Renormalon Model Predictions for Power-Corrections to Flavour Singlet Deep Inelastic Structure Functions

We analyze power corrections to flavour singlet deep inelastic scattering structure functions in the framework of the infrared renormalon model. Our calculations, together with previous results for the non-singlet contribution, allow to model the x-dependence of higher twist corrections to F_2, F_L and g_1 in the whole x domain.Comment: LaTeX, 25 pages, 8 eps figures included, one figure was added. Final version for publication in Nucl.Phys.

Transverse Polarisation of Quarks in Hadrons

We review the present state of knowledge regarding the transverse polarisation (or transversity) distributions of quarks. After some generalities on transverse polarisation, we formally define the transversity distributions within the framework of a classification of all leading-twist distribution functions. We describe the QCD evolution of transversity at leading and next-to-leading order. A comprehensive treatment of non-perturbative calculations of transversity distributions (within the framework of quark models, lattice QCD and QCD sum rules) is presented. The phenomenology of transversity (in particular, in Drell-Yan processes and semi-inclusive leptoproduction) is discussed in some detail. Finally, the prospects for future measurements are outlined.Comment: small changes, references added, as finally published in Physics Report

Spin Structure of the Proton from Polarized Inclusive Deep-Inelastic Muon-Proton Scattering

We have measured the spin-dependent structure function $g_1^p$ in inclusive deep-inelastic scattering of polarized muons off polarized protons, in the kinematic range $0.003 < x < 0.7$ and $1 GeV^2 < Q^2 < 60 GeV^2$. A next-to-leading order QCD analysis is used to evolve the measured $g_1^p(x,Q^2)$ to a fixed $Q^2_0$. The first moment of $g_1^p$ at $Q^2_0 = 10 GeV^2$ is $\Gamma^p = 0.136\pm 0.013(stat.) \pm 0.009(syst.)\pm 0.005(evol.)$. This result is below the prediction of the Ellis-Jaffe sum rule by more than two standard deviations. The singlet axial charge $a_0$ is found to be $0.28 \pm 0.16$. In the Adler-Bardeen factorization scheme, $\Delta g \simeq 2$ is required to bring $\Delta \Sigma$ in agreement with the Quark-Parton Model. A combined analysis of all available proton and deuteron data confirms the Bjorken sum rule.Comment: 33 pages, 22 figures, uses ReVTex and smc.sty. submitted to Physical Review

Probing Nucleon Spin Structure

One of the important questions in high energy physics is the relation of quark and gluon spin to that of the nucleons which they comprise. Polarization experiments provide a mechanism to probe the spin properties of elementary particles and provide crucial tests of Quantum Chromodynamics (QCD). The theoretical and experimental status of this fundamental question will be reviewed in this paper.Comment: 65 pages, 3 Postscript figures, LaTeX. To be published in "Progress in Particle and Nuclear Physics

Determination of nutrient salts by automatic methods both in seawater and brackish water: the phosphate blank

9 páginas, 2 tablas, 2 figurasThe main inconvenience in determining nutrients in seawater by automatic methods is simply solved: the preparation of a suitable blank which corrects the effect of the refractive index change on the recorded signal. Two procedures are proposed, one physical (a simple equation to estimate the effect) and the other chemical (removal of the dissolved phosphorus with ferric hydroxide).Support for this work came from CICYT (MAR88-0245 project) and Conselleria de Pesca de la Xunta de GaliciaPeer reviewe

Johann Gottfried Walther als Theoretiker von Hermann Gehrmann.

Vita. --- Inaugural-Dissertation zur Erlangung der Doktorwèurde von der Philosophischen Fakultèat der Kèoniglichen Friedrich-Wilhelms-Universitèat zu Berlin

Vergleich von thermischen Verfahren zur Nutzung von Rückständen aus der Bioethanolerzeugung und Zuckerherstellung in Brasilien

Within the BMBF-funded Brazilian-German cooperation project ASHES, the thermal utilization of bagasse and other residuals from the sugar processing industry was examined. In the laboratory scale, tests were carried out on the KLEAA system of the KIT-ITC to determine relevant fuel parameters. Subsequently, Fraunhofer UMSICHT carried out tests on combustion plants on a technical scale with different plant sizes of 30 kW, 100 kW and 440 kW. The primary objective was to gain knowledge regardimg the combustion and emission behavior of these fuels. Experiments were also carried out at the CUTEC's ArtFuel facility, a gasification unit in the pilot plant scale, and thus gained information regarding the gasification behavior of bagasse and other residuals from sugar cane processing industry. These findings were used to identify optimization potentials at various points and elaborate concepts for their improvement. Within in the next steps of the project future development of these concepts will be focused. In cooperation with the Brazilian project partners several of these concepts should be implemented into practice after the project