bluuebunny/crossref_metadata_2025 huggingface dataset:
An Investigation on the Thermal Conductivity of Porous Materials and its Application to Porous Rook
Authors: Sugawara A , Yoshizawa Y
Published: May 2011

The thermal conductivity of porous materials, particularly the effect of porosity and of temperature on thermal conductivity, has been investigated. A" comparison method " was used for measurement and the experiment was carried out with three types of models. A generalized formula for thermal conductivity is derived empirically. This formula can represent other formulas on the thermal conductivity of porous materials, and the formula can be applied to sandstones having different porosity as a typical example of porous materials.
Geomagnetic Micropulsations
Authors: Kato Y
Published: May 2011

Incorporating world-wide data, a summary of observational knowledge of geomagnetic pulsation is given.
Magnetic Bays at Macquarie Island
Authors: Cole KD
Published: May 2011

Robertson (1959) has examined a year's (1954) records of magnetic bays in H, 1J.., Z obtained at the Australian National Antarctic Research Expedition's station at Macquarie I. (54�5� S., 15~ E.). Robertson's Table 1 contains 450 bays in H. Of these 152 are positive bays, and 298 negative. These numbers do not include 38 periods (each of greater than 4 hr duration) of overlapping bay activity or in which bay activity is obliterated by a magnetic storm.
A Seismic Experiment Using Quarry Blasts Near Sydney
Authors: Bolt BA
Published: May 2011

The seismic waves generated by quarry blasts from 2 to 6 tons in weight, over an interval of 7 months, at Prospect, about 30 kIn west of Sydney, are examined. Shot times at the quarry were measured from radio time signals. The waves were recorded by seismographs at 10 seismological stations ranging in distance from 20 kIn (Riverview) to 380 kIn (Geehi in the Snowy Mountains). Analysis of the seismograms indicated two main bodily-wave phases, called PI and S1" The SI waves, which possess considerable energy relative to the compressional first-arrivals PI' appear to be shear waves generated in part by the unsymmetrical nature of the source.
A Corrected Formula for the Spectral Sensitivity Function in Radio Astronomy
Authors: Bracewell RN
Published: May 2011

According to Bracewell and Roberts (1954) the spectral sensitivity function .1(s) is calculated from an aerial aperture distribution .
On Nucleon Magnetic Moments
Authors: Kundu SK
Published: May 2011

The magnetic moments of the proton and neutron are computed for the pseudoscalar-pseudovector symmetric meson field considering the magnetic moments as the time average of the proton and the meson magnetic moments. Using the perturbation theory, the meson contribution is calculated from the self-energy of a nucleon in presence of a weak homogeneous magnetic field where the term due to meson magnetic energy was introduced from the expression for the force exerted on the emitted meson by the magnetic field. The self-energy is made finite with the idea of a fundamental length as introduced by Heisenberg and the cut-off so obtained fits exactly with that suggested by Chew in the extended-source theory. It is also found that mesons need to be present only about 25% of the time to explain the observed magnitudes of the anomalous nucleon magnetic moments.
The Positions and Movements of the Sources of Solar Radio Bursts of Spectral Type II
Authors: Weiss AA
Published: May 2011

The east-west position coordinates of the sources of 22 type II radio bursts, measured in the range 40-70 Mc/s using a swept-frequency interferometer, are analysed and discussed, in conjunction with dynamic spectra obtained in the frequency range 15-210 Mc/s. Many bursts are multiple and consist of a number of separate bursts excited by disturbances ejected in different directions from the vicinity of an optical flare, which may be equally complex.
An Exactly Soluble Two-body Problem with Non-central Forces
Authors: Davies B , Delves LM
Published: May 2011

A class of local potentials is given which includes hard cores and a finite.range central, tensor, and L.S part, and for which the lowest two neutron.proton states (J = 0, 7T = +1 and J = I, 7T = +1) are exactly soluble. A numerical example is given in which the form factor for the potentials is a hard core plus square well.
Polarization Measurements of Jupiter Radio Bursts at 10·1 Mc/s
Authors: Dowden RL
Published: May 2011

At 10�1 Mc/s Jupiter bursts of both senses of circular polarization are readily observed. The algebraic mean axial ratio is a strong function of Jovian longitude. This is almost entirely due to variation with longitude of the relative proportion of bursts of opposite sense of polarization. If bursts of the two senses (L.H. and R.H.) are analysed separately the two mean axial ratios show little or no variation with longitude and are equal and opposite in sign. The axial ratio distribution and other observations are compared with the predictions of the Doppler.shifted cyclotron theory
Ambipolar Diffusion in Meteor Trails
Authors: Francey JLA
Published: May 2011

Ambipolar diffusion and the formulation of the equations of continuity for a diffusing cloud of electrons and ions are briefly discussed. A numerical method for the solution of the equations is outlined and the solutions are presented in graphical form. The results indicate that, for concentrations higher than a critical value, electrons and ions diffuse at the same rate and that the major part of the radio echo from a meteor trail will occur under conditions of ambipolar diffusion. However, a sheath of electrons is to be expected surrounding the diffusing cloud. The ratio mobility: diffusion coefficient is shown to be an important parameter in controlling the transition from ambipolar to free diffusion.
The Directions of Auroral Rays. II. Methods of Determination
Authors: Cole KD
Published: May 2011

