bluuebunny/crossref_metadata_2025 huggingface dataset:
RADIOACTIVE DECAY OF Au200
Authors: Roy J. C. , Roy L. P.
Published: April 2011

The half-life of Au200 has been measured to be 48.4 ± 0.3 minutes. The beta radiations emitted in the decay of Au200 have been studied by absorption in aluminum, and the gamma radiations with a multichannel scintillation spectrometer. Two beta rays with end-point energies of 2.25 ± 0.20 and 0.7 ± 0.1 Mev and respective abundance of (75 ± 3)% and (25 ± 3)% were detected. Three gamma rays with energies of 0.367, 1.23, and 1.60 Mev were observed. It was established that the 0.367- and 1.23-Mev gamma rays are in coincidence. A decay scheme for Au200 is proposed.
INTERCOMPARISON OF 11 RESISTANCE THERMOMETERS AT THE ICE, STEAM, TIN, CADMIUM, AND ZINC POINTS
Authors: McLaren E. H.
Published: April 2011

Eleven standard platinum resistance thermometers, including thermometers having three different types of construction, have been intercompared at the triple point of water, boiling point of water, and the liquidus points of high purity tin, cadmium, and zinc. Temperature coefficients determined from measurements at the triple and boiling points of water and the zinc point were used to calibrate the thermometers for the temperature calculations on measurements at the tin and cadmium points. The results show that, although the measurements were made at a precision of about 0.0002 °C at each fixed point, distinctive deviations from quadratic resistance–temperature relations were not found for the 11 thermometers. This verification of the quadratic form for the resistance–temperature relationship realized with these thermometers gives strong support for the use of the liquidus point of high purity indium, tin, or cadmium as a precision alternative to the steam point on the International Temperature Scale.
SOME PHYSICAL PROPERTIES OF SEA ICE. I
Authors: Pounder E. R. , Little E. M.
Published: April 2011

This preliminary study is based mostly on work done at a shore station in Shippegan, N.B., during the winter of 1956–57, with some data from an icebreaker expedition in the summer of 1956. The Shippegan site had unrafted ice, tides of 5 feet or less, and negligible fresh-water runoff. The thickness of the ice was about proportional to the square root of the freezing exposure. Tritium dating of sea ice is an unsatisfactory method because of variable tritium concentration in Arctic waters. The jaggedness of ice crystals is suggested as a measure combining effects of age and thermal regime. Measurements of specific gravity, salinity, electrical resistivity, and permeability profiles all show progressive changes in annual sea ice throughout the winter. The tensile strength of sea ice at −20 °C was around 200 to 500 p.s.i., at various angles to the grain. For fresh-water ice, with stress parallel to the grain, it was in the range 500 to 1000 p.s.i. Shear strengths, with the shear plane parallel to the grain, were 80 to 160 p.s.i. for sea ice at −20 °C and 160 to 280 p.s.i. for pond ice, also at −20 °C.
ABSOLUTE β-COUNTING IN A PROPORTIONAL FLOW-COUNTER
Authors: Roalsvig J. P. , Haslam R. N. H.
Published: April 2011

Self-absorption and backscattering of β-particles have been studied in a proportional flow-counter, and empirical formulae are obtained to correct for these factors in absolute β-counting. The correction factors will depend on the thickness of the sample, the atomic number of the backscattering material, and the maximum energy of the β-particles. Relationships between the mass-absorption coefficient and the maximum energy of the β-particles for the primary β-particles, and between the mass-absorption coefficient, the maximum energy of the β-particles, and the atomic number of the backscattering material for the backscattered β-particles, are obtained. The backscattering function is found to depend on the atomic number of the backscattering material alone.
SELF AND EXTERNAL MESON FIELDS
Authors: Sharp R. T.
Published: April 2011

Instead of a single (isotopic vector) field to describe pions, it is sometimes advantageous to introduce several such fields with identical properties except for their coupling to the sources of the field (the baryons). In this way one can formally distinguish between self pions (roughly, those which can be emitted and absorbed by the same baryon) and external pions (roughly, those which are only exchanged between baryons or emitted into or absorbed from free states). K-mesons can be treated similarly. The device, which is of general applicability, simplifies many derivations and calculations in quantum field theory. As an illustration of the method it is used to derive the Low equations for scattering of pions and K-mesons by nucleons and for associated production. A suggestion is made for treating the nucleon–nucleon interaction.
THE IMPEDANCE, RECTIFICATION, AND ELECTROLUMINESCENCE OF ANODIC OXIDE FILMS ON ALUMINUM
Authors: Smith Archibald W.
Published: April 2011

An experimental investigation was made of the impedance, rectification, and electroluminescence of anodic oxide films formed on aluminum, in an electrolyte of boric acid and ammonium hydroxide. These properties were studied, where appropriate, as a function of the surface condition before anodization, the formation voltage, the conductivity of the electrolyte, and the frequency. A constant-voltage formation technique was used. The interpretation of the results suggests that the oxide itself is a good dielectric, but that the film contains defects whose number and form depend on the conditions of formation. The defects appear to control the rectification and electroluminescence and have an appreciable influence on the impedance. The frequency dependence of the capacitance was much smaller than that found by previous workers although there was an appreciable contribution arising from geometrical effects in the electrolytic cell. The zero-thickness potential for the film was found to be in agreement with a theoretical estimate.
STUDY OF PHASE PROPAGATION IN SUPERCONDUCTING ALUMINUM BY ULTRASONIC ATTENUATION MEASUREMENTS
Authors: Chopra K. L. , Hutchison T. S.
Published: April 2011

