cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Revival-collapse phenomenon in the quadrature squeezing of the multiphoton Jaynes-Cummings model with the binomial states
Creators: name: El-Orany, Faisal A. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this paper we study the interaction between two-level atom and quantized single-mode field, namely, Jaynes-Cummings model (JCM). The field and the atom are initially prepared in the binomial state and the excited atomic state, respectively. For this system we prove that the revival-collapse phenomenon exhibited in the atomic inversion of the standard JCM can be numerically (naturally) manifested in the evolution of the squeezing factor of the three-photon (standard) JCM provided that the initial photon-number distribution of the radiation has a smooth envelope.
description: 14 pages, 4 figures, Comments are most welcome
Cournot Retrouvé under Price or Supply Function Competition
Creators: name: Delbono, Flavio
name: Lambertini, Luca
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2015
Subjects: SECS-P/01 Economia politica

description: This paper aims at participating in the long-lasting debate about the analytical foundations of the Cournot equilibrium. In a homogeneous oligopoly, under standard regularity conditions, we prove that Cournot-Nash emerges both under (i) price competition and Cournot conjectures; and (ii) supply function competition with ex post market clearing. We demonstrate both results within a model of exogenous product differentiation.
Novae heat their food: mass transfer by irradiation
Creators: name: Ginzburg, Sivan
name: Quataert, Eliot
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: A nova eruption irradiates and heats the donor star in a cataclysmic variable to high temperatures $T_{\rm irr}$, causing its outer layers to expand and overflow the Roche lobe. We calculate the donor's heating and expansion both analytically and numerically, under the assumption of spherical symmetry, and find that irradiation drives enhanced mass transfer from the donor at a rate $\dot{m}\propto T_{\rm irr}^{5/3}$, which reaches $\dot{m}\sim 10^{-6}\textrm{ M}_\odot\textrm{ yr}^{-1}$ at the peak of the eruption - about a thousand times faster than during quiescence. As the nova subsides and the white dwarf cools down, $\dot{m}$ drops to lower values. We find that under certain circumstances, the decline halts and the mass transfer persists at a self-sustaining rate of $\dot{m}\sim 10^{-7}\textrm{ M}_\odot\textrm{ yr}^{-1}$ for up to $\sim 10^3$ yr after the eruption. At this rate, irradiation by the white dwarf's accretion luminosity is sufficient to drive the mass transfer on its own. The self-sustaining rate is close to the white dwarf's stable burning limit, such that this bootstrapping mechanism can simultaneously explain two classes of puzzling binary systems: recurrent novae with orbital periods $\approx 2$ h (T Pyxidis and IM Normae) and long-lived supersoft X-ray sources with periods $\approx 4$ h (RX J0537.7-7034 and 1E 0035.4-7230). Whether or not a system reaches the self-sustaining state is sensitive to the donor's chromosphere structure, as well as to the orbital period change during nova eruptions.
description: Matches published version: added order-unity coefficients, a more detailed comparison with previous calculations, and some discussion
Women's experiences of radical surgery for gynecological cancer : a feminist phenomenological study
Creators: name: Janyce, Dayna Gayle
Publisher: name: University of British Columbia
Year: 2010

description: It is recognized that radical surgery for gynecological cancer causes significant negative effects on women's body image, sexuality, and self-esteem. However, researchers are uncertain why women experience feelings of depression and negativity towards body image even two years after removal of the uterus due to cancer. To gain an understanding of specific factors which cause these prolonged negative feelings, information was sought on the subjective experiences of women following this radical surgery. The study's feminist theoretical framework gave direction to investigate women's subjective experiences through language. The phenomenological research method was chosen as it allowed the discovery of women's subjective experiences through analyzing their verbal perceptions. The women described their emotional and physical needs and experiences related to this surgery which included finding out about cancer, needing support from others, understanding the surgery, physical recovery, sexual needs, beliefs and feelings about cancer, and changes in body structure and function. The study's findings show that this surgery was an emotionally and physically traumatic experience. It was concluded that these women did not receive adequate professional emotional support and information about the effects of this surgery. It was also concluded that, although the women's perception of self-worth was enhanced by surviving this surgery, this perception was also significantly inhibited by the grieving process which intensified several months after surgery. The implications of the study's findings for nursing practice, education, and research were outlined.
Composite Messenger Baryon as a Cold Dark Matter
Creators: name: Hamaguchi, K.
name: Shirai, S.
name: Yanagida, T. T.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Among various supersymmetric (SUSY) models, gauge-mediated SUSY breaking models with an ultra-light gravitino of mass m_{3/2} \lesssim O(10) eV are very attractive, since they are completely free from notorious gravitino problems. A drawback of such a scenario is the absence of the supersymmetric cold dark matter. In this letter, we propose that a baryonic bound state of strongly interacting messenger particles, with a mass of O(100) TeV, can naturally be the cold dark matter. We also exemplify a model which realizes such a scenario.
description: 7 pages, 1 figure
title: Вымысел и реальность в (авто)биографиях Ильи Сельвинского: 1918–1920 годы
Creators: name: Krasnikova, Anna
Publisher: name: AvtobiografiЯ
Year: 2020

