cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Phosphorous Emitter Redistribution Study under Laser Doping
Creators: name: Moussi, A.
name: Bendimered, M.K.
name: Mahiou, L.
name: Bourai, K.
name: Noukaz, S.
name: Beggar, R.
Publisher: name: WIP
Year: 2012
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Manufacturing Issues and Processing

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 1117-1119
description: Emitters of 60 Ω/ have been laser treated to obtain deeper junction on multi-crystalline silicon. Two
parameters, speed and power, have been used by the YLia M20 laser to treat areas of 1cm². The patterning is made by
a laser pulse with a spot of 10 microns scanning the surface at different speeds (2 to 20 mm/sec) and power (0.5 and
20 Watt). We used two kinds of surface emitters a: as diffused and with phosphosilicate glass PSG and b: with a thin
layer of phosphoric acid H3PO4 after PSG removal. We analyzed three parameters of the emitters: sheet resistance,
profile concentration and surface morphology for both surfaces.
The results show sheet resistance decrease from 60 to 18 (Ω/) for surface with PSG. The figure indicates that the
higher the power the lower the sheet resistance and also the lower the laser speed pattern the lower the sheet
resistance.
The emitter profile measured by Electrochemical Capacitance-Voltage Profiling (ECV) technique of as diffused and
after laser treatment presents a very light enhancement of junction depth from 0.303 μm to 0.318 μm. In contrast, the
surface concentration increases drastically from 3.98x1019 to 6.6x1020 cm-3.
SEM observation show that a pattern is formed on the laser doped surface. This pattern is more pronounced when the
power is high and/or the speed is low. After treatment at P=7W a 30 μm large channels parallel to the laser scan are
created on the surface.
This study has shown that the laser treatment can redistribute the inactive phosphorous present in the PSG layer. With
the latter we obtain a more uniform emitter sheet resistance than H3PO4 one. With this we can proceed to realize
selective emitters for solar cell application.
Particle Swarms Reformulated towards a Unified and Flexible Framework
Creators: name: Innocente, Mauro Sebastián
Publisher: name: arXiv
Year: 2021
Subjects: subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: The Particle Swarm Optimisation (PSO) algorithm has undergone countless modifications and adaptations since its original formulation in 1995. Some of these have become mainstream whereas many others have not been adopted and faded away. Thus, a myriad of alternative formulations have been proposed to the extent that the question arises as to what the basic features of an algorithm must be to belong in the PSO family. The aim of this paper is to establish what defines a PSO algorithm and to attempt to formulate it in such a way that it encompasses many existing variants. Therefore, different versions of the method may be posed as settings within the proposed unified framework. In addition, the proposed formulation generalises, decouples and incorporates features to the method providing more flexibility to the behaviour of each particle. The closed forms of the trajectory difference equation are obtained, different types of behaviour are identified, stochasticity is decoupled, and traditionally global features such as sociometries and constraint-handling are re-defined as particle's attributes.
description: Preprint The final authenticated article will be published by Springer-Nature in the Lecture Notes in Computer Science series. This research will be presented at the Twelfth International Conference on Swarm Intelligence (ICSI 2021)
Advanced Production Challenges for Automated Ultra-Thin Wafer Handling
Creators: name: Giesen, T.
name: Wertz, R.
name: Fischmann, C.
name: Kreck, G.
name: Govaerts, J.
name: Vaes, J.
name: Debucquoy, M.
name: Verl, A.
Publisher: name: WIP
Year: 2012
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Manufacturing Issues and Processing

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 1165-1170
description: The handling of thin wafers in today’s production lines demands high standards of the automation as
well as complex investigations with a closer look on the actual and future needs for an economic and competitive
production of solar cells. This paper describes the analysis and evaluation methods developed by the authors for ultrathin
wafers (<100 μm) which are created by a newly developed wafering technique. A short overview about the new
handling experiments within the automation test platform at the Fraunhofer Institute for Manufacturing Engineering
and Automation (IPA) is subsequently followed by detailed ultra-thin wafer handling experiments. Different
approaches were tested for the automated handling of the ultra-thin silicon foils. The difference in handling of curled
and flat substrates, caused by the newly developed wafering method, will be pointed out as well as the difficulties for
transportation with high-speed parameter settings. While looking for a reliable gripping advanced production
challenges are given due to the requirement of certain cleanliness.
