cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Individual choice behaviour and urban commuting
Creators: name: Torchinsky, Raymon Lev
Publisher: name: University of British Columbia
Year: 2010

description: Urban commuting patterns can be viewed as the spatial manifestation of the outcome of labour market processes. Recent theoretical and empirical work investigating urban labour markets has emphasized the role of spatial wage differentials in mediating the interrelationship between labour supply and demand distributions and the dynamics of land-use change. This thesis represents an extension of such research. A simulation approach to commuting modelling, based on the explicit characterization of the interrelationship between urban location and interaction in terms of labour market processes, is developed. The solution path logic of the simulation model is designed to provide normative commuting outcomes, given the spatial pattern of labour supply and demand, under a wide range of assumptions concerning labour market processes and choice-making behaviour of market participants. An explicit characterization of the labour market, based on the specification of an endogenous behavioural assumption set, defines a model version. Thus, the model may be used to test the ability of various behavioural constructs to explain empirical commuting patterns. The justification and internal logic underlying the development of a specific model version is presented. This version is based on the assumption that the decision by a worker to apply for a job is objectively rational, given that the market environment does not provide certainty as to the outcome of an application. It is shown that such choice behaviour is analogous to the game-theoretic mixed strategy solution to non-cooperative games under uncertainty. The algorithm of the operational model incorporating this approach is detailed. The model was tested on empirical commuting patterns derived from Vancouver Census data, and model results were compared with those obtained from a positive entropy-based model. Commuting predictions exhibited a level of accuracy comparable to that achieved by the calibrated entropy model.
Scalar-tensor black holes coupled to Euler-Heisenberg nonlinear electrodynamics
Creators: name: Stefanov, Ivan Zh.
name: Yazadjiev, Stoytcho S.
name: Todorov, Michail D.
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The no-scalar-hair conjecture rules out the existence of asymptotically flat black holes with a scalar dressing for a large class of theories. No-scalar-hair theorems have been proved for the cases of neutral black holes and for charged black holes in the Maxwell electrodynamics. These theorems, however, do not apply in the case of non-linear electrodynamics. In the present work numerical solutions describing charged black holes coupled to Euler-Heisenberg type non-linear electrodynamics in scalar-tensor theories of gravity with massless scalar field are found. In comparison to the corresponding solution in General Relativity the presented solution has a simpler causal structure the reason for which is the presence of the scalar field. The present class of black holes has a single, non-degenerate horizon, i.e., its causal structure resembles that of the Schwarzschild black hole.
description: 16 pages, 7 figures, Mod. Phys. Lett. A22, (2007) 1217-1231
Establishing phone-pair co-usage by comparing mobility patterns
Creators: name: Bosma, Wauter
name: Dalm, Sander
name: van Eijk, Erwin
name: Harchaoui, Rachid el
name: Rijgersberg, Edwin
name: Tops, Hannah Tereza
name: Veenstra, Alle
name: Ypma, Rolf
Publisher: name: arXiv
Year: 2021
Subjects: subject: Applications (stat.AP)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: In forensic investigations it is often of value to establish whether two phones were used by the same person during a given time period. We present a method that uses time and location of cell tower registrations of mobile phones to assess the strength of evidence that any pair of phones were used by the same person. The method is transparent as it uses logistic regression to discriminate between the hypotheses of same and different user, and a standard kernel density estimation to quantify the weight of evidence in terms of a likelihood ratio. We further add to previous theoretical work by training and validating our method on real world data, paving the way for application in practice. The method shows good performance under different modeling choices and robustness under lower quantity or quality of data. We discuss practical usage in court.
Metallization and Firing Process Impact on Voc – A Simulation Study
Creators: name: Koduvelikulathu, L.J.
name: Edler, A.
name: Mihailetchi, V.D.
name: Comparotto, C.
name: Halm, A.
name: Kopecek, R.
name: Peter, K.
Publisher: name: WIP
Year: 2012
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cell Characterization and Modelling

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 1432-1434
description: Realization of cost effective high efficiency solar cells is challenging. In screen printed n-type solar
cells, despite the observed high implied VOC on non-metalized cells, the screen printing and the subsequent firing
process limits the cell VOC. A considerable drop in the cell VOC v/s implied VOC is observed. This paper outlines a
systematic study of the experimentally observed loss phenomenon, using Silvaco TCAD simulation tool ATLAS. The
simulation highlights the detrimental role of the metal pastes during the contact formation mechanism. Reduced
doping profile dependent shielding effect of the minority carriers from the highly recombinative metal area results in
an increased recombination current underneath the metal finger and thereby accounts for the observed losses in VOC.
Fréchet algebras with a dominating Hilbert algebra norm
Creators: name: Ciaś, Tomasz
Publisher: name: arXiv
Year: 2021
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 46J25 (Primary) 46A11, 46A63, 46E25, 46K15, 47L60 (Secondary)

