A method for measurements of neutral fragments kinetic energies released to a specific dissociation threshold: optical translational spectroscopy

International Nuclear Information System (INIS)

Roney, A.; Frigon, C.; Larzilliere, M.

1999-01-01

The optical translational spectroscopy technique, based on the principles of fast ion beam laser spectroscopy (FIBLAS) and translational spectroscopy, allows the kinetic energies study of neutral fragments released through free dissociation of a neutral molecule. This method presents interesting features such as near-threshold energy measurements and selection of a specific dissociation limit. The fragments resulting from free dissociation (not induced) of neutral molecules, produced by charge exchange processes with a fast ion beam, are probed by laser radiation. Monitoring of the laser-induced fluorescence allows high-resolution spectra due to the kinematic compression of the velocity spread. Measurements of kinetic energies released to the second limit of dissociation H(1s) + H(2l) of H 2 are put forth and compared with those obtained by means of off-axis translational spectroscopy

Cultivation mode research of practical application talents for optical engineering major

Science.gov (United States)

Liu, Zhiying

2017-08-01

The requirements on science and technology graduates are more and higher with modern science progress and society market economy development. Because optical engineering major is with very long practicality, practice should be paid more attention from analysis of optical engineering major and students' foundation. To play role of practice to a large amount, the practice need be systemic and correlation. It should be combination of foundation and profundity. Modern foundation professional knowledge is studied with traditional optical concept and technology at the same time. Systemic regularity and correlation should be embodied in the contents. Start from basic geometrical optics concept, the optical parameter of optical instrument is analyzed, the optical module is built and ray tracing is completed during geometrical optics practice. With foundation of primary aberration calculation, the optical system is further designed and evaluated during optical design practice course. With the optical model and given instrument functions and requirements, the optical-mechanism is matched. The accuracy is calculated, analyzed and distributed in every motion segment. And the mechanism should guarantee the alignment and adjustment. The optical mechanism is designed during the instrument and element design practice. When the optical and mechanism drawings are completed, the system is ready to be fabricated. Students can complete grinding, polishing and coating process by themselves through optical fabricating practice. With the optical and mechanical elements, the system can be assembled and aligned during the thesis practice. With a set of correlated and logical practices, the students can acquire the whole process knowledge about optical instrument. All details are contained in every practice process. These practical experiences provide students working ability. They do not need much adaption anymore when they go to work after graduation. It is favorable to both student

Energetic neutral atom precipitation during magnetic storms: optical emission, ionization, and energy deposition at low and middle latitudes

International Nuclear Information System (INIS)

Tinsley, B.A.

1979-01-01

Observations of hydrogen Balmer β and He + 4686-A emission made at Huancayo, Peru, during two magnetic storms are consistent with the expectations of energetic neutral atom precipitation resulting from charge exchange loss of ring current ions and support the view that charge exchange is the major loss process for larger geomagnetic storms. The intensities are consistent with previous satellite observations of the emission (called the equatorial aurora) and when translated into ionization rates for the upper E region give production rates in order of magnitude larger than normal nighttime levels. Such ionization enhancements have previously been measured by ionosondes and incoherent scatter at low latitudes and attributed to electron precipitation. New calculations of the latitude variation correct earlier work and show that for a ring current with pitch angle distribution isotropic to the loss cone, located on shells of L value 2 to 6, the maximum influx rate of precipitating neutrals is found at magnetic latitudes 25 0 to 50 0 . Most of the energetic neutrals are lost to interplanetary space, and the fraction impacting the thermosphere has been recalculated to range from 11 to 2.2% for L values 2 to 6. For a typical magnetic storm with energy loss rate due to charge exchange, the equivalent to a Dst rate of change of 20 n T/h, the energy input into the thermosphere at the latitude of maximum is calculated to be 0.15 to 0.05 mW/m 2 from L shells 2 to 6. The ionization production can be of the order of 10 ions cm 3 s 1 at 140 km, and optical emission, of the order of 1 rayleigh (R), both varying according to the species and energy of the impacting neutrals (i.e., the former ring current ions). The latitude distribution shrinks toward the equator after injection has ceased, as the magnetospheric pitch angle distribution evolves toward 90 0 , on a time scale (for protons <30 keV at L=3) of the order of 2 hours

Measurements of the toroidal plasma rotation velocity in TFTR major-radius compression experiments with auxiliary neutral beam heating

International Nuclear Information System (INIS)

Bitter, M.; Wong, K.L.; Scott, S.; Hsuan, H.; Grek, B.; Johnson, D.; Tait, G.

1990-01-01

The time history of the central toroidal plasma rotation velocity in Tokamak Fusion Test Reactor (TFTR) experiments [Phys. Rev. Lett. 55, 2587 (1985)] with auxiliary heating by neutral deuterium beam injection and major-radius compression has been measured from the Doppler shift of the emitted Ti XXI Kα line radiation. The experiments were conducted for neutral beam powers in the range 2.1--3.8 MW and line-averaged densities in the range 1.8--3.0x10 19 m -2 . The observed rotation velocity increase during compression is consistent with theoretical estimates

What does brain response to neutral faces tell us about major depression? evidence from machine learning and fMRI.

Science.gov (United States)

Oliveira, Leticia; Ladouceur, Cecile D; Phillips, Mary L; Brammer, Michael; Mourao-Miranda, Janaina

2013-01-01

A considerable number of previous studies have shown abnormalities in the processing of emotional faces in major depression. Fewer studies, however, have focused specifically on abnormal processing of neutral faces despite evidence that depressed patients are slow and less accurate at recognizing neutral expressions in comparison with healthy controls. The current study aimed to investigate whether this misclassification described behaviourally for neutral faces also occurred when classifying patterns of brain activation to neutral faces for these patients. TWO INDEPENDENT DEPRESSED SAMPLES: (1) Nineteen medication-free patients with depression and 19 healthy volunteers and (2) Eighteen depressed individuals and 18 age and gender-ratio-matched healthy volunteers viewed emotional faces (sad/neutral; happy/neutral) during an fMRI experiment. We used a new pattern recognition framework: first, we trained the classifier to discriminate between two brain states (e.g. viewing happy faces vs. viewing neutral faces) using data only from healthy controls (HC). Second, we tested the classifier using patterns of brain activation of a patient and a healthy control for the same stimuli. Finally, we tested if the classifier's predictions (predictive probabilities) for emotional and neutral face classification were different for healthy controls and depressed patients. Predictive probabilities to patterns of brain activation to neutral faces in both groups of patients were significantly lower in comparison to the healthy controls. This difference was specific to neutral faces. There were no significant differences in predictive probabilities to patterns of brain activation to sad faces (sample 1) and happy faces (samples 2) between depressed patients and healthy controls. Our results suggest that the pattern of brain activation to neutral faces in depressed patients is not consistent with the pattern observed in healthy controls subject to the same stimuli. This difference in

What does brain response to neutral faces tell us about major depression? evidence from machine learning and fMRI.

Directory of Open Access Journals (Sweden)

Leticia Oliveira

Full Text Available A considerable number of previous studies have shown abnormalities in the processing of emotional faces in major depression. Fewer studies, however, have focused specifically on abnormal processing of neutral faces despite evidence that depressed patients are slow and less accurate at recognizing neutral expressions in comparison with healthy controls. The current study aimed to investigate whether this misclassification described behaviourally for neutral faces also occurred when classifying patterns of brain activation to neutral faces for these patients.TWO INDEPENDENT DEPRESSED SAMPLES: (1 Nineteen medication-free patients with depression and 19 healthy volunteers and (2 Eighteen depressed individuals and 18 age and gender-ratio-matched healthy volunteers viewed emotional faces (sad/neutral; happy/neutral during an fMRI experiment. We used a new pattern recognition framework: first, we trained the classifier to discriminate between two brain states (e.g. viewing happy faces vs. viewing neutral faces using data only from healthy controls (HC. Second, we tested the classifier using patterns of brain activation of a patient and a healthy control for the same stimuli. Finally, we tested if the classifier's predictions (predictive probabilities for emotional and neutral face classification were different for healthy controls and depressed patients.Predictive probabilities to patterns of brain activation to neutral faces in both groups of patients were significantly lower in comparison to the healthy controls. This difference was specific to neutral faces. There were no significant differences in predictive probabilities to patterns of brain activation to sad faces (sample 1 and happy faces (samples 2 between depressed patients and healthy controls.Our results suggest that the pattern of brain activation to neutral faces in depressed patients is not consistent with the pattern observed in healthy controls subject to the same stimuli. This

ORNL positive ion neutral beam program

International Nuclear Information System (INIS)

Whealton, J.H.; Haselton, H.H.; Barber, G.C.

1978-01-01

The neutral beam group at Oak Ridge National Laboratory has constructed neutral beam generators for the ORMAK and PLT devices, is presently constructing neutral beam devices for the ISX and PDX devices, and is contemplating the construction of neutral beam systems for the advanced TNS device. These neutral beam devices stem from the pioneering work on ion sources of G. G. Kelley and O. B. Morgan. We describe the ion sources under development at this Laboratory, the beam optics exhibited by these sources, as well as some theoretical considerations, and finally the remainder of the beamline design

EPR and optical spectroscopic studies of neutral free radicals in an adamantane matrix

International Nuclear Information System (INIS)

Jordan, J.E.

1975-03-01

Recent work in our laboratory has demonstrated that neutral free radicals produced by x-irradiation and trapped in adamantane exhibit exceedingly long lifetimes because of the lack of rapid diffusion in the solid matrix. This observation and the fact that samples can be pressed into pellets with high optical transparency in the visible and near uv regions of the spectrum suggested to us that this unique matrix might be used for studying the optical properties of free radicals. The results of a wide variety of experiments of this type are described in this thesis. These include experiments in which secondary free radicals are produced by photoinduced decomposition of primary free radicals by selective irradiation with visible light, the observation of strong optical absorption spectra of free radicals at room temperature using a Cary 14 spectrophotometer, the finding that certain free radicals exhibit strong, visible fluorescence when irradiated with uv light, and the discovery that the absorption intensity of multiplicity-forbidden transition in singlet and doublet state species is enhanced relative to spin-allowed transitions by at least three orders of magnitude. An analysis of these results in terms of molecular orbital theory is given, and experiments designed to obtain the epr spectra of electronically-excited states of free radicals are described

Measurements of the toroidal plasma rotation velocity in TFTR major-radius compression experiments with auxiliary neutral beam heating

International Nuclear Information System (INIS)

Bitter, M.; Scott, S.; Wong, K.L.

1986-07-01

The time history of the central toroidal plasma rotation velocity in Tokamak Fusion Test Reactor (TFTR) experiments with auxiliary heating by neutral deuterium beam injection and major-radius compression has been measured from the Doppler shift of the emitted TiXXI-Kα line radiation. The experiments were conducted for neutral beam powers in the range from 2.1 to 3.8 MW and line-averaged densities in the range from 1.8 to 3.0 x 10 19 m -2 . The observed rotation velocity increase during compression is in agreement with results from modeling calculations which assume classical slowing-down of the injected fast deuterium ions and momentum damping at the rate established in the precompression plasma

Instrumentation system for long-pulse MFTF neutral beams

International Nuclear Information System (INIS)

Risch, D.M.

1981-01-01

The instrumentation system for long pulse neutral beams for MFTFS consists of monitoring and protective circuitry. Global synchronization of high speed monitoring data across twenty-four neutral beams is achieved via an experiment wide fiber optic timing system. Fiber optics are also used as a means of isolating signals at elevated voltages. An excess current monitor, interrupt monitor, sparkdown detector, spot detector and gradient grid ratio detector form the primary protection for the neutral beam source. A unique hierarchical interlocking scheme allows other protective devices to be factored into the shutdown circuitry of the power supply so that the initiating cause of a shutdown can be isolated and even allows some non-critical devices to be safely ignored for a period of time

Application of diffusion theory to neutral atom transport in fusion plasmas

International Nuclear Information System (INIS)

Hasan, M.Z.; Conn, R.W.; Pomraning, G.C.

1986-05-01

It is found that energy dependent diffusion theory provides excellent accuracy in the modelling of transport of neutral atoms in fusion plasmas. Two reasons in particular explain the good accuracy. First, while the plasma is optically thick for low energy neutrals, it is optically thin for high energy neutrals and diffusion theory with Marshak boundary conditions gives accurate results for an optically thin medium even for small values of 'c', the ratio of the scattering to the total cross section. Second, the effective value of 'c' at low energy becomes very close to one due to the down-scattering via collisions of high energy neutrals. The first reason is proven both computationally and theoretically by solving the transport equation in a power series in 'c' and the diffusion equation with 'general' Marshak boundary conditions. The second reason is established numerically by comparing the results from a one-dimensional, general geometry, multigroup diffusion theory code, written for this purpose, with the results obtained using the transport code ANISN

ORNL neutral-beam program in 1978

International Nuclear Information System (INIS)

Whealton, J.H.

1982-12-01

This report was presented at the ion source workshop held at Culham Laboratory, Abingdon, Oxfordshire, in 1978. Because the proceedings of that conference are unavailable, and because the material in this report is still not to be found elsewhere, it is issued as a laboratory report. The neutral beam group at Oak Ridge National Laboratory has constructed neutral beam generators for the ORMAK and PLT devices, is presently constructing neutral beam devices for the ISX and PDX devices, and is contemplating the construction of neutral beam systems for the advanced TNS device. These neutral beam devices stem from the pioneering work on ion sources of G.G. Kelley and O.B. Morgan. We describe the ion sources under development at this laboratory, the beam optics exhibited by these sources, as well as some theoretical considerations, and finally the remainder of the beamline design

Effect of equatorial electrodynamics on low-latitude thermosphere as inferred from neutral optical dayglow emission observations

Science.gov (United States)

Karan, D. K.; Duggirala, P. R.

2017-12-01

The diurnal variations in daytime airglow emission intensity measurements at three wavelengths OI 777.4 nm, OI 630.0 nm, and OI 557.7 nm made from a low-latitude location, Hyderabad (Geographic 17.50 N, 78.40 E; 8.90 N Mag. Lat) in India have been investigated. The intensity patterns showed both symmetric and asymmetric behavior in their respective diurnal emission variability with respect to local noon. The asymmetric diurnal behavior is not expected considering the photochemical nature of the production mechanisms. The reason for this observed asymmetric diurnal behavior has been found to be predominantly the temporal variation in the equatorial electrodynamics. The plasma that is transported across latitudes due to the action of varying electric field strength over the magnetic equator in the daytime contributes to the asymmetric diurnal behavior in the neutral daytime airglow emissions. Independent magnetic and radio measurements support this finding. It is also noted that this asymmetric diurnal behavior in the neutral emission intensities has a solar cycle dependence with more number of days during high solar activity period showing asymmetric diurnal behavior compared to those during low-solar activity epoch. These intensity variations over long time scale demonstrate that the daytime neutral optical emissions are extremely sensitive to the changes in the eastward electric field over low- and equatorial-latitudes.

BEAM TRANSPORT AND STORAGE WITH COLD NEUTRAL ATOMS AND MOLECULES

Energy Technology Data Exchange (ETDEWEB)

Walstrom, Peter L. [Los Alamos National Laboratory

2012-05-15

A large class of cold neutral atoms and molecules is subject to magnetic field-gradient forces. In the presence of a field, hyperfine atomic states are split into several Zeeman levels. The slopes of these curves vs. field are the effective magnetic moments. By means of optical pumping in a field, Zeeman states of neutral lithium atoms and CaH molecules with effective magnetic moments of nearly {+-} one Bohr magneton can be selected. Particles in Zeeman states for which the energy increases with field are repelled by increasing fields; particles in states for which the energy decreases with field are attracted to increasing fields. For stable magnetic confinement, field-repelled states are required. Neutral-particle velocities in the present study are on the order of tens to hundreds of m/s and the magnetic fields needed for transport and injection are on the order of in the range of 0.01-1T. Many of the general concepts of charged-particle beam transport carry over into neutral particle spin-force optics, but with important differences. In general, the role of bending dipoles in charged particle optics is played by quadrupoles in neutral particle optics; the role of quadrupoles is played by sextupoles. The neutralparticle analog of charge-exchange injection into storage rings is the use of lasers to flip the state of particles from field-seeking to field-repelled. Preliminary tracking results for two neutral atom/molecule storage ring configurations are presented. It was found that orbit instabilities limit the confinment time in a racetrack-shaped ring with discrete magnetic elements with drift spaces between them; stable behavior was observed in a toroidal ring with a continuous sextupole field. An alternative concept using a linear sextupole or octupole channel with solenoids on the ends is presently being considered.

Synthesis and solution aggregation studies of a suite of mixed neutral and zwitterionic chromophores for second-order nonlinear optics.

Science.gov (United States)

Peddie, Victoria; Anderson, Jack; Harvey, Joanne E; Smith, Gerald J; Kay, Andrew

2014-11-07

We report details of the synthesis of a series of bi- and trichromophores. These compounds contain mixtures of chromophores that have zwitterionic (ZWI) and neutral ground state (NGS) components covalently attached to each other. The neutral ground state moieties are based on dyes with aniline donors--such as Disperse Red 1--whereas the zwitterionic components are derived from chromophores with pro-aromatic donors such as 1,4-dihydropyridinylidene. By combining both ZWI and NGS components, we aim to develop novel compounds for nonlinear optics in which there is an enhancement of the overall hyperpolarizability coupled with a decrease in the net dipole moment. Thus, this approach should eliminate the electrostatic effects that result when only one type of chromophore is used, and so reduce the likelihood of undesirable aggregation occurring. This, in turn, should enable us to realize organic materials with large macroscopic optical nonlinearities. An analysis of the UV-vis results suggests that there is a strong dependence on solvent polarity that determines whether the embedded constituents should be treated as discrete elements; in low polarity solvents, there appear to be strong intramolecular interactions occurring, particularly when a 1,4-quinolinylidene-based donor is used in the ZWI component.

Regulated 15-V, 7500-A, neutral-beam filament supply

International Nuclear Information System (INIS)

Reass, W.

1977-01-01

Lawrence Livermore Laboratory (LLL) designed a cost-effective, regulated 15-V, 7500-A filament supply for use with the High-Voltage Test Stand , a major ERDA developmental neutral-beam test facility. The filament supply can float to 200 kV and can provide pulse widths up to 30 s. Powered by a 24-V, 0.5-TJ battery bank, it avoids the use of expensive isolation transformers and induction voltage regulators (IVR's). Battery output is regulated by a water-cooled resistor-contactor combination in which contactors are closed in sequential format to create a staircase current waveform. A fine-tuning network tunes in-between the ''steps'' for regulation to less than 0.5 percent. The regulator is digitally controlled except for the sense amplifiers, which are optically coupled to the digital controller. All ground telemetry uses optical links to minimize effects of rfi and emi noise in the data channels

Improved laser damage threshold performance of calcium fluoride optical surfaces via Accelerated Neutral Atom Beam (ANAB) processing

Science.gov (United States)

Kirkpatrick, S.; Walsh, M.; Svrluga, R.; Thomas, M.

2015-11-01

Optics are not keeping up with the pace of laser advancements. The laser industry is rapidly increasing its power capabilities and reducing wavelengths which have exposed the optics as a weak link in lifetime failures for these advanced systems. Nanometer sized surface defects (scratches, pits, bumps and residual particles) on the surface of optics are a significant limiting factor to high end performance. Angstrom level smoothing of materials such as calcium fluoride, spinel, magnesium fluoride, zinc sulfide, LBO and others presents a unique challenge for traditional polishing techniques. Exogenesis Corporation, using its new and proprietary Accelerated Neutral Atom Beam (ANAB) technology, is able to remove nano-scale surface damage and particle contamination leaving many material surfaces with roughness typically around one Angstrom. This surface defect mitigation via ANAB processing can be shown to increase performance properties of high intensity optical materials. This paper describes the ANAB technology and summarizes smoothing results for calcium fluoride laser windows. It further correlates laser damage threshold improvements with the smoothing produced by ANAB surface treatment. All ANAB processing was performed at Exogenesis Corporation using an nAccel100TM Accelerated Particle Beam processing tool. All surface measurement data for the paper was produced via AFM analysis on a Park Model XE70 AFM, and all laser damage testing was performed at Spica Technologies, Inc. Exogenesis Corporation's ANAB processing technology is a new and unique surface modification technique that has demonstrated to be highly effective at correcting nano-scale surface defects. ANAB is a non-contact vacuum process comprised of an intense beam of accelerated, electrically neutral gas atoms with average energies of a few tens of electron volts. The ANAB process does not apply mechanical forces associated with traditional polishing techniques. ANAB efficiently removes surface

Galactic neutral hydrogen emission-absorption observations from Arecibo

International Nuclear Information System (INIS)

Dickey, J.M.; Salpeter, E.E.; Terzian, Y.

1978-01-01

We have observed the interstellar medium in the directions of 27 extragalactic sources at high and intermediate galactic latitudes (vertical-barb/sup ii/vertical-bar>5 0 ) at 21 cm wavelength with the upgraded Arecibo telescope (HPBW=3'.2, gainapprox.6 K Jy -1 ). The small beam greatly reduces the uncertainty in the derived on-source emission profile and increases confidence that it corresponds to the same material as the absorption spectrum. Each region has been observed for approximately 2 hours to tetect optical depths as low as 10 -2 in most cases. The data allow the derivation of optical depths, harmonic mean spin temperatures, and column densities for the neutral hydrogen as a function of velocity in the range -200 -1 (LSR) with resolution as fine as 0.25 km s -1 . Spin temperatures as high as 1000 K are evident with a significant fraction of the neutral hydrogen still hotter. The cooler material is distributed over all temperatures from 30 K to at least 800 K. At latitudes below vertical-barb/sup ii/vertical-bar 0 values for the harmonic mean temperature T/sub spin/ in the range 100 K to 300 K are most common.We have detected 66 separate absorption features, tentatively associated with neutral hydrogen clouds, with central temperatures ranging from 30 to 500 K. These features conform well to the relationship T/sub spin/=45(1-e/sup -tau/)/sup -0.5/ (K), over a broad range of values of the optical depth. The velocity distribution of these clouds shows a significant negative-velocity ''tail'' at high and intermediate latitudes. The mean square velocity of the clouds seems to depend on optical depth: v/sub rms/ is greater (approx.11 km s -1 ) for the optically thin clouds (tau -1 ). High-negative-velocity emission (v -1 ) has been detected in six directions; in two of these corresponding absorption features are evident, indicating cool neutral material

Visual optics under the wavefront perspective

Directory of Open Access Journals (Sweden)

Sidney Júlio Faria-E-Sousa

2014-08-01

Full Text Available Some intriguing concepts of visual optics cannot be explained by ray tracing. However, they can be clarified using wavefront formalism. Its main advantage is in the use of the concept of vergence, which is very helpful in interpreting the optical phenomena involved in the neutralization of the ametropias. In this line of thinking, the major role of a lens is in the creation of a new light source (the image point that orientates the refracted waves. Once the nature and position of this source is known, one can easily predict the behavior of the wavefronts. The formalism also allows for an easier understanding on how wavefronts relate to light rays and on how algebraic signs are assigned to optical distances.

Spatial profiling of ion and neutral excitation in noble gas electron cyclotron resonance plasmas

International Nuclear Information System (INIS)

Rhoades, R.L.; Gorbatkin, S.M.

1994-01-01

Optical emission from neutrals and ions of several noble gases has been profiled in an electron cyclotron resonance plasma system. In argon plasmas with a net microwave power of 750 W, the neutral (696.5-nm) and ion (488-nm) emission profiles are slightly center peaked at 0.32 mTorr and gradually shift to a hollow appearance at 2.5 mTorr. Neon profiles show a similar trend from 2.5 to 10.0 mTorr. For the noble gases, transition pressure scales with the ionization potential of the gas, which is consistent with neutral depletion. Studies of noble gas mixtures, however, indicate that neutral depletion is not always dominant in the formation of hollow profiles. For Kr/Ar, Ar/Ne, and Ne/He plasmas, the majority gas tends to set the overall shape of the profile at any given pressure. For the conditions of the current system, plasma density appears to be more dominant than electron temperature in the formation of hollow profiles. The general method described is also a straightforward, inexpensive technique for measuring the spatial distribution of power deposited in plasmas, particularly where absolute scale can be calibrated by some other means

Instrumentation and control of the Doublet III Neutral Beam Injector System

Energy Technology Data Exchange (ETDEWEB)

Kohli, J.C.; Moore, C.D.; Drobnis, D.D.; Elischer, V.P.; Kilgore, R.; Uber, D.

1980-03-01

The hardware and software required for the operation of the Doublet III Neutral Beam Injector System (NBIS) are described. Development and implementation of this Instrumentation and Control System was divided between the major participants - General Atomic Company and Lawrence Berkeley Laboratory. The subdivision of responsibilities and the coordination of the participants' activities are described with reference to hardware and software requirements in support of the entire system. Included are a description of the operators' consoles, the interlock system and the CAMAC system. One feature of the control software is source modeling. This feature includes feedback on a shot to shot basis and adaptive control. Adaptive control permits the computer system to automatically adjust parameters after a shot, and to control the system to automatically compensate for time varying NBIS components. The Neutral Beam Power Supply features power supply modeling, fiber optic transmission of analog signals and digital control of power supply power-up/interlocks.

Instrumentation and control of the Doublet III Neutral Beam Injector System

International Nuclear Information System (INIS)

Kohli, J.C.; Moore, C.D.; Drobnis, D.D.; Elischer, V.P.; Kilgore, R.; Uber, D.

1980-03-01

The hardware and software required for the operation of the Doublet III Neutral Beam Injector System (NBIS) are described. Development and implementation of this Instrumentation and Control System was divided between the major participants - General Atomic Company and Lawrence Berkeley Laboratory. The subdivision of responsibilities and the coordination of the participants' activities are described with reference to hardware and software requirements in support of the entire system. Included are a description of the operators' consoles, the interlock system and the CAMAC system. One feature of the control software is source modeling. This feature includes feedback on a shot to shot basis and adaptive control. Adaptive control permits the computer system to automatically adjust parameters after a shot, and to control the system to automatically compensate for time varying NBIS components. The Neutral Beam Power Supply features power supply modeling, fiber optic transmission of analog signals and digital control of power supply power-up/interlocks

Neutral beam program

International Nuclear Information System (INIS)

Anon.

1979-01-01

The structure of the beam injection program for the Doublet-3 device is discussed. The design considerations for the beam line and design parameters for the Doublet-3 ion souce are given. Major components of the neutral beam injector system are discussed in detail. These include the neutralizer, magnetic shielding, reflecting magnets, vacuum system, calorimeter and beam dumps, and drift duct. The planned location of the two-injector system for Doublet-3 is illustrated and site preparation is considered. The status of beamline units 1 and 2 and the future program schedule are discussed

Identification of minute damage in composite bridge structures equipped with fiber optic sensors using the location of neutral axis and finite element analysis

Science.gov (United States)

Li, Xi; Glisic, Branko

2016-04-01

By definition, the neutral axis of a loaded composite beam structure is the curve along which the section experiences zero bending strain. When no axial loading is present, the location of the neutral axis passes through the centroid of stiffness of the beam cross-section. In the presence of damage, the centroid of stiffness, as well as the neutral axis, shift from the healthy position. The concept of neutral axis can be widely applied to all beam-like structures. According to literature, a change in location of the neutral axis can be associated with damage in the corresponding cross-section. In this paper, the movement of neutral axis near locations of minute damage in a composite bridge structure was studied using finite element analysis and experimental results. The finite element model was developed based on a physical scale model of a composite simply-supported structure with controlled minute damage in the reinforced concrete deck. The structure was equipped with long-gauge fiber optic strain and temperature sensors at a healthy reference location as well as two locations of damage. A total of 12 strain sensors were installed during construction and used to monitor the structure during various loading events. This paper aims to explain previous experimental results which showed that the observed positions of neutral axis near damage locations were higher than the predicted healthy locations in some loading events. Analysis has shown that finite element analysis has potential to simulate and explain the physical behavior of the test structure.

Hexon and fiber of adenovirus type 14 and 55 are major targets of neutralizing antibody but only fiber-specific antibody contributes to cross-neutralizing activity.

Science.gov (United States)

Feng, Ying; Sun, Xikui; Ye, Xianmiao; Feng, Yupeng; Wang, Jinlin; Zheng, Xuehua; Liu, Xinglong; Yi, Changhua; Hao, Mingli; Wang, Qian; Li, Feng; Xu, Wei; Li, Liang; Li, Chufang; Zhou, Rong; Chen, Ling; Feng, Liqiang

2018-05-01

Re-emerging human adenoviruses type 14 (HAdV14) and 55 (HAdV55) represent two highly virulent adenoviruses. The neutralizing antibody (nAb) responses elicited by infection or immunization remain largely unknown. Herein, we generated hexon-chimeric HAdV14 viruses harboring each single or entire hexon hyper-variable-regions (HVR) from HAdV55, and determined the neutralizing epitopes of human and mouse nAbs. In human sera, hexon-targeting nAbs are type-specific and mainly recognize HVR2, 5, and 7. Fiber-targeting nAbs are only detectable in sera cross-neutralizing HAdV14 and HAdV55 and contribute substantially to cross-neutralization. Penton-binding antibodies, however, show no significant neutralizing activities. In mice immunized with HAdV14 or HAdV55, a single immunization mainly elicited hexon-specific nAbs, which recognized HAdV14 HVR1, 2, and 7 and HAdV55 HVR1 and 2, respectively. After a booster immunization, cross-neutralizing fiber-specific nAbs became detectable. These results indicated that hexon elicits type-specific nAbs whereas fiber induces cross-neutralizing nAbs to HAdV14 and HAdV55, which are of significance in vaccine development. Copyright © 2018 Elsevier Inc. All rights reserved.

Neutral-beam performance analysis using a CCD camera

International Nuclear Information System (INIS)

Hill, D.N.; Allen, S.L.; Pincosy, P.A.

1986-01-01

We have developed an optical diagnostic system suitable for characterizing the performance of energetic neutral beams. An absolutely calibrated CCD video camera is used to view the neutral beam as it passes through a relatively high pressure (10 -5 Torr) region outside the neutralizer: collisional excitation of the fast deuterium atoms produces H/sub proportional to/ emission (lambda = 6561A) that is proportional to the local atomic current density, independent of the species mix of accelerated ions over the energy range 5 to 20 keV. Digital processing of the video signal provides profile and aiming information for beam optimization. 6 refs., 3 figs

Beam optics study of a negative ion source for neutral beam injection application at ASIPP

Energy Technology Data Exchange (ETDEWEB)

Wei, Jiang-Long; Liang, Li-Zhen [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Jiang, Cai-Chao [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Graduate school, University of Science and Technology of China, Hefei 230026 (China); Xie, Ya-Hong, E-mail: xieyh@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Hu, Chun-Dong; Li, Jun; Gu, Yu-Ming; Chen, Yu-Qian [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Li, Jing-Yong; Wu, Ming-Shan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Graduate school, University of Science and Technology of China, Hefei 230026 (China)

2017-04-15

In order to study the generation and extraction of negative ions for neutral beam injection application, a negative ion source is being designed and constructed at Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). Through a four electrode grids system inside the accelerator, a negative ion beam will be extracted and accelerated up to −60 kV on a reduced scale extraction area of 12 × 50 cm{sup 2} (the area of PG apertures is 185 cm{sup 2}). The beam optics is a key issue for the accelerator design, and greatly determine the source experimental performance in term of beam current, heat load on the grid, beam divergence, and so on. In this paper, the trajectories of electrons and negative ions were simulated in the electrode grids of the negative ion source. The filter capability of electron deflection magnet on the co-extracted electrons is evaluated and confirmed. The negative ion beam optics was designed according to the calculated results of beam divergence and beam radius along the beamlet in different acceleration voltages. The deflection effect of the electron deflection magnet on the negative ion beam was investigated in the single beamlet case and multi-beamlets case.

Multi-slit triode ion optical system with ballistic beam focusing

Energy Technology Data Exchange (ETDEWEB)

Davydenko, V., E-mail: V.I.Davydenko@inp.nsk.su; Amirov, V.; Gorbovsky, A.; Deichuli, P.; Ivanov, A.; Kolmogorov, A.; Kapitonov, V.; Mishagin, V.; Shikhovtsev, I.; Sorokin, A.; Stupishin, N. [Budker Institute of Nuclear Physics, Novosibirsk 630090 (Russian Federation); Karpushov, A. N. [Ecole Polytechnique Fédérale de Lausanne, Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne (Switzerland); Smirnov, A. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Uhlemann, R. [Institute of Energy and Climate Research-Plasma Physics, Research Center Juelich, 52425 Juelich (Germany)

2016-02-15

Multi-slit triode ion-optical systems with spherical electrodes are of interest for formation of intense focused neutral beams for plasma heating. At present, two versions of focusing multi-slit triode ion optical system are developed. The first ion optical system forms the proton beam with 15 keV energy, 140 A current, and 30 ms duration. The second ion optical system is intended for heating neutral beam injector of Tokamak Configuration Variable (TCV). The injector produces focused deuterium neutral beam with 35 keV energy, 1 MW power, and 2 s duration. In the later case, the angular beam divergence of the neutral beam is 20-22 mrad in the direction across the slits of the ion optical system and 12 mrad in the direction along the slits.

Application of diffusion theory to neutral atom transport in fusion plasmas

International Nuclear Information System (INIS)

Hasan, M.Z.; Conn, R.W.; Pomraning, G.C.

1987-01-01

It is found that the energy dependent diffusion theory provides excellent accuracy in the modelling of transport of neutral atoms in fusion plasmas. Two reasons in particular explain the good accuracy. First, while the plasma is optically thick for low energy neutrals, it is optically thin for high energy neutrals and the diffusion theory with Marshak boundary conditions gives accurate results for an optically thin medium, even for small values of c, the ratio of the scattering cross-section to the total cross-section. Second, the effective value of c at low energy is very close to 1 because of the downscattering via collisions of high energy neutrals. The first reason is proven computationally and theoretically by solving the transport equation in a power series in c and solving the diffusion equation with 'general' Marshak boundary conditions. The second reason is established numerically by comparing the results from a one-dimensional, general geometry, multigroup diffusion theory code, written for this purpose, with the results obtained using the transport code ANISN. Earlier studies comparing one-speed diffusion and transport theory indicated that the diffusion theory would be inaccurate. A detailed analysis shows that this conclusion is limited to a very specific case. Surprisingly, for a very wide range of conditions and when energy dependence is included, the diffusion theory is highly accurate. (author)

Well separated trion and neutral excitons on superacid treated MoS{sub 2} monolayers

Energy Technology Data Exchange (ETDEWEB)

Cadiz, Fabian, E-mail: cadiz@insa-toulouse.fr; Tricard, Simon; Gay, Maxime; Lagarde, Delphine; Wang, Gang; Robert, Cedric; Renucci, Pierre; Urbaszek, Bernhard; Marie, Xavier [Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077 Toulouse (France)

2016-06-20

Developments in optoelectronics and spin-optronics based on transition metal dichalcogenide monolayers (MLs) need materials with efficient optical emission and well-defined transition energies. In as-exfoliated MoS{sub 2} MLs, the photoluminescence (PL) spectra even at low temperature consist typically of broad, overlapping contributions from neutral, charged excitons (trions) and localized states. Here, we show that in superacid treated MoS{sub 2} MLs, the PL intensity increases by up to 60 times at room temperature. The neutral and charged exciton transitions are spectrally well separated in PL and reflectivity at T = 4 K, with linewidth for the neutral exciton of 15 meV, but both transitions have similar intensities compared to the ones in as-exfoliated MLs at the same temperature. Time resolved experiments uncover picoseconds recombination dynamics analyzed separately for charged and neutral exciton emissions. Using the chiral interband selection rules, we demonstrate optically induced valley polarization for both complexes and valley coherence for only the neutral exciton.

Quantum computing implementations with neutral particles

DEFF Research Database (Denmark)

Negretti, Antonio; Treutlein, Philipp; Calarco, Tommaso

2011-01-01

We review quantum information processing with cold neutral particles, that is, atoms or polar molecules. First, we analyze the best suited degrees of freedom of these particles for storing quantum information, and then we discuss both single- and two-qubit gate implementations. We focus our discu...... optimal control theory might be a powerful tool to enhance the speed up of the gate operations as well as to achieve high fidelities required for fault tolerant quantum computation.......We review quantum information processing with cold neutral particles, that is, atoms or polar molecules. First, we analyze the best suited degrees of freedom of these particles for storing quantum information, and then we discuss both single- and two-qubit gate implementations. We focus our...... discussion mainly on collisional quantum gates, which are best suited for atom-chip-like devices, as well as on gate proposals conceived for optical lattices. Additionally, we analyze schemes both for cold atoms confined in optical cavities and hybrid approaches to entanglement generation, and we show how...

Neutral theory and the species abundance distribution: recent developments and prospects for unifying niche and neutral perspectives

Science.gov (United States)

Matthews, Thomas J; Whittaker, Robert J

2014-01-01

Published in 2001, The Unified Neutral Theory of Biodiversity and Biogeography (UNTB) emphasizes the importance of stochastic processes in ecological community structure, and has challenged the traditional niche-based view of ecology. While neutral models have since been applied to a broad range of ecological and macroecological phenomena, the majority of research relating to neutral theory has focused exclusively on the species abundance distribution (SAD). Here, we synthesize the large body of work on neutral theory in the context of the species abundance distribution, with a particular focus on integrating ideas from neutral theory with traditional niche theory. First, we summarize the basic tenets of neutral theory; both in general and in the context of SADs. Second, we explore the issues associated with neutral theory and the SAD, such as complications with fitting and model comparison, the underlying assumptions of neutral models, and the difficultly of linking pattern to process. Third, we highlight the advances in understanding of SADs that have resulted from neutral theory and models. Finally, we focus consideration on recent developments aimed at unifying neutral- and niche-based approaches to ecology, with a particular emphasis on what this means for SAD theory, embracing, for instance, ideas of emergent neutrality and stochastic niche theory. We put forward the argument that the prospect of the unification of niche and neutral perspectives represents one of the most promising future avenues of neutral theory research. PMID:25360266

Neutral theory and the species abundance distribution: recent developments and prospects for unifying niche and neutral perspectives.

Science.gov (United States)

Matthews, Thomas J; Whittaker, Robert J

2014-06-01

Published in 2001, The Unified Neutral Theory of Biodiversity and Biogeography (UNTB) emphasizes the importance of stochastic processes in ecological community structure, and has challenged the traditional niche-based view of ecology. While neutral models have since been applied to a broad range of ecological and macroecological phenomena, the majority of research relating to neutral theory has focused exclusively on the species abundance distribution (SAD). Here, we synthesize the large body of work on neutral theory in the context of the species abundance distribution, with a particular focus on integrating ideas from neutral theory with traditional niche theory. First, we summarize the basic tenets of neutral theory; both in general and in the context of SADs. Second, we explore the issues associated with neutral theory and the SAD, such as complications with fitting and model comparison, the underlying assumptions of neutral models, and the difficultly of linking pattern to process. Third, we highlight the advances in understanding of SADs that have resulted from neutral theory and models. Finally, we focus consideration on recent developments aimed at unifying neutral- and niche-based approaches to ecology, with a particular emphasis on what this means for SAD theory, embracing, for instance, ideas of emergent neutrality and stochastic niche theory. We put forward the argument that the prospect of the unification of niche and neutral perspectives represents one of the most promising future avenues of neutral theory research.

Designing neutral-atom nanotraps with integrated optical waveguides

International Nuclear Information System (INIS)

Burke, James P. Jr.; Chu, S.-T.; Bryant, Garnett W.; Williams, C.J.; Julienne, P.S.

2002-01-01

Integrated optical structures offer the intriguing potential of compact, reproducible waveguide arrays, rings, Y junctions, etc., that could be used to design evanescent field traps to transport, store, and interact atoms in networks as complicated as any integrated optical waveguide circuit. We theoretically investigate three approaches to trapping atoms above linear integrated optical waveguides. A two-color scheme balances the decaying evanescent fields of red- and blue-detuned light to produce a potential minimum above the guide. A one-color surface trap proposal uses blue-detuned light and the attractive surface interaction to provide a potential minimum. A third proposal uses blue-detuned light in two guides positioned above and below one another. The atoms are confined to the 'dark' spot in the vacuum gap between the guides. We find that all three approaches can be used to trap atoms in two or three dimensions with approximately 100 mW of laser power. We show that the dark spot guide is robust to light scatter and provides the most viable approach for constructing integrated optical circuits that could be used to transport and manipulate atoms in a controlled manner

Neutral beam in ALVAND IIC tokamak

International Nuclear Information System (INIS)

Ghrannevisse, M.; Moradshahi, M.; Avakian, M.

1992-01-01

Neutral beams have a wide application in tokamak experiments. It used to heat; fuel; adjust electric potentials in plasmas and diagnose particles densities and momentum distributions. It may be used to sustain currents in tokamaks to extend the pulse length. A 5 KV; 500 mA ion source has been constructed by plasma physics group, AEOI and it used to produce plasma and study the plasma parameters. Recently this ion source has been neutralized and it adapted to a neutral beam source; and it used to heat a cylindrical DC plasma and the plasma of ALVAND IIC Tokamak which is a small research tokamak with a minor radius of 12.6 cm, and a major radius of 45.5 cm. In this paper we report the neutralization of the ion beam and the results obtained by injection of this neutral beam into plasmas. (author) 2 refs., 4 figs

Neutral and Non-Neutral Evolution of Duplicated Genes with Gene Conversion

Directory of Open Access Journals (Sweden)

Jeffrey A. Fawcett

2011-02-01

Full Text Available Gene conversion is one of the major mutational mechanisms involved in the DNA sequence evolution of duplicated genes. It contributes to create unique patters of DNA polymorphism within species and divergence between species. A typical pattern is so-called concerted evolution, in which the divergence between duplicates is maintained low for a long time because of frequent exchanges of DNA fragments. In addition, gene conversion affects the DNA evolution of duplicates in various ways especially when selection operates. Here, we review theoretical models to understand the evolution of duplicates in both neutral and non-neutral cases. We also explain how these theories contribute to interpreting real polymorphism and divergence data by using some intriguing examples.

Real time neutral beam power control on MAST

Energy Technology Data Exchange (ETDEWEB)

Homfray, David A., E-mail: david.homfray@ccfe.ac.uk [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon (United Kingdom); Benn, A.; Ciric, D.; Day, I.; Dunkley, V.; Keeling, D.; Khilar, S.; King, D.; King, R. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon (United Kingdom); Kurutz, U. [Department of Experimental Plasma Physics, University of Augsburg, Augsburg (Germany); Payne, D.; Simmonds, M.; Stevenson, P.; Tame, C. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon (United Kingdom)

2011-10-15

Real time power control of neutral beam provides an excellent tool for many different plasma physics studies. Power control at a better resolution than the level of a single injector is usually achieved by modulating individual power supplies. However, the short beam slowing down time on MAST is such that the plasma would be sensitive to modulating the neutral beam using this 100% on-off pulse-width modulation method. A novel alternative method of power control has been demonstrated, where the arc current, and hence beam current, has been controlled in real time allowing variations in neutral beam power. This has been demonstrated in a MAST plasma with almost no loss of transmission as a consequence of the optical properties of the high perveance MAST neutral beam system. This paper will detail the methodology, experiment and results and discuss the full implementation of this method that will allow MAST to control the beam power in real time.

Toward A Neutral Mercury Optical Lattice Clock: Determination of the Magic Wavelength for the Ultraviolet clock Transition

International Nuclear Information System (INIS)

Mejri, Sinda

2012-01-01

A lattice clock combines the advantages of ion and neutral atom based clocks, namely the recoil and first order Doppler free spectroscopy allowed by the Lamb-Dicke regime. This lattice light field shifts the energy levels of the clock transition. However a wavelength can be found where the light-shift of the clock states cancelled to first order. In this thesis, we present the latest advances in optical lattice clock with mercury atoms developed at LNE-SYRTE. After a review of the current performances of different optical clock are currently under development, we focus on the concept of optical lattice clock and the features of the mercury that make him an excellent candidate for the realization of an optical lattice clock achievement the uncertainty of the level of 10 -17 . The second part is devoted to the characterization of the mercury MOT, using a sensitive detection system, which allowed us to evaluate the temperature of different isotopes present in the MOT and have a good evidence of sub-Doppler cooling for the fermionic isotopes. The third part of this these, present the experimental aspects of the implementation and the development of the laser source required for trapping mercury atoms operating near the predicted magic wavelength. Finally, we report on the Lamb-Dicke spectroscopy of the 1S0 →3 P0 clock transition in the 199 Hg atoms confined in lattice trap. With use of the ultra-stable laser system, linked to LNE-SYRTE primary frequency reference, we have determined the center frequency of the transition for a range of lattice wavelengths and different lattice depths. Analyzing these measurement, we have carried out the first experimental determination of the magic wavelength, which is the crucial step towards achieving a highly accurate frequency standard using mercury. (author)

Concepts for the magnetic design of the MITICA neutral beam test facility ion accelerator.

Science.gov (United States)

Chitarin, G; Agostinetti, P; Marconato, N; Marcuzzi, D; Sartori, E; Serianni, G; Sonato, P

2012-02-01

The megavolt ITER injector concept advancement neutral injector test facility will be constituted by a RF-driven negative ion source and by an electrostatic Accelerator, designed to produce a negative Ion with a specific energy up to 1 MeV. The beam is then neutralized in order to obtain a focused 17 MW neutral beam. The magnetic configuration inside the accelerator is of crucial importance for the achievement of a good beam efficiency, with the early deflection of the co-extracted and stripped electrons, and also of the required beam optic quality, with the correction of undesired ion beamlet deflections. Several alternative magnetic design concepts have been considered, comparing in detail the magnetic and beam optics simulation results, evidencing the advantages and drawbacks of each solution both from the physics and engineering point of view.

Are "Market Neutral" Hedge Funds Really Market Neutral?

OpenAIRE

Andrew J. Patton

2009-01-01

Using a variety of different definitions of "neutrality," this study presents significant evidence against the neutrality to market risk of hedge funds in a range of style categories. I generalize standard definitions of "market neutrality," and propose five different neutrality concepts. I suggest statistical tests for each neutrality concept, and apply these tests to a database of monthly returns on 1423 hedge funds from five style categories. For the "market neutral" style, approximately o...

Playing with Light: Adventures in Optics and Spectroscopy for Honors and Majors General Chemistry

Science.gov (United States)

van Staveren, Marie N.; Edwards, Kimberly D.; Apkarian, V. A.

2012-01-01

A lab was developed for use in an undergraduate honors and majors general chemistry laboratory to introduce students to optics, spectroscopy, and the underlying principles of quantum mechanics. This lab includes four mini-experiments exploring total internal reflection, the tunneling of light, spectra of sparklers and colored candles, and emission…

Neutral hydrogen observations of southern galaxies

International Nuclear Information System (INIS)

Davies, R.D.; Staveley-Smith, L.; Murray, J.D.

1989-01-01

21-cm neutral hydrogen observations, made using the 64-m Parkes radio telescope, are presented for 48 galaxies, 39 of which are clear detections. The H I properties and homogeneous optical data, including new photometry, are tabulated for the galaxies. A high signal-to-noise ratio subset of these observations is used to demonstrate that the overall flux-density scale is within a few per cent of northern (Jodrell Bank and Green Bank) scales. The remainder are used elsewhere in a new determination of the Local Group peculiar velocity. H I-optical diameter correlations are shown to be a useful discriminant between competing diameter systems and indicate that the Lauberts ESO(B) catalogue is the most useful currently available source of southern galaxy diameters. (author)

Design of a negative ion neutral beam system for TNS

International Nuclear Information System (INIS)

Easoz, J.R.

1978-05-01

A conceptual design of a neutral beam line based on the neutralization of negative deuterium ions is presented. This work is a detailed design of a complete neutral beam line based on using negative ions from a direct extraction source. Anticipating major technological advancements, beam line components have been scaled including the negative ion sources and components for the direct energy recovery of charged beams and high speed cryogenic pumping. With application to the next step in experimental fusion reactors (TNS), the neutral beam injector system that has been designed provides 10 MW of 200 keV neutral deuterium atoms. Several arms are required for plasma ignition

The neural fate of neutral information in emotion-enhanced memory.

Science.gov (United States)

Watts, Sarah; Buratto, Luciano G; Brotherhood, Emilie V; Barnacle, Gemma E; Schaefer, Alexandre

2014-07-01

In this study, we report evidence that neural activity reflecting the encoding of emotionally neutral information in memory is reduced when neutral and emotional stimuli are intermixed during encoding. Specifically, participants studied emotional and neutral pictures organized in mixed lists (in which emotional and neutral pictures were intermixed) or in pure lists (only-neutral or only-emotional pictures) and performed a recall test. To estimate encoding efficiency, we used the Dm effect, measured with event-related potentials. Recall for neutral items was lower in mixed compared to pure lists and posterior Dm activity for neutral items was reduced in mixed lists, whereas it remained robust in pure lists. These findings might be caused by an asymmetrical competition for attentional and working memory resources between emotional and neutral information, which could be a major determinant of emotional memory effects. Copyright © 2014 Society for Psychophysiological Research.

Design and development of neutral beam module components

International Nuclear Information System (INIS)

Holl, P.M.; Bulmer, R.H.; Dilgard, L.W.; Horvath, J.A.; Molvik, A.W.; Porter, G.D.; Shearer, J.W.; Slack, D.S.; Colonias, J.S.

1979-01-01

The Mirror Fusion Test Facility (MFTF) injection system consists of twenty 20 keV start-up, and twenty-four 80 keV sustaining neutral beam source modules. The neutral beam modules are mounted in four clusters equally spaced around the waist of the vacuum vessel which contains the superconducting magnets. A module is defined here as an assembly consisting of a beam source and the interfacing components between that beam source and the vacuum chamber. Six major interfacing components are the subject of this paper. They are the magnetic shield, the neutralizer duct, the isolation valve, mounting gimbals, aiming bellows and actuators

Control, data acquisition and analysis for the JET neutral injection test bed

International Nuclear Information System (INIS)

Jones, T.T.C.; Brenan, P.R.; Rodgers, M.E.; Stork, D.; Young, I.D.

1984-01-01

The Neutral Injection Test-Bed (NITB) is a major experimental assembly in support of the Neutral Beam Heating Programme for JET. In addition to its prime function of testing the Neutral Injection hardware, the Test Bed serves as the prototype to test the computer control and data acquisition system, which is described. (author)

Prediction of meat spectral patterns based on optical properties and concentrations of the major constituents.

Science.gov (United States)

ElMasry, Gamal; Nakauchi, Shigeki

2016-03-01

A simulation method for approximating spectral signatures of minced meat samples was developed depending on concentrations and optical properties of the major chemical constituents. Minced beef samples of different compositions scanned on a near-infrared spectroscopy and on a hyperspectral imaging system were examined. Chemical composition determined heuristically and optical properties collected from authenticated references were simulated to approximate samples' spectral signatures. In short-wave infrared range, the resulting spectrum equals the sum of the absorption of three individual absorbers, that is, water, protein, and fat. By assuming homogeneous distributions of the main chromophores in the mince samples, the obtained absorption spectra are found to be a linear combination of the absorption spectra of the major chromophores present in the sample. Results revealed that developed models were good enough to derive spectral signatures of minced meat samples with a reasonable level of robustness of a high agreement index value more than 0.90 and ratio of performance to deviation more than 1.4.

Neutral Hydrogen Optical Depth near Star-forming Galaxies at z ≈ 2.4 in the Keck Baryonic Structure Survey

Science.gov (United States)

Rakic, Olivera; Schaye, Joop; Steidel, Charles C.; Rudie, Gwen C.

2012-06-01

We study the interface between galaxies and the intergalactic medium by measuring the absorption by neutral hydrogen in the vicinity of star-forming galaxies at z ≈ 2.4. Our sample consists of 679 rest-frame UV-selected galaxies with spectroscopic redshifts that have impact parameters advantage of all available Lyman series lines. The median optical depth, and hence the median density of atomic hydrogen, drops by more than an order of magnitude around 100 kpc, which is similar to the virial radius of the halos thought to host the galaxies. The median remains enhanced, at the >3σ level, out to at least 2.8 Mpc (i.e., >9 comoving Mpc), but the scatter at a given distance is large compared with the median excess optical depth, suggesting that the gas is clumpy. Within 100 (200) kpc, and over ±165 km s-1, the covering fraction of gas with Lyα optical depth greater than unity is 100+0 - 32% (66% ± 16%). Absorbers with τLyα > 0.1 are typically closer to galaxies than random. The mean galaxy overdensity around absorbers increases with the optical depth and also as the length scale over which the galaxy overdensity is evaluated is decreased. Absorbers with τLyα ~ 1 reside in regions where the galaxy number density is close to the cosmic mean on scales >=0.25 Mpc. We clearly detect two types of redshift space anisotropies. On scales 3σ significance), an effect that we attribute to large-scale infall (i.e., the Kaiser effect). Based on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA, and was made possible by the generous financial support of the W. M. Keck Foundation.

Feline Immunodeficiency Virus (FIV Neutralization: A Review

Directory of Open Access Journals (Sweden)

Margaret J. Hosie

2011-10-01

Full Text Available One of the major obstacles that must be overcome in the design of effective lentiviral vaccines is the ability of lentiviruses to evolve in order to escape from neutralizing antibodies. The primary target for neutralizing antibodies is the highly variable viral envelope glycoprotein (Env, a glycoprotein that is essential for viral entry and comprises both variable and conserved regions. As a result of the complex trimeric nature of Env, there is steric hindrance of conserved epitopes required for receptor binding so that these are not accessible to antibodies. Instead, the humoral response is targeted towards decoy immunodominant epitopes on variable domains such as the third hypervariable loop (V3 of Env. For feline immunodeficiency virus (FIV, as well as the related human immunodeficiency virus-1 (HIV-1, little is known about the factors that lead to the development of broadly neutralizing antibodies. In cats infected with FIV and patients infected with HIV-1, only rarely are plasma samples found that contain antibodies capable of neutralizing isolates from other clades. In this review we examine the neutralizing response to FIV, comparing and contrasting with the response to HIV. We ask whether broadly neutralizing antibodies are induced by FIV infection and discuss the comparative value of studies of neutralizing antibodies in FIV infection for the development of more effective vaccine strategies against lentiviral infections in general, including HIV-1.

The control of powerful neutral beams

International Nuclear Information System (INIS)

Theil, E.; Jacobson, V.

1986-01-01

While significant progress has been made in the development of neutral beams for the heating and sustaining of plasmas in large fusion experiments, the control of such devices has largely been a matter of hardware interlocks and operator experience. The need for computer-assisted control becomes more evident, however, with the initiation of multi-beamline experiments. This paper describes a software system that incorporates simple mathematical models coupled to Kalman filters for control of the high power (6 to 8 MW) beams currently under development at Lawrence Berkeley Laboratory's Neutral Beam Engineering Test Facility. Among the principal features of the system are: reduction of a large number of operator variables to just a few (usually one or two); the ability to describe most of the major neutral beams in use and under development; a foundation resting on statistical data analysis and control system principles rather than rules-of-thumb

On becoming neutral: effects of experimental neutralizing reconsidered.

Science.gov (United States)

van den Hout, M; van Pol, M; Peters, M

2001-12-01

Behaviour Research and Therapy 34 (1996) 889-898 found that writing out a negative thought produced anxiety and an urge to neutralize the thought, that instructing participants to neutralize the thought reduced anxiety/neutralization urge in the short run (i.e. within 2 min), but that in the control group 20 min without instruction was attended by the same reduction in anxiety/urge to neutralize ("natural decay"). The observations were made with pariticipants who scored high on "thought action fusion" and the experiment was set up as exerimental model of obsessions. We repeated the study with participants that were not selected on thought action fusion. All the findings reported by Behaviour Research and Therapy 34 (1996) 889-898 were replicated. Correlational analysis indicated that the strength of the effect was not related to scores on scales measuring "thought action fusion". Behaviour Research and Therapy 34 (1996) 889-898 did not assess whether non-neutralizing was followed by immediate reductions in distress. We did assess this and found that the larger part of the immediate reduction of distress after neutralization also occurs when no neutralization instruction is given. The effects of neutralization instructions in the present type of experiment are considerably less powerful than suggested earlier.

