cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Quantum algorithms for Gibbs sampling and hitting-time estimation
Creators: name: Chowdhury, Anirban Narayan
name: Somma, Rolando D.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present quantum algorithms for solving two problems regarding stochastic processes. The first algorithm prepares the thermal Gibbs state of a quantum system and runs in time almost linear in $\sqrt{N β/{\cal Z}}$ and polynomial in $\log(1/ε)$, where $N$ is the Hilbert space dimension, $β$ is the inverse temperature, ${\cal Z}$ is the partition function, and $ε$ is the desired precision of the output state. Our quantum algorithm exponentially improves the dependence on $1/ε$ and quadratically improves the dependence on $β$ of known quantum algorithms for this problem. The second algorithm estimates the hitting time of a Markov chain. For a sparse stochastic matrix $P$, it runs in time almost linear in $1/(εΔ^{3/2})$, where $ε$ is the absolute precision in the estimation and $Δ$ is a parameter determined by $P$, and whose inverse is an upper bound of the hitting time. Our quantum algorithm quadratically improves the dependence on $1/ε$ and $1/Δ$ of the analog classical algorithm for hitting-time estimation. Both algorithms use tools recently developed in the context of Hamiltonian simulation, spectral gap amplification, and solving linear systems of equations.
description: 13 pages
Sodium Density Control in Cu(In,Ga)Se2 Absorber Layers and Application in High-Efficiency Flexible Solar Cells
Creators: name: Ishizuka, S.
name: Matsubara, K.
name: Yamada, A.
name: Fons, P.
name: Sakurai, K.
name: Niki, S.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Thin Films
CIS, CdTe and Other (II-VI) Ternary Thin Film Cells

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2654-2656
description: Cu(In,Ga)Se2 (CIGS) solar cells were fabricated on flexible Ti-foil substrates. Control of the Na
density in the CIGS absorber layers was demonstrated using soda-lime glass thin films (SLGTF) of various
thicknesses deposited on substrates prior to the sputtering of the Mo back contact layer. The extent of the
improvement in the photovoltaic performance was found to depend on the SLGTF thickness. Although the cell
efficiency was enhanced with the use of SLGTF due to the Na incorporation into the CIGS layer, degradation in cell
efficiency was observed when excessively thick SLGTF were used. The presence of Na in CIGS was found to lead to
not only an enhancement in cell performance manifested by improvements in Voc and FF, but also a reduction in
elemental inter-diffusion during CIGS growth resulting in small CIGS grains. These effects are trade-offs. Using
optimized thickness SLGTF, a cell efficiency of 17.4% has been demonstrated from a flexible Ti-foil CIGS solar cell.
On the red giant branch mass loss in 47 Tucanae: Constraints from the horizontal branch morphology
Creators: name: Salaris, Maurizio
name: Cassisi, Santi
name: Pietrinferni, Adriano
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We obtain stringent constraints on the actual efficiency of mass loss for red giant branch stars in the Galactic globular cluster 47 Tuc, by comparing synthetic modeling based on stellar evolution tracks with the observed distribution of stars along the horizontal branch in the colour-magnitude-diagram. We confirm that the observed, wedge-shaped distribution of the horizontal branch can be reproduced only by accounting for a range of initial He abundances --in agreement with inferences from the analysis of the main sequence-- and a red giant branch mass loss with a small dispersion. We have carefully investigated several possible sources of uncertainty that could affect the results of the horizontal branch modeling, stemming from uncertainties in both stellar model computations and the cluster properties such as heavy element abundances, reddening and age. We determine a firm lower limit of ~0.17$Mo for the mass lost by red giant branch stars, corresponding to horizontal branch stellar masses between ~0.65Mo and ~0.73Mo (the range driven by the range of initial helium abundances). We also derive that in this cluster the amount of mass lost along the asymptotic giant branch stars is comparable to the mass lost during the previous red giant branch phase. These results confirm for this cluster the disagreement between colour-magnitude-diagram analyses and inferences from recent studies of the dynamics of the cluster stars, that predict a much less efficient red giant branch mass loss. A comparison between the results from these two techniques applied to other clusters is required, to gain more insights about the origin of this disagreement.
description: 11 pages, 9 figures, accepted for publication in A&A
Parameters of Photovoltaic CIS Cells in Dependence on Irradiance and Temperature
Creators: name: Machacek, Z.
name: Benda, V.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Thin Films
CIS, CdTe and Other (II-VI) Ternary Thin Film Cells

