bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation of interfacial thermal transport across graphene and an organic semiconductor using molecular dynamics simulations
Authors: Wang Xinyu , Zhang Jingchao , Chen Yue , Chan Paddy K. L.
Published: May 2017

We investigate the thermal transport across graphene and an organic semiconductor at different temperatures, levels of hydrogenation and vacancies.
Colloidal diffusion in confined geometries
Authors: Nygård Kim
Published: May 2017

Colloidal diffusion in confined geometries is analysed at the level of anisotropic pair densities.
Preparation and characterization of a calcium–phosphate–silicon coating on a Mg–Zn–Ca alloy via two-step micro-arc oxidation
Authors: Dou Jinhe , Chen Yang , Chi Yiming , Li Huancai , Gu Guochao , Chen Chuanzhong
Published: May 2017

Magnesium alloys are the most promising implant materials due to their excellent biodegradability.
Correction: A new potential for methylammonium lead iodide
Authors: Handley C. M. , Freeman C. L.
Published: May 2017

Correction for ‘A new potential for methylammonium lead iodide’ by C. M. Handley et al., Phys. Chem. Chem. Phys., 2017, 19, 2313–2321.
Structure and luminescence analyses of simultaneously synthesised (Lu1−xGdx)2O2S:Tb3+ and (Lu1−xGdx)2O3:Tb3+
Authors: Pasberg Natalie , den Engelsen Daniel , Fern George R. , Harris Paul G. , Ireland Terry G. , Silver Jack
Published: May 2017

Photoluminescence spectra and simultaneous synthesis of (Lu1−y–xGdx)2O2S:Tby and (Lu1−y–xGdx)2O3:Tby phosphors are reported/discussed along with cathodoluminescence spectra obtained from sub-micron particles.
Near-infrared-emitting heteroleptic cationic iridium complexes derived from 2,3-diphenylbenzo[g]quinoxaline as in vitro theranostic photodynamic therapy agents
Authors: Wang Li , Yin Huimin , Cui Peng , Hetu Marc , Wang Chengzhe , Monro Susan , Schaller Richard D. , Cameron Colin G. , Liu Bingqing , Kilina Svetlana , McFarland Sherri A. , Sun Wenfang
Published: May 2017

Cationic iridium complexes are promising near-infrared-emittingin vitrotheranostic photodynamic therapy agents.
TiO2 nanomaterial detection in calcium rich matrices by spICPMS. A matter of resolution and treatment
Authors: Tharaud Mickaël , Gondikas Andreas P. , Benedetti Marc F. , von der Kammer Frank , Hofmann Thilo , Cornelis Geert
Published: May 2017

This efficient spICP-MS methodology (48Ti + high-resolution + deconvolution) allows the measurement of never-reached titanium nanomaterial sizes in Ca-rich matrices.
Responses of human adipose-derived stem cells to interstitial level of extremely low shear flows regarding differentiation, morphology, and proliferation
Authors: Kim Sung-Hwan , Ahn Kihoon , Park Joong Yull
Published: May 2017

We developed a shear stress-gradient chip, which mimickedin vivointerstitial level of flow. With this system, hASCs' quantitative responses to the interstitial level of shear flow are identified.
Fluorous-tag assisted synthesis of bile acid–bisphosphonate conjugates via orthogonal click reactions: an access to potential anti-resorption bone drugs
Authors: Massarenti Chiara , Bortolini Olga , Fantin Giancarlo , Cristofaro Dario , Ragno Daniele , Perrone Daniela , Marchesi Elena , Toniolo Gianluca , Massi Alessandro
Published: May 2017

Click reactions and fluorous separations afford bile acid–bisphosphonate conjugates.
Correction: Materials with high proton conductivity above 200 °C based on a nanoporous metal–organic framework and non-aqueous ionic media
Authors: Ponomareva Valentina G. , Aliev Sokhrab B. , Shutova Elena S. , Pishchur Denis P. , Dybtsev Danil N. , Fedin Vladimir P.
Published: May 2017

Correction for ‘Materials with high proton conductivity above 200 °C based on a nanoporous metal–organic framework and non-aqueous ionic media’ by Valentina G. Ponomareva et al., RSC Adv., 2017, 7, 403–407.
Suppression of microRNA-135b-5p protects against myocardial ischemia/reperfusion injury by activating JAK2/STAT3 signaling pathway in mice during sevoflurane anesthesia
Authors: Xie Xiao-Juan , Fan Dong-Mei , Xi Kai , Chen Ya-Wei , Qi Peng-Wei , Li Qian-Hui , Fang Liang , Ma Li-Gang
Published: May 2017

