Micropatterning of Plasma Fluorinated Super-hydrophobic Surfaces

Photolithographic patterning of super-hydrophobic CF₄ plasma fluorinated polybutadiene films is shown to provide sufficient surface energy contrast to facilitate spatially organized deposition of metal salts and polystyrene microspheres from a nebulized mist or solution.     

Multistrange Baryon elliptic flow in Au+Au collisions at square root of sNN=200 GeV

We report on the first measurement of elliptic flow v2(pT) of multistrange baryons Xi- +Xi+ and Omega- + Omega+ in heavy-ion collisions. In minimum-bias Au+Au collisions at square root of s(NN)=200 GeV, a significant amount of elliptic flow, comparable to other nonstrange baryons, is observed for multistrange baryons which are expected to be particularly sensitive to the dynamics of the partonic stage of heavy-ion collisions. The pT dependence of v2 of the multistrange baryons confirms the number of constituent quark scaling previously observed for lighter hadrons. These results support the idea that a substantial fraction of the observed collective motion is developed at the early partonic stage in ultrarelativistic nuclear collisions at the Relativistic Heavy Ion Collider.     

A systematic study of the energy independent behaviour of the fragmentation regions in16O-Em interactions from 3.7 to 200A GeV

The scaling behaviour in the fragmentation regions is investigated for¹⁶O-Em interactions from 3.7 to 200A GeV. It is found that in both the projectile- and the target-fragmentation regions, the multiplicity and pseudo-rapidity distributions as well as the two-particle pseudo-rapidity correlations are independent of incident energy. The intermittency indices at 14.6, 60 and 200A GeV are the same within the experimental errors, indicating that the limiting fragmentation hypothesis works with regard to dynamical as well as statistical fluctuations.     

Photooxidation of polystyrene by O2 and N2O

Strips of polystyrene held in a flowing O₂ or N₂O atmosphere have been exposed to 240-600 nm radiation. The extent of photooxidation has been followed by x-ray photoelectron spectroscopy (XPS). Although N₂O is a more reactive gas than O₂, it produces a less oxidized polymer surface. This surprising observation can be correlated to the photochemistry occurring at the gas/polystyrene interface. © 1992 John Wiley & Sons, Inc.     

Variation of average charged particle multiplicity inp-nucleus interactions with energy and the two component description of particle production at high energies

Experimental data on average shower particle multiplicity (〈N _s〉) accumulated onp-nucleus interactions in the wide momentum region of 7.1–8000 GeV/c is investigated. It is observed that 〈N _s〉 is represented exceedingly well as a function of (v _vS). There are two physical processes which represent the experimental data reasonably well in the two momentum regionsviz 7.1–67.9 GeV/c and 67.9–8000 GeV/c. 〈N _s〉=a( _v ^S)/a+b fits the data in the low momentum region, whereas 〈N _s〉=a +b ln (v _vS) fits the experimental data in the high momentum region. The two physical processes are unified and represented by a single equation which is shown to be the consequence of two component theory and collective models.     

Substrate-independent approach for polymer brush growth by surface atom transfer radical polymerization

A simple method for growing polymer brushes by atom transfer radical polymerization (ATRP) off solid surfaces has been devised. This entails pulsed plasmachemical deposition of a halogen-containing initiator layer, followed by either organic or aqueous phase controlled surface polymerization. The wide-scale applicability of this approach is exemplified by functionalizing flat substrates, microbeads, and nonwoven textiles.     

Functionalization of solid surfaces with thermoresponsive protein-resistant films

Pulsed plasma polymerization of N-isopropylacrylamide leads to the deposition of thermoresponsive films. The reversible (switching) behavior of these poly(N-isopropylacrylamide) surfaces has been exemplified by screening the adsorption of fibrinogen and fluorescein isothiocyanate labeled bovine serum albumin proteins by surface plasmon resonance (SPR) and fluorescence microscopy at low and elevated temperatures.     

Poly(N-acryloylsarcosine methyl ester) protein-resistant surfaces

A new class of protein-resistant film based on N-substituted glycine derivatives is described. Pulsed plasma deposited poly(N-acryloylsarcosine methyl ester) coatings are shown to be resistant toward the adsorption of fibrinogen and lysozyme. Deposition and UV irradiation of the polymer through a masked grid are found to be effective ways for generating negative and positive image protein arrays, respectively, onto a range of different substrate materials.     

Open charm yields in d+Au collisions at squareroot[sNN]=200 GeV

Midrapidity open charm spectra from direct reconstruction of D0(D0)-->K-/+pi+/- in d+Au collisions and indirect electron-positron measurements via charm semileptonic decays in p+p and d+Au collisions at squareroot[sNN]=200 GeV are reported. The D0(D0) spectrum covers a transverse momentum (pT) range of 0.1相似文献