cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Relation between the thermodynamic Casimir effect in Bose-gas slabs and critical Casimir forces
Creators: name: Gambassi, A.
name: Dietrich, S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In a recent letter, Martin and Zagrebnov [Europhys. Lett., 73 (2006) 1] discussed the thermodynamic Casimir effect for the ideal Bose gas confined in a thin film. We point out that their findings can be expressed in terms of previous general results for the Casimir effect induced by confined critical fluctuations. This highlights the links between the Casimir effect in the contexts of critical phenomena and Bose-Einstein condensation.
description: Comment on cond-mat/0507263
The Sulfur Abundance Anomaly in Planetary Nebulae
Creators: name: Henry, R. B. C.
name: Skinner, J. N.
name: Kwitter, K. B.
name: Milingo, M. B.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The failure of S and O abundances in most planetary nebulae to display the same strong direct correlation that is observed in extragalactic H II regions represents one of the most perplexing problems in the area of PN abundances today. Galactic chemical evolution models as well as large amounts of observational evidence from H II region studies support the contention that cosmic abundances of alpha elements such as O, Ne, S, Cl, and Ar increase together in lockstep. Yet abundance results from the Henry, Kwitter, & Balick (2004) database show a strong tendency for most PNe to have S abundances that are significantly less than expected from the observed level of O. One reasonable hypothesis for the sulfur anomaly is the past failure to properly measure the abundances of unseen ionization stages above S^+2. Future observations with Spitzer will allow us to test this hypothesis.
description: Two pages, two figures. Contributed paper, IAU Symp. 234, ``Planetary Nebulae in our Galaxy and Beyond.''
Transverse momentum broadening of vector boson production in high energy nuclear collisions
Creators: name: Kang, Zhong-Bo
name: Qiu, Jian-Wei
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We calculate in perturbative QCD the transverse momentum broadening of vector boson production in high energy nuclear collisions. We evaluate the effect of initial-state parton multiple scattering for the production of the Drell-Yan virtual photon and $W/Z$ bosons. We calculate both the initial- and final-state multiple scattering effect for the production of heavy quarkonia and their transverse momentum broadening in both NRQCD and Color Evaporation model of quarkonium formation. We find that J/$ψ$ and $Υ$ broadening in hadron-nucleus collision is close to $2C_A/C_F$ times the corresponding Drell-Yan broadening, which gives a good description of existing Fermilab data. Our calculations are also consistent with RHIC data on J/$ψ$ broadening in relativistic heavy ion collisions. We predict the transverse momentum broadening of vector boson (J/$ψ$, $Υ$, and $W/Z$) production in relativistic heavy ion collisions at the LHC, and discuss the role of the vector boson broadening in diagnosing medium properties.
description: 22 pages, 10 figures, revised version to appear in Phys. Rev. D
Hit Song Prediction Based on Early Adopter Data and Audio Features
Creators: name: Herremans, Dorien
name: Bergmans, Tom
Publisher: name: arXiv
Year: 2020
Subjects: subject: Sound (cs.SD)
subject: Machine Learning (cs.LG)
subject: Multimedia (cs.MM)
subject: FOS: Computer and information sciences

