cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Reducing energy system model distortions from unintended storage cycling through variable costs
Creators: name: Parzen, Maximilian
name: Kittel, Martin
name: Friedrich, Daniel
name: Kiprakis, Aristides
Publisher: name: arXiv
Year: 2021
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: Energy model distortions may unknowingly appear and represent unrealistic and non-physical effects that can mislead optimal model decisions. A prominent misleading effect is unintended storage cycling that was observed in previous literature by simultaneous charging and discharging of the same storage in 12 of 18 energy models. Especially for popular net-zero energy model scenarios, unintended storage cycling can cause high distortions and, hence, urges for its removal. Methods to remove such misleading effects exist, but are not computational efficient and sometimes not effective such as MILP formulations. Other techniques are successful, but only if renewable energy target constraints exist. This paper explores how to eradicate unintended storage cycling for models without renewable target constraints by correctly setting variable costs of relevant system components. We find through 124 simulations that determining appropriate levels of variable costs depends on the solver accuracy used for the optimization. If set too loose, the solver prevents the removal of unintended storage cycling. We further find that reliable data for variable costs in energy modelling needs to be improved and provide a list of recommended model inputs as well as a minimum variable cost threshold that can significantly reduce the magnitude and likeliness of unintended storage cycling. Finally, our results suggest that variable cost additives may remove other known unintended energy cycling effects, such as unintended line cycling or sector cycling.
description: 11 pages, 6 figures
Improved heralded single-photon source with a photon-number-resolving superconducting nanowire detector
Creators: name: Davis, Samantha I.
name: Mueller, Andrew
name: Valivarthi, Raju
name: Lauk, Nikolai
name: Narvaez, Lautaro
name: Korzh, Boris
name: Beyer, Andrew D.
name: Colangelo, Marco
name: Berggren, Karl K.
name: Shaw, Matthew D.
name: Sinclair, Neil
name: Spiropulu, Maria
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Deterministic generation of single photons is essential for many quantum information technologies. A bulk optical nonlinearity emitting a photon pair, where the measurement of one of the photons heralds the presence of the other, is commonly used with the caveat that the single-photon emission rate is constrained due to a trade-off between multiphoton events and pair emission rate. Using an efficient and low noise photon-number-resolving superconducting nanowire detector we herald, in real time, a single photon at telecommunication wavelength. We perform a second-order photon correlation $g^{2}(0)$ measurement of the signal mode conditioned on the measured photon number of the idler mode for various pump powers and demonstrate an improvement of a heralded single-photon source. We develop an analytical model using a phase-space formalism that encompasses all multiphoton effects and relevant imperfections, such as loss and multiple Schmidt modes. We perform a maximum-likelihood fit to test the agreement of the model to the data and extract the best-fit mean photon number $μ$ of the pair source for each pump power. A maximum reduction of $0.118 \pm 0.012$ in the photon $g^{2}(0)$ correlation function at $μ= 0.327 \pm 0.007$ is obtained, indicating a strong suppression of multiphoton emissions. For a fixed $g^{2}(0) = 7e-3$, we increase the single pair generation probability by 25%. Our experiment, built using fiber-coupled and off-the-shelf components, delineates a path to engineering ideal sources of single photons.
description: Model and analysis integrated into main text. Corrected equations. 17 pages, 11 figures
The subarcsecond mid-infrared view of local active galactic nuclei: III. Polar dust emission
Creators: name: Asmus, D.
name: Hönig, S. F.
name: Gandhi, P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Recent mid-infrared (MIR) interferometric observations showed in few active galactic nuclei (AGN) that the bulk of the infrared emission originates from the polar region above the putative torus, where only little dust should be present. Here, we investigate whether such strong polar dust emission is common in AGN. Out of 149 Seyferts in the MIR atlas of local AGN (Asmus et al.), 21 show extended MIR emission on single dish images. In 18 objects, the extended MIR emission aligns with the system axis position angle, established by [OIII], radio, polarisation and maser based position angle measurements. The relative amount of resolved MIR emission is at least 40 per cent and scales with the [OIV] fluxes implying a strong connection between the extended continuum and [OIV] emitters. These results together with the radio-quiet nature of the Seyferts support the scenario that the bulk of MIR emission is emitted by dust in the polar region and not by the torus, which would demand a new paradigm for the infrared emission structure in AGN. The current low detection rate of polar dust in the AGN of the MIR atlas is explained by the lack of sufficient high quality MIR data and the requirement for the orientation, NLR strength and distance of the AGN. The James-Webb Space Telescope will enable much deeper nuclear MIR studies with comparable angular resolution, allowing us to resolve the polar emission and surroundings in most of the nearby AGN.
description: Accepted for publication in ApJ on Mar 08 (submitted Dec 22)
Computing the nonfree locus of the moduli space of arrangements and Terao's freeness conjecture
Creators: name: Barakat, Mohamed
name: Kühne, Lukas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Algebraic Geometry (math.AG)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: In this paper, we show how to compute using Fitting ideals the nonfree locus of the moduli space of arrangements of a rank $3$ simple matroid, i.e., the subset of all points of the moduli space which parametrize nonfree arrangements. Our approach relies on the so-called Ziegler restriction and Yoshinaga's freeness criterion for multiarrangements. We use these computations to verify Terao's freeness conjecture for rank $3$ central arrangements with up to $14$ hyperplanes in any characteristic.
Symmetry of surface nanopatterns induced by ion-beam sputtering: the role of anisotropic surface diffusion
Creators: name: Renedo, Javier
name: Muñoz-García, Javier
name: Castro, Mario
name: Cuerno, Rodolfo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: Ion Beam Sputtering (IBS) is a cost-effective technique able to produce ordered nanopatterns on the surfaces of different materials. To date, most theoretical studies of this process have focused on systems which become amorphous under irradiation, e.g. semiconductors at room temperature. Thus, in spite of the large amount of experimental work on metals, or more recently on semiconductors at high temperatures, such experimental contexts have received relatively little theoretical attention. These systems are characterized by transport mechanisms, e.g. surface diffusion, which are anisotropic as a reflection of the crystalline structure not being overruled by the irradiation. Here, we generalize a previous continuum theory of IBS at normal incidence, in order to account for anisotropic surface diffusion. We explore systematically our generalized model in order to understand the role of anisotropy in the space ordering properties of the resulting patterns. In particular, we derive a height equation which predicts morphological transitions among hexagonal and rectangular patterns as a function of system parameters and employ an angular correlation function to assess these pattern symmetries. By suitably choosing experimental conditions, it is found that one might be able to experimentally control the type of order displayed by the patterns produced.
description: 13 pages, 6 figures; submitted
Bounds for the radii of univalence of some special functions
Creators: name: Aktaş, Ibrahim
name: Baricz, Árpád
name: Yağmur, Nihat
Publisher: name: arXiv
Year: 2016
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 30C45, 30C15, 33C10