The phase propagation in superconducting aluminum has been studied by measuring the time rate of change of ultrasonic attenuation. The time taken for the destruction of the superconducting phase in a cylindrical specimen, by means of a magnetic field, H, greater than the critical field, Hc, is approximately proportional to{H/(H–Hc)} in agreement with eddy-current theory. In the converse case, where the superconducting phase is restored by switching off the magnetic field H (>Hc), the total time taken is nearly independent of the temperature (or Hc) as well as H. The superconducting phase grows at a non-uniform volume rate which is considerably less than the uniform rate of collapse.
ANALYSIS OF TWO INTERFERING 1/2+ LEVELS IN THE DISINTEGRATION OF C14 BY PROTONS
Authors: Ferguson A. J. , Gove H. E.
Published: April 2011

Two interfering resonances occurring at bombarding energies of 1.32 Mev and 1.51 Mev in the reactions C14(pn)N14 and C14(pγ)N15 have been analyzed in terms of Wigner's two-level formula. Resonant energies and reduced widths have been found which give good fits to the shapes of the yield curves for both processes in the neighborhood of the resonances. The absolute cross sections for the C14(pn)N14 and N14(np)C14 reactions are obtained from the analysis without reference to the measured cross sections. The calculated cross sections are found to be about 40% lower than the measured ones.
THE PHOTODISINTEGRATION OF TANTALUM
Authors: Parsons R. W. , Katz L.
Published: April 2011

The cross section for the absorption of photons by Ta181 has been deduced from measurements of the neutrons emitted when tantalum is irradiated in the X-ray beam of a 22-Mev betatron. The cross section has well-defined peaks at 12.75 ±.25 and 15.25 ±.25 Mev, and from this the intrinsic electric quadrupole moment is deduced to be 5.7 ± 1.3 barns.
MODIFICATION OF PbS NOISE SPECTRA BY RADIATION
Authors: Williams R. L.
Published: April 2011

The noise spectra of PbS photoconductive cells can be modified by optically excited carriers. Detailed wavelength studies at CO2 temperatures have shown that g–r noise can be obtained using light of the 2.4-micron region, and the 1/f form with radiation of the 1.0-micron region. The effect is explained by assuming that minority carrier lifetimes in Kodak Ektron detectors are very short. The 1/f noise is only observed when optical carriers are produced very near the cell surface.
THE ONSET TIMES OF FORBUSH-TYPE COSMIC RAY INTENSITY DECREASES
Authors: Fenton A. G. , McCracken K. G. , Rose D. C. , Wilson B. G.
Published: April 2011

The onset times of a number of Forbush-type decreases observed at four widely spaced stations are compared, and it is shown that appreciable differences occur. The stations selected were Hobart, Mawson, Ottawa, and Sulphur Mountain. It was found that a consistent pattern is obtained for the events studied when the onset times are plotted as a function of the direction of maximum sensitivity of the recorders relative to the earth-sun line. This is interpreted as being due to a directional anisotropy that exists in the mechanism producing the decreases, at least in the early stages. The depression occurs first for particles arriving from directions between 30° and 120° west of the earth–sun line. The relation between these observations and geomagnetic disturbances and the quiet-day daily variation is discussed.
ON "PLASTIC" WAVES IN SOLIDS
Authors: Bowsher John M.
Published: April 2011

The study of the propagation of "plastic" waves in solids has reached a stage where it is necessary to consider which direction future research should take. In the past 90 or so years many experiments, mostly designed to elucidate certain points of engineering significance, and a few attempts at a theoretical study have cast some light on the subject and revealed it as one of formidable difficulty.Nearly all the experiments have of necessity relied on rather dubious theories for their interpretation, and part of the present paper will be devoted to a description of an apparatus which gives results capable of being interpreted with a very minimum of theory. The remainder of the paper is devoted to a short review of past work with particular emphasis on basic phenomena and to a brief discussion on the most pressing problems still remaining. The experiments described in the present paper bring to light a factor in the propagation of "plastic" waves that seems to have been overlooked in previous work.
ROTATIONAL STATES OF EVEN–EVEN NUCLEI
Authors: DeMille G. R. , Kavanagh T. M. , Moore R. B. , Weaver R. S. , White W.
Published: April 2011

Rotational energy levels of axially asymmetric nuclei have been calculated in the manner of Davydov and Filippov, and a comparison with experiment shows good quantitative agreement. It is suggested that agreement may be improved by introducing the Bohr–Mottelson vibration–rotation interaction and a centrifugal stretching correction analogous to the type used in molecular spectra. The D–F method seems to be particularly useful for nuclei in the transition regions between "rotational" and "near-harmonic" modes of collective excitation.
IRREVERSIBLE THERMODYNAMICS AND KINETIC THEORY IN THE DERIVATION OF THERMOELECTRIC RELATIONS
Authors: Leech J. W.
Published: April 2011

The variety of experimental behavior found in thermoelectricity at low temperatures provides an incentive for extending the theoretical treatment. In the past, irreversible thermodynamics has been used to provide a satisfactory derivation of the Thomson relations. It appears that what one might call a general "primary equation" of thermoelectricity can be derived from irreversible thermodynamics, and that this should be of direct use in kinetic discussions. The form of the equation suggests that an even more direct approach to the thermoelectric problem should be possible.
HEAVY-LIQUID BUBBLE CHAMBERS
Authors: Williams Robert W.
Published: April 2011

