@article{61014,
  abstract     = {{<jats:p>To obtain a more comprehensive understanding of the specific properties of complex-shaped technical aerosols—such as partially sintered aggregates formed in combustion processes or structured particles resulting from complex synthesis processes—it is essential to measure more than a single equivalent size. This study examines a novel method for determining a two-dimensional distribution of two distinct particle properties within the size range from 50nm to 1000nm: the Centrifugal Differential Mobility Analyzer (CDMA). The CDMA enables the simultaneous measurement of both mobility and Stokes equivalent diameters, providing a detailed two-dimensional particle property distribution. This, in turn, allows for the extraction of shape-related information, which is essential for characterizing particles in terms of their chemical composition, reactivity, and other physicochemical properties. This paper presents a detailed evaluation of a first CDMA prototype. First, CFD simulations of the flow field within the classifier are presented in order to assess and understand non-idealities arising from the exact geometry. Subsequently, the transfer function is evaluated by particle trajectory calculations based on the simulated flow field. It can be demonstrated that the simulated transfer functions agree quite well with transfer functions derived from streamlines of an ideal flow field, indicating that the non-idealities in the classifying region are almost negligible in their effect on the classification result. An experimental determination of the transfer function shows additional effects not covered by the previous simulations, like broadening by diffusion and losses due to diffusion and precipitation within the in- and outlet of the classifier. Finally, the determined transfer functions are used to determine the full two-dimensional distribution with regard to the mobility and Stokes equivalent diameter of real aerosols, like spherical particles and aggregates at different sintering stages, respectively.</jats:p>}},
  author       = {{Rüther, Torben Norbert and Gröne, Sebastian and Dechert, Christopher and Schmid, Hans-Joachim}},
  issn         = {{2674-0516}},
  journal      = {{Powders}},
  keywords     = {{centrifugal differential mobility analysis, 2D-measurement, particle characterization, moving reference frame CFD-simulation, transfer function}},
  number       = {{2}},
  publisher    = {{MDPI AG}},
  title        = {{{Centrifugal Differential Mobility Analysis—Validation and First Two-Dimensional Measurements}}},
  doi          = {{10.3390/powders4020011}},
  volume       = {{4}},
  year         = {{2025}},
}

@misc{51133,
  abstract     = {{In order to standardize spray flame synthesis (SFS) studies, intensive work has been done in recent years on the design of burner types. Thus, in 2019, the so-called SpraySyn1 burner was introduced (SS1), which was subsequently characterized in numerical and experimental studies. Based on this research, a modification of the nozzle design was proposed, which has now been considered in the successor model, SpraySyn2 (SS2). As little is known about the effect of the nozzle adaptation on the particle formation, we operated both burners under identical operating conditions to produce maghemite. The final powder comparison showed that SS2 yielded considerable higher specific surface areas (associated with smaller primary particle sizes), lower polydispersity, and higher phase purity. To obtain further information on the size distributions of aggregates and agglomerates generated by SS2, aerosol samples were extracted by hole in a tube (HIAT) sampling and characterized by scanning mobility particle sizing (SMPS). Samples were extracted along the centerline at different heights above the burner (HAB) above the visible flame tip (>7 cm), and quenching experiments were performed to extract the aerosol samples at different dilution rates. Thereby, it was demonstrated that performing detailed quenching experiments is crucial for obtaining representative HIAT-SMPS data. In particular, agglomerates/aggregate sizes were overestimated by up to ~70 % if samples were not sufficiently diluted. If sufficient dilution was applied, distribution widths and mean particle mobility diameters were determined with high accuracy (sample standard derivation <5 %). Our data suggested the evolution of primary particle sizes was mostly completed <7 cm HAB and it was shown aggregates/agglomerates present above the visible flame were compact in structure (non- fractal). The mean diameter of the particle ensemble grew along the centerline from 6.9 nm (7 cm) to 11.4 nm (15 cm), while distribution widths grew from 1.42 to 1.52.}},
  booktitle    = {{Applications in Energy and Combustion Science}},
  editor       = {{Tischendorf, Ricardo and Massopo, Orlando and Schmid, Hans-Joachim and Pyrmak, Olek and Dupont, Sophie and Fröde, Fabian and Pitsch, Heinz and Kneer, Reinhold}},
  keywords     = {{Flame Spray Pyrolysis, SpraySyn2, Spray flame synthesis, Maghemite nanoparticles, Gas to particle-conversion, Hole in a tube sampling}},
  publisher    = {{Elsevier}},
  title        = {{{Maghemite nanoparticles synthesis via spray flame synthesis and particle characterization by hole in a tube sampling and scanning mobility particle sizing (HIAT-SMPS)}}},
  doi          = {{https://doi.org/10.1016/j.jaecs.2023.100235}},
  year         = {{2024}},
}

