cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
From Popov-Fedotov trick to universal fermionization
Creators: name: Prokof'ev, Nikolay
name: Svistunov, Boris
Publisher: name: arXiv
Year: 2011
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We show that Popov-Fedotov trick of mapping spin-1/2 lattice systems on two-component fermions with imaginary chemical potential readily generalizes to bosons with a fixed (but not limited) maximal site occupation number, as well as to fermionic Hamiltonians with various constraints on the site Fock states. In a general case, the mapping---fermionization---is on multi-component fermions with many-body non-Hermitian interactions. Additionally, the fermionization approach allows one to convert large many-body couplings into single-particle energies, rendering the diagrammatic series free of large expansion parameters; the latter is essential for the efficiency and convergence of the diagrammatic Monte Carlo method.
description: 4 pages, no figures (v2 contains some improvements; the most important one is the generic complex chemical potential trick for spins/bosons)
Semiclassical Boltzmann transport theory for graphene multilayers
Creators: name: Min, Hongki
name: Jain, Parakh
name: Adam, S.
name: Stiles, M. D.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We calculate the conductivity of arbitrarily stacked multilayer graphene sheets within a relaxation time approximation, considering both short-range and long-range impurities. We theoretically investigate the feasibility of identifying the stacking order of these multilayers using transport measurements. For relatively clean samples, the conductivities of the various stacking configurations depend on the carrier density as a power-law for over two decades. This dependence arises from a low density decomposition of the multilayer band structure into a sum of chiral Hamiltonians. For dirty samples, the simple power-law relationship no longer holds. Nonetheless, identification of the number of layers and stacking sequence is still possible by careful comparison of experimental data to the results presented here.
description: 13 pages, 5 figures; The revised version has been accepted for publication in PRB, and includes the effects of multiband screening and interband/intervalley scattering
Li+ Pre-Insertion Leads to Formation of Solid Electrolyte Interface on TiO2 Nanotubes That Enables High-Performance Anodes for Sodium Ion Batteries
Creators: name: Cha, Gihoon
name: Mohajernia, Shiva
name: Nguyen, Nhat Truong
name: Mazare, Anca
name: Denisov, Nikita
name: Hwang, Imgon
name: Schmuki, Patrik
Publisher: name: FID GEO
Year: 2019

description: Abstract Recently, sodium ion batteries (SIBs) have been widely investigated as one of the most promising candidates for replacing lithium ion batteries (LIBs). For SIBs or LIBs, designing a stable and uniform solid electrolyte interphase (SEI) at the electrode–electrolyte interface is the key factor to provide high capacity, long-term cycling, and high-rate performance. In this paper, it is described how a remarkably enhanced SEI layer can be obtained on TiO2 nanotube (TiO2 NTs) arrays that allows for a strongly improved performance of sodium battery systems. Key is that a Li+ pre-insertion in TiO2 NTs can condition the SEI for Na+ replacement. SIBs constructed with Li-pre-inserted NTs deliver an exceptional Na+ cycling stability (e.g., 99.9 ± 0.1% capacity retention during 250 cycles at a current rate of 50 mA g−1) and an excellent rate capability (e.g., 132 mA h g−1 at a current rate of 1 A g−1). The key factor in this outstanding performance is that Li-pre-insertion into TiO2 NTs leads not only to an enhanced electronic conductivity in the tubes, but also expands the anatase lattice for facilitated subsequent Na+ cycling.
Splash singularity for water waves
Creators: name: Castro, Angel
name: Córdoba, Diego
name: Fefferman, Charles
name: Gancedo, Francisco
name: Gómez-Serrano, Javier
Publisher: name: arXiv
Year: 2011
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We exhibit smooth initial data for the 2D water wave equation for which we prove that smoothness of the interface breaks down in finite time. Moreover, we show a stability result together with numerical evidence that there exist solutions of the 2D water wave equation that start from a graph, turn over and collapse in a splash singularity (self intersecting curve in one point) in finite time.
description: 19 pages, 4 figures
Quantitative study of two- and three-dimensional strong localization of matter waves by atomic scatterers
Creators: name: Antezza, Mauro
name: Castin, Yvan
name: Hutchinson, David
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: We study the strong localization of atomic matter waves in a disordered potential created by atoms pinned at the nodes of a lattice, for both three-dimensional (3D) and two-dimensional (2D) systems. The localization length of the matter wave, the density of localized states, and the occurrence of energy mobility edges (for the 3D system), are numerically investigated as a function of the effective scattering length between the atomic matter wave and the pinned atoms. Both positive and negative matter wave energies are explored. Interesting features of the density of states are discovered at negative energies, where maxima in the density of bound states for the system can be interpreted in terms of bound states of a matter wave atom with a few pinned atomic scatterers. In 3D we found evidence of up to three mobility edges, one at positive energies, and two at negative energies, the latter corresponding to transitions between extended and localized bound states. In 2D, no mobility edge is found, and a rapid exponential-like increase of the localization length is observed at high energy.
Sensory deafferentation modulates and redistributes neurocan in the rat auditory brainstem
Creators: name: Heusinger, Josef
name: Hildebrandt, Heika
name: Illing, Robert-Benjamin
Publisher: name: FID GEO
Year: 2019

