cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Novel concepts for power electronics control : introducing the dynamic physical limits, the average natural trajectories, and the centric-based controller
Creators: name: Galiano Zurbriggen, Ignacio
Publisher: name: University of British Columbia
Year: 2013

description: Controllers are an essential component in power conversion systems that have a significant impact on characteristic features such as performance, efficiency, size, and cost, among many others. During the last four decades, countless efforts have been made to find better controllers for power electronics systems in order to improve the converters steady state and dynamic behaviour, increase power densities and reduce losses in the system. Small-signal based linear controllers have been the preferred alternative during decades. This technique features fixed switching frequency and low computation/sensing requirements, while the dynamic response can be improved to only a limited extent and the global stability cannot be ensured. On the other hand, excellent dynamic performances and global stability are achieved by boundary controllers, in which the switching frequency is variable and faster sensors are required. The first part of this work presents a practical tool which allows to objectively quantize improvements made by the controllers to the performance of power converters. The theoretical optimal dynamic behaviour of buck converters is determined, analyzed, and characterized using closed-form mathematical expressions, setting a strong benchmark point for the performance evaluation. Taking the physical limits of dynamic performance into account, and merging the advantages of linear and boundary techniques, a novel control scheme is developed for buck converters. The proposed controller is based on a large-signal model introduced here: the Average Natural Trajectories (ANTs). Enhanced dynamic performance and global stability are achieved while low sensing and computational requirements are maintained, which makes the technique very appealing for use in high-volume production applications. Due to the outstanding results in the basic buck converter, and in order to illustrate the application of the ideas introduced in this work for different topologies, the ANTs and the centric-based controller are developed for boost converters. The obtained results confirm the enhanced dynamic response and fixed frequency operation as natural advantages of the proposed control scheme. The theoretical findings are supported by detailed mathematical procedures and validated by experimental results, which highlight the practical usefulness of the concepts introduced in this work.
Additional file 6: of Transcriptome profiling of Puccinellia tenuiflora during seed germination under a long-term saline-alkali stress
Creators: name: Ye, Xiaoxue
name: Wang, Hao
name: Cao, Xiuling
name: Jin, Xuejiao
name: Cui, Fuqiang
name: Bu, Yuanyuan
name: Liu, Hua
name: Wu, Wenwu
name: Takano, Tetsuo
name: Liu, Shenkui
Publisher: name: figshare
Year: 2019
Subjects: subject: Microbiology
subject: FOS: Biological sciences
subject: Genetics
subject: Molecular Biology
subject: Environmental Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: Inorganic Chemistry
subject: FOS: Chemical sciences
subject: Computational Biology

description: Figure S6. Additional analysis of DEGs. (a) Heatmap of 278 transport unigenes that share a significantly upregulated pattern. (b) Heatmap of 272 oxidation-reduction process unigenes that share a significantly upregulated pattern. (c) Heatmap of 271 organic acid metabolic process unigenes that share a significantly upregulated pattern. (PDF 162 kb)
Precision Measurement of the 6He Half-Life and the Weak Axial Current in Nuclei
Creators: name: Knecht, A.
name: Hong, R.
name: Zumwalt, D. W.
name: Delbridge, B. G.
name: Garcia, A.
name: Mueller, P.
name: Swanson, H. E.
name: Towner, I. S.
name: Utsuno, S.
name: Williams, W.
name: Wrede, C.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Studies of 6He beta decay along with tritium can play an important role in testing ab-initio nuclear wave-function calculations and may allow for fixing low-energy constants in effective field theories. Here, we present an improved determination of the 6He half-life to a relative precision of 3x10^(-4). Our value of 806.89 \pm 0.11(stat)^{+0.23}_{-0.19}(syst) ms resolves a major discrepancy between previous measurements. Calculating the statistical rate function we determined the ft-value to be 803.04 ^{+0.26}_{-0.23} s. The extracted Gamow-Teller matrix element agrees within a few percent with ab-initio calculations.
description: 5 pages, 2 figures, published in Physical Review Letters
Golden perch (Macquaria ambigua) otolith microchemistry: modern validations and ancient applications
Creators: name: Long, Kelsie Elizabeth
Publisher: name: The Australian National University
Year: 2018
Subjects: otolith
golden perch
oxygen isotopes
trace elements
lake level changes
Lake Mungo
Willandra Lakes
archaeology

