cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Searching for Perfect Fluids: Quantum Viscosity in a Universal Fermi Gas
Creators: name: Cao, C.
name: Elliott, E.
name: Wu, H.
name: Thomas, J. E.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We measure the shear viscosity in a two-component Fermi gas of atoms, tuned to a broad s-wave collisional (Feshbach) resonance. At resonance, the atoms strongly interact and exhibit universal behavior, where the equilibrium thermodynamic properties and the transport coefficients are universal functions of the density $n$ and temperature $T$. We present a new calibration of the temperature as a function of global energy, which is directly measured from the cloud profiles. Using the calibration, the trap-averaged shear viscosity in units of $\hbar\,n$ is determined as a function of the reduced temperature at the trap center, from nearly the ground state to the unitary two-body regime. Low temperature data is obtained from the damping rate of the radial breathing mode, while high temperature data is obtained from hydrodynamic expansion measurements. We also show that the best fit to the high temperature expansion data is obtained for a vanishing bulk viscosity. The measured trap-averaged entropy per particle and shear viscosity are used to estimate the ratio of the shear viscosity to the entropy density, which is compared that conjectured for a perfect fluid.
description: 20 pages, 10 figures
Fitting in and feeling real : state authenticity as fit between identity and environment
Creators: name: Aday, Audrey
Publisher: name: University of British Columbia
Year: 2018

description: State authenticity (SA) is defined as “the sense or feeling that one is currently in alignment with one’s true or genuine self” (Sedikides et al., 2017). Recent models have conceptualized SA as distinct from trait authenticity and as a key predictor of situation selection with implications for how people self-sort by social identities (see Schmader & Sedikides, 2017). Critically, experiences of SA are predicted to arise from three distinct types of fit to the environment: self-concept, goal, and social fit. The present work aims to empirically test key assumptions of the SAFE (State Authenticity as Fit to the Environment) model and apply this model to academic (Chapter 2) and cultural (Chapter 3) contexts. In Chapter 2 (Studies 1-2), I review how identification with engineering versus psychology predicts greater approach intentions in the environment associated with engineering versus psychology, as fully mediated by SA. In Study 2, I review how SA can be understood as a mechanism of gendered occupational segregation. In Chapter 3 (Studies 3-4), I review how identification with mainstream culture predicts greater SA, as mediated by the three types of fit to the environment. In Study 4, I review how these outcomes also translate into student motivation on campus. Together, these findings add to current understandings of SA and highlight identification with one’s environment as a key antecedent to fit and authenticity.
Production and characterization of thermo-mechanical properties of hydroxyapatitefilled polycarbonatecomposite filaments for FDM printing
Creators: name: Uysalman, Tugce
name: Leskeri, Berkay Metin
name: Sarikanat, Mehmet
name: Altay, Lutfiye
name: Seki, Yoldas
Publisher: name: Journal of Additive Manufacturing Technologies
Year: 2022

description: The number of 3D printer filament development studies are increasing day by day by using composite materials to respond the need to create implants which have personalized design by using fused deposition modelling (FDM) 3D printing technology in bone tissue engineering. The aim of this study is to investigate the effect of Hydroxyapatite content in properties of composites and to produce filaments from developed composite materials. 10%, 15%, 20% and 25 wt. % Hydroxyapatite (HA) filled Polycarbonate (PC) composite granules were produced by using twin-screw extruder. Filaments were produced by filament production line. Characterization samples were obtained by using hot press in accordance with the standard dimensions. Density and MFI (Melt Flow Index) measurements, thermogravimetric analysis (TGA), and mechanical tests including tensile, three-point bending, and Izod un-notched impact strength tests are performed. Scanning Electron Microscopy (SEM) analysis was carried out to investigate the morphological changes. Tensile strength and elongation at break values were decreased but Young’s modulus was increased with increasing amount of HA in the composition. Similar results were obtained for flexural tests. Izod impact strength values were decreased by increasing HA amount. 3D printer filaments were produced and flexural test specimens were printed in 3D printer.
description: Journal of Additive Manufacturing Technologies, Vol. 1 No. 3 (2021): J AM Tech
Nuevos sitios de memoria del legado africano en Cuba.
Creators: name: Guanche, Jesús
Publisher: name: Zenodo
Year: 2006
Subjects: sitios de memoria, legado africano, patrimonio cultural