Optimization of a traveling wave superconducting radiofrequency cavity for upgrading the International Linear Collider
Creators: name: Shemelin, V.
name: Padamsee, H.
name: Yakovlev, V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: FOS: Physical sciences

description: The Standing Wave (SW) TESLA niobium-based superconducting radio frequency structure is limited to an accelerating gradient of about 50 MV/m by the critical RF magnetic field. To break through this barrier, we explore the option of niobium-based traveling wave (TW) structures. Optimization of TW structures was done considering experimentally known limiting electric and magnetic fields. It is shown that a TW structure can have an accelerating gradient above 70 MeV/m that is about 1.5 times higher than contemporary standing wave structures with the same critical magnetic field. The other benefit of TW structures shown is R/Q about 2 times higher than TESLA structure that reduces the dynamic heat load by a factor of 2. A method is proposed how to make TW structures multipactor-free. Some design proposals are offered to facilitate fabrication. Further increase of the real-estate gradient (equivalent to 80 MV/m active gradient) is also possible by increasing the length of the accelerating structure because of higher group velocity and cell-to-cell coupling. Realization of this work opens paths to ILC energy upgrades beyond 1 TeV to 3 TeV in competition with CLIC. The paper will discuss corresponding opportunities and challenges.
description: 13 pages, 14 figures
Higgs-pair Production in Littlest Higgs Model with T-parity
Creators: name: Wang, Lei
name: Wang, Wenyu
name: Yang, Jin Min
name: Zhang, Huanjun
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The Higgs-pair production process at the CERN Large Hadron Collider (LHC), which will provide a way to test the Higgs boson self-coupling, may be sensitive to new physics. In the framework of the littlest Higgs model with T-parity, such Higgs-pair production can proceed through additional loop diagrams and thus the production rate can be quite different from the Standard Model (SM) prediction. Our calculations show that, due to the loop contributions of both T-even and T-odd quarks predicted in this model, the production rate can be significantly enhanced relative to the SM prediction and also can be larger than the production rate in the minimal supersymmetric model. Also, we find that the T-odd quark contributions, which were ignored in a previous study, are equally important compared with the T-even quark contributions.
description: 11 pages, 3 figs
Estimating Community Feedback Effect on Topic Choice in Social Media with Predictive Modeling
Creators: name: Adelani, David Ifeoluwa
name: Kobayashi, Ryota
name: Weber, Ingmar
name: Grabowicz, Przemyslaw A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: Social media users post content on various topics. A defining feature of social media is that other users can provide feedback -- called community feedback -- to their content in the form of comments, replies, and retweets. We hypothesize that the amount of received feedback influences the choice of topics on which a social media user posts. However, it is challenging to test this hypothesis as user heterogeneity and external confounders complicate measuring the feedback effect. Here, we investigate this hypothesis with a predictive approach based on an interpretable model of an author's decision to continue the topic of their previous post. We explore the confounding factors, including author's topic preferences and unobserved external factors such as news and social events, by optimizing the predictive accuracy. This approach enables us to identify which users are susceptible to community feedback. Overall, we find that 33\% and 14\% of active users in Reddit and Twitter, respectively, are influenced by community feedback. The model suggests that this feedback alters the probability of topic continuation up to 14\%, depending on the user and the amount of feedback.
description: Published at EPJ Data science in 2020
Self-scattering on large, porous grains in protoplanetary disks with dust settling
Creators: name: Brunngräber, Robert
name: Wolf, Sebastian
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Observations of protoplanetary disks (PPDs) at sub-mm wavelengths suggest that polarisation is caused by scattering of thermal radiation. Most of the dust models that are used to explain these observations have major drawbacks: They either use much smaller grains than expected from dust evolution models, or result in lower polarisations than observed. We investigate the effect of dust grain porosity on the polarisation due to scattering at sub-mm wavelengths arising from grains of up to mm sizes, as they are expected to be present in the midplane of PPDs. Using the effective medium theory, we calculated the optical properties of porous dust and used them to predict the behaviour of the scattering polarisation. Subsequently, radiative transfer simulations for PPDs with porous dust were performed to analyse the additional effect of the optical depth structure, and thus the effect of multiple scattering events and inhomogeneous temperature distributions on the polarisation. We find that porous dust with moderate filling factors of about 10\% increase the polarisation compared to compact grains. For higher grain porosities, that is, grains with a filling factor of 1\% or lower, the extinction opacity decreases, as does the optical depth of a disk with constant mass. Consequently, the unpolarised direct radiation dominates the scattered flux, and the polarisation drops rapidly. Even though the simulated polarisation is higher than in the case of compact grains, it is still below the typical observed values for face-on disks. However, the polarisation can be increased when crucial model assumptions derived from disk and dust evolution theories, for instance, dust settling and mm-sized dust grains, are dropped. In the case of inclined disks, however, our reference model is able to achieve polarisation degrees of about 1\%, and using higher disk masses, even higher than this.
