bluuebunny/crossref_metadata_2025 huggingface dataset:
Systematic review of efficacy of LIFT procedure in crpytoglandular fistula-in-ano
Authors: Murugesan Jothi , Mor Isabella , Fulham Stephen , Hitos Kerry
Published: April 2014

Background fistula-in-ano is a common problem. Ligation of intersphincteric fistula tract (LIFT) is a new addition to the list of operations available to deal with complex fistula-in-ano.

Objective we sought to qualitatively analyze studies describing LIFT for crpytoglandular fistula-in-ano and determine its efficacy.

Data sources MEDLINE (Pubmed, Ovid), Embase, Scopus and Cochrane Library were searched.

Study selection all clinical trials which studied LIFT or compared LIFT with other methods of treatment for anal fistulae, prospective observational studies, clinical registry data and retrospective case series which reported clinical healing of the fistula as the outcome were included. Case reports, studies reporting a combination with other technique, modified technique, abstracts, letters and comments were excluded.

Intervention the intervention was ligation of intersphincteric fistula tract in crpytoglandular fistula-in-ano.

Main outcome measure primary outcome measured was success rate (fistula healing rate) and length of follow-up.
Caspase‐8 mutations in head and neck cancer confer resistance to death receptor‐mediated apoptosis and enhance migration, invasion, and tumor growth
Authors: Li Changyou , Egloff Ann Marie , Sen Malabika , Grandis Jennifer R. , Johnson Daniel E.
Published: April 2014

Little is known regarding molecular markers in head and neck squamous cell carcinoma (HNSCC) that predict responsiveness to different therapeutic regimens or predict HNSCC progression. Mutations in procaspase‐8 occur in 9% of HNSCC primary tumors, but the functional consequences of these mutations are poorly understood. In this study, we examined the impact of four, representative, HNSCC‐associated procaspase‐8 mutations on activation of the extrinsic apoptosis pathway, as well as cellular migration and invasion, and in vivo tumor growth. All four mutant proteins acted to potently inhibit activation of apoptosis following treatment with TRAIL or agonistic anti‐Fas. In contrast to wild‐type procaspase‐8, the mutant proteins were not recruited to FADD following treatment with TRAIL or anti‐Fas, but may be constitutively bound by FADD. Three of the four procaspase‐8 mutants promoted enhanced cellular migration and invasion through matrigel, relative to that seen with the wild‐type procaspase‐8 protein. Procaspase‐8 mutation also stimulated the growth of HNSCC xenograft tumors. These findings indicate that HNSCC‐associated procaspase‐8 mutations inhibit activation of the extrinsic apoptosis pathway and are likely to represent markers for resistance to therapeutic regimens incorporating death receptor activators. Moreover, procaspase‐8 mutations may serve as markers of HNSCC tumor progression, as exemplified by enhanced migration, invasion, and tumor growth.
Neuropsychologische Schlüsselprobleme der Musiktherapie
Authors: Mastnak Wolfgang
Published: April 2014

Neuropsychologie trägt zur wissenschaftlichen Fundierung von Musiktherapie bei und liefert Erklärungsmodelle zu psychophysiologischen Wirkprozessen und klinischer Effizienz. Dabei spielen interdisziplinäre Ansätze in Bezug auf Chronobiologie, Regulationsmedizin und Ethnomedizin eine wichtige Rolle. Spezifische Hirnareale und neuronale Prozesse werden im Hinblick auf psychische Korrelate und musiktherapeutische Funktionen dargestellt und Aspekte für zukünftige Forschung skizziert.
Sozialpräventive und musiktherapeutische Arbeit auf Mauritius
Authors: Wettges Martin , Voit Nina
Published: April 2014

Der folgende Artikel beschreibt ein Projekt, welches auf besondere Art und Weise sozialpräventive, pädagogische und musiktherapeutische Ansätze verbindet und daher ein Beispiel für gelungene interdisziplinäre Arbeit darstellt. Da dieses Projekt–Vent d’un Rêve–bisher lokal auf die Insel Mauritius beschränkt ist, wird zu Beginn ein historischer Überblick über die gesellschaftliche und musikalische Entwicklung der Inselrepublik gegeben. Dieser offenbart die reiche kulturelle Vielfalt und das Potential für Musikpädagogik und das Konzert- und Opernwesen. Nach genauer Beschreibung des Musikschulprojekts, das seine ideologischen Wurzeln in der venezolanischen Orchesterbewegung „El Sistema” hat, folgt eine Zusammenfassung der musiktherapeutischen und sozialpräventiven Möglichkeiten, die „Vent d’un Rêve” zu einem Vorbild für die internationale Sozialpädagogik und Musikpädagogik macht.
Highly efficient Mo2C nanotubes as a counter electrode catalyst for organic redox shuttles in dye-sensitized solar cells
Authors: Wu Mingxing , Lin Ya-nan , Guo Hongyue , Wu Kezhong , Lin Xiao
Published: April 2014

As an efficient counter electrode catalyst, Mo2C nanotubes were introduced into dye-sensitized solar cells for the regeneration of an organic sulfide redox shuttle.
A σ-hole interaction with radical species as electron donors: does single-electron tetrel bonding exist?
Authors: Li Qingzhong , Guo Xin , Yang Xin , Li Wenzuo , Cheng Jianbo , Li Hai-Bei
Published: April 2014

