cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Pulsewidth Dependence of Laser Scribing of Transparent Conductive Oxides in the Picosecond Regime
Creators: name: Baird, B.
name: Gerke, T.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
CdTe, CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2356-2358
description: Continuous improvement and innovation in laser processing methods and laser architectures are
needed to further improve device efficiencies and reduce overall device manufacturing costs. In particular, P1 and P3
laser scribes of transparent conductive oxide layers, such as F:SnO2 or Al:ZnO (AZO) employed in thin film solar
cell devices conventionally have been processed by Q-switched diode-pumped solid state lasers (DPSS) operating in
the nanosecond regime. The principal wavelength employed for F:SnO2 scribing has been in the near infrared at or
near 1064 nm while AZO has also been widely scribed at harmonic wavelengths, including in the near ultraviolet at
or near 355 nm. Scribes produced with these laser systems often display undesirable sidewall non-uniformities, heat
affected zones, film lift off, cracking, and excessive residual debris. Further, Q-switched DPSS laser architectures
face scaling challenges as improvements in beam positioning technology demand laser performance at pulse
repetition frequencies substantially higher than 200 KHz in order to keep pace with improvements in beam
positioning speed and overall system throughput requirements. In addition, the lifetime and reliability of Q-switched
ultraviolet DPSS lasers are well-known to be negatively impacted by the high photon energy in comparison to
comparable pulse energy infrared laser systems. Recently, substantial work has been performed to investigate the
effectiveness of sub-nanonsecond lasers on key laser scribing processes, including P1 molybdenum and P2 and P3
CdTe and a-Si scribes. In this work, we extend these investigations to evaluate the pulsewidth dependence of TCO
laser scribe process performance and quality produced by 1064 nm master oscillator fiber power amplifier (MOFPA)
laser systems in the picosecond regime.
First-Principle Calculations of Band-Structures and Optical Properties of SnS, Cu2SnS3 and Cu2ZnSnS4 for Photovoltaics
Creators: name: Shaposhnikov, V.L.
name: Krivosheeva, A.V.
name: Borisenko, V.E.
name: Lazzari, J.-L.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
CdTe, CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2364-2367
description: In order to find CIGS-replacing materials to be used for production of cheaper and environment
friendly solar cells, we present computer simulation of structural, electronic and optical properties of SnS, Cu2SnS3
and Cu2ZnSnS4 compounds performed in the frame of Density Functional Theory (DFT). According to our
calculations, in spite of numerical underestimations of the band gap values, -SnS, monoclinic Cu2SnS3 and
Cu2ZnSnS4 were found to have the averaged absorption coefficients the same order of magnitude in the visible
spectrum range as that of GaAs. Thus, these materials or their multilayer combinations can become adequate for
CIGS substitution being built on neither nontoxic nor rare elements.
Thermodynamics, transport and relaxation in non-conformal theories
Creators: name: Attems, Maximilian
name: Casalderrey-Solana, Jorge
name: Mateos, David
name: Papadimitriou, Ioannis
name: Santos-Oliván, Daniel
name: Sopuerta, Carlos F.
name: Triana, Miquel
name: Zilhão, Miguel
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We study the equilibrium and near-equilibrium properties of a holographic five-dimensional model consisting of Einstein gravity coupled to a scalar field with a non-trivial potential. The dual four-dimensional gauge theory is not conformal and, at zero temperature, exhibits a renormalisation group flow between two different fixed points. We quantify the deviations from conformality both in terms of thermodynamic observables and in terms of the bulk viscosity of the theory. The ratio of bulk over shear viscosity violates Buchel's bound. We study relaxation of small-amplitude, homogeneous perturbations by computing the quasi-normal modes of the system at zero spatial momentum. In this approximation we identify two different relaxation channels. At high temperatures, the different pressures first become approximately equal to one another, and subsequently this average pressure evolves towards the equilibrium value dictated by the equation of state. At low temperatures, the average pressure first evolves towards the equilibrium pressure, and only later the different pressures become approximately equal to one another.
