cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
MatRec: Matrix Factorization for Highly Skewed Dataset
Creators: name: Wang, Hao
name: Ruan, Bing
Publisher: name: arXiv
Year: 2020
Subjects: subject: Information Retrieval (cs.IR)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Recommender systems is one of the most successful AI technologies applied in the internet cooperations. Popular internet products such as TikTok, Amazon, and YouTube have all integrated recommender systems as their core product feature. Although recommender systems have received great success, it is well known for highly skewed datasets, engineers and researchers need to adjust their methods to tackle the specific problem to yield good results. Inability to deal with highly skewed dataset usually generates hard computational problems for big data clusters and unsatisfactory results for customers. In this paper, we propose a new algorithm solving the problem in the framework of matrix factorization. We model the data skewness factors in the theoretic modeling of the approach with easy to interpret and easy to implement formulas. We prove in experiments our method generates comparably favorite results with popular recommender system algorithms such as Learning to Rank , Alternating Least Squares and Deep Matrix Factorization.
Coping with contradictions : doctoral student experiences at a Canadian research university
Creators: name: Ridding, Paul John
Publisher: name: University of British Columbia
Year: 2009

description: This study examines the experiences of doctoral students at a Canadian research university in four selected departments: Physics, Chemical Engineering, History, and Education. In the context of shifting expectations concerning the role of higher education in Canada, doctoral students operate on the boundaries of the academic professions. Because the PhD degree acts as certification for membership in those professions, an important aspect of doctoral education is professional socialization. A basic assumption underlying this research is that discipline cultures have a significant effect on the experiences of doctoral students, and research into doctoral studies is enriched by studies that examine doctoral student experiences across a variety of disciplines. At the outset of the research, the concepts of professionalism, socialization, and culture were key sensitizing concepts. As the research progressed, the importance of the related concepts of expertise, autonomy, and isolation became apparent. Ethnographic techniques such as ethnographic interviews and participant observation are employed for exploring students' understandings and interpretations of their experiences. The study examines the ways students across the departments understand and experience departmental enforcement of standards to judge their professional expertise. It also relates students' belief in individual autonomy as researchers to the nature of the discipline in which they are located. Their common sense of isolation is explained in the context of a fragile student culture. The study shows how this isolation works to obscure fundamental contradictions that become apparent in the various departments' enforcement of professional standards and the differing degrees to which students find it important to assert individual autonomy. The promise of professional status and authority discourages PhD students from developing a sustained critique of important elements of their doctoral education such as the the notion of expertise upon which academic professions derive their status and authority. Although students' ability to cope with contradictions is important professional training, this study argues it diminishes their critical commitments in a wider public culture. Reform of the PhD degree is needed that minimizes the role of doctoral education as training for professional expertise, and fosters students' commitments as social critics.
Exteriors to bouncing collapse models
Creators: name: Schmitz, Tim
Publisher: name: arXiv
Year: 2020
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We construct a large class of spacetimes that are smoothly matched to homogeneous, spherically symmetric clouds of matter. The evolution of the clouds is left arbitrary to allow for the incorporation of modifications by quantum effects, which can in particular lead to bounces. We further discuss two simple yet illustrative examples of these spacetimes, both in general terms and for a specific form of the bounce, with a focus on horizon behavior and relevant timescales.
description: 13 pages, 6 figures
Orbital and Maxillofacial Computer Aided Surgery: Patient-Specific Finite Element Models To Predict Surgical Outcomes
Creators: name: Luboz, Vincent
name: Chabanas, Matthieu
name: Swider, Pascal
name: Payan, Yohan
Publisher: name: arXiv
Year: 2006
Subjects: subject: Medical Physics (physics.med-ph)
subject: FOS: Physical sciences

description: This paper addresses an important issue raised for the clinical relevance of Computer-Assisted Surgical applications, namely the methodology used to automatically build patient-specific Finite Element (FE) models of anatomical structures. From this perspective, a method is proposed, based on a technique called the Mesh-Matching method, followed by a process that corrects mesh irregularities. The Mesh-Matching algorithm generates patient-specific volume meshes from an existing generic model. The mesh regularization process is based on the Jacobian matrix transform related to the FE reference element and the current element. This method for generating patient-specific FE models is first applied to Computer-Assisted maxillofacial surgery, and more precisely to the FE elastic modelling of patient facial soft tissues. For each patient, the planned bone osteotomies (mandible, maxilla, chin) are used as boundary conditions to deform the FE face model, in order to predict the aesthetic outcome of the surgery. Seven FE patient-specific models were successfully generated by our method. For one patient, the prediction of the FE model is qualitatively compared with the patient's post-operative appearance, measured from a Computer Tomography scan. Then, our methodology is applied to Computer-Assisted orbital surgery. It is, therefore, evaluated for the generation of eleven patient-specific FE poroelastic models of the orbital soft tissues. These models are used to predict the consequences of the surgical decompression of the orbit. More precisely, an average law is extrapolated from the simulations carried out for each patient model. This law links the size of the osteotomy (i.e. the surgical gesture) and the backward displacement of the eyeball (the consequence of the surgical gesture).
Σχεδιασμός ενισχυτών ραδιοσυχνοτήτων με το MATLAB:
Creators: name: Γιουτίκας, Απόστολος Στεργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Ραδιοσυχνότητες
Ενισχυτές
MATLAB
Radiofrequencies
Amplifiers