description: Como resultado del encuentro internacional auspiciado por la Oficina Regional de Cultura para América Latina y el Caribe de la UNESCO sobre Sitios de Memoria de la Ruta del Esclavo en el Caribe Latino, efectuado en La Habana, Cuba, del 17 al 19 de mayo del 2006, se propuso elaborar por cada uno de los países que conforman el cluster que atiende esta Oficina (Cuba, Haití, República Dominicana y Aruba), cinco nuevos sitios de memoria donde se combinan por primera vez el patrimonio edificado o el natural con el patrimonio cultural vivo, también denominado en diversos documentos y contextos como «patrimonio cultural inmaterial» o «patrimonio cultural intangible». En esa ocasión, junto con la evaluación del primer decenio de trabajo relacionado con el Proyecto UNESCO sobre La Ruta del Esclavo (1994-2004) se propone su continuidad a partir de las relaciones de los contenidos de varias Convenciones de la UNESCO, el primer lugar la CONVENCIÓN SOBRE LA PROTECCIÓN DEL PATRIMONIO MUNDIAL, CULTURAL Y NATURAL (1972) y especialmente las dos más recientes: la CONVENCIÓN PARA LA SALVAGUARDIA DEL PATRIMONIO CULTURAL INMATERIAL (París, 17 de octubre de 2003) y la CONVENCIÓN SOBRE LA PROTECCIÓN Y PROMOCIÓN DE LA DIVERSIDAD DE LAS EXPRESIONES CULTURALES (París, 20 de octubre de 2005). De este modo, el patrimonio cultural construido o de carácter natural se vincula con sus creadores, portadores y transmisores, a la vez que evidencia la riqueza y los modos en que se manifiesta la diversidad cultural mediante los nuevos sitios de memoria propuestos.
description: En ORCALC-UNESCO, La Habana, 2006.
Small area estimation of the homeless in Los Angeles: An application of cost-sensitive stochastic gradient boosting
Creators: name: Kriegler, Brian
name: Berk, Richard
Publisher: name: arXiv
Year: 2010
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: In many metropolitan areas efforts are made to count the homeless to ensure proper provision of social services. Some areas are very large, which makes spatial sampling a viable alternative to an enumeration of the entire terrain. Counts are observed in sampled regions but must be imputed in unvisited areas. Along with the imputation process, the costs of underestimating and overestimating may be different. For example, if precise estimation in areas with large homeless c ounts is critical, then underestimation should be penalized more than overestimation in the loss function. We analyze data from the 2004--2005 Los Angeles County homeless study using an augmentation of $L_1$ stochastic gradient boosting that can weight overestimates and underestimates asymmetrically. We discuss our choice to utilize stochastic gradient boosting over other function estimation procedures. In-sample fitted and out-of-sample imputed values, as well as relationships between the response and predictors, are analyzed for various cost functions. Practical usage and policy implications of these results are discussed briefly.
description: Published in at http://dx.doi.org/10.1214/10-AOAS328 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Disproportionate exposure to adversity and trauma among students who experience school discipline - A scoping review protocol
Creators: name: Sanders, Jane
name: Swiatek, Emma
name: Igor, Elo
name: Joseph, Andrea
name: Massey, Michael
Publisher: name: figshare
Year: 2021
Subjects: Education

description: Abstract Objective: The objective of this scoping review is to understand the current state of the literature on school discipline and trauma. This study will seek to identify and describe what is already known about exposure to trauma or adversity related to school discipline, identify any gaps in our understanding, and understand how trauma/adversity is contextualized or theorized within school discipline. Introduction: The disproportionate application of discipline reflects and feeds into the overall racial and gender opportunity gap. While there is extensive literature on the rate and impact of trauma and adversity in education, its role specific to school discipline is understudied. Understanding the lives of students is essential for healthy relationships and connections within schools, which in turn fosters school success, as well as, playing a key role in schools that have low rates of suspension. Inclusion criteria: This scoping review will include research related to students, parents, staff and any other data that considers adversity or trauma within school discipline. The concept includes expanded forms of adversity, Adverse Childhood Experiences (ACEs), potentially traumatic experiences, or the identification of symptoms, characteristics or expressions of trauma among students who have been disciplined in school. Research that discusses adversity or trauma in education but not specific to discipline are excluded. Research that discusses adversity or trauma in the home or community but not specific to discipline are excluded. The context for this scoping review is interdisciplinary, global understanding of the role of trauma or adversity within school discipline. This takes place in a context of disproportionate impact of school discipline, notably, suspension and expulsion on specific students, notably Black and Indigenous students. Methods: The proposed scoping review search strategy will aim to locate published studies of school discipline that include adversity or trauma. The first stage of the three stage search strategy, an initial limited search was conducted January, 2021. From this, a full search strategy was developed for Criminal Justice Abstracts, ERIC, PsychInfo (Proquest), Scopus, Social Service Abstracts, Social Work Abstracts, Sociological Abstracts. The reference list of all included articles will be searched for additional relevant studies as the third step to this three step process. Studies published in English will be included with no beginning date identified.
Gait Phase Detection of Stair Ambulation using Inertial Measurement of Lower Limb
Creators: name: STANLEY, MICHAEL
Publisher: name: Monash University
Year: 2021
Subjects: subject: 110906 Sensory Systems
subject: FOS: Clinical medicine

description: Accurate and timely detection is a crucial component in the operation of wearable assistive devices. Stair climbing is an activity with fewer investigation than level walking, yet a crucial and physically more demanding gait in daily life. This thesis develops an adaptive approach in determining the gait phases of stair climbing in real-time. It is tested on healthy individuals, and its performance is compared to machine learning approaches commonly used in literature.
Gentrification and Facadism in the Royal Borough of Kensington and Chelsea, London: a tale of three buildings
Creators: name: Rozena, Sharda
Publisher: name: University of Leicester
Year: 2023
Subjects: Uncategorized