description: Accepted by A&A
The Repetition Property for Sequences on Tori Generated by Polynomials or Skew-Shifts
Creators: name: Boshernitzan, Michael
name: Damanik, David
Publisher: name: arXiv
Year: 2007
Subjects: subject: Dynamical Systems (math.DS)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics

description: The repetition property of a sequence in a metric space, a notion introduced by us in an earlier paper, is of importance in the spectral analysis of ergodic Schrödinger operators. It may be used to exclude eigenvalues for such operators. In this paper we study the question of when a sequence on a torus that is generated by a polynomial or a skew-shift has the repetition property. This provides classes of ergodic Schrödinger operators with potentials generated by skew-shifts on tori that have, contrary to earlier belief, no eigenvalues.
description: 10 pages
The dilepton probe in heavy-ion collisions
Creators: name: van Hees, H.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Dileptons provide direct observables of the electromagnetic current-current correlator in the hot and/or dense medium formed in heavy-ion collisions. In this article an overview is given about the status of the theoretical understanding of the dilepton phenomenology in heavy-ion collisions from studies of the in-medium properties of hadrons and partons within many-body theory and about connections to fundamental questions concerning the chiral phase transition.
description: 8 pages, 2 figures, contribution to the proceedings of the 20th International Conference on Ultra-Relativistic Nucleus Nucleus Collisions (Quark Matter 2008); v2: Version accepted for publication at J. Phys. G
Vacuumless kinks systems from vacuum ones, an example
Creators: name: Dutra, Alvaro de Souza
name: Faria, A. C. Amaro de
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Some years ago, Cho and Vilenkin, introduced a model which presents topological solutions, despite not having degenerate vacua as is usually expected. Here we present a new model with topological defects, connecting degenerate vacua but which in a certain limit recovers precisely the one proposed originally by Cho and Vilenkin. In other words, we found a kind of parent model for the so called vacuumless model. Then the idea is extended to a model recently introduced by Bazeia et al. Finally, we trace some comments the case of the Liouville model.
description: 11 pages, 4 figures
Does Planck mass run on the cosmological horizon scale?
Creators: name: Robbers, Georg
name: Afshordi, Niayesh
name: Doran, Michael
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Einstein's theory of general relativity, which contains a universal value of the Planck mass, has been so far successfully invoked to explain gravitational dynamics from sub-millimeter scales to the scale of the cosmological horizon. However, one may envisage that in alternative theories of gravity, the effective value of the Planck mass (or Newton's constant), which quantifies the coupling of matter to metric perturbations, can run on the cosmological horizon scale. In this letter, we study the consequences of a glitch in the Planck mass from sub-horizon to super-horizon scales. We first give three examples of models that naturally exhibit this feature, and then show that current cosmological observations severely constrain this glitch to less than 1.2%. This is the strongest constraint to date, on natural (i.e. non-fine-tuned) deviations from Einstein gravity on the cosmological horizon scale.
description: 5 pages, 1 figure
THE DIFFERENCE IN TERMS OF SEX IN TECHNOLOGY USE AND LANGUAGE LEARNING
Creators: name: Muico, Earl Jones
Publisher: name: figshare
Year: 2022
Subjects: subject: 200302 English Language
subject: FOS: Languages and literature

description: The study sought to determine level of Technology Use and the Language Learning of the AB-English students of UM Tagum College. The study used the data from level of language learning as well as the level of Utilization of technology in language learning. The data was analyzed whether there is difference on the level language learning when grouped according to gender and more specifically whether there is a significant relationship between the technology use and language learning of the Ab-English Students. The study used a descriptive correlational design that involved 60 students from the AB-English Program. The researchers devised a researcher-made questionnaire for the Utilization of Technology and an adapted and modified test questionnaire for Language Learning. The study used Mean, T-test, and Pearson-r for the statistical treatment. The results of the study revealed that the overall level for utilization of technology is very high and the overall level of language learning is high. However, there was no significant difference in language learning when grouped according to gender. Further, it was also found that there is no significant relationship between technology use and language learning. Based on the results, the researchers recommend for teachers to choose technology-based approaches critically in teaching language.
An Approach in the Utilization of the Per-Unit-Method in PV Megawatt-Class Utility Scale Systems: Comparison between Simulations and Measurements
Creators: name: Méndez-Hernández, Y.
name: Müggenburg, E.
name: Lynass, M.
name: Gómez Padrón, M.G.
name: Stern, O.
name: Hartung, M.
name: Bernal Serra, E.
name: Zettl, M.
name: Heller, C.
name: Bucher, M.
name: Schmidt, M.
name: El-Barbari, S.
name: Stromberger, J.
name: Mayer, O.
Publisher: name: WIP
Year: 2012
Subjects: PV Systems
Large PV Power Plants and Distributed PV: System Aspects and Grid Connection

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 3997-4001
description: With the increasing penetration of megawatt photovoltaic plants (PV Utility Scale) at distribution and
transmission level in electric power systems, the utilization of tools and methods for their modeling plays an
important role in the reliable operation of electric grids. In these regards the per-unit method (PU-method) offers a
promising option of simplification in calculations, such as load flow, short-circuit, stability, harmonics, etc. This
publication is an attempt to standardize the electric parameters and propose the references for the modeling of
megawatt PV plants. The measurements performed at a real PV plant will be analyzed and compared with the results
of the simulations in order to reflect the fidelity of the results. As a conclusion, the PU-method allows a simplified
presentation and quick information of the electric parameters in megawatt range PV plants and reduces complexity in
their operation.