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2610-2612
description: For photovoltaic applications, the knowledge about system behaviour in real operating conditions is
desirable. Presented paper describes the dependences of all important parameters of CIS photovoltaic mini-module
on both temperature and irradiance obtained using cell tester Pasan IIc.
Keywords: CIS, Thermal Performance, Irradiance
Formation of Terrestrial Planets in Disks with Different Surface Density Profiles
Creators: name: Haghighipour, Nader
name: Winter, Othon C.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We present the results of an extensive study of the final stage of terrestrial planet formation in disks with different surface density profiles and for different orbits of Jupiter and Saturn. We carried out simulations for disk densities proportional to r^-0.5, r^-1, and r^-1.5, and also for partially depleted disks as in the recent model of Mars formation by Izidoro et al (2014). The purpose of our study is to determine how the final assembly of planets and their physical properties are affected by the total mass of the disk and its radial profile. Because of the important roles of secular resonances in orbits and properties of the final planets, we studied the effects of these resonances as well. We have divided this study into two parts. In Part 1, we are interested in examining the effects of secular resonances on the formation of Mars and orbital stability of terrestrial planets. In Part 2, our goal is to determine trends that may exist between the disk surface density profile and the final properties of terrestrial planets. In the context of the depleted disk model, results show that the nu_5 resonance does not have a significant effect on the final orbits of terrestrial planets. However, nu_6 and nu_16 resonances play important roles in clearing their affected areas ensuring that no additional mass will be scattered into the accretion zone of Mars so that it can maintain its mass and orbital stability. In Part 2, our results indicate that despite some small correlations, in general, no trend seems to exist between the disk surface density profile and the mean number of the final planets, their masses, time of formation, and distances to the central star. We present the results of our simulations and discuss their implications for the formation of Mars and other terrestrial planets, as well as the physical properties of these objects such as their masses and water contents.
description: 36 pages, 14 figures. Part 1 presents a complete study of the effects of secular resonances in the classical and depleted-disk models for different disk surface density profiles. Part 2 (page 25) presents a detailed analysis of the orbital and physical properties of the final planets for different disk surface densities. Accepted for publication in Celestial Mechanics and Dynamical Astronomy
Optimization of Laser Processes in n+ Emitter Formation for c-Si Solar Cells
Creators: name: Orpella, A.
name: Martín, I.
name: Blanque, S.
name: Voz, C.
name: Sánchez Aniorte, I.
name: Colina, M.
name: Molpeceres, C.
name: Alcubilla, R.
Publisher: name: WIP-Munich
Year: 2009
Subjects: Wafer-based Silicon Solar Cells and Materials Technology
Mono- and Multicrystalline Silicon Materials and Cells

description: 24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 1798-1802
description: Punctual phosphorus diffused emitters were achieved by laser patterning phosphorus doped a-SiCx:H
films deposited by PECVD as a doping source. Two different lasers at wavelengths of 1064 nm and 532 nm were
used. Phosphorus diffusion was confirmed by Secondary Ion Mass Spectroscopy. We explored the effect of pulse
energy and number of pulses per diffused point. The results show that a fine tune of the energy pulse is critical while
the number of pulses has minor effects. Scanning Electron Microscopy (SEM) pictures and optical profilometry
showed a laser affected area where the c-Si is melted, ejected and solidified quickly again. Typically, the diameter of
the affected area for 1064 nm laser is between two and four times greater than for 532 nm laser. Optimum parameters
for both lasers were determined to obtain best J-V curves nearly to ideal diode behavior. Comparing best J-V results,
lower emitter saturation current density (Jo) and contact resistance are obtained with 532 nm laser. The improvement
in Jo can be related mainly to the smaller affected areas observed by SEM while lower contact resistance can be
attributed to that 532 nm laser has a more superficial action resulting in higher phosphorus concentration at the
surface. The expected open voltage circuit for finished solar cells using these emitters is in the range of 640 mV for
532 nm laser and 620 mV for 1064 nm one.
Order-by-disorder effects in antiferromagnets on face-centered cubic lattice
Creators: name: Batalov, L. A.
name: Syromyatnikov, A. V.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We discuss the role of quantum fluctuations in Heisenberg antiferromagnets on face-centered cubic lattice with small dipolar interaction in which the next-nearest-neighbor exchange coupling dominates over the nearest-neighbor one. It is well known that a collinear magnetic structure which contains (111) ferromagnetic planes arranged antiferromagnetically along one of the space diagonals of the cube is stabilized in this model via order-by-disorder mechanism. On the mean-field level, the dipolar interaction forces spins to lie within (111) planes. By considering 1/S - corrections to the ground state energy, we demonstrate that quantum fluctuations lead to an anisotropy within (111) planes favoring three equivalent directions for the staggered magnetization (e.g., $[11\overline{2}]$, $[1\overline{2}1]$, and $[\overline{2}11]$ directions for (111) plane). Such in-plane anisotropy was obtained experimentally in related materials MnO, $α$-MnS, $α$-MnSe, EuTe, and EuSe. We find that the order-by-disorder mechanism can contribute significantly to the value of the in-plane anisotropy in EuTe. Magnon spectrum is also derived in the first order in 1/S.
description: 9 pages, 1 colour figures
MOVPE Growth of III-V Solar Cells on Silicon in 300 mm Closed Coupled Showerhead Reactor
Creators: name: Roesener, T.
name: Döscher, H.
name: Beyer, A.
name: Brückner, S.
name: Klinger, V.
name: Wekkeli, A.
name: Kleinschmidt, P.
name: Jurecka, C.
name: Ohlmann, J.
name: Volz, K.
name: Stolz, W.
name: Hannappel, T.
name: Bett, A.W.
name: Dimroth, F.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Advanced Photovoltaics: New Concepts and Ultra-high Efficiency
Terrestrial Concentrator Systems

