Energy dependence of multiplicity in proton-nucleus collisions and models of multiparticle production

This is a continuation of our earlier investigation (Gurtuet al 1974Phys. Lett. 50 B 391) on multiparticle production in proton-nucleus collisions based on an exposure of emulsion stack to 200 GeV/c beam at the NAL. It is found that the ratioR _em = 〈n _s〉/〈n _ch〉, where 〈n _ch〉 is the charged particle multiplicity in pp-collisions, increases slowly from about 1 at 10 GeV/c to 1·6 at 68 GeV/c and attains a constant value of 1·71 ± 0·04 in the region 200 to 8000 GeV/c. Furthermore,R _em = 1·71 implies an effectiveA-dependence ofR _A =A ^0.18,i.e., a very weak dependence. Predictions ofR _em on various models are discussed and compared with the emulsion data. Data seem to favour models of hadron-nucleon collisions in which production of particles takes place through adouble step mechanism,e.g., diffractive excitation, hydrodynamical and energy flux cascade as opposed to models which envisage instantaneous production.     

Screen printed electrodes provide micro-domain sites for fabricating disposable electro-catalytic ensembles

We demonstrate that bespoke screen printed electrodes which are basal plane-like in nature can be used as a template to produce randomly dispersed electro-catalytic micro-domains for analytical sensing purposes. Proof-of-concept is shown for the case of copper ensembles for nitrate detection and palladium ensembles for hydrazine sensing. The advantageous disposable nature of the ensemble precludes the need of pre-treatment between measurements. The screen printed ensembles act as excellent substrates for the deposition of a range of metals allowing the screen printed electrodes to act as a template for micro-domain ensembles of many different electrode materials for a variety of analytical challenges.     

Working group report: Heavy-ion physics and quark-gluon plasma

This is the report of Heavy Ion Physics and Quark-Gluon Plasma at WHEPP-09 which was part of Working Group-4. Discussion and work on some aspects of quark-gluon plasma believed to have created in heavy-ion collisions and in early Universe are reported.     

Plaster-trodes for electro-analytical sensing via electrodeposition with electro-catalytic metals

We demonstrate that commercially available plasters (band aids), usually used for wound healing, can be electrolytically modified with a range of electro-catalytic metals for analytical sensing purposes. These 'Plaster-trodes' consist of a mesh type surface which have star-shaped type microelectrodes of ～150 micron radius in a hexagonal pattern which are separated from its nearest neighbours by ～1250 microns with interlinking connections between each microelectrode which are generally electrochemically active resulting in micro-band-type connections. Proof-of-concept is shown where the Plaster-trode is electrolytically modified with palladium for the sensing of hydrazine and nickel for the direct oxidation of ethanol. Given the low cost of the Plaster-trode which can be readily modified with electro-catalytic metals, we expect this new electrode to be widely utilised in electro-analysis.     

On the size of the localisation domain

We introduce and discuss a delocalisation criterion for electrons in disordered systems, based on the size of the localisation domain. Results are presented for weak disorder limit and a generalisation to arbitrary disorders is indicated.     

Photochemistry of halogenated benzene derivatives. I. Trichlorobenzenes : reductive dechlorination,isomerization and formation of polychlorobiphenyls

Irradiation of the three trichlorobenzenes with λ > 285 nm in a few solvents results in reductive dechlorination as the major reaction, and isomerization and formation of polychlorobiphenyls in some cases.     

The conversion of asperuloside to an optically active prostaglandin intermediate

Synthesis of optically active intermediate $\text{1a}$ for PGF_2α or (+)-11-deoxy-11α-hydroxymethyl PGF_2α from asperuloside is described.     

Short-term changes in delta(13)C and delta(15)N signatures of water discharged from grazed grasslands

The composition of dissolved organic matter (DOM) in a soil is the product of a variety of soil processes. Changes in the composition of DOM in water discharged from soil should, therefore, give an important insight into modifications in these soil processes. We hypothesise that these processes in soils, under different grassland management regimes, would be affected to different extents by the short-term disturbance of a storm event and that evidence of this could be detected in delta(13)C and delta(15)N signatures in drainage and surface runoff waters. During a storm event we collected discharge waters from 1 ha grassland lysimeters, with or without artificial drainage, which received contrasting fertiliser inputs, and delta(13)C and delta(15)N signatures were determined. Changes in (13)C enrichment during the storm event were clearly identifiable, as were differences between plots for (13)C and (15)N, illustrating that this technique has potential to be a useful tool for identifying and investigating short- and long-term changes in soil organic matter dynamics. Copyright 1999 John Wiley & Sons, Ltd.     

Relativistic Effects on Stimulated Brillouin Scattering of Self-Focused q-Gaussian Laser Beams in Plasmas with Axial Density Ramp

Journal of Russian Laser Research - We investigate the phenomenon of stimulated Brillouin scattering (SBS) of q-Gaussian laser beams nonlinearly-interacting with underdense plasmas. When an intense...     

Conversion of carbamates to amidosulfones and amides. Synthesis of the [14C]-labeled antiobesity agent Ro23-7637

[reaction: see text] Carbamates of primary and secondary amines react with the dianion of methyl phenyl sulfone to yield amidosulfones. Alylation of the amidosulfone followed by reductive removal of the sulfonyl residue gives an amide.