The y-ray tomographic sensor invented by the CastScan consortium at MIT for the non-invasive real time monitoring of the solidification front in the continuous casting of metals is a new industrial computed tomography (CT) tool. The sensor potentially offers great economic benefits to the continuous casting industry by preventing break-outs, and increasing productivity and efficiency through op...

4 Abstract — Satellite communication systems operating at Ku (12/14 GHz) and Ka band (20/30 GHz) frequencies are used for broadband multimedia and internet based services. At these frequencies, the signal will be affected by various propagation impairments such as rain attenuation, cloud attenuation, tropospheric scintillation, ionospheric scintillation, water vapour attenuation, and rain and i...

OBJECTIVES: To review the computed tomography (CT) findings of common and uncommon high-attenuation pulmonary lesions and to present a classification scheme of the various entities that can result in high-attenuation pulmonary abnormalities based on the pattern and distribution of findings on CT. BACKGROUND: High-attenuation pulmonary abnormalities can result from the deposition of calcium or,...

BACKGROUND Attenuation correction of a single photon emission computed tomography (SPECT) image is possible using computed tomography (CT)-based attenuation maps with hybrid SPECT/CT. CT attenuation maps acquired during breath holding can be misaligned with SPECT, generating artifacts in the reconstructed images. The purpose of this study was to investigate the effects of respiratory phase duri...

in many seismological applications, the earth is considered as a perfectly elastic, homogeneous, and isotropic body. although this assumption is approximately valid, it is known that seismic waves pass through the real earth that is anelastic, inhomogeneous and anisotropic.  we consider four processes that can reduce wave amplitude, i.e.: geometrical spreading, scattering, multi-pathing, and an...

In this paper, the link quality in SHF and EHF ranges are studied. In order to achieve high data rate higher frequencies must be used – centimeter waves (SHF), millimeter waves (EHF) or optical range. However, there are significant problem when a radio link work in that diapason – rain attenuation and attenuation in earth’s atmosphere. Based on statistical rain rates data for Bulgaria, the link...

Little information is available regarding triple-phase computed tomography (CT) of canine pancreatic insulinoma. A few case reports with small numbers of cases have indicated that hyper-attenuation in the arterial phase was a common finding on multi-phasic CT in dogs with insulinoma. Our purpose was to clarify the characteristic findings of dogs with insulinoma on triple-phase CT. Nine dogs wit...

BACKGROUND Generally, attenuation correction is made by incorporating a linear attenuation coefficient, which is based on the attenuation coefficient map (mu-map) created from a computed tomography scan, into the ordered subsets-expectation maximization reconstruction method in non-uniform domains. A non-uniform Chang's attenuation correction method that uses the mu-map created from a computed ...

Depressive symptoms and alcohol use are frequently positively associated during adolescence. This study aimed to assess the heritability of each phenotype across adolescence; to assess potential shared liabilities; to examine changes in the nature of shared liabilities across adolescence; and to investigate potential causal relationships between depressive symptoms and alcohol use. We studied a...

Background Chronic respiratory symptoms are common among children living with human immunodeficiency virus (HIV). We investigated the radiological features of chronic lung disease in children aged 6-16 years receiving antiretroviral therapy for ≥6 months in Harare, Zimbabwe. Methods Consecutive participants from a HIV clinic underwent clinical assessment and chest radiography. Participants wi...