cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Passive and active colloidal chemotaxis in a microfluidic channel: mesoscopic and stochastic models
Creators: name: Deprez, Laurens
name: de Buyl, Pierre
Publisher: name: arXiv
Year: 2017
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Chemotaxis is the response of a particle to a gradient in the chemical composition of the environment. While it was originally observed for biological organisms, it is of great interest in the context of synthetic active particles such as nanomotors. Experimental demonstration of chemotaxis for chemically-powered colloidal nanomotor was reported in the literature in the context of chemo-attraction in a still fluid or in a microfluidic channel where the gradient is sustained by a specific inlet geometry. In this work, we use mesoscopic particle-based simulations of the colloid and solvent to demonstrate chemotaxis in a microfluidic channel. On the basis of this particle-based model, we evaluate the chemical concentration profiles in the presence of passive or chemically active colloids, compute the chemotactic force acting upon them and propose a stochastic model that rationalises our findings on colloidal chemotaxis. Our model is also able to explain the results of an earlier simulation work that uses a simpler geometry and to extend its interpretation.
description: 12 pages, 12 figures, revised version. Published version open-access (see journal reference and DOI), Soft Matter (2017)
Energy-level alignment at interfaces between manganese phthalocyanine and C60
Creators: name: Waas, Daniel
name: Rückerl, Florian
name: Knupfer, Martin
name: Büchner, Bernd
Publisher: name: Frankfurt, M. : Beilstein-Institut zur Förderung der Chemischen Wissenschaften
Year: 2017
Subjects: subject: C60
subject: Manganese phthalocyanine (MnPc)
subject: Organic interfaces
subject: Photoelectron spectroscopy (PES)
subject: 620
subject: 540

description: We have used photoelectron spectroscopy to determine the energy-level alignment at organic heterojunctions made of manganese phthalocyanine (MnPc) and the fullerene C60. We show that this energy-level alignment depends upon the preparation sequence, which is explained by different molecular orientations. Moreover, our results demonstrate that MnPc/C60 interfaces are hardly suited for application in organic photovoltaic devices, since the energy difference of the two lowest unoccupied molecular orbitals (LUMOs) is rather small.
Non-supersymmetric D-branes with Vanishing Cylinder Amplitudes in Asymmetric Orbifolds
Creators: name: Satoh, Yuji
name: Sugawara, Yuji
name: Uetoko, Takahiro
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the type II string vacua with chiral space-time SUSY constructed as asymmetric orbifolds of torus and $ K3 $ compactifications. Despite the fact that all the D-branes are non-BPS in any chiral SUSY vacua, we show that the relevant non-geometric vacua of asymmetric orbifolds allow rather generally configurations of D-branes which lead to vanishing cylinder amplitudes, implying the bose-fermi cancellation at each mass level of the open string spectrum. After working on simple models of toroidal asymmetric orbifolds, we focus on the asymmetric orbifolds of $ T^2 \times {\cal M} $, where $ {\cal M} $ is described by a general $ {\cal N} =4 $ SCFT with $ c=6 $ defined by the Gepner construction for $ K3 $. Even when the modular invariant partition functions in the bulk remain unchanged, the spectra of such non-BPS D-branes with the bose-fermi cancellation can vary significantly according to the choice of orbifolding.
description: 32 pages, no figures; (v2) comments and discussion added on properties of D-branes
Probing the magnetic superexchange couplings between terminal CuII ions in heterotrinuclear bis(oxamidato) type complexes
Creators: name: Abdulmalic, Mohammad A.
name: Weheabby, Saddam
name: Meva, Francois E.
name: Aliabadi, Azar
name: Kataev, Vladislav
name: Büchner, Bernd
name: Schleife, Frederik
name: Kersting, Berthold
name: Rüffer, Tobias
Publisher: name: Frankfurt, M. : Beilstein-Institut zur Förderung der Chemischen Wissenschaften
Year: 2017
Subjects: subject: Bis(oxamidato)
subject: Crystallographic characterization
subject: Diamagnetic
subject: Heteronuclear complexes
subject: Magnetic superexchange coupling
subject: Molecular structure
subject: 620
subject: 540