The study aims to explore the effects of miR-135b-5p on myocardial ischemia/reperfusion (I/R) injuries by regulating Janus protein tyrosine kinase 2 (JAK2)/signal transducer and activator of transcription (STAT) signaling pathway by mediating inhalation anesthesia with sevoflurane. A sum of 120 healthy Wistar male mice was assigned into six groups. Left ventricular ejection fraction (LVEF) and left ventricular shortening fraction (LVSF) were detected. Cardiomyocyte apoptosis was determined by terminal dexynucleotidyl transferase mediated dUTP-biotin nick end labeling (TUNEL) assay. MiR-135b-5p expression, mRNA and protein expression of p-STAT3, p-JAK2, STAT3, JAK2, B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein B (Bax) were detected by quantitative real-time PCR (qRT-PCR) and Western blotting. Target relationship between miR-135b-5p and JAK2 was confirmed by dual-luciferase reporter assay. The other five groups exhibited increased cardiomyocyte necrosis, apoptosis, miR-135b-5p and Bax expression, mRNA expression of JAK2 and STAT3, and protein expression of p-STAT3 and p-JAK2 compared with the sham group, but showed decreased LVEF, LVFS, and Bcl-2 expression. Compared with the model and AG490 + Sevo groups, the Sevo, inhibitor + Sevo and inhibitor + AG490 + Sevo groups displayed reduced cardiomyocyte necrosis, apoptosis, miR-135b-5p and Bax expression, but displayed elevated mRNA expression of JAK2 and STAT3, protein expression of p-STAT3 and p-JAK2, LVEF, LVFS and Bcl-2 expression. Compared with the Sevo and inhibitor + AG490 + Sevo groups, the AG490 + Sevo group showed decreased LVEF, LVFS, Bcl-2 expression, mRNA expressions of JAK2 and STAT3, and protein expressions of p-STAT3 and p-JAK2, but increased cardiomyocyte necrosis, apoptosis, and Bax expressions. MiR-135b-5p negatively targetted JAK2. Inhibition of miR-135b-5p can protect against myocardial I/R injury by activating JAK2/STAT3 signaling pathway through mediation of inhalation anesthesia with sevoflurane.
Stochastic, structural and functional factors influencing AMPA and NMDA synaptic response variability: a review
Authors: Maio Vito Di , Ventriglia Francesco , Santillo Silvia
Published: May 2017

Synaptic transmission is the basic mechanism of information transfer between neurons not only in the brain, but along all the nervous system. In this review we will briefly summarize some of the main parameters that produce stochastic variability in the synaptic response. This variability produces different effects on important brain phenomena, like learning and memory, and, alterations of its basic factors can cause brain malfunctioning.
Thieme Chemistry Journals Awardees – Where Are They Now? Improved Fmoc Deprotection Methods for the Synthesis of
Thioamide-Containing Peptides and Proteins
Authors: Szantai-Kis D. , Walters Christopher , Barrett Taylor , Hoang Eileen , Petersson E.
Published: May 2017

Site-selective incorporation of thioamides into peptides and proteins provides a useful tool for a wide range of applications. Current incorporation methods suffer from low yields as well as epimerization. Here, we describe how the use of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) rather than piperidine in fluorenylmethyloxycarbonyl (Fmoc) deprotection reduces epimerization and increases yields of thioamide-containing peptides. Furthermore, we demonstrate that the use of DBU avoids byproduct formation when synthesizing peptides containing side-chain thioamides.
Vestibular Schwannoma with Contralateral Facial Nerve Palsy: A False Localizing Sign
Authors: Bhaskar Mukesh , Kumar Rakesh , Singh Sunil , Meel M.
Published: May 2017

Vestibular schwannomas are the most common cerebellopontine angle tumors. These tumors commonly present with ipsilateral dysfunction of acoustic, vestibular, trigeminal, and facial nerves. Vestibular schwannoma with involvement of contralateral facial nerve is very unusual, and whenever present, it is considered as a false localizing sign. It seems that displacement and distortion of the brainstem by the large mass lesion may lead to this atypical presentation. We report a case of vestibular schwannoma with contralateral abducens and facial nerve paresis.
Indikatoren für Sprachverständnis bei Kindern mit Migrationshintergrund. Ein Extremgruppenvergleich
Authors: Kiese-Himmel Christiane , Poinstingl Herbert , von Steinbüchel Nicole
Published: May 2017

Hintergrund Kinder mit Migrationshintergrund und Deutsch als Zweitsprache (DaZ) gelten häufig als sprachauffällig, was jedoch mangels fehlender Untersuchungsinstrumente im jungen Alter schwer zu objektivieren ist. Hierfür sollten empirisch Risikofaktoren bestimmt werden.

Material und Methoden Aus dem Datenpool einer Entwicklungslängsschnittstudie in 7 Kitas in Frankfurt/M. u. Darmstadt wurden Migrantenkinder im Alter von 3–5;11 Jahren durch ihre Testleistung im oralen Sprachverständnis 2 Extremgruppen zugewiesen: „unauffällig“ bei T-Wert ≥46 (N=61) vs. „auffällig“ bei T-Wert ≤32 (N=65). Gruppenunterschiede wurden anhand von Testergebnissen (Intelligenz; Verständnis grammatischer Strukturen; sprachliche Begriffsbildung; Erkennen von semantischen und grammatischen Inkonsistenzen) analysiert.

Ergebnisse Die Intelligenz war in beiden Gruppen durchschnittlich, in der unauffälligen Gruppe über dem Altersmittel gelegen: T-W 54,1; SD 6,7, in der auffälligen darunter: T-W 42,2; SD 8,8 (p<0,001). In allen Sprachleistungen unterschieden sich die Gruppen durchgängig signifikant. Diskriminanzanalytisch wurden 4 Merkmale für die Güte von DaZ identifiziert: Intelligenzhöhe; Erkennen von Sprachinkonsistenzen; Bildungsstand der Mutter; Grammatikbasiertes Sprachverständnis. Bzgl. der vorhergesagten Gruppenzugehörigkeit wurden 88% der Kinder mit auffälligem und 84% der mit unauffälligem Sprachverständnis korrekt zugeordnet.

