cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Convection and dynamo action in B stars
Creators: name: Augustson, Kyle C.
name: Brun, Allan S.
name: Toomre, Juri
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Main-sequence massive stars possess convective cores that likely harbor strong dynamo action. To assess the role of core convection in building magnetic fields within these stars, we employ the 3-D anelastic spherical harmonic (ASH) code to model turbulent dynamics within a 10 solar mass main-sequence (MS) B-type star rotating at 4 times the solar rate. We find that strong (900 kG) magnetic fields arise within the turbulence of the core and penetrate into the stably stratified radiative zone. These fields exhibit complex, time-dependent behavior including reversals in magnetic polarity and shifts between which hemisphere dominates the total magnetic energy.
description: 2 pages, 1 figure; IAU symposium 271, Astrophysical Dynamics: From Galaxies to Stars
Nanosecond magnetic relaxation processes in ultrathin metallic films prepared by MBE
Creators: name: Urban, R.
name: Heinrich, B.
name: Woltersdorf, Georg
name: Ajdari, K.
name: Myrtle, K.
name: Cochran, J. F.
name: Rozenberg, E.
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: 530 Physik
subject: 76.50.+g
subject: 75.70.-i
subject: 75.30.-m

description: Magnetic relaxation processes were investigated by ferromagnetic resonance (FMR) using crystalline Cr/Fe/GaAs(001) ultrathin film structures grown by molecular beam epitaxy (MBE). For Fe films thicker than 1.5 nm the extrinsic relaxation term showed evidence of two magnon scattering. Above 10 GHz the in-plane FMR linewidth was linearly dependent on the microwave frequency with an appreciable zero-frequency offset. The zero frequency offset measures the strength of extrinsic damping. The in-plane Gilbert damping includes both the intrinsic and extrinsic Gilbert contributions in qualitative agreement with recent predictions by Arias and Mills.
Influence of language immersion and phonological-based instruction on literacy skills of English language learners in Xi’an, China
Creators: name: Huo, Shuting
Publisher: name: University of British Columbia
Year: 2018

description: Every child in China is required to learn English as a foreign language (EFL) in elementary school. They learn to not only speak the language but also read and write. Phonological awareness and phonological decoding are foundational skills to learning to read in English. Teaching these skills to young children can enhance their performance on word reading and spelling. Meanwhile, many Chinese children speak and understand very little English due to the lack of English language input in their daily lives. This research investigated the effectiveness of the phonological-based instruction, namely phonological awareness instruction and phonics, among Chinese children. I also examined the moderating effects of English oral language proficiency and language learning environment on the instructional effectiveness. Study 1 is a longitudinal study which followed 110 Chinese children who were learning English as a foreign language throughout an academic year in a school located in Xi’an, China, during which the students received systematic instruction on phonics. The participants were from two programs: one was an English immersion program in which intensive English instruction was delivered, and the other was the standardized program wherein students received less intensive English instruction. Developmental trajectories of two groups of students were compared. The findings indicated that the two groups improved at the same rate on real word reading, but students in the immersion program improved faster in pseudoword reading. Study 2 investigated the effectiveness of phonological awareness (PA) instruction in primary school EFL students. Eight classes from a school in Xi’an, China, were randomly assigned into two groups. Experimental classes received ten weeks of instruction, for a total of 380 minutes of instruction, on phonological awareness. The findings indicated that immediately after the instruction, the experimental group performed better at phonemic awareness and pseudoword reading. The instructional effects were not, however, sustained five months later after all the participants received phonics instruction. English expressive vocabulary at pretest significantly moderated the instructional effect on phonemic awareness. The results consistently suggested that Chinese children with better English oral proficiency and in enriched English language environment benefit more from the English phonological-based instruction.
Strongly enhanced magnetic moments in ferromagnetic FeMnP$_{0.50}$Si$_{0.50}$
Creators: name: Hudl, Matthias
name: Häggström, Lennart
name: Delczeg-Czirjak, Erna-Krisztina
name: Höglin, Viktor
name: Sahlberg, Martin
name: Vitos, Levente
name: Eriksson, Olle
name: Nordblad, Per
name: Andersson, Yvonne
Publisher: name: arXiv
Year: 2011
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The compound FeMnP$_{0.50}$Si$_{0.50}$ has been studied by magnetic measurements, Mössbauer spectroscopy and electronic structure and total energy calculations. An unexpected high magnetic hyperfine field for Fe atoms located at the tetrahedral Me(1) site in the Fe$_2$P structure is found. The saturation moment derived from magnetic measurements corresponds to 4.4 $μ_B$/f.u. at low temperatures, a value substantially higher than previously reported, but in accord with the results from our electron structure calculations. This high saturation moment, a first order nature of the ferromagnetic transition and a tunable transition temperature make the Fe$_{2-x}$Mn$_{x}$P$_{1-y}$Si$y$ system promising for magnetocaloric applications.
description: 3 pages, 4 figures
Constraints from Unrealistic Vacua in Supersymmetric Standard Model with Neutrino Mass Operators
Creators: name: Kanehata, Yoshimi
name: Kobayashi, Tatsuo
name: Konishi, Yasufumi
name: Shimomura, Takashi
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We analyze a scalar potential of the minimal supersymmetric standard model (MSSM) with neutrino mass operators along Unbounded-From-Below (UFB) and Color and/or Charged Breaking (CCB) directions. We show necessary conditions to avoid the potential minima which can be deeper than the realistic vacuum. These conditions would constrain more strongly than conditions in the MSSM without taking into account neutrino mass operators, and can improve the predictive power of supersymmetric models with neutrino mass operators.
description: 11 pages, 4 figures
Role of dynamic exchange coupling in magnetic relaxations of metallic multilayer films (invited)
Creators: name: Heinrich, B.
name: Woltersdorf, Georg
name: Urban, R.
name: Simanek, E.
Publisher: name: Universität Regensburg
Year: 2003
Subjects: subject: 530 Physik
subject: 75.70.Cn
subject: 75.50.Bb
subject: 75.30.Et
subject: 76.50.+g
subject: 72.25.Mk
subject: 75.30.Gw

