scholarly journals A Transmission-Based Dielectric Property Probe for Clinical Applications

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3484 ◽  
Author(s):  
Paul Meaney ◽  
Tomas Rydholm ◽  
Helena Brisby
Keyword(s):  
Dielectric Properties ◽  
Dielectric Property ◽  
Measurement Technique ◽  
Clinical Applications ◽  
Clinical Implementation ◽  
Compact Spaces ◽  
Low Profile ◽  
Typical Range ◽  
Initial Results ◽  
Good Agreement

We have developed a transmission-based, open-ended coaxial dielectric probe that can be used in clinical situations and overcomes many of the limitations related to the typical reflection-based dielectric probes. The approach utilizes the low profile, open-ended coaxial cables enabling clinicians to still probe relatively compact spaces. The sensing depth can be extended to as large as 1.5 to 2 cm compared with the more typical range of 0.3 mm for conventional probes and is dramatically less affected by measurement technique variability including poor sample contact and cable bending. As a precursor to an actual clinical implementation, we study the technique in a range of homogeneous liquids with substantially varying dielectric properties. The initial results demonstrate good agreement between the transmission-based probe and commercial, reflection-based probes and pave the way for more substantial clinical implementation.

Density Dependence of High Temperature Dielectric Properties of Debased Alumina and the Effect of a High Loss Additive

1994 ◽  
Vol 347 ◽  
Author(s):  
N. G. Evans ◽  
M. G. Hamlyn
Keyword(s):  
High Temperature ◽  
Dielectric Properties ◽  
Dielectric Property ◽  
Density Dependence ◽  
Measurement Technique ◽  
Process Technology ◽  
High Loss ◽  
Property Data ◽  
Powder Samples ◽  
Property Measurement

Research into microwave firing at Staffordshire University has been carried out since 1988 and dielectric property measurements have been used to help in developing process technology. The dielectric property measurement technique (cavity perturbation [1]) is that designed by Atomic Energy of Canada Ltd (A.E.C.L) [2]. The technique was chosen because of it's ability to analyse powder samples as well as solids. In order for dielectric property data to be of use in developing microwave processing, measurements have to be made on the starting materials of the process (i.e powders). When measurements are made on powders it is important to quote the bulk density at which the measurement was made since dielectric properties vary with density as well as frequency and temperature.

A low-profile FSS-based high capacity chipless RFID tag for sensing and encoding applications

2021 ◽  
pp. 1-9
Author(s):  
Shahid Habib ◽  
Amjad Ali ◽  
Ghaffer Iqbal Kiani ◽  
Wagma Ayub ◽  
Syed Muzahir Abbas ◽  
...  
Keyword(s):  
Radio Frequency Identification ◽  
High Capacity ◽  
Frequency Selective Surface ◽  
Rfid Tag ◽  
Sensing Applications ◽  
Low Profile ◽  
Simple Geometry ◽  
Chipless Rfid ◽  
Frequency Identification ◽  
Good Agreement

Abstract This paper presents a polarization-independent 11-bit chipless RFID tag based on frequency-selective surface which has been designed for encoding and relative humidity (RH) sensing applications. The 10 exterior U-shaped resonators are used for item encoding whereas Kapton has been incorporated with the interior resonator for RH sensing. This radio-frequency identification (RFID) tag operates in S- and C-frequency bands. The proposed design offers enhanced fractional bandwidth up to 88% with the density of 4.46 bits/cm2. Both single- and dual-layer tags have been investigated. The simulated results are in good agreement with measured results and a comparison with existing literature is presented to show the performance. Simple geometry, high code density, large frequency signature bandwidth, high magnitude bit, high radar cross-section, and angular stability for more than 75° are the unique outcomes of the proposed design. In addition, RH sensing has been achieved by integrating the Kapton on the same RFID tag.

scholarly journals A NEW RAMPED PYROXIDATION/COMBUSTION FACILITY AT 14CHRONO, BELFAST: SETUP DESCRIPTION AND INITIAL RESULTS

Radiocarbon ◽  
2021 ◽  
pp. 1-14
Author(s):  
Evelyn M Keaveney ◽  
Gerard T Barrett ◽  
Kerry Allen ◽  
Paula J Reimer
Keyword(s):  
Bulk Material ◽  
Correction Method ◽  
Source Attribution ◽  
Radiocarbon Age ◽  
Targeted Analysis ◽  
Consensus Values ◽  
Background Material ◽  
Initial Results ◽  
Blank Correction ◽  
Good Agreement