description: The reaction of one equivalent of [n-Bu4N]2[Ni(opboR2)] with two equivalents of [Cu(pmdta)(X)2] afforded the heterotrinuclear CuIINiIICuII containing bis(oxamidato) type complexes [Cu2Ni(opboR2)(pmdta)2]X2 (R = Me, X = NO3– (1); R = Et, X = ClO4– (2); R = n-Pr, X = NO3– (3); opboR2 = o-phenylenebis(NR-substituted oxamidato); pmdta = N,N,N’,N”,N”-pentamethyldiethylenetriamine). The identities of the heterotrinuclear complexes 1–3 were established by IR spectroscopy, elemental analysis and single-crystal X-ray diffraction studies, which revealed the cationic complex fragments [Cu2Ni(opboR2)(pmdta)2]2+ as not involved in any further intermolecular interactions. As a consequence thereof, the complexes 1–3 possess terminal paramagnetic [Cu(pmdta)]2+ fragments separated by [NiII(opboR2)]2– bridging units representing diamagnetic SNi = 0 states. The magnetic field dependence of the magnetization M(H) of 1–3 at T = 1.8 K has been determined and is shown to be highly reproducible with the Brillouin function for an ideal paramagnetic spin = 1/2 system, verifying experimentally that no magnetic superexchange couplings exists between the terminal paramagnetic [Cu(pmdta)]2+ fragments. Susceptibility measurements versus temperature of 1–3 between 1.8–300 K were performed to reinforce the statement of the absence of magnetic superexchange couplings in these three heterotrinuclear complexes.
Adsorption characteristics of Er3N@C80on W(110) and Au(111) studied via scanning tunneling microscopy and spectroscopy
Creators: name: Schimmel, Sebastian
name: Sun, Zhixiang
name: Baumann, Danny
name: Krylov, Denis
name: Samoylova, Nataliya
name: Popov, Alexey
name: Büchner, Bernd
name: Hess, Christian
Publisher: name: Frankfurt, M. : Beilstein-Institut zur Förderung der Chemischen Wissenschaften
Year: 2017
Subjects: subject: Adsorption
subject: Au(111)
subject: Er3NC80
subject: Scanning tunnelling microscopy
subject: Scanning tunnelling spectroscopy
subject: W(110)
subject: 620
subject: 540

description: We performed a study on the fundamental adsorption characteristics of Er3N@C80 deposited on W(110) and Au(111) via room temperature scanning tunneling microscopy and spectroscopy. Adsorbed on W(110), a comparatively strong bond to the endohedral fullerenes inhibited the formation of ordered monolayer islands. In contrast, the Au(111)-surface provides a sufficiently high mobility for the molecules to arrange in monolayer islands after annealing. Interestingly, the fullerenes modify the herringbone reconstruction indicating that the molecule–substrate interaction is of considerable extent. Investigations concerning the electronic structure of Er3N@C80/Au(111) reveals spatial variations dependent on the termination of the Au(111) at the interface.
CHARACTERISTICS OF THE ANGLO-JAPANESE NATION IN THE WORKS OF K. ISHIGURO.
Creators: name: Irsaliyeva, Madinakhon
Publisher: name: Zenodo
Year: 2024

description: It is known that modern English literature is rich in famous writers and Kadzuo Ishiguro is one of them. He is also considered as multicultural writer because we come across English and Japanese images in his most works. As he was born in Japan then moved to England and became English novelist. This writing provides some essential information about characteristics of the Anglo-Japanese nation in the works of K. Ishiguro.
Transformation thermal convection: Cloaking, concentrating, and camouflage
Creators: name: Dai, Gaole
name: Shang, Jin
name: Huang, Jiping
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Heat can generally transfer via thermal conduction, thermal radiation, and thermal convection. All the existing theories of transformation thermotics and optics can treat thermal conduction and thermal radiation, respectively. Unfortunately, thermal convection has never been touched in transformation theories due to the lack of a suitable theory, thus limiting applications associated with heat transfer through fluids (liquid or gas). Here, we develop, for the first time, a general theory of transformation thermal convection by considering the convection-diffusion equation, the Navier-Stokes equation, and the Darcy law. By introducing porous media, we get a set of coupled equations keeping their forms under coordinate transformation. As model applications, the theory helps to show the effects of cloaking, concentrating, and camouflage. Our finite element simulations confirm the theoretical findings. This work offers a general transformation theory for thermal convection, thus revealing some novel behaviors of thermal convection; it not only provides new hints on how to control heat transfer by combining thermal conduction, thermal radiation, and thermal convection, but also benefits the study of mass diffusion and other related fields that contain a set of equations and need to transform velocities at the same time.
description: 17 pages, 6 figures
Generating friendly learning environment and inclusive education for effective basic education in Nigeria.pdf
Creators: name: Orji, Evelyn   Ijeoma
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 399999
subject: Other education not elsewhere classified

description: It has become expedient for educators in Nigeria to acknowledge the fact that the global journey towards achieving education for all: (EFA) does depend on the effective basic education delivery to all her school going age children. Basic education school children in Nigeria comprise the young ones who constitute the potential human resources for leadership needed for the continuity of development of society. The young population at the basic level of education in Nigeria should not be deprived of access to …
Power Factor Measurement and Correction using Digital Controller Implemented on FPGA
Creators: name: IJMVSC
Publisher: name: Zenodo
Year: 2015

