cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Saxifraga purpurea L.
Creators: name: Becherer
Publisher: name: Zenodo
Year: 1956
Subjects: Biodiversity
Taxonomy

description: D. purpurea L. Cat. L. Als Gartenflüchtling und verschleppt. l: St-Maurice, Gartenflüchtling (d'Angreville,Fl. Vallais.,S. 97 [1863]); Les Marecottes, in einer Erdbeerpflanzung, seit 1949, aus Kultur verwildert (Wurgler); Bois d'Alesse ob Dorenaz, 1600 m, etwa15 Exemplare (Oberson 1948 und 1949), offenbar Neuansiedlung(vgl. Oberson Lit. 1951).
description: Published as part of Becherer, 1956, Florae Vallesiacae Supplementum, pp. 1-556 in Denkschriften der Schweizerischen Naturforschenden Gesellschaft 71 on pages 1-556
Studies on Noricumazole A derivatives and their HCV p7 inhibitory activity
Creators: name: Lekova, Dobromira
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2022
Subjects: subject: Noricumazole ion channel
subject: HCV p7
subject: ion channel
subject: Noricumazole
subject: Ionenkanal
subject: Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie

description: Noricumazoles A is a natural product isolated for the first time from myxobacterium Sorangium celluloum, So ce399. Noricumazole A has been found to have hepatitis C specific antiviral activity by directly effecting the virus life-cycle while maintaining low cytotoxicity towards the host cell ([IC50] = 8.6 nM, [CC50] = 12.8 nM). Furthermore, Noricumazole A has shown above average inhibitory activity of the voltage-sensitive sodium channel NaV1.7 as well as stabilizing and inhibitory effect on the pH and voltage-dependent potassium ion channel KcsA. In this work, different strategies towards new Noricumazole A derivatives have been investigated. Initially a convergent approach to synthesize a derivative that constitutes of all activity relevant structural elements has been followed. The envisioned structure contained a thiazole ring that has been observed to decrease cytotoxicity as well as the acylated hydroxyl groups at C3 and C11 that have shown to inhibit above average increase of activity. The key coupling step between the two final fragments has been unsuccessful due to the initial oxidation step of the western fragment that has given none-reproducible results. A different strategy towards structurally different Noricumazole derivative has also been pursued – a derivative lacking the hydroxilic group at C13. The convergent synthesis was directed towards two key fragments that would be brought together in an o-lithiation end-game reaction. Furthermore, an optical transport test was developed to study the effect of Noricumazole A derivatives on the viroporin HCV p7. For this purpose, the fluorescent dye PBFI was used as an optical potassium sensor of detecting the HCV p7 mediated potassium transport activity of potassium ions into the liposomes. The transport capacity was reconstituted with PBFI and purified HCV p7 ion channel in liposomes. This made it possible to observe the transport activity of HCV p7 as a function of time. The change in the fluorescence intensity is interpreted as transport activity and is generated by injecting a concentrated potassium chloride solution into the current kinetics. The absence of HCV p7 ion channels in the control liposomes generates little response to the potassium chloride injection, while the presence of HCV p7 shows a drastic increase in the fluorescence signal. In the presence of Noricumazole A, the transport activity is reduced depending on the concentration and results in a dose-response dependence of an IC50 of 4 µM.
TMD evolution of the Sivers asymmetry
Creators: name: Boer, Daniel
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The energy scale dependence of the Sivers asymmetry in semi-inclusive deep inelastic scattering is studied numerically within the framework of TMD factorization that was put forward in 2011. The comparison to previous results in the literature shows that the treatment of next-to-leading logarithmic effects is important for the fall-off of the Sivers asymmetry with energy in the measurable regime. The TMD factorization based approach indicates that the peak of the Sivers asymmetry falls off with energy scale Q to good approximation as 1/Q^{0.7}, somewhat faster than found previously based on the first TMD factorization expressions by Collins and Soper in 1981. It is found that the peak of the asymmetry moves rather slowly towards higher transverse momentum values as $Q$ increases, which may be due to the absence of perturbative tails of the TMDs in the presented treatments. We conclude that the behavior of the peak of the asymmetry as a function of energy {\it and} transverse momentum allows for valuable tests of the TMD formalism and the considered approximations. To confront the TMD approach with experiment, high energy experimental data from an Electron-Ion Collider is required.
description: 10 pages, 5 figures
Improving Resolution and Run Outs of a Superconducting Noncontact Device for Precision Positioning
Creators: name: Valiente-Blanco, I.
name: Diez-Jimenez, E.
name: Sanchez-Garcia-Casarrubios, J.
name: Perez-Diaz, J. L.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: This paper describes the improvement of the performance of a long-stroke high-precision positioning slider suitable for cryogenic environments due to the application of a set of design rules given in a previous paper. The device, based on superconducting magnetic levitation, is self-stable and does notmake contact between the slider and the guideline, avoiding tribological and lubrication problems associated with cryogenics.
description: accepted paper after embargo period
Continued fraction analysis of dressed systems: application to periodically driven optical lattices
Creators: name: Zanon-Willette, Thomas
name: de Clercq, Emeric
name: Arimondo, Ennio
Publisher: name: arXiv
Year: 2013
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: Radio-frequency quantum engineering of spins is based on the dressing by a non resonant electromagnetic field. Radio-frequency dressing occurs also for the motion of particles, electrons or ultracold atoms, within a periodic spatial potential. The dressing, producing a renormalisation and also a freeze of the system energy, is described by different approaches, dressed atom, magnetic resonance semiclassical treatment, continued fraction solution of the Schrödinger equation. A comparison between those solutions points out that the semiclassical treatment, to be denoted as the $S$-solution, represents the most convenient tool to evaluate the tunneling renormalization of ultracold atoms.
