cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Einstein's Physical Strategy, Energy Conservation, Symmetries, and Stability: "but Grossmann & I believed that the conservation laws were not satisfied"
Creators: name: Pitts, J. Brian
Publisher: name: arXiv
Year: 2016
Subjects: subject: History and Philosophy of Physics (physics.hist-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Recent work on the history of General Relativity by Renn, Sauer, Janssen et al. shows that Einstein found his field equations partly by a physical strategy including the Newtonian limit, the electromagnetic analogy, and energy conservation. Such themes are similar to those later used by particle physicists. How do Einstein's physical strategy and the particle physics derivations compare? What energy-momentum complex(es) did he use and why? Did Einstein tie conservation to symmetries, and if so, to which? Einstein used an identity from his assumed linear coordinate covariance x'= Mx to relate it to the canonical tensor. Usually he avoided using matter Euler-Lagrange equations and so was not well positioned to use or reinvent the Herglotz-Mie-Born understanding that the canonical tensor was conserved due to translation symmetries, a result with roots in Lagrange, Hamilton and Jacobi. Whereas Mie and Born were concerned about the canonical tensor's asymmetry, Einstein did not need to worry because his Entwurf Lagrangian is modeled not so much on Maxwell's theory as on a scalar theory. As a result, it also has 3 ghosts, failing a 1920s-30s a priori particle physics stability test with antecedents in Lagrange's and Dirichlet's stability work. This critique of the Entwurf theory can be compared with Einstein's 1915 critique of his Entwurf theory for not admitting rotating coordinates and not getting Mercury's perihelion right. Particle physics also can be useful in the historiography of gravity and space-time. This topic can be a useful case study in the history of science on recently reconsidered questions of presentism, whiggism and the like.
description: 50 pages
Hydride Vapor Phase Epitaxy of GaN on Silicon Covered by Nanostructures
Creators: name: Jahn, U.
name: Musolino, M.
name: Lähnemann, J.
name: Dogan, P.
name: Garrido, S. Fernández
name: Wang, J. F.
name: Xu, K.
name: Cai, D.
name: Bian, L. F.
name: Gong, X. J.
name: Yang, H.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Several ten $μ$m GaN have been deposited on a silicon substrate using a two-step hydride vapor phase epitaxy (HVPE) process. The substrates have been covered by AlN layers and GaN nanostructures grown by plasma-assisted molecular-beam epitaxy. During the first low-temperature (low-T) HVPE step, stacking faults (SF) form, which show distinct luminescence lines and stripe-like features in cathodoluminescence images of the cross-section of the layers. These cathodoluminescence features allow for an insight into the growth process. During a second high-temperature (high-T) step, the SFs disappear, and the luminescence of this part of the GaN layer is dominated by the donor-bound exciton. For templates consisting of both a thin AlN buffer and GaN nanostructures, a silicon incorporation into the GaN grown by HVPE is not observed. Moreover, the growth mode of the (high-T) HVPE step depends on the specific structure of the AlN/GaN template, where in a first case, the epitaxy is dominated by the formation of slowly growing facets, while in a second case, the epitaxy proceeds directly along the c-axis.
description: 19 pages, 11 figures
Influence of Abrasive Shape and Size Distribution on the Wire Sawing Process
Creators: name: Anspach, O.
name: Hurka, B.
name: Zeh, J.
name: Schulze, F.-W.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Wafer-based Silicon Solar Cells and Materials Technology
Silicon Feedstock, Crystallisation and Wafering

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 1041-1046
description: Slots were cut into multicrystalline silicon using a standard industrial wire saw with three isolated
windings. In this work slurries containing silicon carbide particles with extreme shape and size distributions were
chosen to investigate not only the wire sawing conditions but also its resulting slots. The shape and the size
distribution of the abrasive used in the wire sawing process play an important role in the slot width at the wire entry
side on one hand and in the total slot width variation on the other hand. Furthermore, the approach of a classification
of cutting particles along the slot was pursued. Larger particles cut at the wire entry while smaller particles cut at the
wire exit side. Surface roughness measurements at 42 wafers underline this approach.
Upconversion to Enhance Silicon Solar Cell Efficiency - Detailed Experimental Analysis with Both Coherent Monochromatic Irradiation and White Light Illumination
Creators: name: Goldschmidt, J.C.
name: Fischer, S.
name: Löper, P.
name: Krämer, K.W.
name: Biner, D.
name: Hermle, M.
name: Glunz, S.W.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Advanced Photovoltaics: New Concepts and Ultra-high Efficiency
New Materials, Cells and Modules

