cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Temperature measurements on fast-rotating objects using a thermographic camera with an optomechanical image derotator
Creators: name: Altmann, Bettina
name: Pape, Christian
name: Reithmeier, Eduard
Publisher: name: Bellingham, Wash. : SPIE
Year: 2017
Subjects: subject: Infrared imaging
subject: Optomechanical image derotator
subject: Rolling bearings
subject: Rotating machinery
subject: Temperature measurements
subject: Bearings (machine parts)
subject: Cameras
subject: Data acquisition
subject: Image segmentation
subject: Infrared detectors
subject: Infrared devices
subject: Infrared radiation
subject: Machine components
subject: Machinery
subject: Reflection
subject: Shafts (machine components)
subject: Temperature measurement
subject: Thermography (imaging)
subject: Automotive applications
subject: Higher resolution
subject: Optomechanical
subject: Region of interest
subject: Stroboscopic measurements
subject: Thermographic cameras
subject: Thermographic measurement
subject: Roller bearings
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Increasing requirements concerning the quality and lifetime of machine components in industrial and automotive applications require comprehensive investigations of the components in conditions close to the application. Irregularities in heating of mechanical parts reveal regions with increased loading of pressure, draft or friction. In the long run this leads to damage and total failure of the machine. Thermographic measurements of rotating objects, e.g., rolling bearings, brakes, and clutches provide an approach to investigate those defects. However, it is challenging to measure fast-rotating objects accurately. Currently one contact-free approach is performing stroboscopic measurements using an infrared sensor. The data acquisition is triggered so that the image is taken once per revolution. This leads to a huge loss of information on the majority of the movement and to motion blur. The objective of this research is showing the potential of using an optomechanical image derotator together with a thermographic camera. The derotator follows the rotation of the measurement object so that quasi-stationary thermal images during motion can be acquired by the infrared sensor. Unlike conventional derotators which use a glass prism to achieve this effect, the derotator within this work is equipped with a sophisticated reflector assembly. These reflectors are made of aluminum to transfer infrared radiation emitted by the rotating object. Because of the resulting stationary thermal image, the operation can be monitored continuously even for fast-rotating objects. The field of view can also be set to a small off-axis region of interest which then can be investigated with higher resolution or frame rate. To depict the potential of this approach, thermographic measurements on a rolling bearings in different operating states are presented. © 2017 SPIE.
Mathematize urbes by humanizing them: Cities as Isobenefit Landscapes. Psycho-Economical distances and Isobenefit Lines
Creators: name: D'Acci, Luca
Publisher: name: arXiv
Year: 2013
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: The city reading proposed is a modern postmodern urbanism approach which quantifies but by passing through subjectivism. The isobenefit lines shown translate cities into benefit landscapes, subjective and continually changeable according to personal moods needs preferences and urban transformations. They read attractiveness and how they flow throughout the city. Doing it for each urban point and for each urban attraction, we obtain the isobenefit orography of the city, namely a map of its urban attractions and of their flows. This is a liquid surface rather than solid, as it varies across time and people. It is in this liquidness where resides the complexity of cities, their bottom up spirit and the dynamicity of equilibriums and networks. People do not necessarily go in the most accessible points, but where they need and want to, and, they flow through paths they need or choose to pass through. It is also introduced the likeability of places and paths: in addition to the usual parameters currently used, which weight distances in terms of physical distance, cost, time or mental easiness representations, psycho-economical distances used in the isobenefit lines proposed here, also consider how a place and a path pleases us. According to the Underground Hedonic Theory, this pleasure to pass through or to stay in agreeable areas has an underground and an inertia effect too which contributes to delight our lives. The final purpose of the science of cities and urban design is to understand cities and make them efficient and attractive to please our lives in them.
description: 32 pages, 20 figures
Reconstructing top quark-antiquark events with one lost jet
Creators: name: Demina, Regina
name: Harel, Amnon
name: Orbaker, Douglas
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We present a technique for reconstructing the kinematics of pair-produced top quarks that decay to a charged lepton, a neutrino and four final state quarks in the subset of events where only three jets are reconstructed. We present a figure of merit that allows for a fair comparison of reconstruction algorithms without requiring their calibration. The new reconstruction of events with only three jets is fully competitive with the full reconstruction typically used for four jet events.
Documento compartido para ejercicios, notas y preguntas curso ¡Presente! Recursos para Encuentros Activos
Creators: name: MetaDocencia Team
Publisher: name: Zenodo
Year: 2022
Subjects: Ciencia Abierta
docencia
pedagogía
enseñanza
Latin America
clases virtuales
Teaching
Comunidad
Cursos

