cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds: VI. Perseus Observed with MIPS
Creators: name: Rebull, L. M.
name: Stapelfeldt, K. R.
name: Evans, N. J.
name: Joergensen, J. K.
name: Harvey, P. M.
name: Brooke, T. Y.
name: Bourke, T. L.
name: Padgett, D. L.
name: Chapman, N. L.
name: Lai, S. -P.
name: Spiesmann, W. J.
name: Noreiga-Crespo, A.
name: Merin, B.
name: Huard, T.
name: Allen, L. E.
name: Blake, G. A.
name: Jarrett, T.
name: Koerner, D. W.
name: Mundy, L. G.
name: Myers, P. C.
name: Sargent, A. I.
name: van Dishoeck, E. F.
name: Wahhaj, Z.
name: Young, K. E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present observations of 10.6 square degrees of the Perseus molecular cloud at 24, 70, and 160 microns with the Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS). The image mosaics show prominent, complex extended emission dominated by illuminating B stars on the East side of the cloud, and by cold filaments of 160 micron emission on the West side. Of 3950 point sources identified at 24 microns, 1141 have 2MASS counterparts. A quarter of these populate regions of the Ks vs. Ks-[24] diagram that are distinct from stellar photospheres and background galaxies, and thus are likely to be cloud members with infrared excess. Nearly half (46%) of these 24 micron excess sources are distributed outside the IC 348 and NGC 1333 clusters. NGC 1333 shows the highest fraction of stars with flat or rising spectral energy distributions (28%), while Class II SEDs are most common in IC 348. These results are consistent with previous relative age determinations for the two clusters. The intercluster region contains several tightly clumped (r~0.1 pc) young stellar aggregates whose members exhibit a wide variety of infrared spectral energy distributions characteristic of different circumstellar environments. One possible explanation is a significant age spread among the aggregate members, such that some have had time to evolve more than others. Alternatively, if the aggregate members all formed at roughly the same time, then remarkably rapid circumstellar evolution would be required to account for the association of Class I and Class III sources at ages
description: 82 pages, 32 figures, accepted to ApJS; ALL figures (even line drawings) had to be degraded to be accepted by the system here; the full-res figures are available in the version linked from the 'publications' area available at http://peggysue.as.utexas.edu/SIRTF/
CFT description of the Fully Frustrated XY model and phase diagram analysis
Creators: name: Cristofano, Gerardo
name: Marotta, Vincenzo
name: Minnhagen, Petter
name: Naddeo, Adele
name: Niccoli, Giuliano
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Following a suggestion given in Nucl. Phys. B 300 (1988)611,we show how the U(1)*Z_{2} symmetry of the fully frustrated XY (FFXY) model on a square lattice can be accounted for in the framework of the m-reduction procedure developed for a Quantum Hall system at "paired states" fillings nu =1 (cfr. Cristofano et al.,Mod. Phys. Lett. A 15 (2000)1679;Nucl. Phys. B 641 (2002)547). The resulting twisted conformal field theory (CFT) with central charge c=2 is shown to well describe the physical properties of the FFXY model. In particular the whole phase diagram is recovered by analyzing the flow from the Z_{2} degenerate vacuum of the c=2 CFT to the infrared fixed point unique vacuum of the c=3/2 CFT. The last theory is known to successfully describe the critical behavior of the system at the overlap temperature for the Ising and vortex-unbinding transitions.
description: 18 pages, 1 figure, to appear in JSTAT
On the Origin of Dynamically Cold Rings Around the Milky Way
Creators: name: Younger, Joshua D.
name: Besla, Gurtina
name: Cox, T. J.
name: Hernquist, Lars
name: Robertson, Brant
name: Willman, Beth
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a scenario for the production of dynamically cold rings around the Milky Way via a high-eccentricity, flyby encounter. These initial conditions are more cosmologically motivated than those considered in previous works. We find that the encounters we examine generically produce a series of nearly dynamically cold ring-like features on low-eccentricity orbits that persist over timescales of ~2-4 Gyr via the tidal response of the primary galaxy to the close passage of the satellite. Moreover, they are both qualitatively and quantitatively similar to the distribution, kinematics, and stellar population of the Monoceros ring. Therefore, we find that a high eccentricity flyby by a satellite galaxy represents a cosmologically appealing scenario for forming kinematically distinct ring-like features around the Milky Way.
description: accepted to ApJL; 4 Figures
Modelling and design of a two-phase reciprocating expander for integration in a trilateral flash cycle
Creators: name: Van Heule, Xander
name: Skiadopoulos, Anastasios
name: Manolakos, Dimitrios
name: De Paepe, Michel
name: Lecompte, Steven
Publisher: name: Technical University of Munich
Year: 2021