description: 22 pages, 29 figures; published version
Distributed Model Predictive Control Using a Chain of Tubes
Creators: name: Hernandez, Bernardo
name: Trodden, Paul
Publisher: name: arXiv
Year: 2016
Subjects: subject: Systems and Control (eess.SY)
subject: Optimization and Control (math.OC)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Mathematics

description: A new distributed MPC algorithm for the regulation of dynamically coupled subsystems is presented in this paper. The current control action is computed via two robust controllers working in a nested fashion. The inner controller builds a nominal reference trajectory from a decentralized perspective. The outer controller uses this information to take into account the effects of the coupling and generate a distributed control action. The tube-based approach to robustness is employed. A supplementary constraint is included in the outer optimization problem to provide recursive feasibility of the overall controller
description: Accepted for presentation at the UKACC CONTROL 2016 conference (Belfast, UK)
Neue Methoden zur Entdeckung von Fehlspezifikation bei Latent-Trait-Modellen der Veränderungsmessung
Creators: name: Klein, Stefan
Publisher: name: Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I
Year: 2003
Subjects: subject: Item-Response-Theorie
subject: LLTM
subject: Personenfittests
subject: SAS
subject: Item Response Theory
subject: Person fit test
subject: 150 Psychologie
subject: 11 Psychologie
subject: CS 1500

description: Ziel der Arbeit ist die Entwicklung von Modellen zur Entdeckung von Fehlspezifikation im Linear Logistic Test Model ( = LLTM) und verwandten Modellen der Verände\-rungs\-mes\-sung. Fehlspezifikation bedeutet hierbei, dass dem Modell ein unzutreffendes Muster latenter Traits zugrundegelegt wurde. Dies kann, vgl. z.B. [Baker,1993], zu bedeutenden Schätzfehlern führen. Die hier vorgestellten Methoden ermöglichen es unter leicht zu erfüllenden Annahmen, Aussagen über das Ausmaß der Unkorrektheit der verwendeten Modellspezifikation zu machen, ohne die in der Modellschätzung bestimmten Parameterwerte verwenden zu müssen. Zunächst wird eine auf dem Mantel-Haenszel-Test beruhende Methodik vorgestellt, die bei Tests bezüglich der Veränderungsparameter eines LLTMs als direkte Konkurrenz zu den bekannten Likelihood-Ratio-Tests für das LLTM anzusehen ist, wie sie z.B. bei [Fischer,1995a] vorgestellt werden. Weiterhin werden für das LLTM optimierte Personenfittests und daraus abgeleitete Effektgrößen vorgestellt. Diese ermöglichen das Auffinden von Subpopulationen, bei denen eine Abweichung zum angenommenen Modell aufgetreten ist. Es werden die statistischen Eigenschaften dieser Tests resp. Effektgrößen mittels Simulation und Teststärkeberechnung untersucht und Anwendungsbeispiele für diese Methoden vorgestellt.
description: In this thesis, new methods are developed for the detection of misspecification within Linear Logistic Test Models (=LLTM) and similar model classes for the measurement of change. The phrase "misspecification" will be used if a wrong selection of latent traits is chosen for the estimation of the LLTM. Misspecification can lead to erronious estimation [Baker,1993]). Using the newly developed methods, it is possible to measure the extent of deviations between the proposed model and the data. This can be done without using estimated parameter values. First a method is introduced which is based on the well-known Mantel-Haenszel-test. For some hypotheses, this method can be used instead of a Likelihood Ratio Test (e.g. [Fischer,1995a]). The Main topic of this thesis are uniformly most powerful tests for the measurement of person fit and related effect measures. These effect measures can be used for the identification of subpopulations where the proposed model does not hold. Statistical properties of these tests resp. effect measures are examined by simulations and power calculations using the SAS software. Furthermore, examples of the application of these methods are given.
Maintaining extensivity in evolutionary multiplex networks
Creators: name: Antonopoulos, Chris G.
name: Baptista, Murilo S.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: In this paper, we explore the role of network topology on maintaining the extensive property of entropy. We study analytically and numerically how the topology contributes to maintaining extensivity of entropy in multiplex networks, i.e. networks of subnetworks (layers), by means of the sum of the positive Lyapunov exponents, $H_{KS}$, a quantity related to entropy. We show that extensivity relies not only on the interplay between the coupling strengths of the dynamics associated to the intra (short-range) and inter (long-range) interactions, but also on the sum of the intra-degrees of the nodes of the layers. For the analytically treated networks of size $N$, among several other results, we show that if the sum of the intra-degrees (and the sum of inter-degrees) scales as $N^{θ+1},\;θ>0$, extensivity can be maintained if the intra-coupling (and the inter-coupling) strength scales as $N^{-θ}$, when evolution is driven by the maximisation of $H_{KS}$. We then verify our analytical results by performing numerical simulations in multiplex networks formed by electrically and chemically coupled neurons.
description: 17 pages, 2 figures
TEM and EDX Elemental X-Ray Mapping of Cu(In,Ga)(S,Se)2 Thin Films
Creators: name: Ihlal, A.
name: Bouabid, K.
name: Alahyane, L.
name: Elfanaoui, A.
name: Kirou, H.
name: Boulkaddat, L.
name: Nya, M.
name: Bechiri, L.
name: Portier, X.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
CdTe, CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2305-2307
description: The present work presents our recent results concerning the chemical analyses performed using TEM/EDX
on electrodeposited polycrystalline Cu-chalcogenide thin films. The spatial repartition of the elements in the vicinity and
far from the grain boundaries is investigated. Elemental X-ray mapping were recorded on our samples. It was
demonstrated the presence of copper-rich phases in the samples. KCN etching has lead to the removal of such phases and
lead to a relatively homogeneous distribution of the elements over the sample. Quantitative analyses have shown that the
samples were almost stoichiometric upon KCN attack. Finally, elemental analysis was performed across grain boundaries
to detect any segregation or depletion of the elements. A slight reduction of the concentration of the elements is observed
at the level of the Grain boundary synonymous of the depletion of this region. However, these results should be
considered carefully. Indeed, a preferential etching at the level of the GB could happen during the preparation of the
samples for TEM observations and can then explain the origin of such reduction in the concentrations of the elements.