description: Power factor is a measure of how effectively the VA – rating of electrical equipment is being utilized. A high power factor means more effective utilization. It is also beneficial from the point of view of voltage regulation and reduction in ohmic losses. Therefore PFC-devices are being widely used in industry. The simplest way to improve power factor is to insert switchable static capacitors at the receiving end of a distribution system. The paper presents a novel digital power factor correction technique using Field Programmable Gate Array (FPGA) for a system. A hardware-efficient algorithm for power factor improvement has been developed. State diagram is used to design the phase angle measurement circuit. It attempts to keep the power fact or within narrow bounds (0.95-0.97 lagging).Experimental results have been presented to show the effectiveness of the proposed technique.The general purpose SPARTANE 3AN FPGA kit has been employed for developing the digital controller. All the coding has been done using the hardware description language VERILOG.
Functionalization of Ti-40Nb implant material with strontium by reactive sputtering
Creators: name: Göttlicher, Markus
name: Rohnke, Marcus
name: Moryson, Yannik
name: Thomas, Jürgen
name: Sann, Joachim
name: Lode, Anja
name: Schumacher, Matthias
name: Schmidt, Romy
name: Pilz, Stefan
name: Gebert, Annett
name: Gemming, Thomas
name: Janek, Jürgen
Publisher: name: London : BioMed Central
Year: 2017
Subjects: subject: Biocompatibility
subject: Osteoporosis
subject: Plasma deposition
subject: Strontium release
subject: Surface coating
subject: Titanium alloy
subject: 610
subject: 570
subject: 620
subject: 670

description: Background: Surface functionalization of orthopedic implants with pharmaceutically active agents is a modern approach to enhance osseointegration in systemically altered bone. A local release of strontium, a verified bone building therapeutic agent, at the fracture site would diminish side effects, which could occur otherwise by oral administration. Strontium surface functionalization of specially designed titanium-niobium (Ti-40Nb) implant alloy would provide an advanced implant system that is mechanically adapted to altered bone with the ability to stimulate bone formation. Methods: Strontium-containing coatings were prepared by reactive sputtering of strontium chloride (SrCl2) in a self-constructed capacitively coupled radio frequency (RF) plasma reactor. Film morphology, structure and composition were investigated by scanning electron microscopy (SEM), time of flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS). High-resolution transmission electron microscopy (HR-TEM) was used for the investigation of thickness and growth direction of the product layer. TEM lamellae were prepared using the focused ion beam (FIB) technique. Bioactivity of the surface coatings was tested by cultivation of primary human osteoblasts and subsequent analysis of cell morphology, viability, proliferation and differentiation. The results are correlated with the amount of strontium that is released from the coating in biomedical buffer solution, quantified by inductively coupled plasma mass spectrometry (ICP-MS). Results: Dense coatings, consisting of SrOxCly, of more than 100 nm thickness and columnar structure, were prepared. TEM images of cross sections clearly show an incoherent but well-structured interface between coating and substrate without any cracks. Sr2+ is released from the SrOxCly coating into physiological solution as proven by ICP-MS analysis. Cell culture studies showed excellent biocompatibility of the functionalized alloy. Conclusions: Ti-40Nb alloy, a potential orthopedic implant material for osteoporosis patients, could be successfully plasma coated with a dense SrOxCly film. The material performed well in in vitro tests. Nevertheless, the Sr2+ release must be optimized in future work to meet the requirements of an effective drug delivery system.
Non-Keplerian Charged Accretion Disk Orbiting a Black Hole~Pulsar
Creators: name: Trova, Audrey
name: Hackmann, Eva
Publisher: name: arXiv
Year: 2025
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Recent studies have focused on how spinning black holes (BHs) within a binary system containing a strongly magnetized neutron star, then immersed in external magnetic fields, can acquire charge through mechanisms like the Wald process and how this charge could power pulsar-like electromagnetic radiation. Those objects called ``Black hole pulsar'' mimic the behaviour of a traditional pulsar, and they can generate electromagnetic fields, such as magnetic dipoles. Charged particles within an accretion disk around the black hole would then be influenced not only by the gravitational forces but also by electromagnetic forces, leading to different geometries and dynamics. In this context, we focus here on the interplay of the magnetic dipole and the accretion disk. We construct the equilibrium structures of non-conducting charged perfect fluids orbiting Kerr black holes under the influence of a dipole magnetic field aligned with the rotation axis of the BH. The dynamics of the accretion disk in such a system are shaped by a complex interplay between the non-uniform, non-Keplerian angular momentum distribution, the black hole's induced magnetic dipole, and the fluid's charge. We show how these factors jointly influence key properties of the disk, such as its geometry, aspect ratio, size, and rest mass density.
description: 17 pages, 9 Figures (25 files)
Universality of the helimagnetic transition in cubic chiral magnets: Small angle neutron scattering and neutron spin echo spectroscopy studies of Fe$_{1-x}$Co$_x$Si
Creators: name: Bannenberg, L. J.
name: Kakurai, K.
name: Falus, P.
name: Lelièvre-Berna, E.
name: Dalgliesh, R. M.
name: Dewhurst, C. D.
name: Qian, F.
name: Onose, Y.
name: Endoh, Y.
name: Tokura, Y.
name: Pappas, C.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a comprehensive Small Angle Neutron Scattering (SANS) and Neutron Spin Echo Spectroscopy (NSE) study of the structural and dynamical aspects of the helimagnetic transition in Fe$_{1-x}$Co$_x$Si with $x$ = 0.30. In contrast to the sharp transition observed in the archetype chiral magnet MnSi, the transition in Fe$_{1-x}$Co$_x$Si is gradual and long-range helimagnetic ordering coexists with short-range correlations over a wide temperature range. The dynamics are more complex than in MnSi and involve long relaxation times with a stretched exponential relaxation which persists even under magnetic field. These results in conjunction with an analysis of the hierarchy of the relevant length scales show that the helimagnetic transition in Fe$_{1-x}$Co$_x$Si differs substantially from the transition in MnSi and question the validity of a universal approach to the helimagnetic transition in chiral magnets.
Tuning the spin coherence time of Cu(II)−(bis)oxamato and Cu(II)−(bis)oxamidato complexes by advanced ESR pulse protocols
Creators: name: Zaripov, Ruslan
name: Vavilova, Evgeniya
name: Khairuzhdinov, Iskander
name: Salikhov, Kev
name: Voronkova, Violeta
name: Abdulmalic, Mohammad A.
name: Meva, Francois E.
name: Weheabby, Saddam
name: Rüffer, Tobias
name: Büchner, Bernd
name: Kataev, Vladislav
Publisher: name: Frankfurt, M. : Beilstein-Institut zur Förderung der Chemischen Wissenschaften
Year: 2017
Subjects: subject: Electron spin echo
subject: ESR
subject: Hyperfine interaction
subject: Molecular complexes
subject: Spin coherence
subject: 620
subject: 540