description: Η παρούσα διπλωματική εργασία παρουσιάζει την μέθοδο σχεδίασης των γραμμικών μικροκυματικών ενισχυτών με βάση τις παραμέτρους σκέδασης των χρησιμοποιούμενων τρανζίστορ (S-Parameter Linear RF/MW Amplifier Design). Στο πλαίσιο αυτό αναλύονται διεξοδικά τόσο τα φυσικά μεγέθη χαρακτηρισμού των ενισχυτικών διατάξεων, όσο και οι επιμέρους παράμετροι, που καθορίζουν την σχεδιαστική διαδικασία. Κατόπιν διασαφηνίζονται οι εξειδικευμένες τεχνικές σχεδίασης των επιμέρους ενισχυτών με τέτοιο τρόπο, ώστε να είναι ικανές να προσαρμόζονται στις ζητούμενες προδιαγραφές λειτουργίας τους. Οι τεχνικές αυτές εφαρμόστηκαν κατάλληλα στο Matlab με σκοπό το σχεδιασμό τριών διαφορετικών ενισχυτικών διατάξεων. Για την ολοκλήρωση της σχεδιαστικής διαδικασίας χρησιμοποιήθηκε το εξειδικευμένο πακέτο συναρτήσεων και εντολών, που παρέχει στον χρήστη η εργαλειοθήκη ραδιοσυχνοτήτων (RF Toolbox) του Matlab. Η συγκεκριμένη μεθοδολογία υλοποίησης γραμμικών ενισχυτών, που βασίζεται στις S-παραμέτρους, είναι πολύ σημαντική στην μικροκυματική τεχνολογία, καθώς συνιστά την σχεδιαστική βάση δημιουργίας ενισχυτών χαμηλού θορύβου. Οι ενισχυτές αυτοί παίζουν πολύ σημαντικό ρόλο στους δέκτες των τηλεπικοινωνιακών συστημάτων, δεδομένου ότι μπορούν να καθορίσουν τις στάθμες θορύβου του συνολικού συστήματος λήψης των μεταδιδομένων σημάτων.
description: This diploma thesis aims to present the basic method that is adopted for the design of linear RF/MW small-signal amplifiers. The bipolar transistors, which are implemented for this procedure, are treated primarily in terms of their terminal characteristics using the measured scattering parameters (S-Parameters). The S-Parameter design method is considered to be accurate and convenient for the construction of such amplifiers. Besides, this presentation involves the most important physical parameters that characterize the operation of each microwave amplifier, such as Power Gain, Noise Figure, Mismatch Loss, Return Loss and deals with stability and bandwidth considerations. In addition to the theoretical analysis of the mathematical formulas, that are related to the linear RF amplifier operation, this diploma thesis presents the different techniques of the S-Parameter design method, that are applied for the creation of amplifiers with different specifications. These techniques were properly implemented in the Matlab environment and lead to the creation of low noise or maximum gain amplifiers. The Matlab RF Toolbox provided the necessary functions, methods and graphical tools for the various design applications.
UVIT/ASTROSAT studies of Blue Straggler stars and post-mass transfer systems in star clusters: Detection of one more blue lurker in M67
Creators: name: Subramaniam, Annapurni
name: Pandey, Sindhu
name: Jadhav, Vikrant V.
name: Sahu, Snehalata
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The blue straggler stars (BSSs) are main-sequence (MS) stars, which have evaded stellar evolution by acquiring mass while on the MS. The detection of extremely low mass (ELM) white dwarf (WD) companions to two BSSs and one yellow straggler star (YSS) from our earlier study using UVIT/ASTROSAT, as well as WD companions to main-sequence stars (known as blue lurkers) suggest a good fraction of post-mass transfer binaries in M67. Using deeper UVIT observations, here we report the detection of another blue lurker in M67, with an ELM WD companion. The post-mass transfer systems with the presence of ELM WDs, including BSSs, are formed from Case A/B mass transfer and are unlikely to show any difference in surface abundances. We find a correlation between the temperature of the WD and the $v\ sin i$ of the BSSs. We also find that the progenitors of the massive WDs are likely to belong to the hot and luminous group of BSSs in M67. The only detected BSS+WD system by UVIT in the globular cluster NGC 5466, has a normal WD and suggests that open cluster like environment might be present in the outskirts of low density globular clusters.
description: Accepted for publication in the Journal of Astrophysics and Astronomy, in the special issue titled, 150 years of periodic table- Chemical elements in the Universe: origin and evolution
Redfield reduced dynamics and entanglement
Creators: name: Anderloni, S.
name: Benatti, F.
name: Floreanini, R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In phenomenological applications the time evolution of subsystems immersed in an external environment are sometimes described by Markovian semigroups of Redfield type that result non-positive: the appearence of negative probabilities is avoided by restricting the admissible initial conditions to those states that remain positive under the action of the dynamics. We show that this often adopted procedure may lead to physical inconsistencies in presence of entanglement.
description: 10 pages, 1 figure
Initial Reports of the Deep Sea Drilling Project - Volume 82
Creators: name: Bougault, H.
name: Cande, S.C.
name: The Leg 82 Science Party
Publisher: name: U.S. Government Printing Office
Year: 1985
Subjects: Deep Sea Drilling Project
Glomar Challenger
DSDP
Leg 82
Site 556
Site 557
Site 558
Site 559
Site 560
Site 561
Site 562
Site 563
Site 564
Mid-Atlantic Ridge
Azores Triple Junction
Azores hot spot
North Cenral Atlantic Ocean