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 229-233
description: Upconversion (UC) of sub-band-gap photons is a promising approach to increase solar cell
efficiencies, because it makes these sub-band-gap photons useful as well. We investigate the application of
-NaYF4:20% Er3+ to silicon solar cells. We determine the external quantum efficiency of an UC silicon solar cell,
both under monochromatic excitation and under white light illumination. We demonstrate that an UC silicon solar
cell responds under white light with an average UC efficiency of 1.07 ± 0.13% in the spectral range from 1460 to
1600 nm. Concepts are discussed how the narrow absorption range of the UC material can be overcome.
Transparent and Bifacial Sphelar® Panel
Creators: name: Imoto, S.
name: Taira, K.
name: Nakata, J.
name: Inagawa, I.
name: Ohtani, S.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Advanced Photovoltaics: New Concepts and Ultra-high Efficiency
New Materials, Cells and Modules

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 241-244
description: Laminated glass modules made of Sphelar® cells, invented and developed by Kyosemi, have distinctive
features of optional transparency, bifacial response and flexibility in the layout of the cells. In this paper, the effect of
their bifacial response on energy production is studied in outdoor conditions. A size 15 x 15 cm2 transparent glass
Sphelar® modules have been compared to similar-sized commercially-available single-crystalline flat PV (mono-facial)
modules. The investigations were performed on a rooftop in Eniwa, Hokkaido in the summer, autumn and winter of
2009-2010. Two Sphelar modules and two flat commercial PV modules are vertically mounted, and one of the two
modules faces south and the other faces west. The direct comparison of cumulated energy gained per 1Wp of each
module at standard test conditions during sunny and cloudly days has been studied. Further, analysis of energy gained
during a 1-month peirod was conducted. Sphelar® modules exhibit higher value of cumulated energy per 1Wp in any of
these cases regardless of the module configurations. The resulting relative performance is attributable to the bifacial
response of the Sphelar® modules.
Metabolite transport through glial networks stabilizes the dynamics of learning
Creators: name: Virkar, Yogesh S.
name: Shew, Woodrow L.
name: Restrepo, Juan G.
name: Ott, Edward
Publisher: name: arXiv
Year: 2016
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: Learning and memory are acquired through long-lasting changes in synapses. In the simplest models, such synaptic potentiation typically leads to runaway excitation, but in reality there must exist processes that robustly preserve overall stability of the neural system dynamics. How is this accomplished? Various approaches to this basic question have been considered. Here we propose a particularly compelling and natural mechanism for preserving stability of learning neural systems. This mechanism is based on the global processes by which metabolic resources are distributed to the neurons by glial cells. Specifically, we introduce and study a model comprised of two interacting networks: a model neural network interconnected by synapses which undergo spike-timing dependent plasticity (STDP); and a model glial network interconnected by gap junctions which diffusively transport metabolic resources among the glia and, ultimately, to neural synapses where they are consumed. Our main result is that the biophysical constraints imposed by diffusive transport of metabolic resources through the glial network can prevent runaway growth of synaptic strength, both during ongoing activity and during learning. Our findings suggest a previously unappreciated role for glial transport of metabolites in the feedback control stabilization of neural network dynamics during learning.
description: 8 pages, 5 figures
On section conditions of E7(7) exceptional field theory and superparticle in N=8 central charge superspace
Creators: name: Bandos, Igor
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We study the properties of section conditions of the E7(7) exceptional field theory from the perspective of superparticle model in N=8 D=4 superspace enlarged by additional bosonic coordinates related to the central charge of the maximal supersymmetry superalgebra. In particular, the superparticle model suggests that only a part of the section conditions corresponding to generators of SU(8) subgroup of E7(7) is independent, and we show that this part indeed suffices to obtain the (classical counterpart of the) general solution of the strong section condition.
description: 17 pages. V2. misprint corrected, references added
Two-dimensional Hybrid Simulations of Kinetic Plasma Turbulence: Current and Vorticity vs Proton Temperature
Creators: name: Franci, Luca
name: Hellinger, Petr
name: Matteini, Lorenzo
name: Verdini, Andrea
name: Landi, Simone
Publisher: name: arXiv
Year: 2016
Subjects: subject: Space Physics (physics.space-ph)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Proton temperature anisotropies between the directions parallel and perpendicular to the mean magnetic field are usually observed in the solar wind plasma. Here, we employ a high-resolution hybrid particle-in-cell simulation in order to investigate the relation between spatial properties of the proton temperature and the peaks in the current density and in the flow vorticity. Our results indicate that, although regions where the proton temperature is enhanced and temperature anisotropies are larger correspond approximately to regions where many thin current sheets form, no firm quantitative evidence supports the idea of a direct causality between the two phenomena. On the other hand, quite a clear correlation between the behavior of the proton temperature and the out-of-plane vorticity is obtained.
description: 4 pages, 2 figures, Proceedings of the Fourteenth International Solar Wind Conference
Symmetry and localization in periodic crystals: triviality of Bloch bundles with a fermionic time-reversal symmetry
Creators: name: Monaco, Domenico
name: Panati, Gianluca
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We describe some applications of group- and bundle-theoretic methods in solid state physics, showing how symmetries lead to a proof of the localization of electrons in gapped crystalline solids, as e.g. insulators and semiconductors. We shortly review the Bloch-Floquet decomposition of periodic operators, and the related concepts of Bloch frames and composite Wannier functions. We show that the latter are almost-exponentially localized if and only if there exists a smooth periodic Bloch frame, and that the obstruction to the latter condition is the triviality of a Hermitian vector bundle, called the Bloch bundle. The role of additional $\mathbb{Z}_2$-symmetries, as time-reversal and space-reflection symmetry, is discussed, showing how time-reversal symmetry implies the triviality of the Bloch bundle, both in the bosonic and in the fermionic case. Moreover, the same $\mathbb{Z}_2$-symmetry allows to define a finer notion of isomorphism and, consequently, to define new topological invariants, which agree with the indices introduced by Fu, Kane and Mele in the context of topological insulators.
description: Contribution to the proceedings of the conference "SPT2014 - Symmetry and Perturbation Theory", Cala Gonone, Italy (2014). Keywords: Periodic Schr\"{o}dinger operators, composite Wannier functions, Bloch bundle, Bloch frames, time-reversal symmetry, space-reflection symmetry, invariants of topological insulators
Piecewise Flat Curvature and Ricci Flow in Three Dimensions
Creators: name: Conboye, Rory
name: Miller, Warner A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics

