cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
H, He-like recombination spectra I: $l$-changing collisions for hydrogen
Creators: name: Guzmán, F.
name: Badnell, N. R.
name: Williams, R. J. R.
name: van Hoof, P. A. M.
name: Chatzikos, M.
name: Ferland, G. J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Hydrogen and helium emission lines in nebulae form by radiative recombination. This is a simple process which, in principle, can be described to very high precision. Ratios of He I and H I emission lines can be used to measure the He$^+$/H$^+$ abundance ratio to the same precision as the recombination rate coefficients. This paper investigates the controversy over the correct theory to describe dipole $l$-changing collisions ($nl\rightarrow nl'=l\pm 1$) between energy-degenerate states within an $n$-shell. The work of Pengelly & Seaton (1964) has, for half-a-century, been considered the definitive study which "solved" the problem. Recent work by Vrinceanu et al.(2012) recommended the use of rate coefficients from a semi-classical approximation which are nearly an order of magnitude smaller than those of Pengelly & Seaton (1964), with the result that significantly higher densities are needed for the $nl$ populations to come into local thermodynamic equilibrium. Here, we compare predicted H~I emissivities from the two works and find widespread differences, of up to $\approx 10$%. This far exceeds the 1% precision required to obtain the primordial He/H abundance ratio from observations so as to constrain Big Bang cosmologies. We recommend using the rate coefficients of Pengelly & Seaton (1964) for $l$-changing collisions, to describe the H recombination spectrum, based-on their quantum mechanical representation of the long-range dipole interaction.
description: 6 pages, 3 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society
Contact Resistivity Measurements of Point-Contacting by Localised Dielectric Breakdown Structures by the Transmission Line Method
Creators: name: Western, N.J.
name: Bremner, S.P.
Publisher: name: WIP
Year: 2015
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 31st European Photovoltaic Solar Energy Conference and Exhibition; 629-632
description: Point-contacting by Localised Dielectric Breakdown is an effective method for creating ohmic contact
through a passivation dielectric. When combined with laser doped point contacts, it can be applied to the rear surface
of commercial p-type solar cells where laser damage to the dielectric is avoided. We report on the detailed analysis of
contact resistivity for these contacts using the Transmission Line Method. Standard assumptions are addressed to
maintain the validity of the measurement for these structures. Measured values of contact resistivity below 1 mΩcm2
demonstrate the applicability of this technique to a rear surface point contact structure. A change in both the contact
resistance and the laser doped line resistance occurs with a change in the laser doping speed. This reflects the
expected increase in total doping dose with an increased laser energy density. No significant difference is observed
for three commonly used surface passivation dielectrics.
Causal-aware Safe Policy Improvement for Task-oriented dialogue
Creators: name: Ramachandran, Govardana Sachithanandam
name: Hashimoto, Kazuma
name: Xiong, Caiming
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computation and Language (cs.CL)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: The recent success of reinforcement learning's (RL) in solving complex tasks is most often attributed to its capacity to explore and exploit an environment where it has been trained. Sample efficiency is usually not an issue since cheap simulators are available to sample data on-policy. On the other hand, task oriented dialogues are usually learnt from offline data collected using human demonstrations. Collecting diverse demonstrations and annotating them is expensive. Unfortunately, use of RL methods trained on off-policy data are prone to issues of bias and generalization, which are further exacerbated by stochasticity in human response and non-markovian belief state of a dialogue management system. To this end, we propose a batch RL framework for task oriented dialogue policy learning: causal aware safe policy improvement (CASPI). This method gives guarantees on dialogue policy's performance and also learns to shape rewards according to intentions behind human responses, rather than just mimicking demonstration data; this couple with batch-RL helps overall with sample efficiency of the framework. We demonstrate the effectiveness of this framework on a dialogue-context-to-text Generation and end-to-end dialogue task of the Multiwoz2.0 dataset. The proposed method outperforms the current state of the art on these metrics, in both case. In the end-to-end case, our method trained only on 10\% of the data was able to out perform current state in three out of four evaluation metrics.
Dobsonia minor
Creators: name: Koopman, Karl F.
Publisher: name: Zenodo
Year: 1993
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Chiroptera
Pteropodidae
Dobsonia
Dobsonia minor