description: Billions of USD are invested in new artists and songs by the music industry every year. This research provides a new strategy for assessing the hit potential of songs, which can help record companies support their investment decisions. A number of models were developed that use both audio data, and a novel feature based on social media listening behaviour. The results show that models based on early adopter behaviour perform well when predicting top 20 dance hits.
Generalized Permeability Function and Field Energy Density in Artificial Magnetics Using the Equivalent Circuit Method
Creators: name: Ikonen, Pekka
name: Tretyakov, Sergei
Publisher: name: arXiv
Year: 2006
Subjects: subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: The equivalent circuit model for artificial magnetic materials based on various arrangements of split rings is generalized by taking into account losses in the substrate or matrix material. It is shown that a modification is needed to the known macroscopic permeability function in order to correctly describe these materials. Depending on the dominating loss mechanism (conductive losses in metal parts or dielectric losses in the substrate) the permeability function has different forms. The proposed circuit model and permeability function are experimentally validated. Furthermore, starting from the generalized circuit model we derive an explicit expression for the electromagnetic field energy density in artificial magnetic media. This expression is valid at low frequencies and in the vicinity of the resonance also when dispersion and losses in the material are strong. The presently obtained results for the energy density are compared with the results obtained using different methods.
description: 7 pages, 6 figures, submitted to IEEE Trans. Microwave Theory Techn. Added experimental validation and general discussion; to appear in IEEE Trans. Microw. Theory Tech., Jan. 2007
Strange meson-nucleon states in the quark potential model
Creators: name: Wanng, Hai-Jhun
name: Su, Jun-Chen
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The quark potential model and resonating group method are used to investigate the $\bar{K}N$ bound states and/or resonances. The model potential consists of the t-channel and s-channel one-gluon exchange potentials and the confining potential with incorporating the QCD renormalization correction and the spin-orbital suppression effect in it. It was shown in our previous work that by considering the color octet contribution, use of this model to investigate the $KN$ low energy elastic scattering leads to the results which are in pretty good agreement with the experimental data. In this paper, the same model and method are employed to calculate the masses of the $\bar{K}N$ bound systems. For this purpose, the resonating group equation is transformed into a standard Schrödinger equation in which a nonlocal effective $\bar{K}N$ interaction potential is included. Solving the Schrödinger equation by the variational method, we are able to reproduce the masses of some currently concerned $\bar{K}N$ states and get a view that these states possibly exist as $\bar{K}N$ molecular states. For the $KN$ system, the same calculation gives no support to the existence of the resonance $Θ^{+}(1540)$ which was announced recently.
description: 15 pages, 4 figures
WZW action in odd dimensional gauge theories
Creators: name: Liao, Wei
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: It is shown that Wess-Zumino-Witten (WZW) type actions can be constructed in odd dimensional space-times using Wilson line or Wilson loop. WZW action constructed using Wilson line gives anomalous gauge variations and the WZW action constructed using Wilson loop gives anomalous chiral transformation. We show that pure gauge theory including Yang-Mills action, Chern-Simons action and the WZW action can be defined in odd dimensional space-times with even dimensional boundaries. Examples in 3D and 5D are given. We emphasize that this offers a way to generalize gauge theory in odd dimensions. The WZW action constructed using Wilson line can not be considered as action localized on boundary space-times since it can give anomalous gauge transformations on separated boundaries. We try to show that such WZW action can be obtained in the effective theory when making localized chiral fermions decouple.
description: 19 pages, text shortened, reference added. Version to appear in PRD
COHESIVE Information System (CIS) Virtual Machine Technical Specifications (COHESIVE)
Creators: name: Di Pasquale, Adriano
name: Caldarelli, Valentina
Publisher: name: Zenodo
Year: 2019
Subjects: OHEJP
COHESIVE
COHESIVE Information System
CIS
Workpackage 4
D-JIP2-4.1.1
D 4.1.1
Implemented database
IZSAM
Virtual Machine
Technical Specifications for Virtual Machine of CIS

description: Project JIP2 COHESIVE COHESIVE: One Health Structure In Europe
 Technical Specifications for Virtual Machine of CIS (Cohesive Information System) related to the Deliverable D-JIP2-4.1.1Implemented Database Workpackage 4
title: Investigating human-environmental interactions in the Zagros region during the Late Pleniglacial, Lateglacial, and Holocene period
Creators: name: Rabbani, Maria
Publisher: name: University of Reading
Year: 2023

description: This thesis investigates the environmental history of the Zagros region across the Late Pleniglacial, 
Lateglacial and Holocene (~17,700-2200 yrs BP), which corresponds to the Epipalaeolithic, Neolithic, 
Chalcolithic, Bronze, and Iron Age archaeological periods, in order to characterise and explain the 
changes in the vegetation cover and critically evaluate their interrelationships with anthropogenic 
activity and climate change. 
This research also aims to address the limitations of some of the previous palaeoenvironmental 
studies, which are characterised by the use of low-resolution records, chronological uncertainties and 
low geographic variability. A multi-proxy approach is adopted therefore to reconstruct the 
environmental history of Hashilan wetland (Eastern Zagros) and Lake Ganau (Western Zagros). Two 
high-resolution palaeoenvironmental records were produced using sedimentological, pollen, non-pollen palynomorph, microcharcoal, macrocharcoal, and geochemical analyses (ITRAX), which 
enabled the reconstruction of the vegetation, climate, and fire history. This study has produced 
meaningful data on the exploration of a range of themes, including to the long-standing debate on the 
‘Early Holocene Precipitation Paradox’, the ‘Broad Spectrum Revolution’ and the ‘delayed Quercus
woodland expansion’. The results provide additional evidence for complexity in terms of the regional 
variability of climate change during the Pleistocene and Holocene and highlight differences in 
environmental and climatic conditions between the eastern and western Zagros.
This research has, consequently, not only improved our understanding regarding aspects of climate 
change, vegetation succession, and human-environmental interactions in the Zagros region, but has 
also provided the first high-resolution pollen record for the western Zagros region for the Late 
Pleniglacial and Lateglacial interval. Furthermore, it helps to place climatic and vegetational changes 
as well as human responses in the Zagros region within the wider region and context, while 
appreciating local differences across Southwest Asia.
Some problems on multi-sensor layout optimization
Creators: name: Feng, Siwei
Publisher: name: No Publisher Supplied
Year: 2023

