bluuebunny/crossref_metadata_2025 huggingface dataset:
Auto-ejection of liquid drops from capillary tubes
Authors: Mehrabian Hadi , Feng James J.
Published: July 2014

Wicking flow inside capillary tubes can attain considerable momentum so as to produce a liquid jet at the end of the tube. Auto-ejection refers to the formation of droplets at the tip of such a jet. Experimental observations suggest that a tapering nozzle at the end of the capillary tube is necessary for auto-ejection; it has never been reported for a straight tube. Besides, most experimental realizations require microgravity, although it is possible under normal gravity if the nozzle has a sufficiently sharp contraction. This computational study focuses on two related issues: the critical condition for auto-ejection, and the hydrodynamics of the liquid meniscus as affected by geometric parameters. We adopt a diffuse-interface Cahn–Hilliard model for the moving contact line, and allow the dynamic contact angle to deviate from the static one through wall energy relaxation. From analyzing the dynamics of the meniscus in the straight tube and the nozzle, we establish a critical condition for the onset of auto-ejection based on a Weber number defined at the exit of the nozzle and an effective length that encompasses the geometric features of the tube–nozzle combination. In particular, this shows that capillary ejection is not possible in straight tubes. With steeper contraction in the nozzle, we predict two additional regimes of interfacial rupture: rapid ejection of multiple droplets and air bubble entrapment. The numerical results are in general agreement with available experiments.
Instability of a free-shear layer in the vicinity of a viscosity-stratified layer
Authors: Sahu Kirti Chandra , Govindarajan Rama
Published: July 2014

The stability of a mixing layer made up of two miscible fluids, with a viscosity-stratified layer between them, is studied. The two fluids are of the same density. It is shown that unlike other viscosity-stratified shear flows, where species diffusivity is a dominant factor determining stability, species diffusivity variations over orders of magnitude do not change the answer to any noticeable degree in this case. Viscosity stratification, however, does matter, and can stabilize or destabilize the flow, depending on whether the layer of varying velocity is located within the less or more viscous fluid. By making an inviscid model flow with a slope change across the ‘viscosity’ interface, we show that viscous and inviscid results are in qualitative agreement. The absolute instability of the flow can also be significantly altered by viscosity stratification.
Clinician and practice characteristics influencing delivery and outcomes of the early part of outpatient cognitive behavioural therapy for anorexia nervosa
Authors: Brown Amy , Mountford Victoria , Waller Glenn
Published: July 2014

Cognitive-behavioural therapy (CBT) can be effective for anorexia nervosa. However, there is evidence that the delivery of treatments for the eating disorders is inconsistent. This study examined evidence that clinician characteristics and practice can influence the effective implementation of CBT. The participants were 100 qualified clinicians who routinely offered outpatient CBT to adults with anorexia nervosa. They completed a survey of their demographic characteristics, level of anxiety, clinical practice in CBT for anorexia nervosa, and beliefs about the relationship between weight gain and therapeutic alliance in the early part of such treatment. Greater reported levels of weight gain were associated with the use of manuals, early focus on weight gain as a target, structured eating, and a belief that weight gain precedes a good working alliance. Clinician anxiety and early focus on the therapeutic alliance rather than structured eating were associated with poorer outcomes. These conclusions need to be tested within clinical and research settings. However, they suggest that clinicians should be encouraged to use manual-based approaches when treating anorexia nervosa using CBT, as focusing on techniques might result in the best possible outcome in this early part of treatment.
Associations Between the Residential Environment and Physical Activity in German College Students and the Role of Self-Efficacy as a Mediator
Authors: Baar Johanna , Romppel Matthias , Igel Ulrike , Brähler Elmar , Grande Gesine
Published: July 2014

Social-ecological models suggest that influences on physical activity should be examined on multiple levels, but most of the empirical studies in this area have investigated the different levels separately. To integrate the different levels, we examined self-efficacy with respect to physical exercise as a mediator of the relation between environmental characteristics and physical activity. In a cross-sectional German study, 1,292 college students completed a questionnaire that included measures of their perceived residential environment, self-efficacy, and physical activity. Structural equation modeling was used to assess direct and indirect effects on physical activity. The cycling and walking network was directly positively associated with moderately intense physical activity. The network and trust in neighbors were indirectly positively associated with both moderately and vigorously intense physical activity mediated by self-efficacy. Our results support the importance of environmental influences on physical activity and emphasize the need to consider different levels of social-ecological models. It is likely that the environment stimulates residents’ self-efficacy such that they will use their environmental opportunities for physical activity more effectively. Evidence of such environmental influences can be used to improve community-based interventions.
Human HMGA2 protein overexpressed in mice induces precursor T-cell lymphoblastic leukemia
Authors: Efanov A , Zanesi N , Coppola V , Nuovo G , Bolon B , Wernicle-Jameson D , Lagana A , Hansjuerg A , Pichiorri F , Croce C M
Published: July 2014

