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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.
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.
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.
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%.
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!
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.
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.
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).