cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Vertical Junction Si Micro-Cells for Concentrating Photovoltaics
Creators: name: Sarfaty, R.
name: Cherkun, A.
name: Pozner, R.
name: Segev, G.
name: Zeierman, E.
name: Flitsanov, Y.
name: Kribus, A.
name: Rosenwaks, Y.
Publisher: name: WIP
Year: 2011
Subjects: Advanced Photovoltaics : New Concepts and Ultra-High Efficiency
Terrestrial Concentrator Systems

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 145-147
description: Vertical Junction (VJ) silicon cells have shown potential to operate under high concentration due to low current/high voltage operation leading to lower series resistance losses, but tests have shown so far only modest efficiency of about 20%. We perform a comprehensive 2D and 3D optimization study and show that the efficiency of VMJ cells can be significantly higher, around 30% at concentration of 1000 and higher. Reaching high efficiency requires micro junction width of about 50 microns, which is significantly smaller than previous VMJ cells. This requires a monolithic approach to the fabrication process. We have realized separated vertical junctions with different widths on a SOI wafer. Efficiency characteristic of the VJ as a function of illumination intensity for various VJ widths behave as predicted by the simulation: highest efficiencies have been obtained by micro-VJ of 50 microns width. A 3D VJ structure based on pre-patterned macro-pores is also presented and analyzed. This structure approaches a back contact cell when the pore depth approaches zero. Simulation results show efficiency improvement with increasing pore depth, until the pores almost reach the upper surface. The predicted conversion efficiency at 1000 suns is also about 30%, significantly higher than conventional cells and previously reported VMJ cells.
The influence of dense gas rings on the dynamics of a stellar disk in the Galactic center
Creators: name: Trani, Alessandro Alberto
name: Mapelli, Michela
name: Bressan, Alessandro
name: Pelupessy, Federico Inti
name: van Elteren, Arjen
name: Zwart, Simon Portegies
Publisher: name: arXiv
Year: 2015
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Galactic center hosts several hundred early-type stars, about 20% of which lie in the so-called clockwise disk, while the remaining 80% do not belong to any disks. The circumnuclear ring (CNR), a ring of molecular gas that orbits the supermassive black hole (SMBH) with a radius of 1.5 pc, has been claimed to induce precession and Kozai-Lidov oscillations onto the orbits of stars in the innermost parsec. We investigate the perturbations exerted by a gas ring on a nearly-Keplerian stellar disk orbiting a SMBH by means of combined direct N-body and smoothed particle hydrodynamics simulations. We simulate the formation of gas rings through the infall and disruption of a molecular gas cloud, adopting different inclinations between the infalling gas cloud and the stellar disk. We find that a CNR-like ring is not efficient in affecting the stellar disk on a timescale of 3 Myr. In contrast, a gas ring in the innermost 0.5 pc induces precession of the longitude of the ascending node Omega, significantly affecting the stellar disk inclination. Furthermore, the combined effect of two-body relaxation and Omega-precession drives the stellar disk dismembering, displacing the stars from the disk. The impact of precession on the star orbits is stronger when the stellar disk and the inner gas ring are nearly coplanar. We speculate that the warm gas in the inner cavity might have played a major role in the evolution of the clockwise disk.
description: 10 pages, 10 figures, 1 table, accepted for publication in ApJ
Multiband Solar Cell
Creators: name: Lopez, N.
name: Reichertz, L.A.
name: Yu, K.M.
name: Campman, K.
name: Walukiewicz, W.
Publisher: name: WIP
Year: 2011
Subjects: Advanced Photovoltaics : New Concepts and Ultra-High Efficiency
Fundamental Studies