description: The relaxation processes were investigated by ferromagnetic resonance (FMR) using magnetic single, Au/Fe/GaAs(001), and double layer, Au/Fe/Au/Fe/GaAs(001), structures prepared by molecular beam epitaxy. These structures provided an excellent opportunity to investigate nonlocal damping which is caused by spin transport across a nonmagnetic spacer. In the double layer structures thin Fe layers F1 were separated from a second thick Fe layer F2 by a Au(001), normal metal spacer. The interface magnetic anisotropies separated the FMR fields of F1 and F2 by a big margin which allowed us to investigate FMR in F1 while F2 had a negligible angle of precession. The main result is that the ultrathin Fe films in magnetic double layers acquire a nonlocal interface Gilbert damping. Several mechanisms have been put forward to explain the nonlocal damping. A brief review of each mechanism will be presented. They will be compared with the experimental results allowing one to critically assess their applicability and strength. It will be shown that the precessing layers act as spin pumps and spin sinks. This concept was tested by investigating the FMR linewidth around an accidental crossover of the resonance fields for the layers F1 and F2. (C) 2003 American Institute of Physics.
Nonequilibrium chiral fluid dynamics including dissipation and noise
Creators: name: Nahrgang, Marlene
name: Leupold, Stefan
name: Herold, Christoph
name: Bleicher, Marcus
Publisher: name: arXiv
Year: 2011
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We present a consistent theoretical approach for the study of nonequilibrium effects in chiral fluid dynamics within the framework of the linear sigma model with constituent quarks. Treating the quarks as an equilibrated heat bath we use the influence functional formalism to obtain a Langevin equation for the sigma field. This allows us to calculate the explicit form of the damping coefficient and the noise correlators. For a selfconsistent derivation of both the dynamics of the sigma field and the quark fluid we have to employ the 2PI (two-particle irreducible) effective action formalism. The energy dissipation from the field to the fluid is treated in the exact formalism of the 2PI effective action where a conserved energy-momentum tensor can be constructed. We derive its form and comment on approximations generating additional terms in the energy-momentum balance of the entire system.
N,N'-Dialkyl-1,2-bis(hydroxyphenyl)ethylenediamines and N,N'-dialkyl-4,5-bis(4-hydroxyphenyl)imidazolidines. Syntheses and evaluation of their mammary tumor inhibiting activity
Creators: name: Angerer, Erwin von
name: Egginger, Guenter
name: Kranzfelder, Gerhard
name: Bernhauer, Horst
name: Schönenberger, Helmut
Publisher: name: Universität Regensburg
Year: 1982
Subjects: subject: 540 Chemie

description: Diastereomeric N,”-dialkyl- 1,2-bis(hydroxyphenyl)ethylenediamines (5) were synthesized and tested for their affinity for the estradiol receptor. Only the (&)-1,2-bis(4-hydroxyphenyl)ethylenediamines with the alkyl groups C3H7 [ (&)-5c, K, = 1.1 X lo6)],C ,H9 [(&)-5e,K=, 3.6 X lo6], and CSHll [(*)-5h, K, = 2.2 X lo6] showed a marked affinity, which is mainly due to the (+) enantiomers [e.g., (+)-5e, K, = 2.1 X lo7]. No enhancement of affinity by cyclization to imidazolidines [e.g., (f)-trans-7a, K, = 1.2 X lo7] was observed. These compounds [e.g., (&)-, (+)-, and (-)-5e], which did not produce any uterine response in the mouse, were able to inhibit weakly the growth of the DMBA-induced mammary carcinoma of the rat. The inhibitory effect of (f)-5e against MCF-7 cells, which can be overcome by hexestrol, makes a direct antiestrogenic mode of action probable, since general cytotoxic effects and a central action could be ruled out.
Flood-ResNet50: Optimized Deep Learning Model for Efficient Flood Detection on Edge Device
Creators: name: Khan, Md Azim
name: Ahmed, Nadeem
name: Padela, Joyce
name: Raza, Muhammad Shehrose
name: Gangopadhyay, Aryya
name: Wang, Jianwu
name: Foulds, James
name: Busart, Carl
name: Erbacher, Robert F.
Publisher: name: IEEE
Year: 2024
Subjects: VGG
ResNet50
Transfer learning
Jetson nano
Computational modeling
Image edge detection
Transformers
Wildlife
UMBC Big Data Analytics Lab
Deep learning
Vision transformer
Edge device
Biological system modeling
AlexNet