description: Inland archaeological sites in the Australian arid zone contain few records of past environments. For those archives that do exist, such as sedimentary records, it can be difficult to associate the environmental conditions that they record directly with the time scales of human occupation. At the world heritage site of Lake Mungo, in north western New South Wales, lake shore dunes preserve a record of human occupation, and of alternating phases of wet and dry conditions in the adjacent lake. These two records provide a promising opportunity to generate commensurate behavioural and palaeoenvironmental information. As further surveying of the lunettes is completed and a more detailed and robust chronology using direct Optically Stimulated Luminescence (OSL) dating of the lunettes is constructed, a fuller more nuanced picture of changes in lake level, human occupation and climate will emerge. By finding new samples, new materials and new methods of analysis the chronology of human occupation and lake level changes at Lake Mungo and other Quaternary sites will become more detailed. This study investigates the potential of golden perch otoliths, which are found throughout the shoreline dunes of Lake Mungo, for providing additional detail about lake level fluctuations and general environmental conditions. Fish otoliths are bone-like structures that form in the inner ears of bony fish. They develop by the incremental deposition of calcium carbonate onto an organic matrix, forming annual growth rings. As otolith grow they take up and preserve a record of the trace element and isotopic composition of the ambient water. Some of these chemical markers are affected by changes in water level and temperature. This study analyses the δ18OCaCO3 values and trace element (Sr/Ca and Ba/Ca ratios) composition across the age increments of golden perch otoliths. The δ18OCaCO3 values of modern golden perch from tanks of known δ18OH2O values and temperature conditions were used to validate the assumption that golden perch otoliths form in isotopic equilibrium with the ambient water. Further analyses of modern otoliths from river populations of golden perch and from populations who died in an evaporating lake were examined to determine if known flooding and drying events were preserved in their microchemistry. The same analytical methods were applied to a collection of ancient otoliths excavated from the shorelines of Lake Mungo in the 1970s to investigate changes in water conditions (flooding and drying events) through time. These ancient otoliths were also radiocarbon dated to establish a more detailed chronology of the site. This study also investigates how mass balance models and ancient otolith δ18OCaCO3 values can be used to test scenarios of lake level change at Lake Mungo.
Tensor networks and graphical calculus for open quantum systems
Creators: name: Wood, Christopher J.
name: Biamonte, Jacob D.
name: Cory, David G.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We describe a graphical calculus for completely positive maps and in doing so review the theory of open quantum systems and other fundamental primitives of quantum information theory using the language of tensor networks. In particular we demonstrate the construction of tensor networks to pictographically represent the Liouville-superoperator, Choi-matrix, process-matrix, Kraus, and system-environment representations for the evolution of quantum states, review how these representations interrelate, and illustrate how graphical manipulations of the tensor networks may be used to concisely transform between them. To further demonstrate the utility of the presented graphical calculus we include several examples where we provide arguably simpler graphical proofs of several useful quantities in quantum information theory including the composition and contraction of multipartite channels, a condition for whether an arbitrary bipartite state may be used for ancilla assisted process tomography, and the derivation of expressions for the average gate fidelity and entanglement fidelity of a channel in terms of each of the different representations of the channel.
description: 40 pages, a lot of figures. V3: Published version. Most diagrams moved to inline equations and several typos fixed. V2: Added section on example applications
The informal politics of rural livelihoods in Northern Thailand: A case study of Chiang Mai’s songthaeo drivers
Creators: name: Lane, Ryan
Publisher: name: The Australian National University
Year: 2017

description: This thesis adopts a livelihoods perspective to explore the historical transition and contemporary lives of a group of northern Thai villagers who exited village-based farm work in the 1970s and 1980s to enter the emerging public transport sector of Thailand’s northern capital – Chiang Mai. Through an ethnographic study of these songthaeo drivers, the thesis draws on the story of the drivers’ shift from farm to urban-based, wage labour to interrogate dominant portraits of rural Thai history and to explore the politics through which the drivers have forged and consolidated comparatively healthy livings. In so doing, the thesis contends that rather than a monochromatic history of peasant economic passivity or political resistance to state intervention, the drivers demonstrate an adaptive, aspiration-oriented agency in pursuing enhanced livelihoods. Further, they symbolise a rural politics of actively seeking to cultivate connections with state actors identified as supporting desired exit options away from the land and into more productive labour fields. The thesis proceeds to describe the labour-world ‘invented’ by Chiang Mai’s songthaeo drivers, in terms of both its relatively stable economic dimensions and its familiar rural cultural sociality. It notes that despite the generation of modestly healthy incomes, the drivers remain discontent with their economic position. Describing their livelihoods in desultory terms, the drivers’ pessimistic outlook reflects the ‘status games’ in which they are implicated, indicative of comparisons with men from the professional ranks, and demonstrative of anxieties arising from a new historical epoch marked by the potentially disruptive realities of the Asian Economic Community. To negotiate the new economic era now dawning upon them, and to defend their livelihoods and familiar way of life, the drivers engage in a largely informal mode of politics. Reflective of what Partha Chatterjee has termed ‘political society’, this politics draws on traditional masculine modes of rural Thai power, now deployed within a modern setting of bureaucracy and electoral competition. Centred on the figures of the Presidents of the two largest driving Cooperatives, this politics operates in a murky world of connections, influence, threats, administrative innovations and legal exceptions. Rather than seeking to transform the broader political environment however, this politics is narrowly and parochially focussed, attempting to maintain the status quo rather than fundamentally change it. For the drivers, defending their livelihoods takes precedence over competing political visions of modernising the city or appeasing the city’s growing middle-class residents. As such, the drivers are representative of multiple facets of contemporary Thailand, bridging the formal and informal, rural and the urban, the traditional and the emerging modern within a city itself caught within these often competing dynamics.
Dohrniphora metatarsalis Borgmeier & Prado 1975
Creators: name: Brown, Brian V.
name: Kung, Giar-Ann
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Phoridae
Dohrniphora
Dohrniphora metatarsalis