description: Let $\mathscr{L}^*(s)$ be the maximal $\mathcal{O}^*$-algebra of unbounded operators on $\ell_2$ whose domain is the space $s$ of rapidly decreasing sequences. This is a noncommutative topological algebra with involution which can be identified, for instance, with the algebra $\mathscr L(s)\cap\mathscr L(s')$ or the algebra of multipliers for the algebra $\mathscr{L}(s',s)$ of smooth compact operators. We give a simple characterization of unital commutative Fréchet ${}^*$-subalgebras of $\mathscr{L}^*(s)$ isomorphic as a Fréchet spaces to nuclear power series spaces $Λ_\infty(α)$ of infinite type. It appears that many natural Fréchet ${}^*$-algebras are closed ${}^*$-subalgebras of $\mathscr{L}^*(s)$, for example, the algebras $C^\infty(M)$ of smooth functions on smooth compact manifolds and the algebra $\mathscr S (\mathbb{R}^n)$ of smooth rapidly decreasing functions on $\mathbb{R}^n$.
description: International Conference held at the University of Oulu, July 3-11, 2017
Analysis of Historical Energy Estimates for 235 PV Systems Installed from 2007 to 2011 in the USA
Creators: name: Philip, J.
name: Golnas, A.
Publisher: name: WIP
Year: 2012
Subjects: PV Systems
Large PV Power Plants and Distributed PV: System Aspects and Grid Connection

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 3758-3762
description: SunEdison pioneered the power purchase agreement (PPA) for PV systems during the last decade in
the United States. The third-party investors who provide financing for the projects require an Independent Engineer
(IE), or Technical Advisor, to conduct an initial estimate of the system’s performance over the duration of the PPA
contract. SunEdison retains monitoring and operation of these systems and is able to compare actual performance
with the initial estimates. In this work, we compare energy and performance estimates from a single IE firm for 235
projects constructed between August 2007 and December 2010 and operated by SunEdison in the United States. The
study looks at the evolution of the various simulation assumptions over time. These 235 projects represent a total of
78,337 kWp spread across 12 states with the majority of projects in California (100) and New Jersey (58). This
portfolio of projects consists of 197 rooftop projects, 30 ground-mount projects, and 8 parking canopy projects. We
have established an Investor Performance Index (IPI), the ratio of the delivered energy from the solar plant versus the
predicted energy, and the Operational Performance Index (OPI), which is an insolation-adjusted performance index.
Utilizing the OPI, this paper examines the evolution of the estimates and the corresponding performance of the
systems as well as whether estimation capability has improved over time. Our analysis shows a steady improvement
in the predictions of the particular independent engineer but also highlights the challenges in expanding the scope of
such a study.
Disorder-Induced Stabilization of the Pseudogap in Strongly Correlated Systems
Creators: name: Chiesa, Simone
name: Chakraborty, Prabuddha B.
name: Pickett, Warren E.
name: Scalettar, Richard T.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: The interplay of strong interaction and strong disorder, as contained in the Anderson-Hubbard model, is addressed using two non-perturbative numerical methods: the Lanczos algorithm in the grand canonical ensemble at zero temperature and Quantum Monte Carlo. We find distinctive evidence for a zero-energy anomaly which is robust upon variation of doping, disorder and interaction strength. Its similarities to, and differences from, pseudogap formation in other contexts, including perturbative treatments of interactions and disorder, classical theories of localized charges, and in the clean Hubbard model, are discussed.
description: 4.2 pages, 4 figures
Complex Neural Spatial Filter: Enhancing Multi-channel Target Speech Separation in Complex Domain
Creators: name: Gu, Rongzhi
name: Zhang, Shi-Xiong
name: Zou, Yuexian
name: Yu, Dong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Sound (cs.SD)
subject: Audio and Speech Processing (eess.AS)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: To date, mainstream target speech separation (TSS) approaches are formulated to estimate the complex ratio mask (cRM) of the target speech in time-frequency domain under supervised deep learning framework. However, the existing deep models for estimating cRM are designed in the way that the real and imaginary parts of the cRM are separately modeled using real-valued training data pairs. The research motivation of this study is to design a deep model that fully exploits the temporal-spectral-spatial information of multi-channel signals for estimating cRM directly and efficiently in complex domain. As a result, a novel TSS network is designed consisting of two modules, a complex neural spatial filter (cNSF) and an MVDR. Essentially, cNSF is a cRM estimation model and an MVDR module is cascaded to the cNSF module to reduce the nonlinear speech distortions introduced by neural network. Specifically, to fit the cRM target, all input features of cNSF are reformulated into complex-valued representations following the supervised learning paradigm. Then, to achieve good hierarchical feature abstraction, a complex deep neural network (cDNN) is delicately designed with U-Net structure. Experiments conducted on simulated multi-channel speech data demonstrate the proposed cNSF outperforms the baseline NSF by 12.1% scale-invariant signal-to-distortion ratio and 33.1% word error rate.
description: 5 pages, 3 figures
Local nuclear energy density functional at next-to-next-to-next-to-leading order
Creators: name: Carlsson, B. G.
name: Dobaczewski, J.
name: Kortelainen, M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We construct nuclear energy density functionals in terms of derivatives of densities up to sixth, next-to-next-to-next-to-leading order (N3LO). A phenomenological functional built in this way conforms to the ideas of the density matrix expansion and is rooted in the expansions characteristic to effective theories. It builds on the standard functionals related to the contact and Skyrme forces, which constitute the zero-order (LO) and second-order (NLO) expansions, respectively. At N3LO, the full functional with density-independent coupling constants, and with the isospin degree of freedom taken into account, contains 376 terms, while the functionals restricted by the Galilean and gauge symmetries contain 100 and 42 terms, respectively. For functionals additionally restricted by the spherical, space-inversion, and time-reversal symmetries, the corresponding numbers of terms are equal to 100, 60, and 22, respectively.
description: 25 RevTeX pages, 1 figure, 23 tables, Physical Review C in press, misprints in Appendix C corrected
Examination of Tandem Junction a-Si/μc-Si Photovoltaic Modules in Terms of Their Sensibility to TCO-Corrosion
Creators: name: Farmani, I.
name: Helmke, C.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
Amorphous and Microcrystalline Silicon Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2098-2100
description: The replacement of traditional inverters with incorporated transformers by inverters without transformer
can increase the total annual energy yield of a photovoltaic system by 5 - 8%. Saying this there is still an uncertainty
among PV module users, whether the use of inverters without transformers always leads to TCO corrosion. This
paper describes two test procedure applied and the related results obtained when examining the sensitivity of tandem
junction amorphous / micro-crystalline photovoltaic (PV) modules to TCO corrosion through applying a set of
different electrical potentials to the modules, while the modules are undergoing damp heat testing.
Semiotically-grounded distant viewing of diagrams: insights from two multimodal corpora
Creators: name: Hiippala, Tuomo
name: Bateman, John A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computation and Language (cs.CL)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Multimedia (cs.MM)
subject: FOS: Computer and information sciences