description: Robots or robotic applications, like living beings, perceive the world through a great variety of sensors. For range sensors, be it acoustic like sonar, photic like cameras, laser beams or lidars, the sensing range can, to some extent, be ideally abstracted as either 1D lines or 2D circles. Hence, it would be helpful to study the properties of the underlying geometric problems. The thesis starts in the first chapter with a general review of different sorts of range sensors, especially range and line sensors used in real-world applications. Then, we will give a general overview of the theoretical background and tools used for this thesis. The main body of this thesis is divided into five parts, each of which comes with a specific research problem. The second chapter talks about perimeter guarding with 1D sensors, where the sensing range is assumed to be a continuous line on top of the perimeter of some regions. Two problems are introduced, perimeter guarding with homogeneous sensors and with heterogeneous sensors. The homogeneous case can be solved using only classical algorithms. While the heterogeneous case is NP-hard, but can still be solved with dynamic programming under a reasonable amount of time. The third chapter continues with perimeter guarding but uses circles to represent the coverage range of sensors. The study extends to guarding 2D regions beyond the perimeters. Our study turns out that even for covering the boundary of a simple polygon, the problem of finding the minimum sensing radius is NP-hard to approximate within a factor of 1.152. However, effective approximation algorithms are developed to solve this problem. After the two chapters about covering perimeters or regions, which is essentially separating some critical polygonal regions from the outside. The fourth chapter digs deeper into this problem by studying the separation of more than two polygonal sets. To simplify the problem, a line-of-sight sensing model will be adopted. The problem is NP-hard even for the problem of separating two sets of regions with the minimum number of lines. Still, a near-optimal solution using integer programming is provided. The fifth chapter deals with the dynamic setting, two different but related problems are studied. The first problem is the boundary defense problem in the context of heterogeneous defenders, which is an extension of the perimeter defense problem. The second problem is the coordinated sweeping problem where a group of robots coordinate to sweep a region with obstacles with some certain sweep plan. The sixth chapter discusses a real-world application of the placement of UV (ultra violet) lights to cover the surface of some regions for sanitization purposes. Lastly, we summarize our work and bring out potential future work and studies on this subject.
Leading neutron production at the EIC and LHeC: estimating the impact of the absorptive corrections
Creators: name: Carvalho, F.
name: Gonçalves, V. P.
name: Navarra, F. S.
name: Spiering, D.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Leading neutron (LN) production in $ep$ collisions at high energies is investigated using the color dipole formalism and taking into account saturation effects. We update the treatment of absorptive effects and estimate the impact of these effects on LN spectra in the kinematical range that will be probed by the Electron Ion Collider (EIC) and by the Large Hadron electron Collider (LHeC). We demonstrate that Feynman scaling, associated to saturation, is not violated by the inclusion of absorptive effects. Moreover, our results indicate that the LN spectrum is strongly suppressed at small photon virtualities. These results suggest that absorptive effects cannot be disregarded in future measurements of the $γπ$ cross section to be extracted from data on leading neutron production.
description: 6 pages, 3 figures
Preliminary Seismic Evaluation and Ranking of Bridges on and over the Parkways in Western Kentucky
Creators: name: Xie, Jian
name: Harik, Issam E.
name: Zhao, Tong
name: Hu, Jindong
Publisher: name: Kentucky Transportation Center, University of Kentucky
Year: 2008
Subjects: subject: Transportation Engineering

description: Five parkways in Western Kentucky are located in the region that is greatly influenced by the New Madrid and Wabash Valley Seismic Zones. This report executes a preliminary screening process, known also as the Seismic Rating System, for bridges on and over parkways in Western Kentucky to identify the seismic vulnerable bridges.  The ranking of bridges derived from this rating system is based on: structural vulnerability, seismic and geotechnical hazards, and bridge importance. There are 349 bridges were ranked with the Seismic Inventory of Bridges (SIB), a user-oriented database program developed according to the Seismic Retrofitting Manual. The bridge ranks (R) range from a low of 0 to a high of 75, based on a scale of 100.  According to the seismic rank and regularity of bridges on and over the parkways in Western Kentucky, there are a total of 17 bridges, including parallel bridges, were selected for detailed seismic analysis. The 17-bridges have an average ranking of 58, with a highest bridge rank of 75.
Optical Selection of Faint AGN in the COSMOS Field
Creators: name: Casey, C. M.
name: Impey, C. D.
name: Trump, J. R.
name: Gabor, J.
name: Abraham, R. G.
name: Capak, P.
name: Scoville, N. Z.
name: Brusa, M.
name: Schinnerer, E.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We outline a strategy to select faint (i<24.5) type 1 AGN candidates down to the Seyfert/QSO boundary for spectroscopic targeting in the COSMOS field, picking candidates by their nonstellar colors in broadband ground-based photometry and morphological properties extracted from HST-ACS. AGN optical color selection has not been applied to such faint magnitudes in such a large continuous part of the sky. Hot stars are known to be the dominant contaminant for bright AGN candidate selection at z<2, but we anticipate the highest color contamination at all redshifts to be from faint starburst and compact galaxies. Morphological selection via the Gini Coefficient separates most potential AGN from these faint blue galaxies. Recent models of the quasar luminosity function are used to estimate quasar surface densities, and studies of stellar populations in the COSMOS field infer stellar contamination. We use 292 spectroscopically confirmed type 1 AGN and quasar templates to predict AGN colors with redshift, and contrast those predictions with the colors of known contaminating populations. The motivation of this study and subsequent spectroscopic follow-up is to populate and refine the faint end of the QLF where the population of type 1 AGN is presently not well known. The anticipated AGN observations will add to the ~300 already known AGN in the COSMOS field, making COSMOS a densely packed field of quasars to be used to understand supermassive black holes and probe the structure of the intergalactic medium in the intervening volume.
description: 15 pages, 18 figures; accepted for publication in the Astrophysical Journal
Equivalent Barge and Flotilla Impact Forces on Bridge Piers
Creators: name: Yuan, Peng
name: Harik, Issam E.
Publisher: name: Kentucky Transportation Center, University of Kentucky
Year: 2008
Subjects: subject: Transportation Engineering

