Thermal studies of N-(p-Hexyloxybenzylidene)-p-Toluidene (HBT)

The effect of quenching on phase transitions in monotropic liquid crystal HBT is investigated using DSC, DTA, X-ray diffraction and microscopic techniques. The phases which are normally seen only during the cooling cycle are observed when the substance is quenched from the isotropic liquid phase at appropriate rate.     

Study of copolymer–copolymer interactions and formation of intermacromolecular complexes

Interpolymer complex formation has been studied between methacrylic acid-methacrylamide copolymer and acrylic acid–acrylamide copolymer. The respective co-monomer units of the two copolymers enter into complex formation through H-bonding and ion dipole interactions. The unreacted units in the copolymer complex also interact with homopolymers such as PEO and PVP to form ternary complex. Formation of complexes and replacement reactions could be shown through several experimental techniques, e.g., viscometry, conductometry, and potentiometry.     

Characteristics ofπ −-nucleon collisions at a primary energy of 4·4 GeV

Eight hundred and sixteen nuclear interactions produced by 4·4 GeVπ ^?-mesons in nuclear emulsion have been obtained by “along the track” scanning procedure. Favourable secondary particles from a selected 290π ^?-N (pion-nucleon) collisions have been identified by blob-density and multiple scattering measurements. It is found that the pion often persists in theseπ ^?-N collisions, the average persistence is estimated to be 0·24 per collision. It is estimated thatπ-N andπ-π collisions account for 60% and 28% respectively of the secondary particles. The average number of charged shower particles is 〈n _s〉=2·09±0·12, the average number of created charged particles is 〈n _e±〉=1·94±0·12, the average number of protons with energy greater than 300 MeV is 〈n _p〉=0·15±0·05 and the average number of charged kaons is found to be 〈n _k±〉=0·11±0·06. The integral energy spectra of pions in C-system as well as in L-system are well represented by exponential forms. The average inelasticity of the proton in C-system is found to be 0·52±0·10. The charge retention probability for protons inπ ^?-p collisions is 0·45±0·07.     

A note on bi-criteria transportation problems

The present note reveals a drawback in an algorithm ofAneja/Nair [1979] for the determination of efficient solutions in a bi-criteria transportation problem with an additional time objective function and develops a modified procedure that overcomes this weakness.

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Zusammenfassung In der vorliegenden Arbeit wird ein Fehlschluß im Algorithmus vonAneja/Nair [1979] zum Auffinden aller effizienten Lösungen eines Transportproblems mit zwei Summen- und einer Engpaßzielfunktion aufgezeigt. Ferner wird ein Verfahren angegeben, in dem diese Unstimmigkeiten nicht mehr auftreten.

     

Kationische Copolymerisation von Propylenoxid mit Tetrahydrofuran. 10. Mitt. Variation der Reaktivit?tsverh?ltnisse mit den verschiedenen Reaktionsparametern

Ohne Zusammenfassung     

Properties of pp annihilations into strange particles at 702 and 757 MeV/c

$\text{p}\text{p}$ annihilations, leading to the production of at least one neutral K meson in the final state, have been studied in the incident momentum region of 700–760 MeV/c. Topological cross sections and cross sections for the various exclusive final states are presented. Detailed analyses of the different final states have been carried out to study the importance of resonance production and of quasi two-body and quasi three-body processes. A detailed study of the $\text{K}\text{K}\text{π}$ system in the four-body final states shows that the F₁ meson is a spurious effect due to systematic biases. In the momentum range investigated, the C = +1 final states are strongly suppressed.     

Photo-optical changes in Ge-chalcogenide films

The photoinduced shift in the optical absorption edge and changes in the optical constants and their dispersion in the vicinity of the absorption edge (2–5 eV) have been studied in obliquely deposited thin films of Ge-chalcogenides. The variation of photo-optical changes as a function of various deposition conditions and composition throws light on the role of built-in microstructure and the relevant physical parameters necessary for the occurrence of large photoeffects. The photoinduced optical changes in 80°-films are partly (≈33%) reversible. This (reversible) part is equal to the total (completely reversible) optical changes in 0°-films. The irreversible part (≈67%) has been attributed to the observed photoinduced volume changes. The reversible optical changes have been understood in terms of configurational distortion and modifications in the electronic energy band structure, near the band edges induced by band gap irradiation.