Kinetics of beta-carotene accumulatin and retention in exfoliated cells from supplemented individuals
Creators: name: Cameron, Linda Margaret
Publisher: name: University of British Columbia
Year: 2010

description: Human cancer intervention trials have found beta-carotene to be effective in reducing the genotoxic damage to oral mucosa cells that resulted from carcinogen exposure. Design of intervention trials using beta-carotene has so far lacked an important component, knowledge of the accumulation and retention of this putative chemopreventive agent in the tissues of interest. The factors of dose, timing of administration of supplements, and the effects of confounding factors are aspects of trial design that demand an understanding of the kinetics of beta-carotene in human tissues. The oral mucosa is the only tissue so far that has been investigated for beta-carotene levels in exfoliated cells. A non-invasive technique for sample collection, suitable for sampling populations, in combination with a highly sensitive assay for beta-carotene, is appropriate for use with other epithelial sites that may be targets of intervention trials; one such site is the uro-genital tract. This thesis describes preliminary investigations towards design of an intervention trial with beta-carotene directed at cells of the uro-genital tract. Initial studies established the feasibility of measuring beta-carotene in uro-genital tract cells, and verified that the technical variation in the assays of oral mucosa cells and urogenital tract cells was less than the variation between individuals in the study population. A short-term (four-day) supplementation trial compared the effects of three doses of beta-carotene, given orally, on the beta-carotene content of exfoliated oral mucosa cells. Ingestion of 360 mg, 180 mg, and 90 mg of beta-carotene resulted in a rise in median cell beta-carotene levels from 1.8, 1.5, and 1.0 ng/10⁶ cells to 9.2, 7.7, and 3.9 ng/10⁶ cells, respectively, one week after the loading. Due to variation in response, the effects of the three doses were not significantly different from one another. The elevation in beta-carotene levels persisted for 2 weeks after the loading. The kinetic profile of the accumulation and retention of beta-carotene in uro-genital tract cells differed markedly from that of oral mucosa cells, in individuals who were supplemented for four weeks with a field trial dosage of beta-carotene. Median beta-carotene levels in uro-genital tract cells of beta-carotene-supplemented individuals increased from 0.6 ng/10⁶ cells to 2.8 ng/10⁶ cells during the loading period, a level significantly higher than that of the placebo group, but declined immediately after the end of the loading to levels that were not significantly elevated. In contrast, beta-carotene in exfoliated oral mucosa cells remained at significantly elevated levels until four weeks after the cessation of loading. Tissue-specific features of beta-carotene accumulation in response to its administration need to be taken into consideration when designing intervention strategies that use beta-carotene.
The Effect of Spectral Mismatch on the Annual Energy Output of CdTe-, CIGS- and Si-Based Photovoltaic Modules
Creators: name: Boose, Y.
name: Heller, C.
name: Stern, O.
name: Lynass, M.
Publisher: name: WIP
Year: 2012
Subjects: Components for PV Systems
PV Modules

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 3194-3198
description: The mismatch between short-circuit current to irradiance ratio of three thin-film modules under real sky
spectra and the same ratio under an AM1.5 STC spectrum was investigated by simulations in addition to outdoor
measurements. The simulations were based on the NREL SMARTS2 radiative transfer model and were conducted for
commercial cadmium telluride (CdTe), CuIn(Ga)Se2 (CIGS) and crystalline silicon (c-Si) modules. In the field
experiments which were carried out in Garching near Munich, Germany, the behavior of the characteristic curves of a
CdTe and a CIGS module was analyzed over a time period of two months in spring 2012. The very high temporal
resolution of 1-2 seconds of the outdoor experiments allowed for dissolving the effect of small or fast moving clouds.
The spectral mismatch ranges on average between -8 % and +4 % in both, simulation and outdoor data. Among the three
investigated technologies CdTe proved to be the most sensitive one to solar spectral variations. Spectrally resolved
devices are usually not available in the field. A Si reference cell and a thermopile-based pyranometer were therefore
compared in terms of applicability for correction and monitoring of spectral effects on thin-film modules applying the
simulation method. It was found that due to its similar spectral response the Si cell is more applicable for correction of
spectral effects whereas a pyranometer is better for accurate monitoring of variations in the spectrum because of its broad
spectral response.
