Ansbach University of Applied Sciences
Ansbach, Germany

The Ansbach University of Applied science was founded in 1996 and counts approximately 1,800 students . It belongs to the newest Universities of Applied science of the Free State of Bavaria. The percentage of foreign students is about 6 percent. As of 2010 there are 2,300 students.Beginning with the winter semester 2006/07 the so-called Bologna Process was implemented. Therefore all academic programs with the German degree “Diplom ” were replaced by bachelor programs.In January 2008 the Ansbach University of Applied science came to first place of the “Hochschulranking” which was processed by Despite the fact that the survey cannot be considered as representative it is still an honour for the young and dynamic university. Wikipedia.

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Sover A.,Ansbach University of Applied Sciences | Popp P.,Ansbach University of Applied Sciences | Aydin T.,Ansbach University of Applied Sciences
MATEC Web of Conferences | Year: 2017

Digital Direct Metallization (DDM) is an innovative process for the production of metallic layers on plastic substrates, e.g. to generate electrical circuit path. This paper describes the manufacturing process of Digital Direct Metallization (DDM) in the case of plasma based copper coating on polymeric components. The process-temperature has a significant impact on the metal deposition and can be controlled by the distance between the plasma head and plastic part or/and its cross-runs. The deposition of the copper powder on the polymeric surface was substantial improved by a temperature close to the melting point of the polymer. © 2017 The Authors, published by EDP Sciences.

Benneker L.M.,University of Bern | Gisep A.,AO Development Institute | Krebs J.,RH realHealth International AG | Boger A.,Ansbach University of Applied Sciences | And 2 more authors.
Veterinary and Comparative Orthopaedics and Traumatology | Year: 2012

Introduction: Several studies have described 'open' approach techniques for cementation of sheep and goat vertebrae; however, no percutaneous technique has been developed so far for use in non-primates. The aim of this study was to develop an animal model for percutaneous vertebroplasty under clinical conditions. Methods: In a pilot study with dissected cadaveric ovine vertebrae, the technique and instruments as well as the optimal needle position were determined. In an in vivo animal study using 33 lumbar vertebrae of 11 sheep, a percutaneous vertebroplasty was performed under general anaesthesia. Needle position and cement volume were evaluated from high resolution, quantitative computed tomography imaging. Results: The percutaneous technique for ver-tebroplasty was applicable to the vertebral bodies (L1 to L5) of the ovine lumbar spine without any related adverse effects for the animals. The procedure showed a steep learning curve represented by the reduction of the distance between the actual and planned needle positioning (7.2 mm to 3.7 mm; median value) and shorter surgery times (21.3 min to 15.0 min, average) with progression of the study. Conclusion: The described technique is feasible and repeatable under clinical conditions. This is the first percutaneous vertebroplasty technique for non-primates and we conclude that the sheep is a valid animal model to investigate the effects of cement augmentation in vivo. © Schattauer 2012.

Kinzl M.,Vienna University of Technology | Benneker L.M.,University of Bern | Boger A.,Ansbach University of Applied Sciences | Zysset P.K.,University of Bern | Pahr D.H.,Vienna University of Technology
European Spine Journal | Year: 2012

Purpose Vertebroplasty restores stiffness and strength of fractured vertebral bodies, but alters their stress transfer. This unwanted effect may be reduced by using more compliant cements. However, systematic experimental comparison of structural properties between standard and low-modulus augmentation needs to be done. This study investigated how standard and low-modulus cement augmentation affects apparent stiffness, strength, and endplate pressure distribution of vertebral body sections. Methods Thirty-nine human thoracolumbar vertebral body sections were prepared by removing cortical endplates and posterior elements. The specimens were scanned with a HR-pQCT system and loaded in the elastic range. After augmentation with standard or low-modulus cement they were scanned again and tested in two steps. First, the contact pressure distribution between specimen and loading plates was measured with pressure-sensitive films. Then, they were loaded again in the elastic range and compressed until failure. Apparent stiffness was compared before and after augmentation, whereas apparent strength of augmented specimens was compared to a nonaugmented reference group. Results Vertebral body sections with fillings connecting both endplates were on average 33% stiffer and 47% stronger with standard cement, and 27% stiffer and 30% stronger with low-modulus cement. In contrast, partial fillings showed no significant strengthening for both cements and only a slight stiffness increase (\16%). The averaged endplate pressure above/below the cement was on average 15% lower with low-modulus cement compared to standard cement. Conclusion Augmentation connecting both endplates significantly strengthened and stiffened vertebral body sections also with low-modulus cement. A trend of reduced pressure concentrations above/below the cement was observed with low-modulus cement. © 2011 Springer-Verlag.