description: Dobsonia minor (Dobson, 1879). Proc. Zool. Soc. Lond., 1878:875 [1879]. TYPE LOCALITY: Indonesia, Irian Jaya, Manokwari Div., Amberbaki. DISTRIBUTION: C and W New Guinea and adjacent small islands; Sulawesi. STATUS: IUCN - Insufficiently known.
description: Published as part of Karl F. Koopman, 1993, Order Chiroptera, pp. 137-241 in Mammal Species of the World (2 nd Edition), Washington and London :Smithsonian Institution Press on page 140, DOI: 10.5281/zenodo.7353060
Selective Emitter in n-Type c-Si Solar Cells
Creators: name: Liu, J.
name: Janssen, G.J.M.
name: Koppes, M.
name: Kossen, E.J.
name: Tool, K.
name: Komatsu, Y.
name: Anker, J.
name: Gutjahr, A.
name: Vlooswijk, A.
name: Luchies, J.M.
name: Siareyeva, O.
name: Granneman, E.
name: Romijn, I.
Publisher: name: WIP
Year: 2015
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 31st European Photovoltaic Solar Energy Conference and Exhibition; 633-636
description: A selective emitter is expected to have a better blue response, less Auger recombination, less contact recombination and lower contact resistivity in industrially processed n-type solar cells. In this work, we present a controllable process to make a selective emitter by applying a printable resist on the emitter as a mask. In the subsequent etch process the p+ emitter can be selectively etched to optimize the passivation and conductivity. IV measurements from a batch of solar cells are presented to demonstrate the improvements on Voc and Isc. The mean efficiency of the SE cells is increased by 0.24% absolute compared to the standard homogeneous emitter cells resulting in a highest efficiency of 20.7%.
Pattern Saw Marks on Diamond Wire Cut Wafers – from Wafer to Module
Creators: name: Lanz, M.
name: Bätzner, D.L.
name: Yao, Y.
name: Kramer, R.
name: Andreetta, L.
name: Lachenal, D.
name: Frammelsberger, W.
name: Legradic, B.
name: Meixenberger, J.
name: Papet, P.
name: Strahm, B.
name: Wahli, G.
Publisher: name: WIP
Year: 2015
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Feedstock, Crystallisation and Wafering

description: 31st European Photovoltaic Solar Energy Conference and Exhibition; 615-618
description: wafer surface aspect named pattern saw marks (PSM) is elucidated. PSM occur on solar silicon
wafers cut by the diamond wire (DW) wafer slicing process, due to the back-and-forth mode (also called pilgrim
mode) of cutting. The wavelength of these PSM is equal to the feed per cycle of the cutting process. The PSM show a
profilometric amplitude that can be controlled by the cutting process parameters. We fabricated wafers with different
PSM dimensions by wafer slicing, and we investigated the effect of the PSM on the cell and module fabrication
process steps, and on the solar cell and module performance.
First-time mothers' perceptions of the role of general practitioners
Creators: name: Anderson, Catherine .
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Challenges and Implications of Online Education in Higher Education Institutions in Addis Ababa during COVID-19 Pandemic Lockdown- from the Perspectives of Teachers
Creators: name: Zewditu, Girma
Publisher: name: Journal of Hope Enterprise University College
Year: 2023

description: This study investigated the challenges that higher education (HEI) teachers faced during the COVID-19 pandemic lockdown and their implications on the quality of online teaching, advising, and assessment processes, and competency of graduates. The study found that the most dominant modes of instruction were teachers sending reading materials and written communications through the Google Classroom platform followed by online in real-time with video conferencing. The most challenging factors found were weak internet connection, difficulty in having a definitive measure of students' performance, online security and privacy, and students' digital incompetence in meeting deadlines for submission of examinations and assignments. The study also found that internet strength and online security and privacy had a significant effect on the quality of online teaching, advising, and assessment procedures. The study finally suggested that HEIs in advancing a blended mode of delivery and assessment, as a regular mode of instruction, would adopt supportive applications and computerized adaptive testing for effective course delivery and interaction with students. The study's findings are important because they provide insights into the challenges that HEI teachers faced during the COVID-19 pandemic lockdown and their implications on the quality of online teaching, advising, and assessment processes, and competency of graduates. The study's findings can be used to inform the development of policies and strategies to address these challenges and improve the quality of online education.
description: Journal of Hope Enterprise University College, Vol. 1 No. 1 (2023): Journal of Hope Enterprise University College
High Efficiency Si Solar Cells with Photonic Crystal Rear Reflector
Creators: name: Lee, B.G.
name: Eisenlohr, J.
name: Feldmann, F.
name: Drießen, M.
name: Rachow, T.
name: Tucher, N.
name: Goldschmidt, J.C.
name: Benick, J.
name: Hermle, M.
Publisher: name: WIP
Year: 2015
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 31st European Photovoltaic Solar Energy Conference and Exhibition; 642-644
description: A photonic crystal rear reflector is demonstrated to increase the photocurrent of high efficiency Si
solar cells; specifically, a rear sphere grating structure is shown to improve the performance of a cell by enhancing its
absorption of near-infrared photons. A cell with a planar front surface and rear sphere grating is fabricated and
achieves 22.1% efficiency with a remarkably high short-circuit current density of 38.1 mA/cm2. Solar cell quantum
efficiency (QE) measurements reveal an increase in photocurrent from longer-wavelength light near the bandgap of
Si, as compared to the equivalent cell having a lossless flat mirror at the rear. This demonstrates the effectiveness of
the rear sphere grating as a light-trapping structure that increases the optical path-length and absorption within the
cell. Moreover, optical measurements indicate that a cell having a random pyramid texture on the front side and a
rear sphere grating could almost reach the Yablonovitch limit calculated for light-trapping.
Molecular jet emission and a spectroscopic survey of S235AB
Creators: name: Burns, R. A.
name: Handa, T.
name: Hirota, T.
name: Motogi, K.
name: Imai, I.
name: Omodaka, T.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Context. The S235AB star forming region houses a massive young stellar object which has recently been reported to exhibit possible evidence of jet rotation - an illusive yet crucial component of disk aided star formation theories. Aims. To confirm the presence of a molecular counterpart to the jet and to further study the molecular environment in in S235AB. Methods. We search for velocity wings in the line emission of thermal SiO (J=2-1, v=0), a tracer of shocked gas, which would indicate the presence of jet activity. Utilising other lines detected in our survey we use the relative intensities of intra species transitions, isotopes and hyperfine transitions to derive opacities, temperatures, column densities and abundances of various molecular species in S235AB. Results. The SiO (J=2-1, v=0) emission exhibits velocity wing of up to 75 km/s above and below the velocity of the star, indicating the presence of a jet. The molecular environment describes an evolutionary stage resemblant of a hot molecular core.
Influence of RTP Process on the Carrier Lifetime in Bare Cz Silicon Wafers
Creators: name: Kouhlane, Y.
name: Bouhafs, D.
name: Si-Kaddour, R.
name: Boufnik, R.
name: Khelifati, N.
name: Boucheham, A.
Publisher: name: WIP
Year: 2015
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Feedstock, Crystallisation and Wafering

