cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Velocimetry-based pressure information for spray analysis – novel experimental, processing and evaluation strategies
Creators: name: Kling, Nils Herbert
Publisher: name: Karlsruher Institut für Technologie (KIT)
Year: 2022
Subjects: Spray transport
GDI
Pressure from PIV
DPSA
PINN

description: In der vorliegenden Arbeit wurde der Spraytransport von komplexen Benzindirekteinspritzungssprays (GDI) mittels auf Geschwindigkeitmessung basierter Druckauswertung untersucht. Für diesen Zweck wurden neue Versuchs-, Verarbeitungs- und Auswertestrategien eingeführt, um eine Druckauswertung der Spray-induzierten Strömung zu befähigen und deren Möglichkeiten auszuweiten. Dies umfasst unter anderem ein statistisches Verfahren auf Basis der Unsteady Reynolds-Averaged Navier-Stokes (URANS) Gleichungen und Ensemble-Mittelung, welche die Druckauswertung transienter, statistisch stationärer Strömungen mittels konventioneller Particle Image Velocimetry (PIV) ermöglicht. Darüber hinaus wurde eine neuartige Technik namens Dual-Plane-Stereo-Astigmatismus (DPSA) entwickelt, die die Auswertung momentaner Druckfelder und damit die Analyse einzelner Einspritzereignisse unter Verwendung eines stereoskopischen Aufbaus und einer einzigen Lichtquelle ermöglicht. Abschließend wurde die Methode der Physics-Informed Neural Networks (PINNs) erfolgreich aus dem Bereich des Deep Learnings in die experimentelle Strömungsmechanik und Spray-Analyse übertragen. Das PINN-Verfahren weitet die Möglichkeiten der bisherigen auf Geschwindigkeitsmessung basierenden Druckauswertung aus und ermöglicht die Auswertung von bislang nicht auswertbaren Strömungsbereichen, sowohl in Raum und Zeit. Unter Verwendung der beschriebenen Methoden wurde die Wechselwirkung zwischen Spray und Umgebungsgasströmung für unterschiedliche Betriebsbedingungen und Sprayauslegungen untersucht. Es zeigte sich, dass der Impulsaustausch mit höherem Einspritzdruck, Gasdichte, Kraftstofftemperatur, größerer Relativgeschwindigkeit, Spray-Gas-Grenzfläche, Sprayexpansion und stärkerer Zerstäubung bzw. Flash-Boiling zunimmt. Als eine wesentliche Erkenntnis wurde festgestellt, dass die Ablenkung von Sprays bzw. das Phänomen der Strahl-zu-Strahl-Wechselwirkung und Spraykontraktion auf einen Nettoimpuls zurückzuführen ist, der auf einzelne Spraykeulen infolge von induzierten Druckkräften wirkt. In diesem Zusammenhang wurde das Vorhandensein eines Niederdruckgebiets im Zentrum von Mehrlochsprays experimentell bestätigt. Es wurde aufgezeigt, dass das Ausmaß der Strahl-zu-Strahl-Wechselwirkung und der Spraykontraktion durch eine enge Spritzlochanordnung und -ausrichtung, eine starke Zerstäubung und ein erhöhtes Tropfen-Folgeverhalten begünstigt wird.
Two-regular subgraphs of odd-uniform hypergraphs
Creators: name: Han, Jie
name: Kim, Jaehoon
Publisher: name: arXiv
Year: 2016
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: Let $k\ge 3$ be an odd integer and let $n$ be a sufficiently large integer. We prove that the maximum number of edges in an $n$-vertex $k$-uniform hypergraph containing no $2$-regular subgraphs is $\binom{n-1}{k-1} + \lfloor\frac{n-1}{k} \rfloor$, and the equality holds if and only if $H$ is a full $k$-star with center $v$ together with a maximal matching omitting $v$. This verifies a conjecture of Mubayi and Verstraëte.
Contact Formation on p-Doped Si by Screen-Printing Pure Ag Pastes for Bifacial n-Type Si Solar Cells
Creators: name: Engelhardt, J.
name: Fritz, S.
name: Emre, E.
name: Hahn, G.
Publisher: name: WIP
Year: 2016
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cells Improvements and Innovation