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 964-968
description: III-V multi-junction solar cells grown on Ge substrates have achieved the highest solar cell conversion
efficiency of 41.6 %. However, this device manufacturing is still costly and a major share of the cost can be
attributed to the cost of the Ge substrate. Therefore, a replacement of Ge by Si would be beneficial. However,
elaborate challenges arise from the 4.1% difference in lattice constant for Si and GaAs and due to the non-polar to
polar interface leading to threading dislocations and anti-phase domains, respectively. To meet the required high
crystalline quality for III-V multi-junction solar cells this paper presents approaches for the Si-to-GaAs transition
evaluated on an industrial 300 mm CRIUS Closed Coupled Showerhead MOVPE reactor. Anti-phase domain free
GaP nucleation layers with only 0.36% lattice mismatch at room temperature were grown on Si substrate. On top of
these layers step-graded Ga1-xInxP buffer structures mediate the lattice constant to GaAs although present process
parameters have not yet enabled confinement of threading dislocations inside the buffer structure. A promising
alternative route is the growth of an all Ge buffer layer directly on Si. Here we report on the results of the used twostep
growth process.
Research on security threats posed by legacy RATs (Radio access technologies) in 5G networks
Creators: Liton Kumar Das
Publisher: name: University of Alberta Library
Year: 2023

Due to its impact expected on the economy and society, the fifth generation of mobile telecommunications (5G) is one of the most important innovations of our time. From a conceptual perspective, 5G technology promises to deliver low latency, high speed, and more reliable connections to new generations of autonomous systems and edge-type devices, covering massive and critical machine-type communications. 5G has initiated its full development to satisfy an increasing demand for mobile data traffic and big data bandwidth. Centralized data processing, collaborative radio, real-time cloud infrastructure, and cloud radio access network (C-RAN), along with their excellent advantages, are being sought by more and more operators to meet end-user requirements.

This research paper aims to study the concept of security threats on RAT technology in 5G networks. Its historical background and architecture through the history have evolved. The evolution of networks from 1G to 5G is also discussed as an analysis zed how faster data is required for faster networks.

Proposed 5G architectures are designed to close security gaps from previous iterations of cellular networks, but the pervasive nature of 5G introduces new security challenges outside the traditional space. In addition, 5G’s attractive, transformative services will likely introduce threat vectors not yet seen or experienced. This paper will examine how 5G differs from other wireless architectures and what possible threats, vulnerabilities, and attacks are. Security considerations will discuss various software, virtualization, automation, orchestration, and Radio Access Network (RAN) considerations. Finally, zero-Trust security and several other techniques will be addressed to mitigate the threats, and various recommendations will be proposed for protection.

As an excellent mobile wireless network architecture, compared with traditional RAN, C-RAN has incomparable advantages in terms of low power consumption, reduced base station (BS) numbers, and economic capital and operating expenditure. It can also improve network capacity and BS utilization rate. However, C-RAN technology in 5G mobile communication networks must deal with several security challenges relating to virtual network functions and software-defined networking. This research project aims to study and present a comprehensive evaluation of existing security studies in the field of C-RAN and corresponding security threats and attacks. Furthermore, we indicate open solutions to research issues and propose future research trends.
Supergravity backgrounds and symmetry superalgebras
Creators: name: Ertem, Ümit
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We consider the bosonic sectors of supergravity theories in ten and eleven dimensions which correspond to the low energy limits of string theories and M-theory. The solutions of supergravity field equations are known as supergravity backgrounds and the number of preserved supersymmetries in those backgrounds are determined by Killing spinors. We provide some examples of supergravity backgrounds which preserve different fractions of supersymmetry. An important invariant for the characterization of supergravity backgrounds is their Killing superalgebras which are constructed out of Killing vectors and Killing spinors of the background. After constructing Killing superalgebras of some special supergravity backgrounds, we discuss about the possibilities of the extensions of these superalgebras to include the higher degree hidden symmetries of the background.
description: 11 pages, short review, to appear in Turk. J. Phys. special issue on General Relativity and Related Topics
Lagrangian Transport Structures in Three-dimensional Incompressible Time-periodic Flow
Creators: name: BHARATH RAVU
Publisher: name: Monash University
Year: 2020
Subjects: subject: 91501 Computational Fluid Dynamics
subject: FOS: Other engineering and technologies

description: In this thesis, a closed, 3D incompressible flow is considered that has two invariants in the Stokes regime. First one, and then the second, invariant is destroyed, and the Lagrangian structures in the resulting flows examined. To compute Lagrangian structures accurately, a new divergence-free interpolation method is developed and presented. Here it is shown that global Lagrangian transport structures of one invariant flows can be completely understood and calculated numerically by identifying degenerate points on periodic lines. A new mechanism of 3D chaotic transport that features non-heteroclinic connections of tubular transition regions is observed in the perturbed zero-invariant flow.
The Impact of Ion Energy and Fluence in Ion Beam Assisted Roll-to-Roll Deposition of Cu(In,Ga)Se2 Absorber Films
Creators: name: Zachmann, H.
name: Rahm, A.
name: Otte, K.
name: Stephan, C.
name: Wagner, G.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Thin Films
CIS, CdTe and Other (II-VI) Ternary Thin Film Cells