description: Two-phase expansion devices are used in a multitude of cycles and allow for an increase of the overall system efficiency. It has been shown that the trilateral flash cycle can improve the power output from the recovery of low temperature residual heat compared to the classic subcritical Organic Rankine cycle. Theoretical studies predict an improvement of at least 15%. The expanders that are mainly investigated for the purpose of two-phase expansion are the Lysholm and the reciprocating expanders. From these two, the reciprocating expander has been researched the least as it is not as easy to model. It has been shown that to model the reciprocating expander, there is a need to describe the non-equilibrium state of the phases during the expansion process. This study aims to fill the knowledge gap that exists for two-phase reciprocating expanders, by constructing a predictive model to describe the expansion process and the non-equilibrium phenomena occurring. The constructed model makes use of the homogeneous relaxation model to describe the thermal non-equilibrium between the phases. The working fluid used in initial modelling is cyclopentane. The resulting model will be used to formulate design guidelines for the construction of a two-phase reciprocating expander. This prototype will be used to gain experimental data, with which the theoretically predicted efficiency improvement can be validated.
Structural analysis of a regenerative flow turbine for low temperature organic Rankine cycle systems
Creators: name: Cioccolanti, Luca
name: Mancini, Edoardo
name: Moradi, Ramin
name: Farotti, Emanuele
name: Sasso, Marco
Publisher: name: Technical University of Munich
Year: 2021

description: A Regenerative flow turbine (RFT) is an innovative turbomachine based on the momentum exchange between the impeller and the flow resulting in a helical trajectory in the peripheral direction and generating a pulse pressure variation inside the flow. In general, an RFT shows low isentropic efficiencies compared to other kinds of expanders, but the potential low manufacturing cost makes it an alternative expander for low-temperature Organic Rankine Cycle (ORC) applications. In a previous study carried out by some of the authors, the performances of an RFT for low-grade waste heat recovery (WHR) applications in a non-regenerative ORC system have been preliminarily assessed. In this work, a structural analysis of the same RFT geometry has been performed in ANSYS to evaluate the mechanical stress before its potential manufacturing. More precisely, two different low-cost materials have been investigated namely aluminum and polyphenylene sulfide (PPS), and the most critical parts of the expander identified considering the nominal operating conditions of the ORC system. The analysis has shown that the maximum tensile strength is reached during the thermal transient phase and it is about 127.4 MPa and 50.8 MPa for aluminum and PPS respectively. Under thermal steady-state conditions, instead, the maximum stress lowers to 42 MPa for aluminum and 40 MPa for PPS. Hence, together with the evaluation of the mechanical stress of the expander in low-temperature applications, the analysis has provided useful insights into the expected power output and the potential dilation of the material, which may result in the critical operation of the impeller.
Additional file 1 of Prospective study to characterize adalimumab exposure in pediatric patients with rheumatic diseases
Creators: name: Welzel, Tatjana
name: Golhen, Klervi
name: Atkinson, Andrew
name: Gotta, Verena
name: Ternant, David
name: Kuemmerle-Deschner, Jasmin B.
name: Michler, Christine
name: Koch, Gilbert
name: van den Anker, Johannes N.
name: Pfister, Marc
name: Woerner, Andreas
Publisher: name: figshare
Year: 2024
Subjects: subject: Medicine
subject: Pharmacology
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: Biological Sciences not elsewhere classified
subject: Cancer
subject: Science Policy

description: Additional file 1: Table S1. Study schedule. Table S2. Sample management. Table S3. JIA subgroups by study group. Table S4 Corticosteroids treatment details at inclusion. Table S5. Grading by cells in the field of the chamber (SUN) and JADAS-10 scores in PRD patients with juvenile idiopathic arthritis and uveitis. Table S6. Univariable and multivariable linear mixed effect models investigating relationship between adalimumab concentrations (log-transformed) and study group, visit age and gender. Table S7. Characteristics adalimumab naïve children receiving the first adalimumab dose. Figure S1. Adalimumab concentrations and inflammatory marker. Figure S2. Adalimumab concentrations and disease activity captured by PGA and PPGA. Figure S3. Adalimumab exposure in children with PRD with adalimumab by study group with and without concomitant corticosteroid treatment.
High iron content glasses: an alternative in the use of electric arc furnace dust
Creators: name: Ionescu, Denisa V.
Publisher: name: University of British Columbia
Year: 2009

