The formation of burn-scar tissue in human skin profoundly alters, among other things, the structure of the dermis. We present a method to characterize dermal scar tissue by the measurement of the near-infrared attenuation coefficient using optical coherence tomography (OCT). To generate accurate en face parametric images of attenuation, we found it critical to first identify (using speckle dec...

The aim of this paper was twofold: first, to present a virtual instrument for characterization of the cataract severity in the lens of the eye, based on the indirect measurements of ultrasound attenuation coefficient, second, to evaluate the instrument in vitro by assessment of measurement errors in case of the four different phantoms with a priory known characteristics (pure water, castor oil,...

Density is an important parameter to determine the strength of road, and it will ensure the safety of the use as well as maintaining the quality of road pavement. In this paper, the validation of GPR mixture model based on the microwave nondestructive free space method to determine the density of road pavement typed Hot Mix Asphalt (HMA) will be presented. The frequency range of operation used ...

Epidemiologic studies have demonstrated that physical inactivity is an important determinant of numerous chronic diseases. However, self-reported estimates of physical activity contain measurement errors responsible for attenuating relative risk estimates. A validation study conducted in 2002–2003 at the Alberta Cancer Board (Canada) included a physical activity questionnaire, four 7-day physic...

Using a broadband through-transmission technique, the attenuation coefficient and phase velocity spectra have been measured for a set of multi-wall carbon nanotube (MWCNT)-nylon composites (from pure nylon to 20% MWCNT by weight) in the ultrasonic frequency band from 4 to 14 MHz. The samples were found to be effectively homogeneous on spatial scales from the low end of ultrasonic wavelengths in...

In this research project cosmic ray data will be used to measure signal attenuation and check the geometrical efficiency of the trigger along the G scintillators. For an equal amount of energy lost in the scintillator, the amplitude of the detected signal varies as the hit location along the scintillator varies. Particles that strike the scintillators cause the material to emit photons. The int...

This work presents a monolithic DC~4GHz 6-bit digital attenuator with low insertion phase shift and attenuation error. Based on GaAs E/D pHEMT process, a serial-to-parallel converter is introduced to decrease the control pads of the chip. In the 16dB attenuation bit, a switched-path-type topology is employed in order to extend the bandwidth and achieve low insertion phase shift. The attenuator ...

PURPOSE Conventional clear cell renal cell carcinoma (ccRCC) and papillary renal cell carcinoma (pRCC) have different behavioral characteristics and clinical management strategies (nephrectomy vs. nephron-sparing surgery). Our aim was to retrospectively evaluate the contrast enhancement pattern of ccRCC and pRCC and evaluate its possible diagnostic role for preoperative differentiation using a ...

OBJECTIVE To evaluate how changes in lung volume affect volumetric measurements of lung nodules using a multi-detector row CT. MATERIALS AND METHODS Ten subjects with asthma or chronic bronchitis who had one or more lung nodules were included. For each subject, two sets of CT images were obtained at inspiration and at expiration. A total of 33 nodules (23 nodules > or =3 mm) were identified a...

Epidemiologic studies have demonstrated that physical inactivity is an important determinant of numerous chronic diseases. However, self-reported estimates of physical activity contain measurement errors responsible for attenuating relative risk estimates. A validation study conducted in 2002-2003 at the Alberta Cancer Board (Canada) included a physical activity questionnaire, four 7-day physic...