Schlussfolgerung Die Studie liefert einen akzeptablen Standard, um Migrantenkinder mit gutem Verständnis von DaZ von solchen mit schwachem zu trennen.
Progress towards a more predictive model for hohlraum radiation drive and symmetry
Authors: Jones O. S. , Suter L. J. , Scott H. A. , Barrios M. A. , Farmer W. A. , Hansen S. B. , Liedahl D. A. , Mauche C. W. , Moore A. S. , Rosen M. D. , Salmonson J. D. , Strozzi D. J. , Thomas C. A. , Turnbull D. P.
Published: May 2017

For several years, we have been calculating the radiation drive in laser-heated gold hohlraums using flux-limited heat transport with a limiter of 0.15, tabulated values of local thermodynamic equilibrium gold opacity, and an approximate model for not in a local thermodynamic equilibrium (NLTE) gold emissivity (DCA_2010). This model has been successful in predicting the radiation drive in vacuum hohlraums, but for gas-filled hohlraums used to drive capsule implosions, the model consistently predicts too much drive and capsule bang times earlier than measured. In this work, we introduce a new model that brings the calculated bang time into better agreement with the measured bang time. The new model employs (1) a numerical grid that is fully converged in space, energy, and time, (2) a modified approximate NLTE model that includes more physics and is in better agreement with more detailed offline emissivity models, and (3) a reduced flux limiter value of 0.03. We applied this model to gas-filled hohlraum experiments using high density carbon and plastic ablator capsules that had hohlraum He fill gas densities ranging from 0.06 to 1.6 mg/cc and hohlraum diameters of 5.75 or 6.72 mm. The new model predicts bang times to within ±100 ps for most experiments with low to intermediate fill densities (up to 0.85 mg/cc). This model predicts higher temperatures in the plasma than the old model and also predicts that at higher gas fill densities, a significant amount of inner beam laser energy escapes the hohlraum through the opposite laser entrance hole.
Sub-Doppler infrared spectroscopy of CH2OH radical in a slit supersonic jet: Vibration-rotation-tunneling dynamics in the symmetric CH stretch manifold
Authors: Schuder Michael D. , Wang Fang , Chang Chih-Hsuan , Nesbitt David J.
Published: May 2017

The sub-Doppler CH-symmetric stretch (ν3) infrared absorption spectrum of a hydroxymethyl (CH2OH) radical is observed and analyzed with the radical formed in a slit-jet supersonic discharge expansion (Trot = 18 K) via Cl atom mediated H atom abstraction from methanol. The high sensitivity of the spectrometer and reduced spectral congestion associated with the cooled expansion enable first infrared spectroscopic observation of hydroxymethyl transitions from both ± symmetry tunneling states resulting from large amplitude COH torsional motion. Nuclear spin statistics due to exchange of the two methyl H-atoms aid in unambiguous rovibrational assignment of two A-type Ka = 0 ← 0 and Ka = 1 ← 1 bands out of each ± tunneling state, with additional spectral information obtained from spin-rotation splittings in P, Q, and R branch Ka = 1 ← 1 transitions that become resolved at low N. A high level ab initio potential surface (CCSD(T)-f12b/cc-pvnzf12 (n = 2,3)/CBS) is calculated in the large amplitude COH torsional and CH2 wag coordinates, which in the adiabatic approximation and with zero point correction predicts ground state tunneling splittings in good qualitative agreement with experiment. Of particular astrochemical interest, a combined fit of the present infrared ground state combination differences with recently reported millimeter-wave frequencies permits the determination of improved accuracy rotational constants for the ground vibrational state, which will facilitate ongoing millimeter/microwave searches for a hydroxymethyl radical in the interstellar medium.
An assessment of low-lying excitation energies and triplet instabilities of organic molecules with an ab initio Bethe-Salpeter equation approach and the Tamm-Dancoff approximation
Authors: Rangel Tonatiuh , Hamed Samia M. , Bruneval Fabien , Neaton Jeffrey B.
Published: May 2017

The accurate prediction of singlet and triplet excitation energies is an area of intense research of significant fundamental interest and critical for many applications. Most calculations of singlet and triplet energies use time-dependent density functional theory (TDDFT) in conjunction with an approximate exchange-correlation functional. In this work, we examine and critically assess an alternative method for predicting low-lying neutral excitations with similar computational cost, the ab initio Bethe-Salpeter equation (BSE) approach, and compare results against high-accuracy wavefunction-based methods. We consider singlet and triplet excitations of 27 prototypical organic molecules, including members of Thiel’s set, the acene series, and several aromatic hydrocarbons exhibiting charge-transfer-like excitations. Analogous to its impact in TDDFT, we find that the Tamm-Dancoff approximation (TDA) overcomes triplet instabilities in the BSE approach, improving both triplet and singlet energetics relative to higher level theories. Finally, we find that BSE-TDA calculations built on effective DFT starting points, such as those utilizing optimally tuned range-separated hybrid functionals, can yield accurate singlet and triplet excitation energies for gas-phase organic molecules.
Filter-based ultralow-frequency Raman measurement down to 2 cm−1 for fast Brillouin spectroscopy measurement
Authors: Liu Xue-Lu , Liu He-Nan , Wu Jiang-Bin , Wu Han-Xu , Zhang Tao , Zhao Wei-Qian , Tan Ping-Heng
Published: May 2017

Simultaneous Stokes and anti-Stokes ultralow-frequency (ULF) Raman measurement down to ∼2 cm−1 or 60 GHz is realized by a single-stage spectrometer in combination with volume-Bragg-grating-based notch filters. This system reveals its excellent performance by probing Brillouin signal of acoustic phonons in silicon, germanium, gallium arsenide, and gallium nitride. The deduced sound velocity and elastic constants are in good accordance with previous results determined by various methods. This system can shorten the integration time of the Brillouin signal with a good signal-to-noise ratio by more than 2000-fold compared to a Fabry-Perot interferometer (FPI). This study shows how a filter-based ULF Raman system can be used to reliably achieve Brillouin spectroscopy for condensed materials with high sensitivity and high signal-to-noise ratio, stimulating fast Brillouin spectrum measurements to probe acoustic phonons in semiconductors.
Unitary 2-designs from random X- and Z-diagonal unitaries
Authors: Nakata Yoshifumi , Hirche Christoph , Morgan Ciara , Winter Andreas
Published: May 2017