@inproceedings{51145,
  author       = {{Massopo, Orlando and Schmid, Hans-Joachim and Gonchikzhapov, Munko and Kasper, Tina}},
  keywords     = {{Absolute particle concentration, Flame Spray Pyrolysis, SMPS, Mass Spectrometry}},
  location     = {{Málaga, Spain }},
  title        = {{{Nanoparticle Concentration Measurement in Flame Spray Pyrolysis (Poster)}}},
  year         = {{2023}},
}

@inproceedings{51147,
  author       = {{Massopo, Orlando and Tischendorf, Ricardo and Schmid, Hans-Joachim and Fröde, Fabian and Grenga, Temistocle and Pitsch, Heinz and Bieber, Malte and Reddemann, Manuel and Kneer, Reinhold}},
  keywords     = {{Flame Stability, Particle Sample Extraction, SMPS, Impurities}},
  location     = {{Nürnberg}},
  publisher    = {{International Congress of Particle Technology}},
  title        = {{{Influence of atomization on the particle formation in spray flame pyrolysis (Presentation)}}},
  year         = {{2023}},
}

@inproceedings{51142,
  author       = {{Massopo, Orlando and Tischendorf, Ricardo and Schmid, Hans-Joachim and Fröde, Fabian and Pitsch, Heinz and Reddemann, Manuel and Grenga, Temistocle and Kneer, Reinhold}},
  keywords     = {{SpraySyn, Flammenspraypyrolyse, Maghemite Nanopartikel, Gas to particle-Syntheseweg, Probennahme, Verunreinigung}},
  location     = {{Paderborn}},
  publisher    = {{Jahrestreffen der DECHEMA-Fachgruppen Aerosoltechnik, Gasreinigung, Mehrphasenströmung und Partikelmesstechnik}},
  title        = {{{Einfluss der Zerstäubung auf diePartikelbildung bei der Sprayflammenpyrolyse (Vortrag)}}},
  year         = {{2023}},
}

@article{32865,
  abstract     = {{For the first time, poly(N-isopropylacrylamide) (PNIPAAm) star polymers with a β-cyclodextrin core are characterized in detail by size-exclusion chromatography (SEC) with triple detection to experimentally verify the number of arms. A combination of a refractive index detector, multi-angle laser light scattering detector, and an online-viscosimeter was used for branching analysis. At first, the SEC system was calibrated and the detector setup was validated using linear polystyrene reference polymers. The applicability of the established triple detection SEC for branching analysis was shown by the analysis of two commercially available polystyrene star polymers. Due to the high molar masses of the star polymers, both the contraction ratio g and g′ could be determined independently, thus allowing the calculation of the viscosity shielding ratio ε. Finally, the branching analysis of the PNIPAAm star polymers could experimentally confirm the assumed arm number of up to 21 arms. Moreover, an increasingly compact molecular structure and the influence of the arm number on the viscosity shielding ratio could be shown.}},
  author       = {{Herberg, Artjom and Kuckling, Dirk}},
  issn         = {{1023-666X}},
  journal      = {{International Journal of Polymer Analysis and Characterization}},
  keywords     = {{Size-exclusion chromatography, triple detection, branching analysis, star polymers, poly(N-isopropylacrylamide), β-cyclodextrin}},
  pages        = {{1--19}},
  publisher    = {{Informa UK Limited}},
  title        = {{{Branching analysis of β-cyclodextrin-based poly(<i>N</i>-isopropylacrylamide) star polymers using triple detection SEC}}},
  doi          = {{10.1080/1023666x.2022.2110133}},
  year         = {{2022}},
}