Qualitätssicherung in der additiven Metallfertigung durch hyperspektrale Bildgebung und maschinelles Lernen
Creators: name: Gerdes, Niklas
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2022
Subjects: subject: Metal additive manufacturing
subject: Laser Powder Bed Fusion
subject: Process monitoring
subject: Machine learning
subject: Hyperspectral imaging
subject: Additive Metallfertigung
subject: Prozessüberwachung
subject: Maschinelles Lernen
subject: Hyperspektrale Bildgebung
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: Die additive Metallfertigung ist durch Vorteile wie Geometriefreiheit, werkzeuglose Fertigung ”on-demand“ sowie hohen Bauteilfestigkeiten eine Schlüsseltechnologie zur dezentralen, digitalisierten Fertigung. Eine breite industrielle Nutzung dieser Technologie wird bislang aber durch mangelnde Zuverlässigkeit und Reproduzierbarkeit eingeschränkt. In dieser Arbeit wird deshalb der Einsatz einer Flächen-Hyperspektralkamera zur Prozessüberwachung beim laserbasierten Pulverbettverfahren untersucht. Dazu wird die Funktionsweise der hyperspektralen Bildgebung analysiert und die spektrale Auflösungsfähigkeit der Sensorik charakterisiert. Die Kamera wird in die Fertigungsanlage integriert, sodass Prozessaufnahmen bei der Verarbeitung der Magnesium-Legierung WE43 erhoben werden können. Zur Auswertung der Daten werden Methoden des maschinellen Lernens, insbesondere Convolutional Neural Networks, verwendet, die mit den Prozessaufnahmen trainiert werden. So kann die Oberflächenrauheit Rz, die im Probensatz mit einer mittleren absoluten Abweichung von 14,3 μm schwankt, mit einem mittleren absoluten Fehler von 4,1 μm vorhergesagt werden. Durch die Entwicklung eines Akquise-Systems können Prozessaufnahmen mit der Position des Laserspots im Pulverbett sowie weiteren Maschinendaten verknüpft werden. Dadurch können durch Eisenspäne künstlich erzeugte Prozessfehler mit einem F-Maß von 91% erkannt werden.
Agreement on the Transfer of Materials via the Compound Platform (ComPlat)
Creators: name: Karlsruhe Institute Of Technology, Legal Affairs Unit
Publisher: name: Karlsruhe Institute of Technology
Year: 2023
Subjects: legal matters
Material Transfer Agreement
Compound Platform
ComPlat
Open Science
FAIR Research Data

description: This document contains an agreement between Karlsruhe Institute of Technology (KIT) and a partner institution regarding the transfer of chemical compounds through the Compound Platform (ComPlat). ComPlat is a non-commercial facility at KIT that focuses on the synthesis, collection, and reuse of chemical compounds. The agreement allows KIT scientists and external researchers to use the materials for non-commercial research purposes, following safety and storage guidelines. It defines the transfer process, material usage, and publication of results. The agreement serves as a contractual framework to regulate collaboration between the PROVIDER and KIT through ComPlat. It includes as an attachment the template under which Partner Institutions may order Compounds at KIT ComPlat.
The protoplanetary disks in the nearby massive star forming region Cygnus OB2
Creators: name: Guarcello, M. G.
name: Drake, J. J.
name: Wright, N. J.
name: Drew, J. E.
name: Gutermuth, R. A.
name: Hora, J. L.
name: Naylor, T.
name: Aldcroft, T.
name: Fruscione, A.
name: Garcia-Alvarez, D.
name: Kashyap, V. L.
name: King, R.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The formation of stars in massive clusters is one of the main modes of the star formation process. However, the study of massive star forming regions is hampered by their typically large distances to the Sun. One exception to this is the massive star forming region Cygnus OB2 in the Cygnus X region, at the distance of about 1400 pc. Cygnus OB2 hosts very rich populations of massive and low-mass stars, being the best target in our Galaxy to study the formation of stars, circumstellar disks, and planets in presence of massive stars. In this paper we combine a wide and deep set of photometric data, from the r band to 24 micron, in order to select the disk bearing population of stars in Cygnus OB2 and identify the class I, class II, and stars with transition and pre-transition disks. We selected 1843 sources with infrared excesses in an area of 1 degree x 1 degree centered on Cyg OB2 in several evolutionary stages: 8.4% class I, 13.1% flat-spectrum sources, 72.9% class II, 2.3% pre-transition disks, and 3.3% transition disks. The spatial distribution of these sources shows a central cluster surrounded by a annular overdensity and some clumps of recent star formation in the outer region. Several candidate subclusters are identified, both along the overdensity and in the rest of the association.