Two simple methods are described for finding accurately the direction of an auroral ray from a parallactic pair of photographs. Errors are discussed. The methods reopen an experimental field, namely, the study of the relationship of the direction of the geomagnetic field in the polar ionosphere to that at the ground.
Swept?Frequency Radio Observations at the Time of the Nuclear Explosion over Johnston Island on July 9, 1962
Authors: Sheridan KV , Joisce J
Published: May 2011

The sudden ionospheric disturbance (SID) which occurred at the moment of detonation of the 1�4 megaton nuclear device 400 km above Johnston Island on July 9, 1962 (New Zealand Journal of Geology and Geophysics 1962, Journal of Geophysical Research 1963) was recorded with the 5-210 Mc/s solar radio spectrograph (Sheridan 1963) at Dapto, N.S.W. (latitude _34� 28:3, longitude -150� 45:5, geomagnetic latitude about 42� 30' S.). The reported increase in radio noise due to synchrotron emission (Dyce and Horowitz 1963; Ochs, Farley, and Bowles 1963) from high energy electrons generated by the explosion was not observed.
On External Radio Emission from the Earth's Outer Atmosphere
Authors: Ellis GRA
Published: May 2011

The possibility is considered that cyclotron radiation, generated by fast bunched electrons in the Earth's outer atmosphere, may be observable outside the geomagnetic field. It is shown that the intensity and other properties of such external radiation may be deduced from the known characteristics of v.1.f. hooks. It appears likely that the radiation will occur as short bursts in the frequency range from 200 to 1000 kc/s. The total radiated power may be from 1 to 1000 W, depending on the electron energy.
The Diffusion of Electrons in Dry, Carbon Dioxide Free Air
Authors: Rees JA , Jory RL
Published: May 2011

Values of Townsend's energy factor kl for electrons in dry, carbon dioxide free air have been determined as a function of the parameter E Ip for 0 . 2 < E Ip < 40 at a temperature of 293�K. The results are first compared with those of other workers and are then utilized in a recomparison of the cross sections for electron attachment deduced from swarm and beam-type experiments.
Photoneutron Angular Distributions from Lead and Bismuth
Authors: Allum FR , Quirk TW , Spicer BM
Published: May 2011

The angular distributions of photoneutrons emitted from lead and .bismuth under irradiation by 17�5 MeV bremstrahlung have been measured. This work wa part of a program aimed at understanding systematic features of photoneutronangular distributions as the target atomic mass number is varied.
Transient Heat Conduction Between a Sphere and a Surrounding Medium of Different Thermal Properties
Authors: Philip JR
Published: May 2011

The paper treats the redistribution of heat between a sphere and an infinite medium of different thermal properties and different initial temperature. The problem is relevant to two geophysical questions: the cooling of laccoliths, and the psychrometry of the growth and evaporation of droplets and ice crystals.
21 cm Hydrogen-line Survey of the Large Magellanic Cloud. I. Stellar, Nebular, and Neutral Hydrogen Radial Velocities
Authors: McGee RX
Published: May 2011

A recent survey of the neutral hydrogen in the Large Magellanic Cloud with a 14'�5 beam and the 48�channel H�line receiver has afforded an opportunity to compare the radial velocities of a number of optical objects with the radial velocities of the hydrogen gas in their directions.
The Temperature Dependence of the Elastic Constants of a Lattice
Authors: Lloyd P
Published: May 2011

The temperature dependence of the elastic constants of a cubic lattice are calculated in the classical limit by means of a Bethe approximation. The expressions so derived are then applied to a simple model of some metals. The agreement between the derived and measured temperature dependence of the elastic constants of these metals is satisfactory
Parameters of Two Levels of the 17F Nucleus
Authors: Toutenhoofd W
Published: May 2011

The resonance structures in the 16O(p, p)16O excitation curve at the bombarding energies of 10.52 and 12.40 MeV as found by a University of Wisconsin group have been analysed. Spin and parity for the levels of 17F at 10.50 and 12.26 MeV are believed to be 7/2? and 3/2? respectively.
Monte Carlo Calculations of the Radial Distribution Functions for a Proton?Electron Plasma
Authors: Barker AA
Published: May 2011

A general method is presented for computation of radial distribution functions for plasmas over a wide range of temperatures and densities. The method uses the Monte Carlo technique applied by Wood and Parker, and extends this to long-range forces using results borrowed from crystal lattice theory. The approach is then used to calculate the radial distribution functions for a proton-electron plasma of density 1018 electrons/cm3 at a temperature of 104 OK. The results show the usefulness of the method if sufficient computing facilities are available.
The Polarization Structure of Type III Solar Radio Bursts
Authors: Gopala Rao UV
Published: May 2011

The polarization of type III bursts was measured, using a swept.phase technique, at 40 and 60 Mc/s. The great majority of type III bursts show slight to moderate polarization. The results indicate a double structure for the type III burst-a sharp, intense, drifting feature with relatively strong polarization, and a diffuse background of longer duration with relatively weak or zero polarization.
The Parkes Catalogue of Radio Sources Declination Zone ?60° to ?90°
Authors: Price RM , Milne DK
Published: May 2011

A catalogue of 247 radio sources between declinations -60� and _90� is presented. In the zone -60� to -75�, the sources were selected from an initial finding survey at 408 Mc/s, while from _75� to _90� a 1410 Mc/s survey was carried out. The survey covers an area of 0�8 steradians, omitting the region near the galactic plane. Flux densities determined from source measurements at 408, 14lO, and 2650 Mc/s are presented together with suggested optical identifications, radio spectra, and preliminary polarization information.
Electromagnetic 2p Decay of K02
Authors: Kundu SK
Published: May 2011