T-cell acute lymphoblastic leukemia (T-ALL) is a neoplasia of thymocytes characterized by the rapid accumulation of the precursors of T lymphocytes. HMGA2 (high-mobility group AT-hook 2) gene expression is extremely low in normal adult tissues, but it is overexpressed in many tumors. To identify the biological function of HMGA2, we generated transgenic mice carrying the human HMGA2 gene under control of the VH promoter/Eμ enhancer. Approximately 90% of Eμ-HMGA2 transgenic mice became visibly sick between 4 and 8 months due to the onset and progression of a T-ALL-like disease. Characteristic features included severe alopecia (30% of mice); enlarged lymph nodes and spleen; and profound immunological abnormalities (altered cytokine levels, hypoimmunoglobulinemia) leading to reduced immune responsiveness. Immunophenotyping showed accumulation of CD5+CD4+, CD5+CD8+ or CD5+CD8+CD4+ T-cell populations in the spleens and bone marrow of sick animals. These findings show that HMGA2-driven leukemia in mice closely resembles spontaneous human T-ALL, indicating that HMGA2 transgenic mice should serve as an important model for investigating basic mechanisms and potential new therapies of relevance to human T-ALL.
The subgingival microbiome of clinically healthy current and never smokers
Authors: Mason Matthew R , Preshaw Philip M , Nagaraja Haikady N , Dabdoub Shareef M , Rahman Anis , Kumar Purnima S
Published: July 2014

Dysbiotic oral bacterial communities have a critical role in the etiology and progression of periodontal diseases. The goal of this study was to investigate the extent to which smoking increases risk for disease by influencing the composition of the subgingival microbiome in states of clinical health. Subgingival plaque samples were collected from 200 systemically and periodontally healthy smokers and nonsmokers. 16S pyrotag sequencing was preformed generating 1 623 713 classifiable sequences, which were compared with a curated version of the Greengenes database using the quantitative insights into microbial ecology pipeline. The subgingival microbial profiles of smokers and never-smokers were different at all taxonomic levels, and principal coordinate analysis revealed distinct clustering of the microbial communities based on smoking status. Smokers demonstrated a highly diverse, pathogen-rich, commensal-poor, anaerobic microbiome that is more closely aligned with a disease-associated community in clinically healthy individuals, suggesting that it creates an at-risk-for-harm environment that is primed for a future ecological catastrophe.
Bacteria on leaves: a previously unrecognised source of N2O in grazed pastures
Authors: Bowatte Saman , Newton Paul C D , Brock Shona , Theobald Phil , Luo Dongwen
Published: July 2014

Nitrous oxide (N2O) emissions from grazed pastures are a product of microbial transformations of nitrogen and the prevailing view is that these only occur in the soil. Here we show this is not the case. We have found ammonia-oxidising bacteria (AOB) are present on plant leaves where they produce N2O just as in soil. AOB (Nitrosospira sp. predominantly) on the pasture grass Lolium perenne converted 0.02–0.42% (mean 0.12%) of the oxidised ammonia to N2O. As we have found AOB to be ubiquitous on grasses sampled from urine patches, we propose a ‘plant’ source of N2O may be a feature of grazed grassland.
Widespread expression of conserved small RNAs in small symbiont genomes
Authors: Hansen Allison K , Degnan Patrick H
Published: July 2014

Genome architecture of a microbe markedly changes when it transitions from a free-living lifestyle to an obligate symbiotic association within eukaryotic cells. These symbiont genomes experience numerous rearrangements and massive gene loss, which is expected to radically alter gene regulatory networks compared with those of free-living relatives. As such, it remains unclear whether and how these small symbiont genomes regulate gene expression. Here, using a label-free mass-spec quantification approach we found that differential protein regulation occurs in Buchnera, a model symbiont with a reduced genome, when it transitions between two distinct life stages. However, differential mRNA expression could not be detected between Buchnera life stages, despite the presence of a small number of putative transcriptional regulators. Instead a comparative analysis of small RNA expression profiles among five divergent Buchnera lineages, spanning a variety of Buchnera life stages, reveals 140 novel intergenic and antisense small RNAs and 517 untranslated regions that were significantly expressed, some of which have been conserved for ∼65 million years. In addition, the majority of these small RNAs exhibit both sequence covariation and thermodynamic stability, indicators of a potential structural RNA role. Together, these data suggest that gene regulation at the post-transcriptional level may be important in Buchnera. This is the first study to empirically identify Buchnera small RNAs, and we propose that these novel small RNAs may facilitate post-transcriptional regulation through translational inhibition/activation, and/or transcript stability. Ultimately, post-transcriptional regulation may shape metabolic complementation between Buchnera and its aphid host, thus impacting the animal’s ecology and evolution.
Bright emission from a random Raman laser
Authors: Hokr Brett H. , Bixler Joel N. , Cone Michael T. , Mason John D. , Beier Hope T. , Noojin Gary D. , Petrov Georgi I. , Golovan Leonid A. , Thomas Robert J. , Rockwell Benjamin A. , Yakovlev Vladislav V.
Published: July 2014