description: In this article, we bring together theories of multimodal communication and computational methods to study how primary school science diagrams combine multiple expressive resources. We position our work within the field of digital humanities, and show how annotations informed by multimodality research, which target expressive resources and discourse structure, allow imposing structure on the output of computational methods. We illustrate our approach by analysing two multimodal diagram corpora: the first corpus is intended to support research on automatic diagram processing, whereas the second is oriented towards studying diagrams as a mode of communication. Our results show that multimodally-informed annotations can bring out structural patterns in the diagrams, which also extend across diagrams that deal with different topics.
description: 22 pages, 11 figures. Under review at Digital Scholarship in the Humanities
Influence of Selenization Conditions on Wide-Bandgap CuAlSe2 Thin Films
Creators: name: López-García, J.
name: Sotelo, C.
name: Montero, J.
name: Guillén, C.
name: Herrero, J.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
CdTe, CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2815-2818
description: Wide-bandgap chalcopyrite CuAlSe2 (CAS) can be used as absorbent layer in multijunction devices.
Moreover, a complete knowledge of this material is essential to obtain high quality solar cells based on CuIn1-xAlxSe2
(CIAS) chalcopyrite. Al/Cu/Al matallic layers have been evaporated sequentially and selenized in a graphite box
under flowing Ar atmosphere. The structural, optical, morphological, electrical and compositional properties of the
samples have been analyzed. The selenization time to obtain a complete formation and crystallization of the
compound has been studied. Annealing times from 30 to 180 minutes have been tested obtaining a complete and
homogeneous formation and recrystallization of CuAlSe2 thin films for the highest selenization time. Selenium
incorporation to the film, crystallite size, band gap energy, resistivity and photoconductivity increases and the lattice
parameter are closer to the theoretical values as the selenization time increases.
Frequency Resolved Photoluminescence
Creators: name: Azkona, N.
name: Recart, F.
name: Jimeno, J.C.
Publisher: name: WIP
Year: 2012
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cell Characterization and Modelling