A single-electron tetrel bond was predicted and characterized in FXH3⋯CH3 (X = C, Si, Ge, and Sn) complexes.
Excellent anti-fogging dye-sensitized solar cells based on superhydrophilic nanoparticle coatings
Authors: Park Jung Tae , Kim Jong Hak , Lee Daeyeon
Published: April 2014

We present a method for eliminating the negative impact of fogging on dye-sensitized solar cells using superhydrophilic nanoparticle coatings. Superhydrophilic coatings made of spin-coated SiO2 nanoparticles suppress fogging on the photoanodes of solid-state dye-sensitized solar cells and in turn significantly improve the device efficiency under fogging conditions. We believe that this one-step SiO2 colloidal coating is extremely useful for enhancing light harvesting.
Bio-functionalized Pt nanoparticles based electrochemical impedance immunosensor for human cardiac myoglobin
Authors: Mishra Sujeet K. , Srivastava Avanish K. , Kumar Devendra , Rajesh Rajesh
Published: April 2014

We report the covalent immobilization of three-dimensional carboxyl-functionalized Pt(MPA) nanoparticles with myoglobin protein antibody by carbodiimide coupling reaction deposited onto an indium-tin-oxide-coated glass plate for the construction of a bioelectrode.
La0.6Sr0.4Co0.2Fe0.8O3−δ hollow fibre membrane performance improvement by coating of Ba0.5Sr0.5Co0.9Nb0.1O3−δ porous layer
Authors: Han Dezhi , Wu Jinhu , Yan Zifeng , Zhang Kun , Liu Jian , Liu Shaomin
Published: April 2014

The oxygen permeation performance of perovskite La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) hollow fibre membranes was enhanced by surface modification via coating of a Ba0.5Sr0.5Co0.9Nb0.1O3−δ (BSCN) porous layer.
The development and deployment of a ground-based, laser-induced fluorescence instrument for the in situ detection of iodine monoxide radicals
Authors: Thurlow M. E. , Co D. T. , O'Brien A. S. , Hannun R. A. , Lapson L. B. , Hanisco T. F. , Anderson J. G.
Published: April 2014

High abundances of iodine monoxide (IO) are known to exist and to participate in local photochemistry of the marine boundary layer. Of particular interest are the roles IO plays in the formation of new particles in coastal marine environments and in depletion episodes of ozone and mercury in the Arctic polar spring. This paper describes a ground-based instrument that measures IO at mixing ratios less than one part in 1012. The IO radical is measured by detecting laser-induced fluorescence at wavelengths longer that 500 nm. Tunable visible light is used to pump the A2Π3/2 (v′ = 2) ← X2Π3/2 (v″ = 0) transition of IO near 445 nm. The laser light is produced by a solid-state, Nd:YAG-pumped Ti:Sapphire laser at 5 kHz repetition rate. The laser-induced fluorescence instrument performs reliably with very high signal-to-noise ratios (>10) achieved in short integration times (<1 min). The observations from a validation deployment to the Shoals Marine Lab on Appledore Island, ME are presented and are broadly consistent with in situ observations from European Coastal Sites. Mixing ratios ranged from the instrumental detection limit (<1 pptv) to 10 pptv. These data represent the first in situ point measurements of IO in North America.
Automated high-pressure titration system with in situ infrared spectroscopic detection
Authors: Thompson Christopher J. , Martin Paul F. , Chen Jeffrey , Benezeth Pascale , Schaef Herbert T. , Rosso Kevin M. , Felmy Andrew R. , Loring John S.
Published: April 2014

A fully automated titration system with infrared detection was developed for investigating interfacial chemistry at high pressures. The apparatus consists of a high-pressure fluid generation and delivery system coupled to a high-pressure cell with infrared optics. A manifold of electronically actuated valves is used to direct pressurized fluids into the cell. Precise reagent additions to the pressurized cell are made with calibrated tubing loops that are filled with reagent and placed in-line with the cell and a syringe pump. The cell's infrared optics facilitate both transmission and attenuated total reflection (ATR) measurements to monitor bulk-fluid composition and solid-surface phenomena such as adsorption, desorption, complexation, dissolution, and precipitation. Switching between the two measurement modes is accomplished with moveable mirrors that direct the light path of a Fourier transform infrared spectrometer into the cell along transmission or ATR light paths. The versatility of the high-pressure IR titration system was demonstrated with three case studies. First, we titrated water into supercritical CO2 (scCO2) to generate an infrared calibration curve and determine the solubility of water in CO2 at 50 °C and 90 bar. Next, we characterized the partitioning of water between a montmorillonite clay and scCO2 at 50 °C and 90 bar. Transmission-mode spectra were used to quantify changes in the clay's sorbed water concentration as a function of scCO2 hydration, and ATR measurements provided insights into competitive residency of water and CO2 on the clay surface and in the interlayer. Finally, we demonstrated how time-dependent studies can be conducted with the system by monitoring the carbonation reaction of forsterite (Mg2SiO4) in water-bearing scCO2 at 50 °C and 90 bar. Immediately after water dissolved in the scCO2, a thin film of adsorbed water formed on the mineral surface, and the film thickness increased with time as the forsterite began to dissolve. However, after approximately 2.5 h, the trend reversed, and a carbonate precipitate began to form on the forsterite surface, exposing dramatic chemical changes in the thin-water film. Collectively, these applications illustrate how the high-pressure IR titration system can provide molecular-level information about the interactions between variably wet scCO2 and minerals relevant to underground storage of CO2 (geologic carbon sequestration). The apparatus could also be utilized to study high-pressure interfacial chemistry in other areas such as catalysis, polymerization, food processing, and oil and gas recovery.
Thermal decomposition of 1,3,3-trinitroazetidine (TNAZ): A density functional theory andab initiostudy
Authors: Veals Jeffrey D. , Thompson Donald L.
Published: April 2014