Random lasers are a developing class of light sources that utilize a highly disordered gain medium as opposed to a conventional optical cavity. Although traditional random lasers often have a relatively broad emission spectrum, a random laser that utilizes vibration transitions via Raman scattering allows for an extremely narrow bandwidth, on the order of 10 cm−1. Here we demonstrate the first experimental evidence of lasing via a Raman interaction in a bulk three-dimensional random medium, with conversion efficiencies on the order of a few percent. Furthermore, Monte Carlo simulations are used to study the complex spatial and temporal dynamics of nonlinear processes in turbid media. In addition to providing a large signal, characteristic of the Raman medium, the random Raman laser offers us an entirely new tool for studying the dynamics of gain in a turbid medium.
Cyclen-based cationic lipids with double hydrophobic tails for efficient gene delivery
Authors: Wang Hai-Jiao , Liu Yan-Hong , Zhang Ji , Zhang Yang , Xia Yan , Yu Xiao-Qi
Published: July 2014

The gene transfection abilities and structure–activity relationship of newly designed cationic lipids were studied in detail.
A one-pot, three-component reaction for the synthesis of novel 7-arylbenzo[c]acridine-5,6-diones
Authors: Mahajan Shivani , Khullar Sadhika , Mandal Sanjay K. , Singh Inder Pal
Published: July 2014

A one pot domino protocol for an efficient synthesis of 7-arylbenzo[c]acridine-5,6-diones, with a novel nucleus, has been developed by reacting 2-hydroxynaphthalene-1,4-dione, aromatic aldehydes and aromatic amines using environmentally benevolentp-toluene sulphonic acid as a catalyst.
A combined77Se NMR and molecular dynamics contribution to the structural understanding of the chalcogenide glasses
Authors: Sykina Kateryna , Bureau Bruno , Le Pollès Laurent , Roiland Claire , Deschamps Michaël , Pickard Chris J. , Furet Eric
Published: July 2014

Fully-relaxed solid-state77Se NMR experiments on isotopically enriched and natural abundance samples, molecular dynamics simulations and DFT calculations have been performed for a better understanding of the chalcogenide glasses.
Hyperpolarisation through reversible interactions with parahydrogen
Authors: Lloyd Lyrelle S. , Asghar Aziz , Burns Michael J. , Charlton Adrian , Coombes Steven , Cowley Michael J. , Dear Gordon J. , Duckett Simon B. , Genov Georgi R. , Green Gary G. R. , Highton Louise A. R. , Hooper Alexander J. J. , Khan Majid , Khazal Iman G. , Lewis Richard. J. , Mewis Ryan E. , Roberts Andrew D. , Ruddlesden Amy J.
Published: July 2014

Ir(COD)(NHC)Cl complexes provide significant insight into the catalytic processes underpinning SABRE hyperpolarization.
Dendritic phosphotungstate hybrids efficiently catalyze the selective oxidation of alcohols with H2O2
Authors: Chen Yaju , Tan Rong , Zheng Weiguo , Zhang Yaoyao , Zhao Guangwu , Yin Donghong
Published: July 2014

Dendritic phosphotungstate hybrids are highly efficient and recyclable catalysts for the selective oxidation of alcohols with H2O2.
An organic ionic plastic crystal electrolyte for rate capability and stability of ambient temperature lithium batteries
Authors: Jin Liyu , Howlett Patrick C. , Pringle Jennifer M. , Janikowski Judith , Armand Michel , MacFarlane Douglas R. , Forsyth Maria
Published: July 2014

For the first time, practical lithium cell performance is achieved at ambient temperature with an organic ionic plastic crystal solid electrolyte.
Synthesis of face-centred cubic Cs3C60in THF
Authors: McLennan Alec G. , Ganin Alexey Y. , Takabayashi Yasuhiro , Colman Ross H. , Zadik Ruth H. , Rosseinsky Matthew J. , Prassides Kosmas
Published: July 2014

A solution chemistry synthetic route yields Cs3C60with a face-centred cubic structure. The described method uses well-established Schlenk techniques and THF as a solvent. The controlled addition of an organo-metallic salt reducing agent prevents the formation of C604−salts. The final product can be precipitated from the solution using hexane as an anti-solvent.
Determination of129I in Arctic snow by a novel analytical approach using IC-ICP-SFMS
Authors: Ežerinskis Žilvinas , Spolaor Andrea , Kirchgeorg Torben , Cozzi Giulio , Vallelonga Paul , Kjær Helle A. , Šapolaitė Justina , Barbante Carlo , Druteikienė Rūta
Published: July 2014

The environmental radiation background has increased in the last century due to human nuclear activities and in this context129I may be used to evaluate the anthropogenic contribution to global nuclear contamination.
Femtosecond laser 3D micromachining: a powerful tool for the fabrication of microfluidic, optofluidic, and electrofluidic devices based on glass
Authors: Sugioka Koji , Xu Jian , Wu Dong , Hanada Yasutaka , Wang Zhongke , Cheng Ya , Midorikawa Katsumi
Published: July 2014

Femtosecond laser micromachining can directly fabricate three-dimensional (3D) microfluidic devices integrated with functional microcomponents in glass microchips.
An EWOD-based microfluidic chip for single-cell isolation, mRNA purification and subsequent multiplex qPCR
Authors: Rival A. , Jary D. , Delattre C. , Fouillet Y. , Castellan G. , Bellemin-Comte A. , Gidrol X.
Published: July 2014