description: There are still many gaps in the biography of Il'ja Sel'vinskij (1899-1968). Even if we consider the periods of his life that are relatively well described, most of the texts offer us intriguing legends and contain much less verified facts and exact dates. The paper investigates the 1918–1920-s, about which much has been written, but the information from different sources does not coincide and some facts contradict others.
Focusing on autobiographies of Sel'vinskij, but also using his letters, diaries and other sources, the author tries to find out which facts are reliable, which are doubtful, and which are false.
Oral medication administration : the effect of two instructional techniques on nursing student learning
Creators: name: Ettles, Violet Helen
Publisher: name: University of British Columbia
Year: 2010

description: This experimental study was designed to examine the effects of two selected instructional techniques on nursing student learning of oral medication administration. The research questions asked in this study concerned the effects of these selected Instructional techniques on cognitive learning, performance, and feeling of satisfaction toward the learning experience. The study was conducted in a three-year diploma nursing program associated with a large metropolitan hospital. A total of 66 first-year students participated in the study. There were 32 students in the experimental group and 34 students in the control group. All subjects were taught relevant content, prepared "drug cards", and completed a cognitive learning pretest prior to the oral medication administration laboratory. During the laboratory, the experimental subjects were taught by demonstration-return demonstration using simulation and the control subjects were taught by demonstration-return demonstration. Following the laboratory, all subjects were administered the pretest as a posttest, a feeling of satisfaction questionnaire, and a personal data questionnaire. Additionally, they were evaluated through the use of a performance checklist during their first administration of a medication(s) to a patient. Data obtained from the cognitive learning tests and performance checklist were analyzed using independent t-tests, and data obtained from the feeling of satisfaction questionnaire were analyzed using the chi-square test. Study findings showed that the two groups were similar when compared on selected personal characteristics. Differences between the groups for cognitive learning, performance, and feeling of satisfaction toward the learning experience were revealed not to be significant at the established level of D. = .05. This finding suggests that demonstration-return demonstration using simulation is a viable alternate technique for teaching oral medication administration.
Key Challenges in Defending Against Malicious Socialbots
Creators: name: Boshmaf, Yazan
name: Muslukhov, Ildar
name: Beznosov, Konstantin
name: Ripeanu, Matei
Publisher: name: Zenodo
Year: 2012
Subjects: Socialbots
Social Network Security
Large-scale Infiltration
Online Social Networks
Botnets

description: The ease with which we adopt online personas and relationships has created a soft spot that cyber criminals are willing to exploit. Advances in artificial intelligence make it feasible to design bots that sense, think and act cooperatively in social settings just like human beings. In the wrong hands, these bots can be used to infiltrate online communities, build up trust over time and then send personalized messages to elicit information, sway opinions and call to action. In this position paper, we observe that defending against such malicious bots raises a set of unique challenges that relate to web automation, online-offline identity binding and usable security.
Nanometer-Resolved Collective Micromeniscus Oscillations through Optical Diffraction
Creators: name: Rathgen, Helmut
name: Sugiyama, Kazuyasu
name: Ohl, Claus-Dieter
name: Lohse, Detlef
name: Mugele, Frieder
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We study the dynamics of periodic arrays of micrometer-sized liquid-gas menisci formed at superhydrophobic surfaces immersed into water. By measuring the intensity of optical diffraction peaks in real time we are able to resolve nanometer scale oscillations of the menisci with sub-microsecond time resolution. Upon driving the system with an ultrasound field at variable frequency we observe a pronounced resonance at a few hundred kHz, depending on the exact geometry. Modeling the system using the unsteady Stokes equation, we find that this low resonance frequency is caused by a collective mode of the acoustically coupled oscillating menisci.
description: 4 pages, 5 figures
Melomys Thomas 1922
Creators: name: Fabre, Pierre-Henri
name: Fitriana, Yuli S.
name: Semiadi, Gono
name: Pagès, Marie
name: Aplin, Ken
name: Supriatna, Nanang
name: Helgen, Kristofer M.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Mammalia
Rodentia
Muridae
Melomys