ABSTRACT The Belfast Ramped Pyroxidation/Combustion (RPO/RC) facility was established at the 14CHRONO Centre (Queen’s University Belfast). The facility was created to provide targeted analysis of bulk material for refined chronological analysis and carbon source attribution for a range of sample types. Here we report initial RPO results, principally on background material, but also including secondary standards that are routinely analyzed at 14CHRONO. A description of our setup, methodology, and background (blank) correction method for the system are provided. The backgrounds (anthracite, spar calcite, Pargas marble) reported by the system are in excess of 35,000 14C years BP with a mean age of 39,345 14C years BP (1σ = 36,497–43,800 years BP, N=44) with F14C = 0.0075 ± 0.0032. Initial results for standards are also in good agreement with consensus values: TIRI-B pine radiocarbon age = 4482 ± 47 years BP (N=13, consensus = 4508 years BP); IAEA-C6 ANU Sucrose F14C= 1.5036 ± 0.0034 (N=10, consensus F14C = 1.503). These initial tests have allowed problematic issues to be identified and improvements made for future analyses.

scholarly journals Mechanical and Dielectric Properties of Aligned Electrospun Fibers

Fibers ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 4
Author(s):  
Blesson Isaac ◽  
Robert M. Taylor ◽  
Kenneth Reifsnider
Keyword(s):  
Dielectric Properties ◽  
Dielectric Property ◽  
Electrospun Nanofibers ◽  
Cold Drawing ◽  
General Interest ◽  
Electrospun Fibers ◽  
Energy Storage Devices ◽  
Electrospinning Technique ◽  
Specific Strength ◽  
Aligned Nanofibers

This review paper examines the current state-of-the-art in fabrication of aligned fibers via electrospinning techniques and the effects of these techniques on the mechanical and dielectric properties of electrospun fibers. Molecular orientation, system configuration to align fibers, and post-drawing treatment, like hot/cold drawing process, contribute to better specific strength and specific stiffness properties of nanofibers. The authors suggest that these improved, aligned nanofibers, when applied in composites, have better mechanical and dielectric properties for many structural and multifunctional applications, including advanced aerospace applications and energy storage devices. For these applications, most fiber alignment electrospinning research has focused on either mechanical property improvement or dielectric property improvement alone, but not both simultaneously. Relative to many other nanofiber formation techniques, the electrospinning technique exhibits superior nanofiber formation when considering cost and manufacturing complexity for many situations. Even though the dielectric property of pure nanofiber mat may not be of general interest, the analysis of the combined effect of mechanical and dielectric properties is relevant to the present analysis of improved and aligned nanofibers. A plethora of nanofibers, in particular, polyacrylonitrile (PAN) electrospun nanofibers, are discussed for their mechanical and dielectric properties. In addition, other types of electrospun nanofibers are explored for their mechanical and dielectric properties. An exploratory study by the author demonstrates the relationship between mechanical and dielectric properties for specimens obtained from a rotating mandrel horizontal setup.

Bone permittivity and its effect on using ground-penetrating radar

Geophysics ◽  
2018 ◽  
Vol 83 (1) ◽  
pp. H1-H11
Author(s):  
Blair B. Schneider ◽  
Georgios Tsoflias ◽  
Don W. Steeples ◽  
Rolfe Mandel ◽  
Jack Hofman
Keyword(s):  
Dielectric Properties ◽  
Dielectric Property ◽  
Ground Penetrating Radar ◽  
Relative Permittivity ◽  
Water Saturation ◽  
Mixing Models ◽  
Bone Properties ◽  
Animal Bone ◽  
Bone Minerals ◽  
Ground Penetrating

Ground-penetrating radar (GPR) is a powerful tool that is still being developed for archaeological investigations. We investigated the dielectric properties of mammoth bone and bone from modern bison, cow, deer, and elk as a proxy for applying GPR for detecting prehistoric animal remains. Sample dielectric properties (relative permittivity, loss factor, and loss-tangent values) were measured with an impedance analyzer over frequencies ranging from 10 MHz to 1 GHz. Bone-sample porosity, bulk density, water saturation, and volumetric water content of the specimens were also measured. The measured sample-relative permittivity values were then compared with modeled relative permittivity values using common dielectric-mixing models to determine which parameters control the best-fit predictions of relative permittivity of animal bone. We observe statistically significant dielectric-property differences among different animal fauna, as well as variation as a function of frequency. In addition, we determine that the relative permittivity values of 8–9 for similar minerals, such as apatite, are not suitable as a proxy for predicting animal bone properties. We estimate new relative permittivity values of 3–5 for dry animal bone minerals in the frequency range of 100–1000 MHz using these common dielectric-mixing models. We postulate that differences in bone microstructure contribute to dielectric-property variability.

scholarly journals Triple Band Fractal Antenna for Radio Navigation and Fixed Satellite Services using Dragonfly Optimization

2019 ◽  
Vol 8 (3) ◽  
pp. 43-49 ◽  
Author(s):  
A. Kumar ◽  
A. P. S. Pharwaha
Keyword(s):  
Coplanar Waveguide ◽  
Performance Parameter ◽  
Fractal Antenna ◽  
Radio Navigation ◽  
Simulated Performance ◽  
Low Profile ◽  
X Band ◽  
Good Agreement ◽  
Triple Band

