Values Of Ne Research Articles

Genetic diversity of five Chinese goat breeds assessed by microsatellite markers

The genetic diversity was studied using microsatellite DNA markers in Laoshan dairy goat (LS), Xinong Saanen dairy goat (SN), Guanzhong dairy goat (GZ), Banjiao goat (BJ) and Guizhou white goat (GW). Within the nine polymorphic loci, allele frequencies, number of effective alleles (Ne), heterozygosity (He), polymorphism information content (PIC), genetic identity (I) and Nei’s standard genetic distance (D) were calculated, and UPGMA phylogenetic tree was constructed based on allele frequencies. The average number of alleles was 9.4, ranging from four to eleven at the nine assessed loci. The average values of Ne, He, PIC of all loci were 4.716, 0.765, 0.732, respectively. The GZ population showed the highest variability (PIC = 0.78, He = 0.80). There was a relatively high level of genetic diversity in these goat breeds. A UPGMA diagram, based on Nei’s standard genetic distances, yielded relationships between populations that agreed with what is known about their origin, history and geographical distribution.

The Structure of the Local Interstellar Medium. V. Electron Densities

We present a comprehensive survey of C iiabsorption detections toward stars within 100 pc in order to measure the distribution of electron densities present in the local interstellar medium (LISM). Using high spectral resolution observations obtainedbyGHRS andSTISonboardHST,wesearched foralldetectionsof LISM Ciiabsorption.We identify13sightlineswith23individualCiiabsorption components,whichprovide electrondensitymeasurements. We employ several strategies to determine more accurate C ii column densities from the saturated C ii resonance line, including constraints of the line width from the optically thin C iiline, constraints from independent temperature measurementsof theLISMgasbasedonlinewidthsof otherions,andthird,usingmeasuredSiicolumndensitiesasa proxyforCiicolumndensities.Thedistributionof electrondensitiesbasedonusingSiiasaproxyforCiiissimilarto the distribution based on carbon alone, while significantly tighter, and proves to be a promising technique to avoid grossly overestimating the C ii column density based on the saturated line profile. The sample of electron densities appears consistent with a lognormal distribution and an unweighted mean value of ne(C iiS ii) ¼ 0:11 þ0:10 � 0:05 cm � 3 . Seven individual sight lines probe the Local Interstellar Cloud (LIC), and all present a similar value for the electron density, with a weighted mean of ne(LIC) ¼ 0:12 � 0:04 cm � 3 . Given some simple assumptions, the range of ob- served electron densities translates into a range of thermal pressures, P/k ¼ 3300 þ5500 � 1900 Kc m � 3 . This work greatly expands the number of electron density measurements and provides important constraints on the ionization, abun- dance, and evolutionary models of the LISM. Subject headingg atomic processes — ISM: abundances — line: profiles — solar neighborhood — techniques: spectroscopic — ultraviolet: ISM

Pseudoprime reductions of elliptic curves

Let b ≥ 2 be an integer and let E/ be a fixed elliptic curve. In this paper, we estimate the number of primes p ≤ x such that the number of points nE(p) on the reduction of E modulo p is a base b prime or pseudoprime. In particular, we improve previously known bounds which applied only to prime values of nE(p).

Determination of the optical escape factor in the He I line intensity ratio technique applied for weakly ionized plasmas

Radiation trapping of the He I UV resonance transition (λ = 53.7 nm) has been experimentally confirmed in weakly ionized (ionization degree of ∼1–10%)helium plasmas in the PISCES-A linear divertor plasma simulator by using visible line emission with the same upper state as the UV transition. To study the effect of UV opacity on visible line ratios, the radiation trapping of UV resonance transitions was included in a He I collisional–radiative code with the optical escape factor method. The modified code is used to derive electron density ne and temperature Te with the standard He I line intensity ratios, 667.8 nm/728.1 nm and 728.1 nm/706.5 nm. The predicted values of ne and Te are compared with Langmuir probe measurements. Best agreement (within ±30%) is obtained when including radiation trapping and the correct (measured) neutral temperature and using the vacuum chamber radius (as opposed to the smaller plasma radius) for the characteristic length of the system. Neglecting radiation trapping entirely is found to give errors as large as 10 × (3 ×) in the predicted values of ne (Te).