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2621-2624
description: Flexible Cu(In,Ga)Se2 thin film solar cells were fabricated on a polyimide foil by a adapted coevaporation
process. In contrast to conventional co-evaporation of CIGS, selenium is provided by an broad ion beam
source hence allowing an ion beam assisted deposition (IBAD) of the CIGS absorber layer. In order to study the
impact of selenium ions on the growing CIGS absorber a set of samples with different selenium ion energies and
fluences was investigated by means of XRD, SIMS and TEM. Moreover, we determined the influence of the
different selenium ion energies on the efficiency of a series of complete solar cells. The optimum value for the ion
energy determined leads to an increase of the relative efficiency of about 20 % compared to cells formed during a
standard process. A further increase of the ion energy leads to an increase of the structural deterioration which
overcompensates the benefits for the crystal growth kinetics in the IBAD process.
A Comparative Study on Life-Cycle Analysis of 20 Different PV Modules Installed at a Hokuto Mega-Solar Plant
Creators: name: Ito, M.
name: Kudou, M.
name: Nagura, M.
name: Kurokawa, K.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Components for PV Systems
PV System Engineering and Standards, Socio-economic Aspects, and Sustainability

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 3899-3903
description: The purpose of this study is to obtain the suitable type of the Mega-solar system from environmental
viewpoint. The authors have evaluated 6 type of 20 PV modules by the Life-cycle analysis (LCA) with actual
equipments data. They are single crystalline silicon (sc-Si), amorphous silicon (a-Si)/sc-Si, multi crystalline silicon
(mc-Si), a-Si, micro crystalline silicon (μc-Si)/a-Si and CIS. The boundary of the LCA is from mining to waste
management. Mining, manufacturing and waste management were from LCA database. Transport, construction and
amount of equipments were obtained from actual systems. Because irradiation data and output electricity were also
actual data, we can avoid difficulties of assumptions, such as actual output power of thin-films. In addition, they were
installed at one plant, it is suitable for comparing PV systems.
As a result, energy requirement was from 18 to 48 GJ/kW. Energy payback time was from 1.4 to 3.8 years. CO2
emissions were 1.2 to 2.7 t-CO2/kW. CO2 emissions rate were 31 to 67 g-CO2/kWh. Multi-crystalline (mc-Si) and
CIS got good result. Because the mc-Si and the CIS PV module have high efficiency and lower energy requirement.
Especially, the CIS module generate more electricity than expected electricity with catalogue efficiency. The singlecrystalline
silicon PV module did not get good result. Because considering its energy requirement, it is not high
efficiency, especially the PV modules installed in this site. However, if we think about the CO2 emissions rate, it is
much smaller than fossil power plant. Therefore, it has potentials to mitigate global warming.
Electron-Hole Asymmetry in the Electron-phonon Coupling in Top-gated Phosphorene Transistor
Creators: name: Chakraborty, Biswanath
name: Gupta, Satyendra Nath
name: Singh, Anjali
name: Kuiri, Manabendra
name: Kumar, Chandan
name: Muthu, D. V. S.
name: Das, Anindya
name: Waghmare, U. V.
name: Sood, A. K.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using in-situ Raman scattering from phosphorene channel in an electrochemically top-gated field effect transistor, we show that its phonons with A$_g$ symmetry depend much more strongly on concentration of electrons than that of holes, while the phonons with B$_g$ symmetry are insensitive to doping. With first-principles theoretical analysis, we show that the observed electon-hole asymmetry arises from the radically different constitution of its conduction and valence bands involving $π$ and $σ$ bonding states respectively, whose symmetry permits coupling with only the phonons that preserve the lattice symmetry. Thus, Raman spectroscopy is a non-invasive tool for measuring electron concentration in phosphorene-based nanoelectronic devices.
Modelling rock fractures using SPH with an embedded fracture process zone
Creators: name: YINGNAN WANG
Publisher: name: Monash University
Year: 2020
Subjects: subject: 90501 Civil Geotechnical Engineering
subject: FOS: Civil engineering