description: Abstract Introduction Cochlear ablation causing sensory deafferentation (SD) of the cochlear nucleus triggers complex re-arrangements in the cellular and molecular communication networks of the adult mammalian central auditory system. Participation of the extracellular matrix (ECM) in these processes is not well understood. Methods We investigated consequences of unilateral SD for the expression and distribution of the chondroitin sulfate proteoglycans, neurocan (Ncan) and aggrecan (Agg), alongside various plasticity markers in the auditory brainstem of the adult rat using immunohistochemical techniques. Results In the deafferented ventral cochlear nucleus (VCN), Ncan expression increased massively within 3 postoperative days (POD), but rapidly decreased thereafter. Agg showed a similar but less pronounced progression. Decrease in Ncan was spatially and temporally related to the re-innervation of VCN documented by the emergence of growth-associated protein Gap43 contained in nerve fibers and presynaptic boutons. Concurrently, astrocytes grew and expressed matrix metalloproteinase-2 (MMP2), an enzyme known to emerge only under re-innervation of VCN. MMP2 is capable of cleaving both Ncan and Agg when released. A transient modulation of the ECM in the central inferior colliculus on the side opposite to SD occurred by POD1. Modulations of glutamatergic synapses and Gap43 expression were detected, reflecting state changes of the surrounding tissue induced by transsynaptic effects of SD. Conclusions The ECM variously participates in adaptive responses to sudden deafness by SD on several levels along the central auditory pathway, with a striking spatial and temporal relationship of Ncan modulation to astrocytic activation and to synaptogenesis.
The weak password problem: chaos, criticality, and encrypted p-CAPTCHAs
Creators: name: Laptyeva, T. V.
name: Flach, S.
name: Kladko, K.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cryptography and Security (cs.CR)
subject: Other Condensed Matter (cond-mat.other)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Vulnerabilities related to weak passwords are a pressing global economic and security issue. We report a novel, simple, and effective approach to address the weak password problem. Building upon chaotic dynamics, criticality at phase transitions, CAPTCHA recognition, and computational round-off errors we design an algorithm that strengthens security of passwords. The core idea of our method is to split a long and secure password into two components. The first component is memorized by the user. The second component is transformed into a CAPTCHA image and then protected using evolution of a two-dimensional dynamical system close to a phase transition, in such a way that standard brute-force attacks become ineffective. We expect our approach to have wide applications for authentication and encryption technologies.
description: 5 pages, 6 figers
Shedding Light on the Galaxy Luminosity Function
Creators: name: Johnston, Russell
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: From as early as the 1930s, astronomers have tried to quantify the statistical nature of the evolution and large-scale structure of galaxies by studying their luminosity distribution as a function of redshift - known as the galaxy luminosity function (LF). Accurately constructing the LF remains a popular and yet tricky pursuit in modern observational cosmology where the presence of observational selection effects due to e.g. detection thresholds in apparent magnitude, colour, surface brightness or some combination thereof can render any given galaxy survey incomplete and thus introduce bias into the LF. Over the last seventy years there have been numerous sophisticated statistical approaches devised to tackle these issues; all have advantages -- but not one is perfect. This review takes a broad historical look at the key statistical tools that have been developed over this period, discussing their relative merits and highlighting any significant extensions and modifications. In addition, the more generalised methods that have emerged within the last few years are examined. These methods propose a more rigorous statistical framework within which to determine the LF compared to some of the more traditional methods. I also look at how photometric redshift estimations are being incorporated into the LF methodology as well as considering the construction of bivariate LFs. Finally, I review the ongoing development of completeness estimators which test some of the fundamental assumptions going into LF estimators and can be powerful probes of any residual systematic effects inherent magnitude-redshift data.
description: 95 pages, 23 figures, 3 tables. Now published in The Astronomy & Astrophysics Review. This version: bring in line with A&AR format requirements, also minor typo corrections made, additional citations and higher rez images added
Diagnosis of Malaria Parasites Plasmodium spp. in Endemic Areas: Current Strategies for an Ancient Disease
Creators: name: Gitta, Brian
name: Kilian, Nicole
Publisher: name: FID GEO
Year: 2019

description: Abstract Fast and effective detection of the causative agent of malaria in humans, protozoan Plasmodium parasites, is of crucial importance for increasing the effectiveness of treatment and to control a devastating disease that affects millions of people living in endemic areas. The microscopic examination of Giemsa-stained blood films still remains the gold-standard in Plasmodium detection today. However, there is a high demand for alternative diagnostic methods that are simple, fast, highly sensitive, ideally do not rely on blood-drawing and can potentially be conducted by the patients themselves. Here, the history of Plasmodium detection is discussed, and advantages and disadvantages of diagnostic methods that are currently being applied are assessed.
The role of electron-electron scattering in spin transport
Creators: name: Kamra, Akashdeep
name: Ghosh, Bahniman
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We investigate spin transport in quasi 2DEG formed by III-V semiconductor heterojunctions using the Monte Carlo method. The results obtained with and without electron-electron scattering are compared and appreciable difference between the two is found. The electron-electron scattering leads to suppression of Dyakonov-Perel mechanism (DP) and enhancement of Elliott-Yafet mechanism (EY). Finally, spin transport in InSb and GaAs heterostructures is investigated considering both DP and EY mechanisms. While DP mechanism dominates spin decoherence in GaAs, EY mechanism is found to dominate in high mobility InSb. Our simulations predict a lower spin relaxation/decoherence rate in wide gap semiconductors which is desirable for spin transport.
description: to appear in Journal of Applied Physics
Thermodynamic Reaction Control of Nucleoside Phosphorolysis
Creators: name: Kaspar, Felix
name: Giessmann, Robert T.
name: Neubauer, Peter
name: Wagner, Anke
name: Gimpel, Matthias
Publisher: name: FID GEO
Year: 2020