description: 31st European Photovoltaic Solar Energy Conference and Exhibition; 626-628
description: Solar cells made from Boron doped Czochralski grown silicon ingots (Cz-Si) have the advantage of a
higher efficiency potential. However, the lifetime of minority charge carrier main indicator of crystalline silicon
wafers quality, is limited by degradation under light illumination (LID), caused by metastable defects. It is possible to
increase the stable lifetime after LID degradation permanently, using a rapid thermal process (RTP). In this
perspective, we studied the effect of RTP cycle with different peak temperatures (620, 675, 730, 785 and 830 °C) on
monocrystalline Cz-Si p-type wafers. The treated wafers have undergone a light degradation step with different light
exposure time. Minority charge carrier lifetime’s (n) measurement was performed by the quasi-steady state (QSSPC)
method. A reduction of LID phenomena degradation was observed. This lead to an improvement of the stable
effective lifetime enhanced by RTP process. Also, analysis of Shockley–Read–Hall (SRH) lifetime shows the
presence of defects with a deep level energy. Therefore, the impact of boron-oxygen complex (B-O) on n
degradation was confirmed by the calculated of effective defect concentration (Nt) and the defect annihilation rate
(Rann). Finally, the results of recovery with a stabilized lifetime by a RTP process are very promising to ameliorate
the electrical quality of the Cz-Si wafer which contributes to reach higher solar cell efficiency whti a long life time
PV modules performances.
Optimization of BBr3 Diffusion Processes for n-Type Silicon Solar Cells
Creators: name: Werner, S.
name: Lohmüller, E.
name: Belledin, U.
name: Vlooswijk, A.H.G.
name: Naber, R.C.G.
name: Mack, S.
name: Wolf, A.
Publisher: name: WIP
Year: 2015
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Solar Cell Improvements

description: 31st European Photovoltaic Solar Energy Conference and Exhibition; 637-641
description: In this work, we investigate boron diffusion processes for emitter formation on the front side of n-type Cz-Si solar cells with an edge length of 156 mm. The processes are performed in an industrial tube furnace from Tempress Systems using boron tribromide (BBr3) as liquid dopant source. An initial optimization of BBr3 diffusion processes yields a significant improvement in the homogeneity in sheet resistance Rsh across the wafers and from wafer to wafer for full load runs. A standard deviation  of the Rsh across the wafer in the range of 3% is achieved for a mean Rsh ≈ 70 Ω/sq. Dark saturation current density j0e = 60 fA/cm² is extracted from lifetime samples with alkaline textured surface and PECVD Al2O3/SiNx passivation after firing. A second optimization aimed at reducing emitter recombination by decreasing the maximum boron doping concentration Nmax near the surface. By adapting the post-oxidation incorporated within the BBr3 diffusion process, Nmax is decreased to 1.8·1019 cm-3 while the junction depth increases to slightly above 800 nm (Rsh ≈ 115 Ω/sq,  below 4%). This results in a reduction in j0e to a value of j0e = 30 fA/cm², which corresponds to an open-circuit voltage limit of 717 mV. Despite the fairly low Nmax, low spe-cific contact resistance below 4 mΩcm² is found for screen-printed and fired contacts using commercially available silver-aluminum paste. Hence, post-oxidation is found to be a promising method for manipulating boron doping profiles while maintaining high homogeneity in Rsh.
Robust High-speed Running for Quadruped Robots via Deep Reinforcement Learning
Creators: name: Bellegarda, Guillaume
name: Chen, Yiyu
name: Liu, Zhuochen
name: Nguyen, Quan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Robotics (cs.RO)
subject: Machine Learning (cs.LG)
subject: Systems and Control (eess.SY)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Deep reinforcement learning has emerged as a popular and powerful way to develop locomotion controllers for quadruped robots. Common approaches have largely focused on learning actions directly in joint space, or learning to modify and offset foot positions produced by trajectory generators. Both approaches typically require careful reward shaping and training for millions of time steps, and with trajectory generators introduce human bias into the resulting control policies. In this paper, we present a learning framework that leads to the natural emergence of fast and robust bounding policies for quadruped robots. The agent both selects and controls actions directly in task space to track desired velocity commands subject to environmental noise including model uncertainty and rough terrain. We observe that this framework improves sample efficiency, necessitates little reward shaping, leads to the emergence of natural gaits such as galloping and bounding, and eases the sim-to-real transfer at running speeds. Policies can be learned in only a few million time steps, even for challenging tasks of running over rough terrain with loads of over 100% of the nominal quadruped mass. Training occurs in PyBullet, and we perform a sim-to-sim transfer to Gazebo and sim-to-real transfer to the Unitree A1 hardware. For sim-to-sim, our results show the quadruped is able to run at over 4 m/s without a load, and 3.5 m/s with a 10 kg load, which is over 83% of the nominal quadruped mass. For sim-to-real, the Unitree A1 is able to bound at 2 m/s with a 5 kg load, representing 42% of the nominal quadruped mass.
title: Nautische optimalisatie CP Nieuwe Sluis Zeebrugge: deelrapport 2. Impact passerende vaart op Vismijn: Huidige condities
Creators: name: Verwilligen, Jeroen
name: Eloot, Katrien
Publisher: name: Flanders Hydraulics Research
Year: 2022