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 1435-1438
description: When using photoluminescense (PL) to extract solar cell parameters, a situation that allows the simplification of the
continuation equation is preferred; i.e. steady / quasi-steady-state (QSS) or free decay conditions are desirable.
However, the behaviour of the cell under a periodic excitation treasures information in its modulus and in its phase
that has not been explored yet by means of its PL response. This work analyses the behaviour of the PL response of a
cell under periodic illuminations for a wide range of frequencies. Parameters such us the ideality factor of the diode
or the effective lifetime of the cell can be extracted for several injection levels. The theoretical approach presented in
the first section is then validated with simulations and, afterwards, bv experimental results.
Synthesis and characterization of super-nonazethrene
Creators: name: Turco, Elia
name: Mishra, Shantanu
name: Melidonie, Jason
name: Eimre, Kristjan
name: Obermann, Sebastian
name: Pignedoli, Carlo A.
name: Fasel, Roman
name: Feng, Xinliang
name: Ruffieux, Pascal
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Beginning with the early work of Clar et al. in 1955, zethrenes and their laterally-extended homologues, super-zethrenes, have been intensively studied in the solution phase, and are widely investigated as optical and charge transport materials. Super-zethrenes are also considered to exhibit an open-shell ground state. Zethrenes may thus serve as model compounds to investigate nanoscale pi-magnetism. However, their synthesis is extremely challenging due to their high reactivity. We report here a combined in-solution and on-surface synthesis of the hitherto largest zethrene homologue - super-nonazethrene - on Au(111). Using single-molecule scanning tunneling microscopy and spectroscopy, we show that super-nonazethrene exhibits an open-shell singlet ground state featuring a large spin polarization-driven electronic gap of 1 eV. We obtain real-space maps of the frontier molecular orbitals, and find that they correspond to singly occupied molecular orbitals. In consistence with the emergence of an open-shell ground state, high-resolution tunneling spectroscopy reveals inelastic singlet-triplet spin excitations in super-nonazethrene, characterized by a strong intramolecular magnetic exchange coupling of 51 meV. Further insights are gained by mean-field and many-body perturbation theory calculations. Given the paucity of zethrene chemistry on surfaces, our results therefore provide unprecedented access to large open-shell zethrene compounds amenable to scanning probe measurements, with potential application in molecular spintronics.
description: 7 pages, 4 main figures and 1 Table of Contents artwork; supplementary information containing additional data is included
The Holographic Interpretation of Hawking Radiation
Creators: name: Fabbri, Alessandro
name: Procopio, Giovanni Paolo
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Holography gives us a tool to view the Hawking effect from a new, classical perspective. In the context of Randall-Sundrum braneworld models, we show that the basic features of four-dimensional evaporating solutions are nicely translated into classical five-dimensional language. This includes the dual bulk description of particles tunneling through the horizon.
description: 10 pages, 1 figure, Honorable Mention in the Gravity Research Foundation Essay Competition 2007
CuInSe2 Thin Films Deposited on Transparent Conducting Oxide Coated Glass Substrates by Selenization
Creators: name: López-García, J.
name: Montero, J.
name: Guillén, C.
name: Herrero, J.
Publisher: name: WIP
Year: 2012
Subjects: Thin Film Solar Cells
CdTe, CIS and Related Ternary and Quaternary Thin Film Solar Cells

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 2819-2824
description: CuInSe2 (CIS) thin films have been obtained by selenization of sequentially evaporated metallic precursor layers with
elemental Se vapour at 500ºC in flowing Ar. CIS samples have been deposited onto bare and tin-doped indium oxide (ITO),
as well as interesting alternative back electrodes as aluminium-doped zinc oxide (AZO) and antimonium-doped tin oxide
(ATO)-coated glass substrates. The structural, optical, morphological and electrical properties of the CIS thin films have been
studied for different thicknesses and substrates. Polycrystalline CuInSe2 thin films with tetragonal chalcopyrite structure and
orientation along the (112) plane have been achieved for all substrates and thicknesses. To growth crystalline semiconductor
on highly crystalline substrates promote larger crystallite sizes. The (112) reflection shifts slightly towards higher diffraction
angles in CIS deposited on AZO substrates which can be related to Zn incorporation into the selenized films. Similar
diffusion of Sn in CIS/ATO samples is observed. The CIS/TCO contacts have exhibited ohmic characteristics in all cases.
Main effects of the Earth's rotation on the stationary states of ultra-cold neutrons
Creators: name: Arminjon, Mayeul
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The relativistic corrections in the Hamiltonian for a particle in a uniformly rotating frame are discussed. They are shown to be negligible in the case of ultra-cold neutrons (UCN) in the Earth's gravity. The effect, on the energy levels of UCN, of the main term due to the Earth's rotation, i.e. the angular-momentum term, is calculated. The energy shift is found proportional to the energy level itself.
description: 12 pages in standard LaTeX. v3: Former sect. 2 (derivation of the non-relativistic Hamiltonian) suppressed, new refs., interpretation of the energy shift added, and new redactional improvements, to meet the editorial demands. To appear in Physics Letters A
Stabbing simplices by points and flats
Creators: name: Bukh, Boris
name: Matoušek, Jiří
name: Nivasch, Gabriel
Publisher: name: arXiv
Year: 2008
Subjects: subject: Combinatorics (math.CO)
subject: Computational Geometry (cs.CG)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 52C10, 52C35, 52A35, 54C99