description: vi. Dohrniphora metatarsalis group
Diagnosis. Foretarsomeres inflated, enlarged. Likely, this is not a monophyletic group (see discussion in Brown & Kung 2007).
 Included species. Dohrniphora crinitiauris, D. lamella Borgmeier & Prado, D. luteifrons Borgmeier, D. acanthiventris, D. aprosmicta, D. avispasensis, D. fuller, D. fundula, D. megasoma, D. metatarsalis Borgmeier & Prado, D. nakayamai, D. ocellifrons, D. smithi Brown & Kung, and 12 other species in couplets 4–13 of the key in Brown & Kung (2007).
description: Published as part of Brown, Brian V. & Kung, Giar-Ann, 2010, 2699, pp. 1-142 in Zootaxa 2699 on page 31
Cherenkov Tau Shower Earth-Skimming Method for PeV-EeV Tau Neutrino Observation with Ashra
Creators: name: Asaoka, Yoichi
name: Sasaki, Makoto
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: We describe a method of observation for PeV--EeV tau neutrinos using Cherenkov light from the air showers of decayed taus produced by tau neutrino interactions in the Earth. Aiming for the realization of neutrino astronomy utilizing the Earth-skimming tau neutrino detection technique, highly precise determination of arrival direction is key due to the following issues: (1) Clear identification of neutrinos by identifying those vertices originating within the Earth's surface; (2) Identification of very high energy neutrino sources. The Ashra detector uses newly developed light collectors which realize both a 42 degree-diameter field-of-view and arcminute resolution. Therefore, it has superior angular resolution for imaging Cherenkov air showers. In this paper, we estimate the sensitivity of and cosmic-ray background resulting from application of the Ashra-1 Cherenkov tau shower observation method. Both data from a commissioning run and a long-term observation (with fully equipped trigger system and one light collector) are presented. Our estimates are based on a detailed Monte Carlo simulation which describes all relevant shower processes from neutrino interaction to Cherenkov photon detection produced by tau air showers. In addition, the potential to determine the arrival direction of Cherenkov showers is evaluated by using the maximum likelihood method. We conclude that the Ashra-1 detector is a unique probe into detection of very high energy neutrinos and their accelerators.
description: 15 pages, 7 figures, accepted for publication in Astroparticle Physics
MPEC 2023-X115 : 2023 XP2
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2023 XP2

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Strange stars in Krori-Barua space-time
Creators: name: Rahaman, Farook
name: Sharma, Ranjan
name: Ray, Saibal
name: Maulick, Raju
name: Karar, Indrani
Publisher: name: arXiv
Year: 2011
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The singularity space-time metric obtained by Krori and Barua\cite{Krori1975} satisfies the physical requirements of a realistic star. Consequently, we explore the possibility of applying the Krori and Barua model to describe ultra-compact objects like strange stars. For it to become a viable model for strange stars, bounds on the model parameters have been obtained. Consequences of a mathematical description to model strange stars have been analyzed.
description: 9 pages (two column), 12 figures. Some changes have been made. " To appear in European Physical Journal C"
Towards resolution of the Fermi surface in underdoped high-Tc superconductors
Creators: name: Sebastian, Suchitra E.
name: Harrison, Neil
name: Lonzarich, Gilbert G.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We survey recent experimental results including quantum oscillations and complementary measurements probing the electronic structure of underdoped cuprates, and theoretical proposals to explain them. We discuss quantum oscillations measured at high magnetic fields in the underdoped cuprates that reveal a small Fermi surface section comprising quasiparticles that obey Fermi-Dirac statistics, unaccompanied by other states of comparable thermodynamic mass at the Fermi level. The location of the observed Fermi surface section at the nodes is indicated by a body of evidence including the collapse in Fermi velocity measured by quantum oscillations, which is found to be associated with the nodal density of states observed in angular resolved photoemission, the persistence of quantum oscillations down to low fields in the vortex state, the small value of density of states from heat capacity and the multiple frequency quantum oscillation pattern consistent with nodal magnetic breakdown of bilayer-split pockets. A nodal Fermi surface pocket is further consistent with the observation of a density of states at the Fermi level concentrated at the nodes in photoemission experiments, and the antinodal pseudogap observed by photoemission, optical conductivity, nuclear magnetic resonance Knight shift, as well as other complementary diffraction, transport and thermodynamic measurements. One of the possibilities considered is that the small Fermi surface pockets observed at high magnetic fields can be understood in terms of Fermi surface reconstruction by a form of small wavevector charge order, observed over long lengthscales in experiments such as nuclear magnetic resonance and x-ray scattering, potentially accompanied by an additional mechanism to gap the antinodal density of states.
description: 33 pages, 15 figures (this version updated with new figures and additional text, as published)
Electrochemically generated CuI and CuSCN nanocrystals on Cu surfaces as raman enhancing substrates
Creators: name: Perez-Estebanez, Martin
name: Cheuquepan, William
name: Heras, Aranzazu
name: Colina, Alvaro
Publisher: name: University of Limerick
Year: 2024
Subjects: classificationCode: 34
subject: Chemical sciences
subject: FOS: Chemical sciences