Unitary 2-designs are random unitaries simulating up to the second order statistical moments of the uniformly distributed random unitaries, often referred to as Haar random unitaries. They are used in a wide variety of theoretical and practical quantum information protocols and also have been used to model the dynamics in complex quantum many-body systems. Here, we show that unitary 2-designs can be approximately implemented by alternately repeating random unitaries diagonal in the Pauli-Z basis and Pauli-X basis. We also provide a converse about the number of repetitions needed to achieve unitary 2-designs. These results imply that the process after ℓ repetitions achieves a Θ(d−ℓ)-approximate unitary 2-design. Based on the construction, we further provide quantum circuits that efficiently implement approximate unitary 2-designs. Although a more efficient implementation of unitary 2-designs is known, our quantum circuit has its own merit that it is divided into a constant number of commuting parts, which enables us to apply all commuting gates simultaneously and leads to a possible reduction of an actual execution time. We finally interpret the result in terms of the dynamics generated by time-dependent Hamiltonians and provide for the first time a random disordered time-dependent Hamiltonian that generates a unitary 2-design after switching interactions only a few times.
Highly excited electronic image states of metallic nanorings
Authors: Fey Christian , Jabusch Henrik , Knörzer Johannes , Schmelcher Peter
Published: May 2017

We study electronic image states around a metallic nanoring and show that the interplay between the attractive polarization force and a repulsive centrifugal force gives rise to Rydberg-like image states trapped several nanometers away from the surface. The nanoring is modeled as a perfectly conducting isolated torus whose classical electrostatic image potential is derived analytically. The image states are computed via a two-dimensional finite-difference scheme as solutions of the effective Schrödinger equation describing the outer electron subject to this image potential. These findings demonstrate not only the existence of detached image states around nanorings but allow us also to provide general criteria on the ring geometry, i.e., the aspect ratio of the torus, that need to be fulfilled in order to support such states.
The electron shuffle: Cerium influences samarium 4f orbital occupancy in heteronuclear Ce–Sm oxide clusters
Authors: Kafader Jared O. , Topolski Josey E. , Marrero-Colon Vicmarie , Iyengar Srinivasan S. , Jarrold Caroline Chick
Published: May 2017

The anion photoelectron (PE) spectra along with supporting results of density functional theory (DFT) calculations on SmO−, SmCeOy−, and Sm2Oy− (y = 1, 2) are reported and compared to previous results on CeO− [M. Ray et al., J. Chem. Phys. 142, 064305 (2015)] and Ce2Oy− (y = 1, 2) [J. O. Kafader et al., J. Chem. Phys. 145, 154306 (2016)]. Similar to the results on CexOy− clusters, the PE spectra of SmO−, SmCeOy−, and Sm2Oy− (y = 1, 2) all exhibit electronic transitions to the neutral ground state at approximately 1 eV e−BE. The Sm centers in SmO and Sm2O2 neutrals can be described with the 4f56s superconfiguration, which is analogous to CeO and Ce2O2 neutrals in which the Ce centers can be described with the 4f 6s superconfiguration (ZCe = ZSm − 4). The Sm center in CeSmO2, in contrast, has a 4f6 occupancy, while the Ce center maintains the 4f 6s superconfiguration. The less oxidized Sm centers in both Sm2O and SmCeO have 4f6 6s occupancies. The 4f6 subshell occupancy results in relatively weak Sm–O bond strengths. If this extra 4f occupancy also occurs in bulk Sm-doped ceria, it may play a role in the enhanced O2− ionic conductivity in Sm-doped ceria. Based on the results of DFT calculations, the heteronuclear Ce–Sm oxides have molecular orbitals that are distinctly localized Sm 4f, Sm 6s, Ce 4f, and Ce 6s orbitals. The relative intensity of two electronic bands in the PE spectrum of Sm2O− exhibits an unusual photon energy-dependence, and the PE spectrum of Sm2O2− exhibits a photon energy-dependent continuum signal between two electronic transitions. Several explanations, including the high magnetic moment of these suboxide species and the presence of low-lying quasi-bound anion states, are considered.
Hybrid-array-based optoacoustic and ultrasound (OPUS) imaging of biological tissues
Authors: Deán-Ben X. L. , Merčep E. , Razansky D.
Published: May 2017

Hybrid optoacoustic and pulse-echo ultrasound imaging is an attractive multi-modal combination owing to the highly complementary contrast of the two techniques. Efficient hybridization is often hampered by significant dissimilarities between their optimal data acquisition and image formation strategies. Herein, we introduce an approach for combined optoacoustic and ultrasound imaging based on a plano-concave detector array design with a non-uniform pitch distribution. The hybrid design optimized for both modalities allows for maintaining an extended field of view for efficient ultrasound navigation while simultaneously providing broad tomographic coverage for optimal optoacoustic imaging performance. Imaging sessions performed in tissue-mimicking phantoms and healthy volunteers demonstrate that the suggested approach renders an enhanced imaging performance as compared with the previously reported hybrid optoacoustic and ultrasound imaging approaches. Thus, it can greatly facilitate clinical translation of the optoacoustic imaging technology by means of its efficient combination with ultrasonography, a well-established clinical imaging modality.
Resonance tunneling electron-vibrational spectroscopy of polyoxometalates
Authors: Dalidchik F. I. , Kovalevskii S. A. , Balashov E. M.
Published: May 2017

