Zur Reliabilität der Volumendetermination des humanen Kiefergelenkspaltes

Das Kiefergelenk nimmt eine Sonderstellung unter den Gelenken ein. Es stellt die bewegliche Verbindung zwischen Unterkiefer und der Schädelbasis dar. Die Volumetrie des Kiefergelenkspaltes erfordert die Berücksichtigung der dritten Dimension. Zur bildgebenden Darstellung des Kiefergelenkspaltes ist die Computertomographie das geeignete Hilfsmittel um das Volumen zu erfassen. Es wurden 200 computertomographische Patientendatensätze untersucht und das Kiefergelenkspaltvolumen bestimmt. Definierte Regeln sind erstellt worden, die die Segmentierung des Kiefergelenkspaltes erleichtern und ein konstantes Verfahren ermöglichen. Die Reliabilität der Durchführung der Volumendetermination wurde anhand einer zweiten Messung an 100 Patientendatensätzen durchgeführt. Der Methodenfehlers der Segmentierung nach beträgt 1,04, also 4%. Außerdem wurde der Zuverlässigkeitskoeffizient nach Houston bestimmt. Das Ergebnis lieferte einen Wert von 0,96

Testing the meson cloud in the nucleon in Drell-Yan processes

We discuss the present status of the \bar u-\bar d asymmetry in the nucleon and analize the quantities which are best suited to verify the asymmetry. We find that the Drell-Yan asymmetry is the quantity insensitive to the valence quark distributions and very sensitive to the flavour asymmetry of the sea. We compare the prediction of the meson cloud model with different experimental data including the Fermilab E772 data and recent data of the NA51 Collaboration at CERN and make predictions for the planned Drell-Yan experiments.Comment: written in ReVTeX, 26 pages + 10 PS-figure

Reactors for microbial electrobiotechnology

From the first electromicrobial experiment to a sophisticated microbial electrochemical process - it all takes place in a reactor. Whereas the reactor design and materials used strongly influence the obtained results, there are no common platforms for MES reactors. This is a critical convention gap, as cross-comparison and benchmarking among MES as well as MES vs. conventional biotechnological processes is needed. Only knowledge driven engineering of MES reactors will pave the way to application and commercialization. In this chapter we first assess the requirements on reactors to be used for bioelectrochemical systems as well as potential losses caused by the reactor design. Subsequently, we compile the main types and designs of reactors used for MES so far, starting from simple H-cells to stirred tank reactors. We conclude with a discussion on the weaknesses and strengths of the existing types of reactors for bioelectrochemical systems that are scored on design criteria and draw conclusions for the future engineering of MES reactors. [GRAPHICS]

Reggeon and pion contributions in semi-exclusive diffractive processes at HERA

A detailed analysis of semi-exclusive diffractive processes in e-p DIS at HERA, with the diffractive final states in the forward direction is presented. The contributions of the subleading f_2, \omega, a_2, \rho reggeons and the pion exchanges to the diffractive structure function with the forward proton or neutron are estimated. It is found that the (a_2,\rho) reggeons are entirely responsible for the forward neutron production at x_P < 10^{-3}. The \pi N production in the forward region is estimated using the Deck mechanism. The significance of this reaction for the processes measured at HERA, especially with the leading neutron, is discussed.Comment: Strongly revised version accepted for publication in Phys.Rev.D. Latex, 14 pages with 5 eps figures include

Upper Bound On Gluino Mass From Thermal Leptogenesis

Thermal leptogenesis requires the reheating temperature T_R \gsim 3\times 10^{9} GeV, which contradicts a recently obtained constraint on the reheating temperature, T_R \lsim 10^6 GeV, for the gravitino mass of 100 GeV-10 TeV. This stringent constraint comes from the fact that the hadronic decays of gravitinos destroy very efficiently light elements produced by the Big-Bang nucleosynthesis. However, it is not applicable if the gravitino is the lightest supersymmetric particle (LSP). We show that this solution to the gravitino problem works for the case where the next LSP is a scalar charged lepton or a scalar neutrino. We point out that there is an upper bound on the gluino mass as m_{\rm gluino} \lsim 1.8 TeV so that the energy density of gravitino does not exceed the observed dark matter density $\Omega_{\rm DM}h^2\simeq 0.11$.Comment: 11 pages, 3 figures. Minor corrections, new references added, to appear in PL