@techreport{HoellerZeitlerSabourin, author = {H{\"o}ller, Christoph and Zeitler, Berndt and Sabourin, Ivan}, title = {Airborne and impact sound insulation data for cold-formed steel-framed walls and floors}, publisher = {National Research Council of Canada. Construction}, doi = {10.4224/23002823}, abstract = {This report presents the results of an extensive series of direct sound insulation tests of cold-formed steel-framed walls and floors. The direct airborne sound insulation of 30 walls with cold-formed steel framing was measured in accordance with ASTM E90-09. The walls had steel studs with a depth of 92 mm (3-5/8") or 152 mm (6"), and with a steel thickness of 1.09 mm (0.043") or 1.37 mm (0.054"). Other parameters that were investigated included the number of layers and thickness of gypsum board, the cavity insulation, the stud spacing, and the use of resilient channels. The test results for some non-standard wall configurations that were tested for research purposes (e.g. for walls with gypsum board on one side only) are also included in this report. The direct airborne and impact sound insulation of 17 floors with cold-formed steel framing was measured in accordance with ASTM E90-09 and ASTM E492-09, respectively. The floors had steel joists with a depth of 254 mm (10") or 317 mm (12.5"), and with a steel thickness of 1.37 mm (0.054"). The top surface of the floor/ceiling assemblies was composed of a corrugated steel deck with poured gypsum concrete, while the bottom surface was composed of a gypsum board ceiling on resilient channels. The influence of the joist depth and the number of layers and thickness of the ceiling gypsum board was investigated, as well as the influence of several floor coverings (e.g. laminate or carpet). The report presents the detailed specimen descriptions and specimen properties and the results from the standardized tests according to ASTM E90-09 and ASTM E492-09. Brief analyses of the parameters affecting the sound insulation of the steel-framed assemblies are provided. The tests presented in this report were part of a large research study that also included an investigation into the flanking sound transmission in cold-formed steel-framed buildings. The results of that study are described in the NRC Research Report RR-337, "Apparent Sound Insulation in Cold-Formed Steel-Framed Buildings" [1]. The NRC Research Report RR-337 also includes some of the airborne sound insulation results presented here, albeit without listing the detailed specimen descriptions and specimen properties that are provided in this report.}, language = {en} } @article{HoellerGibbs, author = {H{\"o}ller, Christoph and Gibbs, Barry M.}, title = {Source substitution method for obtaining the power transmission from vibrating sources in buildings}, series = {Applied Acoustics}, volume = {141}, journal = {Applied Acoustics}, publisher = {Elsevier}, doi = {10.1016/j.apacoust.2018.07.014}, pages = {240 -- 249}, abstract = {This paper describes a method analogous to the airborne sound source substitution method, to estimate the vibrational power injected by a structure-borne sound source into the supporting building element. The injected vibrational power is required for prediction of the structure-borne sound pressure from vibrating equipment in buildings. The paper focuses on high-mobility sources connected to low-mobility receivers, a situation which is commonly encountered in heavyweight construction. The mobility mismatch simplifies the transformation of laboratory measurement data to prediction of transmitted power in-situ. Three case studies were performed. In the first study, the power injected by a simple test source into a resiliently supported aluminium plate was determined using direct and indirect methods. Source substitution was investigated with different calibration options: steady-state excitation, transient excitation, and spatial averaging. The source power could be determined within 4 dB, compared with direct measurements of the injected power. In the second study, the power injected by a second source into a concrete transmission suite floor was determined. The third study was of a combined heating and power unit on a masonry wall. In this study, a reference sound pressure level in a receiver room was calculated and compared with a criterion curve for the assessment of low-frequency noise complaints. The case studies demonstrate that structure-borne sound source substitution is a promising development of the reception plate method. While the latter can be used if a free reception plate is available, the former circumvents problems of determining the transmitted power into coupled plates and therefore has application to real building conditions. The use of the instrumented hammer for the calibration and the use of spatial averaging significantly simplify the method.}, language = {en} } @article{LievensHoellerDietrichetal., author = {Lievens, Matthias and H{\"o}ller, Christoph and Dietrich, Pascal and Vorl{\"a}nder, Michael}, title = {Predicting the Interaction Between Structure-Borne Sound Sources and Receiver Structures from Independently Measured Quantities}, series = {Acta Acustica united with Acustica}, volume = {100}, journal = {Acta Acustica united with Acustica}, number = {1}, publisher = {European Acoustics Association (EAA)}, doi = {10.3813/AAA.918688}, pages = {79 -- 92}, abstract = {Structure-borne sound sources are usually characterised by their source activity and source mobility. By combining this data with the mobility of receiver structures it is theoretically possible to predict the sound pressure level in a building. In a case study of a washing machine on a wooden joist floor this prediction process was investigated. The prediction was based on the normal force component only. The contact area at the feet of the washing machine was made as small as possible to avoid the influence of moments while the in-plane components were assumed negligible. These conditions proved to allow for accurate predictions in the coupled state in a previous publication [1]. The results show that the prediction from independently measured normal source and receiver quantities yields large errors below 125 Hz as a consequence of the above assumption. Between 125 and 900 Hz the error of the prediction is within ± 5 dB. The case study further investigated two assumptions frequently encountered in practice: low and high-mobility sources and no cross-coupling between the feet}, language = {en} } @techreport{HoellerMahnQuirtetal., author = {H{\"o}ller, Christoph and Mahn, Jeffrey and Quirt, David and Schoenwald, Stefan and Zeitler, Berndt}, title = {Apparent sound insulation in cross-laminated timber buildings}, publisher = {National Research Council of Canada. Construction}, doi = {10.4224/23002009}, pages = {116}, abstract = {This Report presents the results from experimental studies of airborne sound transmission, together with an explanation of calculation procedures to predict the apparent airborne sound transmission between adjacent spaces in a building whose construction is based on cross-laminated timber (CLT) panels. There are several types of CLT constructions which are commercially available in Canada, but this study only focused on CLT panels that have adhesive between the faces of the timber elements in adjacent layers, but no adhesive bonding the adjacent timber elements within a given layer. There were noticeable gaps (up to 3 mm wide) between some of the timber elements comprising each layer of the CLT assembly. These CLT panels could be called "Face-Laminated CLT Panels" but are simply referred to as CLT panels in this Report. Another form of CLT panels has adhesive between the faces of the timber elements in adjacent layers as well as adhesive to bond the adjacent timber elements within a given layer. These are referred to as "Fully-Bonded CLT Panels" in this Report. Because fully-bonded CLT panels have different properties than face-laminated CLT panels, the sound transmission data and predictions in this Report do not apply to fully-bonded CLT panels.}, language = {en} } @article{HoellerGibbs, author = {H{\"o}ller, Christoph and Gibbs, Barry M.}, title = {Indirect determination of the mobility of structure-borne sound sources}, series = {Journal of Sound and Vibration}, volume = {344}, journal = {Journal of Sound and Vibration}, publisher = {Elsevier}, doi = {10.1016/j.jsv.2015.01.011}, pages = {38 -- 58}, abstract = {Methods are considered for the indirect determination of the mobility of structure-borne sound sources. Instead of performing measurements on the source in the free state, the source mobility is obtained from measurements made in-situ. This approach is beneficial if the source is difficult to suspend, or if it contains nonlinear structural elements. Two formulations for an indirect source mobility are derived theoretically. The first requires measurement of velocities at or near to the contact points. The second involves measurement of remote velocities only. Neither of the methods requires excitation at the contacts in the coupled state. Numerical simulations of coupled beams are used to validate the two methods and investigate their accuracy and reliability with respect to typical measurement errors, such as background noise and inaccuracies in sensor positioning. It is found that these can have a significant effect on the methods considered. Several experimental case studies with single-contact and multi-contact sources are performed. The results confirm the validity of the two methods in principle, but highlight their sensitivity to experimental errors. In a representative case study with a fan unit, average errors range between ±5 dB and ±10 dB, with occasional errors of up to 30 dB.