description: The following result was proved by Barany in 1982: For every d >= 1 there exists c_d > 0 such that for every n-point set S in R^d there is a point p in R^d contained in at least c_d n^{d+1} - O(n^d) of the simplices spanned by S. We investigate the largest possible value of c_d. It was known that c_d <= 1/(2^d(d+1)!) (this estimate actually holds for every point set S). We construct sets showing that c_d <= (d+1)^{-(d+1)}, and we conjecture this estimate to be tight. The best known lower bound, due to Wagner, is c_d >= gamma_d := (d^2+1)/((d+1)!(d+1)^{d+1}); in his method, p can be chosen as any centerpoint of S. We construct n-point sets with a centerpoint that is contained in no more than gamma_d n^{d+1}+O(n^d) simplices spanned by S, thus showing that the approach using an arbitrary centerpoint cannot be further improved. We also prove that for every n-point set S in R^d there exists a (d-2)-flat that stabs at least c_{d,d-2} n^3 - O(n^2) of the triangles spanned by S, with c_{d,d-2}>=(1/24)(1- 1/(2d-1)^2). To this end, we establish an equipartition result of independent interest (generalizing planar results of Buck and Buck and of Ceder): Every mass distribution in R^d can be divided into 4d-2 equal parts by 2d-1 hyperplanes intersecting in a common (d-2)-flat.
description: 18 pages, 5 figures
Optimization of Back Side Reflectors for High Efficiency Silicon Solar Cells
Creators: name: Katkhouda, K.
name: Grote, D.
name: Feistritzer, G.
name: Böscke, T.
name: Geppert, T.
Publisher: name: WIP
Year: 2012
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cell Improvements

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 1809-1813
description: Back side reflectors of high efficiency silicon solar cells usually consist of a passivating dielectric layer
or stack covered by metallization. Besides enhancing surface passivation and formation of electrical contact, these
reflectors enhance the internal reflectivity and light trapping, thereby increasing cell efficiency. This work
investigates optical properties of various dielectric back side reflectors on wafers with textured front side and planar
rear surface. We used SiNx, SiO2, SiNx/SiO2, and SiO2/a-Si/SiO2-Bragg-reflectors combined with sputtered Al, Ti and
Ti/Al-stack. The results of the metallization variations reveal that Ti significantly reduces the back side reflectivity
and hence the short circuit current compared to Al or Ag. Efforts to overcome the poor reflectivity of Ti showed that
an optimization of the passivation remarkably enhances the reflectivity of Ti though just to a certain level, far below
an optimized Al-reflector. In addition, more sophisticated Bragg-reflectors showed only a slight improvement of the
reflectivity compared to thick SiO2 when applied to silicon solar cells with textured front side.
Raman and Infrared Microscopical Analysis of Multilayer Backsheets
Creators: name: Geretschläger, K.-J.
name: Wallner, G.M.
name: Fischer, J.
Publisher: name: WIP
Year: 2012
Subjects: Components for PV Systems
PV Modules