description: The name, The Royal Borough of Kensington and Chelsea, has connotations of affluence, aristocracy, and the elite. This is the borough of a royal residence, Kensington Palace, situated on Kensington Palace Gardens. The road was known locally as Millionaires’ Row when I was growing up, but now it’s Billionaires’ Row, an avenue of private homes, embassies, and a royal palace on the most expensive residential street in Britain (Da Silva 2021). As a child, I would occasionally walk back from school playing hide and seek on this road with my mum although with tall, gated houses either side and regular security guard patrols, there were only a few places to hide – behind a Rolls Royce or secreted in the corner of a white gated column where I would jump out as she walked past. Near to Kensington Palace Gardens are high-end department stores like Harrods and Harvey Nichols (the latter I have never been inside), and supercars, Ferraris and Lamborghinis, speed down Knightsbridge into Chelsea. In March 2022, ITV News reported that residents were pleading for a larger fine, more than the current £100, for supercars that were as loud as jet planes and would wake people up in the night (Harris 2022).
Green's Functions and the Adiabatic Hyperspherical Method
Creators: name: Rittenhouse, Seth T.
name: Mehta, N. P.
name: Greene, Chris H.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We address the few-body problem using the adiabatic hyperspherical representation. A general form for the hyperangular Green's function in $d$-dimensions is derived. The resulting Lippmann-Schwinger equation is solved for the case of three-particles with s-wave zero-range interactions. Identical particle symmetry is incorporated in a general and intuitive way. Complete semi-analytic expressions for the nonadiabatic channel couplings are derived. Finally, a model to describe the atom-loss due to three-body recombination for a three-component fermi-gas of $^{6}$Li atoms is presented.
description: 14 pages, 8 figures, 2 tables
Vršnjačka podrška je najbolja podrška: Vodič za programe vršnjačkog mentorstva sa mladima iz sistema socijalne zaštite
Creators: name: CEPORA-Centar Za Pozitivan Razvoj Dece I Omladine
name: Legjobb Vagyok
Publisher: name: Zenodo
Year: 2021
Subjects: vršnjačko mentorstvo, programi, mladi iz sistema socijalne zaštite

description: Publikacija je nastala u okviru Erazmus+ projekta strateškog partnerstva u oblasti mladih „Vršnjački mentori u akciji: Socijalna inkluzija kroz vršnjačko mentorstvo“. Sadržaj publikacije organizovan je u četiri dela: I - O programima vršnjačkog mentorstva, II - Model programa vršnjačkog mentorstva za mlade iz sistema socijalne zaštite - Srbija, III - Model programam vršnjačkog mentorstva za mlade u sistemu socijalne zaštite - Mađarska, IV - Zaključci i preporuke.
Spatio-temporal Constraints on the Zoo Hypothesis, and the Breakdown of Total Hegemony
Creators: name: Forgan, Duncan H
Publisher: name: arXiv
Year: 2011
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Zoo Hypothesis posits that we have not detected extraterrestrial intelligences (ETIs) because they deliberately prevent us from detecting them. While a valid solution to Fermi's Paradox, it is not particularly amenable to rigorous scientific analysis, as it implicitly assumes a great deal about the sociological structure of a plurality of civilisations. Any attempt to assess its worth must begin with its most basic assumption - that ETIs share a uniformity of motive in shielding Earth from extraterrestrial contact. This motive is often presumed to be generated by the influence of the first civilisation to arrive in the Galaxy. I show that recent work on inter-arrival time analysis, while necessary, is insufficient to assess the validity of the Zoo Hypothesis (and its related variants). The finite speed of light prevents an early civilisation from exerting immediate cultural influence over a later civilisation if they are sufficiently distant. I show that if civilisation arrival times and spatial locations are completely uncorrelated, this strictly prevents the establishment of total hegemony throughout the Galaxy. I finish by presenting similar results derived from more realistic Monte Carlo Realisation simulations (where arrival time and spatial locations are partially correlated). These also show that total hegemony is typically broken, even when the total population of civilisations remains low. In the terminology of previous studies of solutions to Fermi's Paradox, this confirms the Zoo Hypothesis as a "soft" solution. However, an important question to be resolved by future work is the extent to which many separate hegemonies are established, and to what extent this affects the Zoo Hypothesis.
description: 14 pages, 10 figures, accepted for publication in the International Journal of Astrobiology
On the ${\cal{U}}_{q}[sl(2)]$ Temperley-Lieb reflection matrices
Creators: name: Lima-Santos, A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: This work concerns the boundary integrability of the spin-s ${\cal{U}}_{q}[sl(2)]$ Temperley-Lieb model. A systematic computation method is used to constructed the solutions of the boundary Yang-Baxter equations. For $s$ half-integer, a general $2s(s+1)+3/2$ free parameter solution is presented. It turns that for $s$ integer, the general solution has $2s(s+1)+1$ free parameters. Moreover, some particular solutions are discussed.
description: LaTex 17 pages
Peridynamics-informed effect of micro-cracks on topology optimization of lightweight structures
Creators: name: Motlagh, Peyman Lahe
name: Kendibilir, Abdullah
name: Koc, Bahattin
name: Kefal, Adnan
Publisher: name: Journal of Additive Manufacturing Technologies
Year: 2021