description: Bridge piers located in navigable inland waterways are designed to resist impact forces from barges and flotillas in addition to other design considerations (e.g., scour, dead and live loads, etc.). The primary design tool for estimating these forces is the AASHTO Guide Specification which provides a simple hand calculation method for determining an “equivalent impact force”. The simplicity comes at a cost of excluding the effect of the pier shape, impact duration, and interaction between barges in a flotilla. The objective of this report is to present a hand calculation method for determining barge or flotilla equivalent static impact forces on bridge piers. The primary advantage of this approach lies in its incorporation of pier geometry, interaction between barges, and impact duration. The proposed method is derived from the conduct of hundreds of finite element dynamic simulations of barges and various flotilla configurations impacting rigid and flexible rectangular and circular (or rounded end) bridge piers at different velocities. Results are presented and compared with ones derived from the AASHTO method and detailed finite element modeling. The results generated by the proposed method compare very well with ones derived from the FE modeling, while the AASHTO results are up to twice as large as one from the proposed method for the examples presented in this report.
Experimental Concrete Coating Application on the Median Barrier of I-65 in Louisville
Creators: name: Younce, Rick
name: Hopwood, Theodore
name: Palle, Sudhir
Publisher: name: Kentucky Transportation Center, University of Kentucky
Year: 2008
Subjects: subject: Transportation Engineering

description: The objectives of this research were to evaluate the experimental protective coating that was applied to approximately 1,200 linear feet of concrete median barrier along the paving project on a section of I 65 between mile points 131.289 and 136.421 in downtown Louisville.  The project was completed generally in accordance with the specifications and special notes. This experimental project is the first trial of concrete coatings identified under KYSPR 05-271 Coatings, Sealants and Fillers to Address Bridge Concrete Deterioration and Aesthetics-Phase 1. The coatings systems identified under that study were intended to provide improved protection and aesthetics for reinforced concrete. This project proved that one candidate coatings system could be applied successfully on existing concrete. It is recommended that KYTC further pursue use of this knowledge by conducting more experimental/ prototype projects to further investigate how coatings hold up on new and old concrete barriers.
Observational constraints and stability in viscous $f(T,\mathcal{T})$ gravity
Creators: name: Mirzaei-Rezaei, T.
name: Amani, Alireza
name: Yusofi, E.
name: Rouhani, S.
name: Ramzanpour, M. A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper, we study the $f(T,\mathcal{T})$ gravity model in the presence of the bulk viscosity by the flat-FRW metric. The field equation is obtained by teleparallel gravity with tetrad field. The universe components are considered as matter and dark energy which the dark energy component associates from the viscous $f(T,\mathcal{T})$ gravity. After calculating the Friedmann equations, we obtain the energy density, the pressure and the EoS of dark energy in terms of the redshift parameter. Afterward, we plot the corresponding cosmological parameters versus the redshift parameter and examine the accelerated expansion of the universe. In the end, we explore the system stability by a function called the speed sound parameter.
description: 14 pages, 5 figures
A Realist Interpretation of the Quantum Measurement Problem
Creators: name: Zhang, Xiaolei
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A new, realist interpretation of the quantum measurement processes is given. In this scenario a quantum measurement is a non-equilibrium phase transition in a ``resonant cavity'' formed by the entire physical universe including all its material and energy content. Both the amplitude and the phase of the quantum mechanical wavefunction acquire substantial meaning in this picture, and the probabilistic element is removed from the foundations of quantum mechanics, its apparent presence in the quantum measurement process is viewed as a result of the sensitive dependence on initial/boundary conditions of the non-equilibrium phase transitions in a many degree-of-freedom system. The implications of adopting this realist ontology to the clarification and resolution of lingering issues in the foundations of quantum mechanics, such as wave-particle duality, Heisenberg's uncertainty relation, Schrodinger's Cat paradox, first and higher order coherence of photons and atoms, virtual particles, the existence of commutation relations and quantized behavior, etc., are also presented.
description: 8 pages, submiited to the Proceedings of the international conference "Albert Einstein Century", held July 2005 in Paris, France
A Possible Mechanism for the Low Shear Viscosity in the QGP Created by RHIC
Creators: name: Giannakis, I.
name: Hou, Defu
name: Li, Jia-rong
name: Ren, Hai-cang
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the Anderson Localization effect on the shear viscosity in a system with random medium by Kubo formula. We show that this effect can reduce the shear viscosity nonperturbatively. Then we discuss its possible implementation in heavy-ion collisions, where the created heavy bound states or other collective modes may play the role of the random scatterer underlying Anderson Localization effect.
description: typos corrected,references added,figures updated
The pro-$p$ Hom-form of the birational anabelian conjecture
Creators: name: Corry, Scott
name: Pop, Florian
Publisher: name: arXiv
Year: 2006
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 11S20, 12F10, 14G32, 14H30 (Primary), 11G20, 14H05 (Secondary)