description: Melomys Thomas 1922a
Type species
Melomys rufescens (Alston 1877), by original designation.
Diagnosis
p = p-value. (cp <0.001). Df, degree of freedom. F, F statistic provided by R. The symbols “:” indicates tested interactions between explanatory variables.
Melomys is a murid genus classified in the subfamily Murinae (sensu Musser and Carleton 2005), within the tribe Hydromyini (Aplin and Helgen 2010), in the “ Uromys Division” of Musser and Carleton (2005). Species within this genus are small to medium-sized (HB max 190 mm) and are characterized by external characters (Tables 4 and 5) including (1) raised tail scales, (2) one or three short hairs per tail scale, (3) a broad hindfoot, and (4) a long first hindfoot digit reaching the origin of digits 2–4. To diagnose this genus Menzies (1996) used the following set of craniodental characters: (1) broad skull with a convex profile, (2) a palate terminating before the posterior end of the molar row, (3) a zygomatic plate sloping forward at the shoulder, (4) nasal bones that do not significantly extend past the premaxillae, (5) large auditory bullae compared to species of Paramelomys (cf. Menzies 1996), (6) narrow and deep pterygoid fossae, (7) lateral extension of the parietal bone, (8) a wide alisphenoid strut that is fused to the alisphenoid canal and foramen ovale, (9) very well-developed lambdoid crests which curl forward over the squamoso-mastoid foramen, (10) a carotid arterial circulation that is primitive for murine rodents, as opposed to the derived pattern seen in Mammelomys (11) a large M 3 compared to Paramelomys, with an antero-internal cusp always present, and (12) only two pairs of inguinal teats (mammary formula 0 + 2 = 4). The Melomys population from Halmahera is characterized by small to medium body size in the genus (Weight range = 110–141 g), and has all of the diagnostic characters listed above.
Legend similar to that of Table 1. The symbol “:” indicates tested interactions between explanatory variables. (ap <0.05, bp <0.01).
Content and distribution. The genus Melomys contains 23 species (Musser and Carleton 2005). It is distributed in eastern and northern Australia, throughout New Guinea, and in adjacent archipelagos, from the Moluccas in the west to the Solomon Islands in the east (Helgen 2003, Breed and Aplin 2008).
description: Published as part of Fabre, Pierre-Henri, Fitriana, Yuli S., Semiadi, Gono, Pagès, Marie, Aplin, Ken, Supriatna, Nanang & Helgen, Kristofer M., 2018, New record of Melomys burtoni (Mammalia, Rodentia, Murinae) from Halmahera (North Moluccas, Indonesia): a review of Moluccan Melomys, pp. 218-247 in Mammalia (Warsaw, Poland) (Warsaw, Poland) 82 (3) on pages 227-228, DOI: 10.1515/mammalia-2016-0137, http://zenodo.org/record/7837666
Solar disinfection of secondary effluent and the subsequent bacterial regrowth: considerations, limitations and environmental perspectives
Creators: name: Γιαννάκης, Στέφανος Φ.
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: Ηλιακή ενέργεια
Βακτηριακή επανανάπτυξη
Απολύμανση λυμάτων
Υπεριώδης ακτινοβολία
Solar energy
Bacterial regrowth
Wastewater disinfection
Ultraviolet irradiation

description: Η παρούσα Διδακτορική Διατριβή πραγματεύεται την απολύμανση δευτεροβάθμια επεξεργασμένων τεχνητών λυμάτων υπό ελεγχόμενες συνθήκες, μελετώντας το φαινόμενο της επανανάπτυξης / επανεμφάνισης των μικροοργανισμών μετά την ακτινοβολία των λυμάτων. Αντικείμενό της είναι η μελέτη της επίδρασης μιας ευρείας γκάμας ενδογενών και εξωγενών παραγόντων τόσο κατά την διαδικασία της απολύμανσης, όσο και στην κινητική του βακτηριακού πληθυσμού. Με τη χρήση κοινών οργανισμών δεικτών κοπρανώδους μόλυνσης, μελετήθηκε η επίδραση του αρχικού βακτηριακού πληθυσμού, η ένταση και το μήκος κύματος της ακτινοβολίας, η θερμοκρασία απολύμανσης και ο τρόπος παροχής του φωτός (συνεχής-ασυνεχής) κατά την διαδικασία. Μελετήθηκαν ακόμα τα φαινόμενα που λαμβάνουν χώρα μετά την ακτινοβολία, όπως το φαινόμενο της επανανάπτυξης του βακτηριακού πληθυσμού στο σκοτάδι, η φωτο-επιδιόρθωση και η επιβίωση των μικροοργανισμών σε φυσικά νερά μετά την ακτινοβολία. Διερευνήθηκε τέλος η δυνατότητα χρήσης αντιδραστήρων συνεχούς ροής με επανακυκλοφορία και ο συνδυασμός εφαρμογής προχωρημένων μεθόδων οξείδωσης (αντιδραστήριο photo-Fenton) με υπερήχους, στοχεύοντας στην ελαχιστοποίηση της πιθανότητας επανανάπτυξης των μικροοργανισμών. Τα αποτελέσματα κατέδειξαν ενδεδειγμένες πρακτικές εφαρμογής, συμπεράσματα για την καταλληλότητα της ηλιακής ακτινοβολίας ως μεθόδου απολύμανσης δευτεροβάθμια επεξεργασμένων λυμάτων, προβληματισμούς όσον αφορά τις τεχνικές λεπτομέρειες και περιβαλλοντικές ανησυχίες.
description: The present Thesis deals with the solar disinfection of synthetic secondary effluent under laboratory controlled conditions, focusing on the post-irradiation bacterial regrowth. The influence of various internal and external factors and their effect on solar disinfection, as well as bacterial regrowth kinetics are the subject under question. With the aid of a common fecal indicator microorganism, the effects of light intensity, temperature, initial bacterial concentration, light energy (wavelength), manner of delivery (continuous-intermittent) were investigated. Also, the post-treatment events, such as dark repair, photoreactivation and the survival in natural water matrices were assessed, along with the use of technical means (flow photoreactors with recirculation) and advanced oxidation processes (photo-Fenton and sonication) for regrowth risk minimization. The findings provided valuable output, conclusions on the suitability of solar irradiation as a secondary wastewater disinfection technique, indicating the limitations of its applicability, the considerations on the treatment specifications and its environmental perspectives.
Quantum Master Equation for QED in Exact Renormalization Group
Creators: name: Igarashi, Yuji
name: Itoh, Katsumi
name: Sonoda, Hidenori
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Recently, one of us (H.S.) gave an explicit form of the Ward-Takahashi identity for the Wilson action of QED. We first rederive the identity using a functional method. The identity makes it possible to realize the gauge symmetry even in the presence of a momentum cutoff. In the cutoff dependent realization, the abelian nature of the gauge symmetry is lost, breaking the nilpotency of the BRS transformation. Using the Batalin-Vilkovisky formalism, we extend the Wilson action by including the antifield contributions. Then, the Ward-Takahashi identity for the Wilson action is lifted to a quantum master equation, and the modified BRS transformation regains nilpotency. We also obtain a flow equation for the extended Wilson action.
description: 15 pages, no figure
Surrogate Approximation of the Grad-Shafranov Free Boundary Problem via Stochastic Collocation on Sparse Grids
Creators: name: Elman, Howard C.
name: Liang, Jiaxing
name: Sánchez-Vizuet, Tonatiuh
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: Computational Physics (physics.comp-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 65C30, 65C05, 65N35, 65N99, 65Z05