description: This volume covers Leg 82 of the cruises of the Drilling Vessel Glomar Challenger. Very little is known about temporal variations in the composition of basalts derived from one or several mantle sources associated with both normal and anomalously shallow sections of the mid-ocean ridges. A more detailed knowledge of these variations is required if we are to better understand the relationship between mantle sources and anomalous topographic features. The principal objective of Leg 82 of the Glomar Challenger was to try to relate regional variations in basalt chemistry to the geodynamics of an abnormal section of the mid-ocean ridge. Specifically, we planned to relate the chemical characteristics of basalts sampled on the flanks of the Mid-Atlantic Ridge to the functioning of the Azores Triple Junction topographic high or "Azores hot spot." The Azores area was chosen for this study because it is perhaps the best studied abnormal region of mid-ocean ridge. Leg 82 began in Ponta Delgada, Azores and ended in Balboa, Panama, taking place between September and November 1981.
Diálogo Inicial: princípios CARE na adequação de dados de saúde indígena pela Secretaria de Saúde Indígena no contexto do Governo Aberto Brasileiro
Creators: name: Macêdo, Diego José
name: Mártires Pinto, Elton
name: Cardoso Paiva, Gustavo
name: Vechi, Bernardo Dionízio
name: Torres Schiessl, Ingrid
name: Shintaku, Milton
Publisher: name: Zenodo
Year: 2024

description: Apresentação realizada na sessão Pecha Kucha I, da 15ª Conferência Lusófona de Ciência Aberta, na Escola Superior de Enfermagem do Porto (ESEP), de 01 a 04 de outubro de 2024.
Cooperation and emergence of role differentiation in the dynamics of social networks
Creators: name: Eguluz, Victor M.
name: Zimmermann, Martin G.
name: Cela-Conde, Camilo J.
name: Miguel, Maxi San
Publisher: name: arXiv
Year: 2006
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: Models of cooperation grounded on social networks and on the ability of individuals to choose actions and partners aim to describe human social behavior. Extensive computer simulations of these models give important insight in the social mechanisms behind emerging collective behavior. We consider the entangled co-evolution of actions and social structure in a new version of a spatial Prisoner's Dilemma model that naturally gives way to a process of social differentiation. Diverse social roles emerge from the dynamics of the system: leaders -individuals getting a large payoff who are imitated by a considerable fraction of the population-, conformists -unsatisfied cooperative agents that keep cooperating-, and exploiters -Defectors with a payoff larger than the average one obtained by Cooperators. The dynamics generates a social network that can have the topology of a small world network. The network has a strong hierarchical structure in which the leaders play an essential role sustaining a highly cooperative stable regime. The social structure is shown to be very sensitive to perturbations acting on the leaders. Such perturbations produce social crisis described as dynamical cascades that propagate through the network.
description: (15 pages, 7 figures; for related material visit http://www.imedea.uib.es/physdept)
Διαχείριση της κυκλοφορίας ενσωματωμένη στην αστική ανάπτυξη μιας περιοχής
Creators: name: Βεράνη, Ελένη Γεωργίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Πολεοδομικός σχεδιασμός
Κυκλοφοριακός σχεδιασμός
Urban planning
Transport planning