description: Discrete forms of the scalar, sectional and Ricci curvatures are constructed on simplicial piecewise flat triangulations of smooth manifolds, depending directly on the simplicial structure and a choice of dual tessellation. This is done by integrating over volumes which include appropriate samplings of hinges for each type of curvature, with the integrals based on the parallel transport of vectors around hinges. Computations for triangulations of a diverse set of manifolds show these piecewise flat curvatures to converge to their smooth values. The Ricci curvature also gives a piecewise flat Ricci flow as a fractional rate of change of edge-lengths, again converging to the smooth Ricci flow for the manifolds tested.
Asteroid models from the Lowell Photometric Database
Creators: name: Durech, J.
name: Hanus, J.
name: Oszkiewicz, D.
name: Vanco, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We use the lightcurve inversion method to derive new shape models and spin states of asteroids from the sparse-in-time photometry compiled in the Lowell Photometric Database. To speed up the time-consuming process of scanning the period parameter space through the use of convex shape models, we use the distributed computing project Asteroids@home, running on the Berkeley Open Infrastructure for Network Computing (BOINC) platform. This way, the period-search interval is divided into hundreds of smaller intervals. These intervals are scanned separately by different volunteers and then joined together. We also use an alternative, faster, approach when searching the best-fit period by using a model of triaxial ellipsoid. By this, we can independently confirm periods found with convex models and also find rotation periods for some of those asteroids for which the convex-model approach gives too many solutions. From the analysis of Lowell photometric data of the first 100,000 numbered asteroids, we derived 328 new models. This almost doubles the number of available models. We tested the reliability of our results by comparing models that were derived from purely Lowell data with those based on dense lightcurves, and we found that the rate of false-positive solutions is very low. We also present updated plots of the distribution of spin obliquities and pole ecliptic longitudes that confirm previous findings about a non-uniform distribution of spin axes. However, the models reconstructed from noisy sparse data are heavily biased towards more elongated bodies with high lightcurve amplitudes.
First-Principles Momentum-Dependent Local Ansatz Wavefunction and Momentum Distribution Function Bands of Iron
Creators: name: Kakehashi, Yoshiro
name: Chandra, Sumal
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We have developed a first-principles local ansatz wavefunction approach with momentum-dependent variational parameters on the basis of the tight-binding LDA+U Hamiltonian. The theory goes beyond the first-principles Gutzwiller approach and quantitatively describes correlated electron systems. Using the theory, we find that the momentum distribution function (MDF) bands of paramagnetic bcc Fe along high-symmetry lines show a large deviation from the Fermi-Dirac function for the $d$ electrons with $e_{g}$ symmetry and yield the momentum-dependent mass enhancement factors. The calculated average mass enhancement $m^{\ast}/m = 1.65$ is consistent with low-temperature specific heat data as well as recent angle-resolved photoemission spectroscopy (ARPES) data.
description: 12 pages, 2 figures, 2 tables
Large-scale instabilities of helical flows
Creators: name: Cameron, Alexandre
name: Alexakis, Alexandros
name: Brachet, Marc-Étienne
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Large-scale hydrodynamic instabilities of periodic helical flows are investigated using $3$D Floquet numerical computations. A minimal three-modes analytical model that reproduce and explains some of the full Floquet results is derived. The growth-rate $σ$ of the most unstable modes (at small scale, low Reynolds number $Re$ and small wavenumber $q$) is found to scale differently in the presence or absence of anisotropic kinetic alpha (\AKA{}) effect. When an $AKA$ effect is present the scaling $σ\propto q\; Re\,$ predicted by the $AKA$ effect theory [U. Frisch, Z. S. She, and P. L. Sulem, Physica D: Nonlinear Phenomena 28, 382 (1987)] is recovered for $Re\ll 1$ as expected (with most of the energy of the unstable mode concentrated in the large scales). However, as $Re$ increases, the growth-rate is found to saturate and most of the energy is found at small scales. In the absence of \AKA{} effect, it is found that flows can still have large-scale instabilities, but with a negative eddy-viscosity scaling $σ\propto ν(b Re^2-1) q^2$. The instability appears only above a critical value of the Reynolds number $Re^{c}$. For values of $Re$ above a second critical value $Re^{c}_{S}$ beyond which small-scale instabilities are present, the growth-rate becomes independent of $q$ and the energy of the perturbation at large scales decreases with scale separation. A simple two-modes model is derived that well describes the behaviors of energy concentration and growth-rates of various unstable flows. In the non-linear regime (at moderate values of $Re$) and in the presence of scale separation, the forcing scale and the largest scales of the system are found to be the most dominant energetically.
description: 13 pages, 25 figures
Three blind moles: Molecular evolutionary insights on the tempo and mode of convergent eye degeneration in Notoryctes typhlops (southern marsupial mole) and two chrysochlorids (golden moles)
Creators: name: Springer, Mark
name: Gatesy, John
name: A. Emerling, Christopher
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 310410
subject: Phylogeny and comparative analysis