description: Electric arc furnace baghouse dust (EAF) represents an environmental problem, both in terms of temporary storage and, ultimately, safe disposal. Vitrification of the dust so that hazardous components (such as zinc, lead, chromium, cobalt, barium, and arsenic) are incorporated into the glassy structure is one option for environmentally benign disposal which is currently being explored commercially in silica-based glasses with levels of iron up to 15 wt%. However, the ability of vitreous materials to resist leaching of hazardous components may be substantially reduced by components which promote crystallinity, in particular Fe, Zn, Cd, and other transition elements. In the present work, the impact of Fe₂O₃on the vitrification process has been explored experimentally, with the objective to generate glasses of high iron content. Several compositions were prepared in the system Fe₂O₃- ZnO - CaO - MgO - Na₂O at 50 wt% SiO₂and 1500 °C. Amorphous products were obtained with Fe₂O₃content varying from 15 to 35 wt%. The influence of Zn, Cd, and Pb in the silicate melt was also studied, with emphasis on the effect of these elements on high iron content glasses. The addition levels were within the range of variation of these elements in E A F dusts. The suitability of high iron vitreous products to retain hazardous metallics is normally tested under standard leaching tests designed by special wastes protocols. Silica glasses with zinc and glasses containing both iron and zinc, as well as their crystallized samples, were tested in order to determine both the leaching resistance and the influence of crystallinity on the leaching process. Satisfactory results in the leaching tests show the versatility of silica glass to incorporate hazardous elements such as zinc, render the products non-toxic and hence create an alternative to expensive disposal costs associated with EAF dust.
Complementary Capabilities of Photoacoustic Imaging to Existing Optical Ocular Imaging Techniques
Creators: name: Kumar, Dipen
name: Goyal, Anju
name: Truhan, Alan
name: Abrams, Gary
name: Manwar, Rayyan
Publisher: name: arXiv
Year: 2020
Subjects: subject: Medical Physics (physics.med-ph)
subject: Image and Video Processing (eess.IV)
subject: FOS: Physical sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: In this chapter, we will give a brief overview of fundus photography, SLO, and OCT while discussing photoacoustic imaging potential as the next major ocular imaging modality.
Thermodynamic low-order model for the simulation of two-phase expansion within a TFC unit
Creators: name: Skiadopoulos, Anastasios
name: Van Heule, Xander
name: Kosmadakis, George
name: Manolakos, Dimitrios
name: De Paepe, Michel
name: Lecompte, Steven
Publisher: name: Technical University of Munich
Year: 2021

