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Particle and Gaseous Emissions of Diesel Engines Fuelled by Different Non-Esterified Plant Oils
(2007)
The particulate matter and gas emissions of several plant oils are analyzed in the hot exhaust gas under various engine conditions at different speeds and loads The measurement data are compared to the emission values of conventional diesel fuel (gas oil). The investigation concentrates on a modern common rail TDI light duty diesel, four cylinders, for passenger cars. The differences in the gas and particulate matter emission - compared to conventional diesel fuel - are remarkably low for the diesel engine which is properly adjusted for the plant oils. Emission data of an old heavy duty diesel engine are also shown for comparison reasons and reveals large differences. Differences are found in the pressures of the indicator diagram, time resolved over the crank angle. Plant oils consistently exhibit a higher cylinder pressure. The TEM investigation confirms the differences found by the LPME (long path multi-wavelength extinction) on-line analysis.
Solartechnik
(2007)
Energietechnik
(2007)
Dieses Lehrbuch vermittelt dem Leser anschaulich ein solides, grundlegendes Verständnis für die Zusammenhänge der Energieumwandlungsprozesse. Es umfasst die gesamte Bandbreite der Energietechnik, angefangen bei den Grundlagen der Energie-Verfahrenstechnik über die Beschreibung ausgeführter aktuellster Anlagen (aller Kraftwerkstypen) bis zur Energieverteilung und -speicherung. Schwerpunkte sind regenerative/nachhaltige Energietechniken, Kombianlagen (z. B. Gas- und Dampfturbinen-Kraftwerke) und Anlagen mit Kraft-Wärme-Kopplung (z. B. BHKW).
Neu aufgenommen wurden das Kapitel Kyoto-Protokoll sowie Konzepte zu emissionsfreien Kohlekraftwerken. Das Kapitel zur Liberalisierung der Energiemärkte erfuhr eine neue Fassung. Zahlreiche Verbesserungen an Texten und Bildern wurden eingearbeitet.
Auf Grund des didaktischen Konzepts ist dieses Buch nicht nur Studierenden zu empfehlen, sondern auch jedem, der an aktuellen Fragestellungen zur Energietechnik interessiert ist.
In-situ densitometry for qualitative or quantitative purposes is a key step in thin-layer chromatography (TLC). It is a simple means of quantification by measurement of the optical density of the separated spots directly on the plate. A new scanner has been developed which is capable of measuring TLC or HPTLC (high-performance thin-layer chromatography) plates simultaneously at different wavelengths without damaging the plate surface. Fiber optics and special fiber interfaces are used in combination with a diode-array detector. With this new scanner sophisticated plate evaluation is now possible, which enables use of chemometric methods in HPTLC. Different regression models have been introduced which enable appropriate evaluation of all analytical questions. Fluorescent measurements are possible without filters or special lamps and signal-to-noise ratios can be improved by wavelength bundling. Because of the richly structured spectra obtained from PAH, diode-array HPTLC enables quantification of all 16 EPA PAH on one track. Although the separation is incomplete all 16 compounds can be quantified by use of suitable wavelengths. All these aspects are enable substantial improvement of in-situ quantitative densitometric analysis.
The identification and quantification of compounds in the gas phase becomes of increasing interest in the context of environmental protection, as well as in the analytical field. In this respect, the high extinction coefficients of vapours and gases in the ultraviolet wavelength region allow a very sensitive measurement system. In addition, the increased performance of the components necessary for setting up a measurement system, such as fibres, light sources and detectors has been improved. In particular the light sources and detectors offer improved stability, and the deep UV performance and solarisation resistance of fused silica fibres allow have been significantly optimized in the past years. Therefore a compact and reliable detection system with high measuring accuracy is developed. Within this paper possible applications of the system under development and recent results will be discussed.
The identification and quantification of compounds in the gas phase becomes of increasing interest in the context of environmental protection, as well as in the analytical field. In this respect, the high extinction coefficients of vapours and gases in the ultraviolet wavelength region allow a very sensitive measurement system. In addition, the increased performance of the components necessary for setting up a measurement system, such as fibres, light sources and detectors has been improved. In particular the light sources and detectors offer improved stability, and the deep UV performance and solarisation resistance of fused silica fibres allow have been significantly optimized in the past years. Therefore a compact and reliable detection system with high measuring accuracy is developed. Within this paper possible applications of the system under development and recent results will be discussed.
Soot particles emitted from a light duty (LD) Volkswagen diesel engine running at different operating points (speed and torque levels) are analyzed for mean size determination using a laser‐based three Wavelength Extinction Method (3‐WEM). For this reason, collected soot samples are suspended using an appropriate sample preparation technique with optimized conditions of sonication as it revealed its effect on the soot mean particle size measured by 3‐WEM.
An online Scanning Mobility Particle Analyzer (SMPS) is also used to measure soot emission at identical engine operating points. Size values obtained from SMPS are lower than those of suspended soot samples obtained from 3‐WEM. The size discrepancies are mainly related to the required sample preparation procedure employed for 3‐WEM measurements. The engine operating points affect, differently, the size measurements obtained from SMPS and 3‐WEM.
Sedimentation Field‐Flow Fractionation (SdFFF) is used for density determination of soot samples based on size measurements of fractions collected at peak maxima of fractograms using the off‐line hyphenation with 3‐WEM. It is assumed that a size dependent separation of soot particles occurred with a uniform particle density over the whole size distribution. An average density value is used for the conversion of soot fractograms to size distributions. Discrepancies are also found with size distribution profiles obtained from SMPS for the same engine operating points, due to the sample preparation procedure employed for SdFFF measurements.