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 647-650
description: n-type solar cell concepts increasingly utilize emitter formation by diffusion from boron doped sources.
Combining the advantage of n-type silicon material and bifacial cell architecture enables high-efficiency and versatile
photovoltaics. In case of boron emitters, it was standard until now to form a metal-semiconductor contact by screenprinting
Al containing Ag pastes. Instead of utilizing Al to enable Ag to form a sufficient contact with the risk in loss
of VOC and FF, different glass compositions for pure Ag pastes were developed to form a contact with low impact on
cell efficiency. In direct comparison this method in the first try already surpasses the performance of commercial Al
containing Ag pastes in direct comparison. The experimental pastes show a distinctive gain in solar cell
characteristics in contrast to commercial pure Ag pastes. In this case we reached an overall efficiency of 18.6% using
pure Ag pastes. Contact resistivity values thereby range below 1-2 mcm² comparable to pure Ag pastes on n-type
emitters and Ag/Al pastes on p-type emitters.
Suppression of photon shot noise dephasing in a tunable coupling superconducting qubit
Creators: name: Zhang, Gengyan
name: Liu, Yanbing
name: Raftery, James J.
name: Houck, Andrew A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We demonstrate the suppression of photon shot noise dephasing in a superconducting qubit by eliminating its dispersive coupling to the readout cavity. This is achieved in a tunable coupling qubit, where the qubit frequency and coupling rate can be controlled independently. We observe that the coherence time approaches twice the relaxation time and becomes less sensitive to thermal photon noise when the dispersive coupling rate is tuned from several MHz to 22 kHz. This work provides a promising building block in circuit quantum electrodynamics that can hold high coherence and be integrated into larger systems.
Edge States in the Climate System: Exploring Global Instabilities and Critical Transitions
Creators: name: Lucarini, Valerio
name: Bodai, Tamas
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Chaotic Dynamics (nlin.CD)
subject: Computational Physics (physics.comp-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Multistability is a ubiquitous feature in systems of geophysical relevance and provides key challenges for our ability to predict a system's response to perturbations. Near critical transitions small causes can lead to large effects and - for all practical purposes - irreversible changes in the properties of the system. The Earth climate is multistable: present astronomical and astrophysical conditions support two stable regimes, the warm climate we live in, and a snowball climate, characterized by global glaciation. We first provide an overview of methods and ideas relevant for studying the climate response to forcings and focus on the properties of critical transitions. Following an idea developed by Eckhardt and co. for the investigation of multistable turbulent flows, we study the global instability giving rise to the snowball/warm multistability in the climate system by identifying the climatic edge state, a saddle embedded in the boundary between the two basins of attraction of the stable climates. The edge state attracts initial conditions belonging to such a boundary and is the gate facilitating noise-induced transitions between competing attractors. We use a simplified yet Earth-like climate model constructed by coupling a primitive equations model of the atmosphere with a simple diffusive ocean. We refer to the climatic edge states as Melancholia states. We study their dynamics, their symmetry properties, and we follow a complex set of bifurcations. We find situations where the Melancholia state has chaotic dynamics. In these cases, the basin boundary between the two basins of attraction is a strange geometric set with a nearly zero codimension, and relate this feature to the time scale separation between instabilities occurring on weather and climatic time scales. We also discover a new stable climatic state characterized by non-trivial symmetry properties.
description: 43 pages; 15 figures. Revised version with additional figures, extended discussion, and new results on the boundary between the basins of attraction
A Computer Test of Holographic Flavour Dynamics
Creators: name: Filev, Veselin G.
name: O'Connor, Denjoe
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We perform computer simulations of the Berkooz-Douglas (BD) matrix model, holographically dual to the D0/D4-brane intersection. We generate the fundamental condensate versus bare mass curve of the theory both holographically and from simulations of the BD model. Our studies show excellent agreement of the two approaches in the deconfined phase of the theory and significant deviations in the confined phase. We argue the discrepancy in the confined phase is explained by the embedding of the D4-brane which yields stronger $α'$ corrections to the condensate in this phase.
description: 29 pages, 3 figures, updated to match the published version
Wet Oxidation Effects on the Electrical and Interface Properties of ALD Al2O3 and ALD-AlOx/SiNx Passivation Stacks for PERC Solar Cells
Creators: name: Joonwichien, S.
name: Shirasawa, K.
name: Simayi, S.
name: Tanahashi, K.
name: Takato, H.
Publisher: name: WIP
Year: 2016
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cells Improvements and Innovation

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 660-663
description: We investigated the impact of wet oxidation on the electrical and interface properties of aluminum
oxide (Al2O3) using atomic layer deposition (ALD) and aluminum oxide/silicon nitride (AlOx/SiNx) passivation
stacks on silicon. Wet oxidation has been observed to have a significant effect on the field-effect passivation,
showing an increase in the flat-band voltage shift (Vfb), and on the chemical passivation, which resulted in a reduction
of the interface trap density (Dit). The decrease in Dit resulted in an increase in the lifetime and open-circuit voltages
(Voc). This effect may be attributed to additional negatively charged traps originating from interstitial oxygen and
hydrogen in the steam during wet oxidation. These results suggest that thermal annealing under ambient humidity is
desirable to improve the quality of the passivation stacks on the rear side. This leads to high-performance passivated
emitter rear cells (PERC).
High Mobility and Transmittance Transparent Conductive HF-Doped In2O3 Thin Films and Its Application to Silicon Heterojunction Solar Cells
Creators: name: Wang, W.J.
name: Wang, G.H.
name: Zhao, L.
name: Diao, H.W.
Publisher: name: WIP
Year: 2016
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cells Improvements and Innovation

