München, Germany
München, Germany

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Vestner S.,Ingenieurburo Prof. Dauberschmidt and Vestner MbH | Dauberschmidt C.,Hochschule Munich
Bautechnik | Year: 2014

Cathodic Protection (CP) of reinforced concrete members is an established repair method in parking buildings. Compared to a traditional repair (by removal of the chloride-contaminated concrete) this corrosion protection concept has some technical and economic advantages but also disadvantages, which have to be taken into account at the choice of the repair concept and which also have to be discussed with the client. CP is as generally accepted rule technology, even though an approval in the individual case must be obtained mostly. While there are numerous application examples and rules for the application on the surface of decks or on column and wall feet, special construction elements or points of detail are common in reinforced concrete members making a planning and application "off the peg" impossible. For some of these points of detail solutions are presented and discussed: this is on one hand protecting the rear reinforcement layer of false ceilings with separating cracks by installing the CP-system on the top of the ceiling. On the other hand is presented as columns with high static loads, which have a high degree of damage of the reinforcement, can be repaired using a combination of reinforcement addition and cathodic protection. Furthermore bar anodes can be used to protect inaccessible places. The CP of metallic installation parts have to be planned with a special attention on a proper current distribution. Here results of a sample are presented. Finally, the application of slotted anodes for the repair of underground car parks are presented. This design allows a CP repair without having to change the component dimension and applying an additional load. © Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

Dauberschmidt C.,Hochschule Munich | Vestner S.,Ingenieurburo Prof. Dauberschmidt and Vestner mbH
Bautechnik | Year: 2015

Abstract Planning of underground floor slabs, special attention must be paid on the durability of the construction as a result of the severe chloride exposure. This durability has to be ensured by a thick concrete cover with a chloride dense concrete or by the application of a surface protection system. Further measures have to be taken to prevent chlorides to penetrate into cracks. These measures are specified within the existing rules and regulations. In the design of new DBV Guide to Good Practise, Design Principles are provided, from which construction alternatives can be derived. For the implementation of the Design Principles at the construction of underground floor slabs three examples are given. Copyright © 2015 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

Mohring M.,Hochschule Munich | Schmidt R.,Hochschule Munich | Harting R.-C.,Aalen University of Applied Sciences | Reichstein C.,Aalen University of Applied Sciences
Lecture Notes in Business Information Processing | Year: 2016

Improving the quality and efficiency of modeling is an important goal of many research approaches. A number of influence factors outside the modeling environment are investigated. To measure the influence objective measures are necessary. Therefore, this paper strives to create a foundation for such a measures, by measuring the influence of caffeine on the modeling performance. Choosing caffeine has the important advantage to provide an unbiased setting. The possible path of influence of caffeine on the modeling performance is analyzed. A research model is developed and the result of a pre-study are discussed. © Springer International Publishing Switzerland 2016.

Rapp S.,Hochschule Munich | Rapp S.,Friedrich - Alexander - University, Erlangen - Nuremberg | Heinrich G.,TU Ilmenau | Domke M.,Vorarlberg University of Applied Sciences | Huber H.P.,Hochschule Munich
Physics Procedia | Year: 2014

In the production process of microelectronic devices and high efficiency solar cells, local openings in thin dielectric layers are required. Instead of photolithographic, laser based processing enables to open these dielectric layers locally in a low-cost mass production step. In this work, thin silicon nitride layers deposited on planar silicon wafers are processed by single infrared Gaussian shaped 660 fs laser pulses. The transparent silicon nitride layer, becoming absorptive at fluences higher than 0.3 J/cm2, is selectively removed by confined ablation at fluences below that value. At pulse peak fluences exceeding 1.0 J/cm2 a "SiNx island" is created by direct ablation in the spot center. In this article, the selective SiNx ablation by a combination of confined and direct laser ablation at the medium pulse peak fluence of 0.5 J/cm2 is investigated. To clarify the influence of the nonlinear absorption in the pulse center, the ablation behavior is investigated by time-and space-resolved pump-probe microscopy experiments. The results show phase changes in the silicon and in the silicon nitride in the first picoseconds after excitation, the ablation onset at around 10 ps and the subsequent mechanical material motion after a few nanoseconds. The actual silicon nitride layer removal starts after around 10 ns, whereas confined ablation processes are the driving mechanisms even in the nonlinearly absorbing spot center. A comparison of the energetic ablation efficiency of the SiNx layer system to further dielectric thin films shows no detrimental influence of the nonlinear absorbance. © 2014 The Authors. Published by Elsevier B.V.

Lusic M.,Nurnberg University of Applied Sciences | Wimmer M.,Hochschule Munich | Maurer C.,Hochschule Munich | Hornfeck R.,Nurnberg University of Applied Sciences
Procedia CIRP | Year: 2015

Mass customisation is in contradiction with established manufacturing systems, which produce high quantities of identical parts. Even though products assembled according to individual customer demands are widely available in many areas, the shape of the individual parts of the assembled product is generally fixed. To enable mass customisation regarding the shape of these parts, new manufacturing technologies are needed. Additive manufacturing proved to be an enabling technology for this purpose. For large panels with free-form surfaces and similar parts with curvilinear and large surfaces, however, additive manufacturing is not in such an economical way commonly useful. In addition, panels additive manufactured require a postprocess for smoothing since the staircase effect is related to additive manufacturing. In conclusion, traditional die making is still being used to produce customised panels and the reason why they cannot be produced economically. As addressed in this article, pin-type tooling, however, is a technology that could enable mass customised panels. This paper analyses the challenges of mass customisation and assign them to the characteristics of pin-type tooling. Since new manufacturing technologies and business processes require suitable engineering processes, an engineering framework for producing such mass customised panels with pin-type tooling is introduced. © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.