In this paper a practical way for fatigue life prediction of rubber products under multiaxial loads is shown. This is done by means of fracture mechanical concepts and the energy release rate as the failure criterion. Due to a FEA post-processor the potential energy release rate might be calculated at every material point supposed there was a crack. And therefore the risk of failure and with the help of a strain number curve the time to fatigue is able to be calculated by FEA. This concept is applied for an estimation of the life time of a test specimen with tensile loading from fatigue data of a shear loaded specimen of different design. This rather more theoretical concept of the energy release rate is complemented by experimental crack growth data by a Tear Fatigue Analyzer with its great advantage of reduction of testing time and costs compared to those of fatigue tests. For some materials a thorough characterization of crack growth and fatigue behavior is presented and is applied to estimate the time to fatigue by FEA for a real component under multiaxial loads.
Der Gesetzgeber verfolgt mit dem Gesetz über den Vorrang Erneuerbarer Energien (EEG) anders als die Vorläuferregelung das Ziel, den Anteil Erneuerbarer Energien an der Stromversorgung deutlich zu erhöhen. Unternehmen mit einem hohen Strombedarf sind von den damit verbundenen Kosten besonders betroffen.
Durch die Besondere Ausgleichsregelung des § 16 EEG sollen die Stromkosten von privilegierten Unternehmen mit einem hohen Strombedarf reduziert werden. Sie können unter bestimmten Voraussetzungen weitgehend von den durch die Vergütung des EEG entstehenden Kosten befreit werden.
Der nachfolgende Beitrag verdeutlicht am Beispiel von Unternehmen des produzierenden Gewerbes, dass dieses Regelungsziel für neu gegründete Unternehmen nachhaltig verfehlt wird. Entgegen der Ankündigung des Bundesumweltministeriums ist davon auszugehen, dass auch die geplante Novellierung des EEG diesbezüglich keine geeignete Abhilfe schaffen wird.
The authors present an abiotically catalyzed glucose fuel cell and demonstrate its application as energy harvesting power source for a cardiac pacemaker. This is enabled by an optimized DC-DC converter operating at 40 % conversion efficiency, which surpasses commercial low-power DC-DC converters. The required fuel cell surface area can thus be reduced from about 125 cm2 to 18 cm2, which would allow for its direct integration onto the pacemaker casing.
Having 22 GW of nominal power installed Germany is the leading nation in wind energy conversion. While the number of suitable installation sites ashore is limited, and the average windspeed and thus the utilization level offshore is significantly higher, more and more offshore wind farms are planned. In order to reduce the cost of building the foundations and of connecting the wind turbines to the power grid, the single plant is designed as powerful as possible and therefore the components become huge and weighty. For instance: In order to lift the nacelle with around 500 tons of weight up on the tower - which can be up to 120 m above the water level - at the time special ships and cranes are designed and built. But those firstly will be very expensive and secondly will be available only on a limited scale. Hence the installation cost of those huge wind turbines significantly influence the rentability of a wind farm. Against this background a joint research project supported by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) was started comprising the project partners Ed. Züblin AG, Berg-idl GmbH (an engineering company and a maker of special purpose machines in Altlußheim, Germany), the IPEK (institute for product development) at the university of Karlsruhe and the Hochschule Offenburg, university of applied science. Project target is the conceptual design of a heavy-duty elevator, which can be used to install the tower segments and the nacelle of a wind turbine offshore without a crane. The most relevant challenges in this context result of holding up extreme loads by means of comparatively filigree carrying structures. The paper shows some examples of structural analysis and optimization work accomplished during the project. For the structural analysis of the heavy loaded components ANSYS workbench was used. The development process was also supported by optimization tools like TOSCA and OPTIMUS. The linking of the FE solver and the optimizer provides important hints concerning improvement of the topology and the dimensions of the components. Examples of designs illustrate the development process and the methods applied.
Beim vorliegenden EnBau-Forschungsvorhaben sollte im Rahmen des ENOB-Förderprogramm ein Langzeitmonitoring des Neubauvorhabens Solar Info Center Freiburg (SIC) mit folgenden Untersuchungsschwerpunkten durchgeführt werden:
• Natürliche Klimatisierung mit Nachtlüftung und Einzelanbindung der Büroflächen
• Erdsondenkühlung für Seminarraum und Foyer
• Zonenweise Abschaltung und Optimierung des Heizbetriebs
• Optimierung Lüftungsbetrieb
• Sonnenschutzanlagen
• Analyse Stromverbrauch / Gesamtenergiebilanz
• Bedarfsanalyse der Nutzer
• Erstellung einer „Betriebsanleitung“ für das Gebäude
• Kurzzeitmessungen
• Gebäudeautomation
Die gesamte Projektlaufzeit wurde auf drei Jahre angesetzt die Datenerfassung für das Monitoring sollte dabei mindestens 2 Jahre betragen.
Im Rahmen einer Master Thesis wurde ausgehend von einem vorhandenen System On Chip Design, welches eingehende EKG-Datensignale verarbeitet, das bestehende System so erweitert dass es komplett über den standardisierten SPI-Bus steuerbar und auslesbar ist.