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 592-594
description: Hf-doped In2O3 transparent conductive films (IHfO) are developed at a low substrate temperature of 150 oC by radio frequency magnetron sputtering for the applications to silicon heterojunction solar cell. The maximum Hall mobility of 79.6 cm2/Vs and the minimum resistivity of 3.76×10-4 Ω cm are obtained. The average transmittance of IHfO films with thickness 94 nm and 436nm in the wavelength range of 300-1100 nm is about 85%. IHfO is applied to a-Si/c-Si heterojunction solar cells, 16.77% of conversion efficiency has been obtained. We aim to improve the efficiency of solar cell in the future.
Laminar chaos in systems with quasiperiodic delay
Creators: name: Müller-Bender, David
name: Radons, Günter
Publisher: name: arXiv
Year: 2022
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: A new type of chaos called laminar chaos was found in singularly perturbed dynamical systems with periodic time-varying delay [Phys. Rev. Lett. 120, 084102 (2018)]. It is characterized by nearly constant laminar phases, which are periodically interrupted by irregular bursts, where the intensity levels of the laminar phases vary chaotically from phase to phase. In this paper, we demonstrate that laminar chaos can also be observed in systems with quasiperiodic delay, where we generalize the concept of conservative and dissipative delays to such systems. It turns out that the durations of the laminar phases vary quasiperiodically and follow the dynamics of a torus map in contrast to the periodic variation observed for periodic delay. Theoretical and numerical results indicate that introducing a quasiperiodic delay modulation into a time-delay system can lead to a giant reduction of the dimension of the chaotic attractors. By varying the mean delay and keeping other parameters fixed, we found that the Kaplan-Yorke dimension is modulated quasiperiodically over several orders of magnitudes, where the dynamics switches quasiperiodically between different types of high- and low-dimensional types of chaos.
description: 17 pages, 9 figures; corrected a typo in the inline equation in the last line of the caption of Fig. 1
Optical Reflection Spectra of Silicon Surface with Nanowires Produced by Special Electrochemical Etching
Creators: name: Treideris, M.
name: Strazdiené, V.
name: Šimkiene, I.
name: Bukauskas, V.
name: Reza, A.
name: Indrišiunas, S.
name: Kamarauskas, M.
name: Setkus, A.
Publisher: name: WIP
Year: 2016
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cells Improvements and Innovation

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 598-601
description: In this work, we present promising simple method for a modification of optical response in c-Si solar cells.
In this approach the spectral dependence of the optical reflectance is intentionally changed by strictly controlled
electrochemical etching of the surfaces. It is demonstrated that the etching produces a layer with randomly ordered
silicon nanowires (SiNW) that changes the optical response of the surface. The change in the reflectance spectrum
depends on the dimensions of the SiNWs that are intentionally tuned by controlling the conditions of the etching. Our
experimental results demonstrate that a maximum appears in the reflectance spectrum of c-Si surface with the SiNW in
the interval of the visible wavelengths. The position of the maximum depends on the length of the SiNW and can be
varied within entire interval of the visible light. We describe the relationships between the etching conditions, the
properties of the SiNW layer and the optical response in this report. The technological parameters that produce the most
significant effect on the dimensions of the SiNW and the reflectance are identified.
Realizing posets as prime spectra of Leavitt path algebras
Creators: name: Abrams, Gene
name: Pino, Gonzalo Aranda
name: Mesyan, Zachary
name: Smith, Christopher
Publisher: name: arXiv
Year: 2015
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 16W10, 16D25, 06A06

description: We associate in a natural way to any partially ordered set $(P,\leq)$ a directed graph $E_P$ (where the vertices of $E_P$ correspond to the elements of $P$, and the edges of $E_P$ correspond to related pairs of elements of $P$), and then describe the prime spectrum of the resulting Leavitt path algebra $L_K(E_P)$. This construction allows us to realize a wide class of partially ordered sets as the prime spectra of rings. More specifically, any partially ordered set in which every downward directed subset has a greatest lower bound, and where these greatest lower bounds satisfy certain compatibility conditions, can be so realized. In particular, any partially ordered set satisfying the descending chain condition is in this class.
description: 27 pages. In the second version an appendix with new set-theoretic results has been added, more references have been included, several minor errors and misprints have been corrected, and the title has been changed
Development of Cost-Effective Silver Alloy Front-Side Paste for Si Solar Cells
Creators: name: Corbett, D.
name: Savidis, A.
name: Goodall, R.
name: Corteen, J.
name: Raj, E.
name: Johnson, S.
name: Orman, R.
name: Kerr, G.
Publisher: name: WIP
Year: 2016
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cells Improvements and Innovation