description: We prove a pro-$p$ Hom-form of the birational anabelian conjecture for function fields over sub-$p$-adic fields. Our starting point is the Theorem of Mochizuki in the case of transcendence degree 1.
description: 9 pages; substantially revised version with a new introduction, more details, and added references
Muon spin rotation studies of electronic excitations and magnetism in the vortex cores of superconductors
Creators: name: Sonier, J. E.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The focus of this paper is on recent progress in muon spin rotation (muSR) studies of the vortex cores in type-II superconductors. By comparison of muSR measurements of the vortex core size in a variety of materials with results from techniques that directly probe electronic states, the effect of delocalized quasiparticles on the spatial variation of field in a lattice of interacting vortices has been determined for both single-band and multi-band superconductors. These studies demonstrate the remarkable accuracy of what some still consider an exotic technique. In recent years muSR has also been used to search for magnetism in and around the vortex cores of high-temperature superconductors. As a local probe muSR is specially suited for detecting static or quasistatic magnetism having short-range or random spatial correlations. As discussed in this review, muSR experiments support a generic phase diagram of competing superconducting and magnetic order parameters, characterized by a quantum phase transition to a state where the competing order is spatially nonuniform.
description: 28 pages, 22 figures
A deep X-ray observation of M82 with XMM-Newton
Creators: name: Ranalli, Piero
name: Comastri, Andrea
name: Origlia, Livia
name: Maiolino, Roberto
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report on the analysis of a deep (100 ks) observation of the starburst galaxy M82 with the EPIC and RGS instruments on board the X-ray telescope XMM-Newton. The broad-band (0.5-10 keV) emission is due to at least three spectral components: i) continuum emission from point sources; ii) thermal plasma emission from hot gas; iii) charge exchange emission from neutral metals (Mg and Si). The plasma emission has a double-peaked differential emission measure, with the peaks at ~0.5 keV and ~7 keV. Spatially resolved spectroscopy has shown that the chemical absolute abundances are not uniformly distributed in the outflow, but are larger in the outskirts and smaller close to the galaxy centre. The abundance ratios also show spatial variations. The X-ray derived Oxygen abundance is lower than that measured in the atmospheres of red supergiant stars, leading to the hypothesis that a significant fraction of Oxygen ions have already cooled off and no longer emit at energies > ~0.5 keV.
description: Accepted for publication in MNRAS. 20 pages, 15 figures, LaTeX2e
Variational ground states of 2D antiferromagnets in the valence bond basis
Creators: name: Lou, J.
name: Sandvik, A. W.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study a variational wave function for the ground state of the two-dimensional S=1/2 Heisenberg antiferromagnet in the valence bond basis. The expansion coefficients are products of amplitudes h(x,y) for valence bonds connecting spins separated by (x,y) lattice spacings. In contrast to previous studies, in which a functional form for h(x,y) was assumed, we here optimize all the amplitudes for lattices with up to 32*32 spins. We use two different schemes for optimizing the amplitudes; a Newton/conjugate-gradient method and a stochastic method which requires only the signs of the first derivatives of the energy. The latter method performs significantly better. The energy for large systems deviates by only approx. 0.06% from its exact value (calculated using unbiased quantum Monte Carlo simulations). The spin correlations are also well reproduced, falling approx. 2% below the exact ones at long distances. The amplitudes h(r) for valence bonds of long length r decay as 1/r^3. We also discuss some results for small frustrated lattices.
description: v2: 8 pages, 5 figures, significantly expanded, new optimization method, improved results
Regular multihorizon black holes in General Relativity
Creators: name: Rodrigues, Manuel E.
name: Silva, Marcos V. de S.
name: de Siqueira, Andrew S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this work, new solutions for regular black holes that have multihorizons are proposed. These are formed by the direct product of solutions already published in the literature, which are described through the coupling of gravity with nonlinear electrodynamics. We analyze the regularity of the spacetime, the electric field, and the energy conditions of each solution. The strong energy condition is always violated within the event horizon in all solutions, while other energy conditions depend on the ratio between extreme charges of isolated solutions. For solutions with four horizons, we present two examples, Bardeen-Culetu and Balart-Culetu. Both solutions are regular, but the first do not satisfy all the energy conditions, except the strong, because it has an extreme charge ratio of 1.57581, great value. The second solution, on the other hand, can satisfy all other energy conditions, except the SEC, and has an extreme charge ratio of 1.09915, a value that allows this feature. It's also proposed a regular solution with up to six horizons, Balart-Culetu-Dymnikova, where, for a given charge value, we can verify that it satisfies all energy conditions, except the strong one. This was possible due to the ratio between extreme charges that are neither too high nor too close. We propose solutions with any number of horizons. We show that points where $-F(r)$ has a non null minimum represent a cusp in the Lagrangian $-L(F)$. We also show an example of multihorizon solution with magnetic charge. Multihorizon solutions may exhibit exotic properties, such as negative energy density, or violation of energy conditions, but which can be circumvented with a selected choice of customized solutions and extreme charge values, resulting in regular black hole solutions that satisfy all energy conditions, less the strong.
description: 17 pages, 18 figures
การเปรียบเทียบผลสัมฤทธิ์ทางเรียนและทักษะการสื่อสารภาษาอังกฤษเรื่อง ทักษะการอ่านของนักเรียนชั้นประถมศึกษาปีที่ 5 ระหว่างการจัดกิจกรรมการเรียนรู้แบบโต้ตอบทางสรีระและการจัดกิจกรรมกลุ่มร่วมมือแบบจิ๊กซอร์
Creators: name: อรพินทร์ เพียพล
name: ทัศนา ประสานตรี
name: มนตรี อนันตรักษ์
Publisher: name: มหาวิทยาลัยนครพนม
Year: 2558
Subjects: การจัดกิจกรรมการเรียนรู้แบบโต้ตอบทางสรีระ, การจัดกิจกรรมกลุ่มร่วมมือแบบจิ๊กซอร์, ผลสัมฤทธิ์ทางการเรียน, ทักษะการสื่อสารภาษาอังกฤษ