Große Solaranlagen
(2008)
Während solare Kleinanlagen (bis 30m² Kollektorfläche) zur Trinkwassererwärmung und Heizungsunterstützung weitgehend standardisiert und weit verbreitet sind, besteht bei Großanlagen, speziell bei den nicht ausschließlich zur Trinkwassererwärmung genutzten Anlagen, noch Entwicklungsbedarf. Eine Standardisierung der Anlagen ist in diesem Bereich auch nur bedingt möglich, da die Voraussetzungen für die Einbindung solcher Anlagen, insbesondere in bestehende Heizungsanlagen, sehr unterschiedlich und dementsprechend individuelle Anpassungen notwendig sind.
Trotzdem finden solare Großanlagen in vielen Fällen Anwendung. Neben der bereits erwähnten Nutzung zur Warmwasserbereitung werden sie heute auch als Kombianlagen zur zusätzlichen Heizungsunterstüzung, in Wärmenetzen, zur Kälteerzeugung mittels thermischer Kältemaschinen und zur Bereitstellung von Prozesswärme eingesetzt.
Die Anlagentypen unterscheiden sich zum einen in der hydraulischen Verschaltung und in den Bedingungen, unter denen die Solaranlage betrieben wird. Bei Trinkwasseranlagen sind zudem hygienische Vorkehrungen zu treffen, um ein Legionellenwachstum zu vermeiden. Ein bedeutender Unterschied ist außerdem das Temperaturniveau, bei dem die Solaranlagen betrieben werden müssen. Bei allen Anlagentypen sind zum Ausgleich des zeitlichen Versatzes von Solarertrag und Wärmeverbrauch Solarspeicher notwendig. Diese können bei Anlagen zur solaren Raumklimatisierung (Kühlung) kleiner ausfallen, da der größte Leistungsbedarf zeitlich nahezu mit der größten solaren Leistung zusammenfällt.
Grundzüge der Strömungslehre
(2008)
Dieses erfolgreiche, didaktisch ausgereifte Lehrbuch wurde zuletzt fachlich in der Gasdynamik, der Behandlung des Verdichtungsstoßes und bei den verlustbehafteten Strömungen ergänzt. Außerdem wurde der allgemeine Energiesatz aufgenommen. Das Buch zeichnet sich durch eine prägnant kurze, mathematisch verständliche und anwendbare Einführung in die Grundlagen aus und gibt dem Leser Gelegenheit, sein Verständnis durch Übungen zu vertiefen. Die 7. Auflage enthält einige Verbesserungen bei Abbildungen und die Berichtigung von Druckfehlern in Text- und Formelsatz. Das Literaturverzeichnis wurde ergänzt und aktualisiert.
HPTLC on amino plates, with simple heating of the plates for derivatization, has been used for quantification of glucosamine in nutritional supplements. On heating the plate glucosamine reacts to form a compound which strongly absorbs light between 305 and 330 nm, with weak fluorescence. The reaction product can be detected sensitively either by absorption of light or by fluorescence detection. The detection limit in absorption mode is approximately 25 ng per spot. In fluorescence mode a detection limit of 15 ng is achievable. A calibration plot for absorption detection is linear in the range 25 to 4000 ng glucosamine. The derivative formed from glucosamine by heating is stable for months, and the relative standard deviation is 1.64% for 600 ng glucosamine. The amounts of glucosamine found in nutritional supplements were in agreement with the label declarations.
We present an improved quantification method for urethane found in spirits. The quantification is based on a derivatization reaction using cinnamaldehyde in combination with phosphoric acid. Measurements were carried out in the wavelength range from 445 to 460 nm using a diode-TLC device. An LED was used for illumination purposes. It emits very dense light at 365 nm. The quantification range of urethane is in the lower ng range. By applying 20 µL of sprits, the urethane quantification range is from 320 µg/L to 8.1 mg urethane per litre of spirit. The range of linearity covers nearly two magnitudes. The method is cheap, fast and reliable, and is able to monitor all European legislation limits without time-consuming sample pre-treatments.
The efficiency of a chromatographic analytical method is determined by the selectivity of the chromatographic separation and the specificity of the detection method. In high-performance thin-layer chromatography (HPTLC) the separated components can be detected and quantified directly on the plate by physical and chemical methods. By coupling high-performance thin-layer chromatography with biological or biochemical inhibition tests it is possible to detect toxic substances in situ.
Plant oils may be used as a sustainable, nearly CO2neutral fuel for diesel engines. This work investigates experimentally the particulate and gaseous emissions of diesel engines fuelled with different non-esterified, pure plant oils. The data are collected from three engines: a) Common rail 1.7 liter passenger car engine from Opel AG b) 12.8 liter truck engine from VOLVO c) Truck engine from MAN AG.
The emissions of the MAN engine have been used to perform AMES tests to analyze possible health impacts of plant oil operation. Finally, all emission results with plant oils have been compared to traditional gas oils.
Im Fahrzeug stehen große Wärmeströme zur Verfügung, die nicht genutzt werden. Die Energie des Abgases weist gegenüber der des Motor/Kühlsystems eine wesentlich höhere Arbeitsfähigkeit auf. Untersuchungen zielen dahin, diese thermische Energie zum Beispiel mithilfe eines thermoelektrischen Generators wieder in das System einzukoppeln und als Energiequelle für Verbraucher zu nutzen.
