scholarly journals Application of Temperature-Dependent Fluorescent Dyes to the Measurement of Millimeter Wave Absorption in Water Applied to Biomedical Experiments

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Nataliia Kuzkova ◽  
Oleksandr Popenko ◽  
Andrey Yakunov
Keyword(s):  
Millimeter Wave ◽  
Millimeter Waves ◽  
Temperature Effects ◽  
Fluorescent Dyes ◽  
Organic Dyes ◽  
Temperature Dependent ◽  
Wave Absorption ◽  
Biological Objects ◽  
Novel Method ◽  
Local Temperature Increase

Temperature sensitivity of the fluorescence intensity of the organic dyes solutions was used for noncontact measurement of the electromagnetic millimeter wave absorption in water. By using two different dyes with opposite temperature effects, local temperature increase in the capillary that is placed inside a rectangular waveguide in which millimeter waves propagate was defined. The application of this noncontact temperature sensing is a simple and novel method to detect temperature change in small biological objects.

scholarly journals A Novel Method for Prediction of Attenuation of Millimeter Waves by Fog and Smoke

2019 ◽  
Vol 8 (3) ◽  
pp. 2080-2085
Keyword(s):  
Wave Propagation ◽  
Water Vapor ◽  
Radio Wave ◽  
Millimeter Wave ◽  
Millimeter Waves ◽  
The Other ◽  
Radio Waves ◽  
Weather Phenomenon ◽  
Novel Method ◽  
And Diffusion

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.

scholarly journals Temperature Characterization of Liquid Crystal Dielectric Image Line Phase Shifter for Millimeter-Wave Applications

Crystals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 63
Author(s):  
Henning Tesmer ◽  
Rani Razzouk ◽  
Ersin Polat ◽  
Dongwei Wang ◽  
Rolf Jakoby ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Millimeter Wave ◽  
Insertion Loss ◽  
Phase Shifter ◽  
Ground Plane ◽  
Temperature Dependent ◽  
Differential Phase ◽  
Dependent Behavior ◽  
The Impact ◽  
Temperature Dependent Behavior

In this paper we investigate the temperature dependent behavior of a liquid crystal (LC) loaded tunable dielectric image guide (DIG) phase shifter at millimeter-wave frequencies from 80 GHz to 110 GHz for future high data rate communications. The adhesive, necessary for precise fabrication, is analyzed before temperature dependent behavior of the component is shown, using the nematic LC-mixture GT7-29001. The temperature characterization is conducted by changing the temperature of the LC DIG’s ground plane between −10∘C and 80 ∘C. The orientation of the LC molecules, and therefore the effective macroscopic relative permittivity of the DIG, is changed by inserting the temperature setup in a fixture with rotatable magnets. Temperature independent matching can be observed, while the insertion loss gradually increases with temperature for both highest and lowest permittivity of the LC. At 80 ∘C the insertion loss is up to 1.3dB higher and at −10∘C it is 0.6dB lower than the insertion loss present at 20 ∘C. In addition, the achievable differential phase is reduced with increasing temperature. The impact of molecule alignment to this reduction is shown for the phase shifter and an estimated 85% of the anisotropy is still usable with an LC DIG phase shifter when increasing the temperature from 20 ∘C to 80 ∘C. Higher reduction of differential phase is present at higher frequencies as the electrical length of the phase shifter increases. A maximum difference in differential phase of 72∘ is present at 110 GHz, when increasing the temperature from 20 ∘C to 80 ∘C. Nevertheless, a well predictable, quasi-linear behavior can be observed at the covered temperature range, highlighting the potential of LC-based dielectric components at millimeter wave frequencies.

Millimeter-wave absorption properties of BaTiO3/Co3O4 composite powders controlled by high-frequency resonances of permittivity and permeability

2018 ◽  
Vol 6 (47) ◽  
pp. 12965-12975 ◽  
Author(s):  
Wei Tian ◽  
Ruoyang Ma ◽  
Jian Gu ◽  
Zongrong Wang ◽  
Ning Ma ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
High Frequency ◽  
Composite Powders ◽  
Absorption Properties ◽  
Wave Absorption ◽  
Wave Resonance ◽  
Permittivity And Permeability ◽  
5 Ghz

Millimeter-wave resonance of permittivity–permeability-contributed double absorption peaks in BaTiO3/Co3O4, exhibiting RL of ∼−40 dB and a bandwidth of 5 GHz around 35 GHz.

Millimeter wave absorption spectra of biological samples

1980 ◽  
Vol 1 (3) ◽  
pp. 285-298 ◽  
Author(s):  
O. P. Gandhi ◽  
M. J. Hagmann ◽  
D. W. Hill ◽  
L. M. Partlow ◽  
L. Bush
Keyword(s):  
Absorption Spectra ◽  
Millimeter Wave ◽  
Biological Samples ◽  
Wave Absorption

Low-cost palladium decorated on m-aminophenol-formaldehyde-derived porous carbon spheres for the enhanced catalytic reduction of organic dyes

2018 ◽  
Vol 5 (2) ◽  
pp. 354-363 ◽  
Author(s):  
Pitchaimani Veerakumar ◽  
I. Panneer Muthuselvam ◽  
Pounraj Thanasekaran ◽  
King-Chuen Lin
Keyword(s):  
Porous Carbon ◽  
Catalytic Reduction ◽  
Organic Dyes ◽  
Low Cost ◽  
Carbon Spheres ◽  
Novel Method ◽  
Porous Carbon Spheres

A novel method for the synthesis of recyclable Pd@PCS catalyst was applied for the reduction of CV, EY, and SY.

Laboratory Results on Millimeter-Wave Absorption in Silicate Grain Materials at Cryogenic Temperatures

1996 ◽  
Vol 462 ◽  
pp. 1026 ◽  
Author(s):  
N. I. Agladze ◽  
A. J. Sievers ◽  
S. A. Jones ◽  
J. M. Burlitch ◽  
S. V. W. Beckwith
Keyword(s):  
Millimeter Wave ◽  
Cryogenic Temperatures ◽  
Wave Absorption ◽  
Laboratory Results
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