description: Most structures are preferred to be light-weighted when they are used in industrial applications such as automotive, aerospace, and naval structures. Classical continuum mechanics (CCM) formulations are commonly adopted to solve the topology optimization problems. However, CCM brings about some restrictions to the modeling, analysis, and solution of complex structures with structural discontinuities, defects, and micro/macro damages. Unlike CCM, peridynamic theory provides a wider range of analysis options because of its nonlocal integration nature, which can eliminate the need for partial derivatives in the equation of motion, thereby being suitable for effective modeling of cracks, damages, etc. This paper presents an application of peridynamics based topology optimization (PD-TO) to study the effect of micro-damages for designing lightweight engineering structures. The PD-TO algorithm used herein is based on the coupling of bond-based method and Optimality Criteria (OC) topology optimization method. The structure is designed by locating various microcracks for investigating the microdamage effect on the optimal topologies. To this end, the PD-TO model is implemented using an in-house MATLAB code, and strain energy density distributions are compared between different topologies. As a result, the importance of including damage regions within the lightweight design optimization stage is revealed.
description: Journal of Additive Manufacturing Technologies, Vol. 1 No. 3 (2021): J AM Tech
Comparison of landscape and vegetation metrics between wetlands in the northern great lakes region and high elevation central Appalachian wetlands
Creators: name: K.E., Francl,
Publisher: name: University of Notre Dame
Year: 2023

description: I surveyed 58 wetlands in northern Wisconsin and Michigan’s Upper Peninsula to examine patterns in vegetation community composition. In a principal components analysis of genera-weighted values, riverine sites were distinctly different from lacustrine and palustrine sites. Site loadings of the first principal component were correlated with site pH and a weighted site index of wetland plants. Similarity among wetlands was not influenced by distance among sites, and relative species richness was not influenced by wetland area. I then compared these northern wetland results to identical vegetation surveys of 20 high elevation wetlands in northern West Virginia and western Maryland, using plant community measures as relative disturbance indicators. Comparisons of the two regions indicated that more wetland-obligate and -facultative species were present in the northern wetlands than in relicts further south, and that relative species richness of non-woody species was higher in northern wetlands. Vegetation disturbance indicators, though relatively higher in northern wetlands than in central Appalachian relicts, revealed markedly low disturbance measures in both regions. The minimal levels of disturbance indicate the potential use of both regional sets of wetlands as baseline data for future disturbance studies.
Numerical simulation of multimaterial polymer mixing for bioprinting applications
Creators: name: Ates, Gokhan
name: Bártolo, Paulo Jorge
Publisher: name: Journal of Additive Manufacturing Technologies
Year: 2021

description: In tissue engineering, three-dimensional (3D) functional constructs (cellular or acellular) with tailored biological properties are needed to be able to mimic the hierarchical structure of biological tissues. Recent developments in extrusion based additive manufacturing considerably improved the ability to fabricate sophisticated tissue constructs by allowing to extrude multiple materials through different printing heads. This paper investigates the flow behavior of two miscible biomaterials inside an extrusion chamber incorporated with a Kenics static mixer (KSM). A computational fluid dynamics (CFD) model for isothermal non-Newtonian fluid flow was developed to numerically analyze the flow behavior of the fluids. The power-law model was used to characterize the shear-thinning behavior of the studied biomaterials. The mixing performance of designed chamber was also investigated by varying the inlet angles and velocities as well as the effect of the number of mixing units, pseudoplastic behavior of fluids, and pressure drop throughout the fluid domain. The results indicated that the inlet angle did not have a significant impact on the mixing quality and the proposed mixing channel showed good mixing performance regardless of the inlet velocities. The mixing index increases by increasing the power-law index and the shear-thinning behavior decreases the pressure drop value compared to Newtonian fluids.
description: Journal of Additive Manufacturing Technologies, Vol. 1 No. 3 (2021): J AM Tech
3D thermal modelling and simulation of selective laser melting
Creators: name: Demiray, Mehmet Alper
name: Şekerci, Bahri
name: Kayacan, M. Cengiz
name: Baykasoglu, Cengiz
Publisher: name: Journal of Additive Manufacturing Technologies
Year: 2021