Grundkurs Regelungstechnik
(2009)
Komprimierte, mathematisch ausgerichtete Einführung in Grundlagen der Regelungstechnik für Studierende der Ingenieurwissenschaften an Fachhochschulen und Universitäten. Neuausgabe von "Kompaktkurs Regelungstechnik" (ID 17/02), die um ca. 50 Seiten erweitert (Abschnitt über betriebliche Systeme) und durchgehend aktualisiert wurde. Ist jetzt auf Bachelorstudiengänge ausgerichtet und enthält zahlreiche Übungsaufgaben und durchgerechnete Beispiele. Die alte Ausgabe sollte ersetzt werden.
Zur Messung geringer Massenkonzentrationen und der Partikelgrößenverteilung unter hohen Druck- und Temperaturbedingungen, wie sie z.B. bei Überwachung des Gasstromes in Druckwirbelschichtfeuerungen oder in Druckkohlestaubfeuerungen vorkommen, wird ein kompensiertes Streulichtfotometer vorgeschlagen. Streulicht- und Transmissionswerte des Partikelkollektivs werden erfasst und miteinander verknüpft. Als Vorteil dieses Mess- und Auswerteprinzips ergibt sich im Gegensatz zu konventionellen Fotometern eine weitgehende Unempfindlichkeit gegenüber Fenster-Verschmutzung und Alterung von Komponenten. Das neue Konzept ist bis etwa 900 ºC einsatzfähig.
There are additional long-term effects which also change the micro-structure of the polymer network and consequently the effective number of polymer chains in the material. These effects are summarized by ageing processes and will be used in the following to explain the basic assumptions of the model which can be generalized to simulate the viscous behaviour of the material. An implementation of these concepts into FEM codes is straightforward and has been carried out to the solver ABAQUS, Baaser & Ziegler (2006), Baaser et al. (2009).
An interlaboratory comparison was carried out to evaluate the effectiveness of a method based on HPTLC in which reagent-free derivatization is followed by UV/fluorescence detection. The method was tested for the determination of sucralose (C12H19C13O8; (2R,3R,4R,5S,6R)-2-[(2R,3S,4S,5S)-2,5-bis(chloromethyl)-3,4-dihydroxyoxolan-2-yl]oxy-5-chloro-6-hydroxymethyl)oxane-3, 4-diol; CAS Registry No. 56038-13-2) in carbonated and still beverages at the proposed European regulatory limits. For still beverages, a portion of the sample was diluted with methanol-water. For carbonated beverages, a portion of the sample was degassed in an ultrasonic bath before dilution. Turbid beverages were filtered after dilution through an HPLC syringe filter. The separation of sucralose was performed by direct application on amino-bonded (NH2) silica gel HPTLC plates (no cleanup needed) with the mobile phase acetonitrile-water. Sucralose was determined after reagent-free derivatization at 190 degrees C; it was quantified by measurements of both UV absorption and fluorescence. The samples, both spiked and containing sucralose, were sent to 14 laboratories in five different countries. Test portions of a sample found to contain no sucralose were spiked at levels of 30.5, 100.7, and 299 mg/L. Recoveries ranged from 104.3 to 124.6% and averaged 112% for determination by UV detection; recoveries ranged from 98.4 to 101.3% and averaged 99.9% for determination by fluorescence detection. On the basis of the results for spiked samples (blind duplicates at three levels), as well as sucralose-containing samples (blind duplicates at three levels and one split level), the values for the RSDr ranged from 10.3 to 31.4% for determinations by UV detection and from 8.9 to 15.9% for determinations by fluorescence detection. The values for the RSDR values ranged from 13.5 to 31.4% for determinations by UV detection and from 8.9 to 20.7% for determinations by fluorescence detection.
Für die solarunterstützte CO2-neutrale Nahwärmeversorgung des Neubaugebiets Hülben in Holzgerlingen wurden Holzpelletskessel mit einer 249m²-großen Solaranlage kombiniert. Im ersten Intensivmessjahr vom 01.03.2007 bis 29.02.2008 wurde eine Gesamt-Wärmeabgabe ins Nahwärmenetz von 920.606 kWh gemessen, wobei der solare Anteil bei 84.033 kWh lag. Es wurden ein Systemnutzungsgrad von 23,8 % und ein solarer Deckungsanteil von 9,5% gemessen. Die vom Lieferanten abgegebene Energiegarantie wurde in der ersten Intensivmessphase nicht erreicht.
Kühlen mit Wärme
(2009)
Die Hochschule Offenburg begleitet seit Juli 2006 in Zusammenarbeit mit dem Fraunhofer ISE in Freiburg, die solar unterstützte Klimatisierung der Festo AG & Co. KG in Esslingen im Rahmen des Forschungsvorhabens Solarthermie2000plus. Dabei wurde die bereits bestehende Adsorptionskälteanlage, die bisher mit Gaskesseln und Kompressorenabwärme betrieben wurde, durch eine Solaranlage als dritte Wärmequelle ergänzt.
Non-Esterified Plant Oils as Fuel -Engine Characteristics, Emissions and Mutagenic effects of PM-
(2009)
Plant oils may be used as a sustainable, nearly CO2 neutral fuel for diesel engines. This work investigates experimentally the particulate and gaseous emissions of diesel engines fuelled with non-esterified, pure plant oils with the quality standard of DIN V 51605 (Weihen-stephan RK-Qualitätsstandard 05/2000). The data are collected from three engines:
Common rail passenger car engine from OPEL AG
Truck engine from VOLVO
Truck engine from MAN AG
All engines have been correctly adjusted to plant oil operation.