}, language = {de} } @article{HoellerGibbs, author = {H{\"o}ller, Christoph and Gibbs, Barry M.}, title = {Inverse Method to Obtain Blocked Forces of Vibrating Sound Sources in Buildings}, series = {Acta Acustica united with Acustica}, volume = {103}, journal = {Acta Acustica united with Acustica}, number = {4}, publisher = {ingenta}, doi = {10.3813/AAA.919092}, pages = {639 -- 649}, abstract = {Vibrating sources, such as building service equipment, are major contributors to noise in buildings. In order to predict and subsequently reduce the sound pressure levels generated by these devices, it is necessary to first predict the total vibrational power injected by them into the supporting building structure. Whilst simplified methods are available for the calculation of the total power through all contacts, it would be beneficial to have more detailed knowledge of the dominant contact powers. For sources on low-mobility building elements, the contact powers are determined by the blocked force, along with the real part of the receiver mobility at each contact. This paper describes a novel inverse method to obtain the blocked forces at each contact. The method employs an instrumented reception plate, which is numerically modelled to allow optimum accelerometer positions to be selected, for any source and any location. The underlying theory and measurement procedure are described, and experimental validations are presented.}, language = {en} } @techreport{MahnQuirtHoelleretal., author = {Mahn, Jeffrey and Quirt, David and H{\"o}ller, Christoph and M{\"u}ller-Trapet, Markus}, title = {Addendum to RR-335: sound transmission through Nail-Laminated Timber (NLT) assemblies}, publisher = {National Research Council of Canada. Construction}, doi = {10.4224/40000417}, abstract = {This report is published as an addendum to NRC Research Report RR-335 "Apparent Sound Insulation in Cross-Laminated Timber Buildings." It is intended that this addendum will be merged with RR-335 in the future as a report for predicting the sound insulation in buildings using mass-timber constructions including NLT assemblies. This report presents the results from experimental studies of airborne sound transmission through assemblies of nail-laminated timber (NLT) with various linings. To put the data presented in this report in the proper context, this report begins with a brief explanation of calculation procedures to predict the apparent sound transmission class (ASTC) between adjacent spaces in a building whose structure is a combination of mass-timber assemblies such as nail-laminated timber (NLT) or cross-laminated timber (CLT) panels.}, language = {en} } @techreport{HoellerMuellerTrapetKingetal., author = {H{\"o}ller, Christoph and M{\"u}ller-Trapet, Markus and King, Frances and Bradley, John}, title = {Evaluation of the communication performance of the C4 chemical, biological, radiological and nuclear mask}, doi = {10.4224/23003981}, abstract = {The Canadian Armed Forces (CAF) are using chemical, biological, radiological and nuclear (CBRN) general service respirators (GSRs) to defend against CBRN threats and hazards to protect personnel and ensure that they can safely and successfully carry out missions. The CBRN GSR currently in use by the CAF is the C4 respirator. The National Research Council of Canada assessed the communication performance of the C4 respirator. This report presents the results of the performance test. The method for assessing the communication performance used in this study was the NIOSH standard test procedure TEB-CBRN-APR-STP-0313 [1]. Other methods exist to evaluate the communication performance of respirators, but historically the NIOSH standard test procedure has been used. This report details the implementation and results of the tests conducted at the National Research Council of Canada, following the NIOSH standard test procedure.}, language = {en} } @techreport{HoellerQuirtZeitleretal., author = {H{\"o}ller, Christoph and Quirt, David and Zeitler, Berndt and Sabourin, Ivan}, title = {Apparent sound insulation in cold-formed steel-framed buildings}, publisher = {National Research Council of Canada. Construction}, doi = {10.4224/23001843}, abstract = {This Report presents the results from substantial experimental studies of sound transmission, together with an explanation of calculation procedures to predict the sound transmission between adjacent spaces in a building whose walls and floors have cold-formed steel (CFS) framing. This first edition contains mainly data for loadbearing steel framing formed from sheet steel with thickness from 1.37 mm (16 gauge) to 0.94 mm (20 gauge). Non-loadbearing CFS studs formed from thinner steel (nominally 0.54 mm) are also commonly used but these are not included in the data tables for sound transmission through wall assemblies in this Report.}, language = {en} } @phdthesis{Hoeller, author = {H{\"o}ller, Christoph}, title = {Indirect methods of obtaining activity and mobility of structure-borne sound sources}, publisher = {University of Liverpool}, address = {Liverpool}, abstract = {The work reported in this thesis focuses on the development of indirect methods for the experimental determination of important source parameters for structure-borne sound source characterization. In the first part of the thesis, matrix inversion methods for the determination of blocked forces are investigated. A simplified measurement procedure is proposed which offers a solution to the two major challenges to these methods, namely the acquisition of the FRF matrix and the problems associated with matrix inversion. The proposed procedure involves a free, low-mobility receiver plate which is modelled numerically. Calculated FRFs are used together with measured velocity responses to inversely determine the blocked forces. It is found that while the method has great potential in principle, in practice the accurate modelling of the receiver plate is of critical importance. In the second part of the thesis, three formulations are considered for the indirect determination of source mobility. Instead of performing measurements on the source in the free state, the source mobility is obtained from measurements made in-situ. This approach is beneficial if the source is difficult to suspend, or if it contains non-linear structural elements. The three formulations are validated numerically and experimentally. It is found that the methods can quantify source mobilities of single-contact and multi-contact sources from in-situ measurements. However, typical measurement errors, such as background noise or inaccuracies in sensor positioning, can significantly reduce the accuracy and reliability of the methods. In the final part of the thesis, the reception plate method for the determination of the power injected by a high-mobility source into a low-mobility receiver is reviewed, and a source substitution method proposed as a development. The substitution method circumvents problems that may arise when the reception plate method is applied to coupled walls and floors. A special focus of investigation is on the calibration of the receiver structure. It is found that the calibration can be performed with shaker or hammer, and that an average calibration factor may be used. The source substitution method thus offers a potential alternative to the reception plate method, for application with coupled plates.}, language = {en} } @article{BauhuberMikrievskijLechner, author = {Bauhuber, Michael and Mikrievskij, Andreas and Lechner, Alfred}, title = {Isotropic wet chemical etching of deep channels with optical surface quality in silicon with HNA based etching solutions}, series = {Materials Science in Semiconductor Processing}, volume = {16}, journal = {Materials Science in Semiconductor Processing}, number = {6}, publisher = {Elsevier}, doi = {10.1016/j.mssp.2013.05.017}, pages = {1428 -- 1433}, abstract = {Online trace analysis based on UV/Vis spectroscopy requires long detection paths. Therefore an isotropic wet etch process in silicon is developed to fabricate a 300 µm deep channel with low channel wall roughness for desired light guidance application. Four etchant compositions were compared in terms of etching rate, surface roughness and selectivity in a beaker process. The best fitting mixture was selected. To further increase the surface quality (bubble issue) a spin etcher tool is used for producing the channels. The dependence of homogeneity and defect density on media flux, and rotation velocity was investigated. Results show that high rotation velocity and high media flux lead to great defects in the channel wall. Through rotation of the wafer during etching, the etching rate of silicon rises compared to the beaker process due to the rapid removal of etch products and simultaneous supply of fresh etchant. After 38 min of etching, 300 µm deep semi-circular channels with high optical quality (Rq=10 nm±2 nm) over 3 m were produced.