Density functional theory and ab initio methods are employed to investigate decomposition pathways of 1,3,3-trinitroazetidine initiated by unimolecular loss of NO2 or HONO. Geometry optimizations are performed using M06/cc-pVTZ and coupled-cluster (CC) theory with single, double, and perturbative triple excitations, CCSD(T), is used to calculate accurate single-point energies for those geometries. The CCSD(T)/cc-pVTZ energies for NO2 elimination by N–N and C–N bond fission are, including zero-point energy (ZPE) corrections, 43.21 kcal/mol and 50.46 kcal/mol, respectively. The decomposition initiated by trans-HONO elimination can occur by a concerted H-atom and nitramine NO2 group elimination or by a concerted H-atom and nitroalkyl NO2 group elimination via barriers (at the CCSD(T)/cc-pVTZ level with ZPE corrections) of 47.00 kcal/mol and 48.27 kcal/mol, respectively. Thus, at the CCSD(T)/cc-pVTZ level, the ordering of these four decomposition steps from energetically most favored to least favored is: NO2 elimination by N–N bond fission, HONO elimination involving the nitramine NO2 group, HONO elimination involving a nitroalkyl NO2 group, and finally NO2 elimination by C–N bond fission.
Magneto-tunable one-dimensional graphene-based photonic crystal
Authors: Jahani D. , Soltani-Vala A. , Barvestani J. , Hajian H.
Published: April 2014

We investigate the effect of a perpendicular static magnetic field on the optical bandgap of a one-dimensional (1D) graphene-dielectric photonic crystal in order to examine the possibility of reaching a rich tunable photonic bandgap. The solution of the wave equation in the presence of the anisotropic Hall situation suggests two decoupled circularly polarized wave each exhibiting different degrees of bandgap tunability. It is also numerically demonstrated that applying different values of field intensity lead to perceptible changes in photonic bandgap of such a structure. Finally, the effect of opening a finite electronic gap in the spectrum of graphene on the optical dispersion solution of such a 1D photonic crystal is reported. It is shown that increasing the value of the electronic gap results in the shrinkage of the associated photonic bandgaps.
A spatially resolved retarding field energy analyzer design suitable for uniformity analysis across the surface of a semiconductor wafer
Authors: Sharma S. , Gahan D. , Kechkar S. , Daniels S. , Hopkins M. B.
Published: April 2014

A novel retarding field energy analyzer design capable of measuring the spatial uniformity of the ion energy and ion flux across the surface of a semiconductor wafer is presented. The design consists of 13 individual, compact-sized, analyzers, all of which are multiplexed and controlled by a single acquisition unit. The analyzers were tested to have less than 2% variability from unit to unit due to tight manufacturing tolerances. The main sensor assembly consists of a 300 mm disk to mimic a semiconductor wafer and the plasma sampling orifices of each sensor are flush with disk surface. This device is placed directly on top of the rf biased electrode, at the wafer location, in an industrial capacitively coupled plasma reactor without the need for any modification to the electrode structure. The ion energy distribution, average ion energy, and average ion flux were measured at the 13 locations over the surface of the powered electrode to determine the degree of spatial nonuniformity. The ion energy and ion flux are shown to vary by approximately 20% and 5%, respectively, across the surface of the electrode for the range of conditions investigated in this study.
Range-based control of dual-stage nanopositioning systems
Authors: Clayton Garrett M. , Dudley Christopher J. , Leang Kam K.
Published: April 2014

A novel dual-stage nanopositioner control framework is presented that considers range constraints. Dual-stage nanopositioners are becoming increasingly popular in applications such as scanning probe microscopy due to their unique ability to achieve long-range and high-speed operation. The proposed control approach addresses the issue that some precision positioning trajectories are not achievable through existing control schemes. Specifically, short-range, low-speed inputs are typically diverted to the long-range actuator, which coincidentally has lower positioning resolution. This approach then limits the dual-stage nanopositioner's ability to achieve the required positioning resolution that is needed in applications where range and frequency are not inversely correlated (which is a typical, but not always the correct assumption for dual stage systems). The proposed range-based control approach is proposed to overcome the limitations of existing control methods. Experimental results show that the proposed control strategy is effective.
Energy density functionals from the strong-coupling limit applied to the anions of the He isoelectronic series
Authors: Mirtschink André , Umrigar C. J. , Morgan John D. , Gori-Giorgi Paola
Published: April 2014

Anions and radicals are important for many applications including environmental chemistry, semiconductors, and charge transfer, but are poorly described by the available approximate energy density functionals. Here we test an approximate exchange-correlation functional based on the exact strong-coupling limit of the Hohenberg-Kohn functional on the prototypical case of the He isoelectronic series with varying nuclear charge Z < 2, which includes weakly bound negative ions and a quantum phase transition at a critical value of Z, representing a big challenge for density functional theory. We use accurate wavefunction calculations to validate our results, comparing energies and Kohn-Sham potentials, thus also providing useful reference data close to and at the quantum phase transition. We show that our functional is able to bind H− and to capture in general the physics of loosely bound anions, with a tendency to strongly overbind that can be proven mathematically. We also include corrections based on the uniform electron gas which improve the results.
Modeling the adsorption of short alkanes in the zeolite SSZ-13 using “van der Waals” DFT exchange correlation functionals: Understanding the advantages and limitations of such functionals
Authors: Göltl Florian , Sautet Philippe
Published: April 2014