description: Numerical modeling of the two-phase expansion phenomenon may provide valuable tools for the evaluation of the efficiency of a Trilateral Flash Cycle (TFC) unit, as well as in the sizing and design optimization process of two-phase expanders. In the present work, a low-order thermodynamic model for the simulation of two-phase expansion in twin-screw expanders has been developed. The model simulates the phase change in the expansion chamber by discretizing it in a sufficient number of sub chambers. At every sub-chamber, the energy and mass balance equations are solved for both liquid and gas phases, similar to a two-fluid model approach. The modeling procedure applies a lumped parameter approach, which requires the calculation of a set of parameters to provide a closure for the mass and energy balance of the expander under different operating conditions. The necessary set of parameters for the two-phase expansion in twin-screw expanders has been identified based on available experimental data. The values of the parameters have been calculated by solving a properly defined optimization problem. The results from the simulations indicate that the developed model can predict with satisfying accuracy the two-phase expansion along the expansion chamber.
Generation of bipartite spin entanglement via spin-independent scattering
Creators: name: Lamata, Lucas
name: Leon, Juan
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider the bipartite spin entanglement between two identical fermions generated in spin-independent scattering. We show how the spatial degrees of freedom act as ancillas for the creation of entanglement to a degree that depends on the scattering angle, $θ$. The number of Slater determinants generated in the process is greater than 1, corresponding to genuine quantum correlations between the identical fermions. The maximal entanglement attainable of 1 ebit is reached at $θ=π/2$. We also analyze a simple $θ$ dependent Bell's inequality, which is violated for $π/4
description: 5 pages and 3 figures. Accepted in PRA
Two-loop QED corrections in few-electron ions
Creators: name: Yerokhin, V. A.
name: Indelicato, P.
name: Shabaev, V. M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Results of a calculation valid to all orders in the nuclear-strength parameter Zαare presented for the two-loop Lamb shift, notably for the two-loop self-energy correction, for the ground and first excited states of ions with the nuclear charge numbers Z=60-100. A detailed comparison of the all-order calculation with earlier investigations based on an expansion in the parameter Zαis given. The calculation removes the largest theoretical uncertainty for the 2p_j-2s transition energies in heavy Li-like ions and is important for interpretation of experimental data.
description: talk at PSAS 2006, Venice, Italy
Data embedding and prediction by sparse tropical matrix factorization
Creators: name: Omanović, Amra
name: Kazan, Hilal
name: Oblak, Polona
name: Curk, Tomaž
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Matrix factorization methods are linear models, with limited capability to model complex relations. In our work, we use tropical semiring to introduce non-linearity into matrix factorization models. We propose a method called Sparse Tropical Matrix Factorization (STMF) for the estimation of missing (unknown) values. We evaluate the efficiency of the STMF method on both synthetic data and biological data in the form of gene expression measurements downloaded from The Cancer Genome Atlas (TCGA) database. Tests on unique synthetic data showed that STMF approximation achieves a higher correlation than non-negative matrix factorization (NMF), which is unable to recover patterns effectively. On real data, STMF outperforms NMF on six out of nine gene expression datasets. While NMF assumes normal distribution and tends toward the mean value, STMF can better fit to extreme values and distributions. STMF is the first work that uses tropical semiring on sparse data. We show that in certain cases semirings are useful because they consider the structure, which is different and simpler to understand than it is with standard linear algebra.
Yields and elliptic flow of d(dbar) and He3(He3bar) in Au+Au collisions at sqrt(sNN)= 200 GeV
Creators: name: Liu, Haidong
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We present the transverse momentum spectra at mid-rapidity for $d$, $\bar{d}$ ($1
description: 4 pages, 3 figures
Creation of X-ray cavities in galaxy clusters with cosmic rays
Creators: name: Mathews, W. G.
name: Brighenti, F.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We describe how AGN-produced cosmic rays form large X-ray cavities and radio lobes in the hot diffuse gas in galaxy groups and clusters. Cosmic rays are assumed to be produced in a small shocked region near the cavity center, such as at the working surface of a radio jet. The coupled equations for gasdynamics and cosmic ray diffusion are solved with various assumptions about the diffusion coefficient. To form large, long-lived cavities similar to those observed, the diffusion coefficient must not exceed kappa = 10^28 cm^2/s in the hot gas, very similar to values required in models of cosmic ray diffusion in the Milky Way. When kappa does not exceed 10^28, cosmic rays are confined within the cavities for times comparable to the cavity buoyancy time, as implied by observations of X-ray cavities and their radio synchrotron emission. Collisions of proton cosmic rays with thermal plasma nuclei followed by pion decay can result in enhanced gamma ray emission from the cavity walls.
description: 16 pages, 10 figures, accepted by ApJ
Electric dipole moment in storage ring experiments
Creators: name: Porshnev, Peter I
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The measurement of electric dipole moment in storage rings can potentially exceed the sensitivity of tests with neutral systems. The spin dynamics under such conditions is described by the Bargmann-Michel-Telegdi equation. It can be derived in the semiclassical approximation under several assumptions one of which is the zero pseudoscalar bilinear. However, many promising extensions to the standard model consider scalar-pseudoscalar couplings which assume nonzero electron pseudoscalar. We re-derive the spin precession equation under conditions that do not assume that pseudoscalar is zero. It leads to a correction term that might be required for matching the storage ring measurements with QFT evaluations.
description: Accepted by Physica Scripta (Particles, fields, and nuclear physics)
Decoherence of flux qubits due to 1/f flux noise
Creators: name: Yoshihara, F.
name: Harrabi, K.
name: Niskanen, A. O.
name: Nakamura, Y.
name: Tsai, J. S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We have investigated decoherence in Josephson-junction flux qubits. Based on the measurements of decoherence at various bias conditions, we discriminate contributions of different noise sources. In particular, we present a Gaussian decay function of the echo signal as evidence of dephasing due to $1/f$ flux noise whose spectral density is evaluated to be about $(10^{-6} Φ_0)^2$/Hz at 1 Hz. We also demonstrate that at an optimal bias condition where the noise sources are well decoupled the coherence observed in the echo measurement is mainly limited by energy relaxation of the qubit.
description: 4 pages, error in Fig.4 corrected, to appear in PRL
Additional file 1 of Towards a standardized program of transitional care for adolescents with juvenile idiopathic arthritis for Turkey: a national survey study
Creators: name: Sözeri, Betül
name: Şahin, Nihal
name: Açarı, Ceyhun
name: Avar Aydın, Pinar Ozge
name: Baba, Ozge
name: Bağlan, Esra
name: Bakkaloğlu, Sevcan
name: Bakırcı, Sibel
name: Bilginer, Yelda
name: Bozkaya, Burcu Yücel
name: Çağlayan, Şengül
name: Çakan, Mustafa
name: Çakmak, Figen
name: Coşkuner, Taner
name: Demir, Ferhat
name: Demirkan, Fatma Gül
name: Doğantan, Şeyda
name: Adıgüzel Dündar, Hatice
name: Ersözlü, Emine Duygu
name: Gücenmez, Sercan
name: Gürler, Oğuz
name: İşgüder, Rana
name: Küçük, Adem
name: Kalyoncu, Mukaddes
name: Kılıç, Levent
name: Kılıç, Sara Şebnem
name: Kısaoğlu, Hakan
name: Paç Kısaarslan, Ayşenur
name: Kızıldağ, Zehra
name: Kurtuluş, Duygu
name: Özdel, Semanur
name: Öztürk, Kübra
name: Şenol, Pelin
name: Tanatar, Ayşe
name: Taşkın, Sema Nur
name: Tuncer Kuru, Fatma
name: Türkuçar, Serkan
name: Ulu, Kadir
name: Ünsal, Erbil
name: Yazıcı, Ayten
name: Gezgin Yıldırım, Deniz
name: Yüksel, Selçuk
name: Kasapçopur, Özgür
name: Özen, Seza
name: Aktay Ayaz, Nuray
name: Sönmez, Hafize Emine
Publisher: name: figshare
Year: 2024
Subjects: subject: Medicine
subject: Geology
subject: FOS: Earth and related environmental sciences
subject: Ecology
subject: FOS: Biological sciences
subject: Sociology
subject: FOS: Sociology
subject: Infectious Diseases
subject: FOS: Health sciences