}, language = {de} } @inproceedings{HoellerZeitler, author = {H{\"o}ller, Christoph and Zeitler, Berndt}, title = {Laboratory study on flanking sound transmission in cold-formed steel-framed constructions}, series = {Towards a quieter future : 45th International Congress and Exposition on Noise Control Engineering (Internoise 2016) : Hamburg, Germany, 21-24 August 2016, Vol 8}, booktitle = {Towards a quieter future : 45th International Congress and Exposition on Noise Control Engineering (Internoise 2016) : Hamburg, Germany, 21-24 August 2016, Vol 8}, publisher = {Curran Associates Inc.}, pages = {6238 -- 6249}, abstract = {In a recent study at the National Research Council Canada, the sound transmission in cold-formed steel-framed constructions was investigated. The results of direct sound insulation tests of wall and floor assemblies were reported at EURONOISE 2015 and INTERNOISE 2015. This paper focuses on flanking sound transmission in cold-formed steel-framed constructions. A representative full-scale mock-up specimen was constructed in NRC's 8-room flanking transmission facility. The specimen consists of four loadbearing walls with 152 mm deep steel studs, four non-loadbearing walls with 92mm deep steel studs, and four floor-ceiling assemblies consisting of steel joists and a composite steel deck with gypsum concrete. Measurements were conducted according to the indirect method described in ISO 10848. The individual flanking paths were measured by a sequence of transmission loss measurements in which other transmission paths were suppressed by shielding. For the bare specimen without linings, the sound transmission for horizontally adjacent rooms with continuous subfloors is dominated by the floor-floor flanking paths. Floor coverings or floor toppings are needed to meet the requirements in the National Building Code of Canada. This paper presents details of the measurements, highlights some of the results and discusses implications.}, language = {en} } @article{HuttererBauhuberHummeletal., author = {Hutterer, Albert and Bauhuber, Michael and Hummel, Helmut and Lechner, Alfred}, title = {Real-time analyses of metal contaminations in the ppb-range}, series = {Solid State Phenomena}, volume = {195}, journal = {Solid State Phenomena}, publisher = {Trans Tech Publications}, doi = {10.4028/www.scientific.net/SSP.195}, pages = {269 -- 273}, abstract = {In high-tech processing even smallest concentrations of metal ions in process media are of the utmost significance because they cause expensive production failures. Currently, cost-intensive equipment, special trained staff and time consuming analyses are necessary to detect these contaminations in order to avoid failures. The Centers of Excellence Nanochem and Sensorics at the University of Applied Sciences Regensburg (owner of patent PCT/EP2010/064833) and their industrial partner Micro-Epsilon GmbH are developing a new miniaturized measurement device which allows cost-effective real-time analysis of fluidic media for the first time. The system is fully automated and can be directly connected to wet-etch benches. Hence it allows continuous real-time surveillance of metal contaminations in the ppb-range through absorption spectroscopy in process media. For this purpose a very small sample amount of the process medium and a specific complexing agent are mixed together. This leads to an increase in the molar extinction coefficients and though even smallest contaminations become visible. The main parts of our development are the simulation of the different system components, their production and chemical analyses with the evaluation model.}, language = {en} } @inproceedings{HoellerZeitlerMahn, author = {H{\"o}ller, Christoph and Zeitler, Berndt and Mahn, Jeffrey}, title = {Direct sound transmission loss of heavy gauge steel stud walls}, series = {Proceedings of Euronoise 2015 : 10th European Congress and Exposition on Noise Control Engineering : Maastricht, 31 May - 3 June 2015}, booktitle = {Proceedings of Euronoise 2015 : 10th European Congress and Exposition on Noise Control Engineering : Maastricht, 31 May - 3 June 2015}, address = {Maastricht}, pages = {1121 -- 1126}, language = {en} } @article{Jungnitsch, author = {Jungnitsch, Georg}, title = {Psychotherapeutische Verfahren bei chronischen Schmerzen}, series = {Fortschritte der Medizin}, volume = {108}, journal = {Fortschritte der Medizin}, number = {8}, pages = {50 -- 58}, abstract = {Psychotherapeutic possibilities of treating chronic pain are employed in two different ways: Firstly in the form of psychotherapy in patients whose strategies for coping with pain and/or pain genesis can be described in terms of psychopathological categories; secondly in the form of pain-coping training, which is generally indicated in the presence of chronic pain, in particular that which is traditionally termed organic. With respect to their effectiveness in achieving, in the first place, mood change, and in the assessment of symptoms, the individual procedures have been well tested. The question as to differential indication, which can most readily be applied to the use of biofeedback, remains largely unanswered.}, language = {de} } @article{PeterDalmerLechneretal., author = {Peter, Daniel and Dalmer, Michael and Lechner, Alfred and Gigler, Alexander M. and Stark, Robert W. and Bensch, Wolfgang}, title = {Measurement of the mechanical stability of semiconductor line structures in drying liquids with application to pattern collapse}, series = {Journal of Micromechanics and Microengineering}, volume = {21}, journal = {Journal of Micromechanics and Microengineering}, number = {2}, publisher = {IOP Science}, doi = {10.1088/0960-1317/21/2/025001}, abstract = {Enhanced particle removal processes in wet cleaning as well as drying processes of semiconductor wafers can cause significant lateral forces on surface structures. These forces, however, must not exceed the mechanical stability of structures on the wafer. Thus, a mechanical fracture test was used to assess the lateral mechanical stability of polysilicon line structures in relevant process liquids. The mechanical test was based on nanomanipulation with an atomic force microscope. Compared to fracture tests in air, data acquired in liquid isopropanol revealed a stabilizing effect. The differences in fracture forces can be attributed to a stress corrosion process on the surface. The size of the generated damage was influenced by the viscosity of the surrounding media.}, language = {en} } @inproceedings{PeterDalmerLotnyketal., author = {Peter, Daniel and Dalmer, Michael and Lotnyk, Andriy and Kienle, Lorenz and Lechner, Alfred and Bensch, Wolfgang}, title = {Solid bridging during pattern collapse (stiction) studied on silicon nanoparticles}, series = {MRS Online Proceedings Library}, volume = {1299}, booktitle = {MRS Online Proceedings Library}, publisher = {Springer Nature}, doi = {10.1557/opl.2011.397}, pages = {191 -- 196}, abstract = {The high surface to volume ratio of nanoparticles allows a detailed experimental study of the surface phenomena associated with solid bridging. Besides bulk analyses, the local view on the structure and composition via HRTEM is particularly essential. 50 nm core shell particles consisting of a silicon (Si) core and a SiO2 shell were used as model system to understand surface phenomena appearing for Si-based nanostructures. Evaporative drying from de-ionized water shows the most significant bridging effect based on SiO2. There is only a localized deposition of oxides between the particles during the drying process and no overall oxidation. For the deposition material, silicates are the most likely candidates.}, language = {en} } @inproceedings{ZeitlerHoellerMahn, author = {Zeitler, Berndt and H{\"o}ller, Christoph and Mahn, Jeffrey}, title = {Empirical model of direct sound transmission through lightweight wood-framed construction}, series = {Implementing noise control technology : 44th International Congress and Exposition on Noise Control Engineering (Internoise 2015) : San Francisco, California, USA, 9 - 12 August 2015}, booktitle = {Implementing noise control technology : 44th International Congress and Exposition on Noise Control Engineering (Internoise 2015) : San Francisco, California, USA, 9 - 12 August 2015}, publisher = {Curran}, address = {Red Hook, NY}, abstract = {Tools to predict sound transmission through building elements are beneficial from both amarketing and a research standpoint. Prediction models can assist with the optimization ofelement performance and often reduce both cost and time in projects. However, the morephysical phenomena are to be included in the model, the more input data that is needed,which in some cases can be quite time-consuming and costly to collect. A balance is neededbetween the input and modeling effort and the output, which is usually delivered in onethird octave frequency bands or single number ratings. Many different types of models arecommonly used, including analytical, numerical, and empirical are used, all of which haveadvantages and disadvantages. In this paper, the latter type is presented using a set ofphysical properties of lightweight wood elements, and the errors made in the prediction arequantified. The disadvantage of empirical compared to analytical modeling is that thephysical phenomena are more difficult to identify. The advantage is often the simplicityand accuracy of the prediction results.