Methods of calculating the "Snell Experiment" (the exponential experiment in natural uranium) are examined. It is found that integral transport theory is required for accurate predictions. The effect of spatial transients upon measured quantities is studied and it is found that experiments have not been done in a large enough mass of uranium to achieve an asymptotic neutron distribution. However deviations from the asymptotic values of integral quantities are not large and corrections are calculated and applied to recent experiments. It is shown that the use of recent cross section data improves the agreement between theory and experiment. The relaxation length and all spectral indices are in fairly good agreement except for Np237 to U238 average fission cross section ratio.

In the fall of 1961 an extensive program of investigation of high energy p-p interactions was begun at the Brookhaven AGS. The BNL 20" liquid hydrogen bubble chamber and an electrostatically separated beam were used to obtain a total (to date) of 300,000 exposure with about 15 antiprotons per pulse. The exposures were made at antiproton momenta of 3.25 Bev/c and 3.69 Bev/c in the laboratory. Approximately 80% of the exposures were made 3.69 Bev/c antiprotons. A wide variety of reactions occur in these collisions. Some of these such as elastic scattering, pion production, and associated production of hyperons and K-mesons have analogues in p-p collisions. The similarities and differences between the p-p and p-p results can usually be understood in a qualitative way and in some cases quantitative comparison with theory has been possible. The annihilation reactions leading to final states containing pions alone or pions with K-mesons are unique to the nucleon-antinucleon system as are the reactions in which a hyperon, anti-hyperon pair is produced. In the following, we report the principal characteristics of proton-antiproton reactions. Although the scope of this paper is comprehensive it is not a definitive report of the experiment as much of the work …

Buckling measurements at BNL have employed two experimental methods which in principle should yield identical results but in practice show a systematic and significant discrepancy. In this paper the experimental evidence of these errors is reviewed and their source is traced by means of theory to the radial flux transients which perturb the asymptotic neutron spectrum in the exponential assemblies. Some alternate and apparently more precise methods of analyzing the data are examined theoretically, including the possibility of anisotropy in the leakage probability.

Since the discovery of the Straub and Feuer as well as Laki et al. that ATP bound to G-actin is transformed to ADP and inorganic phosphate during polymerization of actin (1, 2), it has become increasingly clear that the chemical changes in the nucleotide are related to the change in the physical state of the protein. Barany, Biro, Molnar and Straub have shown that highly purified actin preparation free of any enzyme which would use ATP, ADP or AMP as a substrate still catalyze the breakdown of ATP (3) thus supporting the original idea that the ATP to ADP transformation is related to the globular to fibrous transformation of the actin protein itself. Mommaerts was the first to show that the ADP formed during polymerization remains bound to F-actin and Ulbrecht et al. while extending Mommaert's finding on exhaustively purified actin preparations have shown that the P1 formed during polymerization is not bound to F-actin. The stoichiometry of the splitting and the tightness of binding of the ADP lead inevitably to questions in regard to the position of bond breaking during the hydrolysis and to the nature of the forces involved in the tight binding of ADP to F-actin. To …

We wish to report unequivocal evidence for the water promoted, aluminum chloride induced intramolecular rearrangement of the benzene rings in diphenyl. When diphenyl 1→1,1'-C14, prepared in 80% yield via an Ullmann reaction on iodobenzene-1-C1 14, was heated to 100° for 30 min. with 10 mole % of aluminum chloride and 1 mole % of water, the radioactivity, originally localized at the two connecting carbons had been randomly distributed. Recovered active diphenyl was also shown to be randomized when the reaction was carried out for 12 hrs. in a refluxing benzene solution. The degradation method used is outlined in Fig. 1. The view that the reaction in intramolecular is supported by the following facts: (1) The inactive benzene used in the solvent experiments was devoid of activity at the end of a run within the precision of our assay methods. A rearrangement carried out with inactive diphenyl in benzene-1-C- 14 yielded diphenul having an activity indicating less than 0.001% intermolecularity.

Treatment of Pisum root meristems with nutrient solutions containing tritiated thymidine (H3-T) and colchicine simultaneously labeled cells in two different segments of the mitotic cycle. Tracings of the serial progression of these differently labeled cells through mitosis resembled sine-cosine curves. When the labeled cells are in interphase the sign of the curves is negative, when they are in mitosis the sign is positive. The concept of the mitotic cycle in terms of trigonometric functions was presented as one way of transferring cycle from a celestial time scale to that of a biological clock.

One of the more apparent differences between acute and chronic irradiation is that exposure in the former is generally confined to a small fraction of a single mitotic cycle while in the latter; exposure of mitotically active tissue usually involves at least several cycles. Because of this difference, the number of cells in each stage of interphase would be of primary importance in acute radiation experiments since radiosensitivity is not the same in the G1, S and G2 periods. The duration of the total mitotic cycle should be more important in chronic experiments because most of the cells in the tissue will have passed through each of the interphase stages (G1, S and G2) during the period of irradiation thus negating any different effect.