description: Abstract Nucleoside analogs represent a class of important drugs for cancer and antiviral treatments. Nucleoside phosphorylases (NPases) catalyze the phosphorolysis of nucleosides and are widely employed for the synthesis of pentose-1-phosphates and nucleoside analogs, which are difficult to access via conventional synthetic methods. However, for the vast majority of nucleosides, it has been observed that either no or incomplete conversion of the starting materials is achieved in NPase-catalyzed reactions. For some substrates, it has been shown that these reactions are reversible equilibrium reactions that adhere to the law of mass action. In this contribution, we broadly demonstrate that nucleoside phosphorolysis is a thermodynamically controlled endothermic reaction that proceeds to a reaction equilibrium dictated by the substrate-specific equilibrium constant of phosphorolysis, irrespective of the type or amount of NPase used, as shown by several examples. Furthermore, we explored the temperature-dependency of nucleoside phosphorolysis equilibrium states and provide the apparent transformed reaction enthalpy and apparent transformed reaction entropy for 24 nucleosides, confirming that these conversions are thermodynamically controlled endothermic reactions. This data allows calculation of the Gibbs free energy and, consequently, the equilibrium constant of phosphorolysis at any given reaction temperature. Overall, our investigations revealed that pyrimidine nucleosides are generally more susceptible to phosphorolysis than purine nucleosides. The data disclosed in this work allow the accurate prediction of phosphorolysis or transglycosylation yields for a range of pyrimidine and purine nucleosides and thus serve to empower further research in the field of nucleoside biocatalysis. image
Exploring repletism in honeypot ants through an evolutionary and microbial lens
Creators: name: Sawh, Indira
Publisher: name: No Publisher Supplied
Year: 2023

description: Through time, ants have developed different adaptations as a means of survival, one being caste specialization. Lineages with a specialized honeypot ant replete caste have acquired an innovative means of food storage. Honeypot ant repletes store liquid food in their crop which is redistributed through trophallaxis when food sources are scarce. Repletism is found across distantly related ant genera, but the temporal history and phylogenetic distribution of this phenotypic phenomena remains unknown. I reconstructed the evolutionary history of this adaptive behavior and examine the role of microbes in repletism. I expected that this dietary adaptation would be consistent with a conserved microbiota. I described the first known instance of repletism in the fossil record in the genus Leptomyrmex from Dominican amber dating to approximately 16 mya. I mapped the history of this trait onto a time-calibrated phylogeny of extant ants; results suggest that certain lineages are more prone to repletism, and that the origin likely occurred in the Eocene and Miocene. To determine if honeypot ants have a resident gut microbiome, I isolated bacteria from the crop and midgut of Myrmecocystus honeypot ants. I isolated a total of 150 microbes, belonging to five phyla: Bacillota, Actinomycetota, Proteobacteria, Ascomycota and Basidiomycota. Using 16S rRNA sequences, I reconstructed phylogenies of the isolated microbes and closely related strains from the same genera. I used presence/absence data of these different genera to look for patterns of association with their ant hosts. Additionally, I performed tannin degradation assays using isolates to test the degradation of known acids from the toxic creosote bush, a common food source for Myrmecocystus honeypot ants. My preliminary data suggest that honeypot ants have a resident gut microbiome and some of these microbes may play a role in detoxifying tannins. The gut microbiome may play an important role in the ability of repletes to retain liquid for long periods of time, remediate toxins, or supplement nutrients. My study of the evolutionary history of this behavior in combination with analysis of the gut microbiome provides the starting point to further studies of the evolution and natural history of this convergently-evolved trait.
Casimir micro-sphere diclusters and three-body effects in fluids
Creators: name: Varela, Jaime
name: Rodriguez, Alejandro W.
name: McCauley, Alexander P.
name: Johnson, Steven G.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Our previous article [Phys. Rev. Lett. 104, 060401 (2010)] predicted that Casimir forces induced by the material-dispersion properties of certain dielectrics can give rise to stable configurations of objects. This phenomenon was illustrated via a dicluster configuration of non-touching objects consisting of two spheres immersed in a fluid and suspended against gravity above a plate. Here, we examine these predictions from the perspective of a practical experiment and consider the influence of non-additive, three-body, and nonzero-temperature effects on the stability of the two spheres. We conclude that the presence of Brownian motion reduces the set of experimentally realizable silicon/teflon spherical diclusters to those consisting of layered micro-spheres, such as the hollow- core (spherical shells) considered here.
description: 11 pages, 9 figures
Nonlinear order parameter oscillations and lattice coupling in strongly-driven charge-density-wave systems
Creators: name: Kusar, P.
name: Mertelj, T.
name: Kabanov, V. V.
name: Fisher, I. R.
name: Berger, H.
name: Forró, L.
name: Mihailovic, D.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The anharmonic response of charge-density wave (CDW) order to strong laser-pulse perturbations in 1T-TaS_2 and TbTe_3 is investigated by means of a multiple-pump-pulse time-resolved femtosecond optical spectroscopy. We observe remarkable anharmonic effects hitherto undetected in the systems exhibiting collective charge ordering. The efficiency for additional excitation of the amplitude mode by a laser pulse becomes periodically modulated after the mode is strongly excited into a coherently oscillating state. A similar effect is observed also for some other phonons, where the cross-modulation at the amplitude-mode frequency indicates anharmonic interaction of those phonons with the amplitude mode. By analyzing the observed phenomena in the framework of time-dependent Ginzburg-Landau theory we attribute the effects to the anharmonicity of the mode potentials inherent to the broken symmetry state of the CDW systems.
On Non-Linear Actions for Massive Gravity
Creators: name: Hassan, S. F.
name: Rosen, Rachel A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In this work we present a systematic construction of the potentially ghost-free non-linear massive gravity actions. The most general action can be regarded as a 2-parameter deformation of a minimal massive action. Further extensions vanish in 4 dimensions. The general mass term is constructed in terms of a "deformed" determinant from which this property can clearly be seen. In addition, our formulation identifies non-dynamical terms that appear in previous constructions and which do not contribute to the equations of motion. We elaborate on the formal structure of these theories as well as some of their implications.
description: v3: 22 pages, minor comments added, version to appear in JHEP
A new risk score for patients after first recurrence of stage 4 neuroblastoma aged ≥18 months at first diagnosis
Creators: name: Kreitz, Kiana
name: Ernst, Angela
name: Schmidt, René
name: Simon, Thorsten
name: Fischer, Matthias
name: Volland, Ruth
name: Hero, Barbara
name: Berthold, Frank
Publisher: name: FID GEO
Year: 2019