description: Tight lower and upper bounds for the radius of univalence of some normalized Bessel, Struve and Lommel functions of the first kind are obtained via Euler-Rayleigh inequalities. It is shown also that the radius of univalence of the Struve functions is greater than the corresponding radius of univalence of Bessel functions. Moreover, by using the idea of Kreyszig and Todd, and Wilf it is proved that the radii of univalence of some normalized Struve and Lommel functions are exactly the radii of starlikeness of the same functions. The Laguerre-Pólya class of entire functions plays an important role in our study.
description: 12 pages
Computationally Efficient Approximations for Matrix-based Renyi's Entropy
Creators: name: Gong, Tieliang
name: Dong, Yuxin
name: Yu, Shujian
name: Dong, Bo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: The recently developed matrix based Renyi's entropy enables measurement of information in data simply using the eigenspectrum of symmetric positive semi definite (PSD) matrices in reproducing kernel Hilbert space, without estimation of the underlying data distribution. This intriguing property makes the new information measurement widely adopted in multiple statistical inference and learning tasks. However, the computation of such quantity involves the trace operator on a PSD matrix $G$ to power $α$(i.e., $tr(G^α)$), with a normal complexity of nearly $O(n^3)$, which severely hampers its practical usage when the number of samples (i.e., $n$) is large. In this work, we present computationally efficient approximations to this new entropy functional that can reduce its complexity to even significantly less than $O(n^2)$. To this end, we leverage the recent progress on Randomized Numerical Linear Algebra, developing Taylor, Chebyshev and Lanczos approximations to $tr(G^α)$ for arbitrary values of $α$ by converting it into matrix-vector multiplications problem. We also establish the connection between the matrix-based Renyi's entropy and PSD matrix approximation, which enables exploiting both clustering and block low-rank structure of $G$ to further reduce the computational cost. We theoretically provide approximation accuracy guarantees and illustrate the properties of different approximations. Large-scale experimental evaluations on both synthetic and real-world data corroborate our theoretical findings, showing promising speedup with negligible loss in accuracy.
Long-Term Performance Degradation of Various Technology of Photovoltaic Modules
Creators: name: Salas, V.
name: Débora, P.J.
name: Fabero, F.
name: Alonso-Abella, M.
name: Olías Ruiz, E.
name: Chenlo, F.
name: Vela, N.
Publisher: name: WIP
Year: 2011
Subjects: Components for PV Systems
PV Modules

