cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Passive flow control mechanisms with bioinspired flexible blades in cross-flow tidal turbines
Creators: name: Hoerner, Stefan
name: Abbaszadeh, Shokoofeh
name: Cleynen, Olivier
name: Bonamy, Cyrille
name: Maître, Thierry
name: Thévenin, Dominique
Publisher: name: Universitäts- und Landesbibliothek Sachsen-Anhalt
Year: 2021
Subjects: subject: Passive flow control mechanisms
subject: Cross‑flow tidal turbines
subject: bioinspired flexible blades
subject: 660

description: State-of-the-art technologies for wind and tidal energy exploitation focus mostly on axial turbines. However, cross-flow hydrokinetic tidal turbines possess interesting features, such as higher area-based power density in array installations and shallow water, as well as a generally simpler design. Up to now, the highly unsteady flow conditions and cyclic blade stall have hindered deployment at large scales because of the resulting low single-turbine efficiency and fatigue failure challenges. Concepts exist which overcome these drawbacks by actively controlling the flow, at the cost of increased mechatronical complexity. Here, we propose a bioinspired approach with hyperflexible turbine blades. The rotor naturally adapts to the flow through deformation, reducing flow separation and stall in a passive manner. This results in higher efficiency and increased turbine lifetime through decreased structural loads, without compromising on the simplicity of the design.
The German Joint Project ‘Flexible CIGSe Thin Film Solar Cells for Space Applications’
Creators: name: Caballero, R.
name: Kaufmann, C.A.
name: Klenk, R.
name: Schock, H.W.
name: Zajac, K.
name: Brunner, S.
name: John, R.
name: Rahm, A.
name: Zachmann, H.
name: Scheit, C.
name: Braun, A.
name: Otte, K.
name: Wagner, M.
name: Würz, R.
name: Kessler, F.
name: Schülke, P.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Advanced Photovoltaics
Solar Cells, Modules and PV Systems for Space Applications

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 707-710
description: A group of partners with an academic and/or industrial background are developing a flexible
Cu(In,Ga)Se2 (CIGSe) thin film solar cell technology on a polyimide substrate (PI) that aims to be a future alternative
to current solar cell technologies for space applications. Three production technologies are investigated in this
project: batch type multi-stage co-evaporation, in-line multi-stage co-evaporation and roll-to-roll co-evaporation. So
far, a maximum total area solar cell efficiency of 14.1 % has been achieved for lab scale devices (1.0 cm2, AM 1.5,
no AR). On a large area, standardized device an active area efficiency of 12.7 % has been achieved (25.9 cm2, AM
1.5, no AR) based on an industrial roll-to-roll process.
Darker and brighter branes: Suppression and enhancement of photon production in a strongly coupled magnetized plasma
Creators: name: Ávila, Daniel
name: Nettel, Francisco
name: Patiño, Leonardo
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We extend our holographic analysis of the emission of photons by a strongly coupled plasma subject to a very intense external magnetic field. We previously showed that in a particular model, any photon produced by the plasma had to be in its only polarization state parallel to the reaction plane. In this paper we consider a construction that relaxes a formerly imposed constraint, permitting the emission of photons with either out-plane or in-plane polarization. This constitutes a completion of our former study because the fully back-reacted equations decouple for these two polarization states in such a manner that those involving the in-plane are identical to the ones we explored previously. In view of the above, part of the details concerning the calculations and of the numerical results for the differential rate of emitted photons that we present here correspond exactly to those omitted in our preceding letter. One of our main results is that the production of photons is increased by the introduction of a non-vanishing magnetic field with an intensity up to a value $B_{\vartheta}$, above which the effect is reversed and said production becomes lower than the $B=0$ case. The characteristic intensity $B_{\vartheta}$ depends on the propagation direction and tends to zero as the photon momentum becomes aligned with the magnetic field. Additionally, we also show that the magnetic field has the effect of increasing the value of the elliptic flow, providing a possible explanation for the excess measured in collision experiments. The holographic model is constructed using an effective five-dimensional action that includes a scalar field in addition to the constant magnetic field.
description: 18 pages, 19 figures. Updated to the published version. A new section that includes the out-plane polarization states has been added. The discussion section has been extended
Carry trade returns and segmented risk pricing
Creators: name: Schulze, Gordon
Publisher: name: Universitäts- und Landesbibliothek Sachsen-Anhalt
Year: 2021
Subjects: subject: Carry trade
subject: Currency returns
subject: Foreign exchange
subject: Risk aversion
subject: Stochastic discount factor
subject: 330