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 589-591
description: Pure silver is used in conventional solar cells for front-side current collection as it exhibits high conductivity, excellent solderability and good oxidation resistance. The long term cost of silver is expected to continue to rise therefore it is important to reduce silver content in solar cells. Previous attempts to use metal additives to reduce the quantity of pure silver required have resulted in alloys with poor resistivity and/or poor oxidation resistance. This study presents a collaborative research project to develop a lower cost alternative to pure silver using a novel developmental approach to selecting, producing and testing alloys of silver. Multivariable regression techniques were used to predict the properties of binary and tertiary silver alloy systems. Samples were converted to fine powders by gas atomisation and mixed with glass frits to produce pastes. Laboratory measurements of line and contact resistance were duplicated in a solar manufacturing line and screen printed cells produced. The consortium aims to produce an 18% efficient solar cell using an optimised alloy system.
On the equivalence among stress tensors in a gauge-fluid system
Creators: name: Mitra, Arpan Krishna
name: Banerjee, Rabin
name: Ghosh, Subir
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper we bring out the subtleties involved in the study of a first order relativistic field theory with auxiliary field variables playing an essential role. In particular we discuss the nonisentropic Eulerian (or Hamiltonian) fluid model. Interactions are introduced by coupling the fluid to a {\it dynamical} Maxwell ($U(1)$) gauge field. This dynamical nature of the gauge field is crucial in showing the equivalence, on the physical subspace, of the stress tensor derived from two definitions, {\it{ie.}} the canonical (Noether) one and the symmetric one. In the conventional equal-time formalism, we have shown that the generators of the spacetime transformations obtained from these two definitions agree, modulo the Gauss constraint. This equivalence in the physical sector has been achieved only because of the dynamical nature of the gauge fields. Subsequently we have explicitly demonstrated the validity of the Schwinger condition. A detailed analysis of the model in lightcone formalism has also been done where several interesting features are revealed.
description: 20 pages, no figure
Genuine Bifacial Simulation and Optimization of an mc-Silicon PERC Solar Cell
Creators: name: Wöhrle, N.
name: Alapont Sabater, A.
name: Greulich, J.
Publisher: name: WIP
Year: 2016
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cell Characterisation and Modelling

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 539-544
description: Bifacial silicon solar cells gain significantly in importance as they provide a plus in power generation for various illumination scenarios without significantly complicating the manufacturing process. These scenarios can be numerous and are hard to be fully covered in experimental setups. It is suitable to perform computer simulations to gain deeper understanding of the cell characteristics under wide parameter variations and to optimize the layout towards different applications. For this purpose, a numerical simulation model has been developed, which allows a genuine bifacial simulation, i.e., independently selectable illumination windows for both sides. The model is used to simulate a broad variation of different bifacial mc-Si PERC cell layouts under different illumination scenarios. It is shown that physical effects of the front and rear side grid do not couple in good approximation, so both grids can be adjusted independently. Further the simulations show that in case of the presented mc-Si PERC cell, it is possible to find a sweet spot of 110 front fingers and 130 rear fingers where the cell provides close-to-ideal power output under all applied bifacial illumination conditions as well as a broad range of minority carrier lifetimes and base resistances.
22.5% n-PERT Solar Cells on Epitaxially Grown Silicon Wafers
Creators: name: Kuzma-Filipek, I.
name: Récaman Payo, M.
name: Duerinckx, F.
name: Hao, R.
name: Ravi, T.S.
name: Cornagliotti, E.
name: Choulat, P.
name: Sharma, A.
name: John, J.
name: Aleman, M.
name: Tous, L.
name: Russell, R.
name: Uruena, A.
name: Szlufcik, J.
name: Poortmans, J.
Publisher: name: WIP
Year: 2016
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cells Improvements and Innovation

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 560-564
description: This work reports on the fabrication of advanced nPERT (passivated Emitter, Rear Totally diffused) cells by imec on epitaxial wafers from Crystal Solar obtained by direct gas to wafer technology. Crystal Solar has developed a process to grow full-epitaxial monocrystalline wafers of ~180-200μm thick with a limited stacking fault defect density of <1 defect/cm2. The specific growth sequence included the in-situ growth of optimized p+ epitaxial emitter and n-base. EDNA2 simulations were used to determine the total dark saturation current density for these epitaxial emitters based on depth and doping level. Based on this, the experimental doping range of the epitaxial emitter was between 1∙1017 to 5∙1018 cm-3. Imec applied its nPERT process that consisted of a selective n++ Front Surface Field (FSF), Al2O3 emitter passivation and plating sequence suitable to contact lowly doped surfaces. The devices were evaluated using QSS-PL measurements, spectral response, light IV characterization. The potential impact of epitaxial defects on cell performance was examined.
The best performance was realized for a device with a lowly doped emitter passivated by ALD Al2O3/PECVD SiOX reaching a Voc of ~700 mV and an independently confirmed top efficiency of 22.5 % (238.9 cm2).
Use of Time Dependent Data in Bayesian Global 21cm Foreground and Signal Modelling
Creators: name: Anstey, Dominic
name: Acedo, Eloy de Lera
name: Handley, Will
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Global 21cm cosmology aims to investigate the cosmic dawn and epoch of reionisation by measuring the sky averaged HI absorption signal, which requires, accurate modelling of, or correction for, the bright radio foregrounds and distortions arising from chromaticity of the antenna beam. We investigate the effect of improving foreground modelling by fitting data sets from many observation times simultaneously in a single Bayesian analysis, fitting for the same parameter set by performing these fits on simulated data. We find that for a hexagonal dipole antenna, this simultaneous fitting produces a significant improvement in the accuracy of the recovered 21cm signal, relative to fitting a time average of the data. Furthermore, the recovered models of the foreground are also seen to become more accurate by up to a factor of $\sim$2-3 relative to time averaged fitting. For a less chromatic log spiral antenna, no significant improvement in signal recovery was found by this process. However, the modelling of the foregrounds was still significantly improved. We also investigate extending this technique to fit multiple data sets from different antennae simultaneously for the same parameters. This is also found to improve both 21cm signal and foreground modelling, to a higher degree than fitting data set from multiple times from the same antenna.
description: 19 pages, 19 figures
On the Stability of Dielectric Passivation Layers Under Illumination and Temperature Treatments
Creators: name: Sperber, D.
name: Furtwängler, F.
name: Herguth, A.
name: Hahn, G.
Publisher: name: WIP
Year: 2016
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cell Characterisation and Modelling