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 3529-3532
description: The aim of this article is to show the results of outdoor exposure test in which the performance of four PV
different technologies that have been done since 2008. PV modules were undertaken in the UC3M PV Laboratory, Leganes
(Madrid-Spain) to assess their performance with the meteorological parameters. Current-voltage (I-V) characteristic of
module arrays are obtained periodically as complement the continuous data monitoring. Continuous recording of PV
parameters, current-voltage (I-V) characteristic of every module, as well as the meteorological parameters is carried out.
Recorded data were analysed. Current, voltage and power temperature coefficients will be analysed as well other parameters
as the evolution with the cell temperature of power, the fill factor and the efficiency.
Performance Analysis of Crystalline Silicon PV Modules After 18 Months Exposure under Tropical Climate
Creators: name: Mabille, L.
name: Razongles, G.
name: Sicot, L.
name: Merten, J.
Publisher: name: WIP
Year: 2011
Subjects: Components for PV Systems
PV Modules

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 3491-3494
description: This work focuses on the performance analysis of polycrystalline silicon modules
which have spent almost two years at La Réunion Island, France, close to Madagascar, compared to
modules taken from the same series and exposed outdoor at the National Institute for Solar Energy
(INES, Chambéry, France) under continental climate. In this paper, methods used during this work
will be described. Based on the two-diode model, comparison of the electrical equivalent circuit
parameters will be realized between the tropical and continental exposed modules. Tropical
exposed modules showed power degradation of around 10% in 18 months, even if they successfully
passed the IEC 61215 certification test and were guaranteed to produce 90% of their initial power
for at least ten years. Degradation of EEC parameters is more severe for modules exposed in the
tropics than on the continent.
Вестник научной мысли,Выпуск 1 2021
Creators: name: Дагестанский территориальный институт профессиональных бухгалтеров
Publisher: name: Дагестанский территориальный институт профессиональных бухгалтеров
Year: 2021

description: Вестник научной мысли,Выпуск 1 2021
New limits on anomalous contributions to the $Wtb$ vertex
Creators: name: Birman, J. L.
name: Déliot, F.
name: Fiolhais, M. C. N.
name: Onofre, A.
name: Pease, C. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The latest and most precise top quark measurements at the LHC and Tevatron are used to establish new limits on the $Wtb$ vertex. Recent results on the measurements of the $W$-boson helicity fractions and single top quark production cross section are combined in order to establish new limits at 95% CL (confidence level). The allowed regions for these limits are presented, for the first time, in three-dimensional graphics, for both real and imaginary components of the different anomalous couplings, providing a new perspective on the impact of the combination of different physics observables. These results are also combined with the prospected future measurement of the single top quark production cross section and $W$-boson helicity fractions at the LHC.
description: 7 pages, 4 figures
Flexible Sliver Modules
Creators: name: Thomsen, E.
name: Muric-Nesic, J.
name: Rahman, S.
name: Osorio Mayon, Y.
name: Ratcliff, T.
name: Scott, P.
name: Skryabin, I.
name: Everett, V.
name: Blakers, A.
Publisher: name: WIP
Year: 2011
Subjects: Advanced Photovoltaics : New Concepts and Ultra-High Efficiency
New Materials, Cells and Modules

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 437-440
description: This paper presents the design, fabrication, and testing of lightweight, flexible photovoltaic modules.
The modules are constructed using mono-crystalline silicon Sliver cells. The modules are designed to have a power
output of at least 130 W/m2; to have a very high power to weight ratio of over 150 W/kg; to be roll-able around a
radius of curvature of 5 cm or smaller; and to be able to operate under a wide range of operating conditions, including
under partial shading and after structural damage due to punctures.
40-GHz pulse source based on XPM-induced focusing in normally dispersive optical fibers
Creators: name: Nuno, Javier
name: Gilles, Marin
name: Guasoni, Massimiliano
name: Kibler, Bertrand
name: Finot, Christophe
name: Fatome, Julien
Publisher: name: arXiv
Year: 2015
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We theoretically and experimentally investigate the design of a high-repetition rate source delivering well-separated picosecond pulses thanks to the nonlinear compression of a dual-frequency beat signal within a cavity-less normally dispersive fiber-based setup. This system is well described by a set of two coupled NLS equations for which the usual normally dispersive defocusing regime is turned in a focusing temporal lens through a degenerated cross-phase modulation effect. More precisely, the temporal compression of the initial beating is performed by the combined effects of normal GVD and XPM-induced nonlinear phase shift yield by an intense beat-signal on its weak out-of-phase replica copropagating with orthogonal polarizations. This adiabatic reshaping process allows us to generate a 40GHz well-separated 3.3ps pulse train at 1550nm in a 5km long normally dispersive fiber.
Prospects for determining the nature of the secondaries of extreme mass-ratio inspirals using the spin-induced quadrupole deformation
Creators: name: Rahman, Mostafizur
name: Bhattacharyya, Arpan
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The measurement of multipole moments of astrophysical objects through gravitational wave (GW) observations provides a novel way to distinguish black holes from other astrophysical objects. This paper studies the gravitational wave radiation from an extreme mass ratio inspiral (EMRI) system consisting of a supermassive Kerr black hole (the primary object) and a spinning stellar-mass compact object (the secondary object). The quadrupolar deformation induced by the spin of the secondary is different for different astrophysical objects. We compute the effect of the quadrupolar deformation on the GW phase and provide an order of magnitude estimate of whether LISA can distinguish different astrophysical objects through GW phase measurement. We find that although LISA can not distinguish between a black hole and a neutron star, it can distinguish black holes from a large variety of highly spinning astrophysical objects like superspinars and highly deformable exotic compact objects like boson stars for EMRI systems with relatively large mass ratio ($q\sim 10^{-4}$). Furthermore, we show that the effect of spin-induced quadrupolar deformation on the GW phase for white dwarf and brown dwarf-EMRI systems can be quite significant even for small values of mass ratio ($q\lesssim 10^{-6}$).
description: 24 pages, 7 figures, 5 tables. Typos corrected. Accepted for publication in PRD
Monte Carlo Simulation of Complex Fluorescent Concentrator Systems
Creators: name: Rist, T.
name: Hermle, M.
name: Goldschmidt, J.C.
Publisher: name: WIP
Year: 2011
Subjects: Advanced Photovoltaics : New Concepts and Ultra-High Efficiency
New Materials, Cells and Modules