An additive, interacting mechanism of micro and macro-convective heat transfer is proposed to represent boiling heat transfer with net vapor generation to saturated liquid metals in convective flow. Based on this mechanism, a method for calculating boiling coefficients is developed. The correlating is shown to be in fair agreement with early experimental results for convective boiling of potassium and sodium.

Recently, we reported that the administration of the thyroid hormone, L-triiodothyronine (T3), markedly accelerated the development of experimental hypertension associated with a high-salt intake in intact rate. Earlier, Selye and his associates and Masson, Corcoran, and Page has observed a similar effect from thyroxin in uninephrectomized salt-fed rats. We were aware of the fact that oxidative phosphorylation is uncoupled by the thyroid hormone and were intrigued by the possibility that such uncoupling was instrumental in the accelerated development of the hypertension observed. The work reported here was undertaken with this possibility in mind; it was based on the well documented observation of Loomis and Lipmann that dinitrophenol reversibly inhabits oxidative phosphorylation. The present studies indicates that 2, 4-dinitrophenol, like L-triiodothyronine, can also rapidly induce hypertension in salt-fed rate. These observations have led us to develop a working hypothesis that may have general implications relative to the pathogenesis of hypertension in man.

A neutron diffraction program was initiated recently at the Puerto Rico Nuclear Center. The two double crystal spectrometers in use were assembled with the aid of staff members of the Brookhaven National Laboratory. The first research problem to be completed was a single crystal structure analysis of CaWO4. Choosing the origin at the 4(a) tungsten site in the tetragonal I41/a cell. the 16(f) oxygen parameters were found to be as follows: x=0.2413 ± 0.0005, y=0.1511 ± 0.0006, z=0.0861 ± 0.0001. Anisotropic temperature parameters were also determined for all atoms in the least squares analysis of the structure. The magnetic structure of CuSO4 has been determined in a continuation of a study started at Brookhaven in collaboration with Dr. P.J. Brown. Using the Wollan-Koehler-Bertaut notation, the antiferromagnetic spin ordering mode in the orthorhombic Pbnm cell is Ax, with the spin axis parallel to a. A moment of approximately 1 μB was found for the Cu2_ ion. The crystal structure of BaNiO2 was re-examined in a neutron powder diffraction study, and it was found that the earlier x-ray study of Lander is essentially correct. An alternative oxygen arrangement, for which x-rays would not have been very sensitive, had been suspected. BaNiO2 was …

Studies carried on since 1956 indicate that the prosaic breeding procedure of sibbing among the most perennial segregates in the hybrid of 4n maize x 4n perennial teosinte quickly restores perennialism to 50% maize tetraploids through increasing the expression of the rhizomatous habit under selection pressure. Similarly, only two generations of selection at the 75% maize level have resulted in a progressive recovery of the perennial expressive. A high degree of maize-likeness therefore appears to be compatible with the perennial expression at the 4n level.

The recently developed "n" on "p" type silicon solar cell has been evaluated for application as a high-level gamma radiation dose rate meter. The solar cell ionization current was found to be a linear function of dose rate in a range 10 2 to 10 7 rads per hour. A degradation rate of approximately one per cent per megarad was measured after stabilization with twenty megarads of cobalt-60 gamma radiation. The system has proven to be stable over long periods of time. Temperature dependence corrections have been found to be .0 per cent per degree centigrade between 0 and 60 degree centigrade.

For a wide range of statistical experiments, we require a sequence of random variables [unintelligible], which have prescribed mean values μn and variances σn2, with a given autocorrelation ρt. The [unintelligible] are to be generated as a sequence of real functions of independent random numbers [unintelligible], each of which is uniformly distributed in. The reason for this choice of specification for the [unintelligible] is that most computers have standard subroutines which generate such uniform random (or pseudo-random) sequences.

The compound KrF4 was prepared by Grosse et al. by passing an electric discharge through the elements at -196°C. Evidence for formation of KrF2 has been obtained by Pimental and Turner by UV irradiation of the elements frozen into an inert gas matrix at 20°K. Using an electron beam to irradiate krypton and fluorine at -150°C, we have prepared KrF2 in 100mg amounts and examined some of its properties.

Though only recently established, this concept has been developing for a long time. More than thirty years ago Dubinin, Serebrovsky, and other, investigating the phenotypes of a number of "achaete-scute" alleles of Drosophilia melanogaster, found that the alleles could be arranged in a definite series accoding to bristle patters, and also that the heterozygotes lacked only those bristles which were affected in common by both participating alleles. They concluded that the serial classification of alleles according to bristle patters had its counterpart in a similar arrangement of portions of the achaete-scute gene locus. On this assumption they divided the locus into twelve elementary subunits. It was assumed that each allele arose by a change involving a certain combination of these centres. According to their theory, the achaete-scute locus is made up of separate, regularly spaced, and linearly arranged functional units. Several years later, Oliver described the occurrence of crossing over between two alleles of the "lozenge" locus. Then Green and a number of other workers analyzed similar phenomena in different regions of Drosophila chromosome. During the same period Lewis developed the theory of pseudoallelism, which interprets the occurrence of recombinants in interallelic crosses as the result of gene duplications. Thus …

The present communication reports the results of several investigations of magnetic structure and magnetic transitions currently in progress or recently completed at Brookhaven National Laboratory.