The inclusion of non-local interactions is one of the large challenges in density functional theory. Very promising methods are the vdW-DF2 and BEEF-vdW functionals, which combine a semi-local approximation for exchange interactions and a non-local correlation expression. In this work we apply those functionals to model the adsorption of short alkanes in the zeolite SSZ-13. Even though results for energetics are improved with respect to other vdW-DF based methods, we still find a comparatively large error compared to high-level calculations. These errors result from approximations in the determination of the dielectric function and of the van der Waals kernel. The insights presented in this work will help to understand the performance not only of vdW-DF2 and BEEF-vdW, but all vdW-DF based functionals in various chemically or physically important systems.
A cryogenic infrared calibration target
Authors: Wollack E. J. , Kinzer R. E. , Rinehart S. A.
Published: April 2014

A compact cryogenic calibration target is presented that has a peak diffuse reflectance, R ⩽ 0.003, from 800 to 4800 cm−1 (12 − 2 μm). Upon expanding the spectral range under consideration to 400–10 000 cm−1 (25 − 1 μm) the observed performance gracefully degrades to R ⩽ 0.02 at the band edges. In the implementation described, a high-thermal-conductivity metallic substrate is textured with a pyramidal tiling and subsequently coated with a thin lossy dielectric coating that enables high absorption and thermal uniformity across the target. The resulting target assembly is lightweight, has a low-geometric profile, and has survived repeated thermal cycling from room temperature to ∼4 K. Basic design considerations, governing equations, and test data for realizing the structure described are provided. The optical properties of selected absorptive materials—Acktar Fractal Black, Aeroglaze Z306, and Stycast 2850 FT epoxy loaded with stainless steel powder—are characterized and presented.
The role of the anisotropy on the solid-fluid phase transition in core-softened shoulder-dumbbells systems
Authors: Gavazzoni Cristina , Gonzatti Guilherme K. , Pereira Luiz Felipe , Ramos Luis Henrique Coelho , Netz Paulo A. , Barbosa Marcia C.
Published: April 2014

Using molecular dynamics we studied the role of the anisotropy on the phase boundary of 250 dimeric particles interacting by a core-softened potential. This study led us to an unexpected result: the introduction of a rather small anisotropy, quantified by the distance between the particles inside each dimer, leads to an apparent increase of the size of the solid region in the pressure-temperature phase diagram when compared to the isotropic monomeric case. However, as the anisotropy increases beyond a threshold the solid region shrinks. We found that this behavior can be understood by the decoupling of the translational and non-translational kinetic energy components that could be interpreted as if the system would display different translational and non-translational temperatures. The phase boundaries seem to be sensitive to the translational temperature only.
Rotating entangled states of an exchange-coupled dimer of single-molecule magnets
Authors: Owerre S. A.
Published: April 2014

An antiferromagnetically exchange-coupled dimer of single molecule magnets which possesses a large spin tunneling has been investigated. For this system, the ground and first excited states are entangled states, and the Hamiltonian is effectively similar to that of a two-state system at 2sth order in perturbation theory; thus this system can be mapped to an entangled pseudospin 1/2 particles. We study the effects of interaction and rotation of this system about its staggered easy-axis direction. The corresponding Hamiltonian of a rotated two-state entangled spin system is derived with its exact low-energy eigenstates and eigenvalues. We briefly discuss the effect of a dissipative environment on this rotated two-state system.
Effects of size and interparticle interaction of silica nanoparticles on dispersion and electrical conductivity of silver/epoxy nanocomposites
Authors: Woo Cho Hyun , Nam Seungwoong , Lim Soonho , Kim Daeheum , Kim Heesuk , June Sung Bong
Published: April 2014

The agglomeration of nanoparticles (NPs) occurs due to attractive interaction between NPs and worsens the physical properties of materials such as electrical conductivity. When the attractive interaction is sufficiently strong, the agglomerates of NPs may be arrested dynamically in non-equilibrium state with a large relaxation time. We show that when conductive silver NPs form agglomerates in epoxy matrices, one can tune the effective interaction between silver NPs in epoxy matrices by introducing auxiliary non-conductive silica NPs and may prevent the agglomeration easily. More interestingly, as the size of the auxiliary silica NPs decreases, the silver NPs disperse better, thus increasing the electrical conductivity by orders of magnitude. We also perform Monte Carlo simulations and show that the auxiliary silica NPs influence the morphology of silver NPs not entropically but energetically.
Polarization switching characteristics of 0.5BaTi0.8Zr0.2O3-0.5Ba0.7Ca0.3TiO3 lead free ferroelectric thin films by pulsed laser deposition
Authors: Kolekar Y. D. , Bhaumik A. , Shaikh P. A. , Ramana C. V. , Ghosh K.
Published: April 2014