description: Raman enhancing strategies, such as Surface-Enhance Raman scattering (SERS), are a key piece for the development of spectroscopic and analytical strategies based on Raman spectroscopy, due to the intrinsic low sensitivity of the Raman scattering. Some years ago, our group reported an unexpected Raman enhancement process observed during the electrochemical oxidation of metallic electrodes, named Electrochemical Oxidation Surface-Enhanced Raman scattering (EC-SOERS). This Raman enhancement phenomenon was recently explained as an interaction of the analyte and the SERS dielectric substrate promoted by a metal cation. The elucidation of the origin of this enhancement is now leading to the development of new Raman enhancing substrates, such as copper-based substrates. In this work, we present an overview of the use of copper electrodes as EC-SOERS substrates. The presented strategies allow the electrosynthesis of SERS-active CuI nanocrystals on a metallic copper surface, which provides Raman enhancement for a wide number of molecules. The influence of the electrochemical conditions and the structure of the studied molecules are discussed. The use of CuSCN nano-crystals is also explored as substrates to promote Raman enhancement
Roton-type mode softening in a quantum gas with cavity-mediated long-range interactions
Creators: name: Mottl, R.
name: Brennecke, F.
name: Baumann, K.
name: Landig, R.
name: Donner, T.
name: Esslinger, T.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Long-range interactions in quantum gases are predicted to give rise to an excitation spectrum of roton character, similar to that observed in superfluid helium. We investigate the excitation spectrum of a Bose-Einstein condensate with cavity-mediated long-range interactions, which couple all particles to each other. Increasing the strength of the interaction leads to a softening of an excitation mode at a finite momentum, preceding a superfluid to supersolid phase transition. We study the mode softening spectroscopically across the phase transition using a variant of Bragg spectroscopy. The measured spectrum is in very good agreement with ab initio calculations and, at the phase transition, a diverging susceptibility is observed. The work paves the way towards quantum simulation of long-range interacting many-body systems.
description: 10 pages, 5 figures, supplementary materials
Pachycnema Le Peletier de Saint-Fargeau & Audinet-Serville 1828
Creators: name: Allsopp, Peter G.
name: Schoolmeesters, Paul
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Pachycnema

description: Pachycnema Le Peletier de Saint-Fargeau & Audinet-Serville, 1828
[33 species].
Type species Melolontha crassipes Fabricius, 1775, by subsequent designation of Blanchard in Audouin et al. (1843).
Pachypus Billberg, 1820a (not Pachypus Dejean, 1821).
Type species Melolontha crassipes Fabricius, 1775, by monotypy. Nomen oblitum (Bouchard et al. 2011).
Pachycnema (Pachycnemula) Schein, 1959.
Type species Melolontha crassipes Fabricius, 1775, by original designation. Objective synonym of Pachycnema Le Peletier de Saint-Fargeau & Audinet-Serville.
Pachycnema (Physocnema) Burmeister, 1844.
Type species Pachycnema (Physocnema) calcarata Burmeister, 1844, by subsequent designation of Schein (1959).
Pachycnemida Peringuey, 1902.
Type species Pachycnema signatipennis Burmeister, 1844 (= Pachycnema (Physocnema) multiguttata (Thunberg, 1818)), by monotypy. Synonymy by Dombrow (1998).
Pachycnema (Stenocnema) Burmeister, 1844, as Stenocnema.
Type species Stenocnema pudibunda Burmeister, 1844, by monotypy. Status revised to Pachycnema (Stenocnema) by Schein (1959).
Pachycnema (Macacoplia) Cupello & Ribeiro-Costa, 2019.
Type species Pachycnema moerens Péringuey, 1902, by original designation.
description: Published as part of Allsopp, Peter G. & Schoolmeesters, Paul, 2024, All genera of the world: Subfamilies Prototroginae, Cretoscarabaeinae, Dynamopodinae, Electrorubesopsinae, Phaenomeridinae, Orphninae, Allidiostomatinae, Aclopinae, Lichniinae, Melolonthinae, Oncerinae, Podolasiinae, Sericinae, Sericoidinae (Animalia: Arthropoda: Insecta: Coleoptera: Scarabaeidae), pp. 104-175 in Megataxa 12 (1) on page 116, DOI: 10.11646/megataxa.12.1.2, http://zenodo.org/record/14984437
Paraceratochelus Dombrow 2002
Creators: name: Allsopp, Peter G.
name: Schoolmeesters, Paul
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Paraceratochelus