@techreport{46531,
  abstract     = {{Compulsory schooling reforms are often used to estimate monetary returns to education. Such reforms are unrelated to individual characteristics and preferences and thus arguably able to eliminate selection bias. However, as these reforms affect a large number of individuals in the relevant age groups, they might have spillover effects on individuals not directly affected by the reform. Such spillover effects constitute a problem for identification and estimation of returns to schooling. As they are difficult to address, they are mostly ignored in the empirical literature. I show that the introduction of the compulsory ninth grade in Germany led to a labor supply shock that might have increased wages and employment of individuals who were not directly subject to the reform and were assumed not to be affected in previous research. To investigate in this kinds of spillover effects, I exploit the staggered introduction of the compulsory ninth grade across German federal states in a difference-in-differences approach. Based on large scale register and survey data, I find no evidence for persistent spillover effects for men. For women, however, my results suggest that the labor supply shock resulting from the reform may have led to a persistent increase in employment and wages.}},
  author       = {{Schiele, Valentin}},
  keywords     = {{Compulsory schooling, Education, Spillover effects, Cohort size, Wages, Employment}},
  title        = {{{Labor market spillover effects of a compulsory schooling reform in Germany}}},
  year         = {{2022}},
}

@inproceedings{24550,
  abstract     = {{Efficiencies and energy yields of microinverters available on the market during 2014‒2021 have been 
measured, compared, and ranked. Conversion efficiencies as a function of load have been measured indoors with high 
accuracy and ranked according to Euro- and CEC weightings. Energy yields have been measured outdoors via 
identical and calibrated crystalline silicon PV modules of 215 Wp (until 2020) and 360 Wp (starting 2021). Inverters 
with two inputs have been fed by two of those modules. DC input, AC power output and energy yield of each microinverter have been recorded by individual calibrated electricity meters. CEC and EU efficiency rankings have been 
computed and compared. To assess the influence of PV module size, two extremes have been investigated: A rather 
small module with 215 Wp - as it has been used 10 years ago, and a brand-new module (2021) offering 360 Wp. Both 
types of modules contain 60 solar cells in series connection. Appling the low-power modules, the challenge for the 
different micro-inverters has been during weak-light conditions, using the high-power modules, some inverters 
temporarily reach their power limits and yield is reduced. A method using a reference configuration of inverter & 
module and a linear equation y = ax + b resulting in the actual yield, any module & inverter configuration can be 
characterized by just the coefficients a and b.}},
  author       = {{Krauter, Stefan and Bendfeld, Jörg}},
  booktitle    = {{Proceedings of the 38th European Photovoltaic Solar Energy Conference and Exhibition (EU PVSEC 2021)}},
  isbn         = {{3-936338-78-7}},
  keywords     = {{AC-modules, Microinverter, Power Conditioning, Efficiency, Yield, PV module size, saturation, performance}},
  pages        = {{659 -- 663}},
  title        = {{{Module-Inverters (Microinverters): Influence of Module Size on Conversion Efficiencies and Energy Yields}}},
  doi          = {{10.4229/EUPVSEC20212021-4CO.3.4}},
  year         = {{2021}},
}

@article{25046,
  abstract     = {{<jats:p>While increasing digitalization enables multiple advantages for a reliable operation of technical systems, a remaining challenge in the context of condition monitoring is seen in suitable consideration of uncertainties affecting the monitored system. Therefore, a suitable prognostic approach to predict the remaining useful lifetime of complex technical systems is required. To handle different kinds of uncertainties, a novel Multi-Model-Particle Filtering-based prognostic approach is developed and evaluated by the use case of rubber-metal-elements. These elements are maintained preventively due to the strong influence of uncertainties on their behavior. In this paper, two measurement quantities are compared concerning their ability to establish a prediction of the remaining useful lifetime of the monitored elements and the influence of present uncertainties. Based on three performance indices, the results are evaluated. A comparison with predictions of a classical Particle Filter underlines the superiority of the developed Multi-Model-Particle Filter. Finally, the value of the developed method for enabling condition monitoring of technical systems related to uncertainties is given exemplary by a comparison between the preventive and the predictive maintenance strategy for the use case.</jats:p>}},
  author       = {{Bender, Amelie}},
  issn         = {{2075-1702}},
  journal      = {{Machines}},
  keywords     = {{prognostics, RUL predictions, particle filter, uncertainty consideration, Multi-Model-Particle Filter, model-based approach, rubber-metal-elements, predictive maintenance}},
  number       = {{10}},
  title        = {{{A Multi-Model-Particle Filtering-Based Prognostic Approach to Consider Uncertainties in RUL Predictions}}},
  doi          = {{10.3390/machines9100210}},
  volume       = {{9}},
  year         = {{2021}},
}