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 3499-3502
description: For backsheets and frontsheets of PV modules currently a variety of polymeric materials is used.
Fluoropolymers which exhibit good chemical and physical properties are still dominating. However, this material is cost
intensive. Therefore, alternative materials have been developed and introduced into the market. Besides, TPT backsheets
based on PVF (T) and Polyester (P) many other backsheet types, also without fluoropolymers, are now commercially
available. The main objective of this work is to investigate commercially relevant backsheets as to their layer structure
and material composition. Various multilayer backsheet laminates were selected and categorized. Raman and Infrared
microscopical techniques were implemented and applied to analyse the layer structure and materials used. The results
showed that multilayer backsheets are mainly three layer assemblies with an average total thickness of about 350 m.
The predominant core component is PET with a layer thickness of about 220 m. Backsheets with high performance
fluoropolymers exhibit often a symmetric structure. In contrast, fluoropolymer-free backsheets based on engineering
thermoplastics, such as polyester (PET) or polyamide (PA) show also an asymmetric build-up, also with thermoplastic
ethylene vinylacetate (EVA) as an inner layer material. The most important inorganic modifier is the white pigment
Titanium dioxide (TiO2) used in the outer layers. In only two backsheets TiO2 was identified in the middle layer. Raman
microscopy is suitable for the simultaneous identification of inorganic crystalline modifiers and organic polymeric
components. Infrared microscopy is only capable to detect organic compounds. So the combination of these two
techniques provides a powerful tool for backsheet analysis and classification. Due to the small thickness of the adhesive
layers in further work special focus is given on high resolution Raman microscopical techniques.
A Reactive Molecular Dynamics Study of Hydrogenation on Diamond Surfaces
Creators: name: Oliveira, Eliezer F.
name: Neupane, Mahesh R.
name: Li, Chenxi
name: Kannan, Harikishan
name: Zhang, Xiang
name: Puthirath, Anand B.
name: Shah, Pankaj B.
name: Birdwell, A. Glen
name: Ivanov, Tony G.
name: Vajtai, Robert
name: Galvao, Douglas S.
name: Ajayan, Pulickel M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Hydrogenated diamond has been regarded as a promising material in electronic device applications, especially in field-effect transistors (FETs). However, the quality of diamond hydrogenation has not yet been established, nor has the specific orientation that would provide the optimum hydrogen coverage. In addition, most theoretical work in the literature use models with 100% hydrogenated diamond surfaces to study electronic properties, which is far from the experimentally observed hydrogen coverage. In this work, we have carried out a detailed study using fully atomistic reactive molecular dynamics (MD) simulations on low indices diamond surfaces i.e. (001), (013), (110), (113) and (111) to evaluate the quality and hydrogenation thresholds on different diamond surfaces and their possible effects on electronic properties. Our simulation results indicate that the 100% surface hydrogenation in these surfaces is hard to achieve because of the steric repulsion between the terminated hydrogen atoms. Among all the considered surfaces, the (001), (110), and (113) surfaces incorporate a larger number of hydrogen atoms and passivate the surface dangling bonds. Our results on hydrogen stability also suggest that these surfaces with optimum hydrogen coverage are robust under extreme conditions and could provide homogeneous p-type surface conductivity in the diamond surfaces, a key requirement for high-field, high-frequency device applications.
description: 24 pages
Efficient precision quantization in AdS/CFT
Creators: name: Gromov, Nikolay
name: Schafer-Nameki, Sakura
name: Vieira, Pedro
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Understanding finite-size effects is one of the key open questions in solving planar AdS/CFT. In this paper we discuss these effects in the AdS_5xS^5 string theory at one-loop in the world-sheet coupling. First we provide a very general, efficient way to compute the fluctuation frequencies, which allows to determine the energy shift for very general multi-cut solutions. Then we apply this to two-cut solutions, in particular the giant magnon and determine the finite-size corrections at subleading order. The latter are then compared to the finite-size corrections from Luscher-Klassen-Melzer formulas and found to be in perfect agreement.
description: 32 pages, 5 figures; v2: typos corrected, refs added
Influence of the Undoped a-Si:H Buffer Layer on a-Si:H/c-Si Heterojunctions from Planar Conductance and Lifetime Measurements
Creators: name: Varache, R.
name: Gueunier-Farret, M.E.
name: Halliop, B.
name: Kherani, N.P.
name: Kleider, J.-P.
Publisher: name: WIP
Year: 2012
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cell Characterization and Modelling

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 1439-1442
description: In highly efficient amorphous silicon/crystalline silicon heterojunction (a-Si:H/c-Si) solar cells, the c-Si
wafer is passivated by a nanometer-thin buffer layer, which is undoped amorphous silicon. Here, we report on the
systematic measurement of the passivation quality (minority carrier effective lifetime) by photo-conductance decay
and of the band bending in c-Si using the planar conductance technique. The thickness of the buffer layers is varied.
An analytical model to calculate the band bending in c-Si is presented; it aids in understanding the influence of the
buffer layer on the band bending. We find that when the buffer layer thickness increases the passivation quality
increases and the band bending decreases. Therefore, we suggest that an optimum has to be found to reach good
interface defect passivation and a high band bending.
Human breath analysis via cavity-enhanced optical frequency comb spectroscopy
Creators: name: Thorpe, Michael J.
name: Balslev-Clausen, David
name: Kirchner, Matthew S.
name: Ye, Jun
Publisher: name: arXiv
Year: 2007
Subjects: subject: Optics (physics.optics)
subject: Atomic Physics (physics.atom-ph)
subject: Chemical Physics (physics.chem-ph)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: To date, researchers have identified over 1000 different compounds contained in human breath. These molecules have both endogenous and exogenous origins and provide information about physiological processes occurring in the body as well as environment-related ingestion or absorption of contaminants1,2. While the presence and concentration of many of these molecules are poorly understood, many 'biomarker' molecules have been correlated to specific diseases and metabolic processes. Such correlations can result in non-invasive methods of health screening for a wide variety of medical conditions. In this article we present human breath analysis using an optical-frequency-comb-based trace detection system with excellent performance in all criteria: detection sensitivity, ability to identify and distinguish a large number of biomarkers, and measurement time. We demonstrate a minimum detectable absorption of 8 x 10-10 cm-1, a spectral resolution of 800 MHz, and 200 nm of spectral coverage from 1.5 to 1.7 micron where strong and unique molecular fingerprints exist for many biomarkers. We present a series of breath measurements including stable isotope ratios of CO2, breath concentrations of CO, and the presence of trace concentrations of NH3 in high concentrations of H2O.
ATLAS Reef Survey Mat - educational resources
Creators: name: Paterson, Emma
Publisher: name: Zenodo
Year: 2019