description: Paraceratochelus Dombrow, 2002d
[1 species].
Type species Paraceratochelus antennatus Dombrow, 2002, by original designation.
description: Published as part of Allsopp, Peter G. & Schoolmeesters, Paul, 2024, All genera of the world: Subfamilies Prototroginae, Cretoscarabaeinae, Dynamopodinae, Electrorubesopsinae, Phaenomeridinae, Orphninae, Allidiostomatinae, Aclopinae, Lichniinae, Melolonthinae, Oncerinae, Podolasiinae, Sericinae, Sericoidinae (Animalia: Arthropoda: Insecta: Coleoptera: Scarabaeidae), pp. 104-175 in Megataxa 12 (1) on page 116, DOI: 10.11646/megataxa.12.1.2, http://zenodo.org/record/14984437
An Annotated Bibliography of Maria Yakovlevna Frumkina (Esther)
Creators: name: Faigan, Suzanne Sarah
Publisher: name: The Australian National University
Year: 2018
Subjects: Slavic Studies
Slavonic Studies
Judaic Studies
Jewish Studies
Communism Studies
Marxism
Russia
USSR
revolution
Yiddish
Jewish Labour Bund
Jewish Labor Bund
Russian Bund
annotated bibliography
translation

description: This thesis provides the first annotated bibliography of the publications of Maria Yakovlevna Frumkina (Esther), a significant figure in the Russian Jewish political sphere in the pre- and early Soviet period. Often known as Esther Frumkin, this proponent of Bundist and, subsequently, communist ideology intended almost all of her publications for readers of Yiddish who were members of the Jewish working class or Jewish intellectuals like herself who devoted their lives to the masses. While Esther’s written output, and indeed her life’s work, can essentially be seen in terms of two periods, corresponding to before and after the dissolution of the Russian Bund, there is some variety among the publications of each period, in terms of their nature, purpose and audience. Some items are translations, some are memoirs, some are didactic party journalism, some are theoretical, some are poetic, some are for younger readers, some appeal to the emotions, some contain humour or derision, some are moralistic, and so on. All are masterfully crafted, using the same clear, assertive style. Many have a very personal quality, which could only have reinforced their author’s reputation as ‘the famous Esther Frumkin’. These publications thus offer a personal perspective on the historical events they describe. They cast additional light on those events and on the writer herself, although the biographical portrait they sketch is incomplete, and they reveal how contemporary Marxist ideologies were communicated to the Yiddish-reading public during a period when Yiddish was a language of politics. The list of 357 items is not an exhaustive bibliography of Esther’s publications, but it is surely representative and should permit consideration of Esther’s publications beyond the small proportion for which she is best known. To the same end, the majority of the enumerated bibliographic listings are accompanied by an annotation and a translation into English of a brief extract from the item.
Fundamental Studies of Positron Scattering from Atoms and Molecules
Creators: name: Boadle, Roisin Alindia
Publisher: name: The Australian National University
Year: 2018
Subjects: physics
positron
atomic
molecular
reaction microscope
scattering
argon
C60
ionisation
cross section

description: This thesis presents measurements of low-energy positron scattering from Argon and C60. Absolute elastic differential cross sections are presented for positron scattering from Argon in the energy range 2 to 50 eV, as well as absolute total elastic and inelastic cross sections up to 20 eV. These results are compared with theoretical calculations using the convergent close-coupling (CCC) and relativistic optical potential (ROP) methods and it was found that generally the measurements were in closer agreement with the CCC method than the ROP method across the energy range, although the ROP method was an excellent description of the total inelastic cross section in this energy range. Argon was also the focus of the first results from the newly developed positron reaction microscope. Experimental techniques were developed to produce measurements of the kinematics of positron-induced single ionisation of Argon. Single ionisation events were detected in coincidence and their momenta reconstructed using data analysis methods detailed in this thesis. Although further work is required to provide total differential cross sections, the initial data presented in this thesis is in alignment with expectations based upon available theory and experiment and provides a promising starting point for future studies using the positron reaction microscope. Finally, a search was conducted for resonant features in the total scattering and Positronium formation cross sections of C60. Motivated by the predictions of Gianturco and Lucchese (1999), which indicated experimentally-accessible resonances, the present data does not show any features. However, the current results in this thesis represent the first preliminary measurements of the total scattering and Positronium formation cross sections for C60 and follow the expected trend for positron-molecule scattering. Additional data to be collected in the future, would allow for confirmation of the presence, or lack thereof, of resonant features with a higher statistical confidence.
Texture-zero model for the lepton mass matrices
Creators: name: Ferreira, P. M.
name: Lavoura, L.
Publisher: name: arXiv
Year: 2012
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We suggest a simple model, based on the type-I seesaw mechanism, for the lepton mass matrices. The model hinges on an Abelian symmetry which leads to mass matrices with some vanishing matrix elements. The model predicts one massless neutrino and $M_{eμ} = 0$ ($M$ is the effective light-neutrino Majorana mass matrix). We show that these predictions perfectly agree with the present experimental data if the neutrino mass spectrum is inverted, i.e. if $m_3 = 0$, provided the Dirac phase $δ$ is very close to maximal ($\pm π/ 2$). In the case of a normal neutrino mass spectrum, i.e. when $m_1 = 0$, the agreement of our model with the data is less than optimal---the reactor mixing angle $θ_{13}$ is too small in our model. Minimal leptogenesis is not an option in our model due to the vanishing elements in the Yukawa-coupling matrices.
description: 10 pages, 3 figures; version for journal: new fit to data, new plots
Description of the updated nutrition calculation of the Oxford WebQ questionnaire and comparison with the previous version among 207,144 participants in UK Biobank
Creators: name: Perez-Cornago, Aurora
name: Pollard, Zoe
name: Young, Heather
name: Van Uden, Marloes
name: Andrews, Colm
name: Piernas, Carmen
name: Key, Timothy J.
name: Mulligan, Angela
name: Lentjes, Marleen
Publisher: name: Apollo - University of Cambridge Repository
Year: 2021
Subjects: Original Contribution
Online 24-h dietary assessment
Oxford WebQ
UK Biobank
Comparative study
Food composition table