description: Selective laser melting (SLM) is the most common additive manufacturing (AM) method since its manufacturing abilities for metal parts. In this study, heat transfer modelling and multi-track simulations of SLM with different parameters were conducted to predict maximum temperatures and melt pool dimensions depends on parameters such as laser power, scanning speed and hatching distance. Heat transfer equations for selective laser melting was obtained and material properties was revealed as temperature dependent. Goldak volumetric laser heat source model was used as the flux source. Finite Element Analysis (FEA) simulations for different laser power, scanning speed and hatching distance were conducted in ABAQUS FEA software as it provides a parametric job possibility within its Fortran subroutines. During laser scanning, it was concluded in simulation results that powder material is melted by heat source through at least one layer and this leads interlayer connection. Moreover, maximum temperatures were found stable from the beginning to the end of the track until it achieves equilibrium regime in view of temperature distribution. Lastly melt pool dimensions/ dimension ratios were examined comparing to the literature.
description: Journal of Additive Manufacturing Technologies, Vol. 1 No. 3 (2021): J AM Tech
Quantum state transfer in spin chains with q-deformed interaction terms
Creators: name: Jafarov, E. I.
name: Van der Jeugt, J.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We study the time evolution of a single spin excitation state in certain linear spin chains, as a model for quantum communication. Some years ago it was discovered that when the spin chain data (the nearest neighbour interaction strengths and the magnetic field strengths) are related to the Jacobi matrix entries of Krawtchouk polynomials or dual Hahn polynomials, so-called perfect state transfer takes place. The extension of these ideas to other types of discrete orthogonal polynomials did not lead to new models with perfect state transfer, but did allow more insight in the general computation of the correlation function. In the present paper, we extend the study to discrete orthogonal polynomials of q-hypergeometric type. A remarkable result is a new analytic model where perfect state transfer is achieved: this is when the spin chain data are related to the Jacobi matrix of q-Krawtchouk polynomials. The other cases studied here (affine q-Krawtchouk polynomials, quantum q-Krawtchouk polynomials, dual q-Krawtchouk polynomials, q-Hahn polynomials, dual q-Hahn polynomials and q-Racah polynomials) do not give rise to models with perfect state transfer. However, the computation of the correlation function itself is quite interesting, leading to advanced q-series manipulations.
Beurling-Landau's density on compact manifolds
Creators: name: Ortega-Cerdà, Joaquim
name: Pridhnani, Bharti
Publisher: name: arXiv
Year: 2011
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Spectral Theory (math.SP)
subject: FOS: Mathematics
subject: 35P99, 58C35, 58C40

description: Given a compact Riemannian manifold $M$, we consider the subspace of $L^2(M)$ generated by the eigenfunctions of the Laplacian of eigenvalue less than $L\geq 1$. This space behaves like a space of polynomials and we have an analogy with the Paley-Wiener spaces. We study the interpolating and Marcienkiewicz-Zygmund (M-Z) families and provide necessary conditions for sampling and interpolation in terms of the Beurling-Landau densities. As an application, we prove the equidistribution of the Fekete arrays on some compact manifolds.
Lattice density-functional theory on graphene
Creators: name: Ijäs, M.
name: Harju, A.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A density-functional approach on the hexagonal graphene lattice is developed using an exact numerical solution to the Hubbard model as the reference system. Both nearest-neighbour and up to third nearest-neighbour hoppings are considered and exchange-correlation potentials within the local density approximation are parameterized for both variants. The method is used to calculate the ground-state energy and density of graphene flakes and infinite graphene sheet. The results are found to agree with exact diagonalization for small systems, also if local impurities are present. In addition, correct ground-state spin is found in the case of large triangular and bowtie flakes out of the scope of exact diagonalization methods.
Appearance of Gauge Fields and Forces beyond the adiabatic approximation
Creators: name: Gosselin, Pierre
name: Mohrbach, Hervé
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate the origin of quantum geometric phases, gauge fields and forces beyond the adiabatic regime. In particular, we extend the notions of geometric magnetic and electric forces discovered in studies of the Born-Oppenheimer approximation to arbitrary quantum systems described by matrix valued quantum Hamiltonians. The results are illustrated by several physical relevant examples.
description: J . Phys. A (2010) in press
Towards Rehosting Embedded Applications as Linux Applications
Creators: name: Srinivasan, Jayashree
name: Tanksalkar, Sai Ritvik
name: Amusuo, Paschal C.
name: Davis, James C.
name: Machiry, Aravind
Publisher: name: figshare
Year: 2023
Subjects: Automated software engineering
Software and application security
Software testing, verification and validation
Cyberphysical systems and internet of things

description: Paper published in the Proceedings of the 53rd Annual IEEE/IFIP International Conference on Dependable Systems and Networks — Disrupt track (DSN-Disrupt’23) 2023.
Maximal and minimal realizations of reaction kinetic systems: computation and properties
Creators: name: Szederkenyi, Gabor
name: Hangos, Katalin M.
name: Peni, Tamas
Publisher: name: arXiv
Year: 2010
Subjects: subject: Molecular Networks (q-bio.MN)
subject: FOS: Biological sciences
subject: G.1.6
subject: 80A30

