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Nachstehend wird der Wortlaut der Prüfungsordnung für den Masterstudiengang „Simulations- und Experimentaltechnik“ an der Hochschule Düsseldorf vom 17.06.2021 (Verkündungsblatt der Hoch-schule Düsseldorf, Amtliche Mitteilung Nr. 786) unter ihrer neuen Überschrift neu bekannt gemacht. Die Neubekanntmachung berücksichtigt die Erste Satzung zur Änderung der Prüfungsordnung für den Masterstudiengang „Simulations- und Experimentaltechnik“ an der Hochschule Düsseldorf vom 02.03.2022 (Verkündungsblatt der Hochschule Düsseldorf, Amtliche Mitteilung Nr. 829) sowie die Zweite Satzung zur Änderung der Prüfungsordnung für den Masterstudiengang „Simulations- und Ex-perimentaltechnik“ an der Hochschule Düsseldorf vom 14.02.2024 (Verkündungsblatt der Hochschule Düsseldorf, Amtliche Mitteilung Nr. 915).
Magnetic Resonance (MR) elastography is a method for measuring tissue elasticity via phase images acquired with an MR scanner. The propagation of periodic mechanical waves through the tissue can be captured by means of a modified phase contrast sequence. These waves are generated with a mechanical oscillator (actuator) and coupled into the tissue through the skin. The actuator must be capable of generating a sinusoidal excitation with excellent phase and amplitude stability, while not disturbing the MR imaging process. In this work, an actuator based on a piezoelectric principle was developed. Based on the imaging evaluation of several material samples, the housing for the piezoelectric ceramic was constructed of aluminum. Smaller parts of the housing were manufactured from brass and titanium to fulfill the mechanical constraints. A lever was used to transfer the oscillation generated by the piezoelectric ceramic to the point of excitation. The lever amplifies the piezoelectric motion, allowing for a more compact design. Three different lever designs were characterized by an acceleration sensor both outside and inside the magnet. It was shown that the rigidity of the lever, as determined by its material and form, was decisive in determining the resonant frequency of the system and therefore the maximum practical frequency of operation. It was also shown that the motion of the oscillator is unaffected by the electromagnetic fields of the MR imager. The final design can be placed directly in the magnet bore within a few centimeters of the tissue volume to be imaged without generating significant artifacts. An amplitude range of 0–1 mm in the frequency range from 0 to over 300 Hz was achieved, sufficient for performing most MR elastography applications. © 2002 Wiley Periodicals, Inc. Concepts in Magnetic Resonance (Magn Reson Engineering) 15: 239–254, 2002
Men afflicted with hypogonadism have reduced fat-free mass and in some cases a loss in muscle strength. We hypothesize that muscle elasticity of the lower extremities differs between patients with hypogonadism and healthy controls. The shear modulus of the soleus muscle was measured non-invasively using MR elastography (MRE) at 0%, 5%, 10%, 15%, and 20% of the subject’s maximum applied force. The results from this study showed statistical differences between the patients and controls, even though there were no statistical differences in applied force.
Men afflicted with chronic obstructive pulmonary disease (COPD) show signs of muscle dysfunction, such as increased muscle fatigue and acidosis during exercise. We hypothesize that muscle elasticity of the lower extremities differs between patients with COPD and age-related controls. The shear modulus of the soleus muscle was measured non-invasively using MR elastography (MRE) at 0%, 5%, 10%, 15%, and 20% of the subject’s maximum applied force. The results from this study showed statistical differences between the patients and controls, even though there were no statistical differences in the maximum applied force.