First observation of the fourth neutral polarization point in the atmosphere

Science.gov (United States)

Horvath, Gabor; Bernath, Balazs; Suhai, Bence; Barta, Andras; Wehner, Rudiger

2002-10-01

In the clear sky there are three commonly known loci, the Arago, Babinet, and Brewster neutral points, where the skylight is unpolarized. These peculiar celestial points, bearing the names of their discoverers, have been the subject of many ground-based investigations, because their positions are sensitive indicators of the amount and type of atmospheric turbidity. According to theoretical considerations and computer simulations, there should exist an additional neutral point approximately opposite to the Babinet point, which can be observed only at higher altitudes in the air or space. Until now, this anonymous fourth neutral point has not been observed during air- or space-borne polarimetric experiments and has been forgotten, in spite of the fact that the neutral points were a basic tool in atmospheric research for a century. Here, we report on the first observation of this fourth neutral point from a hot air balloon. Using 180-field-of-view imaging polarimetry, we could observe the fourth neutral point at 450, 550, and 650 nm from different altitudes between 900 and 3500 m during and after sunrise at approximately 2240 below the anti-solar point along the anti-solar meridian, depending on the wavelength and solar elevation. We show that the fourth neutral point exists at the expected location and has characteristics similar to those of the Arago, Babinet, and Brewster points. We discuss why the fourth neutral point has not been observed in previous air- or space-borne polarimetric experiments. 2002 Optical Society of America

Serum neutralizing activities from a Beijing homosexual male cohort infected with different subtypes of HIV-1 in China.

Directory of Open Access Journals (Sweden)

Mingshun Zhang

Full Text Available Protective antibodies play a critical role in an effective HIV vaccine; however, eliciting antibodies to block infection by viruses from diverse genetic subtypes remains a major challenge. As the world's most populous country, China has been under the threat of at least three major subtypes of circulating HIV-1 viruses. Understanding the cross reactivity and specificities of serum antibody responses that mediate broad neutralization of the virus in HIV-1 infected Chinese patients will provide valuable information for the design of vaccines to prevent HIV-1 transmission in China. Sera from a cohort of homosexual men, who have been managed by a major HIV clinical center in Beijing, China, were analyzed for cross-sectional neutralizing activities against pseudotyped viruses expressing Env antigens of the major subtype viruses (AE, BC and B subtypes circulating in China. Neutralizing activities in infected patients' blood were most capable of neutralizing viruses in the homologous subtype; however, a subset of blood samples was able to achieve broad neutralizing activities across different subtypes. Such cross neutralizing activity took 1-2 years to develop and CD4 binding site antibodies were critical components in these blood samples. Our study confirmed the presence of broadly neutralizing sera in China's HIV-1 patient population. Understanding the specificity and breadth of these neutralizing activities can guide efforts for the development of HIV vaccines against major HIV-1 viruses in China.

Neutralizing Antibodies and Pathogenesis of Hepatitis C Virus Infection

Directory of Open Access Journals (Sweden)

Françoise Stoll-Keller

2012-10-01

Full Text Available Hepatitis C virus (HCV infection is a major cause of chronic liver disease worldwide. The interplay between the virus and host innate and adaptive immune responses determines the outcome of infection. There is increasing evidence that host neutralizing responses play a relevant role in the resulting pathogenesis. Furthermore, viral evasion from host neutralizing antibodies has been revealed to be an important contributor in leading both to viral persistence in acute liver graft infection following liver transplantation, and to chronic viral infection. The development of novel model systems to study HCV entry and neutralization has allowed a detailed understanding of the molecular mechanisms of virus-host interactions during antibody-mediated neutralization. The understanding of these mechanisms will ultimately contribute to the development of novel antiviral preventive strategies for liver graft infection and an urgently needed vaccine. This review summarizes recent concepts of the role of neutralizing antibodies in viral clearance and protection, and highlights consequences of viral escape from neutralizing antibodies in the pathogenesis of HCV infection.

Feasibility of a fast optical pressure interlock for the ITER neutral beam injectors

International Nuclear Information System (INIS)

Ash, Andrew; Surrey, Elizabeth

2009-01-01

The feasibility of using Balmer-α emission for a high-speed pressure diagnostic and beam interlock for the ITER neutral beam heating system is investigated. An interlock is needed to prevent excessive re-ionisation of the neutral beam when rapid excursions of pressure occur in either the electrostatic residual ion dump (ERID), or the neutral beam duct (NBD). The re-ionised fraction of the beam, will be deflected by stray tokamak fields, potentially causing excessive thermal loads on beam line components. Experience from JET indicates that a response time of order 100 μs is required in order to prevent fast pressure excursions. Fast penning gauges have a time response of around 30-50 ms, however, a faster response (around 1 μs) is possible by monitoring the H α (656.3 nm)/D α (656.1 nm) emission from collisional excitation of the background gas and neutral beam. Published total cross-sections are used to calculate a signal of 3.5x10 13 -3.0x10 17 photons s -1 m -2 sr -1 for normal conditions. This signal must be distinguished from the background light of the tokamak plasma (line emission and bremsstrahlung). The beam emission is Doppler shifted by up to 21 nm (D operation) and up to 27 nm (H operation) depending on angle of observation and this can be used to help distinguish against background line emission. The distribution of background light along the beam line is calculated with a two-dimensional radiosity code, solving the equilibrium energy balance within the beam line enclosure. The Balmer-α signal and background signal due to bremsstrahlung are compared for a 500-MW reference plasma.

Neutralizing antibody response during human immunodeficiency virus type 1 infection: type and group specificity and viral escape

DEFF Research Database (Denmark)

Arendrup, M; Sönnerborg, A; Svennerholm, B

1993-01-01

The paradox that group-specific neutralizing antibodies (NA) exist in the majority of human immunodeficiency virus type 1 (HIV-1)-infected patients, whereas the NA response against autologous HIV-1 virus isolates is highly type-specific, motivated us to study the type- and group-specific NA...... demonstrated, suggesting that the majority of the change in neutralization sensitivity is driven by the selective pressure of type-specific NA. Furthermore, no differences were observed in sensitivity to neutralization by anti-carbohydrate neutralizing monoclonal antibodies or the lectin concanavalin A...

Lawrence Berkeley laboratory neutral-beam engineering test facility power-supply system

International Nuclear Information System (INIS)

Lutz, I.C.; Arthur, C.A.; deVries, G.J.; Owren, H.M.

1981-10-01

The Lawrence Berkeley Laboratory is upgrading the neutral beam source test facility (NBSTF) into a neutral beam engineering test facility (NBETF) with increased capabilities for the development of neutral beam systems. The NBETF will have an accel power supply capable of 170 kV, 70 A, 30 sec pulse length, 10% duty cycle; and the auxiliary power supplies required for the sources. This paper describes the major components, their ratings and capabilities, and the flexibility designed to accomodate the needs of source development

Ionized and Neutral Outflows in the QUEST QSOs

Science.gov (United States)

Veilleux, Sylvain

2011-10-01

The role of galactic winds in gas-rich mergers is of crucial importance to understand galaxy and SMBH evolution. In recent months, our group has had three major scientific breakthroughs in this area: {1} The discovery with Herschel of massive molecular {OH-absorbing} outflows in several ULIRGs, including the nearest quasar, Mrk 231. {2} The independent discovery from mm-wave interferometric observations in the same object of a spatially resolved molecular {CO-emitting} wind with estimated mass outflow rate 3x larger than the star formation rate and spatially coincident with blueshifted neutral {Na ID-absorbing} gas in optical long-slit spectra. {3} The unambiguous determination from recent Gemini/IFU observations that the Na ID outflow in this object is wide-angle, thus driven by a QSO wind rather than a jet. This powerful outflow may be the long-sought "smoking gun" of quasar mechanical feedback purported to transform gas-rich mergers. However, our Herschel survey excludes all FIR-faint {UV-bright} "classic" QSOs by necessity. So here we propose a complementary FUV absorption-line survey of all FIR-bright -and- FIR-faint QSOs from the same parent sample. New {19 targets} and archival {11} spectra will be used to study, for the first time, the gaseous environments of QSOs as a function of host properties and age across the merger sequence ULIRG -> QSO. These data will allow us to distinguish between ionized & neutral quasar-driven outflows, starburst-driven winds, and tidal debris around the mergers. They will also be uniquely suited for a shallow but broad study of the warm & warm-hot intergalactic media, complementary to on-going surveys that are deeper but narrower.

Optics and communication technology major of physics undergraduate degree at King Mongkut's Institute of Technology Ladkrabang

Science.gov (United States)

Buranasiri, Prathan

2014-09-01

A physics undergraduate degree major in optics and communication technology has been offered at King Mongkut's Institute of Technology Ladkrabang (KMITL), Bangkok, Thailand. There are nine required three credit hour courses including two laboratory courses plus a number of selections in optics and communication based technology courses. For independent thinking and industrial working skills, nine credit hours of research project, practical training or overseas studies are included for selection in the final semester. Students are encouraged to participate in international conferences and professional organizations. Recently the program, with support from SPIE and OSA, has organized its first international conference on photonic solutions 2013 (ICPS 2013).

Comparison of NO titration and fiber optics catalytic probes for determination of neutral oxygen atom concentration in plasmas and postglows

International Nuclear Information System (INIS)

Mozetic, Miran; Ricard, Andre; Babic, Dusan; Poberaj, Igor; Levaton, Jacque; Monna, Virginie; Cvelbar, Uros

2003-01-01

A comparative study of two different absolute methods NO titration and fiber optics catalytic probe (FOCP) for determination of neutral oxygen atom density is presented. Both methods were simultaneously applied for measurements of O density in a postglow of an Ar/O 2 plasma created by a surfatron microwave generator with the frequency of 2.45 GHz an adjustable output power between 30 and 160 W. It was found that the two methods gave similar results. The advantages of FOCP were found to be as follows: it is a nondestructive method, it enables real time measuring of the O density, it does not require any toxic gas, and it is much faster than NO titration. The advantage of NO titration was found to be the ability to measure O density in a large range of dissociation of oxygen molecules

Dust in the Diffuse Neutral Interstellar Medium

Science.gov (United States)

Sofia, Ulysses J.

2008-05-01

Studies of interstellar dust have always relied heavily upon Laboratory Astrophysics for interpretation. Laboratory values, in the broad sense that includes theory, are needed for the most basic act of measuring interstellar abundances, to the more complex determination of what grains are responsible for particular extinction. The symbiotic relationship between astronomical observations and Laboratory Astrophysics has prompted both fields to move forward, especially in the era of high-resolution ultraviolet spectroscopy when new elemental species could be interpreted and observations were able to show the limits of laboratory determinations. Thanks to this synergy, we currently have a good idea of the quantity of the most abundant elements incorporated into dust in diffuse neutral interstellar clouds: carbon, oxygen, iron, silicon and magnesium. Now the task is to figure out how, chemically and physically, those elements are integrated into interstellar grains. We can do this by comparing extinction curves to grain populations in radiative transfer models. The limitation at the present time is the availability of optical constants in the infrared through ultraviolet for species that are likely to exist in dust, i.e., those that are easy to form in the physical environments around stars and in molecular clouds. Extinction in some lines of sight can be fit within current abundance limits and with the optical constants that are available. However the inability to reproduce other extinction curves suggests that optical constants can be improved, either in quality for compounds that have been measured, or quantity in the sense of providing data for more materials. This talk will address the current state and the future of dust studies in the diffuse neutral interstellar medium. This work is supported by the grant HST-AR-10979.01-A from the Space Telescope Science Institute to Whitman College.

Component design description of the neutral beam injectors for PLT

International Nuclear Information System (INIS)

Johnson, R.L.; Baer, M.B.; Dagenhart, W.K.; Haselton, H.H.; Mann, T.L.; Queen, C.C.; Stirling, W.L.; Whitfield, P.W.

1977-01-01

Plasma heating by injection of high energy neutrals is one of the experiments to be carried out on Princeton Large Torus (PLT). A four unit neutral beam injection system has been designed, built and tested which should inject a total of 3 MW of neutrals into PLT with a 200 millisecond pulse length. A typical system unit is described where the major components are identified. The following discussion describes each of these items along with some details of the design and fabrication problems encountered. Some early design considerations addressed the problems of separation and dumping of residual ions from the neutral beam, calorimetry of the neutrals with incident fuxes of 25 KW/cm 2 , and pumping speeds of several hundred thousand liters per second for hydrogen gas. Solutions were found for these problems while also resolving the complex dilemma of interfacing four large systems to a tokamak

The diagnostic neutral beam injector with arc-discharge plasma source on the TCV Tokamak

Energy Technology Data Exchange (ETDEWEB)

Karpushov, Alexander N. [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, CH-1015 Lausanne (Switzerland)], E-mail: alexander.karpushov@epfl.ch; Andrebe, Yanis; Duval, Basil P.; Bortolon, Alessandro [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, CH-1015 Lausanne (Switzerland)

2009-06-15

The diagnostic neutral beam injector (DNBI) together with a charge exchange recombination spectroscopy (CXRS) system has been used on the TCV Tokamak as a diagnostic tool for local measurements of plasma ion temperature, velocity and carbon impurity density based on analysis of the beam induced impurity radiation emission since 2000. To improve the performance of the CXRS diagnostic, several upgrades of both the optical system and the neutral beam were performed. An increase of the plasma source size together with beam optimization in 2003 resulted in a twofold increase the beam current. The RF plasma generator was replaced by an arc-discharge plasma source together with a new ion optical system (IOS) in 2006 and subsequent beam optimization is presented herein. This was designed to increase the line brightness of the beam in the CXRS observation region without increasing of the injected power (to avoid plasma perturbation by the beam). The beam characteristics are measured by a multi-chord scanning of Doppler-shifted H{sub {alpha}} emission, thermal measurements on a movable calorimeter and visible optical measurements inside the Tokamak vessel.

Control, data acquisition and analysis for the JET neutral injection test bed

International Nuclear Information System (INIS)

Jones, T.T.C.; Brenan, P.R.; Rodgers, M.E.; Stork, D.; Young, I.D.

1985-01-01

The Neutral Injection Test-Bed (NITB) is a major experimental assembly in support of the Neutral Beam Heating Programme for JET. In addition to its prime function of testing the Neutral Injection hardware, the Test Bed serves as the prototype to test the computer control and data acquisition system, which is described in this paper. The software system has been written in a portable, data-driven manner with the aim to adapt it, with only minor modifications to the operation of the first. Neutral Injection Beamline on JET, which will involve operation both synchronous and asynchronous with that of the JET Tokamak

Entanglement of two ground state neutral atoms using Rydberg blockade

DEFF Research Database (Denmark)

Miroshnychenko, Yevhen; Browaeys, Antoine; Evellin, Charles

2011-01-01

We report on our recent progress in trapping and manipulation of internal states of single neutral rubidium atoms in optical tweezers. We demonstrate the creation of an entangled state between two ground state atoms trapped in separate tweezers using the effect of Rydberg blockade. The quality...... of the entanglement is measured using global rotations of the internal states of both atoms....

Naturally selected hepatitis C virus polymorphisms confer broad neutralizing antibody resistance.

Science.gov (United States)

Bailey, Justin R; Wasilewski, Lisa N; Snider, Anna E; El-Diwany, Ramy; Osburn, William O; Keck, Zhenyong; Foung, Steven K H; Ray, Stuart C

2015-01-01

For hepatitis C virus (HCV) and other highly variable viruses, broadly neutralizing mAbs are an important guide for vaccine development. The development of resistance to anti-HCV mAbs is poorly understood, in part due to a lack of neutralization testing against diverse, representative panels of HCV variants. Here, we developed a neutralization panel expressing diverse, naturally occurring HCV envelopes (E1E2s) and used this panel to characterize neutralizing breadth and resistance mechanisms of 18 previously described broadly neutralizing anti-HCV human mAbs. The observed mAb resistance could not be attributed to polymorphisms in E1E2 at known mAb-binding residues. Additionally, hierarchical clustering analysis of neutralization resistance patterns revealed relationships between mAbs that were not predicted by prior epitope mapping, identifying 3 distinct neutralization clusters. Using this clustering analysis and envelope sequence data, we identified polymorphisms in E2 that confer resistance to multiple broadly neutralizing mAbs. These polymorphisms, which are not at mAb contact residues, also conferred resistance to neutralization by plasma from HCV-infected subjects. Together, our method of neutralization clustering with sequence analysis reveals that polymorphisms at noncontact residues may be a major immune evasion mechanism for HCV, facilitating viral persistence and presenting a challenge for HCV vaccine development.

Toxicity of binary chemical munition destruction products: methylphosphonic acid, methylphosphinic acid, 2-diisopropylaminoethanol, DF neutralent, and QL neutralent.

Science.gov (United States)

Watson, Rebecca E; Hafez, Ahmed M; Kremsky, Jonathan N; Bizzigotti, George O

2007-01-01

This paper reports the toxicity and environmental impact of neutralents produced from the hydrolysis of binary chemical agent precursor chemicals DF (methylphosphonic difluoride) and QL (2-[bis(1-methylethyl)amino]ethyl ethyl methylphosphonite). Following a literature review of the neutralent mixtures and constituents, basic toxicity tests were conducted to fill data gaps, including acute oral and dermal median lethal dose assays, the Ames mutagenicity test, and ecotoxicity tests. For methylphosphonic acid (MPA), a major constituent of DF neutralent, the acute oral LD(50) in the Sprague-Dawley rat was measured at 1888 mg/kg, and the Ames test using typical tester strains of Salmonella typhimurium and Escherichia coli was negative. The 48-h LC(50) values for pH-adjusted DF neutralent with Daphnia magna and Cyprinodon variegatus were > 2500 mg/L and 1593 mg/L, respectively. The acute oral LD(50) values in the rat for QL neutralent constituents methylphosphinic acid (MP) and 2-diisopropylaminoethanol (KB) were both determined to be 940 mg/kg, and the Ames test was negative for both. Good Laboratory Practice (GLP)-compliant ecotoxicity tests for MP and KB gave 48-h D. magna EC(50) values of 6.8 mg/L and 83 mg/L, respectively. GLP-compliant 96-h C. variegatus assays on MP and KB gave LC(50) values of 73 and 252 mg/L, respectively, and NOEC values of 22 and 108 mg/L. QL neutralent LD(50) values for acute oral and dermal toxicity tests were both > 5000 mg/kg, and the 48-h LD(50) values for D. magna and C. variegatus were 249 and 2500 mg/L, respectively. Using these data, the overall toxicity of the neutralents was assessed.

Quantitative Profiling of Major Neutral Lipid Classes in Human Meibum by Direct Infusion Electrospray Ionization Mass Spectrometry

Science.gov (United States)

Chen, Jianzhong; Green, Kari B.; Nichols, Kelly K.

2013-01-01

Purpose. The purpose of this investigation was to better understand lipid composition in human meibum. Methods. Intact lipids in meibum samples were detected by direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis in positive detection mode using sodium iodide (NaI) as an additive. The peak intensities of all major types of lipid species, that is, wax esters (WEs), cholesteryl esters (CEs), and diesters (DEs) were corrected for peak overlapping and isotopic distribution; an additional ionization efficiency correction was performed for WEs and CEs, which was simplified by the observation that the corresponding ionization efficiency was primarily dependent on the specific lipid class and saturation degree of the lipids while independent of the carbon chain length. A set of WE and CE standards was spiked in meibum samples for ionization efficiency determination and absolute quantitation. Results. The absolute amount (μmol/mg) for each of 51 WEs and 31 CEs in meibum samples was determined. The summed masses for 51 WEs and 31 CEs accounted for 48 ± 4% and 40 ± 2%, respectively, of the total meibum lipids. The mass percentages of saturated and unsaturated species were determined to be 75 ± 2% and 25 ± 1% for CEs and 14 ± 1% and 86 ± 1% for WEs. The profiles for two types of DEs were also obtained, which include 42 α,ω Type II DEs, and 21 ω Type I-St DEs. Conclusions. Major neutral lipid classes in meibum samples were quantitatively profiled by ESI-MS analysis with NaI additive. PMID:23847307

The neutral thermosphere at Arecibo during geomagnetic storms

International Nuclear Information System (INIS)

Burnside, R.G.; Tepley, C.A.; Sulzer, M.P.; Fuller-Rowell, T.J.; Torr, D.G.; Roble, R.G.

1991-01-01

Over the past five years, simultaneous incoherent scatter and optical observations have been obtained at Arecibo, Puerto Rico, during two major geomagnetic storms. The first storm the authors examine occurred during the World Day campaign of 12-16 January 1988, where on 14 January 1988, Kp values greater than 7 were recorded. An ion-energy balance calculation shows that atomic oxygen densities at a fixed height on 14 January 1988 were about twice as large as they were on the quiet days in this period. Simultaneous radar and Fabry-Perot interferometer observations were used to infer nightime O densities on 14-15 January 1988 that were about twice as large as on adjacent quiet nights. On this night, unusually high westward ion velocities were observed at Arecibo. The Fabry-Perot measurements show that the normal eastward flow of the neutral wind was reversed on this night. The second storm they examine occured on the night of 13-14 July 1985, when Kp values reached only 4+, but the ionosphere and thermosphere responded in a similar manner as they did in January 1988. On the nights of both 13-14 July 1985 and 14-15 January 1988, the electron densities observed at Arecibo were significantly higher than they were on nearby geomagnetically quiet nights. These results indicate that major storm effects in thermospheric winds and composition propagate to low latitudes and have a pronounced effect on the ionospheric structure over Arecibo

Detection of the Galactic Warm Neutral Medium in HI 21cm absorption

Science.gov (United States)

Patra, Narendra Nath; Kanekar, Nissim; Chengalur, Jayaram N.; Roy, Nirupam

2018-05-01

We report a deep Giant Metrewave Radio Telescope (GMRT) search for Galactic HI 21cm absorption towards the quasar B0438-436, yielding the detection of wide, weak HI 21cm absorption, with a velocity-integrated HI 21cm optical depth of 0.0188 ± 0.0036 km s-1. Comparing this with the HI column density measured in the Parkes Galactic All-Sky Survey gives a column density-weighted harmonic mean spin temperature of 3760 ± 365 K, one of the highest measured in the Galaxy. This is consistent with most of the HI along the sightline arising in the stable warm neutral medium (WNM). The low peak HI 21cm optical depth towards B0438-436 implies negligible self-absorption, allowing a multi-Gaussian joint decomposition of the HI 21cm absorption and emission spectra. This yields a gas kinetic temperature of T_k ≤ (4910 ± 1900) K, and a spin temperature of T_s = (1000 ± 345) K for the gas that gives rise to the HI 21cm absorption. Our data are consistent with the HI 21cm absorption arising from either the stable WNM, with T_s ≪ T_k, T_k ≈ 5000 K, and little penetration of the background Lyman-α radiation field into the neutral hydrogen, or from the unstable neutral medium, with T_s ≈ T_k ≈ 1000K.

Testing the Neutral Theory of Biodiversity with Human Microbiome Datasets

OpenAIRE

Li, Lianwei; Ma, Zhanshan (Sam)

2016-01-01

The human microbiome project (HMP) has made it possible to test important ecological theories for arguably the most important ecosystem to human health?the human microbiome. Existing limited number of studies have reported conflicting evidence in the case of the neutral theory; the present study aims to comprehensively test the neutral theory with extensive HMP datasets covering all five major body sites inhabited by the human microbiome. Utilizing 7437 datasets of bacterial community samples...

From the Laboratory to Space: Neutral and Ionized PAHs in Translucent Interstellar Clouds

Science.gov (United States)

Salama, Farid; Galazutdinov, G.; Biennier, L.; Krelowski, J.

2012-05-01

We describe and discuss the laboratory experiments that were designed to test the proposal of relating the origin of some of the diffuse interstellar bands (DIBs) to neutral and ionized polycyclic aromatic hydrocarbons (PAHs) present in diffuse interstellar clouds. The spectra of several cold, isolated gas-phase PAH ions and neutral molecules have been measured using the COSmIC laboratory facility at NASA-Ames and are compared with an extensive set of astronomical spectra of reddened, early type stars. The COSmIC facility combines a supersonic free jet expansion with discharge plasma and high-sensitivity cavity ringdown spectroscopy to provide experimental conditions that closely mimic the interstellar conditions. This comparison provides - for the first time - accurate upper limits for the abundances of specific PAH molecules and ions along specific lines-of-sight. Something that is not attainable from infrared observations alone. The comparison of these unique laboratory data with high resolution, high S/N ratio astronomical observations leads to major findings regarding the column densities of the individual PAH molecules and ions that are probed in this survey and leads to clear and unambiguous conclusions regarding the expected abundances for PAHs of various sizes and charge states in these environments. This quantitative survey of neutral and ionized PAHs in the optical range opens the way for unambiguous quantitative searches of PAHs and complex organics in a variety of interstellar and circumstellar environments. Acknowledgements: F.S. acknowledges the support of the NASA’s Space Mission Directorate APRA Program. The authors are deeply grateful to the ESO archive as well as to the ESO staff members for their active support.

Neutral Silicon-Vacancy Center in Diamond: Spin Polarization and Lifetimes

Science.gov (United States)

Green, B. L.; Mottishaw, S.; Breeze, B. G.; Edmonds, A. M.; D'Haenens-Johansson, U. F. S.; Doherty, M. W.; Williams, S. D.; Twitchen, D. J.; Newton, M. E.

2017-09-01

We demonstrate optical spin polarization of the neutrally charged silicon-vacancy defect in diamond (SiV0 ), an S =1 defect which emits with a zero-phonon line at 946 nm. The spin polarization is found to be most efficient under resonant excitation, but nonzero at below-resonant energies. We measure an ensemble spin coherence time T2>100 μ s at low-temperature, and a spin relaxation limit of T1>25 s . Optical spin-state initialization around 946 nm allows independent initialization of SiV0 and NV- within the same optically addressed volume, and SiV0 emits within the telecoms down-conversion band to 1550 nm: when combined with its high Debye-Waller factor, our initial results suggest that SiV0 is a promising candidate for a long-range quantum communication technology.

Testing the Neutral Theory of Biodiversity with Human Microbiome Datasets.

Science.gov (United States)

Li, Lianwei; Ma, Zhanshan Sam

2016-08-16

The human microbiome project (HMP) has made it possible to test important ecological theories for arguably the most important ecosystem to human health-the human microbiome. Existing limited number of studies have reported conflicting evidence in the case of the neutral theory; the present study aims to comprehensively test the neutral theory with extensive HMP datasets covering all five major body sites inhabited by the human microbiome. Utilizing 7437 datasets of bacterial community samples, we discovered that only 49 communities (less than 1%) satisfied the neutral theory, and concluded that human microbial communities are not neutral in general. The 49 positive cases, although only a tiny minority, do demonstrate the existence of neutral processes. We realize that the traditional doctrine of microbial biogeography "Everything is everywhere, but the environment selects" first proposed by Baas-Becking resolves the apparent contradiction. The first part of Baas-Becking doctrine states that microbes are not dispersal-limited and therefore are neutral prone, and the second part reiterates that the freely dispersed microbes must endure selection by the environment. Therefore, in most cases, it is the host environment that ultimately shapes the community assembly and tip the human microbiome to niche regime.

Climate Neutral Campus Key Terms and Definitions | Climate Neutral Research

Science.gov (United States)

Campuses | NREL Neutral Campus Key Terms and Definitions Climate Neutral Campus Key Terms and Definitions The term climate neutral evolved along with net zero and a number of other "green" and accuracy in these areas lets research campuses know exactly how close they are to climate

Charge-exchange neutral hydrogen measurements in TFTR using Pd-MOS microsensors

International Nuclear Information System (INIS)

Bastasz, R.; Kilpatrick, S.J.; Ruzic, D.N.

1991-06-01

An array of Pd-metal-oxide semiconductor (Pd-MOS) diodes has been used to monitor the fluence and energy of charge-exchange neutral hydrogen isotopes striking the wall of the Tokamak Fusion Test Reactor (TFTR). The array was positioned 4 cm behind the graphite-tiled wall at the toroidal midplane and exposed to several hundred plasma discharges. Hydrogen isotopes striking the Pd-MOS diodes were detected by measuring the leakage current, which is affected by the presence of these species at the Pd/SiO 2 interface. It was found that the midplane flux strongly increased for neutral-beam heated plasmas and correlated with co-injected neutral beam power. The majority of the neutral flux was <50 eV in energy but its energy distribution extended to above 500 eV. 20 refs., 4 figs

Alkali-Responsive Absorption Spectra and Third-Order Optical Nonlinearities of Imino Squaramides

International Nuclear Information System (INIS)

Li Zhong-Yu; Xu Song; Zhou Xin-Yu; Zhang Fu-Shi

2012-01-01

Third-order optical nonlinearities and dynamic responses of two imino squaramides under neutral and base conditions were studied using the femtosecond degenerate four-wave mixing technique at 800 nm. Ultrafast optical responses have been observed and the magnitude of the second-order hyperpolarizabilities of the squaramides has been measured to be as large as 10 −31 esu. The absorption spectra, color of solution, and third-order optical nonlinearities of two imino squaramides change with the addition of sodium hydroxide. The γ value under the base condition for each dye is approximately 1.25 times larger than that under neutral conditions. (fundamental areas of phenomenology(including applications))

Neutrality Versus Materiality: A Thermodynamic Theory of Neutral Surfaces

Directory of Open Access Journals (Sweden)

Rémi Tailleux

2016-09-01

Full Text Available In this paper, a theory for constructing quasi-neutral density variables γ directly in thermodynamic space is formulated, which is based on minimising the absolute value of a purely thermodynamic quantity J n . Physically, J n has a dual dynamic/thermodynamic interpretation as the quantity controlling the energy cost of adiabatic and isohaline parcel exchanges on material surfaces, as well as the dependence of in-situ density on spiciness, in a description of water masses based on γ, spiciness and pressure. Mathematically, minimising | J n | in thermodynamic space is showed to be equivalent to maximising neutrality in physical space. The physics of epineutral dispersion is also reviewed and discussed. It is argued, in particular, that epineutral dispersion is best understood as the aggregate effect of many individual non-neutral stirring events (being understood here as adiabatic and isohaline events with non-zero buoyancy, so that it is only the net displacement aggregated over many events that is approximately neutral. This new view resolves an apparent paradox between the focus in neutral density theory on zero-buoyancy motions and the overwhelming evidence that lateral dispersion in the ocean is primarily caused by non-zero buoyancy processes such as tides, residual currents and sheared internal waves. The efficiency by which a physical process contributes to lateral dispersion can be characterised by its energy signature, with those processes releasing available potential energy (negative energy cost being more efficient than purely neutral processes with zero energy cost. The latter mechanism occurs in the wedge of instability, and its source of energy is the coupling between baroclinicity, thermobaricity, and density compensated temperature/salinity anomalies. Such a mechanism, which can only exist in a salty ocean, is speculated to be important for dissipating spiciness anomalies and neutral helicity. The paper also discusses potential

Impurities or a neutral Fermi surface? A further examination of the low-energy ac optical conductivity of SmB6

Science.gov (United States)

Laurita, N. J.; Morris, C. M.; Koohpayeh, S. M.; Phelan, W. A.; McQueen, T. M.; Armitage, N. P.

2018-05-01

Recent experiments have uncovered evidence of low energy excitations in the bulk of SmB6 that are perhaps associated with unconventional quasiparticles, bringing into question whether this Kondo "insulator" is truly insulating in the bulk. Recently, we demonstrated that SmB6 possesses significant in-gap bulk ac conduction far in excess of typical disordered semiconductors. Whether such conduction is an intrinsic feature of SmB6, suggesting the formation of an exotic state, or residual conduction from impurities continues to be a topic of debate. Here, we further examine the origin of the ac optical conductivity of SmB6 in light of recent experimental and theoretical developments. The optical conductivity of SmB6 is shown to possess distinct regimes of either dominant free carrier or localized response contributions. The free carrier response is found to be in good qualitative agreement with previous literature, although quantitative differences are revealed and discussed. The localized response, which dominates at the lowest temperatures, is analyzed in the context of models of either in-gap impurity states or an exotic neutral Fermi surface. The charge density or effective mass of this low temperature in-gap conductivity is extracted through a conductivity sum rule analysis and found to be in general alignment with both models in the appropriate limits. Our results shed further light on the nature of the in-gap states of SmB6.

An electrostatic elliptical mirror for neutral polar molecules.

Science.gov (United States)

González Flórez, A Isabel; Meek, Samuel A; Haak, Henrik; Conrad, Horst; Santambrogio, Gabriele; Meijer, Gerard

2011-11-14

Focusing optics for neutral molecules finds application in shaping and steering molecular beams. Here we present an electrostatic elliptical mirror for polar molecules consisting of an array of microstructured gold electrodes deposited on a glass substrate. Alternating positive and negative voltages applied to the electrodes create a repulsive potential for molecules in low-field-seeking states. The equipotential lines are parallel to the substrate surface, which is bent in an elliptical shape. The mirror is characterized by focusing a beam of metastable CO molecules and the results are compared to the outcome of trajectory simulations.

Optical lattice on an atom chip

DEFF Research Database (Denmark)

Gallego, D.; Hofferberth, S.; Schumm, Thorsten

2009-01-01

Optical dipole traps and atom chips are two very powerful tools for the quantum manipulation of neutral atoms. We demonstrate that both methods can be combined by creating an optical lattice potential on an atom chip. A red-detuned laser beam is retroreflected using the atom chip surface as a high......-quality mirror, generating a vertical array of purely optical oblate traps. We transfer thermal atoms from the chip into the lattice and observe cooling into the two-dimensional regime. Using a chip-generated Bose-Einstein condensate, we demonstrate coherent Bloch oscillations in the lattice....

Control and manipulation of cold atoms in optical tweezers

International Nuclear Information System (INIS)

Muldoon, Cecilia; Brandt, Lukas; Dong Jian; Stuart, Dustin; Brainis, Edouard; Himsworth, Matthew; Kuhn, Axel

2012-01-01

Neutral atoms trapped by laser light are among the most promising candidates for storing and processing information in a quantum computer or simulator. The application certainly calls for a scalable and flexible scheme for addressing and manipulating the atoms. We have now made this a reality by implementing a fast and versatile method to dynamically control the position of neutral atoms trapped in optical tweezers. The tweezers result from a spatial light modulator (SLM) controlling and shaping a large number of optical dipole-force traps. Trapped atoms adapt to any change in the potential landscape, such that one can rearrange and randomly access individual sites within atom-trap arrays. (paper)

Modeling of the lithium based neutralizer for ITER neutral beam injector

Energy Technology Data Exchange (ETDEWEB)

Dure, F., E-mail: franck.dure@u-psud.fr [LPGP, Laboratoire de Physique des Gaz et Plasmas, CNRS-Universite Paris Sud, Orsay (France); Lifschitz, A.; Bretagne, J.; Maynard, G. [LPGP, Laboratoire de Physique des Gaz et Plasmas, CNRS-Universite Paris Sud, Orsay (France); Simonin, A. [IRFM, Institut de Recherche sur la Fusion Magnetique, CEA Cadarache, 13108 Saint-Paul lez Durance (France); Minea, T. [LPGP, Laboratoire de Physique des Gaz et Plasmas, CNRS-Universite Paris Sud, Orsay (France)

2012-04-04

Highlights: Black-Right-Pointing-Pointer We compare different lithium based neutraliser configurations to the deuterium one. Black-Right-Pointing-Pointer We study characteristics of the secondary plasma and the propagation of the 1 MeV beam. Black-Right-Pointing-Pointer Using lithium increases the neutralisation effiency keeping correct beam focusing. Black-Right-Pointing-Pointer Using lithium also reduces the backstreaming effect in direction of the ion source. - Abstract: To achieve thermonuclear temperatures necessary to produce fusion reactions in the ITER Tokamak, additional heating systems are required. One of the main method to heat the plasma ions in ITER will be the injection of energetic neutrals (NBI). In the neutral beam injector, negative ions (D{sup -}) are electrostatically accelerated to 1 MeV, and then stripped of their extra electron via collisions with a target gas, in a structure known as neutralizer. In the current ITER specification, the target gas is deuterium. It has been recently proposed to use lithium vapor instead of deuterium as target gas in the neutralizer. This would allow to reduce the gas load in the NBI vessel and to improve the neutralization efficiency. A Particle-in-Cell Monte Carlo code has been developed to study the transport of the beams and the plasma formation in the neutralizer. A comparison between Li and D{sub 2} based neutralizers made with this code is presented here, as well as a parametric study on the geometry of the Li based neutralizer. Results demonstrate the feasibility of a Li based neutralizer, and its advantages with respect to the deuterium based one.

Outgassing measurements and results used in designing the Doublet III Neutral Beam Injector System

International Nuclear Information System (INIS)

Yamamoto, R.M.; Harvey, J.

1979-11-01

Material vacuum properties played an important part in designing the Neutral Beam Injector System for General Atomic's Doublet III Tokamak. Low operating vacuum tank pressures were desired to keep re-ionization of the Neutral Beam to a minimum. Plasma contamination was also a major concern, hence stringent material impurity constraints were imposed. Outgassing Rate Measurement and Residual Gas Analyses were performed on different types of materials to determine if their vacuum properties were compatible with the Neutral Beam Injector System requirements

''Econodump'' design for the Fermilab Direct Neutral Lepton Facility

International Nuclear Information System (INIS)

Childress, S.; Brown, C.; Koizumi, G.; Malensek, A.; Morfin, J.G.; Murphy, T.; Stefanski, R.; Wehman, A.; Lu, B.

1986-08-01

An extensive effort has been directed toward a major redesign of the Fermilab Direct Neutral Lepton Facility (DNLF). The goal has been a very significant cost reduction of the facility, with minimal sacrifice of physics potential. Hence the name ''Econodump'' applied to the redesign effort

Theoretical studies of optics and charge transport in organic conducting oligomers and polymers: Rational design of improved transparent and conducting polymers

Science.gov (United States)

Hutchison, Geoffrey Rogers

Theoretical studies on a variety of oligo- and polyheterocycles elucidate their optical and charge transport properties, suggesting new, improved transparent conductive polymers. First-principles calculations provide accurate methodologies for predicting both optical band gaps of neutral and cationic oligomers and intrinsic charge transfer rates. Multidimensional analysis reveals important motifs in chemical tailorability of oligoheterocycle optical and charge transport properties. The results suggest new directions for design of novel materials. Using both finite oligomer and infinite polymer calculations, the optical band gaps in polyheterocycles follow a modified particle-in-a-box formalism, scaling approximately as 1/N (where N is the number of monomer units) in short chains, saturating for long chains. Calculations demonstrate that band structure changes upon heteroatom substitution, (e.g., from polythiophene to polypyrrole) derive from heteroatom electron affinity. Further investigation of chemical variability in substituted oligoheterocycles using multidimensional statistics reveals the interplay between heteroatom and substituent in correlations between structure and redox/optical properties of neutral and cationic species. A linear correlation between band gaps of neutral and cationic species upon oxidation of conjugated oligomers, shows redshifts of optical absorption for most species and blueshifts for small band gap species. Interstrand charge-transport studies focus on two contributors to hopping-style charge transfer rates: internal reorganization energy and the electronic coupling matrix element. Statistical analysis of chemical variability of reorganization energies in oligoheterocycles proves the importance of reorganization energy in determining intrinsic charge transfer rates (e.g., charge mobility in unsubstituted oligothiophenes). Computed bandwidths across several oligothiophene crystal packing motifs show similar electron and hole bandwidths

Alfalfa discovery of the nearby gas-rich dwarf galaxy LEO P. V. Neutral gas dynamics and kinematics

International Nuclear Information System (INIS)

Bernstein-Cooper, Elijah Z.; Pardy, Stephen A.; Cannon, John M.

2014-01-01

We present new H I spectral line imaging of the extremely metal-poor, star-forming dwarf irregular galaxy Leo P. Our H I images probe the global neutral gas properties and the local conditions of the interstellar medium (ISM). The H I morphology is slightly elongated along the optical major axis. We do not find obvious signatures of interaction or infalling gas at large spatial scales. The neutral gas disk shows obvious rotation, although the velocity dispersion is comparable to the rotation velocity. The rotation amplitude is estimated to be V c =15 ± 5 km s –1 . Within the H I radius probed by these observations, the mass ratio of gas to stars is roughly 2:1, while the ratio of the total mass to the baryonic mass is ≳15:1. We use this information to place Leo P on the baryonic Tully-Fisher relation, testing the baryonic content of cosmic structures in a sparsely populated portion of parameter space that has hitherto been occupied primarily by dwarf spheroidal galaxies. We detect the signature of two temperature components in the neutral ISM of Leo P; the cold and warm components have characteristic velocity widths of 4.2 ± 0.9 km s –1 and 10.1 ± 1.2 km s –1 , corresponding to kinetic temperature upper limits of ∼1100 K and ∼6200 K, respectively. The cold H I component is unresolved at a physical resolution of 200 pc. The highest H I surface densities are observed in close physical proximity to the single H II region. A comparison of the neutral gas properties of Leo P with other extremely metal-deficient (XMD) galaxies reveals that Leo P has the lowest neutral gas mass of any known XMD, and that the dynamical mass of Leo P is more than two orders of magnitude smaller than any known XMD with comparable metallicity.

Alfalfa discovery of the nearby gas-rich dwarf galaxy LEO P. V. Neutral gas dynamics and kinematics

Energy Technology Data Exchange (ETDEWEB)

Bernstein-Cooper, Elijah Z.; Pardy, Stephen A. [Department of Astronomy, University of Wisconsin, 475 N Charter Street, Madison, WI 53706 (United States); Cannon, John M., E-mail: ezbc@astro.wisc.edu, E-mail: spardy@astro.wisc.edu, E-mail: jcannon@macalester.edu [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); and others

2014-08-01

We present new H I spectral line imaging of the extremely metal-poor, star-forming dwarf irregular galaxy Leo P. Our H I images probe the global neutral gas properties and the local conditions of the interstellar medium (ISM). The H I morphology is slightly elongated along the optical major axis. We do not find obvious signatures of interaction or infalling gas at large spatial scales. The neutral gas disk shows obvious rotation, although the velocity dispersion is comparable to the rotation velocity. The rotation amplitude is estimated to be V {sub c} =15 ± 5 km s{sup –1}. Within the H I radius probed by these observations, the mass ratio of gas to stars is roughly 2:1, while the ratio of the total mass to the baryonic mass is ≳15:1. We use this information to place Leo P on the baryonic Tully-Fisher relation, testing the baryonic content of cosmic structures in a sparsely populated portion of parameter space that has hitherto been occupied primarily by dwarf spheroidal galaxies. We detect the signature of two temperature components in the neutral ISM of Leo P; the cold and warm components have characteristic velocity widths of 4.2 ± 0.9 km s{sup –1} and 10.1 ± 1.2 km s{sup –1}, corresponding to kinetic temperature upper limits of ∼1100 K and ∼6200 K, respectively. The cold H I component is unresolved at a physical resolution of 200 pc. The highest H I surface densities are observed in close physical proximity to the single H II region. A comparison of the neutral gas properties of Leo P with other extremely metal-deficient (XMD) galaxies reveals that Leo P has the lowest neutral gas mass of any known XMD, and that the dynamical mass of Leo P is more than two orders of magnitude smaller than any known XMD with comparable metallicity.

Micro-Valences: Affective valence in neutral everyday objects

Directory of Open Access Journals (Sweden)

Sophie eLebrecht

2012-04-01

Full Text Available Affective valence influences both our cognition and our perception of the world. Indeed, the speed and quality with which we recognize objects in a visual scene can vary dramatically depending on its affective content. However, affective processing of visual objects has been typically studied using only stimuli with strong affective valences (e.g., guns or roses. Here we explore whether affective valence must be strong or obvious to exert an effect on our perception. We conclude that the majority of objects carry some affective valence (micro-valences and, thus, nominally neutral objects are not really neutral. Functionally, the perception of valence in everyday objects facilitates perceptually-driven choice behavior, decision-making, and affective responses.

Historical Significance of the Spanish Neutrality in the First World War

Directory of Open Access Journals (Sweden)

Igor Yurievich Mednikov

2014-01-01

Full Text Available The article deals with an insufficiently studied problem, Spanish neutrality during the First World War. The author analyzes its historical significance in the international context, as well in the context of political, economical and social evolution of Spain. Spain was one of the few major European Powers that maintained its neutrality throughout the First World War. Although all Spanish governments during the conflict declared strict neutrality, it was, in actual fact, benevolent towards the Entente Powers, and by the end of hostilities Spain turned into "neutral ally" of Entente. This benevolence towards the future winners and a wide humanitarian campaign supported and headed by the King Alfonso XIII enabled Spain to improve her position in the postwar system of international relations; Spain became one of the non-permanent members of the League of Nations Council. Nevertheless the Spanish neutrality had a negative impact upon the social, political and economical evolution of Spain. The social stratification was increased, the public opinion was deeply divided and the social conflicts were aggravated, that considerably affected the further evolution of the Spanish society.

Human genomic disease variants: a neutral evolutionary explanation.

Science.gov (United States)

Dudley, Joel T; Kim, Yuseob; Liu, Li; Markov, Glenn J; Gerold, Kristyn; Chen, Rong; Butte, Atul J; Kumar, Sudhir

2012-08-01

Many perspectives on the role of evolution in human health include nonempirical assumptions concerning the adaptive evolutionary origins of human diseases. Evolutionary analyses of the increasing wealth of clinical and population genomic data have begun to challenge these presumptions. In order to systematically evaluate such claims, the time has come to build a common framework for an empirical and intellectual unification of evolution and modern medicine. We review the emerging evidence and provide a supporting conceptual framework that establishes the classical neutral theory of molecular evolution (NTME) as the basis for evaluating disease- associated genomic variations in health and medicine. For over a decade, the NTME has already explained the origins and distribution of variants implicated in diseases and has illuminated the power of evolutionary thinking in genomic medicine. We suggest that a majority of disease variants in modern populations will have neutral evolutionary origins (previously neutral), with a relatively smaller fraction exhibiting adaptive evolutionary origins (previously adaptive). This pattern is expected to hold true for common as well as rare disease variants. Ultimately, a neutral evolutionary perspective will provide medicine with an informative and actionable framework that enables objective clinical assessment beyond convenient tendencies to invoke past adaptive events in human history as a root cause of human disease.

Mechanical engineering problems in the TFTR neutral beam system

International Nuclear Information System (INIS)

Cannon, D.D.; Bryant, E.H.; Johnson, R.L.; Kim, J.; Queen, C.C.; Schilling, G.

1975-01-01

A conceptual design of a prototype beam line for the TFTR Neutral Beam System has been developed. The basic components have been defined, cost estimates prepared, and the necessary development programs identified. Four major mechanical engineering problems, potential solutions and the required development programs are discussed

Modeling the LPS Neutralization Activity of Anti-Endotoxins

Directory of Open Access Journals (Sweden)

Virapong Prachayasittikul

2009-05-01

Full Text Available Bacterial lipopolysaccharides (LPS, also known as endotoxins, are major structural components of the outer membrane of Gram-negative bacteria that serve as a barrier and protective shield between them and their surrounding environment. LPS is considered to be a major virulence factor as it strongly stimulates the secretion of pro-inflammatory cytokines which mediate the host immune response and culminating in septic shock. Quantitative structure-activity relationship studies of the LPS neutralization activities of anti-endotoxins were performed using charge and quantum chemical descriptors. Artificial neural network implementing the back-propagation algorithm was selected for the multivariate analysis. The predicted activities from leave-one-out cross-validation were well correlated with the experimental values as observed from the correlation coefficient and root mean square error of 0.930 and 0.162, respectively. Similarly, the external testing set also yielded good predictivity with correlation coefficient and root mean square error of 0.983 and 0.130. The model holds great potential for the rational design of novel and robust compounds with enhanced neutralization activity.

Neutral-beam requirements for compression-boosted ignited tokamak plasmas

International Nuclear Information System (INIS)

Cohn, D.R.; Jassby, D.L.; Kreischer, K.

1977-12-01

Neutral-beam energies of 200 to 500-keV D 0 may be required to insure adequate penetration into the center of ignition-sized tokamak plasmas. However, the beam energy requirement can be reduced by using a start-up scenario in which the final plasma is formed by major-radius compression of a beam-heated plasma whose density-radius product, na, is determined by satisfactory neutral-beam penetration. ''Compression boosting'' is attractive only for plasmas in which ntau/sub E/ increases with na, because a major-radius compression C increases na by C 3 / 2 . The dependence on C of beam energy and beam power for plasmas which obey ''empirical scaling laws'' of the type ntau/sub E/ varies as (na) 2 is analyzed. The dependences on C of stored magnetic energy and TF-coil power dissipation are also determined. It is found that a compression ratio of 1.5 to attain the ignited plasma permits adequate penetration by 150-keV D 0 beams

Diagnostics of gas behind shock waves by refractive optical techniques

International Nuclear Information System (INIS)

Blaha, J.

In a brief outline of optical methods for measuring neutral gas and plasma parameters, techniques are specifically dealt with based on the interferometric measurement of the refractive index. The investigation is shown of gas density changes in a shock tube using the optical Mach-Zehnder interferometer. While in a neutral gas the refractive index is determined by gas density, in a plasma the effects of all components, ie., electrons, ions and atoms are additive. The contributions to refraction from the various components may, in view of the different character and frequencies of the components, be resolved by measurement on more than one wavelength. (J.U.)

Study of neutral particles

International Nuclear Information System (INIS)

Bartel, W.; Bulos, F.; Eisner, A.

1975-01-01

The range of physics problems for which a detector emphasizing neutrals is most suitable is discussed. The primary goals are the all neutrals cross section, sigma/sub o/ (e + e - → neutrals), the characterization of the neutral energy in multi-hadronic events, the search for monoenergetic photons, and good sensitivity in the difficult region of low energy photons. Those features of multi-hadronic events which are most relevant to a neutral detector were calculated using a jet model with parameters extrapolated from SPEAR energies. These distributions are presented and discussed

Neutral face classification using personalized appearance models for fast and robust emotion detection.

Science.gov (United States)

Chiranjeevi, Pojala; Gopalakrishnan, Viswanath; Moogi, Pratibha

2015-09-01

Facial expression recognition is one of the open problems in computer vision. Robust neutral face recognition in real time is a major challenge for various supervised learning-based facial expression recognition methods. This is due to the fact that supervised methods cannot accommodate all appearance variability across the faces with respect to race, pose, lighting, facial biases, and so on, in the limited amount of training data. Moreover, processing each and every frame to classify emotions is not required, as user stays neutral for majority of the time in usual applications like video chat or photo album/web browsing. Detecting neutral state at an early stage, thereby bypassing those frames from emotion classification would save the computational power. In this paper, we propose a light-weight neutral versus emotion classification engine, which acts as a pre-processer to the traditional supervised emotion classification approaches. It dynamically learns neutral appearance at key emotion (KE) points using a statistical texture model, constructed by a set of reference neutral frames for each user. The proposed method is made robust to various types of user head motions by accounting for affine distortions based on a statistical texture model. Robustness to dynamic shift of KE points is achieved by evaluating the similarities on a subset of neighborhood patches around each KE point using the prior information regarding the directionality of specific facial action units acting on the respective KE point. The proposed method, as a result, improves emotion recognition (ER) accuracy and simultaneously reduces computational complexity of the ER system, as validated on multiple databases.

Optical electronics

CERN Document Server

Yariv, Amnon

1991-01-01

This classic text introduces engineering students to the first principles of major phenomena and devices of optoelectronics and optical communication technology. Yariv's "first principles" approach employs real-life examples and extensive problems. The text includes separate chapters on quantum well and semiconductor lasers, as well as phase conjugation and its applications. Optical fiber amplification, signal and noise considerations in optical fiber systems, laser arrays and distributed feedback lasers all are covered extensively in major sections within chapters.

Neutral beam monitoring

International Nuclear Information System (INIS)

Fink, J.H.

1979-01-01

A neutral beam generated by passing accelerated ions through a walled cell containing a low energy neutral gas, such that charge exchange partially neutralizes the high energy beam, is monitored by detecting the current flowing through the cell wall produced by low energy ions which drift to the wall after the charge exchange. By segmenting the wall into radial and longitudinal segments various beam conditions are identified. (U.K.)

Bunched beam neutralization

International Nuclear Information System (INIS)

Gammel, G.M.; Maschke, A.W.; Mobley, R.M.

1979-01-01

One of the steps involved in producing an intense ion beam from conventional accelerators for Heavy Ion Fusion (HIF) is beam bunching. To maintain space charge neutralized transport, neutralization must occur more quickly as the beam bunches. It has been demonstrated at BNL that a 60 mA proton beam from a 750 kV Cockcroft--Walton can be neutralized within a microsecond. The special problem in HIF is that the neutralization must occur in a time scale of nanoseconds. To study neutralization on a faster time scale, a 40 mA, 450 kV proton beam was bunched at 16 MHz. A biased Faraday cup sampled the bunched beam at the position where maximum bunching was nominally expected, about 2.5 meters from the buncher. Part of the drift region, about 1.8 meters, was occupied by a series of Gabor lenses. In addition to enhancing beam transport by transverse focussing, the background cloud of electrons in the lenses provided an extra degree of neutralization. With no lens, the best bunch factor was at least 20. Bunch factor is defined here as the ratio of the distance between bunches to the FWHM bunch length. With the lens, it was hoped that the increased plasma frequency would decrease the neutralization time and cause an increase in the bunch factor. In fact, with the lens, the instantaneous current increased about three times, but the bunch factor dropped to about 10. Even with the lens, the FWHM of the bunches at the position of maximum bunching was still comparable to or less than the oscillation period of the surrounding electron plasma. Thus, the electron density in the lens must increase before neutralization could be effective in this case, or bunching should be done at a lower frequency

Optimization of a constrained linear monochromator design for neutral atom beams.

Science.gov (United States)

Kaltenbacher, Thomas

2016-04-01

A focused ground state, neutral atom beam, exploiting its de Broglie wavelength by means of atom optics, is used for neutral atom microscopy imaging. Employing Fresnel zone plates as a lens for these beams is a well established microscopy technique. To date, even for favorable beam source conditions a minimal focus spot size of slightly below 1μm was reached. This limitation is essentially given by the intrinsic spectral purity of the beam in combination with the chromatic aberration of the diffraction based zone plate. Therefore, it is important to enhance the monochromaticity of the beam, enabling a higher spatial resolution, preferably below 100nm. We propose to increase the monochromaticity of a neutral atom beam by means of a so-called linear monochromator set-up - a Fresnel zone plate in combination with a pinhole aperture - in order to gain more than one order of magnitude in spatial resolution. This configuration is known in X-ray microscopy and has proven to be useful, but has not been applied to neutral atom beams. The main result of this work is optimal design parameters based on models for this linear monochromator set-up followed by a second zone plate for focusing. The optimization was performed for minimizing the focal spot size and maximizing the centre line intensity at the detector position for an atom beam simultaneously. The results presented in this work are for, but not limited to, a neutral helium atom beam. Copyright © 2016 Elsevier B.V. All rights reserved.

Differences between Doppler velocities of ions and neutral atoms in a solar prominence

Science.gov (United States)

Anan, T.; Ichimoto, K.; Hillier, A.

2017-05-01

Context. In astrophysical systems with partially ionized plasma, the motion of ions is governed by the magnetic field while the neutral particles can only feel the magnetic field's Lorentz force indirectly through collisions with ions. The drift in the velocity between ionized and neutral species plays a key role in modifying important physical processes such as magnetic reconnection, damping of magnetohydrodynamic waves, transport of angular momentum in plasma through the magnetic field, and heating. Aims: This paper aims to investigate the differences between Doppler velocities of calcium ions and neutral hydrogen in a solar prominence to look for velocity differences between the neutral and ionized species. Methods: We simultaneously observed spectra of a prominence over an active region in H I 397 nm, H I 434 nm, Ca II 397 nm, and Ca II 854 nm using a high dispersion spectrograph of the Domeless Solar Telescope at Hida observatory. We compared the Doppler velocities, derived from the shift of the peak of the spectral lines presumably emitted from optically-thin plasma. Results: There are instances when the difference in velocities between neutral atoms and ions is significant, for example 1433 events ( 3% of sets of compared profiles) with a difference in velocity between neutral hydrogen atoms and calcium ions greater than 3σ of the measurement error. However, we also found significant differences between the Doppler velocities of two spectral lines emitted from the same species, and the probability density functions of velocity difference between the same species is not significantly different from those between neutral atoms and ions. Conclusions: We interpreted the difference of Doppler velocities as being a result of the motions of different components in the prominence along the line of sight, rather than the decoupling of neutral atoms from plasma. The movie attached to Fig. 1 is available at http://www.aanda.org

Neutral Beam Power System for TPX

International Nuclear Information System (INIS)

Ramakrishnan, S.; Bowen, O.N.; O'Conner, T.; Edwards, J.; Fromm, N.; Hatcher, R.; Newman, R.; Rossi, G.; Stevenson, T.; von Halle, A.