Experience with some high-Z liquids or fluid mixtures in bubble chambers, at M.I.T. and from other groups, is discussed. Measurement procedures are analyzed, and optimum methods are presented for angle measurements, pβc determination from multiple scattering, and momentum determination from magnetic curvature. Magnetic fields will be useful even in strongly scattering liquids. Combined use of magnetic and scattering determination is not much better than one alone. Results are presented on detection efficiency for high-energy gamma rays, and on the severe effects of radiation straggling on energy measurements on electron pairs.
THEORY OF THE PRESSURE-INDUCED ROTATIONAL SPECTRUM OF HYDROGEN
Authors: Kranendonk J. Van , Kiss Z. J.
Published: April 2011

The theory of induced infrared absorption developed previously is applied to the pressure-induced rotational spectrum of hydrogen. The intensity of the rotational band is due mainly to the quadrupolar induction effect, and to a small interference effect between the quadrupolar and overlap moments. From the experimental data on the binary absorption coefficients, values of the angle-dependent overlap moments are obtained for H2–He, H2–H2, H2–Ne, H2–N2, and H2–A. A calculation of the overlap moment for pure H2 is presented. Rosen-type wave functions appear to be inadequate for a calculation of the small angle-dependent rotational as well as vibrational overlap moments. The temperature dependence of the binary absorption coefficient is calculated, taking into account the quantum effects in the pair distribution function, and found to be in good agreement with the experimental data. The dependence on the ortho–para ratio is also discussed. The double rotational line S(1) + S(1) has been observed and its intensity measured.
ON THE POSSIBLE EXISTENCE OF A DERIVATIVE COUPLING IN QUANTUM ELECTRODYNAMICS
Authors: Kaempffer F. A.
Published: April 2011

Within the framework of quantum electrodynamics there exists the possibility of a derivative coupling between source and photon field, referred to as eΛ-charge, which has no classical analogue. For calculations the usual graph technique can be used, provided the factor eγμ contributed by each vertex in a conventional graph is replaced by ieΛkμ, where Λ is a length characteristic of the new interaction. Using as cutoff the nucleon mass M one finds for a bare source of electronic mass m the self-energy in second order to be Λm/m ≈ 200, if Λ−1 ≈ 60 M. It is argued that the large mass difference between muon and electron may be due to this effect, assuming muon and electron to differ only in that the muon has eΛ-charge whereas the electron has not. An estimate is made of the muon–muon scattering cross section caused by the presence of eΛ-charge on the muon, and it is found that the existence of this derivative coupling may have escaped observation.
SURFACE WAVE PROPAGATION OVER A SAND-COVERED CONDUCTING PLANE
Authors: Mungall A. G. , Morris D.
Published: April 2011

The velocity of surface waves propagated over a sand-covered metal plane has been investigated experimentally as a function of the depth of the sand. Measurements were made at a frequency of approximately 9000 Mc/sec, using a phase comparison system. A periodic variation of surface wave velocity with sand depth was found, as predicted theoretically. The possible application of the results to effects found in precise microwave distance measuring techniques is discussed.
A NEW ABSOLUTE NOISE THERMOMETER AT LOW TEMPERATURES
Authors: Fink H. J.
Published: April 2011

If three resistors, which are kept at different temperatures, are arranged in form of a π network and if two of the thermal noise voltages appearing across the π network are multiplied together and averaged with respect to time, then under certain conditions the correlation between those voltages can be made zero. This condition is used to calculate the temperature of one noise source provided all the resistance values and the other temperatures are known. A noise thermometer of this kind was constructed which is capable of measuring temperatures below approximately 140° K. The boiling points of liquid oxygen and liquid nitrogen were determined absolutely within 0.2%. Between 1.3° K and 4.2° K the thermometer had to be calibrated due to errors arising in the equipment and the measured temperatures were then accurate within ± 1%.
CORNER-DRIVEN COUPLED SQUARE LOOP ANTENNAS
Authors: Prasad Sheila
Published: April 2011

A theory for two identical square loop antennas driven in the zeroth-phase sequence (voltages in phase at all four corners) and the second-phase sequence (voltages in and out of phase at the corners) is formulated. Eight independent integral equations are obtained. They are solved individually by the method of iteration, and first-order formulas are obtained for the current distributions and driving point impedances. For each phase sequence, the sum of the symmetrical and antisymmetrical impedances gives the self-impedance and the difference between them gives the mutual impedance. Self and mutual impedances are also obtained for a superposition of the two phase sequences.
THE ANGULAR DISTRIBUTION OF PHOTOFISSION FRAGMENTS
Authors: Baerg A. P. , Bartholomew R. M. , Brown F. , Katz L. , Kowalski S. B.
Published: April 2011