description: This paper presents new results about the optimization based generation of chemical reaction networks (CRNs) of higher deficiency. Firstly, it is shown that the graph structure of the realization containing the maximal number of reactions is unique if the set of possible complexes is fixed. Secondly, a mixed integer programming based numerical procedure is given for computing a realization containing the minimal/maximal number of complexes. Moreover, the linear inequalities corresponding to full reversibility of the CRN realization are also described. The theoretical results are illustrated on meaningful examples.
description: 23 pages, 4 figures
Nachhaltiges Forschungsdatenmanagement und Open Science an der Universität Hamburg
Creators: name: Möllenkamp, Andreas
name: Thiemann, Stefan
Publisher: name: Zenodo
Year: 2019
Subjects: Interviews
Forschungsdatenmanagement
Forschungsdateninfrastrukturen
Datenschutz
Open Access
Open Science
Sozialwissenschaften
Kulturwissenschaften
Geisteswissenschaften

description: Interview von Andreas Möllenkamp mit Stefan Thiemann im Rahmen des Forschungsprojekts "Open Interviews. Auf dem Weg zur Öffnung qualitativer Interviewforschung." Im Interview geht es um Forschungsdatenmanagement, Forschungsinfrastrukturen, Datenschutz, Open Access und Open Science in den Kultur-, Sozial- und Geisteswissenschaften. Das Interview wurde zwischen Januar und März 2019 per Email geführt. Das Projekt wurde durch das Fellow-Programm Freies Wissen vom Stifterverband für die Deutsche Wissenschaft, Wikimedia Deutschland und der VolkswagenStiftung gefördert.
Investigating compressive strength of laser powder bed fusion manufactured Ti6Al4V lattice structures for bone implant applications
Creators: name: Sağbaş, Binnur
name: Gürkan, Doruk
Publisher: name: Journal of Additive Manufacturing Technologies
Year: 2021

description: Lattice structures are becoming more and more attractive and preferred structures day by day because of their ultra-light weight properties with specific strength, load bearing capacity and time-cost-material efficiency. Due to their complex geometries it is impossible to generate these structures by conventional manufacturing methods. Laser powder bed fusion (LPBF), one of the most widely used and rapidly developing additive manufacturing (AM) method, provide opportunity to build up complex geometries. Ti6Al4V is commonly used AM material for biomedical lattice structure applications especially for bone implant researches. Mechanical properties of the lattice structures can be altered with lattice parameters (strut diameter, strut shape, unit cell dimensions and orientation). Compressive strength properties are the most critical concern for biomedical lattice structures as they are mostly employed under high compressive load. So, for developing functional, biomedical lattice geometries it is necessary to investigate the compression behavior of different lattice topologies. In this study, octahedroid, star and dodecahedron cubic lattice structures were manufactured with Ti6Al4V powder by LPBF technique for investigating their compressive behavior. Young moduli, maximum compression stress, experimental load values are determined and compared with literature. Mechanical properties of lattice structures were evaluated for bone implant applications.
description: Journal of Additive Manufacturing Technologies, Vol. 1 No. 3 (2021): J AM Tech
Web Conferencing Traffic - An Analysis using DimDim as Example
Creators: name: Seeling, Patrick
Publisher: name: arXiv
Year: 2010
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: Multimedia (cs.MM)
subject: FOS: Computer and information sciences

description: In this paper, we present an evaluation of the Ethernet traffic for host and attendees of the popular opensource web conferencing system DimDim. While traditional Internet-centric approaches such as the MBONE have been used over the past decades, current trends for web-based conference systems make exclusive use of application-layer multicast. To allow for network dimensioning and QoS provisioning, an understanding of the underlying traffic characteristics is required. We find in our exemplary evaluations that the host of a web conference session produces a large amount of Ethernet traffic, largely due to the required control of the conference session, that is heavily-tailed distributed and exhibits additionally long-range dependence. For different groups of activities within a web conference session, we find distinctive characteristics of the generated traffic.
Comparison of finite element and empirical model prediction of surface residual stress in inconel 718 parts fabricated by laser powder bed fusion additive manufacturing
Creators: name: Kaya, Mert
name: Sunay, Nedim
name: Kaynak, Yusuf
Publisher: name: Journal of Additive Manufacturing Technologies
Year: 2021