description: Σύμφωνα με τις τελευταίες στατιστικές, το 80% των πολιτών της Ευρωπαϊκής Ένωσης μένει σε αστικές περιοχές και το 40% αυτών μένει σε περιοχές ο πληθυσμός των οποίων ξεπερνά τις 200.000 κατοίκους. Η ανάγκη για μετακινήσεις ολοένα και μεγαλώνει δημιουργώντας στην πόλη σοβαρά προβλήματα κυκλοφοριακής συμφόρησης και περιβαλλοντικής υποβάθμισης. Επιπλέον, το φαινόμενο της αστικής διάχυσης εξαφανίζει την αγροτική γη και μέσα από τη διάσπαρτη οικιστική ανάπτυξη διαλύει την κοινωνική συνοχή. Η πόλη του 20ου αιώνα χτίστηκε με βάση το αυτοκίνητο. Σήμερα που τα προβλήματα διογκώνονται η πόλη πρέπει να αλλάξει. Η βιώσιμη πόλη που θα προάγει την οικονομική ευημερία και την κοινωνική συνοχή με περιβαλλοντικούς όρους πρέπει να διέπεται από τις αρχές της βιώσιμης κινητικότητας και τις κατευθύνσεις ενός ολοκληρωμένο πολεοδομικού και συγκοινωνιακού σχεδιασμού. Στόχος πλέον δεν είναι η αύξηση της κινητικότητας, αλλά η αυξημένη πρόσβαση, η πολυτροπική ανάπτυξη των μεταφορών με αναβαθμισμένες και σε ψηλότερη ιεραρχία τις μετακινήσεις πεζών και ποδηλάτων και ένας αστικός σχεδιασμός που θα ενισχύει τις συμπαγής αναπτύξεις (υψηλότερες πυκνότητες και μικτές χρήσεις γης) και θα αναδεικνύει την ανθρώπινη κλίμακα της γειτονιάς.
description: According to the latest statistics, 80% of EU citizens lives in urban areas and 40% of those staying in areas where the population exceeds 200,000 inhabitants. The need for travel in cities increasingly grows creating serious problems such as congestion and environmental degradation. Moreover, the phenomenon of urban sprawl eliminates agricultural land and scattered through the residential development dismantles social cohesion. The city was built in the 20th century under the car. Today the problems swell and the city should be changed. The sustainable city that will promote economic prosperity and social cohesion in environmental conditions shall be governed by the principles of sustainable mobility and the direction of an integrated land use and transportation planning. The aim now is not to increase mobility, but the increased access, the development of multimodal transport and upgraded to a higher hierarchy of pedestrian and bicycle travel and an urban design that enhances its compact growth (higher densities and mixed land use) and highlights the human scale of the neighborhood.
Approximative analytical solutions of the Dirac equation in Schwarzschild spacetime
Creators: name: Cotăescu, Ion I
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Approximative analytic solutions of the Dirac equation in the geometry of Schwarzschild black holes are derived obtaining information about the discrete energy levels and the asymptotic behavior of the energy eigenspinors.
description: 8 pages
Atmospheric turbulence profiling with multi-aperture scintillation of a Shack-Hartmann sensor
Creators: name: Ogane, Hajime
name: Akiyama, Masayuki
name: Oya, Shin
name: Ono, Yoshito
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: Adaptive optics (AO) systems using tomographic estimation of three-dimensional structure of atmospheric turbulence requires vertical atmospheric turbulence profile, which describes turbulence strength as a function of altitude as a prior information. We propose a novel method to reconstruct the profile by applying Multi Aperture Scintillation Sensor (MASS) method to scintillation data obtained by a Shack-Hartmann wavefront sensor (SH-WFS). Compared to the traditional MASS, which uses atmospheric scintillation within 4 concentric annular apertures, the new method utilizes scintillation in several hundreds of spatial patterns, which are created by combinations of SH-WFS subapertures. Accuracy of the turbulence profile reconstruction is evaluated with Bayesian inference, and it is confirmed that turbulence profile with more than 10 layers can be reconstructed thanks to the large number of constraints. We demonstrate the new method with a SH-WFS attached to the 50 cm telescope at Tohoku university and confirm that general characteristics of atmospheric turbulence profile is reproduced.
description: 11 pages, 14 figures. Accepted for publication in MNRAS
Nanoparticles: Tiny but Mighty Tool against Plant Pathogens
Creators: name: Neha Singh, Debjeet Sharma
Publisher: name: Bio Vet Innovator Magazine
Year: 2024

description: Plant pathogens are an unavoidable nuisance to the crops that ultimately hinders the economy of a nation. To manage the plant diseases time to time new methods and technologies are being developed and practiced. Fungicides serve to be one of the most successful management strategies but it comes with some negative aspects like increased pressure on environment and development of resistance in plant pathogens. So new advanced sciences like use of nanoparticles are being utilized as alternate methods to combat plant pathogens. Nanotechnology has the potential to revolutionize disease management in agriculture through the development of nanopesticides. These offer key benefits including improved solubility of poorly water-soluble pesticides, enhanced bioavailability, and reduced toxicity when loaded onto nanoparticles. Nanopesticides also allow for controlled and target-specific delivery, increasing efficacy while minimizing environmental impact. Other advantages include extended shelf-life, pH-dependent release, and smart delivery of RNAi molecules, enhanced UV stability, and rain-fastness. Additionally, nanopesticides offer selective toxicity, improving pest control precision and overcoming pesticide resistance. These innovations position nanoscale materials as critical tools in the agritech revolution, advancing sustainable and effective crop protection. Keywords: Fungicides, Nanotechnology, Nanopesticides, sustainable, bioavailability
Breaking stress of Coulomb crystals in the neutron star crust
Creators: name: Kozhberov, Andrew A
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: It is generally accepted that the Coulomb crystal model can be used to describe matter in the neutron star crust. In [1] we study the properties of deformed Coulomb crystals and how their stability depends on the polarization of the electron background; the breaking stress in the crust $σ_{\max}$ at zero temperature was calculated based on the analysis of the electrostatic energy and the phonon spectrum of the Coulomb crystal. In this paper, I briefly discuss the influence of zero-point and thermal contributions on $σ_{\max}$.
Thermodynamical Properties of Apparent Horizon in Warped DGP Braneworld
Creators: name: Sheykhi, Ahmad
name: Wang, Bin
name: Cai, Rong-Gen
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this paper we first obtain Friedmann equations for the $(n-1)$-dimensional brane embedded in the $(n+1)$-dimensional bulk, with intrinsic curvature term of the brane included in the action (DGP model). Then, we show that one can always rewrite the Friedmann equations in the form of the first law of thermodynamics, $dE=TdS+WdV$, at apparent horizon on the brane, regardless of whether there is the intrinsic curvature term on the brane or a cosmological constant in the bulk. Using the first law, we extract the entropy expression of the apparent horizon on the brane. We also show that in the case without the intrinsic curvature term, the entropy expressions are the same by using the apparent horizon on the brane and by using the bulk geometry. When the intrinsic curvature appears, the entropy of apparent horizon on the brane has two parts, one part follows the $n$-dimensional area formula on the brane, and the other part is the same as the entropy in the case without the intrinsic curvature term. As an interesting result, in the warped DGP model, the entropy expression in the bulk and on the brane are not the same. This is reasonable, since in this model gravity on the brane has two parts, one induced from the $(n+1)$-dimensional bulk gravity and the other due to the intrinsic curvature term on the brane.
description: 15 pages, Latex file, accepted for publication in Nucl. Phys. B
Generating ultra-dense pair beams using 400 GeV/c protons
Creators: name: Arrowsmith, C. D.
name: Shukla, N.
name: Charitonidis, N.
name: Boni, R.
name: Chen, H.
name: Davenne, T.
name: Froula, D. H.
name: Huffman, B. T.
name: Kadi, Y.
name: Reville, B.
name: Richardson, S.
name: Sarkar, S.
name: Shaw, J. L.
name: Silva, L. O.
name: Trines, R. M. G. M.
name: Bingham, R.
name: Gregori, G.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A previously unexplored experimental scheme is presented for generating low-divergence, ultra-dense, relativistic, electron-positron beams using 400 GeV/c protons available at facilities such as HiRadMat and AWAKE at CERN. Preliminary Monte-Carlo and Particle-in-cell simulations demonstrate the possibility of generating beams containing $10^{13}-10^{14}$ electron-positron pairs at sufficiently high densities to drive collisionless beam-plasma instabilities, which are expected to play an important role in magnetic field generation and the related radiation signatures of relativistic astrophysical phenomena. The pair beams are quasi-neutral, with size exceeding several skin-depths in all dimensions, allowing for the first time the examination of the effect of competition between transverse and longitudinal instability modes on the growth of magnetic fields. Furthermore, the presented scheme allows for the possibility of controlling the relative density of hadrons to electron-positron pairs in the beam, making it possible to explore the parameter spaces for different astrophysical environments.
Atom-Tunneling in Chemistry
Creators: name: Meisner, Jan
name: Kästner, Johannes
Publisher: name: arXiv
Year: 2020
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Quantum mechanical tunneling of atoms is increasingly found to play an important role in many chemical transformations. Experimentally, atom-tunneling can be indirectly detected by temperature-independent rate constants at low temperature or by enhanced kinetic isotope effects. On the contrary, using computational investigations the influence of tunneling on the reaction rates can directly be monitored. The tunnel effect, for example, changes reaction paths and branching ratios, enables chemical reactions in an astrochemical environment that would be impossible by thermal transition, and influences biochemical processes.
Embeddings of homogeneous spaces into irreducible modules
Creators: name: Losev, Ivan V.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Representation Theory (math.RT)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14M17, 14R20