description: (1) alignments for protein-coding sequences (CDS) for individual phototransduction and lens/cornea genes (nexus format), (2) maximum likelihood (RAxML) gene trees with bootstrap support values, (3) maximum likelihood species trees with bootstrap values based on concatenated alignments, (4) alignments for codeml analyses (frameshift insertions removed, stop codons replaced with Ns), (5) species trees for codeml analyses, (6) example codeml control files, (7) coverage for validated autapomorphic inactivating mutations in Chrysochloris asiatica and the DNA Zoo individual of Notoryctes typhlops (Table S1), (8) mutations in taxa other than chrysochlorids and Notoryctes typhlops, and (9) an Excel calculator that was used for calculating inactivation times of eye-specific genes (Table S3). New WGS Illumina data for Amblysomus hottentotus and Notoryctes typhlops are available at NCBI BioProject PRJNA1010772.
Wisdom of the Crowd or Wisdom of a Few? An Analysis of Users' Content Generation
Creators: name: Baeza-Yates, Ricardo
name: Saez-Trumper, Diego
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computers and Society (cs.CY)
subject: Social and Information Networks (cs.SI)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: H.2.8; J.4

description: In this paper we analyze how user generated content (UGC) is created, challenging the well known {\it wisdom of crowds} concept. Although it is known that user activity in most settings follow a power law, that is, few people do a lot, while most do nothing, there are few studies that characterize well this activity. In our analysis of datasets from two different social networks, Facebook and Twitter, we find that a small percentage of active users and much less of all users represent 50\% of the UGC. We also analyze the dynamic behavior of the generation of this content to find that the set of most active users is quite stable in time. Moreover, we study the social graph, finding that those active users are highly connected among them. This implies that most of the wisdom comes from a few users, challenging the independence assumption needed to have a wisdom of crowds. We also address the content that is never seen by any people, which we call digital desert, that challenges the assumption that the content of every person should be taken in account in a collective decision. We also compare our results with Wikipedia data and we address the quality of UGC content using an Amazon dataset. At the end our results are not surprising, as the Web is a reflection of our own society, where economical or political power also is in the hands of minorities.
Constraining the size of the carrier of the $λ$5797.1 diffuse interstellar band
Creators: name: Huang, Jane
name: Oka, Takeshi
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The diffuse interstellar band (DIB) at 5797.1 Å is simulated based on three premises: (1) The carrier of the DIB is polar as concluded by T. Oka et al. from the anomalous spectrum toward Herschel 36. (2) The sharp central feature observed by P. J. Sarre's group is the $Q$-branch of a parallel band of a prolate top. (3) The radiative temperature of the environment is $T_r$=2.73 K. A $^2 Π\leftarrow$ $^2Π$ transition of a linear radical is simulated. Results depend on 10 parameters, with the rotational constant $B$ being the most critical. Comparisons of calculated spectra with observed data constrain $B$, which in turn constrains the number of heavy atoms to 5 $\leq n \leq 7$. Upper limits based on the Her 36 spectrum and lower limits based on stability against photodissociation are also discussed. The latter is based on the assumption that the DIB molecules are produced top-down from the breakdown of dust rather than bottom-up by chemical reactions. A difficulty with this limit is that J. P. Maier's laboratory has observed many molecules within this size range, some of which have been tested astronomically. Candidates are discussed in light of many prolate tops observed by the P. Thaddeus and M. C. McCarthy microwave group.
description: 17 pages, 5 figures
Projector operators in clustering
Creators: name: Bagarello, Fabio
name: Cinà, Marco
name: Gargano, Francesco
Publisher: name: arXiv
Year: 2016
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics

