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C-2 is a unique, large compact-toroid (CT) device at Tri Alpha Energy that produces field-reversed configuration (FRC) plasmas by colliding and merging oppositely directed CTs. Significant progress has recently been made on C-2, achieving ~5 ms stable plasmas with a dramatic improvement in confinement, far beyond the prediction from the conventional FRC scaling. This stable, long-lived FRC plasma state is called the high-performance FRC (HPF) regime. The key approaches to achieve the HPF regime are as follows: (i) dynamic FRC formation by collision/merging of super-Alfvenic CTs, (ii) effective control of stability and transport by end-on plasma guns and neutral-beam (NB) injection, and (iii) active wall conditioning using titanium and lithium gettering systems. Moreover, further improvement in FRC confinement has been obtained with improved open-field-line plasma properties such as a lower fluctuation level, reduced transport rates in radial/axial directions, and lower background neutral density a...

Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095, USAA high temperature, stable, long-lived field-reversed configuration (FRC) plasma state has been produced in the C-2 device by dynamically colliding and merging two oppositely directed compact toroids, with combining effects of biasing edge plasma near the FRC separatrix from an end-plasma-gun with magnetic-mirror-plugs andof neutral-beam (NB) injection. The plasma-gun creates an inward radial electric field which mitigates the n = 2rotational instability. The gun also produces E×B velocity shear in the FRC edge layer, which may explain observations of improved transport properties. The FRCs are nearly axisymmetric which enables fast ion confinement, and increasing NB power input clearly extends the FRC lifetime. The combined effects of the plasma-gun with mirror-plugs and of NB injection yield anew High Performance FRC regime with confinement times improved by factors 2 to 4 and FRC lifetimes extended from 1 to 3 ms.

Conventional field-reversed configurations (FRC) face notable stability and confinement concerns, which can be ameliorated by introducing and maintaining a significant fast ion population in the system. This is the conjecture first introduced by Norman Rostoker multiple decades ago and adopted as the central design tenet in Tri Alpha Energy’s advanced beam driven FRC concept. In fact, studying the physics of such neutral beam (NB) driven FRCs over the past decade, considerable improvements were made in confinement and stability. Next to NB injection, the addition of axially streaming plasma guns, magnetic end plugs, as well as advanced surface conditioning lead to dramatic reductions in turbulence driven losses and greatly improved stability. In turn, fast ion confinement improved significantly and allowed for the build-up of a dominant fast particle population. This recently led to the breakthrough of sustaining an advanced beam driven FRC, thereby demonstrating successful maintenance of trapped magnetic flux, plasma dimensions and total pressure inventory for times much longer than all characteristic system time scales and only limited by hardware and electric supply constraints.

This study is concerned with application of the universal one-cycle control (OCC) technique to implement a three-phase AC electronic load. The proposed AC electronic load is able to emulate complex load behaviour. The study describes the principles of operation and the digital implementation of AC electronics load. To validate the approach, the start-up transient of an induction motor was successfully emulated. Both the simulation and experimental results are reported.

Zyxin is an actin regulatory protein that is concentrated at sites of actin-membrane association, particularly cell junctions. Zyxin participates in actin dynamics by binding VASP, an interaction that occurs via proline-rich N-terminal ActA repeats. An intramolecular association of the N-terminal LIM domains at or near the ActA repeats can prevent VASP and other binding partners from binding full-length zyxin. Such a head-tail interaction likely accounts for how zyxin function in actin dynamics, cell adhesion, and cell migration can be regulated by the cell. Since zyxin binding to several partners, via the LIM domains, requires phosphorylation, it seems likely that zyxin phosphorylation might alter the head-tail interaction and, thus, zyxin activity. Here we show that zyxin point mutants at a known phosphorylation site, serine 142, alter the ability of a zyxin fragment to directly bind a separate zyxin LIM domains fragment protein. Further, expression of the zyxin phosphomimetic mutant results in increased localization to cell-cell contacts of MDCK cells and generates a cellular phenotype, namely inability to disassemble cell-cell contacts, precisely like that produced by expression of zyxin mutants that lack the entire regulatory LIM domain region. These data suggest that zyxin phosphorylation at serine 142 results in release of the head-tail interaction, changing zyxin activity at cell-cell contacts.

The Field Reversed Configuration (FRC) is a high-beta Compact Toroid that includes closed and open field line regions of poloidal magnetic field. Improving the transport properties of both regions ...

Field reversed configurations (FRCs) with high confinement are obtained in the C-2 device by combining plasma gun edge biasing and neutral beam injection. The plasma gun creates an inward radial electric field that counters the usual FRC spin-up. The $n=2$ rotational instability is stabilized without applying quadrupole magnetic fields. The FRCs are nearly axisymmetric, which enables fast ion confinement. The plasma gun also produces $E\ifmmode\times\else\texttimes\fi{}B$ shear in the FRC edge layer, which may explain the observed improved particle transport. The FRC confinement times are improved by factors 2 to 4, and the plasma lifetimes are extended from 1 to up to 4 ms.

A high temperature field reversed configuration (FRC) has been produced in the newly built, world’s largest compact toroid (CT) facility, C-2, by colliding and merging two high-β CTs produced using the advanced field-reversed θ-pinch technology. This long-lived, stable merged state exhibits the following key properties: (1) apparent increase in the poloidal flux from the first pass to the final merged state, (2) significantly improved confinement compared to conventional θ-pinch FRCs with flux decay rates approaching classical values in some cases, (3) strong conversion from kinetic energy into thermal energy with total temperature (Te + Ti) exceeding 0.5 keV, predominantly into the ion channel. Detailed modeling using a new 2-D resistive magnetohydrodynamic (MHD) code, LamyRidge, has demonstrated, for the first time, the formation, translation, and merging/reconnection dynamics of such extremely high-β plasmas.