A compact EWOD digital microfluidic chip enables single cell manipulation, sample preparation using magnetic beads and gene expression analysis by qRT-PCR.
Transient absorption microscopy of gold nanorods as spectrally orthogonal labels in live cells
Authors: Chen Tao , Chen Shouhui , Zhou Jihan , Liang Dehai , Chen Xiaoyuan , Huang Yanyi
Published: July 2014

Transient absorption microscopy allows selective imaging of gold nanorods in live cells without interference from background fluorescence or Raman scattering.
Indium-tin-oxide nanorods for efficient light trapping in polymer solar cells
Authors: Chao Yu-Chiang , Zhan Fu-Min , Li Husan-De
Published: July 2014

Nanorods of indium-tin-oxide were used to enhance the performance of polymer solar cells.
Designing stuffed hetero-fullerene nano-clusters: C26B46N12and C14B58N12Li12
Authors: Vidya Kaipanchery , Jemmis Eluvathingal D.
Published: July 2014

The stuffed fullerene-like nano clusters based on the approximately spherical B84, (B12@B12@B60, fragment of the β-rhombohedral boron), are proposed using Wade's Rules and the criterion of overlap matching.
Squaraines as light-capturing materials in photovoltaic cells
Authors: Jiang Jian-Qiao , Sun Chun-Lin , Shi Zi-Fa , Zhang Hao-Li
Published: July 2014

We have summarized the recent developments in the molecular design strategies of squaraines for photovoltaic applications.
Two novel 3D lanthanide supramolecular coordination polymers constructed from paddle wheel SBUs and hydrogen bonding: synthesis, structures and properties
Authors: Li Qipeng , Du Shaowu
Published: July 2014

Two novel 3D lanthanide supramolecular coordination polymers with lanthanide paddle wheel SBUs were synthesized through in situ generation of formate anions. Their structure and temperature dependent luminescent property are investigated.
Wood-based microhaired superhydrophobic and underwater superoleophobic surfaces for oil/water separation
Authors: Kavalenka M. N. , Hopf A. , Schneider M. , Worgull M. , Hölscher H.
Published: July 2014

Wood-based microhaired superhydrophobic and underwater superoleophobic surfaces capable of effective oil/water mixtures separation are fabricated using a scalable replication technique.
Hydrogen physisorption in ionic solid compounds with exposed metal cations at room temperature
Authors: Pareek Kapil , Zhang Qingfan , Rohan Rupesh , Yunfeng Zhang , Cheng Hansong
Published: July 2014

Phenol- and phloroglucinol-based ionic solid complexes for room temperature hydrogen storage via physisorption.
Effect of polyelectrolytes on (de)stability of liquid foam films
Authors: Fauser Heiko , von Klitzing Regine
Published: July 2014

The review addresses the complex interplay between the film surface and core properties on the stability of polylectrolyte–surfactant foam films.
Ferrocene-functionalized polydopamine as a novel redox matrix for H2O2 oxidation
Authors: Kumar T. Naresh , Sivabalan Santhana , Chandrasekaran Naveen , Phani K. L. N.
Published: July 2014

Simple synthesis of a ferrocene-functionalized polydopamine [poly(DA-Fc)] is described. This redox film displays excellent electrocatalytic oxidation of H2O2 in neutral buffer solutions in a Fenton-type reaction, and is found to be selective to H2O2 with negligible interference from other small molecules.
A carbon fiber solder matrix composite for thermal management of microelectronic devices
Authors: Murugesan Murali , Zandén Carl , Luo Xin , Ye Lilei , Jokubavicius Valdas , Syväjärvi Mikael , Liu Johan
Published: July 2014

A novel carbon fiber solder matrix composite for thermal management of microelectronic devices.
Impact of titanium content and postdeposition annealing on the structural and sensing properties of TbTixOysensing membranes
Authors: Pan Tung-Ming , Wang Chih-Wei , Weng Wen-Hui , Pang See-Tong
Published: July 2014

C–Vcurve response and reference voltage plotted as a function of pH for TbTixOyEIS devices.
Highly sensitive conjugated polymer fluorescent sensors based on benzochalcogendiazole for nickel ions in real-time detection
Authors: Lei Yunxiang , Li Hui , Gao Wenxia , Liu Miaochang , Chen Jiuxi , Ding Jinchang , Huang Xiaobo , Wu Huayue
Published: July 2014

Two conjugated polymer fluorescent sensors using a benzochalcogendiazole unit and a triazole unit as cooperative receptors were synthesized for the highly sensitive detection of nickel ions.
eXtensible Markup Language access control model with filtering privacy based on matrix storage
Authors: Guo Lihong , Wang Jian , Wu Haitao , Du He
Published: July 2014