Kinzl M.,Vienna University of Technology | Boger A.,Ansbach University of Applied Sciences | Zysset P.K.,University of Bern | Pahr D.H.,Vienna University of Technology
Journal of Biomechanics | Year: 2012

Recently published compression tests on PMMA/bone specimens extracted after vertebral bone augmentation indicated that PMMA/bone composites were not reinforced by the trabecular bone at all. In this study, the reasons for this unexpected behavior should be investigated by using non-linear micro-FE models. Six human vertebral bodies were augmented with either standard or low-modulus PMMA cement and scanned with a HR-pQCT system before and after augmentation. Six cylindrical PMMA/bone specimens were extracted from the augmented region, scanned with a micro-CT system and tested in compression. Four different micro-FE models were generated from these images which showed different bone tissue material behavior (with/without damage), interface behavior (perfect bonding, frictionless contact) and PMMA shrinkage due to polymerization. The non-linear stress-strain curves were compared between the different micro-FE models as well as to the compression tests of the PMMA/bone specimens. Micro-FE models with contact between bone and cement were 20% more compliant compared to those with perfect bonding. PMMA shrinkage damaged the trabecular bone already before mechanical loading, which further reduced the initial stiffness by 24%. Progressing bone damage during compression dominated the non-linear part of the stress-strain curves. The micro-FE models including bone damage and PMMA shrinkage were in good agreement with the compression tests. The results were similar with both cements. In conclusion, the PMMA/bone interface properties as well as the initial bone damage due to PMMA polymerization shrinkage clearly affected the stress-strain behavior of the composite and explained why trabecular bone did not contribute to the stiffness and strength of augmented bone. © 2012 Elsevier Ltd.

Kolb J.P.,University of Hamburg | Kueny R.A.,TU Hamburg - Harburg | Puschel K.,University of Hamburg | Boger A.,Ansbach University of Applied Sciences | And 4 more authors.
European Spine Journal | Year: 2013

Purpose: Normal progression of osteoporosis or the rigid reinforcement of the fractured vertebral body with polymethyl methacrylate (PMMA) cement is being discussed as a cause for adjacent-level fractures after vertebroplasty. The purpose of this study was to investigate whether augmentation with low stiffness cement can decrease the risk of adjacent-level fractures in low-quality bone. Methods: Eighteen female osteoporotic lumbar specimens (L1-L5) were harvested and divided into three groups according to bone mineral density: (I) native; (II) PMMA; (III) modified PMMA (lower stiffness). For the PMMA and modified PMMA groups, a compression fracture was first mechanically induced in L3, and then the fracture received vertebroplasty treatment. The cement stiffness reduction of the modified PMMA group was achieved via an addition of 8 mL of serum to the typical PMMA base. All specimens were exposed to cyclic loading (4 Hz) and a stepwise increasing applied peak force. Cement stiffness was tested according to ISO 5833. Results: A 51 % decrease in cement stiffness was achieved in the modified PMMA group (954 ± 141 vs. 1,937 ± 478 MPa, p < 0.001). Fatigue fracture force (the force level during cyclic loading at which the deformation experienced a sudden increase; FFF) was significantly affected by bone quality (r 2 = 0.39, p = 0.006) and by the initial fracture force (the force necessary to create the initial fracture in L3 prior to augmentation; r 2 = 0.82, p < 0.001). Using initial fracture force as a covariate, the FFF of the modified PMMA group (1,764 ± 49 N) was significantly higher than in the PMMA group (1,544 ± 55 N; p = 0.03). Conclusions: A possible method to reduce adjacent-level fractures after vertebroplasty in patients with reduced bone quality could be the use of a lower modulus cement. Therefore, mixing cement with biocompatible fluids could prove useful to tailor cement properties in the operating theater. © 2013 Springer-Verlag Berlin Heidelberg.

