Dirac-Schr\"odinger equation for quark-antiquark bound states and derivation of its interaction kerne

The four-dimensional Dirac-Schr\"odinger equation satisfied by quark-antiquark bound states is derived from Quantum Chromodynamics. Different from the Bethe-Salpeter equation, the equation derived is a kind of first-order differential equations of Schr\"odinger-type in the position space. Especially, the interaction kernel in the equation is given by two different closed expressions. One expression which contains only a few types of Green's functions is derived with the aid of the equations of motion satisfied by some kinds of Green's functions. Another expression which is represented in terms of the quark, antiquark and gluon propagators and some kinds of proper vertices is derived by means of the technique of irreducible decomposition of Green's functions. The kernel derived not only can easily be calculated by the perturbation method, but also provides a suitable basis for nonperturbative investigations. Furthermore, it is shown that the four-dimensinal Dirac-Schr\"odinger equation and its kernel can directly be reduced to rigorous three-dimensional forms in the equal-time Lorentz frame and the Dirac-Schr\"odinger equation can be reduced to an equivalent Pauli-Schr\"odinger equation which is represented in the Pauli spinor space. To show the applicability of the closed expressions derived and to demonstrate the equivalence between the two different expressions of the kernel, the t-channel and s-channel one gluon exchange kernels are chosen as an example to show how they are derived from the closed expressions. In addition, the connection of the Dirac-Schr\"odinger equation with the Bethe-Salpeter equation is discussed

Determinants for Successful Agile Collaboration between UX Designers and Software Developers in a Complex Organisation

Agile and User-centered design processes have been reported to frequently putting contradictory demands on people working within these methodological frameworks. The current research addresses this point by focussing on the crucial relationship between software developer and designer. An online survey, a contextual inquiry, and a diary study were employed with 107 developers and designers in a large media organization to determine the factors for success in agile development cycles. The results from the survey show that while developers and designers have similar levels of satisfaction with agile processes, there are differences in the factors predicting those ratings. Developers are happier with the wider teamwork but want more access to and close collaboration with designers, while the latters’ concern was the quality of the wider teamwork. Additional contextual inquiries and a diary study with pairs of designers and developers reflected the survey findings that close cooperation (and proximity) was essential for improving communication, reducing inefficiencies, and avoiding suboptimal products being released. However, organizational processes, the setup of the work environment, and managerial traditions meant that this close collaboration and localized decision-making was found difficult to maintain. Results from the survey, the contextual inquiry, and the diary study found six factors for success from collaborations emerged

Development and Validation of Spectrophotometric, Atomic Absorption and Kinetic Methods for Determination of Moxifloxacin Hydrochloride

Three simple spectrophotometric and atomic absorption spectrometric methods are developed and validated for the determination of moxifloxacin HCl in pure form and in pharmaceutical formulations. Method (A) is a kinetic method based on the oxidation of moxifloxacin HCl by Fe3+ ion in the presence of 1,10 o-phenanthroline (o-phen). Method (B) describes spectrophotometric procedures for determination of moxifloxacin HCl based on its ability to reduce Fe (III) to Fe (II), which was rapidly converted to the corresponding stable coloured complex after reacting with 2,2′ bipyridyl (bipy). The formation of the tris-complex formed in both methods (A) and (B) were carefully studied and their absorbance were measured at 510 and 520 nm respectively. Method (C) is based on the formation of ion- pair associated between the drug and bismuth (III) tetraiodide in acidic medium to form orange—red ion-pair associates. This associate can be quantitatively determined by three different procedures. The formed precipitate is either filtered off, dissolved in acetone and quantified spectrophotometrically at 462 nm (Procedure 1), or decomposed by hydrochloric acid, and the bismuth content is determined by direct atomic absorption spectrometric (Procedure 2). Also the residual unreacted metal complex in the filtrate is determined through its metal content using indirect atomic absorption spectrometric technique (procedure 3). All the proposed methods were validated according to the International Conference on Harmonization (ICH) guidelines, the three proposed methods permit the determination of moxifloxacin HCl in the range of (0.8–6, 0.8–4) for methods A and B, (16–96, 16–96 and 16–72) for procedures 1–3 in method C. The limits of detection and quantitation were calculated, the precision of the methods were satisfactory; the values of relative standard deviations did not exceed 2%. The proposed methods were successfully applied to determine the drug in its pharmaceutical formulations without interference from the common excipients. The results obtained by the proposed methods were comparable with those obtained by the reference method

NN potentials from inverse scattering in the J-matrix approach

An approximate inverse scattering method [7,8] has been used to construct separable potentials with the Laguerre form factors. As an application, we invert the phase shifts of proton-proton in the $^1S_0$ and $^3P_2-^3F_2$ channels and neutron-proton in the $^3S_1-^3D_1$ channel elastic scattering. In the latter case the deuteron wave function of a realistic $np$ potential was used as input.Comment: LaTex2e, 17 pages, 3 Postscript figures; corrected typo

Electromagnetic Meson Form Factors in the Salpeter Model

We present a covariant scheme to calculate mesonic transitions in the framework of the Salpeter equation for $q\bar{q}$-states. The full Bethe Salpeter amplitudes are reconstructed from equal time amplitudes which were obtained in a previous paper\cite{Mue} by solving the Salpeter equation for a confining plus an instanton induced interaction. This method is applied to calculate electromagnetic form factors and decay widths of low lying pseudoscalar and vector mesons including predictions for CEBAF experiments. We also describe the momentum transfer dependence for the processes $\pi^0,\eta,\eta'\rightarrow\gamma\gamma^*$.Comment: 22 pages including 10 figure

A Smalltalk-based extension to traditional Geographic Information Systems

The Dynamic Environmental Effects Model{copyright} (DEEM), under development at Argonne National Laboratory, is a fully object-based modeling software system that supports distributed, dynamic representation of the interlinked processes and behavior of the earth`s surface and near-surface environment, at variable scales of resolution and aggregation. Many of these real world objects are not stored in a format conducive to efficient GIS usage. Their dynamic nature, complexity and number of possible DEEM entity classes precluded efficient integration with traditional GIS technologies due to the loosely coupled nature of their data representations. To address these shortcomings, an intelligent object-oriented GIS engine (OOGIS) was developed. This engine provides not only a spatially optimized object representation, but also direct linkages to the underlying object, its data and behaviors

Characterisation of human glioma resections by Fast Field-Cycling NMR

abstract 58Peer reviewedPublisher PD

Dynamics of Solid Proteins by Means of Nuclear Magnetic Resonance Relaxometry

Funding This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 668119 (project “IDentIFY”).Peer reviewedPublisher PD

Prioritizing urban sustainability solutions: Coordinated approaches must incorporate scale-dependent built environment induced effects

10.1088/1748-9326/10/6/061001Environmental Research Letters1066100