Design of fractional-order differentiator-lowpass filters for extracting the R peaks in ECG signals
An implementation of a fractional-order differentiator-lowpass filter is presented in this work, which is constructed from Operational Transconductance Amplifiers as active cells. This offers the benefits of electronic tuning and, also, of monolithic implementation. The presented scheme has been employed for the extraction of the R peaks in electrocardiogram signals due to its efficiency for performing this task even in a noisy environment. The provided post-layout simulation results confirm the correct operation of this solution as well as its reasonable sensitivity characteristics. © 2019
Implementation of a Pulsed-Wave Spectral Doppler Module on a Programmable Ultrasound System
Pulsed wave Doppler ultrasound is commonly used in the diagnosis of cardiovascular and blood flow abnormalities. Doppler techniques have gained clinical significance due to its safety, real-time performance and affordability. This work presents the development of a pulsed wave spectral Doppler module, which was integrated into a reconfigurable ultrasound system. The targeted system adopts a hardware-software partitioning scheme where an FPGA handles the front-end and a PC performs the back-end. Two factors were considered during the design. First, the data transfer rate between hardware and
Comparative study of fractional filters for Alzheimer disease detection on MRI images
This paper presents a comparative study of four fractional order filters used for edge detection. The noise performance of these filters is analyzed upon the addition of random Gaussian noise, as well as the addition of salt and pepper noise. The peak signal to noise ratio (PSNR) of the detected images is numerically compared. The mean square error (MSE) of the detected images as well as the execution time are also adopted as evaluation methods for comparison. The visual comparison of the filters capability in medical image edge detection is presented, that can help in the diagnosis of
Mathematical analysis of gene regulation activator model
This paper presents a complete analysis of the mathematical model of the gene regulation process. The model describes the induced gene expression under the effect of activators. The model differential equations are solved analytically, and the exact solution of the gene model is introduced. Moreover, a study of the model dynamics, including the fixed points and stability conditions are presented. The parameters effects on the phase plane portraits and the transient responses of the mRNA as well as the protein concentrations are intensively detailed. This work serves as a brick stone towards a
Simple implementations of fractional-order driving-point impedances: Application to biological tissue models
A novel procedure for the circuit implementation of the driving-point impedance of frequency-domain material models, constructed from fractional-order elements of arbitrary type and order, is introduced in this work. Following this newly introduced concept, instead of emulating separately each fractional-order element in the model under consideration, the direct emulation of the complete model can be achieved through the approximation of the total impedance function. The magnitude and phase frequency responses of the impedance function are first extracted and approximated through curve-fitting
Factorial design-optimized and gamma irradiation-assisted fabrication of selenium nanoparticles by chitosan and Pleurotus ostreatus fermented fenugreek for a vigorous in vitro effect against carcinoma cells
The novelty of the present work looks in the synthesis of aqueous dispersed selenium nanoparticles (Se NPs) using gamma rays with the aid of various natural macromolecules such as citrus pectin (CP), sodium alginate (Alg), chitosan (CS) and aqueous extract of fermented fenugreek powder (AEFFP) using Pleurotus ostreatus for investigating their impact in vitro toward carcinoma cell. The synthesized Se NPs were characterized by XRD, UV–Vis., DLS, HRTEM, SEM, EDX and FTIR. Nucleation and growth mechanisms were also discussed. The factorial design was applied to examine the importance of multiple
Fabrication of Ultra-Pure Anisotropic Zinc Oxide Nanoparticles via Simple and Cost-Effective Route: Implications for UTI and EAC Medications
The purposes of this work are to evaluate the antimicrobial, antibiofilm, anticancer, and antioxidant abilities of anisotropic zinc oxide nanoparticles (ZnO NPs) synthesized by a cost-effective and eco-friendly sol–gel method. The synthesized ZnO NPs were entirely characterized by UV-Vis, XRD, FTIR, HRTEM, zeta potential, SEM mapping, BET surface analyzer, and EDX elemental analysis. Antimicrobial and antibiofilm activities of ZnO NPs were investigated against multidrug-resistant (MDR) bacteria and yeast causing serious diseases like urinary tract infection (UTI). The anticancer activity was
Controllable synthesis of Co1−x MxFe2O4 nanoparticles (M = Zn, Cu, and Mn; x = 0.0 and 0.5) by cost-effective sol–gel approach: analysis of structure, elastic, thermal, and magnetic properties
Substitutions of cations were considered to be the main way for improving the performance of ferrite nanocrystalline structures. In this paper, non-magnetic and magnetic ions were conducted to substitute cobalt spinel ferrite nanoparticles CoFe2O4 NPs (CFO NPs). The studied Co1−xMxFe2O4; M = Zn, Cu, and Mn; x = 0.00, and 0.50) samples were synthesized through a cost-effective sol–gel technique. The outstanding properties of the samples are addressed using XRD, FTIR, the inductively coupled plasma optical emission spectrometer (ICP-OES), Raman analyses, HR-TEM, BET surface area analyzer, the
Gum Arabic polymer-stabilized and Gamma rays-assisted synthesis of bimetallic silver-gold nanoparticles: Powerful antimicrobial and antibiofilm activities against pathogenic microbes isolated from diabetic foot patients
In this research, irradiation by gamma rays was employed as an eco-friendly route for the construction of bimetallic silver-gold nanoparticles (Ag-Au NPs), while Gum Arabic polymer was used as a capping agent. Ag-Au NPs were characterized through UV–Vis., XRD, EDX, HR-TEM, FTIR, SEM/mapping and EDX analysis. Antibiofilm and antimicrobial activities were examined against some bacteria and Candida sp. isolates from diabetic foot patients. Our results revealed that the synthesis of Ag-Au NPs depended on the concentrations of tetra-chloroauric acid and silver nitrate. HR-TEM analysis confirmed the
J-aggregates of amphiphilic cyanine dyes for dye-sensitized solar cells: A combination between computational chemistry and experimental device physics
We report on the design and structure principles of 5,5′-6,6′-tetrachloro-1,1′-dioctyl-3,3′-bis-(3-carboxypropyl)-benzimidacarbocyanine (Dye 1). Such metal-free amphiphilic cyanine dyes have many applications in dye-sensitized solar cells. AFM surface topographic investigation of amphiphilic molecules of Dye 1 adsorbed on TiO2 anode reveals the ability of spontaneous self-organization into highly ordered aggregates of fiber-like structure. These aggregates are known to exhibit outstanding optical properties of J-aggregates, namely, efficient exciton coupling and fast exciton energy migration
Pagination
- Previous page ‹‹
- Page 6
- Next page ››