다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

In recent years, there is a growing interest in studying the dielectric behavior of biopolymer composites due to their potential application as a dielectric material in various electronic devices such as microchips, transformers, and circuit boards. Conducting electroactive polymer composites have also been investigated for various potential applications which include biological, biomedical, flexible electrodes, display devices, biosensors, and cells for tissue engineering. In this chapter, the preparation and dielectric behavior of various biopolymer composites is presented. These biopolymer composites generally consist of nanoscale metal nanoparticles and carbon-based nanofillers such as carbon nanotubes, graphene, graphene oxide (GO), etc., dispersed into the polymer matrix. The physical and chemical properties of these fillers and their interactions with polymers have a significant effect on the microstructure and the final properties of nanocomposites. The biopolymer composites with excellent dielectric properties show great promise as an energy storage dielectric layer in high-performance capacitor applications such as embedded capacitors. This chapter highlights some of the examples of such biopolymer composites; their processing and dielectric behavior will be discussed in detail.

Biopolymer Composites With High Dielectric Performance: Interface Engineering

A highly sensitive uric acid (UA) sensor was fabricated using a wet-chemical (co-precipitation) method to prepare doped ZnO/Ag2O/Co3O4 nanoparticles (NPs) and load them onto a glassy carbon electrode (GCE) by an electrochemical approach. The detailed characterization of the NPs was performed by using conventional methods, such as X-ray photoelectron spectroscopy (XPS), ultraviolet-visible spectroscopy (UV-vis.), Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), Tunneling electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray powder diffraction (XRD) analysis. Thermal gravimetric analysis (TGA) of the as-prepared ternary NPs was performed in order to study the stability of NPs in different temperature ranges over which the weight loss and thermal effect are significant. During the electrochemical analysis, the proposed UA sensor was found to be linear over a large linear dynamic range (LRD; 0.1 nM–0.01 mM). The analytical performance of the sensor such as sensitivity (82.3323 μA μM−1 cm−2) was estimated from the slope of the calibration curve and the detection limit (89.14 ± 4.46 pM) was calculated at a signal to noise ratio of 3. The proposed UA biosensor showed reliable reproducibility, a short response time (22.0 s), long-term stability, and no interference effects. The ZnO/Ag2O/Co3O4 NPs/GCE sensor was also validated with real biological samples. Thus, this method might be a prospective and reliable method for the future development of enzyme-free biosensors using doped ternary metal oxides in broad scales.

Detection of uric acid based on doped ZnO/Ag2O/Co3O4 nanoparticle loaded glassy carbon electrode

Dielectric and conductivity behaviors of nano ZnO doped polyvinyl alcohol (PVA) composites for various concentrations of dopant were investigated using impedance spectroscopy for a wide range of temperatures (303 K–423 K) and frequencies (5 Hz–30 MHZ). The dielectric properties of host polymer matrix have been improved by the addition of nano ZnO and are found to be highly temperature dependent. Anomalous dielectric behavior was observed in the frequency range of 2.5 MHz–5 MHz. Increase in dielectric permittivity and dielectric loss was observed with respect to temperature. The Cole-Cole plot could be modeled by low resistance regions in a high resistance matrix and the lowest resistance was observed for the 10 mol. % films. The imaginary part of the electric modulus showed asymmetric peaks with the relaxation following Debye nature below and non-Debye nature above the peaks. The ac conductivity is found to obey Jonscher's power law, whereas the variation of dc conductivity with temperature was found to f...

Temperature dependent dielectric and conductivity studies of polyvinyl alcohol-ZnO nanocomposite films by impedance spectroscopy

Zinc oxide consumption has increased in today’s world. It is one of the most popular nanoparticles with photocatalytic activity under light illumination utilized in different industries, especially in textiles and polymers. Lately, textiles and polymers with new features have been produced through utilization of ZnO nanoparticles to create photocatalytic characteristics, UV absorption, self-cleaning, and antimicrobial properties. Various approaches have been introduced to synthesize and apply nanoparticles on the textile and polymer surfaces such as cotton, polyester, wool, and others. This review presents diverse aspects of nano zinc oxide application in textile and polymer industry and approaches used for in situ and ex situ synthesis and application of nano zinc oxide on different textiles and polymers. This also brings a brief overview on the several studies accomplished in this area.

ZnO nano reactor on textiles and polymers: ex situ and in situ synthesis, application, and characterization.

ZnO nanostructures were synthesized in one step reaction at 80℃ without any ext ra treat ments. (Zn(NO₃)₂.6H2O) and (NaOH) were used for synthesis. Production of ZnO nanostructures occurred relatively in short time. The obtained ZnO nanostructures were characterized by X-ray diffraction (XRD) and the atomic fo rce microscope AFM. Carbo xy methyleted PVA (CPVA) has been prepared and characterized. (CPVA) were co mposite with different ZnO nanoparticles concentrations. The composites are cast into films. The dielectric constant properties of the films were measured with hp LCR meter.

http://article.sapub.org/pdf/10.5923.j.ajps.20120206.01.pdf

Preparation, Characterization and Electrical Study of (Carboxymethylated Polyvinyl Alcohol/ZnO) Nanocomposites

Mesogenic materials incorporating 4H-1,2,4-triazol-3-thiol moiety: Synthesis, characterization and liquid crystals study

Poly (viny1 alcohol) (PVA) of 72000 g mol -1 molar mass was cross linked through cold cast esterification with different mol % of MA and EDTA (10 % , 20 % and 30 % ), and two different mol % mixture of MA / EDTA (20 %/5% and 20%/10%(. Molecular structures of the produced membranes were identified by FTIR spectral analysis .

Dhefaf H. Badri

Papers

Preparation, Characterization and Electrical Study of (Carboxymethylated Polyvinyl Alcohol/ZnO) Nanocomposites

Mesogenic materials incorporating 4H-1,2,4-triazol-3-thiol moiety: Synthesis, characterization and liquid crystals study

Preparation of cross linked PVA with MA,EDTA,and a mixture of MA/EDTA for water uptake membranes at different pH