We report on the ferroelectricity for morphotropic-phase-boundary lead (Pb) free 0.5BaTi0.8Zr0.2O3-0.5Ba0.7Ca0.3TiO3 (0.5BZT-0.5BCT) thin films. Thin films were grown on Pt/Ti/SiO2/Si substrate using pulsed laser deposition. Raman spectroscopic data combined with the X-ray diffraction analyses confirm body centered tetragonal crystallographic structure 0.5BZT-0.5 BCT thin films on Pt/Ti/SiO2/Si. Polarization studies demonstrate that these 0.5BZT-0.5BCT films exhibit a large remnant and saturation polarization of 37 μC/cm2 and 40 μC/cm2, respectively, with a coercive field of 140 kV/cm. A correlation between polarization dynamics, structural distortion, and phonon vibration is established. The splitting of X-ray diffraction peak of the thin film in the 2θ range of 44.5° to 46.5° represents high degree of tetragonality. The tetragonality factor calculated by Rietveld analysis was found to be 0.006 and can be a major cause for the increased remnant polarization value. It is established from Raman spectra that the non-centrosymmetricity due to the displacement of Ti/Zr ions from its octahedral position is related to the peak position as well as the broadening of the A1 (LO) optical phonon mode. This increase of broadness in the thin film causes an increase in the dipole moment of the unit cell and, hence, the net increase in polarization values.
Relationship between boson heat capacity peaks and evolution of heterogeneous structure in metallic glasses
Authors: Huang B. , Bai H. Y. , Wang W. H.
Published: April 2014

The dependence of boson heat capacity peaks of a typical Zr52.5Ti5Cu17.9Ni14.6Al10 metallic glass on different annealing time and quenching rates is studied. It is found that the boson heat capacity peak moves to higher temperatures and reduces intensity when the metallic glass is isothermally annealed or slowly quenched. We show that the intensity and position change of the boson heat capacity peak are associated with the evolution of heterogeneous structure and inelastic regions in metallic glasses. The results might help in understanding the structural features and evolution as well as their effects on boson peak of metallic glasses.
Resistive switching of a TaOx/TaON double layer via ionic control of carrier tunneling
Authors: Jeon Heeyoung , Park Jingyu , Jang Woochool , Kim Hyunjung , Kang Chunho , Song Hyoseok , Seo Hyungtak , Jeon Hyeongtag
Published: April 2014

Resistance random access memory (RRAM) is an attractive candidate for future non-volatile memory due to its superior features. As the oxide thickness is scaled down, the charge transport mechanism is also subject to the transition from hopping to tunneling dominant process, which is critically related to the interfacial electronic band structure. A TaOx/TaON double layer-based RRAM is fabricated and characterized in this work. Upon TaON insertion at the lower interface, the improved switching behavior is observed. The TaON at the bottom electrode interface blocks oxygen vacancy percolation due to strong N-O bonds and also modifies interfacial band alignment to lower the injected electron energy from bottom electrode due to higher tunneling barrier height than that of TaOx/Pt. This study suggested that a defect-minimized insertion layer like TaON with a proper interfacial band alignment is pivotal in RRAM for the effective ionic control of carrier tunneling resulting in non-linear I-V behavior with improved properties.
Study of surface leakage current of AlGaN/GaN high electron mobility transistors
Authors: Chen YongHe , Zhang Kai , Cao MengYi , Zhao ShengLei , Zhang JinCheng , Ma XiaoHua , Hao Yue
Published: April 2014

Temperature-dependent surface current measurements were performed to analyze the mechanism of surface conductance of AlGaN/GaN channel high-electron-mobility transistors by utilizing process-optimized double gate structures. Different temperatures and electric field dependence have been found in surface current measurements. At low electric field, the mechanism of surface conductance is considered to be two-dimensional variable range hopping. At elevated electric field, the Frenkel–Poole trap assisted emission governs the main surface electrons transportation. The extracted energy barrier height of electrons emitting from trapped state near Fermi energy level into a threading dislocations-related continuum state is 0.38 eV. SiN passivation reduces the surface leakage current by two order of magnitude and nearly 4 orders of magnitude at low and high electric fields, respectively. SiN also suppresses the Frenkel–Poole conductance at high temperature by improving the surface states of AlGaN/GaN. A surface treatment process has been introduced to further suppress the surface leakage current at high temperature and high field, which results in a decrease in surface current of almost 3 orders of magnitude at 476 K.
Chemical states and ferromagnetism in heavily Mn-substituted zinc oxide thin films
Authors: Shao Q. , Ku P. S. , Wang X. L. , Zapien J. A. , Leung C. W. , Borgatti F. , Gambardella A. , Dediu V. , Ciprian R. , Ruotolo A.
Published: April 2014

A concentration of Manganese as high as 8% was successfully diluted into Zinc Oxide epitaxial films deposited by pulsed laser deposition. The films showed strong ferromagnetism with a large coercivity. Low temperature X-ray absorption spectroscopy measurements indicated that all the Manganese ions substitute for Zinc sites of the wurtzite lattice in the valency of +2. Photoluminescence measurements excluded the presence of Zinc vacancies, as well as Zn interstitials. All the magnetic moments measured were to ascribe to the formation of bound magnetic polarons, with no other contribution due to Manganese-secondary phases or Zinc vacancy-mediated double exchange interaction.
A simple drain current model for single-walled carbon nanotube network thin-film transistors
Authors: Sano Eiichi , Tanaka Tomo
Published: April 2014