description: The returns to carry trades are controversially discussed. There seems to be no unifying risk-based explanation of currency returns and stock returns, while the countries’ interest rate differential plays a leading part in the carry-trade performance. Therefore, this paper addresses carry-trade returns from a risk-pricing perspective and examines if these returns can be connected to cross-country differences in risk pricing in the interest-rate market compared to the stock market. Data from Thomson Reuters Datastream and Federal Reserve Economic Data covering Australia, Japan, New Zealand, Switzerland and the United States were analyzed based on GMM estimation. The results indicate significant and persistent cross-country differences in risk aversion in the interest-rate market compared to the implied risk aversion in the stock market. This may offer opportunities for risk arbitrage and, therefore, a risk pricing-related explanation of carry-trade returns.
Analysis of Long Term Operation Data of FLATCON® CPV Systems
Creators: name: Gombert, A.
name: Gerstmaier, T.
name: Heile, I.
name: Van Riesen, S.
name: Röttger, M.
name: Wüllner, J.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Advanced Photovoltaics: New Concepts and Ultra-high Efficiency
Terrestrial Concentrator Systems

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 128-132
description: Highly efficient concentrator photovoltaic (CPV) systems use an optical concentrator to focus the solar
radiation on multi-junction solar cells (MJC) based on III-V semiconductors. Concentrix Solar GmbH is
manufacturing and installing concentrating photovoltaic systems. In this paper, operating data of more than two years
are analyzed together with data obtained from long term outdoor module measurements. On a first generation (Gen I)
system a system AC energy efficiency of 20.6% for the whole measurement period of 2 years was measured with
maximum system AC power efficiency values of 23%. A system equipped with second generation (Gen II) modules
was installed in 2009. It achieves system AC power efficiencies of 25%. Using data from continuous outdoor module
monitoring, the parameters for setting up a model were extracted. With these data reliable yield prediction is possible
by using the software “PVSyst” and taking into account the specifics of CPV systems, especially the dependence of
the system performance on the spectrum of the direct normal irradiation.
Radiative processes of two entangled atoms outside a Schwarzschild black hole
Creators: name: Menezes, G.
Publisher: name: arXiv
Year: 2015
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider radiative processes of a quantum system composed by two identical two-level atoms in a black-hole background. We assume that these identical two-level atoms are placed at fixed radial distances outside a Schwarzschild black hole and interacting with a quantum electromagnetic field prepared in one of the usual vacuum states, namely the Boulware, Unruh or the Hartle-Hawking vacuum states. We study the structure of the rate of variation of the atomic energy. The intention is to identify in a quantitative way the contributions of vacuum fluctuations and radiation reaction to the entanglement generation between the atoms as well as the degradation of entangled states in the presence of an event horizon. We find that for a finite observation time the atoms can become entangled for the case of the field in the Boulware vacuum state, even if they are initially prepared in a separable state. In addition, the rate of variation of atomic energy is not well behaved at the event horizon due to the behavior of the proper accelerations of the atoms. We show that the thermal nature of the Hartle-Hawking and Unruh vacuum state allows the atoms to get entangled even if they were initially prepared in the separable ground state.
description: Accepted for publication in Physical Review D
Data-based Control of Feedback Linearizable Systems
Creators: name: Alsalti, Mohammad
name: Lopez, Victor G.
name: Berberich, Julian
name: Allgöwer, Frank
name: Müller, Matthias A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: We present an extension of Willems' Fundamental Lemma to the class of multi-input multi-output discrete-time feedback linearizable nonlinear systems, thus providing a data-based representation of their input-output trajectories. Two sources of uncertainty are considered. First, the unknown linearizing input is inexactly approximated by a set of basis functions. Second, the measured output data is contaminated by additive noise. Further, we propose an approach to approximate the solution of the data-based simulation and output matching problems, and show that the difference from the true solution is bounded. Finally, the results are illustrated on an example of a fully-actuated double inverted pendulum.
Explaining the GeV antiproton/$γ-$ray excesses and W-boson mass anomaly in an inert two Higgs doublet model
Creators: name: Zhu, Cheng-Rui
name: Cui, Ming-Yang
name: Xia, Zi-Qing
name: Yu, Zhao-Huan
name: Huang, Xiaoyuan
name: Yuan, Qiang
name: Fan, Yi-Zhong