description: We have investigated with the pulsed ESR technique at X- and Q-band frequencies the coherence and relaxation of Cu spins S = 1/2 in single crystals of diamagnetically diluted mononuclear [n-Bu4N]2[Cu(opba)] (1%) in the host lattice of [n-Bu4N]2[Ni(opba)] (99%, opba = o-phenylenebis(oxamato)) and of diamagnetically diluted mononuclear [n-Bu4N]2[Cu(opbon-Pr2)] (1%) in the host lattice of [n-Bu4N]2[Ni(opbon-Pr2)] (99%, opbon-Pr2 = o-phenylenebis(N(propyl)oxamidato)). For that we have measured the electron spin dephasing time Tm at different temperatures with the two-pulse primary echo and with the special Carr–Purcell–Meiboom–Gill (CPMG) multiple microwave pulse sequence. Application of the CPMG protocol has led to a substantial increase of the spin coherence lifetime in both complexes as compared to the primary echo results. It shows the efficiency of the suppression of the electron spin decoherence channel in the studied complexes arising due to spectral diffusion induced by a random modulation of the hyperfine interaction with the nuclear spins. We argue that this method can be used as a test for the relevance of the spectral diffusion for the electron spin decoherence. Our results have revealed a prominent role of the opba4– and opbon-Pr24– ligands for the dephasing of the Cu spins. The presence of additional 14N nuclei and protons in [Cu(opbon-Pr2)]2– as compared to [Cu(opba)]2– yields significantly shorter Tm times. Such a detrimental effect of the opbon-Pr24− ligands has to be considered when discussing a potential application of the Cu(II)−(bis)oxamato and Cu(II)−(bis)oxamidato complexes as building blocks of more complex molecular structures in prototype spintronic devices. Furthermore, in our work we propose an improved CPMG pulse protocol that enables elimination of unwanted echoes that inevitably appear in the case of inhomogeneously broadened ESR spectra due to the selective excitation of electron spins.
Root Mean Square Error of Neural Spike Train Sequence Matching with Optogenetics
Creators: name: Noel, Adam
name: Makrakis, Dimitrios
name: Eckford, Andrew W.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: Information Theory (cs.IT)
subject: Biological Physics (physics.bio-ph)
subject: FOS: Biological sciences
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Optogenetics is an emerging field of neuroscience where neurons are genetically modified to express light-sensitive receptors that enable external control over when the neurons fire. Given the prominence of neuronal signaling within the brain and throughout the body, optogenetics has significant potential to improve the understanding of the nervous system and to develop treatments for neurological diseases. This paper uses a simple optogenetic model to compare the timing distortion between a randomly-generated target spike sequence and an externally-stimulated neuron spike sequence. The distortion is measured by filtering each sequence and finding the root mean square error between the two filter outputs. The expected distortion is derived in closed form when the target sequence generation rate is sufficiently low. Derivations are verified via simulations.
description: 6 pages, 5 figures. Will be presented at IEEE Global Communications Conference (IEEE GLOBECOM 2017) in December 2017
Particle-hole symmetry and electromagnetic response of a half-filled Landau level
Creators: name: Levin, Michael
name: Son, Dam Thanh
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We derive exact physical consequences of particle-hole symmetry of the $ν=1/2$ state of electrons in a strong magnetic field. We show that if the symmetry is not spontaneously broken, the Hall conductivity and the susceptibility satisfy an exact relationship, valid at any wave numbers and any frequencies much below the cyclotron frequency. The relationship holds for clean systems and also for systems with statistically particle-hole symmetric disorder. We work out the constraints this relationship imposes on the theory of the Dirac composite fermion. We also argue that that the exact relationship is violated in the Halperin-Lee-Read (HLR) field theory and present an explicit calculation within a Galilean invariant mean-field approximation to the HLR theory to illustrate the breakdown.
description: 17 pages; v2: typos fixed, published version
Relativistic initial conditions for N-body simulations
Creators: name: Fidler, Christian
name: Tram, Thomas
name: Rampf, Cornelius
name: Crittenden, Robert
name: Koyama, Kazuya
name: Wands, David
Publisher: name: arXiv
Year: 2017
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Initial conditions for (Newtonian) cosmological N-body simulations are usually set by re-scaling the present-day power spectrum obtained from linear (relativistic) Boltzmann codes to the desired initial redshift of the simulation. This back-scaling method can account for the effect of inhomogeneous residual thermal radiation at early times, which is absent in the Newtonian simulations. We analyse this procedure from a fully relativistic perspective, employing the recently-proposed Newtonian motion gauge framework. We find that N-body simulations for LambdaCDM cosmology starting from back-scaled initial conditions can be self-consistently embedded in a relativistic space-time with first-order metric potentials calculated using a linear Boltzmann code. This space-time coincides with a simple "N-body gauge" for z<50 for all observable modes. Care must be taken, however, when simulating non-standard cosmologies. As an example, we analyse the back-scaling method in a cosmology with decaying dark matter, and show that metric perturbations become large at early times in the back-scaling approach, indicating a breakdown of the perturbative description. We suggest a suitable "forwards approach" for such cases.
description: 20 pages, 8 figures
Adaptive IGAFEM with optimal convergence rates: Hierarchical B-splines
Creators: name: Gantner, Gregor
name: Haberlik, Daniel
name: Praetorius, Dirk
Publisher: name: arXiv
Year: 2017
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: We consider an adaptive algorithm for finite element methods for the isogeometric analysis (IGAFEM) of elliptic (possibly non-symmetric) second-order partial differential equations in arbitrary space dimension $d\ge2$. We employ hierarchical B-splines of arbitrary degree and different order of smoothness. We propose a refinement strategy to generate a sequence of locally refined meshes and corresponding discrete solutions. Adaptivity is driven by some weighted residual a posteriori error estimator. We prove linear convergence of the error estimator (resp. the sum of energy error plus data oscillations) with optimal algebraic rates. Numerical experiments underpin the theoretical findings.
The Sound of Learning
Creators: name: Tasler, Nathalie
Publisher: name: figshare
Year: 2024
Subjects: classificationCode: 390303
subject: Higher education
classificationCode: 520403
subject: Learning, motivation and emotion

