Tentative Set Research Articles

Energy Levels of Pr+3 in Pr(NO3)3·6H2O

The energy levels of Pr+3 in Pr(NO3)3·6H2O have been determined from optical absorption experiments on single crystals at 77°K. With the exception of three bands, all of the electronic intra-f1 transitions from the ground state multiplet to higher multiplets were observed. The absorption spectrum along with the determined Stark level schemes of the multiplets and their centers of gravity are reported. An expanded “free-ion” Hamiltonian which includes configuration interactions along with spin–other-orbit and spin–spin interactions was used in the analysis of the multiplet centers of gravity. In a least-squares fit calculation the best-fit free-ion parameters found were F2 = 315.44 cm−1, F4 = 51.17 cm−1, F6 = 5.19 cm−1, ζ4f = 741.12 cm−1, α = 18.76 cm−1, β = −756.77 cm−1, γ = 88.05 cm−1, M0 = 0.43 cm−1. The average deviation between the calculated best fit and the experimental “free-ion” energy levels is 27 cm−1. A first-order perturbation calculation was carried out for the Stark levels of the various observed multiplets of the Pr+3(4f2) ion in a crystal field of C1 symmetry. Because of the large number of crystal field parameters involved in the potential, only a tentative set of best-fit B kq parameters were determined from a least-squares calculation.

Measurement of Vehicle Handling by Tethered Testing

The technique of tethered testing is introduced as a method of measurement of vehicle steady state handling, where the vehicle under test is attached to a large parent vehicle by means of an arm attached at its centre of gravity, and the tyre forces, which in the normal free vehicle situation produce a centrifugal acceleration, are simply reacted by this arm. The tethered testing rig built at M.I.R.A. is described. It is shown that the concept of tethered testing leads naturally to the idea of describing vehicle steady state handling by means of a quantity which depends only on lateral acceleration, and suitable quantities are shown to be static margin and the slope of a curve of mean front wheel steer angle against vehicle slip angle. These quantities are defined and their derivation in terms of vehicle stability derivatives is outlined in an appendix. Some examples of tethered test measurements are given in the form of plots of static margin against lateral acceleration, and a tentative set of criteria for good steady state handling is given in terms of the behaviour of static margin with lateral acceleration.

“Subsistence Agriculture”: Analytical Problems and Alternative Concepts

AbstractThis article argues that the concept of “subsistence agriculture”—widely encountered and long used in the literature—is not meaningful enough to be analytically useful as usually employed and should be abandoned. Particularly important for policy is the fact that use of the term “subsistence agriculture” leads to implicitly treating all small‐scale agriculture as a homogeneous residual made up of producers who vary little in their potential contribution to economic development. Data are presented which strongly suggest that small‐scale agriculture in less‐developed countries is not homogeneous so far as decision‐making situations are concerned. The second half of the article considers development of an alternative set of criteria for classifying small‐scale farmers that would reflect meaningful differences in decision‐making experience and decision‐making situations. A tentative set of such criteria for which data are now available, or could be developed with relative ease, are presented to illustrate the relevance of such a classification for development planning and policy.

Currents and Hadron Dynamics

In this paper we continue the investigation of the preceding paper into the possibility that complete, dynamical theories can be formulated in terms of current densities and related operators. Here, these ideas are illustrated by showing how a model of self-interacting charged scalar mesons can be formulated in conformity with them. Because of the relative simplicity of this model as compared to other, more realistic, relativistic models, it is possible to take up in some detail topics like the irreducibility of the coordinates, the Heisenberg equations of motion for the current densities, the determination of the energy-momentum tensor by its equal-time commutation relations, and the use of functional representations of current algebras. It is also shown how electromagnetism can be incorporated into strong-interaction theories based on currents. The results of these two papers are reviewed and an attempt is made to abstract from them a tentative set of working hypotheses.

