Di-jet Shape Modification in Heavy Ion Collisions

We present preliminary results from intermediate $p_T$ (1-5 GeV/c) di-hadron azimuthal correlations induced by hadronic di-jets produced in $AuAu$ collisions at $\sqrt{s_{NN}} = 200 GeV$. The near side ($\Delta\phi\sim 0$) has a typical single-peaked structure which broadens with the centrality of the collision. A qualitatively new phenomenon shows up in the shape of the away side ($\Delta\phi\sim\pi$): it has a symmetric, double-peaked structure in central and mid-central collisions.Comment: Poster proceedings Quark Matter 2005 Conference Budapest; 4 pages, 3 figure

The Length of Harmonic Forms on a Compact Riemannian Manifold

We study $n$ dimensional Riemanniann manifolds with harmonic forms of constant length and first Betti number equal to $n-1$ showing that they are 2-steps nilmanifolds with some special metrics. We also characterise, in terms of properties on the product of harmonic forms, the left invariant metrics among them. This allows us to clarify the case of equality in the stable isosytolic inequalities in that setting. We also discuss other values of the Betti number.Comment: 13 page

Orientifolds of the 3-sphere

We study the geometry of orientifolds in the SU(2) WZW model. They correspond to the two inequivalent, orientation-reversing involutions of $S^3$, whose fixed-point sets are: the north and south poles (O0), or the equator two-sphere (O2). We show how the geometric action of these involutions leads unambiguously to the previously obtained algebraic results for the Klein bottle and Moebius amplitudes. We give a semiclassical derivation of the selection rules and signs in the crosscap couplings, paying particular attention to discrete B-fluxes. A novel observation, which does not follow from consistency of the one-loop vacuum diagrams, is that in the case of the O0 orientifolds only integer- or only half-integer-spin Cardy states may coexist.Comment: Latex file, 19 pages, one figure, uses JHEP.cls. One reference added, final version as it appeared in JHE

MODEL DRIVEN DEVELOPMENT OF ONLINE BANKING SYSTEMS

In case of online applications the cycle of software development varies from the routine. The online environment, the variety of users, the treatability of the mass of information created by them, the reusability and the accessibility from different devices are all factors of these systems complexity. The use of model drive approach brings several advantages that ease up the development process. Working prototypes that simplify client relationship and serve as the base of model tests can be easily made from models describing the system. These systems make possible for the banks clients to make their desired actions from anywhere. The user has the possibility of accessing information or making transactions.MDA, UML, Online Banking, Class diagram, Platform Independent Model

Extraction of jet properties from two particle azimuthal correlations in pp and AuAu collisions at [square root of s subscript NN] = 200 GeV

Two particle azimuthal correlation functions measured in pp and AuAu collisions at sNN = 200 GeV at midrapidity with the central arms of the PHENIX detector are analyzed in order to extract the properties of hadronic jets produced in QCD vacuum and highly excited QCD media, like the jet shape parameters jT and kT, the jet conditional yields (number of associated hadrons per high pT trigger hadron) and the jet fragmentation function.;The analysis of pp data starts with the measurement of the vacuum fragmentation function from which the pT dependence of the mean fragmentation momentum fraction 〈z〉 is extracted. We obtain a constant value of 〈z〉 = 0.74 +/- 0.02 for pT above 3 GeV/c. Soft (non-perturbative) parton fragmentation becomes significant below 3 GeV/c and the slope of the fragmentation function is pT dependent in this region. Gaussian fits to jet induced azimuthal correlations are employed to measure the mean jet fragmentation transverse momentum 〈| jTy|〉 = 359 +/- 11 (stat) +/- 6 (syst) MeV/c and the mean partonic transverse momentum 〈|k Ty|〉 = 964 +/- 49 (stat) +/- 16 (syst) MeV/c.;The analysis of AuAu data is based on azimuthal correlation functions between charged hadrons in the 1.5--3 GeV/c and 3--5 GeV/c pT regions in five classes of collision centrality. The mean jet fragmentation transverse momentum 〈|jTy|〉 is centrality independent and consistent with the value in pp data mentioned above. A strong broadening with the centrality of the extracted mean partonic transverse momentum 〈|kTy|〉 (multiplied by 〈ztrigg〉) is observed. This is an important finding because hadronic jet quenching through energy loss is expected to be accompanied by a broadening effect.;Another important finding is that the jet conditional yields in both the near (Delta&phis; ~ 0) and away (Delta&phis; ~ pi) regions exhibit a slightly raising trend with centrality. This was also expected to accompany the jet quenching found at higher pT based on simple energy conservation considerations

Charge transfer and dipole formation at metal-organic interfaces

The rapidly developing field of organic electronics has stimulated intensive research into the fundamental electronic properties of molecular organic semiconductors and their interfaces with metal electrodes as well as insulating substrates. Theoretical and experimental studies are driven by potential applications where organic molecules constitute active materials in a wide range of electronic devices such as light-emitting diodes (LEDs), filed-effect transistors (FETs), solar cells or biosensors. The thesis is motivated by the modeling of charge injection barriers from metallic contacts into organic materials. Experiments indicate that the energy barriers of electron or hole injection are determined by the formation of an interface dipole layer localized at first\ud molecular layer. Such barriers can be extracted by monitoring the change in the work function, produced upon the deposition of the organic layer. We calculate such work\ud functions using density functional theory (DFT)

Discrete element modelling of high aspect ratio sphero-cylinder particle packing

This paper presents Discrete Element Model simulations of packing of rigid sphero-cylinders. The method has been used before but this study considers higher aspect ratios, up to 30. This posed some modelling challenges in terms of stability which were overcome by imposing limits on the particle motion. The results show very good agreement with experimental data in the literature and more detailed in-house experiments for packing volume fraction. Model results on particle orientation are also shown. The model has the potential for predicting packing of fibrous particles and fibre bundles relevant to the preparation of preforms for the production of polymer and metallic matrix composites. Future model developments will include adding flexibility by connecting sphero-cylinders as subelements to describe a particle

An evolutionary perspective on adiponectin and insulin gene promoters

Insulin, discovered in 1921 by Nicolae Paulescu, and adiponectin, discovered in 1995 by Yuji Matsuzawa's and two other groups, are two important molecules related to the maintenance of human energy homeostasis. The close relationship of these two hormones in the development of metabolic pathology (obesity, metabolic syndrome, type 2 diabetes mellitus) prompted us to use a bioinformatic approach in order to better understand the architecture of their gene promoters. In this study, a comprehensive analysis was undertaken for adiponectin (ADIPOQ) and insulin (INS) gene promoter sequences from 7 species. In our approach we used 14 promoter sequences (7 promoters for each gene) from HomoloGene (NCBI). In order to examine the structural particularities of ADIPOQ and INS gene promoters, we used two-dimensional image-based patterns obtained through Kappa Index of Coincidence (Kappa IC) and (C+G)% values. We observed that C+G content variations of ADIPOQ promoter correlates with body mass, whereas high Kappa IC values of the INS gene promoter appear to be correlated with brain size.Adipobiology 2012; 4: 111-115