1993-01-01

The Tokamak Physics Experiment (TPX) will utilize to the maximum extent the existing Tokamak Fusion Test Reactor (TFTR) equipment and facilities. This is particularly true for the TFTR Neutral Beam (NB) system. Most of the NB hardware, plant facilities, auxiliary sub-systems, power systems, service infrastructure, and control systems can be used as is. The major changes in the NB hardware are driven by the new operating duty cycle. The TFTR Neutral Beam was designed for operation of the Sources for 2 seconds every 150 seconds. The TPX requires operation for 1000 seconds every 4500 seconds. During the Conceptual Design Phase of TPX every component of the TFTR NB Electrical Power System was analyzed to verify whether the equipment can meet the new operational requirements with our without modifications. The Power System converts 13.8 kV prime power to controlled pulsed power required at the NB sources. The major equipment involved are circuit breakers, auto and rectifier transformers surge suppression components, power tetrodes, HV Decks, and HVDC power transmission to sources. Thermal models were developed for the power transformers to simulate the new operational requirements. Heat runs were conducted for the power tetrodes to verify capability. Other components were analyzed to verify their thermal limitations. This paper describes the details of the evaluation and redesign of the electrical power system components to meet the TPX operational requirements

Molecular clock in neutral protein evolution

Directory of Open Access Journals (Sweden)

Wilke Claus O

2004-08-01

Full Text Available Abstract Background A frequent observation in molecular evolution is that amino-acid substitution rates show an index of dispersion (that is, ratio of variance to mean substantially larger than one. This observation has been termed the overdispersed molecular clock. On the basis of in silico protein-evolution experiments, Bastolla and coworkers recently proposed an explanation for this observation: Proteins drift in neutral space, and can temporarily get trapped in regions of substantially reduced neutrality. In these regions, substitution rates are suppressed, which results in an overall substitution process that is not Poissonian. However, the simulation method of Bastolla et al. is representative only for cases in which the product of mutation rate μ and population size Ne is small. How the substitution process behaves when μNe is large is not known. Results Here, I study the behavior of the molecular clock in in silico protein evolution as a function of mutation rate and population size. I find that the index of dispersion decays with increasing μNe, and approaches 1 for large μNe . This observation can be explained with the selective pressure for mutational robustness, which is effective when μNe is large. This pressure keeps the population out of low-neutrality traps, and thus steadies the ticking of the molecular clock. Conclusions The molecular clock in neutral protein evolution can fall into two distinct regimes, a strongly overdispersed one for small μNe, and a mostly Poissonian one for large μNe. The former is relevant for the majority of organisms in the plant and animal kingdom, and the latter may be relevant for RNA viruses.

Optimization of a constrained linear monochromator design for neutral atom beams

International Nuclear Information System (INIS)

Kaltenbacher, Thomas

2016-01-01

A focused ground state, neutral atom beam, exploiting its de Broglie wavelength by means of atom optics, is used for neutral atom microscopy imaging. Employing Fresnel zone plates as a lens for these beams is a well established microscopy technique. To date, even for favorable beam source conditions a minimal focus spot size of slightly below 1 μm was reached. This limitation is essentially given by the intrinsic spectral purity of the beam in combination with the chromatic aberration of the diffraction based zone plate. Therefore, it is important to enhance the monochromaticity of the beam, enabling a higher spatial resolution, preferably below 100 nm. We propose to increase the monochromaticity of a neutral atom beam by means of a so-called linear monochromator set-up – a Fresnel zone plate in combination with a pinhole aperture – in order to gain more than one order of magnitude in spatial resolution. This configuration is known in X-ray microscopy and has proven to be useful, but has not been applied to neutral atom beams. The main result of this work is optimal design parameters based on models for this linear monochromator set-up followed by a second zone plate for focusing. The optimization was performed for minimizing the focal spot size and maximizing the centre line intensity at the detector position for an atom beam simultaneously. The results presented in this work are for, but not limited to, a neutral helium atom beam. - Highlights: • The presented results are essential for optimal operation conditions of a neutral atom microscope set-up. • The key parameters for the experimental arrangement of a neutral microscopy set-up are identified and their interplay is quantified. • Insights in the multidimensional problem provide deep and crucial understanding for pushing beyond the apparent focus limitations. • This work points out the trade-offs for high intensity and high spatial resolution indicating several use cases.

Optimization of a constrained linear monochromator design for neutral atom beams

Energy Technology Data Exchange (ETDEWEB)

Kaltenbacher, Thomas

2016-04-15

A focused ground state, neutral atom beam, exploiting its de Broglie wavelength by means of atom optics, is used for neutral atom microscopy imaging. Employing Fresnel zone plates as a lens for these beams is a well established microscopy technique. To date, even for favorable beam source conditions a minimal focus spot size of slightly below 1 μm was reached. This limitation is essentially given by the intrinsic spectral purity of the beam in combination with the chromatic aberration of the diffraction based zone plate. Therefore, it is important to enhance the monochromaticity of the beam, enabling a higher spatial resolution, preferably below 100 nm. We propose to increase the monochromaticity of a neutral atom beam by means of a so-called linear monochromator set-up – a Fresnel zone plate in combination with a pinhole aperture – in order to gain more than one order of magnitude in spatial resolution. This configuration is known in X-ray microscopy and has proven to be useful, but has not been applied to neutral atom beams. The main result of this work is optimal design parameters based on models for this linear monochromator set-up followed by a second zone plate for focusing. The optimization was performed for minimizing the focal spot size and maximizing the centre line intensity at the detector position for an atom beam simultaneously. The results presented in this work are for, but not limited to, a neutral helium atom beam. - Highlights: • The presented results are essential for optimal operation conditions of a neutral atom microscope set-up. • The key parameters for the experimental arrangement of a neutral microscopy set-up are identified and their interplay is quantified. • Insights in the multidimensional problem provide deep and crucial understanding for pushing beyond the apparent focus limitations. • This work points out the trade-offs for high intensity and high spatial resolution indicating several use cases.

Theory of direct scattering of neutral and charged atoms

Science.gov (United States)

Franco, V.

1979-01-01

The theory for direct elastic and inelastic collisions between composite atomic systems formulated within the framework of the Glauber approximation is presented. It is shown that the phase-shift function is the sum of a point Coulomb contribution and of an expression in terms of the known electron-hydrogen-atom and proton-hydrogen-atom phase shift function. The scattering amplitude is reexpressed, the pure Coulomb scattering in the case of elastic collisions between ions is isolated, and the exact optical profile function is approximated by a first-order expansion in Glauber theory which takes into account some multiple collisions. The approximate optical profile function terms corresponding to interactions involving one and two electrons are obtained in forms of Meijer G functions and as a one-dimensional integral, and for collisions involving one or two neutral atoms, the scattering amplitude is further reduced to a simple closed-form expression.

Poliovirus Mutants Resistant to Neutralization with Soluble Cell Receptors

Science.gov (United States)

Kaplan, Gerardo; Peters, David; Racaniello, Vincent R.

1990-12-01

Poliovirus mutants resistant to neutralization with soluble cellular receptor were isolated. Replication of soluble receptor-resistant (srr) mutants was blocked by a monoclonal antibody directed against the HeLa cell receptor for poliovirus, indicating that the mutants use this receptor to enter cells. The srr mutants showed reduced binding to HeLa cells and cell membranes. However, the reduced binding phenotype did not have a major impact on viral replication, as judged by plaque size and one-step growth curves. These results suggest that the use of soluble receptors as antiviral agents could lead to the selection of neutralization-resistant mutants that are able to bind cell surface receptors, replicate, and cause disease.

The Ursa Major supercluster

International Nuclear Information System (INIS)

Schuch, N.J.

1983-01-01

An optical and a radio survey have been carried out. The optical observations consist of a spectroscopic survey in which redshift data for cluster galaxies and optical identifications of radio sources were obtained with the 98-inch Isaac Newton telescope at the Royal Greenwich Observatory, and the 200-inch Hale telescope; the photographic survey in B, V and R colors was made with the 48-inch Schmidt telescope at Palomar. Some results on the galaxy distribution in the Ursa Major supercluster are briefly discussed. (Auth.)

Neutralized transport experiment

International Nuclear Information System (INIS)

Roy, P.K.; Yu, S.S.; Eylon, S.; Henestroza, E.; Anders, A.; Gilson, E.P.; Bieniosek, F.M.; Greenway, W.G.; Logan, B.G.; Waldron, W.L.; Shuman, D.B.; Vanecek, D.L.; Welch, D.R.; Rose, D.V.; Thoma, C.; Davidson, R.C.; Efthimion, P.C.; Kaganovich, I.; Sefkow, A.B.; Sharp, W.M.

2005-01-01

Experimental details on providing active neutralization of high brightness ion beam have been demonstrated for Heavy Ion Fusion program. A K + beam was extracted from a variable-perveance injector and transported through 2.4 m long quadrupole lattice for final focusing. Neutralization was provided by a localized cathode arc plasma plug and a RF volume plasma system. Effects of beam perveance, emittance, convergence focusing angle, and axial focusing position on neutralization have been investigated. Good agreement has been observed with theory and experiment throughout the study

A neutral sampling formula for multiple samples and an `exact' test of neutrality

NARCIS (Netherlands)

Etienne, R.S.

2007-01-01

As the utility of the neutral theory of biodiversity is increasingly being recognized, there is also an increasing need for proper tools to evaluate the relative importance of neutral processes (dispersal limitation and stochasticity). One of the key features of neutral theory is its close link to

A neutral sampling formula for multiple samples and an 'exact' test of neutrality

NARCIS (Netherlands)

Etienne, Rampal S.

As the utility of the neutral theory of biodiversity is increasingly being recognized, there is also an increasing need for proper tools to evaluate the relative importance of neutral processes (dispersal limitation and stochasticity). One of the key features of neutral theory is its close link to

Fundamentals of low-energy neutral atom imaging

International Nuclear Information System (INIS)

McComas, D.J.; Funsten, H.O.; Gosling, J.T.; Moore, K.R.; Scime, E.E.; Thomsen, M.F.

1994-01-01

Imaging of the space plasma environment via low-energy neutral atoms (LENAs) promises to revolutionize the way in which large-scale space plasma phenomena are viewed and understood. LENAs are produced by charge exchange between plasma ions (less than tens of kilo-electron-volts) and cold geocoronal neutrals; these LENAs radiate outward in all directions from their points of origin. Previously developed methods for imaging higher energy neutrals are not suitable for observing the majority of the terrestrial magnetosphere, which is comprised primarily of lower energy plasma populations. This paper briefly describes both the direct and indirect techniques that have been suggested for imaging LENAs to date. The authors then examine in more detail the most advanced of these techniques appropriate for magnetospheric imaging, indirect detection based on ionization of LENAs as they transit ultra thin foils. Such a LENA imager consists of four basic components: (1) a biased collimator to remove the ambient charged particles and set the azimuthal field of view; (2) an ultra thin foil, which ionizes a portion of the incident LENAs; (3) an electrostatic analyzer to reject UV light and set the energy passband; and (4) a coincidence position detector to measure converted LENAs while rejecting noise and penetrating radiation

Optical absorption and fluorescence spectroscopy studies of Artepillin C, the major component of green propolis

Science.gov (United States)

Camuri, Isamara Julia; Costa, Adriano Batista; Ito, Amando Siuiti; Pazin, Wallance Moreira

2018-06-01

The bioactivity of propolis against several pathogens is well established, leading to the extensive consumption of that bee product to prevent diseases. Brazilian green propolis, collected by the species Apis mellifera, is one of the most consumed in the world. The chemical composition of green propolis is complex and it has been shown that it displays antioxidant, antimicrobial, anti-inflammatory and antitumor activities, especially due to the high content of Artepillin C. The molecule is a derivative of cinnamic acid with two prenylated groups, responsible for the improvement of the affinity of the compound for lipophilic environment. A carboxylic group (COOH) is also present in the molecule, making it a pH-sensitive compound and the pH-dependent structure of Artepillin C, may modulate its biological activity related to interactions with the cellular membrane of organisms and tissues. Molecular properties of Artepillin C on aqueous solution were examined by optical absorption, steady state and time-resolved fluorescence spectroscopies. Acid-base titration based on the spectral position of the near UV absorption band, resulted in the pKa value of 4.65 for the carboxylic group in Artepillin C. In acidic pH, below the pKa value, an absorption band raised around 350 nm at Artepillin C concentration above 50 μM, due to aggregation of the molecule. In neutral pH, with excitation at 310 nm, Artepillin C presents dual emission at 400 and 450 nm. In pH close to the pKa, the optical spectra show contribution from both protonated and deprotonated species. A three-exponential function was necessary to fit the intensity decays at the different pHs, dominated by a very short lifetime component, around 0.060 ns. The fast decay resulted in emission before fluorescence depolarization, and in values of fluorescence anisotropy higher than could be expected for monomeric forms of the compound. The results give fundamental knowledge about the protonation-deprotonation state of the

Mass spectrometer provided with an optical system for separating neutron particles against charged particles

Energy Technology Data Exchange (ETDEWEB)

Reeher, J R; Story, M S; Smith, R D

1977-03-03

This invention concerns a mass spectrometer with an ion focusing optical system that efficiently separates the charged and neutral particles. It concerns an apparatus that can be used in ionisation areas operating at relatively high pressure (> 10/sup -2/ Torr). The invention relates more particularly to a mass spectrometer with an inlet device for the samples to be identified, a sample ionisation system for forming charged and neutral particles, a mass analyser and an optical system for focusing the ions formed in the mass analyser. The optics include several conducting components of which at least one has sides formed of grids, in the direction of the axis, towards the analyser the optics forming a potential well along the axis. The selected charged particles are focused in the analyser and the remaining particles can escape by the openings in the conducting grids.

Search for neutral leptons

International Nuclear Information System (INIS)

Perl, M.L.

1984-12-01

At present we know of three kinds of neutral leptons: the electron neutrino, the muon neutrino, and the tau neutrino. This paper reviews the search for additional neutral leptons. The method and significance of a search depends upon the model used for the neutral lepton being sought. Some models for the properties and decay modes of proposed neutral leptons are described. Past and present searches are reviewed. The limits obtained by some completed searches are given, and the methods of searches in progress are described. Future searches are discussed. 41 references

The Supervisory Control System for the HL-2A Neutral Beam Injector

Science.gov (United States)

Li, Bo; Li, Li; Feng, Kun; Wang, Xueyun; Yang, Jiaxing; Huang, Zhihui; Kang, Zihua; Wang, Mingwei; Zhang, Guoqing; Lei, Guangjiu; Rao, Jun

2009-06-01

Supervisory control and protection system of the neutral beam injector (NBI) in the HL-2A tokamak is presented. The system is used for a safe coordination of all the main NBI subsystems. Because the system is based on computer networks with its transmission medium of optical fiber, its advantages in high operational stability, reliability, security and flexible functional expandability are clearly shown during the NBI commissioning and heating experiment in HL-2A.

Neutral currents

International Nuclear Information System (INIS)

Paschos, E.A.

1977-01-01

It is stated that over the past few years considerable progress has been made in the field of weak interactions. The existence of neutral currents involving leptons and hadrons has been established and some of the questions concerning their detailed structure have been answered. This imposes constraints on the gauge theories and has eliminated large classes of models. New questions have also been raised, one of which concerns the conservation laws obeyed by neutral currents. The wide range of investigations is impressive and is expected to continue with new results from particle, nuclear, and atomic physics. Headings include - various aspects of a gauge theory (choice of group, the symmetry breaking scheme, representation assignments for fermion fields); space-time structure; isospin structure; leptonic neutral currents; and atomic experiments. (U.K.)

The influence of grid positioning on the beam optics in the neutral beam injectors for ITER

Energy Technology Data Exchange (ETDEWEB)

Veltri, Pierluigi, E-mail: pierluigi.veltri@igi.cnr.it [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, Padova (Italy); INFN—Laboratori Nazionali di Legnaro, Viale dell’Università 2, 35020 Legnaro, Padova (Italy); Agostinetti, Piero; Marcuzzi, Diego; Sartori, Emanuele; Serianni, Gianluigi [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, Padova (Italy)

2016-06-15

Neutral beam injectors are routinely used to increase the ion temperature in magnetically confined plasmas. Typically, the beam is produced by neutralizing a bundle of hundreds of ion beamlets, energized in a multi-grid multi-stage accelerator. Precise aiming of each beamlet is required in order to focus the full beam to the plasma, avoiding any interception with beamline surfaces and with the beam duct. This paper describes the effects of grid in-plane and out-of-plane displacements (mispositioning, thermal expansion, grid tilting, etc…) in the case of the MITICA electrostatic accelerator, which is the full scale prototype of the ITER heating neutral beam injector. Various simulations have been carried out with the OPERA 3D code, by self-consistently simulating the beam charged particles travelling in an externally applied electric and magnetic field. The accelerator grids act like a series of electrostatic lenses, and produce a net deflection of the particles when one or more grids are offset. The numerical simulations were used to evaluate the “steering constant” of each grid and also showed that the linear superposition of effects was applicable, multiple causes of mispositioning are combined and used to quantify the overall effect in terms of beam misalignment.

The influence of grid positioning on the beam optics in the neutral beam injectors for ITER

International Nuclear Information System (INIS)

Veltri, Pierluigi; Agostinetti, Piero; Marcuzzi, Diego; Sartori, Emanuele; Serianni, Gianluigi

2016-01-01

Neutral beam injectors are routinely used to increase the ion temperature in magnetically confined plasmas. Typically, the beam is produced by neutralizing a bundle of hundreds of ion beamlets, energized in a multi-grid multi-stage accelerator. Precise aiming of each beamlet is required in order to focus the full beam to the plasma, avoiding any interception with beamline surfaces and with the beam duct. This paper describes the effects of grid in-plane and out-of-plane displacements (mispositioning, thermal expansion, grid tilting, etc…) in the case of the MITICA electrostatic accelerator, which is the full scale prototype of the ITER heating neutral beam injector. Various simulations have been carried out with the OPERA 3D code, by self-consistently simulating the beam charged particles travelling in an externally applied electric and magnetic field. The accelerator grids act like a series of electrostatic lenses, and produce a net deflection of the particles when one or more grids are offset. The numerical simulations were used to evaluate the “steering constant” of each grid and also showed that the linear superposition of effects was applicable, multiple causes of mispositioning are combined and used to quantify the overall effect in terms of beam misalignment

Performance test results of ion beam transport for SST-1 neutral beam injector

Energy Technology Data Exchange (ETDEWEB)

Jana, M R; Mattoo, S K [Institute for Plasma Research Bhat, Gandhinagar-382428, Gujarat (India); Uhlemann, R, E-mail: mukti@ipr.res.i [Forschungszentrum Juelich, Institute fur Energieforschung IEF-4, Plasmaphysik D-52425 Juelich (Germany)

2010-02-01

A neutral beam injector is built at IPR to heat the plasma of SST-1 and its upgrade. It delivers a maximum beam power of 1.7 MW for 55 kV Hydrogen beam or 80 kV Deuterium beam. At lower beam voltage, the delivered power falls to 500 kW at 30 kV Hydrogen beam which is adequate to heat SST-1 plasma ions to {approx} 1 keV. Process of acceleration of ions to the required beam voltage, conversion of ions to neutrals and removal of un-neutralized ions and the beam diagnostic systems occupy a large space. The consequence is that linear extent of the neutral beam injector is at least a few meters. Also, port access provides a very narrow duct. Even a very good injector design and fabrication practices keep beam divergence at a very low but finite value. The result is beam transport becomes an important issue. Since a wide area beam is constructed by hundreds of beam lets, it becomes essential they be focused in such a way that beam transport loss is minimized. Horizontal and vertical focal lengths are two parameters, in addition to beam divergence, which give a description of the beam transport. We have obtained these two parameters for our injector by using beam transport code; making several hundred simulation runs by varying optical parameters of the beam. The selected parameters set has been translated into the engineering features of the extractor grid set of the ion source. Aperture displacement technique is used to secure the horizontal beam focusing at 5.4 m. Combination of both aperture displacement and inclining of two grid halves to {approx} 17 mrad are secured for vertical beam focusing at 7 m from earth grid of the ion source. The gaps between the design, engineered and performance tested values usually arise due to lack of exercising control over fabrication processes or due to inaccuracies in the assumption made in the model calculations of beam optics and beam transport. This has been the case with several injectors, notably with JET injector. To overcome

Structural and optical properties of Si-doped Ag clusters

KAUST Repository

Mokkath, Junais Habeeb

2014-03-06

The structural and optical properties of AgN and Ag N-1Si1 (neutral, cationic, and anionic) clusters (N = 5 to 12) are systematically investigated using the density functional based tight binding method and time-dependent density functional theory, providing insight into recent experiments. The gap between the highest occupied and lowest unoccupied molecular orbitals and therefore the optical spectrum vary significantly under Si doping, which enables flexible tuning of the chemical and optical properties of Ag clusters. © 2014 American Chemical Society.

Structural and optical properties of Si-doped Ag clusters

KAUST Repository

Mokkath, Junais Habeeb; Schwingenschlö gl, Udo

2014-01-01

The structural and optical properties of AgN and Ag N-1Si1 (neutral, cationic, and anionic) clusters (N = 5 to 12) are systematically investigated using the density functional based tight binding method and time-dependent density functional theory, providing insight into recent experiments. The gap between the highest occupied and lowest unoccupied molecular orbitals and therefore the optical spectrum vary significantly under Si doping, which enables flexible tuning of the chemical and optical properties of Ag clusters. © 2014 American Chemical Society.

Evaluation of ITER MSE Viewing Optics

International Nuclear Information System (INIS)

Allen, S; Lerner, S; Morris, K; Jayakumar, J; Holcomb, C; Makowski, M; Latkowski, J; Chipman, R

2007-01-01

The Motional Stark Effect (MSE) diagnostic on ITER determines the local plasma current density by measuring the polarization angle of light resulting from the interaction of a high energy neutral heating beam and the tokamak plasma. This light signal has to be transmitted from the edge and core of the plasma to a polarization analyzer located in the port plug. The optical system should either preserve the polarization information, or it should be possible to reliably calibrate any changes induced by the optics. This LLNL Work for Others project for the US ITER Project Office (USIPO) is focused on the design of the viewing optics for both the edge and core MSE systems. Several design constraints were considered, including: image quality, lack of polarization aberrations, ease of construction and cost of mirrors, neutron shielding, and geometric layout in the equatorial port plugs. The edge MSE optics are located in ITER equatorial port 3 and view Heating Beam 5, and the core system is located in equatorial port 1 viewing heating beam 4. The current work is an extension of previous preliminary design work completed by the ITER central team (ITER resources were not available to complete a detailed optimization of this system, and then the MSE was assigned to the US). The optimization of the optical systems at this level was done with the ZEMAX optical ray tracing code. The final LLNL designs decreased the ''blur'' in the optical system by nearly an order of magnitude, and the polarization blur was reduced by a factor of 3. The mirror sizes were reduced with an estimated cost savings of a factor of 3. The throughput of the system was greater than or equal to the previous ITER design. It was found that optical ray tracing was necessary to accurately measure the throughput. Metal mirrors, while they can introduce polarization aberrations, were used close to the plasma because of the anticipated high heat, particle, and neutron loads. These mirrors formed an intermediate

A solenoidal synthetic field and the non-Abelian Aharonov-Bohm effects in neutral atoms.

Science.gov (United States)

Huo, Ming-Xia; Nie, Wei; Hutchinson, David A W; Kwek, Leong Chuan

2014-08-08

Cold neutral atoms provide a versatile and controllable platform for emulating various quantum systems. Despite efforts to develop artificial gauge fields in these systems, realizing a unique ideal-solenoid-shaped magnetic field within the quantum domain in any real-world physical system remains elusive. Here we propose a scheme to generate a "hairline" solenoid with an extremely small size around 1 micrometer which is smaller than the typical coherence length in cold atoms. Correspondingly, interference effects will play a role in transport. Despite the small size, the magnetic flux imposed on the atoms is very large thanks to the very strong field generated inside the solenoid. By arranging different sets of Laguerre-Gauss (LG) lasers, the generation of Abelian and non-Abelian SU(2) lattice gauge fields is proposed for neutral atoms in ring- and square-shaped optical lattices. As an application, interference patterns of the magnetic type-I Aharonov-Bohm (AB) effect are obtained by evolving atoms along a circle over several tens of lattice cells. During the evolution, the quantum coherence is maintained and the atoms are exposed to a large magnetic flux. The scheme requires only standard optical access, and is robust to weak particle interactions.

A solenoidal synthetic field and the non-Abelian Aharonov-Bohm effects in neutral atoms

Science.gov (United States)

Huo, Ming-Xia; Nie, Wei; Hutchinson, David A. W.; Kwek, Leong Chuan

2014-08-01

Cold neutral atoms provide a versatile and controllable platform for emulating various quantum systems. Despite efforts to develop artificial gauge fields in these systems, realizing a unique ideal-solenoid-shaped magnetic field within the quantum domain in any real-world physical system remains elusive. Here we propose a scheme to generate a ``hairline'' solenoid with an extremely small size around 1 micrometer which is smaller than the typical coherence length in cold atoms. Correspondingly, interference effects will play a role in transport. Despite the small size, the magnetic flux imposed on the atoms is very large thanks to the very strong field generated inside the solenoid. By arranging different sets of Laguerre-Gauss (LG) lasers, the generation of Abelian and non-Abelian SU(2) lattice gauge fields is proposed for neutral atoms in ring- and square-shaped optical lattices. As an application, interference patterns of the magnetic type-I Aharonov-Bohm (AB) effect are obtained by evolving atoms along a circle over several tens of lattice cells. During the evolution, the quantum coherence is maintained and the atoms are exposed to a large magnetic flux. The scheme requires only standard optical access, and is robust to weak particle interactions.

Plasma neutralizer for H- beams

International Nuclear Information System (INIS)

Grossman, M.W.

1977-01-01

Neutralization of H - beams by a hydrogen plasma is discussed. Optimum target thickness and maximum neutralization efficiency as a function of the fraction of the hydrogen target gas ionized is calculated for different H - beam energies. Also, the variation of neutralization efficiency with respect to target thickness for different H - beam energies is computed. The dispersion of the neutralized beam by a magnetic field for different energies and different values of B . z is found. Finally, a type of plasma jet is proposed, which may be suitable for a compact H - neutralizer

Continuous imaging of a single neutral atom in a variant magneto-optical trap

International Nuclear Information System (INIS)

Xia Tian; Zhou Shuyu; Chen Peng; Li Lin; Hong Tao; Wang Yuzhu

2010-01-01

We demonstrate continuous imaging of a single 87 Rb atom confined in a steep magneto-optical trap with an electron-multiplying charge-coupled device (EMCCD) camera and realize a one-dimensional micro-optical trap array with a Dammann grating. We adopt several methods to reduce the noise in the fluorescence signal we obtain with the EMCCD. Step jumping characteristics of the fluorescence demonstrate capturing and losing of individual atoms. (authors)

On the structural logic of curriculum system for the optical instrument major

Science.gov (United States)

Yan, Yufeng; Yan, Juncen; Li, Yang; Shi, Lixia

2017-08-01

The theories of optical instrument are the Interdisciplinary of Optical Engineering and Instrument Science and Technology. The undergraduates should study the knowledge about the optics, precision machine and electronics. The courses such as Theory of Machine, Engineering Optics, even include some courses about Accuracy Analysis of Instrument are offered in the college. There are a lot of correlatives among these courses. This paper focuses on the structural logic of these courses. The order of these courses is researched, The aims of all the courses are clear completely to avoid the same topics to be taught twice in different courses. Therefore, the undergraduates would get the main line of the knowledge, and the professors would teach efficiently.

Generation of 99-mW continuous-wave 285-nm radiation for magneto-optical trapping of Mg atoms

DEFF Research Database (Denmark)

Madsen, Dorte Nørgaard; Yu, Ping; Balslev, Søren

2002-01-01

We have developed a tunable intense narrow-band 285 nm light source based on frequency doubling of 570 nm light in BBO. At input powers of 840 mW (including 130 mW used for locking purposes) we generate 99 mW UV radiation with an intensity profile suitable for laser-cooling experiments. The light...... is used for laser cooling of neutral magnesium atoms in a magneto-optical trap (MOT). We capture about 5 x 10(6) atoms directly from a thermal beam and find that the major loss mechanism of the magnesium MOT is a near-resonant two-photon ionization process....

Neutralization escape mutants define a dominant immunogenic neutralization site on hepatitis A virus

International Nuclear Information System (INIS)

Stapleton, J.T.; Lemon, S.M.

1987-01-01

Hepatitis A virus is an hepatotrophic human picornavirus which demonstrates little antigenic variability. To topologically map immunogenic sites on hepatitis A virus which elicit neutralizing antibodies, eight neutralizing monoclonal antibodies were evaluated in competition immunoassays employing radiolabeled monoclonal antibodies and HM-175 virus. Whereas two antibodies (K3-4C8 and K3-2F2) bound to intimately overlapping epitopes, the epitope bound by a third antibody (B5-B3) was distinctly different as evidenced by a lack of competition between antibodies for binding to the virus. The other five antibodies variably blocked the binding of both K3-4C8-K3-2F2 and B5-B3, suggesting that these epitopes are closely spaced and perhaps part of a single neutralization immunogenic site. Several combinations of monoclonal antibodies blocked the binding of polyclonal human convalescent antibody by greater than 96%, indicating that the neutralization epitopes bound by these antibodies are immunodominant in humans. Spontaneously arising HM-175 mutants were selected for resistance to monoclonal antibody-mediated neutralization. Neutralization resistance was associated with reduced antibody binding. These results suggest that hepatitis A virus may differ from poliovirus in possessing a single, dominant neutralization immunogenic site and therefore may be a better candidate for synthetic peptide or antiidiotype vaccine development

Electrical control of optical orientation of neutral and negatively charged excitons in an n -type semiconductor quantum well

Science.gov (United States)

Dzhioev, R. I.; Korenev, V. L.; Lazarev, M. V.; Sapega, V. F.; Gammon, D.; Bracker, A. S.

2007-01-01

We report electric field induced increase of spin orientation of negatively charged excitons (trions) localized in n -type GaAs/AlGaAs quantum well. Under resonant excitation of free neutral heavy-hole excitons, the polarization of trions increases dramatically with electrical injection of electrons. The polarization enhancement correlates strongly with trion/exciton luminescence intensity ratio. This effect results from a very efficient trapping of free neutral excitons by the quantum well interfacial fluctuations (“natural” quantum dots) containing resident electrons.

On neutral plasma oscillations

International Nuclear Information System (INIS)

Shadwick, B.A.; Morrison, P.J.

1993-06-01

We examine the conditions for the existence of spectrally stable neutral modes in a Vlasov-Poisson plasma and show that for stable equilibria of systems that have unbounded spatial domain, the only possible neutral modes are those with phase velocities that correspond to stationary inflection points of the equilibrium distribution function. It is seen that these neutral modes can possess positive or negative free energy

On neutral plasma oscillations

International Nuclear Information System (INIS)

Shadwick, B.A.; Texas Univ., Austin; Morrison, P.J.; Texas Univ., Austin

1994-01-01

We examine the conditions for the existence of spectrally stable neutral modes in a Vlasov-Poisson plasma and show that for stable equilibria of systems that have unbounded spatial domain, the only possible neutral modes are those with phase velocities that correspond to stationary inflection points of the equilibrium distribution function. It is seen that these neutral modes can posses positive or negative free energy. (orig.)

Multiple track Doppler-shift spectroscopy system for TFTR neutral beam injectors

International Nuclear Information System (INIS)

Kamperschroer, J.H.; Kugel, H.W.; Reale, M.A.

1986-09-01

A Doppler-shift spectroscopy system has been installed on the TFTR neutral beam injection system to measure species composition during both conditioning and injection pulses. Two intensified vidicon detectors and two spectrometers are utilized in a system capable of resolving data from up to twelve ion sources simultaneously. By imaging the light from six ion sources onto one detector, a cost-effective system has been achieved. Fiber optics are used to locate the diagnostic in an area remote from the hazards of the tokamak test cell allowing continuous access, and eliminating the need for radiation shielding of electronic components. Automatic hardware arming and interactive data analysis allow beam composition to be computed between tokamak shots for use in analyzing plasma heating experiments. Measurements have been made using lines of sight into both the neutralizer and the drift duct. Analysis of the data from the drift duct is both simpler and more accurate since only neutral particles are present in the beam at this location. Comparison of the data taken at these two locations reveals the presence of partially accelerated particles possessing an estimated 1/e half-angle divergence of 15 0 and accounting for up to 30% of the extracted power

Automated Facial Coding Software Outperforms People in Recognizing Neutral Faces as Neutral from Standardized Datasets

Directory of Open Access Journals (Sweden)

Peter eLewinski

2015-09-01

Full Text Available Little is known about people’s accuracy of recognizing neutral faces as neutral. In this paper, I demonstrate the importance of knowing how well people recognize neutral faces. I contrasted human recognition scores of 100 typical, neutral front-up facial images with scores of an arguably objective judge – automated facial coding (AFC software. I hypothesized that the software would outperform humans in recognizing neutral faces because of the inherently objective nature of computer algorithms. Results confirmed this hypothesis. I provided the first-ever evidence that computer software (90% was more accurate in recognizing neutral faces than people were (59%. I posited two theoretical mechanisms, i.e. smile-as-a-baseline and false recognition of emotion, as possible explanations for my findings.

First observations of partially neutralized and quasineutral plasmas in the Columbia Non-neutral Torus

Science.gov (United States)

Sarasola, Xabier; Brenner, Paul; Hahn, Michael; Pedersen, Thomas

2009-11-01

The Columbia Non-neutral Torus (CNT) is the first stellarator devoted to the study of pure electron, partially neutralized and positron-electron plasmas. To date, CNT usually operates with electron rich plasmas (with negligible ion density) [1], but a stellarator can also confine plasmas of arbitrary degree of neutralization. In CNT the accumulation of ions alters the equilibrium of electron plasmas and a global instability has been observed when the ion fraction exceeds 10 %. A characterization of this instability is presented in [2], analyzing its parameter dependence and spatial structure (non- resonant with rational surfaces). A new set of experiments is currently underway studying plasmas of arbitrary degree of neutralization, ranging from pure electron to quasineutral plasmas. Basic observations show that the plasma potential decouples from emitter bias when we increase the degree of the neutralization of our plasmas. Partially neutralized plasmas are also characterized by multiple mode behavior with dominant modes between 20 and 200 kHz. When the plasma becomes quasineutral, it reverts to single mode behavior. The first results on partially neutralized plasmas confined on magnetic surfaces will be presented. [1] J. Kremer, PRL 97, (2006) 095003 [2] Q. Marksteiner, PRL 100 (2008) 065002

Charge neutralization as the major factor for the assembly of nucleocapsid-like particles from C-terminal truncated hepatitis C virus core protein.

Science.gov (United States)

de Souza, Theo Luiz Ferraz; de Lima, Sheila Maria Barbosa; Braga, Vanessa L de Azevedo; Peabody, David S; Ferreira, Davis Fernandes; Bianconi, M Lucia; Gomes, Andre Marco de Oliveira; Silva, Jerson Lima; de Oliveira, Andréa Cheble

2016-01-01

Hepatitis C virus (HCV) core protein, in addition to its structural role to form the nucleocapsid assembly, plays a critical role in HCV pathogenesis by interfering in several cellular processes, including microRNA and mRNA homeostasis. The C-terminal truncated HCV core protein (C124) is intrinsically unstructured in solution and is able to interact with unspecific nucleic acids, in the micromolar range, and to assemble into nucleocapsid-like particles (NLPs) in vitro . The specificity and propensity of C124 to the assembly and its implications on HCV pathogenesis are not well understood. Spectroscopic techniques, transmission electron microscopy and calorimetry were used to better understand the propensity of C124 to fold or to multimerize into NLPs when subjected to different conditions or in the presence of unspecific nucleic acids of equivalent size to cellular microRNAs. The structural analysis indicated that C124 has low propensity to self-folding. On the other hand, for the first time, we show that C124, in the absence of nucleic acids, multimerizes into empty NLPs when subjected to a pH close to its isoelectric point (pH ≈ 12), indicating that assembly is mainly driven by charge neutralization. Isothermal calorimetry data showed that the assembly of NLPs promoted by nucleic acids is enthalpy driven. Additionally, data obtained from fluorescence correlation spectroscopy show that C124, in nanomolar range, was able to interact and to sequester a large number of short unspecific nucleic acids into NLPs. Together, our data showed that the charge neutralization is the major factor for the nucleocapsid-like particles assembly from C-terminal truncated HCV core protein. This finding suggests that HCV core protein may physically interact with unspecific cellular polyanions, which may correspond to microRNAs and mRNAs in a host cell infected by HCV, triggering their confinement into infectious particles.

Plasma/Neutral-Beam Etching Apparatus

Science.gov (United States)

Langer, William; Cohen, Samuel; Cuthbertson, John; Manos, Dennis; Motley, Robert

1989-01-01

Energies of neutral particles controllable. Apparatus developed to produce intense beams of reactant atoms for simulating low-Earth-orbit oxygen erosion, for studying beam-gas collisions, and for etching semiconductor substrates. Neutral beam formed by neutralization and reflection of accelerated plasma on metal plate. Plasma ejected from coaxial plasma gun toward neutralizing plate, where turned into beam of atoms or molecules and aimed at substrate to be etched.

Neutral- and Multi-Colored Semitransparent Perovskite Solar Cells.

Science.gov (United States)

Lee, Kyu-Tae; Guo, L Jay; Park, Hui Joon

2016-04-11

In this review, we summarize recent works on perovskite solar cells with neutral- and multi-colored semitransparency for building-integrated photovoltaics and tandem solar cells. The perovskite solar cells exploiting microstructured arrays of perovskite "islands" and transparent electrodes-the latter of which include thin metallic films, metal nanowires, carbon nanotubes, graphenes, and transparent conductive oxides for achieving optical transparency-are investigated. Moreover, the perovskite solar cells with distinctive color generation, which are enabled by engineering the band gap of the perovskite light-harvesting semiconductors with chemical management and integrating with photonic nanostructures, including microcavity, are discussed. We conclude by providing future research directions toward further performance improvements of the semitransparent perovskite solar cells.

On plasma-neutral gas interaction

International Nuclear Information System (INIS)

Venkataramani, N.; Mattoo, S.K.

1980-01-01

The importance of plasma-neutral gas interaction layer has been emphasized by pointing out its application to a wide variety of physical phenomena. The interaction of a magnetised plasma stream penetrating a neutral gas cloud is discussed in the light of Alfven's critical velocity and Varma's threshold velocity on the ionising interaction. Interaction of a moving magnetised plasma with a stationary neutral gas has been studied and described. The device comprises of a plasma gun and an interaction region where neutral gas cloud is injected. The interaction region is provided with a transverse magnetic field of upto 1000 G. Several diagnostics deployed at the interaction region to make measurements on the macroscopic parameters of plasma and neutral gas are described. The parameters of discharge circuits are measured with high current and voltage probes. An interaction between a magnetised plasma stream and a neutral gas cloud is demonstrated. It is shown that this interaction does not have Varma's threshold on their relative velocity. The Alfven's critical velocity phenomenon is shown to depend on the integrated column neutral gas density that a plasma stream encounters while penetrating through it and not on the neutral gas density in the range of 10 17 -10 21 m -3 . (auth.)

Is an inequality-neutral flat tax reform really neutral?

OpenAIRE

Juan Prieto Rodríguez; Juan Gabriel Rodríguez; Rafael Salas

2004-01-01

. Let us assume a revenue- and inequality-neutral flat tax reform shifting from a graduated-rate tax. Is this reform really neutral in terms of the income distribution? Traditionally, there has been a bias toward the inequality analysis, forgetting other relevant aspects of the income distribution. This kind of reforms implies a set of composite transfers, both progressive and regressive, even though inequality remains unchanged. This paper shows that polarization is a useful tool for charact...

Optical fibres

CERN Document Server

Geisler, J; Boutruche, J P

1986-01-01

Optical Fibers covers numerous research works on the significant advances in optical fibers, with particular emphasis on their application.This text is composed of three parts encompassing 15 chapters. The first part deals with the manufacture of optical fibers and the materials used in their production. The second part describes optical-fiber connectors, terminals and branches. The third part is concerned with the major optoelectronic components encountered in optical-communication systems.This book will be of value to research scientists, engineers, and patent workers.

Two Clock Transitions in Neutral Yb for the Highest Sensitivity to Variations of the Fine-Structure Constant

Science.gov (United States)

Safronova, Marianna S.; Porsev, Sergey G.; Sanner, Christian; Ye, Jun

2018-04-01

We propose a new frequency standard based on a 4 f146 s 6 p P0 3 -4 f136 s25 d (J =2 ) transition in neutral Yb. This transition has a potential for high stability and accuracy and the advantage of the highest sensitivity among atomic clocks to variation of the fine-structure constant α . We find its dimensionless α -variation enhancement factor to be K =-15 , in comparison to the most sensitive current clock (Yb+ E 3 , K =-6 ), and it is 18 times larger than in any neutral-atomic clocks (Hg, K =0.8 ). Combined with the unprecedented stability of an optical lattice clock for neutral atoms, this high sensitivity opens new perspectives for searches for ultralight dark matter and for tests of theories beyond the standard model of elementary particles. Moreover, together with the well-established 1S0-3P0 transition, one will have two clock transitions operating in neutral Yb, whose interleaved interrogations may further reduce systematic uncertainties of such clock-comparison experiments.

Neutral Buoyancy Laboratory (NBL)

Data.gov (United States)

Federal Laboratory Consortium — The Neutral Buoyancy Laboratory (NBL) is an astronaut training facility and neutral buoyancy pool operated by NASA and located at the Sonny Carter Training Facility,...

Structural and optical properties of Si-doped GaN

OpenAIRE

Cremades Rodríguez, Ana Isabel; Gorgens, L.; Ambacher, O.; Stutzmann, M.; Scholz, F.

2000-01-01

Structural and optical properties of Si-doped GaN thin films grown by metal-organic chemical vapor deposition have been studied by means of high resolution x-ray diffraction (XRD), atomic force microscopy, photoluminescence, photothermal deflection spectroscopy, and optical transmission measurements. The incorporation of silicon in the GaN films leads to pronounced tensile stress. The energy position of the neutral donor bound excitonic emission correlates with the measured stress. The stress...

Sustaining neutral beam power supply system for the Mirror Fusion Test Facility

International Nuclear Information System (INIS)

Eckard, R.D.; Wilson, J.H.; Van Ness, H.W.

1980-01-01

In late August 1978, a fixed price procurement contract for $25,000,000 was awarded to Aydin Energy Division, Palo Alto, California, for the design, manufacture, installation and acceptance testing of the Lawrence Livermore National Laboratory Mirror Fusion Test Facility (MFTF) Sustaining Neutral Beam Power Supply System (SNBPSS). This system of 24 power supply sets will provide the conditioned power for the 24 neutral beam source modules. Each set will provide the accel potential the arc power, the filament power, and the suppressor power for its associated neutral beam source module. The design and development of the SNBPSS has progressed through the final design phase and is now in production. Testing of the major sub-assembly power supply is proceeding at Aydin and the final acceptance testing of the first two power supplies at LLNL is expected to be completed this year

Neutral currents

International Nuclear Information System (INIS)

Aubert, B.

1994-11-01

The evidence for the existence of weak neutral current has been a very controverted topics in the early 1970's, as well as the muon did in the 1930's. The history is very rich considering the evolution of the experimental techniques in high energy particle physics. The history of the discovery and the study of weak neutral current is reviewed. Later the quest of the intermediate vector boson continues with the decision of the community to build a large proton antiproton collider. (K.A.). 14 refs., 1 fig

Kinetics of Epstein-Barr Virus (EBV) Neutralizing and Virus-Specific Antibodies after Primary Infection with EBV

Science.gov (United States)

Bu, Wei; Hayes, Gregory M.; Liu, Hui; Gemmell, Lorraine; Schmeling, David O.; Radecki, Pierce; Aguilar, Fiona; Burbelo, Peter D.; Woo, Jennifer; Balfour, Henry H.

2016-01-01

Prospective studies of antibodies to multiple Epstein-Barr virus (EBV) proteins and EBV neutralizing antibodies in the same individuals before, during, and after primary EBV infection have not been reported. We studied antibody responses to EBV in college students who acquired primary EBV infection during prospective surveillance and correlated the kinetics of antibody response with the severity of disease. Neutralizing antibodies and enzyme-linked immunosorbent assay (ELISA) antibodies to gp350, the major target of neutralizing antibody, reached peak levels at medians of 179 and 333 days after the onset of symptoms of infectious mononucleosis, respectively. No clear correlation was found between the severity of the symptoms of infectious mononucleosis and the peak levels of antibody to individual viral proteins or to neutralizing antibody. In summary, we found that titers of neutralizing antibody and antibodies to multiple EBV proteins increase over many months after primary infection with EBV. PMID:26888186

A 4π scintillation counter-optical spark chamber system for neutral particles

International Nuclear Information System (INIS)

Demarzo, C.; Distante, A.; Guerriero, L.; Niccolini, C.; Posa, F.; Walder, F.; Chen, G.T.Y.; Fletcher, C.R.; Lanou, R.E. Jr.; Thornton, R.K.; Barton, D.S.; Lyons, T.; Marx, M.; Rosenson, L.; Thern, R.

1975-01-01

The authors describe a scintillation counter-optical spark chamber system developed for the detection of high energy gamma rays and neutrons. They describe the system components and their use in two completed experiments. (Auth.)

Neutral beam deployment on DEMO and its influence on design

Energy Technology Data Exchange (ETDEWEB)

Surrey, Elizabeth, E-mail: elizabeth.surrey@ccfe.ac.uk [EURATOM/CCFE, Culham Science Centre, Abingdon, Oxfordshire, OX14 3DB (United Kingdom); King, Damian; Lister, Jonathan; Porton, Michael; Timmis, William; Ward, David [EURATOM/CCFE, Culham Science Centre, Abingdon, Oxfordshire, OX14 3DB (United Kingdom)

2011-10-15

The demands on the neutral beam heating and current drive system of a DEMO device exceed those of existing fusion experiments by several orders of magnitude. By predicting possible power waveforms it is possible to analyse the technological advances necessary to achieve a system relevant to deployment on a power plant. Achieving the necessary efficiency will require simultaneous improvements in beam current density, neutralization efficiency and beam transmission. Considering the deployment on the tokamak vessel shows no major disruption to the tritium breeder blanket and no requirement to reach a high packing density of injectors. The thermal management of components subjected to low heat flux for many hours is considered and it is shown that radiation cooling can be exploited to control the temperature of such items.

Laser cooling in a feedback-controlled optical shaker

International Nuclear Information System (INIS)

Vilensky, Mark Y.; Averbukh, Ilya Sh.; Prior, Yehiam

2006-01-01

We explore the prospects of optical shaking, a recently suggested generic approach to laser cooling of neutral atoms and molecules. Optical shaking combines elements of Sisyphus cooling and of stochastic cooling techniques and is based on feedback-controlled interaction of particles with strong nonresonant laser fields. The feedback loop guarantees a monotonous energy decrease without a loss of particles. We discuss two types of feedback algorithms and provide an analytical estimation of their cooling rate. We study the robustness of optical shaking against noise and establish minimal stability requirements for the lasers. The analytical predictions are in a good agreement with the results of detailed numerical simulations

A quasi-electrostatic trap for neutral atoms

International Nuclear Information System (INIS)

Engler, H.

2000-01-01

This thesis reports on the realization of a ''quasi-electrostatic trap'' (QUEST) for neutral atoms. Cesium ( 133 Cs) and Lithium ( 7 Li) atoms are stored, which represents for the first time a mixture of different species in an optical dipole trap. The trap is formed by the focused Gaussian beam of a 30 W cw CO 2 -laser. For a beam waist of 108 μm the resulting trap depth is κ B x 118 μK for Cesium and κ B x 48 μK for Lithium. We transfer up to 2 x 10 6 Cesium and 10 5 Lithium atoms from a magneto-optical trap into the QUEST. When simultaneously transferred, the atom number currently is reduced by roughly a factor of 10. Since photon scattering from the trapping light can be neglected, the QUEST represents an almost perfect conservative trapping potential. Atoms in the QUEST populate the electronic ground state sublevels. Arbitrary sublevels can be addressed via optical pumping. Due to the very low background gas pressure of 2 x 10 -11 mbar storage times of several minutes are realized. Evaporative cooling of Cesium is observed. In addition, laser cooling is applied to the trapped Cesium sample, which reduces the temperature from 25 μK to a value below 7 μK. If prepared in the upper hyper-fine ground state sublevel, spin changing collisions are observed not only within one single species, but also between the two different species. The corresponding relaxation rates are quantitatively analyzed. (orig.)

Neutralization of acidic raindrops on leaves of agricultural crop and boreal forest species

Energy Technology Data Exchange (ETDEWEB)

Hutchinson, T.C.; Adams, C.M.; Gaber, B.A.

1986-10-01

The abilities of foliage of selected agricultural crop and native boreal forest species to neutralize acidic raindrops were compared. The species differed widely in their responses. Neutralization was influenced to a large extent by leaf wettability and was poorly related with species' susceptibility to foliar injury from acid rain sprayings. Little neutralization of pH 3.0 droplets occurred on very waxy leaves, e.g. cabbage (Brassica oleracea L.), due to the small contact area between the leaf surface and raindrops. In contrast, on sunflower (Helianthus annuus L.) and radish (Raphanus sativus L.) leaves, which are pubescent and easily wettable, neutralization was considerable. For all agricultural crop species examined, the pH of droplets drying on cotyledons was consistently higher than on the leaves. The pH values of raindrops were also higher when the foliage was injured by the acid rain, probably due to leakage of cellular contents. Among boreal forest species examined, bunchberry (Cornus canadensis L.) was particularly good at neutralizing natural acid rain, increasing the pH from 3.9 to 6.6 after 9 hr of foliar contact, while the response of other boreal species ranged from a final pH of 4.8 to 5.7 under the same conditions. Simulated raindrops on wild sarsaparilla (Aralia nudicaulis L.) were never neutralized but increased in acidity as they evaporated. Chemical analyses of droplets collected from foliage showed calcium (Ca) and potassium (K) to be the major cations entering the neutralized droplets. Neutralization of acidic raindrops appears to occur through two processes; solubilization of alkaline dusts and exudates on the leaf surface, and ion exchange removal of H/sup +/ by the foliage. 14 references.

Neutralization of acidic raindrops on leaves of agricultural crop and boreal forest species

Energy Technology Data Exchange (ETDEWEB)

Hutchinson, T.C.; Adams, C.M.; Gaber, B.A.

1986-11-01

The abilities of foliage of selected agricultural crop and native boreal forest species to neutralize acidic raindrops were compared. The species differed widely in their responses. Neutralization was influenced to a large extent by leaf wettability and was poorly related with species' susceptibility to foliar injury from acid rain sprayings. Little neutralization of pH 3.0 droplets occurred on very waxy leaves, e.g. cabbage (Brassica oleracea L.), due to the small contact area between the leaf surface and raindrops. In contrast, on sunflower (Helianthus annuus L.) and radish (Raphanus sativus L.) leaves, which are pubescent and easily wettable, neutralization was considerable. For all agricultural crop species examined, the pH of droplets drying on cotyledons was consistently higher than on the leaves. The pH values of raindrops were also higher when the foliage was injured by the acid rain, probably due to leakage of cellular contents. Among boreal forest species examined, bunchberry (Cornus canadensis L.) was particularly good at neutralizing natural acid rain, increasing the pH from 3.9 to 6.6 after 9 hr of foliar contact, while the response of other boreal species ranged from a final pH of 4.8 to 5.7 under the same conditions. Simulated raindrops on wild sarsaparilla (Aralia nudicaulis L.) were never neutralized but increased in acidity as they evaporated. Chemical analyses of droplets collected from foliage showed calcium and potassium to be the major cations entering the neutralized droplets. Neutralization of acidic raindrops appears to occur through two processes: solubilization of alkaline dusts and exudates on the leaf surface, and ion exchange removal of H/sup +/ by the foliage. 14 refs.

Phenomenology of neutral current interactions

International Nuclear Information System (INIS)

Sakurai, J.J.

1978-01-01

Neutral-current interactions are discussed within a rather general phenomenological framework without commitment to any particular theoretical model. Three points are kept in mind: what various experiments really measure; the performing of complete experiments to determine the neutral-current couplings; and the testing of models in an objective, emotionally uninvolved manner. The following topics are considered: neutrino-electron scattering, hadronic currents and models, neutrino-induced inclusive hadronic reactions, neutrino-induced exclusive hadronic reactions, and neutral-current phenomena without neutrinos. In conclusion, what has actually been learned about neutral-current interactions is summarized. 9 figures, 2 tables

Molecular clock on a neutral network.

Science.gov (United States)

Raval, Alpan

2007-09-28

The number of fixed mutations accumulated in an evolving population often displays a variance that is significantly larger than the mean (the overdispersed molecular clock). By examining a generic evolutionary process on a neutral network of high-fitness genotypes, we establish a formalism for computing all cumulants of the full probability distribution of accumulated mutations in terms of graph properties of the neutral network, and use the formalism to prove overdispersion of the molecular clock. We further show that significant overdispersion arises naturally in evolution when the neutral network is highly sparse, exhibits large global fluctuations in neutrality, and small local fluctuations in neutrality. The results are also relevant for elucidating aspects of neutral network topology from empirical measurements of the substitution process.

Upgrade of the TCV tokamak, first phase: Neutral beam heating system

Energy Technology Data Exchange (ETDEWEB)

Karpushov, Alexander N., E-mail: alexander.karpushov@epfl.ch [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Alberti, Stefano; Chavan, René [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Davydenko, Vladimir I. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Duval, Basil P. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Ivanov, Alexander A. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Fasel, Damien; Fasoli, Ambrogio [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Gorbovsky, Aleksander I. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Goodman, Timothy [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Kolmogorov, Vyacheslav V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); Martin, Yves; Sauter, Olivier [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, CH-1015 Lausanne (Switzerland); Sorokin, Aleksey V. [Budker Institute of Nuclear Physics SB RAS, 630090 Novosibirsk (Russian Federation); and others

2015-10-15

Highlights: • Widening the parameter range of reactor relevant regimes on the TCV tokamak. • Installation of 1 MW, 30 keV neutral beam, direct ion heating, access to T{sub i}/T{sub e} ≥ 1. • ASTRA simulation of plasma response to NB and EC heating in different regimes. • Specific low divergency neutral beam injector with tunable beam power and energy. - Abstract: Experiments on TCV are designed to complement the work at large integrated tokamak facilities (such as JET) to provide a stepwise approach to extrapolation to ITER and DEMO in areas where medium-size tokamaks can often exploit their experimental capabilities and flexibility. Improving the understanding and control requirements of burning plasmas is a major scientific challenge, requiring access to plasma regimes and configurations with high normalized plasma pressure and a wide range of ion to electron temperature ratios, including T{sub e}/T{sub i} ∼ 1. These conditions will be explored by adding a 1 MW neutral heating beam to TCV's auxiliary for direct ion heating (2015) and increasing the ECH power injected in X-mode at the third harmonic (2 MW in 2015–2016). The manufacturing of the neutral beam injector was launched in 2014.

Is a neutral expression also a neutral stimulus? A study with functional magnetic resonance.

Science.gov (United States)

Carvajal, Fernando; Rubio, Sandra; Serrano, Juan M; Ríos-Lago, Marcos; Alvarez-Linera, Juan; Pacheco, Lara; Martín, Pilar

2013-08-01

Although neutral faces do not initially convey an explicit emotional message, it has been found that individuals tend to assign them an affective content. Moreover, previous research has shown that affective judgments are mediated by the task they have to perform. Using functional magnetic resonance imaging in 21 healthy participants, we focus this study on the cerebral activity patterns triggered by neutral and emotional faces in two different tasks (social or gender judgments). Results obtained, using conjunction analyses, indicated that viewing both emotional and neutral faces evokes activity in several similar brain areas indicating a common neural substrate. Moreover, neutral faces specifically elicit activation of cerebellum, frontal and temporal areas, while emotional faces involve the cuneus, anterior cingulated gyrus, medial orbitofrontal cortex, posterior superior temporal gyrus, precentral/postcentral gyrus and insula. The task selected was also found to influence brain activity, in that the social task recruited frontal areas while the gender task involved the posterior cingulated, inferior parietal lobule and middle temporal gyrus to a greater extent. Specifically, in the social task viewing neutral faces was associated with longer reaction times and increased activity of left dorsolateral frontal cortex compared with viewing facial expressions of emotions. In contrast, in the same task emotional expressions distinctively activated the left amygdale. The results are discussed taking into consideration the fact that, like other facial expressions, neutral expressions are usually assigned some emotional significance. However, neutral faces evoke a greater activation of circuits probably involved in more elaborate cognitive processing.