Finite element modeling of welded butt joint : An experimental approach
Creators: name: Kaphle, Sujan
Publisher: name: Unknown
Year: 2019

description: Welding is a common process used to manufacture unique tools and tooling. However, it has
proven to be a challenge to develop a Finite Element Model (FEM) that predicts the stresses on a
welded structure. The welding process introduces non-uniform stress distribution across the
welded stmcture by abnormally high temperatures and introducing a filler material that is used to
connect two pieces of metal to each other. This senior design project takes an experimental
approach to determine the maximum principle stress at the Heat Affected Zone (HAZ) of a
welded butt joint. This project is completed in collaboration with BWX, Technologies, Inc.
(BWXT), Tooling Department.
The objective of this project is to construct a FEM to predict the stress in a welded V-notch joint.
A test specimen is manufactured with an A3 6 structural steel and welded with a V-notch butt
joint. Using a Wheatstone bridge circuit, an instrumentation amplifier, Data Acquisition System
(DAQ), and Lab VIEW, the strain is measured. A tri-axial strain gage rosette is attached at the
HAZ of the test specimen and the strain is measured with tensile force applied. The strain data is
post processed via MATLAB to obtain the stress at the location of strain gage. The FEM is
constructed in SolidWorks. The pre-loading value for residual stress is approximated at the HAZ
to predict the response of the welded specimen. The boundary conditions and applied load were
defined as well. Maximum error of 22% is reported between the FEM stress to experimental
stress. Multiple strain gages should be used along the HAZ to better understand how stresses
behave and is recommended for future work.
Quantizing the Vector Potential Reveals Alternative Views of the Magnetic Aharonov-Bohm Phase Shift
Creators: name: Pearle, Philip
name: Rizzi, Anthony
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We give a complete quantum analysis of the Aharonov-Bohm (AB) magnetic phase shift involving three entities, the electron, the charges constituting the solenoid current, and the vector potential. The usual calculation supposes that the solenoid's vector potential may be well-approximated as classical. The AB shift is then acquired by the quantized electron moving in this vector potential. Recently, Vaidman presented a semi-classical calculation, later confirmed by a fully quantum calculation of Pearle and Rizzi, where it is supposed that the electron's vector potential may be well-approximated as classical. The AB shift is then acquired by the quantized solenoid charges moving in this vector potential. Here we present a third calculation, which supposes that the electron and solenoid currents may be well-approximated as classical sources. The AB phase shift is then shown to be acquired by the quantized vector potential. We next show these are three equivalent alternative ways of calculating the AB shift. We consider the exact problem where all three entities are quantized. We approximate the wave function as the product of three wave functions, a vector potential wave function, an electron wave function and a solenoid wave function. We apply the variational principle for the exact Schrodinger equation to this approximate form of solution. This leads to three Schrodinger equations, one each for vector potential, electron and solenoid, each with classical sources for the other two entities. However, each Schrodinger equation contains an additional real c-number term, the time derivative of an extra phase. We show that these extra phases are such that the net phase of the total wave function produces the AB shift. Since none of the three entities requires different treatment from any of the others, this leads to three alternative views of the physical cause of the AB magnetic effect.
description: This is the second of a two paper series. Changes to paper I (Quantum Mechanical Inclusion of the Source in the Aharonov-Bohm Effects) lead to new insights and simplified calculations (but identical results), now incorporated into this paper
Higher gap morasses
Creators: name: Cárdenas, Franqui
Publisher: name: Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I
Year: 2005
Subjects: subject: Logik
subject: Mengenlehre
subject: kombinatorische Mathematik
subject: Moraste
subject: Logic
subject: set theory
subject: combinatorics
subject: morasses
subject: 510 Mathematik
subject: 27 Mathematik

description: Velleman beweist die Konsistenz der Existenz vereinfachte Gap 2 Moraste (ein Begriff gleichwertig zu den ursprünglichen Morasten, geschafft von Jensen). Wir haben einen noch einfachen Begriff des vereinfachten Morastes in der Dissertation vorgeschlagen, Details aufgefüllt und wesentlich auch einen verschiedenen Beweis des Satzes erfunden und zwar in beide Stufe des Forcingverfahrens. Wir benötigen auch keine Squarefunktionereihenfolge (die ganz Kohärenzvoraussetzung fehlt aber ist linear und konfinal) sondern ein ``erratendes'' Verfahren für Sequenze, das nicht fest ist und nicht die ganze Kohärenzbedigung erfüllt wie bei Velleman. Wir hoffen, wir haben so eingelegt die Basis für einen zukunftigen Beweis des allgemeines Falls n in ZFC.