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: For the newly discovered $W$-boson mass anomaly, one of the simplest dark matter (DM) models that can account for the anomaly without violating other astrophysical/experimental constraints is the inert two Higgs doublet model, in which the DM mass ($m_{S}$) is found to be within $\sim 54-74$ GeV. In this model, the annihilation of DM via $SS\to b\bar{b}$ and $SS\to WW^{*}$ would produce antiprotons and gamma rays, and may account for the excesses identified previously in both particles. Motivated by this, we re-analyze the AMS-02 antiproton and Fermi-LAT Galactic center gamma-ray data. For the antiproton analysis, the novel treatment is the inclusion of the charge-sign-dependent three-dimensional solar modulation model as constrained by the time-dependent proton data. We find that the excess of antiprotons is more distinct than previous results based on the force-field solar modulation model. The interpretation of this excess as the annihilation of $SS\to WW^{*}$ ($SS\to b\bar{b}$) requires a DM mass of $\sim 40-80$ ($40-60$) GeV and a velocity-averaged cross section of $O(10^{-26})~{\rm cm^3~s^{-1}}$. As for the $γ$-ray data analysis, besides adopting the widely-used spatial template fitting, we employ an orthogonal approach with a data-driven spectral template analysis. The fitting to the GeV $γ$-ray excess yields DM model parameters overlapped with those to fit the antiproton excess via the $WW^{*}$ channel. The consistency of the DM particle properties required to account for the $W$-boson mass anomaly, the GeV antiproton excess, and the GeV $γ$-ray excess suggest a common origin of them.
description: 10 pages, 10 figures, accepted by PRL
Quantized conductance doubling and hard gap in a two-dimensional semiconductor-superconductor heterostructure
Creators: name: Kjaergaard, M.
name: Nichele, F.
name: Suominen, H. J.
name: Nowak, M. P.
name: Wimmer, M.
name: Akhmerov, A. R.
name: Folk, J. A.
name: Flensberg, K.
name: Shabani, J.
name: Palmstrom, C. J.
name: Marcus, C. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The prospect of coupling a two-dimensional (2D) semiconductor heterostructure to a superconductor opens new research and technology opportunities, including fundamental problems in mesoscopic superconductivity, scalable superconducting electronics, and new topological states of matter. For instance, one route toward realizing topological matter is by coupling a 2D electron gas (2DEG) with strong spin-orbit interaction to an s-wave superconductor. Previous efforts along these lines have been hindered by interface disorder and unstable gating. Here, we report measurements on a gateable InGaAs/InAs 2DEG with patterned epitaxial Al, yielding multilayer devices with atomically pristine interfaces between semiconductor and superconductor. Using surface gates to form a quantum point contact (QPC), we find a hard superconducting gap in the tunneling regime, overcoming the soft-gap problem in 2D superconductor-semiconductor hybrid systems. With the QPC in the open regime, we observe a first conductance plateau at 4e^2/h, as expected theoretically for a normal-QPC-superconductor structure. The realization of a hard-gap semiconductor-superconductor system that is amenable to top-down processing provides a means of fabricating scalable multicomponent hybrid systems for applications in low-dissipation electronics and topological quantum information.
description: includes main text, supplementary information and code for simulations. Published version
Quantum circuit dynamics via path integrals: Is there a classical action for discrete-time paths?
Creators: name: Penney, Mark D.
name: Koh, Dax Enshan
name: Spekkens, Robert W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: It is straightforward to give a sum-over-paths expression for the transition amplitudes of a quantum circuit as long as the gates in the circuit are balanced, where to be balanced is to have all nonzero transition amplitudes of equal magnitude. Here we consider the question of whether, for such circuits, the relative phases of different discrete-time paths through the configuration space can be defined in terms of a classical action, as they are for continuous-time paths. We show how to do so for certain kinds of quantum circuits, namely, Clifford circuits where the elementary systems are continuous-variable systems or discrete systems of odd-prime dimension. These types of circuit are distinguished by having phase-space representations that serve to define their classical counterparts. For discrete systems, the phase-space coordinates are also discrete variables. We show that for each gate in the generating set, one can associate a symplectomorphism on the phase-space and to each of these one can associate a generating function, defined on two copies of the configuration space. For discrete systems, the latter association is achieved using tools from algebraic geometry. Finally, we show that if the action functional for a discrete-time path through a sequence of gates is defined using the sum of the corresponding generating functions, then it yields the correct relative phases for the path-sum expression. These results are likely to be relevant for quantizing physical theories where time is fundamentally discrete, characterizing the classical limit of discrete-time quantum dynamics, and proving complexity results for quantum circuits.
description: 31 pages, 2 figures. Comments are welcome!
Parisi formula, disorder chaos and fluctuation for the ground state energy in the spherical mixed p-spin models
Creators: name: Chen, Wei-Kuo
name: Sen, Arnab
Publisher: name: arXiv
Year: 2015
Subjects: subject: Probability (math.PR)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 60K35, 82B44