As alternatives to the observed K~ ->- 271 decay we consider the processes (i) K~ -+ 271+Y and (ii) K~ -+ K~ magnetic conversion. It is shown that the former process is quite unlikely with the photon energy as suggested from experiment, while the second one is not so unlikely. Also suitable experiments are suggested to observe the processes considered here.
Reliability of Calibrations and Comparisons of Reference Standards with an Application to a Group of Line Standards
Authors: Thwaite EG
Published: May 2011

The problem discussed is that of combining interrelated data which refer to the calibration and intercomparison of a group of standards, to give best estimates for the values of the standards together with their reliabilities. A resume is given of least squares in matrix notation, which is particularly suited to computations using automatic computers, and this technique is applied to results obtained over a period of 15 years at the Bureau International des Poid set Mesures and the National Standards Laboratory, in the calibration and intercomparison of five I m reference line standards of length. One of these scales was a platinumiridium prototype (No. 20), while the remainder were in nickel or 58% nickel-steel. The analysis yields time-dependent values, where appropriate, for the lengths of the scales together with their variances, and an estimate of the observational variance. The estimate of the observational variance, (0�077 /Lm)", is based in part on "external consistency", as the data used in the analysis were obtained in more than one laboratory.
Harmonic Structure and Band Splitting of Type II Solar Radio Bursts
Authors: Krishnamurthi M , Sivarama Sastry G , Seshagiri Rao T
Published: May 2011

An analysis of single-frequency records of type II solar radio bursts at 29 Mc/s has been made. Such characteristic features as harmonic structure and band splitting due to coronal magnetic fields have been identified. Calculations indicate that the shock fronts generating the type II bursts experience a deceleration as they move outwards. Existing theories have been used to estimate the magnetic field strengths, which come out to be of the order of 3-8 G at a height of 0�7 solar radius above the photosphere at the time of occurrence of these bursts.
Angular Distributions in the Reactions 11B(d, p)12B and 11B(d, a)9Be
Authors: Sargood DG , Putt GD
Published: May 2011

In recent years considerable interest has centred on the reaction mechanism in nuclear reactions. At bombarding energies of above about 5 MeV, it has been apparent for many years that (d, p) and (d, n) reactions tend to be dominated by the direct stripping reaction. With the advent of distorted wave stripping theories such as those of Tobocman (1959) and Robson (1961), it now appears that those reactions may proceed by a direct mechanism even at very low bombarding energies. Robson and Weigold (1963) have satisfactorily analysed the angular distributions obtained in the reaction llB(d, p)12B at bombarding energies of 1�02 MeV and 700keV.
The Lunar Magnetic Variations at Toolangi
Authors: Petersons HF , Winch DE , Slaucitajs L
Published: May 2011

The lunar semi-diurnal variations in H, D, and Z at Toolangi observatory have been analysed for the 4-yr period 1952-55 of the sunspot minimum.
A Linear Polarization Survey of the Southern Sky at 408 MC/S
Authors: Mathewson DS , Milne DK
Published: May 2011

The results of 408 Mcts linear polarization observations of the southern sky using the 210 ft steerable reflector at Parkes are presented. Combination of this survey with the northern sky survey of the Leiden group shows that almost all of the. polarization at this frequency lies in a band about 60� wide, which contains the great circle that passes through the galactic poles and intersects the plane at lil = 340� and 160�. This large-scale distribution of linear polarization at 408 Mcts may be explained on the basis of synchrotron radiation theory if the Sun lies almost at the centre of a spiral arm that has a magnetic field directed along it towards III = 70� and 250�. The concentrations of relativistic electrons may be confined to regions of higher than average magnetic field strength (5 X 10-5 G) elongated in the direction of the arm. The observations show that the magnetic fields in these "synchrotron" regions are very ordered. The distance to the polarized regions may be about 150 pc. At high latitudes, close correlation is observed between features of the distribution of background polarization and Faraday rotation of extragalactic sources.
A Survey of the Southern Sky at 30 Mc/s
Authors: Mathewson DS , Broten NW , Cole DJ
Published: May 2011

This paper presents the results of a 30 Mcjs survey of the southern sky using the 210 ft steerable reflector at Parkes, N.S.W. The aerial was fed by a right-handed helix with plane reflector giving a tapered illumination that fell to approximately 10% at the edge of the aperture. The resulting main beam was circular and approximately 11 0 between half-power points. The aerial measured left-handed circular polarization relative to the direction of propagation.
Line Shapes of Low Levels in 8Be via the 9Be (p, d)8Be Reaction
Authors: Hay HJ , Scarr EF , Sullivan DJ , Treacy PB
Published: May 2011

Reaction mechanisms and line shapes of energy levels in sBe have been studied in the bombardment of 9Be by protons of energies up to 5� 2 MeV. The (p, d) process was found to follow a pick�up mechanism, and with this information the detailed line shape of the sBe ground state was inferred. An R�matrix description using a conventional channel radius of 3�5 fm was found to be not in agreement with the results.
Double-valued Corepresentations of Magnetic Point Groups
Authors: Cracknell AP , Wong KC
Published: May 2011

The theory of the corepresentations of non-unitary groups, which was developed by Wigner, is applied here to the determination of the double-valued corepresentations of the magnetic point groups. Complete tables are given for the double-valued corepresentations of each of the 58 magnetic point groups. A comparison is made with previous work by Dimmock and Wheeler.
Rotating Polytropes in the Post-Newtonian Approximation
Authors: Sudbury AW
Published: May 2011