description: Velleman proved the consistency of the existence of simplified gap 2 morasses (equivalent to the concrete morasses defined by Jensen) using a two stage forcing. We give an essentially different proof of the same result and fill up some details from Velleman's paper which were not clear or imcomplete. In fact the proof uses a simpler definition of simplified gap 2 morasses. We have also eliminated the use of square-like sequences in the second stage, employing a ``guessing'' procedure for sequences which are not fixed and do not satisfy full coherence requirement. With these steps we hope to have laid the foundation for a future proof of gap n morasses in ZFC.
Towards CIGS Solar Cells with Reduced Film Thickness: A Study of Optical Properties and of Photonic Structures for Light Trapping
Creators: name: Andreani, L.C.
name: Kowalczewski, P.A.
name: Mura, C.I.
name: Patrini, M.
name: Acciarri, M.
name: Binetti, S.
name: Sassella, A.
name: Marchionna, S.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
CdTe, CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2334-2337
description: In view of large-scale exploitation of CuIn1-xGaxSe2 (CIGS) solar cells for photovoltaic energy
conversion, it would be quite important not only to increase the conversion efficiency, but also to reduce the
thickness of CIGS layer in order to decrease the use of rare and expensive elements, especially Indium. In this
work we perform a full study of optical properties of CIGS solar cells grown by a hybrid sputtering/evaporation
process, and use the resulting optical functions for electro-optical simulations. We then introduce a texturization
of the interfaces and investigate the effects of light trapping on the conversion efficiency. Starting from a CIGS
thickness around 2 μm, we show that the same or even higher efficiency can be achieved with much reduced film
thickness, with a sizeable effect due to the photonic structure.
Remark on the Dunne-Unsal relation in exact semi-classics
Creators: name: Gahramanov, Ilmar
name: Tezgin, Kemal
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Other Condensed Matter (cond-mat.other)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Recently, it is realized that non-perturbative instanton effects can be generated to all orders by perturbation theory around a degenerate minima via Dunne-Unsal relation in several quantum mechanical systems. In this work we verify the Dunne-Unsal relation for resonance energy levels of one-dimensional polynomial anharmonic oscillators. We show that the relation is applicable to cubic and quartic anharmonic oscillators which are genus one potentials. However for higher order (higher genus) anharmonic potentials the relation is not satisfied and is subject to a certain extension.
description: 20 pages, v2: minor corrections, comments and refs. added, v3: minor corrections
Stability of the Adhesive Interconnection in Flexible CIGS-Modules After Surface Treatment
Creators: name: Reithe, A.
name: Münch, M.
name: Wolter, K.-J.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
CdTe, CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2281-2285
description: Exposure to environmental influences like temperature changes, humidity, heat or mechanical load
affects flexible solar modules much more than their glass-encapsulated rigid counterparts. To ensure a stable
interconnection between the non-noble molybdenum back-contact and the front-side busbar of the cells using
isotropic conductive adhesive, a pre-treatment of the back contact metal before interconnection was studied. Contact
resistances and microsections have been examined as well as the surface properties of the contact area. It is shown
that a plasma treatment improves the wetting characteristics and surface properties. However the thickness of the
polymer film on the contact surface increased after the plasma treatment. Due to the rheological properties of the
ICA, the contact geometry does also depend on the dispensing parameters. Thus the contact quality results from the
interplay of said factors and it was shown that plasma treatment does not prove necessary for a stable interconnection
of flexible CIGS-cells.
Distortions Observed in Current-Voltage Characteristics of Photovoltaic Solar Cells
Creators: name: Dharmadasa, I.M.
name: Echendu, O.K.
name: Dharmadasa, R.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
CdTe, CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2308-2313
description: Different types of undesirable distortions appear during final assessment of the performance of photovoltaic
solar cells. It is essential to understand the reasons behind these features in order to avoid them in final current-voltage
characteristics. Recent experimental results on GaAs-based solar cells and the results reported in the literature on CuInGaSe2
(CIGS) and CdTe solar cells have been taken as examples to explore the reasons behind these behaviours. Critical analysis of
these results shows that the "roll-over" effects and "cross-over" effects between the dark I-V and light I-V curves could
appear due to the existence of non-ideal metal/insulator/semiconductor (MIS)-type front electrical contacts in photovoltaic
solar cells. This is in addition to the well-known case of the presence of back contact barrier. The methods to avoid these
undesirable features are proposed and discussed.