Regulation of triglyceride metabolism. I. Eukaryotic neutral lipid synthesis: "Many ways to skin ACAT or a DGAT".

Science.gov (United States)

Turkish, Aaron; Sturley, Stephen L

2007-04-01

Esterification of sterols, fatty acids and other alcohols into biologically inert forms conserves lipid resources for many cellular functions. Paradoxically, the accumulation of neutral lipids such as cholesteryl ester or triglyceride, is linked to several major disease pathologies. In a remarkable example of genetic expansion, there are at least eleven acyltransferase reactions that lead to neutral lipid production. In this review, we speculate that the complexity and apparent redundancy of neutral lipid synthesis may actually hasten rather than impede the development of novel, isoform-specific, therapeutic interventions for acne, type 2 diabetes, obesity, hyperlipidemia, fatty liver disease, and atherosclerosis.

Infectious Entry and Neutralization of Pathogenic JC Polyomaviruses

Directory of Open Access Journals (Sweden)

Eileen M. Geoghegan

2017-10-01

Full Text Available Summary: Progressive multifocal leukoencephalopathy (PML is a lethal brain disease caused by uncontrolled replication of JC polyomavirus (JCV. JCV strains recovered from the brains of PML patients carry mutations that prevent the engagement of sialylated glycans, which are thought to serve as receptors for the infectious entry of wild-type JCV. In this report, we show that non-sialylated glycosaminoglycans (GAGs can serve as alternative attachment receptors for the infectious entry of both wild-type and PML mutant JCV strains. After GAG-mediated attachment, PML mutant strains engage non-sialylated non-GAG co-receptor glycans, such as asialo-GM1. JCV-neutralizing monoclonal antibodies isolated from patients who recovered from PML appear to block infection by preventing the docking of post-attachment co-receptor glycans in an apical pocket of the JCV major capsid protein. Identification of the GAG-dependent/sialylated glycan-independent alternative entry pathway should facilitate the development of infection inhibitors, including recombinant neutralizing antibodies. : Geoghegan et al. show that JC polyomavirus strains that cause brain disease infect cells via a pathway involving a heparin-like attachment receptor and a non-sialylated co-receptor. Candidate therapeutic human monoclonal antibodies neutralize by blocking co-receptor engagement. Keywords: polyomavirus, JC, BK, SV40, progressive multifocal leukoencephalopathy, PML, monoclonal antibody, mAb, virus entry, receptor

Relative contributions of neutral and non-neutral processes to clinal variation in calyx lobe length in the series Sakawanum (Asarum: Aristolochiaceae).

Science.gov (United States)

Takahashi, Daiki; Teramine, Tsutomu; Sakaguchi, Shota; Setoguchi, Hiroaki

2018-01-25

Clines, the gradual variation in measurable traits along a geographical axis, play a major role in evolution and can contribute to our understanding of the relative roles of selective and neutral process in trait variation. Using genetic and morphological analyses, the relative contributions of neutral and non-neutral processes were explored to infer the evolutionary history of species of the series Sakawanum (genus Asarum), which shows significant clinal variation in calyx lobe length. A total of 27 populations covering the natural geographical distribution of the series Sakawanum were sampled. Six nuclear microsatellite markers were used to investigate genetic structure and genetic diversity. The lengths of calyx lobes of multiple populations were measured to quantify their geographical and taxonomic differentiation. To detect the potential impact of selective pressure, morphological differentiation was compared with genetic differentiation (QCT-FST comparison). Average calyx lobe length of A. minamitanianum was 124.11 mm, while that of A. costatum was 13.80 mm. Though gradually changing along the geographical axis within series, calyx lobe lengths were significantly differentiated among the taxa. Genetic differentiation between taxa was low (FST = 0.099), but a significant geographical structure along the morphological cline was detected. Except for one taxon pair, pairwise QCT values were significantly higher than the neutral genetic measures of FST and G'ST. Divergent selection may have driven the calyx lobe length variation in series Sakawanum taxa, although the underlying mechanism is still not clear. The low genetic differentiation indicates recent divergence and/or gene flows between geographically close taxa. These neutral processes would also affect the clinal variation in calyx lobe lengths. Overall, this study implies the roles of population history and divergent selection in shaping the current cline of a flower trait in the series Sakawanum. © The

Occurrence and origin of carbohydrates in peat samples from a red mangrove environment as reflected by abundances of neutral monosaccharides

Science.gov (United States)

Moers, M. E. C.; Baas, M.; De Leeuw, J. W.; Boon, J. J.; Schenck, P. A.

1990-09-01

Acid hydrolysates of fractionated red mangrove peat samples and handpicked roots and rootlets of Rhizophora mangle (red mangrove) from Jewfish Key in the Florida Everglades were analysed for neutral monosaccharides. In the peat samples two major sources of carbohydrates could be determined: (1) vascular plant carbohydrates derived from Rhizophora mangle and (2) microbially derived carbohydrates. Significant correlations exist between the relative contributions of most neutral monosaccharides and the total carbohydrate concentration. The fine-grained peat fractions yielded low total neutral monosaccharides whose distributions indicate contributions of microbial carbohydrates. The coarse-grained peat samples yielded high total neutral monosaccharides with distributions indicating major contributions of vascular plant carbohydrates. It is estimated that a substantial part of the sugars analysed in the finegrained samples originates from microorganisms ([cyano] bacteria, algae).The absence of a trend in total neutral monosaccharide concentrations with depth suggests that microbial degradation is limited to the upper levels of the peat and that the microbial sugars determined at lower peat levels are derived from nonviable or dormant microorganisms. Results from factor analysis may suggest differences in microbial populations in the various peat samples.

Vecksler-Macmillan phase stability for neutral atoms accelerated by a laser beam

Science.gov (United States)

Mel'nikov, I. V.; Haus, J. W.; Kazansky, P. G.

2003-05-01

We use a Fokker-Planck equation to study the phenomenon of accelerating a neutral atom bunch by a chirped optical beam. This method enables us to obtain a semi-analytical solution to the problem in which a wide range of parameters can be studied. In addition it provides a simple physical interpretation where the problem is reduced to an analogous problem of charged particles accelerators, that is, the Vecksler-Macmillan principle of phase stability. A possible experimental scenario is suggested, which uses a photonic crystal fiber as the guiding medium.

Optical computing.

Science.gov (United States)

Stroke, G. W.

1972-01-01

Applications of the optical computer include an approach for increasing the sharpness of images obtained from the most powerful electron microscopes and fingerprint/credit card identification. The information-handling capability of the various optical computing processes is very great. Modern synthetic-aperture radars scan upward of 100,000 resolvable elements per second. Fields which have assumed major importance on the basis of optical computing principles are optical image deblurring, coherent side-looking synthetic-aperture radar, and correlative pattern recognition. Some examples of the most dramatic image deblurring results are shown.

Charge neutralization as the major factor for the assembly of nucleocapsid-like particles from C-terminal truncated hepatitis C virus core protein

Directory of Open Access Journals (Sweden)

Theo Luiz Ferraz de Souza

2016-11-01

Full Text Available Background Hepatitis C virus (HCV core protein, in addition to its structural role to form the nucleocapsid assembly, plays a critical role in HCV pathogenesis by interfering in several cellular processes, including microRNA and mRNA homeostasis. The C-terminal truncated HCV core protein (C124 is intrinsically unstructured in solution and is able to interact with unspecific nucleic acids, in the micromolar range, and to assemble into nucleocapsid-like particles (NLPs in vitro. The specificity and propensity of C124 to the assembly and its implications on HCV pathogenesis are not well understood. Methods Spectroscopic techniques, transmission electron microscopy and calorimetry were used to better understand the propensity of C124 to fold or to multimerize into NLPs when subjected to different conditions or in the presence of unspecific nucleic acids of equivalent size to cellular microRNAs. Results The structural analysis indicated that C124 has low propensity to self-folding. On the other hand, for the first time, we show that C124, in the absence of nucleic acids, multimerizes into empty NLPs when subjected to a pH close to its isoelectric point (pH ≈ 12, indicating that assembly is mainly driven by charge neutralization. Isothermal calorimetry data showed that the assembly of NLPs promoted by nucleic acids is enthalpy driven. Additionally, data obtained from fluorescence correlation spectroscopy show that C124, in nanomolar range, was able to interact and to sequester a large number of short unspecific nucleic acids into NLPs. Discussion Together, our data showed that the charge neutralization is the major factor for the nucleocapsid-like particles assembly from C-terminal truncated HCV core protein. This finding suggests that HCV core protein may physically interact with unspecific cellular polyanions, which may correspond to microRNAs and mRNAs in a host cell infected by HCV, triggering their confinement into infectious particles.

Gas cell neutralizers (Fundamental principles)

International Nuclear Information System (INIS)

Fuehrer, B.

1985-06-01

Neutralizing an ion-beam of the size and energy levels involved in the neutral-particle-beam program represents a considerable extension of the state-of-the-art of neutralizer technology. Many different mediums (e.g., solid, liquid, gas, plasma, photons) can be used to strip the hydrogen ion of its extra electron. A large, multidisciplinary R and D effort will no doubt be required to sort out all of the ''pros and cons'' of these various techniques. The purpose of this particular presentation is to discuss some basic configurations and fundamental principles of the gas type of neutralizer cell. Particular emphasis is placed on the ''Gasdynamic Free-Jet'' neutralizer since this configuration has the potential of being much shorter than other type of gas cells (in the beam direction) and it could operate in nearly a continuous mode (CW) if necessary. These were important considerations in the ATSU design which is discussed in some detail in the second presentation entitled ''ATSU Point Design''

New Modulation Strategy to Balance the Neutral-Point Voltage for Three-Level Neutral-Clamped Inverter Systems

DEFF Research Database (Denmark)

Choi, Uimin; Lee, June-Seok; Lee, Kyo-Beum

2014-01-01

This paper proposes a new modulation strategy that balances the neutral-point voltage for three-level neutral-clamped inverter systems. The proposed modulation replaces the P-type or N-type small switching states with other switching states that do not affect the neutral-point voltage. The zero...... and medium switching states are employed to help the neutral-point voltage balancing. This method little bit increases the switching events and output total harmonic distortion. However, this method has a strong balancing ability at all regions. Further, it is very simple to implement in both space vector...

How Objective a Neutral Word Is? A Neutrosophic Approach for the Objectivity Degrees of Neutral Words

Directory of Open Access Journals (Sweden)

Mihaela Colhon

2017-11-01

Full Text Available In the latest studies concerning the sentiment polarity of words, the authors mostly consider the positive and negative constructions, without paying too much attention to the neutral words, which can have, in fact, significant sentiment degrees. More precisely, not all the neutral words have zero positivity or negativity scores, some of them having quite important nonzero scores for these polarities. At this moment, in the literature, a word is considered neutral if its positive and negative scores are equal, which implies two possibilities: (1 zero positive and negative scores; (2 nonzero, but equal positive and negative scores. It is obvious that these cases represent two different categories of neutral words that must be treated separately by a sentiment analysis task. In this paper, we present a comprehensive study about the neutral words applied to English as is developed with the aid of SentiWordNet 3.0: the publicly available lexical resource for opinion mining. We designed our study in order to provide an accurate classification of the so-called “neutral words” described in terms of sentiment scores and using measures from neutrosophy theory. The intended scope is to fill the gap concerning the neutrality aspect by giving precise measurements for the words’ objectivity.

Antibodies to the A27 protein of vaccinia virus neutralize and protect against infection but represent a minor component of Dryvax vaccine--induced immunity.

Science.gov (United States)

He, Yong; Manischewitz, Jody; Meseda, Clement A; Merchlinsky, Michael; Vassell, Russell A; Sirota, Lev; Berkower, Ira; Golding, Hana; Weiss, Carol D

2007-10-01

The smallpox vaccine Dryvax, which consists of replication-competent vaccinia virus, elicits antibodies that play a major role in protection. Several vaccinia proteins generate neutralizing antibodies, but their importance for protection is unknown. We investigated the potency of antibodies to the A27 protein of the mature virion in neutralization and protection experiments and the contributions of A27 antibodies to Dryvax-induced immunity. Using a recombinant A27 protein (rA27), we confirmed that A27 contains neutralizing determinants and that vaccinia immune globulin (VIG) derived from Dryvax recipients contains reactivity to A27. However, VIG neutralization was not significantly reduced when A27 antibodies were removed, and antibodies elicited by an rA27 enhanced the protection conferred by VIG in passive transfer experiments. These findings demonstrate that A27 antibodies do not represent the major fraction of neutralizing activity in VIG and suggest that immunity may be augmented by vaccines and immune globulins that include strong antibody responses to A27.

Neutral-beam-heating applications and development

International Nuclear Information System (INIS)

Menon, M.M.

1981-01-01

The technique of heating the plasma in magnetically confined fusion devices by the injection of intense beams of neutral atoms is described. The basic principles governing the physics of neutral beam heating and considerations involved in determining the injection energy, power, and pulse length required for a fusion reactor are discussed. The pertinent experimental results from various fusion devices are surveyed to illustrate the efficacy of this technique. The second part of the paper is devoted to the technology of producing the neutral beams. A state-of-the-art account o the development of neutral injectors is presented, and the prospects for utilizing neutral injection to heat the plasma in a fusion reactor are examined

Nonlinear Optics and Applications

Science.gov (United States)

Abdeldayem, Hossin A. (Editor); Frazier, Donald O. (Editor)

2007-01-01

Nonlinear optics is the result of laser beam interaction with materials and started with the advent of lasers in the early 1960s. The field is growing daily and plays a major role in emerging photonic technology. Nonlinear optics play a major role in many of the optical applications such as optical signal processing, optical computers, ultrafast switches, ultra-short pulsed lasers, sensors, laser amplifiers, and many others. This special review volume on Nonlinear Optics and Applications is intended for those who want to be aware of the most recent technology. This book presents a survey of the recent advances of nonlinear optical applications. Emphasis will be on novel devices and materials, switching technology, optical computing, and important experimental results. Recent developments in topics which are of historical interest to researchers, and in the same time of potential use in the fields of all-optical communication and computing technologies, are also included. Additionally, a few new related topics which might provoke discussion are presented. The book includes chapters on nonlinear optics and applications; the nonlinear Schrodinger and associated equations that model spatio-temporal propagation; the supercontinuum light source; wideband ultrashort pulse fiber laser sources; lattice fabrication as well as their linear and nonlinear light guiding properties; the second-order EO effect (Pockels), the third-order (Kerr) and thermo-optical effects in optical waveguides and their applications in optical communication; and, the effect of magnetic field and its role in nonlinear optics, among other chapters.

Neutron optical potentials

International Nuclear Information System (INIS)

Wilmore, D.; Hodgson, P.E.

1976-01-01

The purpose of this paper is to provide a guide to the use of optical model computer programs to analyse and calculate neutron data. After a brief discussion of the physical basis of the optical model a survey is given of the most widely used optical model and Hauser-Feshbach computer programs. The range of applicability and reliability of the major optical potentials proposed is assessed by comparison with available experimental data and some observations and suggestions are made for the optimum choice of optical potentials for given purposes of neutron data calculations. (author)

Neutral-point current modeling and control for Neutral-Point Clamped three-level converter drive with small DC-link capacitors

DEFF Research Database (Denmark)

Maheshwari, Ram Krishan; Munk-Nielsen, Stig; Busquets-Monge, Sergio

2011-01-01

A Neutral-Point-Clamped (NPC) three-level inverter with small DC-link capacitors is presented in this paper. This inverter requires zero average neutral-point current for stable neutral-point potential. A simple carrier based modulation strategy is proposed for achieving zero average neutral...... drive with only 14 μF DC-link capacitors. A fast and stable performance of the neutral-point voltage controller is achieved and verified by experiments....

Cross-neutralization of antibodies induced by vaccination with Purified Chick Embryo Cell Vaccine (PCECV) against different Lyssavirus species.

Science.gov (United States)

Malerczyk, Claudius; Freuling, Conrad; Gniel, Dieter; Giesen, Alexandra; Selhorst, Thomas; Müller, Thomas

2014-01-01

Rabies is a neglected zoonotic disease caused by viruses belonging to the genus lyssavirus. In endemic countries of Asia and Africa, where the majority of the estimated 60,000 human rabies deaths occur, it is mainly caused by the classical rabies virus (RABV) transmitted by dogs. Over the last decade new species within the genus lyssavirus have been identified. Meanwhile 15 (proposed or classified) species exist, including Australian bat lyssavirus (ABLV), European bat lyssavirus (EBLV-1 and -2), Duvenhage virus (DUVV), as well as Lagos bat virus (LBV) and Mokola virus (MOKV) and recently identified novel species like Bokeloh bat lyssavirus (BBLV), Ikoma bat lyssavirus (IKOV) or Lleida bat lyssavirus (LLBV). The majority of these lyssavirus species are found in bat reservoirs and some have caused human infection and deaths. Previous work has demonstrated that Purified Chick Embryo Cell Rabies Vaccine (PCECV) not only induces immune responses against classical RABV, but also elicits cross-neutralizing antibodies against ABLV, EBLV-1 and EBLV-2. Using the same serum samples as in our previous study, this study extension investigated cross-neutralizing activities of serum antibodies measured by rapid fluorescent focus inhibition test (RFFIT) against selected other non-classical lyssavirus species of interest, namely DUVV and BBLV, as well as MOKV and LBV. Antibodies developed after vaccination with PCECV have neutralizing capability against BBLV and DUVV in the same range as against ABLV and EBLV-1 and -2. As expected, for the phylogenetically more distant species LBV no cross-neutralizing activity was found. Interestingly, 15 of 94 serum samples (16%) with a positive neutralizing antibody titer against RABV displayed specific cross-neutralizing activity (65-fold lower than against RABV) against one specific MOKV strain (Ethiopia isolate), which was not seen against a different strain (Nigeria isolate). Cross-neutralizing activities partly correlate with the

Net neutrality and audiovisual services

OpenAIRE

van Eijk, N.; Nikoltchev, S.

2011-01-01

Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication networks: the control over the distribution of audiovisual services constitutes a vital part of the problem. In this contribution, the phenomenon of net neutrality is described first. Next, the European a...

Electromagnetic trapping of neutral atoms

International Nuclear Information System (INIS)

Metcalf, H.J.

1986-01-01

Cooling and trapping of neutral atoms is a new branch of applied physics that has potential for application in many areas. The authors present an introduction to laser cooling and magnetic trapping. Some basic ideas and fundamental limitations are discussed, and the first successful experiments are reviewed. Trapping a neutral object depends on the interaction between an inhomogeneous electromagnetic field and a multiple moment that results in the exchange of kinetic for potential energy. In neutral atom traps, the potential energy must be stored as internal atomic energy, resulting in two immediate and extremely important consequences. First, the atomic energy levels will necessarily shift as the atoms move in the trap, and, second, practical traps for ground state neutral atoms atr necessarily very shallow compared to thermal energy. This small depth also dictates stringent vacuum requirements because a trapped atom cannot survive a single collision with a thermal energy background gas molecule. Neutral trapping, therefore, depends on substantial cooling of a thermal atomic sample and is inextricably connected with the cooling process

Assessment of the plasma start-up in Wendelstein 7-X with neutral beam injection

International Nuclear Information System (INIS)

Gradic, D.; Dinklage, A.; Brakel, R.; McNeely, P.; Rust, N.; Wolf, R.; Osakabe, M.

2015-01-01

Plasma start-up by neutral beam injection was investigated for stellarators. A zero-dimensional collisional model was extended to evaluate the temporal evolution of the plasma start-up in a confining toroidal magnetic field. Inclusion of different beam energy components indicated a substantial effect due to the energy dependence of beam–gas collisions. Additional collision processes and particle equations were considered to simulate the plasma start-up in helium–hydrogen mixtures. The isotope effect between operation with hydrogen and deuterium beams was also investigated. As a major objective the conditions necessary for a plasma start-up with neutral beams in W7-X have been examined. The assessed beam configuration in W7-X was found not to allow plasma start-up by neutral beam injection alone. The model has been validated for experimental data from W7-AS and Large Helical Device. Quantitative predictions of this study show that the ratio of the beam–plasma interaction length and the plasma volume is an essential quantity for the successful plasma start-up with neutral beams. (paper)

Plasma neutralizers for H- or D- beams

International Nuclear Information System (INIS)

Berkner, K.H.; Pyle, R.V.; Savas, S.E.; Stalder, K.R.

1980-10-01

Plasma neutralizers can produce higher conversion efficiencies than are obtainable with gas neutralizers for the production of high-energy neutral beams from negative hydrogen ions. Little attention has been paid to experimental neutralizer studies because of the more critical problems connected with the development of negative-ion sources. With the prospect of accelerating ampere dc beams from extrapolatable ion sources some time next year, we are re-examining plasma neutralizers. Some basic considerations, two introductory experiments, and a next-step experiment are described

DIII-D Neutral Beam control system operator interface

International Nuclear Information System (INIS)

Harris, J.J.; Campbell, G.L.

1993-10-01

A centralized graphical user interface has been added to the DIII-D Neutral Beam (NB) control systems for status monitoring and remote control applications. This user interface provides for automatic data acquisition, alarm detection and supervisory control of the four NB programmable logic controllers (PLC) as well as the Mode Control PLC. These PLCs are used for interlocking, control and status of the NB vacuum pumping, gas delivery, and water cooling systems as well as beam mode status and control. The system allows for both a friendly user interface as well as a safe and convenient method of communicating with remote hardware that formerly required interns to access. In the future, to enable high level of control of PLC subsystems, complete procedures is written and executed at the touch of a screen control panel button. The system consists of an IBM compatible 486 computer running the FIX DMACS trademark for Windows trademark data acquisition and control interface software, a Texas Instruments/Siemens communication card and Phoenix Digital optical communications modules. Communication is achieved via the TIWAY (Texas Instruments protocol link utilizing both fiber optic communications and a copper local area network (LAN). Hardware and software capabilities will be reviewed. Data and alarm reporting, extended monitoring and control capabilities will also be discussed

Ion-beam Plasma Neutralization Interaction Images

Energy Technology Data Exchange (ETDEWEB)

Igor D. Kaganovich; Edward Startsev; S. Klasky; Ronald C. Davidson

2002-04-09

Neutralization of the ion beam charge and current is an important scientific issue for many practical applications. The process of ion beam charge and current neutralization is complex because the excitation of nonlinear plasma waves may occur. Computer simulation images of plasma neutralization of the ion beam pulse are presented.

Ion-beam Plasma Neutralization Interaction Images

International Nuclear Information System (INIS)

Igor D. Kaganovich; Edward Startsev; S. Klasky; Ronald C. Davidson

2002-04-01

Neutralization of the ion beam charge and current is an important scientific issue for many practical applications. The process of ion beam charge and current neutralization is complex because the excitation of nonlinear plasma waves may occur. Computer simulation images of plasma neutralization of the ion beam pulse are presented

Dynamics of trapped atoms around an optical nanofiber probed through polarimetry.

Science.gov (United States)

Solano, Pablo; Fatemi, Fredrik K; Orozco, Luis A; Rolston, S L

2017-06-15

The evanescent field outside an optical nanofiber (ONF) can create optical traps for neutral atoms. We present a non-destructive method to characterize such trapping potentials. An off-resonance linearly polarized probe beam that propagates through the ONF experiences a slow axis of polarization produced by trapped atoms on opposite sides along the ONF. The transverse atomic motion is imprinted onto the probe polarization through the changing atomic index of refraction. By applying a transient impulse, we measure a time-dependent polarization rotation of the probe beam that provides both a rapid and non-destructive measurement of the optical trapping frequencies.

Tax Neutrality on International Capital Investments

Directory of Open Access Journals (Sweden)

Gizem KAPUCU

2017-07-01

Full Text Available The tax policies which states follow with regard to developing technology and capital investments with raising mobility due to globalism are need to be discussed in its legal basis. The principle of tax neutrality has the aim of being legal foundation for these policies. According to this, the neutrality principle in taxation of international capital investments is provided with two measures, namely; not effecting the investment decision and not discriminate between investments. In this paper, initially focused on the conceptual framework and the foundations of the tax neutrality principle and later capital export neutrality and capital import neutrality are considered and explained with regard to international capital movements. Moreover, conformity and diversion to the principle of the current situation and regulations in OECD, EU and Turkey are examined.

Optics simulations of the 5 MeV NPBSE FOX telescope

International Nuclear Information System (INIS)

Reusch, M.F.; Bruhwiler, D.L.

1993-01-01

The far-field optics experiment (FOX) is a proposed design for the neutral particle beam space experiment (NPBSE) program. This 425 MHz straight beam line includes a 4.3 meter large-bore telescope. It is designed to deliver an 8 mA, 5 MeV neutral hydrogen beam with a transverse divergence of approximately 30 micro-radians to a target space vehicle (TSV) located up to 5 km away. The authors present zero current simulations, made with Grummann's TOPKARK code, of the telescope optics and the resulting 5 km target footprint. These simulations demonstrate the need for momentum compactation to minimize chromatic aberrations and for the careful use of octupoles to correct geometric aberrations. TOPKARK uses a novel line dipole model for the large-bore, combined function telescope objective lenses, constructed with rods of permanent magnet material, proposed for use in the FOX. The authors describe this model and its effect on the dynamics

The Net Neutrality Debate: The Basics

Science.gov (United States)

Greenfield, Rich

2006-01-01

Rich Greenfield examines the basics of today's net neutrality debate that is likely to be an ongoing issue for society. Greenfield states the problems inherent in the definition of "net neutrality" used by Common Cause: "Network neutrality is the principle that Internet users should be able to access any web content they choose and…

Neutral particle kinetics in fusion devices

International Nuclear Information System (INIS)

Tendler, M.; Heifetz, D.

1986-05-01

The theory of neutral particle kinetics treats the transport of mass, momentum, and energy in a plasma due to neutral particles which themselves are unaffected by magnetic fields. This transport affects the global power and particle balances in fusion devices, as well as profile control and plasma confinement quality, particle and energy fluxes onto device components, performance of pumping systems, and the design of diagnostics and the interpretation of their measurements. This paper reviews the development of analytic, numerical, and Monte Carlo methods of solving the time-independent Boltzmann equation describing neutral kinetics. These models for neutral particle behavior typically use adaptations of techniques developed originally for computing neutron transport, due to the analogy between the two phenomena, where charge-exchange corresponds to scattering and ionization to absorption. Progress in the field depends on developing multidimensional analytic methods, and obtaining experimental data for the physical processes of wall reflection, the neutral/plasma interaction, and for processes in fusion devices which are directly related to neutral transport, such as H/sub α/ emission rates, plenum pressures, and charge-exchange emission spectra

Neutral particle kinetics in fusion devices

Energy Technology Data Exchange (ETDEWEB)

Tendler, M.; Heifetz, D.

1986-05-01

The theory of neutral particle kinetics treats the transport of mass, momentum, and energy in a plasma due to neutral particles which themselves are unaffected by magnetic fields. This transport affects the global power and particle balances in fusion devices, as well as profile control and plasma confinement quality, particle and energy fluxes onto device components, performance of pumping systems, and the design of diagnostics and the interpretation of their measurements. This paper reviews the development of analytic, numerical, and Monte Carlo methods of solving the time-independent Boltzmann equation describing neutral kinetics. These models for neutral particle behavior typically use adaptations of techniques developed originally for computing neutron transport, due to the analogy between the two phenomena, where charge-exchange corresponds to scattering and ionization to absorption. Progress in the field depends on developing multidimensional analytic methods, and obtaining experimental data for the physical processes of wall reflection, the neutral/plasma interaction, and for processes in fusion devices which are directly related to neutral transport, such as H/sub ..cap alpha../ emission rates, plenum pressures, and charge-exchange emission spectra.

Optical metrology for analysis of lobster-eye x-ray optics

International Nuclear Information System (INIS)

Irving, Thomas H.K.; Peele, Andrew G.; Nugent, Keith A.

2003-01-01

A new method that uses optical microscopy to determine the physical structure of lobster-eye x-ray optics is described. This approach offers the ability to predict x-ray performance without having to take an x-ray measurement. An overlapping series of images of the entrance and exit faces of an optic are obtained and examined by purpose-built software. A 24-parameter description of each channel is obtained from which a quantitative analysis of all the major optic defects, except surface roughness, is performed. Results for a planar lobster-eye optic are used to illustrate this technique and discuss its abilities as well as directions for future enhancements

Saturable reactor-controlled power supply system for TCT/TFTR neutral beam sources

International Nuclear Information System (INIS)

Baker, W.R.; Hopkins, D.B.; Dexter, W.L.; Kuenning, R.W.; Smith, B.J.

1975-11-01

Each neutral beam source requires one major power supply, the acceleration supply, and four auxiliary power supplies. The power supplies are designed to permit independent interruption of current to any source and crowbarring within 20 μsec, in the event of a source spark, while not disturbing the normal pulsing of all other adjacent sources. The sources are described

Design problems of a continuous injector of many amperes of MeV deuterium neutrals

International Nuclear Information System (INIS)

Fink, J.H.

1976-10-01

A continuous injector of many amperes of MeV deuterium neutrals will require high currents of negative deuterium ions to be generated, accelerated and stripped of electrons by methods that are not fully developed. Each of these processes as briefly described in this report, introduce constraints upon the ion optics, beam line pumping, and high voltage stand-off that must be mutually resolved. Although the design of such an injector represents a difficult task, there is no fundamental reason that very high current beams cannot be handled

Neutral-beam current drive in tokamaks

International Nuclear Information System (INIS)

Devoto, R.S.

1986-01-01

The theory of neutral-beam current drive in tokamaks is reviewed. Experiments are discussed where neutral beams have been used to drive current directly and also indirectly through neoclassical effects. Application of the theory to an experimental test reactor is described. It is shown that neutral beams formed from negative ions accelerated to 500 to 700 keV are needed for this device

Neutral-beam current drive in tokamaks

International Nuclear Information System (INIS)

Devoto, R.S.

1987-01-01

The theory of neutral-beam current drive in tokamaks is reviewed. Experiments are discussed where neutral beams have been used to drive current directly and also indirectly through neoclassical effects. Application of the theory to an experimental test reactor is described. It is shown that neutral beams formed from negative ions accelerated to 500-700 keV are needed for this device

Development of the TFTR neutral beam injection system

International Nuclear Information System (INIS)

Prichard, B.A. Jr.

1977-01-01

The TFTR Neutral Beam Lines are designed to inject 20 MW of 120 keV neutral deuterium atoms into the plasma. This is accomplished using 12 sources, 65 amperes each, mounted in 4 beam lines. The 120 kV sources and a prototype beam line are being developed. The implementation of these beam lines has required the development of several associated pieces of hardware. 200 kV switch tubes for the power supplies are being developed for modulation and regulation of the accelerating supplies. A 90 cm metallic seal gate valve capable of sealing against atmosphere in either direction is being developed for separating the torus and beam line vacuum systems. A 70 x 80 cm fast shutter valve is also being developed to limit tritium migration from the torus into the beam line. Internal to the beam line a calorimeter, ion dump and deflection magnet have been designed to handle three beams, and optical diagnostics utilizing the doppler broadening and doppler shift of light emitted from the accelerated beam are being developed. The control and monitoring of the 12 sources will be done via the TFTR computer control system (CICADA) as will other parts of the machine, and software is being developed to condition and operate the sources automatically. The prototype beam line is scheduled to begin operation in the fall of 1978 and all four production beam lines on TFTR in 1982

Determining the Effect of Natural Selection on Linked Neutral Divergence across Species.

Science.gov (United States)

Phung, Tanya N; Huber, Christian D; Lohmueller, Kirk E

2016-08-01

A major goal in evolutionary biology is to understand how natural selection has shaped patterns of genetic variation across genomes. Studies in a variety of species have shown that neutral genetic diversity (intra-species differences) has been reduced at sites linked to those under direct selection. However, the effect of linked selection on neutral sequence divergence (inter-species differences) remains ambiguous. While empirical studies have reported correlations between divergence and recombination, which is interpreted as evidence for natural selection reducing linked neutral divergence, theory argues otherwise, especially for species that have diverged long ago. Here we address these outstanding issues by examining whether natural selection can affect divergence between both closely and distantly related species. We show that neutral divergence between closely related species (e.g. human-primate) is negatively correlated with functional content and positively correlated with human recombination rate. We also find that neutral divergence between distantly related species (e.g. human-rodent) is negatively correlated with functional content and positively correlated with estimates of background selection from primates. These patterns persist after accounting for the confounding factors of hypermutable CpG sites, GC content, and biased gene conversion. Coalescent models indicate that even when the contribution of ancestral polymorphism to divergence is small, background selection in the ancestral population can still explain a large proportion of the variance in divergence across the genome, generating the observed correlations. Our findings reveal that, contrary to previous intuition, natural selection can indirectly affect linked neutral divergence between both closely and distantly related species. Though we cannot formally exclude the possibility that the direct effects of purifying selection drive some of these patterns, such a scenario would be possible only

Structural Basis for Differential Neutralization of Ebolaviruses

Directory of Open Access Journals (Sweden)

John M. Dye

2012-04-01

Full Text Available There are five antigenically distinct ebolaviruses that cause hemorrhagic fever in humans or non-human primates (Ebola virus, Sudan virus, Reston virus, Taï Forest virus, and Bundibugyo virus. The small handful of antibodies known to neutralize the ebolaviruses bind to the surface glycoprotein termed GP1,2. Curiously, some antibodies against them are known to neutralize in vitro but not protect in vivo, whereas other antibodies are known to protect animal models in vivo, but not neutralize in vitro. A detailed understanding of what constitutes a neutralizing and/or protective antibody response is critical for development of novel therapeutic strategies. Here, we show that paradoxically, a lower affinity antibody with restricted access to its epitope confers better neutralization than a higher affinity antibody against a similar epitope, suggesting that either subtle differences in epitope, or different characteristics of the GP1,2 molecules themselves, confer differential neutralization susceptibility. Here, we also report the crystal structure of trimeric, prefusion GP1,2 from the original 1976 Boniface variant of Sudan virus complexed with 16F6, the first antibody known to neutralize Sudan virus, and compare the structure to that of Sudan virus, variant Gulu. We discuss new structural details of the GP1-GP2 clamp, thermal motion of various regions in GP1,2 across the two viruses visualized, details of differential interaction of the crystallized neutralizing antibodies, and their relevance for virus neutralization.

The merits of neutral theory

NARCIS (Netherlands)

Alonso, D.; Etienne, R.S.; McKane, A.J.

2006-01-01

Hubbell's neutral theory of biodiversity has challenged the classic niche-based view of ecological community structure. Although there have been many attempts to falsify Hubbell's theory, we argue that falsification should not lead to rejection, because there is more to the theory than neutrality

Fine structure and optical pumping of spins in individual semiconductor quantum dots

Science.gov (United States)

Bracker, Allan S.; Gammon, Daniel; Korenev, Vladimir L.

2008-11-01

We review spin properties of semiconductor quantum dots and their effect on optical spectra. Photoluminescence and other types of spectroscopy are used to probe neutral and charged excitons in individual quantum dots with high spectral and spatial resolution. Spectral fine structure and polarization reveal how quantum dot spins interact with each other and with their environment. By taking advantage of the selectivity of optical selection rules and spin relaxation, optical spin pumping of the ground state electron and nuclear spins is achieved. Through such mechanisms, light can be used to process spins for use as a carrier of information.

Fine structure and optical pumping of spins in individual semiconductor quantum dots

International Nuclear Information System (INIS)

Bracker, Allan S; Gammon, Daniel; Korenev, Vladimir L

2008-01-01

We review spin properties of semiconductor quantum dots and their effect on optical spectra. Photoluminescence and other types of spectroscopy are used to probe neutral and charged excitons in individual quantum dots with high spectral and spatial resolution. Spectral fine structure and polarization reveal how quantum dot spins interact with each other and with their environment. By taking advantage of the selectivity of optical selection rules and spin relaxation, optical spin pumping of the ground state electron and nuclear spins is achieved. Through such mechanisms, light can be used to process spins for use as a carrier of information

Optical emission from Al target irradiated by FLASH

International Nuclear Information System (INIS)

Stránský, M; Rohlena, K

2014-01-01

The following text touches on some peculiarities in optical emission spectroscopy results from experiments on the free-electron laser FLASH [1, 2]. Aluminum targets were irradiated with 13.5 nm ∼ 25 fs pulses at intensities of 10 13 and 10 16 W/cm 2 (20 and 1 μm foci). Surprisingly, only neutral atom lines for the case with wider focus and traces of ion lines in the tighter focus case were observed with the optical emission spectroscopy (200–600 nm range), [2]. The motivating idea behind this work is the suggestion in [1] by Zastrau that the optical spectrometer sees only emissions from a cold expanding lower-density (< 10 22 cm −3 ) plasma plume. In this contribution the notion of UV range screening is analyzed in detail.

A rule-based computer control system for PBX-M neutral beams

International Nuclear Information System (INIS)

Frank, K.T.; Kozub, T.A.; Kugel, H.W.

1987-01-01

The Princeton Beta Experiment (PBX) neutral beams have been routinely operated under automatic computer control. A major upgrade of the computer configuration was undertaken to coincide with the PBX machine modification. The primary tasks included in the computer control system are data acquisition, waveform reduction, automatic control and data storage. The portion of the system which will remain intact is the rule-based approach to automatic control. Increased computational and storage capability will allow the expansion of the knowledge base previously used. The hardware configuration supported by the PBX Neutral Beam (XNB) software includes a dedicated Microvax with five CAMAC crates and four process controllers. The control algorithms are rule-based and goal-driven. The automatic control system raises ion source electrical parameters to selected energy goals and maintains these levels until new goals are requested or faults are detected

Interplay of HIV-1 phenotype and neutralizing antibody response in pathogenesis of AIDS.

Science.gov (United States)

Scarlatti, G; Leitner, T; Hodara, V; Jansson, M; Karlsson, A; Wahlberg, J; Rossi, P; Uhlén, M; Fenyö, E M; Albert, J

1996-06-01

A majority of human immunodeficiency virus type 1 (HIV-1) infected individuals display a rapid loss of CD4+ lymphocytes with fast progression towards overt acquired immunodeficiency syndrome (AIDS). However, a small proportion of individuals infected by HIV-1 remain immunologically intact for many years. In order to identify factors that might influence the pathogenesis of HIV-1 infection, 21 Italian mothers and 11 Swedish homosexual men were studied for the presence of autologous neutralizing antibodies in serum, biological phenotype of virus isolates and envelope variable region 3 (V3) sequences. The results were compared to the risk of mother-to-child transmission and progression of the disease. The presence of a neutralizing antibody response to the autologous virus as well as a virus with slow replicative capacity were linked both to low risk of mother-to-child transmission and non-progression of the disease. Patients whose peripheral blood mononuclear cells contained a mutation in the tip of the V3 loop (Arg318 to serine, lysine or leucine) significantly more often had neutralizing antibodies to autologous virus isolates containing arginine at this position. Thus, it appears that the interplay and balance between neutralizing antibody response of the host and the biological phenotype of HIV-1 strongly influence pathogenesis.

Neutral evolution of mutational robustness

NARCIS (Netherlands)

Nimwegen, Erik van; Crutchfield, James P.; Huynen, Martijn

1999-01-01

We introduce and analyze a general model of a population evolving over a network of selectively neutral genotypes. We show that the population s limit distribution on the neutral network is solely determined by the network topology and given by the principal eigenvector of the network

Nitrogen-neutrality: a step towards sustainability

Science.gov (United States)

Leip, Adrian; Leach, Allison; Musinguzi, Patrick; Tumwesigye, Trust; Olupot, Giregon; Tenywa, John Stephen; Mudiope, Joseph; Hutton, Olivia; Cordovil, Claudia M. d. S.; Bekunda, Mateete; Galloway, James

2014-11-01

We propose a novel indicator measuring one dimension of the sustainability of an entity in modern societies: Nitrogen-neutrality. N-neutrality strives to offset Nr releases an entity exerts on the environment from the release of reactive nitrogen (Nr) to the environment by reducing it and by offsetting the Nr releases elsewhere. N-neutrality also aims to increase awareness about the consequences of unintentional releases of nitrogen to the environment. N-neutrality is composed of two quantified elements: Nr released by an entity (e.g. on the basis of the N footprint) and Nr reduction from management and offset projects (N offset). It includes management strategies to reduce nitrogen losses before they occur (e.g., through energy conservation). Each of those elements faces specific challenges with regard to data availability and conceptual development. Impacts of Nr releases to the environment are manifold, and the impact profile of one unit of Nr release depends strongly on the compound released and the local susceptibility to Nr. As such, N-neutrality is more difficult to conceptualize and calculate than C-neutrality. We developed a workable conceptual framework for N-neutrality which was adapted for the 6th International Nitrogen Conference (N2013, Kampala, November 2013). Total N footprint of the surveyed meals at N2013 was 66 kg N. A total of US 3050 was collected from the participants and used to offset the conference’s N footprint by supporting the UN Millennium Village cluster Ruhiira in South-Western Uganda. The concept needs further development in particular to better incorporate the spatio-temporal variability of impacts and to standardize the methods to quantify the required N offset to neutralize the Nr releases impact. Criteria for compensation projects need to be sharply defined to allow the development of a market for N offset certificates.

Nitrogen-neutrality: a step towards sustainability

International Nuclear Information System (INIS)

Leip, Adrian; Leach, Allison; Hutton, Olivia; Galloway, James; Musinguzi, Patrick; Tumwesigye, Trust; Olupot, Giregon; Stephen Tenywa, John; Mudiope, Joseph; Cordovil, Claudia M d S; Bekunda, Mateete

2014-01-01

We propose a novel indicator measuring one dimension of the sustainability of an entity in modern societies: Nitrogen-neutrality. N-neutrality strives to offset Nr releases an entity exerts on the environment from the release of reactive nitrogen (Nr) to the environment by reducing it and by offsetting the Nr releases elsewhere. N-neutrality also aims to increase awareness about the consequences of unintentional releases of nitrogen to the environment. N-neutrality is composed of two quantified elements: Nr released by an entity (e.g. on the basis of the N footprint) and Nr reduction from management and offset projects (N offset). It includes management strategies to reduce nitrogen losses before they occur (e.g., through energy conservation). Each of those elements faces specific challenges with regard to data availability and conceptual development. Impacts of Nr releases to the environment are manifold, and the impact profile of one unit of Nr release depends strongly on the compound released and the local susceptibility to Nr. As such, N-neutrality is more difficult to conceptualize and calculate than C-neutrality. We developed a workable conceptual framework for N-neutrality which was adapted for the 6th International Nitrogen Conference (N2013, Kampala, November 2013). Total N footprint of the surveyed meals at N2013 was 66 kg N. A total of US$ 3050 was collected from the participants and used to offset the conference’s N footprint by supporting the UN Millennium Village cluster Ruhiira in South-Western Uganda. The concept needs further development in particular to better incorporate the spatio-temporal variability of impacts and to standardize the methods to quantify the required N offset to neutralize the Nr releases impact. Criteria for compensation projects need to be sharply defined to allow the development of a market for N offset certificates. (paper)

Heavy neutral leptons at FASER

Science.gov (United States)

Kling, Felix; Trojanowski, Sebastian

2018-05-01

We study the prospects for discovering heavy neutral leptons at Forward Search Experiment (FASER), the newly proposed detector at the LHC. Previous studies showed that a relatively small detector with ˜10 m length and ≲1 m2 cross sectional area can probe large unconstrained parts of parameter space for dark photons and dark Higgs bosons. In this work, we show that FASER will also be sensitive to heavy neutral leptons that have mixing angles with the active neutrinos that are up to an order of magnitude lower than current bounds. In particular, this is true for heavy neutral leptons produced dominantly in B -meson decays, in which case FASER's discovery potential is comparable to the proposed SHiP detector. We also illustrate how the search for heavy neutral leptons at FASER will be complementary to ongoing searches in high-pT experiments at the LHC and can shed light on the nature of dark matter and the process of baryogenesis in the early Universe.

The Neutral Interest Rate: Estimates for Chile

OpenAIRE

Rodrigo Fuentes S; Fabián Gredig U.

2008-01-01

To estimate the neutral real interest rate for Chile, we use a variety of methods that can be classified into three categories: those derived from economic theory, the neutral rate implicit in financial assets, and statistical procedures using macroeconomic data. We conclude that the neutral rate is not constant over time, but it is closely related with—though not equivalent to—the potential GDP growth rate. The application of the different methods yields fairly similar results. The neutral r...

BEAMS3D Neutral Beam Injection Model

Energy Technology Data Exchange (ETDEWEB)

Lazerson, Samuel

2014-04-14

With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.

Modeling Secondary Neutral Helium in the Heliosphere

International Nuclear Information System (INIS)

Müller, Hans-Reinhard; Möbius, Eberhard; Wood, Brian E.

2016-01-01

An accurate, analytic heliospheric neutral test-particle code for helium atoms from the interstellar medium (ISM) is coupled to global heliospheric models dominated by hydrogen and protons from the solar wind and the ISM. This coupling enables the forward-calculation of secondary helium neutrals from first principles. Secondaries are produced predominantly in the outer heliosheath, upwind of the heliopause, by charge exchange of helium ions with neutral atoms. The forward model integrates the secondary production terms along neutral trajectories and calculates the combined neutral helium phase space density in the innermost heliosphere where it can be related to in-situ observations. The phase space density of the secondary component is lower than that of primary neutral helium, but its presence can change the analysis of primaries and the ISM, and can yield valuable insight into the characteristics of the plasma in the outer heliosheath. (paper)

Neutral particle beam alternative concept for ITER

International Nuclear Information System (INIS)

Sedgley, D.; Brook, J.; Luzzi, T.; Deutsch, L.

1989-01-01

An analysis of an ITER neutral particle beam system is presented. The analysis covers the neutralizer, ion dumps, pumping, and geometric aspects. The US beam concept for ITER consists of three or four clusters of beamlines delivering approximately 80 MW total of 1.6-MeV deuterium to three or four reactor ports. Each cluster has three self-contained beamlines featuring plasma neutralizers and electrostatic ion dumps. In this study, each of the beamlines has two source assemblies with separate gas neutralizers and magnetic ion dumps. Deuterium is injected into the gas neutralizers by a separate system. Saddle-shaped copper coils augment the tokamak poloidal field to turn the charged particles into the ion dumps. The gas flow from the source, neutralizer, and ion dump is pumped by regenerable cryopanels. The effect of the port between the TF coils and the beam injection angle on the plasma footprint was studied

An experimenter's history of neutral currents

International Nuclear Information System (INIS)

Sciulli, F.

1979-01-01

The history of the experimental study of neutral currents, defined as the class of weak interactions engaged in by lepton pairs of net zero charge, is traced under the headings; historical motivations, experimental searches, first positive indications, neutral currents corroborated, neutrino experiments on neutral currents and some general experimental comments. It is concluded that the neutral current does exist and predicted on the basis of gauge theory ideas, and though to connect the weak and electromagnetic interactions, its very general experimental properties are quite consistent with those ideas. Among these are flavor conserving complicated isospin structure, complicated V, A structure and a structure which depends on the type (or quantum numbers) of the target. 50 references. (UK)

Computational study of the first stage of hypersonic ion beam neutralization: The cross neutralization stage

International Nuclear Information System (INIS)

Pomot, C.; Dolique, J.M.

1975-01-01

A study is made of the first stage of evolution of a hypersonic ion beam in which thermoelectrons are emitted by a heated grid, known as the neutralizer. Downstream from the neutralizer there appears successively as a sheath a range of periodic and quasi-stationary electric field and a front where the electric field oscillates with the plasma frequency. The sheath is self-regulated. Some electrons are trapped in the periodic and stationary electric field. The characteristics of the periodic, quasi-stationary range correspond to those of both an experimental study and one-dimensional time-independent macroscopic theory. This quasi-stationary regime builds up in a time smaller than ω/subp/e -1 and is studied for a few periods ω/subP//sube/ -1 . The subsequent evolution of this state of nonequilibrium is not investigated. The experimental study has shown that, as for the neutralization of a subsonic ion beam, it leads to a field-free, homogeneous medium: a ''synthesized plasma.'' The importance of the first stage described herein, which may be called the gross neutralization stage, is due to the properties of mean neutrality in the current and in the charge insured by the regulating sheath, properties which will be preseved downstream

The Dutch disease and its neutralization: a Ricardian approach

Directory of Open Access Journals (Sweden)

Luiz Carlos Bresser-Pereira

2008-03-01

Full Text Available The Dutch disease is a major market failure originated in the existence of cheap and abundant natural or human resources that keep overvalued the currency of a country for an undetermined period of time, thus turning non profitable the production of tradable goods using technology in the state-of-the-art. It is an obstacle to growth on the demand side, because it limits investment opportunities. The severity of the Dutch disease varies according to the extent of the Ricardian rents involved, i.e., according to the difference between two exchange rate equilibriums: the ‘current’ or market rate and the ‘industrial’ rate - the one that make viable efficient tradable industries. Its main symptoms, besides overvalued currency, are low rates of growth of the manufacturing industry, artificially high real wages, and unemployment. Its neutralization requires managing the exchange rate. The principal instrument for that is a sales or export tax on the commodities that give origin to the Dutch disease. In order to neutralize it policymakers face major political obstacles since it involves taxing exports and reducing wages. Finally, this papers argues that there is an extended concept of Dutch disease: besides having its origin in natural resources, it may arise from cheap labor provided that the ‘wage spread’ in the developing country is considerably larger than in the developed one - a condition that is usually present.

Net neutrality and audiovisual services

NARCIS (Netherlands)

van Eijk, N.; Nikoltchev, S.

2011-01-01

Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication

Our Expedition in Linear Neutral Platinum-Acetylide Complexes: The Preparation of Micro/nanostructure Materials, Complicated Topologies, and Dye-Sensitized Solar Cells.

Science.gov (United States)

Xu, Lin; Yang, Hai-Bo

2016-06-01

During the past few decades, the construction of various kinds of platinum-acetylide complexes has attracted considerable attention, because of their wide applications in photovoltaic cells, non-linear optics, and bio-imaging materials. Among these platinum-acetylide complexes, the linear neutral platinum-acetylide complexes, due to their attractive properties, such as well-defined linear geometry, synthetic accessibility, and intriguing photoproperties, have emerged as a rising star in this field. In this personal account, we will discuss how we entered the field of linear neutral platinum-acetylide chemistry and what we found in this field. The preparation of various types of linear neutral platinum-acetylide complexes and their applications in the areas of micro/nanostructure materials, complicated topologies, and dye-sensitized solar cells will be summarized in this account. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Energizing and depletion of neutrals by a collisional plasma

International Nuclear Information System (INIS)

Fruchtman, A

2008-01-01

Neutral depletion can significantly affect the steady state of low temperature plasmas. Recent theoretical analyses predicted previously unexpected effects of neutral depletion in both collisional and collisionless regimes. In this paper we address the effect of the energy deposited in the neutral gas by a collisional plasma. The fraction of power deposited in the neutrals is shown to be independent of the amount of power. The first case we address is of a thermalized neutral gas. It is shown that a low heat conductivity of the neutral gas is followed by a high neutral temperature that results in a high neutral depletion even if the plasma pressure is small. In the second case neutrals are accelerated through charge exchange with ions leading to what we call neutral pumping, which is equivalent to ion pumping in a collisionless plasma. Neutral depletion is found in the second case for both a closed system (no net mass flow) and an open system (a finite mass flow). A thruster that employs a collisional plasma and pumped neutrals is compared with the thruster analyzed before that employs collisionless plasma.

Net Neutrality: Media Discourses and Public Perception

Directory of Open Access Journals (Sweden)

Christine Quail

2010-01-01

Full Text Available This paper analyzes media and public discourses surrounding net neutrality, with particular attention to public utility philosophy, from a critical perspective. The article suggests that further public education about net neutrality would be beneficial. The first portion of this paper provides a survey of the existing literature surrounding net neutrality, highlighting the contentious debate between market-based and public interest perspectives. In order to contextualize the debate, an overview of public utility philosophy is provided, shedding light on how the Internet can be conceptualized as a public good. Following this discussion, an analysis of mainstream media is presented, exploring how the media represents the issue of net neutrality and whether or not the Internet is discussed through the lens of public utility. To further examine how the net neutrality debate is being addressed, and to see the potential impacts of media discourses on the general public, the results of a focus group are reported and analyzed. Finally, a discussion assesses the implications of the net neutrality debate as presented through media discourses, highlighting the future of net neutrality as an important policy issue.

On implicit abstract neutral nonlinear differential equations

Energy Technology Data Exchange (ETDEWEB)

Hernández, Eduardo, E-mail: lalohm@ffclrp.usp.br [Universidade de São Paulo, Departamento de Computação e Matemática, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto (Brazil); O’Regan, Donal, E-mail: donal.oregan@nuigalway.ie [National University of Ireland, School of Mathematics, Statistics and Applied Mathematics (Ireland)

2016-04-15

In this paper we continue our developments in Hernández and O’Regan (J Funct Anal 261:3457–3481, 2011) on the existence of solutions for abstract neutral differential equations. In particular we extend the results in Hernández and O’Regan (J Funct Anal 261:3457–3481, 2011) for the case of implicit nonlinear neutral equations and we focus on applications to partial “nonlinear” neutral differential equations. Some applications involving partial neutral differential equations are presented.

Absorption spectrum of neutral phosphorus (P I) in the range 7700-8256 A

International Nuclear Information System (INIS)

Deng Lunhua; Li Chuanliang; Zhang Junli; Yang Xiaohua; Chen Yangqin

2010-01-01

The absorption spectrum of neutral phosphorus was recorded in the range 7700-8256 A using optical heterodyne magnetic rotation concentration modulation spectroscopy with a tunable Ti:sapphire laser as the light source. Phosphorus atoms were excited by discharging the mixed gases of phosphorus vapor and neon gas. The phosphorus vapor was prepared by heating white phosphorus chips placed on a cylindrical copper electrode during discharge. In total, 234 lines of P I were observed, of which 127 were assigned. The transition frequencies were obtained with an uncertainty of 0.007 cm -1 . Empirical line intensities were provided covering four orders of magnitude.

Absorption spectrum of neutral phosphorus (P I) in the range 7700-8256 Å

Science.gov (United States)

Deng, Lunhua; Li, Chuanliang; Zhang, Junli; Yang, Xiaohua; Chen, Yangqin

2010-12-01

The absorption spectrum of neutral phosphorus was recorded in the range 7700-8256 Å using optical heterodyne magnetic rotation concentration modulation spectroscopy with a tunable Ti:sapphire laser as the light source. Phosphorus atoms were excited by discharging the mixed gases of phosphorus vapor and neon gas. The phosphorus vapor was prepared by heating white phosphorus chips placed on a cylindrical copper electrode during discharge. In total, 234 lines of P I were observed, of which 127 were assigned. The transition frequencies were obtained with an uncertainty of 0.007 cm-1. Empirical line intensities were provided covering four orders of magnitude.

A Measurement of Coherent Neutral Pion Production in Neutrino Neutral Current Interactions in NOMAD experiment

CERN Document Server

Kullenberg, C T

2009-01-01

We present a study of exclusive neutral pion production in neutrino-nucleus Neutral Current interactions using data from the NOMAD experiment at the CERN SPS. The data correspond to $1.44 \\times 10^6$ muon-neutrino Charged Current interactions in the energy range $2.5 \\leq E_{\

Fiber Optics and Library Technology.

Science.gov (United States)

Koenig, Michael

1984-01-01

This article examines fiber optic technology, explains some of the key terminology, and speculates about the way fiber optics will change our world. Applications of fiber optics to library systems in three major areas--linkage of a number of mainframe computers, local area networks, and main trunk communications--are highlighted. (EJS)

Design of the ITER Neutral Beam injectors

International Nuclear Information System (INIS)

Hemsworth, R.S.; Feist, J.; Hanada, M.; Heinemann, B.; Inoue, T.; Kuessel, E.; Kulygin, V.; Krylov, A.; Lotte, P.; Miyamoto, K.; Miyamoto, N.; Murdoch, D.; Nagase, A.; Ohara, Y.; Okumura, Y.; Pamela, J.; Panasenkov, A.; Shibata, K.; Tanii, M.