description: We show that the limiting ground state energy of the spherical mixed p-spin model can be identified as the infimum of certain variational problem. This complements the well-known Parisi formula for the limiting free energy in the spherical model. As an application, we obtain explicit formulas for the limiting ground state energy in the replica symmetry, one level of replica symmetry breaking and full replica symmetry breaking phases at zero temperature. In addition, our approach leads to new results on disorder chaos in spherical mixed even p-spin models. In particular, we prove that when there is no external field, the location of the ground state energy is chaotic under small perturbations of the disorder. We also establish that in the spherical mixed even p-spin model, the ground state energy superconcentrates in the absence of external field, while it obeys a central limit theorem if the external field is present.
description: 40 pages, restructured presentation
Highly Predictive Modelling of Entire Si Solar Cells for Industrial Applications
Creators: name: Altermatt, P.P.
name: Steingrube, S.
name: Yang, Y.
name: Sprodowski, C.
name: Dezhdar, T.
name: Koc, S.
name: Veith, B.
name: Herrman, S.
name: Bock, R.
name: Bothe, K.
name: Schmidt, J.
name: Brendel, R.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Wafer-based Silicon Solar Cells and Materials Technology
Mono- and Multicrystalline Silicon Materials and Cells

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 901-906
description: The prospective efficiency improvements due to advanced metallisation technology of industrially fabricated
Czochralski (Cz) silicon solar cells are assessed by means of highly predictive numerical modelling in two- and three
dimensions. The analysis shows that an improved emitter design is only possible with advanced metallisation
concepts, and that about 19% efficiency can be achieved with this. Then, the fully metallised back surface field (BSF)
limits cell performance. If this BSF is replaced by point contacts without substantial BSF (PERC design), the
efficiency is limited to about 20% because the wafer resistivity must be 0.5 Ωcm at maximum, so Cz material has a
very limited carrier lifetime due to the boron-oxygen complex. If local BSFs are formed at the rear point contacts
(PERL design), higher wafer resistivities can be used, so the base operates under high-injection conditions where the
boron-oxygen complex is less detrimental. However, such improvements to the rear side increase cell efficiency only
substantially if the lifetime in the Cz material, in particular its interstitial oxygen density, is reduced.
An Indoor/Outdoor Method for CPV Power Rating: Application to Draft IEC Standard
Creators: name: Askins, S.
name: Domínguez, C.
name: Antón, I.
name: Sala, G.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Advanced Photovoltaics: New Concepts and Ultra-high Efficiency
Terrestrial Concentrator Systems

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 110-113
description: One important hurdle for the further commercialization of Concentrating Photovoltaic (CPV)
technologies is the lack of appropriate indoor standards. In response, the International Electrotechnical Commission
is drafting IEC- 62670-1, Concentrator Photovoltaic (CPV) Module and Assembly Performance Testing and Energy
Rating. This current draft standard, which will cover measurement of module power for rating purposes allows for
the measurement of the modules using natural sunlight or an appropriate solar simulator, and calls for the
characterization of the CPV modules at multiple irradiance and temperature levels, using a light source that is very
close to the AM1.5D reference spectrum. Indoor measurements are an attractive option for characterization
laboratories because they provide reproducible measurement conditions that are not affected by the availability of the
solar resource. In this work an indoor/outdoor rating procedure is presented, using the IES-UPM CPV solar
simulator with the addition of a temperature controlled chamber and wire meshes for neutral density irradiance
control. This procedure has been carried out on three separate CPV technologies to demonstrate its validity and
applicability to proposed CPV standard.
Development of Crystalline Silicon Based Metal Wrap Through (MWT) Solar Cells for Low Concentrator (2-30x) Applications
Creators: name: Fellmeth, T.
name: Fritz, S.
name: Menkoe, M.
name: Mingirulli, N.
name: Glatthaar, M.
name: Clement, F.
name: Biro, D.
name: Preu, R.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Advanced Photovoltaics
Terrestrial Concentrator Systems

