scholarly journals Исследование динамики формирования плазмоидов в гатчинском разряде

2021 ◽  
Vol 91 (7) ◽  
pp. 1108
Author(s):  
Shixin Zhao ◽  
Chengxun Yuan ◽  
А.А. Кудрявцев ◽  
О.М. Жеребцов ◽  
Г.Д. Шабанов
Keyword(s):  
Electrical Conductivity ◽  
Water Surface ◽  
Spherical Shape ◽  
Ball Lightning ◽  
Second Phase ◽  
Amount Of Substance ◽  
Initial Voltage ◽  
Ionization Region ◽  
Technological University ◽  
First Time

The results of studies of the Gatchina discharge carried out at the Harbin Technological University (China) are presented. The Gatchina discharge is mainly used to create an analogue of ball lightning in the ordinary atmosphere of a laboratory. Most of the research on this discharge by various groups of scientists is devoted to the study of the first phase of the discharge, when an electric discharge is galvanically coupled to an electrode. This is due to the fact that many researchers consider this phase of the discharge to be decisive for the subsequent long-term existence of an autonomous luminous formation - the second phase of the discharge. In this paper, in comparison with similar works, the leader-streamer process on the water surface was demonstrated more fully and with a better resolution. The use of the filter made it possible to better show the role of leaders, streamers, and the ionization region in the immediate vicinity of the water surface and to clarify some of the processes occurring in the autonomous phase of the discharge. In the wavelength range of 400-500 nm, the autonomous luminous formation showed a longer lifetime in the form of a spherical shape than when observed in "white" light. With a sharp increase in the amount of substance introduced to the cathode, a new physical effect was recorded, which consists in the fact that in the medium of an ordinary atmosphere, a complex formation of a white color is formed without losing contact with the electrode (cathode). By varying the electrical conductivity and initial voltage, an unexpectedly small luminous formation with a diameter of 15-17 mm was obtained for the first time, which was not previously observed in a Gatchina discharge. Key words: Gatchina discharge, plasmoid, long-lived luminous formations, plasma sheet, space charge, virtual cathode, ball lightning. By varying the electrical conductivity and the initial voltage, an unexpectedly small luminous formation with a diameter of 15-17 mm was obtained for the first time, which was not previously observed in the Gatchina discharge.

TBE in Sweden

2020 ◽  
Keyword(s):  
Genetic Characterization ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Second Phase ◽  
Serum Samples ◽  
Tick Borne Encephalitis ◽  
Specific Immunoglobulin ◽  
Tick Borne Encephalitis Virus ◽  
First Time

Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.

An Expert Software for Multi-Layer Coatings Design in Surface Engineering

2008 ◽  
Vol 595-598 ◽  
pp. 583-591 ◽  
Author(s):  
Céline Bondoux ◽  
Christophe Degrandcourt ◽  
George Ailinca ◽  
Pierre D'Ans ◽  
Marc Degrez ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Expert System ◽  
Surface Engineering ◽  
Corrosion And Wear ◽  
Surface Finishing ◽  
Future Developments ◽  
First Time ◽  
Layer Coating ◽  
Main Operation

For the first time, a unique expert system able to give assistance to designers in surface engineering has been built. Not only is this software able to provide multi-layer coating solutions, but it is also able to rank different solutions according to their technico-economical interest. In addition to its ability to solve corrosion and wear concerns, it is also able to deal with surface finishing properties (like brightness, weldability, electrical conductivity, biocompatibility, …). This paper describes the structure of this expert system together with its main operation principles and future developments.

scholarly journals Investigation and Modeling of the Electrical Conductivity of Graphene Nanoplatelets-Loaded Doped-Polypyrrole

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1034
Author(s):  
Oladipo Folorunso ◽  
Yskandar Hamam ◽  
Rotimi Sadiku ◽  
Suprakas Sinha Ray ◽  
Neeraj Kumar
Keyword(s):  
Electrical Conductivity ◽  
Structural Changes ◽  
Spherical Shape ◽  
Graphene Nanoplatelets ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Energy Storage Applications ◽  
Electrical Conductivity Data

In this study, a hybrid of graphene nanoplatelets with a polypyrrole having 20 wt.% loading of carbon-black (HGPPy.CB20%), has been fabricated. The thermal stability, structural changes, morphology, and the electrical conductivity of the hybrids were investigated using thermogravimetric analyzer, differential scanning calorimeter, X-ray diffraction analyzer, scanning electron microscope, and laboratory electrical conductivity device. The morphology of the hybrid shows well dispersion of graphene nanoplatelets on the surface of the PPy.CB20% and the transformation of the gravel-like PPy.CB20% shape to compact spherical shape. Moreover, the hybrid’s electrical conductivity measurements showed percolation threshold at 0.15 wt.% of the graphene nanoplatelets content and the curve is non-linear. The electrical conductivity data were analyzed by comparing different existing models (Weber, Clingerman and Taherian). The results show that Taherian and Clingerman models, which consider the aspect ratio, roundness, wettability, filler electrical conductivity, surface interaction, and volume fractions, closely described the experimental data. From these results, it is evident that Taherian and Clingerman models can be modified for better prediction of the hybrids electrical conductivity measurements. In addition, this study shows that graphene nanoplatelets are essential and have a significant influence on the modification of PPy.CB20% for energy storage applications.