@inproceedings{22724,
  abstract     = {{
Predictive Maintenance as a desirable maintenance strategy in industrial applications relies on suitable condition monitoring solutions to reduce costs and risks of the monitored technical systems. In general, those solutions utilize model-based or data-driven methods to diagnose the current state or predict future states of monitored technical systems. However, both methods have their advantages and drawbacks. Combining both methods can improve uncertainty consideration and accuracy. Different combination approaches of those hybrid methods exist to exploit synergy effects. The choice of an appropriate approach depends on different requirements and the goal behind the selection of a hybrid approach.

 

In this work, the hybrid approach for estimating remaining useful lifetime takes potential uncertainties into account. Therefore, a data-driven estimation of new measurements is integrated within a model-based method. To consider uncertainties within the system, a differentiation between different system behavior is realized throughout diverse states of degradation.

The developed hybrid prediction approach bases on a particle filtering method combined with a machine learning method, to estimate the remaining useful lifetime of technical systems. Particle filtering as a Monte Carlo simulation technique is suitable to map and propagate uncertainties. Moreover, it is a state-of-the-art model-based method for predicting remaining useful lifetime of technical systems. To integrate uncertainties a multi-model particle filtering approach is employed. In general, resampling as a part of the particle filtering approach has the potential to lead to an accurate prediction. However, in the case where no future measurements are available, it may increase the uncertainty of the prediction. By estimating new measurements, those uncertainties are reduced within the data-driven part of the approach. Hence, both parts of the hybrid approach strive to account for and reduce uncertainties.

 

Rubber-metal-elements are employed as a use-case to evaluate the developed approach. Rubber-metal-elements, which are used to isolate vibrations in various systems, such as railways, trucks and wind turbines, show various uncertainties in their behavior and their degradation. Those uncertainties are caused by diverse inner and outer factors, such as manufacturing influences and operating conditions. By expert knowledge the influences are described, analyzed and if possible reduced. However, the remaining uncertainties are considered within the hybrid prediction method. Relative temperature is the selected measurand to describe the element’s degradation. In lifetime tests, it is measured as the difference between the element’s temperature and the ambient temperature. Thereby, the influence of the ambient temperature on the element’s temperature is taken into account. Those elements show three typical states of degradation that are identified within the temperature measurements. Depending on the particular state of degradation a new measurement is estimated within the hybrid approach to reduce potential uncertainties.

Finally, the performance of the developed hybrid method is compared to a model-based method for estimating the remaining useful lifetime of the same elements. Suitable performance indices are implemented to underline the differences between the results.}},
  author       = {{Bender, Amelie and Sextro, Walter}},
  booktitle    = {{Proceedings of the European Conference of the PHM Society 2021}},
  editor       = {{Do, Phuc  and King, Steve and Fink,  Olga}},
  keywords     = {{Hybrid prediction method, Multi-model particle filtering, Uncertainty quantification, RUL estimation}},
  number       = {{1}},
  title        = {{{Hybrid Prediction Method for Remaining Useful Lifetime Estimation Considering Uncertainties}}},
  doi          = {{https://doi.org/10.36001/phme.2021.v6i1.2843 }},
  volume       = {{6}},
  year         = {{2021}},
}

@article{30932,
  author       = {{Herberg, Artjom and Yu, Xiaoqian and Kuckling, Dirk}},
  journal      = {{Polymers}},
  keywords     = {{controlled radical polymerization, atom transfer radical polymerization, end group determination, N-isopropylacrylamide, block copolymerization, smart polymers, temperature sensitive polymers, lower critical solution temperature, ESI-TOF mass spectrometry, ion mobility separation, size exclusion chromatography}},
  number       = {{4}},
  publisher    = {{MDPI}},
  title        = {{{End Group Stability of Atom Transfer Radical Polymerization (ATRP)-Synthesized Poly(N-isopropylacrylamide): Perspectives for Diblock Copolymer Synthesis}}},
  doi          = {{https://doi.org/10.3390/polym11040678}},
  volume       = {{11}},
  year         = {{2019}},
}