Revising Social & Environmental Justice Open Educational Resources through UDL and Accessibility Lenses
Creators: name: Basham, Tamara
name: Catano, Laura
name: Gardner, Stephanie
name: Godwin, Amee
name: Groh, David
name: Hutto, Rachel
name: Marsteller, Pat
name: Mulcahy, Mary
name: Orndorf, Hayley
name: Phillips, Molly
name: Villar, Beatriz
Publisher: name: QUBES Educational Resources
Year: 2021

description: The Revising Social & Environmental Justice Open Educational Resources through UDL and Accessibility Lenses Working Group met during the Fall 2021 semester as part of the BIOME Institute. This resource includes a lightning talk describing our activities and plans going forward.
Evaluating PV System Performance of Four Different Module Technologies
Creators: name: Perraki, V.
name: Tsolakos, G.
Publisher: name: WIP
Year: 2012
Subjects: PV Systems
Off-grid Applications

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 4236-4239
description: The aim of this article is to show the results of an outdoor exposure tests in which the performance of
four different PV technologies have been studied. One year of experimental measurements have been realized for the
modules under investigation using a system which records current- voltage (I-V) characteristics of the modules as well
as meteorological parameters such as irradiance, ambient and cell temperature at regular intervals. The data presented
here pertain to the measured energy yield and PR values of these modules and the comparison among the experimental
and simulated results of energy yield for the tested modules.
A simulated result of their efficiency indicates higher values in the winter than during summer except in the case of a-
Si module which has almost identical behavior throughout the year. A test at various angles investigates that the
maximum year-round energy production and solar radiation on the PV plane, corresponds to tilt angles of about 20
degrees in summer and 50 degrees in winter.
A Novel Technique for Studying the Z Boson Transverse Momentum Distribution at Hadron Colliders
Creators: name: Vesterinen, M.
name: Wyatt, T. R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We present a novel method for studying the shape of the Z boson transverse momentum distribution, Q_T, at hadron colliders in ppbar/pp -> Z/gamma* -> l^+l^-. The Q_T is decomposed into two orthogonal components; one transverse and the other parallel to the di-lepton thrust axis. We show that the transverse component is almost insensitive to the momentum resolution of the individual leptons and is thus more precisely determined on an event-by-event basis than the Q_T. Furthermore, we demonstrate that a measurement of the distribution of this transverse component is substantially less sensitive to the dominant experimental systematics (resolution unfolding and Q_T dependence of event selection efficiencies) reported in previous measurements of the Q_T distribution.
description: 13 pages, 12 figures
Low Star Formation Rates for z=1 Early-Type Galaxies in the Very Deep GOODS-MIPS Imaging: Implications for their Optical/Near-Infrared Spectral Energy Distributions
Creators: name: van der Wel, A.
name: Franx, M.
name: Illingworth, G. D.
name: van Dokkum, P. G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We measure the obscured star formation in z~1 early-type galaxies. This constrains the influence of star formation on their optical/near-IR colors, which, we found, are redder than predicted by the model by Bruzual & Charlot (2003). From deep ACS imaging we construct a sample of 95 morphologically selected early-type galaxies in the HDF-N and CDF-S with spectroscopic redshifts in the range 0.852 sigma detections (~25 muJy} is 17(-4,+9)%. Of the 15 galaxies with significant detections at least six have an AGN. Stacking the MIPS images of the galaxies without significant detections and adding the detected galaxies without AGN we find an upper limit on the mean star formation rate (SFR) of 5.2+/-3.0 Msol yr^-1, and on the mean specific SFR of 4.6+/-2.2 * 10^-11 yr^-1. Under the assumption that the average SFR will decline at the same rate as the cosmic average, the in situ growth in stellar mass of the early-type galaxy population is less than 14+/-7% between z=1 and the present. We show that the typically low IR luminosity and SFR imply that the effect of obscured star formation (or AGN) on their rest-frame optical/near-IR SEDs is negligible for ~90% of the galaxies in our sample. Hence, their optical/near-IR colors are most likely dominated by evolved stellar populations. This implies that the colors predicted by the Bruzual & Charlot (2003) model for stellar populations with ages similar to those of z~1 early-type galaxies (~1-3 Gyr) are most likely too blue, and that stellar masses of evolved, high-redshift galaxies can be overestimated by up to a factor of ~2.
description: Accepted for publication in ApJ, 8 pages, 4 figures, 1 table
Flux locking a superfluid interferometer
Creators: name: Sato, Yuki
name: Joshi, Aditya
name: Packard, Richard
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We demonstrate a flux locking technique using injected heat current to linearize the output of a superfluid helium-4 interferometer. A rotation flux through the interferometer loop produces a shift in the phase of the superfluid order parameter. This shift is nullified via negative feedback by a phase-shift caused by the injected heat current. The feedback signal is then a linear function of rotation flux.
