A method is described for measuring pupillary contraction latency period regardless of initial absolute pupil diameter. Pupillary contraction latency period increases with age: the data presented show that the normal pupil, as usually found in healthy you...
National Technical Information Service (NTIS)
... A discussion is given of the theory of measuring the temperature of plasmas in combustion chambers and MHD ducts by recording the absolute ...
DTIC Science & Technology
Studies of the simultaneous changes in the latency and amplitude of the b-wave of the rat electroretinogram (ERG) under three different conditions of adaptation show that the latency is primarily a function of the absolute stimulus intensity, being only slightly affected by conditions that strongly reduce the amplitude. This implies ...
PubMed
... The primary focus on this study was to measure recovery latency periods for both the absolute and relative incapacitation period following a G-LOC ...
... that experimentally observed behavior of a plasma jet in a transverse gradient field is in absolute agreement with elementary plasma drift theory. ...
... Accession Number : AD0481363. Title : ABSOLUTE AND RELATIVE SPECTRAL LINE INTENSITY MEASUREMENTS IN A PLASMA SHOCK TUBE. ...
The sensitivity of the different parameters (absolute latency, interwave latency, latency asymmetry, amplitude) of both cervical and cerebral responses evoked by stimulation of the median nerve at the wrist was assessed in patients with multiple sclerosis by discriminant analysis. The peak ...
PubMed Central
Age and stimulus rise time (RT) effects on response latency were investigated for inferior colliculus (IC) neurons in young-adult and old CBA mice. Single-unit responses were recorded to unmodulated and sinusoidal amplitude modulated (SAM) broadband noise carriers, presented at 35 to 80 dB SPL. Data from 63 young-adult and 76 old phasic units were analyzed to identify the time ...
NASA Astrophysics Data System (ADS)
... PROTEINS, DOSAGE, DAY, SEROLOGY, CONSCIOUSNESS, BLOOD PLASMA, BIOLOGICAL RHYTHMS, HYPNOTICS AND SEDATIVES. ...
The threshold for an absolute parametric instability of the decay type along with the growth rates for two types of interacting oscillations are obtained theoretically for an inhomogeneous plasma layer. (AIP)
Energy Citations Database
We examine the interaction of an electron beam penetrating a strongly correlated plasma. Conditions are established for this unstable interaction to lead to an absolute instability. We propose the absolute instability as a means for probing the strongly correlated plasmas.
... to the influence of a powerful pumping wave is unstable relative to the build up of plasma high-frequency electronic waves (plasmons); this is ...
The nonlinear saturation of the absolute stimulated Raman scattering (SRS) instability is considered in a finite homogeneous plasma. The amplitude of the incident wave exceeds the absolute instability threshold by the fractional amount delta (
... PLASMAS(PHYSICS), *ELECTROMAGNETIC WAVE REFLECTIONS, ELECTROMAGNETIC RADIATION, HEATING, ELECTRON DENSITY ...
A method for precise measurements of absolute electron density in the plasma using plasma frequency is developed. A microwave perturbation of a frequency is introduced to plasma from a network analyzer and transmits in the plasma. The transmitting wave at a distance from a radiating antenna is ...
The plasma control system for the National Spherical Torus Experiment (NSTX) has been upgraded to replace the obsolete SKY computer system. The three main improvements with the new system are 1) higher computer speed, 2) lower latency and 3) a recordable absolute time during the discharge. The eight 333 MHz G4 processors in the Sky ...
Absolute SMBS instability has been observed in a plasma and, in contrast to convective instability, contributes to anomalous heating of the plasma. (AIP)
The coefficient of energy conversion from plasma waves to harmonics is calculated for a laser-produced inhomogeneous plasma below the threshold for the absolute instability.
For one-dimensional three-wave parametric instabilities with oppositely directed group velocities for the decay waves in unbounded plasmas, it is known that for uniform coupling amplitude and constant wave-vector mismatch (dsummationk/sub i//dx = const) there cannot be an absolute instability. It is shown that this is an exceptional case, and that in ...
The theory of absolute and convective instabilities in a plasma is discussed, and it is questionable, as it describes the linear development of instabilities by their behavior in the time asymptotic limit. In order to make sensible predictions on the line...
... Title : Absolutely Calibrated Vacuum Ultraviolet Spectra in the 150 nm to 250 nm Range from Plasmas Generated by the NIKE KrF Laser. ...
The absolute intensity of radiation emitted by fissioning and nonfissioning uranium plasmas in the spectral range from 350 nm to 1000 nm was measured. The plasma was produced in a plasma-focus apparatus and the plasma properties are simular to those anticipated for ...