description: 2023 International Conference on Machine Learning and Applications (ICMLA), 15-16 December 2023, Jacksonville, FL, USA 15-17 Dec. 2023
description: Floods are highly destructive natural disasters that result in significant economic losses and endanger human and wildlife lives. Efficiently monitoring Flooded areas through the utilization of deep learning models can contribute to mitigating these risks. This study focuses on the deployment of deep learning models specifically designed for classifying flooded and non-flooded in UAV images. In consideration of computational costs, we propose modified version of ResNet50 called Flood-ResNet50. By incorporating additional layers and leveraging transfer learning techniques, Flood-ResNet50 achieves comparable performance to larger models like VGG16/19, AlexNet, DenseNet161, EfficientNetB7, Swin(small), and vision transformer. Experimental results demonstrate that the proposed modification of ResNet50, incorporating additional layers, achieves a classification accuracy of 96.43%, F1 score of 86.36%, Recall of 81.11%, Precision of 92.41 %, model size 98MB and FLOPs 4.3 billions for the FloodNet dataset. When deployed on edge devices such as the Jetson Nano, our model demonstrates faster inference speed (820 ms), higher throughput (39.02 fps), and lower average power consumption (6.9 W) compared to larger ResNet101 and ResNet152 models.
The gendered ecology of violent victimization and the stress process
Creators: name: Jackson Soller, Aubrey
name: Coleman, Erin R.
Publisher: name: Elsevier
Year: 2024
Subjects: Youth mental health
Neighborhood
Victimization
Gender stratification
Stress process

description: We draw on the stress process model to investigate how local gender dynamics related to patriarchal violence and socioeconomic resources shape the link between violent victimization and youth mental health. Using multilevel longitudinal data on 1,632 youth we tested whether respondents exhibited fewer psychological distress symptoms following violent victimization when they resided in neighborhoods characterized by less subjective or objective gender stratification. We find that neighborhood-level gender disparities in socioeconomic resources modify the detrimental impact of victimization on girls' and boys' internalizing symptoms. We elaborate on these conditional influences and conclude with a discussion of how our findings advance scholarship on the role of gender and space in the stress process.
The targum (1879:Apr.)
Creators: name: No Name Supplied
Publisher: name: Targum Association
Year: 1879

description: Some University historians indicate that the Targum was first published as an annual in 1867, but of this we have no extant evidence. In January 1869, the Targum as we now know it, made its appearance as a monthly paper that concerned itself with student “literary contributions” and college news as well as serving as a vehicle for bringing news to alumni and the general public. The newspaper, which originally was for sale, varied in frequency over the years as did its title (The Targum, Rutgers Targum, Rutgers Daily Targum, and Daily Targum). The newspaper has continuously been published since 1869 with the exception of 19 months during the second world war, between February 1944 and October 1945. The Targum was published by the students of Rutgers College, and later Rutgers University—New Brunswick represented through the years as the Targum Association, Rutgers Targum Association, and Rutgers College Targum. As a student organization, the Targum operated under the oversight of the dean of students and student government but in October 1980, the Targum became an independent college paper.
Anisotropic Sliding Dynamics, Peak Effect, and Metastability in Stripe Systems
Creators: name: Reichhardt, C. J. Olson
name: Reichhardt, C.
name: Bishop, A. R.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: A variety of soft and hard condensed matter systems are known to form stripe patterns. Here we use numerical simulations to analyze how such stripe states depin and slide when interacting with a random substrate and with driving in different directions with respect to the orientation of the stripes. Depending on the strength and density of the substrate disorder, we find that there can be pronounced anisotropy in the transport produced by different dynamical flow phases. We also find a disorder-induced "peak effect" similar to that observed for superconducting vortex systems, which is marked by a transition from elastic depinning to a state where the stripe structure fragments or partially disorders at depinning. Under the sudden application of a driving force, we observe pronounced metastability effects similar to those found near the order-disorder transition associated with the peak effect regime for three-dimensional superconducting vortices. The characteristic transient time required for the system to reach a steady state diverges in the region where the flow changes from elastic to disordered. We also find that anisotropy of the flow persists in the presence of thermal disorder when thermally-induced particle hopping along the stripes dominates. The thermal effects can wash out the effects of the quenched disorder, leading to a thermally-induced stripe state. We map out the dynamical phase diagram for this system, and discuss how our results could be explored in electron liquid crystal systems, type-1.5 superconductors, and pattern-forming colloidal assemblies.
description: 18 pages, 22 postscript figures
Development of a venting valve for nursing bottles
Creators: name: Amerehbozchalouee, Meitham
Publisher: name: University of British Columbia
Year: 2018