The OPEL and VOLVO engines served for the basic investigations. The emissions of the MAN engine have been used to perform AMES tests to analyze possible health impacts of plant oil operation.
The experimental data show a reduction of particulate matter compared to traditional gasoil which may yield up to 50 % for. The particulate matter shows same primary particle sizes but the agglomerates as collected on TEM grids are different - the plant oil soot particles tend to form larger aggregates [4]. The gaseous emissions of CO and hydrocarbons HC are generally lower compared to the operation with gasoil. However, the NOX emissions are slightly higher. This may be contributed to the measured higher combustion chamber pressures and temperatures when fuelled by plant oils.
Emission samples have been extracted from ESC cycles of 13 step tests to perform the AMES test which give indication on carcinogen substances. The AMES test results gave no indication of mutagenic effects exceeding the detection limits. No significant differences could be found comparing the emissions of plant oil and gasoil operation. Thus, it can be stated that the emission from plant oil operation does not have a health impact different to traditional gas oil. This is in contrast to some other publications — a deeper insight shows that these investigations did not properly modify the engine for plant oils. It is mandatory to make the engine modification to pre-warm the plant oils to approx. 90°C prior to injection. The engine's warm-up phase needs special care to avoid any coking at the injection system and combustion chamber surfaces. The publications where a higher health risk was claimed to be found in the exhaust of plant oil fuels, did not pre-warm the plant oils — cold plant oils have been injected in the combustion chamber instead. This results in incomplete atomization and incomplete combustion with a lot of hazardous emission species (see also [4,11]. Such an operation will damage the engine after relatively short times and is, therefore, not realistic.
The investigated fuels had some influence on the engine characteristics. Higher temperatures and pressures in the cylinder have been detected for some plant oils compared to gasoil. This increase is explained by the higher oxygen content within the plant oils.
After approximately 200 years, a comprehensive access to the texts of Humboldt's extraordinary exploration of the Americans is within sight. To open the legacy to the public for free access the Humboldt Digital Library (HDL) Project has been developing a dynamic amount of data related to studies of Alexander von Humboldt. The Library includes a range of texts, tables and images, as well as many tools that assist mining the data and navigating the system.
The HDL aims to provide an environment in which researchers can work more effectively with a wider variety of primary source materialsùtextual as well as visual. Moreover, the greatest advantage of this dynamic system is its capability to connect data from diverse locations in Humboldt's twenty-nine volumes and allow comparison with modern scientific knowledge and developments.
HDL can recreate the context of a particular text, making it possible to view images, geo-referenced and interactive maps, information about plants and animals, as well as scientific data relevant to Humboldt's observations. By introducing Web 2.0 technology implementations, we are providing new visualizations of the information published in this Digital Library. The perception of the Information Architecture is changing in the era of Web 2.0. By providing more search facilities, creating an academic network around our library and implementing new ways of multi-dimensional navigation we argue that Information Architecture can be extended to new methods of information representation. Facilitating the user navigation to the required information will always be an aim for the managers of high volume data systems. This can be achieved by implementing Information Retrieval modules based on user profiling and by improving the visualization features.
Geothermal Energy in Germany
(2009)
Energietechnik
(2009)
Dieses Lehrbuch vermittelt dem Leser ein grundlegendes Verständnis für die Zusammenhänge der Energieumwandlungsprozesse. Es umfasst die gesamte Bandbreite der Energietechnik. Die Schwerpunkte reichen von nachhaltigen, erneuerbaren Energietechniken, Kombianlagen (z. B. Gas- und Dampfturbinen-Kraftwerke) über Anlagen mit Kraft-Wärme-Kälte-Kopplung bis hin zum Kyoto-Protokoll. Die 4. Auflage beinhaltet erstmals Übungsaufgaben mit ausführlichen Lösungen zu den einzelnen Kapiteln. Mehrere Kapitel sind aktualisiert. Das Kapitel 18 „Liberalisierung der Energiemärkte“ ist neu gefasst.
Hydrogen chloride and sulphur dioxide are gaseous by-products of chloridization processes that employ thionyl chloride. Absorption would be a feasible method to clean the rich gas stream. Two serial connectable absorption columns were equipped with the latest generation of packings to effect product recovery. Therefore, several tests concerning the baffle properties had to be performed. In the first experimental section, the hydraulic parameters pressure drop and hold-up were investigated. The hold up value range of the new baffles Raschig Super Ring (RSR) and Raschig Super Pak (RSP) was clearly below that of the former installed packing, Raschig Ring (RR). However, due to the low maximal flow rate, the range of stagnation and flooding could not be measured. The maximal measured pressure drop value was, for RR, only 0.3 mbar/m, which is very low compared to the measurement error. Batch experiments, where the waste gases were produced by reaction of thionyl chloride in water, showed that for the steady state determination of the separation steps it is advisable to use just one column in simplex mode with a defined gas supply by a gas cylinder. The HTU determination for RSR and a HCl/H2O system delivered a value of HTUHCl,OG = 0.14 ± 0.01 m with a variation coefficient of 24.2%.