description: Title : WL Rapporten. Waterbouwkundig Laboratorium: Antwerpen. Volume : 20_011_2 Issue : Pagination : VII, 19
The Effect of Covid-19 Pandemic in Ethiopian Online Market,
Creators: name: Esayas, Taye
Publisher: name: Journal of Hope Enterprise University College
Year: 2023

description: The COVID-19 pandemic has had a significant impact on the Ethiopian online market. The study found that the majority of respondents had never used the online market before the pandemic, and that more than two-thirds of those who did access social media did not make any purchases. The study also found that using the Internet market in Ethiopia was difficult due to a lack of awareness and inadequate Internet infrastructure. The study recommends that companies that provide services to online markets in Ethiopia focus on creating and designing simpler, easier-to-use platforms that do not necessitate a lot of mental and physical effort to complete transactions. The study's findings are important because they provide insights into the challenges that the Ethiopian online market is facing and the potential opportunities for growth. The study's findings can be used to inform the development of policies and strategies to support the growth of the Ethiopian online market.
description: Journal of Hope Enterprise University College, Vol. 1 No. 1 (2023): Journal of Hope Enterprise University College
Effect of Phosphorus Gettering on Quasi-Single-Crystalline Silicon Wafers
Creators: name: Søndenå, R.
name: Ekstrøm, K.E.
name: Stokkan, G.
name: Dalaker, H.
name: Lehmann, T.
name: Arnberg, L.
name: Di Sabatino, M.
Publisher: name: WIP
Year: 2015
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Feedstock, Crystallisation and Wafering

description: 31st European Photovoltaic Solar Energy Conference and Exhibition; 571-574
description: A quasi-single-crystalline silicon ingot has been produced in a pilot scale furnace. The directional growth is
controlled using a seed layer of equally oriented monocrystalline plates. This seed layer has been specially designed
with different junction gaps. Junctions between seed plates are known to be nucleation sites for dislocation growth.
Angular mismatch between the seeds has been measured using a Laue X-ray scanning method. Both increased
spacing between the seed plates as well as angular mismatch lead to increased dislocation growth. While the large
mono-like areas respond well to phosphorus gettering the improvements are minimal in the dislocation rich areas
directly above the seed junctions.
Distribution Dependent Stochastic Porous Media Equations
Creators: name: Gao, Jingyue
name: Hong, Wei
name: Liu, Wei
Publisher: name: arXiv
Year: 2021
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: Using the generalized variational framework, the strong/weak existence and uniqueness of solutions are derived for a class of distribution dependent stochastic porous media equations on general measure spaces, which also extends the classical well-posedness result of quasilinear SPDE to the distribution dependent case.
description: to appear in Stochastics and Dynamics, Vol. 22, No. 8 (2022) 2240026
Dobsonia moluccensis
Creators: name: Koopman, Karl F.
Publisher: name: Zenodo
Year: 1993
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Chiroptera
Pteropodidae
Dobsonia
Dobsonia moluccensis