}, language = {en} } @inproceedings{ZeitlerMahnSabourinetal., author = {Zeitler, Berndt and Mahn, Jeffrey and Sabourin, Ivan and H{\"o}ller, Christoph and Schoenwald, Stefan}, title = {Apparent airborne sound insulation of hybrid wood-concrete masonry assemblies}, series = {Euronoise 2015 : 10th European Congress and Exposition on Noise Control Engineering : Maastricht, 31 May - 3 June 2015}, booktitle = {Euronoise 2015 : 10th European Congress and Exposition on Noise Control Engineering : Maastricht, 31 May - 3 June 2015}, address = {Maastricht}, organization = {Belgian Acoustical Association (ABAV), Acoustical Society of the Netherlands (NAG), European Acoustics Association (EAA)}, pages = {2515 -- 2520}, abstract = {As part of a research project to develop design solutions for concrete-masonry buildings for the Canadian market, the apparent sound insulation performance of hybrid assemblies with concrete masonry walls and wood joist floors was evaluated. In this paper, the effect of junction coupling is investigated in an ISO 15712 flanking prediction context. Airborne flanking path data predicted according to ISO 15712 are compared to data measured using the indirect ISO 10848 shielding method. Recommendations are made on how appropriate the application of ISO 15712 is for this type of hybrid assembly.}, language = {en} } @article{DamsNavitskiPrommesbergeretal., author = {Dams, Florian and Navitski, Aliaksandr and Prommesberger, Christian and Serbun, Pavel and Langer, Christoph and M{\"u}ller, G{\"u}nter and Schreiner, Rupert}, title = {Homogeneous Field Emission Cathodes With Precisely Adjustable Geometry Fabricated by Silicon Technology}, series = {IEEE Transactions on Electron Devices}, volume = {59}, journal = {IEEE Transactions on Electron Devices}, number = {10}, publisher = {IEEE}, issn = {0018-9383}, doi = {10.1109/TED.2012.2206598}, pages = {2832 -- 2837}, abstract = {Silicon-based cathodes with precisely aligned field emitter arrays of sharp tips applicable for miniaturized electron sources were successfully fabricated and characterized. This was made possible by an improved fabrication process using wet thermal oxidation, wet etching, and reactive-ion etching steps with adjustable anisotropy. As substrate materials, both p-doped silicon and n-doped silicon were used. The cathode chips contain about 3 × 10 5 Si tips/cm 2 in a triangular array with tip heights of 2.5 μm, tip radii of less than 30 nm, and spacing of 20 μm. Well-aligned field emission (FE) and excellent homogeneity from all tips (i.e., 100\% efficiency) and maximum stable currents of typically 0.1 μA (0.6 μA) for p (n)-type Si were reproducibly achieved. The current-voltage characteristics of the p-Si tips exhibit the expected saturation at around 10 nA with around ten times better current stability, whereas the n-Si tips show the usual Fowler-Nordheim behavior. Additional coating of the Si tips with 5-nm Cr and 10-nm Au layers resulted in improved stability and at least five times higher average FE current limits (about 3 μA) at about 30\% higher operation voltage.}, language = {en} } @article{TanYeapChowetal., author = {Tan, Pi Lin and Yeap, Guan Yeow and Chow, Wen Shyang and Schreiner, Rupert and Cheong, Kuan Yew}, title = {Effect of Thickness of Porphyrin on Electrical Properties of Organic Devices}, series = {Advanced Materials Research (AMR)}, volume = {1024}, journal = {Advanced Materials Research (AMR)}, publisher = {Trans Tech Publications Ltd.}, address = {Baech}, issn = {1662-8985}, doi = {10.4028/www.scientific.net/AMR.1024.381}, pages = {381 -- 384}, abstract = {The study on electrical properties for both 2,3,7,8,12,13,17,18-octaethyl-21,23H-porphine Cu (II) (Cu-porphyrin) and 2,3,7,8,12,13,17,18-octaethyl-21,23H-porphine (porphyrin) thin film, which were fabricated using spin coating method was conducted. Porphyrins were diluted with chloroform of various concentrations (0.05 mg/ml, 0.1 mg/ml, 0.5 mg/ml, 2.0 mg/ml and 3.0 mg/ml). The solution was spin coated on top of glass substrates. A layer of aluminum was evaporated on top of the organic thin film through thermal evaporation and shadow mask was placed on top of the organic thin film where two electrodes with a gap of 50 μm were formed. Surface morphology of the organic thin film was observed by scanning electron microscope (SEM) and profilometer. Different concentrations of organic solutions greatly affected the molecular packing and arrangement order of the organic thin film and thickness of the organic layer and eventually affected electrical properties of the devices.}, language = {en} } @article{LangerBerndtSchreiner, author = {Langer, Christoph and Berndt, Dominik and Schreiner, Rupert}, title = {Sensitivity of thermal conductivity vacuum gauges for constant current and constant temperature operation}, series = {Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics}, volume = {40}, journal = {Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics}, number = {5}, publisher = {AIP Publishing}, doi = {10.1116/6.0001964}, abstract = {To optimize the measurement range of thermal conductivity vacuum gauges, an expression for the sensitivity is required that takes into account all geometrical, material-specific, and operating parameters. Therefore, equations of the sensor output signal as a function of the pressure for the constant current and the constant temperature mode have been developed analytically. Based on these equations, the sensitivity of the vacuum gauge and its influencing parameters was investigated and discussed. For comparable conditions, the constant temperature operation shows a significantly higher sensitivity for high pressures, while the constant current operation shows higher sensitivity at low pressures. The sensitivity in both the constant current and the constant temperature mode depends on the ratio of the filament surface area and the parasitic thermal conductance. In addition, for the constant current operation, the sensitivity also depends on the current value and the temperature coefficient of the filament resistor. For the constant temperature operation, the sensitivity additionally depends on the distance of the filament and the reference plane. However, to extend the measurement range of a thermal conductivity vacuum gauge toward low pressures, a reduction of the parasitic thermal conductance is mandatory for both the constant current and the constant temperature mode.}, language = {en} } @inproceedings{DamsPrommesbergerSchreiner, author = {Dams, Florian and Prommesberger, Christian and Schreiner, Rupert}, title = {Fabrication process of silicon-tip-arrays for field emission applications}, series = {24th International Vacuum Nanoelectronics Conference (IVNC), 2011 : 18 - 22 July 2011, Historische Stadthalle Wuppertal, Germany}, booktitle = {24th International Vacuum Nanoelectronics Conference (IVNC), 2011 : 18 - 22 July 2011, Historische Stadthalle Wuppertal, Germany}, publisher = {IEEE}, isbn = {978-3-00-035081-8}, issn = {2380-6311}, pages = {49 -- 50}, abstract = {A micromachined process to assemble homogeneous and reproducible tip arrays for field emission applications is developed and characterized. As substrate material p- as well as n-doped silicon is used. Lateral position of the tips is defined by structuring silicon dioxide to discs in a photolithographic process. Vertical structure of the tips is defined by a combination of RIE dry etching with controlled anisotropy and thermally oxidization of silicon in order to sharpen the tips. Hence field emitter arrays (FEAs) can be assembled both as bare and coated cathodes. To assemble field emission diodes, this fabrication process allows placing a metal anode in a micrometer order distance to the tips by a self-aligning procedure. The anode is placed in an evaporation process whereupon sharpening oxide is used as isolator between anode and cathode. Electrical characterization of the cathodes showed very good homogeneity, well alignment and stability over time of emission current from all tips (i.e. 100\% efficiency).