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 97-100
description: Highly mismatched alloys are a new class of materials that were formed by the substitution of small amount of
isovalent anion elements with very different electronegativities. It has been shown that the incorporation of a small
amount of N into GaAs results in the formation of a narrow band separated from the conduction band. Using this
unique feature of the electronic band structure of highly mismatched GaNxAs1-x alloys, we have designed, fabricated
and tested a single junction multiband photovoltaic device. The device generates electrical power through the use of
three separate energy bands to absorb photons throughout the solar spectrum. The structures were grown on heavily
doped n-type GaAs substrate with Metalorganic Chemical Vapor Deposition and consisted of an active GaNxAs1-x
film with AlGaAs layers blocking the charge transport in the intermediate band. The device was characterized using a
variety of methods including photomodulated reflection and electroluminescence. Altogether, the measurements
provide unambiguous evidence for three optical transitions between the conduction, the valence and the intermediate
band. The transition energies of 0.89 eV, 1.15 eV and 1.99 eV are in good agreement with the predictions of the band
anticrossing model of the electronic band structure of GaNxAs1-x with x=0.024.
Mean-field study of hot beta-stable protoneutron star matter: Impact of the symmetry energy and nucleon effective mass
Creators: name: Tan, Ngo Hai
name: Loan, Doan Thi
name: Khoa, Dao T.
name: Margueron, Jerome
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: A consistent Hartree-Fock study of the equation of state (EOS) of asymmetric nuclear matter at finite temperature has been performed using realistic choices of the effective, density dependent nucleon-nucleon (NN) interaction, which were successfully used in different nuclear structure and reaction studies. Given the importance of the nuclear symmetry energy in the neutron star formation, EOS's associated with different behaviors of the symmetry energy were used to study hot asymmetric nuclear matter. The slope of the symmetry energy and nucleon effective mass with increasing baryon density was found to affect the thermal properties of nuclear matter significantly. Different density dependent NN interactions were further used to study the EOS of hot protoneutron star (PNS) matter of the $npeμν$ composition in $β$-equilibrium. The hydrostatic configurations of PNS in terms of the maximal gravitational mass $M_{\rm max}$ and radius, central density, pressure and temperature at the total entropy per baryon $S/A= 1,2$ and 4 have been determined in both the neutrino-free and neutrino-trapped scenarios. The obtained results show consistently a strong impact of the symmetry energy and nucleon effective mass on thermal properties and composition of hot PNS matter. $M_{\rm max}$ values obtained for the (neutrino-free) $β$-stable PNS at $S/A=4$ were used to assess time $t_{\rm BH}$ of the collapse of 40 $M_\odot$ protoneutron progenitor to black hole, based on a correlation between $t_{\rm BH}$ and $M_{\rm max}$ found from the hydrodynamic simulation by Hempel {\it et al.}.
description: Accepted for publication in Physical Review C
Mortality of III-V Multi-Junction Solar Cells of CPV Systems in the Real Field
Creators: name: Araki, K.
name: Nagai, K
name: Hobo, K.
Publisher: name: WIP
Year: 2011
Subjects: Advanced Photovoltaics : New Concepts and Ultra-High Efficiency
Terrestrial Concentrator Systems

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 159-162
description: Failure of III-V multi-junction solar cells has been acknowledged by experienced CPV system
engineers. The frequency and significance in the real field, however, were not reported. For this purpose, 30 kW
system consist of 5,250 III-V solar cells and 42 strings was intensively monitored for about three years. Current
sensors were applied in all DC strings and observed the change of contribution of each string to detect when failure
occurs and how significant to the loss of system output power. The modules that were found containing many dead
cells were removed and intensively studied. The damaged cells are found concentrating in a single production lot of
receivers and also in a single sorting level, namely, highest Isc bin. This fact suggests there are certainly “weak cells”
and “robust cells”. The monitoring to 42 strings reveals that it looks the cells are degraded or dead simultaneously.
Another distinct fact is the dead cells are found electrically closed position, rather than physically closed position.
These facts imply that some external electrical stress is the direct reason although the robustness of the cell varies.
The fact that the internal resistance of CPV array circuit is low means that the Q-value of resonance circuit consist of
capacitance from junctions and inductance from interconnects is high, which induces high reverse voltage to the
junction due to high frequency resonance by electrical cirtuits. In order to assess the robustness to the electrical stress,
a new test is developed applying high voltage spark between the ground and one of the interconnects. Although the
test does not apply forward bias current to the cell junctions, the spark kills one or several cells along the
interconnects as is seen in the field. The mortality was significantly improved by protecting cells against surge
voltage. The cause of field failure of III-V concentrator cells was understood. The infant mortality and field failure of
III-V concentrator cells was expected significantly improved by proper protection of the cells. It may be concluded it
is important to protect cells from outside electrical stress, rather than expecting III-V cells to be robust and defect free.
Modeling and Simulation of Passenger Traffic in a National Airport
Creators: name: Enciso, Javier
name: Vargas, Juan
name: Martínez, Pablo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Multiagent Systems (cs.MA)
subject: FOS: Computer and information sciences
subject: I.2.11
subject: 90B22 (Primary), 90B20 (Secondary)