description: Dobsonia moluccensis (Quoy and Gaimard, 1830). In d'Urville, Voy...de Astrolabe, Zool., l(L'Homme, Mamm. Oiseaux):86. TYPE LOCALITY: Indonesia, Molucca Isis, Amboina Isl. DISTRIBUTION: Bismarck Arch.; New Guinea; Aru Isis, Batanta, and Mysol (off W New Guinea) and Molucca Isis (including Waigeo Isl); N Queensland (Australia). SYNONYMS: anderseni, magna. COMMENTS: Does not include pannietensis (see Bergmans, 1979). Includes anderseni and magna; see Koopman (1979:6), but see also Bergmans and Sarbini (1985).
description: Published as part of Karl F. Koopman, 1993, Order Chiroptera, pp. 137-241 in Mammal Species of the World (2 nd Edition), Washington and London :Smithsonian Institution Press on page 140, DOI: 10.5281/zenodo.7353060
description: {"references": ["Bergmans, W. 1979. Taxonomy and zoogeography of Dobsonia Palmer, 1898, from the Louisiade Archipelago, the D'Entrecasteaux Group, Trobriand Island and Woodlark Island (Mammalia, Megachiroptera). Beaufortia, 29 (355): 199 - 214.", "Koopman, K. F. 1979. Zoogeography of mammals from islands off the northeastern coast of New Guinea. American Museum Novitates, 2690: 1 - 17.", "Bergmans, W., and S. Sarbini. 1985. Fruit bats of the genus Dobsonia Palmer, 1898, from the islands of Biak, Owii, Numfoor and Yapen, Irian Jaya (Mammalia; Megachiroptera). Beaufortia, 34 (6): 181 - 189."]}
GP's and PTSD : a cross-sectional observational study to determine the attitudes, knowledge and stated practices of Local Medical Officer's (LMO's)/General Practitioner's (GP's) with respect to the diagnosis and management of post traumatic stress disorder (PTSD), including identification of obstacles and barriers to recognition, diagnosis and management
Creators: name: Kelly, Glynn Davydd.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Spontaneous finite momentum pairing in superconductors without inversion symmetry
Creators: name: Steinbok, Aviram
name: Michaeli, Karen
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We analyze the effect of magnetic fluctuations in superconductors with strong spin-orbit coupling and show that they drive a phase transition between two superconducting states: a conventional phase with zero center-of-mass momentum of Cooper pairs, and an exotic phase with non-zero pair momentum. The latter is found to exhibit persistent currents without magnetic field in doubly connected geometries such as rings. Surprisingly, the transition temperature into the superconducting state can be increased by applying a Zeeman magnetic field.
description: 6 pages, 4 figures
Hydrogen passivation of Interstitial Iron in Silicon by Annealing with PECVD Silicon Nitride Films
Creators: name: Liu, A.
name: Sun, C.
name: Macdonald, D.
Publisher: name: WIP
Year: 2015
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Feedstock, Crystallisation and Wafering

description: 31st European Photovoltaic Solar Energy Conference and Exhibition; 623-625
description: This paper reports on the effective passivation of interstitial iron in p-type boron-doped silicon via
annealing with plasma-enhanced chemical vapour deposited (PECVD) silicon nitride films. The concentration of
interstitial iron was shown to reduce by more than 90% after a 30-minute anneal at 600 – 900oC with the silicon
nitride films present. The most effective hydrogenation of iron was found to take place at 700oC, where more than
99% of iron was passivated after 30 minutes. Results show that the observed reductions in the interstitial iron
concentrations are not likely to be caused by the precipitation of iron at structural defects by a hydrogen-enhanced
diffusivity of iron, as has previously been suggested.
Analysis of horizontal flows in the solar granulation
Creators: name: Noda, C. Quintero
name: Shimizu, T.
name: Suematsu, Y.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Solar limb observations sometimes reveal the presence of a satellite lobe in the blue wing of the Stokes I profile from pixels belonging to granules. The presence of this satellite lobe has been associated in the past to strong line of sight gradients and, as the line of sight component is almost parallel to the solar surface, to horizontal granular flows. We aim to increase the knowledge about these horizontal flows studying a spectropolarimetric observation of the north solar pole. We will make use of two state of the art techniques, the spatial deconvolution procedure that increases the quality of the data removing the stray light contamination, and spectropolarimetric inversions that will provide the vertical stratification of the atmospheric physical parameters where the observed spectral lines form. We inverted the Stokes profiles using a two component configuration, obtaining that one component is strongly blueshifted and displays a temperature enhancement at upper photospheric layers while the second component has low redshifted velocities and it is cool at upper layers. In addition, we examined a large number of cases located at different heliocentric angles, finding smaller velocities as we move from the centre to the edge of the granule. Moreover, the height location of the enhancement on the temperature stratification of the blueshifted component also evolves with the spatial location on the granule being positioned on lower heights as we move to the periphery of the granular structure.
description: 8 pages, 6 figures
Scattering properties of the three-dimensional topological insulator Sb2Te3: Coexistence of topologically trivial and non-trivial surface states with opposite spin-momentum helicity
Creators: name: Sessi, P.
name: Storz, O.
name: Bathon, T.
name: Wilfert, S.
name: Kokh, K. A.
name: Tereshchenko, O. E.
name: Bihlmayer, G.
name: Bode, M.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The binary chalcogenides Bi2Te3 and Bi2Se3 are the most widely studied topological insulators. Although the quantum anomalous Hall effect has recently been observed in magnetically doped Sb2Te3 this compound has been studied to a much lesser extend. Here, by using energy resolved quasiparticle interference mapping, we investigate the scattering events of pristine Sb2Te3 surfaces. We find that, in addition to the Dirac fermions, another strongly spin polarized surface resonance emerges at higher energies in the unoccupied electronic states. Although the two surface states are of different origin, i.e. topologically protected and trivial, respectively, both show strongly directional scattering properties and absence of backscattering. Comparison with ab-initio calculations demonstrates that this is a direct consequence of their spin momentum locked spin texture which is found to exhibit an opposite rotational sense for the trivial state and the Dirac state.
SoK: Decentralized Exchanges (DEX) with Automated Market Maker (AMM) Protocols
Creators: name: Xu, Jiahua
name: Paruch, Krzysztof
name: Cousaert, Simon
name: Feng, Yebo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Trading and Market Microstructure (q-fin.TR)
subject: Computer Science and Game Theory (cs.GT)
subject: FOS: Economics and business
subject: FOS: Computer and information sciences