description: Abstract Background The prognosis of patients with recurrences from stage 4 neuroblastoma is not uniformly dismal. The evaluation of new therapies therefore needs to consider the individual risks of the treated patients. This study aims to define clinically useful risk criteria. Patients and Methods Inclusion criteria were: first recurrence of neuroblastoma stage 4 aged ≥18 months and enrollment in first line trials between 1997 and 2016. Patients were randomized into a training set (N = 310) and an independent validation set (N = 159). The primary endpoint was secondary event-free survival. The individual treatment elements the patients received during initial and recurrent disease were analyzed as binary and time-dependent variables. A five-step multiple time-dependent Cox regression analysis was performed on the training set to identify prognostic variables adjusted for the individual frontline treatment. The selected variables resulted in a prognostic index (PI) and were used to build a risk score system. The score was validated with the validation set. Results Of the 469 patients, 372 were treated with curative intent and 97 with palliative intent. The PI included the variables number of recurrence organs (hazard ratio [HR] = 2.27), time to recurrence (HR = 2.03), liver metastasis at diagnosis (HR = 1.77), first recurrence at site of the primary tumor (HR = 1.55), and age (HR = 1.29). Three risk groups were built and confirmed in the validation set. The scoring system was likewise useful for the curatively or palliatively treated subgroups. Conclusion A new risk score system for patients with first recurrence of stage 4 neuroblastoma aged ≥18 months at diagnosis is proposed.
Low-Voltage Operation of Ring Oscillators Based on Room-Temperature-Deposited Amorphous Zinc-Tin-Oxide Channel MESFETs
Creators: name: Lahr, Oliver
name: Vogt, Sofie
name: Von Wenckstern, Holger
name: Grundmann, Marius
Publisher: name: FID GEO
Year: 2019

description: Abstract Schottky diode FET logic (SDFL) ring oscillator circuits comprising metal-semiconductor field-effect transistors (MESFETs) based on amorphous zinc-tin-oxide (ZTO) n-channels are presented. The ZTO channel layers are deposited entirely at room temperature by long-throw magnetron sputtering. Best MESFETs exhibit on/off current ratios as high as 8.6 orders of magnitude, a sub-threshold swing as low as 250 mV dec−1, and a maximum transconductance of 205 µS. Corresponding inverters show peakge gain magnitude (pgm) values of 83 with uncertainty levels as low as 0.5 V at an operating voltage of 5 V. Single stage delay times down to 277 ns are measured for three-stage ring oscillators, corresponding to oscillation frequencies as high as 451 kHz. Oscillations are observed at operating voltages as low as 3 V. These results prove the feasibility of room-temperature-deposited, amorphous semiconducting oxide based integrated circuits with SDFL layout. The presented approach provides more efficient as well as fail-safe device fabrication and similar oscillation frequencies at significantly lower operating voltages compared to conventional, high-temperature processed logic circuits based on insulating gates.
Measurement of the branching fraction of B to tau nu decays at the Belle experiment
Creators: name: Kronenbitter, Bastian
Publisher: name: Karlsruhe
Year: 2014