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 711-716
description: One of the main barriers on the way to mass production of concentrator silicon solar cells is the lack of
industrially feasible process sequences. Therefore, a concentrator silicon based Metal Wrap Through (CMWT) solar
cell completely processed at the Fraunhofer ISE PhotoVoltaic Technology Evaluation Center (PV-TEC) is
introduced. This means no clean room or photolithographic steps are necessary. Under one-sun conditions, a
conversion efficiency of 18.6% could be reached which is so far the highest efficiency reported for a MWT silicon
solar cell. The highest efficiency achieved was 19.5% at 6 suns and even 18.1% at 23 suns. The series resistance as
major loss mechanism concentrator solar cells are suffering from is the main focus in this work. Concerning this
matter an investigation of the Light induced Plating (LiP) step and furthermore a detailed analysis of the
contributions to the series resistance is presented. A simulation tool containing an analytical series resistance model
has been developed and a 2-diode-model was added providing the calculation of the efficiency and fill factor
dependent on the concentration at given parameters.
On the gravitational lensing interpretation of three gravitational wave detections in the mass gap by LIGO and Virgo
Creators: name: Bianconi, Matteo
name: Smith, Graham P.
name: Nicholl, Matt
name: Ryczanowski, Dan
name: Richard, Johan
name: Jauzac, Mathilde
name: Massey, Richard
name: Robertson, Andrew
name: Sharon, Keren
name: Ridley, Evan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We search for gravitational wave (GW) events from LIGO-Virgo's third run that may have been affected by gravitational lensing. Gravitational lensing delays the arrival of GWs, and alters their amplitude -- thus biasing the inferred progenitor masses. This would provide a physically well-understood interpretation of GW detections in the ''mass gap'' between neutron stars and black holes, as gravitationally lensed binary neutron star (BNS) mergers. We selected three GW detections in LIGO-Virgo's third run for which the probability of at least one of the constituent compact objects being in the mass gap was reported as high with low latency -- i.e. candidate lensed BNS mergers. Our observations of powerful strong lensing clusters located adjacent to the peak of their sky localisation error maps reached a sensitivity $\rm AB\simeq25.5$ in the $z'$-band with the GMOS instruments on the Gemini telescopes, and detected no candidate lensed optical counterparts. We combine recent kilonova lightcurve models with recent predictions of the lensed BNS population and the properties of the objects that we followed up to show that realistic optical counterparts were detectable in our observations. Further detailed analysis of two of the candidates suggests that they are a plausible pair of images of the same low-mass binary black hole merger, lensed by a local galaxy or small group of galaxies. This further underlines that access to accurate mass information with low latency would improve the efficiency of candidate lensed BNS selection.
description: Accepted for publication on MNRAS
Numerical simulations of stellar collapse in scalar-tensor theories of gravity
Creators: name: Gerosa, Davide
name: Sperhake, Ulrich
name: Ott, Christian D.
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present numerical-relativity simulations of spherically symmetric core collapse and compact-object formation in scalar-tensor theories of gravity. The additional scalar degree of freedom introduces a propagating monopole gravitational-wave mode. Detection of monopole scalar waves with current and future gravitational-wave experiments may constitute smoking gun evidence for strong-field modifications of General Relativity. We collapse both polytropic and more realistic pre-supernova profiles using a high-resolution shock-capturing scheme and an approximate prescription for the nuclear equation of state. The most promising sources of scalar radiation are protoneutron stars collapsing to black holes. In case of a Galactic core collapse event forming a black hole, Advanced LIGO may be able to place independent constraints on the parameters of the theory at a level comparable to current Solar-System and binary-pulsar measurements. In the region of the parameter space admitting spontaneously scalarised stars, transition to configurations with prominent scalar hair before black-hole formation further enhances the emitted signal. Although a more realistic treatment of the microphysics is necessary to fully investigate the occurrence of spontaneous scalarisation of neutron star remnants, we speculate that formation of such objects could constrain the parameters of the theory beyond the current bounds obtained with Solar-System and binary-pulsar experiments.
description: 37 pages, 8 figures. Accepted for publication in CQG. Supporting material available at http://davidegerosa.com/corecollapse/
The Buried Emitter Solar Cell Concept: Interdigitated Back-Junction Structure with Virtually 100% Emitter Coverage of the Cell Area
Creators: name: Mertens, V.
name: Bordihn, S.
name: Larionova, Y.
name: Harder, N.-P.
name: Brendel, R.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Wafer-based Silicon Solar Cells and Materials Technology
Mono- and Multicrystalline Silicon Materials and Cells

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 934-936
description: The buried emitter back junction back contacted solar cell combines large area emitter allocation with effective
insulation of emitter region by means of a base-type surface region. We present experimental results for two different
concepts of the buried emitter solar cell. The first “partial” approach features 80% emitter coverage in combination
with 50% metallization fraction for emitter and base without the need for an additional insulation layer. Our second
“full area” approach combines the large area emitter with an efficient boron emitter passivation realized by an
oxidized n+-surface region. Our recent experimental result for the “partial” buried emitter solar cell shows 21.0%
efficiency and a short circuit current density of 41.0 mA/cm2, which confirms the efficient current collection of the
large area emitter coverage. The high fill factor of 79.8% indicates that trap-assisted tunneling is not a relevant loss
mechanism of this solar cell despite large areas of n+-p+ overlap. For the “full area” buried emitter solar cell we
report a maximum conversion efficiency of 21.8%.
MAiA - A New Versatile  In-Line Etching/PECVD Tool Concept for Processing Crystalline Silicon Solar Cells
Creators: name: Grimm, M.
name: Schlemm, H.
name: Lux, A.
name: Köhler, G.
name: Decker, D.
name: Richter, M.
name: Uhlig, M.
name: Mehlich, H.
name: Roth, K.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Mono- and Multicrystalline Silicon Cells and Materials, Processing Technology of