scholarly journals Bio-inspired silver selenide nano-chalcogens using aqueous extract of Melilotus officinalis with biological activities

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Seyedeh Zahra Mirzaei ◽  
Hamed Esmaeil Lashgarian ◽  
Maryam Karkhane ◽  
Kiana Shahzamani ◽  
Alaa Kamil Alhameedawi ◽  
...  
Keyword(s):  
Aqueous Extract ◽  
Biomedical Applications ◽  
Size Range ◽  
Biological Activities ◽  
Spherical Shape ◽  
Silver Selenide ◽  
Melilotus Officinalis ◽  
Uv Visible ◽  
Dpph Scavenging ◽  
First Time

AbstractFor the first time, an aqueous extract of Melilotus officinalis was used to synthesize bimetallic silver selenide chalcogenide nanostructures (Ag2Se-NCs). The formation of NCs was confirmed and characterized by UV–visible and FTIR spectroscopy, SEM and TEM imaging, XRD and EDX crystallography, zeta potential (ZP) and size distribution (DLS). The bioactivities of biosynthesized Ag2Se-NCs, such as antibacterial, antibiofilm, antioxidant and cytotoxicity potentials, were then examined. Bio-based Ag2Se-NCs were successfully synthesized with mostly spherical shape in the size range of 20–40 nm. Additionally, the MIC and MBC values of Ag2Se-NCs against β-lactam-resistant Pseudomonas aeruginosa (ATCC 27853) were 3.12 and 50 µg/ml, respectively. The DPPH scavenging potential of Ag2Se-NCs in terms of IC50 was estimated to be 58.52. Green-synthesized Ag2Se-NCs have been shown to have promising benefits and could be used for biomedical applications. Although the findings indicate promising bioactivity of Ag2Se-NCs synthesized by M. officinalis extract (MO), more studies are required to clarify the comprehensive mechanistic biological activities.

scholarly journals Анизотропия анионной проводимости в монокристаллах суперионного проводника CeF-=SUB=-3-=/SUB=-

2021 ◽  
Vol 63 (9) ◽  
pp. 1376
Author(s):  
Н.И. Сорокин ◽  
В.В. Гребенев ◽  
Д.Н. Каримов
Keyword(s):  
Electrical Conductivity ◽  
Atomic Structure ◽  
Unit Cell ◽  
Conductivity Measurements ◽  
Weak Anisotropy ◽  
Tysonite Structure ◽  
Maximum Value ◽  
Anisotropy Effect ◽  
First Time ◽  
Anionic Conductivity

The anisotropy of anionic conductivity in crystals of a superionic conductor CeF3 with the tysonite structure (sp. gr. P-3с1) has been studied for the first time. The conductivity measurements at temperatures from 300 K to 600 K were carried out along the principal a- and c-axes of trigonal unit cell of the crystal. The maximum value of electrical conductivity is observed along the c-axis. The superionic CeF3 crystals have the weak anisotropy of electrical conductivity equal to σ||c/σ||a = 2.4 and σ||c = 5.6 10–4 S/cm at 500 K. The anisotropy effect of anionic conductivity in individual fluorides with the tysonite structure is discussed in connection with the peculiarities of their atomic structure.

scholarly journals Tuning capacitance wire-mesh sensor gains for measurement of conductive fluids

2021 ◽  
Vol 88 (s1) ◽  
pp. s107-s113
Author(s):  
Felipe d. A. Dias ◽  
Philipp Wiedemann ◽  
Marco J. da Silva ◽  
Eckhard Schleicher ◽  
Uwe Hampel
Keyword(s):  
Electrical Conductivity ◽  
Cross Talk ◽  
Tap Water ◽  
Conductivity Measurement ◽  
Wire Mesh ◽  
Energy Losses ◽  
Flow Parameters ◽  
Front End ◽  
Multiphase Fluids ◽  
First Time

Abstract In this paper, the front-end circuit of a capacitance wire-mesh sensor (WMS) is analyzed in detail and a new methodology to tune its feedback gains is reported. This allows, for the first time, a capacitance WMS to be able to provide linear measurements of multiphase fluids with electrical conductivity greater than 100 𝜇S/cm, which is particularly important for tap water, where the conductivity is typically in between 100 S/cm and 500 𝜇S/cm. Experimental and numerical results show that the selected gains using the proposed methodology contribute to suppress cross-talk and energy losses, which in turn, reduces considerably the deviation of the conductivity measurement and the estimation of derived flow parameters, such as local and average phase fraction.