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 523-526
description: Different dielectric layers were deposited onto boron doped floatzone silicon wafers and the stability of
the effective lifetime was investigated at elevated temperatures ranging from 75°C to 250°C with and without
illumination. It was found that samples fired in a belt furnace show an instable behavior on a timescale of minutes to
months. The short term behavior of a sample is strongly influenced by the peak firing temperature whereas the long
term behavior appears to be less influenced by this parameter. Different chemical cleaning procedures during sample
preparation show no significant influence on stability. Via corona charging, the changes at 250°C in darkness could
be associated with changes in chemical passivation quality. It could be shown that a non-fired sample shows a
similar, but less pronounced instability whereas an annealed sample is stable under the given treatment conditions.
Some aspects of (r,k)-parking functions
Creators: name: Stanley, Richard
name: Wang, Yinghui
Publisher: name: arXiv
Year: 2016
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05E05

description: An \emph{$(r,k)$-parking function} of length $n$ may be defined as a sequence $(a_1,\dots,a_n)$ of positive integers whose increasing rearrangement $b_1\leq\cdots\leq b_n$ satisfies $b_i\leq k+(i-1)r$. The case $r=k=1$ corresponds to ordinary parking functions. We develop numerous properties of $(r,k)$-parking functions. In particular, if $F_n^{(r,k)}$ denotes the Frobenius characteristic of the action of the symmetric group $\mathfrak{S}_n$ on the set of all $(r,k)$-parking functions of length $n$, then we find a combinatorial interpretation of the coefficients of the power series $\left( \sum_{n\geq 0}F_n^{(r,1)}t^n\right)^k$ for any $k\in \mathbb{Z}$. When $k>0$, this power series is just $\sum_{n\geq 0} F_n^{(r,k)} t^n$; when $k<0$, we obtain a dual to $(r,k)$-parking functions. We also give a $q$-analogue of this result. For fixed $r$, we can use the symmetric functions $F_n^{(r,1)}$ to define a multiplicative basis for the ring $Λ$ of symmetric functions. We investigate some of the properties of this basis.
Characterization of anomalous diffusion through convolutional transformers
Creators: name: Firbas, Nicolás
name: Garibo-i-Orts, Òscar
name: Garcia-March, Miguel Ángel
name: Conejero, J. Alberto
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences
subject: I.2
subject: 68T07

description: The results of the Anomalous Diffusion Challenge (AnDi Challenge) have shown that machine learning methods can outperform classical statistical methodology at the characterization of anomalous diffusion in both the inference of the anomalous diffusion exponent alpha associated with each trajectory (Task 1), and the determination of the underlying diffusive regime which produced such trajectories (Task 2). Furthermore, of the five teams that finished in the top three across both tasks of the AnDi challenge, three of those teams used recurrent neural networks (RNNs). While RNNs, like the long short-term memory (LSTM) network, are effective at learning long-term dependencies in sequential data, their key disadvantage is that they must be trained sequentially. In order to facilitate training with larger data sets, by training in parallel, we propose a new transformer based neural network architecture for the characterization of anomalous diffusion. Our new architecture, the Convolutional Transformer (ConvTransformer) uses a bi-layered convolutional neural network to extract features from our diffusive trajectories that can be thought of as being words in a sentence. These features are then fed to two transformer encoding blocks that perform either regression or classification. To our knowledge, this is the first time transformers have been used for characterizing anomalous diffusion. Moreover, this may be the first time that a transformer encoding block has been used with a convolutional neural network and without the need for a transformer decoding block or positional encoding. Apart from being able to train in parallel, we show that the ConvTransformer is able to outperform the previous state of the art at determining the underlying diffusive regime in short trajectories (length 10-50 steps), which are the most important for experimental researchers.
description: 20 pages, 13 figures
Measures for Eliminating Light-Induced Lifetime Degradation in Multicrystalline Silicon
Creators: name: Bredemeier, D.
name: Walter, D.C.
name: Herlufsen, S.
name: Schmidt, J.
Publisher: name: WIP
Year: 2016
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cells Improvements and Innovation