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 1801-1804
description: Roth&Rau AG is introducing the MAiA (Multiple Application inline Apparatus), a new in-line tool concept for processing silicon solar cells. Due to the trend to thinner wafers on the one hand and an increasing number of process steps on the other hand, reducing the number of handling steps becomes much more crucial and leads direct to a higher yield of a solar cell production line. For this purpose we developed a versatile in-line tool where different dry etching and deposition steps of passivation or AR layers can be carried out in one system after each other without touching the wafers between the processes. Due to the modular concept almost every combination of etching and deposition steps is possible and the tools can be adapted to the special needs of the customer. In this paper, we describe the concept of possible MAiA tools in general and in detail for already delivered deposition tools.
The MPVT (Multi-Purpose PV Module Tester) Project – A Highly Innovative and Versatile Solar Simulator
Creators: name: Virtuani, A.
name: Friesen, G.
name: Chianese, D.
name: Dozio, G.C.
name: Rigamonti, G.
name: Pegurion, M.
name: Beljean, P.-R.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Components for PV Systems
PV Modules

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 4361-4365
description: The purpose of this paper is to present the activity of the MPVT (Multi-Purpose PV Module Tester)
project funded by the Innovation Promotion Agency (CTI) of the Swiss Confederation. The aim of the project is to
develop an extremely versatile measurement equipment for the indoor testing of PV modules by upgrading and
integrating new functionalities into an existing pulsed solar-simulator based IV measurement set-up.
The newly developed MPVT set-up will be able to realize IV measurements at standard test conditions, temperature
coefficients (TCO’s) and measurement at different irradiance levels. In addition, a set-up to measure spectral
response (SR) of large-area module will be implemented in the system.
The MPVT system will be adapted to the needs of the different PV technologies present today on the market, which
require a larger flexibility in terms of electrical measurement conditions (high-voltage/low-current thin film PV and
high-current/low-voltage c-Si technologies). Moreover, traditional or alternative solutions will be implemented to
overcome problems - related to the short duration of the light pulse - which some technologies may encounter when
performing power measurements with flashers, as for example, high efficient c-Si modules, which are characterized
by high cell capacitances.
Machine learning identification of organic compounds using visible light
Creators: name: Bikku, Thulasi
name: Fritz, Rubén A.
name: Colón, Yamil J.
name: Herrera, Felipe
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Chemical Physics (physics.chem-ph)
subject: Optics (physics.optics)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Identifying chemical compounds is essential in several areas of science and engineering. Laser-based techniques are promising for autonomous compound detection because the optical response of materials encodes enough electronic and vibrational information for remote chemical identification. This has been exploited using the fingerprint region of infrared absorption spectra, which involves a dense set of absorption peaks that are unique to individual molecules, thus facilitating chemical identification. However, optical identification using visible light has not been realized. Using decades of experimental refractive index data in the scientific literature of pure organic compounds and polymers over a broad range of frequencies from the ultraviolet to the far-infrared, we develop a machine learning classifier that can accurately identify organic species based on a single-wavelength dispersive measurement in the visible spectral region, away from absorption resonances. The optical classifier proposed here could be applied to autonomous material identification protocols or applications.
description: 18 pages, 7 figures. Open database and python code. Version adds comparison with Raman classifiers (Table 1)
Characterization of Concentrator Optical Surfaces Based on CCD Camera Measurement
Creators: name: Herrero, R.
name: Anton, I.
name: Vivar, M.
name: Sala, G.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Advanced Photovoltaics
Terrestrial Concentrator Systems