With eXtensible Markup Language (XML) becoming a ubiquitous language for data storage and transmission in various domains, effectively safeguarding the XML document containing sensitive information is a critical issue. In this study, the authors propose a new access control model with filtering privacy. Based on the idea of separating the structure and content of the XML document, they provide a method to extract the main structure of the XML document and use matrix to save the structure information, at the same time, the start–end region encoding is used to combine the corresponding structure and content skillfully. These not only save the storage space but also efficiently speed up the search and make it convenient to find the relevant elements, especially the finding of the related content. In order to evaluate the security and efficiency of this model, the security analysis and simulation experiment verify its performance in this work.
Ising model observables and non-backtracking walks
Authors: Helmuth Tyler
Published: July 2014

This paper presents an alternative proof of the connection between the partition function of the Ising model on a finite graph G and the set of non-backtracking walks on G. The techniques used also give formulas for spin-spin correlation functions in terms of non-backtracking walks. The main tools used are Viennot's theory of heaps of pieces and turning numbers on surfaces.
Dynamic mean field theory for lattice gas models of fluids confined in porous materials: Higher order theory based on the Bethe-Peierls and path probability method approximations
Authors: Edison John R. , Monson Peter A.
Published: July 2014

Recently we have developed a dynamic mean field theory (DMFT) for lattice gas models of fluids in porous materials [P. A. Monson, J. Chem. Phys. 128(8), 084701 (2008)]. The theory can be used to describe the relaxation processes in the approach to equilibrium or metastable states for fluids in pores and is especially useful for studying system exhibiting adsorption/desorption hysteresis. In this paper we discuss the extension of the theory to higher order by means of the path probability method (PPM) of Kikuchi and co-workers. We show that this leads to a treatment of the dynamics that is consistent with thermodynamics coming from the Bethe-Peierls or Quasi-Chemical approximation for the equilibrium or metastable equilibrium states of the lattice model. We compare the results from the PPM with those from DMFT and from dynamic Monte Carlo simulations. We find that the predictions from PPM are qualitatively similar to those from DMFT but give somewhat improved quantitative accuracy, in part due to the superior treatment of the underlying thermodynamics. This comes at the cost of greater computational expense associated with the larger number of equations that must be solved.
Spatial evolution of supersonic streamwise vortices
Authors: Hiejima Toshihiko
Published: July 2014

In this paper, the spatial developments of high Mach number streamwise vortices have been investigated using direct numerical simulations for Mach numbers from 2.5 to 9.0. The particular streamwise vortices studied here are those with uniform stagnation temperatures and those with constant entropy. For vortices with uniform stagnation temperatures, the calculated spatial evolutions show that for small swirl parameters, a bending wave mode is excited and spiral structures of low-wavenumber modes only develop downstream. In contrast, for swirl parameters larger than a moderate amount (approximately 0.5), relaminarization occurs downstream. This study also found that the relation between the circulation and the freestream Mach number contributes to a necessary condition as to whether perturbations can grow in supersonic flows. For isentropic streamwise vortices, instability properties at high Mach numbers parallel those in low-speed flows because the evolution can give rise to high-wavenumbers within the core. The resulting entropy instability is analogous to the Rayleigh-Taylor instability and has the advantage of being insensitive to compressibility effects in supersonic flows.
Indium tin oxide-free transparent and conductive electrode based on SnOx | Ag | SnOx for organic solar cells
Authors: Bou A. , Torchio Ph. , Barakel D. , Thierry F. , Sangar A. , Thoulon P.-Y. , Ricci M.
Published: July 2014

A SnOx | Ag | SnOx multilayer deposited by E-beam evaporation is proposed as transparent anode for a (poly-3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) bulk heterojunction based Organic Solar Cell (OSC). Such multilayers are studied and manufactured with the objective to give to the electrode its best conductivity and transparency in the visible spectral range. A transfer matrix method numerical optimization of the thicknesses of each layer of the electrode is developed to limit the number of test samples which would have been manufactured whether an empirical method was chosen. Optical characterization of the deposited SnOx and Ag thin films is performed to determine the dispersion of the complex refractive indices which are used as input parameters in the model. A satisfying agreement between numerical and experimental optical properties is found. The bare tri-layer electrodes show low sheet resistance (as low as 6.7 Ω/□) and the whole Glass | SnOx | Ag | SnOx structure presents a mean transparency on 400–700 nm spectral band as high as 67%. The multilayer is then numerically studied as anode for a P3HT:PCBM bulk heterojunction based OSC. Intrinsic absorption inside the sole active layer is calculated giving the possibility to perform optical optimization on the intrinsic absorption efficiency inside the active area by considering the media embedding the electrodes. An additional study using the morphology of the silver inserted between both oxide layers as input data is performed with a finite difference time domain 3D-method to improve the accordance between optical measurements and numerical results.
Novel type of chimera spiral waves arising from decoupling of a diffusible component
Authors: Tang Xiaodong , Yang Tao , Epstein Irving R. , Liu Yang , Zhao Yuemin , Gao Qingyu
Published: July 2014