description: This research is aimed to develop an advanced computational framework that includes intrinsic spatial and temporal scales. In this computational framework, a new continuum-based constitutive model with embedded discontinuity is developed and then incorporated into the mesh-free smoothed particle hydrodynamics (SPH) method, capable of handling problems involving complex fracture networks.
Shot noise generated by graphene p-n junctions in the quantum Hall effect regime
Creators: name: Kumada, N.
name: Parmentier, F. D.
name: Hibino, H.
name: Glattli, D. C.
name: Roulleau, P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Owing to a linear and gapless band structure and a tunability of the charge carrier type, graphene offers a unique system to investigate transport of Dirac Fermions at p-n junctions (PNJs). In a magnetic field, combination of quantum Hall physics and the characteristic transport across PNJs leads to a fractionally quantized conductance associated with the mixing of electron-like and hole-like modes and their subsequent partitioning. The mixing and partitioning suggest that a PNJ could be used as an electronic beam-splitter. Here we report the shot noise study of the mode mixing process and demonstrate the crucial role of the PNJ length. For short PNJs, the amplitude of the noise is consistent with an electronic beam-splitter behavior, whereas, for longer PNJs, it is reduced by the energy relaxation. Remarkably, the relaxation length is much larger than typical size of mesoscopic devices, encouraging using graphene for electron quantum optics and quantum information processing.
Observational signatures of neutron stars in low-mass X-ray binaries climbing a stability peak
Creators: name: Kantor, Elena
name: Gusakov, Mikhail
name: Chugunov, Andrey
Publisher: name: arXiv
Year: 2015
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: In the recent papers by Gusakov, Chugunov, and Kantor (2014) a new scenario describing evolution of rapidly rotating neutron stars in low-mass X-ray binaries was proposed. The scenario accounts for a resonant interaction of normal r modes with superfluid inertial modes at some specific internal stellar temperatures ("resonance temperatures"). This interaction results in an enhanced damping of r mode and appearance of the "stability peaks" in the temperature -- spin frequency plane, which split the r-mode instability window in the vicinity of the resonance temperatures. The scenario suggests that the hot and rapidly rotating NSs spend most of their life climbing up these peaks and, in particular, are observed there at the moment. We analyze in detail possible observational signatures of this suggestion. In particular, we show that these objects may exhibit `anti-glitches' -- sudden frequency jumps on a time scale of hours-months.
description: 19 pages, 5 figures, published in MNRAS
One-way deficit and quantum phase transitions in $XX$ Model
Creators: name: Wang, Yao-Kun
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum correlations including entanglement and quantum discord has drawn much attention in characterizing quantum phase transitions. Quantum deficit originates in questions regarding work extraction from quantum systems coupled to a heat bath [Phys. Rev. Lett. 89, 180402 (2002)]. It links quantum thermodynamics with quantum correlations and provides a new standpoint for understanding quantum non-locality. In this paper, we evaluate the one-way deficit of two adjacent spins in the bulk for the XX model. In the thermodynamic limit, the XX model undergoes a first order transition from fully polarized to a critical phase with quasi-long-range order with decrease of quantum parameter. We find that the one-way deficit becomes nonzero after the critical point. Therefore, the one-way deficit characterizes the quantum phase transition in the XX model.
description: 5 pages, 1 figure
Thermal transport size effects in silicon membranes featuring nanopillars as local resonators
Creators: name: Honarvar, Hossein
name: Yang, Lina
name: Hussein, Mahmoud I.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Silicon membranes patterned by nanometer-scale pillars standing on the surface provide a practical platform for thermal conductivity reduction by resonance hybridization. Using molecular simulations, we investigate the effect of nanopillar size, unit-cell size, and finite-structure size on the net capacity of the local resonators in reducing the thermal conductivity of the base membrane. The results indicate that the thermal conductivity reduction increases as the ratio of the volumetric size of a unit nanopillar to that of the base membrane is increased, and the intensity of this reduction varies with unit-cell size at a rate dependent on the volumetric ratio. Considering sample size, the resonance-induced thermal conductivity drop is shown to increase slightly with the number of unit cells until it would eventually level off.
description: Manuscript is submitted for journal publication
Horizon Shells and BMS-like Soldering Transformations
Creators: name: Blau, Matthias
name: O'Loughlin, Martin
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We revisit the theory of null shells in general relativity, with a particular emphasis on null shells placed at horizons of black holes. We study in detail the considerable freedom that is available in the case that one solders two metrics together across null hypersurfaces (such as Killing horizons) for which the induced metric is invariant under translations along the null generators. In this case the group of soldering transformations turns out to be infinite dimensional, and these solderings create non-trivial horizon shells containing both massless matter and impulsive gravitational wave components. We also rephrase this result in the language of Carrollian symmetry groups. To illustrate this phenomenon we discuss in detail the example of shells on the horizon of the Schwarzschild black hole (with equal interior and exterior mass), uncovering a rich classical structure at the horizon and deriving an explicit expression for the general horizon shell energy-momentum tensor. In the special case of BMS-like soldering supertranslations we find a conserved shell-energy that is strikingly similar to the standard expression for asymptotic BMS supertranslation charges, suggesting a direct relation between the physical properties of these horizon shells and the recently proposed BMS supertranslation hair of a black hole.
description: 23 pages
Prime Gamma Rings with Centralizing and Commuting Generalized Derivations
Creators: name: Hoque, Md Fazlul
name: Paul, A C
Publisher: name: arXiv
Year: 2016
Subjects: subject: Commutative Algebra (math.AC)
subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics

description: Let $M$ be a prime $Γ$-ring satisfying a certain assumption and $D$ a nonzero derivation on $M$. Let $f:M\rightarrow M$ be a generalized derivation such that $f$ is centralizing and commuting on a left ideal $J$ of $M$. Then we prove that $M$ is commutative.
description: 7 pages
Topological interactions of two-dimensional non-Abelian quantum vortices in spinor Bose–Einstein condensates
Creators: name: THOMAS GEOFFREY MAWSON
Publisher: name: Monash University
Year: 2019
Subjects: subject: Quantum Mechanics
subject: Atomic Physics
subject: Computational Physics
subject: Condensed Matter Physics
subject: FOS: Physical sciences

description: This thesis studies collision and braiding dynamics of types of non-Abelian vortices in ultra-cold atomic gases. It identifies a new kind of collision dynamics for these vortices with potential applications to quantum information processing and storage, as well as quantum turbulence.
Structured Back Gates for High-Mobility Two-Dimensional Electron Systems Using Oxygen Ion Implantation
Creators: name: Berl, Matthias
name: Tiemann, Lars
name: Dietsche, Werner
name: Karl, Helmut
name: Wegscheider, Werner
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present a new approach of back gate patterning that is compatible with the requirements of highest mobility molecular beam epitaxy. Contrary to common back gating techniques, our method is simple, reliable and can be scaled up for entire wafers. The back gate structures are defined by local oxygen implantation into a silicon doped GaAs epilayer, which suppresses the conductance without affecting the surface quality.
description: The following article has been submitted to Applied Physics Letters
Black silicon based materials for photoelectrochemical nitrogen reduction
Creators: name: MUATAZ ADNAN ALI AL-AGELE
Publisher: name: Monash University
Year: 2019
Subjects: subject: 90605 Photodetectors, Optical Sensors and Solar Cells
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: 30604 Electrochemistry
subject: FOS: Chemical sciences
subject: 100708 Nanomaterials
subject: FOS: Nanotechnology
subject: Environmental Chemistry

description: This work is an endeavour to employ photocatalytic reaction to mimic the natural synthesis of ammonia, adopting only sunlight, water and nitrogen as reactants. Silicon has been modified, decorated with gold nanoparticles and used to reduce molecular nitrogen into ammonia. The developed prototype has been further studied, and the reaction conditions was optimised, as well. Variety of catalyst used to boost the cell efficiency and dispersed Ru(III) found to have a significant impact in favour of increasing the cell efficiency.
MultiLayer Perceptron Neural Network for flood prediction
Creators: name: Brandão, Abderraman Roger Amorim
Publisher: name: Zenodo
Year: 2023
Subjects: MultiLayer Perceptron Neural Network
Artificial neural networks
Flood prediction

description: Artificial neural networks (ANN) has been widely applied and has gained prominence in water resources and here we provide codes used to build a MultiLayer Perceptron Neural Network for flood prediction. The code were used in the specific basin of Paranaíba River basin (Brazil), but can be adapted and employed at other sites.
Using Reflection with Peers to Help Students Learn Effective Problem Solving Strategies
Creators: name: Mason, Andrew
name: Singh, Chandralekha
Publisher: name: arXiv
Year: 2016
Subjects: subject: Physics Education (physics.ed-ph)
subject: FOS: Physical sciences

description: We describe a study in which introductory physics students engage in reflection with peers about problem solving. The recitations for an introductory physics course with 200 students were broken into the "Peer Reflection" (PR) group and the traditional group. Each week in recitation, students in the PR group reflected in small teams on selected problems from the homework. The graduate and undergraduate teaching assistants (TAs) in the PR group recitations provided guidance and coaching to help students learn effective problem solving heuristics. In the recitations for the traditional group, students had the opportunity to ask the graduate TA questions about the homework before they took a weekly quiz. On the final exam with only multiple-choice questions, the PR group drew diagrams on more problems than the traditional group, even when there was no external reward for doing so. Since there was no partial credit for drawing the diagrams on the scratch books, students did not draw diagrams simply to get credit for the effort shown and must value the use of diagrams for solving problems if they drew them. We also find that, regardless of whether the students belonged to the traditional or PR groups, those who drew more diagrams for the multiple-choice questions outperformed those who did not draw them.
description: 4 pages, 01.40Fk,01.40.gb,01.40G-,1.30.Rr. Proceedings of the Physics Education Research Conference
Ab Initio Modeling of Optoelectronic Properties of Chalcopyrites and of their Point Defects
Creators: name: Vidal, J.
name: Huang, L.
name: Domain, C.
name: Olsson, P.
name: Guillemoles, J.F.
name: Gatti, M.
name: Botti, S.
name: Reining, L.
Publisher: name: WIP-Munich
Year: 2008
Subjects: Thin Films
CIS, CdTe and Other (II-VI) Ternary Thin Film Cells

