4 results
Search Results
Now showing 1 - 4 of 4
Article Citation - WoS: 7Citation - Scopus: 7Dynamical and Passive Characteristics of the Ag/Tlgases Rf Resonators(Wiley-v C H verlag Gmbh, 2012) Qasrawi, A. F.; Elayyat, S. M. S.; Gasanly, N. M.Ag contacts on the surface of the TlGaSeS single crystals are observed to exhibit Schottky characteristics. The ideality factor of the Ag/ TlGaSeS/Ag device decreased from 5.2 to 1.3 by the reduction of series resistance effect on the I-V characteristics. Cheung's model analysis revealed a series resistance and barrier height of 40.6 KO and 0.32 V, respectively. The device was run on the passive mode by injection with an alternating ac signal of variable frequency in the frequency range of 0-120 MHz and recoding the device capacitance. Several resonance-antiresonance positions in the range of 27-350 KHz were observed. The tangent loss factor of the passive device was observed to decrease with increasing frequency. It exhibited a very low loss value of the order of 10-5 at 120 MHz. Such property is a characteristic of high performance tunable device being suitable as processor clock controller.Article Citation - WoS: 2Citation - Scopus: 2Effects of Laser Excitation and Temperature on Ag/Gase0.5< Microwave Filters(Springer, 2014) Qasrawi, A. F.; Khanfar, H. K.The effects of temperature, illumination, and microwave signals on Ag/GaS0.5S0.5/C Schottky-type microwave filters have been investigated. The devices, which were produced from thin layers of GaSe0.5S0.5 single crystal, had room temperature barrier height and ideality factor of 0.65 eV and 3.28, respectively. Barrier height increased uniformly with increasing temperature, at 2.12 x 10(-2) eV/K, and the ideality factor approached ideality. The devices can even function at 95A degrees C. A current switching phenomenon from low to high injection ("On/Off") was also observed; this current switching appears at a particular voltage, V (s), that shifts toward lower values as the temperature is increased. When the devices were reverse-biased and illuminated with a laser beam of wavelength 406 nm, a readily distinguishable V (s) was observed that shifted with increasing laser power. When the devices were run in passive mode and excited with an ac signal of power 0.0-20.0 dBm and frequency 0.05-3.0 GHz they behaved as band filters that reject signals at 1.69 GHz. Device resistance was more sensitive to signal amplitude at low frequencies (50 MHz) than at high frequencies. The features of these Ag/GaS0.5S0.5/C Schottky devices imply that they may be used as optical switches, as self standing, low band-pass, band reject filters, and as high band-pass microwave filters.Review Citation - WoS: 13Citation - Scopus: 14Molecularly Imprinted Polymer-Based Sensors for the Detection of Skeletal- and Cardiac-Muscle Analytes(Mdpi, 2023) Ostrovidov, Serge; Ramalingam, Murugan; Bae, Hojae; Orive, Gorka; Fujie, Toshinori; Hori, Takeshi; Kaji, HirokazuMolecularly imprinted polymers (MIPs) are synthetic polymers with specific binding sites that present high affinity and spatial and chemical complementarities to a targeted analyte. They mimic the molecular recognition seen naturally in the antibody/antigen complementarity. Because of their specificity, MIPs can be included in sensors as a recognition element coupled to a transducer part that converts the interaction of MIP/analyte into a quantifiable signal. Such sensors have important applications in the biomedical field in diagnosis and drug discovery, and are a necessary complement of tissue engineering for analyzing the functionalities of the engineered tissues. Therefore, in this review, we provide an overview of MIP sensors that have been used for the detection of skeletal- and cardiac-muscle-related analytes. We organized this review by targeted analytes in alphabetical order. Thus, after an introduction to the fabrication of MIPs, we highlight different types of MIP sensors with an emphasis on recent works and show their great diversity, their fabrication, their linear range for a given analyte, their limit of detection (LOD), specificity, and reproducibility. We conclude the review with future developments and perspectives.Article Citation - WoS: 5Citation - Scopus: 5Dielectric and photo-dielectric properties of TlGaSeS crystals(indian Acad Sciences, 2014) Qasrawi, A. F.; Abu-Zaid, Samah F.; Ghanameh, Salam A.; Gasanly, N. M.The room temperature, dark and photo-dielectric properties of the novel crystals TlGaSeS are investigated in the frequency, intensity and biasing voltage having ranges of similar to 1-120 MHz, 14-40 klux and 0-1 V, respectively. The crystals are observed to exhibit a dark high frequency effective dielectric constant value of similar to 10.65 x 10(3) with a quality factor of similar to 8.84 x 10(4) at similar to 120 MHz. The dielectric spectra showed sharp resonance-antiresonance peaks in the frequency range of similar to 25-250 kHz. When photoexcited, pronounced increase in the dielectric constant and in the quality factor values with increasing illumination intensity are observed. Signal amplification up to similar to 33% with improved signal quality up to similar to 29% is attainable via photoexcitation. On the other hand, the illuminated capacitance voltage characteristics of the crystals reflected a downward shift in the voltage biasing and in the built-in voltage of the device that is associated with increase in the uncompensated carrier density. The increase in the dielectric constant with increasing illumination intensity is ascribed to the decrease in the crystal's resistance as a result of increased free carrier density. The light sensitivity of the crystals, the improved dielectric properties and the lower biasing voltage obtained via photoexcitation and the well-enhanced signal quality factor of the crystals make them promising candidates for optical communication systems.
