An electrocapillary study to test the applicability of the Flory-Huggins isotherm

The Flory-Huggins isotherm with interaction parameter has been tested using accurate electrocapillary data for four aliphatic compounds at the mercury-electrolytic solution interface. When surface coverages derived by differentiation of surface pressure-activity data were tested in the Flory-Huggins isotherm and when all parameters were freely optimized, the equation fit the data very well in all cases, but the size ratio parameter thus obtained was about 0.5. When parameters of the Flory-Huggins isotherm were fixed by limiting properties of surface pressure-activity data directly (with no differentiations performed), the size parameter was about 1.0. The size parameter expected physically is about 3.0. The Flory-Huggins isotherm with realistic size parameters did not fit the data as well as the simpler Frumkin equation in any of the cases considered. The physical basis underlying both models is weak for interaction parameters as large as encountered in aqueous-organic solute systems.     

Measurement of the nuclear spin diffusion barrier around Eu2+ ions in CaF2

The NMR spectrum of discrete ¹⁹F nuclear spins surrounding paramagnetic Eu²⁺ impurities in CaF₂ is observed at 1.6 K by high-sensitivity NMR. All but the very nearest nuclei are found to have an appreciable thermal contact with the bulk nuclei. A microscopic analysis of the electron-nuclear and nuclear-nuclear spin coupling mechanisms gives results in accord with this observation.     

The beta branching ratio and conversion coefficients in the137Cs decay

The decay of¹³⁷Cs has been reinvestigated using several precision counting methods. The emission rate ofβ-particles plus internal conversion electrons was measured by the 4π-proportional counter method using vacuum evaporated sources free of self-absorption and checked by the liquid scintillation method. TheK-conversion coefficient was determined by the electron X-ray coincidence method using a magnetic spectrometer and a high resolution Si(Li) detector. TheK/(L+M+...) conversion ratio and a second less accurate value for the β-branching ratio were obtained from the recorded electron spectra. Theγ-ray emission rate of all sources was determined to within ±0.14%, on the average, with a calibrated NaI(Tl) crystal detector. As results the intensity of theβ-decay to the ground state of¹³⁷Ba could be determined to (5.4±0.3)% of the¹³⁷Cs decays, theK-conversion coefficient to 0.0916±0.0004, and theK/(L+M+...) conversion ratio to 4.41±0.04. From these values the γ-ray emission intensity is (85.1±0.4)% of the¹³⁷Cs decays and theK X-ray emission intensity is (8.13±0.10)% of the emittedγ-rays. All errors are discussed in detail.     

Variations-Störungsrechnung bei Einzentren-Problemen

Zusammenfassung Der Hamiltonoperator H eines Einzentren-Problems sei derart in H = H ⁰ + H ¹ aufgeteilt, daß das Problem mit H ⁰ exakt lösbar ist und H ¹ nur Anteile potentieller Energie enthält. Dann kann man zeigen, daß der Erwartungswert der Störung H ¹ im Minimum der Gesamtenergie exakt verschwindet.

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Let the Hamiltonian H of a one-center problem be so partitioned in H = H ⁰ + H ¹ that the problem with H ⁰ is exactly soluble and H ¹ contains potential energy terms only. One, then, can show that the average value of the perturbation H ¹ vanishes identically if the total energy is minimized.

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Résumé L'opérateur hamiltonien H d'une problème à un centre est séparé en deux parties: H = H ⁰ + H ¹, de manière à ce que le problème relatif à H ⁰ soit exactement soluble et à ce que H ¹ tienne compte d'une part seulement de l'énergie potentielle. On peut, alors montrer que l'espérance mathématique de la perturbation H ¹ au minimum de l'énergie totale s'annule exactement.

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Erstmalig vor einem kleineren Kreis in Frankfurt am Main am 28. Juli 1962, zuletzt auszugsweise auf der 65. Hauptversammlung der Deutschen-Bunsen-Gesellschaft für Physikalische Chemie in Freudenstadt, 19. bis 22. Mai 1966, vorgetragen.

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Die vorliegende Arbeit wurde überwiegend in den Jahren 1960 bis 1962 durchgeführt. Für das in dieser Zeit gewährte Stipendium danke ich der Deutschen Forschungsgemeinschaft.

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Herrn Professor Dr. H. Hartmann danke ich für die großzügige Förderung in der Folgezeit (und dafür, daß er mich vor dem publish-or-perish bewahrt hat).     

A partial wave analysis of the Q enhancement in the reaction K−p→K−π−π+p at 3.95 GeV/c

We present results on the partial wave analysis of the Kππ system in the mass interval 1.1 to 1.6 GeV/c², in the reaction K^?p→K^?π^?π⁺p at 3.95 GeV/c. Our results are compared to those at higher energies, and we note certain differences. In particular, we find very much less of the ?K decay mode of the 1⁺S 0⁺ wave. In addition, the relative phase between the 1⁺S 0⁺ (K¹π) and the 2⁺D 1⁺ (K¹π) wave has been measured.     

Coherent Josephson radiation from an array of two Dayem bridges

Phase-locking of two independently biased thin-film microbridge (Josephson)-oscillators separated by a short length of superconductor has been observed experimentally using a broad band microwave coupling of the bridges to the receiver.     

Influence of cytotoxic agents on thermogenesis in streptococcus faecalis

Changes in the thermogenesis of S. faecalis cells resulting from the addition of cyanide, fluoride, penicillin, tetracycline, or human serum have been observed using isothermal calorimetry. The character and extent of the decrease in the thermogenesis rate is reproducible and different for each cytotoxic agent studied. The changes in thermogenesis on addition of tetracycline are quantitatively related to the concentration of antibiotic added to the bacterial culture.     

Abrupt change between smooth and oscillatory angular distributions in 16O induced transfer reactions on 26Mg

Angular distributions from (¹⁶O, ¹⁵N) and (¹⁶O, ¹⁴C) reactions on ²⁶Mg have been measured at both 45 and 60 MeV bombarding energies. The two reactions have approximately the same peak cross sections, but the (¹⁶O, ¹⁵N) distributions vary smoothly with angle while the (¹⁶O, ¹⁴C) cross section oscillates strongly as a function of angle. It is shown that the angular distribution shape is strongly dependent on the steepness of the form factor and that the magnitude of the (¹⁶O, ¹⁴C) cross section is very sensitive to the absorptive part of the optical potential.