Schätzung der modalen Parameter unter Berücksichtigung systematischer Fehler der Frequenzgänge

Zusammenfassung Aufgrund von Eingangs- und Ausgangsst?rungen des Me?systems sowie einer endlichen Frequenzaufl?sung treten stets systematische (Bias-) und zuf?llige Fehler bei gemessenen Frequenzg?ngen und deren Varianzen auf. Auf solchen Frequenzg?ngen und Varianzen beruhende Sch?tzungen der modalen Parameter sind damit ebenfalls systematisch verzerrt. Um die Genauigkeit und Sicherheit der modalen Parameter zu erh?hen, wird ein Sch?tzverfahren vorgestellt, in dem der Einflu? der Biasfehler auf die Sch?tzung n?herungsweise in einer diagonalen Wichtungsmatrix berücksichtigt wird. Es wird gezeigt, da? die systematischen Fehler Einflu? auf die Absch?tzung der statistischen Sicherheit der modalen Parameter haben. Anhand zweier Beispiele wird die Wirksamkeit des Sch?tzverfahrens demonstriert. Prof. Dr.-Ing. Dr.-Ing. E.h.H.K. T?nshoff: Dipl.-Ing.Z. Liu, Institut für Fertigungstechnik und Spanende Werkzeugmaschinen (IFW), Universit?t Hannover.     

A Study of The Moisture-Uptake Kinetics of a Hygroscopic Pharmaceutical Powder

The moisture-uptake kinetics of a hygroscopic powder, sodium heparin contained in a cylindrical container, was determined using a novel moisture-uptake measuring device under a constant convective air flow. The amount of moisture uptake increased with the increase in the relative humidity of the air. The effect of powder-bed height on the total amount of moisture uptake was found to be significant only at the highest relative humidity (75%) evaluated in this study. However, the percent of weight increase of the powder as a result of moisture uptake decreases as the height of the powder bed increases. The results of this study are explained by the dynamic nature of the moisture-uptake process associated with the instrument.     

Prevention of marital distress: Results of a German prospective longitudinal study.

This article reports on the development and long-term evaluation of a marital distress prevention program for German couples, the Ein Partnerschaftliches Lernprogramm (EPL, A Couple's Learning Program). The EPL is a 6-session program designed to teach couples effective communication and problem-solving skills. In the current article, the EPL is evaluated in a prospective, quasi-experimental, controlled trial. The results of the 3-year follow-up are reported, contrasting 55 EPL couples with a control group of 17 couples. Significant differences emerged with regard to the couples' dissolution rates, relationship satisfaction, and positive and negative communication behavior favoring the EPL couples. These results demonstrate the utility of the EPL program in assisting happy couples who are preparing for marriage. The implications of the findings for prevention research and for the dissemination of prevention programs are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Characterization of Apo-Form Selective Inhibition of Indoleamine 2,3-Dioxygenase**

Indoleamine-2,3-dioxygenase 1 (IDO1) is a heme-containing enzyme that catalyzes the rate-limiting step in the kynurenine pathway of tryptophan (TRP) metabolism. As it is an inflammation-induced immunoregulatory enzyme, pharmacological inhibition of IDO1 activity is currently being pursued as a potential therapeutic tool for the treatment of cancer and other disease states. As such, a detailed understanding of the mechanism of action of IDO1 inhibitors with various mechanisms of inhibition is of great interest. Comparison of an apo-form-binding IDO1 inhibitor (GSK5628) to the heme-coordinating compound, epacadostat (Incyte), allows us to explore the details of the apo-binding inhibition of IDO1. Herein, we demonstrate that GSK5628 inhibits IDO1 by competing with heme for binding to a heme-free conformation of the enzyme (apo-IDO1), whereas epacadostat coordinates its binding with the iron atom of the IDO1 heme cofactor. Comparison of these two compounds in cellular systems reveals a long-lasting inhibitory effect of GSK5628, previously undescribed for other known IDO1 inhibitors. Detailed characterization of this apo-binding mechanism for IDO1 inhibition might help design superior inhibitors or could confer a unique competitive advantage over other IDO1 inhibitors vis-à-vis specificity and pharmacokinetic parameters.     

Photocurrents and degradation rates on particulate TiO2 layers: Effect of layer thickness, concentration of oxidizable substance and illumination direction

Different routes for immobilization of TiO₂ on conducting substrates were compared to find active and stable photocatalysts, which could either be operated in open circuit (photocatalysis) or with applied electric potential (photoelectrocatalysis). The advantage of applying an electric potential was investigated. Polarization curves and photoelectrochemical degradation reactions served to characterize catalysts and to find a way of predicting the optimum synthesis conditions. The difference between front side (EE) and back side (SE) illumination is discussed as a function of layer thickness, as well as the influence of oxidizable substance concentration on photocurrents. Stability of catalysts was investigated in repetitive degradation experiments.     