}, language = {en} } @unpublished{RueckMuellerJobstetal., author = {R{\"u}ck, Thomas and M{\"u}ller, Max and Jobst, Simon and Weigl, Stefan and Pangerl, Jonas and Bierl, Rudolf and Matysik, Frank-Michael}, title = {Digital Twin of a Photoacoustic Trace Gas Sensor for Monitoring Methane in Complex Gas Compositions}, publisher = {Elsevier / SSRN}, doi = {10.2139/ssrn.4215170}, pages = {22}, abstract = {The digitalization of industrial processes requires smart sensor systems. Photoacoustic spectroscopy is well suited for this purpose as it allows for small-sized and low-cost trace gas analysis. However, the method is susceptible to changes in measurement conditions and standard calibration routines often fail to correct for all changes. We therefore created a Digital Twin (DT) of a photoacoustic trace gas sensor for methane and evaluated it regarding variations in gas composition (CH4, N2, O2, CO2, H2O), temperature and pressure. With a mean absolute percentage error of 0.8 \% the accuracy of the sensor after DT compensation significantly exceeds the 24 \% achieved based on standard calibration in nitrogen. For the first time, we can fully analytically compute the photoacoustic signal under moderate ambient conditions with an error in the ppbV range by taking a holistic approach. Assuming knowledge of the underlying energy transfer processes, the model of this Digital Twin can be adapted to any microphone based photoacoustic sensor for monitoring any analyte species.}, language = {en} } @article{SchuezDraegerRichteretal., author = {Sch{\"u}z, B. and Dr{\"a}ger, D. and Richter, Stefanie and Kummer, K. and Kuhlmey, Adelheid and Tesch-R{\"o}mer, C.}, title = {Autonomie trotz Multimorbidit{\"a}t im Alter - Der Berliner Forschungsverbund AMA}, series = {Zeitschrift f{\"u}r Gerontologie und Geriatrie}, journal = {Zeitschrift f{\"u}r Gerontologie und Geriatrie}, number = {Sonderheft 2}, publisher = {Springer}, pages = {9 -- 25}, abstract = {Mit zunehmendem Alter steigt der Anteil mehrfach erkrankter Menschen und immer mehr Menschen erreichen ein sehr hohes Lebensalter. Trotz des medizinischen Fortschritts und verbesserter Lebenslagen m{\"u}ssen viele alte Menschen k{\"o}rperliche, psychische und soziale Einschr{\"a}nkungen bew{\"a}ltigen. Es ist eine große gesundheits- und sozialpolitische Herausforderung, diese alten Frauen und M{\"a}nner mit gesundheitlichen Beeintr{\"a}chtigungen in ihrem Bestreben nach einer weitestgehend autonomen Lebensgestaltung zu unterst{\"u}tzen und zu st{\"a}rken. Vor diesem Hintergrund widmete sich der Forschungsverbund „Autonomie trotz Multimorbidit{\"a}t im Alter" (AMA I) der Leitfrage, inwieweit eine selbstbestimmte Lebensgestaltung alter mehrfach erkrankter Menschen erhalten werden kann. Um der Vielfalt der Lebenswelten {\"a}lterer Menschen gerecht zu werden, wurden im Alltag wenig eingeschr{\"a}nkte und pflegebed{\"u}rftige sowie kognitiv beeintr{\"a}chtigte Personen in die Untersuchung einbezogen. Darunter waren Frauen und M{\"a}nner, die noch im eigenen Haushalt und solche die im Pflegeheim lebten. Im Fokus der Untersuchungen standen die Ressourcen, die den alten Menschen in ihrer jeweiligen Lebenssituation zur Verf{\"u}gung standen und die Frage, wie diese gest{\"a}rkt werden k{\"o}nnen. Der Beitrag pr{\"a}sentiert Ergebnisse zu dieser Forschungsfrage aus der 1. F{\"o}rderphase des AMA-Verbundes. Darauf aufbauend werden in einer 2. F{\"o}rderphase (2011-2013, AMA II) nunmehr nachhaltige praxisrelevante Interventionen zur Mobilisierung von autonomierelevanten Ressourcen mehrfach erkrankter alter Menschen entwickelt und auf ihre Praxistauglichkeit getestet.}, language = {de} } @article{ScheidtNaveRichterFuchsetal., author = {Scheidt-Nave, Christa and Richter, Stefanie and Fuchs, Judith and Kuhlmey, Adelheid}, title = {Herausforderungen an die Gesundheitsforschung f{\"u}r eine alternde Gesellschaft am Beispiel "Multimorbidit{\"a}t"}, series = {Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz}, volume = {53}, journal = {Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz}, number = {5}, pages = {441 -- 450}, abstract = {Indem ein wachsender Anteil der Bev{\"o}lkerung ein hohes Alter erreicht, {\"a}ndern sich Krankheitsspektrum und Versorgungsbedarf. Besondere Herausforderungen f{\"u}r das Gesundheitssystem ergeben sich durch Mehrfacherkrankung (Multimorbidit{\"a}t) {\"a}lterer Menschen. Im Gegensatz zu krankheitsspezifischen Endpunkten treten Funktion im Alltag und subjektive Ergebnisdimensionen wie selbstbestimmte Lebensf{\"u}hrung (Autonomie), soziale Teilhabe und Lebensqualit{\"a}t als Pr{\"a}ventions- und Behandlungsziel in den Vordergrund. Die Gesundheitsforschung hat die Aufgabe, auf die Bed{\"u}rfnisse spezifischer Zielgruppen alter Menschen abgestimmte Pr{\"a}ventions- und Versorgungsmodelle zu entwickeln. Entscheidend dabei ist die St{\"a}rkung von personalen, sozialen und organisatorischen Ressourcen. Voraussetzung hierf{\"u}r sind genaue Kenntnisse zur Entwicklung und zum Verlauf des Krankheitsgeschehens und zu zentralen Einflussfaktoren auf der Grundlage epidemiologischer Beobachtungsstudien. Gezielte Maßnahmen sind in Interventions- und Evaluationsstudien auf Wirksamkeit, Wirkung und Wirtschaftlichkeit zu {\"u}berpr{\"u}fen. Der vom Bundesministerium f{\"u}r Bildung und Forschung (BMBF) initiierte F{\"o}rderungsschwerpunkt „Gesundheit im Alter" f{\"o}rdert insgesamt sechs Forschungsverb{\"u}nde zum Thema Multimorbidit{\"a}t, die hier kurz vorgestellt werden.}, language = {de} } @incollection{RichterKuhlmey, author = {Richter, Stefanie and Kuhlmey, Adelheid}, title = {Alter, Altern und Gesundheit als Herausforderung f{\"u}r Forschung in Verbundzusammenh{\"a}ngen}, series = {Autonomie trotz Multimorbidit{\"a}t}, booktitle = {Autonomie trotz Multimorbidit{\"a}t}, editor = {Tesch-R{\"o}mer, Clemens}, publisher = {Hogrefe}, pages = {203 -- 220}, abstract = {Angesichts der zunehmenden Alterung der Bev{\"o}lkerung wird die Frage nach dem Erhalt von Autonomie alter Menschen trotz Mehrfacherkrankungen immer brisanter. Die Beitr{\"a}ge in diesem Band besch{\"a}ftigen sich mit der Frage, wie alte Menschen trotz Multimorbidit{\"a}t und Gesundheitseinbußen autonom und selbstbestimmt leben k{\"o}nnen.Die Autoren pr{\"a}sentieren Befunde, die den Entwicklungsstand altersangemessener, zielgruppenspezifischer Instrumente sowie Zugangswege zur Erfassung von Multimorbidit{\"a}t und Autonomie aufzeigen. Weitere Beitr{\"a}ge thematisieren u.a. personale, preofessionelle und sozial-r{\"a}umliche Faktoren, die Autonomie angesichts von Multimorbidit{\"a}t unterst{\"u}tzen und als Ressourcen wirken. Wie diese Ressourcen einzeln und in ihrer Wechselbeziehung zum Autonomieerhalt beitragen, wie sie erhalten und gef{\"o}rdert werden k{\"o}nnen, wird beispielhaft im Kontext komplexer autonomierelevanter Gesundheitsprobleme wie Schmerz, Sturz- und Schlafst{\"o}rungen gezeigt.}, language = {de} } @article{RichterFlickKuhlmey, author = {Richter, Stefanie and Flick, Uwe and Kuhlmey, Adelheid}, title = {Alter(n) und Gesundheit. Chancen und H{\"u}rden einer disziplinen{\"u}bergreifenden Zusammenarbeit}, series = {G+G Wissenschaft}, volume = {11}, journal = {G+G Wissenschaft}, number = {2}, publisher = {GGW}, pages = {7 -- 15}, abstract = {Eine umfassende theoretische und empirische Auseinandersetzung mit Fragestellungen und Problemen des Alter(n)s setzt eine inter- beziehungsweise transdisziplin{\"a}re Wissenschaftspraxis voraus. Deren Realisierung st{\"o}ßt allerdings immer wieder an Grenzen, denn eine disziplinen{\"u}bergreifende Zusammenarbeit steht einem Wissenschaftssystem gegen{\"u}ber, dem Ausdifferenzierung, Abgrenzung, Spezialisierung und die Bildung disziplinenspezifischer Kulturen anhaften. Hinzu kommen Publikationsstrukturen mit den Regeln eines akademischen Karrieremarktes, der eine enge (sub)disziplin{\"a}re Fokussierung belohnt. Der Beitrag beleuchtet die Probleme und L{\"o}sungsstrategien der disziplinen{\"u}bergreifenden Zusammenarbeit in der Gerontologie am Beispiel des Forschungsverbundes "Gesundheit im Alter"}, language = {de} } @inproceedings{MuellerRueckJobstetal., author = {M{\"u}ller, Max and R{\"u}ck, Thomas and Jobst, Simon and Pangerl, Jonas and Bierl, Rudolf and Matysik, Frank-Michael}, title = {Creating a Digital Twin of a Photoacoustic Gas Sensor for Methane Detection in Complex Gas Matrices}, series = {Proceedings Optical Sensors and Sensing Congress 2022 (AIS, LACSEA, Sensors, ES): 11-15 July 2022, Vancouver, British Columbia, Canada}, booktitle = {Proceedings Optical Sensors and Sensing Congress 2022 (AIS, LACSEA, Sensors, ES): 11-15 July 2022, Vancouver, British Columbia, Canada}, publisher = {Optica Publishing Group}, isbn = {978-1-957171-10-4}, doi = {10.1364/LACSEA.2022.LW4D.2}, abstract = {We present the calculation results from a digital twin (DT) of our photoacoustic (PA) sensor for methane detection, regarding gas composition, temperature and pressure variations.}, language = {en} } @article{PeterHolsteynsDalmeretal., author = {Peter, Daniel and Holsteyns, Frank and Dalmer, Michael and Kruwinus, Hans and Lechner, Alfred and Bensch, Wolfgang}, title = {A Study on the Structure Collapse Mechanisms for High Aspect Ratio Structures with Application to Clean Processing}, series = {ECS Meeting Abstracts}, volume = {MA2009-02}, journal = {ECS Meeting Abstracts}, number = {24}, publisher = {IOP Science}, doi = {10.1149/MA2009-02/24/2084}, language = {en} } @incollection{Skornia, author = {Skornia, Christoph}, title = {Sicherheit in der Cloud}, series = {IT-Sicherheit}, booktitle = {IT-Sicherheit}, editor = {Lang, Michael and L{\"o}hr, Hans and Angermeier, Daniel}, publisher = {Hanser}, address = {M{\"u}nchen}, isbn = {978-3-446-47223-5}, doi = {10.3139/9783446473478.015}, pages = {263 -- 278}, language = {de} } @inproceedings{SchreinerMulotWiedmannetal., author = {Schreiner, Rupert and Mulot, M. and Wiedmann, J{\"o}rg and Coenning, W. and Porsche, J. and Gentner, Jean-Louis and Berroth, Manfred and Scholz, Ferdinand and Schwizer, H.