description: This week my teaching picks up again, making me reflect about a course I had begun taking on Coursera “Diversity and Inclusion in Education” just to see where I stand with the topic, and what I still ought to learn.Now there was an interesting prompt for reflection, about how we think about our learners, when we are planning their learning (yes I know that alone is a whole different blog post). Basically, what image–stereotype–do we have in our heads, and I thought that was such a strange question. Because this is not how I think when I plan my teaching. I think about the information, the story this content is telling, and how to create spaces within this story for engagement, ownership, play, reflection.
Stable schemes for dissipative particle dynamics with conserved energy
Creators: name: Stoltz, Gabriel
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Numerical Analysis (math.NA)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: This article presents a new numerical scheme for the discretization of dissipative particle dynamics with conserved energy. The key idea is to reduce elementary pairwise stochastic dynamics (either fluctuation/dissipation or thermal conduction) to effective single-variable dynamics, and to approximate the solution of these dynamics with one step of a Metropolis-Hastings algorithm. This ensures by construction that no negative internal energies are encountered during the simulation, and hence allows to increase the admissible timesteps to integrate the dynamics, even for systems with small heat capacities. Stability is only limited by the Hamiltonian part of the dynamics, which suggests resorting to multiple timestep strategies where the stochastic part is integrated less frequently than the Hamiltonian one.
Constraints of chromoelectric dipole moments to natural SUSY type sfermion spectrum
Creators: name: Maekawa, Nobuhiro
name: Muramatsu, Yu
name: Shigekami, Yoshihiro
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We investigate the lower bounds of sfermion masses from the constraints of chromoelectric dipole moments (CEDMs) in the natural SUSY-type sfermion mass spectrum, in which stop mass $m_{\tilde t}$ is much smaller than the other sfermion masses $m_0$. The natural SUSY-type sfermion mass spectrum has been studied since the supersymmetric (SUSY) flavor-changing neutral currents (FCNC) are suppressed because of large sfermion masses of the first two generations, and the weak scale is stabilized because of the light stop. However, this type of sfermion mass spectrum is severely constrained by CEDM, because the light stop contributions to the up quark CEDM are not decoupled in the limit $m_0\rightarrow\infty$, while the down quark CEDM is decoupled in the limit. It is important that the constraints are severe even if SUSY-breaking parameters (and Higgsino mass) are taken to be real because complex diagonalizing matrices of Yukawa matrices, which are from complex Yukawa couplings, generate nonvanishing CP phases in off-diagonal elements of sfermion mass matrices. We calculate the CEDM of up and down quarks numerically in the minimal SUSY standard model, and give the lower bounds for stop mass and the other sfermion masses. We show that the lower bound of stop mass becomes 7 TeV to satisfy the CEDM constraints from Hg EDM. The result is not acceptable if the weak scale stability is considered seriously. We show that if the up-type Yukawa couplings are taken to be real at the grand unification scale, the CEDM constraints are satisfied even if $m_{\tilde t}\sim 1$ TeV.
description: 22 pages, 9 figures, v3: texts are improved, comments are added, v4: texts are improved
Antiferromagnetic textures and dynamics on the surface of a heavy metal
Creators: name: Zarzuela, Ricardo
name: Tserkovnyak, Yaroslav
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We investigate the formation and dynamics of spin textures in antiferromagnetic insulators adjacent to a heavy-metal substrate with strong spin-orbit interactions. Exchange coupling to conduction electrons engenders an effective anisotropy, Dzyaloshinskii-Moriya interactions, and a magnetoelectric effect for the Néel order, which can conspire to produce nontrivial antiferromagnetic textures. Current-driven spin transfer enabled by the heavy metal, furthermore, triggers ultrafast (THz) oscillations of the Néel order for dc currents exceeding a critical threshold, opening up the possibility of Terahertz spin-torque self-oscillators. For a commonly invoked antidamping-torque geometry, however, the instability current scales with the energy gap of the antiferromagnetic insulator and, therefore, may be challenging to reach experimentally. We propose an alternative generic geometry for inducing ultrafast autonomous antiferromagnetic dynamics.
description: 5+2 pages, 3 figures
Charged-lepton decays from soft flavour violation
Creators: name: Aeikens, E. H.
name: Grimus, W.
name: Lavoura, L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We consider a two-Higgs-doublet extension of the Standard Model, with three right-handed neutrino singlets and the seesaw mechanism, wherein all the Yukawa-coupling matrices are lepton flavour-diagonal and lepton flavour violation is soft, originating solely in the non-flavour-diagonal Majorana mass matrix of the right-handed neutrinos. We consider the limit $m_R \to \infty$ of this model, where $m_R$ is the seesaw scale. We demonstrate that there is a region in parameter space where the branching ratios of all five charged-lepton decays $\ell_1^- \to \ell_2^- \ell_3^+ \ell_3^-$ are close to their experimental upper bounds, while the radiative decays $\ell_1^- \to \ell_2^- γ$ are invisible because their branching ratios are suppressed by $m_R^{-4}$. We also consider the anomalous magnetic moment of the muon and show that in our model the contributions from the extra scalars, both charged and neutral, can remove the discrepancy between its experimental and theoretical values.
description: 18 pages, changes in the abstract, extensive rewritting of section 5, three figures and one reference added, version matches publication in PLB
Empirische Untersuchung zum Wert von Versorgungssicherheit in Privathaushalten – eine Fallstudie im Energy Smart Home Lab
Creators: name: Scharnhorst, Leandra
name: Sandmeier, Thorben
name: Appel, Benedikt
name: Ardone, Armin
name: Fichtner, Wolf
Publisher: name: Karlsruher Institut für Technologie (KIT)
Year: 2023
Subjects: Zahlungsbereitschaft
Akzeptanzbereitschaft
Versorgungssicherheit
Privathaushalte