description: As an integral part of the decentralized finance (DeFi) ecosystem, decentralized exchanges (DEXs) with automated market maker (AMM) protocols have gained massive traction with the recently revived interest in blockchain and distributed ledger technology (DLT) in general. Instead of matching the buy and sell sides, automated market makers (AMMs) employ a peer-to-pool method and determine asset price algorithmically through a so-called conservation function. To facilitate the improvement and development of automated market maker (AMM)-based decentralized exchanges (DEXs), we create the first systematization of knowledge in this area. We first establish a general automated market maker (AMM) framework describing the economics and formalizing the system's state-space representation. We then employ our framework to systematically compare the top automated market maker (AMM) protocols' mechanics, illustrating their conservation functions, as well as slippage and divergence loss functions. We further discuss security and privacy concerns, how they are enabled by automated market maker (AMM)-based decentralized exchanges (DEXs)' inherent properties, and explore mitigating solutions. Finally, we conduct a comprehensive literature review on related work covering both decentralized finance (DeFi) and conventional market microstructure.
Effects of Superimpose Low and Medium Frequency Magnetic Fields in Induction Direction Solidification System
Creators: name: Dughiero, F.
name: Forzan, M.
name: Sempreboni, N.
name: Tolomio, A.
Publisher: name: WIP
Year: 2015
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Feedstock, Crystallisation and Wafering

description: 31st European Photovoltaic Solar Energy Conference and Exhibition; 591-594
description: Nowadays, the PV market is still dominated by solar panels that are based on Silicon technology. The
manufacturing process to obtain c-Si solar cells has numerous phases, among which, the casting process is one of the
most energy consuming. In PV production the methods of silicon casting which have achieved a strengthened industrial
maturity are Czochralski (Cz) technique and Directional Solidification method (DS).
Previous works have demonstrated the effectiveness of the induction heating applied to DS processes, mostly in order
to improve the control and reduce the process time. In addition, appreciable results have been achieved in producing
high quality multi-crystal wafer, mc-wafer, in a prototype of iDSS (induction Directional Solidification System)
furnace.
In this paper, the application of a magnetic field at lower frequency respect to the actual frequency applied for heating
in the furnace is studied in order to analyse the flow motion of the molten Silicon inside the crucible. The goal is to
increase the mixing effect and consequently to delay the formation of SiC particles and focusing the impurity
concentration in the last phase of solidification. The study has been conducted on numerical models of a G2 iDSS
prototype installed at the Laboratory of Electroheat of Padua University.
Determinants of Financial Performance of Floriculture Companies in Oromia Regional State of East Shoa Zone
Creators: name: Kassaye, Haile
Publisher: name: Journal of Hope Enterprise University College
Year: 2023

description: This study aimed to investigate the determinants of the financial performance of floriculture companies in the Oromia Regional State - East Shoa Zone. The study used an explanatory research design with panel data for the period of 2011 to 2020 by selecting purposively 10 samples out of 11 farms. Financial performance is represented by the return on assets. Liquidity, leverage, asset utilization, operating expense, cash conversion cycle, innovation, farm size, and age were used as independent variables, and an exchange rate as a control variable. Furthermore, the collected data were analyzed by using descriptive, correlation, and regression analysis techniques. The random effects model was chosen, and the data were summarized using E-views 10 statistical software. The findings revealed that leverage, asset utilization, cash convection cycle, and farm size had a positive and significant effect on return on assets, whereas liquidity, operating expenses, innovation, and farm age had negative and significant effects, yet exchange rate had a negative and insignificant effect. The findings of the study suggest that reinvestment of idle resources, maintaining an optimum level of debt, arranging group exporting, capital-intensive approach, outsourcing non-operating activities, locally supplying rose seeds, and diversifying the asset base are recommended to be in place to sustainably enhance the return for flower farms.
description: Journal of Hope Enterprise University College, Vol. 1 No. 1 (2023): Journal of Hope Enterprise University College
Dobsonia pannietensis
Creators: name: Koopman, Karl F.
Publisher: name: Zenodo
Year: 1993
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Chiroptera
Pteropodidae
Dobsonia
Dobsonia pannietensis

