Plasma Generation

1983 ◽  
Vol 30 ◽  
Author(s):  
E. Pfender
Keyword(s):  
Electrical Conductivity ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Hydrogen Plasma ◽  
Plasma Temperature ◽  
Thermonuclear Fusion ◽  
Neutral Species ◽  
Plasma Generation ◽  
Electrical Conductivities ◽  
Copper Plasma

In general, a plasma consists of a mixture of electrons, ions,and neutral species. Although there are free electric charges in a plasma, negative and positive charges compensate each other, i.e. overall a plasma is electrically neutral, a property which is known as quasi-neutrality. In contrast to an ordinary gas, the free electric charges in a plasma give rise to high electrical conductivities which may even surpass those of metals. A hydrogen plasma, for example, at atmospheric pressure heated to temperatures of 106 K, has the same electrical conductivity as copper at room temperature. As the plasma temperature increases, the electrical conductivity increases beyond that of copper. Plasma temperatures of the order of 106 K and above are typical for thermonuclear fusion experiments.

scholarly journals Electrospray characteristics of aqueous KCl solutions with various electrical conductivities

2018 ◽  
Author(s):  
Sahand Faraji ◽  
Behnam Sadri ◽  
Babak Vajdi Hokmabad ◽  
Esmaeil Esmaeilzadeh ◽  
Navid Jadidoleslam
Keyword(s):  
Electrical Conductivity ◽  
Experimental Study ◽  
Stainless Steel ◽  
High Voltage ◽  
Room Temperature ◽  
High Voltage Electrode ◽  
Flow Rates ◽  
Conductivity Variation ◽  
Electrical Conductivities ◽  
Stainless Steel Ring

In the present experimental study, the effects of electrical conductivity on electrospraying procedure are investigated.A metallic nozzle with 600 m ID as high voltage electrode and a stainless steel ring as a groundelectrode were employed. Experiments were carried out in still room temperature. Four different aqueous KClsolutions were sprayed in various high voltages and flow rates. Results confirm that spraying modes changeswith conductivity variation. For forming a cone shape, emerging from the nozzle, required applied electric fielddecreases with conductivity increasing. Results also revealed that conductivity of dispersed solution acts a mainrole on forming and elongation of the cones in electrospraying procedure. The size and velocity of emanateddroplets are also investigated in order to gaining some insight to the electrospraying phenomenon.

Temperature Dependence of the Electrical Conductivity of Poly(Benzo[1,2-b:4,5-b'] Dithiophene-4,8-Diyl Vinylene) and Poly(Dodecylthiophene)

1997 ◽  
Vol 488 ◽  
Author(s):  
R. C Hyer ◽  
R. G. Pethe ◽  
T. Yogi ◽  
S. C. Sharma ◽  
J. Wang ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Temperature Dependence ◽  
Low Temperatures ◽  
Room Temperature ◽  
Thermal Fluctuation ◽  
Variable Range Hopping ◽  
Tunneling Model ◽  
Three Samples ◽  
Electrical Conductivities

AbstractWe present results for the electrical conductivity (σ) of thin films of poly(benzo[1,2-b:4,5- b']dithiophene-4,8-diyl vinylene) (PBDV) and poly (dodecylthiophene) (PDDT) as a function of temperature in the range 15-295K. The polymers were doped with FeC13 and PF6 which resulted in electrical conductivities differing by two orders of magnitude at room temperature. We examine three sets of σ(T)-data by using the variable-range hopping (VRH) model that predicts a linear relationship between ln(T1/2σ) and T1/4. We observe a change in the slope of the ln(T1/2σ) vs T14 relationship in all three samples at low temperatures. We also analyze the temperature dependence of the resistivity of PBDV by using the thermal fluctuation-induced tunneling model.

scholarly journals Boosting the Power Factor of Benzodithiophene Based Donor–Acceptor Copolymers/SWCNTs Composites through Doping

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1447
Author(s):  
Zhongming Chen ◽  
Mengfei Lai ◽  
Lirong Cai ◽  
Wenqiao Zhou ◽  
Dexun Xie ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Power Factor ◽  
Room Temperature ◽  
Composite Films ◽  
Side Chain ◽  
Seebeck Coefficients ◽  
Electrical Conductivities ◽  
Before And After ◽  
Donor Acceptor ◽  
Walled Carbon Nanotubes