Numerical simulation of effects of the August 11, 1999 solar eclipse in the outer ionosphere

The results of a numerical simulation of such parameters of the topside ionosphere as concentration N e and temperature T e of electrons, and concentration n(H+) and fluxes along the magnetic field lines Φ(H+) of H+ ions at an altitude of ∼2000 km for the conditions of the August 11, 1999 solar eclipse are presented. The calculations were performed using the Global Self-consistent Model of the Thermosphere, Ionosphere, and Protonosphere of the Earth (GSM TIP). It is shown that during the eclipse, in addition to a region of decreased values of T e in the Northern Hemisphere and in the magnetically conjugate region in the Southern Hemisphere, regions of electron heating emerge in both hemispheres. Simultaneously, an extended region of decreased values of N e comes into existence and moves behind the Moon’s shadow. Regions with decreased (down to ∼30%) and enhanced (up to ∼50%) concentrations of H+ ions are detected in the global distribution of these ions.

Characterization of a high-pressure hydrogen microwave plasma torch using the method of dBR

A hydrogen plasma flame produced by an axial injection torch powered at the microwave frequency of 2.45 GHz is studied using the method of disturbed Bilateral Relations (dBR). The application of this method which relates the influence of equilibrium disturbing, as produced by transport, to equilibrium restoring processes, reveals that the most dominant excitation balance is the Excitation Saturation Balance. Moreover, a global discharge model leads to an electron density of ne = 4.1020m−3 and an electron temperature of Te = 0.86 eV. The gas temperature was estimated to be Th = 0.3 eV. The values of ne and Te were found to be in good agreement with the value obtained with the modified Boltzmann-plot and the crossing method of Stark broadening. The dBR method points out that the first level in partial local Saha equilibrium will be the level with principal quantum number p = 10 which is in fair agreement with experimental results.

Volume production of D− negative ions in low-pressure D2 plasmas—negative ion densities versus plasma parameters

Pure volume production of D− negative ions is studied in a rectangular arc chamber. Production and control of D2 plasmas are tested by varying the intensity of the magnetic filter MF. The values of electron temperature Te and electron density ne in D2 plasmas are slightly higher than those in H2 plasmas. Te in D2 plasmas cannot be decreased below 1 eV in the extraction region with the same MF conditions for optimizing H2 plasmas. A stronger MF field is required for controlling Te in D2 plasmas. Therefore, the transport in or the production of H2 and D2 plasmas is different, i.e. there is an isotope effect, a consequence of which is that the H− and D− densities have different spatial distributions. Extracted H− and D− currents are primarily determined by H− and D− densities in front of the extraction hole, respectively. According to the estimated rate coefficients and collision frequencies of main collision processes, it is reconfirmed that Te in the extraction region should be maintained below 1 eV with ne kept high for the enhancement of H− and D− production. For the enhancement of D− production, preliminary results on VUV emission measurement are presented and discussed briefly.

A spatially resolved relaxation method for pLTE plasma diagnostics in free-burning arcs

We report on a relaxation method to determine the electron-to-gas temperature ratio in the near-cathode region of a low-current free-burning arc operated in argon under atmospheric pressure. We used an intensified CCD camera to record the relaxation process after a fast power-interruption of the discharge with a time resolution better than 1 µs. For the CCD images we applied an ABEL inversion procedure yielding 3D information about the temperature ratio β ≔ Te/Tg with a spatial resolution of 50 µm. We deduced spatially resolved values of β from the relaxation experiment using independently measured values of Te and ne, so we could determine all free parameters in the partial LTE model.

A macroscopic–microscopic study of Ne and Mg nuclei around N = 20

A new set of Nilsson parameters, with the isospin-dependent spin–orbit potential (κ) and l2t term (μ), is proposed for neutron-rich nuclei of Ne and Mg isotopes. The ground-state deformations and B(E2) values of Ne and Mg nuclei around N = 20 are studied within the framework of the macroscopic–microscopic (MM) model with the new set of Nilsson parameters. The calculated results are compared with the experimental data. The experimental large deformations and B(E2) values are well reproduced by the new calculation of this paper. The calculated results are also compared with the recent results of mean-field models and shell models. Detailed discussions of the shell structure around N = 20 are given. It is predicted that the enhanced negative shell correction energies at deformed shape and the weak N = 20 magic shell closure lead to the large deformations for Ne and Mg nuclei around N = 20.