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 441-445
description: Currently, advanced fluorescent concentrators are being developed, which utilize different
fluorescent materials and optical components, such as spectrally selectively reflecting photonic structures. In this
paper, we present our approach to simulate also such complex systems by application of a Monte Carlo based ray
tracing model, and compare the results to measurements. The model reproduces different optical measurements
on the fluorescent collectors well. The changes in light collection efficiency due to bottom reflectors and mirror
foils on free edges are precisely simulated. For more complex geometries, however, the model still overestimates
light collection efficiencies.
Maximal escape rate for shifts
Creators: name: Bonanno, Claudio
name: Cristadoro, Giampaolo
name: Lenci, Marco
Publisher: name: arXiv
Year: 2021
Subjects: subject: Dynamical Systems (math.DS)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We consider the shift transformation on the space of infinite sequences over a finite alphabet endowed with the invariant product measure, and examine the presence of a \emph{hole} on the space. The holes we study are specified by the sequences that do not contain a given finite word as initial sub-string. The measure of the set of sequences that do not fall into the hole in the first $n$ iterates of the shift is known to decay exponentially with $n$, and its exponential rate is called \emph{escape rate}. In this paper we provide a complete characterization of the holes with maximal escape rate. In particular we show that, contrary to the case of equiprobable symbols, ordering the holes by their escape rate corresponds to neither the order by their measure nor by the length of the shortest periodic orbit they contain. Finally, we adapt our technique to the case of shifts endowed with Markov measures, where preliminary results show that a more intricate situation is to be expected.
description: 18 pages, 3 figures. Final version for Discrete and Continuous Dynamical Systems
Degradation Mechanism Investigation of Extended Damp Heat Aged PV Modules
Creators: name: Ketola, B.
name: Norris, A.
Publisher: name: WIP
Year: 2011
Subjects: Components for PV Systems
PV Modules

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 3523-3528
description: The lifetime and sustained power output of a photovoltaic (PV) module impacts the total number of
kilowatt-hours (kWh) produced, which ultimately drives the cost of generated electricity. Because PV module lifetimes
are desired to be greater than 20 years, accelerated testing protocols, such as IEC 61215, have been used to assure that a
20 year lifetime is achievable. In particular, the Damp Heat (85°C/85% relative humidity) protocol has been used to
accelerate potential degradation mechanisms by increasing the temperature and humidity of the modules under test.
This accelerated aging test was applied to PV modules with silicone and ethylene vinyl acetate (EVA) encapsulation
materials to compare their performance. These modules were aged in Damp Heat several times longer than the IEC
standard of 1000 hours. The modules were periodically analyzed for current voltage (IV) by Sun Simulator to compare
the influence of the encapsulant on module power output. At 3000 hours of exposure a significant reduction in power
output was noted in the EVA set of modules, while minimal power degradation was observed in the silicone set. The
power reduction was driven by reduced Fill Factors (FF) and increased Series Resistance (Rs). These reductions were
initially interpreted as corrosion taking place at the electrical interconnects; however, further aging showed a drop in
Short Circuit Current(Isc) indicating that other degradation mechanisms could be at work. Analysis by
electroluminescence (EL) imaging also indicated that factors other than corrosion at the electrical interconnects may
have occurred. This presentation describes the analysis of silicone and EVA encapsulated modules after extended
Damp Heat aging to help determine the degradation mechanisms involved in the power output over time.
Spectral radius and fractional matchings in graphs
Creators: name: O, Suil
Publisher: name: arXiv
Year: 2016
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05C50, 05C70