description: Accepted by ApJ
Simulating human behaviour in social-ecological systems: farmers’ adoption of agricultural innovations
Creators: name: Noeldeke, Beatrice Christa Eleonore
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2022
Subjects: subject: Agricultural Innovations
subject: Agroforestry
subject: Innovation Adoption
subject: Decision-making
subject: Agent-based Modelling
subject: Landwirtschaftliche Innovationen
subject: Agroforstsysteme
subject: Adoption von Innovationen
subject: Entscheidungsfindung
subject: Agentenbasierte Modellierung
subject: Dewey Decimal Classification::300 | Sozialwissenschaften, Soziologie, Anthropologie::330 | Wirtschaft

description: The agricultural sector faces major challenges to produce sufficient food for the world’s rising population. Addressing these challenges requires a transformation towards sustainable agriculture. Although sustainable agricultural practices such as agroforestry provide various benefits, small-scale farmers’ uptake of such practices can be very low in certain regions. Consequently, interventions are required that support farmers’ implementation and raise low adoption rates. Small-scale farmers’ adoption of sustainable agricultural practices and the underlying decision-processes constitute the core of this thesis. Overall, the thesis aims to support policy-makers in developing and implementing effective measures that encourage farmers to adopt innovative sustainable practices. The specific objectives are (1) to identify efficient information seeding strategies to disseminate agricultural knowledge within social networks, (2) compare common behavioural approaches to explain farmers’ adoption decisions, (3) identify intrinsic drivers based on the Theory of Planned Behaviour and evaluate the effectiveness of non-economic policy interventions targeting intrinsic motivational factors, and (4) assess the interrelated human-environmental consequences of farmers’ adoption decisions under different climate scenarios.
Disentangling the entangled: Observations and analysis of the triple non-coeval protostellar system VLA1623
Creators: name: Murillo, Nadia M.
name: Lai, Shih-Ping
Publisher: name: arXiv
Year: 2013
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Commonplace at every evolutionary stage, Multiple Protostellar Systems (MPSs) are thought to be formed through fragmentation, but it is unclear when and how. The youngest MPSs, which have not yet undergone much evolution, provide important constraints to this question. It is then of interest to disentangle early stage MPSs. In this letter we present the results of our work on VLA1623 using our observations and archival data from the Submillimeter Array (SMA). Our continuum and line observations trace VLA1623's components, outflow and envelope, revealing unexpected characteristics. We construct the SED for each component using the results of our work and data from literature, as well as derive physical parameters from continuum and perform a simple kinematical analysis of the circumstellar material. Our results show VLA1623 to be a triple non-coeval system composed of VLA1623A, B & W, with each source driving its own outflow and unevenly distributed circumstellar material. From the SED, physical parameters and IR emission we conclude that VLA1623A & W are Class 0 and I protostars, respectively, and together drive the bulk of the observed outflow. Furthermore, we find two surprising results, first the presence of a rotating disk-like structure about VLA1623A with indications of pure Keplerian rotation, which, if real, would make it one of the first evidence of Keplerian disk structures around Class 0 protostars. Second, we find VLA1623B to be a bonafide extremely young protostellar object between the starless core and Class 0 stages.
description: 22 pages, 4 figures, 1 Table, Accepted to ApJ
Dynamics of a Superconducting Linear Slider
Creators: name: Valiente-Blanco, I.
name: Perez-Diaz, J. L.
name: Diez-Jimenez, E.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: In this paper, the dynamic behavior of a one degree-of-freedom (DOF) contactless linear slider based on superconducting magnetic levitation is experimentally analyzed. The device is intended for precision positioning of an optic mirror in cryogenic environments. Different prototypes of this device have been tested at cryogenic temperatures (77 K), and their mechanical behavior characterized in the sliding direction for forced and unforced oscillations. Experimental results reveal that the slider is self-stable at the initial equilibrium position and the dynamic behavior fits well an underdamped harmonic oscillator. Finally, the device showed great potential for horizontal vibration isolation, acting as a low-pass filter with a resonance at about 0.9 Hz
description: accepted paper after embargo period
Terahertz conductivity of twisted bilayer graphene
Creators: name: Zou, Xingquan
name: Shang, Jingzhi
name: Leaw, Jianing
name: Luo, Zhiqiang
name: Luo, Liyan
name: La-o-vorakiat, Chan
name: Cheng, Liang
name: Su, Haibin
name: Zhu, Jian-Xin
name: Liu, Yanpeng
name: Loh, Kian Ping
name: Neto, A. H. Castro
name: Yu, Ting
name: Chia, Elbert E. M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Using terahertz time-domain spectroscopy, the real part of optical conductivity [$σ_{1}(ω)$] of twisted bilayer graphene was obtained at different temperatures (10 -- 300 K) in the frequency range 0.3 -- 3 THz. On top of a Drude-like response, we see a strong peak in $σ_{1} (ω)$ at $\sim$2.7 THz. We analyze the overall Drude-like response using a disorder-dependent (unitary scattering) model, then attribute the peak at 2.7 THz to an enhanced density of states at that energy, that is caused by the presence of a van Hove singularity arising from a commensurate twisting of the two graphene layers.
description: 4 figures, 5 pages
Potamogeton alpinus L.