Single-walled carbon nanotube (CNT) network thin-film transistors (TFTs) are attractive owing to their simple, low-cost fabrication methods. However, the detailed operation mechanism for TFTs is still unclear. In this paper, we present a simple model for the drain current of CNT network TFTs operated in the linear region. The model is based on the gate electrostatics and the continuity condition of the currents through CNT and CNT-CNT tunnel junction. The model is evaluated by comparing its calculations to experimentally measured drain current and low frequency (1/f) noise parameters. Even though the present model is based on simplified assumptions, it provides useful information to improve the TFT performance.
Investigation of gate leakage mechanism in Al2O3/Al0.55Ga0.45N/GaN metal-oxide-semiconductor high-electron-mobility transistors
Authors: Zhu Jie-Jie , Ma Xiao-Hua , Hou Bin , Chen Wei-Wei , Hao Yue
Published: April 2014

The mechanism of both reverse and forward gate leakage currents in Al2O3/Al0.55Ga0.45N/GaN structures was studied in this Letter by temperature-dependent current-voltage measurement. Poole–Frenkel (PF) emission, an oxygen vacancy-assisted process, was deduced as the dominant mechanism at high-temperatures (>388 K), and the leakage current at mid-temperatures (<388 K) were found greatly impacted by temperature-independent tunneling current. The reverse PF mission current in low-field, mid-field, and high-field region were related to trap states with activation energy of 0.41 eV, 0.49 eV, and 0.71 eV, respectively, and the activation energy of trap states for forward PF emission current was derived as 0.65 eV.
Enhanced acoustic wave localization effect using coupled sonic crystal resonators
Authors: Yang Aichao , Li Ping , Wen Yumei , Lu Caijiang , Peng Xiao , Zhang Jitao , He Wei
Published: April 2014

A coupled resonance structure of two sonic crystal resonators with different sizes is proposed to enhance the acoustic wave localization effect. Due to acoustic resonance coupling between sonic crystal resonators, the enhanced acoustic wave localization is observed in the coupled resonance structure, and the cavity pressure is much larger than that in each individual sonic crystal resonator. The experimental results show that the proposed coupled structure exhibits 2.1–3.3 times larger maximum pressure magnification than each individual sonic crystal resonator. This proposed structure can be further used to improve acoustic energy harvesting, acoustic sensing, and sound concentration.
On the roles of Bi2Sr2CuOx intergrowths in Bi2Sr2CaCu2Ox/Ag round wires: c-axis transport and magnetic flux pinning
Authors: Naderi G. , Schwartz J.
Published: April 2014

Despite progress in the performance of Bi2Sr2CaCu2Ox (Bi2212)/Ag multifilamentary round wires, understanding the impact of microstructural defects on multiple length scales on electrical transport remains a significant challenge. Many recent studies have focused on porosity, but porosity is not the only factor in determining Jc. The primary impurity in partial-melt processed multifilamentary Bi2212 wires is Bi2Sr2CuOx (Bi2201), which forms as mesoscopic grains and nanoscopic intergrowths. Previously, we showed the destructive effect of Bi2201 grains on transport. Here, we relate scanning transmission electron microscopy results to the Bi2212 coherence length, anisotropic magnetization behavior, and magnetic-field dependent transport to study c-axis transport and the effects of Bi2201 intergrowths on magnetic flux pinning. We show that wide Bi2201 intergrowths are barrier to c-axis transport within Bi2212 grains, whereas narrow (half- and full-cell) Bi2201 intergrowths are not detrimental to c-axis transport and are likely magnetic flux pinning centers. These results have significant impact on the understanding of Bi2212/Bi2201 systems and provide important physical insight towards future improvements in devices based upon wires, film, and junctions.
On the lateral fluid motion during pool boiling via preferentially located cavities
Authors: Kapsenberg F. , Strid L. , Thiagarajan N. , Narayanan V. , Bhavnani S. H.
Published: April 2014

Passively generated lateral motion of fluid during pool boiling on asymmetrically textured meso-scale structures is discussed in this Letter. The surface texture is in the form of 30°–60° mm-scale ratchets with re-entrant cavities located on the 30° face. High speed visualization of growing bubbles from cavities indicates growth and departure normal to the 30° face of the ratchets. A semi-empirical model of net axial liquid velocity due to the non-vertical bubble growth is developed and validated in a pool boiling experiment.
Quantitative analysis of interfacial reactions at a graphene/SiO2 interface using the discharge current analysis method
Authors: Jung Ukjin , Gon Lee Young , Goo Kang Chang , Lee Sangchul , Hun Lee Byoung
Published: April 2014

Using the discharge current analysis method, the contribution of charge generation through an interfacial reaction at a graphene /substrate interface is assessed to be on the order of 1014/cm2, which is ∼20% of the total charging sites. The validity of this method, which separately extracts the density of the charging sites related to the initial defect density of the graphene from the contribution of interfacial reactions is examined by measuring the discharge current of graphene field-effect-transistors at different ambient and temperatures. This method will be crucially instrumental in finding an optimal substrate material for graphene devices.
Equilibrium softening of an enzyme explored with the DNA spring
Authors: Tseng Chiao-Yu , Zocchi Giovanni
Published: April 2014