description: 1, 5, วารสารมหาวิทยาลัยนครพนม
Searching for X-ray luminous 'normal' galaxies in 2dfGRS
Creators: name: Tzanavaris, P.
name: Georgantopoulos, I.
name: Georgakakis, A.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We cross-correlated the Chandra XASSIST and XMM-Newton Serendipitous Source Catalogues with the 2 degree Field Galaxy Redshift Survey (2dfGRS) database. Our aim was to identify the most X-ray luminous (L_X > 10^42 erg s^-1) examples of galaxies in the local Universe whose X-ray emission is dominated by stellar processes rather than AGN activity ('normal' galaxies) as well as to test the empirical criterion log(f_X/f_O) < -2 for separating AGN from NGs. With XMM-Newton (Chandra) we covered an area of ~8.2 (~5.8)deg^2 down to a flux limit of ~10^-15 (~1.6 x 10^-15) erg cm^-2 s^-1 and found 18 (20) 2dfGRS galaxies. Using emission-line intensity ratios, we classified 6 2dfGRS spectra as star-forming, H II nuclei, and 2 spectra as possible H II nuclei. The rest of the objects are absorption-line galaxies and AGN, including 3 possible LINERs. No luminous 'normal' galaxies have been found but out of 19 'normal' galaxies in this sample 5 H II and 3 absorption-line galaxies have log(f_X/f_O) > -2. We performed a similar search in two nearby-galaxy samples from the literature. All 44 galaxies in the Zezas (2001) sample have log(f_X/f_O) < -2 and L_X < 10^42 erg s^-1. In the Fabbiano et al. (1992) sample, out of a total of 170 'normal' galaxies, we found 16 galaxies with log(f_X/f_O) >-2, the majority of which are massive ellipticals. Three of these have L_X > 10^42 erg s^-1 .
description: 8 pages, 2 figures. Accepted for publication in Astronomy & Astrophysics
A multiwavelength method to identifying and analyzing galaxy clusters
Creators: name: Doze, Peter Davon
Publisher: name: No Publisher Supplied
Year: 2023