Creators: name: Becherer
Publisher: name: Zenodo
Year: 1956
Subjects: Biodiversity
Taxonomy

description: E. alpinus L. Cat. 275 und 429. Herabsteigend bis etwa 380 m: zwischen St-Gingolph und Bouveret (Mantz). 3: Visperterminen-Gebüdem (Beauverd).
description: Published as part of Becherer, 1956, Florae Vallesiacae Supplementum, pp. 1-556 in Denkschriften der Schweizerischen Naturforschenden Gesellschaft 71 on pages 1-556
Untersuchung der Speziation und des Transferverhaltens von 99-Tc im System Boden–Pflanze
Creators: name: Mandel, Marcus
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2022
Subjects: subject: repository
subject: technetium-99
subject: transfer behaviour
subject: Endlagerung
subject: Technetium-99
subject: Transferverhalten
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: Um ein sicheres Endlager für radioaktive Abfälle gewährleisten zu können, sind Langzeitsicherheitsanalysen erforderlich. Hierfür ist eine genaue Kenntnis über das Umweltverhalten der relevanten Radionuklide nötig. Eines davon ist Technetium-99, welches als Spaltprodukt aus dem Kernbrennstoff hervorgeht und eine 211.000 Jahre lange Halbwertszeit besitzt. Aus der Literatur ist bekannt, dass Tc-99 unter gewissen Bedingungen eine sehr hohe Bioverfügbarkeit besitzt. Daher wurde in dieser Arbeit ein möglichst breites Spektrum des Umweltverhaltens von Tc-99 an vier eigens ausgewählten Referenzböden, welche verschiedene klimatische Entwicklungen widerspiegeln, untersucht. Hierfür wurden zunächst das Sorptions- und Migrationsverhalten von Tc-99 durch Batch- und Säulenexperimente untersucht. Es zeigte sich erwartungsgemäß, dass Tc-99 äußerst geringe Kd - Werte aufweist, was auf eine sehr geringe Sorption hindeutet. Lediglich für RefeSol 03G, einen tonhaltigen Boden mit hohem Anteil an organischer Substanz, konnten erhöhte Kd - Werte gefunden werden. Dieses Verhalten bestätigte sich durch Säulenexperimente, in denen die größten Sorptionseffekte ebenfalls für RefeSol 03G gefunden wurden. Bei der Langzeituntersuchung des Migrationsverhaltens von Tc-99 im RefeSol 01A im Rahmen von Lysimeterexperimenten konnte gezeigt werden, dass es eine starke Migration durch alle Schichten des Lysimeters gab. Jedoch wurde auch deutlich, vor allem durch Modellierungen mittels PhreeqC, dass die Sorptionseigenschaften von der chemischen Spezies abhängig sind, welche wiederum von den vorherrschenden Umgebungseigenschaften dominiert werden. Neben dem Sorptions- und Migrationsverhalten im Boden wurden ebenfalls die Aufnahme und der Transport innerhalb verschiedener Nutzpflanzen untersucht. In Experimenten zur Bestimmung des Transferfaktors wurde deutlich, dass Tc-99 vor allem in die Blätter transportiert wird. Bei der Untersuchung der zeitlichen Aufnahme zeigte sich, dass bereits wenige Stunden nach der Zugabe von Tc-99 ein deutlicher Anstieg der Tc-99 - Konzentration in den essbaren Anteilen und Blättern messbar war und die Aufnahme somit sehr schnell erfolgen muss. Um diesen Effekt genauer zu untersuchen, wurden die Pflanzen mittels eines Kryotoms in dünne Querschnitte aufgeteilt und mittels SIMS und rL - SNMS untersucht. Dabei zeigte sich, dass Tc-99 vor allem im Bereich der Transportsysteme der Pflanzen wiedergefunden wird. Außerdem konnte Tc-99 im Inneren einer einzelnen Epidermiszelle nachgewiesen werden, wodurch bewiesen werden konnte, dass es einen aktiven Transport von Tc-99 innerhalb der Pflanze geben muss.
Explaining two circumnuclear star forming rings in NGC5248
Creators: name: van der Laan, T. P. R.
name: Schinnerer, E.
name: Emsellem, E.
name: Meidt, S.
name: Dumas, G.
name: Boeker, T.
name: Hunt, L.
name: Haan, S.
name: Mundell, C.
name: Wozniak, H.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The distribution of gas in the central kiloparsec of a galaxy has a dynamically rapid evolution. Nonaxisymmetries in the gravitational potential of the galactic disk, such as a large scale stellar bar or spiral, can lead to significant radial motion of gaseous material from larger radii to the central region. The large influx of gas and the subsequent star formation keep the central region constantly changing. However, the ability of gas to reach the nucleus proper to fuel an AGN phase is not guaranteed. Gas inflow can be halted at a circumnuclear star forming ring several hundred parsec away. The nearby galaxy NGC5248 is especially interesting in this sense since it is said to host 2 circumnuclear star forming rings at 100pc and 370pc from its quiescent nucleus. Here we present new subarcsecond PdBI+30m CO(2-1) emission line observations of the central region. For the first time the molecular gas distribution at the smallest stellar ring is resolved into a gas ring, consistent with the presence of a quiescent nucleus. However, the molecular gas shows no ring structure at the larger ring. We combine analyses of the gaseous and stellar content in the central kiloparsec of this galaxy to understand the gas distribution and dynamics of this star forming central region. We discuss the probability of two scenarios leading to the current observations, given our full understanding of this system, and discuss whether there are really two circumnuclear star forming rings in this galaxy.
