A new modified I-MOS varactor for linear range enhancement

2019 ◽  
Vol 90 ◽  
pp. 181-186 ◽  
Author(s):  
Ali Karimi ◽  
Emad Ebrahimi
Keyword(s):  
Linear Range ◽  
Mos Varactor

scholarly journals Potentiometric Carboxylate Sensors Based on Carbazole-Derived Acyclic and Macrocyclic Ionophores

Chemosensors ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 4
Author(s):  
Ville Yrjänä ◽  
Indrek Saar ◽  
Mihkel Ilisson ◽  
Sandip A. Kadam ◽  
Ivo Leito ◽  
...  
Keyword(s):  
Detection Limit ◽  
Vinyl Chloride ◽  
Anion Exchanger ◽  
Linear Range ◽  
Ph Sensitivity ◽  
Ion Selective Electrodes ◽  
Solid Contact ◽  
Response Characteristics ◽  
Potentiometric Response ◽  
Poly Vinyl Chloride

Solid-contact ion-selective electrodes with carbazole-derived ionophores were prepared. They were characterized as acetate sensors, but can be used to determine a number of carboxylates. The potentiometric response characteristics (slope, detection limit, selectivity, and pH sensitivity) of sensors prepared with different membrane compositions (ionophore, ionophore concentration, anion exchanger concentration, and plasticizer) were evaluated. The results show that for the macrocyclic ionophores, a larger cavity provided better selectivity. The sensors exhibited modest selectivity for acetate but good selectivity for benzoate. The carbazole-derived ionophores effectively decreased the interference from lipophilic anions, such as bromide, nitrate, iodide, and thiocyanate. The selectivity, detection limit, and linear range were improved by choosing a suitable plasticizer and by reducing the ionophore and anion exchanger concentrations. The influence of the electrode body’s material upon the composition of the plasticized poly(vinyl chloride) membrane, and thus also upon the sensor characteristics, was also studied. The choice of materials for the electrode body significantly affected the characteristics of the sensors.

scholarly journals Reduced Graphene Oxide Fibre Electrodes for Drug Sensing

Proceedings ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 18
Author(s):  
Sutthima Sriprasertsuk ◽  
John R. Varcoe ◽  
Carol Crean
Keyword(s):  
Cyclic Voltammetry ◽  
Graphene Oxide ◽  
Carbon Fibre ◽  
Reduced Graphene Oxide ◽  
Limit Of Detection ◽  
Linear Range ◽  
Oxidation Peak ◽  
Reduced Graphene ◽  
Fibre Sensor ◽  
Model Drug

Reduced graphene oxide (rGO) fibre electrodes and their ability to sense paracetamol (as model drug) were studied. rGO was electrodeposited onto carbon fibre by two different approaches: potentiostatic deposition and cyclic voltammetry (CV) in the presence of graphene oxide solution. Carbon fibre electrodes coated with rGO (after five CV cycles) could sense paracetamol with an oxidation peak at 0.62 V (vs. Ag/AgCl). The limit of detection of this fibre sensor was found to be 36.3 µM with a linear range of 50–500 µM of paracetamol (R2 = 0.9901).

scholarly journals Quasilinear Riccati-Type Equations with Oscillatory and Singular Data

2020 ◽  
Vol 20 (2) ◽  
pp. 373-384
Author(s):  
Quoc-Hung Nguyen ◽  
Nguyen Cong Phuc
Keyword(s):  
Elliptic Operator ◽  
Bounded Domain ◽  
Existence Of Solutions ◽  
Type Equation ◽  
Linear Range ◽  
Measure Data ◽  
Regularity Conditions ◽  
Compactly Supported ◽  
Singular Data ◽  
Quasilinear Elliptic