description: This thesis describes the measurement of the branching fraction of B to tau nu decays using the full data sample of the Japanese Belle experiment. The measurement uses the semileptonic tagging algorithm and gives a result of [1.25 ± 0.28(stat.) ± 0.27(syst.)] x 10^-4. Another topic described in this thesis is the development of a track-finding algorithm for the upcoming Belle 2 experiment.
Photo-Driven Ion Transport for a Photodetector Based on an Asymmetric Carbon Nitride Nanotube Membrane
Creators: name: Xiao, Kai
name: Tu, Bin
name: Chen, Lu
name: Heil, Tobias
name: Wen, Liping
name: Jiang, Lei
name: Antonietti, Markus
Publisher: name: FID GEO
Year: 2019

description: Abstract Conventional photosensing devices work mainly by electron processing and transport, while visual systems in intelligence work by integrative ion/electron signals. To realize smarter photodetectors, some photoionic device or the combination of ionic and electronic devices are necessary. Now, an ion-transport-based self-powered photodetector is presented based on an asymmetric carbon nitride nanotube membrane, which can realize fast, selective, and stable light detection while being self-powered. Local charges are continuously generated at the irradiated side of the membrane, and none (fewer) at the non-irradiated side. The resulting surface charge gradient in carbon nitride nanotube will drive ion transport in the cavity, thus realizing the function of ionic photodetector. With advantages of low cost and easy fabrication process, the concept of ionic photodetectors based on carbon nitride anticipates wide applications for semiconductor biointerfaces.
Supersymmetry in the Light of Dark Matter and a 125 GeV Higgs Boson
Creators: name: Beskidt, Conny Renate
Publisher: name: Karlsruhe
Year: 2014
Subjects: Supersymmetry
Higgs Boson
Dark Matter

description: Supersymmetry (SUSY) is a well-motivated theory beyond the Standard Model (SM). It solves many problems of the SM simultaneously but the predicted SUSY particles have not been found yet. In this work the parameter space allowed by accelerator and cosmological constraints is determined for two SUSY models and their differences in the Higgs and dark matter sector are highlighted. Furthermore, the discovery reach for current SUSY searches and for the next run of future experiments are estimated.
Field theory of bicritical and tetracritical points. IV. Critical dynamics including reversible terms
Creators: name: Folk, R.
name: Holovatch, Yu.
name: Moser, G.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: This article concludes a series of papers (R. Folk, Yu. Holovatch, and G. Moser, Phys. Rev. E 78, 041124 (2008); 78, 041125 (2008); 79, 031109 (2009)) where the tools of the field theoretical renormalization group were employed to explain and quantitatively describe different types of static and dynamic behavior in the vicinity of multicritical points. Here, we give the complete two loop calculation and analysis of the dynamic renormalization-group flow equations at the multicritical point in anisotropic antiferromagnets in an external magnetic field. We find that the time scales of the order parameters characterizing the parallel and perpendicular ordering with respect to the external field scale in the same way. This holds independent whether the Heisenberg fixed point or the biconical fixed point in statics is the stable one. The non-asymptotic analysis of the dynamic flow equations shows that due to cancelation effects the critical behavior is described - in distances from the critical point accessible to experiments - by the critical behavior qualitatively found in one loop order. Although one may conclude from the effective dynamic exponents (taking almost their one loop values) that weak scaling for the order parameter components is valid, the flow of the time scale ratios is quite different and they do not reach their asymptotic values.
description: 22 pages, 7 figures. Revised version, references updated, Fig. 5 modified, typos corrected
Rapid Assembly of Small Materials Building Blocks (Voxels) into Large Functional 3D Metamaterials
Creators: name: Hahn, Vincent
name: Kiefer, Pascal
name: Frenzel, Tobias
name: Qu, Jingyuan
name: Blasco, Eva
name: Barner-Kowollik, Christopher
name: Wegener, Martin
Publisher: name: FID GEO
Year: 2020

description: Abstract Herein, various 3D additive manufacturing approaches are reviewed in terms of two important figures of merit: maximum voxel printing rate and minimum voxel size. Voxel sizes from several 100 µm down to the 100 nm scale are covered. Original results on multifocus two-photon printing at around voxel printing rates of 107 voxels s−1 are presented in this context, which significantly surpass previous best values. These advances are illustrated by and applied to the making of microstructured 3D (chiral) mechanical metamaterials that are composed of more than one-hundred-thousand unit cells in three dimensions. Previous best values for unit cells of similar complexity are smaller by two orders of magnitude.
Conductivity of interacting massless Dirac particles in graphene: Collisionless regime
Creators: name: Juricic, Vladimir
name: Vafek, Oskar
name: Herbut, Igor F.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We provide detailed calculation of the a.c. conductivity in the case of 1/r-Coulomb interacting massless Dirac particles in graphene in the collisionless limit when ω>> T. The analysis of the electron self-energy, current vertex function and polarization function, which enter into the calculation of physical quantities including the a.c. conductivity, is carried out by checking the Ward-Takahashi identities associated with the electrical charge conservation and making sure that they are satisfied at each step. We adopt a variant of the dimensional regularization of Veltman and t'Hooft by taking the spatial dimension D=2-ε, for ε> 0. The procedure adopted here yields a result for the conductivity correction which, while explicitly preserving charge conservation laws, is nevertheless different from the results reported previously in literature.
description: 32 pages, no figures, published version
A Tetrahedral Boronic Acid Diester Formed by an Unnatural Amino Acid in the Ligand Pocket of an Engineered Lipocalin
Creators: name: Sommer, Carina A.
name: Eichinger, Andreas
name: Skerra, Arne
Publisher: name: FID GEO
Year: 2019