description: A {\it fractional matching} of a graph $G$ is a function $f$ giving each edge a number in $[0,1]$ so that $\sum_{e \in Γ(v)} f(e) \le 1$ for each $v\in V(G)$, where $Γ(v)$ is the set of edges incident to $v$. The {\it fractional matching number} of $G$, written $α'_*(G)$, is the maximum of $\sum_{e \in E(G)} f(e)$ over all fractional matchings $f$. Let $G$ be an $n$-vertex connected graph with minimum degree $d$, let $λ_1(G)$ be the largest eigenvalue of $G$, and let $k$ be a positive integer less than $n$. In this paper, we prove that if $λ_1(G) < d\sqrt{1+\frac{2k}{n-k}}$, then $α'_*(G) > \frac{n-k}{2}$. As a result, we prove $α'_*(G) \ge \frac{nd^2}{λ_1(G)^2 + d^2}$, we characterize when equality holds in the bound.
On Orbifold Gromov-Witten Classes
Creators: name: Tseng, Hsian-Hua
Publisher: name: arXiv
Year: 2021
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14N35

description: We discuss some questions about Gromov-Witten classes of target stacks.
description: v1: 6 pages; v2: 6 pages, minor revison, to appear in Portugaliae Mathematica
Mechanical Properties and Fatigue Behavior of Copper Interconnect Ribbon
Creators: name: Pedevilla, M.
name: Panzenböck, M.
name: Clemens, H.
name: Mitrovitz, N.
Publisher: name: WIP
Year: 2011
Subjects: Components for PV Systems
PV Modules

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 3547-3549
description: During their lifetime, crystalline photovoltaic modules are subjected to mechanical loads and thermal
cycling. Both can cause cyclic changes of the distance between the cells. For this reason, copper interconnect ribbon,
which forms the mechanical and electrical connection between consecutive cells, is subject to cyclic bending in the
space between the cells. This cyclic deformation can lead to breakage of the interconnect ribbon. Possible results of
such failures are electrical losses and even security risks. The purpose of this work is to investigate the fatigue
properties of copper interconnect materials. A test device and procedure for cyclic bending tests was developed.
Different ribbon materials were investigated in terms of microstructure, mechanical properties and fatigue
performance. A correlation between the results of quasi-static mechanical tests and the fatigue performance was
established.
On the Minimal Adversarial Perturbation for Deep Neural Networks with Provable Estimation Error
Creators: name: Brau, Fabio
name: Rossolini, Giulio
name: Biondi, Alessandro
name: Buttazzo, Giorgio
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Differential Geometry (math.DG)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Although Deep Neural Networks (DNNs) have shown incredible performance in perceptive and control tasks, several trustworthy issues are still open. One of the most discussed topics is the existence of adversarial perturbations, which has opened an interesting research line on provable techniques capable of quantifying the robustness of a given input. In this regard, the Euclidean distance of the input from the classification boundary denotes a well-proved robustness assessment as the minimal affordable adversarial perturbation. Unfortunately, computing such a distance is highly complex due the non-convex nature of NNs. Despite several methods have been proposed to address this issue, to the best of our knowledge, no provable results have been presented to estimate and bound the error committed. This paper addresses this issue by proposing two lightweight strategies to find the minimal adversarial perturbation. Differently from the state-of-the-art, the proposed approach allows formulating an error estimation theory of the approximate distance with respect to the theoretical one. Finally, a substantial set of experiments is reported to evaluate the performance of the algorithms and support the theoretical findings. The obtained results show that the proposed strategies approximate the theoretical distance for samples close to the classification boundary, leading to provable robustness guarantees against any adversarial attacks.
description: Under review on IEEE journal Transactions on Pattern Analysis and Machine Intelligence
Optimisation of Luminescent EVA Encapsulation Layers for Increasing The Short-Wavelength Response of PV Modules
Creators: name: Klampaftis, E.
name: Ross, D.
name: Seyrling, S.
name: Tiwari, A.N.
name: Richards, B.S.
Publisher: name: WIP
Year: 2011
Subjects: Advanced Photovoltaics : New Concepts and Ultra-High Efficiency
New Materials, Cells and Modules