description: Accepted for publication in A&A, 14pages + long table
Advanced shape, composition, and property control in colloidal nanocrystal synthesis
Creators: name: Dorfs, Dirk
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2018
Subjects: subject: nanoparticles
subject: semiconductors
subject: metals
subject: plasmons
subject: shape control
subject: Nanopartikel
subject: Halbleiter
subject: Metalle
subject: Plasmonen
subject: Formkontrolle
subject: Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie

description: This thesis summarizes the results of 20 original publications which are covering three closely connected aspects of modern colloidal nanochemistry. The chapters included are described in the following: Chapter one gives an overview over the colloidal synthesis of nanocrystals as well as their main properties which are relevant for this thesis. Hence, important synthesis and growth parameters are discussed. The size quantization effect in semiconducting nanoparticles and the localized surface plasmon resonance effect in conductive nanoparticles are explained in depth. Chapter two of this thesis deals with different aspects of shape control of colloidal nanoparticles. The advanced shape control developed in the various original publications in chapter two shows how far beyond simple (quasi)spherical nanoparticles colloid chemical synthesis can go today. A variety of differently shaped nanoparticles like rods, branched structures but also partially hollow or concave nanoparticles are introduced. All of them could be synthesized with very low degrees of polydispersity of the particle ensembles Chapter three investigates cation exchange reactions with colloidal nanocrystals which are versatile approaches for composition control in these systems. These ion exchange reactions can either fully or also partially transform nanocrystals from one material to another without changing size or shape of the starting particles. Chapter four deals with property control in colloidal nanocrystals with a specific focus on nanoparticles with localized surface plasmon resonances in the near infrared spectral region. Here, nanoparticles from so-called degenerately doped materials are introduced as plasmonic materials which are a promising alternative for the traditional plasmonic noble metal nanoparticles. The thesis is finished by a conclusion and an outlook at future perspectives of colloid chemical nanoparticle synthesis.
Coherent acoustic phonons emission in copper driven by super-diffusive hot electrons
Creators: name: Lejman, M.
name: Shalagatsky, V.
name: Kovalenko, A.
name: Pezeril, T.
name: Temnov, V. V.
name: Ruello, P.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Ultrafast laser excited hot electrons can transport energy supersonically far from the region where they are initially produced. We show that this ultrafast energy transport is responsible of the emission of coherent acoustic phonons deeply beneath the free surface of a copper metal sample. In particular we demonstrate that enough energy carried by these hot electrons over a distance as large as 220nm at room temperature in copper can be converted into coherent acoustic phonons. In order to demonstrate this effect, several configurations of time-resolved optical experiments of time of flight of coherent acoustic phonons and of hot electrons have been performed.
description: 8 pages, 4 figures
The dust environment of Main-Belt Comet P/2012 T1 (PANSTARRS)
Creators: name: Moreno, Fernando
name: Cabrera-Lavers, Antonio
name: Vaduvescu, Ovidiu
name: Licandro, Javier
name: Pozuelos, Francisco
Publisher: name: arXiv
Year: 2013
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Main-Belt Comet P/2012 T1 (PANSTARRS) has been imaged using the 10.4m Gran Telescopio Canarias (GTC) and the 4.2m William Herschel Telescope (WHT) at six epochs in the period from November 2012 to February 2013, with the aim of monitoring its dust environment. The dust tails brightness and morphology are best interpreted in terms of a model of sustained dust emission spanning 4 to 6 months. The total dust mass ejected is estimated at $\sim$6--25$\times10^6$ kg. We assume a time-independent power-law size distribution function, with particles in the micrometer to centimeter size range. Based on the quality of the fits to the isophote fields, an anisotropic emission pattern is favored against an isotropic one, in which the particle ejection is concentrated toward high latitudes ($\pm45^\circ$ to $\pm90^\circ$) in a high obliquity object ($I$=80$^\circ$). This seasonally-driven ejection behavior, along with the modeled particle ejection velocities, are in remarkable agreement to those we found for P/2010 R2 (La Sagra) \citep{Moreno11a}.
description: Accepted for publication in The Astrophysical Journal Letters
Kohärente und dissipative Präparation von Quantenzuständen
Creators: name: Weimer, Hendrik
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2018
Subjects: subject: quantum optics
subject: open quantum systems
subject: many-body physics
subject: quantum information
subject: quantum physics
subject: Quantenphysik
subject: Quantenoptik
subject: Offene Quantensysteme
subject: Vielteilchenphysik
subject: Quanteninformation
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: In den letzten Jahren wurden bei der Kontrolle von Quantenzuständen einzelner Atome, Moleküle und Spins in Festkörpern bahnbrechende Erfolge erzielt, und sogar quantenmechanische Verschränkung zwischen einzelnen Quantenobjekten beobachtet. Für eine Nutzbarmachung in Quantentechnologien, wie Quantensimulation oder Quantencomputing ist die Skalierung auf größere Teilchenzahlen die zentrale Herausforderung. Dabei stellen zu einer Dekohährenz des Quantenzustands führende Kopplungen an die Umgebung die größte Schwierigkeit dar. Die vorliegende Habilitationschrift umfasst wissenschaftliche Arbeiten, welche diese ungelösten Probleme auf zwei Arten adressieren. Zum einen werden neue Wege vorgestellt, wie sich durch die kohärente Kontrolle von Vielteilchensystemen der Einfluss von Dekohärenzprozessen mindern lässt. Zum anderen wird, wie sich kontrollierte Dissipationskanäle ausnutzen lassen, um Vielteilchenzustände mit maßgeschneiderten Eigenschaften zu erzeugen.