Spiral waves composed of coherent traveling waves surrounding a core containing stochastically distributed stationary areas are found in numerical simulations of a three-variable reaction-diffusion system with one diffusible species. In the spiral core, diffusion of this component (w) mediates transitions between dynamic states of the subsystem formed by the other two components, whose dynamics is more rapid than that of w. Diffusive coupling between adjacent sites can be “on” or “off” depending on the subsystem state. The incoherent structures in the spiral core are produced by this decoupling of the slow diffusive component from the fast non-diffusing subsystem. The phase diagram reveals that the region of incoherent behavior in chimera spirals grows drastically, leading to modulation and breakup of the spirals, in the transition zones between 1n-1 and 1n local mixed-mode oscillations.
Hydrodynamic equations for electrons in graphene obtained from the maximum entropy principle
Authors: Barletti Luigi
Published: July 2014

The maximum entropy principle is applied to the formal derivation of isothermal, Euler-like equations for semiclassical fermions (electrons and holes) in graphene. After proving general mathematical properties of the equations so obtained, their asymptotic form corresponding to significant physical regimes is investigated. In particular, the diffusive regime, the Maxwell-Boltzmann regime (high temperature), the collimation regime and the degenerate gas limit (vanishing temperature) are considered.
Evidence of exchange bias effect originating from the interaction between antiferromagnetic core and spin glass shell
Authors: Zhang X. K. , Tang S. L. , Xu L. Q. , Yuan J. J. , Yu H. J. , Zhu X. R. , Xie Y. M.
Published: July 2014

Spin glass behavior and exchange bias effect have been observed in antiferromagnetic SrMn3O6−x nanoribbons synthesized via a self-sacrificing template process. The magnetic field dependence of thermoremanent magnetization and isothermal remanent magnetization shows that the sample is good correspondence to spin glass and diluted antiferromagnetic system for the applied field H < 2 T and H > 2 T, respectively. By detailed analysis of training effect using Binek's model, we argue that the observed exchange bias effect in SrMn3O6−x nanoribbons arises entirely from an interface exchange coupling between the antiferromagnetic core and spin glass shell. The present study is useful for understanding the nature of shell layer and the origin of exchange bias effect in other antiferromagnetic nanosystems as well.
Comparative ion insertion study into a nanostructured vanadium oxide in aqueous salt solutions
Authors: Yuan Q. , Ren S. L. , Zukowski J. , Pomeroy M. , Soghomonian V.
Published: July 2014

We present a comparative study for the electrochemical insertion of different cations into a nanostructured vanadium oxide material. The oxide is hydrothemally synthesized and electrically characterized by variable temperature measurements. The electrochemical reactions are performed in aqueous chloride solutions of lithium, sodium, potassium, and ammonium, and the electrochemical behavior of various cycles are correlated with visual changes in the vanadium oxide nanosheets as observed by scanning electron microscopy. We note an increase in the specific charge per cycle in the cases of sodium and ammonium ions only, correlated with minimal physical changes to the nanosheets. The differing behavior of the various ions has implications for their use in electrical energy storage applications.
Dendritic instability in YBa2Cu3O7–δ films triggered by transient magnetic fields
Authors: Baziljevich M. , Baruch-El E. , Johansen T. H. , Yeshurun Y.
Published: July 2014

Superconducting films of YBa2Cu3O7–δ are shown to become thermomagnetically unstable when experiencing a time-varying perpendicular magnetic field. Using magneto-optical imaging and ramping the applied field at rates up to 3000 T/s, dendritic flux avalanches were observed in two different films, one grown by evaporation on sapphire and one by laser ablation on SrTiO3. The unstable behavior occurs over a wide temperature range limited by an upper threshold value of 40 K for the film on sapphire, and 20 K for the one on SrTiO3. At 7 K for the same films, the threshold ramping rates are 1000 T/s and 3000 T/s, respectively. The avalanches are causing permanent damage by leaving a micron wide track where the superconductor melted during the thermomagnetic runaway.
Pressure-induced magnetic, structural, and electronic phase transitions in LaFeO3: A density functional theory (generalized gradient approximation) + U study
Authors: Javaid Saqib , Javed Akhtar M.
Published: July 2014

We have investigated the behavior of orthoferrite LaFeO3 at ambient conditions and under pressure using DFT (generalized gradient approximation (GGA)) + U approach. Ground state electronic (band gap) and magnetic properties are considerably improved due to the Hubbard correction. Moreover, the experimentally observed pressure-driven phase transition, namely, the simultaneous occurrence of spin crossover, isostructural volume collapse, and drastic reduction in electrical resistance (electronic phase transition) is nicely described by GGA + U calculations. In particular, despite a sharp drop in resistance, a small band gap still remains in the low spin state indicating an insulator to semiconductor phase transition, in good agreement with the experiments but in contrast to GGA, which predicts metallic behavior in low spin state. We discuss the origin of variation in electronic structure of LaFeO3 in low spin state as obtained from GGA to GGA + U methods. These results emphasize the importance of correlation effects in describing the pressure-driven phase transition in LaFeO3 and other rare-earth orthoferrites.
Direct Vlasov simulations of electron-attracting cylindrical Langmuir probes in flowing plasmas
Authors: Sánchez-Arriaga G. , Pastor-Moreno D.
Published: July 2014