Flows in nature and technology are often associated with specific structures and pattern. This paper deals with the development and behaviour of such flow pattern. Flow structures are important for the mass, momentum and energy transport. The behaviour of different flow pattern is used by engineers to obtain an efficient mass and energy consumption. Mechanical power is transmitted via the momentum of rotating machine parts. Therefore the physical and mathematical knowledge of these basic concepts is important. Theoretical and experimental investigations of principle experiments are described in the following. We start with the classical problem of the flow between two concentric cylinders where the inner cylinder rotates. Periodic instabilities occur which are called Taylor vortices. The analogy between the cylindrical gap flow, the heat transfer in a horizontal fluid layer exposed to the gravity field and the boundary layer flow along concave boundaries concerning their stability behaviour is addressed. The vortex breakdown phenomenon in a cylinder with rotating cover is also described. A generalization to spherical sectors leads then to investigations with different boundary conditions. The spherical gap flow exhibits interesting phenomena concerning the nonlinear character of the Navier-Stokes equations. Multiple solutions in the nonlinear regime give rise to different routes during the laminar-turbulent transition. The interaction of two rotating spheres results in flow structures with separation and stagnation lines. Experimental results are confirmed by numerical simulations.
We report improved separation of the highly toxic contact herbicides paraquat, diquat, difenzoquat, mepiquat, and chloromequat by HPTLC. Quantification was based on a new derivatization reaction using sodium tetraphenylborate. Measurements were in the wavelength range from 440 to 480 nm or from 440 to 590 nm. An LED emitting very intense light at 365 nm was used for excitation. The quantification limits of paraquat and diquat in water, using improved solid-phase extraction, was in the low ng L −1 range. The linear range covered more than two orders of magnitude. Recovery was investigated for all the compounds, and was insufficient, ranging from 11 to 92%, but the method is inexpensive, rapid, and works reliably.
A diode array HPTLC method for dequalinium chloride in pharmaceutical preparations is presented. For separation a Nano TLC silica gel plate (Merck) is used with the mobile phase methanol-7.8% aqueous NH(4)(+)CH(3)COO(-) (17:3, v/v) over a distance of 6 cm. Dequalinium chloride shows an R(F) value of 0.58. Pure dequalinium chloride is measured in the wavelength range from 200 to 500 nm and shows several by-products, contour plot visualized in absorption, fluorescence and using the Kubelka-Munk transformation. Scanning of a single track in absorption and fluorescence measuring 600 spectra in the range from 200 to 1100 nm takes 30s. As a sample pre-treatment of an ointment it is simply dissolved in methanol and can be quantified in absorption from 315 to 340 nm. The same separation can also be quantified using fluorescence spectrometry in the range from 355 to 370 nm. A new staining method for dequalinium chloride, using sodium tetraphenyl borate/HCl in water allows a fluorescence quantification in the range from 445 to 485 nm. The linearity range of absorption and fluorescence measurements is from 10 to 2000 ng. Sugar-containing preparations like liquids or lozenges with a reduced sample pre-treatment can be reliably quantified only in fluorescence. The total for the quantification of an ointment sample (measuring four standards and five samples), including all sample pre-treatment steps takes less than 45 min!
Today, thermoforming moulds are mostly produced using conventional mould-building technologies (e.g. milling and drilling) and are made of metal (e.g. aluminium or steel) or hardwood. The tools thus produced are very robust, but are only cost-effective in mass production. For the production of small batches of thermoformed parts, there is a need for moulds which can be produced quickly and economically. A new approach which significantly reduces the production time and cost is the 3D printing process (3DP). The use of this technology to produce thermoforming moulds offers many new options in the geometries which can be manufactured, and in manufacturing time and costs. In a case study of a thermoformed part (a scaled automotive model), the pre-processing of the CAD model of a mould is demonstrated. The mould can be printed within a few hours, and is sufficiently heat-resistant for moulding processes. The important advantages of moulds printed in 3D, in comparison to moulds built using conventional technologies, are the ability to create any shape of channels for the vacuum and the simplification in the production of tool mock-ups. This paper also discusses the economics of the technique, such as a comparison of material costs and manufacturing costs in relation to conventional production technologies and materials.
Prädiktive Betriebsverfahren
(2010)
Durch die Nutzung von Wetterprognosen lässt sich der Betrieb moderner Bürogebäude hinsichtlich Energiebedarf und Komfort verbessern. Ziel dieses Vorhabens ist es, mathematische Optimierungsverfahren für die Nutzung in der Gebäudeautomation zu entwickeln. Die Entwicklung einer vom Internet unabhängigen Versorgung mit Wetterprognosen über einen Langwellensender ist ebenfalls Gegenstand des Forschungsprojekts.
BioPower
(2009)
Das Projekt BioPower ist eine Kooperation des Instituts für Angewandte Forschung (IAF) der Hochschule Offenburg mit dem Institut für Mikrosystemtechnik (IMTEK) der Universität Freiburg. Es handelt sich um den Versuch, die im Körper vorhandenen Energiequellen sozusagen direkt anzuzapfen, um sie für technische Zwecke zu nutzen. Von den vielen bestehenden Möglichkeiten konzentriert sich die Forschung hier auf die Nutzung der Glukose im Blut, die auch sonst als Energieträger zur Versorgung der Zellen im Körper dient.