It has been suggested by Fowler (1966) that rotation would make a star more stable, and Durney and Roxburgh (1967) have arrived at the same result, but so far the problem has not been treated without assuming that the star retains its shape (which it does not), and the post-Newtonian rotation terms have not been included. As a first step the equilibrium problem must be solved, and in this case the star is assumed to be a poly trope.
An Investigation of Interference and Resonance Asymmetry Effects in the Theory of Neutron Absorption in Reactors
Authors: Cook JL , Kletzmayr EK
Published: May 2011

The nuclear effects that lead to asynunetric behaviour of neutron resonancecross sections are investigated and general expressions for cross sections developed.These are shown to be of a form suitable for calculation of escape probabilities,and the functions that arise from them are tabulated.
The Akhieser?Pomeranchuk-Blair Model for Elastic Scattering
Authors: Sen Gupta HM , Rahman M , Khan AH
Published: May 2011

The semiclassical APE model is employed in analysing the angular distribution of protons elastically scattered from Fe, Cu, and Ag; deuterons from Ni, Zr, Ag, and Er; aHe.particles from Cd and I; and a-particles from 1. Effects of different parameters have been studied and the best�fit parameters obtained.
Some Observations of Shell-type Galactic Radio Sources
Authors: Hill ER
Published: May 2011

Radio evidence for two new supernova remnants in the Southern Milky Way is presented. Some new observations of the known supernova remnant, source 1439-62, and of the Rosette nebula, a shell source but not a supernova remnant, are also presented. The problem of finding model shells to fit the radio observations is considered and it is shown that the radio emission from 1439-62 is unlikely to originate in a shell with spherical symmetry.
18 cm OH-Line Radiation from NGC 6334
Authors: Gardner FF , McGee RX , Robinson BJ
Published: May 2011

A survey of the OH�line radiation from the region of NGC 6334 has been made with the Parkes 210 ft telescope (beamwidth 12'� 2 arc, bandwidth 10 kHz). Observations of both circular and linear polarization were made at 1665 MHz, and less completely at 1667 MHz.
Multip Article Collisions. II. Application of Unitarity
Authors: Cook JL
Published: May 2011

The application of unitarity to multiparticle production processes is studied and relationships between production and scattering amplitudes are derived.
The Effects of Thermal Energy and Ion-Removal Time on the "Pulsed Source" Method for Mass Spectrometer Investigations of Ion?Molecule Reactions
Authors: Challinor RA , Duncan RA
Published: May 2011

This paper examines two aspects of an experimental technique designed to investigate the dependence of ion-molecule specific reaction rates on primary ion energy. In this experiment the reaction proceeds in a mass spectrometer ion source under a constant electric field, and the ratio of secondary to primary ions is recorded as a function of time.
The Parkes Catalogue of Radio Sources Declination Zone +20° to +27°
Authors: Shimmins AJ , Day GA
Published: May 2011

This paper gives details of 397 radio sources between declina.tions + 200 and +270 which were compiled from a finding survey made at 635 MHz with the 210 ft reflector at the Australian National Radio Astronomy Observatory, Parkes, N.S.W.
Dielectric Saturation in Ionic Crystals. II. Deformable Ions
Authors: Oitmaa J
Published: May 2011

The lowest order field-dependent term in ~he static dielectric constant is calculated for an ionic crystal with deformable ions, and is evaluated numerically for NaI using a simple shell model. Some terms of higher order are also calculated.
Propagation of Shock Waves in a Polytrope with a Poloidal Magnetic Field
Authors: K Sinha Narendra
Published: May 2011

The propagation of a spherically developed shock wave in a poly trope with a poloida.l magnetic field has been studied using a generalization of Whitham's method. The effect of the magnetic field on the geometry of the front as well as on the effects brought about by the shock has been discussed.
A Continuum Survey of the Southern Milky Way at 1410 MHz
Authors: Hill ER
Published: May 2011

This paper presents a contour map of the Southern Milky Way at 1410 MHz obtained using the 210 ft radio telescope at Parkes.
Observations of the Southern Sky at 10·02 MHz
Authors: Hamilton PA , Haynes RF
Published: May 2011

The brightness distribution of cosmic radio noise has been surveyed at 10�02 MHz between declinations _2� and -65� with an aerial beam of 4� by 5�. The galactic plane appears as a region of low brightness. Spectra of sources observed are discuseed.
The Background Radiation in Isotropic World Models
Authors: Payne AD
Published: May 2011

A general equation for the extragalactic background intensity is derived for the general case of an isotropic homogeneous universe. The extragalactic radio spectrum depends critically on the thermal history of the universe and numerical results have been obtained for different possible models. A brief discussion is given on the conclusions drawn from the comparison of these results with the observed background spectrum.
An Analysis of Total Gamma Ray Cross Sections in the Energy Region from 40 to 80 keV in Cu, Sn, W, and Pb
Authors: Raja Rao M , Parthasaradhi K
Published: May 2011

In Table 1 the values of the experimental total y-ray cross sections measured by Wiedenbeck (1962), Bearden (1966), Knerr and Vonach (1967), and McCrary et al. (1967) at energies of 40,50, 60, 70, and 80 keY in the elements Cu, Sn, W, and Pb are given. It will be seen that in Cu at 80 keY, in Sn at 40 keY, in W at 50 keY, and in Pb at 40, 50, and 70 ke V these values do not agree well amongst themselves, even after considering the error limits.
Accurate Positions and Some Optical Identifications for 255 Radio Sources Between Declinations +20° and ?33°
Authors: K Merkelijn Jeannette
Published: May 2011