The Chylla–Haase polymerization reactor is widely accepted as a benchmark process for the evaluation of control strategies for batch reactors. In this contribution a control concept based on Exact I/O-Linearization is proposed and compared to a conventional cascade control structure. In order to adapt the exact linearization control strategy to various polymerization products and batch conditions, an advanced probabilistic inference algorithm (Sigma-Point Kalman Filter) is applied and investigated. Sigma-Point Kalman Filters have the major improvement of simplified implementation compared to local linearization methods (i.e. Extended Kalman Filter) because no analytical Jacobians are required. Stochastic simulation studies are introduced and show the effectiveness, accuracy and benefit of the control concept. Within several scenarios a satisfying robustness against structural errors in the underlying model equations for the nonlinear control law and the inference algorithm is demonstrated. Furthermore it is pointed out, that with little effort in reassembling the plant design, control performance can be improved significantly.
This article deals with the cost optimal commitment of power systems. System stability is often only considered after solving the commitment problem. We show by example that a cost optimization may result in a mode of operation that, while economically optimal, is unstable or has otherwise unacceptable dynamics. As a remedy, we propose to use the so-called normal vector method, which has been developed for the optimization of nonlinear dynamical systems with stability boundaries and uncertain parameters. We apply the method to a small sample power grid, where the optimization goal is to minimize the energy production costs for a given power consumption.
Stability and cost optimality of power generation and supply systems must not be considered independently from one another. Simple examples show that optimizing cost without considering stability may result in modes of operation that, while economically optimal, are unstable. We demonstrate that stability, robustness, and optimality can be considered systematically and simultaneously by combining bifurcation theory and nonlinear optimization. Essentially, the proposed method enforces a backoff distance between the optimal point of operation and operational or stability boundaries in the space of the optimization variables, where bifurcation theory is used to describe nonlinear stability boundaries.
We present a control scheme for a parabolic trough power plant that is equipped with a molten salt thermal energy storage system. We show that the multivariable control problem for the solar field can be decoupled by controlling the three way valve that splits the heat transfer fluid between the storage system and the steam generator. The steam generation cycle is regulated with inlet pressure control. The subsystems of the plant are modeled based on first principles, where we focus on the steam generation cycle. A multi-group extraction turbine with pre- and reheater is considered, which is suitable for solar power plants. We demonstrate the benefits of the proposed control scheme with a day-to-day simulation.
We derive a nonlinear model of the steam cycle of a solar power plant, estimate its unknown parameters with measured data, and design a linear model predictive controller based on the resulting model. Simulations show that the linear model predictive controller is able to regulate the electrical power of the nonlinear steam process of the plant to a given reference trajectory very well. Moreover, it results in very good disturbance rejection.
Aufgrund der §§ 2 Abs. 4 S. 1, 26 Abs. 3 S. 2 des Gesetzes über die Hochschulen des Landes Nord-rhein-Westfalen (Hochschulgesetz - HG) vom 16.09.2014 (GV. NRW. S. 547) in der aktuell gültigen Fassung und der Grundordnung der Hochschule Düsseldorf vom 08.10.2015 (Verkündungsblatt der Hochschule Düsseldorf, Amtliche Mitteilung Nr. 414) in der aktuell gültigen Fassung hat die Hoch-schule Düsseldorf die folgende Ordnung als Satzung erlassen.
Nachstehend wird der Wortlaut der Rahmenprüfungsordnung für den Fachbereich Maschinenbau und Verfahrenstechnik an der Hochschule Düsseldorf vom 15.02.2016 (Verkündungsblatt der Hochschule Düsseldorf, Amtliche Mitteilung Nr. 423) neu bekannt gemacht. Die Neubekanntmachung berücksichtigt die Erste Satzung zur Änderung der Rahmenprüfungsordnung für den Fachbereich Maschinenbau und Verfahrenstechnik an der Hochschule Düsseldorf vom 07.06.2016 (Verkündungsblatt der Hochschule Düsseldorf, Amtliche Mitteilung Nr. 456), die Zweite Satzung zur Änderung der Rahmenprüfungsordnung für den Fachbereich Maschinenbau und Verfahrenstechnik an der Hochschule Düsseldorf vom 15.11.2018 (Verkündungsblatt der Hochschule Düsseldorf, Amtliche Mitteilung Nr. 635) sowie die Dritte Satzung zur Änderung der Rahmenprüfungsordnung für den Fachbereich Maschinenbau und Verfahrenstechnik an der Hochschule Düsseldorf vom 18.02.2021 (Verkündungsblatt der Hochschule Düsseldorf, Amtliche Mitteilung Nr. 738).
