The cathodic reduction of PbO in the passive layer on lead in aqueous sulphuric acid

1984 ◽  
Vol 62 (3) ◽  
pp. 596-600 ◽  
Author(s):  
R. G. Barradas ◽  
D. S. Nadezhdin
Keyword(s):  
Experimental Data ◽  
Three Dimensional ◽  
Reference Electrode ◽  
Linear Sweep Voltammetry ◽  
Passive Layer ◽  
Cathodic Reduction ◽  
Linear Sweep ◽  
Current Time ◽  
Lead Monoxide ◽  
Two Peaks

The cathodic reduction of the lead monoxide layer formed on lead in 30% aqueous H2SO4 under anodic oxidation at 0.6 V (vs. Hg/HgSO4 reference electrode) was investigated by linear sweep voltammetry, potential step and admittance measurements. The experimental data were analyzed respectively in terms of thin-layer electrochemistry, electrocrystallisation, and changes of resistance of the PbO layer under reduction. The results seem to be best interpreted from the theory of three-dimensional electrocrystallisation as PbO is reduced to Pb. At sub-zero temperatures the PbO peak observed on our voltammograms and potentiostatic current time transients reveals the splitting of the curves into two peaks, which may be a result of reduction of the same material but of different phases, namely, orthorhombic and tetragonal PbO.

scholarly journals Electrochemical quantification of chlorpyrifos in white (Allium cepa L.) and green (Allium fistulosum L.) onions Cuantificación voltamétrica de clorpirifos en cebolla de bulbo (Allium cepa L.) y cebolla de rama (Allium fistulosum L.)

2019 ◽  
Vol 68 (3) ◽  
pp. 237-243
Author(s):  
José Mauricio García Colmenares ◽  
Leidy Paola Páez Cepeda ◽  
Sandra Patricia Chaparro
Keyword(s):  
Allium Cepa ◽  
Counter Electrode ◽  
Reference Electrode ◽  
Reference Method ◽  
Analytical Techniques ◽  
Linear Sweep Voltammetry ◽  
Allium Fistulosum ◽  
Organophosphate Pesticide ◽  
Linear Sweep ◽  
Allium Cepa L

The Linear sweep voltammetry method (LSP) of a common pesticide such as chlorpyrifos (CP) an organophosphate pesticide (OPP) in white (Allium cepa L.) and green onions (Allium fistulosum L.) was investigated. A hanging mercury drop electrode (HMDE) Ag/AgCl was used as reference electrode and platinum as a counter electrode. The OPP was extracted from the onion through liquid-liquid partition using acetone/dichloromethane as the solvent. Validated method was compared with GC/ECD as a reference method. CP concentration was not different between the two analytical techniques; the analysis was performed with a confidence level of 90%, corresponding to the polarographic method. CP concentration was 0.8400 ± 0.062 ppm in Allium cepa and 0.062 ± 0.300 ppm in Allium fistulosum L. These values exceed the ADI and ARD values for chlorpyrifos established by current regulations.

The linear sweep voltammetry of random arrays of microdisc electrodes: Fitting of experimental data

2006 ◽  
Vol 592 (2) ◽  
pp. 126-130 ◽  
Author(s):  
Olga Ordeig ◽  
Craig E. Banks ◽  
Trevor J. Davies ◽  
Javier del Campo ◽  
Francesc Xavier Muñoz ◽  
...  
Keyword(s):  
Experimental Data ◽  
Linear Sweep Voltammetry ◽  
Linear Sweep ◽  
Random Arrays ◽  
Microdisc Electrodes

The voltammetric determination of Mo in seawater after adsorptive accumulation of the Eriochrome Blue Black R complex

1987 ◽  
Vol 65 (5) ◽  
pp. 957-960 ◽  
Author(s):  
S. N. Willie ◽  
S. S. Berman ◽  
J. A. Page ◽  
G. W. VanLoon
Keyword(s):  
Limit Of Detection ◽  
Reference Electrode ◽  
Direct Determination ◽  
Linear Sweep Voltammetry ◽  
Linear Sweep ◽  
Negative Direction ◽  
Seawater Samples ◽  
Certified Values ◽  
A Current