description: Galaxy clusters are complicated objects that sit at the crossroads of cosmology and astrophysics. As massive objects, they trace large-scale structure and contain vast amounts of dark matter along with hot interacting gas and galaxies. Clusters’ multifaceted mass composition leads to the necessity for a multiwavelength analysis to fully understand them, and scaling laws to relate various cluster observables. In this work, multiwavelength observations are used to confirm cluster candidates and characterize the cluster properties of ACT-CL J0034.4+0225. We focus on confirming galaxy cluster candidates found through millimeter band observations in the Planck data release (Planck Collaboration et al., 2014, 2016b). First, we use optical data from the Kitt Peak National Observatory Mayall-4m telescope, where we confirmed 15 cluster candidates. Then in another project, we use Swift x-ray data to estimate Planck cluster candidates’ x-ray luminosities. The massive cluster, ACT-CL J0034.4+0225, was detected in the Atacama Cosmology Telescope’s fifth data release (Hilton et al., 2020), (another millimeter band observatory) with a strong signal-to-noise that motivated us to investigate. We discovered evidence of an ongoing merger that was previously unrecognized. An in-depth analysis involving x-ray, optical, and radio observations confirmed the cluster to be a merger at a redshift of z = 0.38588 ± 0.00068 with at least 60 cluster members. Follow-up simulation comparisons and strong lensing analyses constrained the merger near first pericenter with a mass ratio between 1:1 to 1:20. We finally began a project (still ongoing) to relate millimeter band observables from the Atacama Cosmology Telescope to Swift x-ray observables, specifically the luminosity. This project takes elements from all previous projects as we take a catalog of clusters and perform an in-depth x-ray analysis.
A Set of Benchmark Tests for Validation of 3D Particle In Cell Methods
Creators: name: O'Connor, S.
name: Crawford, Z. D.
name: Verboncoeur, J.
name: Lugisland, J.
name: Shanker, B.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: While the particle-in-cell (PIC) method is quite mature, verification and validation of both newly developed methods and individual codes has largely focused on an idiosyncratic choice of a few test cases. Many of these test cases involve either one- or two-dimensional simulations. This is either due to availability of (quasi) analytic solutions or historical reasons. Additionally, tests often focus on investigation of particular physics problems, such as particle emission or collisions, and do not necessarily study the combined impact of the suite of algorithms necessary for a full featured PIC code. As three dimensional (3D) codes become the norm, there is a lack of benchmarks test that can establish the validity of these codes; existing papers either do not delve into the details of the numerical experiment or provide other measurable numeric metrics (such as noise) that are outcomes of the simulation. This paper seeks to provide several test cases that can be used for validation and bench-marking of particle in cell codes in 3D. We focus on examples that are collisionless, and can be run with a reasonable amount of computational power. Four test cases are presented in significant detail; these include, basic particle motion, beam expansion, adiabatic expansion of plasma, and two stream instability. All presented cases are compared either against existing analytical data or other codes. We anticipate that these cases should help fill the void of bench-marking and validation problems and help the development of new particle in cell codes.
Examples on the sharpness of an inequality about multiplicities over hyperfields
Creators: name: Liu, Ziqi
Publisher: name: arXiv
Year: 2020
Subjects: subject: Number Theory (math.NT)
subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics

description: In this paper, the author introduces hyperfields and give some facts about the roots and multiplicities of polynomials over hyperfield based on \cite{2} and \cite{3}. Then he tests the sharpness of an inequality in Baker's former work \cite{2} about the behavior of multiplicities under homomorphisms between hyperfields and show that the inequality is not sharp under the natural homomorphisms $\mathbb{C}\rightarrow\mathbb{P}$ and $\mathbb{C}\rightarrow\mathbb{V}$ while it is sharp under the natural homomorphisms $\mathbb{C}\rightarrow\mathbb{K}$, $\mathbb{R}\rightarrow\mathbb{S}$ and $\mathbb{R}\rightarrow\mathbb{T}$ according to the previous work \cite{2} of Baker and Lorscheid.
description: undergraduate research work, 15 pages
Gravitational Perfect Fluid Collapse With Cosmological Constant
Creators: name: Sharif, M.
name: Ahmad, Zahid
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper, the effect of a positive cosmological constant on spherically symmetric collapse with perfect fluid has been investigated. The matching conditions between static exterior and non-static interior spacetimes are given in the presence of a cosmological constant. We also study the apparent horizons and their physical significance. It is concluded that the cosmological constant slows down the collapse of matter and hence limit the size of the black hole. This analysis gives the generalization of the dust case to the perfect fluid. We recover the results of the dust case for $p=0$.
description: LaTex 13 pages, accepted for publication in Mod. Phys. Lett. A
Impedance measurements in undoped and doped regioregular poly(3-hexylthiophene)
Creators: name: Mandal, Sougata
name: Menon, Reghu
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: The semiconducting properties of regioregular poly(3-hexylthiophene) are characterized by impedance measurements, from 40 Hz to 100 MHz. X-ray diffraction shows the presence of both ordered and disordered regions. The analysis of impedance data by Nyquist plots show two semi-circular arcs, and its size is reduced by d.c. bias. Also, the carrier variation by light and chemical doping alters the shape and size of arcs. The fits to the data and equivalent circuits show considerable changes in the resistive, capacitive and constant-phase element parameters as the carrier density increases. The increase in carrier density reduces the relaxation time in ordered regions, and it does not alter much in disordered regions.
description: 13 pages with 10 figures; published in Journal of Physics D: Applied Physics
Alterations : renovations and additions to the Parson’s School of Fashion Design
Creators: name: Barrett, Leslie Larissa
Publisher: name: University of British Columbia
Year: 2009