description: Inconel 718 parts produced by Laser Powder Bed Fusion (LPBF) generally have excessive residual stresses (RS) due to the extreme temperature gradients and high cooling rates that occur during production. These stresses can damage the mechanical properties and fatigue life of parts. Therefore, RS are one of the main reasons that hinder the widespread use of the LPBF process. The main purpose of this study is to predict the RS that may occur by finite element modeling and empirical approach of the production process in order to minimize the RS and distortions that occur during production. According to the simulation and theoretical calculation results, it has been observed that the RS in the build direction are generally large tensile stresses in the upper and lower regions and compressive stresses in a large middle region in between. One of the most important parameters that determine the residual stress magnitude is the scanning speed, which affects the energy density. The change in energy density due to constant laser power and increasing laser speed alters the amount of residual stress in the parts. This paper illustrates that when fabricating components with lower energy density leads to an increase of tensile residual stress, however, increasing energy density with altering process parameters results in reduced tensile residual stress.
description: Journal of Additive Manufacturing Technologies, Vol. 1 No. 3 (2021): J AM Tech
Astrometry with the MCAO instrument MAD - An analysis of single-epoch data obtained in the layer-oriented mode
Creators: name: Meyer, Eva
name: Kuerster, Martin
name: Arcidiacono, Carmelo
name: Ragazzoni, Roberto
name: Rix, Hans-Walter
Publisher: name: arXiv
Year: 2011
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context: Current instrument developments at the largest telescopes worldwide have provisions for Multi-Conjugated Adaptive Optics (MCAO) modules. The large field of view and more uniform correction provided by these systems is not only highly beneficial for photometric studies but also for astrometric analysis of, e.g., large dense clusters and exoplanet detection and characterization. The Multi-conjugated Adaptive optics Demonstrator (MAD) is the first such instrument and was temporarily installed and tested at the ESO/VLT in 2007. We analyzed two globular cluster data sets in terms of achievable astrometric precision. Data were obtained in the layer-oriented correction mode, one in full MCAO correction mode with two layers corrected (NGC 6388) and the other applying ground-layer correction only (47 Tuc). Aims: We aim at analyzing the first available MCAO imaging data in the layer-oriented mode obtained with the MAD instrument in terms of astrometric precision and stability. Methods: We calculated Strehl maps for each frame in both data sets. Distortion corrections were performed and the astrometric precision was analyzed by calculating mean stellar positions over all frames and by investigation of the positional residuals present in each frame after transformation to a master-coordinate-frame. Results: The mean positional precision for stars between K = 14-18 mag is ~1.2 mas in the full MCAO correction mode data of the cluster NGC 6388. The precision measured in the GLAO data (47 Tuc) reaches ~1.0 mas for stars corresponding to 2MASS K magnitudes between 9 and 12. The observations were such that stars in these magnitude ranges correspond to the same detector flux range. The jitter movement used to scan a larger field of view introduced additional distortions in the frames, leading to a degradation of the achievable precision.
description: 11 pages, 6 figures, accepted for publication in Astronomy & Astrophysics
CancelRx case study: implications for clinic and community pharmacy work systems
Creators: name: Watterson, Taylor L
name: Stone, Jamie A
name: Kleinschmidt, Peter C
name: Chui, Michelle A
Publisher: name: University of Illinois at Chicago
Year: 2023
Subjects: classificationCode: 4203
subject: Health services and systems
classificationCode: 4206
subject: Public health
classificationCode: 4205
subject: Nursing
subject: FOS: Health sciences
classificationCode: 42
subject: Health sciences
classificationCode: 4610
subject: Library and information studies

description: Abstract
 Background
 Medication prescribing and discontinuation processes are complex and involve the patient, numerous health care professionals, organizations, health information technology (IT). CancelRx is a health IT that automatically communicates medication discontinuations from the clinic electronic health record to the community pharmacy dispensing platform, theoretically improving communication. CancelRx was implemented across a Midwest academic health system in October 2017. The health system also operates 15 outpatient community pharmacies.

 Objective
 The goal of this qualitative study was to describe how both the clinic and community pharmacy work systems change and interact over time regarding medication discontinuations, before and after CancelRx implantation.

 Approach
 Medical Assistants (n = 9), Community Pharmacists (n = 12), and Pharmacy Administrators (n = 3), employed by the health system were interviewed across 3-time periods between 2017 and 2018— 3-months prior to CancelRx implementation, 3-months after CancelRx implementation, and 9-months after CancelRx implementation. Interviews were audio recorded, transcribed, and conducted a hybrid analysis with deductive content analysis following the Systems Engineering Initiative for Patient Safety (SEIPS) framework and inductive analysis to capture additional codes and themes.

 Key results
 CancelRx changed the medication discontinuation process at both clinics and community pharmacies. In the clinics, the workflows and medication discontinuation tasks changed over time while MA roles and clinic staff communication practices remained variable. In the pharmacy, CancelRx automated and streamlined how medication discontinuation messages were received and processed, but also increased workload for the pharmacists and introduced new errors.

 Conclusions
 This study utilizes a systems approach to assess disparate systems within a patient network. Future studies may consider health IT implications for systems that are not in the same health system as well as assessing the role of implementation decisions on health IT use and dissemination.
Influence of laser energy density on geometrical forms produced by laser metal deposition of PH 13-8 Mo stainless steel
Creators: name: Muslim, Talha
name: Karagoz, Taner
name: Ozkok, Recep
name: Yilmaz, Oguzhan
name: Kas, Mustafa
Publisher: name: Journal of Additive Manufacturing Technologies
Year: 2021

description: Additive manufacturing (AM) is getting more popular in many industries due to direct manufacturing facilities, design flexibility and effective lead time. Directed energy deposition (DED) is a variation of AM and laser metal deposition (LMD) is regarded as a DED process and it uses laser as a heat source to melt and deposit the raw material fed through a nozzle in the powder form. This paper presents a research work that investigates the forms of laser metal deposited parts in S-shaped using PH 13-8 Mo stainless steel powders. Experimental work was conducted to produce S-shaped single bead walls with main process parameters affecting the energy density. The results have been discussed by considering the energy density levels as low, medium and high. It is clear to observe that the low energy density level parameters produce no or improper S-shaped walls. However, high energy density level parameters produce relatively well deposited walls but the geometrical forms of the walls are not steady due to heat accumulation during the deposition. Balling on the deposited walls can be seen in each energy density level. This defect occurs when there is insufficient heat energy to melt and deposit the powder from the moving nozzle.
description: Journal of Additive Manufacturing Technologies, Vol. 1 No. 3 (2021): J AM Tech
A numerical approach to assess the impact of the SLM laser parameters on thermal variables
Creators: name: Majeed, Mobin
name: Khan, Hamaid Mahmood
name: Wheatley, Greg
name: Situ, Rong
Publisher: name: Journal of Additive Manufacturing Technologies
Year: 2021