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 827-830
description: Roughness, dust and another surfaces imperfections cause light scattering at the optical collector on a
CPV system. Consequently, part of the scattered rays in concentrator systems should be definitively lost because
they cannot be focused onto the receivers. For this reason, it is important to characterize optical elements involved in
CPV systems in order to achieve higher efficiency. A method based on CCD camera for measuring light scattering
and absorption is presented in order to acquire enough information about optical performance of CPV optic
materials. By means of CCD images, we are able to characterize the light profile before and after going through the
optical material. Several features as light sources, mirror and glasses surfaces and angle acceptance functions can be
evaluated in order to achieve a good CPV performance.
Risk-Averse Multi-Armed Bandit Problems under Mean-Variance Measure
Creators: name: Vakili, Sattar
name: Zhao, Qing
Publisher: name: arXiv
Year: 2016
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: The multi-armed bandit problems have been studied mainly under the measure of expected total reward accrued over a horizon of length $T$. In this paper, we address the issue of risk in multi-armed bandit problems and develop parallel results under the measure of mean-variance, a commonly adopted risk measure in economics and mathematical finance. We show that the model-specific regret and the model-independent regret in terms of the mean-variance of the reward process are lower bounded by $Ω(\log T)$ and $Ω(T^{2/3})$, respectively. We then show that variations of the UCB policy and the DSEE policy developed for the classic risk-neutral MAB achieve these lower bounds.
Bosonic pair production and squeezing for optical phase measurements in long-lived dipoles coupled to a cavity
Creators: name: Sundar, Bhuvanesh
name: Barberena, Diego
name: Orioli, Asier Piñeiro
name: Chu, Anjun
name: Thompson, James K.
name: Rey, Ana Maria
name: Lewis-Swan, Robert J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We propose to simulate bosonic pair creation using large arrays of long-lived dipoles with multilevel internal structure coupled to an undriven optical cavity. Entanglement between the atoms, generated by the exchange of virtual photons through a common cavity mode, grows exponentially fast and is described by two-mode squeezing of effective bosonic quadratures. The mapping between an effective bosonic model and the natural spin description of the dipoles allows us to realize the analog of optical homodyne measurements via straightforward global rotations and population measurements of the electronic states, and we propose to exploit this for quantum-enhanced sensing of an optical phase (common and differential between two ensembles). We discuss a specific implementation based on Sr atoms and show that our sensing protocol is robust to sources of decoherence intrinsic to cavity platforms. Our proposal can open unique opportunities for next-generation optical atomic clocks.
description: 5 pages + 3 figures + references + supplement; Updated parts of main text and supplement
Dynamic Mechanical Load Tests on Crystalline Silicon Modules
Creators: name: Koch, S.
name: Kupke, J.
name: Tornow, D.
name: Schoppa, M.
name: Krauter, S.
name: Grunow, P.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Components for PV Systems
PV Modules

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 3998-4001
description: The mechanical load test in the actual standard for photovoltaic module product qualification is
simulating the combined wind and snow load by the means of a static load. Critical issues are the size, thickness and
treatment of the module front glass, the stability of the framing and mounting scheme and the mechanical reliability
of the solder joints. For crystalline silicon modules, micro cracks offer an additional risk. But operating conditions in
the field and conditions during handling and transportation are not necessarily static. In this work we compare the
effects of dynamic and static load tests and investigate their interaction with climatic stress tests. Different test
combinations and sequences are evaluated with respect to electrical power losses and to possible changes that can be
observed via electro-luminescence. The aim is to prove or improve the existing reliability tests towards a more
complete simulation of real operating conditions and to broaden the portfolio of very fast reliability tests beyond the
existing standards. Various test sequences are probed on identical commercial modules and the results are compared
to the statistical test data from the laboratory’s database.
Point Cloud Compression with Sibling Context and Surface Priors
Creators: name: Chen, Zhili
name: Qian, Zian
name: Wang, Sukai
name: Chen, Qifeng
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: We present a novel octree-based multi-level framework for large-scale point cloud compression, which can organize sparse and unstructured point clouds in a memory-efficient way. In this framework, we propose a new entropy model that explores the hierarchical dependency in an octree using the context of siblings' children, ancestors, and neighbors to encode the occupancy information of each non-leaf octree node into a bitstream. Moreover, we locally fit quadratic surfaces with a voxel-based geometry-aware module to provide geometric priors in entropy encoding. These strong priors empower our entropy framework to encode the octree into a more compact bitstream. In the decoding stage, we apply a two-step heuristic strategy to restore point clouds with better reconstruction quality. The quantitative evaluation shows that our method outperforms state-of-the-art baselines with a bitrate improvement of 11-16% and 12-14% on the KITTI Odometry and nuScenes datasets, respectively.
Removal of a Possible Split Interstitial (N-As)As Recombination Center in GaAsN Grown by Chemical Beam Epitaxy Using Proton Implantation
Creators: name: Bouzazi, B.
name: Lee, J.-H.
name: Suzuki, H.
name: Kojima, N.
name: Ohshita, Y.
name: Yamaguchi, M.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Advanced Photovoltaics: New Concepts and Ultra-high Efficiency
Fundamental Studies