description: The concepts guiding this project originate from an interest in the connectivity between perception, architecture, and the forms and functions of the city. The project aims to foster a visual morphology particular to its midtown Manhattan site in order to . establish an architecture that shares an experiential, and spatial logic with the city. It is the intention of this project to exploit the built-, in interdependence and capacity for simultaneity of Manhattan by developing a building that conflates the oppositions and boundaries that also characterize the city. Oppositions that are brought together in this project include public and private, interior and exterior, foreground and background, banal and extraordinary, the scale of the body and of the city, seeing and being seen, old and new. A reweaving of existing conditions in terms of passage, experience, vision, materiality, and program is the key strategy in the project. Addressing the city and its architecture as a completed body to be reinterpreted, I have selected a renovation project that adopts a mid strata rooftop as the site for a program that serves both public and private institutions. The Parson's School of Fashion Design located in the midtown Fashion District is presently housed in a near windowless six story building originally designed as a synagogue and men's club by William Lescaze in 1959. A community facility to be established by the Fashion Center business organization in conjunction with the school consists of a library, gallery, archive, and show space, is to be sited on the roof of the Parson's building. A symbiotic relationship between the programs is echoed in the relationship between the architecture of the original building and the addition. By bringing together differences and calibrating them in the architecture it is the goal of this project to enrich the urban experience by offering a moment of heightened simultaneity.
Lattice study of the infrared behavior of QCD Green's functions in Landau gauge
Creators: name: Sternbeck, A.
name: Ilgenfritz, E. -M.
name: Müller-Preussker, M.
name: Schiller, A.
name: Bogolubsky, I. L.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We summarize the current status of our numerical results for the gluon and ghost propagators and for the Kugo-Ojima confinement parameter in quenched SU(3) lattice Landau gauge theory. The data for the propagators are compared to our results obtained in the case of full QCD, simulated using two flavors of dynamical clover-improved Wilson fermions. We demonstrate that the infrared behavior of the ghost propagator is consistent with the Kugo-Ojima confinement criterion. Explicit violation of reflection positivity by the gluon propagator is shown. Additionally, we present results of a running coupling constant both at low and at large momenta.
description: 7 pages, 8 figures, talk presented at Lattice2006 (Confinement and Topology)
A review of rice husk silica as a heterogeneous catalyst support
Creators: name: Izzati NASIR
Publisher: name: Metallurgy and Materials Science Research Institute Chulalongkorn University
Year: 2021
Subjects: Rice husk
Rice husk ash
Amorphous silica
Modified silica catalyst

description: Journal of Metals, Materials and Minerals, 31, 4, 1-12
title: Flying Wing Aerodynamic Design and Airbrake Integration
Creators: name: Mantz, Philip Lawson
Publisher: name: Old Dominion University
publisherIdentifier: https://ror.org/04zjtrb98
publisherIdentifierScheme: ROR
Year: 2024

description: During the 2022-2023 Academic year, the defense contractor, AeroVironment, tasked the Unmanned Aerial Systems Laboratory at Old Dominion University with designing an autonomous drone platform. A brief summary of the aerodynamic requirements included that the drone should cruise at a target cruise speed of 30m/s, the drone would operate up to an altitude of 1500m and be able to land within a 20m radius of a designated landing spot. The laboratory chose a flying wing model. Additionally, the aircraft would have an airbrake system integrated into the platform.

The aerodynamic requirements were configurated through the use of a ‘constraint diagram’. The airfoil was selected by conducting a literature search and constructing an airfoil performance matrix. The airframe was designed computationally using the software XFLR5, a Vortex Lattice Method solver for low Reynolds numbers. The airframe was then flight tested and validated using the autopilot logs to confirm the predicted aerodynamic performance.

The airbrake system was implemented post flight testing of the airframe and was designed using Stat-Ease 360 software, which is a compiled GUI interface used to generate designed experiments. A response surface was generated using airbrake models created in XFLR5. This response surface was then used to find a list of potential airbrake solutions. The most promising solutions were selected to be wind tunnel tested. After successful wind tunnel testing, another design of experiments was created to flight test the airbrake system. The airbrake system unfortunately was never able to be flight tested due to complications with a launcher system designed outside of the scope of this thesis. Alternatively, the methodology of how to flight test an airbrake system was documented and a trainer aircraft fitted with an airbrake system was flight tested with all data logged and analyzed postflight.

After validating the aerodynamic profile and airbrake system, the aerodynamic performance of the aircraft outperformed all predictions. Additionally, while the airbrake system itself was never flight tested, all computational and experimental data points toward encouraging results. If the launcher system is improved, a future flight test using the methodology created could confirm the performance of the airbrake system.
Enhanced mechanical and thermal properties of fly ash-based geopolymer composites by wollastonite reinforcement
Creators: name: Khanthima HEMRA
Publisher: name: Metallurgy and Materials Science Research Institute Chulalongkorn University
Year: 2021
Subjects: Wollastonite
Geopolymer composite
Compressive strength

description: Journal of Metals, Materials and Minerals, 31, 4, 13-25