@article{64018,
  abstract     = {{CO oxidation is an extensively studied reaction in heterogeneous catalysis due to its seeming simplicity and its great importance for emission control. However, the role of particle size and more specifically structure sensitivity in this reaction is still controversial. In the present study, colloidal “surfactant-free” Pt nanoparticles (NPs) in a size regime of 1–4 nm with narrow size distribution and control over particle size were synthesized and subsequently supported on Al2O3 to prepare model catalysts. CO oxidation was performed using Pt NPs catalysts with particles sizes of 1, 2, 3, and 4 nm at different reaction temperatures. It is shown that the reaction exhibits a particle size effect that depends strongly on the reaction conditions. At 170 °C, the reaction seems to proceed within the same kinetic regime for all particle sizes, but the surface normalized activity depends strongly on the particle size, with maximum activity for nanoparticles 2 nm in diameter. A temperature increase to 200 °C leads to a change of the kinetic regime that depends on the particle size. For Pt NPs 1 nm in diameter a reaction order of 1 for O2 was observed, indicating that O2 adsorbs molecularly and dissociates in a following step, which represents the generally accepted mechanism on Pt surfaces. The reaction order of −1 for CO demonstrates that the surface is saturated with CO under reaction conditions. With increasing particle size, the reaction orders of O2 and CO change. For particles 2 nm in size, an increase in temperature also results in reaction orders of 1 for O2 and −1 for CO; NPs of 3 and 4 nm, even at higher temperatures, show no clear kinetic behavior that can be explained by a single reaction mechanism. Instead, the Boudouard reaction between two adjacent adsorbed CO molecules was identified as an important additional reaction pathway that occurs preferentially on large particles and causes more complex kinetics.}},
  author       = {{Neumann, Sarah and Gutmann, Torsten and Buntkowsky, Gerd and Paul, Stephen and Thiele, Greg and Sievers, Heiko and Bäumer, Marcus and Kunz, Sebastian}},
  journal      = {{Journal of Catalysis}},
  keywords     = {{Solid state NMR, “Surfactant-free” platinum nanoparticles, CO oxidation, Particle size effect, Structure sensitivity}},
  pages        = {{662–672}},
  title        = {{{Insights into the reaction mechanism and particle size effects of CO oxidation over supported Pt nanoparticle catalysts}}},
  doi          = {{10.1016/j.jcat.2019.07.049}},
  volume       = {{377}},
  year         = {{2019}},
}

@article{63991,
  abstract     = {{A series of 1 and 2 nm sized platinum nanoparticles (Pt-NPs) deposited on different support materials, namely, gamma-alumina (gamma-Al2O3), titanium dioxide (TiO2), silicon dioxide (SiO2) and fumed silica are investigated by solid-state NMR and dynamic nuclear polarization enhanced NMR spectroscopy (DNP). DNP signal enhancement factors up to 170 enable gaining deeper insight into the surface chemistry of Pt-NPs. Carbon monoxide is used as a probe molecule to analyze the adsorption process and the surface chemistry on the supported Pt-NPs. The studied systems show significant catalytic activity in carbon monoxide oxidation on their surface at room temperature. The underlying catalytic mechanism is the water-gas shift reaction. In the case of alumina as the support the produced CO2 reacts with the surface to form carbonate, which is revealed by solid-state NMR. A similar carbonate formation is also observed when physical mixtures of neat alumina with silica, fumed silica and titania supported Pt-NPs are studied.}},
  author       = {{Klimavicius, V. and Neumann, S. and Kunz, S. and Gutmann, Torsten and Buntkowsky, G.}},
  issn         = {{2044-4753}},
  journal      = {{Catalysis Science & Technology}},
  keywords     = {{Chemistry, gamma-alumina, hydrogenation, silica, c-13, interactions, metal-catalysts, particle-size, platinum nanoparticles, sites, surface, water-gas shift}},
  number       = {{14}},
  pages        = {{3743–3752}},
  title        = {{{Room temperature CO oxidation catalysed by supported Pt nanoparticles revealed by solid-state NMR and DNP spectroscopy}}},
  doi          = {{10.1039/c9cy00684b}},
  volume       = {{9}},
  year         = {{2019}},
}

