49 research outputs found
High Power Argon, Nitrogen Plasma Torches
© Published under licence by IOP Publishing Ltd. The paper describes a high power supply for Argon and Nitrogen plasma torches. A high frequency was used in order to drive the pulse width modulation circuit. The average output current consumption (AOCC) was modified from 20A up to 80A by increasing the pulse width from 2μsec up to 3μsec for Argon gas plasma torches. The (AOCC) was reduced from 70A down to 25A by increasing the pulse width from 6μsec up to 8μsec in the case of Nitrogen gas plasma torches
Step-Down dc-dc Converter for Low Temperature Plasma
© 2018 Institute of Physics Publishing. All rights reserved. This paper presents a step down converter with a high speed rectifier and filter for Argon plasma torches. Buck circuit with a high frequency pulse width modulation control and very fast MOSFET transistor were used for switching. For Argon (Ar) gas Plasma Torches, and by increasing the pulse width, the average output voltage has modified from 80 V up to 100 V. The frequency of the designed step down converter was steady at 20 KHz
Experimental setup for plasma treatment of disperse materials in the arc plasma jet
The experimental setup for the plasma treatment of particulate materials was created. Spend the processing of composite powder of chromium oxide with aluminium oxide
Practical experience of using ultrasound flowmeters at the measurement associated petroleum gas
© Published under licence by IOP Publishing Ltd. The results of field tests of several ultrasound flowmeters at existing oil and gas extraction objects are given in the paper. Measured medium - associated petroleum gas. This work aims to create a unified system for measuring the amount and parameters of APG in order to reduce operating costs
Novel self-assembling system based on resorcinarene and cationic surfactant
Mixed association of calix[4]resorcinarene with ethyl sulfonate groups on the lower rim and dimethylaminomethyl groups on the upper rim (CR) and cationic surfactant 4-aza-1-hexadecyl-azoniabicyclo[2.2.2]octane bromide (DABCO-16) is studied by methods of tensiometry, conductometry, potentiometry and NMR spectroscopy at fixed CR concentration and varied surfactant concentration. Beyond ca. 0.4 mM of DABCO-16, mixed aggregates enriched by CR are proved to be formed due to electrostatic forces, while beyond ca. 5 mM, aggregates enriched by surfactant occur due to the hydrophobic effect. Spectrophotometry monitoring of the solubilization of a hydrophobic dye, Orange OT, demonstrated that only the second type of mixed aggregate enriched by DABCO-16 is capable of binding the organic probe, while the mixed system where the surfactant is a minor component shows no binding capacity towards Orange OT. This finding can be used for the design of nanocontainers with controllable binding/release properties.Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
Regularity Properties and Pathologies of Position-Space Renormalization-Group Transformations
We reconsider the conceptual foundations of the renormalization-group (RG)
formalism, and prove some rigorous theorems on the regularity properties and
possible pathologies of the RG map. Regarding regularity, we show that the RG
map, defined on a suitable space of interactions (= formal Hamiltonians), is
always single-valued and Lipschitz continuous on its domain of definition. This
rules out a recently proposed scenario for the RG description of first-order
phase transitions. On the pathological side, we make rigorous some arguments of
Griffiths, Pearce and Israel, and prove in several cases that the renormalized
measure is not a Gibbs measure for any reasonable interaction. This means that
the RG map is ill-defined, and that the conventional RG description of
first-order phase transitions is not universally valid. For decimation or
Kadanoff transformations applied to the Ising model in dimension ,
these pathologies occur in a full neighborhood of the low-temperature part of the first-order
phase-transition surface. For block-averaging transformations applied to the
Ising model in dimension , the pathologies occur at low temperatures
for arbitrary magnetic-field strength. Pathologies may also occur in the
critical region for Ising models in dimension . We discuss in detail
the distinction between Gibbsian and non-Gibbsian measures, and give a rather
complete catalogue of the known examples. Finally, we discuss the heuristic and
numerical evidence on RG pathologies in the light of our rigorous theorems.Comment: 273 pages including 14 figures, Postscript, See also
ftp.scri.fsu.edu:hep-lat/papers/9210/9210032.ps.
Athlome Project Consortium: a concerted effort to discover genomic and other "omic" markers of athletic performance.
Despite numerous attempts to discover genetic variants associated with elite athletic performance, injury predisposition, and elite/world-class athletic status, there has been limited progress to date. Past reliance on candidate gene studies predominantly focusing on genotyping a limited number of single nucleotide polymorphisms or the insertion/deletion variants in small, often heterogeneous cohorts (i.e., made up of athletes of quite different sport specialties) have not generated the kind of results that could offer solid opportunities to bridge the gap between basic research in exercise sciences and deliverables in biomedicine. A retrospective view of genetic association studies with complex disease traits indicates that transition to hypothesis-free genome-wide approaches will be more fruitful. In studies of complex disease, it is well recognized that the magnitude of genetic association is often smaller than initially anticipated, and, as such, large sample sizes are required to identify the gene effects robustly. A symposium was held in Athens and on the Greek island of Santorini from 14-17 May 2015 to review the main findings in exercise genetics and genomics and to explore promising trends and possibilities. The symposium also offered a forum for the development of a position stand (the Santorini Declaration). Among the participants, many were involved in ongoing collaborative studies (e.g., ELITE, GAMES, Gene SMART, GENESIS, and POWERGENE). A consensus emerged among participants that it would be advantageous to bring together all current studies and those recently launched into one new large collaborative initiative, which was subsequently named the Athlome Project Consortium
High Frequency High Power Full Bridge Converter for Plasma Torches
© Published under licence by IOP Publishing Ltd.This paper presents a full bridge converter with a high speed rectifier and filter for plasma torches. Full bridge circuit with high frequency pulse width modulation control is used and high frequency transformer to insulate is adopted. For Argon (Ar) gas Plasma Torches, and by increasing the pulse width the average power consumption has modified from 1KW to 5.6KW (positive load). For Nitrogen (N2) gas Plasma Torches, and by increasing the pulse width the average power consumption has reduced from 7.7KW down to 3KW (negative load). For the Plasma Torches load the frequency of converter was steady at 50KHz
Changing their world : concepts and practices of women's movements
© Published under licence by IOP Publishing Ltd.This paper presents a full bridge converter with a high speed rectifier and filter for plasma torches. Full bridge circuit with high frequency pulse width modulation control is used and high frequency transformer to insulate is adopted. For Argon (Ar) gas Plasma Torches, and by increasing the pulse width the average power consumption has modified from 1KW to 5.6KW (positive load). For Nitrogen (N2) gas Plasma Torches, and by increasing the pulse width the average power consumption has reduced from 7.7KW down to 3KW (negative load). For the Plasma Torches load the frequency of converter was steady at 50KHz
High Power Argon, Nitrogen Plasma Torches
© Published under licence by IOP Publishing Ltd. The paper describes a high power supply for Argon and Nitrogen plasma torches. A high frequency was used in order to drive the pulse width modulation circuit. The average output current consumption (AOCC) was modified from 20A up to 80A by increasing the pulse width from 2μsec up to 3μsec for Argon gas plasma torches. The (AOCC) was reduced from 70A down to 25A by increasing the pulse width from 6μsec up to 8μsec in the case of Nitrogen gas plasma torches