The tunneling spectra of the ordered monolayer films of decamolybdodicobaltate (DMDC) compounds deposited from aqueous solutions on HOPG were measured by scanning tunnel microscopy in air. The DMDC spectra, as well as the tunneling spectra of other polyoxometalates (POMs), exhibit well-defined negative differential resistances (NDRs). The mechanism of formation of these spectral features was established from the collection of revealed NDR dependences on the external varying parameters and found to be common to all systems exhibiting Wannier–Stark localization. A model of biresonance tunneling was developed to provide an explanation for the totality of experimental data, both the literature and original, on the tunneling POM probing. A variant of the tunneling electron-vibrational POM spectroscopy was proposed allowing the determination of the three basic energy parameters—energy gaps between the occupied and unoccupied states, frequencies of the vibrational transitions accompanying biresonance electron-tunneling processes, and electron-vibrational interaction constants on the monomolecular level.
Isotactic poly(4-methyl-1-pentene) melt as a porous liquid: Reduction of compressibility due to penetration of pressure medium
Authors: Chiba Ayano , Inui Masanori , Kajihara Yukio , Fuchizaki Kazuhiro , Akiyama Ryo
Published: May 2017

A pressure-induced structural change of a polymer isotactic poly(4-methyl-1-pentene) (P4MP1) in the melted state at 270 °C has been investigated by high-pressure in situ x-ray diffraction, where high pressures up to 1.8 kbar were applied using helium gas. The first sharp diffraction peak (FSDP) position of the melt shows a less pressure dependence than that of the normal compression using a solid pressure transmitting medium. The contraction using helium gas was about 10% at 2 kbar, smaller than about 20% at the same pressure using a solid medium. The result indicates that helium entered the interstitial space between the main chains. The helium/monomer molar ratio was estimated to be 0.3 at 2 kbar from the FSDP positions. These results suggest that the compressibility of the P4MP1 melt can be largely dependent on the pressure transmitting media. As the pore size is reversibly and continuously controllable by compression, we suggest that the P4MP1 melt can be an ideal porous liquid for investigating a novel mechanical response of the pores in a non-crystalline substance.
Central limit theorem and related results for the elephant random walk
Authors: Coletti Cristian F. , Gava Renato , Schütz Gunter M.
Published: May 2017

We study the so-called elephant random walk (ERW) which is a non-Markovian discrete-time random walk on ℤ with unbounded memory which exhibits a phase transition from a diffusive to superdiffusive behavior. We prove a law of large numbers and a central limit theorem. Remarkably the central limit theorem applies not only to the diffusive regime but also to the phase transition point which is superdiffusive. Inside the superdiffusive regime, the ERW converges to a non-degenerate random variable which is not normal. We also obtain explicit expressions for the correlations of increments of the ERW.
On the accuracy of one- and two-particle solvation entropies
Authors: Irwin Benedict W. J. , Huggins David J.
Published: May 2017

Evaluating solvation entropies directly and combining with direct energy calculations is one way of calculating free energies of solvation and is used by Inhomogeneous Fluid Solvation Theory (IFST). The configurational entropy of a fluid is a function of the interatomic correlations and can thus be expressed in terms of correlation functions. The entropies in this work are directly calculated from a truncated series of integrals over these correlation functions. Many studies truncate all terms higher than the solvent-solute correlations. This study includes an additional solvent-solvent correlation term and assesses the associated free energy when IFST is applied to a fixed Lennard-Jones particle solvated in neon. The strength of the central potential is varied to imitate larger solutes. Average free energy estimates with both levels of IFST are able to reproduce the estimate made using the Free energy Perturbation (FEP) to within 0.16 kcal/mol. We find that the signal from the solvent-solvent correlations is very weak. Our conclusion is that for monatomic fluids simulated by pairwise classical potentials the correction term is relatively small in magnitude. This study shows it is possible to reproduce the free energy from a path based method like FEP, by only considering the endpoints of the path. This method can be directly applied to more complex solutes which break the spherical symmetry of this study.
Curvature in Hamiltonian mechanics and the Einstein-Maxwell-dilaton action
Authors: Rajeev S. G.
Published: May 2017

Riemannian geometry is a particular case of Hamiltonian mechanics: the orbits of the Hamiltonian H=12gijpipj are the geodesics. Given a symplectic manifold (Γ,ω), a Hamiltonian H:Γ→ℝ, and a Lagrangian sub-manifold M⊂Γ, we find a generalization of the notion of curvature. The particular case H=12gij[pi−Ai][pj−Aj]+ϕ of a particle moving in gravitational, electromagnetic, and scalar fields is studied in more detail. The integral of the generalized Ricci tensor with respect to the Boltzmann weight reduces to the action principle ∫[R+14FikFjlgklgij−gij∂iϕ∂jϕ]e−ϕgdnq for the scalar, vector and tensor fields.
Experimental analysis of density fingering instability modified by precipitation
Authors: Binda L. , El Hasi C. , Zalts A. , D'Onofrio A.
Published: May 2017