description: Optimal operation of a country's air transport infrastructure plays a major role in the economic development of nations. Due to the increasing use of air transportation in today's world, flights' boarding times have become a concern for both airlines and airports, thus the importance of knowing beforehand how changes in flights demand parameters and physical airport layout will affect passengers flow and boarding times. This paper presents a pedestrian modeling study in which a national airport passenger flow was analyzed. The study was conducted at Vanguardia National Airport in Villavicencio, Meta, Colombia. Different effects of structural changes are shown and provide judging elements for decision makers regarding passenger traffic in airport design.
description: 8 pages, submitted to LACCEI 2016
Optical Two-dimensional Coherent Spectroscopy of Cold Atoms
Creators: name: Liang, Danfu
name: Rodriguez, Lexter Savio
name: Zhou, Haitao
name: Zhu, Yifu
name: Li, Hebin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We report an experimental demonstration of optical 2DCS in cold atoms. The experiment integrates a collinear 2DCS setup with a magneto-optical trap (MOT), in which cold rubidium (Rb) atoms are prepared at a temperature of about 200 $μ$K and a number density of $10^{10}$ cm$^{-3}$. With a sequence of femtosecond laser pulses, we first obtained one-dimensional second- and fourth-order nonlinear signals and then acquired both one-quantum and zero-quantum 2D spectra of cold Rb atoms. The capability of performing optical 2DCS in cold atoms is an important step toward optical 2DCS study of many-body physics in cold atoms and ultimately in atom arrays and trapped ions. Optical 2DCS in cold atoms/molecules can also be a new avenue to probe chemical reaction dynamics in cold molecules.
description: 5 pages, 4 figures
Auf den Leib gerückt
Creators: name: Degler, Anna
Publisher: name: 21: Inquiries into Art, History, and the Visual
Year: 2023

description: This essay addresses the question of ethics and aesthetics of distance from a particular angle: the very instable fiction that is the human body. Wavering, it tries to trace how and what kind of distances collapse when the human body in all its resistance as an artistic and academic ‘object’ is approached. How does this interfere with scientific objectivity or the figure of historical distance? The paper touches upon (Christian) concepts of the human body and their entanglement with philosophical and, in its wake, art historical writing with a special focus on early modern European art. It grasps the subject via a medial experience with Eve from the Ghent Altarpiece by Hubert and Jan van Eyck, thereby aiming to explore relations between new media, painting techniques, or style as a means of operating distance effects. By examining relations of closeness and distance through media, technique, style, and the (art historical) discourses on bodies, the essay ventures into a self-critical destabilization of European concepts and formations of bodies.
description: 21: Inquiries into Art, History, and the Visual, Vol. 4 No. 3 (2023): 21: Inquiries into Art, History, and the Visual. Beiträge zur Kunstgeschichte und visuellen Kultur
Classical quantum friction at water-carbon interfaces
Creators: name: Bui, Anna T.
name: Thiemann, Fabian L.
name: Michaelides, Angelos
name: Cox, Stephen J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Friction at water-carbon interfaces remains a major puzzle with theories and simulations unable to explain experimental trends in nanoscale waterflow. A recent theoretical framework -- quantum friction (QF)-- proposes to resolve these experimental observations by considering nonadiabatic coupling between dielectric fluctuations in water and graphitic surfaces. Here, using a classical model that enables fine-tuning of the solid's dielectric spectrum, we provide evidence from simulations in general support of QF. In particular, as features in the solid's dielectric spectrum begin to overlap with water's librational and Debye modes, we find an increase in friction in line with that proposed by QF. At the microscopic level, we find that this contribution to friction manifests more distinctly in the dynamics of the solid's charge density than that of water. Our findings suggest that experimental signatures of QF may be more pronounced in the solid's response rather than liquid water's.
Validation of Proposed Photovoltaic Energy Rating Standard and Sensitivity to Environmental Parameters
Creators: name: Roy, J.
name: Betts, T.R.
name: Gottschalg, R.
name: Mau, S.
name: Zamini, S.
name: Kenny, R.P.
name: Müllejans, H.
name: Friesen, G.
name: Dittmann, S.
name: Beyer, H.G.
name: Jagomägi, A.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Components for PV Systems
PV Modules