In this study, a benzodithiophene (BDT)-based donor (D)–acceptor (A) polymer containing carbazole segment in the side-chain was designed and synthesized and the thermoelectric composites with 50 wt % of single walled carbon nanotubes (SWCNTs) were prepared via ultrasonication method. Strong interfacial interactions existed in both of the composites before and after immersing into the 2,3,5,6-Tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) solution as confirmed by UV-Vis-NIR, Raman, XRD and SEM characterizations. After doping the composites by F4TCNQ, the electrical conductivity of the composites increased from 120.32 S cm−1 to 1044.92 S cm−1 in the room temperature. With increasing the temperature, the electrical conductivities and Seebeck coefficients of the undoped composites both decreased significantly for the composites; the power factor at 475 K was only 6.8 μW m−1 K−2, which was about nine times smaller than the power factor at room temperature (55.9 μW m−1 K−2). In the case of doped composites, although the electrical conductivity was deceased from 1044.9 S cm−1 to 504.17 S cm−1, the Seebeck coefficient increased from 23.76 μV K−1 to 35.69 μW m−1 K−2, therefore, the power factors of the doped composites were almost no change with heating the composite films.

Investigation on Microstructure and Properties of Heavily Cold Rolled Cu-Fe Alloys

2010 ◽  
Vol 150-151 ◽  
pp. 847-851
Author(s):  
Zhi Ming Zhou ◽  
Li Wen Tang ◽  
Min Min Cao ◽  
Bin Bin Lei
Keyword(s):  
Electrical Conductivity ◽  
Mass Fraction ◽  
Room Temperature ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Master Alloys ◽  
Electrical Conductivities ◽  
Cold Rolled ◽  
Fe Alloys ◽  
Rolling Strain

CuFe10 and CuFe15 (mass fraction) alloys were prepared by vacuum induction melting and were cold rolled heavily at room temperature. Microstructure, microhardness and electrical conductivity of these alloys were measured at various cold rolled strain levels. The experimental results showed that the microhardness increased rapidly and the electrical conductivity decreases gradually with the increase of rolling strain at first. The microhardness increased slowly while the strain η greater than 2.3. The Fe-rich phases are deformed to ribbons filaments. However, the electrical conductivity increases again after deforming to a certain degree. The final electrical conductivities of heavily cold rolled CuFe10 and CuFe15 alloys were slight lower than vacuum inducing melted master alloys, however, the microhardness had increased about 44% and 47%, respectively.

scholarly journals In-Situ and Ion Implantation Nitrogen Doping on Near Stoichiometric a-SiC:H Films

2004 ◽  
Vol 1 (2) ◽  
pp. 26-30
Author(s):  
A. R. Oliveira ◽  
M. N. P. Carreño
Keyword(s):  
Activation Energy ◽  
Electrical Conductivity ◽  
Ion Implantation ◽  
Nitrogen Doping ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Dark Conductivity ◽  
Implantation Technique ◽  
Electrical Conductivities

In this work we study the nitrogen n-type electrical doping of a-Si0.5C0.5:H films obtained by plasma enhanced chemical vapor deposition (PECVD) utilizing and comparing two doping techniques: in-situ (during the material growth) and ion implantation. The in-situ doped a-SiC:H films were obtained adding different amounts of N2 to the precursor gas mixture. For ion implantation four different nitrogen implanted concentrations were studied (between 1018 and 1021 atoms/ cm3) using multiple energies and doses to define a homogeneously doped layer. The doping experiments are carried out on a-SiC:H samples that present different structural order. The results show that high levels of electrical conductivity can be obtained with ion implantation technique. For in-situ technique the doping effect is also observed but must be improved in order to attain higher electrical conductivities. In the best case the room temperature dark conductivity for the sample implanted with 1021 nitrogens/cm3 was ~10-7 (Ω.cm)-1 and the activation energy was 0.2 eV. For in-situ doping the electrical dark conductivity reached values near 10-10 (Ω.cm)-1 at high temperatures and the activation energy was ~0.6 eV. Despite of the apparent low values of the electrical conductivity, these results are promising because we are dealing with a wide gap material and the doping processes are still not optimized.

