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Mechanisms of electrical conductivity, quantum capacity and negative capacitance effects in InSe (PTHQ) nanohybrid

Ivashchyshyn Fedir, Maksymych Vitaliy, Calus Dariusz, Klapchuk Myroslava, Baryshnikov Glib, Galagan Rostislav, Litvin Valentina, Chabecki Piotr, Bordun Ihor

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2022

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Vol. 70, nr 1

art. no. e139958

EN

In this work, we present findings on the syntheses and study of properties of InSe < PTHQ > nanohybrid. The introduction of guest component in GaSe matrix leads to an increase in inhomogeneities, which is clearly confirmed by the strengthening of the low-frequency horizontal branch of Nyquist diagrams. A constant magnetic field counteracts this effect and changes the behavior of the impedance hodograph at low frequencies to the opposite. Illumination leads to a colossal increase in quantum capacitance, which is clearly demonstrated in the Nyquist diagram. For the synthesized InSe < PTHQ > nanohybrid the interesting behavior of the current-voltage characteristic is reported. As a result of studies of the synthesized InSe < PTHQ > nanohybrid the effect of “negative capacity” is observed, the magnitude of which can be controlled by the electric field. Based on the constructed impedance model and proposed N-barrier model, the physical mechanisms of the investigated processes are suggested.

2

An in Situ Crystal Growth of Metal Organic Frameworks-5 on Electrospun PVA Nanofibers

Talmoudi H., Khenoussi N., Adolphe D., Said A. H., Schacher L.

Autex Research Journal

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2018

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Vol. 18, no. 3

308--313

EN

In this study, a simple, general and straightforward method for growing metal-organic frameworks (MOFs) crystals directly on nanofibers is presented. A chelating polymer was first blent with metal cation and then electrospun. The obtained nanofibers were immersed in a linker solution. Metal cations were released and the metal-organic frameworks crystals were grown on the fibers’ surface. In this work, this method was tested with polyvinyl alcohol as chelating polymer, Zn2+ as metal cation and Terephthalic acid as linker. The pair cation/linker corresponds to the MOF-5. The latter is a robust metal organic framework formed from Zn4O nodes with 1,4-benzodicarboxylic acid struts between the nodes. SEM images revealed that the MOF-5 nanocrystals have grown along the PVA/Zn2+ nanofibers that served as the crystals’ growth template by providing the Zn2+ ions. This result was also confirmed by infrared spectroscopy, which indicates the presence of characteristic bands of MOF-5 in the modified nanofibers spectrum. Moreover, the X-ray diffraction showed that MOF-5 material was well crystallized on the nanofibers surface according to a cubic symmetry with a space group Fm-3m and a lattice constant a = 25.8849 Å.

3

The use of hierarchical structures for design of high-speed digital comparators on FPGA/SoC

Salauyou V.

Measurement Automation Monitoring

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2016

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Vol. 62, No. 6

196--198

EN

This paper presents a design method of high-speed digital comparators on FPGA/SoC by means of hierarchical structures. A synthesis technique of hierarchical structures for comparators is offered. In this technique, the comparator best hierarchical structure is empirically found for a certain FPGA family. The proposed method allows reducing a delay for 256-bits comparators by 1.245 to 2.516 times as compared with a traditional approach, and for 512-bits comparators by 3.399 times. The method also allows reducing an area by 40.2% on occasion.

4

Hierarchical control structures

Findeisen W.

Control and Cybernetics

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2000

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Vol. 29, no 1

69-78

EN

Control of complex systems, where maany detailed decisions are to be made on a current basis, along with long-term considerations, calls for structures composed of a multitude of decision units. This, in turn, may lead to various conflicts. The latter are to be predicted and counteracted by appropriate measures in the design of decision structure as well as in the course of its operation. Allocation of information and the language of communication between various levels of the hierarchy also are of the prime importance.

5

Diagnostics of processes in decentralized structures

Kościelny J. M.

Archives of Control Sciences

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1998

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Vol. 7, no. 3/4

181-202

EN

The paper presents rules for diagnosis formulation in hierarchical systems. The rules can be applied in industrial process diagnostics realized in decentralized structures. Formalized description of an object of diagnosis as well as general rules for diagnosis formulation have been presented in the paper. The method of hierarchical description of the object of diagnosis has been given. Decentralized structures have feedbacks between the subobjects that cause symptoms of faults in one subobject to appear in other ones. Rules for fault isolation in such structures have been presented. Considerations are illustrated with help of examples.