Schaeck S.,BMW AG | Stoermer A.O.,BMW AG | Kaiser F.,BMW AG | Koehler L.,Hochschule Munich | And 2 more authors.
Journal of Power Sources | Year: 2011

Micro-hybrid electric vehicles were launched by BMW in March 2007. These are equipped with brake energy regeneration (BER) and the automatic start and stop function (ASSF) of the internal combustion engine. These functions are based on common 14 V series components and lead-acid (LA) batteries. The novelty is given by the intelligent onboard energy management, which upgrades the conventional electric system to the micro-hybrid power system (MHPS). In part I of this publication the key factors for the operation of LA batteries in the MHPS are discussed. Especially for BER one is high dynamic charge acceptance (DCA) for effective boost charging. Vehicle rest time is identified as a particular negative parameter for DCA. It can be refreshed by regular fully charging at elevated charge voltage. Thus, the batteries have to be outstandingly robust against overcharge and water loss. This can be accomplished for valve-regulated lead-acid (VRLA) batteries at least if they are mounted in the trunk. ASSF goes along with frequent high-rate loads for warm cranking. The internal resistance determines the drop of the power net voltage during cranking and is preferably low for reasons of power net stability even after years of operation. Investigations have to be done with aged 90 Ah VRLA-absorbent glass mat (AGM) batteries. Battery operation at partial state-of-charge gives a higher risk of deep discharging (overdischarging). Subsequent re-charging then is likely to lead to the formation of micro-short circuits in the absorbent glass mat separator. © 2010 Elsevier B.V.

Durr A.,Hochschule Munich | Durr A.,Hochtief Group | Gong F.,Hochtief Group
Stahlbau | Year: 2016

Plant structures in industrial facilities can reach a height of 150 m. The towers are commonly built as a framework structure in steel or concrete. However, as an alternative, the columns of these structures can be built as composite construction. In recent years, the concrete filled steel tubes, i. e. the so-called mega composite columns, have been investigated extensively by HOCHTIEF. In this paper, two types of cross-sections, the rectangular and circular hollow-section, are explained and compared in detail from a static, structural and manufacturing point of view. Moreover, the most significant characteristics in the design and construction of mega composite columns are highlighted within this paper. © 2016 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

PubMed | Hochschule Munich, TU Munich, The Smith Kettlewell Eye Research Institute and Fachgebiet Computerlinguistik
Type: Journal Article | Journal: Der Ophthalmologe : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft | Year: 2016

Reading performance that can be measured by reading tests depends on whether reading material with or without contextual continuity is used.The goal of this study was to create a German version of the SKread test and to evaluate it in a clinical setting.The evaluation of the SKread test was first performed on two groups of visually healthy subjects of different ages: a junior group of 25 persons with ages between 20 and 30 years (mean= 25.84 years, SD 2.41 years) and a senior group of 25 persons with ages between 51 and 84 years (mean= 62.40 8.46 years). The same measurements were also performed on a group of 18 patients with age-related macular degeneration (AMD) with ages between 75 and 95 years (mean= 81.89 5.48 years). The reading performance was also measured using Radner charts.Using reading material without syntactic continuity considerably slowed down the reading speed and increased the error rate. Median reading rates of 11.53 characters/s (CPS) for the junior group and 8.96 CPS for the senior group were clearly lower than those for the Radner charts (22.02CPS and 18.48CPS, respectively). In the AMD patients, a statistical analysis of the error rates showed a highly significant difference between the Radner charts and the SKread test (p= 0.00014). Furthermore, by analyzing the errors made in the SKread test information could be obtained about the position of central scotomas. The test-retest reliability of the SKread was very good.Information about the position of a central scotoma can be acquired by using the SKread test and an analysis of reading errors, which can augment effective clinical monitoring in AMD and subsequent visual rehabilitation.

Steinmann R.,Hochschule Munich
Betonwerk und Fertigteil-Technik/Concrete Plant and Precast Technology | Year: 2014

BIM is a method for optimized design, construction, and operation of buildings. The objective is to make decision-relevant information on processes available as early and as transparently as possible in order to recognize conflicts early and to prevent misunderstandings and incorrect decisions. The networking of information enables design trades and construction teams to work together much more closely than in the past. Integrated utilization of the BIM method, however, gives rise to new responsibilities for its users. Downstream trades must rely on the information provided by trades earlier at work. Since users employ such information directly, new responsibilities arise that must be regulated in contracts. Many successful projects carried out based on BIM show, however, that this hurdle is manageable and that economic advantages clearly dominate.

Julich F.,Hochschule Munich | Koch A.W.,TU Munich | Roths J.,Hochschule Munich
Technisches Messen | Year: 2012

With spreading of the fibre-Bragggrating (FBG) based sensor technology the demand for highly accurate sensors is growing. This study shows the limitation of the accuracy of standard FBG-sensors (FBGS) and an approach is presented to the development of highly accurate FBGS. FBGs inscribed into highly birefringent (HiBi) optical fibres show promising properties to reach an accuracy higher than Standard-FBG. In this study FBGs were inscribed into several HiBi-fibres and the effective refractive indices as well as the birefringence were determined. These investigations are important to establish a reproducible fabrication process for HiBi-FBGs that can be used for highly accurate fibre based measurements. © Oldenbourg Wissenschaftsverlag.

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