earthquakes travel times inversion for determination of velocity structure of crust is one of the most important objectives in seismology. in the simultaneous inversion method, the parameters of earthquakes and velocity model are determined initially and are improved during inversion steps. in this study, we have used more than 22000 calculated travel times for first arrivals of 6000 earthquake...

detection of subsurface structures by means of gravity method can be used to determine mass distribution and density contrast of rock units. this distribution could be detected by different geophysical methods, especially gravity method. however, gravity techniques have some drawbacks and can't be always successful in distinguishing subsurface structures. performance of the gravity technique co...

background: pulse wave velocity (pwv) is widely used for estimating the stiffness of an artery. v arious invasive and non-invasive methods have been developed to determine pwv over the years. in the present research , the non-invasive estimation of the pwv of large arteries was used as an index for arterial stiffness. methods: a dynamic model based on the navier-stokes equations coupled to elas...

this study investigated the influence of nanoclay on the impact damage resistance of glass fiber-epoxy composites under high velocity ice impact loading. addition of 0.5 wt. % nanoclay into epoxy was shown to improve damage resistance compared to composite plates having no nanoclay platelet. the glass fiber-epoxy composites containing nanoclay brought about substantial improvement in ice impact...

this paper presents the prediction of vehicle's velocity time series using neural networks. for this purpose, driving data is firstly collected in real world traffic conditions in the city of tehran using advance vehicle location devices installed on private cars. a multi-layer perceptron network is then designed for driving time series forecasting. in addition, the results of this study a...

the objective of the present study was to examine the effects of chilling period on semen quality of sannan and jamunapari. semen of goat breeds were collected with artificial vagina and chilled at 5-9˚c. volume, colour and ph were determined on fresh semen. after dilution, microscopic examination was performed for the progressive motility and sperm viability. diluted semen of both breed was co...

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...

accurate measurements of physical characteristics of bone are essential for diagnosis, assessment of change following treatment, and therefore, indirectly, for evaluation of new forms of therapy. this is particularly true of osteoporosis and aging skeleton, in which fractures occur easily. methods: in this study an ultrasonic system was set-up and calibrated on plexiglas tubes of variable thick...