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Consideration is directed toward electromagnetic compatibility as viewed from the control aspect. Emphasis is placed upon an inter-system approach to the improvement of the over-all electromagnetic environment.

Summary of Conference Papers

The subject of temperature measurement below 0.3 K is reviewed, with particular attention paid to developments reported in the period 1970–1974. Sensors, measurement techniques, primary and secondary thermometers, and fixed points are discussed and attempts are made to assess the accuracy and relative merits of the various devices and methods.

Recent experimental studies of the electronic properties of the 3d ferromagnets iron, cobalt, and nickel are reviewed in relation to models for the majority-spin and minority-spin band structures and Fermi surfaces. Attention is focussed on the experimentally observed consequences of spin-orbit coupling; this interaction causes the band structures and Fermi surfaces of these metals to depend on the orientation of the magnetization vector, and it can result in the formation of “spin-hybridized” sheets of the Fermi surface. A discussion is also given of the use of the de Haas-van Alphen effect to search for changes in the ferromagnetic band splitting as a function of temperature.

After an introduction to the hydrodynamical properties of He II, a survey is given of the flow properties of superfluid helium in the film. Special attention is given to some unsolved problems, such as: has rotating He II (co < cool) a shrunken temperature-dependent parabolic meniscus and is a stationary moving He Il film thinner than a static film? A review will be given of the present state of affairs both from an experimental and theoretical point of view.

It is the author's intention to present a concise dissertation on the MTF criterion for image evaluation in a fashion which hopefully will prove to be both tractable and enlightening, even to those in the field whose background in this subject is not extensive. The general nature of this paper is qualitative rather than quantitative, with the concepts involved being elucidated by frequent appeals to the reader's intuition; however, mathematical analyses are nonetheless occasionally required for clarification purposes. Although tutorial, this paper also seeks to present the necessary foundations for the final paper in this series, which covers a study conducted by the author at Bell & Howell Company. This study employed the MTF criterion in the design, testing, and manufacturing stages of a "Super 8" movie camera system to determine both the degree of image degradation occurring at each of these operations and the effectiveness of current testing procedures.

The study of image evaluation is a complex subject requiring the simultaneous consideration of the object, optical system, detector, and mechanism for processing the detector's signals. Image quality for any given photo-optical system depends upon such diverse considerations as granularity, light scattering, numerical aperture, tone reproduction, the degree of correction in the image-forming optics, etc.

We apologize here for some misprints which appeared on a recent paper (1) by the author. A list of them is given at the end of this letter.

The apparent detachment rate observed by Hackam and Lennon in O2-N2 mixtures is most likely not due solely to collisional detachment by N2 molecules.

My aunt has warned me against writing the story of Tante Amira. She says the lady is her friend and I shouldn’t start gossiping with my pen and paper. I try to convince her … I speak to her about the history of women’s oppression, the comingof the feminist movement, some human rights’ achievements … I tell her certain things would not have been possible were it not for what she calls the gossip of pen and paper ... I tell her changes would not have been conceivable had we all kept silent…

Call for Papers: Violence in the Middle EastGrants: Global Fund for Women Offers Grants to Women's Groups Outside the United States

Call for papers: Feminist Theory is a new international interdisciplinary journal published by Sage publications in April 2000. The journal is being launched to provide a forum for critical analysis and constructive debate within feminist theory.

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If it is really possible to do good variational calculations of the ground state of a film, it may not be very much more difficult to calculate the superfluid density at 0°K. What one must do, is to calculate variationally the lowest energy of the film with the constraint that the average of the gradient of the phase of the Bose condensate be equal to some small nonzero vector k, parallel to the surface of the film. For example, if the substrate is periodic in the x and y directions, we need a solution with a Bose condensate of the form ~k(r) = eikru(r) where u(r) is a (complex) periodic function o fx and y, to be determined variationally. I believe that this kind of constraint could be built in by relatively small modifications of the kinds of variational wave functions now used in ground-state calculations. The superfluid density of the film is then determined by the exact relation

The sensitized luminescence of naphthacene embedded into 1,2,5,6-dibenzanthracene crystals has been investigated on different substrates. Since the fluorescence intensity of the energy donor and the energy acceptor is proportional to the quantity of the components, they can be determined with high accuracy. On Whatman 1 filter paper, 10 -10 M/l naphthacene (i.e. the absolute quantity of 10 -13 g) and 5 × 10 -5 M/l of 1,2,5,6-dibenzanthracene (that is, 10 -7 g) have been determined. The experimental results of the quantitative analysis clearly display the delayed fluorescence of the system.