description: Este documento se comparte durante la case para llevar adelante, de manera colaborativa, ejercicios, notas y preguntas sobre el curso ¡Presente! Recursos para Encuentros Activos. Una vez finalizado el dictado del curso, el documento queda disponible para quienes asistieron al mismo.
Spaser operation below threshold: autonomous vs. driven spasers
Creators: name: Andrianov, E. S.
name: Dorofeenko, A. V.
name: Pukhov, A. A.
name: Vinogradov, A. P.
name: Lisyansky, A. A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: At the plasmon resonance, high Joule losses in a metal nanoparticle of a spaser result in its low Q-factor. Due to the latter, to achieve the spasing regime, in which the number of coherent plasmons exceeds the number of incoherent plasmons, unsustainably high pump rates may be required. We show that under the condition of loss compensation by a spaser driven by an external optical wave, the number of coherent plasmons increases dramatically, and the quantum noise is suppressed. Since the compensation of losses of the driving wave may occur even near the spasing threshold, the number of coherent plasmons may exceed the number of spontaneously excited plasmons at achievable pump rates.
title: Ποιότητα επικοινωνίας και διαπροσωπικές σχέσεις σε δημόσιο οργανισμό: Μελέτη περίπτωσης του οργανισμού ΕΦΚΑ Λάρισας
titleType: AlternativeTitle
Creators: name: Αλβανού, Μαρία
Publisher: name: University of Thessaly
Year: 2019
Subjects: Εθνικός Φορέας Κοινωνικής Ασφάλισης (Ε.Φ.Κ.Α) -- Ελλάδα -- Λάρισα
Διαπροσωπικές σχέσεις
Εργασιακές σχέσεις
Επικοινωνία
Δημόσια διοίκηση

description: Σημείωση: διατίθεται συμπληρωματικό υλικό σε ξεχωριστό αρχείο.
Micro pixel LEDs: Design challenge and implementation for high-resolution headlamps
Creators: name: Held, Marcel Philipp
name: Kloppenburg, Gerolf
name: Lachmayer, Roland
Publisher: name: Bellingham, Wash. : SPIE
Year: 2019
Subjects: subject: AFS
subject: AFS/ADB
subject: Automotive Lighting
subject: High-resolution headlamps
subject: Imaging optics
subject: Micro Pixel LED
subject: Monolithic LED
subject: Pixel light system
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: High-resolution vehicle headlamps represent a future-oriented technology that can be used to increase traffic safety and driving comfort. Typically, selective absorbing of light using a spatial modulator like DMD, LCD or LCoS creates the light distribution of such headlamp systems. A similar effect can be generated by using LED arrays. Its additive principle generates light only in specific segments if necessary. In general, these arrays can be distinguished between conventional LEDs arranged in an array and micro pixel LEDs. Conventional LED arrays characterize by the design (THT or SMD) with typically a few millimeters edge length. In contrast, a micro-pixel LED uses COB technology, in which individual LED dies are packed in a single housing directly next to each other at a distance of a few microns. By increasing the array resolution, the challenges in designing an optical system for high-resolution headlamps rise. High efficiencies and contrasts call for small, accurate lens geometries and negligibly scattered light effects. Due to limited installation space and manufacturing tolerances, compromises have to be made. Ideally, the optics have to be accurate enough to image each pixel of the micro LED with high contrasts and high efficiency and still be too blurry to project the gaps between each pixel. This results in small distances between LED and optics and therefore in diffcult to manufacture radii of curvature. In this paper we specify the challenges to implement micro pixel LEDs in headlamp systems, as well as present the controllability of scattered light effects of these systems. © COPYRIGHT SPIE
Form factors of spin 1 analogue of the eight-vertex model
Creators: name: Quano, Yas-Hiro
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Algebra (math.QA)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 81T40

description: The twenty-one-vertex model, the spin $1$ analogue of the eight-vertex model is considered on the basis of free field representations of vertex operators in the $2\times 2$-fold fusion SOS model and vertex-face transformation. The tail operators, which translate corner transfer matrices of the twenty-one-vertex model into those of the fusion SOS model, are constructed by using free bosons and fermions for both diagonal and off-diagonal matrix elements with respect to the ground state sectors. Form factors of any local operators are therefore obtained in terms of multiple integral formulae, in principle. As the simplest example, the two-particle form factor of the spin operator is calculated explicitly.
description: 35 pages, 4 figures. As the simplest example, the two-particle form factor of the spin operator is calculated explicitly. Trigonometric limit of the form factors is examined. Many mistakes were removed
Temperature-Dependent Changes in Resolution and Coercivity of Superparamagnetic and Superferromagnetic Iron Oxide Nanoparticles
Creators: name: Doyle, Owen
name: Bryan, Jacob
name: Kim, Melissa
name: Saayujya, Chinmoy
name: Nazarian, Sophie
name: Mokkarala-Lopez, Javier
name: Kuo, Renesmee
name: Yousuf, Mariam
name: Chandrasekharan, Prashant
name: Fellows, Benjamin
name: Conolly, Steven
Publisher: name: International Journal on Magnetic Particle Imaging IJMPI
Year: 2023

