9 research outputs found
A new sensitive electrochemical method for the determination of vanadium(IV) and vanadium(V) in Benfield sample
Vanadium(IV) and vanadium(V) can be determined by using differential pulse cathodic stripping voltammetry technique (DPCSV). Cupferron (ammonium N-nitrosophenylhydroxylamine) was used as ligand to form complex compounds with vanadium ions in Britton-Robinson buffer (BRB) solution. At concentration lower than 1.0Ă10-6 M, both V(IV) and V(V) cupferron complexes showed a single cathodic peak at -0.576 V in BRB of pH 4; thus V(IV) and V(V) ions cannot be differentiated at low concentration. However, the ionic species of vanadium can be differentiated at high concentration in the presence of cupferron. Parameters including pH of BRB solution, initial potential and accumulation potential were optimized. Under the optimized parameters, the limit of detection (LOD) was 0.09 nM, and the peak current was linear in the concentration range 0.01-0.9 ”M total vanadium ions. The determination of V(IV) and V(V) ions was carried out at higher concentration in the sample using calibration plot method. At higher concentration range of 10-60 ”M V(IV) and V(V) ions were determined with LOD of 1.2 and 1.1 ”M, respectively. The developed method was successfully applied to 10,00,000 fold diluted Benfield sample and 0.6227 M total vanadium ions were determined. The determination of V(IV) and V(V) ions were also successfully carried out in artificial sample as well as Benfield sample (dilution factor, 10,000). The concentration of V(IV) and V(V) ions was 22.52 ”M and 38.91 ”M, respectively, giving total vanadium concentration of 0.6143 M in Benfield sample
A Survey on Security Issues and Attacks of Fog Computing
There is a link between the cloud and the Internet of Things (IoT). The layer that makes up the dispersed network environment is exactly what it is. Cloud computing is brought out to the edge of the network through the type of networking topology referred as fog computing. Users can benefit greatly from fog computing. Fog's primary role, similar to cloud computing, is to allow people mobility. Fog computing is becoming more and more popular, whereas at the same time, security dangers are growing every day. Users' identification & verification are crucial. The fact of fog computing cannot effectively utilize the security and privacy solutions provided by cloud computing must be emphasized. The risks, issues, and solutions linked to security in fog computing are outlined throughout this study. The poll then includes information on ongoing research projects as well as open security and safety concerns for fog computing
Methods for the determination of endocrine-disrupting phthalate esters
Phthalates are endocrine disruptors frequently occurring in the general and industrial environment and in many industrial products. Moreover, they are also suspected of being carcinogenic, teratogenic, and mutagenic, and they show diverse toxicity profiles depending on their structures. The European Union and the United States Environmental Protection Agency (US EPA) have included many phthalates in the list of priority substances with potential endocrine-disrupting action. They are: dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butylbenzyl phthalate (BBP), diethylhexyl phthalate (DEHP), di-iso-nonyl phthalate (DINP), di-iso-decyl phthalate (DIDP), di-n-decyl phthalate (DnDP), and dioctyl phthalate (DOP). There is an ever-increasing demand for new analytical methods suitable for monitoring different phthalates in various environmental, biological, and other matrices. Separation and spectrometric methods are most frequently used. However, modern electroanalytical methods can also play a useful role in this field because of their high sensitivity, reasonable selectivity, easy automation, and miniaturization, and especially low investment and running costs, which makes them suitable for large-scale monitoring. Therefore, this review outlines possibilities and limitations of various analytical methods for determination of endocrine-disruptor phthalate esters in various matrices, including somewhat neglected electroanalytical methods
L-cysteine-mediated self-assembled Ag-Au nanoparticles as fractal patterns with bowling-alley-like hollow arrays for electrochemical sensing of dopamine
In this study, hierarchical self-assembly of Au-Ag fractal patterns with bowling-alley-like hollow arrays was achieved by a hydrothermal method using L-cysteine as an environmentally friendly reducing and stabilizing reagent. Here, free thiol groups of cysteine molecules electrostatically stabilized gold and silver nanoparticles (NPs). The plasmonic resonance red-shift of Au-Ag was confirmed from self-assembled fractal patterns that consist of micro/nano fern structures forming bowling-alley-like hollow arrays. The as-synthesized large-area hierarchical self-assembly of Au-Ag fractal patterns with the synergistic catalytic advantage of a Au and Ag NPs/glassy carbon electrode (GCE) is investigated as a potential electrochemical dopamine (DA) sensor. The biosensor based on a GCE modified with bimetallic nanoparticle fractals exhibited a reversible electrochemical behavior with limits of detection and quantification of 0.014 and 0.048 mu M, respectively. Detection of DA using the developed electrochemical sensor has several advantages, such as low cost, ease-of-use, sensitivity, and stability, that can be potentially applied for detection in a variety of chemical and biosensing applications