Fliri L.,AO Research Institute Davos | Lenz M.,AO Research Institute Davos | Boger A.,Ansbach University of Applied Sciences | Windolf M.,AO Research Institute Davos
Journal of Trauma and Acute Care Surgery | Year: 2012

BACKGROUND: Previous studies have clearly demonstrated superior biomechanical behavior of augmented proximal femoral nail antirotation (PFNA) blades compared with nonaugmented ones with respect to implant cutout. Nevertheless, there is concern about thermal bone necrosis due to exothermic curing of polymethylmethacrylate (PMMA)-based bone cements. The objective of this study was to quantify the temperatures arising around perforated titanium PFNA blades when augmenting with PMMA. METHODS: Cylindrical samples from six pairs of fresh frozen human cadaveric femoral heads implanted with a PFNA blade were placed in a 37°C water bath and augmented with 3 mL and 6 mL PMMA. During augmentation, temperatures were measured using six K-type thermocouples that were placed at controlled distances around the implant. With the help of high-resolution quantitative computed tomography images, the locations of all thermocouples with respect to the cement-bone interface were reconstructed. RESULTS: No temperatures higher than 45°C were measured in the interface region and the surrounding cement-free cancellous bone. In the same regions, the longest exposure time above 41°C was 8.5 minutes and was measured in a 6-mL sample. Average maximum temperature was significantly lower for the 3-mL group compared with the 6-mL group (p = 0.017). CONCLUSION: The results of this study suggest that augmentation of titanium PFNA blades is not associated with a risk of thermal bone necrosis when using up to 6 mL of PMMA. However, larger amounts of cement lead to higher temperatures. PMMA application should therefore be kept low to minimally alter the biological system. Copyright © 2012 by Lippincott Williams & Wilkins.

Brinkhaus M.,Ansbach University of Applied Sciences | Jarosch D.,Ansbach University of Applied Sciences | Kapischke J.,Ansbach University of Applied Sciences
Solar Energy | Year: 2011

The objective of the project is an all-year secure supply of alternating current based on a solar energy island grid consisting of serial components and seasonal energy storage. Photovoltaic modules, inverters, electrolysers, batteries, hydrogen stores and fuel cells form the basis of the independent power supply system. For this, selected load profiles were analysed and evaluated in theory and practice.The analysis is based on the results of the test runs of the system and the simulations, in which the combined hydrogen-battery-system is compared to the battery system.It was revealed that it is sensible to complement an island grid operating on lead batteries for shortterm energy supply with hydrogen as a long-term store. This ensures a year-round supply security based on solar energy and the extension of the life span of the batteries required for hydrogen-based power stores. The systems based purely on batteries can not provide perfect supply security during long periods of low solar radiation since they do not possess energy stores which allow long-term energy storage.Hence a seasonal energy store, such as hydrogen, is required to guarantee reliable power supply for every day of the year.Autonomous power supply systems with long-term energy stores operate independently from the public grid system and can be implemented without elaborate intelligent energy management. For this, however, the costs of the serial components must be reduced and the efficiency of the system must be improved. © 2011 Elsevier Ltd.

Heling B.,Friedrich - Alexander - University, Erlangen - Nuremberg | Aschenbrenner A.,Friedrich - Alexander - University, Erlangen - Nuremberg | Walter M.S.J.,Ansbach University of Applied Sciences | Wartzack S.,Friedrich - Alexander - University, Erlangen - Nuremberg
Procedia CIRP | Year: 2016

Identifying a suitable compromise between tight and thus expensive tolerances and wide tolerances that may negatively influence the product quality is a major challenge. This paper focuses on the tolerance-cost-optimization of mechanical assemblies with interrelated dimension chains considering dependencies between the tolerance-cost-relationships. Taking into account interrelated dimension chains the crux is, however, that modifications of a single tolerance can influence several dimension chains as well as the resulting production costs. Based on different existing approaches for the statistical tolerance-cost-optimization, the authors will provide appropriate guidance for the product developer dealing with interrelated dimension chains. © 2016 The Authors.

Poepel C.,Ansbach University of Applied Sciences
ACM International Conference Proceeding Series | Year: 2014

This paper presents a method of evaluating computer-based musical instruments. The method is based on a paired comparison of sound files produced by the instruments to be evaluated. The same input signal imparting performers' actions to generate musical expression is applied to different instruments. Each output is recorded and the different recordings are compared by listeners in relation to factors relevant for musical expression. A study using this method is presented. The results show that there are significant differences between the instruments compared and that the evaluation method used allows insight into specific features of the evaluated instruments. The method used in this study can be adapted to compare and evaluate new developments in the field of new interfaces for musical expression providing the same input signal can be used and fed into the instruments. Copyright 2014 ACM.

One way to explain the mechanism of powder mixing is the Fokker-Planck equation. The equation comprises two decisive parameters, the transport coefficient U that depends on the active transport of the mixing device and the dispersion coefficient D which describes the mobility of the single particles. The idea is to calculate the dispersion and transport coefficient by using the powder characteristics. To verify this assumption, measurements with different components and different rotation speeds were made. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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