Systemtechnik
(2010)
Kühlen im großen Stil
(2010)
Die Hochschule Offenburg begleitet seit Juli 2006 in Zusammenarbeit mit dem Fraunhofer ISE in Freiburg und der HfT Stuttgart die solar unterstützte Klimatisierung der Festo AG & Co. KG in Esslingen. Die Anlage wurde im Rahmen des Forschungsvorhabens „Solarthermie2000plus“ vom Bundesumweltministerium gefördert. Dabei wurde die bereits bestehende Adsorptionskälteanlage, die bisher mit Kompressorabwärme und Gaskesseln betrieben wurde, durch eine Solaranlage als drittem Wärmelieferanten ergänzt.
Mit dem Wetter sparen
(2010)
Energietechnik
(2010)
Dieses Lehrbuch vermittelt dem Leser ein grundlegendes Verständnis für die Zusammenhänge der Energieumwandlungsprozesse. Es umfasst die gesamte Bandbreite der Energietechnik. Die Schwerpunkte reichen von nachhaltigen, erneuerbaren Energietechniken, Kombianlagen (z. B. Gas- und Dampfturbinen-Kraftwerke) über Anlagen mit Kraft-Wärme-Kälte-Kopplung bis hin zum Kyoto-Protokoll.
In der fünften Auflage wurden neue Trends in der Energietechnik eingearbeitet. Das Kapitel Windkraftanlagen wurde um Off-Shore-Anlagen ergänzt, das Kapitel Kernenergie wurde überarbeitet und erhielt den neuen Schwerpunkt Reaktorsicherheit.
Synthesis and crystal structure of a novel copper-based MOF material are presented. The tetragonal crystal structure of [ ∞ 3 ( Cu 4 ( μ 4 -O ) ( μ 2 -OH ) 2 ( Me 2 trz p ba ) 4 ] possesses a calculated solvent-accessible pore volume of 57%. Besides the preparation of single crystals, synthesis routes to microcrystalline materials are reported. While PXRD measurements ensure the phase purity of the as-synthesized material, TD-PXRD measurements and coupled DTA–TG–MS analysis confirm the stability of the network up to 230 °C. The pore volume of the microcrystalline material determined by nitrogen adsorption at 77 K depends on the synthetic conditions applied. After synthesis in DMF/H2O/MeOH the pores are blocked for nitrogen, whereas they are accessible for nitrogen after synthesis in H2O/EtOH and subsequent MeOH Soxhleth extraction. The corresponding experimental pore volume was determined by nitrogen adsorption to be V Pore = 0.58 cm 3 g - 1 . In order to characterize the new material and to show its adsorption potential, comprehensive adsorption studies with different adsorptives such as nitrogen, argon, carbon dioxide, methanol and methane at different temperatures were carried out. Unusual adsorption–desorption isotherms with one or two hysteresis loops are found – a remarkable feature of the new flexible MOF material.
Thin-layer chromatography is a rapid and reliable working method for quantification of mycotoxins which is suitable for checking EC legislation aflatoxin limits for dried figs without an RP-18 pre-column cleaning step. We describe normal-phase chromatography on silica gel plates with 2.4:0.05:0.1:0.05 ( v/v ) methyl t -butyl ether-water-methanol-cyclohexane as mobile phase and reversed-phase chromatography on RP-18 plates with methanol-4% aqueous ZnSO 4 solution-ethyl methyl ketone 15:15:3 ( v/v ) as mobile phase. Sample pretreatment was by modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) extraction with tetrahydrofuran or acetone. NaCl was used as QuEChERS salt. Response was a linear function of amount chromatographed in the ranges 3 to 100 pg per zone for aflatoxins B 2 and G 2 , 10 to 350 pg per zone for the aflatoxins B 1 and G 1 , and 0.25 to 2.5 ng per zone for ochratoxin A. Quantification limits for the aflatoxins were between 13 and 35 pg per zone (equivalent to 1.5 and 2.4 ppb, taking the pre-treatment procedure into account). Ochratoxin A was detectable with a limit of quantification of 970 pg per zone, corresponding to 56 ppb in the sample. Normal phase and RP-18 separations work rapidly, reliably, and at low cost. They are also suitable for checking the content of the mycotoxins patulin, penicillic acid, zearalenone, and deoxynivalenol.
The engineering company Evomotiv GmbH and the University of Applied Sciences Offenburg have developed a drive concept for light city scooters since 2008. The electrical drive train's goal is the series production of the highly-integrated, non-transmission and non-ferrous wheel-hub motor. The German Federal Ministry of Economy and Technology (BMWi) supports this project. The concept of this wheel-hub motor was awarded with the Bosch-Innovation prize in 2006. In 2011 Evomotiv will test the first prototypes with its cooperation partners on the track.
High pressure adsorption phenomena are discussed for different gases on HKUST-1 (Cu3(BTC)2, commercially available product BasoliteTM C300). Sorption isotherms for hydrogen, nitrogen, methane and carbon dioxide on HKUST-1 were measured in the temperature range of 273–343 K and at pressures up to 50 MPa. The calculated surface excess adsorption capacities for all four adsorptive are one of the highest reported in the literature for HKUST-1 samples. All surface excess data were further calculated from the experimental data by using the helium buoyancy correction. A detailed description was given.
Also a procedure to calculate the absolute amount adsorbed from the surface excess amount by using two different models is shown. Using one model, the density and the volume of the adsorbed phase can be calculated. The density of the adsorbed phase ρads corresponds to the liquid density of the adsorptive at its boiling point ρliq,BP. In case of hydrogen no excess maximum was found up to 50 MPa, so that one model could not be applied. Finally, the isosteric heat of adsorption for each gas was calculated by using the Clausius–Clapeyron equation.
