Review of respiratory mechanics in animals. 3. Methodical and physiologic aspects of the use of the impulse oscilloresistometry system (OIS)

The impulse oscillometry system (IOS) which was originally developed for human medicine was found to be suitable for analysing respiratory mechanics in spontaneously breathing animals. This technique is non-invasive. METHODOLOGICAL ASPECTS: In order to use the IOS-technique in animals, a tightly fitting face mask is necessary. Furthermore, a flexible tube needs to be inserted into the measuring system. While the tube does not influence the measured results significantly, the face mask may affect the measurements. Therefore, its influence on the measured respiratory impedance must be taken into account. To prevent methodological errors, the head and body position of the animal should be standardised during the IOS-measurement. Since the methodological variability of the system is very small, the measuring results are highly reproducible. PHYSIOLOGICAL ASPECTS: In growing subjects, all parameters of respiratory mechanics depend on body weight. Since respiratory physiology is influenced by circadian rhythms, measurements of different days are only comparable when they have been done each day at the same hour. Comparing the respiratory impedance of different animals of similar age and body weight, a considerable inter-individual variability was observed. Due to the low level of physiological intra-individual variability, the method seems to be especially useful for studying influences on the respiratory system (i.e. pharmaceutics, therapeutics) in long-term studies using the same group of subjects.     

Über die Reaktionsfähigkeit von Al2O3 und NiAl2O4 in Chlor und Chlor-Sauerstoffgemischen bei höheren Temperaturen

Reactivity of Al₂O₃ and NiAl₂O₄ in chlorine and chlorine-oxygen mixtures at elevated temperatures To test the reaction inhibiting efficiency of Al₂O₃ or NiAl₂O₄ as a protective layer formed on Ni-Cr-Al alloys in chlorine at higher temperatures, for the present the rate of chlorination of Al₂O₃ and NiAl₂O₄ pellets has been investigated in Cl₂ and Cl₂-O₂-mixtures between 700 and 1000°C. The rate of chlorination of Al₂O₃ with 5,8 × 10^?2 mg/cm²h at 1000°C is significantly smaller than the corresponding rate of NiAl₂O₄ with 2,6 mg/cm²h at 800 °C. The rate of chlorination of Al₂O₃ is increased with increasing Cl₂ pressure and decreased with increasing O₂ pressure. As expected, for NiAl₂O₄ no oxygen pressure dependence of the chlorination rate was detected.     

Congruent strategies for carbohydrate sequencing. 3. OSCAR: an algorithm for assigning oligosaccharide topology from MSn data

This is the third in a sequence of reports devoted to the development of congruent strategies for carbohydrate sequencing. Two previous reports outlined the strategies for observing structural detail from MSn data and introduced tools that compile, search, and compare fragment spectra in a bottom-up approach to oligosaccharide sequencing. In this third report, we introduce the operational details of an algorithm that we define as the Oligosaccharide Subtree Constraint Algorithm (OSCAR). This algorithm assimilates analyst-selected MSn ion fragmentation pathways into oligosaccharide topology (branching and linkage) using what may be considered a top-down sequencing strategy. Guided by a series of logical constraints, this de novo algorithm provides molecular topology without presumed biosynthetic constraints or external comparisons. In this introductory study, OSCAR is applied to a series of permethylated oligomers and isomeric glycans, and topologies are assigned in a few hundredths of a second.     

Krümmungsmessung an belasteten Platten nach dem Ligtenbergschen Moiré-Verfahren

Zusammenfassung Das Verfahren von F. K. Ligtenberg wurde derart abgewandelt, da? man es—nach kleinen Erg?nzungen— mit der üblichen Ausstattung eines spannungsoptischen Laboratoriums anwenden kann. Ferner wurden Auswertungsformeln für krummlinige Koordinaten entwickelt, ein zeichnerisches Verfahren zum unmittelbaren Bestimmen der Hauptkrümmungslinien aus den Moirélinien angegeben und das Aufl?sungsverm?gen des Verfahrens überschl?gig berechnet. Das abgewandelte Verfahren ist an Beispielen erprobt worden.     

Temperaturmessungen an Sauerstoffschiebern

Die Aufklärung von Unfällen an Sauerstoffschiebern, die gegen eine drucklose Leitung öffneten, ließ thermodynamische Ursachen vermuten. Bei der hohen Affinität des Schieberwandmaterials Stahl zum reinen Sauerstoff genügt die punktförmige Erzeugung der Entzündungstemperatur zum Beginn einer explosionsartigen Verbrennung des Schieberkörpers. Theoretisch und versuchsmäßig wird nachgewiesen, daß thermodynamische Prozesse existieren, die bei geeigneter Abstimmung der beteiligten geometrischen und thermodynamischen Parameter als Unfallursache in Frage kommen. Zur Nachprüfung wurde das Temperaturverhalten realer Sauerstoffschieber beim Betrieb mit Druckluft experimentell ermittelt.     

Schutzsysteme für Verschraubungselemente in Kontakt mit Leichtmetall

Protective coating systems for fasteners in contact with light weight metals A review of the recent use of fasteners for light weight alloys in automotive car production is given. Mechanical design, materials selection and protective coating concepts for Magnesium- and Aluminum-alloys are presented. The specific problems caused by galvanic corrosion are discussed by the use of electrochemical data of the protective coating systems on fasteners for joining Magnesium. Experience from outdoor exposure in automotive applications up to date are considered.