description: Due to extraordinarily high heating and cooling rates, understanding the selective laser melting (SLM) process remains a challenge. To evaluate the impact of processing parameters on distinct underlying surfaces, a three-dimensional finite element model is presented. To forecast the temperature distribution inside a finite solid model, a moving Gaussian heat source was created to scan the model with temperature-dependent material properties. In the finite model, the impact of processing factors such as laser power, scan rate, and scan spacing were investigated to measure thermal variables such as cooling rate, thermal gradient, and solidification rate in a layer with solid and powder bases. The maximum track temperature was observed to be increasing over the whole track length, which had a substantial influence on the thermal gradient, cooling rate, and solidification rate. The maximum track temperature, melt pool form, and thermal variables were shown to be strongly influenced by laser power and scan speed when compared to scan spacing. Furthermore, the underlying base had a substantial influence on the observed temperature values and melt pool shape.
description: Journal of Additive Manufacturing Technologies, Vol. 1 No. 3 (2021): J AM Tech
Embedding information on additively manufactured parts using Mondrian patterns
Creators: name: Talhouet, Kilyan Emre
name: Yaman, Ulaş
Publisher: name: Journal of Additive Manufacturing Technologies
Year: 2021

description: With Additive Manufacturing (AM), parts having complex geometries can be produced easily compared to the traditional manufacturing methods. AM gives the opportunity to produce those complex parts in a very straightforward manner. This simplification creates the capability of embedding different structures, patterns or assets to the part without the burden of additional manufacturing processes. It has been observed that the most common approach for this purpose is to use QR codes. This article discusses a different method combining science and art together. A simple coding approach inspired by the Dutch painter Mondrian, who is known to have paintings consisting of grids and contrast colors, has been developed. In this paper, details of the proposed method to embed information onto the AM parts are presented and results are discussed.
description: Journal of Additive Manufacturing Technologies, Vol. 1 No. 3 (2021): J AM Tech
An approximate hard sphere method for densely packed granular flows
Creators: name: Guttenberg, Nicholas
Publisher: name: arXiv
Year: 2011
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: The simulation of granular media is usually done either with event-driven codes that treat collisions as instantaneous but have difficulty with very dense packings, or with molecular dynamics methods that approximate rigid grains using a stiff viscoelastic spring. There is a little-known method that combines several collision events into a single timestep in order to retain the instantaneous collisions of event-driven dynamics but also be able to handle dense packings. However, it is poorly characterized as to its regime of validity and failure modes. We present a modification of this method to reduce the introduction of overlap error, and test it using the problem of 2D granular Couette flow, a densely packed system that has been well-characterized by previous work. We find that this method can successfully replicate the results of previous work up to the point of jamming, and that it can do so a factor of 10 faster than comparable MD methods.
description: 7 pages, 6 figures
Deposition path planning strategy for geometries with varying cross-sections in wire arc additive manufacturing
Creators: name: Naseri, Babak
name: Bol, Nevzat
name: Yilmaz, Oguzhan
name: Kara, Ozge Ece
name: Sen, Ahmet Ali
Publisher: name: Journal of Additive Manufacturing Technologies
Year: 2021

description: Wire arc additive manufacturing (WAAM) method has emerged as a powerful platform for fabricating medium-to-large scale dense structural parts having low cost, higher deposition rate and material efficiencies compared to other additive manufacturing (AM) methods. This research work proposes a deposition tool path strategy for the parts with varying cross-sections in building directions. Different cross-section profiles in workpiece geometry complicate and increase the complexity of the tool path planning. Moreover, changing the cross-section profiles may cause to change in the heat dissipation and heat accumulation in various points of each layer. Thus, heat dissipation affects the dimensional tolerances of the workpiece during the process. In this study, firstly the deposition characteristics as Wire Feed Speed (WFS) and Torch Travel Speed (TTS) were determined based on the material, number of layers and thickness of the wall. Afterward, a specific tool path has been generated by considering the geometric attributes such as cross-section area, profile, type of border lines, curves, and their continuities. Finally, the workpiece was built up by using WAAM process with a robotic cold metal transfer (CMT) system using aluminum wire (AWS ER5356) material. The results have shown that the proposed deposition strategy results with steady transition from circular cross-section deposition to hexagonal cross-section with less distortion and waviness in the final geometry of the part.
description: Journal of Additive Manufacturing Technologies, Vol. 1 No. 3 (2021): J AM Tech