Exhaust Gas Optimization of Modern Scooters by Velocity Control

This paper investigates the optimization of the exhaust gas composition by applying a velocity-controlled Throttle-by-Wire-System on modern 50 cc scooters (Euro 5). Nowadays combustion-powered scooters are still inefficiently restricted, resulting in an unreasonably high fuel consumption and unfavorable exhaust emissions. The velocity control prevents restriction by negatively shifting the ignition timing and regulates the throttle valve opening instead. Injection quantity, engine speed, ignition timing, cylinder wall temperature, exhaust gas temperature, oxygen sensor data, crankshaft position and in-cylinder pressure were acquired to measure engine parameters. At the same time, vehicle data on the CAN bus, such as throttle opening angle, the rider's acceleration command and vehicle velocity were recorded. For determination of the exhaust gas composition, five probes were sensing CO, CO2, NOx, O2 and HC in addition to the temperature and mass flow. A Peugeot Kisbee 50 4T (Euro 5) serves as test vehicle. The original and the optimized restriction were subjected to various gradients on a roller dynamometer at top speed. Thus, a statement can be made about all operating points of restriction. The resistance parameters required, were previously determined in a coast down test. When driving on level ground, a difference of 50% in the throttle opening leads to a 17% improvement in fuel economy. By measuring the engine parameters, optimum ignition timing could be proven with increasing internal cylinder pressure. Further, 17% reduction in exhaust gas flow was demonstrated. CO emissions decreased by a factor of 8.4, CO2 by 1.17 and HC by 2.1 while NOx increased by a factor of 3

Dezentrale Kompostierung - sinnvolle Variante der Bioabfallverwertung?

Nativ-organische Abfälle bilden mit ca. 30 Gew. % den Hauptteil des Hausmülls. Daher leistet die Bioabfallkompostierung einen bedeutenden Schritt hin zu einer sinnvollen Abfallverwertung. Bundesweit werden derzeit jährlich etwa 750 000 t Bioabfallkompost erzeugt. Mit Ausnahme von sieben Land- und Stadtkreisen planen die Landkreise Baden-Württembergs die getrennte Sammlung von Bioabfällen: Einwohner von 23 Landkreisen waren 1993, zum Teil versuchsweise, an Biotonnen angeschlossen. Die Notwendigkeit der Bioabfallkompostierung scheint außer Frage zu stehen, intensiv erörtert werden jedoch die Verfahrenskonzepte, die der Bioabfallkompostierung zugrunde liegen. Kern der Diskussion ist, ob einfache Kompostierungsverfahren wie die dezentrale Kompostierung den technisch aufwendigeren Verfahren zentraler Anlagen gleichwertig sind. Als erster Landkreis in Baden Württemberg hat der Landkreis Sigmaringen bei der Entsorgung des bei 120 000 Einwohnern im Kreis anfallenden organischen Abfalls neue Wege beschritten und die Landwirtschaft in den Stoffkreislauf miteinbezogen, anstatt das anfallende Material zu deponieren. Auf dem Hintergrund der TA-Siedlungsabfall, die vorschreibt, daß nach einer Übergangszeit organische Abfälle nicht mehr deponiert werden dürfen, sondern kompostiert oder thermisch behandelt werden müssen, hat der Landkreis Sigmaringen im Jahr 1992 ein Konzept zur dezentralen Kompostierung verabschiedet

Probing Surface and Interfacial Tension of Ionic Liquids in Vacuum with the Pendant Drop and Sessile Drop Method

We report on the surface and interface tension measurements of the two ionic liquids (ILs) [C8C1Im][PF6] and [m(PEGn)2Im]I (n = 2, 4, 6) in a surface science approach. The measurements were performed in a newly developed and unique experimental setup, which allows for surface tension (ST) measurements using the pendant drop method and for contact angle measurements using the sessile drop method under the well-defined conditions of a high vacuum (from 10−7 mbar). The setup also allows for in vacuum transfer to an ultrahigh vacuum system for surface preparation and analysis, such as in angle-resolved X-ray photoelectron spectroscopy. For [C8C1Im][PF6], we observe a linear decrease in the surface tension with increasing temperature. The ST measured under high vacuum is consistently found to be larger than under ambient conditions, which is attributed to the influence of water uptake in air by the IL. For [m(PEGn)2Im]I (n = 2, 4, 6), we observe a decrease in the ST with increasing polyethylene glycol chain length in a vacuum, similar to very recent observations under 1 bar Argon. This decrease is attributed to an increasing enrichment of the PEG chains at the surface. The ST data obtained under these ultraclean conditions are essential for a fundamental understanding of the relevant parameters determining ST on the microscopic level and can serve as a benchmark for theoretical calculations, such as molecular dynamic simulations. In addition to the ST measurements, proof-of-principle data are presented for sessile drop measurements in HV, and a detailed description and characterization of the new setup is provided