description: Magnetic Particle Imaging (MPI) is a tracer-based imaging modality with immense promise as a radiation-free alternative to nuclear medicine imaging techniques. Nuclear medicine requires "hot chemistry" wherein radioactive tracers must be synthesized on-site, requiring expensive infrastructure and labor costs. MPI's magnetic nanoparticles, superparamagnetic iron oxide nanoparticles (SPIOs), have no significant signal decay over time which removes cost barriers associated with nuclear medicine studies such as FDG-PET. While SPIOs are the current industry standard MPI tracer, recent developments in synthesizing superferromagnetic iron oxide nanoparticles (SFMIOs) and high resolution SPIOs (HR-SPIOs), a new class of nanoparticle with almost zero coercivity, have yielded a 30-fold improvement in resolution (0.4 mT) and SNR. To better understand the long-term performance of these new nanoparticles, this investigation reports changes in SPIO (VivoTrax Plus), HR-SPIO, and SFMIO resolution, along with SFMIO coercivity, at low temperatures (-2, 2 °C) and room temperature (18-22 °C) over 12 weeks. We find that changes in HR-SPIO resolution are more sensitive to storage temperature than SFMIOs. Additionally, we observe no appreciable difference in SFMIO coercivity between the two temperatures over time. These results can inform research on optimizing tracer synthesis while lending practical information to future hospitals about the highly accessible conditions for the transit and storage of tracers.
description: International Journal on Magnetic Particle Imaging IJMPI, Vol 9 No 1 Suppl 1 (2023)
Semantic denoising autoencoders for retinal optical coherence tomography
Creators: name: Laves, Max-Heinrich
name: Ihler, Sontje
name: Kahrs, Lüder Alexander
name: Ortmaier, Tobias
Publisher: name: Bellingham, Wash. : SPIE
Year: 2019
Subjects: subject: Computer-aided diagnosis
subject: Image classication
subject: Image enhancement
subject: Machine learning
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Noise in speckle-prone optical coherence tomography tends to obfuscate important details necessary for medical diagnosis. In this paper, a denoising approach that preserves disease characteristics on retinal optical coherence tomography images in ophthalmology is presented. We propose semantic denoising autoencoders, which combine a convolutional denoising autoencoder with a priorly trained ResNet image classifier as regularizer during training. This promotes the perceptibility of delicate details in the denoised images that are important for diagnosis and filters out only informationless background noise. With our approach, higher peak signal-to-noise ratios with PSNR = 31.0 dB and higher classification performance of F1 = 0.92 can be achieved for denoised images compared to state-of-the-art denoising. It is shown that semantically regularized autoencoders are capable of denoising retinal OCT images without blurring details of diseases.
Finite-dimensional representations of the elliptic modular double
Creators: name: Derkachov, S. E.
name: Spiridonov, V. P.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Algebra (math.QA)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We investigate the kernel space of an integral operator M(g) depending on the "spin" g and describing an elliptic Fourier transformation. The operator M(g) is an intertwiner for the elliptic modular double formed from a pair of Sklyanin algebras with the parameters $η$ and $τ$, Im$ τ>0$, Im$η>0$. For two-dimensional lattices $g=nη+ mτ/2$ and $g=1/2+nη+ mτ/2$ with incommensurate $1, 2η,τ$ and integers $n,m>0$, the operator M(g) has a finite-dimensional kernel that consists of the products of theta functions with two different modular parameters and is invariant under the action of generators of the elliptic modular double.
description: 25 pp., published version
Evaluation of magnetization dynamics influenced by Brownian relaxation in magnetic nanoparticles
Creators: name: Ota, Satoshi
name: Takemura, Yasushi
Publisher: name: International Journal on Magnetic Particle Imaging IJMPI
Year: 2023