Meisterwerke des 17. bis 19. Jahrhunderts in den Sammlungen des Stiftes Einsiedeln
Creators: name: Euw, Anton Von
Publisher: name: Aachener Kunstblätter
Year: 2017

description: -
description: Aachener Kunstblätter, Bd. 39 (1969): Aachener Kunstlbätter
Towards post-quantum blockchain: A review on blockchain cryptography resistant to quantum computing attacks
Creators: name: Fernandez-Carames, Tiago M.
name: Fraga-Lamas, Paula
Publisher: name: arXiv
Year: 2024
Subjects: subject: Cryptography and Security (cs.CR)
subject: Quantum Physics (quant-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Blockchain and other Distributed Ledger Technologies (DLTs) have evolved significantly in the last years and their use has been suggested for numerous applications due to their ability to provide transparency, redundancy and accountability. In the case of blockchain, such characteristics are provided through public-key cryptography and hash functions. However, the fast progress of quantum computing has opened the possibility of performing attacks based on Grover's and Shor's algorithms in the near future. Such algorithms threaten both public-key cryptography and hash functions, forcing to redesign blockchains to make use of cryptosystems that withstand quantum attacks, thus creating which are known as post-quantum, quantum-proof, quantum-safe or quantum-resistant cryptosystems. For such a purpose, this article first studies current state of the art on post-quantum cryptosystems and how they can be applied to blockchains and DLTs. Moreover, the most relevant post-quantum blockchain systems are studied, as well as their main challenges. Furthermore, extensive comparisons are provided on the characteristics and performance of the most promising post-quantum public-key encryption and digital signature schemes for blockchains. Thus, this article seeks to provide a broad view and useful guidelines on post-quantum blockchain security to future blockchain researchers and developers.
description: Accepted version of an IEEE Access journal paper
Maxillary Sinus
Creators: name: Valenzuela-Fuenzalida, Juan José
name: Orellana, Mathias
Publisher: name: Open Science Framework
Year: 2023
Subjects: subject: Medicine and Health Sciences
subject: Anatomical variations
subject: Maxillary sinus
subject: Anomalies
subject: Sinusitis
subject: Clinical Anatomy
subject: Paranasal Sinus

description: Objective: The objective of this review is to investigate and analyze the anatomical variations present in the MS, through the examination of the prevalence of these variations, as well as the corresponding prevalence of clinically significant pathologies and complications associated with them. Methods The search process was carried out in the following databases; MEDLINE, SCIELO, WOS, CINHAL, SCOPUS, and GOOGLE SCHOLAR, using as search terms; "Maxillary bone", "Maxillary sinus", "Paranasal sinus", "Anatomical variations", "Sinusitis" and "Clinical anatomy". Results A total of 26 articles and 12969 samples were included, from which 12594 subjects had their sex recorded giving a total of 5802 males and 6792 females. The variants reported by the included were Haller cells, Concha Bullosa, Number of septa, Hypoplastic sinus, Agger Nasi, 3 Thickening of the MS mucosa, Deviation of the nasal septum, Accessory ostium, and Onodi cells. Among the mentioned, the ones that presented the greatest number of studies (between eight and ten studies included) were: the Haller Cells, the Concha Bullosa, and the Number of septa, where prevalence was 0. 30, 0.36, 0.39 respectively. These variations can lead to sinusitis, cause some types of tumors, or affect neighboring structures that could be compromised by this variation. Conclusion As a result, it is certainly complex to distinguish the presence of anatomical variations from pathological abnormalities. Therefore, knowledge of the different variations and their clinical relationships could be a useful asset for clinicians dedicated to this region.
Equisetum arvense L.
Creators: name: Becherer
Publisher: name: Zenodo
Year: 1956
Subjects: Biodiversity
Taxonomy

description: M. arvense L. Cat. 279. Ssp. arvense (L.) Ronniger (ssp. eu-arvense Beauverd) -2: Ardon-Aven (Oberson); Montorge bei Sitten (Wolf u. a.); Siders (Wolf); Raron-Mund (Stehler). - 3: Salins (Wolf); Brig (idem).
description: Published as part of Becherer, 1956, Florae Vallesiacae Supplementum, pp. 1-556 in Denkschriften der Schweizerischen Naturforschenden Gesellschaft 71 on pages 1-556
Stellar population properties for a sample of hard X-ray AGNs
Creators: name: Morelli, L.
name: Calvi, V.
name: Masetti, N.
name: Parisi, P.
name: Landi, R.
name: Maiorano, E.
name: Minniti, D.