... either a persistent infection or viral latency. The purpose of this research was to ... plasma cells to constantly produce antibodies. It is assumed that ... ...
NBII National Biological Information Infrastructure
The decay of an electromagnetic wave into two plasma waves in an inhomogeneous unmagnetized plasma is studied. The resulting instability is of an absolute nature in both collisional and collisionless plasmas. The instability threshold is found as a function of the damping rate of the plasma ...
The purpose of the work reported herein is to examine absolute modes of the TPD instability in two dimensions in an infinite homogeneous plasma. Briggs has shown that the condition for absolute instability in this case is the existence of a solution of th...
A novel combination of a plasma optical light detector and a Cerenkov detector has been used to give absolute timing between the maximum compression of the plasma and the production of a relativistic electron beam (E > 180 keV) in a Mather type plasma focus. The observation of an electron beam prior to the first ...
Recent evidence from the study of Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus supports a model in which terminal differentiation of B cells to plasma cells leads to virus reactivation. Here we address the role of Blimp-1, the master transcriptional regulator of plasma cell differentiation, in murine gammaherpesvirus 68 (MHV68) ...
The information content of a sexual signal may predict its importance in a multiple signal system. Many studies have correlated sexual signal expression with the absolute levels of nutrient reserves. In contrast, the changes of nutrient reserves associated with signal expression are largely unknown in the wild due to technical limitations although they are important ...
The parametric decay of an electromagnetic wave into two electron plasma waves is considered. The electromagnetic wave is obliquely incident on the density gradient. The resulting analysis shows that the threshold for absolute instability decreases as the...
This experiment investigated the effects of nitrogen narcosis on reaction time (RT) and P300 latency and amplitude. Ten subjects breathed either air or a non-narcotic 20% oxygen-80% helium (heliox) mixture in a hyperbaric chamber at 6.5, 8.3 and 10 atmospheres absolute (ATA). The subjects responded under controlled accuracy conditions to visually presented ...
... The micro-instability is absolute and develops fastest for a critical perturbation wavelength, of the order of several times the thickness of the plasma ...
... Absolute negative conductance, unstable plasma oscillations and parametric amplificatoin of intense field harmonics destroy these states. ...
An integral equation is derived to describe the absolute instability in an inhomogeneous plasma.(AIP)
The problem of convective and absolute instability in the interactions of charged particle beams with plasma and with each other was analyzed. (R.V.J.)
The nonlinear stage of the absolute parametric instability in an inhomogeneous bounded plasma is examined theoretically.(AIP)
The radial variation of the ionization in a coaxial plasma gun is determined spectroscopically. The discharge current in the plasma gun is limited by external resistors in order to keep the plasma weakly ionized. The radial variation in the absolute inten...
The scaling for the ignition of beam plasma discharge observed in many laboratory experiments is consistent with the requirement for triggering an absolute instability near the plasma frequency (omega sub e). The transition in the scaling with pressure can be attributed to transition from Bohm to classical diffusion losses.
A theory is developed of absolute parametric aperiodic instability in a spatially inhomogeneous plasma, when the electromagnetic waves generated in the plasma are trapped by the plasma near the peaks of the pumping-wave field.
The decay of an electromagnetic wave into two plasma waves in an inhomogeneous, nonmagnetized plasma is analyzed. It is demonstrated that the instability which arises in this case has an absolute nature both in a plasma with collisions and in a collisionl...
The authors derive the equations describing the decay of an intense, coherent EM wave into a scattered EM wave and a plasma wave in an inhomogeneous plasma. The plasma wave becomes nonpropagating in the vicinity of the cut-off of the scattered EM wave. Th...
A small spherical probe is used in conjunction with a network analyzer to determine the impedance of the probe-plasma system over a wide frequency range. Impedance curves are in good agreement with accepted circuit models with plasma-sheath and electron plasma frequency resonances easily identifiable. Clear transitions between ...
A plasma subjected to the action of an intense pumping verve is unstable with respect to buildup of plasma high-frequency electron waves (plasmons) due to decay of the pumping wave into two plasmons. The effect of spatial inhomogeneity of the plasma on such parametric instability is studied. It is shown that allowance for ...
This paper provides a simulation-based understanding of the effects of three physical system properties upon ground vehicle tracking performance: (1) command quantization, (2) command data latency, and (3) actuation bandwidth. The proposed metric for evaluating effects of these properties was integrated absolute lateral error (IAE). Under this metric, ...