description: In magnetic confinement fusion devices, the equilibrium configuration of a plasma is determined by the balance between the hydrostatic pressure in the fluid and the magnetic forces generated by an array of external coils and the plasma itself. The location of the plasma is not known a priori and must be obtained as the solution to a free boundary problem. The partial differential equation that determines the behavior of the combined magnetic field depends on a set of physical parameters (location of the coils, intensity of the electric currents going through them, magnetic permeability, etc.) that are subject to uncertainty and variability. The confinement region is in turn a function of these stochastic parameters as well. In this work, we consider variations on the current intensities running through the external coils as the dominant source of uncertainty. This leads to a parameter space of dimension equal to the number of coils in the reactor. With the aid of a surrogate function built on a sparse grid in parameter space, a Monte Carlo strategy is used to explore the effect that stochasticity in the parameters has on important features of the plasma boundary such as the location of the x-point, the strike points, and shaping attributes such as triangularity and elongation. The use of the surrogate function reduces the time required for the Monte Carlo simulations by factors that range between 7 and over 30.
The new Beam Halo Monitor for the CMS experiment at the LHC
Creators: name: Tosi, Nicolo <1987>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2015
Subjects: FIS/04 Fisica nucleare e subnucleare

description: In the context of increasing beam energy and luminosity of the LHC accelerator at CERN, it will be important to accurately measure the Machine Induced Background.
A new monitoring system will be installed in the CMS cavern for measuring the beam background at high radius. This detector, called the Beam Halo Monitor, will provide an online, bunch-by-bunch measurement of background induced by beam halo interactions, separately for each beam.
The detector is composed of synthetic quartz Cherenkov radiators, coupled to fast UV sensitive photomultiplier tubes. The directional and fast response of the system allows the discrimination of the background particles from the dominant flux in the cavern induced by pp collision debris, produced within the 25 ns bunch spacing.
The readout electronics of this detector will make use of many components developed for the upgrade of the CMS Hadron Calorimeter electronics, with a dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal will be digitized by a charge integrating ASIC, providing both the signal rise time and the charge integrated over one bunch crossing. The backend electronics will record bunch-by-bunch histograms, which will be published to CMS and the LHC using the newly designed CMS beam instrumentation specific DAQ.
A calibration and monitoring system has been designed to generate triggered pulses of UV light to monitor the efficiency of the system.
The experimental results validating the design of the detector, the calibration system and the electronics will be presented.
First year performance and root egress of white spruce (Picea glauca (Moench) Voss) and lodgepole pine (Pinus contorta Dougl.) seedlings in mechanically prepared and untreated planting sport in North Central British Columbia
Creators: name: Von Der Gonna, Marc A.
Publisher: name: University of British Columbia
Year: 2010