1996-01-01

This paper describes the Neutral Beam Injection system which is presently being designed in Europe, Japan and Russia, with co-ordination by the Joint Central Team of ITER at Naka, Japan. The proposed system consists of three negative ion based neutral injectors, delivering a total of 50 MW of 1 MeV D 0 to the ITER plasma for pulse length of ≥1000 s. The injectors each use a single caesiated volume arc discharge negative ion source, and a multi-grid, multi-aperture accelerator, to produce about 40 A of 1 MeV D - . This will be neutralized in a sub-divided gas neutralizer, which has a conversion efficiency of about 60%. The charged fraction of the beam emerging from the neutralizer is dumped in an electrostatic residual ion dump. A water cooled calorimeter can be moved into the beam path to intercept the neutral beam, allowing commissioning of the injector independent of ITER. copyright 1996 American Institute of Physics

Field aligned flows driven by neutral puffing at MAST

Science.gov (United States)

Waters, I.; Frerichs, H.; Silburn, S.; Feng, Y.; Harrison, J.; Kirk, A.; Schmitz, O.

2018-06-01

Neutral deuterium gas puffing at the high field side of the mega ampere spherical tokamak (MAST) is shown to drive carbon impurity flows that are aligned with the trajectory of the magnetic field lines in the plasma scrape-off-layer. These impurity flows were directly imaged with emissions from C2+ ions at MAST by coherence imaging spectroscopy and were qualitatively reproduced in deuterium plasmas by modeling with the EMC3-EIRENE plasma edge fluid and kinetic neutral transport code. A reduced one-dimensional momentum and particle balance shows that a localized increase in the static plasma pressure in front of the neutral gas puff yields an acceleration of the plasma due to local ionization. Perpendicular particle transport yields a decay from which a parallel length scale can be determined. Parameter scans in EMC3-EIRENE were carried out to determine the sensitivity of the deuterium plasma flow phenomena to local fueling and diffusion parameters and it is found that these flows robustly form across a wide variety of plasma conditions. Finally, efforts to couple this behavior in the background plasma directly to the impurity flows observed experimentally in MAST using a trace impurity model are discussed. These results provide insight into the fueling and exhaust features at this pivotal point of the radial and parallel particle flux balance, which is a major part of the plasma fueling and exhaust characteristics in a magnetically confined fusion device.

Optical Pumping of the Electronic and Nuclear Spin of Single Charge-Tunable Quantum Dots

Science.gov (United States)

Bracker, A. S.; Stinaff, E. A.; Gammon, D.; Ware, M. E.; Tischler, J. G.; Shabaev, A.; Efros, Al. L.; Park, D.; Gershoni, D.; Korenev, V. L.; Merkulov, I. A.

2005-02-01

We present a comprehensive examination of optical pumping of spins in individual GaAs quantum dots as we change the net charge from positive to neutral to negative with a charge-tunable heterostructure. Negative photoluminescence polarization memory is enhanced by optical pumping of ground state electron spins, which we prove with the first measurements of the Hanle effect on an individual quantum dot. We use the Overhauser effect in a high longitudinal magnetic field to demonstrate efficient optical pumping of nuclear spins for all three charge states of the quantum dot.

Optical system design

CERN Document Server

Fischer, Robert F

2008-01-01

Honed for more than 20 years in an SPIE professional course taught by renowned optical systems designer Robert E. Fischer, Optical System Design, Second Edition brings you the latest cutting-edge design techniques and more than 400 detailed diagrams that clearly illustrate every major procedure in optical design. This thoroughly updated resource helps you work better and faster with computer-aided optical design techniques, diffractive optics, and the latest applications, including digital imaging, telecommunications, and machine vision. No need for complex, unnecessary mathematical derivations-instead, you get hundreds of examples that break the techniques down into understandable steps. For twenty-first century optical design without the mystery, the authoritative Optical Systems Design, Second Edition features: Computer-aided design use explained through sample problems Case studies of third-millennium applications in digital imaging, sensors, lasers, machine vision, and more New chapters on optomechanic...

Weak neutral-current interactions

International Nuclear Information System (INIS)

Barnett, R.M.

1978-08-01

The roles of each type of experiment in establishing uniquely the values of the the neutral-current couplings of u and d quarks are analyzed together with their implications for gauge models of the weak and electromagnetic interactions. An analysis of the neutral-current couplings of electrons and of the data based on the assumption that only one Z 0 boson exists is given. Also a model-independent analysis of parity violation experiments is discussed. 85 references

Structural basis for the antibody neutralization of Herpes simplex virus

Energy Technology Data Exchange (ETDEWEB)

Lee, Cheng-Chung; Lin, Li-Ling [Academia Sinica, Taipei 115, Taiwan (China); Academia Sinica, Taipei 115, Taiwan (China); Chan, Woan-Eng [Development Center for Biotechnology, New Taipei City 221, Taiwan (China); Ko, Tzu-Ping [Academia Sinica, Taipei 115, Taiwan (China); Academia Sinica, Taipei 115, Taiwan (China); Lai, Jiann-Shiun [Development Center for Biotechnology, New Taipei City 221, Taiwan (China); Ministry of Economic Affairs, Taipei 100, Taiwan (China); Wang, Andrew H.-J., E-mail: ahjwang@gate.sinica.edu.tw [Academia Sinica, Taipei 115, Taiwan (China); Academia Sinica, Taipei 115, Taiwan (China); Taipei Medical University, Taipei 110, Taiwan (China)

2013-10-01

The gD–E317-Fab complex crystal revealed the conformational epitope of human mAb E317 on HSV gD, providing a molecular basis for understanding the viral neutralization mechanism. Glycoprotein D (gD) of Herpes simplex virus (HSV) binds to a host cell surface receptor, which is required to trigger membrane fusion for virion entry into the host cell. gD has become a validated anti-HSV target for therapeutic antibody development. The highly inhibitory human monoclonal antibody E317 (mAb E317) was previously raised against HSV gD for viral neutralization. To understand the structural basis of antibody neutralization, crystals of the gD ectodomain bound to the E317 Fab domain were obtained. The structure of the complex reveals that E317 interacts with gD mainly through the heavy chain, which covers a large area for epitope recognition on gD, with a flexible N-terminal and C-terminal conformation. The epitope core structure maps to the external surface of gD, corresponding to the binding sites of two receptors, herpesvirus entry mediator (HVEM) and nectin-1, which mediate HSV infection. E317 directly recognizes the gD–nectin-1 interface and occludes the HVEM contact site of gD to block its binding to either receptor. The binding of E317 to gD also prohibits the formation of the N-terminal hairpin of gD for HVEM recognition. The major E317-binding site on gD overlaps with either the nectin-1-binding residues or the neutralizing antigenic sites identified thus far (Tyr38, Asp215, Arg222 and Phe223). The epitopes of gD for E317 binding are highly conserved between two types of human herpesvirus (HSV-1 and HSV-2). This study enables the virus-neutralizing epitopes to be correlated with the receptor-binding regions. The results further strengthen the previously demonstrated therapeutic and diagnostic potential of the E317 antibody.

Transport of neutral atoms and molecules in TFCX

International Nuclear Information System (INIS)

Boley, C.D.

1984-09-01

The distribution of neutrals in the proposed reactor TFCX has been modeled by the 3-D Monte Carlo neutral transport code DEGAS, which has been run in conjunction with the 1-1/2-D time-dependent plasma transport code WHIST. The former code contains the best available treatment of neutral-particle physics, including a selection of wall reflection models. The latter code has a comprehensive set of plasma transport coefficients, an MHD equilibrium package, and provision for source terms such as those involving neutrals. It has a simple scrape-off model involving sound-speed flow to the neutralizer plates. The codes are run in iteration, so that the flux-surface averaged particle and energy sources due to interactions with neutrals are consistent with the plasma profiles. The design considered here has a bottom limiter with a pumping plenum. Results are given for the power balance, the mutually consistent plasma and neutral distributions set up in the edge region, the neutral density in the plenum, and the charge-exchange power deposition and erosion along the limiter

Divergence at neutral and non-neutral loci in Drosophila buzzatii populations and their hybrids

DEFF Research Database (Denmark)

Andersen, Ditte Holm; Pertoldi, Cino; Loeschcke, Volker

2008-01-01

The impact of intraspecific hybridisation on fitness and morphological traits depends on the history of natural selection and genetic drift, which may have led to differently coadapted gene-complexes in the parental populations. The divergence at neutral and non-neutral loci between populations can...... populations of Drosophila buzzatii, one between populations from Argentina and the Canary Islands (separated for 200 years), and the other between populations from Argentina and Australia (separated for 80 years). We observed the highest divergence at neutral loci between the Argentinean and Canary Island...

Intense ion beam neutralization using underdense background plasma

Energy Technology Data Exchange (ETDEWEB)

Berdanier, William [Department of Physics, The University of Texas at Austin, Austin, Texas 78712 (United States); Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States); Roy, Prabir K. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Kaganovich, Igor [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

2015-01-15

Producing an overdense background plasma for neutralization purposes with a density that is high compared to the beam density is not always experimentally possible. We show that even an underdense background plasma with a small relative density can achieve high neutralization of intense ion beam pulses. Using particle-in-cell simulations, we show that if the total plasma electron charge is not sufficient to neutralize the beam charge, electron emitters are necessary for effective neutralization but are not needed if the plasma volume is so large that the total available charge in the electrons exceeds that of the ion beam. Several regimes of possible underdense/tenuous neutralization plasma densities are investigated with and without electron emitters or dense plasma at periphery regions, including the case of electron emitters without plasma, which does not effectively neutralize the beam. Over 95% neutralization is achieved for even very underdense background plasma with plasma density 1/15th the beam density. We compare results of particle-in-cell simulations with an analytic model of neutralization and find close agreement with the particle-in-cell simulations. Further, we show experimental data from the National Drift Compression experiment-II group that verifies the result that underdense plasma can neutralize intense heavy ion beams effectively.

Handbook of fiber optic data communication a practical guide to optical networking

CERN Document Server

DeCusatis, Casimer

2008-01-01

The third edition of this Handbook provides a comprehensive, easy to use guide to the field of optical fiber data communications. Written by experts in the industry from major companies such as IBM, Cisco and Nortel, the Handbook is a key reference for optical fiber technology, networking, protocols, applications, manufacturing, and future directions. It includes chapters on all the major industry standards, written by the same experts who developed them.This edition contains new material on transceiver form factors (QSFP, SFP +, XFP, X2), manufacturing standards, including JEDEC and R

Optical scattering characteristic of annealed niobium oxide films

International Nuclear Information System (INIS)

Lai Fachun; Li Ming; Wang Haiqian; Hu Hailong; Wang Xiaoping; Hou, J.G.; Song Yizhou; Jiang Yousong

2005-01-01

Niobium oxide (Nb 2 O 5 ) films with thicknesses ranging from 200 to 1600 nm were deposited on fused silica at room temperature by low frequency reactive magnetron sputtering system. In order to study the optical losses resulting from the microstructures, the films with 500 nm thickness were annealed at temperatures between 600 and 1100 deg. C, and films with thicknesses from 200 to 1600 nm were annealed at 800 deg. C. Scanning electron microscopy and atomic force microscopy images show that the root mean square of surface roughness, the grain size, voids, microcracks, and grain boundaries increase with increasing both the annealing temperature and the thickness. Correspondingly, the optical transmittance and reflectance decrease, and the optical loss increases. The mechanisms of the optical losses are discussed. The results suggest that defects in the volume and the surface roughness should be the major source for the optical losses of the annealed films by causing pronounced scattering. For samples with a determined thickness, there is a critical annealing temperature, above which the surface scattering contributes to the major optical losses. In the experimental scope, for the films annealed at temperatures below 900 deg. C, the major optical losses resulted from volume scattering. However, surface roughness was the major source for the optical losses when the 500-nm films were annealed at temperatures above 900 deg. C

Optics in the United kingdom.

Science.gov (United States)

Ditchburn, R W

1969-10-01

Optics is interpreted to include x-ray optics, electronic optics, and short wave radiooptics as well as the more conventional visible, uv, and ir optics. Recent work in Britain on x-ray optics (applied to molecular biology), on scanning electron microscopy, and in radioastronomy (discovery of pulsars) is mentioned. In the optics of the visible and ir there is an increasing interest in over-all systems design. .The formation of large industrial units capable of carrying through major design program, requiring advanced mechanical and electronic design associated with new lens systems, is welcomed.

A hepatitis C virus (HCV) vaccine comprising envelope glycoproteins gpE1/gpE2 derived from a single isolate elicits broad cross-genotype neutralizing antibodies in humans

DEFF Research Database (Denmark)

Law, John Lok Man; Chen, Chao; Wong, Jason

2013-01-01

of genotype 1a). Cross neutralization was tested in Huh-7.5 human hepatoma cell cultures using infectious recombinant HCV (HCVcc) expressing structural proteins of heterologous HCV strains from all known major genotypes, 1-7. Vaccination induced significant neutralizing antibodies against heterologous HCV...... genotype 1a virus which represents the most common genotype in North America. Of the 16 vaccinees tested, 3 were selected on the basis of strong 1a virus neutralization for testing of broad cross-neutralizing responses. At least 1 vaccinee was shown to elicit broad cross-neutralization against all HCV...

Progress in the design of the ITER Neutral Beam cell Remote Handling System

Energy Technology Data Exchange (ETDEWEB)

Shuff, R., E-mail: robin.shuff@f4e.europa.eu [Fusion for Energy, Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Van Uffelen, M.; Damiani, C. [Fusion for Energy, Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain); Tesini, A.; Choi, C.-H. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul-lez-Durance (France); Meek, R. [Oxford Technologies Limited, 7 Nuffield Way, Abingdon OX14 1RL (United Kingdom)

2014-10-15

The ITER Neutral Beam cell will include a suite of Remote Handling equipment for maintenance tasks. This paper summarises the current status and recent developments in the design of the ITER Neutral Beam Remote Handling System. Its concept design was successfully completed in July 2012 by CCFE in the frame of a grant agreement with F4E, in collaboration with the ITER Organisation, including major systems like monorail crane, Beam Line Transporter, beam source equipment, upper port and neutron shield equipment and associated tooling. Research and development activities are now underway on the monorail crane radiation hardened on-board control system and first of a kind remote pipe and lip seal maintenance tooling for the beam line vessel, reported in this paper.

Progress in the design of the ITER Neutral Beam cell Remote Handling System

International Nuclear Information System (INIS)

Shuff, R.; Van Uffelen, M.; Damiani, C.; Tesini, A.; Choi, C.-H.; Meek, R.

2014-01-01

The ITER Neutral Beam cell will include a suite of Remote Handling equipment for maintenance tasks. This paper summarises the current status and recent developments in the design of the ITER Neutral Beam Remote Handling System. Its concept design was successfully completed in July 2012 by CCFE in the frame of a grant agreement with F4E, in collaboration with the ITER Organisation, including major systems like monorail crane, Beam Line Transporter, beam source equipment, upper port and neutron shield equipment and associated tooling. Research and development activities are now underway on the monorail crane radiation hardened on-board control system and first of a kind remote pipe and lip seal maintenance tooling for the beam line vessel, reported in this paper

Importance of Neutralizing Monoclonal Antibodies Targeting Multiple Antigenic Sites on the Middle East Respiratory Syndrome Coronavirus Spike Glycoprotein To Avoid Neutralization Escape

Energy Technology Data Exchange (ETDEWEB)

Wang, Lingshu; Shi, Wei; Chappell, James D.; Joyce, M. Gordon; Zhang, Yi; Kanekiyo, Masaru; Becker, Michelle M.; van Doremalen, Neeltje; Fischer, Robert; Wang, Nianshuang; Corbett, Kizzmekia S.; Choe, Misook; Mason, Rosemarie D.; Van Galen, Joseph G.; Zhou, Tongqing; Saunders, Kevin O.; Tatti, Kathleen M.; Haynes, Lia M.; Kwong, Peter D.; Modjarrad, Kayvon; Kong, Wing-Pui; McLellan, Jason S.; Denison, Mark R.; Munster, Vincent J.; Mascola, John R.; Graham, Barney S.; Gallagher, Tom

2018-03-07

Middle East respiratory syndrome coronavirus (MERS-CoV) causes a highly lethal pulmonary infection with ~35% mortality. The potential for a future pandemic originating from animal reservoirs or health care-associated events is a major public health concern. There are no vaccines or therapeutic agents currently available for MERS-CoV. Using a probe-based single B cell cloning strategy, we have identified and characterized multiple neutralizing monoclonal antibodies (MAbs) specifically binding to the receptor-binding domain (RBD) or S1 (non-RBD) regions from a convalescent MERS-CoV-infected patient and from immunized rhesus macaques. RBD-specific MAbs tended to have greater neutralizing potency than non-RBD S1-specific MAbs. Six RBD-specific and five S1-specific MAbs could be sorted into four RBD and three non-RBD distinct binding patterns, based on competition assays, mapping neutralization escape variants, and structural analysis. We determined cocrystal structures for two MAbs targeting the RBD from different angles and show they can bind the RBD only in the “out” position. We then showed that selected RBD-specific, non-RBD S1-specific, and S2-specific MAbs given prophylactically prevented MERS-CoV replication in lungs and protected mice from lethal challenge. Importantly, combining RBD- and non-RBD MAbs delayed the emergence of escape mutations in a cell-based virus escape assay. These studies identify MAbs targeting different antigenic sites on S that will be useful for defining mechanisms of MERS-CoV neutralization and for developing more effective interventions to prevent or treat MERS-CoV infections.

IMPORTANCEMERS-CoV causes a highly lethal respiratory infection for which no vaccines or antiviral therapeutic options are currently available. Based on continuing exposure from established reservoirs in dromedary camels and bats, transmission of MERS-CoV into humans and future outbreaks are expected. Using

Money neutrality: Rethinking the myth

Directory of Open Access Journals (Sweden)

Issaoui Fakhri

2015-01-01

Full Text Available Considered as an axiomatic basis of classical, neoclassical, and monetarist theories, the long-run money neutrality assumption does not always seem to be verified. Indeed, in our view, the money, in the sense of M2, can constitute a long-run channel of growth transmission. Thus, this paper examines the long-term relationship among money supply (M2, income (GDP, and prices (CPI. The subprime crisis in 2007 has shown that the demand for money does not only meet motives of transaction, precaution, and speculation but also of fictional or quasi-fictional future demands due to the fact that they are created without real counterparts. The capacity of production systems in developed countries to respond to increases in money supply by creating more wealth, involves the assumption of money neutrality in the long-run. However, in developing countries, the excess of money supply may lead to inflation trends. The present study has confirmed the long-term non-neutrality of money supply in the USA, and its neutrality in Gabon and Morocco.

Controllability Problem of Fractional Neutral Systems: A Survey

Directory of Open Access Journals (Sweden)

Artur Babiarz

2017-01-01

Full Text Available The following article presents recent results of controllability problem of dynamical systems in infinite-dimensional space. Generally speaking, we describe selected controllability problems of fractional order systems, including approximate controllability of fractional impulsive partial neutral integrodifferential inclusions with infinite delay in Hilbert spaces, controllability of nonlinear neutral fractional impulsive differential inclusions in Banach space, controllability for a class of fractional neutral integrodifferential equations with unbounded delay, controllability of neutral fractional functional equations with impulses and infinite delay, and controllability for a class of fractional order neutral evolution control systems.

Laser Cooling and Trapping of Neutral Strontium for Spectroscopic Measurements of Casimir-Polder Potentials

Science.gov (United States)

Cook, Eryn C.

Casimir and Casimir-Polder effects are forces between electrically neutral bodies and particles in vacuum, arising entirely from quantum fluctuations. The modification to the vacuum electromagnetic-field modes imposed by the presence of any particle or surface can result in these mechanical forces, which are often the dominant interaction at small separations. These effects play an increasingly critical role in the operation of micro- and nano-mechanical systems as well as miniaturized atomic traps for precision sensors and quantum-information devices. Despite their fundamental importance, calculations present theoretical and numeric challenges, and precise atom-surface potential measurements are lacking in many geometric and distance regimes. The spectroscopic measurement of Casimir-Polder-induced energy level shifts in optical-lattice trapped atoms offers a new experimental method to probe atom-surface interactions. Strontium, the current front-runner among optical frequency metrology systems, has demonstrated characteristics ideal for such precision measurements. An alkaline earth atom possessing ultra-narrow intercombination transitions, strontium can be loaded into an optical lattice at the "magic" wavelength where the probe transition is unperturbed by the trap light. Translation of the lattice will permit controlled transport of tightly-confined atomic samples to well-calibrated atom-surface separations, while optical transition shifts serve as a direct probe of the Casimir-Polder potential. We have constructed a strontium magneto-optical trap (MOT) for future Casimir-Polder experiments. This thesis will describe the strontium apparatus, initial trap performance, and some details of the proposed measurement procedure.

Solar Adaptive Optics

Directory of Open Access Journals (Sweden)

Thomas R. Rimmele

2011-06-01

Full Text Available Adaptive optics (AO has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO and Ground-Layer AO (GLAO will be given.

Method to Minimize the Low-Frequency Neutral-Point Voltage Oscillations With Time-Offset Injection for Neutral-Point-Clamped Inverters

DEFF Research Database (Denmark)

Choi, Ui-Min; Blaabjerg, Frede; Lee, Kyo-Beum

2015-01-01

time of small- and medium-voltage vectors. However, if the power factor is lower, there is a limitation to eliminate neutral-point oscillations. In this case, the proposed method can be improved by changing the switching sequence properly. Additionally, a method for neutral-point voltage balancing......This paper proposes a method to reduce the low-frequency neutral-point voltage oscillations. The neutral-point voltage oscillations are considerably reduced by adding a time offset to the three-phase turn-on times. The proper time offset is simply calculated considering the phase currents and dwell...

Challenges to the development of vaccines to hepatitis C virus that elicit neutralizing antibodies.

Directory of Open Access Journals (Sweden)

Heidi Edelgard Drummer

2014-07-01

Full Text Available Despite 20 years of research, a vaccine to prevent hepatitis C virus (HCV infection has not been developed. A vaccine to prevent HCV will need to induce broadly reactive immunity able to prevent infection by the 7 genetically and antigenically distinct genotypes circulating world-wide. Hepatitis C virus encodes two surface exposed glycoproteins, E1 and E2 that function as a heterodimer to mediate viral entry. Neutralizing antibodies (NAbs to both E1 and E2 have been described with the major NAb target being E2. The function of E2 is to attach virions to host cells via cell surface receptors that include, but is not limited to, the tetraspanin CD81 and scavenger receptor B class I. However, E2 has developed a number of immune evasion strategies to limit the effectiveness of the NAb response and possibly limit the ability of the immune system to generate potent NAbs in natural infection. Hypervariable regions that shield the underlying core domain, subdominant neutralization epitopes and glycan shielding combine to make E2 a difficult target for the immune system. This review summarizes recent information on the role of neutralizing antibodies to prevent HCV infection, the targets of the neutralizing antibody response and structural information on glycoprotein E2 in complex with neutralizing antibodies. This new information should provide a framework for the rational design of new vaccine candidates that elicit highly potent broadly reactive NAbs to prevent HCV infection.

Wafer-scale micro-optics fabrication

Science.gov (United States)

Voelkel, Reinhard

2012-07-01

Micro-optics is an indispensable key enabling technology for many products and applications today. Probably the most prestigious examples are the diffractive light shaping elements used in high-end DUV lithography steppers. Highly-efficient refractive and diffractive micro-optical elements are used for precise beam and pupil shaping. Micro-optics had a major impact on the reduction of aberrations and diffraction effects in projection lithography, allowing a resolution enhancement from 250 nm to 45 nm within the past decade. Micro-optics also plays a decisive role in medical devices (endoscopes, ophthalmology), in all laser-based devices and fiber communication networks, bringing high-speed internet to our homes. Even our modern smart phones contain a variety of micro-optical elements. For example, LED flash light shaping elements, the secondary camera, ambient light and proximity sensors. Wherever light is involved, micro-optics offers the chance to further miniaturize a device, to improve its performance, or to reduce manufacturing and packaging costs. Wafer-scale micro-optics fabrication is based on technology established by the semiconductor industry. Thousands of components are fabricated in parallel on a wafer. This review paper recapitulates major steps and inventions in wafer-scale micro-optics technology. The state-of-the-art of fabrication, testing and packaging technology is summarized.

Neutrality in mediation: an ambiguous ethical value

OpenAIRE

Bailey, Paul

2014-01-01

Mediator neutrality would appear, by definition, to be a necessary and required ethical principle for all mediators to practice. But what is meant by neutrality in mediation? Is it practically possible to be completely neutral between parties in mediation while at the same time being fair to both of them? This paper attempts to answer these two questions.

Neutral-beam development plan, FY 1982-1987

International Nuclear Information System (INIS)

1981-09-01

The following chapters are included: (1) status of BNL negative ion source development, (2) source development program plan, (3) status of beam transport and acceleration, (4) accelerator development program plan, (5) neutralizer concepts, (6) neutralization program plan, (7) neutral beam systems, (8) test facilities, (9) program milestones and time schedules, (10) organization and Grumman participation, and (11) funding tables

ITER neutral beam system US conceptual design

International Nuclear Information System (INIS)

Purgalis, P.

1990-09-01

In this document we present the US conceptual design of a neutral beam system for International Thermonuclear Experimental Reactor (ITER). The design incorporates a barium surface conversion D - source feeding a linear array of accelerator channels. The system uses a dc accelerator with electrostatic quadrupoles for strong focusing. A high voltage power supply that is integrated with the accelerator is presented as an attractive option. A gas neutralizer is used and residual ions exiting the neutralizer are deflected to water-cooled dumps. Cryopanels are located at the accelerator exit to pump excess gas from the source and the neutralizer, and in the ion dump cavity to pump re-neutralized ions and neutralizer gas. All the above components are packaged in compact identical, independent modules which can be removed for remote maintenance. The neutral beam system delivers 75 MW of DO at 1.3 MeV, into three ports with a total of 9 modules arranged in stacks of three modules per port . To increase reliability each module is designed to deliver up to 10 MW; this allows eight modules operating at partial capacity to deliver the required power in the event one module is out of service, and provides 20% excess capacity to improve availability. Radiation protection is provided by shielding and by locating critical components in the source and accelerator 46.5 m from the torus centerline. Neutron shielding in the drift duct and neutralizer provides the added feature of limiting conductance and thus reducing gas flow to and from the torus

Structures of phlebovirus glycoprotein Gn and identification of a neutralizing antibody epitope.

Science.gov (United States)

Wu, Yan; Zhu, Yaohua; Gao, Feng; Jiao, Yongjun; Oladejo, Babayemi O; Chai, Yan; Bi, Yuhai; Lu, Shan; Dong, Mengqiu; Zhang, Chang; Huang, Guangmei; Wong, Gary; Li, Na; Zhang, Yanfang; Li, Yan; Feng, Wen-Hai; Shi, Yi; Liang, Mifang; Zhang, Rongguang; Qi, Jianxun; Gao, George F

2017-09-05

Severe fever with thrombocytopenia syndrome virus (SFTSV) and Rift Valley fever virus (RVFV) are two arthropod-borne phleboviruses in the Bunyaviridae family, which cause severe illness in humans and animals. Glycoprotein N (Gn) is one of the envelope proteins on the virus surface and is a major antigenic component. Despite its importance for virus entry and fusion, the molecular features of the phleboviruse Gn were unknown. Here, we present the crystal structures of the Gn head domain from both SFTSV and RVFV, which display a similar compact triangular shape overall, while the three subdomains (domains I, II, and III) making up the Gn head display different arrangements. Ten cysteines in the Gn stem region are conserved among phleboviruses, four of which are responsible for Gn dimerization, as revealed in this study, and they are highly conserved for all members in Bunyaviridae Therefore, we propose an anchoring mode on the viral surface. The complex structure of the SFTSV Gn head and human neutralizing antibody MAb 4-5 reveals that helices α6 in subdomain III is the key component for neutralization. Importantly, the structure indicates that domain III is an ideal region recognized by specific neutralizing antibodies, while domain II is probably recognized by broadly neutralizing antibodies. Collectively, Gn is a desirable vaccine target, and our data provide a molecular basis for the rational design of vaccines against the diseases caused by phleboviruses and a model for bunyavirus Gn embedding on the viral surface.

Output power characteristics of the neutral xenon long laser

Energy Technology Data Exchange (ETDEWEB)

Linford, G.J. [TRW Space and Electronics Group, Redondo Beach, CA (United States). Space and Technology Div.

1994-12-31

Lasers which oscillate within inhomogeneously broadened gain media exhibit spectral hole burning and concomitant reduction in output power compared with equivalent homogeneously-broadened laser gain media. By increasing the cavity length, it may be possible to demonstrate at least a partial transition from an inhomogeneous laser cavity mode spectrum to a homogeneous spectrum. There are a number of high gain laser lines which are inhomogeneously-broadened transitions in electric discharges of neutral xenon. In neutral xenon lasers, as in the cases of many other gas lasers, the inhomogeneous spectral broadening mechanism arises from Doppler shifts, {Delta}{nu}{sub D}, of individual atoms in thermal motion within the electric discharge comprising the laser gain medium. Optical transitions corresponding to these noble gas atoms have natural linewidths, {Delta}{nu}{sub n}{lt}{Delta}{nu}{sub D}. Simulations of the output power characteristics of the xenon laser were carried out as a function of laser cavity parameters, including the cavity length, L. These calculations showed that when the intracavity mode spacing frequency, c/2L{lt}{Delta}{nu}{sub n}, the inhomogeneously broadened xenon mode spectrum converted to a homogeneously broadened oscillation spectrum with an increase in output power. These simulations are compared with experimental results obtained for the long laser oscillation characteristics of the (5d[5/2]{degree}{sub 2}{r_arrow}6p[3/2]{sub 1}) transition corresponding to the strong, high-gain 3.508 {mu} line in xenon.

Entangling two transportable neutral atoms via local spin exchange.

Science.gov (United States)

Kaufman, A M; Lester, B J; Foss-Feig, M; Wall, M L; Rey, A M; Regal, C A

2015-11-12

To advance quantum information science, physical systems are sought that meet the stringent requirements for creating and preserving quantum entanglement. In atomic physics, robust two-qubit entanglement is typically achieved by strong, long-range interactions in the form of either Coulomb interactions between ions or dipolar interactions between Rydberg atoms. Although such interactions allow fast quantum gates, the interacting atoms must overcome the associated coupling to the environment and cross-talk among qubits. Local interactions, such as those requiring substantial wavefunction overlap, can alleviate these detrimental effects; however, such interactions present a new challenge: to distribute entanglement, qubits must be transported, merged for interaction, and then isolated for storage and subsequent operations. Here we show how, using a mobile optical tweezer, it is possible to prepare and locally entangle two ultracold neutral atoms, and then separate them while preserving their entanglement. Ground-state neutral atom experiments have measured dynamics consistent with spin entanglement, and have detected entanglement with macroscopic observables; we are now able to demonstrate position-resolved two-particle coherence via application of a local gradient and parity measurements. This new entanglement-verification protocol could be applied to arbitrary spin-entangled states of spatially separated atoms. The local entangling operation is achieved via spin-exchange interactions, and quantum tunnelling is used to combine and separate atoms. These techniques provide a framework for dynamically entangling remote qubits via local operations within a large-scale quantum register.

Active ion temperature measurement with heating neutral beam

International Nuclear Information System (INIS)

Miura, Yukitoshi; Matsuda, Toshiaki; Yamamoto, Shin

1987-03-01

When the heating neutral-beam (hydrogen beam) is injected into a deuterium plasma, the density of neutral particles is increased locally. By using this increased neutral particles, the local ion temperature is measured by the active charge-exchange method. The analyzer is the E//B type mass-separated neutral particle energy analyzer and the measured position is about one third outside of the plasma radius. The deuterium energy spectrum is Maxwellian, and the temperature is increased from 350 eV to 900 eV during heating. Since the local hydrogen to deuterium density concentration and the density of the heating neutral-beam as well as the ion temperature can be obtained good S/N ratio, the usefulness of this method during neutral-beam heating is confirmed by this experiment. (author)

Lack of protection following passive transfer of polyclonal highly functional low-dose non-neutralizing antibodies.

Directory of Open Access Journals (Sweden)

Anne-Sophie Dugast

Full Text Available Recent immune correlates analysis from the RV144 vaccine trial has renewed interest in the role of non-neutralizing antibodies in mediating protection from infection. While neutralizing antibodies have proven difficult to induce through vaccination, extra-neutralizing antibodies, such as those that mediate antibody-dependent cellular cytotoxicity (ADCC, are associated with long-term control of infection. However, while several non-neutralizing monoclonal antibodies have been tested for their protective efficacy in vivo, no studies to date have tested the protective activity of naturally produced polyclonal antibodies from individuals harboring potent ADCC activity. Because ADCC-inducing antibodies are highly enriched in elite controllers (EC, we passively transferred highly functional non-neutralizing polyclonal antibodies, purified from an EC, to assess the potential impact of polyclonal non-neutralizing antibodies on a stringent SHIV-SF162P3 challenge in rhesus monkeys. Passive transfer of a low-dose of ADCC inducing antibodies did not protect from infection following SHIV-SF162P3 challenge. Passively administered antibody titers and gp120-specific, but not gp41-specific, ADCC and antibody induced phagocytosis (ADCP were detected in the majority of the monkeys, but did not correlate with post infection viral control. Thus these data raise the possibility that gp120-specific ADCC activity alone may not be sufficient to control viremia post infection but that other specificities or Fc-effector profiles, alone or in combination, may have an impact on viral control and should be tested in future passive transfer experiments.

Kinetics of neutralization of Po-218

International Nuclear Information System (INIS)

Chu, K.D.

1987-01-01

In a well-defined experimental system the neutralization of polonium-218 ions was investigated as a function of the physical and chemical properties of the controlled composition atmosphere. The mobilities of Po + and PoO 2 + are determined by combining experimental results with a computer model of the system. Three neutralization mechanisms were individually studied. The small ion recombination rate has been found to be proportional to the square root of radon concentration. The electron scavenging mechanism is responsible for the neutralization of Po + in NO 2 or H 2 O in nitrogen. When PoO 2 + is formed, the electron transfer mechanism dominates the neutralization process. The electron is transferred to PoO 2 + from molecules with lower ionization potentials. The ionization potential of PoO 2 + is also determined to be 10.44 +/- 0.05 eV

Neutral signature Walker-VSI metrics

International Nuclear Information System (INIS)

Coley, A; McNutt, D; Musoke, N; Brooks, D; Hervik, S

2014-01-01

We will construct explicit examples of four-dimensional neutral signature Walker (but not necessarily degenerate Kundt) spaces for which all of the polynomial scalar curvature invariants vanish. We then investigate the properties of some particular subclasses of Ricci flat spaces. We also briefly describe some four-dimensional neutral signature Einstein spaces for which all of the polynomial scalar curvature invariants are constant. (paper)

Criticality in the fabrication of ion extraction system for SST-1 neutral beam injector

International Nuclear Information System (INIS)

Jana, M.R.; Mattoo, S.K.

2008-01-01

For the heating of plasma in steady-state superconducting tokamak (SST-1) (Y.C. Saxena, SST-1 Team, Present status of the SST-1 project, Nucl. Fusion 40 (2000) 1069-1082; D. Bora, SST-1 Team, Test results on systems developed for the SST-1 tokamak, Nucl. Fusion 43 (2003) 1748-1758), a neutral beam injector is provided to raise the ion temperature to ∼1 keV. This injector has a capability of injecting hydrogen beam with the power of 0.5 MW at 30 keV. For the upgrade of SST-1, power of 1.7 MW at 55 KeV is required. Further, beam power is to be provided for a pulse length of 1000S. We have designed a neutral beam injector (S.K. Mattoo, A.K. Chakraborty, U.K. Baruah, P.K. Jayakumar, M. Bandyopadhyay, N. Bisai, Ch. Chakrapani, M.R. Jana, R. Onali, V. Prahlad, P.J. Patel, G.B. Patel, B. Prajapati, N.V.M. Rao, S. Rambabu, C. Rotti, S.K. Sharma, S. Shah, V. Sharma, M.J. Singh, Engineering design of the steady-state neutral beam injector for SST-1, Fusion Eng. Des. 56 (2001) 685-691; A.K. Chakraborty, N. Bisai, M.R. Jana, P.K. Jayakumar, U.K. Baruah, P.J. Patel, K. Rajasekar, S.K. Mattoo, Neutral beam injector for steady-state superconducting tokamak, Fusion Technol. (1996) 657-660; P.K. Jayakumar, M.R. Jana, N. Bisai, M. Bajpai, N.P. Singh, U.K. Baruah, A.K. Chakraborty, M. Bandyopadhyay, C. Chrakrapani, D. Patel, G.B. Patel, P. Patel, V. Prahlad, N.V.M. Rao, C. Rotti, V. Sreedhar, S.K. Mattoo, Engineering issues of a 1000S neutral beam ion source, Fusion Technol. 1 (1998) 419-422) satisfying the requirements for both SST-1 and its upgrade. Since intense power is to be transported to SST-1 situated at a distance of several meters from the ion source, the optical quality of the beam becomes a primary concern. This in turn, is determined by the uniformity of the ion source plasma and the extractor geometry. To obtain the desired optical quality of the beam, stringent tolerances are to be met during the fabrication of ion extractor system. SST-1 neutral beam injector is

Neutral hydrogen and spiral structure in M33

International Nuclear Information System (INIS)

Newton, K.

1980-01-01

Observations of neutral hydrogen (H I) in the galaxy M33 are presented which have sufficient angular resolution (47 x 93 arcsec) to distinguish detailed H I spiral structure for the first time. H I spiral features extend over the entire disc; the pattern is broken and multi-armed with the best-defined arms lying at radii outside the brightest optical features. Several very narrow spiral 'filaments' are unresolved by the beam, implying true widths -1 , is perturbed near the inner spiral arms. These perturbations agree with the predictions of density-wave theory but may simply arise from the self-gravity of massive arms whether or not they are a quasi-stationary wave phenomenon. If the outer spiral features form a rigidly rotating density-wave pattern, the absence of large radial streaming motions along the features implies a small pattern speed ( -1 kpc -1 ), with corotation in the outer parts of the disc. (author)

Fast Neutral Pressure Measurements in NSTX

International Nuclear Information System (INIS)

R. Raman; H.W. Kugel; T. Provost; R. Gernhardt; T.R. Jarboe; M.G. Bell

2002-01-01

Several fast neutral pressure gauges have been installed on NSTX [National Spherical Torus Experiment] to measure the vessel and divertor pressure during inductive and coaxial helicity injected (CHI) plasma operations. Modified, PDX [Poloidal Divertor Experiment]-type Penning gauges have been installed on the upper and lower divertors. Neutral pressure measurements during plasma operations from these and from two shielded fast Micro ion gauges at different toroidal locations on the vessel mid-plane are described. A new unshielded ion gauge, referred to as the In-vessel Neutral Pressure (INP) gauge is under development

A large neutral fraction of cosmic hydrogen a billion years after the Big Bang.

Science.gov (United States)

Wyithe, J Stuart B; Loeb, Abraham

2004-02-26

The fraction of ionized hydrogen left over from the Big Bang provides evidence for the time of formation of the first stars and quasar black holes in the early Universe; such objects provide the high-energy photons necessary to ionize hydrogen. Spectra of the two most distant known quasars show nearly complete absorption of photons with wavelengths shorter than the Lyman alpha transition of neutral hydrogen, indicating that hydrogen in the intergalactic medium (IGM) had not been completely ionized at a redshift of z approximately 6.3, about one billion years after the Big Bang. Here we show that the IGM surrounding these quasars had a neutral hydrogen fraction of tens of per cent before the quasar activity started, much higher than the previous lower limits of approximately 0.1 per cent. Our results, when combined with the recent inference of a large cumulative optical depth to electron scattering after cosmological recombination therefore suggest the presence of a second peak in the mean ionization history of the Universe.

Edge momentum transport by neutrals: an interpretive numerical framework

Science.gov (United States)

Omotani, J. T.; Newton, S. L.; Pusztai, I.; Viezzer, E.; Fülöp, T.; The ASDEX Upgrade Team

2017-06-01

Due to their high cross-field mobility, neutrals can contribute to momentum transport even at the low relative densities found inside the separatrix and they can generate intrinsic rotation. We use a charge-exchange dominated solution to the neutral kinetic equation, coupled to neoclassical ions, to evaluate the momentum transport due to neutrals. Numerical solutions to the drift-kinetic equation allow us to cover the full range of collisionality, including the intermediate levels typical of the tokamak edge. In the edge there are several processes likely to contribute to momentum transport in addition to neutrals. Therefore, we present here an interpretive framework that can evaluate the momentum transport through neutrals based on radial plasma profiles. We demonstrate its application by analysing the neutral angular momentum flux for an L-mode discharge in the ASDEX Upgrade tokamak. The magnitudes of the angular momentum fluxes we find here due to neutrals of 0.6-2 \\text{N} \\text{m} are comparable to the net torque on the plasma from neutral beam injection, indicating the importance of neutrals for rotation in the edge.

Neutralization of wastewater from nitrite passivation

International Nuclear Information System (INIS)

Pawlowski, L.; Mientki, B.; Wasag, H.

1982-01-01

A method for neutralization of wastewater formed in nitrite passivation has been presented. The method consists of introducing urea into wastewater and acidifying it with sulphuric acid. Wastewater is neutralized with lime. After clarification, wastewater can be drained outside the plant

Effect of neutral atoms on tokamak edge plasmas

International Nuclear Information System (INIS)

Fueloep, T.; Catto, Peter J.; Helander, P.

2001-01-01

Neutral atoms can significantly influence the physics of tokamak edge plasmas, e.g., by affecting the radial electric field and plasma flow there, which may, in turn, be important for plasma confinement. Earlier work [Fueloep et al., Phys. Plasmas 5, 3969 (1998)], assuming short mean-free path neutrals and Pfirsch-Schlueter ions, has shown that the ion-neutral coupling through charge-exchange affects the neoclassical flow velocity significantly. However, the mean-free path of the neutrals is not always small in comparison with the radial scale length of densities and temperatures in the edge pedestal. It is therefore desirable to determine what happens in the limit when the neutral mean-free path is comparable with the scale length. In the present work a self-similar solution for the neutral distribution function allowing for strong temperature and density variation is used, following the analysis of Helander and Krasheninnikov [Phys. Plasmas 3, 226 (1995)]. The self-similar solution is possible if the ratio of the mean-free path to the temperature and density scale length is constant throughout the edge plasma. The resulting neutral distribution function is used to investigate the neutral effects on the ion flow and electrostatic potential as this ratio varies from much less than one to order unity

The value of Network Neutrality for the Internet of Tomorrow : Report of the Dynamic Coalition on Network Neutrality

OpenAIRE

Belli , Luca; De Filippi , Primavera

2013-01-01

The report explores some of the most crucial facets of Network Neutrality, underscoring its close relationship with the full enjoyment of end-users fundamental rights. The report also includes a proposal for a Model Framework on Network Neutrality that has been elaborated by the Dynamic Coalition through an open, inclusive and multi-stakeholder effort, in order to promote an efficient safeguard of the Net Neutrality principle in accordance with international human rights standards.

High energy laser optics manufacturing: a preliminary study

International Nuclear Information System (INIS)

Baird, E.D.

1980-07-01

This report presents concepts and methods, major conclusions, and major recommendations concerning the fabrication of high energy laser optics (HELO) that are to be machined by the Large Optics Diamond Turning Machine (LODTM) at the Lawrence Livermore National Laboratory (LLNL). Detailed discussions of concepts and methods proposed for metrological operations, polishing of reflective surfaces, mounting of optical components, construction of mirror substrates, and applications of coatings are included

Recent DIII-D neutral beam calibration results

International Nuclear Information System (INIS)

Wight, J.; Hong, R.M.; Phillips, J.

1991-10-01

Injected DIII-D neutral beam power is estimated based on three principle quantities: the fraction of ion beam that is neutralized in the neutralizer gas cell, the beamline transmission efficiency, and the fraction of beam reionized in the drift duct. System changes in the past few years have included a new gradient grid voltage operating point, ion source arc regulation, routine deuterium operations and new neutralizer gas flow controllers. Additionally, beam diagnostics have been improved and better calibrated. To properly characterize the beams the principle quantities have been re-measured. Two diagnostics are primarily used to measure the quantities. The beamline waterflow calorimetry system measures the neutralization efficiency and the beamline transmission efficiency, and the target tile thermocouples measure the reionization loss. An additional diagnostic, the target tile pyrometer, confirmed the reionization loss measurement. Descriptions and results of these measurements will be presented. 4 refs., 5 figs., 2 tabs

Transnasal Endoscopic Optic Nerve Decompression in Post Traumatic Optic Neuropathy.

Science.gov (United States)

Gupta, Devang; Gadodia, Monica

2018-03-01

To quantify the successful outcome in patients following optic nerve decompression in post traumatic unilateral optic neuropathy in form of improvement in visual acuity. A prospective study was carried out over a period of 5 years (January 2011 to June 2016) at civil hospital Ahmedabad. Total 20 patients were selected with optic neuropathy including patients with direct and indirect trauma to unilateral optic nerve, not responding to conservative management, leading to optic neuropathy and subsequent impairment in vision and blindness. Decompression was done via Transnasal-Ethmo-sphenoidal route and outcome was assessed in form of post-operative visual acuity improvement at 1 month, 6 months and 1 year follow up. After surgical decompression complete recovery of visual acuity was achieved in 16 (80%) patients and partial recovery in 4 (20%). Endoscopic transnasal approach is beneficial in traumatic optic neuropathy not responding to steroid therapy and can prevent permanent disability if earlier intervention is done prior to irreversible damage to the nerve. Endoscopic optic nerve surgery can decompress the traumatic and oedematous optic nerve with proper exposure of orbital apex and optic canal without any major intracranial, intraorbital and transnasal complications.

Rheological evaluation of simulated neutralized current acid waste - transuranics

International Nuclear Information System (INIS)

Fow, C.L.; McCarthy, D.; Thornton, G.T.; Scott, P.A.; Bray, L.A.

1986-09-01

At the Hanford Plutonium and Uranium Extraction Plant (PUREX), in Richland, Washington, plutonium and uranium products are recovered from irradiated fuel by a solvent extraction process. A byproduct of this process is an aqueous waste stream that contains fission products. This waste stream, called current acid waste (CAW), is chemically neutralized and stored in double shell tanks (DSTs) on the Hanford Site. This neutralized current acid waste (NCAW) will be transported by pipe to B-Plant, a processing plant located nearby. In B-Plant, the transuranic (TRU) elements in NCAW are separated from the non-TRU elements. The majority of the TRU elements in NCAW are in the solids. Therefore, the primary processing operation is to separate the NCAW solids (NCAW-TRU) from the NCAW liquid. These two waste streams will be pumped to suitable holding tanks before being further processed for permanent disposal. To ensure that the retrieval and transportation of NCAW and NCAW-TRU are successful, researchers at Pacific Northwest Laboratory (PNL) evaluated the rheological and transport properties of the slurries. This evaluation had two phases. First, researchers conducted laboratory rheological evaluations of simulated NCAW and NCAW-TRU. The results of these evaluations were then correlated with classical rheological models and scaled up to predict the performance that is likely to occur in the full-scale system. This scale-up procedure has already been successfully used to predict the critical transport properties of a slurry (Neutralized Cladding Removal Waste) with rheological properties similar to those displayed by NCAW and NCAW-TRU

Negative ion based neutral beams for plasma heating

International Nuclear Information System (INIS)

Prelec, K.

1978-01-01

Neutral beam systems based on negative ions have been considered because of a high expected power efficiency. Methods for the production, acceleration and neutralization of negative ions will be reviewed and possibilities for an application in neutral beam lines explored

The electronic and optical properties of amorphous silica with hydrogen defects by ab initio calculations

Science.gov (United States)

Ren, Dahua; Xiang, Baoyan; Hu, Cheng; Qian, Kai; Cheng, Xinlu

2018-04-01

Hydrogen can be trapped in the bulk materials in four forms: interstitial molecular H2, interstitial atom H, O‑H+(2Si=O–H)+, Si‑H‑( {{4O}}\\bar \\equiv {{Si&x2212H}})‑ to affect the electronic and optical properties of amorphous silica. Therefore, the electronic and optical properties of defect-free and hydrogen defects in amorphous silica were performed within the scheme of density functional theory. Initially, the negative charged states hydrogen defects introduced new defect level between the valence band top and conduction band bottom. However, the neutral and positive charged state hydrogen defects made both the valence band and conduction band transfer to the lower energy. Subsequently, the optical properties such as absorption spectra, conductivity and loss functions were analyzed. It is indicated that the negative hydrogen defects caused the absorption peak ranging from 0 to 2.0 eV while the positive states produced absorption peaks at lower energy and two strong absorption peaks arose at 6.9 and 9.0 eV. However, the neutral hydrogen defects just improved the intensity of absorption spectrum. This may give insights into understanding the mechanism of laser-induced damage for optical materials. Project supported by the Science and Technology of Hubei Provincial Department of Education (No. B2017098).

Targets for high power neutral beams

International Nuclear Information System (INIS)

Kim, J.

1980-01-01

Stopping high-power, long-pulse beams is fast becoming an engineering challenge, particularly in neutral beam injectors for heating magnetically confined plasmas. A brief review of neutral beam target technology is presented along with heat transfer calculations for some selected target designs

Neutralizing antibodies against two HIV-1 strains in consecutively collected serum samples: cross neutralization and association to HIV-1 related disease

DEFF Research Database (Denmark)

Arendrup, M; Nielsen, C M; Hansen, J E

1992-01-01

97 sera collected during a 10-year period from 10 HIV-1 infected individuals were tested for neutralizing capacity against a virus isolate FICPH-22 obtained from a Danish AIDS patient, and the laboratory strain HTLV-IIIB. Three patterns of serum neutralizing activity were demonstrated: (a) patients...... developing high neutralizing activity against both HIV strains; (b) patients developing high neutralizing activity against the Danish virus isolate; and (c) patients developing only low titers of neutralizing antibodies (NA) against both HIV strains. The HTLV-IIIB strain was less sensitive to serum...... neutralization than the FICPH-22 isolate and the appearance of NA against HTLV-IIIB was typically lacking several years behind that against FICPH-22 indicating a broadening of the NA response over time. No difference in clinical outcome was observed comparing patients reaching high titers of NA and patients...

Improved numerical calculation of the generation of a neutral beam by charge transfer between chlorine ions/neutrals and a graphite surface

International Nuclear Information System (INIS)

Kubota, Tomohiro; Samukawa, Seiji; Watanabe, Naoki; Ohtsuka, Shingo; Iwasaki, Takuya; Ono, Kohei; Iriye, Yasuroh

2014-01-01

The charge transfer process between chlorine particles (ions or neutrals) and a graphite surface on collision was investigated by using a highly stable numerical simulator based on time-dependent density functional theory to understand the generation mechanism of a high-efficiency neutral beam developed by Samukawa et al (2001 Japan. J. Appl. Phys. 40 L779). A straightforward calculation was achieved by adopting a large enough unit cell. The dependence of the neutralization efficiency on the incident energy of the particle was investigated, and the trend of the experimental result was reproduced. It was also found that doping the electrons and holes into graphite could change the charge transfer process and neutralization probability. This result suggests that it is possible to develop a neutral beam source that has high neutralization efficiency for both positive and negative ions. (paper)

Optical observations on the CRIT-II Critical Ionization Velocity Experiment

International Nuclear Information System (INIS)

Stenbaek-Nielsen, H.C.; Wescott, E.M.; Haerendel, G.; Valenzuela, A.

1990-01-01

A rocket borne Critical Ionization Velocity (CIV) experiment was carried out from Wallops Island at dusk on May 4, 1989. Two barium shaped charges were released below the solar terminator (to prevent photoionization) at altitudes near 400 km. The ambient ionospheric electron density was 5x10 5 cm -3 . The neutral barium jet was directed upwards and at an angle of nominally 45 degrees to B which gives approximately 3x10 23 neutrals with super critical velocity. Ions created by a CIV process in the region of the neutral jet would travel up along B into sunlight where they can be detected optically. Well defined ion clouds (max. brightness 750 R) were observed in both releases. An ionization rate of 0.8%s -1 (125s ionization time constant) can account for the observed ion cloud near the release field line, but the ionization rate falls off with increasing distance from the release. It is concluded that a CIV process was present in the neutral jet out to about 50 km from the release, which is significantly further than allowed by current theories

Characteristics of a long-pulse (30-s), high-power (4-MW) ion source for neutral beam injection

International Nuclear Information System (INIS)

Menon, M.M.; Barber, G.C.; Combs, S.K.

1983-01-01

A quasi-steady-state ion source has been developed for neutral beam injection applications. It is of the duoPIGatron type designed for delivering 50 A of hydrogen ions at 80 keV for 30-s-long pulses. Ion beams of 40 A at 75 keV were extracted for pulse lengths up to 30 s, maintaining excellent optical quality in the beam for the entire pulse duration. The design features and operational characteristics of the ion source are elaborated

Precision-analog fiber-optic transmission system

International Nuclear Information System (INIS)

Stover, G.

1981-06-01

This article describes the design, experimental development, and construction of a DC-coupled precision analog fiber optic link. Topics to be covered include overall electrical and mechanical system parameters, basic circuit organization, modulation format, optical system design, optical receiver circuit analysis, and the experimental verification of the major design parameters

Catching Attention in Fiber Optics Class

OpenAIRE

Kezerashvili, R. Ya.; Leng, L.

2004-01-01

Following a brief review on the history and the current development of fiber optics, the significance of teaching fiber optics for science and non-science major college students is addressed. Several experimental demonstrations designed to aid the teaching and learning process in fiber optics lectures are presented. Sample laboratory projects are also proposed to help the students to understand the physical principles of fiber optics.

Mechanical design criteria for continuously operating neutral beams

International Nuclear Information System (INIS)

Vosen, S.R.; Bender, D.J.; Fink, J.H.; Lee, J.D.

1977-01-01

A schematic of a neutral beam injector is shown. Neutral gas is injected into the ion source, where a discharge ionizes the gas. The ions are drawn from the source by an extractor grid and then accelerated to full energy by the accel grids. After acceleration the ions pass through the neutralizer cell. Once through the neutralizer cell, the beam consists of neutrals and ions. The ions traveling with the beam are space charge neutralized by background electrons. The grid which precedes the direct converter is negatively charged and acts to separate the electrons from the rest of the beam. As a result of the beam's uncompensated space charge the remaining ions spread out from the beam to be collected at the direct converter. This paper presents a generalized analysis which will be useful in determining effects of energy and particle fluxes on the long-term performance of the grids

Sputtering of neutral and ionic indium clusters

International Nuclear Information System (INIS)

Ma, Z.; Coon, S.R.; Calaway, W.F.; Pellin, M.J.; Gruen, D.M.; Von Nagy-Felsobuki, E.I.

1993-01-01

Secondary neutral and secondary ion cluster yields were measured during the sputtering of a polycrystalline indium surface by normally incident ∼4 keV Ar + ions. In the secondary neutral mass spectra, indium clusters as large as In 32 were observed. In the secondary ion mass spectra, indium clusters up to In 18 + were recorded. Cluster yields obtained from both the neutral and ion channel exhibited a power law dependence on the number of constituent atoms, n, in the cluster, with the exponents measured to be -5.6 and -4. 1, respectively. An abundance drop was observed at n=8, 15, and 16 in both the neutral and ion yield distributions suggesting that the stability of the ion (either secondary ion or photoion) plays a significant role in the observed distributions. In addition, our experiments suggest that unimolecular decomposition of the neutral cluster may also plays an important role in the measured yield distributions

Mode and sawtooth behaviour during neutral beam injection in the W VII-A stellarator

International Nuclear Information System (INIS)

Grieger, G.; Renner, H.; Sapper, J.; Wobig, H.; Dorst, D.; Cattanei, G.; Javel, P.; Rau, F.; Zippe, M.; Jaeckel, H.