description: In a recent paper the notion of {\em quantum perceptron} has been introduced in connection with projection operators. Here we extend this idea, using these kind of operators to produce a {\em clustering machine}, i.e. a framework which generates different clusters from a set of input data. Also, we consider what happens when the orthonormal bases first used in the definition of the projectors are replaced by frames, and how these can be useful when trying to connect some noised signal to a given cluster.
In-Vitro Biofilm Removal Efficacy Using Water Jet in Combination with Cold Plasma Technology on Dental Titanium Implants
Creators: name: Matthes, Rutger
name: Jablonowski, Lukasz
name: Miebach, Lea
name: Pitchika, Vinay
name: Holtfreter, Birte
name: Eberhard, Christian
name: Seifert, Leo
name: Gerling, Torsten
name: Schlüter, Rabea
name: Kocher, Thomas
name: Bekeschus, Sander
Publisher: name: Basel : Molecular Diversity Preservation International
Year: 2023
Subjects: subject: biofilm
subject: cold physical plasma
subject: dental implants
subject: inflammation
subject: PBMC
subject: peri-implantitis
subject: 570
subject: 540

description: Peri-implantitis-associated inflammation can lead to bone loss and implant failure. Current decontamination measures are ineffective due to the implants’ complex geometry and rough surfaces providing niches for microbial biofilms. A modified water jet system (WaterJet) was combined with cold plasma technology (CAP) to achieve superior antimicrobial efficacy compared to cotton gauze treatment. Seven-day-old multi-species-contaminated titanium discs and implants were investigated as model systems. The efficacy of decontamination on implants was determined by rolling the implants over agar and determining colony-forming units supported by scanning electron microscopy image quantification of implant surface features. The inflammatory consequences of mono and combination treatments were investigated with peripheral blood mononuclear cell surface marker expression and chemokine and cytokine release profiles on titanium discs. In addition, titanium discs were assayed using fluorescence microscopy. Cotton gauze was inferior to WaterJet treatment according to all types of analysis. In combination with the antimicrobial effect of CAP, decontamination was improved accordingly. Mono and CAP-combined treatment on titanium surfaces alone did not unleash inflammation. Simultaneously, chemokine and cytokine release was dramatically reduced in samples that had benefited from additional antimicrobial effects through CAP. The combined treatment with WaterJet and CAP potently removed biofilm and disinfected rough titanium implant surfaces. At the same time, non-favorable rendering of the surface structure or its pro-inflammatory potential through CAP was not observed.
Efficiency of Thin Film Silicon Solar Cells with Spectral Down-Converter from Rare-Earth Ion Doped Thin Films
Creators: name: Baumgartner, K.
name: Ahrens, B.
name: Angelov, O.
name: Sendova-Vassileva, M.
name: Dimova-Malinovska, D.
name: Holländer, B.
name: Schweizer, S.
name: Carius, R.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Advanced Photovoltaics: New Concepts and Ultra-high Efficiency
New Materials, Cells and Modules

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 245-250
description: Solar cells with glass as cover or superstrate have a poor response in the blue and near UV spectral range
due to absorption in the glass, the front contact layer and the doped layer. The efficiency of these solar cells can be improved
by applying a spectral down-converter on top of the glass. Tb-doped SiO2 and Al2O3 films and a Tb-doped fluorozirconate
glass were investigated for their suitability as a down-converter. Tb absorbs light in the spectral range from
250 to 380 nm and emits it in the spectral range between 400 and 630 nm, which transmits through the first layers and is
efficiently absorbed by the active layer of the solar cell. Tb-doped SiO2 and Al2O3 films with concentrations between
0.04 and 14 at.% Tb were prepared by magnetron co-sputtering and afterwards annealed in order to enhance their conversion
efficiency. The overall highest PL intensity was found for SiO2:Tb films with 2 at.% Tb annealed at 700 °C.
These films were successfully integrated into amorphous thin film silicon solar cells and an average enhancement in the
internal quantum efficiency of 3 % in the spectral range from 300 to 380 nm was observed, with a maximum gain of
33 % at 308 nm.
Microcombs for Timekeeping and RF Photonics
Creators: name: O'Malley, Nathan Patrick
Publisher: name: Purdue University Graduate School
Year: 2023
Subjects: classificationCode: 510203
subject: Nonlinear optics and spectroscopy
classificationCode: 510204
subject: Photonics, optoelectronics and optical communications