description: Root zone temperature and root egress were studied during the first growing season on white spruce and lodgepole pine seedlings planted in various forms of mechanically prepared microsites. Mounded microsites had higher summer soil temperatures and greater diurnal ranges, at a depth of 10 cm, than the patch and control treatments. Mounded microsites, however, showed the greatest response to changes in weather and decreasing solar radiation inputs in the fall, being the first to record soil temperatures below freezing. Seedlings planted in the deep mineral soil over inverted humus mounds created by the Ministry Mounder had significantly greater numbers of new roots greater than 1 cm long than did seedlings planted in patch and control treatments at 45 and 70 days after planting. Seedlings planted in other mound and plowing treatments had high to intermediate numbers of new roots. At 95 days after planting, seedlings planted on all mounded treatments generally had higher root area indices, root dry weights and total dry weights than did seedlings on other treatments. Variation in treatment results over the three spruce sites studied reflect differences in site conditions, primarily soil moisture regimes. High and fluctuating water tables negatively affected seedlings planted in patch and control treatments.
The time evolution of cosmological redshift as a test of dark energy
Creators: name: Balbi, A.
name: Quercellini, C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The variation of the expansion rate of the Universe with time produces an evolution in the cosmological redshift of distant sources (for example quasar Lyman-$α$ absorption lines), that might be directly observed by future ultra stable, high-resolution spectrographs (such as CODEX) coupled to extremely large telescopes (such as European Southern Observatory's Extremely Large Telescope, ELT). This would open a new window to explore the physical mechanism responsible for the current acceleration of the Universe. We investigate the evolution of cosmological redshift from a variety of dark energy models, and compare it with simulated data. We perform a Fisher matrix analysis and discuss the prospects for constraining the parameters of these models and for discriminating among competing candidates. We find that, because of parameter degeneracies, and of the inherent technical difficulties involved in this kind of observations, the uncertainties on parameter reconstruction can be rather large unless strong external priors are assumed. However, the method could be a valuable complementary cosmological tool, and give important insights on the dynamics of dark energy, not obtainable using other probes.
description: 9 pages, 2 figures. Matching published version
The XMM-Newton view of IRAS 09104+4109: evidence for a changing-look Type 2 quasar?
Creators: name: Piconcelli, E.
name: Fiore, F.
name: Nicastro, F.
name: Mathur, S.
name: Brusa, M.
name: Comastri, A.
name: Puccetti, S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We analyzed the spectroscopic data from the PN and the MOS cameras in the 0.4-10 keV band. We also used an archival BeppoSAX 1-50 keV observation of IRAS 09104+4109 to investigate possible variations of the quasar emission. The X-ray emission in the EPIC band is dominated by the intra-cluster medium thermal emission. We found that the quasar contributes ~35% of the total flux in the 2-10 keV band. Both a transmission- (through a Compton-thin absorber with a Compton optical depth of τ_C~0.3, i.e. Nh~5 x 10^{23} cm^-2) and a reflection-dominated (τ_C>1) model provide an excellent fit to the quasar continuum emission. However, the value measured for the EW of Fe Kalpha emission line is only marginally consistent with the presence of a Compton-thick absorber in a reflection-dominated scenario, which had been suggested by a previous, marginal (i.e. 2.5σ) detection with the hard X-ray (15-50 keV), non-imaging BeppoSAX/PDS instrument. Moreover, the value of luminosity in the 2-10 keV band measured by the transmission-dominated model is fully consistent with that expected on the basis of the bolometric luminosity of IRAS 09104+4109. From the analysis of the XMM-Newton data we therefore suggest the possibility that the absorber along the line of sight to the nucleus of IRAS 09104+4109 is Compton-thin. Alternatively, the absorber column density could have changed from Compton-thick to -thin in the five years elapsed between the observations. If this is the case, then IRAS 09104+4109 is the first 'changing-look' quasar ever detected.
description: Accepted by Astronomy and Astrophysics
Groundlessness and possibilities of meaning: young Wittgenstein and Jacques Lacan respond to experiences of limitation
Creators: name: Μπαλάσκα, Μαρία Γ.
Publisher: name: Aristotle University of Thessaloniki
Year: 2014
Subjects: Νόημα
Εμπειρία ορίου
Ηθική
Γλώσσα
Groundlessness
Meaning
Ethics
Language

