Pion-proton elastic scattering at 200 GeV/c

Recent measurements of differential and elastic cross-sections, slope parameters and ratios of the real and imaginary parts of the forward scattering amplitudes for pion-proton elastic scattering at 200 GeV/c have been fitted by using a simple Regge pole model with phenomenological residue functions. The computed results for total cross-sections have also been compared with the experimental data.     

Microdetermination of spermidine, 1,3-diaminopropane,and p-phenylenediamine with chloranil

Spermidine, 1,3-diaminopropane, and p-phenylenediamine form molecular complexes with chloranil at pH 9. The composition and stability of these complexes have been studied spectrophotometrically. The results indicate that complexes were of 1:1 type and their stability increases with the basicities. The method of complexation was used to determine spectrophotometrically a ppm amount of SD, DAP, and PhDA in solution. The accuracy and precision of the method were found to be very high.     

Studies on tungstate gels

Summary The magnetic susceptibilities of certain vanadium pentoxide systems supported by kieselgur have been determined in the temperature interval 30° to 400° C. The plot of reciprocal susceptibility against temperature for all the systems studied indicates sudden deflections at temperatures which are about 150° lower than those of optimum catalytic activity. It has been suggested that these points may mark the temperatures of commencement of structural changes which may be responsible for the activity of these catalysts.

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Zusammenfassung Die magnetische Susceptibilit?t gewisser Vanadium-Pentoxyd-Systeme mit Kieselgur als Tr?ger wurden im Temperaturintervall zwischen 30 und 400° C bestimmt. Die Auftragung der reziproken Susceptibilit?t gegen die Temperatur zeigt für alle untersuchten Systeme pl?tzliche Knicke bei Temperaturen, die etwa 150° niedriger liegen als die optimale katalytische Aktivit?t. Es wird vermutet, da? diese Knickpunkte die Temperaturen des Beginns von Struktur?nderungen zeigen, die für die Aktivit?t dieser Katalysatoren verantwortlich sind.

     

Simple regge pole model for the reactionπ − p →η’n

The most recently measured differential cross-section data forπ ⁻ p → η’n has been fitted by using a simple Regge pole model with phenomenological residue functions. It has also been observed that this inelastic process has the scaling property.     

Synthesis and absolute configuration of (+)-2,3,3-trimethyl-2-hydroxybutanoic acid

The absolute configuration of (+)-2,3,3-trimethyl-2-hydroxybutanoic acid, a key intermediate in the synthesis of the HIV-protease inhibitor 1a (isomer A), has been confirmed as (R) on the basis of X-ray analysis.     

trans-cis Photoisomerization of a photoactive yellow protein model chromophore in crystalline phase

We have studied the photoinduced trans/cis isomerization of the protonated form of p-hydroxycinnamic thiophenyl ester, a model chromophore of the photoactive yellow protein (PYP), in crystalline phase, by both fluorescence and infrared spectroscopies. The conversion from trans to cis configuration is revealed by a shift of the fluorescence peak and by inspection of the infrared maker bands. The crystal packing apparently stabilizes the cis photoproduct, suggesting different environmental effects from the solvent molecules for this model chromophore in liquid solutions or from the amino acid residues for the PYP chromophore.     

Spectroscopic characteristics of Sm3+-doped alkali fluorophosphate glasses

Optical absorption, luminescence and lifetime measurements of Sm(3+)-doped alkali fluorophosphate glasses with molar compositions of 50(NaPO(3))(6)+10TeO(2)+20AlF(3)+19RF+1Sm(2)O(3) (R=Li, Na and K) are described. The variation of optical properties with glass composition plays a dominant role in the determination of efficient laser materials. From the experimental oscillator strengths of f-f electric dipole transitions, the phenomenological Judd-Ofelt parameters have been evaluated and are used to evaluate radiative parameters such as radiative transition probabilities (A(R)), branching ratios (beta(R)), lifetimes (tau(R)) and integrated absorption cross-section (sigma(a)) for various excited levels. The predicted values of tau(R) and beta(R) from the (4)G(5/2) excited level to its lower levels are compared with the experimentally measured values. Stimulated emission cross-sections (sigma(e)) were also determined for (4)G(5/2)-->(6)H(J) (J=5/2, 7/2, 9/2 and 11/2) emission transitions. From the emission transitions of Sm(3+) in these alkali tellurofluorophosphate glasses certain potential laser transitions have been identified.     

Flat map areal topography in Macaca mulatta based on combined MRI and histology

Flattened representations are a useful approach to represent the convoluted complex surface of the neocortex of primates and other large-brained mammals. In this study, we compared the flattened representation of neocortical areas obtained from the recently published MRI and histology atlas of the rhesus monkey brain (Saleem KS, Logothetis NK. A combined MRI and histology atlas of the rhesus monkey brain in stereotaxic coordinates. London: Academic; 2007) with other previously published maps. Our results confirm that flat map representations are advantageous due to their ease of use and that current flat maps are well comparable to each other. Some differences arise due to different distinguishing criteria and here too flat maps can help to reveal them.     

Current-driven electron drift solitons

The soliton formation by the current-driven drift-like wave is investigated for heavier ion (such as barium) plasma experiments planned to be performed in future. It is pointed out that the sheared flow of electrons can give rise to short scale solitary structures in the presence of stationary heavier ions. The nonlinearity appears due to convective term in the parallel equation of motion and not because of temperature gradient unlike the case of low frequency usual drift wave soliton. This higher frequency drift-like wave requires sheared flow of electrons and not the density gradient to exist.