description: Additional file 1.
Massive U(1)s and Heterotic Five-Branes on K3
Creators: name: Honecker, Gabriele
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We systematically consider heterotic SO(32) and E8 x E8 compactifications on K3 with Abelian and non-Abelian backgrounds as well as an arbitrary number of five-branes. The masses of the U(1) factors depend on the first Chern classes of the bundles and some combinatorial factors specifying the embedding in SO(32) or E8. The form of the generalised Green-Schwarz counter-terms in six dimensions constrains the possible heterotic five-brane actions. Some supersymmetric examples on K3 realisations as toric complete intersection spaces with up to three explicit two-forms are given.
description: 26 pages, 1 figure; v2: refs added, over-all normalisation of GS & CS terms changed by 2
What to do about income inequality
Creators: name: Fadda, Sebastiano
Publisher: name: Università degli Studi di Urbino Carlo Bo
Year: 2015
Subjects: Income distribution; income inequality, redistribution

description: The first question dealt with in the paper is whether it’s worth worrying about unequal income distribution. The supposed long run constant factor shares, the positive effects of inequality and the greater importance of absolute level of income compared to its unequal distribution seems to deny this need. On the contrary,  economic, social and fairness reasons support the need to care about unequal income distribution. Therefore, measures should be taken about income inequality, and a distinction has to be made between measures to prevent excessive inequality from happening and measures to redistribute income once inequality has taken place. In order to envisage appropriate measures it is necessary to find out what causes the growing trend of increasing inequality in income distribution: economic and institutional factors are taken into consideration. Consequently a range of measures are suggested, which go from reducing the “degree of monopoly” in the economy to  regulating the financial system, from improving the system of collective bargaining to curbing the “predatory behaviour” of the executives. Redistribution measures are also discussed, with a warning about the risk of causing with them more harm than the inequality they are supposed to counteract.
description: Argomenti, N° 1 (2015): maggio-agosto
An introduction to Pythagorean Arithmetic
Creators: name: Nicholson, Jason Scott
Publisher: name: University of British Columbia
Year: 2009

description: This thesis provides a look at some aspects of Pythagorean Arithmetic. The topic is introduced by looking at the historical context in which the Pythagoreans nourished, that is at the arithmetic known to the ancient Egyptians and Babylonians. The view of mathematics that the Pythagoreans held is introduced via a look at the extraordinary life of Pythagoras and a description of the mystical mathematical doctrine that he taught. His disciples, the Pythagoreans, and their school and history are briefly mentioned. Also, the lives and works of some of the authors of the main sources for Pythagorean arithmetic and thought, namely Euclid and the Neo-Pythagoreans Nicomachus of Gerasa, Theon of Smyrna, and Proclus of Lycia, are looked at in more detail. Finally, an overview of the content of the arithmetic of the Pythagoreans is given, with particular attention paid to their relationship to incommensurable or irrational numbers. With this overview in hand, the topics of Perfect and Friendly Numbers, Figurate Numbers, Relative Numbers (the Pythagorean view of ratios and fractions), and Side and Diagonal numbers are explored in more detail. In particular, a selection of the works of Nicomachus, Theon, and Proclus that deal with these topics are analyzed carefully, and their content is reformulated and commented upon using clearer and more modern terminology.
Il finanziamento delle PMI nei principali paesi dell’UE durante la grande recessione
Creators: name: Bonsi, Silvia
name: Bruzzo, Aurelio
Publisher: name: Università degli Studi di Urbino Carlo Bo
Year: 2015

description: The article has the purpose to illustrate the financing of SME occurred in the main European countries in the period 2009-2014, to study the features of SME, problems met in access to credit in a period of recession like the present. In particular the aim is going to study through the reworking of the data collected in the research “Survey on the Access to finance of Enterprises” promoted by EU, the evolution of the sources of external financing, the obstacles faced by SME and future expectations.
description: Argomenti, N° 1 (2015): maggio-agosto
Improved ORC cycle for power production by using low temperature heat
Creators: name: Krail, Jürgen
name: Beckmann, Georg
name: Schittl, Florian
Publisher: name: Technical University of Munich
Year: 2021

