Cofermentation of rutin and hesperidin during two-stage anaerobic pre-treatment of high-loaded brewery wastewater.

In a lab-scale two-stage digester (consisting of an acidification and a methane reactor) operated continuously with high-loaded brewers wastewater (psiCOD 9.000 mg1(-1)) as the primary substrate, the cofermentation of two commonly found flavonoids (rutin and hesperidin) was studied. At overall hydraulic retention times of 48-50 h and organic loading rates in the methane reactor ranging from 8 to 10 g COD 1R(-1) d(-1) the addition of up to (0.71 g 1R(-1) d(-1) of either rutin or hesperidin did not cause adverse effects on the reactor performance, in terms of VFA pattern, COD removal efficiency, and specific biogas production. The added flavonoid glycosides were rapidly converted in the acidification reactor yielding several hydroxyaromatic metabolites. With hesperidin as the cosubstrate, all of the formed metabolites were completely removed during passage through the methane reactor whereas in case of rutin, substantial amounts of m-cresol and 4-hydroxyphenylacetate were built up in the medium and remained in the effluent of the methane reactor.     

Mathematical modelling of flows and discrete phase behaviour in a V‐shaped tundish

In steelmaking processes, various efforts are made in order to enhance steel cleanness. Among other approaches, the volume of the tundish has been increased and flow‐controlling devices are used. The extended mean residence time of steel in the tundish leads to an improved inclusion separation. In the present study, the degree of inclusion separation in different tundish configurations is determined through numerical modelling. Flows in the tundish has been calculated under isothermal and non‐isothermal conditions. The numerical model is based on a Euler Lagrange approach. The flow and the temperature field are described through Reynolds averaged transport equations in conjunction with a turbulence model.     

Elektrochemische Bestimmung der Sauerstoffpartialdrücke in Wasserdampf-Wasserstoff-Gemischen und sauerstoffhaltigen Eisenschmelzen

Die Sauerstoffionenleitung in stabilisiertem Zirkondioxyd. CaO-stabilisiertes Zirkondioxyd als Elektrolyt in Sauerstoffkonzentrationsketten. Elektrochemische Bestimmung der Sauerstoffpartialdrücke in H₂O-H₂-Gasgemischen an der Kette Luft/ZrO₂ + CaO/H₂O, H₂ bei 800 bis 1750 °C und in sauerstoffhaltigen Eisenschmelzen an der Kette H₂O, H₂/ZrO₂ + CaO/[O]_Fe bei 1550 bis 1750 °C. Ermittlung der Temperaturabhängigkeit der Freien Enthalpie für die Reaktionen {H₂} + 1/2 {O₂} = {H₂O} und 1/2 {O₂} = [O]_Fe. Berechnung der Überführungszahlen der Ionen und der kritischen Sauerstoffdrücke der beginnenden Elektronenleitung für den ZrO₂-CaO-Elektrolyten.     

Festelektrolytzellen mit gasförmigen Vergleichselektroden zur Messung der Sauerstoffaktivität in Eisenschmelzen

Kritische Überprüfung des Anwendungsbereichs von stabilisiertem Zirkonoxid, Mullit und Magnesiumoxid in einer Festelektrolytzelle mit Luft als Sauerstoffvergleichspotential. Nachweis der Sauerstoffdurchlässigkeit fester Elektrolyte und der Ausbildung von Sauerstoffdiffusionsschichten an der Phasengrenze Festelektrolyt/Eisenschmelze. Voraussetzungen für eine korrekturfreie elektrochemische Sauerstoffbestimmung in Eisenschmelzen bei Verwendung von gasförmigen Sauerstoffvergleichspotentialen.     

Fluidization characteristics and charging behavior of fly ash in a vibro-fluidized bed

Fluidization characteristics of fly ash were investigated in a fluidized bed subjected to mechanical vibrations. In the presence of mechanical vibrations, the minimum fluidization velocity decreased from 4.0 to 1.0 mm/s, and the pressure drop increased slightly. The charge-to-mass ratios of fly ash along the fluidized column revealed that charging behavior of fly ash in the freeboard region significantly differed from that in the dense bed region. In the dense bed region, the net charges of fly ash were slightly negative or almost neutral, whereas fly ash in the freeboard region tended to carry positive charges. Loss-on-ignition (LOI) of fly ash was examined in different regions of the fluidized bed, and the results showed that LOI varied considerably inside the column, generally being lower in the freeboard than in the dense bed since finer particles were entrained into the freeboard. In the dense bed, particle–wall collisions resulted in positively charged carbon and negatively charged ash particles, whereas carbon particles in the freeboard region tended to carry negative charges. The findings demonstrate the potential for separating unburned carbon from fly ash by utilizing a vibro-fluidized bed as a tribocharger.     

Weiterentwicklung einer Methode zur Bienenbruthaltung unter Laborbedingungen

In the LAVES Institute for Apiculture honey bee brood has been reared in the laboratory according to the method of Aupinel et al. (Bull Insectol 58:107?C111, 2005) for studies on the effects of plant protection products as well as for further improvement of the method since 2008. The introduced methodological changes have a positive effect on the number of larvae available for experimental purposes. Furthermore, the treatment with MBC-solution (methyl-benzethonium chloride) could be replaced by pasteurization, which is to be viewed positively from a health perspective for the personnel but also in terms of possible synergistic effects with active ingredients.     