Interleukin-1 haplotype and periodontal disease progression following therapy

The purpose of this study was to assess the prognostic value of the IL-1 haplotype on the progression of periodontal disease following therapy. 48 adult patients with untreated periodontitis harboring Actinobacillus actinomycetemcomitans and/or Porphyromonas gingivalis were randomly assigned to receive full-mouth scaling alone (control) or in combination with systemic metronidazole plus amoxicillin and supragingival irrigation with chlorhexidine digluconate (test). All patients received supportive periodontal therapy at 3 to 6 months intervals. In 33 patients, lymphocyte DNA was analyzed for polymorphism in the IL-1A gene at position -889 and IL-1B gene at position +3953. Overall, 16 of 33 patients (7 of 17 test and 9 of 16 control) carried the IL-1 haplotype. 2 years following initial periodontal therapy, no differences in the survival rates of sites or teeth not exhibiting probing attachment loss of 2 mm or more compared to baseline, were found between patients who tested positive (85% sites, 53% teeth) and patients who tested negative (89% sites, 56% teeth) for the IL-1 haplotype. The results indicated that the IL-1 haplotype may be of limited value for the prognosis of periodontal disease progression following non-surgical periodontal therapy. © Munksgaard, 1999.link_to_subscribed_fulltex

Development of an approach for a "Cross Learning Factory Product Production System" for circular economy

Circular economy aims to support reuse and extends the product life cycles through repair, remanufacturing, upgrades and retrofits, as well as closing material cycles through recycling. To successfully manage the necessary transformation processes to circular economy, manufacturing enterprises rely on the competency of their employees. The definition of competency requirements for circular economy-oriented production networks will contribute to the operationalization of circular economy. The International Association of Learning Factories (IALF) statesin its mission the development of learning systems addressing these challenges for training of students and further education of industry employees. To identify the required competencies for circular economy, the major changes of the product life cycle phases have been investigated based on the state of the science and compared to the socio-technical infrastructure and thematic fields of the learning factories considered in this paper. To operationalize the circular economy approach in the product design and production phase in learning factories, an approach for a cross learning factory network (so called "Cross Learning Factory Product Production System (CLFPPS)") has been developed. The proposed CLFPPS represents a network on the design dimensions of learning factories. This approach contributes to the promotion of circular economy in learning factories as it makes use of and combines the focus areas of different learning factories. This enables the CLFPPS to offer a holistic view on the product life cycle in production networks

Development of an Approach for a "Cross Learning Factory Product Production System" for Circular Economy

Circular economy aims to support reuse and extends the product life cycles through repair, remanufacturing, upgrades and retrofits, as well as closing material cycles through recycling. To successfully manage the necessary transformation processes to circular economy, manufacturing enterprises rely on the competency of their employees. The definition of competency requirements for circular economy-oriented production networks will contribute to the operationalization of circular economy. The International Association of Learning Factories (IALF) statesin its mission the development of learning systems addressing these challenges for training of students and further education of industry employees. To identify the required competencies for circular economy, the major changes of the product life cycle phases have been investigated based on the state of the science and compared to the socio-technical infrastructure and thematic fields of the learning factories considered in this paper. To operationalize the circular economy approach in the product design and production phase in learning factories, an approach for a cross learning factory network (so called "Cross Learning Factory Product Production System (CLFPPS)") has been developed. The proposed CLFPPS represents a network on the design dimensions of learning factories. This approach contributes to the promotion of circular economy in learning factories as it makes use of and combines the focus areas of different learning factories. This enables the CLFPPS to offer a holistic view on the product life cycle in production networks