Search results for "Electric discharge"
showing 10 items of 13 documents
Exotic SiO(2)H(2) Isomers: Theory and Experiment Working in Harmony.
2016
Replacing carbon with silicon can result in dramatic and unanticipated changes in isomeric stability, as the well-studied CO2H2 and the essentially unknown SiO2H2 systems illustrate. Guided by coupled-cluster calculations, three SiO2H2 isomers have been detected and spectroscopically characterized in a molecular beam discharge source using rotational spectroscopy. The cis,trans conformer of dihydroxysilylene HOSiOH, the ground-state isomer, and the high-energy, metastable dioxasilirane c-H2SiO2 are abundantly produced in a dilute SiH4/O2 electrical discharge, enabling precise structural determinations of both by a combination of isotopic measurements and calculated vibrational corrections. …
Inverting Multiple Residual Stress Components from Multiple Cuts with the Contour Method
2007
An extension of the contour method is presented which allows the measurement of multiple stress components by making multiple cuts. In the contour method, a body is carefully cut in two using wire electric discharge machining (EDM). The contours, or shapes, of the cut surfaces are then measured and used to calculate the original residual stress normal to the cut plane using a simple finite element calculation. In the extension presented here, the two pieces from the original body can be cut again in a transverse direction, and the contours of the new cut surfaces are measured. The stresses calculated on the planes of these second cuts have been affected by the first cut. Then a simple inver…
Atomic Force Microscopy Study of Yeast Cells Influenced by High Voltage Electrical Discharge
2008
Human cells are the eukaryotic ones. Simulation of wide-spectrum electromagnetic radiation influence on eukaryotic cells was performed with yeast which is usually used now in molecular biological and medical biological investigations as the ideal model of eukaryotic system. The aim of the research was to observe possible induced alterations of the cell morphology. Atomic force microscopy (AFM) and electron scanning microscopy (ESM) have been applied to image the surface of cells exposed to electromagnetic radiation.
Individual arc-discharge synthesized multiwalled carbon nanotubes probed with multiple measurement techniques
2020
Arc-discharge synthesized multiwalled carbon nanotubes (AD-MWNT), or related MWNTs, exhibit a good quality compared to the more common type of MWNT synthesized by catalytic chemical vapor deposition methods. Yet experimental measurements on these are rather few and typically have not correlated data from different measurement techniques. Here, the authors report Raman spectroscopy, scanning probe microscopy, conductivity measurements, and force microscopy on single AD-MWNTs. The results demonstrate the high quality of AD-MWNTs and are compatible with the view of them as the best approximation of MWNTs as an assembly of defect-free concentric individual single-walled carbon nanotubes. The au…
The squeezer ion guide
1992
Abstract The properties of an ordinary ion guide can be improved by inserting a grid between the nozzle and the skimmer. When positive ions are transported, an electric potential lower than +10 V is connected to the grid and one of the order of − 10 V to the skimmer. Efficient focusing is achieved between the nozzle and the grid by a combined action of the viscous helium flow field and the weak electric field. The focusing device is called a “squeezer”. It can be extended by adding more grids, a second skimmer, and differential pumping. Contrary to the first grid, the additional elements act more or less like electrostatic lenses in medium vacuum. With the squeezer ion guide, ions created i…
The ion-guide isotope separator on-line at the Tohoku University Cyclotron
1987
Abstract The status of the ion-guide isotope separator on-line at the Tohoku University Cyclotron is reported. The optimum ion-guide parameters were determined from test experiments using atomic and molecular ions ionized with an electric discharge inside the target chamber as well as using 64 Ga(T 1 2 = 2.6 m ) ions produced by the 64Zn(p, n) reaction. Using the present system together with a ΔE−E plastic counter telescope and a germanium detector we identified 16 short-lived nuclei including the first mass-separated nuclei 57Cu and 45V. The efficiency of mass separation for 64Ga was ϵ ∼ 1%, where ϵ is defined as the number of atoms collected at the end of the separator divided by that rec…
Plasma Effecton Pulse Parameters of Sound Wave
2019
This article presents the experimental results of the effect of gas discharge plasma on an acoustic wave. It is shown that after a certain intensity of the acoustic wave, the presence of plasma leads to a decrease in the Q -factor of the acoustic resonator, a shift in the acoustic resonance in the gas discharge tube at a lower frequency, and after switching off the acoustics, low-frequency gas oscillations with a frequency of 2 Hz are generated in the tube.
A dense polarized 3He target based on compression of optically pumped gas
1992
Abstract 3 He-gas is spin polarized by the method of optical pumping of metastables and metastability exchange in a low pressure gas discharge. At a pressure of p ≈ 1.5 Torr a volume of 1 l is polarized within about 30 s to a degree of 50% with 300 mW of incident light from an argon-ion laser pumped LNA laser, tuned to the λ = 1.083 μm resonance line. The polarized gas is compressed by a Toepler pump into a target cell of 120 cm 3 volume. In a first attempt a steady state polarization of 30% has been achieved in the target at a pressure of 685 Torr. The paper analyses the essential parameters governing this technique and pilotes its experimental realization.
Objectivization of the electrical discharge measurement results taken by the acoustic emission method
2006
The subject matter of this paper refers to the improvement of the acoustic emission method (AE) in its application for diagnostics of insulation systems of power appliances whereas the detailed subject matter is connected with determining the possibilities and indicating the range of using statistical and digital methods of signal processing for the evaluation of the AE pulses generated by partial discharges (PDs), which can occur in paper-oil insulation of power transformers.
Toward more realistic viscosity measurements of tyre rubber–bitumen blends
2014
AbstractThe measurement of rheological properties of the tyre rubber bitumen blends is often challenging due to presence of suspended tyre rubber’s crumbs. Furthermore, the phase separation during the course of measurements makes the viscosity of these non-homogeneous blends difficult to ascertain. In this study, a new dual helical impeller was designed and manufactured to be used with a rotational viscometer in order to have a real-time control of the viscosity while performing a laboratory mixing of the blends. Layer based manufacturing techniques showed to be a convenient method to produce complex shaped impeller prototypes before manufacturing the more expensive stainless steel assembly…