We analyze the effect of precipitate formation on the development of density induced hydrodynamic instabilities. In this case, the precipitate is BaCO3, obtained by reaction of CO2 with aqueous BaCl2. CO2(g) dissolution increases the local density of the aqueous phase, triggering Rayleigh–Taylor instabilities and BaCO3 formation. It was observed that at first the precipitate was formed at the finger front. As the particles became bigger, they began to fall down from the front. These particles were used as tracers using PIV technique to visualize the particle streamlines and to obtain the velocity of that movement. This falling produced a downward flow that might increase the mixing zone. Contrary to expectations, it was observed that the finger length decreased, indicating that for the mixing zone development, the consumption of CO2 to form the precipitate is more important than the downward flow. The mixing zone length was recovered by increasing the availability of the reactant (higher CO2 partial pressure), compensating the CO2 used for BaCO3 formation. Mixing zone development rates reached constant values at shorter times when the precipitate is absent than when it is present. An analysis of the nonlinear regime with and without the precipitate is performed.
Collimated thermal radiation transfer via half Maxwell's fish-eye lens for thermophotovoltaics
Authors: Chung Haejun , Zhou Zhiguang , Bermel Peter
Published: May 2017

Thermophotovoltaics (TPV) convert heat into electricity by capturing thermal radiation with a photovoltaic (PV) cell, ideally at efficiencies of 50% or more. However, excess heating of the PV cell from close proximity to the emitter substantially reduces the system efficiency. In this work, we theoretically develop and numerically demonstrate an approach to fundamentally improving TPV systems that allow for a much greater separation of an emitter and a receiver. Thus, we solve the excess heating dilemma, required for achieving theoretically high efficiencies. It consists of a spherically graded index lens known as Maxwell's Fish-Eye (MFE) structure, capable of collimating hemispherical emission into a much narrower range of angles, close to the normal direction. To fully characterize the power radiation profile of the MFE, we perform finite-difference time-domain simulations for a quarter MFE and then map it onto a Gaussian beam approximation. The modeled beam properties are subsequently used to study a half MFE. In an optimized half MFE design, 90% of all thermal photons reach a receiver at a distance of 100 λ; by comparison, only 15.6% of a blackbody emitter reach a receiver in the same geometry. It is also shown that the emission achieved by a half MFE can lead to a photon recycling rate above 95% for below bandgap photons at an emitter-receiver separation of 100 λ. By applying a half MFE, the absolute TPV efficiency can be improved from 5.74% to 37.15%, which represents a significant step forward in realizing high-efficiency TPV systems.
Molecular adsorption at electrolyte/α-Al2O3 interface of aluminum electrolytic capacitor revealed by sum frequency vibrational spectroscopy
Authors: Jia Ming , Hu Xiaoyu , Liu Jin , Liu Yexiang , Ai Liang
Published: May 2017

The operating voltage of an aluminum electrolytic capacitor is determined by the breakdown voltage (Ub) of the Al2O3 anode. Ub is related to the molecular adsorption at the Al2O3/electrolyte interface. Therefore, we have employed sum-frequency vibrational spectroscopy (SFVS) to study the adsorption states of a simple electrolyte, ethylene glycol (EG) solution with ammonium adipate, on an α-Al2O3 surface. In an acidic electrolyte (pH < 6), the Al2O3 surface is positively charged. The observed SFVS spectra show that long chain molecules poly ethylene glycol and ethylene glycol adipate adopt a “lying” orientation at the interface. In an alkaline electrolyte (pH > 8), the Al2O3 surface is negatively charged and the short chain EG molecules adopt a “tilting” orientation. The Ub results exhibit a much higher value at pH < 6 compared with that at pH > 8. Since the “lying” long chain molecules cover and protect the Al2O3 surface, Ub increases with a decrease of pH. These findings provide new insights to study the breakdown mechanisms and to develop new electrolytes for high operating voltage capacitors.
Thermal resistance between amorphous silica nanoparticles
Authors: Meng Fanhe , Elsahati Muftah , Liu Jin , Richards Robert F.
Published: May 2017

Nanoparticle-based materials have been used as thermal insulation in a variety of macroscale and microscale applications. In this work, we investigate the heat transfer between nanoparticles using non-equilibrium molecular dynamics simulations. We calculate the total thermal resistance and thermal boundary resistance between adjacent amorphous silica nanoparticles. Numerical results are compared to interparticle resistances determined from experimental measurements of heat transfer across packed silica nanoparticle beds. The thermal resistance between nanoparticles is shown to increase rapidly as the particle contact radius decreases. More significantly, the interparticle resistance depends strongly on the forces between particles, in particular, the presence or absence of chemical bonds between nanoparticles. In addition, the effect of interfacial force strength on thermal resistance increases as the nanoparticle diameter decreases. The simulations results are shown to be in good agreement with experimental results for 20 nm silica nanoparticles.
Gain and bandwidth investigation in dual-pumped non-collinear optical parametric chirped pulse amplification
Authors: Rajablou Zahra , Jahangiri Fazel
Published: May 2017

Dual-pumped non-collinear parametric amplification of a chirped laser pulse is numerically studied by employing the pump beams of different wavelengths. Our results reveal that the output bandwidth and the efficiency-bandwidth product are improved, when non-collinear angles and phase matching conditions are separately optimized for each individual pump beam. Moreover, by studying the dependence of the bandwidth of the amplified signal on the pump intensity, gain stability and its fluctuations are compared in small signal gain and saturation regimes. It is verified that the effective interaction length in this dual-pumped configuration is reduced as a consequent of increased bandwidth, compared to that in a single pump scheme.
The effect of spin orbit interaction on the physical properties of LaTSi3 (T = Ir, Pd, and Rh): First-principles calculations
Authors: Uzunok H. Y. , Tütüncü H. M. , Srivastava G. P. , İpsara E. , Baṣoǧlu A.
Published: May 2017