description: This project aims to develop an innovative venting technique for nursing bottles with natural flow. Conventional nursing bottles are completely sealed except for the small hole on the teat. Without appropriate venting, the partial vacuum (i.e., negative pressure) inside the bottle results in gastrointestinal disorders in infants such as colic and secretory otitis. In addition, intraoral negative pressure transmitted to middle ear causes secretory otitis with a risk for delayed speech development. This study presents the design, modeling and fabrication process of new venting system for the nursing bottle based on an innovative flexible valve. Liquid silicon rubber was used to fabricate the valve, which was able to respond to the pressure difference between the inside and outside of the bottle. It not only closes the air entrance when the bottle stands on its base but also opens the air path while the infant sucks the milk. The specific geometry of the valve adjusts the response based on the pressure difference. The static structural response of the valve to both positive and negative pressures was simulated with finite element analysis. Moreover, the fluid-structural interaction analysis was carried out to show the transient response of both fluid flow and flexible structure to the pressure difference. In order to optimize the design, valves with different thicknesses and curvatures were tested. An experimental set-up was built using a nursing bottle equipped with pressure sensors and a vacuum pump to test the actual infant’s sucking condition. Five valves with different geometries were fabricated for the experiments. The experimental results were validated by the simulation results. Criterion parameters of the system, such as intake volume of milk, minimum pressure, working pressure, and temporal characteristics of the valves were statistically analyzed. Finally, the optimization based on the statistical results provided the most reliable design that can deliver the more comfortable feeding condition.
Review of Jillian M. Hess's How Romantics and Victorians Organized Information. Commonplace Books, Scrapbooks, and Albums
Creators: name: Shattock, Joanne
Publisher: name: George Eliot Review Online
Year: 2023
Subjects: Biography

description: Article from the George Eliot Review. Digitized and hosted by the George Eliot Review Online, editor Beverley Park Rilett.
Kontrollierte Oligomerisierung von Lewis-Säure/Base-stabilisierten Phosphanylalanen [Controlled oligomerisation of Lewis acid/base stabilised phosphanylalanes]
Creators: name: Bodensteiner, Michael
name: Vogel, Ulf
name: Timoshkin, Alexey Y.
name: Scheer, Manfred
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: Aluminium; H2-Eliminierungen; Lewis-Basen; Lewis-Säuren; Phosphor
subject: 540 Chemie

description: Durch Feinabstimmung der Temperatur- und Lösungsmittelbedingungen gelingt die kontrollierte H2-Eliminierung aus dem Lewis-Säure/Base-stabilisierten Phosphanylalan 1 (siehe Schema). Das entstehende cyclo-Trimer 2 bildet durch weitere H2-Eliminierung die Leiterverbindung 3. 2 und 3 sind die ersten Vertreter einer neuen Substanzklasse von 13/15-Verbindungen ohne zusätzliche Donor-Akzeptor-Bindungen innerhalb des Gerüsts
Nonlinear optical probing of nanocrystalline orientation in epitaxial ferroelectric thin films
Creators: name: Woltersdorf, Georg
name: Seifert, G.
name: Graener, H.
name: Pignolet, A.
name: Hesse, D.
Publisher: name: Universität Regensburg
Year: 2002
Subjects: subject: barium compounds, bismuth compounds, ferroelectric materials, ferroelectric thin films, optical harmonic generation, X-ray diffraction, electron microscopy
subject: 530 Physik
subject: 77.80.-e
subject: 77.84.Ek
subject: 77.84.Cg
subject: 77.55.-g
subject: 42.65.Ky
subject: 78.66.Nk

description: Epitaxially grown ferroelectric BaBi4Ti4O15 thin films were studied by optical second-harmonic (SH) generation using a femtosecond titanium:sapphire laser at 800 nm wavelength. By varying both the incidence and the azimuthal angle and registering the second-harmonic intensity, a significant correlation was found between the azimuthal dependence of the measured SH signal and the nanoscopic texture of the samples, which was determined by electron microscopy and x-ray diffraction. In particular, two different types of grains with different crystallographic orientations generate different SH intensity maxima with fourfold azimuthal symmetry, distinguishable from an isotropic background due to a c-axis oriented main layer. This correlation suggests the use of the SH technique for a purely optical characterization of the film orientation and thickness. (C) 2002 American Institute of Physics.
Assimilating data into an αω dynamo model of the sun: A variational approach
Creators: name: Jouve, Laurene
name: Brun, Allan Sacha
name: Talagrand, Olivier
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We have developed a variational data assimilation technique for the Sun using a toy αΩ dynamo model. The purpose of this work is to apply modern data assimilation techniques to solar data using a physically based model. This work represents the first step toward a complete variational model of solar magnetism. We derive the adjoint αΩ dynamo code and use a minimization procedure to invert the spatial dependence of key physical ingredients of the model. We find that the variational technique is very powerful and leads to encouraging results that will be applied to a more realistic model of the solar dynamo. We also note that the continuous adjoint mean-field induction equation is derived in the appendix.
description: 16 pages, 14 figures, accepted for publication in ApJ
Failure of the Hasse principle for Enriques surfaces
Creators: name: Várilly-Alvarado, Anthony
name: Viray, Bianca
Publisher: name: arXiv
Year: 2010
Subjects: subject: Number Theory (math.NT)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 11G35, 14G05, 14G25, 14G40