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 504-506
description: We examine the light-induced degradation and regeneration in multicrystalline silicon (mc-Si) under illumination at
elevated temperature. Samples are treated with process steps typically applied in industrial solar cell production. We
observe a pronounced degradation in lifetime after rapid thermal annealing (RTA) at 900°C. However, we detect only
a weak lifetime instability in mc-Si wafers which are RTA-treated at 650°C. We pay particular attention to the
regeneration of the lifetime which takes place under prolonged illumination at elevated temperature. It is found that
this regeneration can be significantly accelerated by increasing the temperature. Additionally we have tested the
stability of the regenerated state under illumination and elevated temperature. We show that the regeneration cannot
be further accelerated by increasing the applied light intensity, as the regeneration rate does not depend on the
illumination intensity for intensities exceeding 1 sun. We hence propose three measures for elimating the lightinduced
degradation: (i) the adaption of the firing profile, (ii) the growth of metal-reduced mc-Si blocks, and (iii) by
regeneration at illumination at increased temperature.
Topological Casimir effect in a quantum LC circuit: real-time dynamics
Creators: name: Yao, Yuan
name: Zhitnitsky, Ariel R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study novel contributions to the partition function of the Maxwell system defined on a small compact manifold ${\mathbb{M}}$ with nontrivial mappings $π_1[U(1)]\cong\mathbb{Z}$. These contributions cannot be described in terms of conventional physical propagating photons with two transverse polarizations, and instead emerge as a result of tunneling transitions between topologically different but physically identical vacuum winding states.\exclude{These new terms give an extra contribution to the Casimir pressure, yet to be measured.} We argue that if the same system is considered in the background of a small external time-dependent E\&M field, then real physical photons will be emitted from the vacuum, similar to the dynamical Casimir effect (DCE) where photons are radiated from the vacuum due to time-dependent boundary conditions. The fundamental technical difficulty for such an analysis is that the radiation of physical photons on mass shell is inherently a real-time Minkowskian phenomenon while the vacuum fluctuations interpolating between topological $|k\rangle$ sectors rest upon a Euclidean instanton formulation. We overcome this obstacle by introducing auxiliary topological fields which allows for a simple analytical continuation between Minkowski and Euclidean descriptions, and develop a quantum mechanical technique to compute these effects. We also propose an experimental realization of such small effects using a microwave cavity with appropriate boundary conditions. Finally, we comment on the possible cosmological implications of this effect.
description: matches the published version, title changed, appendices added to clarify the relation between the Hamiltonian description in Minkowski space and the path integral description in Euclidean formulation
Investigation of Al2O3 Passivation Layers by Photoluminescence Imaging under Applied Voltage
Creators: name: Haug, H.
name: Yameng, B.
name: Savin, H.
name: Marstein, E.S.
Publisher: name: WIP
Year: 2016
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cell Characterisation and Modelling