description: Η διατριβή επικεντρώνεται σε αυτό που αποκαλεί εμπειρία ορίου. Η εμπειρία αυτή συνδέεται με αυτό που ο Βιτγκενστάιν αποκαλεί “εμπειρία πρόσκρουσης στο όριο” και με αυτό που ο Λακάν θα αποκαλούσε εμπειρία ορίου. Η περιγραφή μίας τέτοιας εμπειρίας αντλεί επίσης από αυτό που η Diamondαποκαλεί “δυσκολία της πραγματικότητας”. Τέτοιες εμπειρίες μοιάζει να έχουν απόλυτη αξία και ως απόλυτη εννοώ την αξία που μοιάζει να μην μπορεί να τύχει έκφρασης στη γλώσσα. Έτσι οι εμπειρίες αυτές μοιάζει να οδηγούν κατ' ανάγκην στην παραγωγή ανοησίας θέτοντας ένα πρόβλημα σε σχέση με το νόημά (meaning)τους. Αυτό που διακυβεύεται σε αυτές τις εμπειρίες είναι το πώς κάτι που μοιάζει να έχει απόλυτη αξία μπορεί να αρθρωθεί στη γλώσσα και το διακύβευμα για την διατριβή είναι η αποδοχή του ότι το νόημα δε θεμελιώνεται μεταφυσικά αλλά αναδύεται ως δυνατότητες προς οικειοποιήση, δυνατότητες που συνδέονται με τη χρήση της γλώσσας σε διαφορετικά πλαίσια μορφών ζωής. Ο στόχος της διατριβής είναι λοιπόννα εξετάσει μία έννοια νοήματος που μπορεί να εμπεριέξει τέτοιες εμπειρίες και να επιτρέψει “την απόλυτη αξία” χωρίς να καθιστά απαραίτητη την εγκατάλειψη της εν χρήσει γλώσσας (της καθημερινής γλώσσας). Στην διατριβή υποστηρίζεται η θέση ότι τόσο ο Βιτγκενστάιν όσο και ο Λακάν μας παρέχουν τα εργαλεία της σκέψης για να χειριστούμε τέτοιες εμπειρίες, βλέποντας την ίδια τη γλώσσα ως τον τόπο αυτής της “απόλυτης αξίας” χωρίς να προσπαθούμε να θεμελιώσουμε το νόημα στη μεταφυσική.
description: The thesis focuses onwhat is called an experience of limitation. This could be also called a “running up against the limit experience” in Wittgensteinian terms, or “an experience of the real” in Lacanian terms. Thedescription of this experienceis also articulated in relation to Diamond's notion of “difficulty of reality”. Such experiences seem to have absolute value and by abolutevaluewe mean value which seems as if it cannot be expressed in language. Thus such experiences seem to necessarily generate nonsense and therefore pose a question on meaning. For the thesis, the task which arises in staying exposed at such experiences is the task of accepting that meaning cannot be grounded in some metaphysical anchorage but it emerges as recoverable possibilities attached to our use of language in the different contexts of our forms of life. The aim of the thesis is to explore adifferent notion of meaning which can bear this “absolute value” andto show how an experience of limitation can make us attentive to it. What I try to argue is that both Wittgenstein and Lacan can offer us athird way to treat such experiences, a way which allows us to see language as a locus of value (through meaning) without seeking to ground meaning in metaphysics (or in a realm beyond language).
Numerical and Analytical Methods for Laser-Plasma Acceleration Physics
Creators: name: Rossi, Francesco <1987>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2015
Subjects: FIS/07 Fisica applicata (a beni culturali, ambientali, biologia e medicina)

description: Theories and numerical modeling are fundamental tools for understanding, optimizing and designing present and future laser-plasma accelerators (LPAs).
Laser evolution and plasma wave excitation in a LPA driven by a weakly relativistically intense, short-pulse laser propagating in a preformed parabolic plasma channel, is studied analytically in 3D including the effects of pulse steepening and energy depletion. At higher laser intensities, the process of electron self-injection in the nonlinear bubble wake regime is studied by means of fully self-consistent Particle-in-Cell simulations. Considering a non-evolving laser driver propagating with a prescribed velocity, the geometrical properties of the non-evolving bubble wake are studied. For a range of parameters of interest for laser plasma acceleration, The dependence of the threshold for self-injection in the non-evolving wake on laser intensity and wake velocity is characterized. 
Due to the nonlinear and complex nature of the Physics involved, computationally challenging numerical simulations are required to model laser-plasma accelerators operating at relativistic laser intensities. The numerical and computational optimizations, that combined in the codes INF&RNO and INF&RNO/quasi-static give the possibility to accurately model multi-GeV laser wakefield acceleration stages with present supercomputing architectures, are discussed. The PIC code jasmine, capable of efficiently running laser-plasma simulations on Graphics Processing Units (GPUs) clusters, is presented. GPUs deliver exceptional performance to PIC codes, but the core algorithms had to be redesigned for satisfying the constraints imposed by the intrinsic parallelism of the architecture. The simulation campaigns, run with the code jasmine for modeling the recent LPA experiments with the INFN-FLAME and CNR-ILIL laser systems, are also presented.
Measurement of the $B^0$ - $\bar{B}^0$ and $B^0_s$ - $\bar{B}^0_s$ production asymmetries in pp collisions at $\sqrt{s}=7$ TeV and $\sqrt{s}=8$ TeV with the LHCb experiment
Creators: name: Zangoli, Maria <1986>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2015
Subjects: FIS/04 Fisica nucleare e subnucleare

description: The production rate of $b$ and $\bar{b}$ hadrons in $pp$ collisions are not expected to be strictly identical,  due to imbalance between quarks and anti-quarks in the initial state.  This phenomenon can be naively related to the fact that the $\bar{b}$ quark produced in the hard scattering might combine with a $u$ or $d$ valence quark from the colliding protons, whereas the same cannot happen for a $b$ quark. 
This thesis presents the analysis performed to determine the production asymmetries of $B^0$ and $B^0_s$. The analysis relies on data samples collected by the LHCb detector at the Large Hadron Collider (LHC) during the 2011 and 2012 data takings at two different values of the centre of mass energy $\sqrt{s}=7$ TeV and at $\sqrt{s}=8$ TeV, corresponding respectively to an integrated luminosity of 1 fb$^{-1}$ and of 2 fb$^{-1}$. 
The production asymmetry is one of the key ingredients to perform measurements of $CP$ violation in b-hadron decays at the LHC, since $CP$ asymmetries must be disentangled from other sources. 
The measurements of the production asymmetries are performed in bins of $p_\mathrm{T}$ and $\eta$ of the $B$-meson.
The values of the production asymmetries, integrated in the ranges $4 < p_\mathrm{T} < 30$ GeV/c and $2.5
Role of (R)-9-hydroxystearic acid in zebrafish development
Creators: name: Naso, Federica <1987>
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2015
Subjects: BIO/10 Biochimica