description: Let $G$ be a connected reductive group. We find a necessary and sufficient condition for a quasiaffine homogeneous space of $G$ to be embeddable into an irreducible $G$-module. In addition, for an affine homogeneous space we find a criterium for a closed embedding to exist
description: v2 8 pages, a gap in the proof is corrected, some examples are added v3 new theorem answering whether there is a closed embedding is added
Now we’re a university college: a kaleidoscope of meanings
Creators: name: Owen, Starr Leona Allaby
Publisher: name: University of British Columbia
Year: 2009

description: I conducted a case study at Multisite (a pseudonym), an established community college that is becoming a university college. I explored and attempted to understand (a) the organizational culture, and (b) how faculty members interpret this transition. I conducted prolonged observations and interviews with 39 faculty members. I explored the culture by means of what I label the themes of family, of participation, and of institutional mission. I also explored it using multiple perspectives, especially a fragmentation perspective (Martin, 1992). I used the metaphor of a kaleidoscope to signify shared frames of reference without consensus on meanings. I modified Geertz' (1973) sensemaking perspectives and developed a framework. It entails three elements: (i) a perspective, (ii) a symbol or issue, and (iii) the interpretation of (ii) within (i). It is consistent with Weick's (1995) description of organizational sensemaking. An individual may focus on (a) traditional (e.g., communal and participatory) cultural values, (b) emergent (e.g., academic) cultural values, or (c) pragmatic interests. The interpretation may be positive, negative, neutral, or postponed, depending on the perceived status of the cultural value or of the pragmatic issue. Interpretations seem not to be associated directly with objective characteristics, such as length of service, program affiliation, or academic credentials attained. Fragmented meaning systems are associated with fragmented interpretations; fragmented interpretations are associated with fragmented patterns of organizational commitment and job satisfaction. Faculty who use a traditional cultural perspective indicate that they or their colleagues retain their level of commitment or have lost it, according to whether traditional values seem retained or lost. If they are uncertain what will happen to traditional values, they are uncertain whether they or their colleagues will remain engaged. Faculty who use an emergent cultural perspective indicate an increased job satisfaction; they may indicate decreased organizational commitment. Faculty who use a pragmatic perspective may see the transition positively and express enthusiasm for their work; they may see it negatively and express low levels of organizational commitment. I suggest that factors in the external environment have precipitated changes in organizational values which, in turn, have precipitated changes in organizational commitment and job satisfaction.
Quasiparticle relaxation in optically excited high-Q superconducting resonators
Creators: name: Barends, R.
name: Baselmans, J. J. A.
name: Yates, S. J. C.
name: Gao, J. R.
name: Hovenier, J. N.
name: Klapwijk, T. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The quasiparticle relaxation time in superconducting films has been measured as a function of temperature using the response of the complex conductivity to photon flux. For tantalum and aluminium, chosen for their difference in electron-phonon coupling strength, we find that at high temperatures the relaxation time increases with decreasing temperature, as expected for electron-phonon interaction. At low temperatures we find in both superconducting materials a saturation of the relaxation time, suggesting the presence of a second relaxation channel not due to electron-phonon interaction.
description: 4 pages, 3 figures
Metal (boro-) hydrides for high energy density storage and relevant emerging technologies
Creators: name: Bannenberg, L. J.
name: Heere, M.
name: Benzidi, H.
name: Montero, J.
name: Dematteis, E. M.
name: Suwarno, S.
name: Jaroń, T.
name: Winny, M.
name: Orłowski, P. A.
name: Wegner, W.
name: Starobrat, A.
name: Fijałkowski, K. J.
name: Grochala, W.
name: Qian, Z.
name: Bonnet, J. -P.
name: Nuta, I.
name: Lohstroh, W.
name: Zlotea, C.
name: Mounkachi, O.
name: Cuevas, F.
name: Chatillon, C.
name: Latroche, M.
name: Fichtner, M.
name: Baricco, M.
name: Hauback, B. C.
name: Kharbachi, A. El
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The current energy transition imposes a rapid implementation of energy storage systems with high energy density and eminent regeneration and cycling efficiency. Metal hydrides are potential candidates for generalized energy storage, when coupled with fuel cell units and/or batteries. An overview of ongoing research is reported and discussed in this review work on the light of application as hydrogen and heat storage matrices, as well as thin films for hydrogen optical sensors. These include a selection of single-metal hydrides, Ti-V(Fe) based intermetallics, multi-principal element alloys (high-entropy alloys), and a series of novel synthetically accessible metal borohydrides. Metal hydride materials can be as well of important usefulness for MH-based electrodes with high capacity (e.g. MgH2 ~ 2000 mAh g-1) and solid-state electrolytes displaying high ionic conductivity suitable, respectively, for Li-ion and Li/Mg battery technologies. To boost further research and development directions some characterization techniques dedicated to the study of M-H interactions, their equilibrium reactions, and additional quantification of hydrogen concentration in thin film and bulk hydrides are presented at the end of this manuscript.
A white dwarf with an unsual composition as the potential product of a binary merger
Creators: name: Hollands, Mark
Publisher: name: Zenodo
Year: 2019