Angular distributions of photofission fragments relative to the photon beam have been measured as a function of maximum bremsstrahlung energy in the range 6–20 Mev. The nuclides U-233, U-235, Np-237, Pu-239, and Am-241 give an isotropic distribution at all energies studied. The nuclides Th-232, U-234, U-236, U-238, and Pu-240 give anisotropic distributions which can be described by an equation of the form W(θ) = 1 + α sin2 θ where θ is the angle between fragment and beam. The degree of anisotropy is large at low energy and falls rapidly as the energy is increased. At a given energy Th-232 has the greatest degree of anisotropy and Pu-240 the least.
NOUVELLES ÉMULSIONS IONOGRAPHIQUES À L'ALCOOL POLYVINYLIQUE
Authors: Demers Joseph , Demers Pierre , Fujii Etsuo , Fujii Hideko
Published: April 2011

not available
THE EFFECT OF DEFORMATION ON THE INTERNAL FRICTION OF IRON MEASURED AT THE CARBON PEAK POSITION
Authors: Boswell F. W. C.
Published: April 2011

Experiments have been carried out to investigate the influence of deformation on the internal friction of iron measured at the carbon peak. As a result of deformation the internal friction increased and then decreased with time. These changes, corrected for a background change associated with the deformation, were shown to follow a time law predicted for carbon segregation to dislocations. It is concluded that the amount of carbon in random solid solution is increased by the deformation. By analyzing the rate of decrease of internal friction following deformation in terms of strain-aging theory the final dislocation densities were determined. The results also indicate that in some cases the carbon put into solution by the deformation was initially present in the form of iron carbide particles.
ABSOLUTE YIELDS OF THE XENON AND KRYPTON ISOTOPES IN U238 SPONTANEOUS FISSION
Authors: Young B. G. , Thode H. G.
Published: April 2011

The absolute abundances of the isotopes of fission-product xenon and krypton in six uranium minerals have been determined mass spectrometrically using the isotope dilution technique. The fission products were resolved into a U238 spontaneous fission component, a U235 neutron-induced fission component, and a U238 neutron-induced fission component. Internal consistency in the analysis was achieved only when the Xe129 yield used for the U235 thermal neutron fission component was 20% lower than that reported by Purkayastha and Martin at I129. This discrepancy in the mass 129 chain yield measured at I129 and at Xe129 has not been resolved.Only one of the six minerals, Cinch Lake pitchblende, retained essentially all of its fission product inert gases throughout geological time. Inert gas losses from the remaining five minerals ranged from 20% to 75%. The absolute yields of the stable xenon and krypton fission products in U238 spontaneous fission were determined from an analysis of the inert gases from the Cinch Lake mineral. This analysis showed that 95.9% of the fission gas in this case resulted from the spontaneous fission and only 4.1% from neutron-induced fission.
A NOTE ON DIFFRACTION BY AN INFINITE SLIT
Authors: Millar R. F.
Published: April 2011

The two-dimensional problem of diffraction of a plane wave by a narrow slit is considered. The assumed boundary values on the screen are the vanishing of either the total wave function or its normal derivative. In the former case, a differential–integral equation is obtained for the unknown function in the slit; in the latter, a pure integral equation is found. Solutions to these equations are given in the form of series in powers of ε (where ε/π is the ratio of slit width to wavelength), the coefficients of which depend on log ε. Expressions are found for the transmission coefficients as functions of ε and the angle of incidence; these are compared with previous determinations of other authors.A brief outline is given for the treatment of diffraction of a cylindrical wave by the slit.
THE RADAR CROSS SECTION OF A SEMI-INFINITE BODY
Authors: Brysk H.
Published: April 2011

The concept of cross section as applied to a semi-infinite scattering body seems to require some clarification. The need for careful formulation of the problem arises because of the simultaneous occurrence of two characteristic lengths tending to infinity: the range from the radar to the target, and the size of the target. The infinite range assumption in the definition of the cross section allows the incident wave to be approximated as a plane wave in the case of a finite scatterer. For a semi-infinite body, it is customary to retain the plane-wave incidence, and introduce ad hoc arguments to dispose of the awkwardness due to the infinite extent of the scatterer. A return to the basic definition of a cross section, and examination of its motivation, lead here to an unequivocal formulation for the cross section of a semi-infinite body. Its consequences are pursued in the physical optics approximation. In particular, the nose-on backscattering from a body of revolution is exhibited, and results are computed for the paraboloid and the cone (which turn out to agree with the traditional ones). The broadside backscattering from a cylinder is also calculated, and the difference in this case between mono-static backscattering and the return in the backward direction from an incident plane wave is discussed.
MEASUREMENT OF RADIATIVE CAPTURE RESONANCE INTEGRALS IN A THERMAL REACTOR SPECTRUM, AND THE THERMAL CROSS SECTION OF Pu-240
Authors: Walker W. H. , Westcott C. H. , Alexander T. K.
Published: April 2011

An apparatus is described which detects γ-rays emitted by a thin target placed in a well-denned neutron beam. It has been used to determine the Cd ratios of Au and Pu-240, from which the ratio of the resonance integral to the 2200 m/s cross section for radiative neutron capture in Pu-240 has been deduced, using Au as a reference standard. Using this ratio and previously measured values of the resonance integral of Pu-240 and its effective cross section in two positions in the NRX reactor, three separate estimates of the 2200 m/s cross section of Pu-240 have been made. The mean value is 270 ± 17 barns.In an auxiliary experiment to indicate the shape of the epithermal spectrum of the neutron beam, the activation Cd ratios of Mn and In were compared with that of Au. These results, combined with the known 2200 m/s capture cross sections of these nuclides, yield new values of the radiative capture resonance integrals for both Mn and In.
ANALYSIS AND SYNTHESIS OF RADIATION PATTERNS FROM CIRCULAR APERTURES
Authors: Ishimaru A. , Held G.
Published: April 2011