description: Abstract Boronic acids have long been known to form cyclic diesters with cis-diol compounds, including many carbohydrates. This phenomenon was previously exploited to create an artificial lectin by incorporating p-borono-l-phenylalanine (Bpa) into the ligand pocket of an engineered lipocalin, resulting in a so-called Borocalin. Here we describe the X-ray analysis of its covalent complex with 4-nitrocatechol as a high-affinity model ligand. As expected, the crystal structure reveals the formation of a cyclic diester between the biosynthetic boronate side chain and the two ortho-hydroxy substituents of the benzene ring. Interestingly, the boron also has a hydroxide ion associated, despite an only moderately basic pH 8.5 in the crystallization buffer. The complex is stabilized by a polar contact to the side chain of Asn134 within the ligand pocket, thus validating the functional design of the Borocalin as an artificial sugar-binding protein. Our structural analysis demonstrates how a boronate can form a thermodynamically stable diester with a vicinal diol in a tetrahedral configuration in aqueous solution near physiological pH. Moreover, our data provide a basis for the further engineering of the Borocalin with the goal of specific recognition of biologically relevant glycans.
On Compositional Hierarchical Models for holistic Lane and Road Perception in Intelligent Vehicles
Creators: name: Töpfer, Daniel
Publisher: name: Karlsruhe
Year: 2014
Subjects: Multi-lane road perception
lane detection
hierarchical models
nonparametric belief propagation

description: This work is a contribution to the vision based perception of multi lane roads of urban intersections. Given multiple input features the proposed probabilistic hierarchical model infers the lane structure as well as the location of stoplines and the turn directions of individual lanes. Thereby, it expresses prior expectations on the road topology using weak probabilistic constraints which allows for the detection of parallel lanes as well as splitting and merging lanes.
Elektrochemischer Zugang zu aza-polycyclischen aromatischen Kohlenwasserstoffen: Rhoda-elektrokatalytische Domino-Alkin-Anellierungen
Creators: name: Kong, Wei-Jun
name: Shen, Zhigao
name: Finger, Lars H.
name: Ackermann, Lutz
Publisher: name: FID GEO
Year: 2020

description: Abstract Stickstoff-dotierte polycyclische aromatische Kohlenwasserstoffe (Aza-PAKs) finden vielfältige Anwendungen in den Materialwissenschaften. Hier wurde eine modulare elektrochemische Synthese von Aza-PAKs über eine Rhodium-katalysierte Kaskaden-C-H-Aktivierung und Alkinanellierung entwickelt. Ein multifunktionales O-Methylamidoxim ermöglichte hohe Chemo- und Regioselekivitäten. Die Isolierung von zwei rhodacyclischen Schlüsselintermediaten erlaubte es, die Reihenfolge der drei C-H-Aktivierungsschritte genau zu bestimmen. Zusätzlich zeichnet sich die Metalla-elektrokatalytische dreifache C-H-Transformation durch eine einzigartige Verträglichkeit mit funktionellen Gruppen aus, einschließlich hoch reaktiver Iod- und Azidsubstituenten.
Depinning and transport in disordered one-dimensional arrays of Josephson junctions
Creators: name: Vogt, Nicolas Franz Wolfgang
Publisher: name: Karlsruhe
Year: 2014
Subjects: Josephson-junction-arrays
quantum-phase-slip
depinning
stochastic-Bloch-Redfield

description: In this thesis the transport behaviour of one-dimensional arrays of Josephson junctions in the insulating phase is studied. A voltage biased array undergoes a transition from the Coulomb blockaded insulating to the transport regime at the switching voltage. We provide a quantitative expression for the switching voltage based on depinning theory. We also introduce the numerical stochastic Bloch-Redfield algorithm to simulate the transport of dressed Cooper pairs through the junction array.
Biophysikalische Untersuchungen an antimikrobiellen Peptiden: von der Modellmembran zur natürlichen Umgebung
Creators: name: Misiewicz, Julia
Publisher: name: Karlsruhe
Year: 2014