Accurate positions have been measured at 2700 MHz for 255 sources from the Parkes catalogue between declinations +20� and -33�. The estimated accuracy in both coordinates is approximately 15N arc. For 103 of the sources, identifications are suggested using the accurate positions. Sixty-two of the sources are identified with galaxies and 41 with quasi-stellar objects.
2+ States of 8Be
Authors: Barker FC
Published: May 2011

Analysis by many-level R-matrix theory of the d-wave "'-'" scattering phase shift suggests the existence of broad 2+ excited states of 8Be, but their properties depend sensitively on the assumed channel radius a2. A simultaneous fit to the 9Be(p, d)8Be deuteron spectrum near the 2, 9 MeV peak requires a2 "'" 7�1 fm, while a simultaneous fit to the ",-particle spectra following 8Li and 8B p-decays requires a2 "'" 6� 7 fm. For the best overall fit with a2 = 6�75 fm, the first 2+ excited state is at 2� 84 MeV excitation energy with a width at half maximum of 1�30 MeV. It is shown that data from other reactions which appeared to give much larger widths for this level can be fitted using the same R-matrix parameters. A second 2+ excited state is obtained at about 9 MeV with a width of about 10 MeV. Properties of the narrow 2+ states at 16�6 and 16�9 MeV are also discussed.
Effect of the Statistical Compound Nucleus Process in Elastic Scattering Measurements
Authors: Dallimore PJ
Published: May 2011

The errors in elastic scattering cross section calculations due to a statistical compound nucleus component are investigated. It is found that the spin of the target nucleus is a major parameter in the estimation of these errors.
Dispersion of Phonons in Ideal Crystals
Authors: Gupta NP
Published: May 2011

A quasiharmonic central force rigid-atom model has been used to study the lattice vibrations of frozen rare gases. The model takes care of interactions up to fourth neighbour and estimates zero-point energy and its volume derivatives by the Debye theory of specific heats. The theoretical frequency distribution and phonon dispersion curves are found to compare reasonably well with the available experimental data. Various causes of the discrepancies and possibilities of improvement of the results are discussed.
Vibrational Stability of Pure Helium Stars Surrounded by Pure Hydrogen Envelopes
Authors: Van Der Borght R.
Published: May 2011

This paper investigates the influence of a pure hydrogen envelope on the vibrational stability of pure helium stars and establishes the limiting mass 88 a function of the fractional mass of such an envelope. It is found that an envelope with a mass fraction of the order of 10-4 will make the star vibrationa.lly stable, even when the total mass of the star is well above the limiting mass for pure helium stars.
Analogues of Excited States in 91Zr
Authors: Jones GA , Morrison GC , Taylor RB
Published: May 2011

The level structure in 91Zr has been investigated by Cohen and Chubinsky (1963) with the 90Zr (d, p)91Zr reaction. They noted some 14 levels up to an excitation energy of 3�9 MeV. All these states were found to have positive parity and their structure is fairly well understood in terms of coupling a single-particle neutron to the ground state and the first two excited states of 90Zr (Ramavataram 1964). A study of the isobaric analogues of the 9lZr states with the 90Zr(p, pO)90Zr reaction was carried out by Moore (1964).
Some Short-term Auroral Breakup Effects on Sporadic?E
Authors: Cheney BJ
Published: May 2011

The development of the auroral substorm and the auroral breakup has been described in detail by Asafoku (1964). Swift (1967) gives some striking examples of the breakup from all-sky camera records and from his study he has separated the breakup into three phases:
MHD Acceleration in the Unsteady Expansion of a Shock Tube Driver
Authors: Cashman JD
Published: June 2011

The isentropic unsteady expansion of the driver gas in a shock tube is made to pass through an MHD interaction. The interaction is tailored so as to produce a new isentropic unsteady expansion downstream with greater energy than the original, which will drive a new shock of greater but constant velocity. Illustrative examples are calculated.
Accurate Flux Densities at 8·87 GHz of 195 Radio Sources
Authors: Shimmins AJ , Wall JV
Published: June 2011

Accurate flux densities at 8�87 GHz have been determined with the Parkes 64 m telescope for 195 radio sources, using an on-off integration method. The sources were selected from the Parkes 408 and 2700 MHz catalogues as those having estimated flux densities at 8�87 GHz greater than O' 5 f.u. and relatively small angular sizes. Eighty of the selected sources are identified with QSO's, 40 with galaxies, and one with an HII region, while 74 have not been identified. The estimated accuracy of the flux density is �0�02 f.u. (r.m.s.) due to system noise and �3'5% due to other causes. A list of known or newly suspected radio variables in the sample is given.
Application of the Hydromagnetic Energy Principle to a Plasma Between Electrodes
Authors: Seymour PW , James MK
Published: June 2011

The approach of Van Kampen and Felderhof (1967) is extended to derive the variation of potential energy t5W for a finite magnetized plasma contained by a vacuum magnetic field and in contact with conducting electrodes supported by insulators. The method gives a result in agreement with that of Bernstein et al. (1958) except for modification of the vacuum contribution. It leads to proof that the usual interpretation of the surface contribution to t5W is incorrect because of modification of the vacuum magnetic field energy associated with second-order distortion of the plasma boundary surface.
Possible Polarization Measurement for pp ® KK, p+p? Reaction
Authors: Peaslee DC
Published: June 2011