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 514-518
description: In this work, the passivation properties of Al2O3 thin films deposited by atomic layer deposition on p-type Si substrates has been studied by photoluminescence imaging under applied bias (PL-V). By measuring the carrier lifetime as a function of voltage this method enables investigations of the recombination properties of the Al2O3/c-Si interface under various band bending conditions in a simple and reproducible manner. The results were interpreted in the framework of the extended Shockley-Read-Hall theory using the fixed charge density  and surface recombination velocity parameters 0 and 0 as fitting parameters. The extracted  values were also found to be in good agreement with results from capacitance-voltage measurements. A high carrier lifetime above 1.5 ms was obtained with the traditionally used precursors Trimethylaluminum (TMA) and ozone (O3), producing layers with a large negative  of −4×1012 cm-2. Samples were also deposited using a combination of TMA and the low-cost alternative precursor dimethylaluminium chloride (DMACl), also providing good passivation with carrier lifetimes over 1 ms on Cz substrates. For these samples, , 0 and 0 were all observed to decrease with increasing deposition temperature from 100 °C to 300 °C, with the best passivation quality obtained at 300 °C. For all the investigated samples 0 was found to be larger than 0 by a factor between 2 and 5.
Magnetic Field Driven Nodal Topological Superconductivity in Monolayer Transition Metal Dichalcogenides
Creators: name: He, Wen-Yu
name: Zhou, Benjamin T.
name: He, James J.
name: Yuan, Noah F. Q.
name: Zhang, Ting
name: Law, K. T.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Recently, Ising superconductors which possess in-plane upper critical fields much larger than the Pauli limit field are under intense experimental study. Many monolayer or few layer transition metal dichalcogenides are shown to be Ising superconductors. In this work, we show that in a wide range of experimentally accessible regimes where the in-plane magnetic field is higher than the Pauli limit field but lower than $H_{c2}$, a 2H-structure monolayer NbSe$_2$ or simiarly TaS$_2$ becomes a nodal topological superconductor. The bulk nodal points appear on the $Γ- M$ lines of the Brillouin zone where the Ising SOC vanishes. The nodal points are connected by Majorana flat bands, similar to the Weyl points being connected by surface Fermi arcs in Weyl semimetals. The Majorana flat bands are associated with a large number of zero energy Majorana fermion edge modes which induce spin-triplet Cooper pairs. This work demonstrates an experimentally feasible way to realise Majorana fermions in nodal topological superconductor, without any fining tuning of experimental parameters.
description: 5 pages, 4 figures, plus supplementary material. Comments are welcome
Trust-Region Methods for Nonlinear Elliptic Equations with Radial Basis Functions
Creators: name: Bernal, Francisco
Publisher: name: arXiv
Year: 2015
Subjects: subject: Numerical Analysis (math.NA)
subject: Analysis of PDEs (math.AP)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: We consider the numerical solution of nonlinear elliptic boundary value problems with Kansa's method. We derive analytic formulas for the Jacobian and Hessian of the resulting nonlinear collocation system and exploit them within the framework of the trust-region algorithm. This ansatz is tested on semilinear, quasilinear and fully nonlinear elliptic PDEs (including Plateau's problem, Hele-Shaw flow and the Monge-Ampère equation) with excellent results. The new approach distinctly outperforms previous ones based on linearization or finite-difference Jacobians.
description: Original research paper
Lower bounds of concurrence for $N$-qubit systems and the detection of $k$-nonseparability of multipartite quantum systems
Creators: name: Qi, Xianfei
name: Gao, Ting
name: Yan, Femgli
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Concurrence, as one of entanglement measures, is a useful tool to characterize quantum entanglement in various quantum systems. However, the computation of the concurrence involves difficult optimizations and only for the case of two qubits an exact formula was found. We investigate the concurrence of four-qubit quantum states and derive analytical lower bound of concurrence using the multiqubit monogamy inequality. It is shown that this lower bound is able to improve the existing bounds. This approach can be generalized to arbitrary qubit systems. We present an exact formula of concurrence for some mixed quantum states. For even-qubit states, we derive an improved lower bound of concurrence using a monogamy equality for qubit systems. At the same time, we show that a multipartite state is $k$-nonseparable if the multipartite concurrence is larger than a constant related to the value of $k$, the qudit number and the dimension of the subsystems. Our results can be applied to detect the multipartite $k$-nonseparable states.
description: 8 pages
Magnetic anisotropy of large floating-zone-grown single-crystals of SrRuO3
Creators: name: Kunkemöller, S.
name: Sauer, F.
name: Nugroho, A. A.
name: Braden, M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: SrRuO3 is a highly interesting material due to its anomalous-metal properties related with ferromagnetism and its relevance as conductive perovskite layer or substrate in heterostructure devices. We have used optical floating zone technique in an infrared image furnace to grow large single crystals of SrRuO3 with volumes attaining several hundred mm3. Crystals obtained for optimized growth parameters exhibit a high ferromagnetic Curie temperature of 165 K and a low-temperature magnetization of 1.6 muB at a magnetic field of 6 T. The high quality of the crystals is further documented by large residual resistance ratios of 75 and by crystal structure and chemical analyzes. With these crystals the magnetic anisotropy could be determined.
description: 7 pages, 6 figures
Search for dark matter particles in proton-proton collisions at sqrt(s) = 8 TeV using the razor variables
Creators: name: CMS Collaboration
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: A search for dark matter particles directly produced in proton-proton collisions recorded by the CMS experiment at the LHC is presented. The data correspond to an integrated luminosity of 18.8 inverse femtobarns, at a center-of-mass energy of 8 TeV. The event selection requires at least two jets and no isolated leptons. The razor variables are used to quantify the transverse momentum balance in the jet momenta. The study is performed separately for events with and without jets originating from b quarks. The observed yields are consistent with the expected backgrounds and, depending on the nature of the production mechanism, dark matter production at the LHC is excluded at 90% confidence level for a mediator mass scale Lambda below 1 TeV. The use of razor variables yields results that complement those previously published.
description: Replaced with the published version. Added the journal reference and DOI. All the figures and tables can be at http://cms-results.web.cern.ch/cms-results/public-results/publications/EXO-14-004/index.html
Flow noise in planar sonar applications
Creators: name: Henke, Christian
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: In this paper an investigation of flow noise in sonar applications is presented. Based on a careful identification of the dominant coupling effects, the acoustic noise at the sensor position resulting from the turbulent wall pressure fluctuations is modelled with a system of hydrodynamic, bending and acoustic waves. We describe for the first time an analytical solution of the problem which is based on a biorthogonal system which can be solved in the spectral domain without the usual simplifying assumptions. Finally, it is demonstrated that the analytical solution describes the flow noise generation and propagation mechanisms of the considered sea trials.
description: 19 pages, 12 figures
Pairing Dynamics of Polar States in a Quenched p-wave Superfluid Fermi Gas
Creators: name: Yoon, Sukjin
name: Watanabe, Gentaro
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Superconductivity (cond-mat.supr-con)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We study the pairing dynamics of polar states in a single species p-wave superfluid Fermi gas following a sudden change of the interaction strength. The anisotropy of pair interaction together with the presence of the centrifugal barrier results in profoundly different pairing dynamics compared to the s-wave case. Depending on the direction of quenches, quench to the BCS regime results in a large oscillatory depletion of momentum occupation inside the Fermi sea or a large filling of momentum occupation. We elucidate a crucial role of the resonant state supported by the centrifugal barrier in the pairing dynamics.
description: 5 pages, 5 figures
BioExcel-2 D2.7 – Final release of demonstration workflows
Creators: name: Hospital, Adam
name: Genís Bayarri
name: Reyes, Stian Soiland-
name: Lowe, Douglas
name: Gelpí, Josep Lluís
name: Andrio, Pau
name: Lezzi, Daniele
name: Ejarque, Jorge
name: Butcher, Sarah
name: Niewielska, Ania
name: Eusebi, Alberto
name: Sala, Esther
name: Aristarc Surinach
name: Martí Municoy
name: Badia, Rosa Maria
name: Vargas, Rodrigo
name: Bonvin, Alexandre
Publisher: name: Zenodo
Year: 2022
Subjects: computational workflows