Laser spectroscopy for measuring the parameters of a plasma containing helium and argon

Laser spectroscopy diagnostics used in experiments on the PNX-U facility are described. The working gas was argon with an additive of helium. The 23 P → 33 D transition was excited by means of optical pumping, and helium fluorescence at wavelengths of 388 and 706.5 nm was observed. The Doppler temperature of helium atoms was determined by scanning the profile of the absorption line with the help of a tunable laser. The sum of the signals so obtained provides information on the local density of helium atoms. It was proposed to determine the local value of the electron density N e (R) from the ratio between the fluorescence intensities at wavelengths of 388 and 706.5 nm. The ratio of these intensities as a function of N e for He I was calculated in the collisional-radiative model, and relevant measurements of N e in the PNX-U facility were performed. When diagnosing the argon component, the main attention was paid to measurements of the ion temperature T i (R, t). In the course these measurements, anomalous heating of Ar II ions was revealed. The concentration of singly charged argon ions was estimated.

Deformations and B(E2) Values of Ne and Mg Nucleiaround N = 20

The ground-state deformations and B(E2) values of Ne and Mg nucleiaround N = 20 are studied within the framework of the macroscopic–microscopic (MM) model with isospin-dependent Nilssonpotential. The calculated results are compared with those obtained fromstandard Nilsson parameters and with experimental ones. It is found thatthe calculations with new Nilsson parameters well reproduce theexperimental large deformations and B(E2) values for Ne and Mg nucleiaround N = 20. The N = 20 shell closure of Ne and Mg isotopes disappearsin the MM model and this agrees with experimental data.

Diagnostics of a nonequilibrium nitrogen plasma from the emission spectra of the second positive system of N2

A method is proposed for determining the electron density Ne and the electric field E in the non-equilibrium nitrogen plasma of a low-pressure discharge from the spectra of the second positive system of N2. The method is based on measuring the specific energy deposition in the plasma and the distribution of nitrogen molecules over the vibrational levels of the C3Πu state, as well as on modeling this distribution for a given energy deposition. The fitting parameters of the model are the values of Ne and E. A kinetic model of the processes governing the steady-state density of the C3Πu nitrogen molecules is developed. The testing of this method showed it to be quite reliable. The method is of particular interest for diagnosing electrodeless discharges and provides detailed information on the processes occurring in the discharge plasma. Preliminary data are obtained on the plasma parameters in a cavity microwave discharge and an electrode microwave discharge. In particular, it is found that the electric field in an electrode microwave discharge in nitrogen is lower than that in a hydrogen discharge. This effect is shown to be produced by stepwise and associative processes with the participation of excited particles in nitrogen.

Characterization of compact bright soft X-ray source based on picosecond laser plasma

Radiation emission of silicon and aluminum plasmas produced by 40-ps laser pulses with peak intensity above 1014 W/cm2 was studied. High-resolution soft X-rayspectra of H-like and He-like ions were analyzed to determine plasma parameters. We compared the line shape of resonance transitions and their intensity ratios to corresponding dielectronic satellites and the intensities of the intercombination lines of He-like ions with the results of model calculations. Such comparisons gave average values of the electron number density Ne=(1-1.9)×1021 cm-3 and the electron temperature Te=460–560 eV for Si plasmas and about 560 eV for Al plasmas produced by the first and the second laser harmonics. The plasma size is about 100 μm. According to our estimations, more than 1012 photons were produced within the resonance line spectral width and in the solid angle 2π during the total decay period.

Effect of bending and torsion rigidity on self-diffusion in polymer melts: A molecular-dynamics study

Extensive molecular-dynamics simulations have been performed to study the effect of chain conformational rigidity, controlled by bending and torsion potentials, on self-diffusion in polymer melts. The polymer model employs a novel torsion potential that avoids computational singularities without the need to impose rigid constraints on the bending angles. Two power laws are traditionally used to characterize the dependence of the self-diffusion coefficient on polymer length: D proportional to N(-nu) with nu=1 for N<Ne (Rouse regime) and with nu=2 for N>Ne (reptation regime), Ne being the entanglement length. Our simulations, at constant temperature and density, up to N=250 reveal that, as the chain rigidity increases, the exponent nu gradually increases towards nu=2.0 for N<Ne and nu=2.2 for N>Ne. The value of Ne is slightly increased from 70 for flexible chains, up to the point where the crossover becomes undefined. This behavior is confirmed also by an analysis of the bead mean-square displacement. Subsequent investigations of the Rouse modes, dynamical structure factor, and chain trajectories indicate that the pre-reptation regime, for short stiff chains, is a modified Rouse regime rather than reptation.

Artificial birefringence introduced by porosity in GaP

Porosity-induced birefringence in a GaP membrane is studied using a method based on the analysis of beats in unpolarized and polarized transmittance spectra as well as in angular dependence of optical spectra. Birefringence as high as ne − no = 0.25 was measured in a porous GaP membrane with the degree of porosity close to 40%. The measured values of ne and no are compared with those calculated in the frame of effective medium theory for a GaP membrane with appropriate morphology.