Polarization measurements are suggested for nucleon-antinucleon annihilation into two pseudoscalar mesons in the S region (total energy r-.J 1�9-2�0 GeV). The particular purpose is to distinguish the dominant J value of suspected 3D resonances; measurements with both beams and targets polarized would be especially revealing.
An Interpretation of De-excitation Gamma Ray Measurements Following the Photodisintegration of 12C, 16O, and 40Ca
Authors: Spicer BM
Published: June 2011

The relative populations of final states in photonuclear reactions for 12C, 160, and 40Ca are examined in the light of information on the known major configurations present in the wavefunctions of those final states, with the assumption that the nucleon excited in the radiation absorption process is in fact the one emitted. This assumption is investigated and found to be reasonable for 12C and 160 but not for 40Ca. The data on relative populations of final states are interpreted to give information on the relative strengths of configurations in the wavefunctions of the ground states of the three nuclei.
Calculation of the Prompt Gamma Energy of Individual Fission Fragments from the Prompt Neutron Numbers
Authors: Mukherji Shankar , Lal KB , Sharma Tejasvi
Published: June 2011

Approximate calculations of the prompt )I-ray energies of fission fragments and the total kinetic energies of different fragment pairs have been made on the basis of a liquid-drop model. In addition, reliable estimates� of the quantum energy for collective quadrupolar vibration have been used to calculate the number of prompt )I-ray quanta emitted by the fragments from the thermal-neutron-induced fission of 235U. There seems to be good agreement with the available experimental data. About 30 pairs of fission fragments from the thermal-neutron-induced fission of 233U, 235U, and 239Pu and the spontaneous fission of 252Cf have been included in this preliminary treatment.
The Effect of Rotation on Nonlinear Thermal Convection
Authors: Van der Borght R , Murphy JO
Published: June 2011

The effect of rotation on nonlinear thermal convection is investigated, in particular at high Rayleigh number. The Boussinesq approximation is adopted in the basic equations and the free boundary conditions are applied. The results derived from asymptotic and perturbation methods are found to be in very good agreement with those obtained by numerical integration.
Measurements of Source Strengths at 29·9 MHz
Authors: Finlay EA , Jones BB
Published: June 2011

A survey of the region of sky between declinations _4� and -64� has been completed at a frequency of 29�9 MHz at the Fleurs Radio Observatory of the School of Electrical Engineering, University of Sydney. Aperture synthesis has been used to form a beam of 0�.8 diameter. The flux densities of 175 sources have been measured and referred to absolute measurements of certain strong sources. Most of the source fluxes are consistent with an extrapolation of the power law spectra determined from high frequency measurements but a few show significant deviations. Absorption by the interstellar medium of sources at low galactic latitudes has only been observed for I b I < 3� and appears to be negligible at higher latitudes.
A Note on Resonance Angular Distributions with Application to Nucleon?Antinucleon Scattering and Annihilation
Authors: Peaslee DC , Rosalky DM
Published: June 2011

Angular distributions have been calculated for the reactions NN -+ NN and NN -+ 2 pseudoscalar mesons by assuming the formation of an intermediate isolated state. The scattering distributions are only found to have the characteristic oscillatory shape for unnatural parity resonances whereas those for natural parity states are smooth. The annihilation distributions display an exact degeneracy with respect to the interchange of orbital and total angular momenta. For both reactions, the width of the forward and backward peak is approximately inversely proportional to the resonance spin.
A Simple Derivation of the Bloch Equations for Localized Moment E.S.R. in Metals in the Presence of Anisotropy
Authors: Smith DA
Published: June 2011

A density-matrix approach is used to derive the coupled Bloch equations for the electron spin resonance of localized moments and conduction electrons in metals, including anisotropy fields acting on the local moments. The equations agree with those obtained elsewhere by more sophisticated many-body techniques. In particular, it is demonstrated explicitly that relaxation proceeds towards instantaneous equilibrium.
The Carina Nebula at 30 MHz
Authors: Jones BB
Published: June 2011

A map of the Carina nebula, with 50' arc resolution, has been made using the 30 MHz aperture synthesis telescope at Fleurs. At this frequency the nebula appears in absorption. A strong nonthermal source, presumably a supernova remnant, has been found in front of the nebula. Estimates of the emissivity in this region from brightness temperatures are found to vary markedly over the extent of the nebula. The average measured emissivity is lower than that in the local arm, suggesting the presence of an interarm gap between the Sun and the nebula.
The Measurement of Statistical Properties of Radio Noise Using Pulse Techniques
Authors: Clay RW , McDonald DM , Prescott JR
Published: June 2011

The statistical properties of radio noise have been investigated by means of a wide-band radio receiving system and techniques similar to those employed in nuclear physics. Measurement of the amplitude probability distribution of broad-band noise at a rural location has shown that it can be represented by a Rayleigh distribution over a much wider dynamic range than is commonly observed. The time distribution of the largest observed noise amplitudes appears to be non-random.
Quantum-Mechanical Wave Equation for Two Particles of Arbitrary Spin with Instantaneous Interaction
Authors: Tam Kwong-Chuen
Published: June 2011

A quantum-mechanical wave equation for two particles of arbitrary spin is derived for any instantaneous interaction. The starting point is an integral equation which is a relativistic generalization of the SchrOdinger integral equation and is similar to the Bethe-Salpeter equation. The final two-particle wave equation contains the sum of the Hamiltonians of the two particles and has only one time variable. It reduces to the two-particle Schrodinger equation in the non-relativistic limit
Self-Consistent Approximation and Fifth Virial Coefficients for a Square Well Potential
Authors: Gopala Rao RV , Narasimha Swamy K
Published: June 2011

