Recent observation of high-pT hadron spectra suppression and mono-jet production in central Au + Au collisions and their absence in d + Au collisions at RHIC have confirmed the long predicted phenomenon of jet quenching in high-energy heavy-ion collisions. Detailed analyses of the experimental data also show parton energy loss as the mechanism for the discovered jet quenching. Using a pQCD part...

Fluorescence quenching of pyranine by tryptophan, phenylalanine, and nicotinic acid was investigated by using steady state and time resolved fluorescence spectroscopy. On a comparative basis, nicotinic acid is a very strong quencher of pyranine fluorescence, tryptophan is a moderate quencher and phenylalanine is a weak quencher. The strong quenching is the result of the hydrogen bonding complex...

We present high transverse momentum (p T) measurements made at the Relativis-tic Heavy Ion Collider (RHIC) for Au+Au, d+Au, and p+p collisions at √ s N N = 200 GeV, as well as for Au+Au collisions at √ s N N = 62 GeV. We observe a suppression in the yield of high p T hadrons measured in central Au+Au collisions, relative to the yield in p+p collisions scaled by the number of binary nucleon-nucl...

How fluctuations can be eliminated or attenuated is a matter of general interest in the study of steadily-forced dissipative nonlinear dynamical systems. Here, we extend previous work on “nonlinear quenching” [Hide, 1997] by investigating the phenomenon in systems governed by the novel autonomous set of nonlinear ordinary differential equations (ODE’s) ẋ = ay − ax, ẏ = −xzq + bx − y and ż = xyq...

The surface parameter of nanoparticles such as hydrophobicity and a hydrophilicity on protein structure and function is very important. In this study, conformational changes of glucose oxidase (GOx) in the mercaptopurine: GNPs and 11-mercaptoundecanoic acid: GNPs as a hydrophobic and a hydrophilic GNPs surface was investigated by various spectroscopic techniques, including: UV-Vis absorption, f...

In this study the Taguchi method, has been applied to optimize the heat treatment parameters for the corrosion resistance of AA6061 aluminum alloy. The experimental design consisted of four parameters (aging temperature, aging time, quenching environment and NaCl concentration), each containing three levels. Tafel polarization measurements were carried out to determine the corrosion resistance ...

The fluorescence rise kinetics in saturating light display two well separated com ponents with largely different properties. The rapid rise from F„ to a first intermediate level, I ,, is photochemically controlled, while the following phases leading to a secondary intermediate level, I2, and to a peak level, P , are limited by thermal reactions. Treatm ents which primarily affect components at ...

We have studied the time-resolved fluorescence properties of the light-harvesting complexes (Lhc) of photosystem II (Lhcb) in order to obtain information on the mechanism of energy dissipation (non-photochemical quenching) which is correlated to the conversion of violaxanthin to zeaxanthin in excess light conditions. The chlorophyll fluorescence decay of Lhcb proteins LHCII, CP29, CP26, and CP2...

We report here that photoinitiated electron flow involving a metal-substituted (M = Mg, Zn) myoglobin (Mb) and its physiological partner protein, cytochrome b5 (cyt b5) can be "symmetrized": the [Mb:cyt b5] complex stabilized by three D/E → K mutations on Mb (D44K/D60K/E85K, denoted MMb) exhibits both oxidative and reductive ET quenching of both the singlet and triplet photoexcited MMb states, ...

Energy-dependent quenching of excess absorbed light energy (qE) is a vital mechanism for regulating photosynthetic light harvesting in higher plants. All of the physiological characteristics of qE have been positively correlated with charge transfer between coupled chlorophyll and zeaxanthin molecules in the light-harvesting antenna of photosystem II (PSII). We found evidence for charge-transfe...