description: 23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 2634-2636
description: CuIn1-xAlxSe2 (CIAS) thin films were grown by a two stage process. Cu, In and Al layers were sequentially
evaporated and subsequently heated with elemental selenium in a quasi-closed graphite box. Different x values
(x>0.4) were obtained by varying the Al and In precursor layers thicknesses. Selenization conditions such as Se
amount provided during the selenization process were adjusted in order to optimize the film properties. Polycrystalline
CuIn1-XAlXSe2 thin films with chalcopyrite structure were obtained. Referred to CuInSe2 thin films the lattice parameters,
the (112) orientation and the average crystallite size decreased and the band gap energy increased with increasing
Al content. The incorporation of Al changed the thin film morphology towards smaller grain sizes and an
open structure less dense. The ternary compound CuAlSe2 was formed in isolated areas and some samples showed
coexistence of CuInSe2 and CuIn1-xAlxSe2 phases.
Drones, dykes and discontinuities: the role of intrusions in the construction and destruction of ocean island volcanoes
Creators: name: SAMUEL THOMAS THIELE
Publisher: name: Monash University
Year: 2019
Subjects: subject: 40312 Structural Geology
subject: FOS: Earth and related environmental sciences
subject: 40314 Volcanology
subject: 40604 Natural Hazards
subject: 90905 Photogrammetry and Remote Sensing
subject: FOS: Environmental engineering

description: During volcanic eruptions, magma flows from an underground magma chamber to the Earth’s surface. Some of this magma solidifies before erupting, forming sheets of strong rock called dykes. The distribution of dykes in a volcano on the island of La Palma was mapped using drone-mounted cameras, and their orientation and geometry quantified. The dykes appear to form a rigid framework that stabilizes the volcano, but can rapidly collapse to cause volcanic landslides. Older dykes also deflect younger ones, affecting the location of future eruptions. These findings have the potential to help predict future volcanic activity and manage associated risks.
Joint Face Detection and Alignment using Multi-task Cascaded Convolutional Networks
Creators: name: Zhang, Kaipeng
name: Zhang, Zhanpeng
name: Li, Zhifeng
name: Qiao, Yu
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Face detection and alignment in unconstrained environment are challenging due to various poses, illuminations and occlusions. Recent studies show that deep learning approaches can achieve impressive performance on these two tasks. In this paper, we propose a deep cascaded multi-task framework which exploits the inherent correlation between them to boost up their performance. In particular, our framework adopts a cascaded structure with three stages of carefully designed deep convolutional networks that predict face and landmark location in a coarse-to-fine manner. In addition, in the learning process, we propose a new online hard sample mining strategy that can improve the performance automatically without manual sample selection. Our method achieves superior accuracy over the state-of-the-art techniques on the challenging FDDB and WIDER FACE benchmark for face detection, and AFLW benchmark for face alignment, while keeps real time performance.
description: Submitted to IEEE Signal Processing Letters
All-electron self-consistent GW in the Matsubara-time domain: implementation and benchmarks of semiconductors and insulators
Creators: name: Chu, Iek-Heng
name: Trinastic, Jonathan P.
name: Wang, Yun-Peng
name: Eguiluz, Adolfo G.
name: Kozhevnikov, Anton
name: Schulthess, Thomas C.
name: Cheng, Hai-Ping
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The GW approximation is a well-known method to improve electronic structure predictions calculated within density functional theory. In this work, we have implemented a computationally efficient GW approach that calculates central properties within the Matsubara-time domain using the modified version of Elk, the full-potential linearized augmented plane wave (FP-LAPW) package. Continuous-pole expansion (CPE), a recently proposed analytic continuation method, has been incorporated and compared to the widely used Pade approximation. Full crystal symmetry has been employed for computational speedup. We have applied our approach to 18 well-studied semiconductors/insulators that cover a wide range of band gaps computed at the levels of single-shot G0W0, partially self-consistent GW0, and fully self-consistent GW (scGW). Our calculations show that G0W0 leads to band gaps that agree well with experiment for the case of simple s-p electron systems, whereas scGW is required for improving the band gaps in 3-d electron systems. In addition, GW0 almost always predicts larger band gap values compared to scGW, likely due to the substantial underestimation of screening effects. Both the CPE method and Pade approximation lead to similar band gaps for most systems except strontium titantate, suggesting further investigation into the latter approximation is necessary for strongly correlated systems. Our computed band gaps serve as important benchmarks for the accuracy of the Matsubara-time GW approach.
description: 4 tables, 3 figures
Mathematical and stochastic modelling of reaction-diffusion processes in the Wnt signalling pathway
Creators: name: JAMES CHARLES NICHOLAS CAVALLO
Publisher: name: Monash University
Year: 2019
Subjects: subject: 10299 Applied Mathematics not elsewhere classified
subject: FOS: Mathematics