description: We construct an Enriques surface X over Q with empty étale-Brauer set (and hence no rational points) for which there is no algebraic Brauer-Manin obstruction to the Hasse principle. In addition, if there is a transcendental obstruction on X, then we obtain a K3 surface that has a transcendental obstruction to the Hasse principle.
description: 16 pages, 2 tables, Magma code included at the end of the source file
I am in the Homeless Home or I Am Always on the Way Home: Formatting Identity and Transcultural Adaptation Through Ethnic and Host Communication
Creators: name: Chao, Chin-Chung
name: Xie, Ming
Publisher: name: De Gruyter
Year: 2024
Subjects: host communication
international students
ethnic communication
transcultural identity
transcultural adaptation

description: This study uses a phenomenological approach and 25 in-depth interviews to better understand ethnic and host communication by Chinese international students in U.S. higher education and the impact of such communication practices on their cultural identity transformation and transcultural adaptation. The research findings reveal that their ethnic communication reflects their dynamic negotiation of cultural identities and their efforts to integrate their original cultural background and their expectations of others to redefine their own cultural identities and communicative behaviors. It also highlights that Chinese students engage in ethnic communication not only for community building and cultural identity reinforcement but also assertively to express themselves and educate others.
Warm Spitzer Photometry of the Transiting Exoplanets CoRoT-1 and CoRoT-2 at Secondary Eclipse
Creators: name: Deming, Drake
name: Knutson, Heather
name: Agol, Eric
name: Desert, Jean-Michel
name: Burrows, Adam
name: Fortney, Jonathan J.
name: Charbonneau, David
name: Cowan, Nicolas B.
name: Laughlin, Gregory
name: Langton, Jonathan
name: Showman, Adam P.
name: Lewis, Nikole K.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We measure secondary eclipses of the hot giant exoplanets CoRoT-1 at 3.6 and 4.5 microns, and CoRoT-2 at 3.6 microns, both using Warm Spitzer. We find that the Warm Spitzer mission is working very well for exoplanet science. For consistency of our analysis we also re-analyze archival cryogenic Spitzer data for secondary eclipses of CoRoT-2 at 4.5 and 8 microns. We compare the total data for both planets, including optical eclipse measurements by the CoRoT mission, and ground-based eclipse measurements at 2 microns, to existing models. Both planets exhibit stronger eclipses at 4.5 than at 3.6 microns, which is often indicative of an atmospheric temperature inversion. The spectrum of CoRoT-1 is best reproduced by a 2460K blackbody, due either to a high altitude layer that strongly absorbs stellar irradiance, or an isothermal region in the planetary atmosphere. The spectrum of CoRoT-2 is unusual because the 8 micron contrast is anomalously low. Non-inverted atmospheres could potentially produce the CoRoT-2 spectrum if the planet exhibits line emission from CO at 4.5 microns, caused by tidal-induced mass loss. However, the viability of that hypothesis is questionable because the emitting region cannot be more than about 30-percent larger than the planet's transit radius, based on the ingress and egress times at eclipse. An alternative possibility to account for the spectrum of CoRoT-2 is an additional opacity source that acts strongly at wavelengths less than 5 microns, heating the upper atmosphere while allowing the deeper atmosphere seen at 8 microns to remain cooler. We obtain a similar result as Gillon et al. for the phase of the secondary eclipse of CoRoT-2, implying an eccentric orbit with e*cos(omega)=-0.0030 +/- 0.0004.
description: 15 pages, 5 figures, 2 tables. Accepted for the Astrophysical Journal
Dynamic exchange coupling in magnetic bilayers
Creators: name: Heinrich, B.
name: Tserkovnyak, Y.
name: Woltersdorf, Georg
name: Brataas, A.
name: Urban, R.
name: Bauer, G. E. W.
Publisher: name: Universität Regensburg
Year: 2003
Subjects: subject: 530 Physik
subject: 76.50.+g
subject: 75.30.Et
subject: 75.40.Gb
subject: 75.70.Cn

description: A long-range dynamic interaction between ferromagnetic films separated by normal-metal spacers is reported, which is communicated by nonequilibrium spin currents. It is measured by ferromagnetic resonance and explained by an adiabatic spin-pump theory. In such a resonance the spin-pump mechanism of spatially separated magnetic moments leads to an appreciable increase in the resonant linewidth when the resonance fields are well apart, and results in a dramatic linewidth narrowing when the resonant fields approach each other.
Magnetic anisotropy of epitaxial (Ga,Mn)As on (113)A GaAs
Creators: name: Stefanowicz, Wiktor
name: Sliwa, Cezary
name: Aleshkevych, Pavlo
name: Dietl, Tomasz
name: Döppe, Matthias
name: Wurstbauer, Ursula
name: Wegscheider, Werner
name: Weiss, Dieter
name: Sawicki, Maciej
Publisher: name: Universität Regensburg
Year: 2010
Subjects: subject: 530 Physik
subject: 75.50.Pp, 75.30.Gw