description: Optical frequency combs have revolutionized metrology and advanced other fields such as RF photonics and astronomy. While powerful, they can be bulky, expensive, and difficult to manufacture. This tends to limit uses in real-world scenarios. Within the last decade or so, coherent frequency combs have begun to be generated in millimeter-scale, CMOS fabrication-compatible nonlinear crystals. These so-called “microcombs” have led to hopes of overcoming deployability constraints of more traditional bulk combs.One of the first applications for \textit{bulk} frequency combs after their explosion in 2000 was the optical atomic clock. It promised extreme long-term time stability better than that of the Cesium clock that currently defines the SI second. More recently, interest in a fully portable optical atomic clock has grown. Such a device could reliably keep time even without the aid of GPS references, and potentially with greater accuracy than current GPS synchronization can provide.Frequency combs have also been used to sample electrical signals more rapidly than traditional electronics can accomplish. This has been used to achieve dramatically increased effective frequency bandwidths for signal detection architectures. One can imagine how this capability would be beneficial in a portable (microcomb-driven) form: a lightweight, comb-enhanced receiver able to capture a broadband snapshot of its surrounding electromagnetic environment could be a powerful tool.Timekeeping and RF photonics are the primary applications of microcombs focused upon here. I will attempt to roughly summarize important concepts and highlight relevant work in both subjects in the Introduction. Then I will move a step closer to the hands-on lab work that has largely kept me preoccupied over the last several years and describe important or commonly-employed Methods for experiments. A collection of three journal manuscripts (two published, and the third recently submitted) will follow in the Publications chapter, highlighting some experimental results. Finally, I will conclude with a brief Outlook.
Speeding up adiabatic quantum state transfer by using dressed states
Creators: name: Baksic, Alexandre
name: Ribeiro, Hugo
name: Clerk, Aashish A.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We develop new pulse schemes to significantly speed up adiabatic state transfer protocols. Our general strategy involves adding corrections to an initial control Hamiltonian which harness non-adiabatic transitions. These corrections define a set of dressed states that the system follows exactly during the state transfer. We apply this approach to STIRAP protocols and show that a suitable choice of dressed states allows one to design fast protocols that do not require additional couplings, while simultaneously minimizing the occupancy of the "intermediate" level.
description: 4 pages, 3 figures; Supplemental: 4 pages, 3 figures
The extended uncertainty principle effects on the phase transitions of Reissner-Nordström and Schwarzschild black holes
Creators: name: Ökcü, Özgür
name: Aydiner, Ekrem
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper, we investigate the phase transitions of Reissner-Nordström (RN) and Schwarzschild black holes for the extended uncertainty principle (EUP) framework. Considering temperature $T$, charge $Q$ and electric potential $Φ$ as the state parameters, we show the van der Waals (vdW) like phase transition of RN black hole in $Q-Φ$ diagrams and find the critical points depending on EUP parameter $α$. Furthermore, we find Hawking-Page like phase transition for Schwarzschild black hole. The results imply that the black holes in asymptotically flat space have the similar phase structure with the black holes in anti-de Sitter (AdS) space.
description: 11 pages, 6 figures
Stone Chips to Silicon Chips: A Grounded Theory of Information and Communication Technology adoption in Australian Indigenous households rural, urban and remote.
Creators: name: Radoll, Peter John
Publisher: name: The Australian National University
Year: 2010
Subjects: Aboriginal and Torres Strait Islander
Indigenous
Aboriginal
Torres Strait Islander
Remote
Rural
Urban
Information Technology
Information and Communication Technology
ICT
IT
Diffusion
Adoption
TAM
DOI
TRA
UTAUT
Giddens
Bourdieu
Habitus
Structure
Agency

description: Information and Communication Technologies (ICTs) have become an everyday part of life. Communication networks within Australia link financial, educational, government and non-government services to Australian households. Both the 2001 and 2006 Australian Census data demonstrate that Indigenous Australians are 69% less likely to access the Internet at home than the rest of the Australian population. This study examines the factors affecting the adoption of Information and Communication Technologies in Australian Indigenous households and provides a plausible explanation as to why this gap exists. This study uses a multiple case study approach and draws on the Glaserian Grounded Theory Methodology to examine Indigenous household ICT adoption in a rural Indigenous community, an urban Indigenous community and a remote Indigenous community, to identify differences and commonalities of ICT adoption and non-adoption in diverse cultural and geographical locations across Australia. The theoretical lens draws on Pierre Bourdieu's theory of habitus to develop a practice perspective of household ICT adoption established through the habitus concepts of structures and agency or society and individual. The research establishes the existence of the Indigenous substantive field and postulates that new practices are formed with the intersection of the Indigenous field and external fields. Through the development of substantive fields this thesis develops a theoretical framework of Indigenous household ICT adoption. The findings suggest that a single model of ICT adoption can be applied to all Indigenous communities across Australia.The results could have considerable practical and policy significance.
Plasma Cluster Processing for Advanced Solar Cell Manufacturing
Creators: name: Rentsch, J.
name: Seiffe, J.
name: Walter, F.
name: Hofmann, M.
name: Weiss, L.
name: Gautero, L.
name: Decker, D.
name: Schlemm, H.
name: Preu, R.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Mono- and Multicrystalline Silicon Cells and Materials, Processing Technology of