description: The merger of two white dwarfs with a combined mass below the Chandrasekhar-limit is expected to be non-explosive, resulting in a single massive white dwarf. However, because single star evolution can also produce massive white dwarfs, few known degenerate stars have categorically been confirmed as merger products.
 We report the identification of a 1.15 Msun mass white dwarf with a unique photospheric composition that cannot be explained through standard models of single star evolution. The stellar atmosphere is dominated by hydrogen, but with a C/H ratio of 0.15. The spectroscopic non-detection of helium and maximum convection zone mass of Mcvz/Mwd = 1E-10, imply an extremely small stellar envelope with a remarkably low helium fraction (considering the dredge up carbon from the interior). This new discovery thus provides a unique opportunity to investigate a rare channel of binary-star evolution.
The interior spacetimes of stars in Palatini f(R) gravity
Creators: name: Kainulainen, Kimmo
name: Reijonen, Vappu
name: Sunhede, Daniel
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study the interior spacetimes of stars in the Palatini formalism of f(R) gravity and derive a generalized Tolman-Oppenheimer-Volkoff and mass equation for a static, spherically symmetric star. We show that matching the interior solution with the exterior Schwarzschild-De Sitter solution in general gives a relation between the gravitational mass and the density profile of a star, which is different from the one in General Relativity. These modifications become neglible in models for which $δF(R) \equiv \partial f/\partial R - 1$ is a decreasing function of R however. As a result, both Solar System constraints and stellar dynamics are perfectly consistent with $f(R) = R - μ^4/R$.
description: Published version, 6 pages, 1 figure
Η διήγηση της Ταβιθά (Πραξ Αποστ 36-43): Θεολογική και Ερμηνευτική προσέγγιση
Creators: name: Παγούνης, Λάμπρος Αθανασίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Ταβιθά
Ιόππη
Πέτρος
Tavitha
Ioppi
Petros