Part I considers the problem of determining the source distribution over a circular aperture required to produce a prescribed radiation pattern. In particular, the problem of optimizing the narrow broadside pattern from a circular aperture is discussed in detail and an improved design method over Taylor's for line source is devised. Numerical examples are given.Part II deals with the analysis of the radiation pattern from a circular aperture from γ1 to γ2 with the traveling wave type source functions. Expressions suitable to the analysis and the synthesis are obtained and the narrow-beam and shaped-beam synthesis are discussed.
THE RADIATION CHARACTERISTICS OF A SINUATE ANTENNA
Authors: Loh S. C.
Published: April 2011

Rigorous expressions for the radiation field of an antenna of sinusoidal shape are derived on the assumption of a travelling-wave type of current distribution along the conductor. In order to illustrate the derived results an endfire antenna is designed and some calculations of radiation field are presented.
THE K–LL AUGER SPECTRUM OF 62Sm152
Authors: Ewan G. T. , Graham R. L. , Grodzins L.
Published: April 2011

The K–LL Auger spectrum of 62Sm152 has been studied in the Chalk River high-resolution β-ray spectrometer with a proportional counter detector. Seven lines were observed in the Auger spectrum with the following energies and relative intensities:[Formula: see text]These measurements are compared with the theoretical predictions of Asaad and Burhop. The measured energies are ~50–60 ev higher than their predictions. Discrepancies exist in the relative intensities but these are smaller than were observed at Z = 94.
KLEIN–DUNHAM POTENTIAL ENERGY FUNCTIONS IN SIMPLIFIED ANALYTICAL FORM
Authors: Jarmain W. R.
Published: April 2011

A simple formula, based originally on the work of Klein and Rees, is developed for calculating potential energy curves, except near the dissociation limit, for electronic states of diatomic molecules. Classical turning points r1,2 are given as functions of vibrational quantum number (V ≡ ν + 1/2), with coefficients depending on observed spectroscopic constants, in the form[Formula: see text]where[Formula: see text]For most states convergence is rapid, but as a rule more so for heavy molecules than for light molecules. Assuming it to be close to the 'true' potential, such a representation affords a convenient means of assessing the accuracy of the Morse or other empirical potential function. Morse curves have also been fitted by least squares to Klein–Rees turning points.Term-by-term comparison between the inverted Dunham series and an equivalent form of the above has led to the surprising discovery that if Dunham's small correction terms are neglected, Klein and Dunham potentials are mathematically identical. This is contrary to the generally held belief that the two should be used in mutually exclusive regions. In the present form these series exhibit better behavior over a wider range than a series giving potential energy as a function of internuclear separation.
THE SCATTERING OF A PLANE WAVE BY A ROW OF SMALL CYLINDERS
Authors: Millar R. F.
Published: April 2011

Consideration is given to the scattering of a plane wave by N cylinders equispaced in a row. The problems associated with scatterers, both "soft" and "hard" in the acoustical sense, are treated. An application of Green's theorem together with the appropriate boundary condition on the cylinders leads to a set of simultaneous integral equations in the unknown function on the cylinders.Solutions in the form of series in powers of a small parameter δ (essentially the ratio of cylinder dimension to wavelength) are assumed. In the case of elliptic cylinders, the integral equations are reduced to sets of linear algebraic equations. Only for the first term in the solution for "soft" cylinders is it necessary to solve N simultaneous equations in N unknowns; all other equations involve essentially only one unknown. Far-fields and scattering cross sections are calculated. The case of two "soft" cylinders is given particular attention.Conditions for justification of the neglect of higher-order terms are discussed. It is found that all terms but the first (in either problem) may be neglected if [Formula: see text] and (N–1)/(ka) is sufficiently small. (Here a is the spacing between centers of adjacent cylinders, and k is the wave number.) For this reason these solutions are most useful when the number of cylinders is small.
IMPURITY CONCENTRATION PROFILES IN ICE BY AN ANTHRONE METHOD
Authors: Smith M. , Pounder E. R.
Published: April 2011

Solutions of sodium carboxymethyl cellulose (CMC), sodium chloride, ethylene glycol, and ethyl alcohol in water were prepared and frozen under controlled conditions. The ice in each case was divided into horizontal sections, melted, and the amount of each impurity measured. The organic liquid and salt concentrations were found from refractive index values using a dipping refractometer, and the CMC content, after treatment with an anthrone solution, was measured with a spectrophotometer. Developments in the anthrone method are described. Qualitative tests were also made by freezing solutions of soluble dyes.In the freezing of aqueous solutions of CMC and the dyes, rejection of the impurity is almost complete. When solutions of salt or alcohol or glycol in water, or of CMC and alcohol or glycol in water, are frozen a surface concentration peak and a second peak about 7 mm below the surface, corresponding to a previously observed discontinuity in the crystal structure of impure ice, are found. The ability of alcohol or glycol to carry CMC or a dye to places in the ice structure not available to them in the absence of the organic liquid is noted.
INFRARED TEMPERATURE AND LINE STRENGTH MEASUREMENTS ON CARBON MONOXIDE EXCITED IN A RADIO-FREQUENCY DISCHARGE
Authors: Eaton D. R.
Published: April 2011