description: Organic Rankine Cycles (ORC) are a modification of the classical water-steam process and are particularly suitable for electricity generation from low and medium temperature heat sources, e.g., industrial waste heat or geothermal energy. In contrast to the water-steam process, the ORC process uses organic fluids as working fluids. When using working fluids of the dry class (e.g. n-pentane), a recuperator is frequently installed in state-of-the-art ORC processes to increase the cycle efficiency. This paper analyses an improved ORC process design: A liquid working fluid stream is mixed with the vapour flow between the high-pressure stage and the medium-pressure stage of the turbine. Furthermore, the recuperator is replaced by a spray condenser. These two improvements were analysed by thermodynamic process simulations. As a use case, electricity production from clinker cooler waste heat at a temperature level of 275°C was simulated. The improved process as described would lead to an increase in the overall net efficiency up to 14%, compared to a state-of-the-art ORC process.
Formation of spiral structure from the violent relaxation of self-gravitating disks
Creators: name: Worrakitpoonpon, Tirawut
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We present the numerical study of the formation of spiral structure in the context of violent relaxation. Initial conditions are the out-of-equilibrium disks of self-gravitating particles in rigid rotation. By that mechanism, robust and non-stationary spiral arms can be formed within a few free-fall times by the shearing of the mass ejection following the collapse. With a closer look, we find different properties of the arms in connection with the initial configuration. The winding degree tends to increase with initial angular speed provided that a disk is thin. If disk surface is circular, both number and position of arms are governed by the Poissonian density fluctuations that produce more arms as more particles are introduced. On the contrary, if the surface ellipticity is imposed, the number of arms and their placement are effectively controlled. Otherwise, the increase of thickness leads to a complicated outcome since the number of arms and winding degree are less effectively controlled. We speculate that this complexity is caused by a strong non-axisymmetric field during the violent relaxation that disorganizes the pre-collapse motion and the concentration of particles.
description: 12 pages; 13 figures; to appear in Astronomische Nachrichten (AN)
Evaluation of Plant Configurations for Geothermal Trigeneration Systems with Organic Rankine Cycles
Creators: name: Schifflechner, Christopher
name: Kaufmann, Florian
name: Irrgang, Ludwig
name: Kuhnert, Lara
name: Dawo, Fabian
name: Wieland, Christoph
name: Spliethoff, Hartmut
Publisher: name: Technical University of Munich
Year: 2021
Subjects: Geothermal energy; ORC; polygeneration; trigeneration; part-load operation; plant desing

description: Due to the expected increasing importance of cooling applications within the next decades, geothermal trigeneration systems might be of high interest in the future. This work aims at evaluating different plant layouts against the background of more advanced plant configurations and part load behavior. Four different plant configurations are analyzed for a geothermal heat source with a temperature of 130 °C and a mass flow rate of 140 kg/s. The highest net power output is achieved by an advanced serialparallel configuration. With an annual net power production of 25.91 GWh, the power output is between 2 and 42 % higher compared with the other three configurations (parallel, serial and serial-parallel). The application of a recuperator within the ORC system has a significant impact on the serial concepts, but only marginally increases the power output of the parallel layouts. Depending on the plant configuration, there is an optimal desorber temperature of the absorption chiller. In case of serial concepts, the desorber temperature affects only the brine reinjection temperature, but not the ORC net power. For serial concepts, an optimal desorber temperature between 65 and 70 °C is revealed. Finally, the results highlight the importance of considering part load effects when evaluating the annual performance of geothermal trigeneration systems.
A Numerical Renormalization Group for Continuum One-Dimensional Systems
Creators: name: Konik, Robert M.
name: Adamov, Yury
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present a renormalization group (RG) procedure which works naturally on a wide class of interacting one-dimension models based on perturbed (possibly strongly) continuum conformal and integrable models. This procedure integrates Kenneth Wilson's numerical renormalization group with Al. B. Zamolodchikov's truncated conformal spectrum approach. Key to the method is that such theories provide a set of completely understood eigenstates for which matrix elements can be exactly computed. In this procedure the RG flow of physical observables can be studied both numerically and analytically. To demonstrate the approach, we study the spectrum of a pair of coupled quantum Ising chains and correlation functions in a single quantum Ising chain in the presence of a magnetic field.
description: 4 pages, 4 figures
Stellar parameters, disk-phases changes and new insight about the line-profile variability of π Aquarii
Creators: name: Concha, David Alfonso
Publisher: name: Zenodo
Year: 2024

description: π Aquarii is a bright, rapidly rotating classical Be star observed for over 100 years, exhibiting significant mid- and long-term variability. Here, we analyzed Hα profile variability over 23 years (2001-2023). We used the BeSOS and BeSS surveys. We utilized the ZPEKTR code, (based on TLUSTY models) for fast-rotating stars  to fit the HeI 4471 line. We used the BeAtlas grid, based on he HDUST code and considered a power-law for the density distribution in the disk to obtain the diskparameters.
Angular distributions in Monte Carlo event generation of weak single-pion production
Creators: name: Niewczas, K.
name: Nikolakopoulos, A.
name: Sobczyk, J. T.
name: Jachowicz, N.
name: González-Jiménez, R.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: One of the substantial sources of systematic errors in neutrino oscillation experiments that utilize neutrinos from accelerator sources stems from a lack of precision in modeling single-pion production (SPP). Oscillation analyses rely on Monte Carlo event generators (MC), providing theoretical predictions of neutrino interactions on nuclear targets. Pions produced in these processes provide a significant fraction of oscillation signal and background on both elementary scattering and detector simulation levels. Thus, it is of critical importance to develop techniques that will allow us to accommodate state-of-the-art theoretical models describing SPP into MCs. In this work, we investigate various algorithms to implement single-pion production models in Monte Carlo event generators. Based on comparison studies, we propose a novel implementation strategy that combines satisfactory efficiency with high precision in reproducing details of theoretical models predictions, including pion angular distributions. The proposed implementation is model-independent, thereby providing a framework that can include any model for SPP. We have tested the new algorithm with the Ghent Low Energy Model for single-pion production implemented in the NuWro Monte Carlo event generator.
description: 13 pages, 8 figures
Investigation of the effects of plate patterns on effectiveness and entropy generation in plate heat exchangers
Creators: name: Barış Gürel
name: Keçebaş, Ali
name: Akkaya, Volkan Ramazan
name: Algan, Ramazan
name: Göltaş, Merve
name: Güler, Onur Vahip
Publisher: name: Technical University of Munich
Year: 2021

