Sensitivity ofn-p scattering observables to charge-independence breaking of the3 P N-N phase shifts

The sensitivity of neutron-proton scattering observables to the recently reported charge-independence breaking of the isospinT=1³ P nucleon-nucleon interaction has been calculated. It is shown that only the analyzing powerA _y () at extreme forward angles and at =90° c.m. and the spin-correlation coefficientA _zx () at 90° c.m. exhibit a measurable sensitivity. It is concluded that the determination ofA _y at 90° c.m. is currently the most accurate approach to verify independently charge-independence breaking in the³ P nucleon-nucleon phase shifts, considering the status of present experimental techniques.     

Hyper-rook Domain Inequalities

A hyper-rook domain of an element x in the space (words of length n over alphabets with k elements) is a sphere with center x and fixed radius j in Hamming distance. The number j determines the dimension of the hyper-rook domain. The classical (and far from solved) problem of covering by rook domains (here considered as the 1-dimensional case) is the problem of finding minimal coverings of by such spheres. Very few results are known in the literature for dimensions ≥ 2. We prove in this paper certain classes of inequalities based on coverings using matrices, which give upper and lower bounds for several cases of the problem for higher dimensions.     

Replacement-Policy Development: A Case Study of Glove Replacement at a Nuclear Processing Facility

Individual/group replacement models were used to identify the minimum-cost policy for replacing protective gloves that are utilized in product fabrication at a nuclear processing facility. Since historical data on glove longevity were not available to determine the failure-rate distribution, the classical replacement model for items that fail was modified to consider glove life as a normally distributed variable. Moreover, the absence of replacement-cost required that the classical model be transformed to incorporate the ratio of single to unit-group replacement cost. Sensitivity analysis on these two input parameter values provided guidance for the development of an appropriate replacement policy.     

Approximate neutrality of large-Z ions

LetN(Z) denote the number of electrons which a nucleus of chargeZ can bind in non-relativistic quantum mechanics (assuming that electrons are fermions). We prove thatN(Z)/Z1 asZ.Research partially supported by the NSERC under Grant NA7901 and by the USNSF under Grants DMS-8416049 and PHY 85-15288-A01     

Complexometric titration of phosphorus in organic compounds

Summary A new complexometric method for the determination of phosphorus in organic compounds is described. After combustion in an oxygen-flask, phosphorus is precipitated as cerous phosphate. The excess cerous ion is back-titrated at pH 6–7 with EDTA in the presence of methylthymol blue or xylenol orange indicators. Alkaline hypobromite is used as an absorbent. Tight clamping of the paper carrier in the platinum holder insures complete combustion.

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Komplexometrische Titration von Phosphor in organischen Verbindungen

Zusammenfassung Die Probe wird im Sauerstoffkolben nach Schöniger verbrannt und der Phosphor als Cer(III)-phosphat ausgefällt. Der Überschuß an Cer(III) wird bei pH 6–7 mit ÄDTA zurücktitriert, wobei Methylthymolblau oder Xylenolorange als Indicator dient. Als Absorptionsmittel wird alkalische Hypobromitlösung verwendet. Um eine vollständige Verbrennung zu gewährleisten, ist es wichtig, daß das Papier mit der Probe fest am Platinhalter angeklammert wird.

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This work was performed under the auspices of the U.S. Atomic Energy Commission.     

Synthese und Fluoreszenzeigenschaften von cyansubstituierten 2-Aminopyridinen

The synthesis of several 2-aminopyridines is described. The reaction of tetracyanoethylene with 3-imino-propane-carbonitrile gives 2-amino-3,4,5-tricyano-pyridines with alkyl and aryl-substituents, resp., in position 6. Nucleophilic substitution of 2-amino-6-chloro-3,5-dicyanopyridines and 2-amino-6-chloro-3,4,5-tricyano-pyridines with phenolates leads to a variety of pyridines. Spectroscopical data of absorption and fluorescence are presented and the influence of the cyano groups is discussed. The results are in good agreement with quantum chemical calculations (PPP).

Herrn Univ-Prof. Dr.A. Holasek zum 60. Geburtstag gewidmet.     

Chemical Synthesis,Proton NMR. Parameters,Hydrogen- and Calcium-Ion. Complexation of L-γ-Carboxyglutamyl-L-γ-carboxyglutamic Acid and D-γ-Carboxyglutamyl-L-leucine

The purpose of this communication is to describe the preparation and some properties of the first two synthetic peptides containing D - and L -γ-carboxyglutamic acid. Use was made of N-protected γ,γ′-di-t-butyl-γ-carboxyglutamic acids (D , L , and DL ) described earlier [1 a]. Preliminary ¹H-NMR. data (360 MHz) indicate a restricted rotation of the Gla side chain in the free amino acid as well as in the C-terminal Gla of Gla-Gla in H₂O solution at acid pH. The proton dissociation from Gla and Gla-Gla was studied by potentiometric titration and NMR. methods. The pH titration in the presence of Ca²⁺ ions shows that Gla-Gla has a much higher association constant for this cation than Gla. It is almost as great as that of prothrombin (pCa²⁺ = 3.2 vs. 3.5).     

On the magnetic properties and the phase composition of the Cr2O3?MnOx-system (2 ≥ x ≥ 1.5)

The mixed oxide system Cr₂O₃? MnO_x (2 ≥ x ≥ 1.5) was investigated by X-ray diffraction, by measurements of magnetic susceptibility, and by chemical determination of excess oxygen (BUNSEN'S method). The Presence of the antiferromagnetic oxides Cr₂O₃, β-MnO₂, α-Mn₂O₃ and a ferromagnetic phase Cr_1?yMn_yO₂ was stated. The formation of the latter with fourvalent chromium is explained by a lattice induction effect of the MnO₂ (rutile type).     

Beitrag zur Kenntnis des Systems Vanadin—Chrom—Stickstoff

The System V–Cr–N has been investigated at 1100 and 1400 °C and at nitrogen pressures between 1 and 1000 atmospheres by X-ray techniques. VN and CrN on the one hand and V₂N and Cr₂N on the other are forming complete series of solid solutions. The phase field of the mononitride solid solution is dependent on nitrogen pressure and temperature conditions.

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Auszug aus der Diplomarbeit des Herrn Dipl.-Ing. Dr.W. Schebesta.     

PHYTOCHROME-MEDIATED GERMINATION: EFFECTS OF BRIEF HIGH TEMPERATURE TREATMENTS

Abstract— Brief high temperature treatments, applied early in the pregerminative period to radiation-requiring seeds of lettuce, inhibited both dark and radiation-induced germination. The inhibition increased with increasing incubation temperature. There was little difference in the germination percentage whether the inductive irradiation was applied before or after the high temperature treatment. When the high temperature treatment preceded induction, there was an increase in the radiation dosage required for maximum germination. These findings are interpreted in terms of lability of physiologically active phytochrome to higher temperatures.