@article{64054,
  abstract     = {{In this work, the preparation of porous hybrid particle-based films by core-shell particle design and convenient film preparation is reported. Monodisperse core particles consisting of poly(methyl methacrylate‑co‑allyl methacrylate) (P(MMA‑co‑ALMA)) were synthesized by starved-feed emulsion polymerization followed by the introduction of an initiator-containing monomer (inimer) for subsequent atom transfer radical polymerization (ATRP). The inimer shell allowed for the introduction of allylhydrido polycarbosilane (SMP-10) under ATRP conditions by grafting to the core particles. The functionalization of the prepared core-shell particles was investigated by IR spectroscopy (FTIR), scanning transmission electron microscopy (STEM) and solid-state NMR combined with dynamic nuclear polarization (DNP). The obtained hard core/soft preceramic shell particles were subjected to the melt-shear organization technique, enabling a convenient alignment into a colloidal crystal structure in one single step without the presence of a dispersion medium or solvent for the designed particles. Moreover, the hybrid particle-based films were converted into a porous ceramic structure upon thermal treatment. As a result, freestanding ceramic porous films have been obtained after degradation of the organic template core particles. Noteworthy, the conversion of the matrix material consisting of SMP-10 into the ceramic occurred with preservation of the pristine colloidal crystal template structure. Herein, the first example of core-shell particle preparation by combining different polymerization methodologies and application of the convenient melt-shear organization technique is shown, paving a new way to ceramic materials with tailored morphology and porosity.}},
  author       = {{Vowinkel, Steffen and Boehm, Anna and Schäfer, Timmy and Gutmann, Torsten and Ionescu, Emanuel and Gallei, Markus}},
  journal      = {{Materials & Design}},
  keywords     = {{emulsion polymerization, self-assembly, ATRP, Colloidal crystal, Hybrid film, Particle processing}},
  pages        = {{926–935}},
  title        = {{{Preceramic core-shell particles for the preparation of hybrid colloidal crystal films by melt-shear organization and conversion into porous ceramics}}},
  doi          = {{10.1016/j.matdes.2018.10.032}},
  volume       = {{160}},
  year         = {{2018}},
}

@article{64053,
  abstract     = {{The utilization and preparation of functional hybrid films for optical sensing applications and membranes is of utmost importance. In this work, we report the convenient and scalable preparation of self-crosslinking particle-based films derived by directed self-assembly of alkoxysilane-based cross-linkers as part of a core-shell particle architecture. The synthesis of well-designed monodisperse core-shell particles by emulsion polymerization is the basic prerequisite for subsequent particle processing via the melt-shear organization technique. In more detail, the core particles consist of polystyrene (PS) or poly(methyl methacrylate) (PMMA), while the comparably soft particle shell consists of poly(ethyl acrylate) (PEA) and different alkoxysilane-based poly(methacrylate)s. For hybrid film formation and convenient self-cross-linking, different alkyl groups at the siloxane moieties were investigated in detail by solid-state Magic-Angle Spinning Nuclear Magnetic Resonance (MAS, NMR) spectroscopy revealing different crosslinking capabilities, which strongly influence the properties of the core or shell particle films with respect to transparency and iridescent reflection colors. Furthermore, solid-state NMR spectroscopy and investigation of the thermal properties by differential scanning calorimetry (DSC) measurements allow for insights into the cross-linking capabilities prior to and after synthesis, as well as after the thermally and pressure-induced processing steps. Subsequently, free-standing and self-crosslinked particle-based films featuring excellent particle order are obtained by application of the melt-shear organization technique, as shown by microscopy (TEM, SEM).}},
  author       = {{Vowinkel, S. and Paul, S. and Gutmann, Torsten and Gallei, M.}},
  issn         = {{2079-4991}},
  journal      = {{Nanomaterials}},
  keywords     = {{Materials Science, Science & Technology - Other Topics, solid-state nmr, spectroscopy, catalysts, colloidal crystals, colloids, cross-linking, elastomeric opal films, emulsion polymerization, gamma-methacryloxypropyltrimethoxysilane, hybrid films, melt-shear organization, nanoparticles, particle, photons, polymers, processing, self-assembly, transition}},
  number       = {{11}},
  pages        = {{390}},
  title        = {{{Free-Standing and Self-Crosslinkable Hybrid Films by Core-Shell Particle Design and Processing}}},
  doi          = {{10.3390/nano7110390}},
  volume       = {{7}},
  year         = {{2017}},
}