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 1188-1192
description: The industrial fabrication of high-efficiency structures with passivated emitter and rear (PERC) solar cell structures affords the implementation of subsequent etching and deposition processes on industrial equipment with high wafer throughput. Such process sequences can be realized in the future within plasma cluster tools without breaking the vacuum. A newly developed industrial inline plasma system from Roth&Rau for etching and deposition (MAiA) is presented. Within this study, different fields of application of plasma cluster tools for standard as well as high efficiency processing are discussed. First realizations of plasma process clustering for PSG removal, cleaning and AR coating, for passivation stack deposition as well as for surface conditioning and passivation are demonstrated and the results are discussed.
Decay dynamics of the unbound $^{25}$O and $^{26}$O nuclei
Creators: name: Hagino, K.
name: Sagawa, H.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We study the ground and excited resonance states of $^{26}$O with a three-body model of $^{24}$O+n+n taking into account the coupling to the continuum. To this end, we use the new experimental data for the invariant mass spectroscopy of the unbound $^{25}$O and $^{26}$O nuclei, and present an update of three-body model calculations for the two-neutron decay of the $^{26}$O nucleus. With the new model inputs determined with the ground state decay of $^{26}$O, we discuss the di-neurtron correlations and a halo nature of this nucleus, as well as the structure of the excited states. For the energy of the 2$^+$ state, we achieve an excellent agreement with the experimental data with this calculation. We show that the 2$^+$ state consists predominantly of the $(d_{3/2})^2$ configuration, for which the pairing interaction between the valence neutrons slightly decreases its energy from the unperturbed one. We also discuss the structure of excited 0$^+$ states of the $^{26}$O nucleus. In particular, we show the existence of an excited 0$^+$ state at 3.38 MeV, which is mainly composed of the $(f_{7/2})^2$ configuration.
description: 12 pages, 13 figures. To appear in Phys. Rev. C
New Active Galactic Nuclei Detected by the ART-XC and eROSITA Telescopes Onboard the SRG Observatory during an All-Sky X-ray Survey
Creators: name: Uskov, Grigory
name: Zaznobin, Igor
name: Sazonov, Sergey
name: Semena, Andrey
name: Gilfanov, Marat
name: Burenin, Rodion
name: Eselevich, Maksim
name: Krivonos, Roman
name: Lyapin, Alexander
name: Medvedev, Pavel
name: Khorunzhev, Georgii
name: Sunyaev, Rashid
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present the results of our identification of 17 X-ray sources detected in the 4-12 keV energy range by the Mikhail Pavlinsky ART-XC telescope during the first year of the SRG all-sky survey. Three of them have been discovered by the ART-XC telescopes, while the remaining ones have already been known previously as X-ray sources, but their nature has remained unknown. We took optical spectra for nine sources located in the northern sky $δ> -20$ deg with the 1.6-m AZT-33IK telescope at the Sayan Observatory (the Institute of Solar-Terrestrial Physics, the Siberian Branch of the Russian Academy of Sciences) and the 1.5-m Russian-Turkish telescope at the TUBITAK National Observatory. For the remaining objects we have analyzed the archival optical spectra taken during the 6dF survey. All of the investigated objects have turned out to be Seyfert galaxies (eight of type 1, seven of type 2, and two of intermediate type 1.8) at redshifts up to $z\approx 0.15$. Based on data from the eROSITA and ART-XC telescopes onboard the SRG observatory, we have obtained X-ray spectra in the energy range 0.2-20 keV for eight sources. A significant intrinsic absorption ($N_H > 10^{22}$ cm$^{-2}$) has been detected in three of them, with two of them being probably strongly absorbed ($N_H \sim 10^{23}$ cm$^{-2}$). This paper is a continuation of the series of publications on the optical identification of active galactic nuclei detected by the ART-XC telescope.
description: Published in Astronomy Letters, 2022, Vol. 48, No. 2
Teacher Job Satisfaction and Retention Among Non-Muslim Teachers in Islamic Schools in Peninsular Malaysia
Creators: name: REDZAWAN, REZA HEZRIQUE BIN
Publisher: name: Monash University
Year: 2023
Subjects: Educational administration, management and leadership
Other education not elsewhere classified
Teacher education and professional development of educators

description: This research aims to understand the contributing factors toward job satisfaction and retention among non-Muslim teachers working in Islamic schools in Malaysia. This understanding has been framed within the mismatch between the non-Muslim teachers' religion or beliefs to the religion and culture in Islamic schools and the organisational system. Through individual interviews with the participants, different levels of environment (personal, organisation and socio-political) responsible in enabling or inhibiting teacher job satisfaction and retention are identified. Every individual confronts events and circumstances that happen around them differently. Teachers who experience more job satisfaction are more likely to demonstrate greater sense of internal locus of control and may decide remain to in the school and profession
Studies of Compensation Behaviour in p-Type mc-Silicon
Creators: name: Herzog, B.
name: Hahn, G.
name: Knopf, C.
name: Wambach, K.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Wafer-based Silicon Solar Cells and Materials Technology
Silicon Feedstock, Crystallisation and Wafering