The series of conferences on Environmental Best Practices (EBP) was inaugurated at the University of Warmia and Mazury in Olsztyn, Poland in 2006 and continued at the Jagiellonian University in Kraków, Poland in 2009. This year the University of Applied Sciences Offenburg produly hosted the third event (EPB3).
Digital libraries are providing an increasing amount of data, which is normally structured in a classical way by documents and described by metadata as keywords. The data, even in scientific systems such as digital libraries and virtual research environments, will contain a great amount of noise or information unnecessary for our personal interests. Although there has been a lot of progress in the field of information retrieval, search techniques and other content finding methods, there is still much to be done in the field of information retrieval based on user behavior. This paper presents an approach deployed in the Humboldt Digital Library (HDL) to facilitate the retrieval of relevant information to the users of the system, making recommendations of paragraphs based on their profile and the behavior of other users who share similar profiles. The Humboldt digital library represents an innovative system of open access to the legacy of Alexander von Humboldt in a digital form on the Internet (www.avhumboldt.net). It contributes to the key question, how to present interconnected data in a proper form using information technologies.
The German Weather Service (DWD) releases a heat warning, when the weather forecast provides a warm, humid, sunny, and windless weather condition during the next days. The heat stress is calculated by the so called Klima-Michel model. If the apparent air temperature exceeds ca. 32°C / 38°C, there is a strong / extreme heat stress. The smallest forecast area is each administrative district. As people (and especially the vulnerable population) stay most of the time indoors, the heat health warning system was extended by the prediction of heat stress in typical rooms. Therewith it is feasible to forecast the heat stress using a combination of the outdoor and indoor heat stress. The prediction for the indoor heat stress is based on the same weather forecast like the Heat Health Warning Systems (HHWS).and calculates the heat stress by the PMV-model (predicted mean vote). Based on a sophisticated data analysis and simulation study, realistic but summer-critical living situations were defined and implemented in the building simulation program ESP-r. As the simulation runs especially for extreme weather conditions, a simplified building model cannot be used. Standardized input/output routines and an adaptive handover of start values provide for short run times for each forecast area. Good building designs and urban planning provide effective measures to reduce heat stress in cities. However, we have to also pay attention to the present building stock under climate change and a higher heat-wave risk. The extended German HHWS provide information for the emergency services to support the social assistants during heat waves.
This study presents some results from a monitoring project with night ventilation and earthto-air heat exchanger. Both techniques refer to air-based low-energy cooling. As these technologies are limited to specific boundary conditions (e.g. moderate summer climate, low temperatures during night, or low ground temperatures, respectively), water-based low-energy cooling may be preferred in many projects. A comparison of the night-ventilated building with a ground-cooled building shows major differences in both concepts.
Einblick in die deutsche TGA-Landschaft. Energietechniker der Hochschule Offenbach auf Exkursion
(2011)
Das Projekt Yaffa "Yeast Analysis by Field Flow Fractionation" ist ein Verbundprojekt der Hochschule Offenburg und der Hochschule Wiesbaden in Kooperation mit der Forschungsanstalt Geisenheim, der Université Limoges, mehreren Industriepartnern der Weinbaubranche sowie der Postnova Analytics GmbH. Ziel ist es, für die Weinherstellung ein praxistaugliches und wirtschafltiches Analyseverfahren mit Feldflussfraktionierung zu entwickeln. Das Analyseverfahren soll zur Qualitätsüberwachung des Weinfermetationsprozesses eingesetzt werden, wodurch z. B. Gärstörungen rechtzeitig erkannt und geeignete Gegenmaßnahmen eingeleitet werden können.
Mit gleichem kommunalem Mehrzweck-Fahrzeug (Abb. 1) wurden mehrere Fahrzyklen mit konventionellem Dieselantrieb und mit parallelem diesel-elektrischem Hybridantrieb simuliert. Aus den Ergebnissen der realen Fahrzyklen mit konventionellem Dieselmotorantrieb ließen sich die Kraftstoffeinsparpotenziale mit dem Hybridmotor und den verschiedenen Maßnahmen wie Start-Stopp, Rekuperation und Boost ermitteln. Selbst bei diesem Kommunalfahrzeug lassen sich Kraftstoffeinsparungen bis über 20 % nachweisen, obwohl die Fahrzyklen für Hybridanwendungen nicht besonders attraktiv sind. Deutlich höhere Potenziale liegen beispielsweise bei Gabelstaplern und Baumaschinen vor.
Das Ziel dieses Projekts ist die Entwicklung und Charakterisierung einer mikrobiellen Brennstoffzelle (MBZ). Die MBZ unterscheidet sich von einer herkömmlichen Brennstoffzelle darin, dass die an der Anode erzeugten Elektronen nicht vom molekularen Wasserstoff, sondern direkt von der im Anodenkompartiment wachsenden Biomasse aus organischen Verbindungen stammen. Die Funktionsweise einer solchen Zelle ist in Abbildung 3.4-1 dargestellt. Im Gegensatz zur herkömmlichen Brennstoffzelle können in einer MBZ auch Abwasserteilströme z. B. aus der Lebensmittelindustrie als Substrat eingesetzt werden. Der große Vorteil der MBZ besteht somit darin, dass Abwässer biologisch abgebaut und gleichzeitig elektrischer Strom erzeugt werden kann.