We have presented the structural, elastic, electronic, phononic, and electron-phonon interaction properties of the La-based noncentrosymmetric superconductors, such as LaIrSi3, LaRhSi3, and LaPdSi3, by using the generalized gradient approximation of the density functional theory. The calculated elastic constants reveal the mechanical stability of all the studied compounds in their noncentrosymmetric structure, while the lack of inversion symmetry gives rise to lift the degeneracy of their electronic bands, except in the Γ-Z and X-P directions. The calculated Eliashberg spectral function shows that all phonon branches of these materials couple considerably with electrons, and thus, all of them make contribution to the average electron-phonon coupling parameter λ. Using the calculated values of λ and the logarithmically averaged phonon frequency ωln, the superconducting critical temperature Tc values for LaIrSi3, LaRhSi3, and LaPdSi3 are estimated to be 0.89, 2.56, and 2.40 K, respectively, which accord very well with their corresponding experimental values of 0.77, 2.16, and 2.60 K.
Ambipolar transport in Mn2CoAl films by ionic liquid gating
Authors: Ueda Kenji , Hirose Shingo , Asano Hidefumi
Published: May 2017

We demonstrate ambipolar transport and modulation of electronic properties of Mn2CoAl (MCA), one of the most promising candidates for spin gapless semiconductors (SGSs), by using ionic liquid gating in electronic double-layer transistors. The carrier concentration and mobility of MCA films were systematically changed with carrier polarity inversion from the p- to the n-type by the gating technique. The ambipolar transport is one of the most significant properties of SGSs and strongly promotes the gapless features of MCA. The present results pave the way for the use of MCA as a spin source of both spin-polarized electrons and holes.
Ferroelectricity and the phase transition in large area evaporated vinylidene fluoride oligomer thin films
Authors: Foreman K. , Poddar Shashi , Ducharme Stephen , Adenwalla S.
Published: May 2017

Organic ferroelectric materials, including the well-known poly(vinylidene fluoride) and its copolymers, have been extensively studied and used for a variety of applications. In contrast, the VDF oligomer has not been thoroughly investigated and is not widely used, if used at all. One key advantage the oligomer has over the polymer is that it can be thermally evaporated in vacuum, allowing for the growth of complex heterostructures while maintaining interfacial cleanliness. Here, we report on the ferroelectric properties of high-quality VDF oligomer thin films over relatively large areas on the order of mm2. The operating temperature is identified via differential scanning calorimetry and pyroelectric measurements. Pyroelectric measurements also reveal a stable remanent polarization for these films which persists over very long time scales, an important result for non-volatile data storage. Temperature dependent pyroelectric and capacitance measurements provide compelling evidence for the phase transition in these films. Capacitance-voltage and current-voltage measurements are used to confirm ferroelectricity, quantify the dielectric loss, and calculate the spontaneous polarization. Finally, piezoresponse force microscopy is used to demonstrate large area, low-voltage ferroelectric domain reading/writing in VDF oligomer thin films. This work enables new channels for VDF oligomer applications and research.
Topological characterization and early detection of bifurcations and chaos in complex systems using persistent homology
Authors: Mittal Khushboo , Gupta Shalabh
Published: May 2017

Early detection of bifurcations and chaos and understanding their topological characteristics are essential for safe and reliable operation of various electrical, chemical, physical, and industrial processes. However, the presence of non-linearity and high-dimensionality in system behavior makes this analysis a challenging task. The existing methods for dynamical system analysis provide useful tools for anomaly detection (e.g., Bendixson-Dulac and Poincare-Bendixson criteria can detect the presence of limit cycles); however, they do not provide a detailed topological understanding about system evolution during bifurcations and chaos, such as the changes in the number of subcycles and their positions, lifetimes, and sizes. This paper addresses this research gap by using topological data analysis as a tool to study system evolution and develop a mathematical framework for detecting the topological changes in the underlying system using persistent homology. Using the proposed technique, topological features (e.g., number of relevant k-dimensional holes, etc.) are extracted from nonlinear time series data which are useful for deeper analysis of the system behavior and early detection of bifurcations and chaos. When applied to a Logistic map, a Duffing oscillator, and a real life Op-amp based Jerk circuit, these features are shown to accurately characterize the system dynamics and detect the onset of chaos.
Efficient extraction of oil from droplet microfluidic emulsions
Authors: Haliburton J. R. , Kim S. C. , Clark I. C. , Sperling R. A. , Weitz D. A. , Abate A. R.
Published: May 2017

Droplet microfluidic techniques can perform large numbers of single molecule and cell reactions but often require controlled, periodic flow to merge, split, and sort droplets. Here, we describe a simple method to convert aperiodic flows into periodic ones. Using an oil extraction module, we efficiently remove oil from emulsions to readjust the droplet volume fraction, velocity, and packing, producing periodic flows. The extractor acts as a universal adaptor to connect microfluidic modules that do not operate under identical flow conditions, such as droplet generators, incubators, and merger devices.
Highly polarized single mode nanobelt laser
Authors: Xu P. , Liu S. , Tang M. , Xu X. , Lin X. , Wu Z. , ZhuGe M. , Ren Z. , Wang Z. , Liu X. , Yang Z. , Raghavan N. , Yang Q.
Published: May 2017