We explore enzyme mechanics using a system of two mechanically coupled biomolecules. Measurements of the mechanical modulation of enzymatic activity in a Luciferase—DNA chimera are presented. These are molecules where the enzyme is deformed by the action of a DNA spring. The response of the enzyme for different states of stress is examined. It is found that small changes in the stress cause large changes in activity. This nonlinear behavior is qualitatively interpreted as arising from a soft regime of the enzyme beyond linear elasticity. This soft regime may enable large conformational motion in enzymes.
Facile fabrication processes for hydrogel-based microfluidic devices made of natural biopolymers
Authors: Yajima Yuya , Yamada Masumi , Yamada Emi , Iwase Masaki , Seki Minoru
Published: April 2014

We present facile strategies for the fabrication of two types of microfluidic devices made of hydrogels using the natural biopolymers, alginate, and gelatin as substrates. The processes presented include the molding-based preparation of hydrogel plates and their chemical bonding. To prepare calcium-alginate hydrogel microdevices, we suppressed the volume shrinkage of the alginate solution during gelation using propylene glycol alginate in the precursor solution along with sodium alginate. In addition, a chemical bonding method was developed using a polyelectrolyte membrane of poly-L-lysine as the electrostatic glue. To prepare gelatin-based microdevices, we used microbial transglutaminase to bond hydrogel plates chemically and to cross-link and stabilize the hydrogel matrix. As an application, mammalian cells (fibroblasts and vascular endothelial cells) were cultivated on the microchannel surface to form three-dimensional capillary-embedding tissue models for biological research and tissue engineering.
Characterizations of kinetic power and propulsion of the nematode Caenorhabditis elegans based on a micro-particle image velocimetry system
Authors: Kuo Wan-Jung , Sie Yue-Syun , Chuang Han-Sheng
Published: April 2014

Quantifying the motility of micro-organisms is beneficial in understanding their biomechanical properties. This paper presents a simple image-based algorithm to derive the kinetic power and propulsive force of the nematode Caenorhabditis elegans. To avoid unnecessary disturbance, each worm was confined in an aqueous droplet of 0.5 μl. The droplet was sandwiched between two glass slides and sealed with mineral oil to prevent evaporation. For motion visualization, 3-μm fluorescent particles were dispersed in the droplet. Since the droplet formed an isolated environment, the fluid drag and energy loss due to wall frictions were associated with the worm's kinetic power and propulsion. A microparticle image velocimetry system was used to acquire consecutive particle images for fluid analysis. The short-time interval (Δt < 20 ms) between images enabled quasi real-time measurements. A numerical simulation of the flow in a straight channel showed that the relative error of this algorithm was significantly mitigated as the image was divided into small interrogation windows. The time-averaged power and propulsive force of a N2 adult worm over three swimming cycles were estimated to be 5.2 ± 3.1 pW and 1.0 ± 0.8 nN, respectively. In addition, a mutant, KG532 [kin-2(ce179) X], and a wild-type (N2) worm in a viscous medium were investigated. Both cases showed an increase in the kinetic power as compared with the N2 worm in the nematode growth medium due to the hyperactive nature of the kin-2 mutant and the high viscosity medium used. Overall, the technique deals with less sophisticated calculations and is automation possible.
Experimental investigation of the latent heat of vaporization in aqueous nanofluids
Authors: Lee Soochan , Phelan Patrick E. , Dai Lenore , Prasher Ravi , Gunawan Andrey , Taylor Robert A.
Published: April 2014

This paper reports an experimental investigation of the latent heat of vaporization (hfg) in nanofluids. Two different types of nanoparticles, graphite and silver, suspended in deionized water were exposed to a continuous laser beam (130 mW, 532 nm) to generate boiling. The latent heat of vaporization in the nanofluids was determined by the measured vapor mass generation and the heat input. To ensure that the measured hfg values are independent of heating method, the experiments were repeated with an electrically heated hot wire as a primary heat input. These experiments show considerable variation in the hfg of nanofluids. That is, graphite nanofluid exhibits an increased hfg and silver nanofluid shows a decrease in hfg compared to the value for pure water. As such, these results indicate that relatively low mass fractions of nanoparticles can apparently create large changes in hfg.
The emergence of Cognitive Sociolinguistics
Authors: Pütz Martin , Robinson Justyna A. , Reif Monika
Published: April 2014

This paper explores the contexts of emergence and application of Cognitive Sociolinguistics. This novel field of scientific enquiry draws on the convergence of methods and theoretical frameworks typically associated with Cognitive Linguistics and Sociolinguistics. Here, we trace and systematize the key theoretical and epistemological bases for the emergence of Cognitive Sociolinguistics, by outlining main research strands and highlighting some challenges that face the development of this field. More specifically, we focus on the following terms and concepts which are foundational to the discussion of Cognitive Sociolinguistics: (i) usage-based linguistics and language-internal variation; (ii) rule-based vs. usage-based conceptions of language; (iii) meaning variation; (iv) categorization and prototypes; and (v) the interplay between language, culture, and ideology. Finally, we consider the benefits of taking a Cognitive Sociolinguistic perspective in research by looking at the actual studies that are presented in the current volume.
What is to be learned
Authors: Labov William
Published: April 2014

This paper is an effort to define the target of the language learner: asking, what are the data that the child pays attention to in the process of becoming a native speaker? In so doing, we will necessarily be engaged in the more general effort to define language itself. The general argument to be advanced here is that the human language learning capacity is outward bound, that is, aimed at the acquisition of the general pattern used in the speech community. The end result is a high degree of uniformity in both the categorical and variable aspects of language production, where individual variation is reduced below the level of linguistic significance.
Pragmatic variation and cultural models
Authors: Schneider Klaus P.
Published: April 2014