description: Magnetic relaxations determine the magnetization properties of magnetic nanoparticles for biomedical applications such as the tracer of magnetic particle imaging. In this study, the magnetization dynamics influenced by the dynamics of the particle body as the easy axes of magnetic nanoparticles of different structures were evaluated measuring the magnetization curves, intensity of harmonic components in magnetization, and oscillation and orientation of the easy axis. To observe the effects of the Brownian relaxation associated with particle rotation, we prepared magnetic nanoparticles fixed with epoxy resin to inhibit the particle rotation and dispersed them in water where the particle rotation occurred. It is indicated that the Brownian relaxation observed as the particle oscillation and orientation significantly affected the magnetization dynamics of magnetic nanoparticles in the ferromagnetic regime.
description: International Journal on Magnetic Particle Imaging IJMPI, Vol 9 No 1 Suppl 1 (2023)
Fractionally-Supervised Classification
Creators: name: Vrbik, Irene
name: McNicholas, Paul D.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Methodology (stat.ME)
subject: Applications (stat.AP)
subject: Computation (stat.CO)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Traditionally, there are three species of classification: unsupervised, supervised, and semi-supervised. Supervised and semi-supervised classification differ by whether or not weight is given to unlabelled observations in the classification procedure. In unsupervised classification, or clustering, all observations are unlabeled and hence full weight is given to unlabelled observations. When some observations are unlabelled, it can be very difficult to \textit{a~priori} choose the optimal level of supervision, and the consequences of a sub-optimal choice can be non-trivial. A flexible fractionally-supervised approach to classification is introduced, where any level of supervision --- ranging from unsupervised to supervised --- can be attained. Our approach uses a weighted likelihood, wherein weights control the relative role that labelled and unlabelled data have in building a classifier. A comparison between our approach and the traditional species is presented using simulated and real data. Gaussian mixture models are used as a vehicle to illustrate our fractionally-supervised classification approach; however, it is broadly applicable and variations on the postulated model can be easily made.
Data-constrained MHD simulation for the eruption of a filament-sigmoid system in solar active region 11520
Creators: name: Liu, Tie
name: Fan, Yuhong
name: Su, Yingna
name: Guo, Yang
name: Wang, Ya
name: Ji, Haisheng
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The separation of a filament and sigmoid is observed during an X1.4 flare on July 12, 2012 in solar active region 11520, but the corresponding magnetic field change is not clear. We construct a data-constrained magnetohydrodynamic simulation of the filament-sigmoid system with the flux rope insertion method and magnetic flux eruption code, which produces the magnetic field evolution that may explain the separation of the low-lying filament and high-lying hot channel (sigmoid). The initial state of the magnetic model contains a magnetic flux rope with a hyperbolic flux tube, a null point structure and overlying confining magnetic fields. We find that the magnetic reconnections at the null point make the right footpoint of the sigmoid move from one positive magnetic polarity (P1) to another (P3). The tether-cutting reconnection at the hyperbolic flux tube occurs and quickly cuts off the connection of the low-lying filament and high-lying sigmoid. In the end, the high-lying sigmoid erupts and grows into a coronal mass ejection, while the low-lying filament stays stable. The observed double J-shaped flare ribbons, semi-circular ribbon, and brightenings of several loops are reproduced in the simulation, where the eruption of the magnetic flux rope includes the impulsive acceleration and propagation phases.
description: This paper has been accepted for publication in the ApJ
Visualization of dynamic stress conditions in elastic solids utilizing high frequency stroboscopic LED arrays
Creators: name: Shi, Jian
name: Ohrdes, Hendrik
name: Weinstein, Michael
name: Twiefel, Jens
Publisher: name: Bellingham, Wash. : SPIE
Year: 2019
Subjects: subject: Dynamic photoelasticity
subject: IGBT
subject: Stroboscopic LED array
subject: Ultrasound
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Ultrasonic mechanical vibrations in solids are widely used in non-destructive testing, and high-power applications such as ultrasonic welding or soldering. The visualization of ultrasonic wave propagation in transparent solids is helpful for understanding the ultrasonic behaviours. The classical method of photoelasticity allows the visualization of the static stress distribution in birefringent materials. Utilizing recent high-power LEDs in the photoelasticity allows to capture dynamic stresses by high frequency stroboscopic light. High frequency stationary and transient oscillation processes in elastic solids can be visualized with this method. The designed LED array in this paper has a dimension of 210 mm 300 mm, and every LED has distance of 38mm to each other, and the light intensity has a homogeneity value. The temporal and spatial resolution of stress-optic systems depends mainly on the dynamic properties of the lighting technology used. The high speed synchronization of the stroboscopic light sources results in a high temporal resolution of the photoelasticity analyses. This enables the photoelastic investigation of highly dynamic load conditions, such as longitudinal waves and transverse waves.
Magnetic Particle Imaging for the Evaluation of Gastrointestinal Health by Measuring Gastrointestinal Permeability
Creators: name: Yousuf, Mariam
name: Chandrasekharan, Prashant
name: Conolly, Steven
Publisher: name: International Journal on Magnetic Particle Imaging IJMPI
Year: 2023