description: Durch die fortschreitende Dekarbonisierung des Energiesystems, sowie einem Mangel an Übertragungskapazitäten, steht die Gewährleistung der Versorgungssicherheit vor neuen Herausforderungen. Ein Lösungsansatz zum Umgang mit Extremsituationen besteht in der kontrollierten Abschaltung von Verbrauchen. In der Industrie bereits zum Teil umgesetzt, wurde für Privathaushalte die Bereitschaft zur Erbringung von Flexibilität durch kontrollierte Stromabschaltungen bislang nur durch hypothetische Szenarien in Befragungen untersucht.

Zur näheren Analyse wurde ein Praxis-Experiment im Reallabor Energy Smart Home Lab durchgeführt. Dabei wurden die VerbraucherInnen mit kontrollierten Stromabschaltungen unter Berücksichtigung der Akzeptanz- und Zahlungsbereitschaften konfrontiert. Neben einer Bewertung der Versorgungssicherheit, beleuchten wir die Reaktionen und Verhaltensanpassungen der VerbraucherInnen.
Mandated Learning: Administrators' Perceptions of Unfunded Mandates in Online Education
Creators: name: Hennen, Ronald Aaron
Publisher: name: Zenodo
Year: 2023
Subjects: online learning, unfunded mandates, administrator perception, policy, survey research, education

description: Online education has become a solution for many states to facilitate the growing requests from state legislatures to lower educational costs while meeting the academic needs of students. Legislation from Florida provided the impetus for this study, after Florida CS/CS/HB 7197 mandated that all students enroll in an online class for 1 credit as a graduation requirement. While the rationale for such legislation may be cost savings, for most school districts, implementation may be viewed as an unfunded state mandate. The purpose of this study was to examine administrator’s perceptions of mandated online teaching as an additional financial burden on school districts. This quantitative study explored administrator’s perceptions of online learning and the relationship of these perceptions to unfunded mandates requiring online coursework. While no significant relationship was found in administrator perceptions of online learning and perceptions of unfunded mandates, administrators generally agreed that unfunded mandates impact almost every aspect of their professional role and responsibilities as an administrator, including work conditions, and work satisfaction. This study took place during the global pandemic; however, the intent of this study was not to research the effects of the COVID -19 pandemic on education. Recommendations for future study and implications are included.
On Geodesic Completeness for Riemannian Metrics on Smooth Probability Densities
Creators: name: Bauer, Martin
name: Joshi, Sarang
name: Modin, Klas
Publisher: name: arXiv
Year: 2017
Subjects: subject: Analysis of PDEs (math.AP)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 58B20, 58E10, 35G25, 35Q31, 76N10