Using multiple time scale analysis, the nonlinear saturation of the absolute stimulated Raman scattering instability is examined in a finite homogeneous collisional plasma. The amplitude of the incident wave is assumed to exceed the absolute instability threshold by the fractional amount ..delta..(<<1). A single backscattered ...
The density distribution of cylindrically symmetric deuterium plasmas can be measured by probing the plasma with an energetic deuterium beam and observing the protons from the D(d,p)T reaction. This technique measures the absolute deuterium density with g...
A plasma which is subjected to the influence of a powerful pumping wave is unstable relative to the build up of plasma high-frequency electronic waves (plasmons); this is caused by the decay of the pumping wave into two plasmons. The article that follows ...
Finite-bandwidth effects are investigated by using the random phase approximation. The conditions of validity are checked by solving exactly a particular model. It is found that a finite coherence length for the pump wave can favor the existence of absolute instability. (AIP)
Contrary to previous theoretical predictions, it is shown that the dissipative drift-wave instabilities are absolute in tokamak plasmas. The existence of unstable eigenmodes is shown to be associated with a new eigenmode branch induced by the finite toroidal couplings.
Absolutely calibrated measurements of the neutron yield are important for the evaluation of the plasma performance such as the fusion gain Q in DD operating tokamaks. Total neutron yield is measured with (sup 235)U and (sup 238)U fission chambers and (sup...
Contrary to previous theoretical predictions, it is shown that the dissipative drift-wave instabilities are absolute in tokamak plasmas. The existence of unstable eigenmodes is shown to be associated with a new eigenmode branch induced by the finite toroi...
A theory is derived for the absolute parametric instabilities which are excited in a nonuniform magnetized plasma by electromagnetic radiation at a frequency comparable to the electron plasma frequency. The thresholds and growth rates are determined for the aperiodic instability, for the decay into a lower-hybrid wave and an ...
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The persistence of HIV-1 latent reservoirs represents a major barrier to virus eradication in infected patients under HAART since interruption of the treatment inevitably leads to a rebound of plasma viremia. Latency establishes early ...
E-print Network
The present paper reports on experimental observations of saturation of absolute beam-plasma instability that can be shown to result from beam trapping. The details of the trapping differ from the convectively unstable case in that the wave is large near the electron gun, and the beam is suddenly trapped in this large-amplitude wave. The experimental ...
The parametric decay of an electromagnetic wave into two electron plasma waves in an inhomogeneous plasma is considered. The electromagnetic wave is obliquely incident on the density gradient. The resulting analysis shows that the threshold for absolute instability decreases as the angle of incidence of the electromagnetic wave ...
Absolute x-ray calibration of laser-produced plasmas was performed using a CCD linear array and a focusing crystal spectrometer. The plasmas were created by a Nd glass laser and a high repetition rate Nd-YAG laser. A commercial CCD was used for x-ray detection. The CCD linear array has 3724 pixels giving a total length of approximately ...
Recent work suggests the existence of a dual corticosteroid feedback mechanism of stress-induced ACTH secretion in the rat. This possibility led us to study the kinetics of suppression of ACTH levels by corticosteroid administration in patients with nonstress ACTH hypersecretion secondary to hypoadrenocorticism. Cortisol was administered according to different protocols, which were chosen to ...
... absolute measurements of RF power, and turbulence measurements over a dynamic range of 80 dB. Very few other university-based plasma ...
Since a Maxwellian plasma is free of absolute instabilities, steady state solutions of (29) can exist for W real, and most generally k ...
NASA Website
Near forward scattering of electromagnetic radiation from ion acoustic waves in the presence of a density gradient is studied. Two absolutely unstable modes are found, neither of which is suppressed by the density gradient.
Induction Heated Plasmas. United Aircraft Research Laboratories Report .... 1962 and was originally employed for induction heating .... millimeters of mercury absolute pressure and establishiqg a low-pressure glow discharge with the ...
The nonlinear saturation of the absolute stimulated Raman scattering (SRS) instability is considered in a finite homogeneous plasma. The amplitude of the incident wave exceeds the absolute instability threshold by the fractional amount (<<1). A single backscattered wave and a single plasma wave grow until ...
... As water density ratio in one atmospheric pressure in room tern- ... mode of the jet instability. ... 'A Bers, Handbook of Plasma Physics (North-Holland ...
... to overcome the heat of fusion of the ... and Characteristics of Stationary Plasma Thrusters with ... JD, "Absolute Cross Sections of Lithium and Other ...