description: This deliverable presents the final release of demonstration workflows for the BioExcel-2 project, including a wrap-up of all the work done for the BioBB library, its associated workflows, and a final analysis of the milestones achieved
 from the initial roadmap. The current release of the BioExcel Building Blocks library is presented in the first section, underlining the FAIR development process followed, including the automatic generation of the BioBB adapters from the Python documentation. The current available modules (categories) in the library are listed. Finally, the landing website and its different sections are briefly described. The second section enumerates the final collection of demonstration workflows, with a brief description of what each workflow does, the tools used, and links to the source code and documentation. The library versatility, validated with the collection of demonstration workflows, is explained, and links to the different workflow flavours are presented in a summary table. The power of the pre-exascale demonstration workflows is presented in the fourth section, with examples of workflows successfully applied to real scientific projects (success stories). The following section focuses on the broad range of possibilities to find and execute BioExcel workflows, from local or HPC installations, to web-based interfaces. Visibility and uptake is discussed in the sixth section, listing a number of training events, webinars and scientific drafts with the presence of the library and the demonstration workflows. The final section revisits the proposed roadmap for the WP2, analysing the status of the intended milestones at the end of the project, with comments on the progress, potential issues and redefined tasks.
Fluid/gravity correspondence: Second order transport coefficients in compactified D4-branes
Creators: name: Wu, Chao
name: Chen, Yidian
name: Huang, Mei
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We develop the boundary derivative expansion (BDE) formalism of fluid/gravity correspondence to nonconformal version through the compactified, near-extremal black D4-brane. We offer an explicit calculation of 9 second order transport coefficients, i.e., the $τ_π,~τ_π^*,~τ_Π,~λ_{1,2,3}$ and $ξ_{1,2,3}$ for the strongly coupled, uncharged and nonconformal relativistic fluid which is the holographic dual of compactified, near extremal black D4-brane. We also show that the nonconformal fluid considered in this work is free of causal problem and admits the Haack-Yarom relation $4λ_1+λ_2=2ητ_π$.
description: 41 pages and 4 tables
n-PERT Solar Cells with Passivated Contact Technology Based on LPCVD Polysilicon and Fire-through Contact Metallization
Creators: name: Naber, R.C.G.
name: Lenes, M.
name: Vlooswijk, A.H.G.
name: Luchies, J.R.M.
name: Wang, J.
name: Zheng, F.
name: Lin, J.
name: Zhang, Z.
Publisher: name: WIP
Year: 2016
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cells Improvements and Innovation

description: 32nd European Photovoltaic Solar Energy Conference and Exhibition; 430-433
description: We present an n-PERT solar cell technology with a passivated rear side contact obtained by depositing
thin LPCVD polysilicon layers and contacting these layers with standard fire-through silver pastes. The ability to use
standard contact metallization processes for this application is a novel development which we hope will significantly
enhance the potential for passivated contact technology based on polysilicon layers. By adding the polysilicon
deposition step to an existing process flow that is in use for the large-scale production of n-PERT solar cells and by
using standard Cz wafer material we obtained an efficiency of 20.8% and a VOC of 667 mV for a 239 cm2 solar cell.
Compared to normal production cells without polysilicon the results show an average cell efficiency enhancement of
0.4-0.6% (absolute) and characterization of the cells indicates that the 20.8% cell efficiency will increase to more
than 21% after further optimization of the polysilicon and anti-reflection coating layer thicknesses alone.