description: This is a reef survey floor mat in a high resolution pdf file printed on a large scale. The ATLAS project use this printed on vinyl banner material 1.5m tall x 3m long. Printing companies can produce this for around €100. Alternatively, it can be printed on A3 paper for class/group activities. There is also a Reef Survey sheet in English, French, German and Spanish. This explains the activity and provides a kit list. There are corresponding answer sheets.
Heavy Quark Potential at Finite Temperature Using the Holographic Correspondence
Creators: name: Albacete, Javier L.
name: Kovchegov, Yuri V.
name: Taliotis, Anastasios
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We revisit the calculation of a heavy quark potential in N =4 supersymmetric Yang-Mills theory at finite temperature using the AdS/CFT correspondence. As is widely known, the potential calculated in the pioneering works of Rey et al. and Brandhuber et al. is zero for separation distances r between the quark and the anti-quark above a certain critical separation, at which the potential has a kink. We point out that by analytically continuing the string configurations into the complex plane, and using a slightly different renormalization subtraction, one obtains a smooth non-zero (negative definite) potential without a kink. The obtained potential also has a non-zero imaginary (absorptive) part for separations r > r_c = 0.870/πT . At large separations r the real part of the potential does not exhibit the exponential Debye falloff expected from perturbation theory and instead falls off as a power law, proportional to 1/r^4 for r > r_0 = 2.702 / πT.
description: 5 pages, 3 figures. Title modified. Discussion extended and references modified
Unconditionally optimal convergence of an energy-conserving and linearly implicit scheme for nonlinear wave equations
Creators: name: Cao, Waixiang
name: Li, Dongfang
name: Zhang, Zhimin
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: F.2.2
subject: 65M60, 65M12, 65N12

description: In this paper, we present and analyze an energy-conserving and linearly implicit scheme for solving the nonlinear wave equations. Optimal error estimates in time and superconvergent error estimates in space are established without time-step dependent on the spatial mesh size. The key is to estimate directly the solution bounds in the $H^2$-norm for both the nonlinear wave equation and the corresponding fully discrete scheme, while the previous investigations rely on the temporal-spatial error splitting approach. Numerical examples are presented to confirm energy-conserving properties, unconditional convergence, and optimal error estimates, respectively, of the proposed fully discrete schemes.
description: 21 pages, 4 figures
The Sherlock Librarian: Investigating the Workplace
Creators: name: Sewell, Claire
Publisher: name: Apollo - University of Cambridge Repository
Year: 2017

description: Library staff are often involved in problem solving as part of their daily roles, either on behalf of users or for themselves. Conducting research in the workplace is the next step but many find this a difficult one to take and often don't consider their work as research. Undertaking research in the workplace, both formal and informal, can help to generate solutions to problems, support a case of find out about your library but where do you start? This one hour workshop introduces participants to the basics of undertaking workplace research including turning a problem into an actionable question, the skills needed and how to overcome common barriers. The workshop is suitable for complete novices, people wanting a quick refresher and those with just a passing interest.
High Efficiency Phosphorus Emitters for Industrial Solar Cells: Comparing Advanced Homogeneous Emitter Cells and Selective Emitters Using Silicon Ink Technology
Creators: name: Scardera, G.
name: Meisel, A.
name: Mikeska, K.R.
name: Carroll, A.F.
name: Burrows, M.Z.
name: Poplavskyy, D.
name: Abbott, M.
name: Lemmi, F.
name: Antoniadis, H.
Publisher: name: WIP
Year: 2012
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cell Improvements

