasonic velocity of propagation in the material under test. It is precisely for this reason that most ultrasonic measurements are often carried out with thermostated samples by using either water tanks or climate chambers. This approach is viable in a laboratory and when the measured or characterize...

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