This study reports the design of a coplanar waveguide (CPW)-fed triple band fractal antenna for radio navigation and fixed satellite services. Reported antenna has low profile, multiband and wideband performance which make it suitable for the radio navigation and fixed satellite services in S band, C bandand X band. Proposed antenna resonates at 2.6GHz, 4.4GHz, and 8.7 GHz having bandwidth of 0.2457GHz, 0.700GHz, and 4.1980 GHz respectively. Maximumgain for the resonating bands is 3.6 dB, 5.5 dB, and 7.3 dB respectively. Simulated performance parameter of proposed antenna is verified experimentally by testing the fabricated antenna. Measured and simulated results are in good agreement

Development and Miniaturized of Circularly Polarization Diversity at Cavity Backed SIW Antenna for X-Band Application

Frequenz ◽  
2019 ◽  
Vol 73 (9-10) ◽  
pp. 317-320
Author(s):  
Saeid Karamzadeh ◽  
Vahid Rafiei ◽  
Hasan Saygin
Keyword(s):  
Schottky Diodes ◽  
Axial Ratio ◽  
Impedance Bandwidth ◽  
Polarization Diversity ◽  
Circularly Polarized ◽  
Left Hand ◽  
Low Profile ◽  
X Band ◽  
Coaxial Feed ◽  
Good Agreement

Abstract In this work circularly polarization diversity has been achieved by utilizing two Schottky diodes on low profile cavity-backed substrate integrated waveguide (CBSIW). In comparison with other studies in the literature, the size of antenna has been reduced to 0.54λg × 0.76λg by helping a 50-Ohm coaxial feed line. The impedance bandwidth, axial ratio bandwidth and antenna gain are improved to 10.02 %, 5.2 % and 7.68dBi, respectively. In addition, the proposed antenna can generate either a left-hand circularly polarized (LHCP) or a right-hand circularly polarized (RHCP) radiation. The developed antenna was fabricated and tested and the achieved results were in good agreement with the simulated one.

scholarly journals Low-Profile Spidron Fractal Dipole Antenna with a Ferrite-Loaded Artificial Magnetic Conductor for Manpack Applications

2020 ◽  
Vol 10 (24) ◽  
pp. 8843
Author(s):  
Oh Heon Kwon ◽  
Keum Cheol Hwang
Keyword(s):  
High Frequency ◽  
Dipole Antenna ◽  
Magnetic Conductor ◽  
Very High Frequency ◽  
Artificial Magnetic Conductor ◽  
Received Power ◽  
Low Profile ◽  
Profile Characteristics ◽  
Very High ◽  
Good Agreement

In this paper, a Spidron fractal dipole antenna with a ferrite-loaded artificial magnetic conductor (AMC) is presented. By applying ferrite composed of nickel–zinc with a high permeability value, a compact AMC that operates in the broadband frequency range within the high-frequency/very-high-frequency/ultra-high-frequency (HF/VHF/UHF) bands was designed. A Spidron fractal-shaped dipole antenna with a quasi-self-complementary structure was designed and combined with a miniaturized ferrite-loaded AMC. This allowed the designed AMC-integrated dipole antenna to operate in a wide frequency band, covering the HF/VHF/UHF bands, with low-profile characteristics. A prototype of the proposed Spidron fractal dipole antenna with the AMC was manufactured and measured and found to meet low VSWR (voltage standing wave radios) specifications of <3.5 within the 20–500 MHz bandwidth range. The simulated and measured results are in good agreement. The size of the Spidron fractal dipole antenna with the AMC is 0.03×0.026×0.001λ3 relative to the wavelength of the lowest operating frequency. The received power of the Spidron fractal dipole antenna with the AMC was also measured when it was applied to relatively small applications, such as a manpack in this case.

Characterization of Dielectric Properties of Alkoxy-Derived (Y,Yb)MnO3 Ferroelectrics/Insulator Stacking Layers

2006 ◽  
Vol 301 ◽  
pp. 65-70 ◽  
Author(s):  
Kazuyuki Suzuki ◽  
Kiyotaka Tanaka ◽  
Tatsuo Kimura ◽  
Kaori Nishizawa ◽  
Takeshi Miki ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Dielectric Property ◽  
Surface Morphology ◽  
Insulator Layer ◽  
Surface Smoothness ◽  
Y2o3 Layer ◽  
Mno3 Film ◽  
Mfis Structure

The (Y,Yb)MnO3 films were crystallized on Y2O3 layers using alkoxy-derived precursor solutions. As a result of investigation of the effect of the Y2O3 layer on the dielectric properties of the (Y,Yb)MnO3/Y2O3/Si, the crystallographic properties such as the orientation and surface morphology of the (Y,Yb)MnO3 thin films depended on the crystallographic appearance of the insulator layer. Following that, the dielectric properties of the MFIS structures varied. For the construction of excellent MFIS structure, the improvement of the orientation, crystallinity, and surface smoothness of the (Y,Yb)MnO3 film by the optimization of the microstructure and dielectric property of the insulator is necessary.

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