1980-02-01

The mode behaviour during Neutral Beam Injection in the WENDELSTEIN VII-A stellarator is presented. The analysis is mainly relying on soft X-ray measurements. Two types of discharges were found during Neutral Beam Injection with plasma currents >= 20 kA. The first type is dominated by large, regular and long sawteeth, which are caused by a (m,n) = (1,1) mode. In the second type the sawteeth disappear completely. Later in the discharge a local disruption causes a transition to the first type; this disruption has a (3,2) mode precursor. A new mode (2,2) is found and phase coupled to the (3,2) mode. Even at a high external rotational transform (t 0 = 0.23) a large (2,1) mode is found after the (3,2) mode has caused the local disruption. At slightly lower external rotational transform values major current disruptions may even occur. This is mainly due to the enhanced edge heating by the Neutral Beam Injection. Results of simulations of the mode structures are also presendet. (orig./GG)

Inhibition of Neutral Red Photolysis with Different Antioxidants

Directory of Open Access Journals (Sweden)

Zlatan Rimpapa

2007-02-01

Full Text Available Neutral red is a dye the azine structure which has been used as an acido-base indicator and a dye in histochemistry. In 1960 Goldhaber introduced Neutral red into the medium of resorbing bone cultures to localize the osteoclast in the living cultures. Using time-lapse microcinematography in order to follow the osteoclasts, he reported excellent contrast could be obtained with Neutral red due to the avidity of osteoclasts for this dye. Unfortunately, however, the photodynamic effect resulting from subsequent exposure of these cultures to light precluded this approach, and again in 1963. it was observed that the death of the osteoclasts was probably due to a photodynamic effect related to the dye in the cell, the presence of oxygen and the frequent exposure of light by our time-lapse photography. VIS and UV irradiation induced photolysis of Neutral red, and from Neutral red cation produced with photons a Neutral red radical. This Neutral red radical can be inhibited with action of an antioxidant, such as melatonin, glutathione, ascorbic acid, E vitamin, etc. We developed an assay with Neutral redphotolysis which utilizes a VIS and UV irradiation technique for quantification the inhibition of photolysis with action of an antioxidant. In this method Neutral red acts double, as a free radical generator and as a photosensitizer.

Soviet exoatmospheric neutral particle beam research

International Nuclear Information System (INIS)

Leiss, J.E.; Abrams, R.H.; Ehlers, K.W.; Farrell, J.A.; Gillespie, G.H.; Jameson, R.A.; Keefe, D.; Parker, R.K.

1988-02-01

This technical assessment was performed by a panel of eight U.S. scientists and engineers who are familiar with Soviet research through their own research experience, their knowledge of the published scientific literature and conference proceedings, and personal contacts with Soviet scientists and other foreign colleagues. Most of the technical components of a neutral particle beam generating system including the ion source, the accelerator, the accelerator radio frequency power supply, the beam conditioning and aiming system, and the beam neutralizer system are addressed. It does not address a number of other areas important to an exoatmospheric neutral beam system

Optical fiber communications

CERN Document Server

Keiser, Gerd

2008-01-01

The fourth edition of this popular text and reference book presents the fundamental principles for understanding and applying optical fiber technology to sophisticated modern telecommunication systems. Optical-fiber-based telecommunication networks have become a major information-transmission-system, with high capacity links encircling the globe in both terrestrial and undersea installations. Numerous passive and active optical devices within these links perform complex transmission and networking functions in the optical domain, such as signal amplification, restoration, routing, and switching. Along with the need to understand the functions of these devices comes the necessity to measure both component and network performance, and to model and stimulate the complex behavior of reliable high-capacity networks.

Solar Adaptive Optics.

Science.gov (United States)

Rimmele, Thomas R; Marino, Jose

Adaptive optics (AO) has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO) and Ground-Layer AO (GLAO) will be given. Supplementary material is available for this article at 10.12942/lrsp-2011-2.

Two dimensional neutral transport analysis in tokamak plasma

International Nuclear Information System (INIS)

Shimizu, Katsuhiro; Azumi, Masafumi

1987-02-01

Neutral particle influences the particle and energy balance, and play an important role on sputtering impurity and the charge exchange loss of neutral beam injection. In order to study neutral particle behaviour including the effects of asymmetric source and divertor configuration, the two dimensional neutral transport code has been developed using the Monte-Carlo techniques. This code includes the calculation of the H α radiation intensity based on the collisional-radiation model. The particle confinement time of the joule heated plasma in JT-60 tokamak is evaluated by comparing the calculated H α radiation intensity with the experimental data. The effect of the equilibrium on the neutral density profile in high-β plasma is also investigated. (author)

Loss Distribution Analysis of Three-Level Active Neutral-Point-Clamped (3L-ANPC) Converter with Different PWM Strategies

DEFF Research Database (Denmark)

Zhang, Gang; Yang, Yongheng; Iannuzzo, Francesco

2016-01-01

The three-level (3L) Active Neutral-Point-Clamped (ANPC) topology has been introduced to resolve the uneven loss distribution issue in the classical 3L Neutral-Point-Clamped (NPC) topology. This Pulse-Width-Modulation (PWM) strategy is then an important means to fully explore the potential benefits...... are separated in order to improve the loss distribution among the power devices. A comparison between the proposed strategy and other major PWM strategies for the loss distribution is also carried out in this paper. Benchmarking results show that the proposed strategy has effective and superior performance...

Reactivity of human sera in a sensitive, high-throughput pseudovirus-based papillomavirus neutralization assay for HPV16 and HPV18

International Nuclear Information System (INIS)

Pastrana, Diana V.; Buck, Christopher B.; Pang, Y.-Y. S.; Thompson, Cynthia D.; Castle, Philip E.; FitzGerald, Peter C.; Krueger Kjaer, Susanne; Lowy, Douglas R.; Schiller, John T.

2004-01-01

Sensitive high-throughput neutralization assays, based upon pseudoviruses carrying a secreted alkaline phosphatase (SEAP) reporter gene, were developed and validated for human papillomavirus (HPV)16, HPV18, and bovine papillomavirus 1 (BPV1). SEAP pseudoviruses were produced by transient transfection of codon-modified papillomavirus structural genes into an SV40 T antigen expressing line derived from 293 cells, yielding sufficient pseudovirus from one flask for thousands of titrations. In a 96-well plate format, in this initial characterization, the assay was reproducible and appears to be as sensitive as, but more specific than, a standard papillomavirus-like particle (VLP)-based enzyme-linked immunosorbent assay (ELISA). The neutralization assay detected type-specific HPV16 or HPV18 neutralizing antibodies (titers of 160-10240) in sera of the majority of a group of women infected with the corresponding HPV type, but not in virgin women. Sera from HPV16 VLP vaccinees had high anti-HPV16 neutralizing titers (mean: 45000; range: 5120-163840), but no anti-HPV18 neutralizing activity. The SEAP pseudovirus-based neutralization assay should be a practical method for quantifying potentially protective antibody responses in HPV natural history and prophylactic vaccine studies

Hemagglutinin-specific neutralization of subacute sclerosing panencephalitis viruses.

Directory of Open Access Journals (Sweden)

Miguel Ángel Muñoz-Alía

Full Text Available Subacute sclerosing panencephalitis (SSPE is a progressive, lethal complication of measles caused by particular mutants of measles virus (MeV that persist in the brain despite high levels of neutralizing antibodies. We addressed the hypothesis that antigenic drift is involved in the pathogenetic mechanism of SSPE by analyzing antigenic alterations in the MeV envelope hemagglutinin protein (MeV-H found in patients with SSPE in relation to major circulating MeV genotypes. To this aim, we obtained cDNA for the MeV-H gene from tissue taken at brain autopsy from 3 deceased persons with SSPE who had short (3-4 months, SMa79, average (3.5 years, SMa84, and long (18 years, SMa94 disease courses. Recombinant MeVs with a substituted MeV-H gene were generated by a reverse genetic system. Virus neutralization assays with a panel of anti-MeV-H murine monoclonal antibodies (mAbs or vaccine-immunized mouse anti-MeV-H polyclonal sera were performed to determine the antigenic relatedness. Functional and receptor-binding analysis of the SSPE MeV-H showed activity in a SLAM/nectin-4-dependent manner. Similar to our panel of wild-type viruses, our SSPE viruses showed an altered antigenic profile. Genotypes A, G3, and F (SSPE case SMa79 were the exception, with an intact antigenic structure. Genotypes D7 and F (SSPE SMa79 showed enhanced neutralization by mAbs targeting antigenic site IIa. Genotypes H1 and the recently reported D4.2 were the most antigenically altered genotypes. Epitope mapping of neutralizing mAbs BH015 and BH130 reveal a new antigenic site on MeV-H, which we designated Φ for its intermediate position between previously defined antigenic sites Ia and Ib. We conclude that SSPE-causing viruses show similar antigenic properties to currently circulating MeV genotypes. The absence of a direct correlation between antigenic changes and predisposition of a certain genotype to cause SSPE does not lend support to the proposed antigenic drift as a

Fractionation of fecal neutral steroids by high performance liquid chromatography

International Nuclear Information System (INIS)

Jackson, E.M.; Kloss, C.A.; Weintraub, S.T.; Mott, G.E.

1985-01-01

Fecal neutral steroids were fractionated by high performance liquid chromatography (HPLC) into three major fractions: 5 beta-H, 3-keto steroids; 5 beta-H, 3 beta-hydroxy steroids; and 5 alpha-H and delta 5-3 beta-hydroxy steroids. This separation was achieved in about 10 minutes, with greater than 97% recovery of standards in each fraction. Gas-liquid chromatographic quantitation of fecal steroids fractionated by either HPLC or thin-layer chromatography gave nearly identical results. A method using both C18 reverse phase and silica HPLC to purify radiolabeled sterols is also described

New insights on the collisional escape of light neutrals from Mars

Science.gov (United States)

Gacesa, Marko; Zahnle, Kevin

2017-04-01

Photodissociative recombination (PDR) of atmospheric molecules on Mars is a major mechanism of production of hot (suprathermal) atoms with sufficient kinetic energy to either directly escape to space or to eject other atmospheric species. This collisional ejection mechanism is important for evaluating the escape rates of all light neutrals that are too heavy to escape via Jeans escape. In particular, it plays a role in estimating the total volume of escaped water constituents (i.e., O and H) from Mars, as well as influences evolution of the atmospheric [D]/[H] ratio1. We present revised estimates of total collisional escape rates of neutral light elements including H, He, and H2, based on recent (years 2015-2016) atmospheric density profiles obtained from the NASA Mars Atmosphere and Volatile Evolution (MAVEN) mission. We also estimate the contribution to the collisional escape from Energetic Neutral Atoms (ENAs) produced in charge-exchange of solar wind H+ and He+ ions with atmospheric gases2,3. Scattering of hot oxygen and atmospheric species of interest is modeled using fully-quantum reactive scattering formalism1,3. The escape rates are evaluated using a 1D model of the atmosphere supplemented with MAVEN measurements of the neutrals. Finally, new estimates of contributions of these non-thermal mechanisms to the estimated PDR escape rates from young Mars4 are presented. [1] M. Gacesa and V. Kharchenko, "Non-thermal escape of molecular hydrogen from Mars", Geophys. Res. Lett., 39, L10203 (2012). [2] N. Lewkow and V. Kharchenko, "Precipitation of Energetic Neutral Atoms and Escape Fluxes induced from the Mars Atmosphere", Astroph. J., 790, 98 (2014). [3] M. Gacesa, N. Lewkow, and V. Kharchenko, "Non-thermal production and escape of OH from the upper atmosphere of Mars", Icarus 284, 90 (2017). [4] J. Zhao, F. Tian, Y. Ni, and X. Huang, "DR-induced escape of O and C from early Mars", Icarus 284, 305 (2017).

Temporal behavior of neutral particle fluxes in TFTR [Tokamak Fusion Test Reactor] neutral beam injectors

International Nuclear Information System (INIS)

Kamperschroer, J.H.; Gammel, G.M.; Roquemore, A.L.

1989-09-01

Data from an E parallel B charge exchange neutral analyzer (CENA), which views down the axis of a neutral beamline through an aperture in the target chamber calorimeter of the TFTR neutral beam test facility, exhibit two curious effects. First, there is a turn-on transient lasting tens of milliseconds having a magnitude up to three times that of the steady-state level. Second, there is a 720 Hz, up to 20% peak-to-peak fluctuation persisting the entire pulse duration. The turn-on transient occurs as the neutralizer/ion source system reaches a new pressure equilibrium following the effective ion source gas throughput reduction by particle removal as ion beam. Widths of the transient are a function of the gas throughput into the ion source, decreasing as the gas supply rate is reduced. Heating of the neutalizer gas by the beam is assumed responsible, with gas temperature increasing as gas supply rate is decreased. At low gas supply rates, the transient is primarliy due to dynamic changes in the neutralizer line density and/or beam species composition. Light emission from the drift duct corroborate the CENA data. At high gas supply rates, dynamic changes in component divergence and/or spatial profiles of the source plasma are necessary to explain the observations. The 720 Hz fluctuation is attributed to a 3% peak-to-peak ripple of 720 Hz on the arc power supply amplified by the quadratic relationship between beam divergence and beam current. Tight collimation by CENA apertures cause it to accept a very small part of the ion source's velocity space, producing a signal linearly proportional to beam divergence. Estimated fluctuations in the peak power density delivered to the plasma under these conditions are a modest 3--8% peak to peak. The efffects of both phenomena on the injected neutral beam can be ameliorated by careful operion of the ion sources. 21 refs., 11 figs., 2 tabs

Net Neutrality and Inflation of Traffic

NARCIS (Netherlands)

Peitz, M.; Schütt, F.

2015-01-01

Under strict net neutrality Internet service providers (ISPs) are required to carry data without any differentiation and at no cost to the content provider. We provide a simple framework with a monopoly ISP to evaluate different net neutrality rules. Content differs in its sensitivity to delay.

Formation and mobilization of neutral lipids in the yeast Saccharomyces cerevisiae.

Science.gov (United States)

Wagner, A; Daum, G

2005-11-01

Since energy storage is a basic metabolic process, the synthesis of neutral lipids occurs in all kingdoms of life. The yeast Saccharomyces cerevisiae, widely accepted as a model eukaryotic cell, contains two classes of neutral lipids, namely STEs (steryl esters) and TAGs (triacylglycerols). TAGs are synthesized through two pathways governed by the acyl-CoA diacylglycerol acyltransferase Dga1p and the phospholipid diacylglycerol acyltransferase Lro1p. STEs are formed by two STE synthases Are1p and Are2p, two enzymes with overlapping function, which also catalyse TAG formation, although to a minor extent. Neutral lipids are stored in the so-called lipid particles and can be utilized for membrane formation under conditions of lipid depletion. For this purpose, storage lipids have to be mobilized by TAG lipases and STE hydrolases. A TAG lipase named Tgl3p was identified as a major yeast TAG hydrolytic enzyme in lipid particles. Recently, a new family of hydrolases was detected which is required for STE mobilization in S. cerevisiae. These enzymes, named Yeh1p, Yeh2p and Tgl1p, are paralogues of the mammalian acid lipase family. The role of these proteins in biosynthesis and mobilization of TAG and STE, and the regulation of these processes will be discussed in this minireview.

A human monoclonal antibody with neutralizing activity against highly divergent influenza subtypes.

Directory of Open Access Journals (Sweden)

Nicola Clementi

Full Text Available The interest in broad-range anti-influenza A monoclonal antibodies (mAbs has recently been strengthened by the identification of anti-hemagglutinin (HA mAbs endowed with heterosubtypic neutralizing activity to be used in the design of "universal" prophylactic or therapeutic tools. However, the majority of the single mAbs described to date do not bind and neutralize viral isolates belonging to highly divergent subtypes clustering into the two different HA-based influenza phylogenetic groups: the group 1 including, among others, subtypes H1, H2, H5 and H9 and the group 2 including, among others, H3 subtype. Here, we describe a human mAb, named PN-SIA28, capable of binding and neutralizing all tested isolates belonging to phylogenetic group 1, including H1N1, H2N2, H5N1 and H9N2 subtypes and several isolates belonging to group 2, including H3N2 isolates from the first period of the 1968 pandemic. Therefore, PN-SIA28 is capable of neutralizing isolates belonging to subtypes responsible of all the reported pandemics, as well as other subtypes with pandemic potential. The region recognized by PN-SIA28 has been identified on the stem region of HA and includes residues highly conserved among the different influenza subtypes. A deep characterization of PN-SIA28 features may represent a useful help in the improvement of available anti-influenza therapeutic strategies and can provide new tools for the development of universal vaccinal strategies.

Optical computer switching network

Science.gov (United States)

Clymer, B.; Collins, S. A., Jr.

1985-01-01

The design for an optical switching system for minicomputers that uses an optical spatial light modulator such as a Hughes liquid crystal light valve is presented. The switching system is designed to connect 80 minicomputers coupled to the switching system by optical fibers. The system has two major parts: the connection system that connects the data lines by which the computers communicate via a two-dimensional optical matrix array and the control system that controls which computers are connected. The basic system, the matrix-based connecting system, and some of the optical components to be used are described. Finally, the details of the control system are given and illustrated with a discussion of timing.

ITER Neutral Beam Injection System

International Nuclear Information System (INIS)

Ohara, Yoshihiro; Tanaka, Shigeru; Akiba, Masato

1991-03-01

A Japanese design proposal of the ITER Neutral Beam Injection System (NBS) which is consistent with the ITER common design requirements is described. The injection system is required to deliver a neutral deuterium beam of 75MW at 1.3MeV to the reactor plasma and utilized not only for plasma heating but also for current drive and current profile control. The injection system is composed of 9 modules, each of which is designed so as to inject a 1.3MeV, 10MW neutral beam. The most important point in the design is that the injection system is based on the utilization of a cesium-seeded volume negative ion source which can produce an intense negative ion beam with high current density at a low source operating pressure. The design value of the source is based on the experimental values achieved at JAERI. The utilization of the cesium-seeded volume source is essential to the design of an efficient and compact neutral beam injection system which satisfies the ITER common design requirements. The critical components to realize this design are the 1.3MeV, 17A electrostatic accelerator and the high voltage DC acceleration power supply, whose performances must be demonstrated prior to the construction of ITER NBI system. (author)

Net neutrality and inflation of traffic

NARCIS (Netherlands)

Peitz, M.; Schütt, Florian

Under strict net neutrality Internet service providers (ISPs) are required to carry data without any differentiation and at no cost to the content provider. We provide a simple framework with a monopoly ISP to evaluate the short-run effects of different net neutrality rules. Content differs in its

Role of the Antigen Capture Pathway in the Induction of a Neutralizing Antibody Response to Anthrax Protective Antigen

Directory of Open Access Journals (Sweden)

Anita Verma

2018-02-01

Full Text Available Toxin neutralizing antibodies represent the major mode of protective immunity against a number of toxin-mediated bacterial diseases, including anthrax; however, the cellular mechanisms that lead to optimal neutralizing antibody responses remain ill defined. Here we show that the cellular binding pathway of anthrax protective antigen (PA, the binding component of anthrax toxin, determines the toxin neutralizing antibody response to this antigen. PA, which binds cellular receptors and efficiently enters antigen-presenting cells by receptor-mediated endocytosis, was found to elicit robust anti-PA IgG and toxin neutralizing antibody responses. In contrast, a receptor binding-deficient mutant of PA, which does not bind receptors and only inefficiently enters antigen-presenting cells by macropinocytosis, elicited very poor antibody responses. A chimeric protein consisting of the receptor binding-deficient PA mutant tethered to the binding subunit of cholera toxin, which efficiently enters cells using the cholera toxin receptor rather than the PA receptor, elicited an anti-PA IgG antibody response similar to that elicited by wild-type PA; however, the chimeric protein elicited a poor toxin neutralizing antibody response. Taken together, our results demonstrate that the antigen capture pathway can dictate the magnitudes of the total IgG and toxin neutralizing antibody responses to PA as well as the ratio of the two responses.

The effect of electro-activation and eggshell powder on the neutralization of acid mine drainage

Directory of Open Access Journals (Sweden)

Alexey Kastyuchik

2017-01-01

Full Text Available Acid mine drainage (AMD production by sulfide mine tailing (SMT is a major environmental preoccupation because it can degrade water surface quality on account of its strong acidity and advanced content of sulfide, iron (Fe and other metals and metalloids. Acid neutralization and the precipitation of metals present in AMD were carried out by electro-activation with ion-exchange membranes, which is based on the self-generation of necessary conditions for acid neutralization and metal precipitation. The treatment of SMT was carried out by using an electro-activation cell generated alkaline solution in the cathode compartment. After 60 min of electro-activation, a pHcatholyte of 7.9–9.6, depending on the experimental conditions, was obtained. The absence of Fe and other trace metal ions in the catholyte provide evidence that the electro-activation of SMT promotes the precipitation of insoluble trace metals in the cathode compartment. This approach can be applied to real conditions in combination with a pretreatment of SMT neutralization, in which biological calcareous amendments are available. Finally, the electro-activation technology of acid mine drainage may be a feasible, cost-effective approach for SMT neutralization because it focuses on sustainable development.

All-optical OXC transition strategy from WDM optical network to elastic optical network.

Science.gov (United States)

Chen, Xin; Li, Juhao; Guo, Bingli; Zhu, Paikun; Tang, Ruizhi; Chen, Zhangyuan; He, Yongqi

2016-02-22

Elastic optical network (EON) has been proposed recently as a spectrum-efficient optical layer to adapt to rapidly-increasing traffic demands instead of current deployed wavelength-division-multiplexing (WDM) optical network. In contrast with conventional WDM optical cross-connect (OXCs) based on wavelength selective switches (WSSs), the EON OXCs are based on spectrum selective switches (SSSs) which are much more expensive than WSSs, especially for large-scale switching architectures. So the transition cost from WDM OXCs to EON OXCs is a major obstacle to realizing EON. In this paper, we propose and experimentally demonstrate a transition OXC (TOXC) structure based on 2-stage cascading switching architectures, which make full use of available WSSs in current deployed WDM OXCs to reduce number and port count of required SSSs. Moreover, we propose a contention-aware spectrum allocation (CASA) scheme for EON built with the proposed TOXCs. We show by simulation that the TOXCs reduce the network capital expenditure transiting from WDM optical network to EON about 50%, with a minor traffic blocking performance degradation and about 10% accommodated traffic number detriment compared with all-SSS EON OXC architectures.

Neutral currents, supernovae neutrinos, and nucleosynthesis

International Nuclear Information System (INIS)

Haxton, W.C.

1988-01-01

The inelastic interactions of neutrinos during stellar collapse and neutron star cooling are discussed. The primary mechanism for dissipative neutrino reactions is nuclear excitation by neutral current scattering, a process not included in standard descriptions of supernovae. Charge-current and neutral current ''preheating'' of iron lying outside the shock front appears to be significant in the few milliseconds near shock breakout. This could help produce a more energetic shock. During the cooling phase, the neutral current interactions of muon and taon neutrinos appear to be responsible for some interesting nucleosynthesis. I discuss two examples the production of fluorine and neutrino-induced r-process nucleosynthesis. 26 refs., 1 fig., 3 tabs

Realistic Rashba and Dresselhaus spin-orbit coupling for neutral atoms

International Nuclear Information System (INIS)

Campbell, D. L.; Spielman, I. B.; Juzeliunas, G.

2011-01-01

We describe a new class of atom-laser coupling schemes which lead to spin-orbit-coupled Hamiltonians for ultracold neutral atoms. By properly setting the optical phases, a pair of degenerate pseudospin (a linear combination of internal atomic) states emerge as the lowest-energy eigenstates in the spectrum and are thus immune to collisionally induced decay. These schemes use N cyclically coupled ground or metastable internal states. We focus on two situations: a three-level case and a four-level case, where the latter adds a controllable Dresselhaus contribution. We describe an implementation of the four-level scheme for 87 Rb and analyze its sensitivity to typical laboratory noise sources. Last, we argue that the Rashba Hamiltonian applies only in the large intensity limit since any laser coupling scheme will produce terms nonlinear in momentum that decline with intensity.

Impact of neutral density fluctuations on gas puff imaging diagnostics

Science.gov (United States)

Wersal, C.; Ricci, P.

2017-11-01

A three-dimensional turbulence simulation of the SOL and edge regions of a toroidally limited tokamak is carried out. The simulation couples self-consistently the drift-reduced two-fluid Braginskii equations to a kinetic equation for neutral atoms. A diagnostic neutral gas puff on the low-field side midplane is included and the impact of neutral density fluctuations on D_α light emission investigated. We find that neutral density fluctuations affect the D_α emission. In particular, at a radial distance from the gas puff smaller than the neutral mean free path, neutral density fluctuations are anti-correlated with plasma density, electron temperature, and D_α fluctuations. It follows that the neutral fluctuations reduce the D_α emission in most of the observed region and, therefore, have to be taken into account when interpreting the amplitude of the D_α emission. On the other hand, higher order statistical moments (skewness, kurtosis) and turbulence characteristics (such as correlation length, or the autocorrelation time) are not significantly affected by the neutral fluctuations. At distances from the gas puff larger than the neutral mean free path, a non-local shadowing effect influences the neutral density fluctuations. There, the D_α fluctuations are correlated with the neutral density fluctuations, and the high-order statistical moments and measurements of other turbulence properties are strongly affected by the neutral density fluctuations.

32 CFR 644.323 - Neutral language.

Science.gov (United States)

2010-07-01

... 32 National Defense 4 2010-07-01 2010-07-01 true Neutral language. 644.323 Section 644.323 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal § 644.323 Neutral language. Wherever the words “man”, “men”, or their related...

Functional and structural brain correlates of risk for major depression in children with familial depression

Directory of Open Access Journals (Sweden)

Xiaoqian J. Chai

2015-01-01

Full Text Available Despite growing evidence for atypical amygdala function and structure in major depression, it remains uncertain as to whether these brain differences reflect the clinical state of depression or neurobiological traits that predispose individuals to major depression. We examined function and structure of the amygdala and associated areas in a group of unaffected children of depressed parents (at-risk group and a group of children of parents without a history of major depression (control group. Compared to the control group, the at-risk group showed increased activation to fearful relative to neutral facial expressions in the amygdala and multiple cortical regions, and decreased activation to happy relative to neutral facial expressions in the anterior cingulate cortex and supramarginal gyrus. At-risk children also exhibited reduced amygdala volume. The extensive hyperactivation to negative facial expressions and hypoactivation to positive facial expressions in at-risk children are consistent with behavioral evidence that risk for major depression involves a bias to attend to negative information. These functional and structural brain differences between at-risk children and controls suggest that there are trait neurobiological underpinnings of risk for major depression.

Cross-correlation cosmography with intensity mapping of the neutral hydrogen 21 cm emission

Science.gov (United States)

Pourtsidou, A.; Bacon, D.; Crittenden, R.

2015-11-01

The cross-correlation of a foreground density field with two different background convergence fields can be used to measure cosmographic distance ratios and constrain dark energy parameters. We investigate the possibility of performing such measurements using a combination of optical galaxy surveys and neutral hydrogen (HI) intensity mapping surveys, with emphasis on the performance of the planned Square Kilometre Array (SKA). Using HI intensity mapping to probe the foreground density tracer field and/or the background source fields has the advantage of excellent redshift resolution and a longer lever arm achieved by using the lensing signal from high redshift background sources. Our results show that, for our best SKA-optical configuration of surveys, a constant equation of state for dark energy can be constrained to ≃8 % for a sky coverage fsky=0.5 and assuming a σ (ΩDE)=0.03 prior for the dark energy density parameter. We also show that using the cosmic microwave background as the second source plane is not competitive, even when considering a COrE-like satellite.

Serbia's Military Neutrality: Origins, effects and challenges

Directory of Open Access Journals (Sweden)

Ejdus Filip

2014-10-01

Full Text Available Serbia is the only state in the Western Balkans that is not seeking NATO membership. In December 2007, Serbia declared military neutrality and in spite of its EU membership aspirations, developed very close relations with Moscow. The objective of this paper is threefold. First, I argue that in order to understand why Serbia declared military neutrality, one has to look both at the discursive terrain and domestic power struggles. The key narrative that was strategically used by mnemonic entrepreneurs, most importantly by the former Prime Minister Vojislav Koštunica, to legitimize military neutrality was the trauma of NATO intervention in 1999 and the ensuing secession of Kosovo. In the second part of the paper, I discuss the operational consequences of the military neutrality policy for Serbia's relations with NATO and Russia, as well as for military reform and EU accession. Finally, I spell out the challenges ahead in Serbia's neutrality policy and argue that its decision makers will increasingly be caught between pragmatic foreign policy requirements on the one hand and deeply entrenched traumatic memories on the other.

Modeling neutralization kinetics of HIV by broadly neutralizing monoclonal antibodies in genital secretions coating the cervicovaginal mucosa.

Directory of Open Access Journals (Sweden)

Scott A McKinley

Full Text Available Eliciting broadly neutralizing antibodies (bnAb in cervicovaginal mucus (CVM represents a promising "first line of defense" strategy to reduce vaginal HIV transmission. However, it remains unclear what levels of bnAb must be present in CVM to effectively reduce infection. We approached this complex question by modeling the dynamic tally of bnAb coverage on HIV. This analysis introduces a critical, timescale-dependent competition: to protect, bnAb must accumulate at sufficient stoichiometry to neutralize HIV faster than virions penetrate CVM and reach target cells. We developed a model that incorporates concentrations and diffusivities of HIV and bnAb in semen and CVM, kinetic rates for binding (kon and unbinding (koff of select bnAb, and physiologically relevant thicknesses of CVM and semen layers. Comprehensive model simulations lead to robust conclusions about neutralization kinetics in CVM. First, due to the limited time virions in semen need to penetrate CVM, substantially greater bnAb concentrations than in vitro estimates must be present in CVM to neutralize HIV. Second, the model predicts that bnAb with more rapid kon, almost independent of koff, should offer greater neutralization potency in vivo. These findings suggest the fastest arriving virions at target cells present the greatest likelihood of infection. It also implies the marked improvements in in vitro neutralization potency of many recently discovered bnAb may not translate to comparable reduction in the bnAb dose needed to confer protection against initial vaginal infections. Our modeling framework offers a valuable tool to gaining quantitative insights into the dynamics of mucosal immunity against HIV and other infectious diseases.

Modeling neutralization kinetics of HIV by broadly neutralizing monoclonal antibodies in genital secretions coating the cervicovaginal mucosa.

Science.gov (United States)

McKinley, Scott A; Chen, Alex; Shi, Feng; Wang, Simi; Mucha, Peter J; Forest, M Gregory; Lai, Samuel K

2014-01-01

Eliciting broadly neutralizing antibodies (bnAb) in cervicovaginal mucus (CVM) represents a promising "first line of defense" strategy to reduce vaginal HIV transmission. However, it remains unclear what levels of bnAb must be present in CVM to effectively reduce infection. We approached this complex question by modeling the dynamic tally of bnAb coverage on HIV. This analysis introduces a critical, timescale-dependent competition: to protect, bnAb must accumulate at sufficient stoichiometry to neutralize HIV faster than virions penetrate CVM and reach target cells. We developed a model that incorporates concentrations and diffusivities of HIV and bnAb in semen and CVM, kinetic rates for binding (kon) and unbinding (koff) of select bnAb, and physiologically relevant thicknesses of CVM and semen layers. Comprehensive model simulations lead to robust conclusions about neutralization kinetics in CVM. First, due to the limited time virions in semen need to penetrate CVM, substantially greater bnAb concentrations than in vitro estimates must be present in CVM to neutralize HIV. Second, the model predicts that bnAb with more rapid kon, almost independent of koff, should offer greater neutralization potency in vivo. These findings suggest the fastest arriving virions at target cells present the greatest likelihood of infection. It also implies the marked improvements in in vitro neutralization potency of many recently discovered bnAb may not translate to comparable reduction in the bnAb dose needed to confer protection against initial vaginal infections. Our modeling framework offers a valuable tool to gaining quantitative insights into the dynamics of mucosal immunity against HIV and other infectious diseases.

Corrosion protection method by neutral treatment for boilers

International Nuclear Information System (INIS)

Ishikawa, Hisashige

1978-01-01

The corrosion protection method by neutral treatment has been applied in Europe mainly for boilers and nuclear reactors instead of existing all volatile treatment. The cause of corrosion of steel and copper in water and the effect of neutral treatment, that is the effect of protection film of magnetite in steel and cuprous oxide in copper alloy, are explained with the characteristic figure of PH, electromotive force and chemical formula. The experience of applying this neutral treatment to the Wedel thermal power plant and the system flow sheet, the water treatment equipment, relating instrumentations and the water examination are described in detail. Hydrogen peroxide is injected in this neutral treatment. The comparison between the existing water treatment and the neutral treatment and their merits and demerits are explained. (Nakai, Y.)

The Myth of Neutral Judge: Overcoming Neutrality by the Cognition Theory And the Pursuit of Legal Certainty

Directory of Open Access Journals (Sweden)

Alyane Almeida de Araújo

2016-11-01

Full Text Available The  Law  scientific-rational  character  created  the  image  of  a  neutral  judge;  however, Neuroscience currently shows that the decision-making process involves activations in the prefrontal cortex along with emotions management areas. The aim of this work is to check the subsistence of the neutral judge after the cognition theory, with points of reflexion in post- positivist hermeneutics. Using the comprehensive method on bibliographic prospection, we conclude that despite the neutrality has been overcome, the search for legal certainty continues, which will be achieved through values and social purposes of the onwn normative system.

Initial Results of Optical Vortex Laser Absorption Spectroscopy in the HYPER-I Device

Science.gov (United States)

Yoshimura, Shinji; Asai, Shoma; Aramaki, Mitsutoshi; Terasaka, Kenichiro; Ozawa, Naoya; Tanaka, Masayoshi; Morisaki, Tomohiro

2015-11-01

Optical vortex beams have a potential to make a new Doppler measurement, because not only parallel but perpendicular movement of atoms against the beam axis causes the Doppler shift of their resonant absorption frequency. As the first step of a proof-of-principle experiment, we have performed the optical vortex laser absorption spectroscopy for metastable argon neutrals in an ECR plasma produced in the HYPER-I device at the National Institute for Fusion Science, Japan. An external cavity diode laser (TOPTICA, DL100) of which center wavelength was 696.735 nm in vacuum was used for the light source. The Hermite-Gaussian (HG) beam was converted into the Laguerre-Gaussian (LG) beam (optical vortex) by a computer-generated hologram displayed on the spatial light modulator (Hamamatsu, LCOS-SLM X10468-07). In order to make fast neutral flow across the LG beam, a high speed solenoid valve system was installed on the HYPER-I device. Initial results including the comparison of absorption spectra for HG and LG beams will be presented. This study was supported by NINS young scientists collaboration program for cross-disciplinary study, NIFS collaboration research program (NIFS13KOAP026), and JSPS KAKENHI grant number 15K05365.

Diagnostics of pre-breakdown light emission in a helium coplanar barrier discharge: the presence of neutral bremsstrahlung

Science.gov (United States)

Navrátil, Zdeněk; Morávek, Tomáš; Ráheľ, Jozef; Čech, Jan; Lalinský, Ondřej; Trunec, David

2017-05-01

Weak light emission (˜10-3 of active discharge signal; average count rate ˜ 1 photon s-1 nm-1) associated with surface charge relaxation during the dark phase of a helium diffuse coplanar barrier discharge was studied by optical emission spectroscopy, using a technique of phase-resolved single photon counting. The optical emission spectra of the dark phase contained luminescent bands of the dielectrics used (Al2O3, AlN) and spectral lines from the gas constituents (OH*, {{{N}}}2* , {{{N}}}2+* , He*, He{}2* , O*). During the charge relaxation event, a broad continuum appeared in the optical emission spectra, consisting of bremsstrahlung radiation and amplified luminescence of the dielectric barrier. The analysis presented suggests that the bremsstrahlung radiation originated from slow electrons colliding with neutral helium atoms. The fitting procedure we developed reproduced well the observed shape of the continuum. Moreover, it provided a method for the determination of electric field strength in the discharge during this particular phase. The electric field reached 1 kV cm-1 during the charge relaxation event.

Ion optics of a new time-of-flight mass spectrometer for quantitative surface analysis

International Nuclear Information System (INIS)

Veryovkin, Igor V.; Calaway, Wallis F.; Pellin, Michael J.

2004-01-01

A new time-of-flight instrument for quantitative surface analysis was developed and constructed at Argonne National Laboratory. It implements ion sputtering and laser desorption for probing analyzed samples and can operate in regimes of secondary neutral mass spectrometry with laser post-ionization and secondary ion mass spectrometry. The instrument incorporates two new ion optics developments: (1) 'push-pull' front end ion optics and (2) focusing and deflecting lens. Implementing these novel elements significantly enhance analytical capabilities of the instrument. Extensive three-dimensional computer simulations of the instrument were conducted in SIMION 3D (c) to perfect its ion optics. The operating principles of the new ion optical systems are described, and a scheme of the new instrument is outlined together with its operating modes

Neutral beam development plan

International Nuclear Information System (INIS)

Staten, H.S.

1980-08-01

The national plan is presented for developing advanced injection systems for use on upgrades of existing experiments, and use on future facilities such as ETF, to be built in the late 1980's or early 90's where power production from magnetic fusion will move closer to a reality. Not only must higher power and longer pulse length systems be developed , but they must operate reliably; they must be a tool for the experimenter, not the experiment itself. Neutral beam systems handle large amounts of energy and as such, they often are as complicated as the plasma physics experiment itself. This presents a significant challenge to the neutral beam developer

Photoproduction of neutral pions off protons

NARCIS (Netherlands)

Crede, V.; Sparks, N.; Wilson, A.; Anisovich, A. V.; Bacelar, J. C. S.; Bantes, R.; Bartholomy, O.; Bayadilov, D.; Beck, R.; Beloglazov, Y. A.; Castelijns, R.; Dutz, H.; Elsner, D.; Ewald, R.; Frommberger, F.; Funke, Chr; Gregor, R.; Gridnev, A.; Gutz, E.; Hillert, W.; Hoffmeister, P.; Jaegle, I.; Junkersfeld, J.; Kalinowsky, H.; Kammer, S.; Klein, Frank; Klein, Friedrich; Klempt, E.; Kotulla, M.; Krusche, B.; Löhner, H.; Lopatin, I. V.; Lugert, S.; Menze, D.; Mertens, T.; Messchendorp, J. G.; Metag, V.; Nanova, M.; Nikonov, V. A.; Novinski, D.; Novotny, R.; Ostrick, M.; Pant, L. M.; van Pee, H.; Pfeiffer, M.; Roy, A.; Sarantsev, A. V.; Schadmand, S.; Schmidt, C.; Schmieden, H.; Schoch, B.; Shende, S.; Sokhoyan, V.; Suele, A.; Sumachev, V. V.; Szczepanek, T.; Thoma, U.; Trnka, D.; Varma, R.; Walther, D.; Wendel, Ch

2011-01-01

Photoproduction of neutral pions has been studied with the CBELSA/TAPS detector in the reaction gamma p -> p pi(0) for photon energies between 0.85 and 2.50 GeV. The pi(0) mesons are observed in their dominant neutral decay mode: pi(0) -> gamma gamma. For the first time, the differential cross

Gender Neutrality: Women's Friend or Foe?

Science.gov (United States)

Steuernagel, Trudy

Gender neutral public policies are those that are either silent on the question of the existence of significant gender differences or incorporate a perspective which mandates that such differences be ignored. Prominent voices today contend that gender neutrality favors males and have held the male standard as the one for which women should aspire.…

Application of optical emission spectroscopy to high current proton sources

International Nuclear Information System (INIS)

Castro, G; Mazzaglia, M; Nicolosi, D; Mascali, D; Reitano, R; Celona, L; Leonardi, O; Leone, F; Naselli, E; Neri, L; Torrisi, G; Gammino, S; Zaniol, B

2017-01-01

Optical Emission Spectroscopy (OES) represents a very reliable technique to carry out non-invasive measurements of plasma density and plasma temperature in the range of tens of eV. With respect to other diagnostics, it also can characterize the different populations of neutrals and ionized particles constituting the plasma. At INFN-LNS, OES techniques have been developed and applied to characterize the plasma generated by the Flexible Plasma Trap, an ion source used as 'testbench' of the proton source built for European Spallation Source. This work presents the characterization of the parameters of a hydrogen plasma in different conditions of neutral pressure, microwave power and magnetic field profile, along with perspectives for further upgrades of the OES diagnostics system. (paper)

A safe and reliable neutralization assay based on pseudovirus to measure neutralizing antibody titer against poliovirus.

Science.gov (United States)

Liu, Shaohua; Song, Dongmei; Bai, Han; Lu, Weiwei; Dai, Xinxian; Hao, Chunsheng; Zhang, Zhongyang; Guo, Huijie; Zhang, Yue; Li, Xiuling

2017-12-01

With the promotion of inactivated poliomyelitis vaccine (IPV) and live attenuated oral poliomyelitis vaccine (OPV), the global reported cases of poliomyelitis have reduced sharply from 0.35 million in 1988 to 74 in 2015. The Polio Eradication & Endgame Strategic Plan published by WHO in 2013 included the strategy of implementation of poliovirus safe handling and containment measures to minimize the risks of facility-associated reintroduction of virus into the polio-free community to prevent the re-import of poliovirus. Toward this strategy, we produced replication-incompetent pseudovirus of poliovirus type 1, 2, 3 attenuated strains by constructing poliovirus capsid expression vectors and poliovirus replicon then transfecting HEK293T cells and developed a pseudovirus-based neutralization assay (pNA) to determine neutralizing antibody titer which is more secure, time-saving and reliable than conventional neutralization assay (cNA). By using anti-poliovirus rat serum, we demonstrated excellent correlation between neutralizing antibody titers measured by cNA and pNA. It was concluded that pNA can be a potential alternative to replace cNA as a safe and time-saving system for titer determination after live poliovirus's safekeeping. © 2017 Wiley Periodicals, Inc.

ICAN: High power neutral beam generation

International Nuclear Information System (INIS)

Moustaizis, S.D.; Lalousis, P.; Perrakis, K.; Auvray, P.; Larour, J.; Ducret, J.E.; Balcou, P.

2015-01-01

During the last few years there is an increasing interest on the development of alternative high power new negative ion source for Tokamak applications. The proposed new neutral beam device presents a number of advantages with respect to: the density current, the acceleration voltage, the relative compact dimension of the negative ion source, and the coupling of a high power laser beam for photo-neutralization of the negative ion beam. Here we numerically investigate, using a multi- fluid 1-D code, the acceleration and the extraction of high power ion beam from a Magnetically Insulated Diode (MID). The diode configuration will be coupled to a high power device capable of extracting a current up to a few kA with an accelerating voltage up to MeV. An efficiency of up to 92% of the coupling of the laser beam, is required in order to obtain a high power, up to GW, neutral beam. The new high energy, high average power, high efficiency (up to 30%) ICAN fiber laser is proposed for both the plasma generation and the photo-neutralizer configuration. (authors)

Are Moral Disengagement, Neutralization Techniques, and Self-Serving Cognitive Distortions the Same? Developing a Unified Scale of Moral Neutralization of Aggression

Directory of Open Access Journals (Sweden)

Denis Ribeaud

2010-12-01

Full Text Available

Negative ion formation and neutralization processes, (2)

International Nuclear Information System (INIS)

Sugiura, Toshio

1982-09-01

This review is 2nd part of the report published at January 1982 (JAERI-M-9902). A compilation includes the survey of the data of the cross sections of H - and D - ion formations and the neutralization of these ions. This is also presented new information about the photosensitization by laser beam in dissociative-resonance electron capture of sulfur hexafluoride reported by Chen et al., for reference to enhancement of D - ions in discharge. For neutralization, the data of mutual neutralization and photodetachment are also presented. (author)

Assessing the Penetrating Abilities of Experimental Preparation with Dental Infiltrant Features Using Optical Microscope: Preliminary Study.

Science.gov (United States)

Skucha-Nowak, Małgorzata; Machorowska-Pieniążek, Agnieszka; Tanasiewicz, Marta

2016-01-01

The aim of the infiltration technique is to penetrate demineralized enamel with a low viscosity resin. Icon® (DMG) is the first ever and so far the only dental infiltrant. Bacteriostaticity is one of the properties that should be inherent in dental infiltrants, but Icon lacks this feature. The aim of the preliminary study was to properly choose a dye which would allow us to assess the penetrating abilities of our own, experimental preparation with features of a dental infiltrant with bacteriostatic properties and to compare using an optical microscope the depth of infiltration of the designed experimental preparation with the infiltrant available on the market. The preparation is supposed to infiltrate decalcified human enamel and be assessed with an optical microscope. Eosin, neutral fuchsine and methylene blue were added to experimental preparation with dental infiltrant features and to Icon® (DMG) in order to assess the depth of penetration of the experimental solution into the decalcified layers of enamel. The experimental solution mixes well with eosin, neutral fuchsine, and methylene blue. During the preliminary study, the authors concluded that the experimental solution mixes well with methylene blue, neutral fuchsine, and eosin. An addition of eosin to a preparation which infiltrates inner, demineralized enamel layers, facilitates the assessment of such a preparation with an optical microscope. A designed experimental solution with the main ingredients, i.e., 2-hydroxyethyl methacrylate (HEMA) and tetraethylene glycol dimethacrylate (TEGDMA) with a ratio of 75% to 25% penetrates the demineralized (decalcified) inner parts of the enamel and polymerizes when exposed to light. In order to assess the infiltration of the experimental solution into the demineralized enamel layers, it is required to improve the measurement techniques that utilize optical microscopy.

Neutral axis as damage sensitive feature

International Nuclear Information System (INIS)

Sigurdardottir, D H; Glisic, B

2013-01-01

Structural health monitoring (SHM) is the process of continuously or periodically measuring structural parameters and the transformation of the collected data into information on real structural conditions. The centroid of stiffness is a universal parameter and its position in a cross-section can be evaluated for any load-carrying beam structure as the position of the neutral axis under conveniently chosen loads. Thus, a change in the position of the neutral axis within a cross-section can indicate a change in the position of the centroid of stiffness, i.e., unusual structural behaviors. This paper proposes a novel monitoring method based on deterministic and probabilistic determination of the position of the neutral axis under conveniently chosen conditions. Therefore, the method proposed in this paper is potentially applicable to a large variety of beam-like structures. Data from two existing structures were used to validate the method and assess its performance: Streicker Bridge at Princeton University and the US202/NJ23 highway overpass in Wayne, NJ. The results show that the neutral axis location is varying even when damage is not present. Reasons for this variation are determined and the accuracy in the evaluation assessed. This paper concludes that the position of the neutral axis can be evaluated with sufficient accuracy using static and dynamic strain measurements performed on appropriate time-scales and indicates its potential to be used as a damage sensitive feature. (paper)

Neutral axis as damage sensitive feature

Science.gov (United States)

Sigurdardottir, D. H.; Glisic, B.

2013-07-01

Structural health monitoring (SHM) is the process of continuously or periodically measuring structural parameters and the transformation of the collected data into information on real structural conditions. The centroid of stiffness is a universal parameter and its position in a cross-section can be evaluated for any load-carrying beam structure as the position of the neutral axis under conveniently chosen loads. Thus, a change in the position of the neutral axis within a cross-section can indicate a change in the position of the centroid of stiffness, i.e., unusual structural behaviors. This paper proposes a novel monitoring method based on deterministic and probabilistic determination of the position of the neutral axis under conveniently chosen conditions. Therefore, the method proposed in this paper is potentially applicable to a large variety of beam-like structures. Data from two existing structures were used to validate the method and assess its performance: Streicker Bridge at Princeton University and the US202/NJ23 highway overpass in Wayne, NJ. The results show that the neutral axis location is varying even when damage is not present. Reasons for this variation are determined and the accuracy in the evaluation assessed. This paper concludes that the position of the neutral axis can be evaluated with sufficient accuracy using static and dynamic strain measurements performed on appropriate time-scales and indicates its potential to be used as a damage sensitive feature.

Software upgrade for the DIII-D neutral beam control systems

International Nuclear Information System (INIS)

Cummings, J.W.; Thurgood, P.A.

1991-11-01

The neutral beams are used to heat the plasma in the DIII-D tokamak, a fusion energy research experiment operated by General Atomics (GA) and funded by the Department of Energy (DOE). The experiment is dedicated to demonstrating noninductive current drive of high beta high temperature divertor plasma with good confinement. The neutral beam heating system for the DIII-D tokamak uses four MODCOMP Classic computers for data acquisition and control of the four beamlines. The Neutral Beam Software Upgrade project was launched in early 1990. The major goals were to upgrade the MAX IV operating system to the latest revision (K.1), use standard MODCOMP software (as much as possible), and to develop a very ''user friendly,'' versatile system. Accomplishing these goals required new software to be developed and modifications to existing applications software to make it compatible with the latest operating system. The custom operating system modules to handle the message service and interrupt handling were replaced by the standard MODCOMP Inter Task Communication (ITC) and interrupt routines that are part of the MAX IV operating system. The message service provides the mechanism for doing shot task sequencing (task scheduling). The interrupt routines are used to connect external interrupts to the system. The new software developed consists of a task dispatcher, screen manager, and interrupt tasks. The existing applications software had to be modified to be compatible with the MODCOMP ITC services and consists of the Modcomp Infinity Data Base Manager, a multi-user system, and menu-driven operating system interface routines using the Infinity Data Base Manager

Evolutionary advantage via common action of recombination and neutrality

Science.gov (United States)

Saakian, David B.; Hu, Chin-Kun

2013-11-01

We investigate evolution models with recombination and neutrality. We consider the Crow-Kimura (parallel) mutation-selection model with the neutral fitness landscape, in which there is a central peak with high fitness A, and some of 1-point mutants have the same high fitness A, while the fitness of other sequences is 0. We find that the effect of recombination and neutrality depends on the concrete version of both neutrality and recombination. We consider three versions of neutrality: (a) all the nearest neighbor sequences of the peak sequence have the same high fitness A; (b) all the l-point mutations in a piece of genome of length l≥1 are neutral; (c) the neutral sequences are randomly distributed among the nearest neighbors of the peak sequences. We also consider three versions of recombination: (I) the simple horizontal gene transfer (HGT) of one nucleotide; (II) the exchange of a piece of genome of length l, HGT-l; (III) two-point crossover recombination (2CR). For the case of (a), the 2CR gives a rather strong contribution to the mean fitness, much stronger than that of HGT for a large genome length L. For the random distribution of neutral sequences there is a critical degree of neutrality νc, and for μmutations affect the mean-field-like and fluctuation-like factors similarly. Consequently, recombination can accelerate the non-mean-field (fluctuation) type dynamics without considerably affecting the mean-field-like factors.

Noise Characterization of Devices for Optical Computing

National Research Council Canada - National Science Library

Walkup, John

1998-01-01

The major objective of the research effort is to investigate the noise characteristics of advanced optical Sources, spatial light modulators, and other devices which are candidates for applications in optical computers...

Neutral evolution of proteins: The superfunnel in sequence space and its relation to mutational robustness

Science.gov (United States)

Noirel, Josselin; Simonson, Thomas

2008-11-01

Following Kimura's neutral theory of molecular evolution [M. Kimura, The Neutral Theory of Molecular Evolution (Cambridge University Press, Cambridge, 1983) (reprinted in 1986)], it has become common to assume that the vast majority of viable mutations of a gene confer little or no functional advantage. Yet, in silico models of protein evolution have shown that mutational robustness of sequences could be selected for, even in the context of neutral evolution. The evolution of a biological population can be seen as a diffusion on the network of viable sequences. This network is called a "neutral network." Depending on the mutation rate μ and the population size N, the biological population can evolve purely randomly (μN ≪1) or it can evolve in such a way as to select for sequences of higher mutational robustness (μN ≫1). The stringency of the selection depends not only on the product μN but also on the exact topology of the neutral network, the special arrangement of which was named "superfunnel." Even though the relation between mutation rate, population size, and selection was thoroughly investigated, a study of the salient topological features of the superfunnel that could affect the strength of the selection was wanting. This question is addressed in this study. We use two different models of proteins: on lattice and off lattice. We compare neutral networks computed using these models to random networks. From this, we identify two important factors of the topology that determine the stringency of the selection for mutationally robust sequences. First, the presence of highly connected nodes ("hubs") in the network increases the selection for mutationally robust sequences. Second, the stringency of the selection increases when the correlation between a sequence's mutational robustness and its neighbors' increases. The latter finding relates a global characteristic of the neutral network to a local one, which is attainable through experiments or molecular

Developments of a bonding technique for optical materials by a surface activation method

International Nuclear Information System (INIS)

Sugiyama, Akira; Oda, Tomohiro; Abe, Tomoyuki; Kusunoki, Isao

2005-01-01

We started developing the laser crystal bounding by the surface activation method which can splice crystals together without using hydrogen bonding. For the surface activation, neutral argon beams were used for irradiation of specimens. In the bonding trials with sapphire crystals, we recognized possibility of the bonding method for optical elements. (author)

Applications of fiber optics in physical protection

International Nuclear Information System (INIS)

Buckle, T.H.

1994-03-01

The purpose of this NUREG is to provide technical information useful for the development of fiber-optic communications and intrusion detection subsystems relevant to physical protection. There are major sections on fiber-optic technology and applications. Other topics include fiber-optic system components and systems engineering. This document also contains a glossary, a list of standards and specifications, and a list of fiber-optic equipment vendors

Heavy-atom neutral beams for tandem-mirror end plugs

International Nuclear Information System (INIS)

Post, D.E.; Grisham, L.R.; Santarius, J.F.; Emmert, G.A.

1981-05-01

The advantages of neutral beams with Z greater than or equal to 3 formed from negative ions, accelerated to 0.5 to 1.0 MeV/amu, and neutralized with high efficiency, are investigated for use in tandem mirror reactor end plugs. These beams can produce Q's of 20 to 30, and thus can replace the currently proposed 200 to 500 keV neutral proton beams presently planned for tandem mirror reactors. Thus, these Z greater than or equal to 3 neutral beams increase the potential attractiveness of tandem mirror reactors by offering a substitute for difficult high energy neutral hydrogen end plug beams

Monte Carlo neutral density calculations for ELMO Bumpy Torus

International Nuclear Information System (INIS)

Davis, W.A.; Colchin, R.J.

1986-11-01

The steady-state nature of the ELMO Bumpy Torus (EBT) plasma implies that the neutral density at any point inside the plasma volume will determine the local particle confinement time. This paper describes a Monte Carlo calculation of three-dimensional atomic and molecular neutral density profiles in EBT. The calculation has been done using various models for neutral source points, for launching schemes, for plasma profiles, and for plasma densities and temperatures. Calculated results are compared with experimental observations - principally spectroscopic measurements - both for guidance in normalization and for overall consistency checks. Implications of the predicted neutral profiles for the fast-ion-decay measurement of neutral densities are also addressed

Neutral beams for magnetic fusion

International Nuclear Information System (INIS)

Hooper, B.

1977-01-01

Significant advances in forming energetic beams of neutral hydrogen and deuterium atoms have led to a breakthrough in magnetic fusion: neutral beams are now heating plasmas to thermonuclear temperatures, here at LLL and at other laboratories. For example, in our 2XIIB experiment we have injected a 500-A-equivalent current of neutral deuterium atoms at an average energy of 18 keV, producing a dense plasma (10 14 particles/cm 3 ) at thermonuclear energy (14 keV or 160 million kelvins). Currently, LLL and LBL are developing beam energies in the 80- to 120-keV range for our upcoming MFTF experiment, for the TFTR tokamak experiment at Princeton, and for the Doublet III tokamak experiment at General Atomic. These results increase our long-range prospects of producing high-intensity beams of energies in the hundreds or even thousands of kilo-electron-volts, providing us with optimistic extrapolations for realizing power-producing fusion reactors

Charge neutralization of small ion beam clumps

Energy Technology Data Exchange (ETDEWEB)

Welch, D R [Mission Research Corp., Albuquerque, NM (United States); Olson, C L; Hanson, D L [Sandia National Labs., Albuquerque, NM (United States)

1997-12-31

The mega-ampere currents associated with light ion fusion (LIF) require excellent charge neutralization to prevent divergence growth. As the size and space-charge potential of a beam clump or `beamlet` become small (submillimeter size and kilovolt potentials), the neutralization becomes increasingly difficult. Linear theory predicts that plasma electrons cannot neutralize potentials < {phi}{sub crit} = (1/2)m{sub e}v{sub i}{sup 2}/e, where m{sub e} is the electron mass and v{sub i} is the ion beam velocity. A non-uniform beam would, therefore, have regions with potentials sufficient to add divergence to beam clumps. The neutralization of small beamlets produced on the SABLE accelerator and in numerical simulation has supported the theory, showing a plateau in divergence growths as the potential in the beamlet exceeds {phi}{sub crit}. (author). 1 tab., 2 figs., 4 refs.

Measurement of plasma production and neutralization in gas neutralizers

International Nuclear Information System (INIS)

Maor, D.; Meron, M.; Johnson, B.; Jones, K.; Agagu, A.; Hu, B.

1986-01-01

In order to satisfy the need of experimental data for the designing of gas neutralizers we have started a project aimed at measuring all relevant cross sections for the charge exchange of H - , H 0 and H + projectiles, as well as the cross sections for the production of ions in the target. The expected results of these latter measurements are shown schematically

Superposition Principle in Auger Recombination of Charged and Neutral Multicarrier States in Semiconductor Quantum Dots.