Massless sunset diagrams in finite asymmetric volumes
Creators: name: Niedermayer, Ferenc
name: Weisz, Peter
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: This paper discusses the methods and the results used in an accompanying paper describing the matching of effective chiral Lagrangians in dimensional and lattice regularizations. We present methods to compute 2-loop massless sunset diagrams in finite asymmetric volumes in the framework of these regularizations. We also consider 1-loop sums in both regularizations, extending the results of Hasenfratz and Leutwyler for the case of dimensional regularization and we introduce a new method to calculate precisely the expansion coefficients of the 1-loop lattice sums.
description: published version, 57 pages, no figures
Energy Rating of CIGS Thin Film Modules and Systems
Creators: name: Borowski, P.
name: Heinisch, C.
name: Hampe, A.A.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
CdTe, CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2294-2299
description: With decreasing subsidies and an increasing share of photovoltaic electricity production, predicting the
output of a photovoltaic generator becomes more important. Due to their high STC efficiencies, low production costs and
desirable properties under normal, non-STC conditions, thin film modules made of Copper, Indium, Gallium and
Selenium (CIGS) are expected to contribute significantly to future electricity generation.
For photovoltaic systems consisting of the CIGS modules Avancis PowerMax®, we present different ways of predicting
the yield, using various input and output parameters, which leads to different systematic errors and accuracies. Systems
considered range from individual modules of 0.1kWp up to power plants of several 100kWp and cover time periods from
one hour up to more than two years. We analyse commercially available simulation software (PVsyst and PV*SOL) in
terms of correct implementation of CIGS modules. Excluding the variability in weather forecast, we obtain agreement
between simulated and measured yearly yield within +/-4%.
Selenization of Nanoparticle Precursor Layers for Cu(In,Ga)Se2 Absorbers
Creators: name: Uhl, A.R.
name: Wallerand, A.
name: Koller, M.
name: Fella, C.M.
name: Romanyuk, Y.E.
name: Tiwari, A.N.
name: Magorian-Friedlmeier, T.M.
name: Ahlswede, E.
name: VanGenechten, D.
name: Stassin, F.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
CdTe, CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2318-2320
description: In the framework of the industry-led project NOVA-CIGS, supported by the EU within the FP7 program,
we investigate an alternative, non-vacuum deposition process for Cu(In,Ga)Se2 (CIGS) absorber layers based on the
conversion of hydroxide-based nanoparticle layers. By means of knife-coating and drying of stabilized nanoparticle
dispersions, precursor layers are fabricated and subsequently converted to CIGS material with elemental selenium vapors.
Process-related optimization of the drying and conversion step resulted in efficiencies of up to 5% without the use of an
additional reducing step. Systematic investigation of the drying and selenization conditions of monometallic dispersions
by means of XRF, SEM, EDX, and ex-situ XRD showed the occurrence of binary selenide phases with various metal-toselenide
ratios. By employing an intermediate holding temperature in the selenization process for mixed metal precursors,
we suggest that certain binary phases of copper can be promoted that improve the conversion process in terms of grain
growth and sintering.
Simulation of Different Interface Configurations of CIGSSe Solar Cells
Creators: name: Schubbert, C.
name: Eraerds, P.
name: Richter, M.
name: Parisi, J.
name: Riedel, I.
name: Dalibor, T.
name: Avellán, A.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
CdTe, CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2300-2304
description: The electronic design of the buffer/absorber hetero-interface and its vicinity in Cu(In,Ga)(Se,S)2 solar
cells is essential in order to optimize cell performance. We simulate different interface-near sulphur profiles within
the CIGSSe-absorber for a ZnO:Al/i-ZnO/InxSy/Cu(In,Ga)(Se,S)2-Mo layer stack using the Synopsys TCAD
simulation platform. The [S]/([S]+[Se])-ratio close to the hetero-interface was varied from 0.21 up to 0.97,
corresponding to band gaps of 1.12…1.52 eV, as well as the grading depth within a range of 6…350 nm. We find
that a minimal grading depth of at least 45 nm is required to achieve improvements in cell efficiency, while the
optimal grading depth depends inversely proportional on the sulphur concentration at the hetero-interface. Comparing
the optimized profile with respect to a profile of shallow sulphur depth, an efficiency gain of =1.3% (absolute) is
found. Further efficiency improvement is limited by the appearance of a voltage-dependent conduction band barrier
for deep sulphur profiles (>200 nm). The resulting reduction of the fill factor outweighs the net gain in Voc*Isc (opencircuit
voltage times short-circuit current).
Film Side Laser Patterning of Molybdenum Thin Films Sputter-Deposited onto Glass
Creators: name: Schultz, C.
name: Schüle, M.
name: Stelmaszczyk, K.
name: Bonse, J.
name: Witteck, R.
name: Weizman, M.
name: Rhein, H.
name: Rau, B.
name: Schlatmann, R.
name: Quaschning, V.
name: Stegemann, B.
name: Fink, F.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
CdTe, CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2266-2272
description: Serial interconnection of CIGSe thin film solar modules involves typically glass-side laser patterning
of the molybdenum layer (P1 scribe). In this paper we present a working principle of P1 film side patterning. The
investigated samples were sputter-deposited onto soda-lime glass substrates. For understanding the fundamental
ablation behavior, two kinds of layer systems were studied: on the one hand monolayer systems which are
compressively stressed and on the other hand bilayer systems, consisting of a tensile stressed layer on the substrate
and a second layer on top. The film-side ablation process was studied using a nanosecond as well as a picosecond
laser source. The influence of intrinsic stress was studied by XRD. Time resolved spectroscopy reveals the formation
of plasma as important driving mechanism for ablation. It is shown that by proper adaption of the sputter conditions
high-quality P1 film side patterning is achieved.