description: Reaction-diffusion processes in biological systems have been studied using a range of mathematical- and simulation-based approaches. In this thesis, novel techniques and algorithms are developed for reaction-diffusion processes based on Smoluchowski kinetics to simulate reversible reactions of any order. Simulating such reactions sheds light on the dynamics of Wnt signalling, an important biological process which regulates embryonic development, tissue homoeostasis, and diseases such as cancer. A detailed analysis into the fundamental dynamical properties of Wnt signalling helps explore the relationship between signalling mechanisms, protein binding affinities and the end product of cell fate.
Volume exclusion effects in perovskite charge transport modeling
Creators: name: Abdel, Dilara
name: Courtier, Nicola E.
name: Farrell, Patricio
Publisher: name: Weierstrass Institute
Year: 2022
Subjects: subject: Perovskite modeling
subject: drift-diffusion equations
subject: volume exclusion effects
subject: current density
subject: 35Q81
subject: 35K57

description: Due to their flexible material properties, perovskite materials are a promising candidate for many semiconductor devices such as lasers, memristors, LEDs and solar cells. For example, perovskite-based solar cells have recently become one of the fastest growing photovoltaic tech- nologies. Unfortunately, perovskite devices are far from commercialization due to challenges such as fast degradation. Mathematical models can be used as tools to explain the behavior of such devices, for example drift-diffusion equations portray the ionic and electric motion in perovskites. In this work, we take volume exclusion effects on ion migration within a perovskite crystal lat- tice into account. This results in the formulation of two different ionic current densities for such a drift-diffusion model ? treating either the mobility or the diffusivity as density-dependent while the other quantity remains constant. The influence of incorporating each current density description into a model for a typical perovskite solar cell configuration is investigated numerically, through simulations performed using two different open source tools.
Segmental Character, Peculiarities and Similarity of the Dependences: “Efficiency – Sunlight Concentration Ratio” and “Voltage – Dark Current” in Multijunction Solar Cells
Creators: name: Kalinovsky, V.S.
name: Evstropov, V.V.
name: Lantratov, V.M.
name: Pokrovskiy, P.V.
name: Andreev, V.M.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Advanced Photovoltaics: New Concepts and Ultra-high Efficiency
Terrestrial Concentrator Systems

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 979-985
description: Correlation and similarity of main characteristics of multijunction solar cells (MJ SC): “voltage – dark
forward current density”, V-J; “efficiency (proportional to the introduced auxiliary term – “efficiency” voltage, V) –
sunlight concentration ratio (proportional to the photogenerated current density) ”,  – C have been considered. It
has been shown that V-J and those characteristics have a shape of a continuous function consisting of segments. For
each segment, an analytical dependence is deduces expressing the photogenerated current density through auxiliary
definition – “efficiency” voltage V, which is proportional to the efficiency . The segments of the analytical Jg – V
characteristic contain the same two parameters as the corresponding segments of the initial dark J-V characteristic do
– the preexponential factor J0 and the diode coefficient A. Hence, the Jg – V characteristic is uniquely associated (at
idealization of the connecting part – tunneling diodes in MJ SCs) with the initial dark J-V characteristic. The
equivalent electrical circuit of a MJ SC is considered and adjusted to an electrical circuit of a “virtual” singlejunction
SC. Determined were the preexponential factors J0 and the diode coefficients A for each segment of the J-V
characteristic. For them, electrically idealized  - C characteristics were calculated and plotted. The influence of the
connecting elements (tunneling diodes) has been simulated and taken into account by selecting an ohmic series
resistance RS. A good fit of the calculated  - C dependencies to experimental ones for InGaP/GaAs/Ge MJ SCs has
been obtained. An abrupt increase in the current density has been observed and analyzed in the experimental “voltage
– dark forward current density” characteristics of MJ SCs.
In-Field Characterization of High Concentration Photovoltaic Systems
Creators: name: Recart, F.
name: González Alonso, O.
name: Villaverde, A.
name: Martínez, V.
name: Lago, R.
name: Jimeno, J.C.
Publisher: name: WIP-Munich
Year: 2010
Subjects: Advanced Photovoltaics: New Concepts and Ultra-high Efficiency
Terrestrial Concentrator Systems

description: 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 986-989
description: Besides the issues related to any outdoor measurement, high concentration photovoltaic (HCPV) systems have
inherent difficulties for in-field comprehensive characterization. As sun-tracking is not a perfect process, the
effective alignment of optics and cells with the sun is always shifting, the current-voltage (I-V) curves of every
element are continuously changing and, so, mismatch is varying too. This paper presents a characterization system
that measures the I-V curves of medium power circuits -before the inverter- accurately and fast enough to yield
valuable data for cell-level mismatch -or fault- detection. In addition to the circuit-level I-V curve, the characteristics
of twelve sub-circuits or elements can be simultaneously and iteratively measured. The simultaneity helps to clearly
identify mismatched elements and, as data can be taken iteratively, the resulting I-V curves may be presented in a
movie format, which makes easier the evaluation of the efficiency of the tracking and assists very conveniently
during the set-up or maintenance of the system.