43 research outputs found
Primary ethmoid sinus squamous cell carcinoma in a young adult man
In this case report we describe an aggressive primary ethmoid squamous cell carcinoma in an unusually young patient
Band offsets of metal oxide contacts on TlBr radiation detectors
Metal oxides are investigated as an alternative to metal contacts on thallium bromide (TlBr) radiation detectors. X-ray photoelectron spectroscopy studies of SnO 2/TlBr and ITO/TlBr devices indicate that a type-II staggered heterojunction forms between TlBr and metal oxides upon contacting. By using the Kraut method of valence band offset (VBO) determination, the VBOs of SnO 2/TlBr and ITO/TlBr heterojunctions are determined to be 1.05 ± 0.17 and 0.70 ± 0.17 eV, respectively. The corresponding conduction band offsets are then found to be 0.13 ± 0.17 and 0.45 ± 0.17 eV, respectively. The I-V response of symmetric In/SnO 2/TlBr and In/ITO/TlBr planar devices is almost Ohmic with a leakage current of less than 2.5 nA at 100 V
Clinical validation of the AMTAS automated audiometer
To validate the air- and bone-conduction AMTAS automated audiometry system. Design: Prospective study. Test-retest reliability was determined by assessing adults
with AMTAS air- and bone-conduction audiometry. Accuracy was determined by comparing AMTAS and manual audiometry conducted on adults. AMTAS testing was conducted
in a quiet room and manual audiometry in a sound booth. Study sample: Ten participants for test-retest reliability tests and 44 participants to determine accuracy were included.
Participants had varying degrees of hearing loss. Results: For test-retest reliability the overall difference in air-conduction hearing thresholds (n 119) was 0.5 dB. The spread of
differences (standard deviation of absolute differences) was 4.9 dB. For bone-conduction thresholds (n 99) the overall difference was 0.2 dB, and the spread of differences 4.5 dB.
For accuracy the overall difference in air-conduction hearing thresholds (n 509) between the two techniques was 0.1 dB. The spread of differences was 6.4 dB. For bone-conduction
thresholds (n 295) the overall difference was 0 dB, and the spread of differences 7.7 dB. Conclusions: Variations between air- and bone-conduction audiometry for automated and
manual audiometry were within normally accepted limits for audiometry. However, AMTAS thresholds were elevated but not signifi cantly different compared to other contemporary
studies that included an automated audiometer.http://informahealthcare.com/loi/ijahb201
Reduction of Defects in Germanium-Silicon
It is well established that crystals grown without contact with a container have far superior quality to otherwise similar crystals grown in direct contact with a container. In addition to float-zone processing, detached-Bridgman growth is often cited as a promising tool to improve crystal quality, without the limitations of float zoning. Detached growth has been found to occur quite often during microgravity experiments and considerable improvements of crystal quality have been reported for those cases. However, no thorough understanding of the process or quantitative assessment of the quality improvements exists so far. This project will determine the means to reproducibly grow Ge-Si alloys in the detached mode. Specific objectives include: (1) measurement of the relevant material parameters such as contact angle, growth angle, surface tension, and wetting behavior of the GeSi-melt on potential crucible materials; (2) determination of the mechanism of detached growth including the role of convection; (3) quantitative determination of the differences of defects and impurities among normal Bridgman, detached Bridgman, and floating zone (FZ) growth; (4) investigation of the influence of defined azimuthal or meridional flow due to rotating magnetic fields on the characteristics of detached growth; (5) control time-dependent Marangoni convection in the case of FZ-growth by the use of a rotating magnetic field to examine the influence on the curvature of the solid-liquid interface and the heat and mass transport; and (6) grow high quality GeSi-single crystals with Si-concentration up to 10 at% and diameters up to 20 mm
Band offsets of metal oxide contacts on TlBr radiation detectors
Metal oxides are investigated as an alternative to metal contacts on thallium bromide (TlBr) radiation detectors. X-ray photoelectron spectroscopy studies of SnO 2/TlBr and ITO/TlBr devices indicate that a type-II staggered heterojunction forms between TlBr and metal oxides upon contacting. By using the Kraut method of valence band offset (VBO) determination, the VBOs of SnO 2/TlBr and ITO/TlBr heterojunctions are determined to be 1.05 ± 0.17 and 0.70 ± 0.17 eV, respectively. The corresponding conduction band offsets are then found to be 0.13 ± 0.17 and 0.45 ± 0.17 eV, respectively. The I-V response of symmetric In/SnO 2/TlBr and In/ITO/TlBr planar devices is almost Ohmic with a leakage current of less than 2.5 nA at 100 V
Chronic rhinitis in South Africa – more than just allergy!
Chronic rhinitis is a troublesome condition for sufferers. It is tempting to label all patients with chronic nasal symptoms as having allergic
rhinitis (AR), but many such patients have other causes of chronic rhinitis that need a specific diagnosis and management strategy. Even
when the patient fully fits the definition of AR, their condition will be best served by combining medication with ongoing patient education.http://www.samj.org.zaam2021OtorhinolaryngologyPaediatrics and Child Healt