We demonstrate a highly polarized single mode nanobelt laser with a low threshold. Different from the traditional nanobelt lasers, the laser cavity is formed along the lateral direction of the nanobelt and the wavelength is centered at 712.6 nm with a linewidth of about 0.18 nm. The single mode lasing emission is highly polarized with a polarization ratio of about 0.91. Moreover, the threshold is as low as 18 μJ/cm2 which is about an order of magnitude lower than that of the traditional CdSe nanobelt lasers. These low threshold high polarization single mode nanobelt lasers offer great potential as a low cost and energy efficient choice of technology for applications in visible light communications, displays, optical sensing, and environmental monitoring.
Challenges of feeding dairy cows in Australia and New Zealand
Authors: Wales W. J. , Kolver E. S.
Published: May 2017

There is a continuing evolution of feeding systems in both Australian and New Zealand dairy industries and this presents challenges for the future. Since the turn of the century, the two countries have diverged in industry growth characteristics, with Australian dairying having contracted, with 10% less milk being produced because of 20% fewer cows producing 15% more per cow, whereas New Zealand dairying has expanded, producing 83% more milk driven by a 54% increase in cow numbers and a 31% increase in milk production per cow. Solutions to optimise feed efficiency included the common themes of (1) growing more forage on farm, (2) increasing its utilisation and (3) more efficient use of supplements resulting in increases in DM intake, and they remain relevant. In New Zealand, many of the recent research activities have aimed at improving feed supply while limiting environmental impacts driven by increasing societal concern surrounding the environmental footprint of a growing and intensifying agricultural sector. In Australia, many of the recent research activities have aimed at improving feed efficiency, with a focus on understanding situations where partial mixed ration feeding systems (Australian Farm Systems 3 and 4) are sustainable. Simply growing more feed on farm can no longer be a sole objective; farms must be operated with a view to reduce the environmental footprint, with New Zealand dairy farmers increasingly needing to farm within nitrogen limits. The present review revisits and reinforces many of the concepts developed in previous reviews, but also examines the evolution of feeding systems in both countries and opportunities to improve feed efficiency and profit, while satisfying public expectations around environmental stewardship. We also identify some of the gaps in the current knowledge that warrant further research.
The modification of compound nouns by three adjectives
Authors: Berg Thomas
Published: May 2017

This paper is the final instalment in a series of studies investigating the modification patterns in complex noun phrases (NPs) in English. It particularly focuses on the modification of two-noun compounds by three attributive adjectives. An analysis of all such NPs from the BNC reveals a strong preference for head modification over modifier modification, similar rates of convergent and divergent modification and the non-occurrence of crossed modification. The single most important factor influencing the modification patterns is functional status. The larger the number of adjectives modifying the head of the compound, the higher the frequency of the modification type (modulo a proximity effect). The absence of crossed modification is expected under the no-crossing constraint, which is understood here not as a formal but as a functional principle ensuring successful communication. The various factors can be tied together under the rubric of accessibility. The probability of selecting a particular modification target is argued to be a function of the accessibility of the nouns in an NP.
Patterns of (inter)subjectivity
Authors: Hofmockel Carolin
Published: May 2017

The prevalent hypothesis in research on pragmatic markers suggests that the left periphery of an utterance attracts predominantly subjective meanings, whereas the right periphery is the locus of intersubjective meanings. The goal of this paper is to test this hypothesis forbutas used in a dataset of spoken Glaswegian English, a variety in whichbutmay occur in both left- and right-peripheral positions. Considering thatbutderives its discursive meaning notper se, but from its embeddedness in particularized contexts, the methodological framework integrates the notion of (inter)subjectivity with the interactional-sociolinguistic concept of contextualization cue to identify (inter)subjective patterned co-occurrences forbut. A fine-grained analysis of the patternsbutforms with subjective and intersubjective cues in its local linguistic context shows that discourse patterns of left-peripheralbuttend to foreground subjective meanings, while discourse patterns of right-peripheralbuttend to foreground more intersubjective meanings, supporting the hypothesis of peripheral asymmetry.
We’re talking about semantics here
Authors: Siebörger Ian , Adendorff Ralph
Published: May 2017

This article describes how procedural knowledge is produced in a meeting of the South African parliament’s Portfolio Committee on Transport, using concepts from Systemic Functional Linguistics (SFL) and Legitimation Code Theory (LCT). Members of this committee argue over whether or not to amend a draft committee report and in the process co-construct procedural norms for future committee meetings. Participants on both sides of the argument useaxiological condensation, in which actions and ideas are associated with each other and charged with a particular moral or affective value (Maton 2014: 130) to portray their version of the procedure to be followed as morally superior to that of their opponents. They also useaxiological rarefaction(Maton 2014: 130) to reinforce their positions by making apparent concessions to those on the other side of the argument. This is revealed through an analysis of thecouplingof ideation and Appraisal (Martin 2000: 161) in the logogenetic unfolding of members’ talk, combined with elements of Interactional Sociolinguistics (Gumperz 1982). The analysis suggests that axiological condensation and rarefaction in this meeting reflect competing visions of what it means to be ‘pro-democracy’ in post-apartheid South Africa.
From Bukhara to Dushanbe: Outlining the Evolution of Soviet Tajik Fiction
Authors: Grassi Evelin
Published: May 2017

This article offers an overview of Soviet Tajik Fiction under Stalinism (1920s–1950s) and during de-Stalinization (1950s–1970s) by contemplating the move from Bukhara to Dushanbe as a setting for Tajik stories and novels. In particular, it details the two main literary genres of the period, namely historical and psychological fiction. It argues that when tracing the main stages of evolution of Soviet Tajik fiction from the point of view of the setting one should mainly consider the works by Sadriddin Ayni, Jalol Ikromi and Fazliddin Muhammadiev.