Description of the mature larva and pupa of Ora semibrunnea Pic (Coleoptera: Scirtidae) with notes on its biology

Zootaxa ◽  
2019 ◽  
Vol 4551 (1) ◽  
pp. 53 ◽  
Author(s):  
GABRIELLE JORGE ◽  
MARÍA LAURA LIBONATTI ◽  
CESAR JOÃO BENETTI ◽  
NEUSA HAMADA
Keyword(s):  
Water Surface ◽  
Brazilian Amazon ◽  
First Record ◽  
Biological Information ◽  
Mature Larva ◽  
Natural Lakes ◽  
Morphological Adaptations ◽  
Brazilian Amazon Region ◽  
And Behavior ◽  
First Time

In this paper we describe and illustrate for the first time the immature forms (larva and pupa) of Ora semibrunnea Pic, 1922, including biological information and behavior observed in the laboratory. This is the first record of the occurrence of this species in the Brazilian Amazon region. Larvae and pupae were found in natural lakes associated with macrophyte banks. Pupae are aquatic and have morphological adaptations (well-developed pronotal siphons) to obtain atmospheric O2 at the water surface. 

Effect of Solution Treatment on Second Phase Dissolution for an Al-9.2Zn-2.0Mg-1.9Cu Alloy

2020 ◽  
Vol 993 ◽  
pp. 321-326
Author(s):  
Hong Wei Liu ◽  
Kai Wen ◽  
Xi Wu Li ◽  
Zhi Hui Li ◽  
Li Zhen Yan ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Solution Temperature ◽  
Second Phase ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
Phase Dissolution ◽  
Solution Treated ◽  
The Matrix

The second phase dissolution of Al-9.2Zn-2.0Mg-1.9Cu alloy conducted by various temperatures of 2h was researched with the help of optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), electrical conductivity and differential scanning calorimetry (DSC) analysis. The results gave rise to the second phase existence of Mg(Zn,Cu,Al)2 and Fe-containing phases in the as-extruded alloy. When the alloy solution treated with a temperature varied from 450°C to 470°C, a small quantity of Mg(Zn,Cu,Al)2 phase still existed in the alloy while its content exhibited a decrement trend with the solution temperature rose. For the alloy solution treated at a temperature of 475°C, Mg(Zn,Cu,Al)2 phase dissolved into the matrix completely while Fe-containing phase still remained. The electrical conductivity of quenched alloy decrease with the solution temperature increase and reached a minimum value at 470°C, and then rose slightly for the solution temperature of 475°C.

The Hall Carrier Mobility of AgBiTe2-Ag2Te Composite

2001 ◽  
Vol 691 ◽  
Author(s):  
T. Sakakibara ◽  
Y. Takigawa ◽  
K. Kurosawa
Keyword(s):  
Electrical Conductivity ◽  
Composite Material ◽  
Composite Materials ◽  
Hall Coefficient ◽  
Carrier Mobility ◽  
Matrix Phase ◽  
Second Phase ◽  
Temperature Range ◽  
The Matrix ◽  
Van Der Pauw

ABSTRACTWe prepared a series of (AgBiTe2)1−x(Ag2Te)x(0≤×≤1) composite materials by melt and cool down [1]. The Hall coefficient and the electrical conductivity were measured by the standard van der Pauw technique over the temperature range from 93K to 283K from which the Hall carrier mobility was calculated. Ag2Te had the highest mobility while the mobility of AgBiTe2was the lowest of all samples at 283K. However the mobility of the (AgBiTe2)0.125(Ag2Te)0.875composite material was higher than the motility of Ag2Te below 243K. It seems that a small second phase dispersed in the matrix phase is effective against the increased mobility.

scholarly journals Photocontrolled organic field effect transistors based on the fullerene C60 and spiropyran hybrid molecule

RSC Advances ◽  
2019 ◽  
Vol 9 (13) ◽  
pp. 7505-7508 ◽  
Author(s):  
A. R. Tuktarov ◽  
R. B. Salikhov ◽  
A. A. Khuzin ◽  
N. R. Popod'ko ◽  
I. N. Safargalin ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Active Layer ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Fullerene C60 ◽  
Organic Field Effect Transistors ◽  
Hybrid Molecule ◽  
Hybrid Compound ◽  
First Time

Photocontrolled organic field-effect transistors (OFETs) containing a hybrid compound of fullerene C60 (n-semiconductor) with spiropyran (electrical conductivity photocontroller) as the active layer were fabricated for the first time.

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