G-LOC is one of the main physiological threats to aircrew of high-performance aircraft. The primary focus on this study was to measure recovery latency periods for both the absolute and relative incapacitation period following a G-LOC event and what effec...
Subclinical central and peripheral nervous system dysfunction among lead-exposed workers was studied by measuring short-latency somatosensory evoked potentials (SSEP) and maximal motor and sensory nerve conduction velocities (MCV and SCV) following stimulation of the median nerve at the wrist. The examinations were conducted in 20 gun-metal foundry workers exposed to lead, ...
Fifty-seven insulin dependent (IDDM) and non-insulin dependent (NIDDM) diabetic patients and 25 controls were studied. Patients with history of strokes, hypoglycaemia, hearing impairment, diabetic retinopathy, etc, were excluded. Clinical examination of central nervous system (CNS) and computerised tomography scan of brain were absolutely normal in all cases. ...
The necessary condition for an axisymmetric torus to act as an absolute trap of fusion generated alpha particles was investigated, under the assumption that the fusion reaction occurs only on the elliptic magnetic axis where the plasma pressure is maximum. It was found that more than 50% of fusion generated alpha particles can be ...
Electron collision cross sections for highly reactive CFx (x = 1-3) radicals are required to model technological plasmas. In spite of their importance to industry, experimental studies of electron interactions with CFx radicals are rarely reported in the literature. A new apparatus for measuring absolute elastic differential cross sections for molecular ...
The earliest neural response to a mechanical perturbation, the short-latency stretch response (R1: 20�45 ms), is known to exhibit �automatic gain-scaling� whereby its magnitude is proportional to preperturbation muscle activity. Because gain-scaling likely reflects an intrinsic property of the motoneuron pool (via the size-recruitment principle), counteracting this ...
Low birth weight infants are at risk of iron deficiency (ID), which is associated with impaired nervous system development and may lead to prolonged auditory brainstem response (ABR) latencies. We hypothesized that iron supplementation shortens ABR latencies in marginally low birth weight (MLBW, 2000-2500g) infants. In a randomized, controlled trial, 285 ...
The convective stimulated-Brillouin-scattering instability, which is usually considered in the case of an inhomogeneous low-density plasma, occurs only if the dissipation of sound is rapid. If this dissipation is only slight, an absolute stimulated-Brillouin-scattering instability occurs.
The authors report on experimental measurements of the temperature of a plasma consisting of combustion products in an MHD duct. The measurements were made by a number of different methods: absolute spectral line intensity recording; sodium line reversal;...
We report novel measurement techniques and also validate other methods which permit to make absolute quantitative measurement of gas temperature, radical density, UV intensities, plasma power deposition efficiency, sheath electric field, ionic and neutral...
Free bound Biberman factors (12,000, 13,500 and 14,500 K) for the wavelength range of 250 to 320 nm and 380 to 800 nm are presented. These values were determined by measuring the absolute continuum intensity of thermal argon plasma in a cascade arc (diame...
The existence of a new instability mechanism of a current-carrying plasma which, for a sufficiently long system, may occur after saturation of the two-stream instability is shown. The instability is due to combined asymmetry and nonuniformity of the elect...
The electrostatic instability in a magnetoplasma, omega > omega /sub ce/ , excited by a weak electron beam is found to be either convectively unstable (amplifying) or absolutely unstable (oscillating) depending upon effective plasma electron temperature and beam density. Measurements of the transition between the two types agree with ...
The possibility of deep parametric decay instability suppression by launching a complementary (small power) pump wave possessing a slightly shifted frequency is demonstrated experimentally. This suppression is achieved at an additional pump wave frequency shift equal to the frequency separation of ion acoustic eigenmodes excited in plasma as a result of ...
The boundary-value problem describing stimulated Raman scattering induced by a plane coherent electromagnetic wave normally incident upon plasma with a monotonic density profile is solved on a global basis. Propagation of amplified electrostatic waves between the resonant backward- and forward-scattering points and reflection of forward-scattered electromagnetic waves into the ...
In this paper we report absolute intensities of vacuum ultraviolet and near ultraviolet emission lines (4.8 eV to 18 eV) for aluminum etching discharges in an inductively coupled plasma reactor. We report line intensities as a function of wafer type, pres...
A model-based technique for real-time estimation of absolute fluorine concentration in a CF4/Ar for quantitative interpretation of actinometric data to deduce bulk plasma fluorine concentration in a CF4/Ar measurement is useful for monitoring fluorine in a manufacturing environment and, in particular
