Comparing the energy efficiency of different high rate algal raceway pond designs using computational fluid dynamics

High Rate Algal Ponds with long, shallow, looped channels and powered by paddlewheels have been used since the late 1970s for growing algae to produce nutraceuticals and to remediate wastewater. These high rate or raceway ponds are also being applied to other fields such as CO₂ capture and biodiesel production, where there is an ongoing effort to find ways of minimizing operating and capital costs. One approach for minimizing costs is to improve the energy efficiency of raceway ponds as this would lower operating costs and allow the construction of larger ponds, which should also lower capital costs. A major component of energy loss in a raceway pond is the energy required to circulate the fluid around the raceway, particularly at the hairpin bends.     

Fatty acid composition and eating quality of lamb types derived from four diverse breed × production systems

Carcass composition, muscle fatty acids and eating quality of loin chops were examined in ram lambs from four diverse breed × production system groups: pure Welsh Mountain off upland flora, pure Soays off lowland grass, Suffolk crosses off lowland grass and Suffolk crosses off concentrates. The two Suffolk groups had heavier and better muscled carcasses than the others and Soays were particularly lean. Fatty acid composition was different between the groups. The forage-fed lambs all had high concentrations of n-3 polyunsaturated fatty acids (PUFA) including 18:3 (α-linolenic acid) and 20:5 (eicosapentaenoic acid) compared with Suffolks-concentrates which had high concentrations of the n-6 PUFA 18:2 (linoleic acid) and 20:4 (arachidonic acid). Soays were high in both n-3 and n-6 PUFA. Flavour characteristics in grilled chops were similar in Welsh Mountain and Suffolks-grass which differed from Soays and Suffolks-concentrates. The latter two groups had low scores for lamb flavour and overall liking and high scores for abnormal lamb flavour, metallic, bitter, stale, and rancid. Soays had the highest score for livery. These results extend previous findings of the association between feed, PUFA composition and lamb flavour profile and confirm that forage-fed lamb is preferred by UK taste panellists. They also identify a specific breed effect on the quality of meat from lambs raised on forage. These findings suggest that possibilities exist for the production of meat with specific quality characteristics.     

Die Hirschjagd

Zusammenfassung Die Chace dou cerf ist Frankreichs ältester Beitrag zur nationalen Jagdliteratur in der Sprache des Landes, ein Lehrgedicht eines anonymen Verfassers aus dem letzten Viertel des 13. Jahrhunderts. Beschrieben wird die freie Hetzjagd auf den Rothirsch mit Hunden. Die als Dialog zwischen dem Jägermeister und seinem Eleven in Wechselrede gestaltete ursprüngliche Gedichtform wurde bei der Übersetzung in enger Anlehnung an die altfranzösische Fassung in freie Rede übertragen. Der Text ergänzt und bestätigt in vieler Hinsicht das Bild, das über die mittelalterliche Jagd auf Rotwild besteht.

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Summary The Chace dou cerf is France's oldest contribution to national hunting literature in native language, an anonymous didactic poem of the last quarter of the 13th century. The free, overland chase of red deer stags with hounds is described. The poem's original form was a dialogue between the master of hounds and his apprentice. In translation the form was structured in free speech with close reference to the old French original. The text enlarges and confirmes in many aspects the picture with exists of the middle-age hunting of red deer.

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Résumé La Chace dou Cerf est la contribution la plus ancienne à la littérature cynégétique française. Il s'agit d'un poème didactique d'un auteur anonyme de la fin du 13ème siècle où est décrit le libre courre du Cerf avec chiens. La forme poétique originale, qui correspond à un dialogue entre le maître de chasse et son disciple, a été transposée en prose libre lors de la traduction en allemand. Le texte confirme généralement les conceptions que l'on se fait sur la chasse au Cerf au Moyen-Age.