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 517-521
description: Luminescent down-shifting of the incident light can improve the short-wavelength () response of
photovoltaic (PV) modules without altering the structure and manufacturing methodology of the solar cells. In this
work, the absorption properties of luminescent encapsulation layers made by poly- ethylene vinyl acetate (EVA) are
optimised, by using multiple dye-doping and varying the concentration of the most promising dye. These layers were
used to encapsulate multi-crystalline silicon (mc-Si) solar cells and were also optically coupled to copper indium
gallium (di)selenide (CIGS) solar cells. In the case of mc-Si devices, an external quantum efficiency (EQE)
enhancement of up to 25% is achieved for the region 300 nm <  < 400 nm, leading to an efficiency increase of  =
0.3% absolute for a 59 cm2 single-cell mini-module and the best doping scenario. For CIGS devices, an EQE
enhancement of up to 25% is achieved for the region 300 nm <  < 390 nm, leading to similar efficiency
enhancement of  = 0.3% absolute for a 1 cm2 solar cell. An additional benefit from the inclusion of luminescent
material in the encapsulation layer of PV modules is the colouration of the devices.
Qubit assignment using time reversal
Creators: name: Peters, Evan
name: Shyamsundar, Prasanth
name: Li, Andy C. Y.
name: Perdue, Gabriel
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: As the number of qubits available on noisy quantum computers grows, it will become necessary to efficiently select a subset of physical qubits to use in a quantum computation. For any given quantum program and device there are many ways to assign physical qubits for execution of the program, and assignments will differ in performance due to the variability in quality across qubits and entangling operations on a single device. Evaluating the performance of each assignment using fidelity estimation introduces significant experimental overhead and will be infeasible for many applications, while relying on standard device benchmarks provides incomplete information about the performance of any specific program. Furthermore, the number of possible assignments grows combinatorially in the number of qubits on the device and in the program, motivating the use of heuristic optimization techniques. We approach this problem using simulated annealing with a cost function based on the Loschmidt Echo, a diagnostic that measures the reversibility of a quantum process. We provide theoretical justification for this choice of cost function by demonstrating that the optimal qubit assignment coincides with the optimal qubit assignment based on state fidelity in the weak error limit, and we provide experimental justification using diagnostics performed on Google's superconducting qubit devices. We then establish the performance of simulated annealing for qubit assignment using classical simulations of noisy devices as well as optimization experiments performed on a quantum processor. Our results demonstrate that the use of Loschmidt Echoes and simulated annealing provides a scalable and flexible approach to optimizing qubit assignment on near-term hardware.
description: 27 pages, 12 figures
Silicon Nanowires for Screen-Printed Solar Cell Application
Creators: name: Nemoto, Y.
name: Fukano, K.
name: Dhamrin, M.
name: Kamisako, K.
Publisher: name: WIP
Year: 2011
Subjects: Advanced Photovoltaics : New Concepts and Ultra-High Efficiency
New Materials, Cells and Modules

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 474-477
description: Silicon nanowire (SiNW) solar cells were fabricated by Vapor-Liquid-Solid (VLS) method using
screen-printed front and back contacts. The dependence of reflectance of the SiNWs on the flow rate of PH3 was
studied and the change of surface morphology after SiNWs growth was examined. Very low reflectance is realized by
the fabricated SiNWs on silicon substrates. The minimum reflectance was about 0.7 % for the SiNWs grown with
PH3 of 5 sccm. No significant difference in the length and the diameter of the SiNWs was observed. However,
SiNWs grown at low flow rates of PH3 were straighter than that at high flow rates. PH3 flow rate did not cause critical
impact on the length and the diameter of SiNWs but rather affect the shape of the wires. The reflectances at 700 nm
increased with increasing the PH3 rate due to the bending and deformations of SiNWs at higher PH3 rates. The short
circuit current density decreased with increasing PH3 flow rates due to the increased optical reflectance caused by the
bending deformations of SiNWs. The best efficiency was achieved at 40 sccm flow rate of PH3 and resulted at
12.1 %.
Buy Now, Pay Later (BNPL)...On Your Credit Card
Creators: name: Guttman-Kenney, Benedict
name: Firth, Christopher
name: Gathergood, John
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Economics (econ.GN)
subject: FOS: Economics and business

description: We provide the first economic research on `buy now, pay later' (BNPL): an unregulated FinTech credit product enabling consumers to defer payments into interest-free instalments. We study BNPL using UK credit card transaction data. We document consumers charging BNPL transactions to their credit card. Charging of BNPL to credit cards is most prevalent among younger consumers and those living in the most deprived geographies. Charging a $0\%$ interest, amortizing BNPL debt to credit cards - where typical interest rates are $20\%$ and amortization schedules decades-long - raises doubts on these consumers' ability to pay for BNPL. This prompts a regulatory question as to whether consumers should be allowed to refinance their unsecured debt.
PV Modules and Components Under Extraordinary Environmental Conditions Using the Example of Sodium Chloride Atmospheres
Creators: name: Schinköthe, P.
name: Nieland, S.
name: Michael, J.
name: Kugler, M.
Publisher: name: WIP
Year: 2011
Subjects: Components for PV Systems
PV Modules