AbstractWe characterize the existence of solutions to the quasilinear Riccati-type equation\left\{\begin{aligned} \displaystyle-\operatorname{div}\mathcal{A}(x,\nabla u)% &\displaystyle=|\nabla u|^{q}+\sigma&&\displaystyle\phantom{}\text{in }\Omega,% \\ \displaystyle u&\displaystyle=0&&\displaystyle\phantom{}\text{on }\partial% \Omega,\end{aligned}\right.with a distributional or measure datum σ. Here {\operatorname{div}\mathcal{A}(x,\nabla u)} is a quasilinear elliptic operator modeled after the p-Laplacian ({p>1}), and Ω is a bounded domain whose boundary is sufficiently flat (in the sense of Reifenberg). For distributional data, we assume that {p>1} and {q>p}. For measure data, we assume that they are compactly supported in Ω, {p>\frac{3n-2}{2n-1}}, and q is in the sub-linear range {p-1<q<1}. We also assume more regularity conditions on {\mathcal{A}} and on {\partial\Omega\Omega} in this case.

Cds nanocrystal enhanced TiO2photoelectrochemical aptasensor for sensitive detection of cytochrome c

2021 ◽  
Vol 11 (11) ◽  
pp. 1774-1780
Author(s):  
Shanji Fan ◽  
Hong Huang ◽  
Hong Chen ◽  
Jiachi Xu ◽  
Zecheng Hu ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Limit Of Detection ◽  
Specific Binding ◽  
High Sensitivity ◽  
High Specificity ◽  
Linear Range ◽  
Current Intensity ◽  
Sensitive Detection ◽  
Layer Adsorption ◽  
Ionic Layer

A CdS nanocrystal enhanced TiO2 nanotubes (CdS@TiO2 NATs) photoelectrode was prepared via successive ionic layer adsorption and reaction (SILAR) of CdS on the surface of TiO2 NATs. A HS-aptamer owing a specific binding toward cytochrome c was modified onto the CdS@TiO2 NATs, which resulting a decrease in the photoelectrical current intensity. Cytochrome c is therefore quantified based on the decrease in photoelectrical current. High specificity and high sensitivity were obtained with a linear range from 3 pM to 80 nM, and a limit of detection of 2.53 pM.

Automated flow-injection system for extending the linear range

1998 ◽  
Vol 366 (1-3) ◽  
pp. 271-279 ◽  
Author(s):  
Luis F Gouveia ◽  
José L.F Costa Lima ◽  
José A.G Morais
Keyword(s):  
Flow Injection ◽  
Linear Range ◽  
Injection System ◽  
Flow Injection System

Calibration of pneumotachographs using a calibrated syringe

2003 ◽  
Vol 95 (2) ◽  
pp. 571-576 ◽  
Author(s):  
Yongquan Tang ◽  
Martin J. Turner ◽  
Johnny S. Yem ◽  
A. Barry Baker
Keyword(s):  
Calibration Method ◽  
Linear Range ◽  
Data Sets ◽  
Constant Flow ◽  
Calibration Constant ◽  
Third Order ◽  
Polynomial Coefficients ◽  
Calibration Curves ◽  
Order Polynomial ◽  
Better Than

Pneumotachograph require frequent calibration. Constant-flow methods allow polynomial calibration curves to be derived but are time consuming. The iterative syringe stroke technique is moderately efficient but results in discontinuous conductance arrays. This study investigated the derivation of first-, second-, and third-order polynomial calibration curves from 6 to 50 strokes of a calibration syringe. We used multiple linear regression to derive first-, second-, and third-order polynomial coefficients from two sets of 6–50 syringe strokes. In part A, peak flows did not exceed the specified linear range of the pneumotachograph, whereas flows in part B peaked at 160% of the maximum linear range. Conductance arrays were derived from the same data sets by using a published algorithm. Volume errors of the calibration strokes and of separate sets of 70 validation strokes ( part A) and 140 validation strokes ( part B) were calculated by using the polynomials and conductance arrays. Second- and third-order polynomials derived from 10 calibration strokes achieved volume variability equal to or better than conductance arrays derived from 50 strokes. We found that evaluation of conductance arrays using the calibration syringe strokes yields falsely low volume variances. We conclude that accurate polynomial curves can be derived from as few as 10 syringe strokes, and the new polynomial calibration method is substantially more time efficient than previously published conductance methods.

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