Current research on infrared radiation from rocket exhaust

Infrared radiation heating from rocket exhausts has been of particular interest to NASA in connection with large vehicles of the Saturn class. These vehicles are equipped mainly with two types of rocket engines: the J-2 model for which H 2O is the only radiating species, and the F-1 model for which H 2O, CO 2, CO and carbon particles are the radiating specie. A computer program has been developed to calculate infrared radiant heat transfer from inhomogeneous mixtures of these gases. This program uses a band model to express the absorption coefficients of the gases. The band model parameters necessary for these calculations are the mean line strength S, the mean line half-width γ, the mean line spacing d, averaged over 25 cm −1 increments. Analytical and experimental programs are in progress to complete the determination of these parameters at long path lengths and to include the effects of foreign gases on these parameters. A tentative set of γ's, 1/ d's, S/ d's has been determined, using data and analytical expressions coming principally from the literature. A modified Curtis-Godson approximation is used in the radiative heat transfer calculation and effectively substitutes a hypothetical homogeneous path for the inhomogeneous path. This approximation has been used successfully in predicting atmospheric radiative transmission. This modified Curtis-Godson approximation is experimentally shown to be applicable for strong temperature and concentration gradients for certain wavelengths in the H 2O and CO 2 infrared spectrums.

Infrared Spectra and Protein Conformations in Aqueous Solutions: I. THE AMIDE I BAND IN H2O AND D2O SOLUTIONS

Abstract Infrared absorption spectra of poly-l-lysine, poly-l-glutamic acid, β-lactoglobulin, myoglobin, and αs-casein in the region of absorption of the amide I band have been observed in H2O solution, D2O solution, and in the solid state. The results indicate that characteristic frequencies exhibited by specific conformations of the investigated synthetic polypeptides are not transferable to corresponding conformations of globular proteins. The frequencies obtained for different conformations of globular proteins in H2O and D2O solution are internally consistent, in general agreement with corresponding values of fibrous proteins and with the limited data available in the literature concerning deuterated proteins in D2O solution. Dissolution in aqueous environment by itself does not noticeably alter the amide I frequencies. A tentative set of characteristic frequencies and interaction constants is obtained for the amide I' modes of N-deuterated proteins. These modes are easily observed in D2O solution and show sufficient variations in frequency to permit a distinction between the α-helical, the antiparallel-chain pleated sheet, and the solvated random configurations of globular proteins.

Vacuum Insulation of High Voltages Utilizing Dielectric Coated Electrodes

An experimental research program has demonstrated that the high-voltage performance of a vacuum gap can be improved by the simple expedient of coating the cathode surface with a suitable thin insulating film. Steady voltages ranging to 340 kV were obtained with 5-mm gaps composed of 15-cm-diam Rogowski electrodes. Simultaneously the average gap currents were suppressed to the 10−8 to 10−10 A range. Further, it was shown that an insulating film on the anode can be severely detrimental to gap performance. Experiments were performed, at voltages up to 380 kV, involving 12 different film materials. Film thicknesses ranged from 0.2 to 135 μ and film resistivities ranged from 1011 to 1019 Ω-cm. The dielectric constants were between 1.7 and 3.5, except for one at 90. Based upon the experimental results and their interpretation, a tentative set of specifications can be given for a good cathode film: (1) resistivity of at least 1011 Ω-cm; (2) dielectric constant in the range 1.5 to 4; (3) dielectric strength of at least 106 V/cm; (4) film thickness between 10 and 25 μ; (5) mechanically hard and smooth with high abrasion resistance and high adhesion strength; (6) no gas bubbles within the film. If bubbles are unavoidable they must be substantially smaller than the film thickness; (7) low vapor pressure; (8) the cathode substrate should be of a highly polished metal suitable for quality deposition of the desired film material.

On the Derivation of Area Functions and Acoustic Spectra from Cinéradiographic Films of Speech

The objective of this paper is to determine whether it is possible to derive a transformation, valid for a given talker, for determining area functions corresponding to any speechlike articulatory configuration from measurements on lateral cinéradiographic films of the vocal mechanism. A tentative set of rules for accomplishing this transformation has been established. The rules are specified largely in terms of a series of functions that relate the cross-sectional area at each of a number of points along the vocal tract to linear dimensions determined from the x-ray films and incorporate the effects of jaw and velum positions. The validity of area functions derived through use of these rules has been tested by comparing formant frequencies measured for the corresponding utterances with those calculated (by digital computer) from the area functions. Webster's horn equation is taken as the basis for calculating formant frequencies from area functions. The corresponding spectra are also computed for comparison with the measured spectra of the speech sounds, making certain assumptions regarding source spectra and locations and resonance bandwidths. In general, agreement between computed and measured formant frequencies by the two methods is within a few percent for the first three formants for a variety of consonant and vowel configurations. [Work supported in part by the U. S. Army Signal Corps, U. S. Air Force Office of Scientific Research, and U. S. Office of Naval Research; in part by the National Science Foundation (grant G-16526), the National Institutes of Health, U. S. Department of Health, Education, and Welfare (grants MH-04737-03 and NB-04332-01), and the National Aeronautics and Space Administration (grant NsG-496); and in part by the U. S. Air Force (ESD) under contract AF19 (628)-3325.]