description: Funder: University of Oxford
description: Abstract: Purpose: The Oxford WebQ is a web-based 24-h dietary assessment method which has been used in UK Biobank and other large prospective studies. The food composition table used to calculate nutrient intakes has recently been replaced with the UK Nutrient Databank, which has food composition data closer in time to when participants completed the questionnaire, and new dietary variables were incorporated. Here we describe the updated version of the Oxford WebQ questionnaire nutrient calculation, and compare nutrient intakes with the previous version used. Methods: 207,144 UK Biobank participants completed ≥ 1 Oxford WebQs, and means and standard deviations of nutrient intakes were averaged for all completed 24-h dietary assessments. Spearman correlations and weighted kappa statistics were used to compare the re-classification and agreement of nutrient intakes between the two versions. Results: 35 new nutrients were incorporated in the updated version. Compared to the previous version, most nutrients were very similar in the updated version except for a few nutrients which showed a difference of > 10%: lower with the new version for trans-fat (− 20%), and vitamin C (− 15%), but higher for retinol (+ 42%), vitamin D (+ 26%) and vitamin E (+ 20%). Most participants were in the same (> 60%) or adjacent (> 90%) quintile of intake for the two versions. Except for trans-fat (r = 0.58, κ = 0.42), very high correlations were found between the nutrients calculated using the two versions (r > 0.79 and κ > 0.60). Conclusion: Small absolute differences in nutrient intakes were observed between the two versions, and the ranking of individuals was minimally affected, except for trans-fat.
A Swift Look at SN 2011fe: The Earliest Ultraviolet Observations of a Type Ia Supernova
Creators: name: Brown, Peter J.
name: Dawson, Kyle S.
name: de Pasquale, Massimiliano
name: Gronwall, Caryl
name: Holland, Stephen
name: Immler, Stefan
name: Kuin, Paul
name: Mazzali, Paolo
name: Milne, Peter
name: Oates, Samantha
name: Siegel, Michael
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present the earliest ultraviolet (UV) observations of the bright Type Ia supernova SN 2011fe/PTF11kly in the nearby galaxy M101 at a distance of only 6.4 Mpc. It was discovered shortly after explosion by the Palomar Transient Factory and first observed by Swift/UVOT about a day after explosion. The early UV light is well-defined, with ~20 data points per filter in the five days after explosion. These early and well-sampled UV observations form new template light curves for comparison with observations of other SNe Ia at low and high redshift. We report fits from semi-empirical models of the explosion and find the time evolution of the early UV flux to be well fit by the superposition of two parabolic curves. Finally, we use the early UV flux measurements to examine a possible shock interaction with a non-degenerate companion. From models predicting the measurable shock emission, we find that even a solar mass companion at a distance of a few solar radii is unlikely at more than 95% confidence.
description: Manuscript expanded and modified following the referee's report. Resubmitted to ApJ
Paramicroplus Lacroix 1998
Creators: name: Allsopp, Peter G.
name: Schoolmeesters, Paul
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Paramicroplus

description: Paramicroplus Lacroix, 1998
[9 species].
Type species Microplus strigatus Burmeister, 1844, by original designation.
description: Published as part of Allsopp, Peter G. & Schoolmeesters, Paul, 2024, All genera of the world: Subfamilies Prototroginae, Cretoscarabaeinae, Dynamopodinae, Electrorubesopsinae, Phaenomeridinae, Orphninae, Allidiostomatinae, Aclopinae, Lichniinae, Melolonthinae, Oncerinae, Podolasiinae, Sericinae, Sericoidinae (Animalia: Arthropoda: Insecta: Coleoptera: Scarabaeidae), pp. 104-175 in Megataxa 12 (1) on page 116, DOI: 10.11646/megataxa.12.1.2, http://zenodo.org/record/14984437
Non-axisymmetric complete flow conditioning gauzes
Creators: name: Castillo Pardo, Alejandro
name: Taylor, James V.
Publisher: name: Apollo - University of Cambridge Repository
Year: 2021
Subjects: Research Article