description: Das Verhalten von antimikrobiellen Peptiden in natürlicher Umgebung wurde mit dem in künstlichen Modellsystemen verglichen. Der Einfluss des pH-Wertes auf die Peptid-Lipid-Wechselwirkung wurde mittels Festkörper-NMR und dynamischer Differenz Kalorimetrie untersucht. Die Orientierung antimikrobieller Peptide in nativen Membranen wurde mittels 19F-Festkörper NMR bestimmt. Schließlich wurde die natürliche Erscheinungsform des antimikrobiellen Peptides Gramicidin S als Nano-Granula untersucht.
Solar abundance corrections derived through 3D magnetoconvection simulations
Creators: name: Fabbian, D.
name: Khomenko, E.
name: Moreno-Insertis, F.
name: Nordlund, Å.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We explore the effect of the magnetic field when using realistic three-dimensional convection experiments to determine solar element abundances. By carrying out magnetoconvection simulations with a radiation-hydro code (the Copenhagen stagger code) and through a-posteriori spectral synthesis of three Fe I lines, we obtain evidence that moderate amounts of mean magnetic flux cause a noticeable change in the derived equivalent widths compared with those for a non-magnetic case. The corresponding Fe abundance correction for a mean flux density of 200 G reaches up to ~0.1 dex in magnitude. These results are based on space- and time-averaged line profiles over a time span of 2.5 solar hours in the statistically stationary regime of the convection. The main factors causing the change in equivalent widths, namely the Zeeman broadening and the modification of the temperature stratification, act in different amounts and, for the iron lines considered here, in opposite directions; yet, the resulting $|Δ\logε_{\odot}(Fe)|$ coincides within a factor two in all of them, even though the sign of the total abundance correction is different for the visible and infrared lines. We conclude that magnetic effects should be taken into account when discussing precise values of the solar and stellar abundances and that an extended study is warranted.
description: ApJ accepted
Energy balancing of the Modular Multilevel Matrix Converter based on a new transformed arm power analysis
Creators: name: Kammerer, Felix
name: Gommeringer, Mario
name: Kolb, Johannes
name: Braun, Michael
Publisher: name: Karlsruhe
Year: 2014
Subjects: AC/AC converter
Multilevel converters
Variable speed drive

description: This paper presents a transformed arm power analysis of the Modular Multilevel Matrix Converter (M3C). It enables the energy balancing in the whole frequency range for high power variable-speed drive applications. Four balancing directions are identified for the active power exchange between the converter arms with minimal internal currents. At critical operating points a zero sequence voltage is used. Additionally, the reactive power components can be used to perform a real time calculation of the energy pulsation in all four balancing directions to improve the control performance. A low voltage prototype with 5 cells in each of the nine arms has been realized to verify the theoretical analysis.
Continuous ultrafiltration/diafiltration using a 3D-printed two membrane single pass module
Creators: name: Tan, Ruijie
name: Franzreb, Matthias
Publisher: name: FID GEO
Year: 2019

description: Abstract A 3D printed ultrafiltration/diafiltration (UF/DF) module is presented allowing the continuous, simultaneous concentration of retained (bio-)molecules and reduction or exchange of the salt buffer. Differing from the single-pass UF concepts known from the literature, DF operation does not require the application of several steps or units with intermediating dilution. In contrast, the developed module uses two membranes confining the section in which the molecules are concentrated while the sample is passing. Simultaneously to this concentration process, the two membranes allow a perpendicular in and outflow of DF buffer reducing the salt content in this section. The module showed the continuous concentration of a dissolved protein up to a factor of 4.6 while reducing the salt concentration down to 47% of the initial concentration along a flow path length of only 5 cm. Due to single-pass operation the module shows concentration polarization effects reducing the effective permeability of the applied membrane in case of higher concentration factors. However, because of its simple design and the capability to simultaneously run UF and DF processes in a single module, the development could be economically beneficial for small scale UF/DF applications.
Receptor-Free Signaling at Curved Cellular Membranes
Creators: name: Ebrahimkutty, Mirsana P.
name: Galic, Milos
Publisher: name: FID GEO
Year: 2019

description: Plasma membranes are subject to continuous deformations. Strikingly, some of these transient membrane undulations yield membrane-associated signaling hubs that differ in composition and function, depending on membrane geometry and the availability of co-factors. Here, recent advancements on this ubiquitous type of receptor-independent signaling are reviewed, with a special focus on emerging concepts and technical challenges associated with studying these elusive signaling sites.
Titan(III)-katalysierte, reduktive Decyanierung geminaler Dinitrile ohne freie Radikalintermediate
Creators: name: Weweler, Jens
name: Younas, Sara L.
name: Streuff, Jan
Publisher: name: FID GEO
Year: 2019