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 3504-3508
description: Due to increasing demands for the long term stability and the long term quality of PV modules new
testing and analyzing methods have to be developed. This applies especially for the growing number of new
application fields for PV systems with extraordinary environmental conditions as they can be found in sea close areas
(sodium chloride) and agricultural areas (ammonia). In this paper the results of different salt mist corrosion tests on
different set of materials are presented. Here not only PV modules as a whole were tested. Tests were also performed
on single components and on compounds to test the interaction between them. In addition new analyzing methods
were evaluated and applied. Thereby a mechanical peeltest on a glass-encapsulation compound showed significantly
drops in the adhesion quantified by the energy release rate of polymer materials.
Bulk-Bulk Correspondence in Disordered Non-Hermitian Systems
Creators: name: Zhang, Zhi-Qiang
name: Liu, Hongfang
name: Liu, Haiwen
name: Jiang, Hua
name: Xie, X. C.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: The consistency between eigenvalues calculated under open and periodic boundary conditions, named as {\it bulk-bulk correspondence} ($\mathcal{BBC}$), can be destroyed in systems with non-Hermitian skin effect (NHSE). In spite of the great success of the generalized Brillouin zone (GBZ) theory in clean non-Hermitian systems, the applicability of GBZ theory is questionable when the translational symmetry is broken. Thus, it is of great value to rebuild the $\mathcal{BBC}$ for disorder samples, which extends the application of GBZ theory in non-Hermitian systems. Here, we propose a scheme reconstructing $\mathcal{BBC}$, which can be regarded as the solution of an optimization problem. By solving this optimization problem analytically, we reconstruct the $\mathcal{BBC}$ and obtain the modified GBZ theory in several prototypical disordered non-Hermitian models. The modified GBZ theory gives a precise description of NHSE, which predicts the intriguing disorder-enhanced and disorder-irrelevant NHSEs.
description: 5 pages, 3 figures, including Supplementary Materials
Ion-beam nanopatterning of silicon surfaces under co-deposition of non-silicide-forming impurities
Creators: name: Moon, B.
name: Yoo, S.
name: Kim, J. -S.
name: Kang, S. J.
name: Muñoz-García, J.
name: Cuerno, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: We report experiments on surface nanopatterning of Si targets which are irradiated with 2 keV Ar + ions impinging at near-glancing incidence, under concurrent co-deposition of Au impurities simultaneously extracted from a gold target by the same ion beam. Previous recent experiments by a number of groups suggest that silicide formation is a prerequisite for pattern formation in the presence of metallic impurities. In spite of the fact that Au is known not to form stable compounds with the Si atoms, ripples nonetheless emerge in our experiments with nanometric wavelengths and small amplitudes, and with an orientation that changes with distance to the Au source. We provide results of sample analysis through Auger electron and energy-dispersive X-ray spectroscopies for their space-resolved chemical composition, and through atomic force, scanning transmission electron, and high-resolution transmission microscopies for their morphological properties. We discuss these findings in the light of current continuum models for this class of systems. The composition of and the dynamics within the near-surface amorphized layer that ensues is expected to play a relevant role to account for the unexpected formation of these surface structures.
description: 11 pages, 9 figures; submitted
Contact-mediated signaling enables disorder-driven transitions in cellular assemblies
Creators: name: Kuyyamudi, Chandrashekar
name: Menon, Shakti N.
name: Sinha, Sitabhra
Publisher: name: arXiv
Year: 2022
Subjects: subject: Tissues and Organs (q-bio.TO)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: We show that when cells communicate by contact-mediated interactions, heterogeneity in cell shapes and sizes leads to qualitatively distinct collective behavior in the tissue. For inter-cellular coupling that implements lateral inhibition, such disorder-driven transitions can substantially alter the asymptotic pattern of differentiated cells by modulating their fate choice through changes in the neighborhood geometry. In addition, when contact-induced signals influence inherent cellular oscillations, disorder leads to the emergence of functionally relevant partially-ordered dynamical states.
description: 6 pages, 3 figures + 5 pages Supplementary Information
Towards Event-Related Potential Predictions in Short-Term Responses of Physiological Measures
Creators: name: Isiaka, Fatima
Publisher: name: Advancement in Human Computer Interaction and Human Physiological Response Modelling
Year: 2023