description: Dobsonia pannietensis (De Vis, 1905). Ann. Queensl. Mus., 6:36. TYPE LOCALITY: Papua New Guinea, Louisiade Arch., Panniet Isl. DISTRIBUTION: Louisiade Arch., D'Entrecasteaux Isis, and Trobriand Isis (Papua New Guinea). SYNONYMS: remota. COMMENTS: Considered a subspecies of moluccensis by Laurie and Hill (1954:42), but as a separate species by Bergmans (1979). Includes remota (see Koopman, 1982:6). A record of remota from Bougainville Isl is based on a misidentified inermis (see Bergmans, 1979).
description: Published as part of Karl F. Koopman, 1993, Order Chiroptera, pp. 137-241 in Mammal Species of the World (2 nd Edition), Washington and London :Smithsonian Institution Press on page 140, DOI: 10.5281/zenodo.7353060
description: {"references": ["Laurie, E. M. O., and J. E. Hill. 1954. List of land mammals of New Guinea, Celebes and adjacent islands 1758 - 1952. British Museum (Natural History) Publications, London, 175 pp.", "Bergmans, W. 1979. Taxonomy and zoogeography of Dobsonia Palmer, 1898, from the Louisiade Archipelago, the D'Entrecasteaux Group, Trobriand Island and Woodlark Island (Mammalia, Megachiroptera). Beaufortia, 29 (355): 199 - 214.", "Koopman, K. F. 1982. Results of the Archbold Expeditions. No. 109. Bats from eastern Papua and the east Papuan Islands. American Museum Novitates, 2747: 1 - 34."]}
Spin Coherence and $^{14}$N ESEEM Effects of Nitrogen-Vacancy Centers in Diamond with X-band Pulsed ESR
Creators: name: Rose, B. C.
name: Weis, C. D.
name: Tyryshkin, A. M.
name: Schenkel, T.
name: Lyon, S. A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Pulsed ESR experiments are reported for ensembles of negatively-charged nitrogen-vacancy centers (NV$^-$) in diamonds at X-band magnetic fields (280-400 mT) and low temperatures (2-70 K). The NV$^-$ centers in synthetic type IIb diamonds (nitrogen impurity concentration $<1$~ppm) are prepared with bulk concentrations of $2\cdot 10^{13}$ cm$^{-3}$ to $4\cdot 10^{14}$ cm$^{-3}$ by high-energy electron irradiation and subsequent annealing. We find that a proper post-radiation anneal (1000$^\circ$C for 60 mins) is critically important to repair the radiation damage and to recover long electron spin coherence times for NV$^-$s. After the annealing, spin coherence times of T$_2 = 0.74$~ms at 5~K are achieved, being only limited by $^{13}$C nuclear spectral diffusion in natural abundance diamonds. At X-band magnetic fields, strong electron spin echo envelope modulation (ESEEM) is observed originating from the central $^{14}$N nucleus. The ESEEM spectral analysis allows for accurate determination of the $^{14}$N nuclear hypefine and quadrupole tensors. In addition, the ESEEM effects from two proximal $^{13}$C sites (second-nearest neighbor and fourth-nearest neighbor) are resolved and the respective $^{13}$C hyperfine coupling constants are extracted.
description: 10 pages, 5 figures
Comparison of the LBE and DUGKS methods for DNS of decaying homogeneous isotropic turbulence
Creators: name: Wang, Peng
name: Wang, Lian-Ping
name: Guo, Zhaoli
Publisher: name: arXiv
Year: 2016
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The main objective of this work is to perform a detailed comparison of the lattice Boltzmann equation (LBE) and the recently developed discrete unified gas-kinetic scheme (DUGKS) methods for direct numerical simulation (DNS) of the decaying homogeneous isotropic turbulence (DHIT) in a periodic box. The flow fields and key statistical quantities computed by both methods are compared with those from pseudo-spectral (PS) method. The results show that the LBE and DUGKS have almost the same accuracy when the flow field is well-resolved, and that the LBE is less dissipative and is slightly more efficient than the DUGKS, but the latter has a superior numerical stability, particularly for high Reynolds number flows. Therefore, the DUGKS method can be viewed as a viable tool for DNS of turbulent flows. It should be emphasized that the main advantage of the DUGKS when compared with the LBE method is its feasibility in adopting nonuniform meshes, which is critical for wall-bounded turbulent flows. The present work provides a basis for further applications of DUGKS in studying the physics of the turbulent flows.
description: 32 pages,20 figures
Pulsating low-mass white dwarfs in the frame of new evolutionary sequences: III. The pre-ELM white dwarf instability strip
Creators: name: Córsico, A. H.
name: Althaus, L. G.
name: Serenelli, A. M.
name: Kepler, S. O.
name: Jeffery, C. S.
name: Corti, M. A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Two low-mass pre-white dwarfs, which could be precursors of ELM white dwarfs, have been observed to show multiperiodic photometric variations. They could constitute a new class of pulsating low-mass pre-white dwarf stars. We present a detailed nonadiabatic pulsation study of such stars, employing full evolutionary sequences of low-mass He-core pre-white dwarf models. We have considered models in which element diffusion is accounted for and also models in which it is neglected. We confirm and explore in detail a new instability strip in the domain of low gravities and low effective temperatures of the $T_{\rm eff}-\log g$ diagram, where low-mass pre-white dwarfs are currently found. The destabilized modes are radial and nonradial $p$ and $g$ modes excited by the $κ-γ$ mechanism acting mainly at the zone of the second partial ionization of He, with non-negligible contributions from the region of the first partial ionization of He and the partial ionization of H. The computations with element diffusion are unable to explain the pulsations observed in the two known pulsating pre-white dwarfs, suggesting that element diffusion might be inhibited at these stages of the pre-white dwarf evolution. Our nonadiabatic models without diffusion, on the other hand, naturally explain the existence and range of periods of the pulsating pre-white dwarf star WASP J1628$+$10B, although they fail to explain the pulsations of WASP J0247$-$25B, the other known member of the class, indicating that the He abundance in the driving region of this star might be substantially larger than predicted by our models. Further discoveries of additional members of this new class of pulsating stars and their analysis in the context of the theoretical background presented in this paper will shed new light on the evolutionary history of their progenitor stars.
description: 15 pages, 15 figures, 1 table. To be published in Astronomy and Astrophysics
Influence of the "second gap" on the transparency-conductivity compromise in transparent conducting oxides: an ab initio study
Creators: name: Ha, Viet-Anh
name: Waroquiers, David
name: Rignanese, Gian-Marco
name: Hautier, Geoffroy
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Transparent conducting oxides (TCOs) are essential to many technologies. These materials are doped (\emph{n}- or \emph{p}-type) oxides with a large enough band gap (ideally $>$3~eV) to ensure transparency. However, the high carrier concentration present in TCOs lead additionally to the possibility for optical transitions from the occupied conduction bands to higher states for \emph{n}-type materials and from lower states to the unoccupied valence bands for \emph{p}-type TCOs. The "second gap" formed by these transitions might limit transparency and a large second gap has been sometimes proposed as a design criteria for high performance TCOs. Here, we study the influence of this second gap on optical absorption using \emph{ab initio} computations for several well-known \emph{n}- and \emph{p}-type TCOs. Our work demonstrates that most known \emph{n}-type TCOs do not suffer from second gap absorption in the visible even at very high carrier concentrations. On the contrary, \emph{p}-type oxides show lowering of their optical transmission for high carrier concentrations due to second gap effects. We link this dissimilarity to the different chemistries involved in \emph{n}- versus typical \emph{p}-type TCOs. Quantitatively, we show that second gap effects lead to only moderate loss of transmission (even in p-type TCOs) and suggest that a wide second gap, while beneficial, should not be considered as a needed criteria for a working TCO.
description: 6 pages, 4 figures, APS March Meeting
A versatile ring trap for quantum gases
Creators: name: de Herve, Mathieu de Goër
name: Guo, Yanliang
name: de Rossi, Camilla
name: Kumar, Avinash
name: Badr, Thomas
name: Dubessy, Romain
name: Longchambon, Laurent
name: Perrin, Hélène
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We report on the confinement of a Bose-Einstein condensate in an annular trap with widely tunable parameters. The trap relies on a combination of magnetic, optical and radio-frequency fields. The loading procedure is discussed. We present annular traps with radii adjusted between 20 and 150 micrometers. We demonstrate the preparation of persistent flows both with a rotating laser stirrer and with a global quadrupole deformation of the ring.Our setup is well adapted for the study of superfluid dynamics.
Origin of the Periodic Structures on Silicon Wafers Sawn with Diamond Wire
Creators: name: Sunder, K.
name: Buchwald, R.
name: Anspach, O.
Publisher: name: WIP
Year: 2015
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Feedstock, Crystallisation and Wafering