description: 3 pages, 2 figures
High mass star formation in the IRAS 17233-3606 region: a new nearby and bright hot core in the southern sky
Creators: name: Leurini, S.
name: Hieret, C.
name: Thorwirth, S.
name: Wyrowski, F.
name: Schilke, P.
name: Menten, K. M.
name: Guesten, R.
name: Zapata, L.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present molecular line observations of the massive star forming region IRAS 17233-3606 aimed at studying the molecular core associated with the source. The observations were made using the Atacama Pathfinder Experiment telescope in the CO (3-2) and HCO^+ (4-3) transitions, and in the CH_3OH (6_K-5_K), (7_K-6_K) and CH_3CN (16_K-15_K) bands. For the CO(3-2) and HCO^+ (4-3) transitions, we obtained maps with a size of 70''\times 70''. The typical angular resolution of the data is ~18''. Our observations reveal an exceptionally rich molecular spectrum, a signpost of hot core activity. Comparisons with two other prominent southern hot cores were made through observations in the same frequency setups. We also detected a bipolar outflow in CO (3-2) and HCO^+ (4-3) lines. Modelling reveals a hot core of size ~3'' and a temperature of 150 K in the IRAS17233-3606 region. The parameters of the molecular outflow are derived through the analysis of the CO (3-2) emission, and are typical of outflows driven by high-mass young stellar objects.
description: 9 pages, 10 figures (plus 8 figures as Online material), accepted by A&A
Diagnostics of stellar flares from X-ray observations: from the decay to the rise phase
Creators: name: Reale, F.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The diagnostics of stellar flaring coronal loops have been so far largely based on the analysis of the decay phase. We derive new diagnostics from the analysis of the rise and peak phase of stellar flares. We release the assumption of full equilibrium of the flaring loop at the flare peak, according to the frequently observed delay between the temperature and the density maximum. From scaling laws and hydrodynamic simulations we derive diagnostic formulas as a function of observable quantities and times. We obtain a diagnostic toolset related to the rise phase, including the loop length, density and aspect ratio. We discuss the limitations of this approach and find that the assumption of loop equilibrium in the analysis of the decay leads to a moderate overestimate of the loop length. A few relevant applications to previously analyzed stellar flares are shown. The analysis of the flare rise and peak phase complements and completes the analysis of the decay phase.
description: 10 pages, 7 figures, accepted on refereed journal
Braneworld dynamics in Einstein-Gauss-Bonnet gravity
Creators: name: Maeda, Hideki
name: Sahni, Varun
name: Shtanov, Yuri
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We discuss the cosmological evolution of a braneworld in five dimensional Gauss-Bonnet gravity. Our discussion allows the fifth (bulk) dimension to be space-like as well as time-like. The resulting equations of motion have the form of a cubic equation in the (H^2,(ρ+σ)^2) plane, where σis the brane tension and ρis the matter density. This allows us to conduct a comprehensive pictorial analysis of cosmological evolution for the Gauss-Bonnet brane. The many interesting properties of this braneworld include the possibility of accelerated expansion at late times. For a finite region in parameter space the accelerated expansion can be phantom-like so that w < -1. At late times, this branch approaches de Sitter space (w = -1) and avoids the big-rip singularities usually present in phantom models. For a time-like extra dimension the Gauss-Bonnet brane can bounce and avoid the initial singularity.
description: 23 pages, 7 figures; revised version matches the published Erratum. Two figures altered, main results unchanged
The Successful Prediction of the Extrasolar Planet HD 74156 d
Creators: name: Barnes, Rory
name: Gozdziewski, Krzysztof
name: Raymond, Sean N.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Most of the first-discovered extrasolar multi-planet systems were found to lie close to dynamically unstable configurations. However a few observed multi-planet systems (e.g. HD 74156) did not show this trait. Those systems could share this property if they contain an additional planet in between those that are known. Previous investigations identified the properties of hypothetical planets that would place these systems near instability. The hypothetical planet in HD 74156 was expected to have a mass about equal to that of Saturn, a semi-major axis between 0.9 and 1.4 AU, and an eccentricity less than 0.2. HD 74156 d, a planet with a mass of 1.3 Saturn masses at 1.04 AU with an eccentricity of 0.25, was recently announced. We have reanalyzed all published data on this system in order to place tighter constraints on the properties of the new planet. We find two possible orbits for this planet, one close to that already identified and another (with a slightly better fit to the data) at ~0.89 AU. We also review the current status of other planet predictions, discuss the observed single planet systems, and suggest other systems which may contain planets in between those that are already known. The confirmation of the existence of HD 74156 d suggests that planet formation is an efficient process, and planetary systems should typically contain many planets.