Relative line intensities in the 2 → 0 sequence of bands of carbon monoxide observed in emission from a radio-frequency discharge have been measured. An enhancement of the R branch lines and a diminution of the P branch lines due to vibration–rotation interaction has been observed in agreement with theoretical predictions. Vibrational and rotational temperatures have been calculated and when allowance is made for the vibration–rotation interaction these prove to be equal within experimental error indicating the existence of thermal equilibrium in the discharge.
AN ANALYSIS OF SOME STATISTICAL PROPERTIES OF AURORAL RADAR REFLECTIONS AND THEIR RELATIONSHIPS TO THE DETECTION CAPABILITIES OF THE RADAR
Authors: McNamara A. G.
Published: April 2011

A statistical model of auroral echo occurrence has been made from an analysis of observations at 48.5 Mc/s obtained over a number of years of continuous operation. The probability density distribution of auroral target cross sections (σ) has been examined experimentally, and the resulting curve fitted by simple mathematical relations. Both an inverse power law and an exponential law have been derived, of the forms[Formula: see text]and[Formula: see text]These models have been interpreted in terms of distributed and localized targets, and used to analyze the echo occurrence indices and the effect which variation of radar parameters will have upon them. Both forms of the target law are useful although it is considered that the exponential form yields better agreement with observations over a wider range of the variables.
DAWN ENHANCEMENT OF AURORAL EMISSION
Authors: Lytle E. A. , Hunten D. M.
Published: April 2011

The 0–0 band at 3914 Å was observed once per minute with a scanning spectrometer as sunlight illuminated the upper atmosphere on the morning of September 5, 1958. It is reasonable to assume that the density of [Formula: see text] ions was maintained constant during this time, and that the observed rise of intensity was due to resonance scattering of sunlight. The ions were found to be distributed between 180 and 320 km with peak at 250; density here was 12 × 104 ions/cm3. There was some evidence for another layer at 120 km. Rotational temperatures measured while the main layer was fully illuminated agreed well and gave an average of 1060 ± 100 °K.
ROTATIONAL SPECTRUM OF K39F BY THE MOLECULAR BEAM ELECTRIC RESONANCE METHOD
Authors: Green G. W. , Lew H.
Published: April 2011

Transitions between the J = 0 and J = 1 rotational states of K39F have been measured by means of the molecular beam electric resonance method. The following rotational constants have been determined (all frequencies in Mc/sec):[Formula: see text]The quadrupole interaction constants eqQ as measured in the J = 1 state are found to be[Formula: see text]The equilibrium internuclear distance obtained directly from Be is[Formula: see text]The electric dipole moment in the ν = 0 state is[Formula: see text]
THE FREEZING POINTS OF HIGH PURITY METALS AS PRECISION TEMPERATURE STANDARDS: VI. THERMAL ANALYSES ON FIVE SAMPLES OF LEAD WITH PURITIES GREATER THAN 99.999+%
Authors: McLaren E. H. , Murdock E. G.
Published: April 2011

An investigation has been made of the freezing and melting temperatures of five samples of high purity lead (supplier's analyzed impurity contents < 0.7 to < 4 p.p.m.) including zone refined metal. Using the induced freezing technique, plateaux of essentially constant (< ±0.0001 °C) temperature with durations of over 1 hour are readily obtained on the cooling curves of these samples. A standard deviation in plateau temperature (liquidus point) of ±0.0001 °C was obtained from a series of 30 induced freezes on a particular sample. The pressure effect on the freezing temperature of lead was found to be 0.0080 °C for 1 atmosphere. A value of 327.426 °C (Int. 1948) was determined for the standard liquidus point of pure lead.The liquidus points of the samples were intercompared with a precision of about 0.0002 °C, and alloy melting ranges were examined following different types of freezing with and without overnight anneals near the solidus temperature. Alloy melting range parameters were found to be useful in the selection of the samples of highest purity and at the same time showed that an uncertainty of 0.002 °C in the above value of the liquidus point of pure lead may exist because of residual impurity contents in the purest samples that were examined.
THE WHITE TIN → GREY TIN TRANSITION IN TIN–MERCURY ALLOYS
Authors: Smith R. W.
Published: April 2011

The effect of the addition of mercury on the linear rate of white tin (β) → grey tin (α) transformation in a number of dilute tin-binary alloys has been examined. Rates of transformation at −78° and −25 °C are shown for binary alloys of zone-refined tin and aluminum, arsenic, bismuth, germanium, indium, lead, antimony, and zinc, and also for a number of commercially pure tins. The resultant rates of all of these upon further alloying with 0.6 at.% Hg are likewise given. At −78 °C, the addition of mercury always produces a very low transformation rate, approximately 4×10−4 mm/hr. However, at −25 °C, an increase in rate is observed in certain cases.The results are discussed and a theory is developed to account for them and also to predict the effect of mercury on the β → α transition in any tin-binary system.
A COMPTON-ELECTRON γ-SPECTROMETER WITH TWO-DIRECTIONAL FOCUSING
Authors: Lee-Whiting G. E.
Published: April 2011