description: Compact plate heat exchangers (PHE) are widely used in various industry and power generation fields, especially as condenser and evaporator. Since heat rejection is an essential part of ORC systems, all improvements on heat transfer will lead higher efficiencies. There are some design criteria for such devices. Heat transfer, pressure drop, compactness, entropy generation, and effectiveness are the most essentials. The thermal performance and compactness of these devices can be increased by modifying the surface patterns of plates. However, attention should be paid to pressure drop and entropy generation since any modification on surface can easily led to pressure drop and entropy generation due to viscous effects on the plate surface which increase pumping duty eventually. Thus, there exists an optimization problem that one should take care of. This paper presents an investigation of the effect of the plate surface patterns of a standard PHE and trachea patterned compact PHE in terms of effectiveness and entropy generation. Trachea shaped fins are placed on the surface of the plate to form a trachea patterned PHE designed in accordance with the additive manufacturing method. Compactness which is heat transfer surface area scaled by the heat exchanger volume is an important design parameter for heat exchangers. In order to increase compactness, plate surface is decorated with trachea shaped fins. Consequently, compactness reached to 8150 while it is only 4280 for the standard PHE with three plates. In order to perform the thermodynamic analysis of the trachea pattern compact PHE, different flowrates were taken as 0.01, 0.03 and 0.05 kg/s. As a result of the study, the heat transfer amount was 2950 W, the efficiency was 0.282, and the entropy production was 20.370 W/K.
Subleading Shape-Function Effects and the Extraction of |V_ub|
Creators: name: Lee, Keith S. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We derive a class of formulae relating moments of B -> Xu l nu to B -> Xs gamma in the shape function region, where m_X^2 ~ m_b Lambda_QCD. We also derive an analogous class of formulae involving the decay B -> Xs l+ l-. These results incorporate Lambda_QCD/m_b power corrections, but are independent of leading and subleading hadronic shape functions. Consequently, they enable one to determine |V_ub|/|V_tb V_ts*| to subleading order in a model-independent way.
description: 23 pages
RMC 40 in eruptive phase: CNO and rare-earth elements
Creators: name: Drake, Natalia
name: Borges Fernandes, Marcelo
name: Campagnolo, Julio C.N.
name: Kraus, Michaela
name: Pereira, Claudio B.
name: Guerrero, Carlos Alberto
name: de Almeida, K.P.R.
name: de Almeida, Elisson S. G.
Publisher: name: Zenodo
Year: 2024

description: Using high-resolution optical and infrared spectra of the LBV star in the Small Magellanic Cloud, RMC 40, obtained during the eruptive phase, we determined chemical abundances of the light (CNO) and rare-earth elements. We found strong decrease in carbon abundance and strong enhancement in nitrogen abundance. The abundances of the s- and r-process elements, such as Ba, La, Ce, Pr, Nd, and Dy, are increased compared to solar-scaled values by +(0.60  - 1.0) dex, pointing to strong pollution of the stellar envelope (pseudo-photosphere) by the products of the CNO cycle and the r- and s-processes.
Reaction-diffusion modelling of somite formation : computed dynamics and bifurcation analysis
Creators: name: Orchard, Jeff
Publisher: name: University of British Columbia
Year: 2009

