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Aims: To evaluate a newly developed microscale quantitative suspension test compared to the existing standard suspension test using determination of the bactericidal and yeasticidal activity of glutaral as one step to improve the sustainability of disinfectant testing.Methods: The testing principles of the quantitative suspension test according to VAH method 9 (comparable to EN 13727) was used as a standard suspension test using 8.0 mL product test solution, 1.0 mL organic load and 1.0 mL test suspension. In addition, a micro-scale suspension test was performed in 96-well plates with 160 µL product test solution, 20 µL organic load and 20 µL test suspension. S. aureus ATCC 6538, P. aeruginosa ATCC 15442 and C. albicans ATCC 10231 were test organisms. Glutaral was tested at concentrations of 0.05%, 0.1%, 0.2% and 0.3% with exposure times of 1, 5 and 15 min. Polysorbate 80 (30 g/L), lecithin (9 g/L), L-histidine (1 g/L) and glycine (10 g/L) were used as validated neutralizers. After serial dilution of the disinfectant-neutralizer-mixture, plates were incubated for 48 h at 36°C (bacteria) or 72 hours at 30°C (C. albicans ) and colony forming units (cfu) counted. The lg reduction was calculated as the difference between the results of the water control and the disinfectant at the end of the exposure time. All experiments were done in triplicate under clean conditions. Means of lg reduction were compared with the unpaired t-test, p<0.05 was considered to be significant.Results: Sufficient bactericidal activity according the VAH test requirements of at least 5 lg was found with both methods in 16 data sets of 24 data sets in total, and insufficient bactericidal activity of less than 5 lg was found with both methods in 7 data sets. In one data set, the mean lg reduction was above 5 lg with the microscale method and <5 lg with the VAH method, with no significant difference between the data sets (p=0.3096; 0.2% glutaral, 1 min, P. aeruginosa ). A sufficient yeasticidal activ, Zielsetzung: Evaluierung eines neu entwickelten Mikro-Suspensionstests im Vergleich zur bisherigen Standardmethode am Beispiel der Bestimmung der bakteriziden und levuroziden Wirkung von Glutaral als ein Schritt auf dem Weg zu mehr Nachhaltigkeit in der Desinfektionsmittel-Testung.Methode: Die VAH-Methode 9 wurde als Standard-Suspensionstest mit 8,0 mL Produkttestlösung, 1,0 mL organischer Belastung und 1,0 mL Testsuspension verwendet. Darüber hinaus wurde ein Mikroskala-Suspensionstest (Mikromethode) in 96-Well-Platten mit 160 µL Produkttestlösung, 20 µL organischer Belastung und 20 µL Testsuspension durchgeführt. Als Testorganismen dienten S. aureus ATCC 6538, P . ae ruginosa ATCC 15442 und C. albicans ATCC 10231. Glutaral wurde in Konzentrationen von 0,05%, 0,1%, 0,2% und 0,3% mit Expositionszeiten von 1, 5 und 15 min getestet. Polysorbat 80 (30 g/L), Lecithin (9 g/L), L-Histidin (1 g/L) und Glycin (10 g/L) wurden als validierte Neutralisationssubstanzen verwendet. Nach serieller Verdünnung des Desinfektionsmittel-Neutralisator-Gemischs wurden die Platten 48 h bei 36°C (Bakterien) bzw. 72 h bei 30°C (C. albicans ) bebrütet und die Kolonie bildenden Einheiten (KbE) gezählt. Die lg-Reduktion wurde als Differenz zwischen den Ergebnissen der Wasserkontrolle und des Desinfektionsmittels am Ende der Expositionszeit berechnet. Alle Experimente wurden in dreifacher Ausführung bei geringer Belastung durchgeführt. Die Mittelwerte der lg-Reduktion wurden mit dem ungepaarten t-Test verglichen, wobei ein p-Wert <0,05 als signifikant angesehen wurde.Ergebnisse: Eine ausreichende bakterizide Wirkung von mindestens 5 lg wurde mit beiden Methoden in 16 Datensätzen von insgesamt 24 Datensätzen (je als Mittelwert der Dreifachbestimmung) gefunden, eine unzureichende bakterizide Wirkung von <5 lg wurde mit beiden Methoden in 7 Datensätzen gefunden. In einem Datensatz lag die mittlere lg-Reduktion mit der Mikromethode über 5 lg und mit der VAH-Methode unter 5 lg, wobei kein signifikan

Hot-stamped components are an important part in steel-intensive automobile lightweight design in which the use of the heat-treatable steel 22MnB5 has been established. However, the field of application is limited by the low elongation at break in the hardened state. In order to improve ductility and consequently the crash-performance, the formation of martensite can be locally suppressed. This process known as tailored tempering is accompanied by decreasing tensile strength. Regarding its lightweight potential, 22MnB5 is reaching its limits and new materials come into focus. Promising potential to fulfil the mentioned demands is offered by carbon-martensitic chromium steels. Besides improved tensile strength and elongation at break, this material series has further advantages. Due to its low critical cooling rate, the formation of martensite is achieved in the hot stamping process as well as by cooling at ambient temperature. Moreover, the low martensite-start-temperature allows the use of thin material sheets. However, the process management required to achieve the respective demands for automobile applications is not trivial. Considering the materials X20Cr13 and X46Cr13, this study investigates the influence of varying process parameters on mechanical properties. In order to comprehend the relationship between solution annealing and tempering parameters, a design of experiments has been performed by means of tensile tests. In addition, miniature tensile tests were conducted to obtain flow curves at varying forming temperatures and to examine the effects of varying cooling and strain rates.