}, title = {Dynamic measurements on narrow linewidth complex coupled 1.55 μm DFB lasers with gain and index grating in antiphase}, series = {Conference Proceedings. Eleventh International Conference on Indium Phosphide and Related Materials (IPRM'99), 16-20 May 1999, Davos, Switzerland}, booktitle = {Conference Proceedings. Eleventh International Conference on Indium Phosphide and Related Materials (IPRM'99), 16-20 May 1999, Davos, Switzerland}, publisher = {IEEE}, address = {Piscataway}, isbn = {0-7803-5562-8}, doi = {10.1109/ICIPRM.1999.773626}, pages = {25 -- 28}, abstract = {We report on dynamic measurements on antiphase complex coupled 1.55 /spl mu/m DFB lasers. The antiphase complex coupling mechanism is realized by periodically etching the active layer and quarternary InGaAsP overgrowth. This new fabrication approach results in very narrow linewidths measured on devices with rather short resonator lengths. The minimum linewidth for a 375 /spl mu/m long ridge waveguide laser was only 250 kHz at an optical output power of 4 mW. The RC-limited 3dB-bandwidth for those devices was /spl sim/6 GHz. Using circuit model corrections, the intrinsic bandwidth limitation of those lasers was found to be 17.4 GHz.}, language = {en} } @inproceedings{SchreinerNaegeleKoerbletal., author = {Schreiner, Rupert and Naegele, Peter and Koerbl, Michael and Groening, Albert and Gentner, Jean-Louis and Schweizer, Heinz C.}, title = {Monolithically integrated tunable laterally-coupled distributed feedback lasers with self-aligned Ti/Pt/Au ohmic contacts}, series = {Proceedings Volume 4871, Semiconductor Lasers and Optical Amplifiers for Lightwave Communication SystemsSemiconductor Lasers and Optical Amplifiers for Lightwave Communication Systems}, booktitle = {Proceedings Volume 4871, Semiconductor Lasers and Optical Amplifiers for Lightwave Communication SystemsSemiconductor Lasers and Optical Amplifiers for Lightwave Communication Systems}, editor = {Mirin, Richard P. and Menoni, Carmen S.}, publisher = {SPIE}, doi = {10.1117/12.457281}, pages = {160}, abstract = {We present a new method for fabrication of tunable InGaAsP-InP single mode lasers without epitaxial overgrowth. These devices show the advantage of a considerably simplified fabrication process compared to conventional tunable laser types. The lasers comprise an active Bragg reflector integrated with an uncorrugated separately pumped gain region. To overcome the extensive and expensive overgrowth step we realized a surface grating on both sides of the ridge mesa, which provides DFB operation. By adjusting the current through the Bragg reflector, the wavelength can be tuned between 1590.8 nm and 1595.2 nm. A maximum of 11 wavelength channels with an average spacing of ~0.5 nm and a constant optical output power of ~0.5 mW are addressable.}, language = {en} } @article{CheongAwKarimovetal., author = {Cheong, Kuan Yew and Aw, Kean and Karimov, Khasan S. and Zhao, Feng and Mahroof-Tahir, Mohammad and Schreiner, Rupert}, title = {Advances in Smart Materials and Applications}, series = {Advances in Materials Science and Engineering}, journal = {Advances in Materials Science and Engineering}, publisher = {Hindawi}, doi = {10.1155/2014/517342}, abstract = {This is one of a series of special issues published in Advances in Materials Science and Engineering, focusing on the latest advances of smart materials and their applications. Evolution of engineering materials is strongly depending on the growing transformation of complexity in engineering products. New materials being designed are required to provide specific properties and demonstrate certain functional characteristics by manipulating their dimension, chemistry, and structure through various advanced technologies. Therefore, "smartness" of a material has become the topic of interest. Properties of smart materials may change accordingly to the applied external stimuli. Under the direction of the editorial team, we showcase advances of organic and inorganic based smart materials and their applications in areas of specific interest such as energy, environment, and health. A total of 9 articles are published in this special issue. Six articles are focused on production, synthesis, and optimization of smart materials; and the remaining are dedicated to application of smart materials.}, language = {en} } @inproceedings{SaravananGerlachPeschkeetal., author = {Saravanan, Brem Kumar and Gerlach, Philipp and Peschke, Martin and Knoedl, Thomas and Schreiner, Rupert and Hanke, Christian and Stegmueller, Bernhard}, title = {Integrated DFB laser electro-absorption modulator based on identical MQW-double stack active layer for high-speed modulation beyond 10 GBIT/S}, series = {16th IPRM. 2004 International Conference on Indium Phosphide and Related Materials, 31 May - 04 June 2004, Kagoshima, Japan}, booktitle = {16th IPRM. 2004 International Conference on Indium Phosphide and Related Materials, 31 May - 04 June 2004, Kagoshima, Japan}, publisher = {IEEE}, isbn = {0-7803-8595-0}, doi = {10.1109/ICIPRM.2004.1442656}, pages = {236 -- 238}, abstract = {Integrated DFBLD-EAM-SOA devices utilizing an identical MQW active region have been realized in the AlGaInAs/InP material system. A fiber-coupled optical power of >6 mW with a 10 dB static extinction, 44 dB SMSR single-mode spectrum and a 3 dBe cutoff frequency of 25 GHz was measured.}, language = {en} } @article{ZahnerSchreinerStierstorferetal., author = {Zahner, Th and Schreiner, Rupert and Stierstorfer, R. and Kus, O. and Li, S. T. and Roessler, R. and Pedarnig, J. D. and B{\"a}uerle, D. and Lengfellner, H.}, title = {Off-diagonal Seebeck effect and anisotropic thermopower in Bi2Sr2CaCu2O8 thin films}, series = {Europhysics Letters}, volume = {40}, journal = {Europhysics Letters}, number = {6}, publisher = {IOP Sciences}, doi = {10.1209/epl/i1997-00521-4}, pages = {673 -- 678}, abstract = {The anisotropy ΔS of the thermopower in thin films of the high-Tc superconductor Bi2Sr2CaCu2O8 is investigated using off-c-axis epitaxial film growth and the off-diagonal Seebeck effect. The measurements represent a new method for the investigation of anisotropic transport properties in solids, taking advantage of the availability of oriented grown crystalline thin films instead of using bulk crystals. First results for the temperature dependence ΔS(T) in Bi2Sr2CaCu2O8 thin films are presented and described within a two-band model. Subjecting the films to heat treatments in different gases at relatively low temperatures, ΔS could reversibly be changed in a wide range.}, language = {en} } @inproceedings{KnodlHankeSaravananetal., author = {Knodl, Thomas and Hanke, Christian and Saravanan, Brem Kumar and Peschke, Martin and Schreiner, Rupert and Stegmuller, Bernhard}, title = {Integrated 1.3-μm InGaAlAs-InP laser-modulator with double-stack MQW layer structure}, series = {Proceedings Volume 5451, Integrated Optics and Photonic Integrated Circuits}, booktitle = {Proceedings Volume 5451, Integrated Optics and Photonic Integrated Circuits}, editor = {Righini, Giancarlo C. and Honkanen, Seppo}, publisher = {SPIE}, doi = {10.1117/12.544610}, pages = {1}, abstract = {We present first experimental results of the successful transfer of our monolithic integrated double-stack multi quantum well laser-modulator approach from the traditional InGaAsP/InP to the more promising InGaAlAs/InP material system. In continuous wave operation at room temperature, the devices achieved threshold currents of <21 mA, fiber coupled optical power levels up to 570 μW and static extinction ratios in the range of 15 dB/V. The measured small-signal modulation bandwidth of about 10 GHz is capacitance limited due to a conservative device layout.}, language = {en} } @inproceedings{SchreinerGrabeldingerWiedmannetal., author = {Schreiner, Rupert and Grabeldinger, H. and Wiedmann, J. and Wunstel, K. and Porsche, J. and Scholz, Ferdinand and Schweizer, H.}, title = {Complex coupled 1.55 mu m tunable super-grating DFB lasers and photonic filters}, series = {Compound semiconductors 1999 : proceedings of the Twenty-Sixth International Symposium on Compound Semiconductors held in Berlin, Germany, 22 - 26 August 1999}, booktitle = {Compound semiconductors 1999 : proceedings of the Twenty-Sixth International Symposium on Compound Semiconductors held in Berlin, Germany, 22 - 26 August 1999}, publisher = {Inst. of Physics Publ.}, address = {Bristol [u.a.]}, isbn = {0-7503-0704-8}, abstract = {We report on the investigation and realization of photonic filters based on the combination of fractional compositions of a few basic grating periods. Using a minimum set of two basic periods Lambda(1) and Lambda(2) we demonstrate comb-like few mode photonic band gap structures with arbitrary numbers of bands and frequency spacing between the bands. Optically integrated filters of different comb periods result in switchable wavelength filters for channel selection in WDM applications.