The vibrational spectra between 1000 and 30 cm-1, derived from measurements of the inelastic scattering of "cold" neutrons, are presented for isotactic polypropylene at samples temperatures below and above both the glass transition and the melting point. A tentative assignment of the observed modes is suggested by comparison with recent calculations by Miyazawa, Ideguchi, and Fukushima of the optically active phases of the fundamental vibrations for an isotactic helical polypropylene chain and with the neutron measurements of the low frequency modes in highly-crystalline polyethylene. In addition to the skeletal optical modes, the neutron spectra for isotactic polypropylene indicate the existence of two acoustic modes - skeletal deformation and skeletal torsion - with high frequency limits at 620 ± 50 cm-1 and 110 ± 10 cm-1, respectively. As in polyethylene, these modes appear to be strongly influenced by the presence and phase of the disorder in the sample. Similar spectra for atactic polypropylene above and below the glass transition show a much less pronounced structure, although weak bands are observed which correlate well with the skeletal optical modes observed in the isotactic polymer.

We have measured the rare gas isotopes in mineral concentrates of the Indarch meteorite. We obtained samples from C. Frondel, who crushed some of the meteorite into small particles mainly in the 44 to 88 micron size. He fractionated the minerals into groups according to specific gravity, using heavy liquids and magnetic techniques. The fraction with specific gravity less than 2.4 is approximately 95% tridymite and represents about 1% of the whole stone. The fraction with specific gravity between 2.4 and 2.8 contains calcium sulfide, calcium phosphate, two unidentified minerals, and tridymite and enstatite impurities. This fraction represents a few percent of the meteorite. The fraction with specific gravity between 2.8 and 3.3 consists largely of clinoenstatite and represents about 75% of the meteorite. The troilite is concentrated in the fraction with specific gravity greater than 3.3, and kamacite is concentrated in the magnetic fraction.

The transition from dormancy to growth in plant seeds has been the topic of many biological studies (1,2). Of particular interest to the radiobiologist are the dramatic changes in radiosensitivity occurring soon after the soaking of the seeds (3). These changes are thought to be associated with the commencement of proliferative activity. The recently developed method of labeling DNA with tritiated thymidine allows analysis of proliferative activity in greater detail than was heretofore possible. In the present study, uptake of tritiated thymidine and mitotic counts were used to determine the sequence of activation of proliferation in tissues or organs of the germinating corn embryo.

Two methods are proposed for calculating zero-point energies of molecules. The first makes use of the fact that one can easily write down the quantum mechanical Hamiltonian for a vibration system. The zero-point energy can then be obtained by a perturbation scheme without solving the secular equation. The second method requires a knowledge of the normal modes and frequencies of a reference molecule, but then enables one to calculate isotope effects by a perturbation scheme. The methods are applied to some examples and the convergence of the perturbation series is investigated. The approximate validity of the law of the mean for the isotope effect on zero-point energies is explored within the framework of the methods.

Earlier studies concerned with the influence of various hormones on carbohydrate metabolism in the dog were presented to this Conference in 1952. These studies dealt with the effects of adrenalectomy and hypophysectomy, and of regimens of anterior pituitary and adrenal hormones. Observations of changes in blood glucose concentration brought about by the administration of insulin, a glucose load, or of a epinephrine played a major part in this earlier work.

Interstitial cluster distributions and radiation formation and decomposition reactions are identified by fitting experimentally determined kinetic equations with calculations for consecutive reaction systems. Rate constants for the radiation decomposition of interstitial complexes are temperature independent and depend only on the neutron flux and the cross section of the complex.

Tritiated thymidine (H3TDR), a specific precursor of deoxyribonucleic acid (DNA), has proved to be a valuable tool in the study of in vivo cellular kinetics. Various methods of analysis have been used in autoradiographic investigations of proliferative patterns and time parameters in different cell lines.

Production cross sections and angular distributions of Λ and K° particles produced by 11.4 Bev/c π" mesons in hydrogen have been measured. A systematic investigation was made of all two-body decays of unstable neutral particles. No events inconsistent with γ, Λ, or K° were found. Production cross sections, angular distributions and effective mass distributions of π mesons produced in 4-prong events were also measured. No evidence for dominance of any high mass multi-pion resonance was found. Both the pion production and strange particle production reactions demonstrated peripheral characteristics in that the baryon was strongly peaked backward in the center of mass. The average transverse momentum was observed to be a monotonically increasing function of mass. The experimental total interaction cross section was 25.3 ± 1.5 mb. The effect of the pion-nucleon T ' 3/2 isobar was clearly observed.