description: Living organisms exhibit pattern in many forms. The processes underlying this organization, in general, are not well understood. This thesis proposes a candidate model for the dynamic eruption of somites (the precursors for the structures associated with the spinal column) in vertebrate embryos. We apply the Brusselator reaction-diffusion chemical model in a dynamic setting to not only produce the desired pattern, but also to mimic the propagation of the region of somite production (the "cohesive zone") along the embryo. The model can be rendered into a system of partial differential equations, and studied analytically and numerically. A bifurcation analysis is performed on a certain trajectory in the system's parameter space. Further numerical analysis on a more biologically robust version of the problem yields evidence for more than one stable, steady-state solution for certain parameter sets. Movement of the region of somite formation is simulated by adding a feedback mechanism between the peak value of the X morphogen, and a gradient in the source chemical B. Finally, investigation of the effect of adding a diffusion barrier yields some results that may be tested experimentally, creating evidence either for or against the possibility that a Brusselator-like chemical system is responsible for somite production in vertebrate embryos.
Red Supergiants, Yellow Hypergiants, and Post-RSG Evolution
Creators: name: Gordon, Michael S.
name: Humphreys, Roberta M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: How massive stars end their lives remains an open question in the field of star evolution. While the majority of stars above 9 M_sun will become red supergiants (RSGs), the terminal state of these massive stars can be heavily influenced by their mass-loss histories. Periods of enhanced circumstellar wind activity can drive stars off the RSG branch of the HR Diagram. This phase, known as post-RSG evolution, may well be tied to high mass-loss events or eruptions as seen in the Luminous Blue Variables and other massive stars. This article highlights some of the recent observational and modeling studies that seek to characterize this unique class of stars, the post-RSGs, and link them to other massive objects on the HR Diagram such as LBVs, Yellow Hypergiants, and dusty RSGs.
description: Published in "Luminous stars in Nearby Galaxies." https://www.mdpi.com/journal/galaxies/special_issues/Luminous
Guanidinium can both Cause and Prevent the Hydrophobic Collapse of Biomacromolecules
Creators: name: Heyda, Jan
name: Okur, Halil I.
name: Hladílková, Jana
name: Rembert, Kelvin B.
name: Hunn, William
name: Yang, Tinglu
name: Dzubiella, Joachim
name: Jungwirth, Pavel
name: Cremer, Paul S.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: A combination of Fourier transform infrared and phase transition measurements as well as molecular computer simulations, and thermodynamic modeling were performed to probe the mechanisms by which guanidinium salts influence the stability of the collapsed versus uncollapsed state of an elastin-like polypeptide (ELP), an uncharged thermoresponsive polymer. We found that the cation's action was highly dependent upon the counteranion with which it was paired. Specifically, Gnd+ was depleted from the ELP/water interface and was found to stabilize the collapsed state of the macromolecule when paired with well-hydrated anions such as sulfate. Stabilization in this case occurred via an excluded volume (or depletion) effect, whereby sulfate was strongly partitioned away from the ELP/water interface. Intriguingly, at low salt concentrations, Gnd+ was also found to stabilize the collapsed state of the ELP when paired with SCN-, which is a strong binder for the ELP. In this case, the anion and cation were both found to be enriched in the collapsed state of the polymer. The collapsed state was favored because the Gnd+ crosslinked the polymer chains together. Moreover, the anion helped partition Gnd+ to the polymer surface. At higher salt concentrations (>1.5 M), GndSCN switched to stabilizing the uncollapsed state because a sufficient amount of Gnd+ and SCN- partitioned to the polymer surface to prevent cross-linking from occurring. Finally, in a third case, it was found that salts which interacted in an intermediate fashion with the polymer (e.g. GndCl) favored the uncollapsed conformation at all salt concentrations.
description: 20 pages, 6 figures
Dust Coagulation and Settling in Layered Protoplanetary Disks
Creators: name: Ciesla, Fred J.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Previous models of dust growth in protoplanetary disks considered either uniformly laminar or turbulent disks. This Letter explores how dust growth occurs in a layered protoplanetary disk in which the magnetorotational instability generates turbulence only in the surface layers of a disk. Two cases are considered: a completely laminar dead zone and a dead zone in which turbulence is ``stirred up'' from the MRI acting above. It is found that dust is depleted from high altitudes in layered disks faster than in those cases of a uniformly laminar or turblent disks. This is a result of the accelerated growth of particles in the turbulent regions and their storage in the lower levels where they escape energetic collisions which would result in disruption. Thus the regions of a protoplanetary disk above a dead zone would become rapidly depleted in small dust grains, whereas the outer regions, where the MRI is active throughout, will maintain a small dust poplulation at all heights due to the disruptive collisions and vertical mixing from turbulence. This structure is similar to that which has been inferred for disks around TW Hydra, GM Auriga, and CoKu Tau/4, which are depleted in dust close to the star, but are optically thick at larger heliocentric distances.
description: 4 pages, 3 figures, accepted to ApJ Letters
Transition temperature in QCD with physical light and strange quark masses
Creators: name: Karsch, Frithjof
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We present results from a calculation of the transition temperature in QCD with two light and one heavier (strange) quark mass on lattices with temporal extent N_t =4 and 6. Calculations with improved staggered fermions have been performed with a strange quark mass fixed close to its physical value and for various light to strange quark mass ratios that correspond to light pseudo-scalar masses in the range (150-500) MeV. From a combined extrapolation to the chiral (m_l -> 0) and continuum (aT -> 0) limits we obtain for the transition temperature at the physical point T_c = 192(7)(4) MeV. We also present first results from an ongoing calculation of the QCD equation of state with almost realistic light and strange quark masses.
description: 4 pages, 4 figures, to appear in the proceedings of the 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions, Shanghai, Nov. 2006