A new ONO-tridentate Schiff base ligand (H
2
L) derived from 3-methoxysalicylaldehyde and nicotinic hydrazide was synthesized and characterized by elemental analysis, FT-IR,
1
H NMR,
13
C NMR, ...UV–Vis, and powder XRD studies. Then, oxovanadium(V) and dioxomolybdenum(VI) Schiff base complexes, VOL and MoO
2
L, were also prepared and characterized by different techniques. Moreover, the catalytic activities of both complexes were investigated for the synthesis of benzimidazoles, benzoxazoles, and benzothiazoles under reflux conditions as well as through ultrasonic irradiation. The results revealed several advantages of this procedure, including high product yields, short reaction times, facile work-up procedure, simplicity in operation, eco-friendly reaction conditions, and green aspects by avoiding toxic catalysts and solvents.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The effective, selective, and electrochemically steady cetyltrimethylammonium bromide drop-casted carbon paste electrode was constructed for the detection of amoxicillin in presence of dopamine ...through cyclic voltammetry method. The modified and unmodified electrode materials were characterized by various methods like field emission scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy with acceptable results. The constructed modified sensor delivers a higher electrocatalytic nature for the oxidation of 0.1 mM amoxicillin in 0.1 M phosphate buffer saline of 6.5 pH with high peak current and lower peak potential than the bare carbon paste electrode. The analytical applicability of modified electrode for amoxicillin electro-oxidation was detected by increasing the amoxicillin concentration in the range from 10 to 150 µM with fine limit of detection and the limit of quantification of 5.90 µM and 19.67 µM, respectively. This article discloses a facile and recommended approach for the concurrent inspection of amoxicillin in the presence of dopamine. The modified sensor gives high stability, repeatability, reproducibility, and sensitivity. The premeditated method and modified sensor give a fine recovery for amoxicillin detection in medication sample.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract Since the industrial revolution the world economy has grown thanks to energy generated by cheap and abundant fossil resources. Today, due to climate change caused by human-induced CO 2 and ...other greenhouse gas emissions, we are in the midst of a shift away from fossil fuels and towards renewable energy. It remains to be seen how fast this shift will happen and whether the correlating economics are feasible. Increasingly, experts are asking: what role will catalysis play to help drive energy efficiency? With a 60-year history in industrial catalysis, Clariant’s Catalysts business has been a front runner in catalyst and technology development. For more than a decade we have been working in the catalytic Power-to-X segments. This paper presents our understanding on current developments around the important role of Power-to-X and Waste-to-X technologies to enable a worldwide transition of the energy sector to renewables. Graphical abstract
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Abstract This work is focused on the visualization of latent fingerprints left on unfired brass cartridges. Polymer films were prepared from 2 mM neutral red or 5 mM toluidine blue using two ...different electrochemical methods (cyclic voltammetry or chronoamperometry) with relatively short polymerization times. The conditions for the deposition of conductive polymers, poly(neutral red) and poly(toluidine blue), from a neutral medium (phosphate buffer with 0.1 M KNO 3 or 0.1 M KNO 3 , respectively) were optimized to produce high-quality visualization of the remaining fingerprints on the brass substrates. The surface morphology and quality of the polymer films after the electrochemical deposition of both polyphenazine dyes were characterized by stereomicroscope. Phenazine dyes, which were used for the visualization of fingerprints, have been shown to provide different degrees of homogeneity in the deposited film. Furthermore, the dependence of the stability of the monomer solutions on their age, use, and storage conditions are discussed. Finally, a methodology is proposed for how to apply this technique of visualizing latent fingerprints with observed details of papillary lines in forensic practice. Graphical abstract
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Etoposide is an antineoplastic agent obtained from the plant extract and also has anti-cancer properties. In this study, a pencil graphite electrode was used for the first time for the ...electrochemical properties and quantification of etoposide in the presence of anionic surfactant. For this purpose, square wave and ciyclic voltammetry techniques were used. Etoposide in Britton-Robinson (pH 3.0, containing 5 mM anionic surfactant) medium gave an irreversible oxidation peak at about + 0.732 V. In the suggested voltammetric method, LOQ = 0.521 µM and LOD = 0.156 µM values were obtained in the concentration range of 0.705–6.34 μΜ
I