Improvements in the design of one type of Compton-electron spectrometer for γ-rays are proposed. The design requires a magnetic field of cylindrical symmetry and of slow radial variation, a simply curved radiator, and a system of apertures. Electrons are accepted only if they are ejected from the radiator with small components of momentum in two orthogonal directions perpendicular to the incident γ-ray. Since the magnetic field can also be used to measure the momentum of the selected electrons, the instrument can function as a γ-ray spectrometer. Higher-order aberrations are discussed, and a method of calculating the values of the various spectrometer parameters corresponding to maximum efficiency is given. Calculations of the intrinsic line-width, caused by the motion of the electron within the atom before collision with the photon, are carried out.
FORBIDDEN TRANSITIONS IN DIATOMIC MOLECULES: V. THE ROTATION–VIBRATION SPECTRUM OF THE HYDROGEN-DEUTERIDE (HD) MOLECULE
Authors: Durie R. A. , Herzberg G.
Published: April 2011

The 1–0, 2–0, and 3–0 rotation–vibration bands of HD have been observed with a PbS infrared grating spectrometer and the 3–0 and 4–0 bands have been photographed with a 21-ft concave grating spectrograph. From these spectra precise values of the vibrational and rotational constants of HD in its electronic ground state have been determined. The variation of Bv and ΔG with v is similar to that recently established for H2, that is, the values for v = 0 and 1 are markedly above the values corresponding to a linear extrapolation of the subsequent points. This leads to an uncertainty in the ωe and Be values which is much greater than that of the ΔG and Bv values. The (very low) intensity of the rotation–vibration spectrum of HD is in close agreement with that predicted. The decrease of intensity in going from 1–0 to 4–0 is strikingly slow, far slower than in a normal series of fundamental and overtone bands. This also is in qualitative agreement with theoretical expectation for a molecule like HD which does not have a dipole moment in its equilibrium position.
AN APPROACH TO A THEORY OF GRAVITATION
Authors: Rastall Peter
Published: April 2011

The form of the space–time metric in a scalar theory of gravitation follows from the assumption that the potential is arbitrary to the extent of an additive constant. No field equations are needed. Expressions are found for the gravitational red shift, the perihelion motion of a planet, and the bending of light by the sun. From the observed values of these quantities one can determine the metric and the potential due to a gravitating mass.
A METHOD OF PRECISE FRINGE POINTING
Authors: Smith D. S.
Published: April 2011

Three methods of photoelectric pointing on an interference fringe are examined theoretically and the expected precision of setting is derived for each.An apparatus is described which yielded a precision of 1.2 × 109 compared to the predicted value of 5.8 × 109. The reason for this discrepancy is discussed, and a modification of the apparatus which would reduce the discrepancy is suggested.
THE THERMOELECTRIC POWER OF ANNEALED AND COLD-WORKED SILVER AND GOLD AT LOW TEMPERATURES
Authors: Pearson W. B.
Published: April 2011

Most of the low-temperature thermoelectric behavior of annealed and cold-worked silver and gold samples can be accounted for satisfactorily by using Kohler's equation, S = ΣWiSi/ΣWi, to calculate as a function of temperature the diffusion thermoelectricity under the influence of various competing scattering mechanisms in the metals, and by taking account of the phonon-drag contribution to the thermoelectricity. New data are presented and interpreted.
A THEORY OF IONOSPHERIC CURRENTS ASSOCIATED WITH AURORAE. I
Authors: Weaver J. T. , Skinner R.
Published: April 2011

The current distributions induced by dynamo action in a sheet of partially ionized gas moving with uniform velocity across a perpendicular magnetic field are derived for the case when the gas contains an elliptical region of greater ionization density. Special attention is paid to processes occurring away from the ends of a long narrow ellipse in which the ionization density is much greater than the surrounding region.The results are discussed in relationship to conditions pertaining in the ionosphere when a long homogeneous auroral arc is present. It is concluded that a line current, whose magnitude is linearly dependent on the height-integrated Cowling conductivity within the arc, flows along the arc.
SCATTERING OF RADIO WAVES BY AN IONIZED GAS IN THERMAL EQUILIBRIUM
Authors: Fejer J. A.
Published: April 2011

A theory is developed for the scattering of radio waves by density fluctuations which exist in an ionized gas in thermal equilibrium.Expressions for the frequency power spectrum of the scattered waves are obtained. These expressions make it possible to interpret the results of observations of this type of scattering from the ionosphere in terms of electron density and temperature.It is shown that if the characteristic scale of the scattering irregularities (this scale depends on the wavelength of the incident radio wave and the scattering angle) is much greater than the Debye length then the width of the spectrum of the scattered signal is determined by the thermal velocities (and the collision frequencies if the latter are sufficiently high) of the positive ions, rather than of the electrons.If the characteristic scale is greater than the Debye length then for low collision frequencies the spectrum is flat-topped, with two slightly raised shoulders situated symmetrically above and below the frequency of the incident wave. For high collision frequencies the spectrum has only one maximum situated at the frequency of the incident wave.
CONSIDERATIONS ON A MESON-ATOMIC MODEL OF THE NUCLEON
Authors: Trainor L. E. H.
Published: April 2011

A model of the nucleon is described in which a π-meson moves about a nucleon core under the action of a hyper-Maxwell field. On such a model, the short range of the internucleon force appears as a screening effect. Despite its obvious limitations, the model does possess some interesting features which lead to results in agreement with experiment. The advantage to such models is that they may provide insight into problems which are enormously difficult from the usual field theory point of view. In particular, one might hope to obtain some understanding of the state of the π -meson field in the nuclear many-body problem.
A STUDY OF AURORAL MOTIONS FROM ALL-SKY CAMERA RECORDS
Authors: Bhattacharyya B. K.
Published: April 2011

