Characterization of RF–DC Transfer Difference for Thermal Voltage Converters With Built-in Tees in the Frequency Range 1 MHz to 1 GHz

2007 ◽  
Vol 56 (2) ◽  
pp. 341-345 ◽  
Author(s):  
G.M. Free ◽  
T.E. Lipe ◽  
J.R. Kinard ◽  
J.E. Sims
Keyword(s):  
Frequency Range ◽  
Thermal Voltage

Electrical characterization of aluminous cement at the early age in the 10 Hz–1 GHz frequency range

2000 ◽  
Vol 30 (7) ◽  
pp. 1057-1062 ◽  
Author(s):  
Youssef El Hafiane ◽  
Agnès Smith ◽  
Jean Pierre Bonnet ◽  
Pierre Abelard ◽  
Philippe Blanchart
Keyword(s):  
Electrical Characterization ◽  
Early Age ◽  
Frequency Range ◽  
Aluminous Cement

Thermorheological Characterization of Elastoviscoplastic Carbopol Ultrez 20 Gel

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
M. A. Hassan ◽  
Manabendra Pathak ◽  
Mohd. Kaleem Khan
Keyword(s):  
Experimental Investigation ◽  
Yield Stress ◽  
Elastic Properties ◽  
Viscous Dissipation ◽  
Power Law ◽  
Effect Of Temperature ◽  
Rheological Parameters ◽  
Frequency Range ◽  
Power Law Index

The temperature and concentration play an important role on rheological parameters of the gel. In this work, an experimental investigation of thermorheological properties of aqueous gel Carbopol Ultrez 20 for various concentrations and temperatures has been presented. Both controlled stress ramps and controlled stress oscillatory sweeps were performed for obtaining the rheological data to find out the effect of temperature and concentration. The hysteresis or thixotropic seemed to have negligible effect. Yield stress, consistency factor, and power law index were found to vary with temperature as well as concentration. With gel concentration, the elastic effect was found to increase whereas viscous dissipation effect was found to decrease. Further, the change in elastic properties was insignificant with temperature in higher frequency range of oscillatory stress sweeps.

Experimental Characterization of a Flexible Two-Link Manipulator Arm

1993 ◽  
Author(s):  
Randall L. Mayes ◽  
G. Richard Eisler
Keyword(s):  
Element Model ◽  
Input Voltage ◽  
Analytical Models ◽  
Experimental Characterization ◽  
Frequency Range ◽  
Flexible Links ◽  
Beam Elements ◽  
Output Torque ◽  
Manipulator Arm

Abstract Experiments were performed to verify the analytical models for a robotic manipulator with two flexible links. A finite element model (FEM) employing two-dimensional beam elements was used to model the structure. A proportional model relating input voltage to output torque was used for both hub and elbow joint motors. With some minor adjustments to the link stiffness, the FEM modal frequencies matched the experimentally extracted frequencies within 1.5%. However the voltage-torque relationship for the hub motor was found to exhibit dynamics in the frequency range of interest.

Design and Characterization of an Ultra Low Loss, Dispersion-Flattened Slotted Photonic Crystal Fiber for Terahertz Application

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohammad Rakibul Islam ◽  
Md. Arif Hossain ◽  
Syed Iftekhar Ali ◽  
Jakeya Sultana ◽  
Md. Saiful Islam
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
Single Mode ◽  
Confinement Loss ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Low Loss ◽  
Material Loss ◽  
Crystal Fiber

AbstractA novel photonic crystal fiber (PCF) based on TOPAS, consisting only rectangular slots is presented and analyzed in this paper. The PCF promises not only an extremely low effective material loss (EML) but also a flattened dispersion over a broad frequency range. The modal characteristics of the proposed fiber have been thoroughly investigated using finite element method. The fiber confirms a low EML of 0.009 to 0.01 cm−1 in the frequency range of 0.77–1.05 THz and a flattened dispersion of 0.22±0.01 ps/THz/cm. Besides, some other significant characteristics like birefringence, single mode operation and confinement loss have also been inspected. The simplicity of the fiber makes it easily realizable using the existing fabrication technologies. Thus it is anticipated that the new fiber has the potential to ensure polarization preserving transmission of terahertz signals and to serve as an efficient medium in the terahertz frequency range.