description: Abstract: This paper presents a novel methodology for the design of a gauze that produces distributions of stagnation pressure, swirl angle, pitch angle and turbulence intensity, tailored in both the radial and circumferential directions. A distortion gauze is made from a large number of small-scale circumferential and radial blades with tailored thickness and camber distributions. By controlling the blade design independently in both the radial and circumferential directions, the target inflow pattern can be achieved. 1D correlations are used to initialise the blades and they are refined using full 3D CFD simulations. The final design is additively manufactured for use in rotating rigs. In this paper, the method has been used to reproduce four target inflow patterns with large variations in stagnation pressure and flow angularity. Two examples model the inlet flow distortion seen at the aerodynamic interface plane of an aft-mounted boundary layer ingesting fan. The final two examples model the inlet distortion at inlet to an axial compressor spool caused by upstream structural struts in a swan neck duct. The gauzes are shown to replicate the structures of the target flow in an experimental test. These kind of flow structures would be extremely difficult or impossible to replicate in an experiment in any other way. Graphical abstract:
Gamma Ray Constraints on Flavor Violating Asymmetric Dark Matter
Creators: name: Masina, Isabella
name: Panci, Paolo
name: Sannino, Francesco
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We show how cosmic gamma rays can be used to constrain models of asymmetric Dark Matter decaying into lepton pairs by violating flavor. First of all we require the models to explain the anomalies in the charged cosmic rays measured by PAMELA, FERMI and HESS; performing combined fits we determine the allowed values of the Dark Matter mass and lifetime. For these models, we then determine the constraints coming from the measurement of the isotropic gamma-ray background by FERMI for a complete set of lepton flavor violating primary modes and over a range of DM masses from 100 GeV to 10 TeV. We find that the FERMI constraints rule out the flavor violating asymmetric Dark Matter interpretation of the charged cosmic ray anomalies.
description: 11 pages, 3 figures. v2: constraints derivation slightly modified, conclusions unchanged; some clarifications and some references added; matches version published on JCAP
Oxygen isotope systematics of ordinary chondrite chondrules: insights into the inner solar system planetary reservoir
Creators: name: Baeza Bravo, Leonardo Ismael
Publisher: name: The Australian National University
Year: 2018
Subjects: Chondrules
oxygen isotopes
ordinary chondrites
protoplanetary disk
solar system