A flexible state space model for learning nonlinear dynamical systems
Creators: name: Svensson, Andreas
name: Schön, Thomas B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computation (stat.CO)
subject: Systems and Control (eess.SY)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: We consider a nonlinear state-space model with the state transition and observation functions expressed as basis function expansions. The coefficients in the basis function expansions are learned from data. Using a connection to Gaussian processes we also develop priors on the coefficients, for tuning the model flexibility and to prevent overfitting to data, akin to a Gaussian process state-space model. The priors can alternatively be seen as a regularization, and helps the model in generalizing the data without sacrificing the richness offered by the basis function expansion. To learn the coefficients and other unknown parameters efficiently, we tailor an algorithm using state-of-the-art sequential Monte Carlo methods, which comes with theoretical guarantees on the learning. Our approach indicates promising results when evaluated on a classical benchmark as well as real data.
L’arco di trionfo nel Quattrocento tavola iconografica
Creators: name: Pisani, Daniele; Pizzigoni, Vittorio
Publisher: name: La Rivista di Engramma
Year: 2008
Subjects: Malatesta
Temple
Triumphal Arch

description: Daniele Pisani and Vittorio Pizzigoni trace the motif of the "triumph" in the Italian fifteenth century in an iconographic table through some examples of the architecture that are its emblem: the triumphal arch.
Convergence of the Yamabe flow on manifolds with minimal boundary
Creators: name: Almaraz, Sergio
name: Sun, Liming
Publisher: name: arXiv
Year: 2016
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C44, 53C21, 53C25

description: We study the Yamabe flow on compact Riemannian manifolds of dimensions greater than two with minimal boundary. Convergence to a metric with constant scalar curvature and minimal boundary is established in dimensions up to seven, and in any dimensions if the manifold is spin.
description: Final version. Accepted to Annali della Scuola Normale Superiore di Pisa (Classe di Scienze). arXiv admin note: text overlap with arXiv:1206.1184"
UniSAFE: Vilnius University – institutional policy to address gender-based violence
Creators: name: Andreska, Zuzana
name: Huck, Averil
name: Linkova, Marcela
Publisher: name: Zenodo
Year: 2022
Subjects: Gender based-violence
policy framework
gender+
institutional policy

description: UniSAFE has mapped the policies and measures to address and combat GBV in 48 universities and research organisations in 15 European countries. For each institution, the team created Vignettes which present national context, institutional policy, training, role in knowledge production, content of the policy, institutional procedure and implementation of the policy.
Intrinsically-generated fluctuating activity in excitatory-inhibitory networks
Creators: name: Mastrogiuseppe, Francesca
name: Ostojic, Srdjan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: FOS: Biological sciences

description: Recurrent networks of non-linear units display a variety of dynamical regimes depending on the structure of their synaptic connectivity. A particularly remarkable phenomenon is the appearance of strongly fluctuating, chaotic activity in networks of deterministic, but randomly connected rate units. How this type of intrinsi- cally generated fluctuations appears in more realistic networks of spiking neurons has been a long standing question. To ease the comparison between rate and spiking networks, recent works investigated the dynami- cal regimes of randomly-connected rate networks with segregated excitatory and inhibitory populations, and firing rates constrained to be positive. These works derived general dynamical mean field (DMF) equations describing the fluctuating dynamics, but solved these equations only in the case of purely inhibitory networks. Using a simplified excitatory-inhibitory architecture in which DMF equations are more easily tractable, here we show that the presence of excitation qualitatively modifies the fluctuating activity compared to purely inhibitory networks. In presence of excitation, intrinsically generated fluctuations induce a strong increase in mean firing rates, a phenomenon that is much weaker in purely inhibitory networks. Excitation moreover induces two different fluctuating regimes: for moderate overall coupling, recurrent inhibition is sufficient to stabilize fluctuations, for strong coupling, firing rates are stabilized solely by the upper bound imposed on activity, even if inhibition is stronger than excitation. These results extend to more general network architectures, and to rate networks receiving noisy inputs mimicking spiking activity. Finally, we show that signatures of the second dynamical regime appear in networks of integrate-and-fire neurons.