description: The temperature dependence of magnetic anisotropy in (113)A (Ga,Mn)As layers grown by molecular-beam epitaxy is studied by means of superconducting quantum interference device magnetometry as well as by ferromagnetic resonance (FMR) and magnetooptical effects. Experimental results are described considering cubic and two kinds of uniaxial magnetic anisotropy. The magnitude of cubic and uniaxial anisotropy constants is found to be proportional to the fourth and second power of saturation magnetization, respectively. Similarly to the case of (001) samples, the spin reorientation transition from uniaxial anisotropy with the easy axis along the [1̅ 10] direction at high temperatures to the biaxial ⟨100⟩ anisotropy at low temperatures is observed around 25 K. The determined values of the anisotropy constants have been confirmed by FMR studies. As evidenced by investigations of the polar magnetooptical Kerr effect, the particular combination of magnetic anisotropies allows the out-of-plane component of magnetization to be reversed by an in-plane magnetic field. Theoretical calculations within the p-d Zener model explain the magnitude of the out-of-plane uniaxial anisotropy constant caused by epitaxial strain but do not explain satisfactorily the cubic anisotropy constant. At the same time the findings point to the presence of an additional uniaxial anisotropy of unknown origin. Similarly to the case of (001) films, this additional anisotropy can be explained by assuming the existence of a shear strain. However, in contrast to the (001) samples, this additional strain has an out of the (001) plane character.
title: Selbstreflexion im Studium: Entwicklung und Validierung eines Messinstruments bei Lehramtsstudierenden
Creators: name: Berger, Josephine
Publisher: name: UNSPECIFIED
Year: 2022

description: Die vorliegende Forschungsarbeit beschäftigt sich mit der Entwicklung und Validierung eines Fragebogens und eines Bewertungsschemas zur Erfassung von Selbstreflexion. Grundlage beider Messinstrumente bildete ein Reflexionsmodell, welches neben dem Reflexionsprozess auch die Bereitschaft zur Reflexion und den wahrgenommenen Reflexionserfolg abbildet. Der Modellansatz ermöglicht eine holistische Sicht auf Reflexion und grenzt sich hierdurch von bestehenden Modellen ab. Validiert wurde der Fragebogen mit Konzepten zu Lernstrategien, Selbstreflexion und Rumination. Eine konfirmatorische Faktorenanalyse konnte die sechs-faktorielle Struktur des Fragebogens für Selbstreflexion und Reflexionserfolg zufriedenstellend abbilden. Die Reliabilität wurde mit Cronbachs Alpha und McDonalds Omega überprüft. Insgesamt zeigten die Ergebnisse überwiegend gute bis exzellente Werte. Zur Beurteilung des Reflexionsgehalts in schriftlichen Arbeiten wurde ein Bewertungsschema erstellt. Die Interrater-Reliabilität wurde durch drei Raterinnen überprüft und kann als sehr gut bezeichnet werden. Untersucht wurden e-Portfolios von Studierenden für Lehramt an Gymnasien, die das Begleitseminar während des ersten Schulpraktikums besuchten. Die e-Portfolios wurden anhand ihres Reflexionsgehalts vor und nach dem Schulpraktikum beurteilt. Hierbei konnte eine Steigerung der Reflexionsfähigkeit der Studierenden über die Messzeitpunkte gezeigt werden. Zusätzlich zu dieser Beurteilung, wurde auch der Fragebogen für Selbstreflexion und Reflexionserfolg eingesetzt. Die Reflexionswerte aus dem e-Portfolio und dem Fragebogen wiesen jedoch nur einen geringen Zusammenhang auf. Anhand des Fragebogens für Selbstreflexion und Reflexionserfolg wurde der Einfluss der Bildungsbiografie auf die Reflexionsfähigkeit von Studierenden für Lehramt an Gymnasien (LaG) und für berufliche Schulen (LaB) untersucht. LaB-Studierende zeigten hierbei im Vergleich zu LaG-Studierende einen ausgeprägteren Bezug zur Handlungsoptimierung, eine höhere Reflexionsbereitschaft und einen stärker wahrgenommenen Reflexionserfolg. Diese Studie demonstriert, dass mit dem Fragebogen für Selbstreflexion und Reflexionserfolg ein umfassender Beitrag zur Erhebung von Selbstreflexion im Studium gelungen ist.
Ein sphärisches Molekül mit einem Kohlenstoff-freien Ih-C80-topologischen Gerüst [A spherical molecule with a carbon-free Ih-C80 topological framework]
Creators: name: Scheer, Manfred
name: Schindler, Andrea
name: Gröger, Christian
name: Virovets, Alexander V.
name: Peresypkina, Eugenia V.
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: Carborane; Fullerene; Phosphor; Selbstorganisation; Supramolekulare Chemie
subject: 540 Chemie