description: Various diseases and immune-related issues have been associated with the gastrointestinal system’s health. Gastrointestinal permeability - a measure of transport across the GI tract’s cell lining from the lumen - is a functional parameter that is affected and is a viable factor in GI health assessment. Current diagnosis of GI-related disease involves the use of invasive exploratory surgery to minimally invasive colonoscopy. Magnetic particle imaging (MPI) is a non-radioactive and highly sensitive tracer imaging modality. The nanoparticle tracers used for MPI are FDA approved and can readily be translated into the clinic. In this research, we provide the first proof-of-concept using MPI to evaluate GI permeability in an in vitro model of the epithelial barrier lining of the GI tract.
description: International Journal on Magnetic Particle Imaging IJMPI, Vol 9 No 1 Suppl 1 (2023)
Optical autonomous sensor module communicating with a smartphone using its camera
Creators: name: Dudko, Uliana
name: Pflieger, Keno
name: Overmeyer, Ludger
Publisher: name: Bellingham, Wash. : SPIE
Year: 2019
Subjects: subject: Autonomous sensor module
subject: Energy harvesting
subject: Low-power
subject: Smartphone
subject: Visible light communication
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Wireless optical communication is a viable alternative to conventional RF technology. Our novel design combines optical communication and energy harvesting in one device with a size of 30 x 10 x 5 mm using the latest innovations in lowpower electronics and solar cell technology. In our study, we implement visible light communication between a sensor module and a smartphone. The proposed system design and a communication protocol are specifically developed for environments with illumination levels of 100-500 lux, like industrial halls. The sensor integrated into the module can vary according to application requirements. As an example, in our work, we use a temperature and pressure sensor and an accelerometer. A bright flash from a smartphones build-in LED activates the module. The module takes measurements and sends the result in form of an optical data signal, which is then received by the smartphone camera. This technique is able to provide reliable communication despite low-power restrictions of energy harvesting. By using a smartphone this approach offers more convenience to a user and enables flexible deployment of the modules in industrial machinery. © 2019 SPIE.
Attractors for Navier-Stokes flows with multivalued and nonmonotone subdifferential boundary conditions
Creators: name: Kalita, P.
name: Łukaszewicz, G.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We consider two-dimensional nonstationary Navier-Stokes shear flow with multivalued and nonmonotone boundary conditions on a part of the boundary of the flow domain. We prove the existence of global in time solutions of the considered problem which is governed by a partial differential inclusion with a multivalued term in the form of Clarke subdifferential. Then we prove the existence of a trajectory attractor and a weak global attractor for the associated multivalued semiflow. This research is motivated by control problems for fluid flows in domains with semipermeable walls and membranes.
description: A correction was introduced in assertion (ii) of Definition 4.4 and - accordingly - in the proof of Theorem 4.3
Testing the evolutionary pathways of galaxies and their supermassive black holes and the impact of feedback from Active Galactic Nuclei via large multiwavelength datasets
Creators: name: Mountrichas, George
name: Shankar, Francesco
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: It is still a matter of intense debate how supermassive black holes (SMBH) grow, and the role played by feedback from active galactic nuclei (AGN) in the co-evolution of SMBHs and galaxies. To test the coevolution proposed by theoretical models, we compile a large AGN sample of 5639 X-ray detected AGN, over a wide redshift range, spanning nearly three orders of magnitude in X-ray luminosity. The AGN have been detected in the {\it{COSMOS-Legacy}}, the Bo$\rm \ddot{o}$tes, the XMM-{\it{XXL}} and the eFEDS fields. Using the specific star formation rate estimates, we split the AGN host galaxies into star forming (SF), starburst (SB) and quiescent (Q). Our results show that the AGN accretion is increased in SB systems compared to SF and Q. Our analysis reveals a mild increase of L$_X$ with M$_*$. The L$_X$/SFR ratio has a weak dependence on M$_*$, and at fixed M$_*$ it is highest in Q systems. The latter trend is mostly driven by the significant drop in SFR in the Q state. The measured strong variations in SFR from the SB/SF to Q mirror those predicted in merger models with AGN feedback. However, the observed mild variations in L$_X$ are at variance with the same models. We also study the evolution of SFR for a galaxy control sample and found that it is very similar to that of X-ray AGN. This suggests that either AGN play a minor role in the star formation quenching, or the relative timescales of the two processes are different.
description: MNRAS, accepted, 15 pages, 12 Figures
Modeling of photoluminescence in laser-based lighting systems
Creators: name: Chatzizyrli, Elisavet
name: Tinne, Nadine
name: Lachmayer, Roland
name: Neumann, Jörg
name: Kracht, Dietmar
Publisher: name: Bellingham, Wash. : SPIE
Year: 2017
Subjects: subject: laser
subject: Lighting
subject: modeling
subject: photoluminescence
subject: remote phosphor systems
subject: temperature-dependent
subject: Climate change
subject: Efficiency
subject: Emission spectroscopy
subject: Energy efficiency
subject: Laser beams
subject: Lasers
subject: Light
subject: Light emission
subject: Light emitting diodes
subject: Light sources
subject: Lighting fixtures
subject: Models
subject: Molecular spectroscopy
subject: Phosphors
subject: Photoluminescence
subject: Ray tracing
subject: Temperature distribution
subject: Thermal conductivity
subject: Absorption and emission spectra
subject: Franck-Condon principle
subject: Illumination technology
subject: Low-power consumption
subject: Ray-tracing algorithm
subject: Remote phosphors
subject: Temperature dependence
subject: Temperature dependent
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: The development of laser-based lighting systems has been the latest step towards a revolution in illumination technology brought about by solid-state lighting. Laser-activated remote phosphor systems produce white light sources with significantly higher luminance than LEDs. The weak point of such systems is often considered to be the conversion element. The high-intensity exciting laser beam in combination with the limited thermal conductivity of ceramic phosphor materials leads to thermal quenching, the phenomenon in which the emission efficiency decreases as temperature rises. For this reason, the aim of the presented study is the modeling of remote phosphor systems in order to investigate their thermal limitations and to calculate the parameters for optimizing the efficiency of such systems. The common approach to simulate remote phosphor systems utilizes a combination of different tools such as ray tracing algorithms and wave optics tools for describing the incident and converted light, whereas the modeling of the conversion process itself, i.e. photoluminescence, in most cases is circumvented by using the absorption and emission spectra of the phosphor material. In this study, we describe the processes involved in luminescence quantum-mechanically using the single-configurational-coordinate diagram as well as the Franck-Condon principle and propose a simulation model that incorporates the temperature dependence of these processes. Following an increasing awareness of climate change and environmental issues, the development of ecologically friendly lighting systems featuring low power consumption and high luminous efficiency is imperative more than ever. The better understanding of laser-based lighting systems is an important step towards that aim as they may improve on LEDs in the near future. © 2017 SPIE.
title: Διερευνώντας αντιλήψεις, στάσεις και πρακτικές στις σχέσεις γονέων και εκπαιδευτικών στη σύγχρονη δημόσια πρωτοβάθμια εκπαίδευση στο νομό Λάρισας
titleType: AlternativeTitle
Creators: name: Αποστολός, Σταύρος
Publisher: name: University of Thessaly
Year: 2020
Subjects: Συνεργασία γονέων και εκπαιδευτικών
Εκπαιδευτικοί -- Επιμόρφωση
Οικογένεια και σχολείο
Συνεργασία γονέων και εκπαιδευτικών -- Κοινωνικές Απόψεις
Εκπαιδευτικοί -- Πρωτοβάθμια εκπαίδευση -- Απόψεις -- Ελλάδα -- Λάρισα