     

Effects of the nonionic surfactant tween 80 on microbial reductive dechlorination of chlorinated ethenes

Recent field studies have indicated synergistic effects of coupling microbial reductive dechlorination with physicochemical remediation (e.g., surfactant flushing) of dense nonaqueous phase liquid (DNAPL) source zones. This study explored chlorinated ethene (e.g., tetrachloroethene [PCE]) dechlorination in the presence of 50-5000 mg/L Tween 80, a nonionic surfactant employed in source zone remediation. Tween 80 did not inhibit dechlorination by four pure PCE-to-cis-1,2-dichloroethene (cis-DCE) or PCE-to-trichloroethene (TCE) dechlorinating cultures. In contrast, cis-DCE-dechlorinating Dehalococcoides isolates (strain BAV1 and strain FL2) failed to dechlorinate in the presence of Tween 80. Bio-Dechlor INOCULUM (BDI), a PCE-to-ethene dechlorinating consortium, produced cis-DCE in the presence of Tween 80, further suggesting that Tween 80 inhibits dechlorination by Dehalococcoides organisms. Quantitative real-time PCR analysis applied to BDI revealed that the number of Dehalococcoides cells decayed exponentially (R(2) = 0.85) according to the Chick-Watson disinfection model (pseudo first-order decay rate of 0.13+/-0.02 day(-1)) from an initial value of 6.6 +/-1.5 x 10(8) to 1.3+/-0.8 x 10(5) per mL of culture after 58 days of exposure to 250 mg/L Tween 80. Although Tween 80 exposure prevented ethene formation and reduced Dehalococcoides cell numbers, Dehalococcoides organisms remained viable, and dechlorination activity pist cis-DCE was recovered following the removal of Tween 80. These findings suggest that sequential Tween 80 flushing followed by microbial reductive dechlorination is a promising strategy for remediation of chlorinated ethene-impacted source zones.     

Zur Frage der Entstehung von Nitrosaminen bei der Reaktion von Monosacchariden mit Aminos?uren (Maillard-Reaktion) in Gegenwart von Natriumnitrit 2. Mitteilung

Zusammenfassung Drei Modell-Gemisched-Glucose/dl-Alanin,d-Glucose/l-Lysin undd-Glucose/l-Glutaminsäure wurden unter Zugabe von Natriumnitrit unter Maillard-Bedingungen gebräunt. Die Zugabe von Natriumnitrit erfolgte vor und nach der Bräunung. Im letzteren Fall schloß sich eine kurze Nachbräunung an. Die Reaktionsbedingungen — pH-Wert und Bräunungstemperaturen — wurden variiert. Die Analyse der alkalibeständigen wasserdampfflüchtigen Maillard-Produkte erfolgte durch GC und GC/MS-Analyse. Bei den identifizierten Produkten handelt es sich um alkylierte Pyrazine, Furan- und Pyridin-Derivate. Nitrosopiperidin wurde aus dem Bräunungsansatzd-Glucose/l-Lysin (Nitritzugabe nach der Bräunung) massenspektrometrisch nachgewiesen.Die Änderung des pH-Wertes um eine Einheit, sowie die Änderung der Bräunungstemperatur innerhalb des Temperaturbereiches 100–150° C haben auf die qualitative Zusammensetzung der flüchtigen Maillard-Produkte eines betrachteten Modell-Gemisches keinen Einfluß. Ein geringer Unterschied wird hinsichtlich der quantitativen Zusammensetzung beobachtet.

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The problem of nitrosamine formation by the reaction of monosaccharides with aminoacids (maillard-reaction) in the presence of sodiumnitrite. 2.

Summary Three model mixturesd-glucose/dl-alanine,d-glucose/l-lysine andd-glucose/l-glutamic acid were browned under Maillard conditions with addition of sodium nitrite. The nitrite was added either before or after the browning reaction. When the nitrite was applied after the browning reaction, a second browning was performed.Reaction conditions-pH-values and browning temperatures — were changed. By GC and GC/MS analysis of alkaline stable volatile Maillard products formation of alkylated pyrazines, furan and pyridine derivatives was confirmed. Thus nitrosopiperidine was detected in subsequent addition of sodiumnitrite after browningd-glucose/l-lysine mixtures.The one unit change of the pH-values and the browning temperature within the range of 100–150° C do not have influence on the qualitative composition of the volatile Maillard products for a certain model mixture. Slight differences were established only in the quantitative composition.

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1. Mitt. Z. Lebensm. Unters.-Forsch. 145, 76–84 (1971)     

Patulinbestimmung in Lebensmitteln

Zusammenfassung Für die Bestimmung von Patulin in Apfelsaft wurde eine Analysenmethode mit einer Nachweisgrenze von 40 g/kg ausgearbeitet. Bei Zusätzen von 120–200 g Patulin/kg werden Wiederfindungsraten von 82–90% erhalten.Nach Vorreinigung der Extraktionslösung durch Flüssig-flüssig-Verteilung und Säulenchromatographie wird Patulin densitometrisch bei 273 nm bestimmt.