Current collection by positively polarized cylindrical Langmuir probes immersed in flowing plasmas is analyzed using a non-stationary direct Vlasov-Poisson code. A detailed description of plasma density spatial structure as a function of the probe-to-plasma relative velocity U is presented. Within the considered parametric domain, the well-known electron density maximum close to the probe is weakly affected by U. However, in the probe wake side, the electron density minimum becomes deeper as U increases and a rarified plasma region appears. Sheath radius is larger at the wake than at the front side. Electron and ion distribution functions show specific features that are the signature of probe motion. In particular, the ion distribution function at the probe front side exhibits a filament with positive radial velocity. It corresponds to a population of rammed ions that were reflected by the electric field close to the positively biased probe. Numerical simulations reveal that two populations of trapped electrons exist: one orbiting around the probe and the other with trajectories confined at the probe front side. The latter helps to neutralize the reflected ions, thus explaining a paradox in past probe theory.
Nanoscale mapping of the W/Si(001) Schottky barrier
Authors: Durcan Chris A. , Balsano Robert , LaBella Vincent P.
Published: July 2014

The W/Si(001) Schottky barrier was spatially mapped with nanoscale resolution using ballistic electron emission microscopy (BEEM) and ballistic hole emission microscopy (BHEM) using n-type and p-type silicon substrates. The formation of an interfacial tungsten silicide is observed utilizing transmission electron microscopy and Rutherford backscattering spectrometry. The BEEM and BHEM spectra are fit utilizing a linearization method based on the power law BEEM model using the Prietsch Ludeke fitting exponent. The aggregate of the Schottky barrier heights from n-type (0.71 eV) and p-type (0.47 eV) silicon agrees with the silicon band gap at 80 K. Spatially resolved maps of the Schottky barrier are generated from grids of 7225 spectra taken over a 1 μm × 1 μm area and provide insight into its homogeneity. Histograms of the barrier heights have a Gaussian component consistent with an interface dipole model and show deviations that are localized in the spatial maps and are attributed to compositional fluctuations, nanoscale defects, and foreign materials.
Effect of the plasma shapes on intrinsic rotation due to collisionless ion orbit loss in the tokamak edge plasmas
Authors: Ou Jing , Wu Guojiang , Li Xinxia
Published: July 2014

Distribution of the intrinsic rotation due to collisionless ion orbit loss near the tokamak edge region is studied by using an analytical model based on ion guiding center orbit approximation. A peak of the averaged ion orbit loss momentum fraction is found very near inside the separatrix region in a double null divertor configuration but is not found inside the last closed flux surface region in an outer limiter configuration. For the double null divertor configuration, the intrinsic rotation due to ion orbit loss depends on the plasma shape. With the increase in elongation and triangularity, the peak of the averaged ion orbit loss momentum fraction increases and it moves inward for the lower plasma current.
Operating principles of vertical transistors based on monolayer two-dimensional semiconductor heterojunctions
Authors: Lam Kai Tak , Seol Gyungseon , Guo Jing
Published: July 2014

A vertical transistor based on a double gated, atomically thin heterojunction is theoretically examined. Both p-type and n-type transistor operations can be conveniently achieved by using one of the two gates as the switching gate. The transistor shows excellent saturation of output I-V characteristics due to drain-induced depletion and lack of tunneling barrier layers. The subthreshold slope could be below the thermionic limit due to band filtering as the switching mechanism. The atomically thin vertical PN heterojunction can be electrostatically modulated from a type II heterojunction to a broken bandgap alignment, which is preferred for maximizing the on-current.
Double Fano resonances in nanoring cavity dimers: The effect of plasmon hybridization between dark subradiant modes
Authors: Yin Li-Yan , Huang Yun-Huan , Wang Xia , Ning Si-Tong , Liu Shao-Ding
Published: July 2014

Dark mode which is subradiant plays a key role in the generation of Fano effect. This study proposes that plasmon interaction between dark modes is a favorable method to generate multiple Fano resonances, where plasmon hybridization leads to the formation of a subradiant bonding and a subradiant antibonding combination. It demonstrates that a concentric ring/ring cavity dimer introduces interactions that render bonding quadrupolar ring mode dipole active, resulting in a pronounced Fano resonance. The corresponding antibonding quadrupolar ring mode is excited in a symmetry breaking nonconcentric cavity dimer, and double Fano resonances appear in the spectra.
Photothermal single particle microscopy using a single laser beam
Authors: Selmke Markus , Heber André , Braun Marco , Cichos Frank
Published: July 2014

We introduce a single-laser-beam photothermal microscopy scheme for the detection of single absorbing nano-objects. Here, a modulated incident laser beam with a constant intensity offset serves as pump and probe beam at the same time. Using the out-of-phase scattering response of the retarded thermorefractive wave field, the method provides a selective contrast for absorbers over a possible background of scatterers. The use of a single wavelength and a single beam, considerably simplifies the setup and integration of photothermal detection in existing microscopy schemes.
Experimental and theoretical assessments of thermal boundary resistance between Bi0.4Sb1.6Te3 thin films and metals
Authors: Liu Yu-Lin , Liao Chien-Neng
Published: July 2014