@inproceedings{9868,
  abstract     = {{In order to increase mechanical strength, heat dissipation and ampacity and to decrease failure through fatigue fracture, wedge copper wire bonding is being introduced as a standard interconnection method for mass production. To achieve the same process stability when using copper wire instead of aluminum wire a profound understanding of the bonding process is needed. Due to the higher hardness of copper compared to aluminum wire it is more difficult to approach the surfaces of wire and substrate to a level where van der Waals forces are able to arise between atoms. Also, enough friction energy referred to the total contact area has to be generated to activate the surfaces. Therefore, a friction model is used to simulate the joining process. This model calculates the resulting energy of partial areas in the contact surface and provides information about the adhesion process of each area. The focus here is on the arising of micro joints in the contact area depending on the location in the contact and time. To validate the model, different touchdown forces are used to vary the initial contact areas of wire and substrate. Additionally, a piezoelectric tri-axial force sensor is built up to identify the known phases of pre-deforming, cleaning, adhering and diffusing for the real bonding process to map with the model. Test substrates as DBC and copper plate are used to show the different formations of a wedge bond connection due to hardness and reaction propensity. The experiments were done by using 500 $\mu$m copper wire and a standard V-groove tool.}},
  author       = {{Althoff, Simon and Neuhaus, Jan and Hemsel, Tobias and Sextro, Walter}},
  booktitle    = {{Electronic Components and Technology Conference (ECTC), 2014 IEEE 64th}},
  keywords     = {{adhesion, circuit reliability, deformation, diffusion, fatigue cracks, friction, interconnections, lead bonding, van der Waals forces, Cu, adhering process, adhesion process, ampacity improvement, bond quality improvement, cleaning process, diffusing process, fatigue fracture failure, friction energy, friction model, heat dissipation, mechanical strength, piezoelectric triaxial force sensor, predeforming process, size 500 mum, total contact area, van der Waals forces, wedge copper wire bonding, Bonding, Copper, Finite element analysis, Force, Friction, Substrates, Wires}},
  pages        = {{1549--1555}},
  title        = {{{Improving the bond quality of copper wire bonds using a friction model approach}}},
  doi          = {{10.1109/ECTC.2014.6897500}},
  year         = {{2014}},
}

@article{9878,
  abstract     = {{(K,Na)NbO3 ceramics have attracted much attention as lead-free piezoelectric materials with high piezoelectric properties. High-quality (K,Na)NbO3 ceramics can be sintered using KNbO3 and NaNbO3 powders synthesized by a hydrothermal method. In this study, to enhance the quality factor of the ceramics, high-power ultrasonic irradiation was employed during the hydrothermal method, which led to a reduction in the particle size of the resultant powders.}},
  author       = {{Isobe, G. and Maeda, Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}},
  issn         = {{0885-3010}},
  journal      = {{Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on}},
  keywords     = {{Q-factor, ceramics, crystal growth from solution, particle size, piezoelectric materials, potassium compounds, powders, sintering, sodium compounds, ultrasonic effects, (K0.48Na0.52)NbO3, KNbO3 powders, NaNbO3 powders, high-power ultrasonic irradiation, lead-free piezoelectric materials, lead-free piezoelectric powders, particle size reduction, piezoelectric properties, quality factor, sintered (K0.48Na0.52)NbO3 ceramics, sintering, ultrasonic-assisted hydrothermal method, Acoustics, Ceramics, Lead, Piezoelectric materials, Powders, Radiation effects, Transducers}},
  number       = {{2}},
  pages        = {{225--230}},
  title        = {{{Synthesis of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal method and properties of sintered (K0.48Na0.52)NBO3 ceramics}}},
  doi          = {{10.1109/TUFFC.2014.6722608}},
  volume       = {{61}},
  year         = {{2014}},
}