The present paper focuses on pragmatic variation between national varieties of English, reporting an experimental study conducted in the framework of variational pragmatics. It is argued that experimental methods such as dialogue production tasks do not reveal actual verbal behaviour, which is subject to the specific circumstances of concrete social situations, but the underlying behavioural norms of the respective sociocultural community of speakers. These norms emerge from repeated encounters with similar verbal behaviour in social situations of the same type and are collectively shared prototypical patterns of behaviour stored in cultural models in the long-term memory. Such cultural models specify what is expected and considered appropriate in a given type of situation. More particularly, they specify what can be said when and how, i.e. discourse topics, discourse positions, and speech act realizations, as is exemplified in the empirical study reported on.
Comparing the Position of Canadian Political Parties using French and English Manifestos as Textual Data
Authors: Collette Benôit , Pétry François
Published: April 2014

Recently, computer-assisted, quantitative methods have been developed to position political parties. These word-based textual analysis techniques rely exclusively on the relative frequency of words. As such they do not necessitate the knowledge of any particular language to extract policy positions from texts. However, different languages have different word distributions and other syntactic idiosyncrasies. These differences might provoke word-based textual analysis techniques to extract noticeably different positions from parallel texts that are similar in every aspect except language. How crippling is this potential disadvantage when comparing political texts written in different languages? It is this chapter’s objective to determine the effect of language on the two word frequency methods Wordscores and Wordfish by comparing the policy positions of Canadian parties as extracted from their English and French party manifestos.
Leveraging Textual Sentiment Analysis with Social Network Modelling
Authors: Gryc Wojciech , Moilanen Karo
Published: April 2014

Automatic computational analysis of political texts poses major challenges for state-of-the-art Sentiment Analysis and Natural Language Processing tools. In this initial study, we investigate the feasibility of combining purely linguistic indicators of political sentiment with non-linguistic evidence gained from concomitant social network analysis. The analysis draws on a corpus of 2.8 million political blog posts by 16,741 bloggers. We focus on modeling blogosphere sentiment centered around Barack Obama during the 2008 U.S. presidential election, and describe a series of initial sentiment classification experiments on a data set of 700 crowd-sourced posts labeled for attitude with respect to Obama. Our approach employs a hybrid machine-learning and logic-based framework which operates along three distinct levels of analysis encompassing standard shallow document classification, deep linguistic multi-entity sentiment analysis and scoring and social network modeling. The initial results highlight the inherent complexity of the classification task and point towards the positive effects of learning features that exploit entity-level sentiment and social-network structure.
The Qualitative Analysis of Political Documents
Authors: Wesley Jared J.
Published: April 2014

Qualitative document analysis remains one of the most common, yet methodologically misunderstood, components of political science research. While analysts are accustomed to incorporating manifestos, speeches, and other documents as evidence in their studies, few approach the task with the same level of understanding and sophistication as when applying quantitative methods. Building bridges between the two traditions, this chapter suggests guidelines for the rigorous, qualitative study of political documents. The discussion includes a novel examination of materials from the Poltext Project collection – a compilation of documents from across the Canadian provinces. The paper concludes that, whether approaching their work from a quantitative or non-quantitative perspective, researchers must adhere to similar disciplinary standards if their findings are to be considered trustworthy contributions to political science.
Christians, Feminists, Liberals, Socialists, Workers and Employers
Authors: Eleveld Anja
Published: April 2014

How can actors reach an agreement on the future of social policy when they interpret the world around them very differently? Around the turn of the century diverse groups in The Netherlands, such as workers, employers, feminists, and Socialist, Christian and Liberal political parties, reached an agreement on the introduction of a ‘life-course perspective’ in the social-security system. The system was to anticipate the ways individuals prefer to distribute their time between work and other activities like care, education, leisure, etc. This chapter explains how this unusual coalition between parties and stakeholders could emerge, with attention to methodological aspects concerning the study of ‘discourse coalitions’. The argument is that a central storyline in a life-course perspective works as a cohesive, uniting different actors, because each actor can interpret the signifier ‘life-course perspective’ in his/her own way.
From Text to Political Positions
Authors: van Elfrinkhof Annemarie , Maks Isa , Kaal Bertie
Published: April 2014

This chapter explores how three methods of political text analysis can complement each other to differentiate parties in detail. A word-frequency method and corpus linguistic techniques are joined by critical discourse analysis in an attempt to assess the ideological relation between election manifestos and a coalition agreement. How does this agreement relate to the policy positions presented in individual election manifestos and whose issues appear on the governmental agenda? The chapter discusses the design of three levels of text analysis applying text-as-data analysis; words-as-meaningful-data involving lexical-semantic analysis of subjectivity applying Wordscores; and words-in-context analysis for variation in constructions of worldviews. A comparison of the results reveals (im-)possibilities of combining qualitative with quantitative methods. We found that better results can be achieved for party positioning in combinations of qualitative and quantitative approaches.
Object position and Heavy NP Shift in Old Saxon and beyond
Authors: Walkden George
Published: April 2014

This paper investigates the position of ‘heavy’ nominal objects in Old Saxon and other Germanic languages. A new empirical study of Old Saxon is carried out and regression analysis performed, with information status, grammatical weight and case all serving as predictors. On the theoretical side it is argued that an analysis in terms of movement to specifier positions in a low left periphery goes some of the way towards capturing the observed facts, but still suffers from certain problems.