Fabrication and characterization of machined 3D diffractive optical elements

The production of three dimensional blazed grating structures based on ultra-precision machining is an up-to-date issue. Hence, in the development of manufacturing technologies technology-related failure modes are generated due to structural variations. These failure errors must be recorded in cause and effect and then characterized by their type in order to achieve the optimum quality. This paper addresses the influence of processing parameters on the shape-persistence and hence on the grating quality and explains the possibility of detection and classification of them.     

Managing knowledge on communication and information flow in global software projects

Communication is a key success factor of distributed software projects. Poor communication has been identified as a main obstacle to successful collaboration. Global projects are especially endangered by information gaps between collaborating sites. Different communication styles, technical equipment, and missing awareness of each other can cause severe problems. Knowledge about actual and desired channels, paths, and modes of communication is required for improving communication in a globally distributed project. However, many project participants know little about communication and information flow in their projects. In this contribution, we focus on knowledge about communication and information flow. It is acquired by modelling on‐going and desired flows of information, including documented and non‐documented channels of information flow. We analyzed a distributed software project from the information flow perspective. Based on the findings, we developed specific techniques to improve information flow in distributed software development according to the FLOW Method. In a second distributed project, we evaluated one of the techniques. We found the FLOW mapping technique to be suitable for effectively spreading knowledge about communication and information flow in global software projects.     

Solubility of Propane in Sulpholane at Elevated Pressures

The solubility of propane in sulpholane has been determined at temperatures in the range 298‐403 K at pressures up to 17.6 MPa. The experimental results were correlated by the Peng‐Robinson equation of state, and binary interaction parameters have been obtained for this system. The parameters in the Krichevsky‐Ilinskaya equation were calculated from these interaction parameters.     

Abietoid seed fatty acid composition—A review of the genera Abies, Cedrus, Hesperopeuce, Keteleeria, Pseudolarix, and Tsuga and preliminary inferences on the taxonomy of Pinaceae

The seed fatty acid (FA) compositions of Abietoids (Abies, Cedrus, Hesperopeuce, Keteleeria, Pseudolarix, and Tsuga) are reviewed in the present study in conclusion to our survey of Pinaceae seed FA compositions. Many unpublished data are given. Abietoids and Pinoids (Pinus, Larix, Ficea, and Pseudotsuga)—constituting the family Pinaceae—are united by the presence of several Δ5-olefinic acids, taxoleic (5,9–18∶2), pinolenic (5,9,12–18∶3) coniferonic (5,9,12,15–18∶4), keteleeronic (5,11–20∶2), and sciadonic (5,11,14–20∶3) acids, and of 14-methyl hexadecanoic (anteiso-17∶0) acid. These acids seldom occur in angiosperm seeds. The proportions of individual Δ5-olefinic acids, however, differ between Pinoids and Abietoids. In the first group, pinolenic acid is much greater than taxoleic acid, whereas in the second group, pinolenic acid is greater than or equal to taxoleic acid. Moreover, taxoleic acid in Abietoids is much greater than taxoleic acid in Pinoids, an apparent limit between the two subfamilies being about 4.5% of that acid relative to total FA. Tsuga spp. appear to be a major exception, as their seed FA compositions are much like those of species from the Pinoid group. In this respect, Hesperopeuce mertensiana, also known as Tsuga mertensiana, has little in common with Abietoids and fits the general FA pattern of Pinoids well. Tsuga spp. and H. mertensiana, from their seed FA compositions, should perhaps be separated from the Abietoid group and their taxonomic position revised. It is suggested that a “Tsugoid” subfamily be created, with seed FA in compliance with the Pinoid pattern and other botanical and immunological criteria of the Abietoid type. All Pinaceae genera, with the exception of Pinus, are quite homogeneous when considering their overall seed FA compositions, including Δ5-olefinic acids. In all cases but one (Pinus), variations from one species to another inside a given genus are of small amplitude. Pinus spp., on the other hand, have highly variable levels of Δ5-olefinic acids in their FA compositions, particularly when sections (e.g., Cembroides vs. Pinus sections) or subsections (e.g., Flexiles and Cembrae subsections from the section Strobus) are compared, although they show qualitatively the same FA patterns characteristic of Pinoids. Multicomponent analysis of Abietoid seed FA allowed grouping of individual species into genera that coincide with the same genera otherwise characterized by more classical botanical criteria. Our studies exemplify how seed FA compositions, particularly owing to the presence of Δ5-olefinic acids, may be useful in sustaining and adding some precision to existing taxonomy of the major family of gymnosperms, Pinaceae.