@inproceedings{9879,
  abstract     = {{Application of prognostics and health management (PHM) in the field of Proton Exchange Membrane (PEM) fuel cells is emerging as an important tool in increasing the reliability and availability of these systems. Though a lot of work is currently being conducted to develop PHM systems for fuel cells, various challenges have been encountered including the self-healing effect after characterization as well as accelerated degradation due to dynamic loading, all which make RUL predictions a difficult task. In this study, a prognostic approach based on adaptive particle filter algorithm is proposed. The novelty of the proposed method lies in the introduction of a self-healing factor after each characterization and the adaption of the degradation model parameters to fit to the changing degradation trend. An ensemble of five different state models based on weighted mean is then developed. The results show that the method is effective in estimating the remaining useful life of PEM fuel cells, with majority of the predictions falling within 5\% error. The method was employed in the IEEE 2014 PHM Data Challenge and led to our team emerging the winner of the RUL category of the challenge.}},
  author       = {{Kimotho, James Kuria  and Meyer, Tobias and Sextro, Walter}},
  booktitle    = {{Prognostics and Health Management (PHM), 2014 IEEE Conference on}},
  keywords     = {{ageing, particle filtering (numerical methods), proton exchange membrane fuel cells, remaining life assessment, PEM fuel cell prognostics, PHM, RUL predictions, accelerated degradation, adaptive particle filter algorithm, dynamic loading, model parameter adaptation, prognostics and health management, proton exchange membrane fuel cells, remaining useful life estimation, self-healing effect, Adaptation models, Data models, Degradation, Estimation, Fuel cells, Mathematical model, Prognostics and health management}},
  pages        = {{1--6}},
  title        = {{{PEM fuel cell prognostics using particle filter with model parameter adaptation}}},
  doi          = {{10.1109/ICPHM.2014.7036406}},
  year         = {{2014}},
}

@inproceedings{11943,
  abstract     = {{A marginalized particle filter is proposed for performing single channel speech enhancement with a non-linear dynamic state model. The system consists of a particle filter for tracking line spectral pair (LSP) parameters and a Kalman filter per particle for speech enhancement. The state model for the LSPs has been learnt on clean speech training data. In our approach parameters and speech samples are processed at different time scales by assuming the parameters to be constant for small blocks of data. Further enhancement is obtained by an iteration which can be applied on these small blocks. The experiments show that similar SNR gains are obtained as with the Kalman-LM-iterative algorithm. However better values of the noise level and the log-spectral distance are achieved}},
  author       = {{Windmann, Stefan and Haeb-Umbach, Reinhold}},
  booktitle    = {{IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2006)}},
  keywords     = {{clean speech training data, iterative methods, iterative speech enhancement, Kalman filter, Kalman filters, Kalman-LM-iterative algorithm, line spectral pair parameters, log-spectral distance, marginalized particle filter, noise level, nonlinear dynamic state speech model, particle filtering (numerical methods), single channel speech enhancement, SNR gains, speech enhancement, speech samples}},
  pages        = {{I}},
  title        = {{{Iterative Speech Enhancement using a Non-Linear Dynamic State Model of Speech and its Parameters}}},
  doi          = {{10.1109/ICASSP.2006.1660058}},
  volume       = {{1}},
  year         = {{2006}},
}

@inproceedings{11931,
  abstract     = {{The paper is concerned with binaural signal processing for a bimodal human-robot interface with hearing and vision. The two microphone signals are processed to obtain an enhanced single-channel input signal for the subsequent speech recognizer and to localize the acoustic source, an important information for establishing a natural human-robot communication. We utilize a robust adaptive algorithm for filter-and-sum beamforming (FSB) and extract speaker direction information from the resulting FIR filter coefficients. Further, particle filtering is applied which conducts a nonlinear Bayesian tracking of speaker movement. Good location accuracy can be achieved even in highly reverberant environments. The results obtained outperform the conventional generalized cross correlation (GCC) method.}},
  author       = {{Warsitz, Ernst and Haeb-Umbach, Reinhold}},
  booktitle    = {{IEEE Workshop on Multimedia Signal Processing (MMSP 2004)}},
  keywords     = {{bimodal human-robot interface, binaural signal processing, enhanced single-channel input signal, filter-and-sum beamforming, filtering theory, FIR filter coefficient, generalized cross correlation method, microphones, microphone signal, nonlinear Bayesian tracking, particle filtering, robust adaptive algorithm, robust speaker direction estimation, signal processing, speech enhancement, speech recognition, speech recognizer, user interfaces}},
  pages        = {{367--370}},
  title        = {{{Robust speaker direction estimation with particle filtering}}},
  doi          = {{10.1109/MMSP.2004.1436569}},
  year         = {{2004}},
}