description: Η παρούσα εργασία ασχολείται με τη διήγηση της ανάστασης της Ταβιθά (Πραξ Αποστ 9, 36-43), μια διήγηση που προβάλλει τη δύναμη του Αποστόλου Πέτρου και παράλληλα την προσωπικότητα και το φιλάδελφο έργο μιας πρωτοχριστιανής γυναίκας. Ασχοληθήκαμε με ένα φάσμα προβλημάτων της διήγησης που περιλαμβάνει: πρώτον, τη χειρόγραφη παράδοση του κειμένου και δεύτερον τη συνάφεια της διήγησης. Ακολούθως, σε πρώτη φάση μελετήσαμε τη διήγηση ως αρμό των δύο διηγήσεων που την πλαισιώνουν, δηλ. του Αινέα καί Κορνήλιου και σε δεύτερη συνέχεια επιχειρήσαμε την ερμηνευτική και θεολογική της προσέγγιση (το πρόσωπο και το φιλάνθρωπο έργο της Ταβιθά, την ασθένεια και το θάνατό της, την πρόσκληση και την έλευση του Πέτρου στην Ιόππη, την ανάστασή της, τα αποτελέσματα της ανάστασης της Ταβιθά στον περίγυρό της και τέλος την παραμονή του Πέτρου στην Ιόππη). Βασικό μέρος της εργασίας αποτέλεσε και η σύγκριση της διήγησης της Ταβιθά με άλλες διηγήσεις αναστάσεων στην Παλαιά και τηv Καινή Διαθήκη. Η εργασία αφιερώνει σύντομη αναφορά στη σχέση της διήγησης της Ταβιθά με τη ζωή της Εκκλησίας (λατρεία, υμνολογία και εικονογραφία). Επίσης αναφερθήκαμε στη σκοπιμότητα που εξυπηρετεί η παράθεση στις Πράξεις ενός θαύματος ανάστασης μιας νεκράς γυναίκας, μέλους της πρώτης εκκλησίας. Η εργασία κατακλείεται με τα βασικά συμπεράσματα της μελέτης της διήγησης.
description: This work deals with the story of the resurrection of Tabitha (Acts 9: 36-43), a narrative that highlights the power of St. Peter and also the personality and brotherly-loving work of an early-Christian woman. We dealt with a range of problems of the narrative including: firstly, the hand-written tradition of the manuscript and, secondly, the relevance of the narrative. Then, in the first phase, we studied the narrative as a “joint” of the two stories that frame it, i.e. that of Aeneas’ and that of Cornelius’ and, secondly, we attempted the interpretive and theological approach of it (the person and the charitable work of Tabitha, her illness and her death, the call and the arrival of Peter in Joppa, her resurrection, the consequences of Tabitha’s resurrection on her surrounding environment and, finally, Peter’s residing in Joppa). Key part of the study was a comparison of the narrative of Tabitha with other narratives of resurrections in the Old and New Testaments. The study dedicates a brief reference to the relationship between the narrative of Tabitha and the life of the Church (worship, hymnology and iconography). Furthermore, we talked about the purposefulness served by the disclosure in the Acts of a miracle of resurrection of a dead woman, member of the first church. The paper wraps up with the main conclusions of the study of the narrative.
Ο κατασκευαστικός κλάδος στην Τουρκία: πρόσφορα, ζήτηση, προοπτικές και προϋποθέσεις εισόδου
Creators: name: Ismail Oglou, Aisegkioul (Ισμαήλ Ογλού, Αϊσεγκιούλ Εμβέρ)
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Τουρκία
Κατασκευαστικός κλάδος
Ανάλυση SWOT
Turkey
Construction industry
SWOT analysis

description: Η εργασία αυτή διερευνά τη δομή και τη δυναμική του κατασκευαστικού κλάδου στην Τουρκία. Εξετάζονται η προσφορά, η ζήτηση, οι κύριοι τομείς της κατασκευαστικής αγοράς, καθώς επίσης και οι προοπτικές και οι όροι εισόδου σε αυτήν τόσο των Ελλήνων μηχανικών όσο και ελληνικών κατασκευαστικών εταιρειών. Χρησιμοποιώντας ελληνικές, αγγλικές και τουρκικές ιστοσελίδες, συνεντεύξεις που πραγματοποιήθηκαν με Τούρκους και Έλληνες εργαζόμενους μηχανικούς στην Τουρκία, έρευνα ερωτηματολογίου μικρής κλίμακας και αναλύσεις SWOT, επιχειρήθηκε να δοθούν απαντήσεις στα παραπάνω ζητήματα. Από τα αποτελέσματα αυτής της έρευνας συμπεραίνεται ότι τα δυνατά σημεία και οι ευκαιρίες του κατασκευαστικού τομέα της Τουρκίας είναι φανερά περισσότερες από τις αδυναμίες. Αυτός είναι ένας ισχυρός λόγος και για την Ελλάδα, εν μέσω οικονομικής κρίσης, να στρέψει το βλέμμα της προς τη χώρα αυτή και να προσπαθήσει να συνάψει συνεργασίες με τις τουρκικές κατασκευαστικές εταιρείες, με στόχο την αξιοποίηση από κοινού ευκαιριών που εμφανίζονται τόσο στη γειτονική χώρα όσο και στην ευρύτερη περιοχή. Η προώθηση της συνεργασίας κατασκευαστικών εταιρειών με στόχο το κοινό όφελος μπορεί να ωφελήσει ευρύτερα τις σχέσεις των δύο γειτονικών χωρών.
description: The present study investigates the structure and dynamics of the construction industry in Turkey. Several subjects are being considered such as the supply, the demand and the main sectors of the construction market, as well as the entry prospects and conditions in this market for Greek engineers and Greek construction companies. Using Greek, English and Turkish websites, interviews conducted with both Turkish and Greek engineers working in Turkey, a small-scale questionnaire survey and a SWOT analysis, it was attempted to give an answer to the above questions. The results of this study indicate that the potential and the opportunities of Turkey's construction sector are considerably more than its weakness. This is a strong reason for Greece, currently emerged in the financial crisis, to turn to this country and try to establish partnerships with Turkish construction companies, aiming at exploiting jointly opportunities that appear both in the neighbouring country and the wider region. Promoting cooperation for the mutual benefit within construction companies can benefit further the relations between the two neighbouring countries.
Orbital evolution of a test particle around a black hole: Indirect determination of the self force in the post Newtonian approximation
Creators: name: Burko, Lior M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Comparing the corrections to Kepler's law with orbital evolution under a self force, we extract the finite, already regularized part of the latter in a specific gauge. We apply this method to a quasi-circular orbit around a Schwarzschild black hole of an extreme mass ratio binary, and determine the first- and second-order conservative gravitational self force in a post Newtonian expansion. We use these results in the construction of the gravitational waveform, and revisit the question of the relative contribution of the self force and spin-orbit coupling.
description: 5 pages, 2 figures
Dispersion and asymptotic profiles for Kirchhoff equations
Creators: name: Matsuyama, Tokio
name: Ruzhansky, Michael
Publisher: name: arXiv
Year: 2007
Subjects: subject: Analysis of PDEs (math.AP)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 35L05; 35L10