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 923-925
description: Recent advancements in silver paste technology, which can contact low surface concentration
phosphorus emitters, have enabled higher efficiency homogeneous emitter solar cells. This paper presents a
comparison between two industrial approaches for high efficiency front contact solar cells: (i) lightly doped emitter
cells using advanced silver paste and (ii) selective emitter cells using silicon ink technology. Optimal emiter profiles
were determined for the lightly doped emitter cells in order to compare both technologies. For lightly doped emitter
cells, it was found that phosphorus surface concentrations can be lowered to ~2.5e20 atoms/cm3 providing a 5mV
gain over a conventional cell while maintaining good metal contact. It was also found that a surface concentration
above 2e20 atoms/cm3 is required to minimize recombination at the metal contact. Through process optimization
average efficiencies of 18.9% are reported for lightly doped emitter cells compared to 18.6% for optimized
conventional cells and 19.2% for selective emitter cells using silicon ink. The gains achieved with lightly doped
emitter cells shrink the efficiency gap between the homogeneous emitter and selective emitter cell from 0.6% down to
0.3%. Selective emitters, with their dual doped regions, continue to provide superior Voc, maintain excellent contact and
minimize recombination at the metal contact region. However, with the continuous advancements in Ag paste
technology the gap between selective emitter and homogenous emitter solar cells may continue to shrink.
Improved Laboratory Transition Probabilities for Er II and Applications to the Erbium Abundances of the Sun and Five r-Process Rich, Metal-Poor Stars
Creators: name: Lawler, J. E.
name: Sneden, C.
name: Cowan, J. J.
name: Wyart, J. -F.
name: Ivans, I. I.
name: Sobeck, J. S.
name: Stockett, M. H.
name: Hartog, E. A. Den
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Recent radiative lifetime measurements accurate to +/- 5% (Stockett et al. 2007, J. Phys. B 40, 4529) using laser-induced fluorescence (LIF) on 8 even-parity and 62 odd-parity levels of Er II have been combined with new branching fractions measured using a Fourier transform spectrometer (FTS) to determine transition probabilities for 418 lines of Er II. This work moves Er II onto the growing list of rare earth spectra with extensive and accurate modern transition probability measurements using LIF plus FTS data. This improved laboratory data set has been used to determine a new solar photospheric Er abundance, log epsilon = 0.96 +/- 0.03 (sigma = 0.06 from 8 lines), a value in excellent agreement with the recommended meteoric abundance, log epsilon = 0.95 +/- 0.03. Revised Er abundances have also been derived for the r-process-rich metal-poor giant stars CS 22892-052, BD+17 3248, HD 221170, HD 115444, and CS 31082-001. For these five stars the average Er/Eu abundance ratio, = 0.42, is in very good agreement with the solar-system r-process ratio. This study has further strengthened the finding that r-process nucleosynthesis in the early Galaxy which enriched these metal-poor stars yielded a very similar pattern to the r-process which enriched later stars including the Sun.
description: 20 pages, 4 tables, 10 figures; To be published in the Astrophysical Journal Supplement
Evaluation of the First Tandem Solar Cells Grid Connected Power Station in Libya
Creators: name: Saleh, I.M.
name: Abufares, H.M.
name: Snousi, H.M.
Publisher: name: WIP
Year: 2012
Subjects: PV Systems
Large PV Power Plants and Distributed PV: System Aspects and Grid Connection

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 3979-3982
description: Libya has been one of the pioneer countries in employing standalone power generation systems to supply
electricity for telecommunication stations. For a very long time, the use of standalone photovoltaic systems has proved to be
reliable, inexpensive, and more economic in comparison with the rural stations operated by diesel generators. Thus far, grid
connected systems have not been taking their way as part of the Libyan electricity generating systems. In 2009, a grid
connected photovoltaic system fabricated from Tandem technology with a peak power of 24 KWp was installed at Tripoli
University for the sake of evaluating this type of systems in a harsh climate, and to know the impact of utilizing VLS PV
power generation systems when connecting them to the power grid, especially in the southern shore of the Mediterranean.
This paper presents the results of performance evaluation of a 24 KWp PV grid connected system of Tandem modules after
two years of continuous work under varying climate conditions. The main attention of work is paid to analyzing the data
collected by the system’s monitoring devices to have an estimate of how much energy productions and performance ratios the
system is capable of reaching.
Electrodeposited Copper Conductive Layers for IBC-HJ Solar Cells
Creators: name: Lukyanov, A.
name: Nychyporuk, T.
name: De Vecchi, S.
name: Desrues, T.
name: Lemiti, M.
Publisher: name: WIP
Year: 2012
Subjects: Wafer-Based Silicon Solar Cells and Materials Technology
Silicon Solar Cell Improvements

description: 27th European Photovoltaic Solar Energy Conference and Exhibition; 1680-1683
description: New conductive structures for interdigitated back contact heterojunction (IBC-HJ) solar cell contacts
based on indium tin oxide (ITO) layer, metal seed layer and electroplated copper layer are presented in this study. It
is shown that the Copper (Cu) plating directly on ITO seems to present technological problems. One of the possible
solutions is the using of the intermediate metallic seed layer. Electroplated Ni and Sn as well as evaporated Ni thin
films were tested as such seed layers. It was shown that electroplated Ni and Sn seed layers assured the
electrodeposition of uniform Cu layers with the thicknesses going up to 4 m and specific resistance being about 35-
45 Ohmcm. To what concerns the evaporated Ni seed layers, they permit to obtain the electroplated Cu films much
thicker (up to 6 um) with specific resistance of about 3 Ohmcm. For both cases (electroplate and evaporated seed
layers) the contact resistance between the deposited metal structures and ITO layer varied in the range 20-80
Ohmcm2. It was also shown that Cu electrodeposition with current densities lower than 1 A/dm2 leads to higher
specific resistance of the deposited Cu film, contrary to the case of higher current densities, resulting in the obtaining
of Cu layers with specific resistance close to the one of bulk Cu.