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 69-72
description: Proton implantation is used to discuss the origin of a N-related recombination center (E1), at around
0.33 eV from the conduction band minimum (CBM) of chemical beam epitaxy (CBE) grown GaAsN. After proton
implantation, E1 is completely removed whereas two new defects appear. The first one (HP1) is a hole trap at around
0.11 eV from the valence band minimum, similar to a N-related hole trap in unintentionally doped p-type GaAsN
grown by CBE and expected to be N-H-VGa. The density of HP1 is less than that of E1, which increases the
probability that E1 contains only one N atom in its structure. The second level (EP1) is an electron trap at around
0.41 eV from CBM, identical to EL5 native defect in GaAs and expected to be VGa-Asi or AsGa-VGa. From these
results, the origin of E1 has high probability to be associated with the split interstitial (N-As)As.
Scaling-up quantum heat engines efficiently via shortcuts to adiabaticity
Creators: name: Beau, M.
name: Jaramillo, J.
name: del Campo, A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: The finite-time operation of a quantum heat engine that uses a single particle as a working medium generally increases the output power at the expense of inducing friction that lowers the cycle efficiency. We propose to scale up a quantum heat engine utilizing a many-particle working medium in combination with the use of shortcuts to adiabaticity to boost the nonadiabatic performance by eliminating quantum friction and reducing the cycle time. To this end, we first analyze the finite-time thermodynamics of a quantum Otto cycle implemented with a quantum fluid confined in a time-dependent harmonic trap. We show that nonadiabatic effects can be controlled and tailored to match the adiabatic performance using a variety of shortcuts to adiabaticity. As a result, the nonadiabatic dynamics of the scaled-up many-particle quantum heat engine exhibits no friction and the cycle can be run at maximum efficiency with a tunable output power. We demonstrate our results with a working medium consisting of particles with inverse-square pairwise interactions, that includes noninteracting and hard-core bosons as limiting cases.
description: 15 pages, 3 figures; typo in Eq. (51) fixed. Feature paper in the Special Issue "Quantum Thermodynamics" edited by Prof. Dr. Ronnie Kosloff
Multi species asymmetric simple exclusion process with impurity activated flips
Creators: name: Chatterjee, Amit Kumar
name: Hayakawa, Hisao
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 60G10

description: We obtain an exact matrix product steady state for a class of multi species asymmetric simple exclusion process with impurities, under periodic boundary condition. Alongside the usual hopping dynamics, an additional flip dynamics is activated only in the presence of impurities. Although the microscopic dynamics renders the system to be non-ergodic, exact analytical results for observables are obtained in steady states for a specific class of initial configurations. Interesting physical features including negative differential mobility and transition of correlations from negative to positive with changing vacancy density, have been observed. We discuss plausible connections of this exactly solvable model with multi lane asymmetric simple exclusion processes as well as enzymatic chemical reactions.
description: 43 pages, 15 figures, typos corrected, references added, new appendices added
Energy Prediction of Amonix CPV Solar Power Plants
Creators: name: Kinsey, G.S.
name: Stone, K.
name: Brown, J.
name: Garboushian, V.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Advanced Photovoltaics: New Concepts and Ultra-high Efficiency
Terrestrial Concentrator Systems

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 15-17
description: Amonix CPV Solar Power Plants currently demonstrate AC efficiency of over 25% in the field. A
model has been developed that predicts system performance based on the spectral response of the III-V multijunction
cell corrected for environmental and atmospheric conditions. Historical meteorological data is used to predict future
performance at target locations. With the cleaning schedule as the only adjustable variable, energy production has
been within 1% of prediction after twelve months of continuous operation. The model is used to improve
performance, which is expected to increase by 10% in 2010. These improvements, combined with cost reductions in
the MegaModule® design, put the Amonix CPV systems on track to achieve a levelized cost of electricity below
US$100/MW-hr.
Solvable Lie algebras and graphs
Creators: name: Grantcharov, Gueo
name: Grantcharov, Vladimir
name: Iliev, Plamen
Publisher: name: arXiv
Year: 2016
Subjects: subject: Rings and Algebras (math.RA)
subject: Combinatorics (math.CO)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics

description: We define a solvable extension of the graph 2-step nilpotent Lie algebras of [5] by adding elements corresponding to the 3-cliques of the graph. We study some of their basic properties and we prove that two such Lie algebras are isomorphic if and only if their graphs are isomorphic. We also briefly discuss some metric properties, providing examples of homogeneous spaces with nonpositive curvature operator and solvsolitons.
description: minor changes