description: Der vollständige Einschluss des ortho-Carborans durch ein Fulleren-artiges Bausteinsystem aus Pentaphosphaferrocen und CuICl führt zur Bildung des sphärischen Supermoleküls C2B10H12§[{Cp*Fe(5-P5)}12(CuCl)20]. Dieses Produkt einer templatkontrollierten Aggregation ist das erste Kohlenstoff-freie C80-Analogon mit Ikosaedersymmetrie.
Eigenfunction Statistics on Quantum Graphs
Creators: name: Gnutzmann, S.
name: Keating, J. P.
name: Piotet, F.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We investigate the spatial statistics of the energy eigenfunctions on large quantum graphs. It has previously been conjectured that these should be described by a Gaussian Random Wave Model, by analogy with quantum chaotic systems, for which such a model was proposed by Berry in 1977. The autocorrelation functions we calculate for an individual quantum graph exhibit a universal component, which completely determines a Gaussian Random Wave Model, and a system-dependent deviation. This deviation depends on the graph only through its underlying classical dynamics. Classical criteria for quantum universality to be met asymptotically in the large graph limit (i.e. for the non-universal deviation to vanish) are then extracted. We use an exact field theoretic expression in terms of a variant of a supersymmetric sigma model. A saddle-point analysis of this expression leads to the estimates. In particular, intensity correlations are used to discuss the possible equidistribution of the energy eigenfunctions in the large graph limit. When equidistribution is asymptotically realized, our theory predicts a rate of convergence that is a significant refinement of previous estimates. The universal and system-dependent components of intensity correlation functions are recovered by means of an exact trace formula which we analyse in the diagonal approximation, drawing in this way a parallel between the field theory and semiclassics. Our results provide the first instance where an asymptotic Gaussian Random Wave Model has been established microscopically for eigenfunctions in a system with no disorder.
description: 59 pages, 3 figures
Effect of N,N'-diethyl-1,2-bis(2,6-dichloro-4-hydroxyphenyl)ethylenediamines on the DMBA-induced mammary carcinoma of the rat
Creators: name: Angerer, Erwin von
Publisher: name: Universität Regensburg
Year: 1982
Subjects: subject: 540 Chemie

description: The syntheses and estrogen receptor affinities of meso- and (~)-N,N’-dialkyl-1,2-bis(2,6-dichloro-4-hydroxypheny1) ethylenediamines (2) are described. They show high binding affinities in both diastereomeric forms but with a preference for the meso isomer, reaching a RBA value of 8.6 (meso-2b; 17@-estradiol=1 00). Both stereoisomers of 2b exhibit a strong inhibitory effect on the 7,12-dimethylbenz[a]anthracene( DMBA) induced hormone-dependent mammary carcinoma of the Sprague-Dawley rat, reducing the tumor area by 74 (meso-2b) and 24% [(*)-2b], respectively, after 4 weeks administration of 6 X 6 (mg/kg)/week. The high uterotrophic potency makes a mode of action likely which corresponds to the effect of high doses of estrogens.
Linkage disequilibrium under recurrent bottlenecks
Creators: name: Schaper, E.
name: Eriksson, A.
name: Rafajlovic, M.
name: Sagitov, S.
name: Mehlig, B.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences

description: Understanding patterns of selectively neutral genetic variation is essential in order to model deviations from neutrality, caused for example by different forms of selection. Best understood is neutral genetic variation at a single locus, but additional insights can be gained by investigating genetic variation at multiple loci. The corresponding patterns of variation reflect linkage disequilibrium and provide information about the underlying multi-locus gene genealogies. The statistical properties of two-locus genealogies have been intensively studied for populations of constant census size, as well as for simple demographic histories such as exponential population growth, and single bottlenecks. By contrast, the combined effect of recombination and sustained demographic fluctuations is poorly understood. Addressing this issue, we study a two-locus Wright-Fisher model of a population subject to recurrent bottlenecks. We derive coalescent approximations for the covariance of the times to the most recent common ancestor at two loci. We find, first, that an effective population-size approximation describes the numerically observed linkage disequilibrium provided that recombination occurs either much faster or much more slowly than the population size changes. Second, when recombination occurs frequently between bottlenecks but rarely within bottlenecks, we observe long-range linkage disequilibrium. Third, we show that in the latter case, a commonly used measure of linkage disequilibrium, sigma_d^2 (closely related to r^2), fails to capture long-range linkage disequilibrium because constituent terms, each reflecting long-range linkage disequilibrium, cancel. Fourth, we analyse a limiting case in which long-range linkage disequilibrium can be described in terms of a Xi-coalescent process allowing for simultaneous multiple mergers of ancestral lines.
description: 34 pages, 7 figures
Molecular-beam epitaxy of the half-Heusler alloy NiMnSb on (In,Ga)As/InP (001)
Creators: name: Bach, P.
name: Bader, A. S.
name: Ruster, C.
name: Gould, C.
name: Becker, C. R.
name: Schmidt, G.
name: Molenkamp, L. W.
name: Weigand, W.
name: Kumpf, C.
name: Umbach, E.
name: Urban, R.
name: Woltersdorf, Georg
name: Heinrich, B.
Publisher: name: Universität Regensburg
Year: 2003
Subjects: subject: 530 Physik

description: We report the growth of the half-Heusler alloy NiMnSb on InP (001) by molecular-beam epitaxy using a lattice-matched (In,Ga)As buffer. High-resolution x-ray diffraction confirms a high crystalline quality. Spot-profile analysis low-energy electron diffraction measurements show well-defined surface reconstructions. The samples show the expected high Curie temperature and an uniaxial anisotropy.
The platformation and transformation of the digital public sphere: An introduction
Creators: name: Xie, Ming
Publisher: name: Sage
Year: 2024