description: Σημείωση: διατίθεται συμπληρωματικό υλικό σε ξεχωριστό αρχείο.
Redshift drift cosmography with ELT and SKAO measurements
Creators: name: Rocha, B. A. R.
name: Martins, C. J. A. P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Mapping the expansion history of the universe is a compelling task of physical cosmology, especially in the context of the observational evidence for the recent acceleration of the universe, which demonstrates that canonical theories of cosmology and particle physics are incomplete and that there is new physics still to be discovered. Cosmography is a phenomenological approach to cosmology, where (with some caveats) physical quantities are expanded as a Taylor series in the cosmological redshift $z$, or analogous parameters such as the rescaled redshift $y=z/(1+z)$ or the logarithmic redshift $x=\ln{(1+z)}$. Moreover, the redshift drift of objects following cosmological expansion provides a model-independent observable, detectable by facilities currently under construction, {\it viz.} the Extremely Large Telescope and the Square Kilometre Array Observatory (at least in its full configuration). Here we use simulated redshift drift measurements from the two facilities to carry out an assessment of the cosmological impact and model discriminating power of redshift drift cosmography. We find that the combination of measurements from the two facilities can provide a stringent test of the $Λ$CDM paradigm, and that overall the logarithmic based expansions of the spectroscopic velocity drift are the most reliable ones, performing better than analogous expansions in the redshift or the rescaled redshift: the former nominally gives the smaller error bars for the cosmographic coefficients but is vulnerable to biases in the higher order terms (in other words, it is only reliable at low redshifts), while the latter always performs poorly.
description: 18 pages, 5 figures, 5 tables; in press at MNRAS
Manufacturing and characterization of asymmetric evanescent field polished couplers for grating assisted mode selective fiber coupling
Creators: name: Schlangen, Sebastian
name: Bremer, Kort
name: Zheng, Yulong
name: Isaak, Andreas
name: Wurz, Marc Christopher
name: Böhm, Sebastian
name: Wellmann, Felix
name: Steinke, Michael
name: Pelegrina Bonilla, Gabriel
name: Neumann, Jörg
name: Kracht, Dietmar
name: Roth, Bernhard
name: Overmeyer, Ludger
Publisher: name: Bellingham, Wash. : SPIE
Year: 2018
Subjects: subject: fiber grating
subject: mode division multiplexing
subject: mode selective fiber coupler
subject: polished fiber coupler
subject: space division multiplexing
subject: Bandwidth
subject: Cost effectiveness
subject: Manufacture
subject: Microstructure
subject: Optical fibers
subject: Space division multiple access
subject: Fiber couplers
subject: Fiber gratings
subject: Mode division multiplexing (MDM)
subject: Mode-division multiplexing
subject: Optical telecommunication
subject: Selective coupling
subject: Space division multiplexing
subject: Technological progress
subject: Evanescent fields
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik

description: Mode division multiplexing (MDM) could bring a technological progress in the field of optical telecommunication by increasing the data transmission bandwidth. A key challenge for enabling MDM lies in manufacturing of efficient and cost-effective mode-selective fiber couplers. The fiber grating based mode selective coupling approach is a method that is currently being under research in this context. In this work a novel process for manufacturing of asymmetric evanescent field polished couplers is presented which enables grating assisted mode selective coupling. In addition, we discuss the optical setup developed for characterization of these couplers.
title: Η συμβολή της επικοινωνίας στην αποτελεσματικότητα της ηγεσίας της σχολικής μονάδας
titleType: AlternativeTitle
Creators: name: Τριανταφύλλου, Κωνσταντίνος
Publisher: name: University of Thessaly
Year: 2020
Subjects: Εκπαίδευση -- Ηγεσία
Επικοινωνία
Επικοινωνία στην εκπαίδευση
Συνεργασία
Επικοινωνιακές δεξιότητες
Εκπαιδευτικοί -- Εκπαίδευση -- Ελλάδα