name: Galaz, G.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The aim of this paper is to study the stellar population of galaxies hosting an active galactic nucleus (AGN). We studied a sub-sample of hard X-ray emitting AGNs from the INTEGRAL and Swift catalogs which were previously identified and characterized through optical spectroscopy. Our analysis provides complementary information, namely age and metallicity, which is necessary to complete the panoramic view of such interesting objects. We selected hard X-ray emitting objects identified as AGNs by checking their optical spectra in search for absorption lines suitable for the stellar population analysis. We obtained a final sample consisting of 20 objects with redshift lower than 0.3. We used the full-spectrum fitting method and, in particular, the penalized pixel one applying the PPXF code. After masking all the regions affected by emission lines, we fitted the spectra with the MILES single stellar population templates and we derived mass-weighted ages and metallicities. Most of the objects in our sample show an old stellar population, but three of them are characterized by a bimodal distribution with a non negligible contribution from young stars. The values of the mass-weighted metallicity span a large range of metallicity with most of them slightly above the solar value. No relations between the stellar population properties and the morphological ones have been found.
description: 10 pages, 8 postscript figures and 3 tables. A&A in press
Existence and qualitative aspects of geophysical water waves
Creators: name: Matioc, Anca-Voichita
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2018
Subjects: subject: äquatoriale geophysikalische Wasserströmungen
subject: Coriolis Effekte
subject: nicht-lineare Kapillar-Gravitationswellen
subject: Dewey Decimal Classification::500 | Naturwissenschaften::510 | Mathematik

description: The object of geophysical fluid dynamics is the study of naturally occurring flows on the Earth. Most of the problems that arise are at the large-scale end, where either the rotation of the Earth or density differences (warm and cold air masses, fresh and saline waters) or both are of importance. In this regard, geophysical fluid dynamics comprises rotating-stratified fluid flows. This thesis consists of eleven research papers which are grouped into two parts. The first part is dedicated to the study of nonlinear capillary-gravity water waves traveling at the surface of rotational flows with rough vorticities or of flows with a vertical layering (continuous resp. discontinuous) of density, the emphasis being on developing a rigorous existence theory. The papers collected in the second part of the thesis investigate the existence and the qualitative properties of equatorial geophysical water flows with Coriolis effects in the so-called f-plane approximation. In this part we also present several explicit solutions describing equatorial water flows in the f-plane approximation in different geophysical scenarios −deep-water waves, edge waves, stratified flows− and we analyze their properties.
Domain-wall-controlled transverse spin injection
Creators: name: van der Bijl, E.
name: Troncoso, R. E.
name: Duine, R. A.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose an effect whereby an electric current along the interface between a ferromagnetic and normal metal leads to injection of pure spin current into the normal metal, if the magnetization-direction in the ferromagnet varies along the direction of current. For the specific example of a ferromagnetic domain wall, we compute the inverse spin-Hall effect voltage this spin current gives rise to when injected into a Pt layer. Furthermore, we show that this pure spin current leads to modification of the parameters that govern spin transfer and current-driven domain-wall motion, which can be use to optimize the latter in layered magnetic systems. This effect in principle enables control over the location of spin-current injection in devices.
Dispersive Hydrodynamics in Viscous Fluid Conduits
Creators: name: Lowman, Nicholas K.
name: Hoefer, Mark A.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: The evolution of the interface separating a conduit of light, viscous fluid rising buoyantly through a heavy, more viscous, exterior fluid at small Reynolds numbers is governed by the interplay between nonlinearity and dispersion. Previous authors have proposed an approximate model equation based on physical arguments, but a precise theoretical treatment for this two fluid system with a free boundary is lacking. Here, a derivation of the interfacial equation via a multiple scales, perturbation technique is presented. Perturbations about a state of vertically uniform, laminar conduit flow are considered in the context of the Navier-Stokes equations with appropriate boundary conditions. The ratio of interior to exterior viscosities is the small parameter used in the asymptotic analysis, which leads systematically to a maximal balance between buoyancy driven, nonlinear self-steepening and viscous, interfacial stress induced, nonlinear dispersion. This results in a scalar, nonlinear partial differential equation describing large amplitude dynamics of the cross-sectional area of the intrusive fluid conduit, in agreement with previous derivations. The leading order behavior of the two fluid system is completely characterized in terms of the interfacial dynamics. The regime of model validity is characterized and shown to agree with previous experimental studies. Viscous fluid conduits provide a robust setting for the study of nonlinear, dispersive wave phenomena.
description: 10 pages, 1 figure
Code and input files for "The effect of Magma Poor and Magma Rich rifted margins on Continental Collision Dynamics"
Creators: name: Turino, Valeria
name: Magni, Valentina
name: Kjøll, Hans Jørgen
name: Jakob, Johannes
Publisher: name: Zenodo
Year: 2023

description: Modified version of CitCom (Moresi & Solomatov, 1995; Zhong et al., 2000) and input files for all the models presented in the study.