description: This article introduces the complex landscape of social media platforms and their evolving integration within social and political contexts. Focusing on the concept of platform society, this article discusses the emergence and growth of new platforms as well as the localization trends of mobile communication. This article examines the interplay between technological structures and social, cultural, and political dimensions of mobile communication, focusing on issues such as privacy policies, data protection, and profit-seeking motives of platform owner companies. In addition, this article introduces the six papers chosen for this special issue. The diverse viewpoints presented in this special issue contribute to a deeper understanding of digital communication’s role in advancing democracy, encouraging citizen participation, and transforming public spheres.
Design drivers for a wide-field multi-object spectrograph for the William Herschel Telescope
Creators: name: Balcells, Marc
name: Benn, Chris R.
name: Carter, David
name: Dalton, Gavin B.
name: Trager, Scott C.
name: Feltzing, Sofia
name: Verheijen, Marc A. W.
name: Jarvis, Matt
name: Percival, Will
name: Abrams, Don C.
name: Agocs, Tibor
name: Brown, Anthony G. A.
name: Cano, Diego
name: Evans, Chris
name: Helmi, Amina
name: Lewis, Ian J.
name: McLure, Ross
name: Peletier, Reynier F.
name: Perez-Fournon, Ismael
name: Sharples, Ray M.
name: Tosh, Ian A. J.
name: Trujillo, Ignacio
name: Walton, Nic
name: Westfall, Kyle B.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Wide-field multi-object spectroscopy is a high priority for European astronomy over the next decade. Most 8-10m telescopes have a small field of view, making 4-m class telescopes a particularly attractive option for wide-field instruments. We present a science case and design drivers for a wide-field multi-object spectrograph (MOS) with integral field units for the 4.2-m William Herschel Telescope (WHT) on La Palma. The instrument intends to take advantage of a future prime-focus corrector and atmospheric-dispersion corrector that will deliver a field of view 2 deg in diameter, with good throughput from 370 to 1,000 nm. The science programs cluster into three groups needing three different resolving powers R: (1) high-precision radial-velocities for Gaia-related Milky Way dynamics, cosmological redshift surveys, and galaxy evolution studies (R = 5,000), (2) galaxy disk velocity dispersions (R = 10,000) and (3) high-precision stellar element abundances for Milky Way archaeology (R = 20,000). The multiplex requirements of the different science cases range from a few hundred to a few thousand, and a range of fibre-positioner technologies are considered. Several options for the spectrograph are discussed, building in part on published design studies for E-ELT spectrographs. Indeed, a WHT MOS will not only efficiently deliver data for exploitation of important imaging surveys planned for the coming decade, but will also serve as a test-bed to optimize the design of MOS instruments for the future E-ELT.
description: 15 pages, 4 figures, submitted to SPIE Astronomical Telescopes and Instrumentation 2010
Classical and Nonclassical symmetries of the (2+1)-dimensional Kuramoto-Sivashinsky equation
Creators: name: Nadjafikhah, Mehdi
name: Ahangari, Fatemeh
Publisher: name: arXiv
Year: 2011
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this paper, we have studied the problem of determining the largest possible set of symmetries for an important example of nonlinear dynamical system: the Kuramoto-Sivashinsky (K-S) model in two spatial and one temporal dimensions. By applying the classical symmetry method for the K-S model, we have found the classical symmetry operators. Also, the structure of the Lie algebra of symmetries is discussed and the optimal system of subalgebras of the equation is constructed. The Lie invariants associated to the symmetry generators as well as the corresponding similarity reduced equations are also pointed out. By applying the nonclassical symmetry method for the K-S model we concluded that the analyzed model do not admit supplementary, nonclassical type, symmetries. Using this procedure, the classical Lie operators only were generated.
description: 12 pages
Victimization and internalizing difficulties : the moderating role of social support
Creators: name: Mahboubi, Maryam
Publisher: name: University of British Columbia
Year: 2018

description: Children and adolescents who are targets of peer victimization experience many negative developmental outcomes, including depression and anxiety, which can have lasting effects throughout their lives.  Researchers have sought to identify protective factors that lessen the negative impact of peer victimization on wellbeing.  Social support has been identified as one of the most significant protective factors.  Studies that examine the effect of social support from multiple sources on the wellbeing of students who are victimized by their peers have reported mixed results.  The present research addressed these inconsistent findings by extending the aspects of social support that are measured to include both source and type.  This study sought to answer three questions: (1) Does overall social support (regardless of type) from a) parents, b) teachers, c) classmates and d) close friends moderate the relation between overall victimization and depression and/or anxiety? (2) Does the type of social support provided (emotional, informational, appraisal and/or instrumental support) moderate the relation between victimization and depression and/or anxiety? (3) Does overall social support (regardless of type) from a) parents, b) teachers, c) classmates and/or d) close friends moderate the relation between different forms of victimization (verbal, social, physical and cyber) and depression and/or anxiety? Participants were 720 students in grades 4-7 who completed self-report measures of victimization experiences at school, perceived social support, and a screening index for depression and anxiety. Multiple regression analyses with predictors entered in blocks were run to explore the moderating role of social support in the relation between victimization and depression and/or anxiety. Results indicate that certain sources and types of social support moderate the relation between victimization and depression/anxiety, while other sources and types of social support are associated with higher depression/anxiety among 4th-7th graders.  This held true when considering both overall victimization and various forms of victimization.  Results suggest that the moderating role of social support in the relation between victimization-depression and victimization-anxiety are distinct; when exploring the impact of social support from peers at school, classmates and close friends should be treated as distinct groups; social support from parents can have a positive impact on 4th-7th graders.