scholarly journals CHARACTERIZATION OF PORTAL HYPERTENSION IN GEZIRASTATE (SUDAN) USING ULTRASOUND

2019 ◽  
Vol 7 (7) ◽  
pp. 30-38
Author(s):  
Abdal Gadir Yonis ◽  
Al Safi Ahmed Abdallash ◽  
Mona Ahmed ◽  
Ashraf Mustafa Mohammed Osman
Keyword(s):  
Portal Hypertension ◽  
Endemic Area ◽  
Imaging Modality ◽  
Frequency Range ◽  
Portal Fibrosis ◽  
Portable Ultrasound ◽  
Schistosomiasis Mansoni ◽  
High Incidence ◽  
A Prospective Study

Peri-sinusoidal portal hypertension with frequent episodes of upper gastro intestinal variceal bleeding are hallmarks of hepatic-splenic schistosomiasis (Mansoni or Japonicum). This a prospective study compromise of 306 consecutive patients at North Gezira State between 2016 to 2019, aimed to characterize the portal hypertension &to minimize potentiallysevere and deadly complications. Using  B-mode grayscale ultrasound, The images done by portable Sono- Scape- A6 machine using convex probe with frequency range from 3.5 to 5 MHz and the data analyzed by SPSS version 15.The result showed that the majority of patients were male and portal hypertension had high incidence associated with peri portal fibrosis(schistosomiasis), the result also showed that : out of 360 patients under study, there were 209(58.1%) had portal hypertension, 106(29.4%) had PPF, and 45(12.5%) were normal patients.  The study concluded that the portable ultrasound machine is the most frequently used imaging modality to assess patients for the presence of portal hypertension especially in the endemic area.

scholarly journals Characterization of Optically-Reconfigurable Metasurfaces by a Free Space Microwave Bistatic Technique

2020 ◽  
Vol 10 (12) ◽  
pp. 4353
Author(s):  
Houssemeddine Krraoui ◽  
Charlotte Tripon-Canseliet ◽  
Ivan Maksimovic ◽  
Stefan Varault ◽  
Gregoire Pillet ◽  
...  
Keyword(s):  
Near Infrared ◽  
Optical Power ◽  
Frequency Selective Surface ◽  
Infrared Region ◽  
Photon Absorption ◽  
60 Ghz ◽  
Frequency Range ◽  
Specific Incident ◽  
Absorption Phenomenon

Microwave performance extraction of optically-controlled squared frequency-selective surface (FSS) structures printed on highly resistive (HR) silicon substrate are presented, from a innovative bistatic microwave photonic characterization technique operating in the 40 to 60 GHz frequency range, commonly used for radar cross section (RCS) measurements. According to typical physical photon absorption phenomenon occurring in photoconductive materials, these structures demonstrate experimentally a bandpass filtering frequency response cancellation through reflection coefficient measurements, under specific incident collective illumination in the Near-infrared region (NIR). This behaviour is attributed to their microwave surface impedance modification accordingly to the incident optical power, allowing ultrafast reconfigurability of such devices by optics

Microwave Photoconductivity Measurements to Characterize Semiconductors

1990 ◽  
Vol 189 ◽  
Author(s):  
M. Kunst
Keyword(s):  
Semiconductor Devices ◽  
Microwave Frequency ◽  
Frequency Range ◽  
General Survey ◽  
Characterization Techniques ◽  
Transient Photoconductivity

ABSTRACTAfter a general survey of characterization techniques the use of transient photoconductivity measurements in the microwave frequency range for the characterization of semiconductors and semiconductor devices for (opto)electronic applications is treated. Experimental details and applications of these measurements are given.

The Design of a 1~13 GHz GaAs Travelling Wave Amplifier

2013 ◽  
Vol 427-429 ◽  
pp. 1080-1084
Author(s):  
Yan Pu ◽  
Guo Qiang Wang ◽  
Zheng Rong He ◽  
Lin Tao Liu
Keyword(s):  
Output Power ◽  
Noise Figure ◽  
Travelling Wave ◽  
Equivalent Model ◽  
Small Signal ◽  
Frequency Range ◽  
Minimum Noise ◽  
Minimum Noise Figure

A 4-stage travelling wave amplifier with 10dB ± 1.2 dB gain and 12 GHz bandwidth is presented in the paper. The parameters of the small signal equivalent model about the GaAs PHEMT are extracted to evaluate the characterization of the device, which is also used to design the amplifier. The amplifier has a minimum noise figure lower than 4.8 dB in the frequency range, and the S11 and S22 are below-10 dB and-7 dB, which demonstrate a good performance. The P1dB and IIP3 are 7.3 dBm and 24 dBm, respectively, and the saturation output power is above 20 dBm at 13 GHz.

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