Science.gov (United States)

Wu, Kaifeng; Lim, Jaehoon; Klimov, Victor I

2017-08-22

Application of colloidal semiconductor quantum dots (QDs) in optical and optoelectronic devices is often complicated by unintentional generation of extra charges, which opens fast nonradiative Auger recombination pathways whereby the recombination energy of an exciton is quickly transferred to the extra carrier(s) and ultimately dissipated as heat. Previous studies of Auger recombination have primarily focused on neutral and, more recently, negatively charged multicarrier states. Auger dynamics of positively charged species remains more poorly explored due to difficulties in creating, stabilizing, and detecting excess holes in the QDs. Here we apply photochemical doping to prepare both negatively and positively charged CdSe/CdS QDs with two distinct core/shell interfacial profiles ("sharp" versus "smooth"). Using neutral and charged QD samples we evaluate Auger lifetimes of biexcitons, negative and positive trions (an exciton with an extra electron or a hole, respectively), and multiply negatively charged excitons. Using these measurements, we demonstrate that Auger decay of both neutral and charged multicarrier states can be presented as a superposition of independent elementary three-particle Auger events. As one of the manifestations of the superposition principle, we observe that the biexciton Auger decay rate can be presented as a sum of the Auger rates for independent negative and positive trion pathways. By comparing the measurements on the QDs with the "sharp" versus "smooth" interfaces, we also find that while affecting the absolute values of Auger lifetimes, manipulation of the shape of the confinement potential does not lead to violation of the superposition principle, which still allows us to accurately predict the biexciton Auger lifetimes based on the measured negative and positive trion dynamics. These findings indicate considerable robustness of the superposition principle as applied to Auger decay of charged and neutral multicarrier states

Evaluation of smallpox vaccines using variola neutralization.

Science.gov (United States)

Damon, Inger K; Davidson, Whitni B; Hughes, Christine M; Olson, Victoria A; Smith, Scott K; Holman, Robert C; Frey, Sharon E; Newman, Frances; Belshe, Robert B; Yan, Lihan; Karem, Kevin

2009-08-01

The search for a 'third'-generation smallpox vaccine has resulted in the development and characterization of several vaccine candidates. A significant barrier to acceptance is the absence of challenge models showing induction of correlates of protective immunity against variola virus. In this light, virus neutralization provides one of few experimental methods to show specific 'in vitro' activity of vaccines against variola virus. Here, we provide characterization of the ability of a modified vaccinia virus Ankara vaccine to induce variola virus-neutralizing antibodies, and we provide comparison with the neutralization elicited by standard Dryvax vaccination.

Neutralizing antibodies induced by recombinant virus-like particles of enterovirus 71 genotype C4 inhibit infection at pre- and post-attachment steps.

Directory of Open Access Journals (Sweden)

Zhiqiang Ku

Full Text Available BACKGROUND: Enterovirus 71 (EV71 is a major causative agent of hand, foot and mouth disease, which has been prevalent in Asia-Pacific regions, causing significant morbidity and mortality in young children. Antibodies elicited by experimental EV71 vaccines could neutralize infection in vitro and passively protect animal models from lethal challenge, indicating that neutralizing antibodies play an essential role in protection. However, how neutralizing antibodies inhibit infection in vitro remains unclear. METHODS/FINDINGS: In the present study, we explored the mechanisms of neutralization by antibodies against EV71 virus-like particles (VLPs. Recombinant VLPs of EV71 genotype C4 were produced in insect cells using baculovirus vectors. Immunization with the VLPs elicited a high-titer, EV71-specific antibody response in mice. Anti-VLP mouse sera potently neutralized EV71 infection in vitro. The neutralizing antibodies in the anti-VLP mouse sera were found to target mainly an extremely conserved epitope (FGEHKQEKDLEYGAC located at the GH loop of the VP1 protein. The neutralizing anti-VLP antisera were able to inhibit virus binding to target cells efficiently. In addition, post-attachment treatment of virus-bound cells with the anti-VLP antisera also neutralized virus infection, although the antibody concentration required was higher than that of the pre-attachment treatment. CONCLUSIONS: Collectively, our findings represent a valuable addition to the understanding of mechanisms of EV71 neutralization and have strong implications for EV71 vaccine development.

Characterization of broadly neutralizing antibody responses to HIV-1 in a cohort of long term non-progressors.

Science.gov (United States)

González, Nuria; McKee, Krisha; Lynch, Rebecca M; Georgiev, Ivelin S; Jimenez, Laura; Grau, Eulalia; Yuste, Eloísa; Kwong, Peter D; Mascola, John R; Alcamí, José

2018-01-01

Only a small fraction of HIV-1-infected patients develop broadly neutralizing antibodies (bNAbs), a process generally associated to chronic antigen stimulation. It has been described that rare aviremic HIV-1-infected patients can generate bNAbs but this issue remains controversial. To address this matter we have assessed bNAb responses in a large cohort of long-term non-progressors (LTNPs) with low or undetectable viremia. Samples from the LTNP cohort of the Spanish AIDS Research Network (87 elite and 42 viremic controllers) and a control population of 176 viremic typical-progressors (TPs) were screened for bNAbs using Env-recombinant viruses. bNAb specificities were studied by ELISA using mutated gp120, neutralization assays with mutated viruses, and peptide competition. Epitope specificities were also elucidated from the serum pattern of neutralization against a panel of diverse HIV-1 isolates. Broadly neutralizing sera were found among 9.3% LTNPs, both elite (7%) and viremic controllers (14%). Within the broadly neutralizing sera, CD4 binding site antibodies were detected by ELISA in 4/12 LTNPs (33%), and 16/33 of TPs (48%). Anti-MPER antibodies were detected in 6/12 LTNPs (50%) and 14/33 TPs (42%) whereas glycan-dependent HIV-1 bNAbs were more frequent in LTNPs (11/12, 92%) as compared to TPs (12/33, 36%). A good concordance between standard serum mapping and neutralization-based mapping was observed. LTNPs, both viremic and elite controllers, showed broad humoral immune responses against HIV-1, including activity against many major epitopes involved in bNAbs-mediated protection.

The innovation-enhancing effects of network neutrality

NARCIS (Netherlands)

Kocsis, V.; Weda, J.

2013-01-01

In the past decade, economists, legal experts, and policy makers have been discussing the effects of neutral network structures on - among others - innovations by content and application providers. Does network neutrality - the open and non-discriminatory functioning of the internet - provide

The Framing of Network Neutrality Governance

DEFF Research Database (Denmark)

Perry, James

The neutrality of the internet with regard to applications (e.g. search, social networking, email, to mention only three) has been central to innovation and growth in the knowledge-economy over the past two decades. Until recently, neutrality was built into the internet's design via its core stan...... with a critical analysis of their respective operational paradigms, the paper seeks to understand who is framing the debate, how they are doing so, and to what (systemic) effect....... generative: Useful innovations in applications of the internet could take hold easily, and it was difficult – or indeed impossible - for incumbent business interests to disrupt or sabotage them. However, this neutrality is now under threat. New technologies have given incumbent businesses the ability...

Current neutralization of converging ion beams

International Nuclear Information System (INIS)

Mosher, D.

1978-01-01

It is desired to consider the problem of current neutralization of heavy ion beams traversing gas backgrounds in which the conductivity changes due to beam heating and beam convergence. The procedure is to determine Green's-function solutions to the magnetic-diffusion equation derived from Maxwell's equations and an assumed scaler-plasma conductivity sigma for the background-electron current density j/sub e/. The present calculation is more general than some previously carried out in that arbitrary time variations for the beam current j/sub b/ and conductivity are allowed and the calculation is valid for both weak and strong neutralization. Results presented here must be combined with an appropriate energy-balance equation for the heated background in order to obtain the neutralization self-consistently

Truly neutral microobjects and oscillations in particle physics

International Nuclear Information System (INIS)

Bilenky, S.M.; Pontecorvo, B.

1982-01-01

Oscillation phenomena between different states of neutral elementary particles are discussed. The known kaon oscillation and the proposed neutrino, neutron and other kinds of oscillations are analysed. The proper bound states of neutral objects (neutrinos, neutrons, hydrogen atoms) are investigated in the case of small and strong violation of CP symmetry. Consequences concerning the observable masses and quantum numbers of such neutral objects are drawn. (D.Gy.)

Neutral currents in semileptonic reactions

International Nuclear Information System (INIS)

Paschos, E.A.

1975-05-01

The evidence for weak neutral currents is analyzed in semileptonic reactions with special emphasis on their Lorentz and internal symmetry structure. It is found that present observations are consistent with the expectations of gauge theories, but other possibilities can not be ruled out. Of particular interest in this respect is the presence of a large isoscalar component. The excitation of the Δ-resonance by neutral currents is analyzed, and pion-nucleon mass distributions are presented. Charge asymmetries sensitive to isoscalar-isovector interferences are discussed. (U.S.)

Canine distemper virus neutralization activity is low in human serum and it is sensitive to an amino acid substitution in the hemagglutinin protein.

Science.gov (United States)

Zhang, Xinsheng; Wallace, Olivia L; Domi, Arban; Wright, Kevin J; Driscoll, Jonathan; Anzala, Omu; Sanders, Eduard J; Kamali, Anatoli; Karita, Etienne; Allen, Susan; Fast, Pat; Gilmour, Jill; Price, Matt A; Parks, Christopher L

2015-08-01

Serum was analyzed from 146 healthy adult volunteers in eastern Africa to evaluate measles virus (MV) and canine distemper virus (CDV) neutralizing antibody (nAb) prevalence and potency. MV plaque reduction neutralization test (PRNT) results indicated that all sera were positive for MV nAbs. Furthermore, the 50% neutralizing dose (ND50) for the majority of sera corresponded to antibody titers induced by MV vaccination. CDV nAbs titers were low and generally were detected in sera with high MV nAb titers. A mutant CDV was generated that was less sensitive to neutralization by human serum. The mutant virus genome had 10 nucleotide substitutions, which coded for single amino acid substitutions in the fusion (F) and hemagglutinin (H) glycoproteins and two substitutions in the large polymerase (L) protein. The H substitution occurred in a conserved region involved in receptor interactions among morbilliviruses, implying that this region is a target for cross-reactive neutralizing antibodies. Copyright © 2015 Elsevier Inc. All rights reserved.

A potent human neutralizing antibody Fc-dependently reduces established HBV infections.

Science.gov (United States)

Li, Dan; He, Wenhui; Liu, Ximing; Zheng, Sanduo; Qi, Yonghe; Li, Huiyu; Mao, Fengfeng; Liu, Juan; Sun, Yinyan; Pan, Lijing; Du, Kaixin; Ye, Keqiong; Li, Wenhui; Sui, Jianhua

2017-09-26

Hepatitis B virus (HBV) infection is a major global health problem. Currently-available therapies are ineffective in curing chronic HBV infection. HBV and its satellite hepatitis D virus (HDV) infect hepatocytes via binding of the preS1 domain of its large envelope protein to sodium taurocholate cotransporting polypeptide (NTCP). Here, we developed novel human monoclonal antibodies that block the engagement of preS1 with NTCP and neutralize HBV and HDV with high potency. One antibody, 2H5-A14, functions at picomolar level and exhibited neutralization-activity-mediated prophylactic effects. It also acts therapeutically by eliciting antibody-Fc-dependent immunological effector functions that impose durable suppression of viral infection in HBV-infected mice, resulting in reductions in the levels of the small envelope antigen and viral DNA, with no emergence of escape mutants. Our results illustrate a novel antibody-Fc-dependent approach for HBV treatment and suggest 2H5-A14 as a novel clinical candidate for HBV prevention and treatment of chronic HBV infection.

Mutation exposed: a neutral explanation for extreme base composition of an endosymbiont genome.

Science.gov (United States)

Wernegreen, Jennifer J; Funk, Daniel J

2004-12-01

The influence of neutral mutation pressure versus selection on base composition evolution is a subject of considerable controversy. Yet the present study represents the first explicit population genetic analysis of this issue in prokaryotes, the group in which base composition variation is most dramatic. Here, we explore the impact of mutation and selection on the dynamics of synonymous changes in Buchnera aphidicola, the AT-rich bacterial endosymbiont of aphids. Specifically, we evaluated three forms of evidence. (i) We compared the frequencies of directional base changes (AT-->GC vs. GC-->AT) at synonymous sites within and between Buchnera species, to test for selective preference versus effective neutrality of these mutational categories. Reconstructed mutational changes across a robust intraspecific phylogeny showed a nearly 1:1 AT-->GC:GC-->AT ratio. Likewise, stationarity of base composition among Buchnera species indicated equal rates of AT-->GC and GC-->AT substitutions. The similarity of these patterns within and between species supported the neutral model. (ii) We observed an equivalence of relative per-site AT mutation rate and current AT content at synonymous sites, indicating that base composition is at mutational equilibrium. (iii) We demonstrated statistically greater equality in the frequency of mutational categories in Buchnera than in parallel mammalian studies that documented selection on synonymous sites. Our results indicate that effectively neutral mutational pressure, rather than selection, represents the major force driving base composition evolution in Buchnera. Thus they further corroborate recent evidence for the critical role of reduced N(e) in the molecular evolution of bacterial endosymbionts.

Long-Run Neutrality and Superneutrality in an ARIMA Framework.

OpenAIRE

Fisher, Mark E; Seater, John J

1993-01-01

The authors formalize long-run neutrality and long-run superneutrality in the context of a bivariate ARIMA model; show how the restrictions implied by long-run neutrality and long-run superneutrality depend on the orders of integration of the variables; apply their analysis to previous work, showing how that work is related to long-run neutrality and long-run superneutrality; and provide some new evidence on long-run neutrality and long-run superneutrality. Copyright 1993 by American Economic...

Research on Stress Neutral Layer Offset in the Straightening Process

Directory of Open Access Journals (Sweden)

Hailian Gui

2015-01-01

Full Text Available The stress neutral layer offset is analyzed by theoretical and numerical calculation methods. In traditional straightening theory, the stress neutral layer was consistent with the geometric central layer. However, there is a phenomenon that the stress neutral layer has some offset with the geometric neutral layer. This offset is a very important factor for improving the precision of the straightening force. The formula of the stress neutral layer offset is obtained by a theoretical method and the change law is given by numerical calculation method. The neutral layer offset theory provides the theoretical basis for establishing the model of straightening force precisely.

A General Nonlinear Fluid Model for Reacting Plasma-Neutral Mixtures

Energy Technology Data Exchange (ETDEWEB)

Meier, E T; Shumlak, U

2012-04-06

A generalized, computationally tractable fluid model for capturing the effects of neutral particles in plasmas is derived. The model derivation begins with Boltzmann equations for singly charged ions, electrons, and a single neutral species. Electron-impact ionization, radiative recombination, and resonant charge exchange reactions are included. Moments of the reaction collision terms are detailed. Moments of the Boltzmann equations for electron, ion, and neutral species are combined to yield a two-component plasma-neutral fluid model. Separate density, momentum, and energy equations, each including reaction transfer terms, are produced for the plasma and neutral equations. The required closures for the plasma-neutral model are discussed.

Photoionization and third-order susceptibility of a neutral donor in ZnS/InP/ZnSe core/shell spherical quantum dots

International Nuclear Information System (INIS)

Xie, Wenfang

2014-01-01

The optical properties of a neutral donor in a ZnS/InP/ZnSe core/shell spherical quantum dot have been investigated using the variational method and the compact density-matrix approach. Two parametric potential is chosen as a confinement potential for the shell. Considering the band structure of the system it is assumed that electron is localized in InP shell. It is assumed that the impurity is located in the center of quantum dot core (ZnS). The photoionization cross section as well as the third-order nonlinear optical susceptibility of third harmonic generation has been calculated. The results show that the photoionization and the third-order nonlinear optical susceptibility of a donor in a core/shell spherical quantum dot are strongly affected by the shell thickness. We found that small applied shell thickness will lead to a significant blue shift of the peak positions in the optical spectrum. This kind of structure gives an opportunity to tune and control the photoionization and the third-order nonlinear optical susceptibility of third harmonic generation of a donor impurity by changing the shell thickness

Auditors' Professional Skepticism: Neutrality versus Presumptive Doubt

NARCIS (Netherlands)

Groot, T.L.C.M.; Quadackers, L.M.; Wright, A.

2014-01-01

Although skepticism is widely viewed as essential to audit quality, there is a debate about what form is optimal. The two prevailing perspectives that have surfaced are "neutrality" and "presumptive doubt." With neutrality, auditors neither believe nor disbelieve client management. With presumptive

Neutral theory of chemical reaction networks

International Nuclear Information System (INIS)

Lee, Sang Hoon; Holme, Petter; Minnhagen, Petter; Bernhardsson, Sebastian; Kim, Beom Jun

2012-01-01

To what extent do the characteristic features of a chemical reaction network reflect its purpose and function? In general, one argues that correlations between specific features and specific functions are key to understanding a complex structure. However, specific features may sometimes be neutral and uncorrelated with any system-specific purpose, function or causal chain. Such neutral features are caused by chance and randomness. Here we compare two classes of chemical networks: one that has been subjected to biological evolution (the chemical reaction network of metabolism in living cells) and one that has not (the atmospheric planetary chemical reaction networks). Their degree distributions are shown to share the very same neutral system-independent features. The shape of the broad distributions is to a large extent controlled by a single parameter, the network size. From this perspective, there is little difference between atmospheric and metabolic networks; they are just different sizes of the same random assembling network. In other words, the shape of the degree distribution is a neutral characteristic feature and has no functional or evolutionary implications in itself; it is not a matter of life and death. (paper)

Genome-wide association study on the development of cross-reactive neutralizing antibodies in HIV-1 infected individuals.

Directory of Open Access Journals (Sweden)

Zelda Euler

Full Text Available Broadly neutralizing antibodies may protect against HIV-1 acquisition. In natural infection, only 10-30% of patients have cross-reactive neutralizing humoral immunity which may relate to viral and or host factors. To explore the role of host genetic markers in the formation of cross-reactive neutralizing activity (CrNA in HIV-1 infected individuals, we performed a genome-wide association study (GWAS, in participants of the Amsterdam Cohort Studies with known CrNA in their sera. Single-nucleotide polymorphisms (SNPs with the strongest P-values are located in the major histocompatibility complex (MHC region, close to MICA (P = 7.68 × 10(-7, HLA-B (P = 6.96 × 10(-6 and in the coding region of HCP5 (P = 1.34 × 10(-5. However, none of the signals reached genome-wide significance. Our findings underline the potential involvement of genes close or within the MHC region with the development of CrNA.

Genome-Wide Association Study on the Development of Cross-Reactive Neutralizing Antibodies in HIV-1 Infected Individuals

Science.gov (United States)

Euler, Zelda; van Gils, Marit J.; Boeser-Nunnink, Brigitte D.; Schuitemaker, Hanneke; van Manen, Daniëlle

2013-01-01

Broadly neutralizing antibodies may protect against HIV-1 acquisition. In natural infection, only 10–30% of patients have cross-reactive neutralizing humoral immunity which may relate to viral and or host factors. To explore the role of host genetic markers in the formation of cross-reactive neutralizing activity (CrNA) in HIV-1 infected individuals, we performed a genome-wide association study (GWAS), in participants of the Amsterdam Cohort Studies with known CrNA in their sera. Single-nucleotide polymorphisms (SNPs) with the strongest P-values are located in the major histocompatibility complex (MHC) region, close to MICA (P = 7.68×10−7), HLA-B (P = 6.96×10−6) and in the coding region of HCP5 (P = 1.34×10−5). However, none of the signals reached genome-wide significance. Our findings underline the potential involvement of genes close or within the MHC region with the development of CrNA. PMID:23372753

Structure-based, targeted deglycosylation of HIV-1 gp120 and effects on neutralization sensitivity and antibody recognition

International Nuclear Information System (INIS)

Koch, Markus; Pancera, Marie; Kwong, Peter D.; Kolchinsky, Peter; Grundner, Christoph; Wang Liping; Hendrickson, Wayne A.; Sodroski, Joseph; Wyatt, Richard

2003-01-01

The human immunodeficiency virus (HIV-1) exterior envelope glycoprotein, gp120, mediates receptor binding and is the major target for neutralizing antibodies. Primary HIV-1 isolates are characteristically more resistant to broadly neutralizing antibodies, although the structural basis for this resistance remains obscure. Most broadly neutralizing antibodies are directed against functionally conserved gp120 regions involved in binding to either the primary virus receptor, CD4, or the viral coreceptor molecules that normally function as chemokine receptors. These antibodies are known as CD4 binding site (CD4BS) and CD4-induced (CD4i) antibodies, respectively. Inspection of the gp120 crystal structure reveals that although the receptor-binding regions lack glycosylation, sugar moieties lie proximal to both receptor-binding sites on gp120 and thus in proximity to both the CD4BS and the CD4i epitopes. In this study, guided by the X-ray crystal structure of gp120, we deleted four N-linked glycosylation sites that flank the receptor-binding regions. We examined the effects of selected changes on the sensitivity of two prototypic HIV-1 primary isolates to neutralization by antibodies. Surprisingly, removal of a single N-linked glycosylation site at the base of the gp120 third variable region (V3 loop) increased the sensitivity of the primary viruses to neutralization by CD4BS antibodies. Envelope glycoprotein oligomers on the cell surface derived from the V3 glycan-deficient virus were better recognized by a CD4BS antibody and a V3 loop antibody than were the wild-type glycoproteins. Absence of all four glycosylation sites rendered a primary isolate sensitive to CD4i antibody-mediated neutralization. Thus, carbohydrates that flank receptor-binding regions on gp120 protect primary HIV-1 isolates from antibody-mediated neutralization

Binary optics: Trends and limitations

Science.gov (United States)

Farn, Michael W.; Veldkamp, Wilfrid B.

1993-01-01

We describe the current state of binary optics, addressing both the technology and the industry (i.e., marketplace). With respect to the technology, the two dominant aspects are optical design methods and fabrication capabilities, with the optical design problem being limited by human innovation in the search for new applications and the fabrication issue being limited by the availability of resources required to improve fabrication capabilities. With respect to the industry, the current marketplace does not favor binary optics as a separate product line and so we expect that companies whose primary purpose is the production of binary optics will not represent the bulk of binary optics production. Rather, binary optics' more natural role is as an enabling technology - a technology which will directly result in a competitive advantage in a company's other business areas - and so we expect that the majority of binary optics will be produced for internal use.

Efficient Means of Detecting Neutral Atoms in Space

Science.gov (United States)

Zinicola, W. N.

2006-12-01

This summer, The Society of Physics Students granted me the opportunity to participate in an internship for The National Aeronautics and Space Administration (NASA) and The University of Maryland. Our chief interest was analyzing low energy neutral atoms that were created from random interactions of ions in space plasma. From detecting these neutrals one can project a image of what the plasma's composition is, and how this plasma changes through interactions with the solar wind. Presently, low energy neutral atom detectors have poor efficiency, typically in the range of 1%. Our goal was to increase this efficiency. To detect low energy neutrals we must first convert them from neutral molecules to negatively charged ions. Once converted, these "new" negatively charged ions can be easily detected and completely analyzed giving us information about their energy, mass, and instantaneous direction. The efficiency of the detector is drastically affected by the surface used for converting these neutrals. My job was first to create thin metal conversion surfaces. Then, using an X-ray photoelectron spectrometer, analyze atomic surface composition and gather work function values. Once the work function values were known we placed the surfaces in our neutral detector and measured their conversion efficiencies. Finally, a relation between the work function of the metal surface an its conversion efficiency was generated. With this relationship accurately measured one could use this information to help give suggestions on what surface would be the best to increase our detection efficiency. If we could increase the efficiency of these low energy neutral atom detectors by even 1% we would be able to decrease the size of the detector therefore making it cheaper and more applicable for space exploration.* * A special thanks to Dr. Michael Coplan of the University of Maryland for his support and guidance through all my research.

Development of a high current 60 keV neutral lithium beam injector for beam emission spectroscopy measurements on fusion experiments

Science.gov (United States)

Anda, G.; Dunai, D.; Lampert, M.; Krizsanóczi, T.; Németh, J.; Bató, S.; Nam, Y. U.; Hu, G. H.; Zoletnik, S.

2018-01-01

A 60 keV neutral lithium beam system was designed and built up for beam emission spectroscopy measurement of edge plasma on the KSTAR and EAST tokamaks. The electron density profile and its fluctuation can be measured using the accelerated lithium beam-based emission spectroscopy system. A thermionic ion source was developed with a SiC heater to emit around 4-5 mA ion current from a 14 mm diameter surface. The ion optic is following the 2 step design used on other devices with small modifications to reach about 2-3 cm beam diameter in the plasma at about 4 m from the ion source. A newly developed recirculating sodium vapour neutralizer neutralizes the accelerated ion beam at around 260-280 °C even during long (manipulation techniques are applied to allow optimization, aiming, cleaning, and beam modulation. The maximum 60 keV beam energy with 4 mA ion current was successfully reached at KSTAR and at EAST. Combined with an efficient observation system, the Li-beam diagnostic enables the measurement of the density profile and fluctuations on the plasma turbulence time scale.

Light-Induced Hofstadter's Butterfly Spectrum in Optical Lattices

International Nuclear Information System (INIS)

Hou Jingmin

2009-01-01

We propose a scheme to create an effective magnetic field, which can be perceived by cold neutral atoms in a two-dimensional optical lattice, with a laser field with a space-dependent phase and a conventional laser field acting on Λ-type three-level atoms. When the dimensionless parameter α, being the ratio of flux through a lattice cell to one flux quantum, is rational, the energy spectrum shows a fractal band structure, which is so-called Hofstadter's butterfly. (general)

Detection of extensive cross-neutralization between pandemic and seasonal A/H1N1 Influenza Viruses using a pseudotype neutralization assay.

Directory of Open Access Journals (Sweden)

Béatrice Labrosse

Full Text Available BACKGROUND: Cross-immunity between seasonal and pandemic A/H1N1 influenza viruses remains uncertain. In particular, the extent that previous infection or vaccination by seasonal A/H1N1 viruses can elicit protective immunity against pandemic A/H1N1 is unclear. METHODOLOGY/PRINCIPAL FINDINGS: Neutralizing titers against seasonal A/H1N1 (A/Brisbane/59/2007 and against pandemic A/H1N1 (A/California/04/2009 were measured using an HIV-1-based pseudovirus neutralization assay. Using this highly sensitive assay, we found that a large fraction of subjects who had never been exposed to pandemic A/H1N1 express high levels of pandemic A/H1N1 neutralizing titers. A significant correlation was seen between neutralization of pandemic A/H1N1 and neutralization of a standard seasonal A/H1N1 strain. Significantly higher pandemic A/H1N1 neutralizing titers were measured in subjects who had received vaccination against seasonal influenza in 2008-2009. Higher pandemic neutralizing titers were also measured in subjects over 60 years of age. CONCLUSIONS/SIGNIFICANCE: Our findings reveal that the extent of protective cross-immunity between seasonal and pandemic A/H1N1 influenza viruses may be more important than previously estimated. This cross-immunity could provide a possible explanation of the relatively mild profile of the recent influenza pandemic.

46 CFR 120.376 - Grounded distribution systems (Neutral grounded).

Science.gov (United States)

2010-10-01

....376 Section 120.376 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS... distribution system having a neutral bus or conductor must have the neutral grounded. (c) The neutral or each...

Rare decays of neutral π and eta

International Nuclear Information System (INIS)

Poutissou, J.M.

1983-09-01

The decays of the pseudoscalar neutral mesons π degree and eta degree have provided a test of fundamental principles. The main branch, π degree → 2γ, was investigated in the late 60's in the context of current algebra and the decay rate calculated from the singular triangle diagram is in excellent agreement with experiment. Rare leptonic decays of the neutral pseudoscalar mesons are of interest because of the information they reveal about neutral currents or other exotic interactions between leptons and quarks. The author discusses recent information on the π degree → e + e - decay

THE ROLL-OVER OF HELIOSPHERIC NEUTRAL HYDROGEN BELOW 100 eV: OBSERVATIONS AND IMPLICATIONS

Energy Technology Data Exchange (ETDEWEB)

Galli, A.; Wurz, P. [Physics Institute, University of Bern, Bern, 3012 (Switzerland); Schwadron, N. A.; Kucharek, H.; Möbius, E. [University of New Hampshire, Durham, NH 03824 (United States); Bzowski, M.; Sokół, J. M.; Kubiak, M. A. [Space Research Centre, Polish Academy of Sciences, Warsaw, 00-716 (Poland); Funsten, H. O. [Los Alamos National Laboratory, Intelligence and Space Research Division, Los Alamos, NM 87545 (United States); Fuselier, S. A.; McComas, D. J. [Southwest Research Institute, San Antonio, TX 78228 (United States)

2016-04-20

We present an improved analysis of the energy spectrum of energetic neutral hydrogen from the heliosheath observed with the IBEX -Lo sensor on the Interstellar Boundary EXplorer from the years 2009 to 2012. This analysis allows us to study the lowest energies between 10 and 100 eV although various background sources are more intense than the targeted signal over broad areas of the sky. The results improve our knowledge of the interaction region between our heliosphere and the interstellar plasma because these neutral atoms are direct messengers from the low-energy plasma in the heliosheath. We find a roll-over of the energy spectrum below 100 eV, which has major implications for the pressure balance of the plasma in the inner heliosheath. The results can also be compared directly with in situ observations of the Voyager 1 and 2 spacecraft.

A PC-PCL-based control system for the high-voltage pulsed-power operation of the Intense Diagnostic Neutral Beam (IDNB) Experiment

International Nuclear Information System (INIS)

Gribble, R.

1993-06-01

A stand-alone, semiautomated control system for the high-voltage pulsed-power energy sources on the Intense Diagnostic Neutral Beam Experiment at Los Alamos National Laboratory using personal computer (PC) and programmable logic controller (PLC) technology has been developed and implemented. The control system, consisting of a PC with the graphic operator interface, the network connecting the PC to the PLC, the PLC, the PLC I/O modules, fiber-optic interfaces and software, is described

Development and modelling of a steel slag filter effluent neutralization process with CO2-enriched air from an upstream bioprocess.

Science.gov (United States)

Bove, Patricia; Claveau-Mallet, Dominique; Boutet, Étienne; Lida, Félix; Comeau, Yves

2018-02-01

The main objective of this project was to develop a steel slag filter effluent neutralization process by acidification with CO 2 -enriched air coming from a bioprocess. Sub-objectives were to evaluate the neutralization capacity of different configurations of neutralization units in lab-scale conditions and to propose a design model of steel slag effluent neutralization. Two lab-scale column neutralization units fed with two different types of influent were operated at hydraulic retention time of 10 h. Tested variables were mode of flow (saturated or percolating), type of media (none, gravel, Bionest and AnoxKaldnes K3), type of air (ambient or CO 2 -enriched) and airflow rate. One neutralization field test (saturated and no media, 2000-5000 ppm CO 2 , sequential feeding, hydraulic retention time of 7.8 h) was conducted for 7 days. Lab-scale and field-scale tests resulted in effluent pH of 7.5-9.5 when the aeration rate was sufficiently high. A model was implemented in the PHREEQC software and was based on the carbonate system, CO 2 transfer and calcite precipitation; and was calibrated on ambient air lab tests. The model was validated with CO 2 -enriched air lab and field tests, providing satisfactory validation results over a wide range of CO 2 concentrations. The flow mode had a major impact on CO 2 transfer and hydraulic efficiency, while the type of media had little influence. The flow mode also had a major impact on the calcite surface concentration in the reactor: it was constant in saturated mode and was increasing in percolating mode. Predictions could be made for different steel slag effluent pH and different operation conditions (hydraulic retention time, CO 2 concentration, media and mode of flow). The pH of the steel slag filter effluent and the CO 2 concentration of the enriched air were factors that influenced most the effluent pH of the neutralization process. An increased concentration in CO 2 in the enriched air reduced calcite precipitation

46 CFR 183.376 - Grounded distribution systems (neutral grounded).

Science.gov (United States)

2010-10-01

....376 Section 183.376 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER... propulsion, power, lighting, or distribution system having a neutral bus or conductor must have the neutral... generator to ground before the generator is connected to the bus, except the neutral of an emergency power...

Analysis of variola and vaccinia virus neutralization assays for smallpox vaccines.

Science.gov (United States)

Hughes, Christine M; Newman, Frances K; Davidson, Whitni B; Olson, Victoria A; Smith, Scott K; Holman, Robert C; Yan, Lihan; Frey, Sharon E; Belshe, Robert B; Karem, Kevin L; Damon, Inger K

2012-07-01

Possible smallpox reemergence drives research for third-generation vaccines that effectively neutralize variola virus. A comparison of neutralization assays using different substrates, variola and vaccinia (Dryvax and modified vaccinia Ankara [MVA]), showed significantly different 90% neutralization titers; Dryvax underestimated while MVA overestimated variola neutralization. Third-generation vaccines may rely upon neutralization as a correlate of protection.

The undergraduate optics course at Millersville University

Science.gov (United States)

Gilani, Tariq H.; Dushkina, Natalia M.

2009-06-01

For many years, there was no stand alone course in optics at Millersville University (MU). In the fall of 2007, the Physics Department offered for the first time PHYS 331: Fundamentals in Optics, a discovery based lab course in geometrical, physical and modern optics. This 300-level, 2 credits course consists of four contact hours per week including one-hour lecture and three hours laboratory. This course is required for BS in physics majors, but is open also to other science majors, who have the appropriate background and have met the prerequisites. This course deals with fundamental optics and optical techniques in greater depth so that the student is abreast of the activities in the forefront of the field. The goal of the course is to provide hands-on experience and in-depth preparation of our students for graduate programs in optics or as a workforce for new emerging high-tech local industries. Students learn applied optics through sequence of discovery based laboratory experiments chosen from a broad range of topics in optics and lasers, as the emphasis is on geometrical optics, geometrical aberrations in optical systems, wave optics, microscopy, spectroscopy, polarization, birefringence, laser generation, laser properties and applications, and optical standards. The peer-guided but open-ended approach provides excellent practice for the academic model of science research. Solving problems is embedded in the laboratory part as an introduction to or a conclusion of the experiment performed during the lab period. The homework problems are carefully chosen to reflect the most important relations from the covered material. Important part of the student learning strategy is the individual work on a final mini project which is presented in the class and is included in the final grading. This new course also impacted the department's undergraduate research and training programs. Some of the individual projects were extended to senior research projects in optics as

Optical-lattice Hamiltonians for relativistic quantum electrodynamics

International Nuclear Information System (INIS)

Kapit, Eliot; Mueller, Erich

2011-01-01

We show how interpenetrating optical lattices containing Bose-Fermi mixtures can be constructed to emulate the thermodynamics of quantum electrodynamics (QED). We present models of neutral atoms on lattices in 1+1, 2+1, and 3+1 dimensions whose low-energy effective action reduces to that of photons coupled to Dirac fermions of the corresponding dimensionality. We give special attention to (2+1)-dimensional quantum electrodynamics (QED3) and discuss how two of its most interesting features, chiral symmetry breaking and Chern-Simons physics, could be observed experimentally.

Development of KSTAR Neutral Beam Heating System

Energy Technology Data Exchange (ETDEWEB)

Oh, B. H.; Song, W. S.; Yoon, B. J. (and others)

2007-10-15

The prototype components of a neutral beam injection (NBI) system have been developed for the KSTAR, and a capability of the manufactured components has been tested. High power ion source, acceleration power supply, other ion source power supplies, neutralizer, bending magnet for ion beam separation, calorimeter, and cryo-sorption pump have been developed by using the domestic technologies and tested for a neutral beam injection of 8 MW per beamline with a pulse duration of 300 seconds. The developed components have been continuously upgraded to achieve the design requirements. The development technology of high power and long pulse neutral beam injection system has been proved with the achievement of 5.2 MW output for a short pulse length and 1.6 MW output for a pulse length of 300 seconds. Using these development technologies, the domestic NB technology has been stabilized under the development of high power ion source, NB beamline components, high voltage and current power supplies, NB diagnostics, NB system operation and control.

International Thermonuclear Experimental Reactor (ITER) neutral beam design

International Nuclear Information System (INIS)

Myers, T.J.; Brook, J.W.; Spampinato, P.T.; Mueller, J.P.; Luzzi, T.E.; Sedgley, D.W.

1990-10-01

This report discusses the following topics on ITER neutral beam design: ion dump; neutralizer and module gas flow analysis; vacuum system; cryogenic system; maintainability; power distribution; and system cost

Canine distemper virus neutralization activity is low in human serum and it is sensitive to an amino acid substitution in the hemagglutinin protein

International Nuclear Information System (INIS)

Zhang, Xinsheng; Wallace, Olivia L.; Domi, Arban; Wright, Kevin J.; Driscoll, Jonathan; Anzala, Omu; Sanders, Eduard J.; Kamali, Anatoli; Karita, Etienne; Allen, Susan; Fast, Pat; Gilmour, Jill; Price, Matt A.; Parks, Christopher L.

2015-01-01

Serum was analyzed from 146 healthy adult volunteers in eastern Africa to evaluate measles virus (MV) and canine distemper virus (CDV) neutralizing antibody (nAb) prevalence and potency. MV plaque reduction neutralization test (PRNT) results indicated that all sera were positive for MV nAbs. Furthermore, the 50% neutralizing dose (ND50) for the majority of sera corresponded to antibody titers induced by MV vaccination. CDV nAbs titers were low and generally were detected in sera with high MV nAb titers. A mutant CDV was generated that was less sensitive to neutralization by human serum. The mutant virus genome had 10 nucleotide substitutions, which coded for single amino acid substitutions in the fusion (F) and hemagglutinin (H) glycoproteins and two substitutions in the large polymerase (L) protein. The H substitution occurred in a conserved region involved in receptor interactions among morbilliviruses, implying that this region is a target for cross-reactive neutralizing antibodies. - Highlights: • Screened 146 serum samples for measles virus (MV) and canine distemper virus (CDV) neutralizing antibody (nAb). • MV nAb is prevalent in the sera. • CDV neutralizing activity is generally low or absent and when detected it is present in sera with high MV nAb titers. • A neutralization-resistant CDV mutant was isolated using human serum selection. • A mutation was identified in the receptor-binding region of CDV hemagglutinin protein that confers the neutralization resistance

Canine distemper virus neutralization activity is low in human serum and it is sensitive to an amino acid substitution in the hemagglutinin protein

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xinsheng, E-mail: xzhang@iavi.org [AIDS Vaccine Design and Development Laboratory, International AIDS Vaccine Initiative (IAVI), Brooklyn, NY (United States); Molecular and Cellular Biology Program, State University of New York, Brooklyn, NY (United States); Wallace, Olivia L.; Domi, Arban; Wright, Kevin J.; Driscoll, Jonathan [AIDS Vaccine Design and Development Laboratory, International AIDS Vaccine Initiative (IAVI), Brooklyn, NY (United States); Anzala, Omu [Kenya AIDS Vaccine Initiative (KAVI)-Institute of Clinical Research, Nairobi (Kenya); Sanders, Eduard J. [Centre for Geographic Medicine Research, Kenya Medical Research Institute (KEMRI), Kilifi, Kenya & Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford, Headington (United Kingdom); Kamali, Anatoli [MRC/UVRI Uganda Virus Research Unit on AIDS, Masaka and Entebbe (Uganda); Karita, Etienne [Projet San Francisco, Kigali (Rwanda); Allen, Susan [Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA (United States); Fast, Pat [Department of Medical Affairs, International AIDS Vaccine Initiative, NY, NY (United States); Gilmour, Jill [Human Immunology Laboratory, International AIDS Vaccine Initiative, London (United Kingdom); Price, Matt A. [Department of Medical Affairs, International AIDS Vaccine Initiative, NY, NY (United States); Department of Epidemiology and Biostatistics, University of California at San Francisco, San Francisco, CA (United States); Parks, Christopher L. [AIDS Vaccine Design and Development Laboratory, International AIDS Vaccine Initiative (IAVI), Brooklyn, NY (United States); Molecular and Cellular Biology Program, State University of New York, Brooklyn, NY (United States)

2015-08-15

Serum was analyzed from 146 healthy adult volunteers in eastern Africa to evaluate measles virus (MV) and canine distemper virus (CDV) neutralizing antibody (nAb) prevalence and potency. MV plaque reduction neutralization test (PRNT) results indicated that all sera were positive for MV nAbs. Furthermore, the 50% neutralizing dose (ND50) for the majority of sera corresponded to antibody titers induced by MV vaccination. CDV nAbs titers were low and generally were detected in sera with high MV nAb titers. A mutant CDV was generated that was less sensitive to neutralization by human serum. The mutant virus genome had 10 nucleotide substitutions, which coded for single amino acid substitutions in the fusion (F) and hemagglutinin (H) glycoproteins and two substitutions in the large polymerase (L) protein. The H substitution occurred in a conserved region involved in receptor interactions among morbilliviruses, implying that this region is a target for cross-reactive neutralizing antibodies. - Highlights: • Screened 146 serum samples for measles virus (MV) and canine distemper virus (CDV) neutralizing antibody (nAb). • MV nAb is prevalent in the sera. • CDV neutralizing activity is generally low or absent and when detected it is present in sera with high MV nAb titers. • A neutralization-resistant CDV mutant was isolated using human serum selection. • A mutation was identified in the receptor-binding region of CDV hemagglutinin protein that confers the neutralization resistance.

High Epstein-Barr Virus Load and Genomic Diversity Are Associated with Generation of gp350-Specific Neutralizing Antibodies following Acute Infectious Mononucleosis.

Science.gov (United States)

Weiss, Eric R; Alter, Galit; Ogembo, Javier Gordon; Henderson, Jennifer L; Tabak, Barbara; Bakiş, Yasin; Somasundaran, Mohan; Garber, Manuel; Selin, Liisa; Luzuriaga, Katherine

2017-01-01

The Epstein-Barr virus (EBV) gp350 glycoprotein interacts with the cellular receptor to mediate viral entry and is thought to be the major target for neutralizing antibodies. To better understand the role of EBV-specific antibodies in the control of viral replication and the evolution of sequence diversity, we measured EBV gp350-specific antibody responses and sequenced the gp350 gene in samples obtained from individuals experiencing primary EBV infection (acute infectious mononucleosis [AIM]) and again 6 months later (during convalescence [CONV]). EBV gp350-specific IgG was detected in the sera of 17 (71%) of 24 individuals at the time of AIM and all 24 (100%) individuals during CONV; binding antibody titers increased from AIM through CONV, reaching levels equivalent to those in age-matched, chronically infected individuals. Antibody-dependent cell-mediated phagocytosis (ADCP) was rarely detected during AIM (4 of 24 individuals; 17%) but was commonly detected during CONV (19 of 24 individuals; 79%). The majority (83%) of samples taken during AIM neutralized infection of primary B cells; all samples obtained at 6 months postdiagnosis neutralized EBV infection of cultured and primary target cells. Deep sequencing revealed interpatient gp350 sequence variation but conservation of the CR2-binding site. The levels of gp350-specific neutralizing activity directly correlated with higher peripheral blood EBV DNA levels during AIM and a greater evolution of diversity in gp350 nucleotide sequences from AIM to CONV. In summary, we conclude that the viral load and EBV gp350 diversity during early infection are associated with the development of neutralizing antibody responses following AIM. Antibodies against viral surface proteins can blunt the spread of viral infection by coating viral particles, mediating uptake by immune cells, or blocking interaction with host cell receptors, making them a desirable component of a sterilizing vaccine. The EBV surface protein gp350 is a

(IAM Series No 005) Are “Market Neutral” Hedge Funds Really Market Neutral?

OpenAIRE

Andrew Patton

2004-01-01

One can consider the concept of market neutrality for hedge funds as having breadth and depth: breadth reflects the number of market risks to which a fund is neutral, while depth reflects the completeness of the neutrality of the fund to market risks. We focus on market neutrality depth, and propose five different neutrality concepts. Mean neutrality nests the standard correlation-based definition of neutrality. Variance neutrality, Value-at-Risk neutrality and tail neutrality all relate to t...

Steady state neutral beam injector

International Nuclear Information System (INIS)

Mattoo, S.K.; Bandyopadhyay, M.; Baruah, U.K.; Bisai, N.; Chakbraborty, A.K.; Chakrapani, Ch.; Jana, M.R.; Bajpai, M.; Jaykumar, P.K.; Patel, D.; Patel, G.; Patel, P.J.; Prahlad, V.; Rao, N.V.M.; Rotti, C.; Singh, N.P.; Sridhar, B.

2000-01-01

Learning from operational reliability of neutral beam injectors in particular and various heating schemes including RF in general on TFTR, JET, JT-60, it has become clear that neutral beam injectors may find a greater role assigned to them for maintaining the plasma in steady state devices under construction. Many technological solutions, integrated in the present day generation of injectors have given rise to capability of producing multimegawatt power at many tens of kV. They have already operated for integrated time >10 5 S without deterioration in the performance. However, a new generation of injectors for steady state devices have to address to some basic issues. They stem from material erosion under particle bombardment, heat transfer > 10 MW/m 2 , frequent regeneration of cryopanels, inertial power supplies, data acquisition and control of large volume of data. Some of these engineering issues have been addressed to in the proposed neutral beam injector for SST-1 at our institute; the remaining shall have to wait for the inputs of the database generated from the actual experience with steady state injectors. (author)

Γ-source Neutral Point Clamped Inverter

DEFF Research Database (Denmark)

Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

Transformer based Z-source inverters are recently proposed to achieve promising buck-boost capability. They have improved higher buck-boost capability, smaller size and less components count over Z-source inverters. On the other hand, neutral point clamped inverters have less switching stress...... and better output performance comparing with traditional two-level inverters. Integrating these two types of configurations can help neutral point inverters achieve enhanced votlage buck-boost capability....

Tandem mirror experiment-upgrade neutral beam test stand: a powerful tool for development and quality assurance

International Nuclear Information System (INIS)

Hibbs, S.M.; Kane, R.J.; Kerr, R.G.; Poulsen, P.

1983-01-01

During construction of the Tandem Mirror Experiment-Upgrade (TMX-U), we assembled a test stand to develop electronics for the neutral beam system. In the first six months of test stand use we operated a few neutral beam injector modules and directed considerable effort toward improving the electronic system. As system development progressed, our focus turned toward improving the injector modules themselves. The test stand has proved to be the largest single contributor to the successful operation of neutral beams on TMX-U, primarily because it provides quality assurance andd development capability in conjunction with the scheduled activities of the main experiment. This support falls into five major categories: (1) electronics development, (2) operator training, (3) injector module testing and characterization, (4) injector module improvements, and (5) physics improvements (through areas affected by injector operation). Normal day-to-day operation of the test stand comes under the third category, testing and characterization, and comprises our final quality assurance activity for newly assembled or repaired modules before they are installed on TMX-U

Electron-impact ionization of SiCl{sub 3} using an improved crossed fast-neutral-beam - electron-beam apparatus

Energy Technology Data Exchange (ETDEWEB)

Mahoney, J M; Gutkin, M V; Tarnovsky, V; Becker, K [Department of Physics and Engineering Physics, Stevens Institute of Technology, Hoboken, NJ 07030 (United States)], E-mail: kbecker@poly.edu

2008-05-15

The fast-neutral-beam technique is a versatile approach to the determination of absolute cross sections for electron-impact ionization of atoms, stable molecules as well as free radicals and metastable species. A fast neutral beam of the species under study is prepared by charge-transfer neutralization of a mass-selected ion beam and the species are subsequently ionized by an electron beam. Mass- and energy-dispersive selection separates singly from multiply charged ions and parent from fragment ions and allows the determination of partial ionization cross sections. Here we describe some major improvements that were made recently to the fast-beam apparatus that has been used extensively for ionization cross section measurements for the past 15 years in our group. Experiments using well-established ionization cross sections in conjunction with extensive ion trajectory simulations were carried out to test the satisfactory performance of the modified fast-neutral-beam apparatus. We also report absolute partial cross sections for the formation of various singly charged positive ions produced by electron impact on SiCl{sub 3} for impact energies from threshold to 200 eV in the modified fast-beam apparatus.

Plasma heating with multi-MeV neutral atom beams

International Nuclear Information System (INIS)

Grisham, L.R.; Post, D.E.; Mikkelsen, D.R.; Eubank, H.P.

1981-10-01

We explore the utility and feasibility of neutral beams of greater than or equal to 6 AMU formed from negative ions, and also of D 0 formed from D - . The negative ions would be accelerated to approx. 1 to 2 MeV/AMU and neutralized, whereupon the neutral atoms would be used to heat and, perhaps, to drive current in magnetically confined plasmas. Such beams appear feasible and offer the promise of significant advantages relative to conventional neutral beams based on positive deuterium ions at approx. 150 keV

Net neutrality towards a co-regulatory solution

CERN Document Server

Marsden, Christopher T

2010-01-01

In considering market developments and policy responses to some of the most heated net-neutrality debates in Europe and the United States, Net Neutrality is the first, fully comprehensive overview of the subject. This book is also unique in providing readers with a supplementary outline of recommended policy prescriptives.

Springer handbook of lasers and optics

CERN Document Server

2012-01-01

The Springer Handbook of Lasers and Optics provides fast, up-to-date, comprehensive and authoritative coverage of the wide fields of optics and lasers. It is written for daily use in the office or laboratory and offers explanatory text, data, and references needed for anyone working with lasers and optical instruments. This second edition features numerous updates and additions. Especially four new chapters on Fiber Optics, Integrated Optics, Frequency Combs, and Interferometry reflect the major changes. In addition, chapters Optical Materials and Their Properties, Optical Detectors, Nanooptics, and Optics far Beyond the Diffraction Limit have been thoroughly revised and updated. The now 25 chapters are grouped into four parts which cover basic principles and materials, fabrication and properties of optical components, coherent and incoherent light sources, and, finally, selected applications and special fields such as terahertz photonics, x-ray optics and holography. Each chapter is authored by respected exp...

Non-Cationic Proteins Are Associated with HIV Neutralizing Activity in Genital Secretions of Female Sex Workers.

Science.gov (United States)

Birse, Kenzie D M; Cole, Amy L; Hirbod, Taha; McKinnon, Lyle; Ball, Terry B; Westmacott, Garrett R; Kimani, Joshua; Plummer, Frank; Cole, Alexander M; Burgener, Adam; Broliden, Kristina

2015-01-01

Cationic proteins found in cervicovaginal secretions (CVS) are known to contribute to the early antiviral immune response against HIV-infection in vitro. We here aimed to define additional antiviral factors that are over-expressed in CVS from female sex workers at high risk of infection. CVS were collected from Kenyan HIV-seronegative (n = 34) and HIV-seropositive (n = 12) female sex workers, and were compared with those from HIV-seronegative low-risk women (n = 12). The highly exposed seronegative (HESN) sex workers were further divided into those with less (n = 22) or more (n = 12) than three years of documented sex work. Cationic protein-depleted CVS were assessed for HIV-neutralizing activity by a PBMC-based HIV-neutralizing assay, and then characterized by proteomics. HIV neutralizing activity was detected in all unprocessed CVS, however only CVS from the female sex worker groups maintained its HIV neutralizing activity after cationic protein-depletion. Differentially abundant proteins were identified in the cationic protein-depleted secretions including 26, 42, and 11 in the HESN>3 yr, HESNHIV-positive groups, respectively. Gene ontology placed these proteins into functional categories including proteolysis, oxidation-reduction, and epidermal development. The proteins identified in this study include proteins previously associated with the HESN phenotype in other cohorts as well as novel proteins not yet associated with anti-HIV activities. While cationic proteins appear to contribute to the majority of the intrinsic HIV neutralizing activity in the CVS of low-risk women, a broader range of non-cationic proteins were associated with HIV neutralizing activity in HESN and HIV-positive female sex workers. These results indicate that novel protein factors found in CVS of women with high-risk sexual practices may have inherent antiviral activity, or are involved in other aspects of anti-HIV host defense, and warrant further exploration into their mode of action.

Energy spectrum of neutrals formed in an ion accelerator

International Nuclear Information System (INIS)

Fink, J.H.

1982-01-01

This work presents an estimate of the energy distribution of the neutrals formed in the ion beam accelerator. However it does not determine the fraction of those neutrals which leave the neutral beam injector and go on into the reactor. To do that, more details of the beam line performance are needed

Method to minimize the low-frequency neutral-point voltage oscillations with time-offset injection for neutral-point-clamped inverters

DEFF Research Database (Denmark)

Choi, Uimin; Lee, Kyo-Beum; Blaabjerg, Frede

2013-01-01

This paper proposes a method to reduce the low-frequency neutral-point voltage oscillations. The neutral-point voltage oscillations are considerably reduced by adding a time-offset to the three phase turn-on times. The proper time-offset is simply calculated considering the phase currents and dwell...

Coupled plasma-neutral transport model for the scrape-off region

International Nuclear Information System (INIS)

Galambos, J.D.; Peng, Y.K.M.; Heifetz, D.

1985-03-01

Analysis of the scrape-off region requires treatment of the plasma transport along and across the field lines and inclusion of the neutral transport effects. A method for modeling the scrape-off region that is presented here uses separate models for each of these aspects that are coupled together through an iteration procedure that requires only minimal numerical effort. The method is applied here to estimate the neutral pumping rates in the pump-limiter and divertor options for a proposed deuterium-tritium (D-T) ignition experiment. High neutral recycling in the vicinity of the neutralizer plate dramatically affects pumping rates for both the pump-limiter and divertor. In both cases, the plasma flow into the channel surrounding the neutralizer plate is greatly reduced by the neutral recycling. The fraction of this flow that is pumped can be large (> 50%), but in general it is dependent on the particular geometry and plasma conditions. It is estimated that pumping speeds approximately greater than 10 5 L/s are adequate for the exhaust requirements in the pump-limiter and the divertor cases. Also, high neutral recycling on the front surface of the limiter tends to increase the neutral pumping rate

Economic Features of the Internet and Network Neutrality

OpenAIRE

Nicholas Economides

2015-01-01

We discuss the issue of a possible abolition of network neutrality and the introduction of paid prioritization by residential broadband access networks.We show that, in short run analysis where bandwidth is fixed, and in the absence of congestion, network neutrality tends to maximize total surplus. When an ISP violates network neutrality and invests the extra profits to bandwidth expansion, the presence of more bandwidth alleviates the allocative distortion, and can even reverse it. We also d...

Nonlinear super-resolution nano-optics and applications

CERN Document Server

Wei, Jingsong

2015-01-01

This book covers many advances in the subjects of nano-optics and nano photonics. The author describes the principle and technical schematics of common methods for breaking through the optical diffraction limit and focuses on realizing optical super-resolution with nonlinear effects of thin film materials. The applications of nonlinear optical super-resolution effects in nano-data storage, nanolithography, and nano-imaging are also presented. This book is useful to graduate students majoring in optics and nano science and also serves as a reference book for academic researchers, engineers, technical professionals in the fields of super-resolution optics and laser techniques, nano-optics and nano photonics, nano-data storage, nano imaging, micro/nanofabrication and nanolithography and nonlinear optics.

Vendor neutral archive in PACS

International Nuclear Information System (INIS)

Agarwal, Tapesh Kumar; Sanjeev

2012-01-01

An archive is a location containing a collection of records, documents, or other materials of historical importance. An integral part of Picture Archiving and Communication System (PACS) is archiving. When a hospital needs to migrate a PACS vendor, the complete earlier data need to be migrated in the format of the newly procured PACS. It is both time and money consuming. To address this issue, the new concept of vendor neutral archive (VNA) has emerged. A VNA simply decouples the PACS and workstations at the archival layer. This is achieved by developing an application engine that receives, integrates, and transmits the data using the different syntax of a Digital Imaging and Communication in Medicine (DICOM) format. Transferring the data belonging to the old PACS to a new one is performed by a process called migration of data. In VNA, a number of different data migration techniques are available to facilitate transfer from the old PACS to the new one, the choice depending on the speed of migration and the importance of data. The techniques include simple DICOM migration, prefetch-based DICOM migration, medium migration, and the expensive non-DICOM migration. “Vendor neutral” may not be a suitable term, and “architecture neutral,” “PACS neutral,” “content neutral,” or “third-party neutral” are probably better and preferred terms. Notwithstanding this, the VNA acronym has come to stay in both the medical IT user terminology and in vendor nomenclature, and radiologists need to be aware of its impact in PACS across the globe

Material failures observed in Doublet III neutral beamlines

International Nuclear Information System (INIS)

Bailey, E.W.; Colleraine, A.; Doll, D.; Grunloh, H.; Kim, J.; Langhorn, A.; Thurgood, B.