A method for direct determination of molybdenum in seawater has been developed, and uses linear sweep voltammetry after adsorptive accumulation of the Erichrome Blue Black R (EBBR) complex on a static mercury drop electrode. To an acidified (pH 1.6) seawater (SW) sample, 6.0 × 10−6 M EBBR is added and preconcentration by adsorption is carried out for 30 s at a potential of −0.05 V vs. the Ag/AgCl/SW reference electrode. The potential is then scanned in the negative direction, giving a current peak for the reduction of the Mo—EBBR complex at −0.17 V. Under these conditions the limit of detection is 0.50 ng/mL. Experimental results for Mo in seawater using this technique agree well with certified values for two reference seawater samples (NASS-1, CASS-1).

The cyclic and linear sweep voltammetry of regular arrays of microdisc electrodes: Fitting of experimental data

2005 ◽  
Vol 585 (1) ◽  
pp. 51-62 ◽  
Author(s):  
Trevor J. Davies ◽  
Sarah Ward-Jones ◽  
Craig E. Banks ◽  
Javier del Campo ◽  
Roser Mas ◽  
...  
Keyword(s):  
Experimental Data ◽  
Linear Sweep Voltammetry ◽  
Linear Sweep ◽  
Regular Arrays ◽  
Microdisc Electrodes

Effect of cetyltrimethylammonium bromide on the electrochemiluminiscence and electrooxidation of luminol

1983 ◽  
Vol 48 (2) ◽  
pp. 477-483 ◽  
Author(s):  
Jan Lasovský ◽  
František Grambal
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Linear Sweep Voltammetry ◽  
Critical Micellar Concentration ◽  
Peak Height ◽  
Anodic Peak ◽  
Alkaline Solutions ◽  
Platinum Electrodes ◽  
Micellar Solutions ◽  
Linear Sweep ◽  
Low Concentrations

The electrooxidation of luminol in alkaline solutions in the presence of cetyltrimethylammonium bromide (I) was studied by linear sweep voltammetry on fixed and vibrating platinum electrodes. The presence of I in low concentrations (below the critical micellar concentration) brings about aggregation of the luminol, which is manifested by an increase in the anodic peak height and its shift towards lower potentials. In micellar solutions the peak height decreases owing to the slower diffusion of the bulkier micelles, the shift to lower potentials being preserved. The light-voltage curves correspond with the voltammetric curves, exhibiting identical shifts of the peak potentials in dependence on the concentration of the surfactant.

scholarly journals Adaptive Chaotic Image Encryption Algorithm Based on RNA and Pixel Depth

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1770
Author(s):  
Xiaoqiang Zhang ◽  
Xuangang Yan
Keyword(s):  
Image Encryption ◽  
Three Dimensional ◽  
Encryption Algorithm ◽  
Current Time ◽  
Plain Image ◽  
Scope Of Application ◽  
Selective Diffusion ◽  
Chaotic Image Encryption ◽  
And Diffusion ◽  
Image Encryption Algorithm

To prevent the leakage of image content, image encryption technology has received increasing attention. Most current algorithms are only suitable for the images of certain types and cannot update keys in a timely manner. To tackle such problems, we propose an adaptive chaotic image encryption algorithm based on RNA and pixel depth. Firstly, a novel chaotic system, two-dimensional improved Logistic-adjusted-Sine map is designed. Then, we propose a three-dimensional adaptive Arnold transform for scrambling. Secondly, keys are generated by the hash values of the plain image and current time to achieve one-image, one-key, and one-time pad simultaneously. Thirdly, we build a pre-permuted RNA cube for 3D adaptive scrambling by pixel depth, chaotic sequences, and adaptive RNA coding. Finally, selective diffusion combined with pixel depth and RNA operations is performed, in which the RNA operators are determined by the chemical structure and properties of amino acids. Pixel depth is integrated into the whole procedure of parameter generation, scrambling, and diffusion. Experiments and algorithm analyses show that our algorithm has strong security, desirable performance, and a broader scope of application.