description: The geometric approach to optimal transport and information theory has triggered the interpretation of probability densities as an infinite-dimensional Riemannian manifold. The most studied Riemannian structures are Otto's metric, yielding the $L^2$-Wasserstein distance of optimal mass transport, and the Fisher--Rao metric, predominant in the theory of information geometry. On the space of smooth probability densities, none of these Riemannian metrics are geodesically complete---a property desirable for example in imaging applications. That is, the existence interval for solutions to the geodesic flow equations cannot be extended to the whole real line. Here we study a class of Hamilton--Jacobi-like partial differential equations arising as geodesic flow equations for higher-order Sobolev type metrics on the space of smooth probability densities. We give order conditions for global existence and uniqueness, thereby providing geodesic completeness. The system we study is an interesting example of a flow equation with loss of derivatives, which is well-posed in the smooth category, yet non-parabolic and fully non-linear. On a more general note, the paper establishes a link between geometric analysis on the space of probability densities and analysis of Euler-Arnold equations in topological hydrodynamics.
description: 19 pages, accepted in Calc. Var. Partial Differential Equations (2017)
Additional file 1 of Insulinaemic potential of diet and lifestyle and risk of type 2 diabetes in the Iranian adults: result from Yazd health study
Creators: name: Omrani, Morteza
name: Hosseinzadeh, Mahdieh
name: Shab Bidar, Sakineh
name: Mirzaei, Masoud
name: Teymoori, Farshad
name: Nadjarzadeh, Azadeh
name: Firouzabadi, Fatemeh Dehghani
name: Rahideh, Seyedeh Tayebeh
Publisher: name: figshare
Year: 2023
Subjects: subject: Medicine
subject: Biotechnology
subject: Sociology
subject: FOS: Sociology
subject: Cancer

description: Supplementary Material 1
Synchronization scenarios in the Winfree model of coupled oscillators
Creators: name: Gallego, Rafael
name: Montbrió, Ernest
name: Pazó, Diego
Publisher: name: arXiv
Year: 2017
Subjects: subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: FOS: Physical sciences

description: The emergence of collective synchronization was reproduced long ago by Winfree in a classical model consisting of an ensemble of pulse-coupled phase oscillators. By means of the Ott-Antonsen ansatz, we derive an exact low-dimensional representation which is exhaustively investigated for a variety of pulse types and phase response curves (PRCs). Two structurally different synchronization scenarios are found, which are linked via the mutation of a Bogdanov-Takens point. From our results, we infer a general rule of thumb relating pulse shape and PRC offset with each scenario. Finally, we compare the exact synchronization threshold with the prediction of the averaging approximation given by the Kuramoto-Sakaguchi model. At the leading order, the discrepancy appears to behave as an odd function of the PRC offset.
title: A systematic approach to develop recommendations for surface exploration of siting regions for a radioactive waste repository in Germany
Creators: name:  Richter ,  Lisa
name:  Beilecke ,  Thies
name:  Dlugosch ,  Raphael
name:  Kneuker ,  Tilo
name:  Pollok ,  Lukas
name:  Schubarth-Engelschall ,  Nicole
name:  Semroch,  Ralf
Publisher: name: Deutsche Geologische Gesellschaft - Geologische Vereinigung e.V. (DGGV)
Year: 2021