1983-12-01

The Doublet III neutral beam injectors consist of three separable spools two meters in diameter by four meters long overall when assembled. Contained within these spools are the neutralizers, ion dumps, deflecting magnet, calorimeter dumps, cryogenic panels and beam scraping collimators 3,7. To date three beamlines are in operation on Doublet III, and the beams have accumulated operating time of approximately 32 months, with the oldest having been in operation for 18 months. During this time operation of DIII with the neutral beam sources has demonstrated the following: 7.8 MW injected neutrals from three beamlines (6 sources), high β (4.5%), and non-circular plasma shape. The sources have also exhibited a very reliable injected shot history 4, 5, 6, 8. Material failures encountered during the operation of DIII N.B. injectors and the solutions to these failures are described. Failures include cracking of the neutralizer exit collimator due to heating cycles, failure of cyropanel support rods due to cooling cycles, failure of the sliding drive of the moveable calorimeter due to friction

Harnessing mode-selective nonlinear optics for on-chip multi-channel all-optical signal processing

Directory of Open Access Journals (Sweden)

Ming Ma

2016-11-01

Full Text Available All-optical signal processing based on nonlinear optical effects allows for the realization of important functions in telecommunications including wavelength conversion, optical multiplexing/demultiplexing, Fourier transformation, and regeneration, amongst others, on ultrafast time scales to support high data rate transmission. In integrated photonic subsystems, the majority of all-optical signal processing systems demonstrated to date typically process only a single channel at a time or perform a single processing function, which imposes a serious limitation on the functionality of integrated solutions. Here, we demonstrate how nonlinear optical effects can be harnessed in a mode-selective manner to perform simultaneous multi-channel (two and multi-functional optical signal processing (i.e., regenerative wavelength conversion in an integrated silicon photonic device. This approach, which can be scaled to a higher number of channels, opens up a new degree of freedom for performing a broad range of multi-channel nonlinear optical signal processing functions using a single integrated photonic device.

Post-Test Inspection of NASA's Evolutionary Xenon Thruster Long-Duration Test Hardware: Discharge and Neutralizer Cathodes

Science.gov (United States)

Shastry, Rohit; Soulas, George C.

2016-01-01

The NEXT Long-Duration Test is part of a comprehensive thruster service life assessment intended to demonstrate overall throughput capability, validate service life models, quantify wear rates as a function of time and operating condition, and identify any unknown life-limiting mechanisms. The test was voluntarily terminated in February 2014 after demonstrating 51,184 hours of high-voltage operation, 918 kg of propellant throughput, and 35.5 MN-s of total impulse. The post-test inspection of the thruster hardware began shortly afterwards with a combination of non-destructive and destructive analysis techniques, and is presently nearing completion. This paper presents relevant results of the post-test inspection for both discharge and neutralizer cathodes. Discharge keeper erosion was found to be significantly reduced from what was observed in the NEXT 2 kh wear test and NSTAR Extended Life Test, providing adequate protection of vital cathode components throughout the test with ample lifetime remaining. The area of the discharge cathode orifice plate that was exposed by the keeper orifice exhibited net erosion, leading to cathode plate material building up in the cathode-keeper gap and causing a thermally-induced electrical short observed during the test. Significant erosion of the neutralizer cathode orifice was also found and is believed to be the root cause of an observed loss in flow margin. Deposition within the neutralizer keeper orifice as well as on the downstream surface was thicker than expected, potentially resulting in a facility-induced impact on the measured flow margin from plume mode. Neutralizer keeper wall erosion on the beam side was found to be significantly lower compared to the NEXT 2 kh wear test, likely due to the reduction in beam extraction diameter of the ion optics that resulted in decreased ion impingement. Results from the post-test inspection have led to some minor thruster design improvements.

Fault detection and protection system for neutral beam generators on the Neutral Beam Engineering Test Facility (NBETF)

International Nuclear Information System (INIS)

deVries, G.J.; Chesley, K.L.; Owren, H.M.

1983-12-01

Neutral beam sources, their power supplies and instrumentation can be damaged from high voltage sparkdown or from overheating due to excessive currents. The Neutral Beam Engineering Test Facility (NBETF) in Berkeley has protective electronic hardware that senses a condition outside a safe operating range and generates a response to terminate such a fault condition. A description of this system is presented in this paper. 8 references, 2 figures, 2 tables

42 CFR 412.352 - Budget neutrality adjustment.

Science.gov (United States)

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Budget neutrality adjustment. 412.352 Section 412.352 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... § 412.352 Budget neutrality adjustment. For FY 1992 through FY 1995, CMS will determine an adjustment to...

Probing neutral density at the plasma edge of Tore Supra with CX excited impurity ions

International Nuclear Information System (INIS)

Hess, W.R.; Mattioli, M.; Guirlet, R.

1993-01-01

In Tokamak plasma physics renewed interest in visible spectroscopy has grown for two reasons. The use of fiber optics allows observation of local sources of both impurities and of hydrogen by observing radiation of low ionization states. Moreover, charge exchange spectroscopy (CXS) with either auxiliary or heating neutral beams is a standard technique to determine the ion temperature and impurity density profiles. After a short description of the experimental setup and the ergodic divertor of Tore Supra (TS), two discharges in which space-resolved observations of the CVI (8-7) line clearly show the presence of CX-related effects. A well isolated spectral line at 5304.6 A is discussed. Tentative identification as CIII (1s 2 2s, 7-5) is suggested. The conclusion shows the usefulness of the reported results for probing neutral density at the plasma edge by detecting CX excited impurity ions and that highly ionized C 6+ ions exist in the MARFE regions. To the best of our knowledge, only very low ionization C and O ions (such as CIII or OIV) have been previously reported in these regions

Investigation of edge neutral flux on the ISX-B tokamak using a low-energy charge-exchange analyzer

International Nuclear Information System (INIS)

Thomas, D.M.

1983-08-01

To study the emission of D 0 from the periphery of a tokamak plasma, a low-energy neutral particle spectrometer optimized for (16 0 neutrals and a four-channel electrostatic analyzer to energy analyze the negative ions. The spectrometer was absolutely calibrated using D 0 beams formed by electron capture by positive ions in a gas cell and by photo-detachment of negative ions by a yttrium-aluminum-garnet laser. For the observation region chosen on ISX-B (120 0 toroidally away from the limiter, near the gas puff), the neutral particle flux has a two-component nature. These data are well fit by two separate exponential distributions of equivalent temperatures 6 to 8 eV for particle energies below about 80 eV and 70 to 80 eV for particle energies above 80 eV. For ohmically heated discharges, the measured particle flux in the energy range 25 to 700 eV is approx. 2.5 x 10 15 cm - 2 .s - 1 ; the mean particle energy is approx. 70 eV, and the calculated flux at the wall is approx. 30 mW/cm 2 . The major effect of neutral beam heating is to increase the particle flux in the 25- to 700-eV range by a factor of 3

The gravitational-optical methods for examination of the hypothesis about galaxies and antigalaxies in the Universe

Science.gov (United States)

Gribov, I. A.; Trigger, S. A.

2018-01-01

The optical-gravitational methods for distinction between photons and antiphotons (galaxies, emitting photons and antigalaxies, emitting antiphotons) in the proposed hypothesis of totally gravitationally neutral (TGN)-Universe are considered. These methods are based on the extension of the earlier proposed the gravitationally neutral Universe concept, including now gravitational neutrality of vacuum. This concept contains (i) enlarged unbroken baryon-like, charge, parity and time and full ±M gr gravitational symmetries between all massive elementary particles-antiparticles, including (ia) ordinary matter (OM)-ordinary antimatter (OAM), (ib) dark matter (DM)-dark antimatter (DAM) and (ii) the resulting gravitational repulsion between equally presented (OM+DM)-galactic and (OAM+DAM)-antigalactic clusters, what spatially isolates and preserves their mutual annihilations in the large-scale TGN-Universe. It is assumed the gravitational balance not only between positive and negative gravitational masses of elementary particles and antiparticles, but also between all massless fields of the quantum field theory (QFT), including the opposite gravitational properties of photons and antiphotons, etc, realizing the totally gravitationally neutral vacuum in the QFT. These photons and antiphotons could be distinguishable optically-gravitationally, if one can observe a massive, deviating OM-star or a deviating (OM+DM)-galaxy from our galactic group, moving fast enough on the heavenly sphere, crossing the line directed to spatially separated far-remote galactic clusters (with the visible OM-markers, emitting photons) or antigalactic cluster (with the visible OAM-markers, emitting antiphotons). The deviations and gravitational microlensing with temporarily increased or decreased brightness of their OM and OAM rays will be opposite, indicating the galaxies and antigalaxies in the Universe.

Neutral-particle-beam production and injection

International Nuclear Information System (INIS)

Post, D.; Pyle, R.

1982-07-01

This paper is divided into two sections: the first is a discussion of the interactions of neutral beams with confined plasmas, the second is concerned with the production and diagnosis of the neutral beams. In general we are dealing with atoms, molecules, and ions of the isotopes of hydrogen, but some heavier elements (for example, oxygen) will be mentioned. The emphasis will be on single-particle collisions; selected atomic processes on surfaces will be included

Network Neutrality : A Survey of the Economic Literature

NARCIS (Netherlands)

Schuett, F.

2010-01-01

This paper reviews the small but growing economic literature on network neutrality. It considers a number of possible departures from network neutrality, in particular termination fees, second-degree price discrimination, and vertical foreclosure.

Cooling and trapping neutral atoms with radiative forces

International Nuclear Information System (INIS)

Bagnato, V.S.; Castro, J.C.; Li, M.S.; Zilio, S.C.

1988-01-01

Techniques to slow and trap neutral atoms at high densities with radiative forces are discussed in this review articles. Among several methods of laser cooling, it is emphasized Zeeman Tuning of the electronic levels and frequency-sweeping techniques. Trapping of neutral atoms and recent results obtained in light and magnetic traps are discussed. Techniques to further cool atoms inside traps are presented and the future of laser cooling of neutral atoms by means of radiation pressure is discussed. (A.C.A.S.) [pt

Individuals Diagnosed with Schizophrenia Assign Emotional Importance to Neutral Stimuli: An fMRI Study

OpenAIRE

Lakis, Nadia; Mendrek, Adrianna

2013-01-01

The majority of functional neuroimaging studies investigating neural correlates of emotion processing in schizophrenia report a significant deficit in limbic structures activation in patients relative to control participants. Recently it has been suggested that this apparent “deficit” could be due to an enhanced sensitivity of the neutral material in individuals diagnosed with schizophrenia, rather than due to their inefficiency in emotion processing. The purpose of the present study was to t...

Hydrogen ion species analysis and related neutral beam injection power assessment in the Heliotron E neutral beam injection system

International Nuclear Information System (INIS)

Sano, Fumimichi; Obiki, Tokuhiro; Sasaki, Akihiko; Iiyoshi, Atsuo; Uo, Koji

1982-01-01

The hydrogen ion species in a Heliotron E neutral beam injection system of maximum electric power 6.3 MW were analyzed in order to assess the neutral beam power injected into the torus. The masimum p roton ratio of the cylindrical bucket type ion source used was observed to be more than 90 percent assuming that the angular divergences for the respective species in the beam are the same. The experimental data are compared with calculations using a particle balance model. The analysis indicates that the net injection power reaches nearly 2.7 MW at the optimal conditions of the system considering the geometrical limitation of the neutral beam path. (author)

The handbook of optical communication networks

CERN Document Server

Ilyas, Mohammad

2003-01-01

The Handbook of Optical Communication Networks presents comprehensive, up-to-date technical information on integrated, state-of-the-art optical networks. Beginning with an in-depth intoduction to the field, top international authorities explore every major aspect of optical networks, from basic concepts to research grade material. Their discussions cover all of the essential topics, including protocols, resource management, routing and wavelength assignment in WDM networks, connection management, survivability, enabling technologies, and future trends.

Fabrication and Optimization of Stable, Optically Transparent, and Reusable pH-Responsive Silk Membranes

Directory of Open Access Journals (Sweden)

Andreas Toytziaridis

2016-11-01

Full Text Available The fabrication of silk-based membranes that are stable, optically transparent and reusable is yet to be achieved. To address this bottleneck we have developed a method to produce transparent chromogenic silk patches that are optically responsive to pH. The patches were produced by blending regenerated silk fibroin (RSF, Laponite RD (nano clay and the organic dyes neutral red and Thionine acetate. The Laponite RD played a central role in the patch mechanical integrity and prevention of dye leaching. The process was optimized using a factorial design to maximize the patch response to pH by UV absorbance and fluorescence emission. New patches of the optimized protocol, made from solutions containing 125 μM neutral red or 250 μM of Thionine and 15 mg/mL silk, were further tested for operational stability over several cycles of pH altering. Stability, performance, and reusability were achieved over the tested cycles. The approach could be extended to other reporting molecules or enzymes able to bind to Laponite.

Ballistic-neutralized chamber transport of intense heavy ion beams

International Nuclear Information System (INIS)

Rose, D.V.; Welch, D.R.; Oliver, B.V.; Clark, R.E.; Sharp, W.M.; Friedman, A.

2001-01-01

Two-dimensional particle-in-cell simulations of intense heavy ion beams propagating in an inertial confinement fusion (ICF) reactor chamber are presented. The ballistic-neutralized transport scheme studied uses 4 GeV Pb +1 ion beams injected into a low-density, gas-filled reactor chamber and the beam is ballistically focused onto an ICF target before entering the chamber. Charge and current neutralization of the beam is provided by the low-density background gas. The ballistic-neutralized simulations include stripping of the beam ions as the beam traverses the chamber as well as ionization of the background plasma. In addition, a series of simulations are presented that explore the charge and current neutralization of the ion beam in an evacuated chamber. For this vacuum transport mode, neutralizing electrons are only drawn from sources near the chamber entrance

University Students from Single-Sex and Coeducational High Schools: Differences in Majors and Attitudes at a Catholic University

Science.gov (United States)

Karpiak, Christie P.; Buchanan, James P.; Hosey, Megan; Smith, Allison

2007-01-01

We conducted an archival study at a coeducational Catholic university to test the proposition that single-sex secondary education predicts lasting differences in college majors. Men from single-sex schools were more likely to both declare and graduate in gender-neutral majors than those from coeducational schools. Women from single-sex schools…

On the role of neutral flow in field-aligned currents

Science.gov (United States)

Mannucci, Anthony J.; Verkhoglyadova, Olga P.; Meng, Xing; McGranaghan, Ryan

2018-01-01

In this brief note we explore the role of the neutral atmosphere in magnetosphere-ionosphere coupling. We analyze momentum balance in the ion rest frame to form hypotheses regarding the role of neutral momentum in the lower ionosphere during geomagnetic storms. Neutral momentum that appears in the ion rest frame is likely the result of momentum imparted to ionospheric ions by solar wind flow and the resultant magnetospheric dynamics. The resulting ion-neutral collisions lead to the existence of an electric field. Horizontal electron flow balances the momentum supplied by this electric field. We suggest a possible role played by the neutral atmosphere in generating field-aligned currents due to local auroral heating. Our physical interpretation suggests that thermospheric neutral dynamics plays a complementary role to the high-latitude field-aligned currents and electric fields resulting from magnetospheric dynamics.

Neutral heavy lepton production in e+-e- collisions

International Nuclear Information System (INIS)

Ragiadakos, C.

1977-01-01

The cross-sections of the weak production of different kinds of neutral heavy leptons in e + -e - collisions are calculated and their signatures are studied. A possible electromagnetic production of neutral heavy leptons is also considered

Evidence for parity nonconservation in the weak neutral current

International Nuclear Information System (INIS)

Benvenuti, A.; Cline, D.; Messing, F.; Ford, W.; Imlay, R.; Ling, T.Y.; Mann, A.K.; Reeder, D.D.; Rubbia, C.; Stefanski, R.; Sulak, L.; Wanderer, P.

1976-01-01

Measurements of R/sup nu/ and R/sup nu-bar/, the ratios of neutral current to charged current ν and nu-bar cross sections, yield neutral current rates for ν and nu-bar that are consistent with a pure V-A interaction but 3 standard deviations from pure V or pure A, indicating the presence of parity nonconservation in the weak neutral current

Viper and cobra venom neutralization by beta-sitosterol and stigmasterol isolated from the root extract of Pluchea indica Less. (Asteraceae).

Science.gov (United States)

Gomes, A; Saha, Archita; Chatterjee, Ipshita; Chakravarty, A K

2007-09-01

We reported previously that the methanolic root extract of the Indian medicinal plant Pluchea indica Less. (Asteraceae) could neutralize viper venom-induced action [Alam, M.I., Auddy, B., Gomes, A., 1996. Viper venom neutralization by Indian medicinal plant (Hemidesmus indicus and P. indica) root extracts. Phytother. Res. 10, 58-61]. The present study reports the neutralization of viper and cobra venom by beta-sitosterol and stigmasterol isolated from the root extract of P. indica Less. (Asteraceae). The active fraction (containing the major compound beta-sitosterol and the minor compound stigmasterol) was isolated and purified by silica gel column chromatography and the structure was determined using spectroscopic analysis (EIMS, (1)H NMR, (13)C NMR). Anti-snake venom activity was studied in experimental animals. The active fraction was found to significantly neutralize viper venom-induced lethal, hemorrhagic, defibrinogenation, edema and PLA(2) activity. Cobra venom-induced lethality, cardiotoxicity, neurotoxicity, respiratory changes and PLA(2) activity were also antagonized by the active component. It potentiated commercial snake venom antiserum action against venom-induced lethality in male albino mice. The active fraction could antagonize venom-induced changes in lipid peroxidation and superoxide dismutase activity. This study suggests that beta-sitosterol and stigmasterol may play an important role, along with antiserum, in neutralizing snake venom-induced actions.

Global panel of HIV-1 Env reference strains for standardized assessments of vaccine-elicited neutralizing antibodies.

Science.gov (United States)

deCamp, Allan; Hraber, Peter; Bailer, Robert T; Seaman, Michael S; Ochsenbauer, Christina; Kappes, John; Gottardo, Raphael; Edlefsen, Paul; Self, Steve; Tang, Haili; Greene, Kelli; Gao, Hongmei; Daniell, Xiaoju; Sarzotti-Kelsoe, Marcella; Gorny, Miroslaw K; Zolla-Pazner, Susan; LaBranche, Celia C; Mascola, John R; Korber, Bette T; Montefiori, David C

2014-03-01

Standardized assessments of HIV-1 vaccine-elicited neutralizing antibody responses are complicated by the genetic and antigenic variability of the viral envelope glycoproteins (Envs). To address these issues, suitable reference strains are needed that are representative of the global epidemic. Several panels have been recommended previously, but no clear answers have been available on how many and which strains are best suited for this purpose. We used a statistical model selection method to identify a global panel of reference Env clones from among 219 Env-pseudotyped viruses assayed in TZM-bl cells with sera from 205 HIV-1-infected individuals. The Envs and sera were sampled globally from diverse geographic locations and represented all major genetic subtypes and circulating recombinant forms of the virus. Assays with a panel size of only nine viruses adequately represented the spectrum of HIV-1 serum neutralizing activity seen with the larger panel of 219 viruses. An optimal panel of nine viruses was selected and augmented with three additional viruses for greater genetic and antigenic coverage. The spectrum of HIV-1 serum neutralizing activity seen with the final 12-virus panel closely approximated the activity seen with subtype-matched viruses. Moreover, the final panel was highly sensitive for detection of many of the known broadly neutralizing antibodies. For broader assay applications, all 12 Env clones were converted to infectious molecular clones using a proviral backbone carrying a Renilla luciferase reporter gene (Env.IMC.LucR viruses). This global panel should facilitate highly standardized assessments of vaccine-elicited neutralizing antibodies across multiple HIV-1 vaccine platforms in different parts of the world. An effective HIV-1 vaccine will need to overcome the extraordinary genetic variability of the virus, where most variation occurs in the viral envelope glycoproteins that are the sole targets for neutralizing antibodies. Efforts to elicit

Neutral currents without gauge theory prejudices

International Nuclear Information System (INIS)

Sakurai, J.J.

1976-01-01

The measurement of weak neutral current processes allows a determination of the space-time structure and the isospin structure of these currents. The inclusive production data and the elastic neutrino electron scattering rules out a pure V or A structure of the current. A pure isoscalar current is in disagreement with the experimental data for the one pion production off neutrinos. Further aspects of the neutral current can be determined in neutrino-nucleus-scattering experiments. (BJ) [de

Degradation of unglazed rough graphite-aluminium solar absorber surfaces in simulated acid and neutral rain

International Nuclear Information System (INIS)

Konttinen, P.; Lund, P.D.; Salo, T.

2005-01-01

Degradation mechanisms of unglazed solar absorber surfaces based on aluminium substrate were studied. Rough graphite-aluminium surfaces were total-immersion subjected to aerated and de-aerated simulated neutral and acid rain. Test conditions were based on calculated absorber stagnation temperature and global rain acidity measurements. Changes in optical properties, elemental composition and sample mass were examined by spectrometry, energy dispersive X-ray spectrometry and thermogravimetry, respectively. The absorbers exhibited almost no degradation at pH value of 3.5. At pH 5.5 alumina on the surface hydrated significantly degrading the optical properties of the surfaces severely in most cases. Therefore these absorber surfaces can not be recommended to be used in non-glazed applications if they are exposed to rain with pH exceeding ∼ 3.5-4.5. The total-immersion test needs to be developed further as the test results exhibited poor temperature and time dependency thus preventing accurate service lifetime estimates. Still, these tests were useful in determining favourable and non-favourable operating conditions for the absorber surfaces based on aluminium substrate. (author)

Germany 2050 a greenhouse gas-neutral country. Background paper

Energy Technology Data Exchange (ETDEWEB)

Werner, Kathrin; Nissler, Diana (eds.)

2013-10-15

For several years, the German Federal Environment Agency (UBA) has been looking at the question how the climate target of a GHG-neutral Germany can be achieved. In a multi-disciplinary project launched by the agency, the first point of call was power generation because of its high emissions. It was shown in 2010 that power generation from 100 % renewable energy is possible. Even then it was understood that a renewable energy supply alone would not be enough to completely abolish greenhouse gas emissions. Other sectors of the economy would have to follow suit and undergo major changes, relying on low-GHG technology. Consequently, the study now submitted, ''Greenhouse gas-neutral Germany 2050'', includes in its research all relevant emission sources that are described in the annual National Inventory Report (NIR) on emissions and removal of greenhouse gases. Alongside complete energy supply, including heating and transport, we also look at emissions from industry, waste disposal, agriculture and forestry as well as changes in land use. We develop a target scenario. The transformations that lead to the target and related economic considerations or the selection of appropriate policy instruments, however, are not part of our study. The scenario analysis is based on the assumption that in 2050, Germany will still be an exporting industrial country with an average annual growth of 0.7 % of its gross domestic product.

3He neutral current detectors at SNO

International Nuclear Information System (INIS)

Elliott, S.R.; Browne, M.C.; Doe, P.J.

1998-01-01

The flux of solar neutrinos measured via charged and neutral current interactions can provide a model independent test of neutrino oscillations. Since the Sudbury Neutrino Observatory uses heavy water as a target, it has a large sensitivity to both interactions. A technique for observing the neutral current breakup of the deuteron using 3 He proportional counters is described

Stability of Neutral Fractional Neural Networks with Delay

Institute of Scientific and Technical Information of China (English)

LI Yan; JIANG Wei; HU Bei-bei

2016-01-01

This paper studies stability of neutral fractional neural networks with delay. By introducing the definition of norm and using the uniform stability, the sufficient condition for uniform stability of neutral fractional neural networks with delay is obtained.

Modelling of neutral particle transport in divertor plasma

International Nuclear Information System (INIS)

Kakizuka, Tomonori; Shimizu, Katsuhiro

1995-01-01

An outline of the modelling of neutral particle transport in the diverter plasma was described in the paper. The characteristic properties of divertor plasma were largely affected by interaction between neutral particles and divertor plasma. Accordingly, the behavior of neutral particle should be investigated quantitatively. Moreover, plasma and neutral gas should be traced consistently in the plasma simulation. There are Monte Carlo modelling and the neutral gas fluid modelling as the transport modelling. The former need long calculation time, but it is able to make the physical process modelling. A ultra-large parallel computer is good for the former. In spite of proposing some kinds of models, the latter has not been established. At the view point of reducing calculation time, a work station is good for the simulation of the latter, although some physical problems have not been solved. On the Monte Carlo method particle modelling, reducing the calculation time and introducing the interaction of particles are important subjects to develop 'the evolutional Monte Carlo Method'. To reduce the calculation time, two new methods: 'Implicit Monte Carlo method' and 'Free-and Diffusive-Motion Hybrid Monte-Carlo method' have been developing. (S.Y.)

Are Synonymous Substitutions in Flowering Plant Mitochondria Neutral?

Science.gov (United States)

Wynn, Emily L; Christensen, Alan C

2015-10-01

Angiosperm mitochondrial genes appear to have very low mutation rates, while non-gene regions expand, diverge, and rearrange quickly. One possible explanation for this disparity is that synonymous substitutions in plant mitochondrial genes are not truly neutral and selection keeps their occurrence low. If this were true, the explanation for the disparity in mutation rates in genes and non-genes needs to consider selection as well as mechanisms of DNA repair. Rps14 is co-transcribed with cob and rpl5 in most plant mitochondrial genomes, but in some genomes, rps14 has been duplicated to the nucleus leaving a pseudogene in the mitochondria. This provides an opportunity to compare neutral substitution rates in pseudogenes with synonymous substitution rates in the orthologs. Genes and pseudogenes of rps14 have been aligned among different species and the mutation rates have been calculated. Neutral substitution rates in pseudogenes and synonymous substitution rates in genes are significantly different, providing evidence that synonymous substitutions in plant mitochondrial genes are not completely neutral. The non-neutrality is not sufficient to completely explain the exceptionally low mutation rates in land plant mitochondrial genomes, but selective forces appear to play a small role.

Neutral and plasma shielding model for pellet ablation

International Nuclear Information System (INIS)

Houlberg, W.A.; Milora, S.L.; Attenberger, S.E.

1987-10-01

The neutral gas shielding model for ablation of frozen hydrogenic pellets is extended to include the effects of an initial Maxwelliam distribution of incident electron energies; a cold plasma shield outside the neutral shield and extended along the magnetic field; energetic neutral beam ions and alpha particles; and self-limiting electron ablation in the collisionless plasma limit. Including the full electron distribution increases ablation, but adding the cold ionized shield reduces ablation; the net effect is a modest reduction in pellet penetration compared with the monoenergetic electron neutral shielding model with no plasma shield. Unlike electrons, fast ions can enter the neutral shield directly without passing through the cold ionized shield because their gyro-orbits are typically larger than the diameter of the cold plasma tube. Fast alpha particles should not enhance the ablation rate unless their population exceeds that expected from local classical thermalization. Fast beam ions, however, may enhance ablation in the plasma periphery if their population is high enough. Self-limiting ablation in the collisionless limit leads to a temporary distortion of the original plasma electron Maxwellian distribution function through preferential depopulation of the higher-energy electrons. 23 refs., 9 figs

Heterotypic Protection and Induction of a Broad Heterotypic Neutralization Response by Rotavirus-Like Particles

Science.gov (United States)

Crawford, Sue E.; Estes, Mary K.; Ciarlet, Max; Barone, Christopher; O’Neal, Christine M.; Cohen, Jean; Conner, Margaret E.

1999-01-01

The recognition that rotaviruses are the major cause of life-threatening diarrheal disease and significant morbidity in young children has focused efforts on disease prevention and control of these viruses. Although the correlates of protection in children remain unclear, some studies indicate that serotype-specific antibody is important. Based on this premise, current live attenuated reassortant rotavirus vaccines include the four predominant serotypes of virus. We are evaluating subunit rotavirus vaccines, 2/6/7-VLPs and 2/4/6/7-VLPs, that contain only a single VP7 of serotype G1 or G3. In mice immunized parenterally twice, G3 virus-like particles (VLPs) induced a homotypic, whereas G1 VLPs induced a homotypic and heterotypic (G3) serum neutralizing immune response. Administration of three doses of G1 or G3 VLPs induced serum antibodies that neutralized five of seven different serotype test viruses. The inclusion of VP4 in the VLPs was not essential for the induction of heterotypic neutralizing antibody in mice. To confirm these results in another species, rabbits were immunized parenterally with two doses of 2/4/6/7-VLPs containing a G3 or G1 VP7, sequentially with G3 VLPs followed by G1 (G3/G1) VLPs, or with live or psoralen-inactivated SA11. High-titer homotypic serum neutralizing antibody was induced in all rabbits, and low-level heterotypic neutralizing antibody was induced in a subset of rabbits. The rabbits immunized with the G1 or G3/G1 VLPs in QS-21 were challenged orally with live G3 ALA rotavirus. Protection levels were similar in rabbits immunized with homotypic G3 2/4/6/7-VLPs, heterotypic G1 2/4/6/7-VLPs, or G3/G1 2/4/6/7-VLPs. Therefore, G1 2/4/6/7-VLPs can induce protective immunity against a live heterotypic rotavirus challenge in an adjuvant with potential use in humans. Following challenge, broad serum heterotypic neutralizing antibody responses were detected in rabbits parenterally immunized with G1, G3/G1, or G3 VLPs but not with SA11

Optical Properties of Rotationally Twinned Nanowire Superlattices

DEFF Research Database (Denmark)

Bao, Jiming; Bell, David C.; Capasso, Federico

2008-01-01

We have developed a technique so that both transmission electron microscopy and microphotoluminescence can be performed on the same semiconductor nanowire over a large range of optical power, thus allowing us to directly correlate structural and optical properties of rotationally twinned zinc...... a heterostructure in a chemically homogeneous nanowire material and alter in a major way its optical properties opens new possibilities for band-structure engineering....

Confinement of pure electron plasmas in the Columbia Non-neutral Torus

International Nuclear Information System (INIS)

Berkery, John W.; Pedersen, Thomas Sunn; Kremer, Jason P.; Marksteiner, Quinn R.; Lefrancois, Remi G.; Hahn, Michael S.; Brenner, Paul W.

2007-01-01

The Columbia Non-neutral Torus (CNT) [T. S. Pedersen, J. P. Kremer, R. G. Lefrancois, Q. Marksteiner, N. Pomphrey, W. Reiersen, F. Dahlgreen, and X. Sarasola, Fusion Sci. Technol. 50, 372 (2006)] is a stellarator used to study non-neutral plasmas confined on magnetic surfaces. A detailed experimental study of confinement of pure electron plasmas in CNT is described here. Electrons are introduced into the magnetic surfaces by placing a biased thermionic emitter on the magnetic axis. As reported previously, the insulated rods holding this and other emitter filaments contribute to the radial transport by charging up negatively and creating ExB convective transport cells. A model for the rod-driven transport is presented and compared to the measured transport rates under a number of different conditions, finding good agreement. Neutrals also drive transport, and by varying the neutral pressure in the experiment, the effects of rod-driven and neutral-driven transport are separated. The neutral-driven electron loss rate scales linearly with neutral pressure. The neutral driven transport, presumably caused by electron-neutral collisions, is much greater than theoretical estimates for neoclassical diffusion in a classical stellarator with strong radial electric fields. In fact the confinement time is on the order of the electron-neutral collision time. Ion accumulation, electron attachment, and other effects are considered, but do not explain the observed transport rates

PDX neutral-beam reionization losses

International Nuclear Information System (INIS)

Kugel, H.W.; Dylla, H.F.; Eubank, H.P.; Kozub, T.A.; Moore, R.; Schilling, G.; Stewart, L.D.; von Halle, A.; Williams, M.D.

1982-02-01

Reionization losses for 1.5 MW H 0 and 2 MW D 0 neutral beams injected into the PDX tokamak were studied using pressure gauges, photo-transistors, thermocouples, surface shielding, and surface sample analysis. Considerable outgassing of conventionally prepared 304SS ducts occurred during initial injections and gradually decreased with the cumulative absorption of beam power. Reionization power losses are presently about 5% in the ducts and about 12% total for a beamline including the duct. Present duct pressures are attributed primarily to gas from the ion source and neutralizer with much smaller contributions from residual wall desorption. Physical mechanisms for the observed duct outgassing are discussed

On the role of neutral flow in field-aligned currents

Directory of Open Access Journals (Sweden)

A. J. Mannucci

2018-01-01

Full Text Available In this brief note we explore the role of the neutral atmosphere in magnetosphere–ionosphere coupling. We analyze momentum balance in the ion rest frame to form hypotheses regarding the role of neutral momentum in the lower ionosphere during geomagnetic storms. Neutral momentum that appears in the ion rest frame is likely the result of momentum imparted to ionospheric ions by solar wind flow and the resultant magnetospheric dynamics. The resulting ion-neutral collisions lead to the existence of an electric field. Horizontal electron flow balances the momentum supplied by this electric field. We suggest a possible role played by the neutral atmosphere in generating field-aligned currents due to local auroral heating. Our physical interpretation suggests that thermospheric neutral dynamics plays a complementary role to the high-latitude field-aligned currents and electric fields resulting from magnetospheric dynamics.

Kinetic Properties of the Neutral Solar Wind

International Nuclear Information System (INIS)

Florinski, V.; Heerikhuisen, J.

2017-01-01

Charge-exchange collisions between the solar wind protons and interstellar hydrogen produce a distinctive population of neutral hydrogen streaming radially at nearly the solar-wind speed. This tenuous population, known as the neutral solar wind (NSW) is thought to play a key role in the appearance of the Interplanetary Boundary EXplorer ribbon, a bright circular band in the sky that is the source of neutral hydrogen with energies near 1 keV. According to the leading model of the ribbon, the velocity distribution of NSW hydrogen is imparted on the pickup ions (PUIs) generated via charge exchange with the interstellar protons beyond the heliopause, and in this way controls the stability of the resulting ring distribution of PUIs against hydromagnetic wave generation. In this paper, we examine the velocity distributions of the NSW atoms in the heliosphere and the outer heliosheath regions by following the phase-space trajectories of the Boltzmann equation. It is demonstrated that these distributions are highly anisotropic, with the parallel (radial) temperature greatly exceeding the perpendicular temperature. Ions picked up near 90° from the anisotropic NSW would form a stable ring distribution capable of generating the ribbon flux. We also discuss a second population of neutrals born in charge transfer collisions with interstellar PUIs, the so-called neutralized pickup ion (NPI) component. Their high thermal velocities translate into large parallel velocity spread of the daughter ribbon PUIs, which would adversely affect plasma stability in local interstellar space.

Kinetic Properties of the Neutral Solar Wind

Science.gov (United States)

Florinski, V.; Heerikhuisen, J.

2017-03-01

Charge-exchange collisions between the solar wind protons and interstellar hydrogen produce a distinctive population of neutral hydrogen streaming radially at nearly the solar-wind speed. This tenuous population, known as the neutral solar wind (NSW) is thought to play a key role in the appearance of the Interplanetary Boundary EXplorer ribbon, a bright circular band in the sky that is the source of neutral hydrogen with energies near 1 keV. According to the leading model of the ribbon, the velocity distribution of NSW hydrogen is imparted on the pickup ions (PUIs) generated via charge exchange with the interstellar protons beyond the heliopause, and in this way controls the stability of the resulting ring distribution of PUIs against hydromagnetic wave generation. In this paper, we examine the velocity distributions of the NSW atoms in the heliosphere and the outer heliosheath regions by following the phase-space trajectories of the Boltzmann equation. It is demonstrated that these distributions are highly anisotropic, with the parallel (radial) temperature greatly exceeding the perpendicular temperature. Ions picked up near 90° from the anisotropic NSW would form a stable ring distribution capable of generating the ribbon flux. We also discuss a second population of neutrals born in charge transfer collisions with interstellar PUIs, the so-called neutralized pickup ion (NPI) component. Their high thermal velocities translate into large parallel velocity spread of the daughter ribbon PUIs, which would adversely affect plasma stability in local interstellar space.

Neutralization of positive particle beams by electron trapping

International Nuclear Information System (INIS)

Mobley, R.M.; Irani, A.A.; LeMaire, J.L.; Maschke, A.W.

1977-01-01

Initial results are presented of a planned series of experimental tests of positive ion beam neutralization, involving transverse space charge studies of a 720 keV 60mA H + beam in a drift region of 4.6 meters. Two conclusions drawn from the data are: (1) the change in transmission observed is consistent with complete neutralization in the drift pipe for grounded or negative electrodes, and with complete de-neutralization in the case of greater than +240 V electrodes; and (2) background gas ionization cannot be the main source of electrons

Neutral beam systems for the magnetic fusion program

International Nuclear Information System (INIS)

Beal, J.W.; Staten, H.S.

1977-01-01

The attainment of economic, safe fusion power has been described as the most sophisticated scientific problem ever attacked by mankind. The presently established goal of the magnetic fusion program is to develop and demonstrate pure fusion central electric power stations for commercial applications. Neutral beam heating systems are a basic component of the tokamak and mirror experimental fusion plasma confinement devices. The requirements placed upon neutral beam heating systems are reviewed. The neutral beam systems in use or being developed are presented. Finally, the needs of the future are discussed

Dynamics of ion beam charge neutralization by ferroelectric plasma sources

Energy Technology Data Exchange (ETDEWEB)

Stepanov, Anton D.; Gilson, Erik P.; Grisham, Larry R.; Kaganovich, Igor D.; Davidson, Ronald C. [Princeton Plasma Physics Laboratory, Princeton University, P.O. Box 451, Princeton, New Jersey 08543 (United States)

2016-04-15

Ferroelectric Plasma Sources (FEPSs) can generate plasma that provides effective space-charge neutralization of intense high-perveance ion beams, as has been demonstrated on the Neutralized Drift Compression Experiment NDCX-I and NDCX-II. This article presents experimental results on charge neutralization of a high-perveance 38 keV Ar{sup +} beam by a plasma produced in a FEPS discharge. By comparing the measured beam radius with the envelope model for space-charge expansion, it is shown that a charge neutralization fraction of 98% is attainable with sufficiently dense FEPS plasma. The transverse electrostatic potential of the ion beam is reduced from 15 V before neutralization to 0.3 V, implying that the energy of the neutralizing electrons is below 0.3 eV. Measurements of the time-evolution of beam radius show that near-complete charge neutralization is established ∼5 μs after the driving pulse is applied to the FEPS and can last for 35 μs. It is argued that the duration of neutralization is much longer than a reasonable lifetime of the plasma produced in the sub-μs surface discharge. Measurements of current flow in the driving circuit of the FEPS show the existence of electron emission into vacuum, which lasts for tens of μs after the high voltage pulse is applied. It is argued that the beam is neutralized by the plasma produced by this process and not by a surface discharge plasma that is produced at the instant the high-voltage pulse is applied.

HIV-1 binding and neutralizing antibodies of injecting drug users

Directory of Open Access Journals (Sweden)

E.P. Ouverney

2005-09-01

Full Text Available Previous studies have demonstrated a stronger seroreactivity against some synthetic peptides responsible for inducing neutralizing antibodies in injecting drug users (IDU compared to that of individuals sexually infected with HIV-1 (S, but the effectiveness in terms of the neutralizing ability of these antibodies has not been evaluated. Our objective was to study the humoral immune response of IDU by determining the specificity of their antibodies and the presence of neutralizing antibodies. The neutralization capacity against the HIV-1 isolate MN (genotype B, the primary HIV-1 isolate 95BRRJ021 (genotype F, and the seroreactivity with peptides known to induce neutralizing antibodies, from the V2 and V3 loops of different HIV-1 subtypes, were analyzed. Seroreactivity indicates that IDU plasma are more likely to recognize a broader range of peptides than S plasma, with significantly higher titers, especially of V3 peptides. Similar neutralization frequencies of the MN isolate were observed in plasma of the IDU (16/47 and S (20/60 groups in the 1:10 dilution. The neutralization of the 95BRRJ021 isolate was more frequently observed for plasma from the S group (15/23 than from the IDU group (15/47, P = 0.0108. No correlation between neutralization and seroreactivity with the peptides tested was observed. These results suggest that an important factor responsible for the extensive and broad humoral immune response observed in IDU is their infection route. There was very little difference in neutralizing antibody response between the IDU and S groups despite their differences in seroreactivity and health status.

Enhanced Buck-Boost Three-Level Neutral-Point-Clamped Inverters

DEFF Research Database (Denmark)

Tan, K. K.; Gao, F.; Chiang Loh, Poh

2009-01-01

In traditional three-level neutral-point-clamped (NPC) inverters, a major issue is capacitor voltage imbalance, which results in low order harmonics. The compensation of the capacitor voltages often require additional control complexity, which cannot be conveniently implemented. The "alternative...... phase opposition disposition" (APOD) modulation method used in traditional NPC topologies also has lower harmonics performance as compared to the "phase disposition" (PD) modulation method.In this paper, we introduce a new three-level NPC topology that utilises the harmonically superior PD modulation...... method, with the ability to easily adjust for capacitor voltage imbalances. To further improve the boost capability of the three-level NPC inverters, another new topology introduces 2 additional diodes,achieving higher boost performance while totally eliminating thepossibility of capacitor voltage...

Formation mechanisms of neutral Fe layers in the thermosphere at Antarctica studied with a thermosphere-ionosphere Fe/Fe+ (TIFe) model

Science.gov (United States)

Chu, Xinzhao; Yu, Zhibin

2017-06-01

With a thermosphere-ionosphere Fe/Fe+ (TIFe) model developed from first principles at the University of Colorado, we present the first quantitative investigation of formation mechanisms of thermospheric Fe layers observed by lidar in Antarctica. These recently discovered neutral metal layers in the thermosphere between 100 and 200 km provide unique tracers for studies of fundamental processes in the space-atmosphere interaction region. The TIFe model formulates and expands the TIFe theory originally proposed by Chu et al. that the thermospheric Fe layers are produced through the neutralization of converged Fe+ layers. Through testing mechanisms and reproducing the 28 May 2011 event at McMurdo, we conceive the lifecycle of meteoric metals via deposition, transport, chemistry, and wave dynamics for thermospheric Fe layers with gravity wave signatures. While the meteor injection of iron species is negligible above 120 km, the polar electric field transports metallic ions Fe+ upward from their main deposition region into the E-F regions, providing the major source of Fe+ (and accordingly Fe) in the thermosphere. Atmospheric wave-induced vertical shears of vertical and horizontal winds converge Fe+ to form dense Fe+ layers. Direct electron-Fe+ recombination is the major channel to neutralize Fe+ layers to form Fe above 120 km. Fe layer shapes are determined by multiple factors of neutral winds, electric field, and aurora activity. Gravity-wave-induced vertical wind plays a key role in forming gravity-wave-shaped Fe layers. Aurora particle precipitation enhances Fe+ neutralization by increasing electron density while accelerating Fe loss via charge transfer with enhanced NO+ and O2+ densities.Plain Language SummaryThe discoveries of neutral metal layers reaching near 200 km in the thermosphere have significant scientific merit because such discoveries challenge the current understandings of upper atmospheric composition, chemistry, dynamics, electrodynamics, and

Apparatus for neutralization of accelerated ions

International Nuclear Information System (INIS)

Fink, J.H.; Frank, A.M.

1979-01-01

Apparatus is described for neutralization of a beam of accelerated ions, such as hydrogen negative ions (H - ), using relatively efficient strip diode lasers which emit monochromatically at an appropriate wavelength (lambda = 8000 A for H - ions) to strip the excess electrons by photodetachment. A cavity, formed by two or more reflectors spaced apart, causes the laser beams to undergo multiple reflections within the cavity, thus increasing the efficiency and reducing the illumination required to obtain an acceptable percentage (approx. 85%) of neutralization

STATISTICAL ANALYSIS OF THE HEAVY NEUTRAL ATOMS MEASURED BY IBEX

International Nuclear Information System (INIS)

Park, Jeewoo; Kucharek, Harald; Möbius, Eberhard; Galli, André; Livadiotis, George; Fuselier, Steve A.; McComas, David J.

2015-01-01

We investigate the directional distribution of heavy neutral atoms in the heliosphere by using heavy neutral maps generated with the IBEX-Lo instrument over three years from 2009 to 2011. The interstellar neutral (ISN) O and Ne gas flow was found in the first-year heavy neutral map at 601 keV and its flow direction and temperature were studied. However, due to the low counting statistics, researchers have not treated the full sky maps in detail. The main goal of this study is to evaluate the statistical significance of each pixel in the heavy neutral maps to get a better understanding of the directional distribution of heavy neutral atoms in the heliosphere. Here, we examine three statistical analysis methods: the signal-to-noise filter, the confidence limit method, and the cluster analysis method. These methods allow us to exclude background from areas where the heavy neutral signal is statistically significant. These methods also allow the consistent detection of heavy neutral atom structures. The main emission feature expands toward lower longitude and higher latitude from the observational peak of the ISN O and Ne gas flow. We call this emission the extended tail. It may be an imprint of the secondary oxygen atoms generated by charge exchange between ISN hydrogen atoms and oxygen ions in the outer heliosheath

A Study of Charge-Exchange Neutrals from a Rotating Plasma

DEFF Research Database (Denmark)

Jørgensen, L. W.; Sillesen, Alfred Hegaard

1980-01-01

Measurements of charge-exchange neutrals leaving a rotating plasma (a puffatron device) are reported. Neutrals are observed only during the breakdown phase (2-3 mu s) indicating that the created plasma is fully ionized. Several energy spectra of the neutrals for different plasma parameters are ob....... Neutral particle measurements at different distances from the puffatron midplane show ionization velocities parallel with the magnetic field of about 2*104 ms-1 and plasma expansion velocities of about 5-6*104 ms-1 corresponding to an electron temperature of about 25 eV.......Measurements of charge-exchange neutrals leaving a rotating plasma (a puffatron device) are reported. Neutrals are observed only during the breakdown phase (2-3 mu s) indicating that the created plasma is fully ionized. Several energy spectra of the neutrals for different plasma parameters...... are obtained. These spectra are grossly explained using a single-particle orbit model of the plasma ions. Assuming a Maxwellian distribution for the spread in the ion Larmor energy for the central part of the measured energy spectra, it is possible to determine the ion energy during the breakdown phase...

Neutralized drift compression experiments with a high-intensity ion beam

International Nuclear Information System (INIS)

Roy, P.K.; Yu, S.S.; Waldron, W.L.; Anders, A.; Baca, D.; Barnard, J.J.; Bieniosek, F.M.; Coleman, J.; Davidson, R.C.; Efthimion, P.C.; Eylon, S.; Friedman, A.; Gilson, E.P.; Greenway, W.G.; Henestroza, E.; Kaganovich, I.; Leitner, M.; Logan, B.G.; Sefkow, A.B.; Seidl, P.A.; Sharp, W.M.; Thoma, C.; Welch, D.R.

2007-01-01

To create high-energy density matter and fusion conditions, high-power drivers, such as lasers, ion beams, and X-ray drivers, may be employed to heat targets with short pulses compared to hydro-motion. Both high-energy density physics and ion-driven inertial fusion require the simultaneous transverse and longitudinal compression of an ion beam to achieve high intensities. We have previously studied the effects of plasma neutralization for transverse beam compression. The scaled experiment, the Neutralized Transport Experiment (NTX), demonstrated that an initially un-neutralized beam can be compressed transversely to ∼1 mm radius when charge neutralization by background plasma electrons is provided. Here, we report longitudinal compression of a velocity-tailored, intense, neutralized 25 mA K + beam at 300 keV. The compression takes place in a 1-2 m drift section filled with plasma to provide space-charge neutralization. An induction cell produces a head-to-tail velocity ramp that longitudinally compresses the neutralized beam, enhances the beam peak current by a factor of 50 and produces a pulse duration of about 3 ns. The physics of longitudinal compression, experimental procedure, and the results of the compression experiments are presented

Neutralization kinetics of charged polymer surface

Energy Technology Data Exchange (ETDEWEB)

Mukherjee, S. [Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Mukherjee, M. [Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)], E-mail: manabendra.mukherjee@saha.ac.in

2008-04-15

In case of photoemission spectroscopy of an insulating material the data obtained from the charged surface are normally distorted due to differential charging. Recently, we have developed a controlled surface neutralization technique to study the kinetics of the surface charging. Using this technique and the associated data analysis scheme with an effective charging model, quantitative information from the apparently distorted photoemission data from PTFE surfaces were extracted. The surface charging was controlled by tuning the electron flood current as well as the X-ray intensity. The effective model was found to describe the charging consistently for both the cases. It was shown that the non-linear neutralization response of differential charging around a critical neutralizing electron flux or a critical X-ray emission current was due to percolation of equipotential surface domains. The obtained value of the critical percolation exponent {gamma} close to unity indicates a percolation similar to that of avalanche breakdown or chain reaction.

Antibody neutralization of retargeted measles viruses

Science.gov (United States)

Lech, Patrycja J.; Pappoe, Roland; Nakamura, Takafumi; Tobin, Gregory J.; Nara, Peter L.; Russell, Stephen J.

2014-01-01

The measles virus (MV) vaccine lineage is a promising oncolytic but prior exposure to the measles vaccine or wild-type MV strains limits treatment utility due to the presence of anti-measles antibodies. MV entry can be redirected by displaying a polypeptide ligand on the Hemagglutinin (H) C-terminus. We hypothesized that retargeted MV would escape neutralization by monoclonal antibodies (mAbs) recognizing the H receptor-binding surface and be less susceptible to neutralization by human antisera. Using chimeric H proteins, with and without mutations that ablate MV receptor binding, we show that retargeted MVs escape mAbs that target the H receptor-binding surface by virtue of mutations that ablate infection via SLAM and CD46. However, C-terminally displayed domains do not mediate virus entry in the presence of human antibodies that bind to the underlying H domain. In conclusion, utility of retargeted oncolytic measles viruses does not extend to evasion of human serum neutralization. PMID:24725950

On the possible eigenoscillations of neutral sheets

International Nuclear Information System (INIS)

Almeida, W.A.; Costa, J.M. da; Aruquipa, E.G.; Sudano, J.P.

1974-12-01

A neutral sheet model with hyperbolic tangent equilibrium magnetic field and hyperbolic square secant density profiles is considered. It is shown that the equation for small oscillations takes the form of an eigenvalue oscillation problem. Computed eigenfrequencies of the geomagnetic neutral sheet were found to be in the range of the resonant frequencies of the geomagnetic plasma sheet computed by other authors

Assaying Cellular Viability Using the Neutral Red Uptake Assay.

Science.gov (United States)

Ates, Gamze; Vanhaecke, Tamara; Rogiers, Vera; Rodrigues, Robim M

2017-01-01

The neutral red uptake assay is a cell viability assay that allows in vitro quantification of xenobiotic-induced cytotoxicity. The assay relies on the ability of living cells to incorporate and bind neutral red, a weak cationic dye, in lysosomes. As such, cytotoxicity is expressed as a concentration-dependent reduction of the uptake of neutral red after exposure to the xenobiotic under investigation. The neutral red uptake assay is mainly used for hazard assessment in in vitro toxicology applications. This method has also been introduced in regulatory recommendations as part of 3T3-NRU-phototoxicity-assay, which was regulatory accepted in all EU member states in 2000 and in the OECD member states in 2004 as a test guideline (TG 432). The present protocol describes the neutral red uptake assay using the human hepatoma cell line HepG2, which is often employed as an alternative in vitro model for human hepatocytes. As an example, the cytotoxicity of acetaminophen and acetyl salicylic acid is assessed.

Impaired acid neutralization in the duodenum in pancreatic insufficiency.

Science.gov (United States)

Dutta, S K; Russell, R M; Iber, F L

1979-10-01

The influence of severe exocrine pancreatic disease on the acid-neutralizing capacity of the duodenum was studied in five patients with pancreatic insufficiency (PI) and six control subjects using duodenal perfusion-marker technique. Hydrochloric acid (0.1 N containing 1% PEG) was infused at constant rates (1.2, 4.5 and 7.0 ml/min) into the duodenum just distal to the duodenal bulb. Samples were aspirated from the tip of the duodenal perfusion tube located at the ligament of Treitz. All samples were analyzed for volume, pH, titrable acidity, PEG and [14C]PEG (gastric marker) determination. Patients with PI demonstrated significantly diminished ability to neutralize various acid loads as compared to controls who virtually completely neutralized acid loads in the range of maximal gastric acid secretion. Exogenous secretin did not significantly improve percent acid neutralized in PI. These data clearly indicate that patients with PI have significantly impaired ability to neutralize even small loads of acid in the duodenum.

Neutral Community Dynamics and the Evolution of Species Interactions.

Science.gov (United States)

Coelho, Marco Túlio P; Rangel, Thiago F

2018-04-01

A contemporary goal in ecology is to determine the ecological and evolutionary processes that generate recurring structural patterns in mutualistic networks. One of the great challenges is testing the capacity of neutral processes to replicate observed patterns in ecological networks, since the original formulation of the neutral theory lacks trophic interactions. Here, we develop a stochastic-simulation neutral model adding trophic interactions to the neutral theory of biodiversity. Without invoking ecological differences among individuals of different species, and assuming that ecological interactions emerge randomly, we demonstrate that a spatially explicit multitrophic neutral model is able to capture the recurrent structural patterns of mutualistic networks (i.e., degree distribution, connectance, nestedness, and phylogenetic signal of species interactions). Nonrandom species distribution, caused by probabilistic events of migration and speciation, create nonrandom network patterns. These findings have broad implications for the interpretation of niche-based processes as drivers of ecological networks, as well as for the integration of network structures with demographic stochasticity.

Neutral Atom Diffusion in a Partially Ionized Prominence Plasma

Science.gov (United States)

Gilbert, Holly

2010-01-01

The support of solar prominences is normally described in terms of a magnetic force on the prominence plasma that balances the solar gravitational force. Because the prominence plasma is only partially ionized. it is necessary to consider in addition the support of the neutral component of the prominence plasma. This support is accomplished through a frictional interaction between the neutral and ionized components of the plasma, and its efficacy depends strongly on the degree of ionization of the plasma. More specifically, the frictional force is proportional to the relative flow of neutral and ion species, and for a sufficiently weakly ionized plasma, this flow must be relatively large to produce a frictional force that balances gravity. A large relative flow, of course, implies significant draining of neutral particles from the prominence. We evaluate the importance of this draining effect for a hydrogen-helium plasma, and consider the observational evidence for cross-field diffusion of neutral prominence material,

Reactive formulations for a neutralization of toxic industrial chemicals

Science.gov (United States)

Tucker, Mark D [Albuqueruqe, NM; Betty, Rita G [Rio Rancho, NM

2006-10-24

Decontamination formulations for neutralization of toxic industrial chemicals, and methods of making and using same. The formulations are effective for neutralizing malathion, hydrogen cyanide, sodium cyanide, butyl isocyanate, carbon disulfide, phosgene gas, capsaicin in commercial pepper spray, chlorine gas, anhydrous ammonia gas; and may be effective at neutralizing hydrogen sulfide, sulfur dioxide, formaldehyde, ethylene oxide, methyl bromide, boron trichloride, fluorine, tetraethyl pyrophosphate, phosphorous trichloride, arsine, and tungsten hexafluoride.

Neutral particle dynamics in the Alcator C-Mod tokamak

Energy Technology Data Exchange (ETDEWEB)

Niemczewski, Artur P. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

1995-08-01

This thesis presents an experimental study of neutral particle dynamics in the Alcator C-Mod tokamak. The primary diagnostic used is a set of six neutral pressure gauges, including special-purpose gauges built for in situ tokamak operation. While a low main chamber neutral pressure coincides with high plasma confinement regimes, high divertor pressure is required for heat and particle flux dispersion in future devices such as ITER. Thus we examine conditions that optimize divertor compression, defined here as a divertor-to-midplane pressure ratio. We find both pressures depend primarily on the edge plasma regimes defined by the scrape-off-layer heat transport. While the maximum divertor pressure is achieved at high core plasma densities corresponding to the detached divertor state, the maximum compression is achieved in the high-recycling regime. Variations in the divertor geometry have a weaker effect on the neutral pressures. For otherwise similar plasmas the divertor pressure and compression are maximum when the strike point is at the bottom of the vertical target plate. We introduce a simple flux balance model, which allows us to explain the divertor neutral pressure across a wide range of plasma densities. In particular, high pressure sustained in the detached divertor (despite a considerable drop in the recycling source) can be explained by scattering of neutrals off the cold plasma plugging the divertor throat. Because neutrals are confined in the divertor through scattering and ionization processes (provided the mean-free-paths are much shorter than a typical escape distance) tight mechanical baffling is unnecessary. The analysis suggests that two simple structural modifications may increase the divertor compression in Alcator C-Mod by a factor of about 5. Widening the divertor throat would increase the divertor recycling source, while closing leaks in the divertor structure would eliminate a significant neutral loss mechanism.

Neutral particle dynamics in the Alcator C-Mod tokamak

International Nuclear Information System (INIS)

Niemczewski, A.P.