Limit theorems for counting large continued fraction digits
Creators: name: Kesseböhmer, Marc
name: Schindler, Tanja
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: Dynamical Systems (math.DS)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11K50, 60F20, 60F05

description: We establish a central limit theorem for counting large continued fraction digits $(a_n)$, i.e. we count occurrences $\{a_n>b_n\}$, where $(b_n)$ is a sequence of positive integers. Our result improves a similar result by Philipp which additionally assumes that $b_n$ tends to infinity. Moreover, we give a refinement of the famous Borel-Bernstein Theorem for continued fractions regarding the event that the $n$-th continued fraction digit lies infinitely often between $d_n$ and $d_n(1+1/c_n)$ for given sequences $(c_n)$ and $(d_n)$. Also for these sets we obtain a central limit theorem. As an interesting side result we determine the first $ϕ$-mixing coefficient for the Gauss system explicitly.
description: 14 pages
A Random Bockstein Operator
Creators: name: Zabka, Matthew
Publisher: name: arXiv
Year: 2016
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics

description: As more of topology's tools become popular in analyzing high dimensional data sets, the goal of understanding the underlying probabilistic properties of these tools becomes even more important. While much attention has been given to understanding the probabilistic properties of methods that use homological groups in topological data analysis, the probabilistic properties of methods that employ cohomology operations remain unstudied. In this paper, we investigate the Bockstein operator with randomness in a strictly algebraic setting.
Sampling of General Correlators in Worm Algorithm-based Simulations
Creators: name: Rindlisbacher, Tobias
name: Akerlund, Oscar
name: de Forcrand, Philippe
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: Using the complex $ϕ^4$-model as a prototype for a system which is simulated by a worm algorithm, we show that not only the charged correlator $$, but also more general correlators such as $$ or $$, as well as condensates like $$, can be measured at every step of the Monte Carlo evolution of the worm instead of on closed-worm configurations only. The method generalizes straightforwardly to other systems simulated by worms, such as spin or sigma models.
description: 43 pages, 15 figures
Generalized Kraus operators for the one-qubit depolarizing quantum channel
Creators: name: Arsenijevic, Momir
name: Jeknic-Dugic, Jasmina
name: Dugic, Miroljub
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Microscopic Hamiltonian models of the composite system "open system + environment" typically do not provide the operator-sum Kraus form of the open system's dynamical map. With the use of a recently de- veloped method [16], we derive the Kraus operators starting from the mi- croscopic Hamiltonian model, i.e. from the proper master equation, of the one-qubit depolarizing channel. Those Kraus operators generalize the stan- dard counterparts, which are widely used in the literature. Comparison of the standard and the here obtained Kraus operators is performed via inves- tigating dynamical change of the Bloch sphere volume, entropy production and the open system's state trace distance. We find that the standard depo- larizing channel is more deteriorating than the generalized one.
description: 17 pages, 6 figures, aaccepted for publication in Brazilian Journal of Physics, in press
Scanning tunneling spectroscopy of superconductivity on surfaces of LiTi2O4(111) thin films
Creators: name: Okada, Yoshinori
name: Ando, Yasunobu
name: Shimizu, Ryota
name: Minamitani, Emi
name: Shiraki, Susumu
name: Watanabe, Satoshi
name: Hitosugi, Taro
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Unique superconductivity at surfaces/interfaces, as exemplified by LaAlO3/SrTiO3 interfaces, and the high transition temperature in ultrathin FeSe films, have triggered intense debates on how superconductivity is affected in atomic and electronic reconstructions. The surface of superconducting cubic spinel oxide LiTi2O4 is another interesting system because its inherent surface electronic and atomic reconstructions add complexity to superconducting properties. Investigations of such surfaces are hampered by the lack of single crystals or high-quality thin films. Here, using low-temperature scanning tunneling microscopy, we report an unexpected small superconducting energy gap and a long coherence length on the surface of LiTi2O4 (111) epitaxial thin films. Furthermore, we find that a pseudogap opening at the Fermi energy modifies the surface superconductivity. Our results open an avenue, exploring anomalous superconductivity on the surface of cubic transition-metal oxides where the electronic states are spontaneously modulated with involving rich many-body interactions.
Effective Hamiltonian for protected edge states in graphene
Creators: name: Deshpande, H.
name: Winkler, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Edge states in topological insulators (TIs) disperse symmetrically about one of the time-reversal invariant momenta $Λ$ in the Brillouin zone (BZ) with protected degeneracies at $Λ$. Commonly TIs are distinguished from trivial insulators by the values of one or multiple topological invariants that require an analysis of the bulk band structure across the BZ. We propose an effective two-band Hamiltonian for the electronic states in graphene based on a Taylor expansion of the tight-binding Hamiltonian about the time-reversal invariant $M$ point at the edge of the BZ. This Hamiltonian provides a faithful description of the protected edge states for both zigzag and armchair ribbons though the concept of a BZ is not part of such an effective model. We show that the edge states are determined by a band inversion in both reciprocal and real space, which allows one to select $Λ$ for the edge states without affecting the bulk spectrum.
description: 6 pages, 6 figures
How to Select Phase Change Materials for Tuning Condensation and Frosting?