description: The aim of this article is to describe asymptotic profiles for the Kirchhoff equation, and to establish time decay properties and dispersive estimates for Kirchhoff equations. For this purpose, the method of asymptotic integration is developed for the corresponding linear equations and representation formulae for their solutions are obtained. These formulae are analysed further to obtain the time decay rate of $L^p$--$L^q$ norms of propagators for the corresponding Cauchy problems.
Κατάχρηση αγοράς
Creators: name: Πασχάλη, Ελένη Δημητρίου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Κατάχρηση
Αγορά
Προνομιακή
Abuse
Market
Insider

description: Αντικείμενο της εργασίας είναι η κατάχρηση αγοράς, η οποία περιλαμβάνει δύο κατηγορίες ενεργειών: α) πράξεις που συνιστούν καταχρηστική εκμετάλλευση προνομιακών πληροφοριών και β) πράξεις που αποσκοπούν στην χειραγώγηση των τιμών των αγορών. Αμφότερες οι ως άνω κατηγορίες ενεργειών ρυθμίζονται από το Ν. 3340/2005, με τον οποίο ενσωματώθηκε στο ελληνικό δίκαιο η οδηγία 2006/3 ΕΚ. Στην εργασία εξετάστηκαν ειδικότερα το υποκειμενικό και αντικειμενικό πεδίο εφαρμογής της απαγόρευσης κατάχρησης αγοράς, οι εξαιρέσεις από την αρχή της απαγόρευσης, τα προβλεπόμενα στο νόμο προληπτικά μέτρα, η αρμόδια αρχή καθώς και οι πολιτικές, ποινικές και διοικητικές κυρώσεις σε περίπτωση παραβίασης της απαγόρευσης κατάχρησης αγοράς.
description: The subject of this study is market abuse, which consists of two categories of acts: a) acts constituting insider dealing and b) acts aiming at market manipulation. Both above categories of acts are regulated by Law 3340/2005, by whom Directive 2003/6/EC was incorporated into Greek Law. At this study we examined more specifically the subjective and objective scope of the prohibiton of market abuse, the exceptions from the principle of prohibition, the precautionary measures provided for in the law, the competent authority, as well as the civil, penal and administrative sanctions in case of violation of the prohibition of market abuse.
Χρονοδιάγραμμα συντήρησης εργοταξιακού εξοπλισμού σύμφωνα με το Ευρωπαϊκό Πρότυπο Συντήρησης EN 13460 με το MS Project 2010
Creators: name: Αμαραντίδης, Στυλιανός Νικολάου
Publisher: name: Aristotle University of Thessaloniki
Year: 2012
Subjects: Ευρωπαϊκό Πρότυπο Συντήρησης
Τροφοδοτική Αντλία
Χρονοδιάγραμμα GANTT
European Maintenance Standard
Supply Pump
GANTT Chart

description: Η συντήρηση του μηχανολογικού εξοπλισμού βιομηχανικών εγκαταστάσεων αποτελεί μια κρίσιμη δραστηριότητα τόσο για την ομαλή λειτουργία τους όσο και για την ασφάλεια του προσωπικού. Η επακριβής αποτύπωση και καταγραφή των λειτουργικών μονάδων και η εφαρμογή σύγχρονων και αποτελεσματικών διαδικασιών, σε συνδυασμό με την λεπτομερή τους καταγραφή, είναι κρίσιμες συνιστώσες για μια αποτελεσματική συντήρηση. Στην παρούσα διπλωματική εργασία γίνεται αρχικά μια αναφορά στην ιστορία της συντήρησης και στα διάφορα είδη που υπάρχουν. Στη συνέχεια, περιγράφεται το Ευρωπαϊκό Πρότυπο συντήρησης EN 13460:2009 και πώς αυτό συνδέεται με την παραγωγική διαδικασία. Ακολουθεί μια σύντομη τεχνική περιγραφή των λειτουργικών στοιχείων μιας από τις τρεις τροφοδοτικές αντλίες της 3ης Μονάδος του ΑΗΣ Αγίου Δημητρίου Κοζάνης, και ο τρόπος εφαρμογής του Ευρωπαϊκού Προτύπου στις διαδικασίες της συντήρησης της αντλίας. Παρουσιάζεται η σύνδεση της όλης της διαδικασίας με το MS Project 2010 για τη δημιουργία του αντίστοιχου χρονοδιαγράμματος διεργασιών και η εργασία ολοκληρώνεται με τα συμπεράσματα που εξάγονται από την όλη διαδικασία.
description: The maintenance of mechanical equipment of industrial plants is a critical activity for both the smooth operation and the safety of personnel. The accurate capture and record of modules and implementation of modern and efficient processes, along with detailed registration, are critical components for effective maintenance. At the present thesis, there is an initial report about the history of maintenance and the different types that exist. Then, there is a description of the European Maintenance Standard EN 13460, and how it is related to the whole production process. Below, follows a brief technical description of the functional elements of one of the three supply pumps that are included in total, in the 3rd Unit of the Thermoelectrical Plant of Saint Dimitrios at Kozani, and the implementation of this European Standard in the processes of the maintenance of the supply pump.In the end, there is a presentation of the connection of the whole process with the use of MS Project 2010, in order to create the corresponding timeline of the processes, and the thesis ends with the conclusions drawn from the whole process.