Errata to “A Novel Method of Predicting Site Dependent Specific Rain Attentuation of Millimeter Radio Waves”

2004 ◽  
Vol 52 (1) ◽  
pp. 353-353
Author(s):  
W. Asen ◽  
T. Tjelta
Keyword(s):  
2019 ◽  
Vol 8 (3) ◽  
pp. 2080-2085

Terrestrial radio wave link faces various challenges like attenuation caused by gases, water vapor and other weather phenomenon like rain, storms, snow, fog, cloud etc. These challenges are responsible for absorption and diffusion of energy. Another kind of obstacles observed by the radio waves on terrestrial path is vegetation, lamppost, grills and other urban constructions. Different phenomenon is studied under these conditions like reflection, diffraction, refraction, scattering, depolarization etc. In case of millimeter waves various propagation studies has been performed under different scenarios. More propagation studies are needed to be done especially for fog. In this paper radio wave propagation studies are performed for fog using proposed fog model and results are compared with the other model proposed in the Literature. Another propagation study is performed for smoke which is unique of its kind. This study indicates that even smoke can causes attenuation for millimeter wave frequencies.


1994 ◽  
Vol 144 ◽  
pp. 21-28 ◽  
Author(s):  
G. B. Gelfreikh

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.


Author(s):  
M.A. Gregory ◽  
G.P. Hadley

The insertion of implanted venous access systems for children undergoing prolonged courses of chemotherapy has become a common procedure in pediatric surgical oncology. While not permanently implanted, the devices are expected to remain functional until cure of the primary disease is assured. Despite careful patient selection and standardised insertion and access techniques, some devices fail. The most commonly encountered problems are colonisation of the device with bacteria and catheter occlusion. Both of these difficulties relate to the development of a biofilm within the port and catheter. The morphology and evolution of biofilms in indwelling vascular catheters is the subject of ongoing investigation. To date, however, such investigations have been confined to the examination of fragments of biofilm scraped or sonicated from sections of catheter. This report describes a novel method for the extraction of intact biofilms from indwelling catheters.15 children with Wilm’s tumour and who had received venous implants were studied. Catheters were removed because of infection (n=6) or electively at the end of chemotherapy.


GeroPsych ◽  
2012 ◽  
Vol 25 (4) ◽  
pp. 235-245 ◽  
Author(s):  
Katja Franke ◽  
Christian Gaser

We recently proposed a novel method that aggregates the multidimensional aging pattern across the brain to a single value. This method proved to provide stable and reliable estimates of brain aging – even across different scanners. While investigating longitudinal changes in BrainAGE in about 400 elderly subjects, we discovered that patients with Alzheimer’s disease and subjects who had converted to AD within 3 years showed accelerated brain atrophy by +6 years at baseline. An additional increase in BrainAGE accumulated to a score of about +9 years during follow-up. Accelerated brain aging was related to prospective cognitive decline and disease severity. In conclusion, the BrainAGE framework indicates discrepancies in brain aging and could thus serve as an indicator for cognitive functioning in the future.


1933 ◽  
Vol 148 (5) ◽  
pp. 272-273 ◽  
Author(s):  
J. H. Davis
Keyword(s):  

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