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Determination of Patulin in foodstuffsPart 1: Determination of Patulin in apple juice

Summary For the determination of Patulin in apple juice a method of analysis was developed permitting the detection of 40 g Patulin/kg apple juice. With additions between 120–200 g Patulin/kg the recovery rates lie between 82 and 90%.After a pre-purification of the crude extract by liquid-liquid extraction and column-chromatography the Patulin is determined thinlayer chromatographically by reflectance measurement at 273 nm.

     

Pilot-scale demonstration of surfactant-enhanced PCE solubilization at the Bachman Road site. 2. System operation and evaluation

A pilot-scale demonstration of surfactant-enhanced aquifer remediation (SEAR) was conducted during the summer of 2000 at the Bachman Road site in Oscoda, MI. Part two of this two-part paper describes results from partitioning and nonpartitioning tracer tests, SEAR operations, and post-treatment monitoring. For this field test, 68 400 L of an aqueous solution of 6% (wt) Tween 80 were injected to recover tetrachloroethene-nonaqueous phase liquid (PCE-DNAPL) from a shallow, unconfined aquifer. Results of a nonreactive tracer test, conducted prior to introducing the surfactant solution, demonstrate target zone sweep and hydraulic control, confirming design-phase model predictions. Partitioning tracer test results suggest PCE-DNAPL saturations of up to 0.74% within the pilot-scale treatment zone, consistent with soil core data collected during site characterization. Analyses of effluent samples taken from the extraction well during SEAR operations indicate that a total of 19 L of PCE and 95% of the injected surfactant were recovered. Post-treatment monitoring indicated that PCE concentrations at many locations within the treated zone were reduced by as much as 2 orders of magnitude from pre-SEAR levels and had not rebounded 450 days after SEAR operations ceased. Pilot-scale costs ($365 900) compare favorably with design-phase cost estimates, with approximately 10% of total costs attributable to the intense sampling density and frequency. Results of this pilot-scale test indicate that careful design and implementation of SEAR can result in effective DNAPL mass removal and a substantial reduction in aqueous concentrations within the treated source zone under favorable geologic conditions     

Levelset based fluid topology optimization using the extended finite element method

This study focuses on finding the optimal layout of fluidic devices subjected to incompressible flow at low Reynolds numbers. The proposed approach uses a levelset method to describe the fluid-solid interface geometry. The flow field is modeled by the incompressible Navier?CStokes equations and discretized by the extended finite element method (XFEM). The no-slip condition along the fluid-solid interface is enforced via a stabilized Lagrange multiplier method. Unlike the commonly used porosity approach, the XFEM approach does not rely on a material interpolation scheme, which allows for more flexibility in formulating the design problems. Further, it mitigates shortcomings of the porosity approach, including spurious pressure diffusion through solid material, strong dependency of the accuracy of the boundary enforcement with respect to the model parameters which may affect the optimization results, and poor boundary resolution. Numerical studies verify that the proposed method is able to recover optimization results obtained with the porosity approach. Further, it is demonstrated that the XFEM approach yields physical results for problems that cannot be solved with the porosity approach.     

Bau Sallinger建筑公司办公楼

Hannes Schienegger奥地利Spado建筑事务所合伙人之一建筑师:Spado Architects项目地点:奥地利,Liebenfels项目面积:14,746平方米项目时间:2009-2010年摄影:Kurt Kuball Architects:     

Determination of the residual monomer concentration of ε-caprolactam in polyamide-6 using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy gas analysis

For the anionic polymerization of ε-caprolactam to polyamide-6 the residual monomer concentration in the final polymer is an important characteristic. To determine this residual ε-caprolactam monomer concentration, a fast and fail-safe method was developed, which couples thermogravimetric analysis (TGA) with Fourier transform infrared spectroscopy (FTIR) gas analysis. FTIR allows an identification of the types of gasses released during heat treatment. Calibration of the infrared absorbance of ε-caprolactam and the corresponding mass loss in TGA allows a quantitative evaluation of the ε-caprolactam monomer release. Low-heating rates and powdery samples guarantee high-precision measurements.