description: 11 pages, 2 figures, 1 table. Accepted for publication in ApJ Letters. A version with full resolution figures is available at http://www.lpl.arizona.edu/~rory/publications/bgr08.pdf
A new algorithm for modelling photoionising radiation in smoothed particle hydrodynamics
Creators: name: Dale, James
name: Ercolano, Barbara
name: Clarke, Cathie
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a new fast algorithm which allows the simulation of ionising radiation emitted from point sources to be included in high-resolution three-dimensional smoothed particle hydrodynamics simulations of star cluster formation. We employ a Strömgren volume technique in which we use the densities of particles near the line-of-sight between the source and a given target particle to locate the ionisation front in the direction of the target. Along with one--dimensional tests, we present fully three--dimensional comparisons of our code with the three--dimensional Monte-Carlo radiative transfer code, MOCASSIN, and show that we achieve good agreement, even in the case of highly complex density fields.
description: 10 pages, 7 figures, submitted to MNRAS
How well do we know the Unitarity Triangle? An experimental review
Creators: name: Sciolla, Gabriella
name: Collaboration, representing the Babar
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: In the past 10 years our knowledge of the parameters rho and eta of the Cabibbo-Kobayashi-Maskawa matrix has improved substantially. This article reviews the measurements that contributed to this advance, and discusses their implication in terms of understanding CP violation in the Standard Model and beyond.
description: 9 pages, 8 postscript figures, contributed to the Proceedings of Kaon 2007 (KAON International Conference), May 21-25 2007, Laboratori Nazionali di Frascati dell'INFN, Rome, Italy
CMS search plans and sensitivity to new physics with dijets
Creators: name: Bhatti, Anwar
name: Bollen, Benjamin
name: Cardaci, Marco
name: Chlebana, Frank
name: Esen, Selda
name: Harris, Robert M.
name: Jha, Manoj K.
name: Kousouris, Konstantinos
name: Mason, David
name: Zielinski, Marek
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: CMS will use dijets to search for physics beyond the standard model during early LHC running. The inclusive jet cross section as a function of jet transverse momentum, with 10 inverse picobarns of integrated luminosity, is sensitive to contact interactions beyond the reach of the Tevatron. The dijet mass distribution will be used to search for dijet resonances coming from new particles, for example an excited quark. Additional sensitivity to the existence of contact interactions or dijet resonances can be obtained by comparing dijet rates in two distinct pseudorapidity regions.
description: 10 pages, 4 figures, accepted for publication in J. Phys. G: Nucl. Part. Phys
The growth of luminous red galaxies by merging
Creators: name: Masjedi, Morad
name: Hogg, David W.
name: Blanton, Michael R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the role of major and minor mergers in the mass growth of luminous red galaxies. We present small-scale ($0.01
description: submitted to ApJ
Coherent states engineering with linear optics: Possible and impossible tasks
Creators: name: He, Bing
name: Bergou, János A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The general transformation of the product of coherent states $\prod_{i=1}^N|α_i>$ to the output state $\prod_{i=1}^M|β_i>$ ($N=M$ or $N\neq M$), which is realizable with linear optical circuit, is characterized with a linear map from the vector $(α^{\ast}_1,...,α^{\ast}_N)$ to $(β^{\ast}_1,...,β^{\ast}_M)$. A correspondence between the transformations of a product of coherent states and those of a single photon state is established with such linear maps. It is convenient to apply this linear transformation method to design any linear optical scheme working with coherent states. The examples include message encoding and quantum database searching. The limitation of manipulating entangled coherent states with linear optics is also discussed.
description: 6 pages, 2 figures
An Overview of Patent Application Data in the Field of Photovoltaics
Creators: name: Visentin, A.
name: Boero, M.
name: Königstein, C.
Publisher: name: WIP
Year: 2012
Subjects: PV - a Major Electricity Source
PV Globalisation, Policies and Administrative Barriers

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 4749-4752
description: The present study is aimed at giving an update on patent activities in the photovoltaic (PV) field covering the past 40 years. In this study, the number of patent applications published during this time period, per year and for the whole period, in several of the most relevant solar cell technologies are analysed. Patent filing figures are shown for the different types of solar cells including polymer and organic solar cells, dye sensitized solar cells, and inorganic solar cells. Further data are presented showing the origin of patent
applications for inorganic and organic solar cells as well as for different decades.