description: 9-hydroxystearic acid (9-HSA) belongs to a class of lipid peroxidation products identified in several human and murine cell lines. These products are greatly diminished in tumors compared to normal tissues and their amount is inversely correlated with the malignancy of the tumor.
 9-HSA activity has been tested in cancer cell lines, where it showed to act as a histone deacetylase 1 (HDAC1) inhibitor. In particular, in a colon cancer cell line (HT29), its administration resulted in an inhibition of proliferation together with an induction of differentiation.
In this thesis the effect of (R)-9-hydroxystearic acid has been tested in vivo on cell proliferation and differentiation processes, in the early stages of zebrafish development.
The final aim of this work was to elucidate the role of (R)-9-HSA in the control of cell differentiation and proliferation during normal development, in order to better understand its molecular control of cancerogenesis.
The molecule has been administered via injection in the yolk of zebrafish embryos. The analysis of the histone acetylation pattern showed a hyperacetilation of histone H4 after treatment with the molecule, as detectable in HDAC1 mutants.
(R)-9-HSA was also demonstrated to interfere with the signaling pathways that regulate proliferation and differentiation in zebrafish retina and hindbrain. This resulted in a reduction of proliferation in the hindbrain at 24 hours post injection (hpi), and in a hyperproliferation at 48 and 72 hpi in the retina, with a concomitant inhibition of differentiation.
Finally, (R)-9-HSA effects were evident on proliferation of stem cell located in the ciliary marginal zone (CMZ) of the retina. The presence of ROS and 4-hydroxynoneal in the CMZ of wild-type embryos supports the hypothesis that oxidative stress could regulate stem cells fate in zebrafish retina.
Initiation of granular surface flows in a narrow channel
Creators: name: Jop, Pierre
name: Forterre, Yoël
name: Pouliquen, Olivier
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We experimentally investigate how a long granular pile confined in a narrow channel destabilizes when it is inclined above the angle of repose. A uniform flow then develops, which is localized at the free surface. It first accelerates before reaching a steady uniform regime. During this process, an apparent erosion is observed and the thickness of the flowing layer increases. We precisely study the evolution of the vertical velocity profile in this transient regime. The measurements are compared with the prediction of a visco-plastic model [P. Jop, Y. Forterre and O. Pouliquen, Nature 441, 727 (2006)]
description: 5 pages, 5 figures, to be published in Physics of Fluids
Cyclic coverings of the $p$-adic projective line by Mumford curves
Creators: name: Bradley, Patrick Erik
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14H30