Three-dimensional asymmetric maximum weight lifting prediction considering dynamic joint strength

2021 ◽  
pp. 095441192098703
Author(s):  
Rahid Zaman ◽  
Yujiang Xiang ◽  
Jazmin Cruz ◽  
James Yang
Keyword(s):  
Experimental Data ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Three Dimensional ◽  
Optimization Method ◽  
Weight Lifting ◽  
Joint Torque ◽  
Maximum Weight ◽  
Angular Velocities ◽  
Asymmetric Lifting

In this study, the three-dimensional (3D) asymmetric maximum weight lifting is predicted using an inverse-dynamics-based optimization method considering dynamic joint torque limits. The dynamic joint torque limits are functions of joint angles and angular velocities, and imposed on the hip, knee, ankle, wrist, elbow, shoulder, and lumbar spine joints. The 3D model has 40 degrees of freedom (DOFs) including 34 physical revolute joints and 6 global joints. A multi-objective optimization (MOO) problem is solved by simultaneously maximizing box weight and minimizing the sum of joint torque squares. A total of 12 male subjects were recruited to conduct maximum weight box lifting using squat-lifting strategy. Finally, the predicted lifting motion, ground reaction forces, and maximum lifting weight are validated with the experimental data. The prediction results agree well with the experimental data and the model’s predictive capability is demonstrated. This is the first study that uses MOO to predict maximum lifting weight and 3D asymmetric lifting motion while considering dynamic joint torque limits. The proposed method has the potential to prevent individuals’ risk of injury for lifting.

scholarly journals Electrochemical Approaches for Rapid Characterization of Oxidizable Compounds in Different Oak Alternatives

Beverages ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Jéremie Wirth ◽  
Davide Slaghenaufi ◽  
Stéphane Vidal ◽  
Maurizio Ugliano
Keyword(s):  
Linear Sweep Voltammetry ◽  
Wine Industry ◽  
Wine Aroma ◽  
Total Current ◽  
Strong Correlations ◽  
Tannin Content ◽  
Linear Sweep ◽  
Antioxidant Characteristics ◽  
Rapid Characterization

Oak alternatives (OAs) such as chips, granulates or staves, are becoming increasingly used in the wine industry. Although they are mostly considered for their contribution to wine aroma, they are also a source of phenolic compounds to be released in the wine, in particular ellagitannins contributing to wine mouthfeel and antioxidant characteristics. In the present study, we explore the potential for a rapid analytical method based on linear sweep voltammetry (LSV) combined with disposable sensors to provide a rapid measure of the oxidizable compounds present in different OAs, as well as their characterization. Strong correlations were found between the tannin content of different OAs and the total current measures during LSV analysis, allowing a rapid quantification of the oxidizable compounds present, mostly ellagitannin. Application of derivatization to raw voltammograms allowed extraction of a number of features that can be used for classification purposes, in particular with respect to OAs types (chips or staves) and degree of toasting.

scholarly journals Three-Dimensional Structures of Carbohydrates and Where to Find Them

2020 ◽  
Vol 21 (20) ◽  
pp. 7702 ◽  
Author(s):  
Sofya I. Scherbinina ◽  
Philip V. Toukach
Keyword(s):  
Experimental Data ◽  
Molecular Modeling ◽  
Computational Methods ◽  
Three Dimensional ◽  
Structural Diversity ◽  
Structural Data ◽  
Structural Features ◽  
Data Validation ◽  
Data Generation ◽  
Efficient Treatment

Analysis and systematization of accumulated data on carbohydrate structural diversity is a subject of great interest for structural glycobiology. Despite being a challenging task, development of computational methods for efficient treatment and management of spatial (3D) structural features of carbohydrates breaks new ground in modern glycoscience. This review is dedicated to approaches of chemo- and glyco-informatics towards 3D structural data generation, deposition and processing in regard to carbohydrates and their derivatives. Databases, molecular modeling and experimental data validation services, and structure visualization facilities developed for last five years are reviewed.

Sign in / Sign up

Export Citation Format

Share Document