Negative density of states: screening, Einstein relation, and negative diffusion
Creators: name: Efros, A. L.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: In strongly interacting electron systems with low density and at low temperature the thermodynamic density of states is negative. It creates difficulties with understanding of the Einstein relation between conductivity and diffusion coefficient. Using the expression for electrochemical potential that takes into account the long range part of the Coulomb interaction it is shown that at negative density of states Einstein relation gives a negative sign of the diffusion coefficient D, but under this condition there is no thermodynamic limitation on the sign of D. It happens because the unipolar relaxation of inhomogeneous electron density is not described by the diffusion equation. The relaxation goes much faster due to electric forces caused by electron density and by neutralizing background. Diffusion coefficient is irrelevant in this case and it is not necessarily positive because process of diffusion does not contribute to the positive production of entropy. In the case of bipolar diffusion negative D results in a global absolute instability that leads to formation of neutral excitons. Graphene is considered as an example of a system, where the density relaxation is expected to be due to electric force rather than diffusion. It may also have a negative density of states.
description: 12 pages, no figures, references added, some points clarified
Birefringence and QuasiNormal Modes of the Einstein-Euler-Heisenberg Black Hole
Creators: name: Bretón, Nora
name: López, L. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this contribution we study the birefringence and the quasinormal modes (QNM) in the eikonal approximation, of the Einstein-Euler-Heisenberg black hole (EEH-BH) . The EEH-BH is an exact solution of the Einstein equations coupled to the Euler-Heisenberg nonlinear electrodynamics. It is well known that in the presence of strong electromagnetic fields light rays modify their trajectories and do follow the null geodesics of an effective metric as a result of the nonlinear interaction between light and the intense magnetic or electric background. In the Euler-Heisenberg theory the phenomenon of birefringence arises and then exist two possible light trajectories for polarized light in the vicinity of the EEH-BH. On the other hand, using the correspondence between the parameters of the null unstable geodesics and the quasinormal modes in the eikonal approximation. We determine these QNM for both, the electric and the magnetic EEH-BH and compare them with its linear counterpart, the Reissner-Nordström black hole, since there are two effective metrics, to each one corresponds one null geodesic that renders two possible QNM from the same compact object.
Solar Cell Imaging and Characterization by Terahertz Techniques
Creators: name: Minkevicius, L.
name: Suzanoviciene, R.
name: Molis, G.
name: Krotkus, A.
name: Balakauskas, S.
name: Venckevicius, R.
name: Kašalynas, I.
name: Šimkiene, I.
name: Valušis, G.
name: Tamošiunas, V.
Publisher: name: WIP
Year: 2012
Subjects: Material Studies, New Concepts and Ultra-High Efficiency
Fundamental Material Studies

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 520-523
description: We present our investigations of solar cells and related structures by means of THz imaging. Both continuous wave and pulsed THz imaging set-ups were employed for identification of possible technological defects in various steps of production in a contactless way. We demonstrate that THz imaging can be employed for detecting manufacturing defects of solder tabs, discontinuities of metal fingers, cracks or different reflection coefficients for structured and unstructured surfaces. Continuous wave THz imaging was used to verify the transparence of Cu(In,Ga)Se2 layers in this range for the future work on full 3D characterization of these thin film solar cells. Fourier transform infrared spectroscopy was applied to demonstrate reflectivity variations of CuInS2 films.
A mechanically stable and tunable cryogenic Fabry-Perot microcavity
Creators: name: Fontana, Yannik
name: Zifkin, Rigel
name: Janitz, Erika
name: Rosenblueth, Cesar Daniel Rodriguez
name: Childress, Lilian
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Other Condensed Matter (cond-mat.other)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: High-finesse, open-geometry microcavities have recently emerged as a versatile tool for enhancing interactions between photons and material systems, with a range of applications in quantum optics and quantum information science. However, mechanical vibrations pose a considerable challenge to their operation within a closed-cycle cryostat, particularly when spatial tunability and free-space optical access are required. Here, we present the design and characterization of a system that can achieve $\sim$16 pm-rms passive mechanical stability between two high-finesse mirrors while permitting both three-dimensional positioning of the cavity mode and free-space confocal imaging. The design relies on two cascaded vibration isolation stages connected by leaf springs that decouple axial and lateral motion, and incorporates tuned-mass and magnetic damping. Furthermore, we present a technique for quantifying cavity length displacements similar to or larger than the cavity linewidth, allowing in-situ measurement of vibrations with and without active feedback. Our results facilitate operation of a tunable, high-finesse cavity within a closed-cycle cryostat, representing an enabling technology for cavity coupling to a variety of solid-state systems.
description: Authors Yannik Fontana and Rigel Zifkin contributed equally
Supersolid Bose-Fermi Mixtures in Optical Lattices
Creators: name: Titvinidze, I.
name: Snoek, M.
name: Hofstetter, W.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We study a mixture of strongly interacting bosons and spinless fermions with on-site repulsion in a three-dimensional optical lattice. For this purpose we develop and apply a generalized DMFT scheme, which is exact in infinite dimensions and reliably describes the full range from weak to strong coupling. We restrict ourselves to half filling. For weak Bose-Fermi repulsion a supersolid forms, in which bosonic superfluidity coexists with charge-density wave order. For stronger interspecies repulsion the bosons become localized while the charge density wave order persists. The system is unstable against phase separation for weak repulsion among the bosons.
description: 4 pages, 5 pictures, Published version