description: The site selection procedure for a high-level radioactive waste repository in Germany is based on the Repository Site Selection Act (StandAG, 2017) and comprises three phases. Commissioned by the Bundesgesellschaft für Endlagerung mbH (BGE), the BGR contributes to this procedure with the projects „GeoMePS“ and „ZuBeMErk“, which aim to develop recommendations for phase 2 of the site selection procedure – the surface exploration of siting regions. For this purpose, the BGR has developed a systematic approach that includes (1) deducing exploration targets, (2) compilation of geoscientific and geophysical exploration methods in a database structure, and (3) evaluation of case studies of national and international exploration programs. The deduction of exploration targets was based on the criteria and requirements as defined by the StandAG. Subsequently, the identified exploration targets together with a large number of geoscientific (e.g., geological mapping) and geophysical exploration methods (e.g., reflection seismics) were integrated and linked within the database – the so-called “GeM-DB”. All methods were evaluated according to their suitability and applicability for (a) the three defined host rocks (crystalline rock, claystone, rock salt) and (b) the previously defined exploration targets. In step (3) the BGR evaluates national and international exploration programs, for example the site selection processes for deep geological repositories in Switzerland or Sweden, to infer additional exploration directives.The entire systematic approach aims to develop recommendations for a non-destructive and minimal invasive surface exploration program of siting regions in Germany, regarding the lithological, structural, mechanical, and hydrogeological characterization of the different host rock formations.
Thermal conductance and thermoelectric figure of merit of C$_{60}$-based single-molecule junctions: electrons, phonons, and photons
Creators: name: Klöckner, Jan Christopher
name: Siebler, Robert
name: Cuevas, Juan Carlos
name: Pauly, Fabian
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Motivated by recent experiments, we present here an ab initio study of the impact of the phonon transport on the thermal conductance and thermoelectric figure of merit of C$_{60}$-based single-molecule junctions. To be precise, we combine density functional theory with nonequilibrium Green's function techniques to compute these two quantities in junctions with either a C$_{60}$ monomer or a C$_{60}$ dimer connected to gold electrodes, taking into account the contributions of both electrons and phonons. Our results show that for C$_{60}$ monomer junctions phonon transport plays a minor role in the thermal conductance and, in turn, in the figure of merit, which can reach relatively high values on the order of 0.1, depending on the contact geometry. At the contrary, phonons completely dominate the thermal conductance in C$_{60}$ dimer junctions and strongly reduce the figure of merit as compared to monomer junctions. Thus, claims that by stacking C$_{60}$ molecules one could achieve high thermoelectric performance, which have been made without considering the phonon contribution, are not justified. Moreover, we analyze the relevance of near-field thermal radiation for the figure of merit of these junctions within the framework of fluctuational electrodynamics. We conclude that photon tunneling can be another detrimental factor for the thermoelectric performance, which has been overlooked so far in the field of molecular electronics. Our study illustrates the crucial roles that phonon transport and photon tunneling can play when critically assessing the performance of molecular junctions as potential nanoscale thermoelectric devices.
Thermodynamics of Regular Accelerating Black Holes
Creators: name: Astorino, Marco
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Using the covariant phase space formalism, we compute the conserved charges for a solution, describing an accelerating and electrically charged Reissner-Nordstrom black hole. The metric is regular provided that the acceleration is driven by an external electric field, in spite of the usual string of the standard C-metric. The Smarr formula and the first law of black hole thermodynamics are fulfilled. The resulting mass has the same form of the Christodoulou-Ruffini mass formula. On the basis of these results, we can extrapolate the mass and thermodynamics of the rotating C-metric, which describes a Kerr-Newman-(A)dS black hole accelerated by a pulling string.
description: 17 pages, 2 figures ; v2: extended to fulfil journal requirements, typos corrected
Recovering the mass profile and orbit anisotropy of mock dwarf galaxies with Schwarzschild modelling
Creators: name: Kowalczyk, Klaudia
name: Lokas, Ewa L.
name: Valluri, Monica
Publisher: name: arXiv
Year: 2017
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a new study concerning the application of the Schwarzschild orbit superposition method to model spherical galaxies. The method aims to recover the mass and the orbit anisotropy parameter profiles of the objects using measurements of positions and line-of-sight velocities usually available for resolved stellar populations of dwarf galaxies in the Local Group. To test the reliability of the method, we used different sets of mock data extracted from four numerical realizations of dark matter haloes. The models shared the same density profile but differed in anisotropy profiles, covering a wide range of possibilities, from constant to increasing and decreasing with radius. The tests were done in two steps, first assuming that the mass profile of the dwarf is known and employing the method to retrieve the anisotropy only, and then varying also the mass distribution. We used two kinds of data samples: unrealistically large ones based on over 270 000 particles from the numerical realizations and small ones matching the amount of data available for the Fornax dwarf. For the large data samples we recover both the mass and the anisotropy profiles with very high accuracy. For the realistically small ones we also find a reasonably good agreement between the fitted and the input anisotropies, however the total density profiles can be significantly biased as a result of their oversensitivity to the available data. Our results therefore provide convincing evidence in favour of the applicability of the Schwarzschild method to break the mass-anisotropy degeneracy in dwarf galaxies.
description: 12 pages, 11 figures, accepted for publication in MNRAS
Birth of the GUP and its effect on the entropy of the Universe in Lie-$N$-algebra
Creators: name: Sepehri, Alireza
name: Pradhan, Anirudh
name: Pincak, Richard
name: Rahaman, Farook
name: Beesham, A.
name: Ghaffary, Tooraj
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: In this paper, the origin of the generalized uncertainty principle (GUP) in an $M$-dimensional theory with Lie-$N$-algebra is considered. This theory which we name GLNA(Generalized Lie-$N$-Algebra)-theory can be reduced to $M$-theory with $M=11$ and $N=3$. In this theory, at the beginning, two energies with positive and negative signs are created from nothing and produce two types of branes with opposite quantum numbers and different numbers of timing dimensions. Coincidence with the birth of these branes, various derivatives of bosonic fields emerge in the action of the system which produce the $r$ GUP for bosons. These branes interact with each other, compact and various derivatives of spinor fields appear in the action of the system which leads to the creation of the GUP for fermions. The previous predicted entropy of branes in the GUP is corrected as due to the emergence of higher orders of derivatives and different number of timing dimensions.
description: 15 pages. Published in International Journal of Geometric Methods in Modern Physics, Vol. 14 (2017) 1750130