description: Abstract Es wird über eine titankatalysierte Monodecyanierung geminaler Dinitrile berichtet, die unter milden Bedingungen abläuft, zahlreiche funktionelle Gruppen toleriert und auch auf quartäre Malononitrile angewendet werden kann. Eine entsprechende Desulfonylierung wird ebenfalls vorgestellt. Mechanistische Untersuchungen unterstützen eine katalysatorkontrollierte Spaltung ohne freie Radikale, was im Gegensatz zu den bisherigen stöchiometrischen radikalischen Decyanierungen steht. Die Beteiligung zweier TiIII-Spezies an der C-C-Bindunsspaltung wird vorgeschlagen und die Rolle der Additive ZnCl2 und Coll⋅HCl näher untersucht.
Lovelock black holes with maximally symmetric horizons
Creators: name: Maeda, Hideki
name: Willison, Steven
name: Ray, Sourya
Publisher: name: arXiv
Year: 2011
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We investigate some properties of n(\ge 4)-dimensional spacetimes having symmetries corresponding to the isometries of an (n-2)-dimensional maximally symmetric space in Lovelock gravity under the null or dominant energy condition. The well-posedness of the generalized Misner-Sharp quasi-local mass proposed in the past study is shown. Using this quasi-local mass, we clarify the basic properties of the dynamical black holes defined by a future outer trapping horizon under certain assumptions on the Lovelock coupling constants. The C^2 vacuum solutions are classified into four types: (i) Schwarzschild-Tangherlini-type solution; (ii) Nariai-type solution; (iii) special degenerate vacuum solution; (iv) exceptional vacuum solution. The conditions for the realization of the last two solutions are clarified. The Schwarzschild-Tangherlini-type solution is studied in detail. We prove the first law of black-hole thermodynamics and present the expressions for the heat capacity and the free energy.
description: 50 pages, no figure; v2, revised version. Section 4.2 on exact solutions with matter added. Propositions 17 and 19 and Appendix B improved. References added; v3, Proposition 20 added. Accepted for publication in Classical and Quantum Gravity
Tragverhalten von biegebeanspruchten Stahlmasten mit polygonalen Querschnitten
Creators: name: Reinke, Thomas Christian
Publisher: name: Karlsruhe
Year: 2014
Subjects: Polygon
Stahl
Mast
Stabilität
Beulen

description: Die Dissertation behandelt die Biegetragfähigkeit von dünnwandigen Stahlmasten mit polygonalen Querschnitten.
The role of oxytocin on self-serving lying
Creators: name: Sindermann, Cornelia
name: Luo, Ruixue
name: Becker, Benjamin
name: Kendrick, Keith M.
name: Montag, Christian
Publisher: name: FID GEO
Year: 2020

description: Abstract Introduction The effects of intranasal administration of the neuropeptide oxytocin on social cognition and behavior are highly specific. Potentially situational and personal variables influence these effects. The aim of the present study was to investigate effects of oxytocin administration on self-serving lying, including situational effects. Methods A total of 161 adult males participated in a randomized double-blind placebo-controlled between-subject intranasal oxytocin administration (24 international units) study. Self-serving lying was assessed using three subsequent rounds of the die-in-a-cup paradigm, in which different degrees of lying can be implemented by the participants that can be determined on group level. Results Oxytocin administration seemed to promote self-serving lying, particularly in the third (last) round and only to a certain degree (not to the maximum possible). Conclusions Our findings demonstrate that oxytocin administration can promote self-serving lying when given repeated opportunities to lie. Moreover, exploratory results presented in the Supplementary Material indicate that the sensitivity to the effects of intranasal oxytocin in this domain might be moderated by individual differences in the oxytocin receptor gene.
Towards magnetic resonance in scanning tunneling microscopy using heterodyne detection
Creators: name: Peter, Moritz
Publisher: name: Karlsruhe
Year: 2015
Subjects: STM
spin
magnetic
resonance
heterodyne

description: The present work introduces a new concept for magnetic resonance measurements in the GHz regime inside a scanning tunneling microscope. It is based on heterodyne detection in a spin-polarized tunneling barrier. The experimental requirements, including a new method to suppress transmission effects, are explained. Measurements on three model systems which were studied to validate the new technique are presented and compared to simulations.
Driven k-mers: Correlations in space and time
Creators: name: Gupta, Shamik
name: Barma, Mustansir
name: Basu, Urna
name: Mohanty, P. K.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Steady state properties of hard objects with exclusion interaction and a driven motion along a one-dimensional periodic lattice are investigated. The process is a generalization of the asymmetric simple exclusion process (ASEP) to particles of length k, and is called the k-ASEP. Here, we analyze both static and dynamic properties of the k-ASEP. Density correlations are found to display interesting features, such as pronounced oscillations in both space and time, as a consequence of the extended length of the particles. At long times, the density autocorrelation decays exponentially in time, except at a special k-dependent density when it decays as a power law. In the limit of large k at a finite density of occupied sites, the appropriately scaled system reduces to a nonequilibrium generalization of the Tonks gas describing the motion of hard rods along a continuous line. This allows us to obtain in a simple way the known two-particle distribution for the Tonks gas. For large but finite k, we also obtain the leading-order correction to the Tonks result.
description: 11 pages, 9 figures. Version 2: restructuring with small changes in content, published version
Phosphorus Post-Functionalization of Diphosphahexaarenes
Creators: name: Hindenberg, Philip
name: Rominger, Frank
name: Romero-Nieto, Carlos
Publisher: name: FID GEO
Year: 2019

description: Abstract Diphosphahexaarenes are highly stable π-extended frameworks containing two six-membered phosphorus heterocycles that have emerged recently. Herein, we present a detailed investigation on the post-functionalization reactions of their phosphorus centers with special emphasis on the selectivity of the processes and the impact of the phosphorus functionalizations into the physicochemical properties. These studies reveal that indeed the phosphorus atoms of the diphosphahexaarenes are readily available to be functionalized with quaternizing and oxidizing agents as well as borane groups without compromising the stability of the system. In addition, the optoelectronic properties of the diphosphahexaarenes are impacted by the phosphorus post-modifications.