Y0*and the Low-EnergyK¯NInteraction

An analysis is attempted on the low-energy $\overline{K}N$ data by assuming that the ${{Y}_{0}}^{*}$ is an $S$-wave $\overline{K}N$ bound state. Two tentative sets for the scattering lengths are obtained which are similar to that of Akiba and Capps, and fit all the low-energy data reasonably well.

Self-ConsistentSMatrix with Regge Asymptotic Behavior

A general discussion is given of the formulation of self-consistent equations for two-body strong-interaction $S$ matrix elements, on the assumption that all poles are of the Regge type and that asymptotic behavior is controlled by these poles. A tentative set of specific equations based on the strip approximation is presented and illustrated by a discussion of the $\ensuremath{\pi}\ensuremath{\pi}$ problem. In these equations Regge trajectories and residues for one channel are determined by the top-level Regge poles of the crossed channels. One parameter, the width of the strip, appears in the equations but it is argued that this parameter may be fixed by the principle of maximum strength.

Russian Declensional Morphemes

0. The purpose of this article is twofold: to examine the various patterns of declension found in Russian and establish the MORPHEMES in them; and, by this presentation, to exemplify a possible method of morphemic analysis. The procedure involves the identification of the MORPI-IS that occur, and their assignment as ALLOMORPHS to morphemes. The methods used are summarized and exemplified in the author's treatment of English.' Some additional explanation is in order. The forms that occur are examined in phonemically isolated words (?0.1). They are compared and then segmented mechanically at points that leave partials which recur in more than one form. Thus the forms ruka (see ?0.3 for the orthography), ridku, rdki, rukax enable us to segment into ruk-, -', -, and the partials -a, -u, -i, -ax; these can be compared with noga, ndgu, n6gi, nog'x, and are thus established as recurring; further comparison of rukax, rukam, rukamji establishes the recurring partial -a-, and the partials -x, -m, -mji; and the latter are established as recurring by comparison with n6vix, n6vim, n6vimji. After a tentative set of morphs has been established in this way, the forms are tested in comparable frames and sequences to determine which have identical functions: thus odnA + ruka, odnh + k6stj compared with odnby + ruki, odn6y + k6stji, establish the functional identity of -a in odna and in ruka, and of these instances of -a with the absence of a final vowel in k6stj, this absence being set up as a zero element, -0.1 We can then say that there is a morpheme which contains at least the allomorphs -a and -0; the morpheme can be symbolized by some arbitrary symbol, say V/-N (see ?0.3). That our segmentation is tentative can be shown by the fact that from odnby + ruki and odnby + k6stji alone we could only conclude that -oy and -i are allomorphs of a single morpheme, whereas the introduction of further evidence makes it clear (as will be shown below) that odn6y has to be analyzed as odn-0-6y-0, and that it is the final -0 that goes with -i in a morpheme V-G. In this connection it is emphasized that no zero morphemes exist, but only zero allomorphs of morphemes whose other allomorphs are not zero. Stress patterns are separate morphs, forming suprasegmental morphemes. The constant aim in this procedure is to obtain the smallest possible number of different morphemes, with one morpheme for each category throughout the analysis, and to arrive at the results wholly by inspection and commutation in similar structural frames, without the use of meaning. Since the structural

The development of concept formation in children.