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2728-2734
description: PV devices are currently compared on the basis of the power measurements, which might not be as meaningful as a comparator as the energy yield. The energy rating standard proposed by the IEC promises to overcome this shortcoming. It has been implemented in three institutes and the issues with the current drafts are evaluated.
The data required as the input for the energy rating is normally not available and synthetic datasets will have to be used or parts need to be estimated for validation studies. The validation against outdoor data shows that the uncertainty of the input data, specifically the angular distribution of the diffuse irradiance, makes the energy prediction part virtually not applicable for energy yield calculations. The validation effort shows a reduction of the standard deviation in the measurements, indicating that all environmental effects are considered.
The evaluation of the originally proposed standard days shows that there is little information to be gained in their application as they are not representative of realistic conditions; they are enveloping the possible environments. This will in some cases over-emphasise the importance of certain effects, as their contribution to the overall energy yield might be negligible.
Overall, the proposed standard represents an important advance on power rating. The standard is able to identify differences in device technologies. Further work might be required to make the output more relevant to a wider variety of users, though.
Marginalising instrument systematics in HST WFC3 transit lightcurves
Creators: name: Wakeford, H. R.
name: Sing, D. K.
name: Evans, T.
name: Deming, D.
name: Mandell, A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) infrared observations at 1.1-1.7$μ$m probe primarily the H$_2$O absorption band at 1.4$μ$m, and has provided low resolution transmission spectra for a wide range of exoplanets. We present the application of marginalisation based on Gibson (2014) to analyse exoplanet transit lightcurves obtained from HST WFC3, to better determine important transit parameters such as R$_p$/R$_*$, important for accurate detections of H$_2$O. We approximate the evidence, often referred to as the marginal likelihood, for a grid of systematic models using the Akaike Information Criterion (AIC). We then calculate the evidence-based weight assigned to each systematic model and use the information from all tested models to calculate the final marginalised transit parameters for both the band-integrated, and spectroscopic lightcurves to construct the transmission spectrum. We find that a majority of the highest weight models contain a correction for a linear trend in time, as well as corrections related to HST orbital phase. We additionally test the dependence on the shift in spectral wavelength position over the course of the observations and find that spectroscopic wavelength shifts $δ_λ(λ)$, best describe the associated systematic in the spectroscopic lightcurves for most targets, while fast scan rate observations of bright targets require an additional level of processing to produce a robust transmission spectrum. The use of marginalisation allows for transparent interpretation and understanding of the instrument and the impact of each systematic evaluated statistically for each dataset, expanding the ability to make true and comprehensive comparisons between exoplanet atmospheres.
description: 19 pages, 13 figures, 8 tables, Accepted to ApJ
Distanz zeigen, Nähe erzeugen
Creators: name: Kranen, Annette
Publisher: name: 21: Inquiries into Art, History, and the Visual
Year: 2023

description: Between 1585 and 1600, Maerten de Vos, in cooperation with Jan and Raphael Sadeler and Adriaen Collaert, all active in the Antwerp print trade, published five series of engravings that show hermits in their hermitages. The 132 images in total put forward variations of one subject: the body techniques of asceticism pursued in places of isolation from everyday life. They create a paradoxical effect of making these distant places accessible and bringing them close to an audience. Through an in-depth analysis of the history and aesthetics of these prints, this article examines the reception of this outstanding project of early modern print culture. It shows how the series subtly convey a sense of the desert by visual means, thereby involving the viewers closely in the remote hermitages.
description: 21: Inquiries into Art, History, and the Visual, Vol. 4 No. 3 (2023): 21: Inquiries into Art, History, and the Visual. Beiträge zur Kunstgeschichte und visuellen Kultur
A Note on Alternating Minimization Algorithm for the Matrix Completion Problem
Creators: name: Gamarnik, David
name: Misra, Sidhant
Publisher: name: arXiv
Year: 2016
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: Numerical Analysis (math.NA)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: We consider the problem of reconstructing a low rank matrix from a subset of its entries and analyze two variants of the so-called Alternating Minimization algorithm, which has been proposed in the past. We establish that when the underlying matrix has rank $r=1$, has positive bounded entries, and the graph $\mathcal{G}$ underlying the revealed entries has bounded degree and diameter which is at most logarithmic in the size of the matrix, both algorithms succeed in reconstructing the matrix approximately in polynomial time starting from an arbitrary initialization. We further provide simulation results which suggest that the second algorithm which is based on the message passing type updates, performs significantly better.
description: 8 pages, 2 figures
The extended star graph as a light-harvesting-complex prototype: excitonic absorption speedup by peripheral energy defect tuning
Creators: name: Yalouz, Saad
name: Pouthier, Vincent
Publisher: name: arXiv
Year: 2022
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the quantum dynamics of a photo-excitation uniformly distributed at the periphery of an extended star network (with $N_B$ branches of length $L_B$). More specifically, we address here the question of the energy absorption at the core of the network and how this process can be improved (or not) by the inclusion of peripheral defects with a tunable energy amplitude $Δ$. Our numerical simulations reveal the existence of optimal value of energy defect $Δ^*$ which depends on the network architecture. Around this value, the absorption process presents a strong speedup (i.e. reduction of the absorption time) provided that $L_B \leq L_B^*$ with $L_B^* \approx 12.5/\ln(N_B) $. Analytical/numerical developments are then conducted to interpret this feature. We show that the origin of this speedup takes place in the hybridization of two upper-band excitonic eigenstates. This hybridization is important when $L_B \leq L_B^*$ and vanishes almost totally when $L_B > L_B^*$. These structural rules we draw here could represent a potential guide for the practical design of molecular nano-network dedicated to the realisation of efficient photo-excitation absorption.
Gefühlte Nähe
Creators: name: Prokić, Tanja
name: Schankweiler, Kerstin
Publisher: name: 21: Inquiries into Art, History, and the Visual
Year: 2023