}, language = {en} } @inproceedings{SchreinerSchweizer, author = {Schreiner, Rupert and Schweizer, Heinz C.}, title = {High frequency operation of 1.57 μm laterally gain coupled DFB lasers with self aligned ohmic contacts and nickel surface gratings}, series = {IEEE 18th International Semiconductor Laser Conference; 29 Sept.-3 Oct. 2002, Garmisch, Germany}, booktitle = {IEEE 18th International Semiconductor Laser Conference; 29 Sept.-3 Oct. 2002, Garmisch, Germany}, publisher = {IEEE}, isbn = {0-7803-7598-X}, doi = {10.1109/ISLC.2002.1041099}, pages = {21 -- 22}, abstract = {Laterally coupled DFB lasers with self-aligned ohmic contacts show the advantage of a, considerably simplified fabrication process. Side-mode-suppresion-ratios up to 55 dB and 3 dB-bandwidths beyond 15 GHz were obtained for these devices.}, language = {en} } @unpublished{MuellerWeiglMuellerWilliamsetal., author = {M{\"u}ller, Max and Weigl, Stefan and M{\"u}ller-Williams, Jennifer and Lindauer, Matthias and R{\"u}ck, Thomas and Jobst, Simon and Bierl, Rudolf and Matysik, Frank-Michael}, title = {Ambient methane monitoring at Hohenpeißenberg utilizing photoacoustic spectroscopy and cavity ring down spectroscopy}, doi = {10.5194/egusphere-2023-1010}, abstract = {With an atmospheric concentration of approximately 2000 parts per billion (ppbV, 10-9) methane (CH4) is the second most abundant greenhouse gas (GHG) in the atmosphere after carbon dioxide (CO2). The task of long-term and spatially resolved GHG monitoring to verify whether climate policy actions are effective, is becoming more crucial as climate change progresses. In this paper we report the CH4 concentration readings of our photoacoustic (PA) sensor over a five day period at Hohenpeißenberg, Germany. As a reference device a calibrated cavity ringdown spectrometer Picarro G2301 from the meteorological observatory was employed. Trace gas measurements with photoacoustic instruments promise to provide low detection limits at comparably low costs. However, PA devices are often susceptible to cross-sensitivities related to environmental influences. The obtained results show that relaxation effects due to fluctuating environmental conditions, e.g. ambient humidity, are a non-negligible factor in PA sensor systems. Applying algorithm compensation techniques, which are capable of calculating the influence of relaxational effects on the photoacoustic signal, increase the accuracy of the photoacoustic sensor significantly. With an average relative deviation of 1.11 \% from the G2301, the photoacoustic sensor shows good agreement with the reference instrument.}, language = {en} } @article{DenkSchuengelWeberetal., author = {Denk, Alexander and Sch{\"u}ngel, Verena and Weber, Stefka and Kaulen, Corinna}, title = {Heimexperiment und Online-Dokumentation : Praktische Ausbildung in den MINT-F{\"a}chern}, series = {Chemie in unserer Zeit}, journal = {Chemie in unserer Zeit}, publisher = {Wiley-VCH}, doi = {10.1002/ciuz.202100018}, abstract = {Die Anleitung zum selbst{\"a}ndigen wissenschaftlichen Arbeiten ist ein fester Bestandteil in der naturwissenschaftlichen Ausbildung, der im letzten Jahr durch Distanz-Unterricht stark vernachl{\"a}ssigt wurde. Wir stellen hier einen Ansatz vor, bei dem Studierende zu Hause mit Alltagsgegenst{\"a}nden in Teilaufgaben die Aktivit{\"a}t von Hefe in Abh{\"a}ngigkeit von Temperatur und Substrat untersucht haben. Die Ergebnisse des gesamten Kurses wurden in einem Google-Dokument gesammelt und zentral ausgewertet. Gleichzeitig fand ein Erfahrungsaustausch unter den Lernenden statt und Probleme konnten {\"o}ffentlich diskutiert werden. Dar{\"u}ber hinaus wurden grundlegende F{\"a}higkeiten wie Beobachten, Protokollieren und detailgetreues Berichten ge{\"u}bt. Die Online-Dokumentation und -Erfassung der Ergebnisse stellt somit eine geeignete Methode dar, die Durchf{\"u}hrung von Heimexperimenten zu aktivieren und zu koordinieren.}, language = {de} } @article{PourshahidiJeanKaulenetal., author = {Pourshahidi, Ali Mohammad and Jean, Neha and Kaulen, Corinna and Jakobi, Simon and Krause, Hans-Joachim}, title = {Impact of Particle Size on the Nonlinear Magnetic Response of Iron Oxide Nanoparticles during Frequency Mixing Magnetic Detection}, series = {Sensors}, volume = {24}, journal = {Sensors}, number = {13}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s24134223}, abstract = {Magnetic nanoparticles (MNPs), particularly iron oxide nanoparticles (IONPs), play a pivotal role in biomedical applications ranging from magnetic resonance imaging (MRI) enhancement and cancer hyperthermia treatments to biosensing. This study focuses on the synthesis, characterization, and application of IONPs with two different size distributions for frequency mixing magnetic detection (FMMD), a technique that leverages the nonlinear magnetization properties of MNPs for sensitive biosensing. IONPs are synthesized through thermal decomposition and subsequent growth steps. Our findings highlight the critical influence of IONP size on the FMMD signal, demonstrating that larger particles contribute dominantly to the FMMD signal. This research advances our understanding of IONP behavior, underscoring the importance of size in their application in advanced diagnostic tools.}, language = {en} } @unpublished{SchwarzPastoetterTranetal., author = {Schwarz, Tobias and Past{\"o}tter, Angelina and Tran, Trung and Schlosser, Marc and Kaulen, Corinna and Lechner, Alfred and Kammler, Martin and Slabon, Adam}, title = {Effect of Temperature on the Growth of Cu(I)O Nanocubes: The Impact of the Copper Precursor Species}, series = {SSRN}, journal = {SSRN}, publisher = {Elsevier}, doi = {10.2139/ssrn.4909639}, abstract = {Cuprous oxide (Cu2O) nanoparticles were synthesized using a wet chemical surfactant free method at different synthesis temperatures from 25 ◦C to 60 ◦C. Morphology, size, and chemical composition of the prepared Cu2O nanoparticles were analyzed by SEM, PXRD, and ATR-IR. We discovered that the chemical composition of the Cu2O nanoparticles remained unaffected by the synthesis temperature. However, morphology and size of the nanoparticles showed a strong temperature dependency. This could be attributed to the temperature induced formation of cupric oxide (CuO) species from the copper hydroxide (Cu(OH)2 ) precursor which also functions as copper precursor for the Cu2O nanoparticle growth. The cupric oxide species was determined to be the main cause for the formation of micrometer sized particles, whereas with the Cu(OH)2 precursor species for the Cu2O nanoparticles nanocubes with smaller edge lengths as well as octahedrons were obtained.}, language = {en} } @unpublished{Steffens, author = {Steffens, Oliver}, title = {Binomial Distribution Nomogram after Larson}, abstract = {Following an idea of Larson (1966) we construct a nomogram for cumulative binomial distribution that can be used to perform hypothesis testing, quality management (e.g. test design) and other statistical tasks. The nomogram can be printed and directly used with a simple ruler to read the results. It is instructive and as an analog computing device continuous changes are easily visible.}, language = {en} } @incollection{HoellerBloedt, author = {H{\"o}ller, Christoph and Bl{\"o}dt, Adrian}, title = {Praxisnahe, projektbasierte Lehre in der Bauakustik mit Hilfe von realen Bauobjekten}, series = {Tagungsband - Proceedings "Fortschritte der Akustik - DAGA 2024" : DAGA 2024 - 50. Jahrestagung f{\"u}r Akustik, 18.-21. M{\"a}rz 2024, Hannover}, booktitle = {Tagungsband - Proceedings "Fortschritte der Akustik - DAGA 2024" : DAGA 2024 - 50. Jahrestagung f{\"u}r Akustik, 18.-21. M{\"a}rz 2024, Hannover}, editor = {Rolfes, Raimund and Peissig, J{\"u}rgen}, isbn = {978-3-939296-22-5}, pages = {826 -- 828}, abstract = {Im Rahmen des Masterstudiengangs Bauingenieurwesen k{\"o}nnen Studierende der Ostbayerischen Technische Hochschule Regensburg einen Wahlpflichtkurs zu fortgeschrittener Bauphysik belegen, um ihr Wissen {\"u}ber W{\"a}rme- und Feuchteverhalten, Energieeffizienz von Geb{\"a}uden sowie Raum- und Bauakustik zu vertiefen. Im letzten Jahr wurde dieser Kurs von einer klassischen Frontalvorlesung auf eine interaktivere und praxisn{\"a}here Unterrichtsform umgestellt. Im Fokus stehen nun Gruppenarbeiten und projektbasiertes Lernen mit realen Bauprojekten. F{\"u}r den Bauakustik-Teil wurde ein k{\"u}rzlich errichtetes Mehrfamilienhaus in Holzbauweise als Beispielobjekt verwendet. Die Studierenden wurden in f{\"u}nf Gruppen eingeteilt, die sich jeweils mit einem Aspekt des akustischen Planungsprozesses befassten: Luft- und Trittschalld{\"a}mmung, Raumakustik, Fassadenschalld{\"a}mmung, Ger{\"a}usche von geb{\"a}udetechnischen Anlagen sowie Immissionsschutz. Jede Gruppenaufgabe war so konzipiert, dass sie Berechnungen und messtechnische Aspekte enthielt. Die Studierenden wurden durch ausgew{\"a}hlte Vorlesungen, Kleingruppenbetreuung und einen abschließenden "Messtag" unterst{\"u}tzt. Am Ende des Semesters pr{\"a}sentierte jede Gruppe die f{\"u}r die Projektaufgaben verwendeten Methoden und die Ergebnisse. Die ersten R{\"u}ckmeldungen der Studierenden sind positiv, das Engagement hat sp{\"u}rbar zugenommen. Der praxisorientierte Ansatz impliziert, dass die Studierenden mit realen Herausforderungen konfrontiert werden, wie beispielsweise unbekannten oder fehlerhaften Daten, anspruchsvollen Messger{\"a}ten oder komplexen Vorschriften. Sie lernen, wie sie mit diesen Herausforderungen umgehen k{\"o}nnen. In diesem Beitrag werden Einzelheiten des Projekts und die bisher gesammelten Erfahrungen vorgestellt.