Kohlendioxid, Biomasse und Regenerativer Strom - Ressourcen einer neuen Kohlenstoffwirtschaft?
(2017)
The synthesis of Nb-doped TiO2 nanoparticles by spray drying: an efficient and scalable method
(2011)
The rock material pentlandite with the composition Fe4.5Ni4.5S8 was synthesized via high temperature synthesis from the elements. The structure and composition of the material was characterized via powder X-ray diffraction (PXRD), Mössbauer spectroscopy (MB), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and energy dispersive X-ray spectroscopy (EDX). Two preparation methods of pentlandite bulk electrodes are presented. In the first approach a piece of synthetic pentlandite rock is directly contacted via a wire ferrule. The second approach utilizes pentlandite pellets, pressed from finely ground powder, which is immobilized in a Teflon casing. Both electrodes, whilst being prepared by an additive-free method, reveal high durability during electrocatalytic conversions in comparison to common drop-coating methods. We herein showcase the striking performance of such electrodes to accomplish the hydrogen evolution reaction (HER) and present a standardized method to evaluate the electrocatalytic performance by electrochemical and gas chromatographic methods. Furthermore, we report stability tests via potentiostatic methods at an overpotential of 0.6 V to explore the material limitations of the electrodes during electrolysis under industrial relevant conditions.
Cu–Co-based model catalysts were prepared by a sophisticated alkali-free synthesis method and tested in the conversion of synthesis gas to higher alcohols. MoO3-coated alumina was used as the support, providing both high specific surface area and strongly interacting sites for the deposition of the active metals. A bulk Cu/Co ratio of ~2 was found to be most suitable in terms of activity and product distribution. Surface enrichment of Mo for all samples was observed by XPS, which significantly influenced the performance of the catalysts. Mo was found to be both a structural and a chemical promoter. Strong metal–support interactions were further achieved by modification of alumina with magnesia. With 12 wt% Mg incorporated, the catalysts showed 40% total oxygenate selectivity including 11% selectivity to ethanol.
This paper investigates the implementation of a human body model for the simulation of a jumping motion in Simulink. It contains details to get an insight into modern biomechanics without previous experience. In the simulation, a Hill-Type muscle is used to generate joint momentum with a phenomenologically realistic relationship between muscle length and force. The simulation published with this article is one of many solutions to design a humanoid simulation. The paper guides through the implemented build and explains its range of application.
Small and large deformation analysis with the p- and B-spline versions of the Finite Cell Method
(2012)
A new robust design for imperfection sensitive stiffened cylinders used in aerospace engineering
(2015)
Computational models for the personalized analysis of human femurs contain uncertainties in bone material properties and loads, which affect the simulation results. To quantify the influence we developed a probabilistic framework based on polynomial chaos (PC) that propagates stochastic input variables through any computational model. We considered a stochastic E-ρ relationship and a stochastic hip contact force, representing realistic variability of experimental data. Their influence on the prediction of principal strains (ϵ1 and ϵ3) was quantified for one human proximal femur, including sensitivity and reliability analysis. Large variabilities in the principal strain predictions were found in the cortical shell of the femoral neck, with coefficients of variation of ≈40%. Between 60 and 80% of the variance in ϵ1 and ϵ3 are attributable to the uncertainty in the E-ρ relationship, while ≈10% are caused by the load magnitude and 5-30% by the load direction. Principal strain directions were unaffected by material and loading uncertainties. The antero-superior and medial inferior sides of the neck exhibited the largest probabilities for tensile and compression failure, however all were very small (pf<0.001). In summary, uncertainty quantification with PC has been demonstrated to efficiently and accurately describe the influence of very different stochastic inputs, which increases the credibility and explanatory power of personalized analyses of human proximal femurs.