description: How has digital communication changed expectations and perceptions of proximity and distance? This article traces the media history of a communication mode that relies on intimacy and testifying. By discussing the intrinsic relationship between platform-based information and communication technologies and the attention economy, the development of a communication mode of so-called “presumed intimacy” is elaborated. Drawing on concepts from celebrity studies and advertising, the transformation of spatio-temporal and social distance into felt proximity can be described in more detail. In doing so, the article also stresses the role of images in the fabrication of intimacy and takes selfies and selfie videos of celebrities in the context of protest movements as an example. The connection of protest culture, celebrification and testimonial images demonstrates in a particular way how attention economies in digital communication are structured.
description: 21: Inquiries into Art, History, and the Visual, Vol. 4 No. 3 (2023): 21: Inquiries into Art, History, and the Visual. Beiträge zur Kunstgeschichte und visuellen Kultur
Linear maps as sufficient criteria for entanglement depth and compatibility in many-body systems
Creators: name: Lewenstein, Maciej
name: Müller-Rigat, Guillem
name: Tura, Jordi
name: Sanpera, Anna
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Physical transformations are described by linear maps that are completely positive and trace preserving (CPTP). However, maps that are positive (P) but not completely positive (CP) are instrumental to derive separability/entanglement criteria. Moreover, the properties of such maps can be linked to entanglement properties of the states they detect. Here, we extend the results presented in [Phys. Rev A 93, 042335 (2016)], where sufficient separability criteria for bipartite systems were derived. In particular, we analyze the entanglement depth of an $N$-qubit system by proposing linear maps that, when applied to any state, result in a bi-separable state for the $1:(N-1)$ partitions, i.e., $(N-1)$-entanglement depth. Furthermore, we derive criteria to detect arbitrary $(N-n)$-entanglement depth tailored to states in close vicinity of the completely depolarized state (the normalized identity matrix). We also provide separability (or $1$- entanglement depth) conditions in the symmetric sector, including for diagonal states. Finally, we suggest how similar map techniques can be used to derive sufficient conditions for a set of expectation values to be compatible with separable states or local-hidden-variable theories. We dedicate this paper to the memory of the late Andrzej Kossakowski, our spiritual and intellectual mentor in the field of linear maps.
description: 11 pages. Final version
Distanzbedürfnisse
Creators: name: Von Brevern, Jan
Publisher: name: 21: Inquiries into Art, History, and the Visual
Year: 2023