p
(µA) = 0.6621
C
(μΜ)–0.5755 (
r
= 0.983),
n
= 9). The fact that the developed voltammetric method is simple, fast, and sensitive is seen as an important advantage. In addition, the applicability of this proposed voltammetric method to drug and urine samples has proven the selectivity of the method.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Functional composites of electronic and ionic conductors are the backbone of oxygen and fuel electrodes in solid oxide cells. A typical oxygen electrode is fabricated from a lanthanum strontium ...manganite and yttria-stabilized zirconia (LSM-YSZ) composite, while the fuel electrode is based on a Ni-YSZ cermet. While the composite materials exhibit enhanced kinetic capabilities, the electron-conductive phases, i.e., LSM and Ni, exhibit high electrical conductivity. The goal of this study was to develop an electrode layout with enhanced performance by tailoring the benefits of both, the composites and the single-phase electron conductors, within individual electrodes. The electrodes were fabricated in a two-layer layout with different thicknesses by screen-printing: composite material layer, electron-conductive material. The results suggested that the presence of YSZ is essential in the entire electrode body of a fuel electrode for enhanced performance as it increases the triple phase boundary length, as well as mechanical stability by forming a scaffold for the Ni network. Hence, for the optimal performance a thick layer of Ni-YSZ composite is required. On the contrary, the optimal oxygen electrode requires only very thin layer of the composite, otherwise the presence of YSZ is retarding the electrode’s performance.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The symmetric supercapacitors (SC) are electrochemical capacitors with higher energy density than conventional ones. Both their positive and negative electrodes contain the same type of electrode ...active material. Carbon xerogels are a kind of carbon material which properties can be designed, structurally and chemically, in order to fit the requirements for their final application. They possess tunable porosity, high purity, and electrical conductivity and are very relevant for their use as active material for electrodes in supercapacitors. In this study, the electrochemical properties of symmetric supercapacitors were compared by using a polymer Aquivion™ electrolyte membrane (as electrolyte and separator) and the common aqueous electrolyte (i.e., 1 M KOH). The membrane was previously exchanged to the K
+
-form by immersion in 1 M KOH. The electrode active material was an activated carbon xerogel (AX-1500) prepared by polymerization of resorcinol and formaldehyde in a sol–gel microwave-assisted process. Electrochemical tests were carried out by cyclic voltammetry, galvanostatic charge/discharge measurements, impedance analysis, and long-term durability tests. The relationship between the structure and morphology of the carbon xerogel and the nature of the electrolyte was established, which may be relevant for the design of supercapacitors providing high power and energy densities.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The paper deals with the measurement of the cell impedance parameters during discharging of the Li-ion NCR18650B cell. Re (
Z
) and Im (
Z
) of the battery were measured by PEIS method. The results ...of the impedance changes during discharging and charging were plot to Nyquist diagrams. The important values namely
Rs
,
Rsei
,
Rct
,
Csei
,
Qsei
,
Cdl
,
α
, and
σ
were found during discharging of the Li-ion cell with and without using CPE element.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Capillary electrophoresis methods for the separation of carbohydrates with four different detection techniques, namely direct UV, indirect UV, capacitively coupled conductivity, and laser-induced ...fluorescence detection, were tested and their performance was evaluated and compared in terms of linearity, limits of detection and quantitation, repeatability, recovery, analysis time, and sample treatment. The test set of analytes comprised sucrose, glucose, and fructose. The effect of using lactose as an internal standard on the individual methods was investigated, too. The results showed that laser-induced fluorescence detection is a technique of choice for applications requiring the detection of very low amounts of reducing carbohydrates. Contactless conductivity detection is favorable when detection sensitivity is not a crucial parameter but fast and reliable analysis is required. When only a UV detector is available as a standard part of capillary electrophoresis instruments, direct UV detection can be used when analysis time is not a critical parameter. For fast analysis with UV detectors, indirect UV detection is the technique of choice. Finally, to verify the applicability of the tested methods, samples of cola beverage, honey, and orange juice were analyzed and the results obtained by all four methods were compared.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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