An improved objective procedure has been developed for focusing a spectrograph. A spectral line is selected that has a ratio of spectral line intensity to background intensity of about three. Microphotometer measurements are made of the optical density of this spectral line and of the adjacent background, and the intensity ratio is calculated from these densities for each slit-to-grating distance. In order to select the optimum focal position, a cumulative distribution is calculated from these intensity-ratio data and plotted against slit-to-grating distance on probability graph paper. The resulting graph is linear except at its extreme ends. The slit-to-grating distance corresponding to the cumulative distribution at 50 per cent is selected as the optimum focal position.

Metal and oxide surface reactions formed by heating in the spectrometer at 300–400° at a vacuum of ca. 10 −9 Torr (oil diffusion pumps) were studied. As a result of spectral observations before and after heating, the metals studied were classified into five groups. In the first group, oxide films on the metal surface are easily evaporated because of the high vapour pressure of oxide; in the second, the oxide films are easily reduced in the spectrometer; in the third, the oxide film formed on the metal is reduced but the bulk oxide is not easily reduced; in the fourth, very stable oxide films are formed and the bulk oxide is also stable; and finally in the fifth, the oxide film formed on the metal is apparently reduced, yet the bulk oxide is very stable.

MONODEUTERATED methane (CHxD) has been discovered recently in the atmosphere of Jupiter by an identification”’ of the lines P(2) through P(12) in its vibration-rotation band at 2200 cm-‘. A quantitative interpretation”’ of the observed spectrum”’ that could lead to an estimate of the abundance of CH,D and of the D/H ratio in the atmosphere of Jupiter requires intensity data at the relevant planetary temperatures for this band. Therefore, we have measured in our laboratory the intensities of J-multiplets between P(12) and R(4) and of the fully blended Q-branch, at lOO”K, lSO”K, 200”K, 250°K and 298°K. EXPERIMENTAL PROCEDURE The experimental apparatus is essentially the same as discussed in Ref. (3) for the 2vX-band of methane. The different spectral region considered in the present paper required the use of an infrared glower, 144 l/mm grating and an InSb detector with which we were able to obtain a spectral resolution ranging between 0.15 cm-’ and 0.2 cm-’ and a signal-to-noise ratio of 200 : 1. The time constant of the lock-in-amplifier was set at 100msec. Several mixtures, with the amount of CH,D in Hz ranging from 0.117 to 4 per cent (by volume), were prepared. The gases were allowed to mix for at least a couple of days in lecture bottles before the mixture was introduced into the absorption cells. The sample of CH,D was supplied by the isotope division of Merck, Sharp and Dohme Canada, Limited, with the following batch analysis: 97.46% of CH,D and 2.54% of CH, with no detectable trace of CH2Dz according to mass analysis by the supplier. With the spectral resolution available to us, it has not been possible to measure the intensities of the individual lines (K-components) of each J-multiplet. The procedure we have adapted for deriving multiplet-intensities, S, (cm-’ atm-‘), from measured equivalent widths is quite similar to that described in our paper”’ on the 2v3-band of methane. Construction of curves-of-growth for blended .I-multiplets required (i) the assumption of theoretical formulae@’ for the relative line strengths, SJK (cm-’ atm-I), of individual lines of a J-multiplet, and (ii) the assumption that all of the lines in the band have the same hydrogen-broadened half-width, Y&,+~~ = (3OO/T)“‘O.O75 cm-’ atm-‘, as the rotational lines in the v3 band of methane.“” On theoretical

This paper presents the results of an extensive study of the sensitivity-limiting noise sources in rf-biased SQUID flux detectors. Our investigation has included both experiments with point contact and thin-film SQUIDs and digital computer simulations. The paper begins with a discussion of rf SQUID operation, with special emphasis on those aspects that determine flux detector sensitivity. We then discuss the origin and consequences of intrinsic device noise in rf SQUID systems. We describe a straightforward technique for determining intrinsic noise amplitude directly from SQUID rf I–V characteristics. Deviations in the measured intrinsic noise of many devices from the Kurkijarvi-Webb prediction are attributed to departures from the ideal Josephson sinusoidal current-phase relation in the SQUID weak link. Kurkijarvf's SQUID tank circuit noise analysis is reviewed and we show how SQUID sensitivity can be maximized by an optimal coupling between SQUID ring and tank circuit. This optimal coupling depends upon circuit parameters, ring inductance, and weak-link properties. The analysis reveals that variations in the current-phase relation can result in a difference of as much as a factor of ten in the attainable sensitivity of two otherwise identical SQUID systems. We also suggest efforts in circuit design that are most likely to lead to further improvements in flux detector sensitivity. Finally, other factors, including external magnetic noise and underdamping of the SQUID ring, are discussed.