A proposed self-consistent approximation for the second-order Percus-Yevick and convoluted hypernetted chain theories is used to calculate the fifth virial coefficients for a square well potential. The results are in good agreement with the exact values.
Australian Journal of Physics Astrophysical Supplements
Authors: Bolton JG , Shimmins AJ
Published: June 2011

A catalogue of 885 radio sources is presented, covering right ascensions lOb to 15b and 19b to 07b between declinations -35� and -45�. The catalogue is believed to be complete to 0�22 f.u. at 2700 MHz (940 sources per steradian) and the positions are accurate to �15N arc in both coordinates for sources stronger than 0�3 f.u. Flux densities at 5009 MHz have been measured for 350 of the strong sources. Eighty-eight of the sources have been identified with galaxies and 39 have been identified and confirmed as quasi-stellar objects.
Elimination of Primitive Divergents from Field Theory by Means of Complex Coupling Constants
Authors: Nicholson AF
Published: June 2011

LSZ. iteration theory is extended to accommodate quantum fields coupled by complex constants, while retaining a positive metric and a Hermitian Hamiltonian. Interpolating and particle (~in, out) fields are linked by an operator U(t) which is nonunitary, so that Haag's theorem may be avoided. It is shown that U(t) may be rendered sufficiently well-behaved as t -+ � 00 to allow development of the iteration series for the T function. For certain combinations of fields the coupling constants and masses can then be chosen so as to eliminate the primitive divergents from the iteration series for any S-matrix element. The theory is illustrated by two models: four spinor plus two scalar fields, and the electromagnetic plus several spinor fields. In the second model not every spinor field corresponds to a stable physical particle, and the LSZ formalism is extended to allow for this.
Separable Representation of the Nucleon-Nucleon Interaction in the 3S1?3D1 Channel
Authors: Afnan IR , Read JM
Published: June 2011

A separable representation for the two-nucleon T-matrix in coupled channels has been obtained from a unitary pole expansion for the potential and the method has been tested with the Reid soft-core potential in the 3S,_3D1 channel. A 3-term expansion provides a T-matrix that is sufficiently accurate for a perturbation theory calculation of the three-nucleon bound state, while a IS-term expansion closely reproduces the exact T-matrix. In addition, a unitary pole approximation is presented that gives a better fit to the phase shifts and coupling parameter than that of Siebert et al. (1972).
Spin?Parity Combinations in 32S
Authors: Gardner PR , Kean DC , Spear RH , Baxter AM , Bell RAI , Carlson LE
Published: June 2011

Inelastically scattered IX-particles from the reaction 32S(IX, 1X')32S have been studied with solid state counters at extreme backward angles in order to determine spin-parity combinations for levels in 32S at excitation energies Ex up to 7 �15 MeV. The results confirm the well-established spin and parity values, show that the 5� 798 MeV spin 1 state has negative parity, and provide narrow limits for the possible spin and parity values of the 6'410,6' 666,6' 762, and 6� 854 MeV levels. A previously unreported natural parity level was found at Ex = 6�58 MeV. Magnetic analysis of the reaction 32S(p, p')32S confirmed the existence of this level and established its excitation energy as 6�581�0�003 MeV. Particle-y-ray coincidence studies showed that this level decays predominantly by y-ray transitions to the 2�23 MeV 2 + state.
The Drift Velocity of Electrons in Oxygen at 293 K
Authors: Crompton RW , Elford MT
Published: June 2011

The drift velocity of electrons in oxygen at 293 K has been measured over the range 0.8 ≤ E/N ≤ 12 Td by the Bradbury–Nielsen time-of-flight method. The factors governing the range over which measurements can be made are discussed and it is shown that long drift tubes should be used for drift velocity measurements in oxygen at low values of E/N. A 50 cm drift tube is described. The error in the present results is estimated to be less than 1 % for 1.8 E/N E/N > 6 Td and at 1.5 Td, 5 % at 1 Td, and 10 % at 0.8 Td. The present data are in good agreement with those of Fleming et al. (1972) and Nelson and Davis (1972) over the E/N range where the sets of data overlap.
The Interpretation of Some Observations of Radio Waves Scattered from the Lower Ionosphere
Authors: Vincent RA
Published: June 2011

Possible shapes and spatial scales of ionospheric irregularities in the lower ionosphere have been determined from analyses of two sets of radio wave back-scattering observations: measurements of the spatial scale of the ground pattern of the wave field back-scattered from altitudes near 95 km and measurements of the amount and angular distribution of power back-scattered from solitary horizontally-moving irregularities at altitudes near 75 km. At 95 km the irregularities are anisotropic, with larger horizontal than vertical dimensions. For an assumed Gaussian distribution of ionization, the inferred axial ratio (horizontal to vertical) is about three. It is tentatively concluded that the irregularities at 75 km are sharply bounded and are some kilometres in horizontal extent.
Hydrogen Content of Young Stellar Clusters. II. Clusters NGC2175, 2264, 2353, and 2362
Authors: Tovmassian HM , Shahbazian ET
Published: June 2011