description: Exact bounds for the positions of the branch points for cyclic coverings of the $p$-adic projective line by Mumford curves are calculated in two ways. Firstly, by using Fumiharu Kato's *-trees, and secondly by giving explicit matrix representations of the Schottky groups corresponding to the Mumford curves above the projective line through combinatorial group theory.
description: 17 pages, 3 eps-figures. To appear in manuscripta mathematica
A 2D quantum antiferromagnet with a four-fold degenerate valence-bond-solid ground state
Creators: name: Gellé, Alain
name: Läuchli, Andreas
name: Kumar, Brijesh
name: Mila, Frédéric
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the competition between antiferromagnetic order and valence bond solid formation in a two-dimensional frustrated spin-1/2 model. The J1-J2 model on the square lattice is further frustrated by introducing products of three-spin projectors which stabilize four dimer-product states as degenerate ground states. These four states are reminiscent of the dimerized singlet ground state of the Shastry-Sutherland model. Using exact diagonalizations, we study the evolution of the ground state by varying theratio of interactions. For a large range of parameters (J2 > 0.25J1), our model shows a direct transition between the valence-bond-solid phase and the collinear antiferromagnetic phase. For small values of J2, several intermediate phases appear which are also analyzed.
Scaling Laws of Cognitive Networks
Creators: name: Vu, Mai
name: Devroye, Natasha
name: Sharif, Masoud
name: Tarokh, Vahid
Publisher: name: arXiv
Year: 2007
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: We consider a cognitive network consisting of n random pairs of cognitive transmitters and receivers communicating simultaneously in the presence of multiple primary users. Of interest is how the maximum throughput achieved by the cognitive users scales with n. Furthermore, how far these users must be from a primary user to guarantee a given primary outage. Two scenarios are considered for the network scaling law: (i) when each cognitive transmitter uses constant power to communicate with a cognitive receiver at a bounded distance away, and (ii) when each cognitive transmitter scales its power according to the distance to a considered primary user, allowing the cognitive transmitter-receiver distances to grow. Using single-hop transmission, suitable for cognitive devices of opportunistic nature, we show that, in both scenarios, with path loss larger than 2, the cognitive network throughput scales linearly with the number of cognitive users. We then explore the radius of a primary exclusive region void of cognitive transmitters. We obtain bounds on this radius for a given primary outage constraint. These bounds can help in the design of a primary network with exclusive regions, outside of which cognitive users may transmit freely. Our results show that opportunistic secondary spectrum access using single-hop transmission is promising.
description: significantly revised and extended, 30 pages, 13 figures, submitted to IEEE Journal of Special Topics in Signal Processing
Predicting the self-lensing population in optical surveys
Creators: name: Wiktorowicz, Grzegorz
name: Middleton, Matthew
name: Khan, Norman
name: Ingram, Adam
name: Gandhi, Poshak
name: Dickinson, Hugh
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The vast majority of binaries containing a compact object and a regular star spend most of their time in a quiescent state where no strong interactions occur between components. Detection of these binaries is extremely challenging and only few candidates have been detected through optical spectroscopy. Self-lensing represents a new means of detecting compact objects in binaries, where gravitational lensing of the light from the visible component by the compact object produces periodic optical flares. Here we show that current and planned large-area optical surveys can detect a significant number ($\sim 100$-$10,000$s) of these self-lensing binaries and provide insights into the properties of the compact lenses. We show that many of the predicted population of observable self-lensing binaries will be observed with multiple self-lensing flares; this both improves the chances of detection and also immediately distinguishes them from chance-alignment micro-lensing events. Through self-lensing we can investigate long - but previously hidden - stages of binary evolution and consequently provide new constraints on evolutionary models which impact on the number and nature of double compact object mergers.
description: 11 pages, 6 figures, 3 tables
Radial Dependence of Extinction in Parent Galaxies of Supernovae
Creators: name: Arbutina, Bojan
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The problem of extinction is the most important issue to be dealt with in the process of obtaining true absolute magnitudes of core-collapse supernovae (SNe). The plane-parallel model which gives absorption dependent on galaxy inclination, widely used in the past, was shown not to describe extinction adequately. We try to apply an alternative model which introduces radial ependence of extinction. A certain trend of dimmer SNe with decreasing radius from the center of a galaxy was found, for a chosen sample of stripped-envelope SNe.
description: 4 pages, 1 table, 2 figures, 6th SCSLSA Proc
A study of the size of snow particles in powder snow avalanches
Creators: name: Rastello, Marie
Publisher: name: arXiv
Year: 2007
Subjects: subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: In this work, we study the size of the particles involved in a powder snow avalanche phenomenon. To determine these sizes, we study all the phenomena the particles have to face before arriving in the "body" of the avalanche. We study the boundary layer which is at the bottom of the avalanche. We determine, with the help of experimental data, the range of size of the particles that can be entrained by the avalanche. We then examine the possibility for these particles to reach the top of the boundary layer, and so to take part in the avalanche. Our final result is that the more frequent particles suspended in a powder snow avalanche have a size lower than 200 micrometers.
Photoinduced anomalous Hall effect in the interacting Haldane model: targeting topological states with pump pulses
Creators: name: Shao, Can
name: Sacramento, P. D.
name: Mondaini, Rubem
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We investigate the nonequilibrium dynamics of the spinless Haldane model with nearest-neighbor interactions on the honeycomb lattice by employing an unbiased numerical method. In this system, a first-order transition from the Chern insulator (CI) at weak coupling to the charge-density-wave (CDW) phase at strong coupling can be characterized by a level crossing of the lowest energy levels. Here we show that adiabatically following the eigenstates across this level crossing, their Chern numbers are preserved, leading to the identification of a topologically-nontrivial low-energy excited state in the CDW regime. By promoting a resonant energy excitation via an ultrafast circularly polarized pump pulse, we find that the system acquires a non-vanishing Hall response as a result of the large overlap enhancement between the time-dependent wave-function and the topologically non-trivial excited state. This is suggestive of a photoinduced topological phase transition via unitary dynamics, despite a proper definition of the Chern number remaining elusive for an out-of-equilibrium interacting system. We contrast these results with more common quench protocols, where such features are largely absent in the dynamics even if the post-quench Hamiltonian displays a topologically nontrivial ground state.
description: 8 pages, 9 figures
Pseudospectral versus finite-differences schemes in the numerical integration of stochastic models of surface growth
Creators: name: Gallego, Rafael
name: Castro, Mario
name: López, Juan M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We present a comparison between finite differences schemes and a pseudospectral method applied to the numerical integration of stochastic partial differential equations that model surface growth. We have studied, in 1+1 dimensions, the Kardar, Parisi and Zhang model (KPZ) and the Lai, Das Sarma and Villain model (LDV). The pseudospectral method appears to be the most stable for a given time step for both models. This means that the time up to which we can follow the temporal evolution of a given system is larger for the pseudospectral method. Moreover, for the KPZ model, a pseudospectral scheme gives results closer to the predictions of the continuum model than those obtained through finite difference methods. On the other hand, some numerical instabilities appearing with finite difference methods for the LDV model are absent when a pseudospectral integration is performed. These numerical instabilities give rise to an approximate multiscaling observed in the numerical simulations. With the pseudospectral approach no multiscaling is seen in agreement with the continuum model.
description: 13 single column pages, RevTeX, 6 eps figs