description: 31st European Photovoltaic Solar Energy Conference and Exhibition; 595-599
description: The optimal usage of costly but also high-performing diamond wire in the wafering process requires a
regular back-and-forth movement of the wire web with a small fresh wire supply per cycle (pilgrim mode) instead of
unidirectional movement as in the slurry-based process. This leads to the generation of periodic structures (pilgrim
waves) on the wafer surface that may have an impact on cell production. For this the understanding of the formation and
the manipulation of the pilgrim waves are of great importance. Based on surface topology measurements of wafers from
twelve diamond wire cuts a model for the pilgrim wave formation is proposed. It is shown that both the number and the
depth of the pilgrim waves depend on the sawing parameters. Furthermore the impact of oscillating wire speed on the
shape of pilgrim waves is discussed.
Formation of Metallic Silicon Formed by Carbothermal Reduction of Silica Fabricated Using Shirasu Volcanic Ash
Creators: name: Hatakeyama, K.
name: Sato, K.
name: Itaka, K.
name: Maeda, K.
name: Sakai, K.
name: Nishioka, K.
Publisher: name: WIP
Year: 2015
Subjects: WAFER-BASED SILICON SOLAR CELLS AND MATERIALS TECHNOLOGY
Silicon Feedstock, Crystallisation and Wafering

description: 31st European Photovoltaic Solar Energy Conference and Exhibition; 575-577
description: Metallic silicon was prepared from Shirasu volcanic ash using high-frequency induction furnace. The
high-frequency induction furnace is an electrical furnace in which the heat is applied by induction heating of the
sample. High purity silica fabricated using Shirasu and carbon was mixed. The mixture and the silicon carbide were
layered into a carbon crucible inside the electric furnace. The sample was heated under argon atmosphere for 16
minutes at 1900 °C. The sample was cooled down to room temperature. After the experiment, the sample was
evaluated by X-ray diffraction (XRD, PAnalytical, X’Pert PRO) and energy dispersive X-ray spectroscopy (EDX,
Hitach, S-5500) and Raman spectroscopy.