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 1015-1019
description: We study the effect of different compensation levels on the electrical quality of mc-silicon ingots, on
the solar cell performance along the ingot height and on the carrier lifetime after different process steps. Therefore
three different mc-Si ingots with various compensation levels were grown (one slightly compensated, one stronger
compensated, one uncompensated reference). Wafers from selected positions over the ingot height were
characterised and processed to solar cells. The results showed no difference in the solar cell performance except for
the top region of the stronger compensated ingot, where the doping changes at about 85% ingot height from p-type to
n-type. We observed a beneficial effect of higher resistivities on the minority carrier lifetime in the stronger
compensated top region. This effect is strongly pronounced after P-gettering, due to the decreased negative impact of
segregated impurities in the top region. The beneficial effect is related to the reduced net doping, i.e. reduced
majority carrier concentration in the top region.
Conformal Structure of Quantum Wave Mechanics
Creators: name: Petti, Richard James
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences
subject: 35Q40, 53A30

description: This work interprets the quantum terms in a Lagrangian, and consequently of the wave equation and momentum tensor, in terms of a modified spacetime metric. Part I interprets the quantum terms in the Lagrangian of a Klein Gordon field as scalar curvature of conformal dilation covector nm that is proportional to hbar times the gradient of wave amplitude R. Part II replaces conformal dilation with a conformal factor rho that defines a modified spacetime metric gc = exp(rho) g, where g is the gravitational metric. Quantum terms appear only in metric gc and its metric connection coefficients. Metric gc preserves lengths and angles in classical physics and in the domain of the quantum field itself. gc combines concepts of quantum theory and spacetime geometry in one structure. The conformal factor can be interpreted as the limit of a distribution of inclusions and voids in a lattice that cause the metric to bulge or contract. All components of all free quantum fields satisfy the Klein Gordon equation, so this interpretation extends to all quantum fields. Measurement operations, and elements of quantum field theory are not considered.
description: 17 pages, 2 figures, 30 lines of computer algebra code, 2 Appendices
Evaluation of Power-Enhancement for Photovoltaic Modules
Creators: name: Hirose, J.
name: Takanohashi, H.
name: Ogawa, S.
name: Piliougine Rocha, M.
name: Zorrilla-Casanova, J.
name: Carretero Rubio, J.
name: Sidrach-De-Cardona, M.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Components for PV Systems
PV Modules

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 4087-4093
description: Nowadays it has received a lot of remarkable attentions that the decreasing output of Photovoltaic
(PV) modules is caused by influence of the accumulation of dust on the glass surface of PV modules. The
surface of PV modules is periodically cleaned with water in enormous PV plants. However they have some
problems which are the cost of maintenance and the lack of water to use cleaning especially at desert area.
Several proposals for decreasing dust on PV modules have been suggested. However, those durability tests have
rarely been reported. We have already developed a new hydrophilic coating and reported its fundamental
characters. In this paper, we discuss the results of outdoor exposure test during 1 year in Spain quantitatively. It
is indicated that this coating is able to enhance the performance of PV modules. The daily energy produced by
the PV modules with coating was up to 3% (1% on a yearly average) greater than that without coating. The
difference of output power between with coating and without coating depended on the accumulation of dust on
the surface of PV modules. This study shows reducing dust attraction on the surface of PV modules could be
one of significant factors to maintain output power.
Temperature Effect of Textured (Light-Trapping) Cover Glasses for Solar Modules for Reduced Voc Losses Tested Indoor and Outdoor
Creators: name: Nositschka, A.
name: Neumann, D.
name: Prast, M.-O.
name: Bonnet-Eymard, M.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Components for PV Systems
PV Modules

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 4094-4097
description: We report over a second effect of our deeply textured front glass SGGAlbarino G and SGGAlbarino P.
Due to the texture the surface is larger than of a flat glass. This surface is comparable to “cooling rips” so that the
heat exchange is higher and therefore the module temperature is up to 4 K lower than a standard module measured
indoor in a UV ageing simulator but with full AM1.5 spectrum. A second proof was done outdoor on a warm and
sunny day. Due to that delta in temperature we have measured a gain in Voc in crystalline silicon solar cell modules
of up to 1.2%. This “gain” is reducing the normal loss in Voc under operation (e.g. 58°C instead of 60°C).
With the gain in Isc of up to 2.5% under STC and 1.2%in Voc, the total power gain under STC is more than 3.5%.