In a recent paper the author proposed a self-focusing theory based on linear stability analysis of the quasi-optical equation [1]. Strictly, the theory applies only to a plane wave of infinite aperture. In this paper the theory is extended to beams of finite aperture, which may be initially convergent or divergent.

in order to obtain good agreement between experimental and theoretical data for the selfbroadened line widths of oxygen in the microwave”’ and for the oxygen-broadened line widths of carbon monoxide. (2) The problem of calculating the latter has already been discussed, in considerable detail, elsewhere. (3) Therefore, we need only note here that the values used for the quadrupole and hexadecapole moments of oxygen in Ref. (3) are indeed the same as those considered in the present paper. The value of e(O,) = 1.21 D A is three times as large as the value 0.4 D 8, reported by BUCKINGHAM and much larger than any of the values considered reliable by STOCRYN and STOGRYN(~) among all of the available estimates for this constant. The value obtained by MURPHY and BOGGS(~’ is 0.58 D A and not 1.16 D A, as has been wrongly quoted in Ref. (1). The quadrupole moment defined in Ref. (6) is twice that defined in Refs. (4) and (5) and employed in Refs. (l-3), and in the present paper. Our line width computations are performed under the premise that the quadrupole moment of oxygen is known and is equal to the value 0.4 D 8, measured by BUCKINGHAM. The computation is based upon an expanded version (3) of ANDERSON-TSAO-CURNUTTE theory (7) which includes terms in the interruption function due to the hexadecapole moment of oxygen and due to an empirical anisotropic repulsive force. Although our treatment of the quadrupole-hexadecapole, hexadecapole-quadrupole, hexadecapole-hexadecapole and of the repulsive forces is approximate, the main thrust of our calculation is to argue that the value 0.4 D A for the quadrupole moment of oxygen is consistent with a calculation similar to that of YAMAMOTO and CATTANI(‘) and of BOUANICH, .(2) that is, we wish to demonstrate that by not considering these additional interactions of much shorter range, which are

In this paper we include the rearrangement correction (discussed in the preceding paper) in a coupled Hartree–Fock (CHF) calculation of atomic hyperpolarizabilities and other related properties. We have studied the effect of these corrections on properties like electric dipole hyperpolarizabilities, uniform electric field quadrupole polarizabilities and shielding factors in two-electron ions and have noticed significant changes in the computed values over the CHF results.

PART I of this reaction list for charged-particle-induced nuclear reactions has been prepared from the journal literature for the period from July 1970 through June 1971. Each published experimental paper is listed under the target nucleus in the nuclear reaction with a brief statement of the type of data in the paper. The nuclear reaction is denoted by A(a,b)B, where Ma≥ (one-nucleon mass). There is no restriction on energy. Nuclear reactions involving mesons in the outgoing channel are not included. Beginning with this supplement, theoretical papers which treat directly with the analysis of nuclear reaction data and results are included in the reaction list. In PART II is presented a reaction list for the Coulomb excitation reaction which has been prepared from the journal literature for the period from 1956 through June 1971.

Measurements of power line conducted interference are commonly made on commercial equipment throughout the world using line impedance stabilization network (LISN's) in accordance with industrial and governmental procedures. Procedures in the United States applying to the 0.15-30 MHz frequency range specify an LISN that presents a frequency-dependent RF impedance to the equipment under test (EUT) whereas other national practices specify as LISN having an invariant 150-ohm impedance. This paper explores the expected measurement differences resulting from use of the two LISN's for power line interference measurements. Calculated difference factors, which depend on the EUT power line RF-input impedance, are developed. The factors have utility in assessing expected conducted interference levels in one LISN measurement configuration, given the interference levels and impedance parameters of the other. Measurement differences, in addition to those introduced by the LISN, which are attributed to variations in specified field strength meter parameters (i. e., detector, bandwidth, mechanical time constants, etc.) are beyond the scope of this paper.

In a recent paper Mandel and Wolf use a two-parameter susceptibility function to derive an expression for the spectral density of the induced polarisation in a linear fluctuating medium. Their treatment is restricted to time-stationary fields and media. This paper presents (i) a generalisation of their treatment to include the case of locally stationary fields which is of interest in the study of resonance fluorescence spectroscopy; (ii) a demonstration of the way in which the spectral density of the fluctuations and the atomic spectral response function are combined in the two-parameter description of the susceptibility of an atomic vapour.