}, language = {de} } @inproceedings{PodstranskyHausladenZlamaletal., author = {Podstr{\´a}nsk{\´y}, J{\´a}chym and Hausladen, Matthias and Zl{\´a}mal, Jakub and Kn{\´a}pek, Alexandr and Schreiner, Rupert}, title = {Single Column Multiple Electron Beam Imaging from N-Type Silicon}, series = {37th International Vacuum Nanoelectronics Conference (IVNC), 15-19 July 2024, Brno, Czech Republic}, booktitle = {37th International Vacuum Nanoelectronics Conference (IVNC), 15-19 July 2024, Brno, Czech Republic}, publisher = {IEEE}, isbn = {979-8-3503-7976-1}, doi = {10.1109/IVNC63480.2024.10652470}, pages = {1 -- 2}, abstract = {This work is aimed at measuring the electron emission from multiple cathodes formed by n-doped silicon and imaging the electron beams focused by an einzel lens on a CMOS camera. The experimental results are compared with computer simulation to understand the electron emission from the semiconductor cathode and the observed imaging imperfections. Finally, modifications to the experimental setup are suggested that should lead to improvement in the extraction current and spot size of focused electron beams and also better understanding of the processes taking place in the experiment.}, language = {en} } @inproceedings{HoellerMuellerTrapet, author = {H{\"o}ller, Christoph and M{\"u}ller-Trapet, Markus}, title = {Measured and predicted sound transmission through a laboratory concrete floor}, series = {53rd International Congress and Exposition on Noise Control Engineering (Inter-Noise 2024), 25.-29. August 2024, Nantes France}, booktitle = {53rd International Congress and Exposition on Noise Control Engineering (Inter-Noise 2024), 25.-29. August 2024, Nantes France}, language = {en} } @inproceedings{RiegerDaeubleSchecketal., author = {Rieger, Anna and D{\"a}uble, Lukas and Scheck, Jochen and Zeitler, Berndt and H{\"o}ller, Christoph}, title = {Experimental study on using transient excitation signals in the prediction of sound pressure levels from building services according to EN 12354-5 and EN 15657}, series = {Proceedings of DAS|DAGA 2025, 51st Annual Meeting on Acoustics, March 17-20, 2025, Copenhagen}, booktitle = {Proceedings of DAS|DAGA 2025, 51st Annual Meeting on Acoustics, March 17-20, 2025, Copenhagen}, address = {Berlin}, organization = {Deutsche Gesellschaft f{\"u}r Akustik e.V. (DEGA), Berlin}, isbn = {978-3-939296-23-2}, doi = {10.71568/dasdaga2025.526}, pages = {372 -- 375}, abstract = {EN 12354-5:2023 describes a calculation procedure to predict the sound pressure levels from building service equipment. The procedure uses the blocked force of the source as input data. This quantity can be determined using the reception plate method according to EN 15657:2017. The methods have been developed and validated for stationary excitation signals (Leq). Real structure-borne sound sources often have time-varying excitation signals. In addition, the requirements for sound insulation against noise from building service equipment in Germany (DIN 4109) are given in terms of the maximum, time-weighted sound pressure level (LFmax). This contribution investigates the suitability of the methods described in EN 12354-5 and EN 15657 for structure-borne sound sources with transient excitation signals. A measurement series with time signals ranging from stationary to highly transient was conducted in a building-like laboratory. The reverberation time of the receiving room was adjusted to three different values. The calculations were processed using Leq values, LFmax values and short-time Leq values. The results show the uncertainties that can arise in the prediction of signals with varying transient characteristics compared to stationary excitation signals.}, language = {en} } @inproceedings{HoellerParzingerSchanda, author = {H{\"o}ller, Christoph and Parzinger, Michael and Schanda, Ulrich}, title = {The Sound Reduction Index of Homogeneous Building Elements according to Annex B of ISO 12354-1 - Discussion and Proposal for Changes}, series = {Proceedings of DAS|DAGA 2025, 51st Annual Meeting on Acoustics, March 17-20, 2025, Copenhagen}, booktitle = {Proceedings of DAS|DAGA 2025, 51st Annual Meeting on Acoustics, March 17-20, 2025, Copenhagen}, address = {Berlin}, organization = {Deutsche Gesellschaft f{\"u}r Akustik e.V. (DEGA), Berlin}, isbn = {978-3-939296-23-2}, doi = {10.71568/dasdaga2025.147}, pages = {312 -- 315}, abstract = {Annex B of ISO 12354-1:2017 describes a procedure for the calculation of the frequency-dependent sound reduction index of homogeneous building elements such as concrete floors or masonry walls. With the introduction of EN 12354-5:2023 and an upcoming change in DIN 4109-2 regarding the calculation of sound levels due to service equipment, it is anticipated that the practical relevance and usage of Annex B will increase in the future. For this reason, the procedure has recently been investigated by an informal working group of academics from several German universities. It was found that Annex B contains some errors, missing references, and ambiguities in the calculation procedure. Based on these discussions, some changes were proposed to the committee responsible for the standard (CEN/TC 126/WG 2). While the general calculation procedure was left unchanged, the proposed changes focus on the influence of shear deformation, the radiation factor for free waves, a moving average function to limit the variability in the coincidence region, and the calculation examples provided in the annex. This contribution provides an overview of the procedure, presents some background information on the underlying theory, and discusses the proposed changes.}, language = {en} } @inproceedings{BaeumlerHoeller, author = {B{\"a}umler, Georg and H{\"o}ller, Christoph}, title = {Modifying a Wall Transmission Suite to Measure Diffuse Field Sound Absorption Coefficients - A Case Study}, series = {Proceedings of DAS|DAGA 2025, 51st Annual Meeting on Acoustics, March 17-20, 2025, Copenhagen}, booktitle = {Proceedings of DAS|DAGA 2025, 51st Annual Meeting on Acoustics, March 17-20, 2025, Copenhagen}, address = {Berlin}, organization = {Deutsche Gesellschaft f{\"u}r Akustik e.V. (DEGA), Berlin}, isbn = {978-3-939296-23-2}, doi = {10.71568/dasdaga2025.291}, pages = {1191 -- 1194}, abstract = {The determination of the diffuse field sound absorption coefficient is carried out in reverberation chambers that comply with the requirements of the corresponding standard, ISO 354. No such chamber exists at OTH Regensburg University of Applied Sciences, but a new wall transmission suite according to ISO 10140 is available. This student project investigates the possibility of using the wall transmission suite to measure absorption coefficients for teaching and research purposes.To assess the suitability of the room, the diffusivity was evaluated using the standard deviation of both the reverberation times and the equivalent continuous sound pressure levels at multiple positions within the room. These results, along with a comparison with expected values for a diffuse sound field, guided the design of reflector panels to introduce diffuse reflections. The implementation features acrylic (PMMA) as the primary material in combination with dense viscoelastic damping sheets, resulting in a low vibration solution. Suspended from the ceiling of the chamber, these improved the diffusivity of the sound field, making the room suitable for absorption measurements across a broad frequency range.}, language = {en} } @techreport{BresinskyPetzke, author = {Bresinsky, Markus and Petzke, Jan}, title = {Russland 2030+}, publisher = {OTH Regensburg}, doi = {10.35096/othr/pub-7839}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-78395}, abstract = {Der Bericht "Russland 2030+: Wege in eine ungewisse Zukunft" pr{\"a}sentiert m{\"o}gliche Szenarien f{\"u}r die politische, wirtschaftliche, milit{\"a}rische und gesellschaftliche Entwicklung Russlands bis {\"u}ber das Jahr 2030 hinaus. Er basiert auf einem interdisziplin{\"a}ren Ansatz und verwendet Foresight-Methoden, darunter eine PMESII-Analyse. Diese wurde von Studierenden der OTH Regensburg unter Leitung von Prof. Dr. Markus Bresinsky in Zusammenarbeit mit Vertretern der Bundeswehr durchgef{\"u}hrt. Der Bericht stellt f{\"u}nf Zukuntsbilder vor, die sich jeweils auf unterschiedliche Schl{\"u}sselfaktoren und Annahmen st{\"u}tzen: von einer Fortf{\"u}hrung der autorit{\"a}ren Herrschaft (Putin's Tsardom) {\"u}ber gewaltsame Machtwechsel (Moscow Meltdown) bis hin zur zunehmenden Abh{\"a}ngigkeit von China (Dragon eats Bear). Ziel der Untersuchung ist es, m{\"o}gliche Entwicklungen und deren Implikationen f{\"u}r internationale Akteure aufzuzeigen, um eine fundierte Entscheidungsgrundlage f{\"u}r vorausschauendes Handeln zu schaffen.}, language = {de} }