Technische Möglichkeiten und Akzeptanz mobiler Anwendungen

Mobile data communication applications, referred to in this paper as mobile applications, were one of the technological innovation and investment targets in recent years. From the past it became obvious that mono-disciplinary approaches to investigate mobile applications have shortcomings when it comes to successful innovation and investment decisions as interdependencies are insufficiently addressed. The paper therefore aims at structuring the scientific contributions of computer science, business economics and sociology in the context of mobile applications to approximate a holistic understanding comprising technological feasibility, economic opportunities and human needs.     

Determination ofN-nitrosodiethanolamine in cosmetics and in alkanolamines: results of collaborative studies

Summary Results of collaborative studies on methods for determination ofN-Nitrosodiethanolamine (NDELA), in cosmetics and in alkanolamines are reported. Participants from eleven laboratories in each study examined two freshly prepared model cosmetics, one emulsion and one shower gel and also one sample of triethanolamine. Samples were analyzed unspiked and after fortification with 50 g/kg NDELA. Distribution of unspiked and spiked samples and amounts of NDELA added were not known to the participants. In spiked samples overall mean values (±standard deviation) found for NDELA were 50 ± 9 gg/kg for the emulsion, 53 ± 8 gg/kg for the shower gel and 47 ± 10 g/kg for triethanolamine. With few exceptions, NDELA was not found in unspiked samples at concentrations exceeding the determination limit (10 gg/kg).

---

Ergebnisse von Ringversuchen zur Bestimmung vonN-Nitrosodiethanolamin in Cosmetica und in Alkanolaminen

Zusammenfassung Ergebnisse von Ringversuchen zur Bestimmung vonN-Nitrosodiethanolamin (NDELA) in kosmetischen Mitteln and in Alkanolaminen werden beschrieben. Teilnehmer aus jeweils elf Laboratorien analysierten zwei kosmetische Mittel, die für diese Studie frisch hergestellt wurden, eine Emulsion und ein Duschbad Bowie eine Probe Triethanolamin. Die Proben wurden undotiert Bowie nach Zusatz von jeweils 50 g/kg NDELA untersucht, wobei die Verteilung und Höhe der Dotierung den Teilnehmern nicht bekannt wares. Die Gesamtmittelwerte betrugen für die dotierte Emulsion 50 g/kg NDELA±9 g/kg SD (Standardabweichung), für das dotierte Duschbad 53 g/kg NDELA±8 g/kg SD and fur das dotierte Triethanolamin 47 g/kg NDELA ± 10 g/kg SD. Mit wenigen Ausnahmen wurden in den undotierten Proben keine NDELA-Gehalte gefunden, die die Bestimmungsgrenze von 10 g/kg überschritten.

     

A method for the determination of N-nitrosoalkanolamines in cosmetics

Summary A method für the determination of N-nitrosoalkanolamines in cosmetics and toiletries is described. The ingredients used in their manufacture N-nitroso-bis-(2-hydroxyethyl)amine (N-nitrosodiethanolamine, NDELA) and N-nitroso-bis-(2-hydroxypropyl)amine (NBHPA) are almost exclusively the contaminants. The method has therefore been modified for their determination. N-Nitroso-(2-hydroxyethyl)-(2-hydroxypropyl)amine is used as the internal standard. After dilution with water, the cosmetic is adsorbed onto a kieselguhr column and extracted with n-butanol. The extract is brought to dryness, re-dissolved in chloroform/acetone (5 + 1) and transferred to a silica gel column. The column is washed and eluted with acetone. The eluate is dried and the residue is treated with N-methyl-N-trimethylsilyl-heptafluorobutyramide. Trimethylsilyl (TMS)derivatives of N-nitrosoalkanolamines are determined by gas-chromatography with a thermal energy analyzer (TEA). Recovery of the internal standard is 95% and the determination limit is 5 g/kg, Repeated analyses of a foam bath, spiked with 30 g/kg NDELA, gave an average content of 32 g/kg NDELA (variation coefficient 8.8%;n=10). In order to avoid artefact formation during the clean-up process, kieselguhr containing 50% sodium ascorbate has to be used when cosmetics containing free dialkanolamines are analyzed.

---

Ein Bestimmungsverfahren für N-Nitrosoalkanolamine in kosmetischen Mitteln

Zusammenfassung Ein Verfahren zur Bestimmung von N-Nitrosoalkanolaminen in kosmetischen Mitteln wird beschrieben. Da die technisch eingesetzten Grundstoffe praktisch ausschließlich zu Kontamination mit N-Nitroso-bis-(2-hydroxyethyl)amin (N-Nitrosodiethanolamin, NDELA) und N-Nitroso-bis-(2-hydroxypropyl)amin (NBHPA) führen, ist das Verfahren auf die Erfassung dieser Nitrosamine optimiert. Die mit Wasser verdünnte Probe wird nach Aufgabe auf eine Kieselgursäule mit n-Butanol extrahiert. Das Lösungsmittel wird abgedampft, der Rückstand in Chloroform/Aceton (5 + 1) aufgenommen und auf eine Kieselgelsäule gegeben. Nach Waschen wird mit Aceton eluiert. Das Eluat wird von Aceton befreit, der Rückstand trimethylsilyliert. Trimethylsilyl (TMS)-Derivate der N-Nitrosoalkanolamine werden gaschromatographisch mit dem Thermal Energy Analyzer (TEA) erfaßt. Die Wiederfindung des internen Standards N-Nitroso-(2-hydroxyethyl)-(2-hydroxypropyl)amin (NBHPA) liegt bei 95%, die Bestimmungsgrenze für NDELA bei 5 g/kg. Wiederholte Analysen eines mit 30 g/kg dotierten Schaumbades ergaben einen mittleren Gehalt von 32 g/kg NDELA (Variationskoeffizient = 8,8%,n=10). Zur Vermeidung der Artefaktbildung während der Aufarbeitung muß bei Analysen von kosmetischen Mitteln mit Gehalt an freien Dialkanolaminen Kieselgur mit Zusatz von 50% Natriumascorbat zur Festphasenextraktion verwendet werden.