This paper suggests application of the universal One-Cycle Control (OCC) technique to dynamically control a Three-Phase Load Emulator (TPLE). The paper offers a model of the OCC controlled current loop and derives the relationships between the controlled variables. Based on the analysis the required programming equations are derived. To validate the approach, a case study was conducted to experimentally emulate the start-up transient of a realistic Induction Motor. Experimental results are reported.

A hot stable field-reversed configuration (FRC) has been produced in the C-2 experiment by colliding and merging two high-β plasmoids preformed by the dynamic version of field-reversed θ-pinch technology. The merging process exhibits the highest poloidal flux amplification obtained in a magnetic confinement system (over tenfold increase). Most of the kinetic energy is converted into thermal energy with total temperature (T{i}+T{e}) exceeding 0.5 keV. The final FRC state exhibits a record FRC lifetime with flux confinement approaching classical values. These findings should have significant implications for fusion research and the physics of magnetic reconnection.

Conventional field-reversed configurations (FRCs), high-beta, prolate compact toroids embedded in poloidal magnetic fields, face notable stability and confinement concerns. These can be ameliorated by various control techniques, such as introducing a significant fast ion population. Indeed, adding neutral beam injection into the FRC over the past half-decade has contributed to striking improvements in confinement and stability. Further, the addition of electrically biased plasma guns at the ends, magnetic end plugs, and advanced surface conditioning led to dramatic reductions in turbulence-driven losses and greatly improved stability. Together, these enabled the build-up of a well-confined and dominant fast-ion population. Under such conditions, highly reproducible, macroscopically stable hot FRCs (with total plasma temperature of ∼1 keV) with record lifetimes were achieved. These accomplishments point to the prospect of advanced, beam-driven FRCs as an intriguing path toward fusion reactors. This paper reviews key results and presents context for further interpretation.

To evaluate new indexes predicting weaning outcome from mechanical ventilation.Prospective study with two main end-points: a comparison of weaning indexes between successful and unsuccessful groups and an evaluation of their predicting value.Surgical-Medical Intensive Care Unit.Patients ventilated for more than 72 hours and subjected to a weaning trial until spontaneous ventilation.Traditional weaning parameters [respiratory rate (fsb), expiratory minute volume (Vesb), Maximal Inspiratory Pressure (MIP)] along with the new indexes [fsb/Vtsb) (rate to tidal volume ratio), CROP index (Compliance Rate Oxygenation Pressure), P0.1/MIP, IEQ (Inspiratory Effort Quotient), WI (Weaning Index)] were measured before discontinuation of ventilation support.A statistically significant difference was observed between successful and unsuccessful groups for the following parameters: fsb, MIP, fsb/.Vtsb, CROP, Po.1/MIP and WI while no differences were observed for Vesb and IEQ. The sensitivity and specificity for the new indexes were respectively: fsb/Vtsb: 0.65 and 0.58; CROP: 0.70 and 0.63; P0.1/MIP: 0.85 and 0.36; WI: 0.69 and 0.47.A statistically significant difference between successful and unsuccessful groups was observed for some but not all new indexes; the diagnostic accuracy of the new indexes were no better than additional parameters.

Two Doppler spectroscopy diagnostics with complementary capabilities are developed to measure the ion temperatures and velocities of FRC plasmas in the C-2 device. First, the multichord ion doppler diagnostic can simultaneously measure 15 chords of the plasma using an image intensified camera. Second, a single-chord fast-response ion Doppler diagnostic provides much higher faster time response by using a 16-channel photo-multiplier tube array. To study the neutral density of deuterium under different wall and plasma conditions, a highly sensitive eight-channel D-alpha diagnostic has been developed and calibrated for absolute radiance measurements. These spectroscopic diagnostics capabilities, combined with other plasma diagnostics, are helping to understand and improve the field reversed configuration plasmas in the C-2 device.

One aim of the flux-coil generated field reversed configuration at Tri Alpha Energy (TAE) is to establish the plasma where the ion rotational energy is greater than the ion thermal energy. To verify this, an optical diagnostic was developed to simultaneously measure the Doppler velocity-shift and line-broadening using a 0.75 m, 1800 groves/mm, spectrometer. The output spectrum is magnified and imaged onto a 16-channel photomultiplier tube (PMT) array. The individual PMT outputs are coupled to high-gain, high-frequency, transimpedance amplifiers, providing fast-time response. The Doppler spectroscopy measurements, along with a survey spectrometer and photodiode-light detector, form a suite of diagnostics that provide insights into the time evolution of the plasma-ion distribution and current when accelerated by an azimuthal-electric field.

Sera of rabbits immunized with slime antigen of Pseudomonas aeruginosa ATCC 14.207 were tested for the presence of the correspondent, circulating antibodies by the most common serological tests used in the medical laboratory: double immunodifusion in agar, indirect hemagglutination, complement fixation and indirect immunofluorescence tests. The slime antigen obtained from stationary culture of the bacteria, in trypticase-soy broth grown at 36 degrees C by 72 hours, was extracted from the supernatant of the culture and also from the cell mass through cold ethanol precipitation after buffering of the medium. All the sera had significant antibody titers, with the values changing according to the technique employed. The best results were obtained by hemagglutination and by immunofluorescence tests, there were no cross reactions of antibodies with other bacteria, shown by immunofluorescence tests made using as antigen other microorganisms.