Polarization and Physical Properties of the August 11, 1999 White-Light Corona

Four series of coronal images have been obtained by the expedition of Abastumani Astrophysical Observatory during the August 11, 1999 total solar eclipse with the help of a photographic mirror–lens polarimeter (D = 100 mm, F = 1000 mm). Each series include three images corresponding to three positions of the polarization analyzer. The position of the solar disk center relative to the Moon's center has been determined beforehand. In addition, the background skylight polarization and intensity are calculated. All measurements are absolute given in units of the Sun's average surface brightness. A new technique for separation of the F- and K-coronae is used. It was found that in the equatorial regions the model of hydrostatic distribution of the density with T = constant is not quite accurate for the August 11, 1999 corona and there is a temperature gradient in this region. For r1 = 1.3R⊙ and r2 = 1.8R⊙ we derived T1 = 1.25×106 K and T2 = 1.07×106 K, respectively. The average polarization degree in the equatorial regions changes from 10 to 40%, while in the polar regions the maximum value reaches only 10%. The values of electron densities Ne(r) vary from 1.32×108 cm−3 (r = 1.1R⊙) to 2.0×106 cm−3 (r = 2.0R⊙). Our data are compared with previous measurements.

Effective superconfiguration temperature and the radiative properties of nonlocal thermodynamical equilibrium hot dense plasma

The model of superconfiguration (SC) temperatures has been used extensively for computing the population dynamics of very large systems in hot dense plasmas. Plasmas of Ge, Xe, and Au have been studied for a wide range of values of Te and Ne. For plasmas containing a distribution of a dozen of ionization states, two systems of a few hundreds of linear equations are solved, with one equation per SC. The power of the method lies in the possibility of determining the populations of all the electronic configurations belonging to those SCs. This opens the way to detailed modeling of complex spectra and to calculations of emissivities and opacities in laser-plasma simulations and experiments.

JET divertor geometry and plasma shape effects on the L–H transition threshold

Results from recent experiments to study the effects of divertor geometry and increased plasma shaping on the L–H transition threshold on JET are reported. Equivalent septum configurations run with the new septum replacement plate (SRP) in the MkII Gas Box divertor have shown that the presence of the septum lowers the L–H transition power threshold, Pth, by 20%. For X-point to virtual septum top distances of less than 6 cm, the SRP plasmas also demonstrate a significant decrease of the L–H Pth and pedestal electron temperature, Te with reduced X-point height. Although, the SRP plasma's Pth remains above that with the septum, there is no difference in the pedestal Te at the L–H transition. The influence of plasma shaping on the L–H transition has also been investigated for the first time on JET in a series of density scans at Ip/Bt of 2.5 MA/2.7 T. While keeping the lower triangularity, δlower, and divertor geometry constant, the upper triangularity, δupper, has been increased from 0.23 to 0.34 with no effect on Pth or the pedestal Te or Ti. In a separate edge ne scan, two configurations with different δupper/δlower values of 0.23/0.23 and 0.43/0.33 have been compared. A large difference in the transition threshold is observed at values of edge ne above 1.8 × 1019 m−3, with the higher δ plasmas characterized by Pth of up to 25% lower at the highest densities scanned. This is thought to be the result of lowered X-point and outer strike point heights with increased δ.

New method in computer simulations of electron and ion densities and temperatures in the plasmasphere and low-latitude ionosphere