Left ventricular morphology and function in diabetic and nondiabetic hemodialyzed patients

Morbidity in end-stage renal disease (ESRD) diabetic patients is worse than in patients without diabetes mellitus (DM). This study aims to compare clinical, laboratory, and echocardiographic features between the ESRD patients with and without DM. Fifty-eight ESRD patients on dialysis were prospectively divided into two groups according to the presence of DM. Demographic, clinical, laboratory, and echocardiographic features (ejection fraction and wall motion score index) were compared between the two groups. Overall, 20 out of 58 patients (37.8%) with ESRD had DM. There were no significant differences between the patients with DM and those without DM when it comes to age (60.6 ± 10.6 vs. 59.0 ± 10.6 years, P = 0.665), ejection fraction (52.6% ± 12.8% vs. 54.2% ± 12.8%, P = 0.59), and wall motion score index (1.21 ± 0.3 vs.1.15 ± 0.3, P = 0.37). In multivariant analysis of the interventricular septum, posterior wall thickness and left atrium size correlated positively with DM. There was also no statistical difference in myocardial perfusion disturbances on real-time contrast echocardiography between the groups with and without DM (12 (60%) patients vs. 14 patients (36.8%), P = 0.079). Among diabetics 77.8% had significant atherosclerotic changes, while in the group without DM, only 38.1%, P = 0.01. From the laboratory parameters ferritin and high-sensitivity C-reactive protein levels were significantly higher in the group with DM, P = 0.014 and P = 0.026, respectively. Patients with ESRD and DM have significantly bigger left atrial size, thicker left ventricular walls, and higher serum ferritin and high-sensitivity C-reactive protein levels than the patients without DM. The aforementioned features may be possible risk factors for the development of adverse cardiac events in patients on hemodialysis.     

Nicotine, cotinine, and myosmine determination using polymer films of tailor-designed zinc porphyrins as recognition units for piezoelectric microgravimetry chemosensors

Two electropolymerizable zinc porphyrins with receptor sites tailor-designed for selective recognition of the nicotine, cotinine, or myosmine alkaloids were synthesized. These were 5-(2-phenoxyacetamide)-10,15,20-tris(triphenylamino)porphyrinato zinc(II) 1 and 5-(2,5-phenylene-bis(oxy)diacetamide)-10,15,20-tris(triphenylamino)porphyrinato zinc(II) 2 featuring one and two pendant amide side "pincers", respectively, and three triphenylamine substituents at the meso positions of the porphyrin macrocycles capable of electrochemical polymerization. Thin polymerfilms of these porphyrins served for recognition and the piezoelectric microgravimetry (PM) for analytical signal transduction of a new chemical sensor devised for determination of these alkaloids. The films were deposited by potentiodynamic electropolymerization on the 10 MHz quartz resonators of the electrochemical quartz crystal microbalance (EQCM) without affecting the electronic structure of the porphyrin macrocycles. Under favorable flow injection analysis (FIA) conditions, the alkaloid analytes were determined at the concentration level of 0.1 mM with high sensitivity and selectivity. Affinity toward the analytes of the polymer of 2 was higher than that of 1 due to the higher binding ability offered by two pendant pincers of the former. Because of the selective receptors and PM applied under FIA conditions, the developed procedure offered an alternative to the time-consuming and relatively expensive high-performance liquid chromatography (HPLC), capillary electrophoresis (CE), and gas chromatography mass spectrometry (GC-MS) methods of detection and quantification of these alkaloids.     

Thermodynamic Assessment to Chromium Oxidation in the Production of Stainless Steel

A solution model called ε approach is applied to predict the thermodynamic solution behaviour of Cr in steel melts. The calculated results are supported by the available experimental results. Further predictions on chromium scorification are achieved in view of melting and refining processes for Cr‐containing steels. Chromium reduction from slags after meltdown during EAF melting and AOD or VOD refining treatment is important for the production of Cr‐containing steels. It is thermodynamically predicted that chromium is inevitably oxidized during decarburization process which coincides with the industrial and experimental results. Minimum oxidation of chromium can be reached by lowering the partial pressure of CO gas at high temperatures.     

Feeding Deterrence and Detrimental Effects of Pyrrolizidine Alkaloids Fed to Honey Bees (<Emphasis Type="Italic">Apis mellifera</Emphasis>)

Recent studies have shown the occurrence of plant derived pyrrolizidine alkaloids (PAs) in retail honeys and pollen loads, but little is known about how these compounds influence the fitness of foraging honey bees. In feeding experiments, we tested a mix of tertiary PAs and the corresponding N-oxides from Senecio vernalis, pure monocrotaline, and 1,2-dihydromonocrotaline in 50% (w/w) sucrose solutions. The bees were analyzed chemically to correlate the observed effects to the ingested amount of PAs. PA-N-oxides were deterrent at concentrations >0.2%. 1,2-Unsaturated tertiary PAs were toxic at high concentrations. The observed PAs mortality could be linked directly to the presence of the 1,2-double bond, a well established essential feature of PA cytotoxicity. In contrast, feeding experiments with 1,2-dihydromonocrotaline revealed no toxic effects. Levels of less than 50 μg 1,2-unsaturated tertiary PAs per individual adult bee were tolerated without negative effects. PA-N-oxides fed to bees were reduced partially to the corresponding tertiary PAs. Unlike some specialized insects, bees are not able to actively detoxify PAs through N-oxidation. To gain insight into how PAs are transmitted among bees, we tested for horizontal PA transfer (trophallaxis). Under laboratory conditions, up to 15% of an ingested PA diet was exchanged from bee to bee, disclosing a possible route for incorporation into the honey comb. In the absence of alternative nectar and pollen sources, PA-containing plants might exhibit a threat to vulnerable bee larvae, and this might affect the overall colony fitness.