description: (EEG) readings as a neutral response that is associated with certain sensory, and motor events normally called stimulus and cognitive responses. This is often recorded using scalp EEG and notes the average changesin the current-voltage over some time with the initial time as an onset of the stimulus over several event trials. This paper access the phenomenon behind the ERP for brain process and tends to emulate this with the concept of Electrodermal activities (SCR) in synchronous to other physiological processes like pupil dilation (PupilC), skin temperature (SkinT) and Fixation duration (FixD) using four different filters (Savisky Golar filter (SVGfilter), Moving Average filter (MovAFilter), Peak find filter (FindPeak) and Least mean square (LMS)), to predict the short term time frame for the responses. The performance of each filter is compared to determine which best suits the predictions of synchronous events from physiological responses.
Graviton propagation within the context of the D-material universe
Creators: name: Elghozi, Thomas
name: Mavromatos, Nick E.
name: Sakellariadou, Mairi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Motivated by the recent breakthrough of the detection of Gravitational Waves (GW) from coalescent black holes by the aLIGO interferometers, we study the propagation of GW in the {\sl D-material universe}, which we have recently shown to be compatible with large-scale structure and inflationary phenomenology. The medium of D-particles induces an effective mass for the graviton, as a consequence of the formation of recoil-velocity field condensates due to the underlying Born-Infeld dynamics. There is a competing effect, due to a super-luminal refractive index, as a result of the gravitational energy of D-particles acting as a dark matter component, with which propagating gravitons interact. We examine conditions for the condensate under which the latter effect is sub-leading. We argue that if quantum fluctuations of the recoil velocity are relatively strong, which can happen in the current era of the universe, then the condensate, and hence the induced mass of the graviton, can be several orders of magnitude larger than the magnitude of the cosmological constant today. Hence, we constrain the graviton mass using aLIGO and pulsar timing observations (which give the most stringent bounds at present). In such a sub-luminal graviton case, there is also a gravitational Cherenkov effect for ordinary high energy cosmic matter, which is further constrained by means of ultra-high-energy cosmic ray observations. Assuming cosmic rays of extragalactic origin, the bounds on the quantum condensate strength, based on the gravitational Cherenkov effect, are of the same order as those from aLIGO measurements, in contrast to the case where a galactic origin of the cosmic rays is assumed, in which case the corresponding bounds are much weaker.
description: 21 pages, JCAP style, no figures
Optimization of the Rear Point Contact Scheme of Crystalline Solar Cells Using Laser-Fired Contacts
Creators: name: Ortega, P.
name: Orpella, A.
name: López, G.
name: Martín, I.
name: Voz Sánchez, C.
name: Alcubilla González, R.
name: Sánchez Aniorte, I.
name: Colina Brito, M.
name: Perales, F.
name: Molpeceres, C.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Mono- and Multicrystalline Silicon Materials and Cells

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 2126-2129
description: This paper is focused on the optimization of the rear contact scheme of p-type c-Si LFC-PERC high
efficiency solar cells minimizing base ohmic losses without jeopardize rear passivation. This is carried out optimizing on one
hand the LFC laser conditions for minimum point resistance and on the other hand through a proper design of the contact
grid layout finding the optimum trade off for a given base resistivity between rear passivation and base resistance. LFC
process was carried out through 110 nm thermal SiO2 passivation layer using IR and green lasers. Very low specific contact
resistances, 0.1 mΩcm2 have been achieved independently of the laser used. For optimum rear contacted area fraction
efficiencies over 21.5% and 22%, for IR and green lasers respectively are expected in the 0.5-5 Ωcm resistivity range.
Annealing Behavior of Al2O3 Thin Films Grown on Crystalline Silicon by Atomic Layer Deposition
Creators: name: Lüder, T.
name: Raabe, B.
name: Terheiden, B.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Mono- and Multicrystalline Silicon Materials and Cells

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 2138-2140
description: Al2O3 thin films deposited by Atomic Layer Deposition provide an excellent passivation on both n-type
and p-type silicon surfaces due to a field effect caused by negative fixed charges. To activate the passivation an
annealing step at moderate temperatures (~ 425°C) for 30 min after deposition was reported to be essential. A drop in
minority carrier lifetime was reported if an additional firing step was carried out.
This work demonstrates that the order of the annealing and firing step determines the quality of the surface
recombination velocity (SRV). Applying the firing step before the annealing step results in a lower SRV compared to
the SRV of samples subjected to the reference process. The short firing step is carried out at a peak temperature of
~ 600°C as determined at the wafer surface.
The maximum surface recombination velocity assuming an infinite bulk lifetime of the best samples after firing and
subsequent anneal is determined to be 5.1 cm/s and 5.8 cm/s, whereas the lowest values for the reference process are
8.3 cm/s and 9.7 cm/s for n- and p-type Si wafers, respectively. Moreover, the minority carrier lifetime of the n-type
samples after firing and subsequent annealing is comparable to the one of only annealed samples without any firing
step.