description: Museum barriers – those ropes and cords in front of artworks – seem to be both a nuisance and a necessity. To protect the artworks, they constrain the movements of visitors. Yet it is uncertain if protection really is what barriers are about. In this article, I argue that museum barriers are a material manifestation of deep-seated cultural convictions about how to approach works of art. Even if they are absent, learned and internalized barriers step in. – In recent years, the barrier seems to be disappearing from museum galleries. Reflecting upon the reasons for their presence or absence, I examine some of the functions of barriers in art museums, ask about the relationship of aesthetic and physical distance, and look at how art itself has addressed both the beholder’s desire for proximity and the urge to keep one’s distance.
description: 21: Inquiries into Art, History, and the Visual, Vol. 4 No. 3 (2023): 21: Inquiries into Art, History, and the Visual. Beiträge zur Kunstgeschichte und visuellen Kultur
Topology Optimization for Galvanic Coupled Wireless Intra-body Communication
Creators: name: Swaminathan, Meenupriya
name: Muncuk, Ufuk
name: Chowdhury, Kaushik R.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Implanted sensors and actuators in the human body promise in-situ health monitoring and rapid advancements in personalized medicine. We propose a new paradigm where such implants may communicate wirelessly through a technique called as galvanic coupling, which uses weak electrical signals and the conduction properties of body tissues. While galvanic coupling overcomes the problem of massive absorption of RF waves in the body, the unique intra-body channel raises several questions on the topology of the implants and the external (i.e., on skin) data collection nodes. This paper makes the first contributions towards (i) building an energy-efficient topology through optimal placement of data collection points/relays using measurement-driven tissue channel models, and (ii) balancing the energy consumption over the entire implant network so that the application needs are met. We achieve this via a two-phase iterative clustering algorithm for the implants and formulate an optimization problem that decides the position of external data-gathering points. Our theoretical results are validated via simulations and experimental studies on real tissues, with demonstrated increase in the network lifetime.
description: This paper has been accepted for inclusion in the IEEE INFOCOM 2016 technical program. This is an author copy
Universal QM/MM Approaches for General Nanoscale Applications
Creators: name: Csizi, Katja-Sophia
name: Reiher, Markus
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Biological Physics (physics.bio-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Quantum mechanics/molecular mechanics (QM/MM) hybrid models allow one to address chemical phenomena in complex molecular environments. Whereas this modeling approach can cope with a large system size at moderate computational costs, the models are often tedious to construct and require manual preprocessing and expertise. As a result, transferability to new application areas can be limited and the many parameters are not easy to adjust to reference data that are typically scarce. Therefore, it is desirable to devise automated procedures of controllable accuracy, which enables such modeling in a standardized and black-box-type manner. Although diverse best-practice protocols have been set up for the construction of individual components of a QM/MM model (e.g., the MM potential, the type of embedding, the choice of the QM region), automated procedures that reconcile all steps of the QM/MM model construction are still rare. Here, we review the state of the art of QM/MM modeling with a focus on automation. We elaborate on MM model parametrization, on atom-economical physically-motivated QM region selection, and on embedding schemes that incorporate mutual polarization as critical components of the QM/MM model. In view of the broad scope of the field, we mostly restrict the discussion to methodologies that build \textit{de novo} models based on first-principles data, on uncertainty quantification, and on error mitigation with a high potential for automation. Ultimately, it is desirable to be able to set up reliable QM/MM models in a fast and efficient automated way without being constrained by specific chemical or technical limitations.
description: 60 pages, 3 figures, 1 table
Users Polarization on Facebook and Youtube
Creators: name: Bessi, Alessandro
name: Zollo, Fabiana
name: Del Vicario, Michela
name: Puliga, Michelangelo
name: Scala, Antonio
name: Caldarelli, Guido
name: Uzzi, Brian
name: Quattrociocchi, Walter
Publisher: name: arXiv
Year: 2016
Subjects: subject: Social and Information Networks (cs.SI)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: On social media algorithms for content promotion, accounting for users preferences, might limit the exposure to unsolicited contents. In this work, we study how the same contents (videos) are consumed on different platforms -- i.e. Facebook and YouTube -- over a sample of $12M$ of users. Our findings show that the same content lead to the formation of echo chambers, irrespective of the online social network and thus of the algorithm for content promotion. Finally, we show that the users' commenting patterns are accurate early predictors for the formation of echo-chambers.
Redefinition of the European Efficiency - Finding the Compromise Between Simplicity and Accuracy
Creators: name: Bletterie, B.
name: Bründlinger, R.
name: Häberlin, H.
name: Baumgartner, F.P.
name: Schmidt, H.
name: Burger, B.
name: Klein, G.
name: Alonso-Abella, M.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Components for PV Systems
Balance of System Components

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2735-2742
description: This paper deals with the definition of the European efficiency of photovoltaic (PV) inverters, which is
since the recent introduction of a marking system to compare the performance of PV inverters one of the most topical
issues in this field. This paper questions the adequacy of the current definition(s) of the European efficiency to reflect
accurately the performance of inverters. It proposes a new quantity to quantify the performance of inverters: the
maximal reachable European efficiency. This new definition of the European efficiency is either based on the
distribution of the annual yield as a function of MPP power and voltage or on the existing weighting factors. The
definition of the maximal reachable efficiency is basically based on the concept of required MPP voltage band. It
therefore considers a realistic operation domain in which an average efficiency can be computed. A comparison
between the current definition of the European efficiency and the proposed quantities is provided, also taking into
account the impact of the location. As a good compromise between simplicity and accuracy, the proposed concept of
maximal reachable European efficiency should be adopted to quantify inverters efficiency.
A Method for Spectral Response Measurements of Various PV Modules
Creators: name: Tsuno, Y.
name: Hishikawa, Y.
name: Kurokawa, K.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Components for PV Systems
PV Modules