Creators: name: Chatterjee, Rukmava
name: Chaudhari, Umesh
name: Anand, Sushant
Publisher: name: University of Illinois at Chicago
Year: 2023
Subjects: subject: Chemical sciences
subject: FOS: Chemical sciences
subject: Engineering
subject: Macromolecular and materials chemistry
subject: Physical sciences
subject: FOS: Physical sciences

description: Synthetic surfaces engineered to regulate phase transitions of matter and exercise control over its undesired accrual (liquid or solid) play a pivotal role in diverse industrial applications. Over the years, the design of repellant surfaces has transitioned from solely modifying the surface texture and chemistry to identifying novel material systems. In this study, selection criteria are established to identify bio-friendly phase change materials (PCMs) from an extensive library of vegetable-based/organic/essential oils that can thermally respond by harnessing the latent heat released during condensation and thereby delaying ice/frost formation in the very frigid ambient that is detrimental to its functionality. Concurrently, a comprehensive investigation is conducted to elucidate the relation between microscale heat transport phenomena during condensation and the resulting macroscopic effects (e.g., delayed droplet freezing) on various solidified PCMs as a function of their inherent thermo-mechanical properties. In addition, to freeze protection, many properties that are responsive to the thermal reflex of the surface, such as the ability to dynamically tune optical transparency, moisture harvesting, ice shedding, and quick in-field repairability, are achievable, resulting in the development of protective coatings capable of spanning a wide range of functionalities and thereby having a distinctive edge over conventional solutions.
BosonSampling with single-photon Fock states from a bright solid-state source
Creators: name: Loredo, J. C.
name: Broome, M. A.
name: Hilaire, P.
name: Gazzano, O.
name: Sagnes, I.
name: Lemaitre, A.
name: Almeida, M. P.
name: Senellart, P.
name: White, A. G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A BosonSampling device is a quantum machine expected to perform tasks intractable for a classical computer, yet requiring minimal non-classical resources as compared to full-scale quantum computers. Photonic implementations to date employed sources based on inefficient processes that only simulate heralded single-photon statistics when strongly reducing emission probabilities. BosonSampling with only single-photon input has thus never been realised. Here, we report on a BosonSampling device operated with a bright solid-state source of single-photon Fock states with high photon-number purity: the emission from an efficient and deterministic quantum dot-micropillar system is demultiplexed into three partially-indistinguishable single-photons, with a single-photon purity $1{-}g^{(2)}(0)$ of $0.990{\pm}0.001$, interfering in a linear optics network. Our demultiplexed source is between one and two orders-of-magnitude more efficient than current heralded multi-photon sources based on spontaneous parametric downconversion, allowing us to complete the BosonSampling experiment faster than previous equivalent implementations.
description: Updated version. 11 pages, 8 figures
Remarks on Asymptotic Symmetries and the Sub-leading Soft Photon Theorem
Creators: name: Conde, Eduardo
name: Mao, Pujian
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A deep connection has been recently established between soft theorems and symmetries at null infinity in gravity and gauge theories, recasting the former as Ward identities of the latter. In particular, different orders (in the frequency of the soft particle) in the soft theorems are believed to be controlled by different asymptotic symmetries. In this paper we argue that this needs not be the case by focusing on the soft photon theorem. We argue that the sub-leading soft factor follows from the same symmetry responsible for the leading one, namely certain residual (large) gauge transformations of the gauge theory. In particular, expanding the associated charge in inverse powers of the radial coordinate, the (sub-)leading charge yields the (sub-)leading soft factor.
description: v5: typos corrected in eqs. (8) and (34)
Categories: How I Learned to Stop Worrying and Love Two Sorts
Creators: name: Conradie, Willem
name: Frittella, Sabine
name: Piazzai, Michele
name: Tzimoulis, Apostolos
name: Palmigiano, Alessandra
name: Wijnberg, Nachoem M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics
subject: 03B45

description: RS-frames were introduced by Gehrke as relational semantics for substructural logics. They are two-sorted structures, based on RS-polarities with additional relations used to interpret modalities. We propose an intuitive, epistemic interpretation of RS-frames for modal logic, in terms of categorization systems and agents' subjective interpretations of these systems. Categorization systems are a key to any decision-making process and are widely studied in the social and management sciences. A set of objects together with a set of properties and an incidence relation connecting objects with their properties forms a polarity which can be `pruned' into an RS-polarity. Potential categories emerge as the Galois-stable sets of this polarity, just like the concepts of Formal Concept Analysis. An agent's beliefs about objects and their properties (which might be partial) is modelled by a relation which gives rise to a normal modal operator expressing the agent's beliefs about category membership. Fixed-points of the iterations of the belief modalities of all agents are used to model categories constructed through social interaction.
description: References updated