Kinetische Untersuchungen zum Schwefelübergang zwischen kohlenstoffgesättigtem Eisen und CaO-SiO2-Na2O-Schlacken

Mechanismus und Kinetik des Schwefelüberganges vom Metall zur Schlacke. Messung der Schlackenviskosität während des Ablaufs der Entschwefelungsreaktion. Elektrochemische Untersuchungen der Vorgänge an der Phasengrenze. Deutung der Versuchsergebnisse durch elektrochemische Vorgänge zwischen Metall und Schlacke mit Differentialgleichungen.     

Die Phosphoraktivität im flüssigen Eisen und ihre Beeinflussung durch Nickel,Mangan und Chrom

Temperaturabhängigkeit des Gleichgewichtes von Phosphordampf mit flüssigem Eisen; Wirkungsparameter ?^P_P zwischen 1515 und 1650 °C; Beeinflussung der Phosphoraktivität im flüssigen Eisen durch Nickel, Mangan und Chrom; Phosphoraktivität im System Nickel-Phosphor. Phosphoraktivität im flüssigen an Kohlenstoff gesättigtem Eisen bei gleichzeitiger Anwesenheit von Silizium, Nickel, Mangan und Chrom.     

The design of technical artifacts with regard to work experience: The development of an experience-based documentation system for maintenance workers

The German discussion about experience-guided work has led to the question of how work experience can be regarded within the process of designing technical artifacts. This paper offers a solution for the area of skilled maintenance work. Some considerations about the nature of experience and about the problems skilled workers have in aquiring work competences within computer aided production environments are introduced in order to illustrate the design philosophy: A decision-support-system is described which stimulates workplace learning by enabling previous and present users of the system, including maintenance staff and shop floor workers, to exchange and build on experience.     

Zur Effektivität von Gradientenverfahren für Zuschnittprobleme

Zusammenfassung In dieser Arbeit werden diskrete Gradientenverfahren zur Lösung von ein-, zwei- und dreidimensionalen Zuschnittproblemen vorgeschlagen. Die Effektivität der Algorithmen wird an zwei Parametern gemessen: Arbeitsaufwand und Güte. Wir betrachten aus der Menge aller Lösungsalgorithmen für Zuschnittprobleme vernünftige Algorithmen und geben Güteabschätzungen für diese Klasse an. Eine Klasse eindimensionaler Zuschnittprobleme wird definiert, die zur Klasse P gehört.Unterstützt vom DAAD.     

Intermittent versus continuous administration of 1,25-dihydroxyvitamin D3 in experimental renal hyperparathyroidism

Conflicting results have been reported regarding the efficacy of intermittent versus continuous administration of 1,25(OH)2D3 in renal secondary hyperparathyroidism. To address this issue we examined sham-operated control rats and hyperparathyroid rats with subtotal (5/6) nephrectomy (Nx). The Nx animals (20 to 22 animals per group) were subjected to three treatment protocols: (i) solvent treatment (Nx-solvent); (ii) two i.p. injections of 35 pmol 1,25(OH)2D3 on days 0 and 4 (Nx-bolus); and (iii) continuous infusion of 70 pmol 1,25(OH)2D3 over six days via osmotic minipump (Nx-infusion). All measurements were performed six days after start of treatment. As compared to sham-operated controls, the pre-pro-PTH/beta-actin mRNA ratio was 2.04-fold higher in Nx-solvent. Both modes of administration of 1,25(OH)2D3 resulted in inhibition of PTH mRNA concentrations relative to Nx-solvent. The pre-pro-PTH/beta-actin mRNA ratio was, however, significantly lower (P < 0.05) in Nx-bolus than in Nx-infusion (Nx-bolus 1.26 higher than sham-operated controls; Nx-infusion 1.65 higher than sham-operated controls). Aminoterminal PTH (N-PTH) serum concentrations were higher in Nx-solvent (52 +/- 4 pg/ml) than in sham-operated controls (32 +/- 3 pg/ml, P < 0.01). N-PTH concentrations in Nx-bolus (38 +/- 4 pg/ml) were significantly lower than in Nx-solvent (P < 0.01) and in Nx-infusion (46 +/- 4 pg/ml, P < 0.05). Parathyroid gland weight (microgram/g body wt) was higher in Nx-solvent (1.30 +/- 0.08 pg/ml) than in sham-operated controls (0.79 +/- 0.04 pg/ml, P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)     

Conditions for biphasic competition curves in radioligand binding for ligands subjected to metabolic transformation

The conditions affording biphasic competition curves in radioligand binding for ligands subjected to metabolic transformation was analyzed theoretically. It was shown that when a competing ligand was subjected to transformation to a ligand that showed higher affinity than the parent compound, biphasic competition curves, which might wrongly be interpreted as indicating the presence of two receptor sites, could be observed in binding assays containing a homogenous receptor population. Biphasic competition curves were seen if the conversion of the competitor occurred according to zero and second order kinetics, as well as by enzymatic catalytic processes. However, when the conversion occurred according to a first order kinetics, the competition curves were uniphasic and resolved only into one-site fits, with the apparent affinity of the competitor reflecting the degree of conversion of the competitor to its metabolite. When the metabolic conversion resulted in a metabolite that showed lower affinity for the receptor than the parent compound, the competition curves became supersteep for conversions according to zero and second order kinetics, as well as for conversion by enzymatic catalytic processes.     

A Highly Potent and Cellularly Active β‐Peptidic Inhibitor of the p53/hDM2 Interaction

New and improved : The incorporation of a 6‐chlorotryptophan (6‐Cl‐Trp) into a β‐peptide (M)‐3₁₄ helix leads to a high‐affinity hDM2 inhibitor, as demonstrated by fluorescence fluctuation analysis at single molecule resolution. When conjugated to penetratin, the newly derived hDM2 binder specifically inhibits tumour cell growth in vitro.

     

Zur Querkraftgefährdung bestehender Spannbetonbrücken

Zur Formulierung einer Handlungsanweisung werden in Teil I die geänderten Lastannahmen für Brücken nach DIN Fachbericht 101 mit den Belastungsklassen nach alten Normen verglichen und gezeigt, wie anhand aktueller Verkehrszahlen die Lastansätze modifiziert werden können. Der aktuelle Brückenbestand in Hessen wird mit der Straßeninformationsbank (Teilprojekt Bauwerksdaten) ausgewertet, um Klassifizierungs‐ und Bewertungskriterien zu erarbeiten. Zur Beurteilung des Querkraftwiderstandes werden die Grundlagen der Querkraftbemessung nach DIN 1045, DIN 4227, DIN Fachbericht 102 und aus der Literatur gegenübergestellt. Shear‐Vulnerability of Existing Pre‐Stressed Concrete Bridges. Part One: Basics In Part I, to formulate an operation directive the revised load assumptions for bridges of DIN Technical Report 101 are compared with the loading classes according to old standards and it is demonstrated, how the loading models can be modified based on actual traffic data. The current bridge asset in the Federal State of Hesse is evaluated using the “Road Information Database (Sub‐Project: Structural Data)” in order to work out classification and evaluation criteria. Regarding the assessment of the shear load‐bearing capacity the fundamentals of the shear load design models of DIN 1045, DIN 4227, DIN TR 102 and from the literature are compared.