The Development of Concept Formation in Children SUZANNE REICHARD, MARION SCHNEIDER, and DAVID RAPAPORT The Menninger Clinic, Topeka Aside from the work of Piaget (2) there has been little attempt to study the development of concept formation in children. The need for a developmental study which would provide a tentative set of norms for the evaluation of clinical material prompted the undertaking of the present research. We used two tests of concept formation, the Color-Form Test and the Sorting Test first described by Weigl (4), and later by Goldstein and Sheerer (1). Inasmuch as these tests were originally designed for work with brain-injured patients, we in our clinical work with various neurotics, psychotics, and cases of behavior disorders, found that many new types of reaction to these tests became apparent. The only previous developmental study of these tests is that of Jane Thompson (3), which, however, pursued less specific aims. The subjects employed in the present study were two hundred thirty-four white children ranging in age from four to fourteen years, inclusive. The four-year-olds were drawn from a nursery school, the remainder from the Topeka public school system.1 Only children who were normally placed in their grades were tested. The Color Form Test consists of twelve pieces of cardboard of four different colors and three shapes. The subject first is asked to together those that belong After he has made his first sorting either on the basis of form or of color, he is asked to them together in another way, a different way. Success is marked by the ability to shift from one category to the other; failure by repetition of the first category, or by the construction of patterns or mixed groupings. Scoring accordingly distinguishes between subjects who are able to make two, one, or no groupings. The Sorting Test consists of thirty-three objects which may be grouped according to use, color, form,' material, or existence of pairs. In the first part of the test, the subject is handed seven objects, one at a time, and told to put with each all that belong with it. After he has completed his grouping, he is asked to tell why they belong together. The second part of the test consists of the presentation by the examiner of twelve groupings which the subject is asked to define. In scoring this test, sorting behavior was scored plus, plusminus, minus-plus, minus, according to the accuracy of sorting, and loose or narrow according to whether the subject included more or fewer objects in his sorting than the concept in question required. Loose groupings are characteristic of schizophrenics who tend, for example, to put with a ball any object that contains a rounded portion, while narrow groupings are found in deipressives who have difficulty in finding any object to go with the sample object presented. In addition, the subject's definitions were scored according to the level of conceptualization manifested, where concretistic, funtional, or conceptual. Aside from the concretistic, a number of other types of inadequate

The Development of Concept Formation in Children

The Development of Concept Formation in Children SUZANNE REICHARD, MARION SCHNEIDER, and DAVID RAPAPORT The Menninger Clinic, Topeka Aside from the work of Piaget (2) there has been little attempt to study the development of concept formation in children. The need for a developmental study which would provide a tentative set of norms for the evaluation of clinical material prompted the undertaking of the present research. We used two tests of concept formation, the Color-Form Test and the Sorting Test first described by Weigl (4), and later by Goldstein and Sheerer (1). Inasmuch as these tests were originally designed for work with brain-injured patients, we in our clinical work with various neurotics, psychotics, and cases of behavior disorders, found that many new types of reaction to these tests became apparent. The only previous developmental study of these tests is that of Jane Thompson (3), which, however, pursued less specific aims. The subjects employed in the present study were two hundred thirty-four white children ranging in age from four to fourteen years, inclusive. The four-year-olds were drawn from a nursery school, the remainder from the Topeka public school system.1 Only children who were normally placed in their grades were tested. The Color Form Test consists of twelve pieces of cardboard of four different colors and three shapes. The subject first is asked to together those that belong After he has made his first sorting either on the basis of form or of color, he is asked to them together in another way, a different way. Success is marked by the ability to shift from one category to the other; failure by repetition of the first category, or by the construction of patterns or mixed groupings. Scoring accordingly distinguishes between subjects who are able to make two, one, or no groupings. The Sorting Test consists of thirty-three objects which may be grouped according to use, color, form,' material, or existence of pairs. In the first part of the test, the subject is handed seven objects, one at a time, and told to put with each all that belong with it. After he has completed his grouping, he is asked to tell why they belong together. The second part of the test consists of the presentation by the examiner of twelve groupings which the subject is asked to define. In scoring this test, sorting behavior was scored plus, plusminus, minus-plus, minus, according to the accuracy of sorting, and loose or narrow according to whether the subject included more or fewer objects in his sorting than the concept in question required. Loose groupings are characteristic of schizophrenics who tend, for example, to put with a ball any object that contains a rounded portion, while narrow groupings are found in deipressives who have difficulty in finding any object to go with the sample object presented. In addition, the subject's definitions were scored according to the level of conceptualization manifested, where concretistic, funtional, or conceptual. Aside from the concretistic, a number of other types of inadequate