Structural, magnetic, and nanoscale switching properties of BiFeO3 thin films grown by pulsed electron deposition
Creators: name: Liu, Hongxue
name: Comes, Ryan
name: Pei, Yonghang
name: Lu, Jiwei
name: Wolf, Stuart
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report the epitaxial growth of BiFeO3 by pulsed electron deposition and the resulting crystal quality, magnetic and nanoscale switching properties. X-ray diffraction shows high quality single phase, epitaxial (001) oriented films grown on SrTiO3 (001) substrates. Both field and temperature dependent magnetic properties reveal an antiferromagnetic behavior of the films. For the film with a SrRuO3 bottom electrode, an exchange-enhancement effect between antiferromagnetic BiFeO3 and ferromagnetic SrRuO3 was observed at low temperature. The piezoelectric force microscopy and switching spectroscopy measurements demonstrate the local domain switching process and suggest that the BiFeO3 films are high quality ferroelectrics.
description: submitted to J. Vac. Sci. Technol. B
Light-matter interaction on the few- and sub-cycle timescale
Creators: name: Babushkin, Ihar
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2018
Subjects: subject: strong light-matter interaction
subject: ultrashort pulses
subject: solitons
subject: Ultrakurze Pulse
subject: Ionization
subject: Solitonen
subject: Starke Licht-Materie Wechselwirkung
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: One of the main challenges in modern optics is to explore shorter times scales as well as to extend the frequency range to higher but also to lower frequencies. Last years, the time scales available have been shifted to the attosecond range — well below one femtosecond. The critical ingredient of this progress is the creation of strong few-, single- and even sub-cycle pulses. At the same time, the frequency range where few-cycle pulse generation is possible, quickly increases. In this work the author considers methods for generation of ultrashort few- and sub-cycle pulses in very different frequency ranges, from terahertz (THz) to vacuum ultraviolet (VUV) and for the possibilities to use these generated pulses to test the dynamics of light-matter interaction. In the case of ionization, new frequencies, so called Brunel harmonics, appear, providing a novel tool both as a source of short pulse in THz range, but also as a meter allowing to investigate the processes taking place inside ionization events. Contribution in both of these directions has been provided by the author, who showed how the elementary responses from attosecond-long ionization events form an interference pattern in frequency defining the THz spectrum. Furthermore, the author showed the possibility to use ultrashort pulses for novel ultrafast devices such as fast optical switches based on resonant interaction with atoms and molecules, despite the resonant effects often believed to be “slow”. In the waveguides geometries, the author demonstrated a new mechanism of a dramatic collapse of an optical soliton which gives birth to a very coherent supercontinuum, that is, a very broad spectrum, being compressible to sub-cycle pulses. The author also studied supercontinuum generation and related phenomena in the waveguide arrays and in a free space. The results allow a deeper insight into fundamental questions of nonlinear optics and strong field physics, at the same time opening up new perspectives for future applications of extremely short pulses.
Lightning-triggered electroporation and electrofusion as possible contributors to natural HGT among prokaryotes
Creators: name: Kotnik, Tadej
Publisher: name: arXiv
Year: 2012
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: Phylogenetic studies show that horizontal gene transfer (HGT) is a significant contributor to genetic variability of prokaryotes, and was perhaps even more abundant during early evolution. Hitherto, research of natural HGT has mainly focused on three mechanisms: conjugation, natural competence, and viral transduction. This paper discusses the feasibility of a fourth such mechanism - cell electroporation and/or electrofusion triggered by atmospheric electrostatic discharges (lightnings). A description of electroporation as a phenomenon is followed by a review of experimental evidence that electroporation of prokaryotes in aqueous environments can result in release of non-denatured DNA, as well as uptake of DNA from the surroundings and transformation. Similarly, a description of electrofusion is followed by a review of experiments showing that prokaryotes devoid of cell wall can electrofuse into hybrids expressing the genes of their both precursors. Under sufficiently fine-tuned conditions, electroporation and electrofusion are efficient tools for artificial transformation and hybridization, respectively, but the quantitative analysis developed here shows that conditions for electroporation-based DNA release, DNA uptake and transformation, as well as for electrofusion are also present in many natural aqueous environments exposed to lightnings. Electroporation is thus a plausible contributor to natural HGT among prokaryotes, and could have been particularly important during the early evolution, when the other mechanisms might have been scarcer or nonexistent. In modern prokaryotes, natural absence of the cell wall is rare, but it is reasonable to assume that the wall has formed during evolution, and at least prior to this, electrofusion could also have contributed to HGT. The concluding section outlines several guidelines for assessment of the feasibility of lightning-triggered HGT.
description: 18 pages, 5 figures, 2 tables, 157 references
Interfacial Coupling in Multiferroic-Ferromagnet Heterostructures
Creators: name: Trassin, M.
name: Clarkson, J. D.
name: Bowden, S. R.
name: Liu, Jian
name: Heron, J. T.
name: Paull, R. J.
name: Arenholz, E.
name: Pierce, D. T.
name: Unguris, J.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We report local probe investigations of the magnetic interaction between BiFeO3 films and a ferromagnetic Co0.9Fe0.1 layer. Within the constraints of intralayer exchange coupling in the Co0.9Fe0.1, the multiferroic imprint in the ferromagnet results in a collinear arrangement of the local magnetization and the in-plane BiFeO3 ferroelectric polarization. The magnetic anisotropy is uniaxial, and an in-plane effective coupling field of order 10 mT is derived. Measurements as a function of multiferroic layer thickness show that the influence of the multiferroic layer on the magnetic layer becomes negligible for 3 nm thick BiFeO3 films. We ascribe this breakdown in the exchange coupling to a weakening of the antiferromagnetic order in the ultrathin BiFeO3 film based on our X-ray linear dichroism measurements. These observations are consistent with an interfacial exchange coupling between the CoFe moments and a canted antiferromagnetic moment in the BiFeO3.