description: Chondrules are fundamental objects from which important insights in the conditions of the solar protoplanetary disk can be inferred. In this regard, oxygen isotope composition of chondrules have played a key role tracking the physicochemical environment under which their formation occurred. It has been proposed that chondrite asteroids accreted specific chondrule groups or ‘chondrule populations’ in terms of oxygen isotopes but this hypothesis has never been statistically assessed. Systematic in situ measurements of oxygen isotope composition of chondrule olivine from ordinary chondrites (H, L, and LL groups) by SHRIMP-SI and a robust statistical evaluation allowed us to conclude for the first time that the different ordinary chondrite parent bodies sampled the same main population of chondrules in their accretion location. This population is characterised by a mean of Δ17O = 0.74 ± 0.10‰ (σ95%) with a variability of 0.53‰ (σ95%). Ordinary chondrite chondrules were then formed in the same gaseous oxygen isotope reservoir or region of the protoplanetary disk. This population is formed by chondrules with different chemical composition (Type I and Type II) indicating that their formation region was chemically differentiated and form a chemical continuum rather than two separated classes. Our results together with literature data lead us to propose an oxygen isotope gradient of the protoplanetary disk ambient gas under which these and other astrophysical objects (e.g. refractory inclusions) were formed, 16O-richer closer to the Sun and 16O-poorer at longer radial distances. Ultimately, we suggest a change in the paradigm related to the oxygen isotope reservoirs of the solar system, particularly the so-called planetary reservoir. It is proposed that the gaseous oxygen isotope planetary reservoir is a discrete reservoir enriched in SiOgas molecules and other rock-forming elements present since the earliest stages of the solar system evolution possibly reflecting the average oxygen isotope composition of the primordial dust of the solar nebula. The mean composition of the planetary reservoir is δ18O = 4.64 ± 0.15‰ (σ95%) and δ17O = 3.03 ± 0.10‰ (σ95%), with variabilities of 0.97‰ and 0.52‰ (σ95%), respectively.
Antiprotons from dark matter annihilation in the Galaxy: astrophysical uncertainties
Creators: name: Evoli, Carmelo
name: Cholis, Ilias
name: Grasso, Dario
name: Maccione, Luca
name: Ullio, Piero
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The latest years have seen steady progresses in WIMP dark matter (DM) searches, with hints of possible signals suggested by both direct and indirect detection experiments. Antiprotons can play a key role validating those interpretations since they are copiously produced by WIMP annihilations in the Galactic halo, and the secondary antiproton background produced by Cosmic Ray (CR) interactions is predicted with fair accuracy and matches the observed spectrum very well. Using the publicly available numerical DRAGON code, we reconsider antiprotons as a tool to constrain DM models discussing its power and limitations. We provide updated constraints on a wide class of annihilating DM models by comparing our predictions against the most up-to-date ap measurements, taking also into account the latest spectral information on the p, He and other CR nuclei fluxes. Doing that, we probe carefully the uncertainties associated to both secondary and DM originated antiprotons, by using a variety of distinctively different assumptions for the propagation of CRs and for the DM distribution in the Galaxy. We find that the impact of the astrophysical uncertainties on constraining the DM properties can be much stronger, up to a factor of ~50, than the one due to uncertainties on the DM distribution (~2-6). Remarkably, even reducing the uncertainties on the propagation parameters derived by local observables, non-local effects can still change DM model constraints even by 50%. Nevertheless, current ap data place tight constraints on DM models, excluding some of those suggested in connection with indirect and direct searches. Finally we discuss the power of upcoming CR spectral data from the AMS-02 observatory to drastically reduce the uncertainties discussed in this paper and estimate the expected sensitivity of this instrument to some sets of DM models.
description: 29 pages, 18 figures, 2 tables. Match to the published version in PRD. References updated; Physical Review D, vol. 85, Issue 12, 2012
The two-body B_c {\to} D^{(*)}_{(s)}P, D^{(*)}_{(s)}V decays in the Perturbative QCD Approach
Creators: name: Rui, Zhou
name: Zou, Zhi-Tian
name: Lu, Cai-Dian
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We make a systematic investigation on the two-body nonleptonic decays B_c {\to} D^{(*)}_{(s)}P, D^{(*)}_{(s)}V, by employing the perturbative QCD approach based on k_T factorization, where P and V denote any light pseudoscalar meson and vector meson, respectively. We predict the branching ratios and direct CP-asymmetries of these B_c decays and also the transverse polarization fractions of B_c {\to} D^{*}_{(s)}V decays. It is found that the non-factorizable emission diagrams and annihilation type diagrams have remarkable effects on the physical observables in many channels, especially the color-suppressed and annihilation-dominant decay modes. A possible large direct CP-violation is predicted in some channels; and a large transverse polarization contribution that can reach 50% ~ 70% is predicted in some of the Bc {\to} D^{*}_{(s)}V decays.
description: 28 pages, 5 tables, to appear at PRD
Correlation effects on 3D topological phases: from bulk to boundary
Creators: name: Go, Ara
name: Witczak-Krempa, William
name: Jeon, Gun Sang
name: Park, Kwon
name: Kim, Yong Baek
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Topological phases of quantum matter defy characterization by conventional order parameters but can exhibit quantized electro-magnetic response and/or protected surface states. We examine such phenomena in a model for three-dimensional correlated complex oxides, the pyrochlore iridates. The model realizes interacting topological insulators with and without time-reversal symmetry, and topological Weyl semimetals. We use cellular dynamical mean field theory, a method that incorporates quantum-many-body effects and allows us to evaluate the magneto-electric topological response coefficient in correlated systems. This invariant is used to unravel the presence of an interacting axion insulator absent within a simple mean field study. We corroborate our bulk results by studying the evolution of the topological boundary states in the presence of interactions. Consequences for experiments and for the search for correlated materials with symmetry-protected topological order are given.
description: v2: 4+3 pages, 3+1 figures; presentation improved, published version
Towards improving the usability and security of Web single sign-on systems
Creators: name: Sun, San-Tsai
Publisher: name: University of British Columbia
Year: 2013

description: OpenID and OAuth are open and lightweight web single sign-on (SSO) protocols that have been adopted by high-profile identity providers (IdPs), such as Facebook, Google, Microsoft, and Yahoo, and millions of relying party (RP) websites. However, the average users' perceptions of web SSO and the systems' security guarantee are still poorly understood. Aimed at filling these knowledge gaps, we conducted several studies to further the understanding and improvements of the usability and security of these two mainstream web SSO solutions. First, through several in-lab user studies, we investigated users' perceptions and concerns when using web SSO for authentication. We found that our participants had several misconceptions and concerns that impeded their adoption. This ranged from their inadequate mental models of web SSO, to their concerns about personal data exposure, and a reduction in their perceived web SSO value due to the employment of password management practices. Informed by our findings, we offered a web SSO technology acceptance model, and suggested design improvements. Second, we performed a systematic analysis of the OpenID 2.0 protocol using both formal model checking and an empirical evaluation of 132 popular RP websites. The formal analysis identified three weaknesses in the protocol, and based on the attack traces from the model checking engine, six exploits and a semi-automated vulnerability assessment tool were designed to evaluate how prevalent those weaknesses are in the real-world implementations. Two practical countermeasures were proposed and evaluated to strengthen the uncovered weaknesses in the protocol. Third, we examined the OAuth 2.0 implementations of three major IdPs and 96 popular RP websites. By analyzing browser-relayed messages during SSO, our study uncovered several vulnerabilities that allow an attacker to gain unauthorized access to the victim user's profile and social graph on IdPs, and impersonate the victim on RP websites. We investigated the fundamental causes of these vulnerabilities, and proposed several simple and practical design improvements that can be adopted gradually by individual sites. In addition, we proposed and evaluated an approach for websites to prevent SQL injection attacks, and a user-centric access-control scheme that leverage the OpenID and OAuth protocols.