A study of horizontal motions of visual aurorae as recorded by a 35-mm all-sky camera at Springhill (geographic 45.2 °N., 75.5 °W.; geomagnetic 56.5 °N., 6.9 °W.) near Ottawa has been carried out. The number of occurrences of motions in all the four geomagnetic directions, east, west, north, and south appears to reach its peak within a range of speed from 0 to 150 m/sec and tends to decrease with increase in speed. Very large speeds seem more frequently to be associated with motions to the west and to the south. The distribution curve of speed with the time of night appears to have two peaks, one before and another after midnight, in all the four cases. Auroral motion is predominantly westward in the early part of the night and eastward in the late hours of the night. The reversal of motion from westward to eastward direction seems to be a systematic process, the declining and inclining portions of the two curves as a function of time meeting each other somewhat before local midnight.Auroral speeds either along or perpendicular to geomagnetic parallels of latitude increase nearly linearly with the horizontal and vertical components of the magnetic disturbance vector.
THE THERMODYNAMIC DESCRIPTION OF HETEROGENEOUS DISSIPATIVE SYSTEMS BY VARIATIONAL METHODS: I. A FORMULATION OF THE PRINCIPLE OF MINIMUM RATE OF ENTROPY PRODUCTION WITH APPLICATION TO CERTAIN STATIONARY HETEROGENEOUS CONVECTIVE SYSTEMS
Authors: Kirkaldy J. S.
Published: April 2011

The variational principle[Formula: see text]where, in terms of the system's independent thermodynamic forces, Xi, the rate of entropy production per unit volume is[Formula: see text]is known to describe the integral behavior of certain non-convective, steady (constrained) dissipative processes since the Euler–Lagrange equations corresponding to each degree of freedom define just sufficient steady state conditions to uniquely specify the configuration. It is herein demonstrated that this principle generates the Le Chatelier principle in the presence of constraints which are more general than previously considered. This has made possible the description of certain heterogeneous convective systems which were not previously amenable to unique thermodynamic analysis. In particular, the principle has been used to rationalize cellular or dendritic growth from the melt in alloys. The supporting observation is cited that the non-planar morphology, as compared to a planar one, leads to the maximum rate of conservation of available energy as solute segregation.
THE THERMODYNAMIC DESCRIPTION OF HETEROGENEOUS DISSIPATIVE SYSTEMS BY VARIATIONAL METHODS: II. A VARIATIONAL PRINCIPLE APPLICABLE TO NON-STATIONARY (UNCONSTRAINED) HETEROGENEOUS DISSIPATIVE SYSTEMS
Authors: Kirkaldy J. S.
Published: April 2011

The variational principle[Formula: see text]involving the independent thermodynamic fluxes Ji and forces Xi and subject to the non-holonomic constraint, Xi = constant, gives an expression for the integral behavior of an unconstrained heterogeneous conduction–diffusion–reaction–viscous flow process. The validity of this expression can be checked by performing the variation with respect to the forces to obtain as Euler–Lagrange equations the phenomenological equations,[Formula: see text]This principle allows the unique mathematical specification of certain non-stationary systems which are not easily amenable to differential analysis.As an example, it is demonstrated that the principle generates an approximate expression for the steady growth velocity, v, of an isothermal segregation reaction in terms of the degree of advancement of the reaction, [Formula: see text], and its derivative with respect to v,[Formula: see text]
FURTHER OBSERVATIONS OF THE HORIZONTAL MOVEMENTS OF AURORA
Authors: Kim J. A. , Currie B. W.
Published: April 2011

A previous paper showed that systematic motions of aurora parallel and normal to the geomagnetic meridians could be deduced from successions of all-sky camera photographs. More reliable deductions which are based on a much larger number of observations, including some from a station inside the auroral zone, are reported in this paper. Both southward and northward speeds increase with geomagnetic latitude to the auroral zone where they become constant, or even decrease slightly, before continuing to increase inside the auroral zone. A seasonal variation of north–south speeds does not appear to exist. A diurnal variation of north–south speeds, dependent on geomagnetic latitude, is evident, the speeds decreasing to a minimum during the morning hours to the south of the auroral zone and increasing to a maximum during the same hours to the north of the zone. Large positive correlations exist between north–south speeds and departures of the magnetic field intensity from normal. East–west speeds either decrease or remain constant with increasing geomagnetic latitude. A significant seasonal variation of east–west speeds is not evident. Eastward speeds are at a maximum between 03 and 04 hours L.M.T., and are associated with negative magnetic bays; westward speeds, between 21 and 22 hours L.M.T., and are associated with positive magnetic bays.
VISCOSITY MEASUREMENTS IN LIQUID HELIUM II
Authors: Benson C. B. , Hallett A. C. Hollis
Published: April 2011

Measurements of the viscosity of liquid helium II have been made using an oscillating sphere. This method avoids the necessity of a "corner" correction unavoidable when a circular disk is used, and therefore eliminates the uncertainty associated with such a correction. Calibration experiments showed the presence of a significant contribution to the observed damping of the oscillations which arose from the viscous drag of the gas surrounding the rod which connected the sphere with the torsion suspension fiber. This damping has been calculated and when applied to the results obtained in liquid helium II, the values of the viscosity of the normal component which were obtained agree with those obtained by the rotating cylinder method within the combined experimental uncertainties. The assumed density of the normal fluid was that obtained from the velocity of second sound, and the most accurate thermal data available.