Abstract. A new theoretical model of the Earth’s low- and mid-latitude ionosphere and plasmasphere has been developed. The new model uses a new method in ionospheric and plasmaspheric simulations which is a combination of the Eulerian and Lagrangian approaches in model simulations. The electron and ion continuity and energy equations are solved in a Lagrangian frame of reference which moves with an individual parcel of plasma with the local plasma drift velocity perpendicular to the magnetic and electric fields. As a result, only the time-dependent, one-dimension electron and ion continuity and energy equations are solved in this Lagrangian frame of reference. The new method makes use of an Eulerian computational grid which is fixed in space co-ordinates and chooses the set of the plasma parcels at every time step, so that all the plasma parcels arrive at points which are located between grid lines of the regularly spaced Eulerian computational grid at the next time step. The solution values of electron and ion densities Ne and Ni and temperatures Te and Ti at the Eulerian computational grid are obtained by interpolation. Equations which determine the trajectory of the ionospheric plasma perpendicular to magnetic field lines and take into account that magnetic field lines are "frozen" in the ionospheric plasma are derived and included in the new model. We have presented a comparison between the modeled NmF2 and hmF2 and NmF2 and hmF2 which were observed at the anomaly crest and close to the geomagnetic equator simultaneously by the Huancayo, Chiclayo, Talara, Bogota, Panama, and Puerto Rico ionospheric sounders during the 7 October 1957 geomagnetically quiet time period at solar maximum. The model calculations show that there is a need to revise the model local time dependence of the equatorial upward E × B drift velocity given by Scherliess and Fejer (1999) at solar maximum during quiet daytime equinox conditions. Uncertainties in the calculated Ni , Ne , Te , and Ti resulting from the difference between the NRLMSISE-00 and MSIS-86 neutral temperatures and densities and from the difference between the EUV97 and EUVAC solar fluxes are evaluated. The decrease in the NRLMSISE-00 model [O]/[N2] ratio by a factor of 1.7–2.1 from 16:12 UT to 23:12 UT on 7 October brings the modeled and measured NmF2 and hmF2 into satisfactory agreement. It is shown that the daytime peak values in Te , and Ti above the ionosonde stations result from the daytime peak in the neutral temperature. Our calculations show that the value of Te at F2-region altitudes becomes almost independent of the electron heat flow along the magnetic field line above the Huancayo, Chiclayo, and Talara ionosonde stations, because the near-horizontal magnetic field inhibits the heat flow of electrons. The increase in geomagnetic latitude leads to the increase in the effects of the electron heat flow along the magnetic field line on Te . It is found that at sunrise, there is a rapid heating of the ambient electrons by photoelectrons and the difference between the electron and neutral temperatures could be increased because nighttime electron densities are less than those by day, and the electron cooling during morning conditions is less than that by day. This expands the altitude region at which the ion temperature is less than the electron temperature near the equator and leads to the sunrise electron temperature peaks at hmF2 altitudes above the ionosonde stations. After the abrupt increase at sunrise, the value of Te decreases, owing to the increasing electron density due to the increase in the cooling rate of thermal electrons and due to the decrease in the relative role of the electron heat flow along the magnetic field line in comparison with cooling of thermal electrons. These physical processes lead to the creation of sunrise electron temperature peaks which are calculated above the ionosonde stations at hmF2 altitudes. We found that the main cooling rates of thermal electrons are electron-ion Coulomb collisions, vibrational excitation of N2 and O2, and rotational excitation of N2. It is shown that the increase in the loss rate of O+(4S) ions due to the vibrational excited N2 and O2 leads to the decrease in the calculated NmF2 by a factor of 1.06–1.44 and to the increase in the calculated hmF2, up to the maximum value of 32 km in the low-latitude ionosphere between –30 and +30° of the geomagnetic latitude. Inclusion of vibrationally excited N2 and O2 brings the model and data into better agreement.Key words. Ionosphere (equatorial ionosphere; electric fields and currents, plasma temperature and density; ion chemistry and composition; ionosphere-atmosphere interactions; modeling and forecasting)

Breeding schemes in reindeer husbandry

The objective of the paper was to investigate annual genetic gain from selection (G), and the influence of selection on the inbreeding effective population size (Ne), for different possible breeding schemes within a reindeer herding district. The breeding schemes were analysed for different proportions of the population within a herding district included in the selection programme. Two different breeding schemes were analysed: an open nucleus scheme where males mix and mate between owner flocks, and a closed nucleus scheme where the males in non-selected owner flocks are culled to maximise G in the whole population. The theory of expected long-term genetic contributions was used and maternal effects were included in the analyses. Realistic parameter values were used for the population, modelled with 5000 reindeer in the population and a sex ratio of 14 adult females per male. The standard deviation of calf weights was 4.1 kg. Four different situations were explored and the results showed: 1. When the population was randomly culled, Ne equalled 2400. 2. When the whole population was selected on calf weights, Ne equalled 1700 and the total annual genetic gain (direct + maternal) in calf weight was 0.42 kg. 3. For the open nucleus scheme, G increased monotonically from 0 to 0.42 kg as the proportion of the population included in the selection programme increased from 0 to 1.0, and Ne decreased correspondingly from 2400 to 1700. 4. In the closed nucleus scheme the lowest value of Ne was 1300. For a given proportion of the population included in the selection programme, the difference in G between a closed nucleus scheme and an open one was up to 0.13 kg. We conclude that for mass selection based on calf weights in herding districts with 2000 animals or more, there are no risks of inbreeding effects caused by selection.