Mathew, K T; Robin, Augustine; Ullas, Kalappura G(Wiley InterScience, November , 2008)
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Abstract:
Hydroxyapatite (HAp, Ca10(PO4)6(OH)2) bioceramic and
chitosan (poly [( -1-4) D-glucosamine]) biopolymer show good biocompatibility
in vivo. They have biological origin and show excellent interactions
with microwave. Microwave study of HAp made using different
drying techniques and their composites with chitosan in the ISM band is
presented. Pastes are made using HAp and chitosan with different ratios
of mixing. The dielectric properties of this composites match with that of
human fat, collagen tissues. Some of the compositions exhibit dielectric
property close to that of natural bone. This makes them more
biocompatible and better substitutes for natural bone. Thus composite
bioceramics can be considered as phantom model constituents for
imaging purposes. Their dielectric properties prove that they are
biocompatible.
Monz, Cabrera J; Diaz, Morcillo A; Pedreno, Molina L; Sanchez, Hermandez D(Microwave and Optical Technology Letters, February 4, 2004)
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Abstract:
Usage of a dielectric multilayer around a dielectric Sample
is studied as a means for improving the efficiency in multimode microwave-
heating cavities. The results show that by using additional dielectric
constant layers the appearance of undesired reflections at the
sample-air interface is avoided and higher power -absorption rates
within the sample and high -efficiency designs are obtained
HIV/AIDS is one of the most destructive epidemics in
ever recorded history claims an estimated 2.4 –3.3 million lives every
year. Even though there is no treatment for this pandemic Elisa and
Western Blot tests are the only tests currently available for detecting
HIV/AIDS. This article proposes a new method of detecting HIV/AIDS
based on the measurement of the dielectric properties of blood at the
microwave frequencies. The measurements were made at the S-band of
microwave frequency using rectangular cavity perturbation technique
with the samples of blood from healthy donors as well as from HIV/AIDS patients. An appreciable change is observed in the dielectric properties
of patient samples than with the normal healthy samples and these
measurements were in good agreement with clinical results. This measurement
is an alternative in vitro method of diagnosing HIV/AIDS using microwaves.
Anantharaman, M R; Muhammad, Abdul Jamal E; Joy, P A; Philip, Kurian(Elsevier, January 3, 2010)
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Abstract:
Nickel nanocomposites were prepared by incorporating nickel nanoparticles in a neoprene matrix according
to a specific recipe for various loadings of nickel particles. The dielectric properties of these composites
were evaluated for different frequencies ranging from 100 kHz to 8MHz at different temperatures from
30 ◦C to 120 ◦C. The dielectric permittivity increases with increase of nickel concentration. Increase in
temperature enhances the permittivity initially, till 40 ◦C and thereafter the permittivity decreases. The
dielectric loss exhibits relaxation peaks and the peaks shift to lower frequencies with increase in volume
fraction of the nickel nanoparticles in the matrix. The evaluation of magnetic and dielectric properties
of these composites suggests that the dielectric permittivity can be tailored by an appropriate loading of
the filler using semi-empirical equations and the magnetic properties vary according to simple mixture
equations
Description:
Materials Chemistry and Physics 121 (2010) 154–160
Microwave dielectric ceramics based on GdTiNb,-,.Ta,O6 and Sml _.,Y,TiTa06 have been prepared by conventional solid state
method . The GdTiTaO6 and SmTiTaO6 have aeschenite structure with positive rr and GdTiNbO6 and YTiTaO6 have euxenite
structure with negative rr. The rr of the ceramics has been tuned by preparing solid solution phases between the aeschynites and
euxenites for a possible zero rr material . It is observed that GdTiNbt_YTa.,O6 undergoes a phase transition from aeschynite to
euxenite when x=0.75 and in Sml-,YxTiTa06 for x= 0.73. The microwave dielectric properties change abruptly near the transition
region . The rr value approaches zero near the phase transition region while the samples have poor sinterability and poor quality
factor . The unloaded quality factor, dielectric constant and the sign of rr of the solid solution phases are found to depend on the
average ionic radius of the rare earth ion in RE ,-5RE',TiTaO6. The boundary of the euxenite-aeschynite phase transition occurs at
an average ( RE) ionic radius of 0.915 A in Sm,_, Y,.TiTaO6 solid solution phases