Electrical conductivity studies on silica phases and the effects of phase transformation

2019 ◽  
Vol 104 (12) ◽  
pp. 1800-1805
Author(s):  
George M. Amulele ◽  
Anthony W. Lanati ◽  
Simon M. Clark
Keyword(s):  
Electrical Conductivity ◽  
Activation Volume ◽  
Activation Enthalpy ◽  
Hydrogen Charge ◽  
Charge Compensation ◽  
Composition Analysis ◽  
Conductivity Measurements ◽  
Pressure System ◽  
Electrical Conductivities ◽  
Silica Phases

Abstract Starting with the same sample, the electrical conductivities of quartz and coesite have been measured at pressures of 1, 6, and 8.7 GPa, respectively, over a temperature range of 373–1273 K in a multi-anvil high-pressure system. Results indicate that the electrical conductivity in quartz increases with pressure as well as when the phase change from quartz to coesite occurs, while the activation enthalpy decreases with increasing pressure. Activation enthalpies of 0.89, 0.56, and 0.46 eV, were determined at 1, 6, and 8.7 GPa, respectively, giving an activation volume of –0.052 ± 0.006 cm3/mol. FTIR and composition analysis indicate that the electrical conductivities in silica polymorphs is controlled by substitution of silicon by aluminum with hydrogen charge compensation. Comparing with electrical conductivity measurements in stishovite, reported by Yoshino et al. (2014), our results fall within the aluminum and water content extremes measured in stishovite at 12 GPa. The resulting electrical conductivity model is mapped over the magnetotelluric profile obtained through the tectonically stable Northern Australian Craton. Given their relative abundances, these results imply potentially high electrical conductivities in the crust and mantle from contributions of silica polymorphs. The main results of this paper are as follows:The electrical conductivity of silica polymorphs is determined by impedance spectroscopy up to 8.7 GPa.The activation enthalpy decreases with increasing pressure indicating a negative activation volume across the silica polymorphs.The electrical conductivity results are consistent with measurements observed in stishovite at 12 GPa.

scholarly journals Cat-CrNP as new material with catalytic properties for 2-chloro-2-propen-1-ol and ethylene oligomerizations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jacek Malinowski ◽  
Dagmara Jacewicz ◽  
Artur Sikorski ◽  
Mariusz Urbaniak ◽  
Przemysław Rybiński ◽  
...  
Keyword(s):  
Complex Compound ◽  
Atmospheric Pressure ◽  
Room Temperature ◽  
Organometallic Compounds ◽  
Ethylene Oligomerization ◽  
High Catalytic Activity ◽  
New Material ◽  
Activity Requirement ◽  
Olefin Oligomerization ◽  
Xrd Method

AbstractThe contemporary search for new catalysts for olefin oligomerization and polymerization is based on the study of coordinating compounds and/or organometallic compounds as post-metallocene catalysts. However known catalysts are suffered by many flaws, among others unsatisfactory activity, requirement of high pressure or instability at high temperatures. In this paper, we present a new catalyst i.e. the crystalline complex compound possesing high catalytic activity in the oligomerization of olefins, such as 2-chloro-2-propen-1-ol and ethylene under very mild conditions (room temperature, 0.12 bar for ethylene oligomerization, atmospheric pressure for 2-chloro-2-propen-1-ol oligomerization). New material—Cat-CrNP ([nitrilotriacetato-1,10-phenanthroline]chromium(III) tetrahydrate) has been obtained as crystalline form of the nitrilotriacetate complex compound of chromium(III) with 1,10-phenanthroline and characterized in terms of its crystal structure by the XRD method and by multi-analytical investigations towards its physicochemical propeties The yield of catalytic oligomerization over Cat-CrNP reached to 213.92 g · mmol−1 · h−1· bar−1 and 3232 g · mmol−1 · h−1 · bar−1 for the 2-chloro-2-propen-1-ol and ethylene, respectively. Furthemore, the synthesis of Cat-CrNP is cheap, easy to perform and solvents used during preparation are environmentally friendly.

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