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2723-2727
description: Precise characterization of the spectral response or the quantum efficiency of the series connected PV
modules such as the modules has been investigated. As the cells in PV modules are series connected, measurements
of the spectral responses of the modules and their component cells are not straightforward. In this study, various
factors to affect the measurement of module spectral response are discussed. Measurement conditions to yield
accurate spectral response results are discussed. Measurements of the SR's of commercial-size modules are
demonstrated for various kinds of modules including crystalline Si, thin-film Si, and multi-junction structures. In the
present study based on the measurement of each constituent cell in the module, which irradiates chopped
monochromatic light and white or color bias light on the target cell, and supplemental bias light on other cells.
Measurement of the SR's of commercial-size modules demonstrated that the procedure and apparatus of the present
study is applicable for various kinds of modules including crystalline Si, thin-film Si, CIGS, and multi-junction
structures.
Determining the Bulk Lifetime of Unpassivated Multicrystalline Silicon Wafers
Creators: name: Bothe, K.
name: Krain, R.
name: Brendel, R.
name: Falster, R.
name: Sinton, R.
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; 1828-1833
description: The determination of the bulk lifetime of bare multicrystalline silicon wafers without the need of surface
passivation is a desirable goal. The implementation of an in-line carrier lifetime analysis is only of benefit if the measurements
can be done on bare unprocessed wafers and if the measured effective lifetime is clearly related to the bulk
lifetime of the wafer. In this work we present a detailed experimental study demonstrating the relationship between the
effective carrier lifetime of unpassivated wafers and their bulk carrier lifetime. Numerical modelling using the device simulation
program PC1D is used to describe this relationship for different surface conditions taking into account the impact
of a saw damage layers with poor electronic quality. Our results show that a prediction of the bulk lifetime from quasi-
steady state photo conductance (QSSPC) carrier lifetime measurements on bare wafers is possible. Based on these results
we suggest a simple procedure to implement the analysis for in-line inspection. Furthermore, we examine the relation
between the effective lifetime of the bare, unprocessed wafers and the energy conversion efficiencies of solar cells
made from neighboring wafers and find a clear correlation independent of the wafer position in the multicrystalline
block.
Emitter Epitaxy for Crystalline Silicon Thin Film Solar Cells with New Contact Methods
Creators: name: Schmich, E.
name: Kiefer, F.
name: Hörteis, M.
name: Alemán, M.
name: Glunz, S.
name: Reber, S.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Thin Films Solar Cells
Thin Film Crystalline Silicon Solar Cells and Wafer Equivalents

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 2570-2574
description: This paper presents results from the EpiWE with epitaxial emitter combined with new
contact techniques based on an approach, where the seed layer is thickened by light induced plating. The
high potential of nickel plated and aerosol printed contacts are joined with the advantages of the epitaxial
emitter. In spite of some adhesion problems of the grid with nickel plating, high pseudo fill factors and
open circuit voltages could be reached. Aerosol printed contacts on epitaxial emitters showed high open
circuit voltages up to 622 mV. A good contact formation was possible after a single firing step in contrast
to screen-printed solar cells with epitaxial emitters. Best cell results are reached with the highest firing
temperature and the lowest chain speed. For the first time, EpiWE solar cells with in-situ emitter and
novel industrial relevant contacting techniques are presented.
Change of Optical Band Gap of ZnO Window Layer in Solar Cell
Creators: name: Li, F.
name: Ma, Z.
name: Shen, L.
name: Du, H.W.
name: Ding, H.
name: Xu, F.
Publisher: name: WIP
Year: 2011
Subjects: Thin Film Solar Cells
CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 26th European Photovoltaic Solar Energy Conference and Exhibition; 2926-2929
description: In this paper, the variation of the optical band gap of ZnO films in different oxygen ambient has been
investigated by dint of photoluminescence (PL) emission mode. The pure ZnO films were grown on the polished
silicon (100) wafers and quartz glass by using an R.F magnetron sputtering system in a series of O2/Ar ratio,
respectively. The value of band edge shows no distinctive relationship to the O2/Ar ratios except for the case of 5:1.
The intensity of photoluminescence (PL) from ultraviolet (UV) to green regions increases with the increases of O2
flow from 0:10 to 10:10, which is ascribed to the improved stoichiometric composition of the deposited films. As the
O2/Ar ratio ascends to 30/10 or 50/10, the UV peak is broadened without sacrificing the emission intensity. The
position of PL also shows no direct dependence on the crystal quality. Hence, the intensity and position of PL spectra
is closely dependent on the stoichiometry than the crystallinity of ZnO film. The results are significant for both CIGS,
CdTe, and a-Si:H thin films and SIS heterojunction solar cells.
Long-Term Degradation of Oxide-Passivated Phosphorus-Diffused Silicon
Creators: name: McIntosh, K.R.
name: Tsoi, W.
name: Thomson, A.F.
name: Richards, B.S.
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; 1834-1839
description: The emitter saturation current density J0E of a variety of oxide-passivated phosphorus diffusions is
assessed. The samples were first measured in the year 2000 and then remeasured in 2009. We find that the J0E
increased by a factor of 1.3–2.5 over nine years when the surface concentration was less than ~5 × 1018 cm–3, but
remained constant when above ~5 × 1018 cm–3. In most cases, the samples could be completely repaired by an anneal in
N2 at 200 °C for 1 minute. These results are of significance to high-efficiency silicon solar cells that rely on oxide
passivation.
Claim and Reality of PV Lamps with LEDs
Creators: name: Bopp, G.
name: Grüner, R.
name: Lux, S.
name: Pfanner, N.
name: Zimmermann, A.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Components for PV Systems
Balance of System Components