description: Σημείωση: διατίθεται συμπληρωματικό υλικό σε ξεχωριστό αρχείο.
Modular MPI Component Testing Facility
Creators: name: Aderhold, Eric
name: Graeser, Matthias
name: Wieprecht, Hannes
Publisher: name: International Journal on Magnetic Particle Imaging IJMPI
Year: 2023

description: The image quality of magnetic particle imaging depends on the interference-free measurement of the particle spectrum. Systematic errors due to harmonic distortions in the components used for implementation complicate the development of efficient imaging devices. To test the suitability of parts for the development of MPI scanners, a test bench was developed in which the components to be tested can be integrated, to evaluate their suitability using the measured spectrum. Different forms of connectors integrated into the high-current path were analyzed for their influence on the signal quality using this test bench. An evaluation of this components can be made from the clearly visibible distortions in the spectrum recorded with the high-sensitive test system.
description: International Journal on Magnetic Particle Imaging IJMPI, Vol 9 No 1 Suppl 1 (2023)
A new class of large claim size distributions: Definition, properties, and ruin theory
Creators: name: Beck, Sergej
name: Blath, Jochen
name: Scheutzow, Michael
Publisher: name: arXiv
Year: 2013
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: We investigate a new natural class $\mathcal{J}$ of probability distributions modeling large claim sizes, motivated by the `principle of one big jump'. Though significantly more general than the (sub-)class of subexponential distributions $\mathcal{S}$, many important and desirable structural properties can still be derived. We establish relations to many other important large claim distribution classes (such as $\mathcal{D}$, $\mathcal{S}$, $\mathcal{L}$, $\mathcal {K}$, $\mathcal{OS}$ and $\mathcal{OL}$), discuss the stability of $\mathcal{J}$ under tail-equivalence, convolution, convolution roots, random sums and mixture, and then apply these results to derive a partial analogue of the famous Pakes-Veraverbeke-Embrechts theorem from ruin theory for $\mathcal{J}$. Finally, we discuss the (weak) tail-equivalence of infinitely-divisible distributions in $\mathcal{J}$ with their Lévy measure.
description: Published at http://dx.doi.org/10.3150/14-BEJ651 in the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm)
title: Karl-Heinz Dietz, Wolfgang Czysz, Thomas Fischer & Hans-Jörg Kellner (Hrsg.): Die Römer in Bayern, 1995
Creators: name: Brandl, Ulrich
Publisher: name: University Library Heidelberg
Year: 2014

description: Rezension zu: Karl-Heinz Dietz, Wolfgang Czysz, Thomas Fischer & Hans-Jörg Kellner (Hrsg.): Die Römer in Bayern, 594 Seiten mit zahlreichen Farb- und Schwarzweißabbildungen, Karten und Plänen. Konrad Theiss Verlag. Stuttgart 1995, ISBN 3806210586
Recent progress on monolithic fiber amplifiers for next generation of gravitational wave detectors
Creators: name: Wellmann, Felix
name: Booker, Phillip
name: Hochheim, Sven
name: Theeg, Thomas
name: De Varona, Omar
name: Fittkau, Willy
name: Overmeyer, Ludger
name: Steinke, Michael
name: Weßels, Peter
name: Neumann, Jörg
name: Kracht, Dietmar
Publisher: name: Bellingham, Wash. : SPIE
Year: 2018
Subjects: subject: gravitational waves
subject: monolithic fiber amplifier
subject: single-frequency
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Single-frequency fiber amplifiers in MOPA configuration operating at 1064 nm (Yb3+) and around 1550 nm (Er3+ or Er3+:Yb3+) are promising candidates to fulfill the challenging requirements of laser sources of the next generation of interferometric gravitational wave detectors (GWDs). Most probably, the next generation of GWDs is going to operate not only at 1064 nm but also at 1550 nm to cover a broader range of frequencies in which gravitational waves are detectable. We developed an engineering fiber amplifier prototype at 1064 nm emitting 215 W of linearly-polarized light in the TEM00 mode. The system consists of three modules: the seed source, the pre-amplifier, and the main amplifier. The modular design ensures reliable long-term operation, decreases system complexity and simplifies repairing and maintenance procedures. It also allows for the future integration of upgraded fiber amplifier systems without excessive downtimes. We also developed and characterized a fiber amplifier prototype at around 1550 nm that emits 100 W of linearly-polarized light in the TEM00 mode. This prototype uses an Er3+:Yb3+ codoped fiber that is pumped off-resonant at 940 nm. The off-resonant pumping scheme improves the Yb3+-to-Er3+ energy transfer and prevents excessive generation of Yb3+-ASE.
Weak noise and non-hyperbolic unstable fixed points: Sharp estimates on transit and exit times
Creators: name: Giacomin, Giambattista
name: Merle, Mathieu
Publisher: name: arXiv
Year: 2013
Subjects: subject: Probability (math.PR)
subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics

description: We consider certain one dimensional ordinary stochastic differential equations driven by additive Brownian motion of variance $\varepsilon ^2$. When $\varepsilon =0$ such equations have an unstable non-hyperbolic fixed point and the drift near such a point has a power law behavior. For $\varepsilon >0$ small, the fixed point property disappears, but it is replaced by a random escape or transit time which diverges as $\varepsilon \searrow0$. We show that this random time, under suitable (easily guessed) rescaling, converges to a limit random variable that essentially depends only on the power exponent associated to the fixed point. Such random variables, or laws, have therefore a universal character and they arise of course in a variety of contexts. We then obtain quantitative sharp estimates, notably tail properties, on these universal laws.
description: Published at http://dx.doi.org/10.3150/14-BEJ643 in the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm)
Headlamp innovations: Optical concepts for fully adaptive light distributions
Creators: name: Knöchelmann, Marvin
name: Kloppenburg, Gerolf
name: Lachmayer, Roland
Publisher: name: Bellingham, Wash. : SPIE
Year: 2018
Subjects: subject: DMD
subject: Headlights
subject: High resolution headlamps
subject: Aspect ratio
subject: Efficiency
subject: Glare
subject: Optical systems
subject: Automotive applications
subject: High resolution
subject: Light distribution
subject: Optical efficiency
subject: Optical simulation
subject: Photometric measurements
subject: Pincushion distortion
subject: Resolution enhancement
subject: Adaptive optics
subject: Konferenzschrift
subject: Dewey Decimal Classification::600 | Technik::670 | Industrielle und handwerkliche Fertigung

description: Glare avoidance and marking lights are two of the many functionalities offered by advanced automotive headlamps such as Matrix-LED systems. DMD-based headlamps offer resolution enhancements to these two adaptive lighting functionalities. This is achieved via a precise optical system that exhibits high marking and glare avoidance efficiencies. This work evaluates two concepts for an optical system that enables fully adaptive light distributions. Light distributions from automotive headlamps are characterized by a wide aspect ratio and a centrally located hotspot marked by a high luminous intensity. Due to the popular use of DMDs in video projectors, DMD properties counter-productive to automotive applications are regularly encountered. For example, DMDs for projectors require to be illuminated homogeneously in order to obtain a homogeneous projection whereas headlamps require a hotspot centric distribution. It is possible to digitally create a hotspot with conventional projection optics but the results come with a significant loss in optical efficiency. The two concepts for an optical system compared in this paper are: anamorphic optics and optics with pincushion distortion. This comparison is conducted using optical simulations. Photometric measurements are then taken from a vehicle headlamp based DMD and distorting optics and compared with the simulation as a validation step. Due to the strong distortion of the lens system the relation between the DMD image and the final light distribution is highly non-linear. The paper is concluded with key observations with regards to this non-linearity.
title: Rainer-Maria Weiss: Prähistorische Brandopferplätze in Bayern, 1997
Creators: name: Riemer, Heiko
Publisher: name: University Library Heidelberg
Year: 2014

description: Rezension zu: Rainer-Maria Weiss: Prähistorische Brandopferplätze in Bayern. Internationale Archäologie, Band 35. Verlag Marie Leidorf. Espelkamp 1997. ISBN 3896463071, ISSN 0939561X. 211 S. u. 134 Tafeln
Magnetic particle spectroscopy for monitoring the cellular uptake of magnetic nanoparticles: Impact of the excitation field amplitude
Creators: name: Remmo, Amani
name: Löwa, Norbert
name: Ludwig, Antje
name: Wiekhorst, Frank
Publisher: name: International Journal on Magnetic Particle Imaging IJMPI
Year: 2023

description: Magnetic particle spectroscopy (MPS) is a sensitive method for the quantification of magnetic nanoparticles (MNP). MPS is based on the detection of nonlinear magnetic AC susceptibility and has been established as a rapid and straightforward method for tracer characterization. MPS is also excellent for monitoring the uptake of MNP by cells. The magnetic excitation fields of several millitesla used in MPS measurement raises the possibility of field-induced changes in the MNP sample (e.g., chain formation, aggregation, etc.). In this work, we aim to investigate the field-induced changes in monitoring the uptake of different MNP by THP-1 cells. By using different excitation field amplitudes and measurement scripts, the influence of dynamic magnetic fields on the MPS signal of MNP is investigated and recommendations for continuous MPS measurements of MNP in biological environment are given. We found that the excitation field amplitude and field exposure time can impact the uptake kinetics and influences the temporal resolution. In addition, high SNR can be achieved with a field strength of 12 mT, while at the same time reducing excitation field changes occurring at higher field strengths (such as 25 mT).
description: International Journal on Magnetic Particle Imaging IJMPI, Vol 9 No 1 Suppl 1 (2023)