     

Elevated social anxiety among early maturing girls.

Adolescence is a key period in terms of the development of anxiety psychopathology. An emerging literature suggests that early pubertal maturation is associated with enhanced vulnerability for anxiety symptomatology, although few studies have examined this association with regard to social anxiety. Accordingly, the current study was designed to further elucidate the relation between pubertal timing and social anxiety, with a focus on clarifying the role of gender. Participants were 138 adolescents (ages 12–17 years) recruited from the general community. Level of social anxiety was examined as a function of gender and within-sample pubertal timing. As expected, early maturing girls evidenced significantly higher social anxiety, compared with on-time girls and early maturing boys, and no other differences were found as a function of gender or developmental timing. Findings and future directions are discussed in terms of forwarding developmentally sensitive models of social anxiety etiology and prevention. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Impact of ozonation on ecotoxicity and endocrine activity of tertiary treated wastewater effluent

Tertiary wastewater treatment plant effluent before and after ozonation (0.6-1.1 g O₃/g DOC) was tested for aquatic ecotoxicity in a battery of standardised microbioassays with green algae, daphnids, and zebrafish eggs. In addition, unconjugated estrogen and 17β-hydroxyandrogen immunoreactive substances were quantified by means of enzyme immunoassays, and endocrine effects were analysed in a 21-day fish screening assay with adult male and female medaka (Oryzias latipes). Ozonation decreased estrogen-immunoreactivity by 97.7 ± 1.2% and, to a lesser extent, androgen-immunoreactivity by 56.3 ± 16.5%. None of the short-term exposure ecotoxicity tests revealed any adverse effects of the tertiary effluent, neither before nor after the ozonation step. Similarly in the fish screening assay, reproductive fitness parameters showed no effects attributed to micropollutants, and no detrimental effects of the effluents were observed. Based on the presented screening, ozonation effectively reduced steroid hormone levels in the wastewater treatment plant effluent without increasing the effluent's ecotoxicity.     

Einflüsse von Mo,V, Nb,Ti, Zr und deren Karbiden auf die Korrosion und Wasserstoffaufnahme des Eisens in Schwefelsäure

Effects of Mo, V, Nb, Ti, Zr and their carbides on the corrosion and hydrogen uptake of iron in sulphuric acid The effects of Mo, V, Nb, Ti, Zr and their carbides on the corrosion and hydrogen uptake of iron in 1 M H₂SO₄/N₂/25°C were investigated by electrochemical and surface analytical methods using binary and ternary Fe-Me alloys with about 0.2 at.-%Me. Due to the experimental conditions, no protective surface layers formed. The transition metals were enriched at the iron surface only as a carbide or oxicarbide. Mo or Zr were not markedly enriched. The corrosion current density and the hydrogen activity were decreased only by Mo or Zr. Hydrogen permeation measurements were analysed in terms of the trapping theory. The average binding energy of shallow traps for hydrogen increases with increasing atomic radius of the substituted alloying elements in the order V, Mo, Ti, Nb and Zr. Correspondingly, the hydrogen diffusion coefficient (after saturation of the deep traps) decreases and the hydrogen solubility increases. The steadystate hydrogen permeation rate remains almost unaffected. The total hydrogen content is determined by the density of deep traps and thus mostly independent of the external hydrogen activity. The trapping effect of iron is strongly increased by dissolved Zr or Nb or in the presence of fine dispersed carbides as VC_x. The effect of coarse carbide particles at a lower density is small.     

Enhancing software safety by fault trees: experiences from an application to flight critical software

The fault tree analysis is a well-established method in system safety and reliability assessment. We transferred the principles of this technique to an assembler code analysis, regarding any incorrect output of the software as the undesired top-level event. Starting from the instructions providing the outputs and tracking back to all instructions contributing to these outputs a hierarchical system of references is generated that may graphically be represented as a fault tree. To cope with the large number of relations in the code, a tool suite has been developed, which automatically creates these references and checks for unfulfilled preconditions of instructions. The tool was applied to the operational software of an inertial measurement unit, which provides safety critical signals for artificial stabilization of an aircraft. The method and its implementation as a software tool is presented and the benefits, surprising results, and limitations we have experienced were discussed.     

Magnetotransport properties of Zn90Mn7.5Cu2.5O100 films

Zn₉₀Mn_7.5Cu_2.5O₁₀₀ films have been prepared on a-plane sapphire substrates by pulsed laser deposition. Paramagnetism mainly caused by Mn²⁺ ions was observed in the films from room temperature down to 2 K. Magnetotransport properties (magnetoresistance (MR) and Hall effect) were studied from 5 K to 290 K up to a field of 6 T. Negative MR was observed at temperature above 100 K. Low field positive MR and high field negative MR was observed at 5 K. Clear anomalous Hall effect with a kink at low field was observed below 20 K, indicating that there exist two different scattering mechanisms for the Mn²⁺ and Cu²⁺ ions.