Measurements of the total amount of gaseous hydrogen associated with the O-type stellar clusters NGC 2175, 2264, 2353, and 2362 are reported. For the nebula in which NGC2175 is embedded, a mean electron density of 20cm- 3 and a mass of ionized hydrogen of 1400Mo were obtained. For the nebula in which NGC2264 is embedded, a mean electron density of 10 cm - 3 and a mass of ionized hydrogen of 60Mo (with a possible, though unlikely, additional 40Mo of neutral hydrogen) were obtained. No hydrogen in association with NGC 2353 or 2362 was detected.
Hydrogen Content of Young Stellar Clusters. IV.Clusters NGC6231, 6383, 6514, and 6531
Authors: Tovmassian HM , Nersessian SE , Shahbazian ET
Published: June 2011

The total amount of hydrogen associated with the young stellar clusters NGC6231, 6383, 6514, and 6531 has been obtained from observations in the continuum at 1410 MHz and in the hydrogen-line emission. NGC6231 contains in its southern part a cloud of neutral hydrogen atoms of density 6 cm- 3 and total mass l00M0 and in its northern part a small ionized cloud of the same density and a mass of ~ 50 M 0. NGC 6383 is embedded in a large neutral hydrogen complex, of which a small part of mass ~450M0 is ionized. The Trifid nebula is ionized by a single 07-type star at nearly twice the accepted distance of NGC6514 and the existence of NGC6514 as a physical cluster appears to be doubtful. The mass of the ionization-bounded Trifid nebula is nearly 5000M0 ? Neither neutral nor ionized hydrogen was found in association with NGC6531.
Australian Journal of Physics Astrophysical Supplement
Authors: Wall JV , Cannon RD
Published: June 2011

Identifications are suggested for 105 radio sources in the third part of the Parkes 2700 MHz survey. The identifications, 63 with galaxies and 42 with quasi-stellar objects, were obtained from examination of V, B plate pairs taken with the Uppsala Schmidt telescope at Mount Stromlo Observatory. Additional position measurements with the Parkes 64 m telescope were made on 199 of the 459 catalogue sources covered by these plate pairs. Identification statistics for the area are compared with those of the first two parts of the Parkes 2700 MHz survey.
Statistics for Adler?Adler Resonance Parameters
Authors: Rose EK , Cook JL , Bertram WK
Published: June 2011

An elementary statistical theory for Adler-Adler resonance parameters is derived and the experimental results for 233U and 235U are analysed. Satisfactory agreement is obtained for all parameters.
The Appearance of Relativistic Stellar Systems
Authors: Suffern KG
Published: June 2011

A formula is derived for the projected density distribution on a photographic plate which would arise from a given static spherically-symmetric relativistic stellar system. For weak gravitational fields, a corresponding post-Newtonian expression is derived which is relatively simple to use once a particular proper stellar number density has been specified for the relativistic system under consideration. For application to the outer regions of such a system, this post-Newtonian formula simplifies considerably, and it is possible to solve von Zeipel's problem explicitly for these outer regions to obtain an expression for the proper number density of stars in such a system from the projected density on a photographic plate. We find that, if Newtonian theory alone were used to calculate the stellar number density in a relativistic system from the projected density, the system so constructed would appear to be less centrally condensed than it really is.
Quantum Phenomena and the Mobility of Potassium Ions in Argon
Authors: Watts RO
Published: June 2011

Recent work on the mobilities of alkali metal ions in the noble gases has indicated that there is a pressure dependence of the zero-field reduced mobility. The possibility of temporarily bound dimmers being responsible for this pressure dependence is examined here by quantum mechanical methods for the case of potassium ions in argon and it is shown that the conditions needed for a small pressure dependence do exist at room temperature.
The Ratio DL/ for Electrons in Helium at 293 K
Authors: Elford MT
Published: June 2011

The Bradbury–Nielsen method has been used to measure the ratio of the longitudinal diffusion coefficient DL to the electron mobility μ in helium at 293 K over the E/N range 0024–0.607 Td. The absolute error is estimated to be less than � 3 %. The present results agree with those of Wagner et al. (1967), to within the combined experimental errors over the common range of E/N values, and are also compatible with the values predicted by Lowke and Parker (1969) from calculations based on the momentum transfer cross section of Crompton et al. (1967).
The Mechanism Responsible for 'Shadow' Type III Solar Radio Bursts. I. Absorption due to Langmuir Turbulence
Authors: Melrose DB
Published: June 2011

The hypothesis is advanced that for 'shadow' type III solar radio events (absorption features with drift rates and bandwidths typical of type III bursts or U-bursts) the absorption mechanism involves Langmuir turbulence, such absorption being the inverse of either fundamental (I = J;,) or second harmonic (f = 2/p) plasma emission. The theory for both absorption processes is developed and applied to shadow type III events with the following results: (1) the predicted absorption is confined to a very narrow frequency range (fl.I/ I ~ 10- 3); (2) effective absorption requires an energy density in Langmuir turbulence (with phase speeds ~tc) in excess of 10-9 ergcm- 3 for the fundamental and in excess of 3 x 10-6 ergcm- 3 for the second harmonic; (3) the brightness of the background source must exceed 109 and 1016 K for absorption at the fundamental and second harmonic respectively. Comparison of the theory with the properties of an event discussed by Kai (1973) leads to the conclusions: (1) absorption at the second harmonic is unacceptable because of the high brightness temperature required; (2) to explain the observed bandwidth in terms of absorption at the fundamental, the absorbing region and the background source must overlap in height; (3) to explain the observed reduction in brightness temperature requires that the initial brightness temperature exceed 5�5 X 109 K (the observed value was 109 K).