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2770-2773
description: White light emitting diode (LED) technology is a fast evolving lighting technology that shows great promise for providing efficient (50-80 Lumen/Watt), cost effective and sustainable lighting in a variety of applications. Because these light sources are rugged, easily controlled, applicable over a wide temperature range, have low voltage and are inherently powered by direct current (DC), they show particular promise for use as stand-alone lighting systems, especially for remote non-electrified areas in developing countries.
Because of these good features, a lot of PV lamps with LEDs for Solar Home Systems appeared on the market during the last 2 years. In many of these lamps, power LEDs, which are optimised for high luminance, high current and a long lifetime, are not used. Instead, a cluster of low-power LEDs, which are very inexpensive and normally used only for purposes of indication, are applied. Only a very limited number of these lamps achieve a lifetime of considerably over 10,000 hours. For the most lamps with power LED such a lifetime or more like 30,000h is achievable.
High-sensitivity low-noise photodetector using large-area silicon photomultiplier
Creators: name: Masuda, Takahiko
name: Hiramoto, Ayami
name: Ang, Daniel G.
name: Meisenhelder, Cole
name: Panda, Cristian D.
name: Sasao, Noboru
name: Uetake, Satoshi
name: Wu, Xing
name: DeMille, David P.
name: Doyle, John M.
name: Gabrielse, Gerald
name: Yoshimura, Koji
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: The application of silicon photomultiplier (SiPM) technology for weak-light detection at a single photon level has expanded thanks to its better photon detection efficiency in comparison to a conventional photomultiplier tube (PMT). SiPMs with large detection area have recently become commercially available, enabling applications where the photon flux is low both temporarily and spatially. On the other hand, several drawbacks exist in the usage of SiPMs such as a higher dark count rate, many readout channels, slow response time, and optical crosstalk; therefore, users need to carefully consider the trade-offs. This work presents a SiPM-embedded compact large-area photon detection module. Various techniques are adopted to overcome the disadvantages of SiPMs so that it can be generally utilized as an upgrade from a PMT. A simple cooling component and recently developed optical crosstalk suppression method are adopted to reduce the noise which is more serious for larger-area SiPMs. A dedicated readout circuit increases the response frequency and reduces the number of readout channels. We favorably compare this design with a conventional PMT and obtain both higher photon detection efficiency and larger-area acceptance.
Further Investigations in Optical Confinement and Solar Cell Processing for Crystalline Silicon Thin Film Solar Cells
Creators: name: Lindekugel, S.
name: Mitchell, E.J.
name: Künle, M.
name: Janz, S.
name: Reber, S.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Thin Films Solar Cells
Thin Film Crystalline Silicon Solar Cells and Wafer Equivalents

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 2575-2579
description: This paper presents the investigations in the performance of different SiC and SiO2 intermediate layer (IL)
configurations during a zone melting recrystallisation (ZMR) step. The goal is to implement an IL consisting of an
electrically conductive all-SiC multilayer stack in Recrystallised Wafer Equivalents (RexWE) solar cells. We tested
stoichiometric SiC layers, carbon rich SiC layers and silicon rich SiC layers embedded in SiO2 layers, temperature pretreatments
and several multilayer systems including all-SiC stacks. We also succeeded for the first time with a three layer
SiC stack put together by PECVD to keep structural integrity throughout the ZMR process.
Further investigation on the potential of RexWE solar cells have also been made regarding the pitch in the laser fired rear
access (LFA) process and the resulting series resistance as well as the increase in the short circuit current (Jsc) due to a
plasma texture.
Transformerless Inverters With New Topology in the Power Range 30kW+
Creators: name: Hauser, T.
name: Koch, A.
name: Buchholz, C.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Components for PV Systems
Balance of System Components

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2751-2754
description: General goal of the project was, to develop a novel inverter concept for solar inverters with a nominal output power > 30 kW. The new technology should be distinguished by very high efficiency, a good grid compatibility, a high reliability and a long life time. At the same time it should have been achieved a considerable cost reduction in comparison to the inverters on the market in 2005, where a lot of those have been built like UPS inverters. Those UPS inverters used at the time when the project started and still today mainly
50Hz transformers for the galvanic isolation and therefore those inverters are always worse in efficiency than specially developed transformerless inverters for the use in PV plants. The high weight of this inverters is an enormous disadvantage in handling and installation, in particular in building integrated systems and on-roof systems. The new inverter should also be part of the lightest in their class. By feeding-in three-phase the new inverter improves the grid compatibility. An unequal load splitting by a lot of parallel installed one phase inverters is avoided and therefore an optimum phase symmetry is reached. A further goal was to realize a wide DC input MPP range as well as a high acceptable maximum DC voltage. Thereby the amount of parallel string and the balance of system cost might be reduced. The customers get a higher flexibility on designing and connecting the solar generator. With a max. efficiency of > 97.5%, a European efficiency of > 97% and a very low specific weight of 155 kg, the general goals of the project are excelled. The result of this task convinces not only of a shapely design but also of an extensive function of communication.