An experimental method for measuring thermal boundary resistances of thermoelectrics/metal interfaces using two specially designed multilayer structures is presented. The thermal boundary resistances of Bi0.4Sb1.6Te3 thin films in contact with respective Ni and Ti metal layers are experimentally determined to be 2.65 ± 0.98 × 10−8 and 2.85 ± 1.06 × 10−8 m2K/W. The results agree reasonably well with the predictions from the diffusive mismatch model for Bi0.4Sb1.6Te3/metal interfaces. The effect of phonon transport property of metals on thermal boundary resistance at thermoelectrics/metal interfaces is investigated.
A white organic light-emitting diode with ultra-high color rendering index, high efficiency, and extremely low efficiency roll-off
Authors: Sun Ning , Zhao Yongbiao , Zhao Fangchao , Chen Yonghua , Yang Dezhi , Chen Jiangshan , Ma Dongge
Published: July 2014

Ultra-high color rendering index (>90) is considered to be crucial for lighting in museum, studio, art gallery, medical, and wide-color-gamut display. However, all relevant works reported to exhibit ultra-high color rendering index suffer from a low efficiency and serious efficiency roll-off. In order to achieve ultra-high color rendering index and maintain high device efficiency at the same time, we incorporate four organic dyes in an elaborate device structure. The resulting white organic light-emitting diode exhibits rather high color rendering index up to 94 over a wide brightness range and yields electroluminescence efficiencies up to 14.2%, 26.0 cd/A, and 21.9 lm/W at the brightness of 1000 cd m−2, which are the highest values reported to date for such ultra-high color rendering index white organic light-emitting diodes. In addition, the current issue on efficiency roll-off is well resolved in the resulting device. The critical current density jc is as high as 203 mA cm−2.
Photoluminescence from Chitosan for Bio-Imaging
Authors: Pan Xiaoyong , Ren Wei , Gu Liuqun , Wang Guan , Liu Ye
Published: July 2014

Photoluminescent behaviours of chitosan were investigated. Photoluminescence can be observed from aqueous solution of chitosan, and CO2 treatment can improve the intensity of photoluminescence. The maximum emission is obtained with an excitation at ~336 nm, and the emission wavelength is dependent on the excitation wavelength with a longer excitation wavelength leading to a longer emission wavelength. The chemistry of chitosan before and after CO2 treatment was characterised; and the results reflect that carbamato anion is formed via the reaction between the amines and CO2, and is the fluorophore of the photoluminescence observed. Furthermore, chitosan was applied as an imaging agent for imaging MCF-7 cells using confocal microscopy. Blue and bright green imaging of the cells can be obtained via tuning the excitation and emission wavelength. Together with a low cytotoxicity reflected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide evaluation, fluorescent chitosan is promising for bio-imaging.
Climate change impact and adaptation in agricultural systems - introduction.
Authors: Fuhrer J. , Gregory P. J.
Published: July 2014

This chapter introduces the book 'Climate Change Impact and Adaptation in Agricultural Systems', which is comprised of fifteen chapters. The book provides insights into sensitivities and possible adaptive measures to climate change across a number of different production systems, ranging from intensive cropping and horticultural systems to mixed crop-livestock systems, to intensive livestock systems, and across regions ranging from humid temperate to dryland areas. It also provides a discussion of the opportunities for and the limitations to adaptation.
UK fruit and vegetable production - impacts of climate change and opportunities for adaptation.
Authors: Collier R. , Else M. A.
Published: July 2014

This chapter focuses on the impact of climate change on the production of apples, strawberries and the main types of vegetable grown in the UK. The importance of anticipating and adapting to climate change in order to deliver good yields of quality products is also discussed.
Intensive livestock systems for dairy cows.
Authors: Collier R. J. , Hall L. W. , Smith J. F.
Published: July 2014

This article gives an overview on several aspects of intensive farming system for dairy cows. Focus is given on how heat stress affects production, health and reproduction in dairy cows and the measures that can be used to mitigate it. Topics discussed also include seasonal production patterns, estimating thermal loads on animals using the temperature humidity index, strategies to reduce the impact of heat in dairy cattle facilities, water availability, shade, orientation of naturally ventilated free stalls, taking advantage of natural ventilation, cow cooling, providing a cooler environment for the cow, using multiple methods to cool cows, considerations for dry lots and desert barns, mechanically ventilated free stalls, managing four-row naturally ventilated free stall barns, holding pen cooling and bottlenecks to cow cooling.
Land managed for multiple services.
Authors: Aspinall R.
Published: July 2014

This chapter uses examples from agricultural land use to examine the nature and sources of the multiple goods and services produced by land systems as a set of services that are directly influenced by land management. First, the global-scale and scope of land change and pressures on land are reviewed briefly; this reveals the extent of the impacts of management on the global system. Second, the specification of land systems as coupled human-environment systems incorporating natural, technological, financial and human capital and flows is emphasized. This system's formulation supports the analysis and understanding of land dynamics at multiple spatial, temporal and organizational scales, and helps to reveal the full range of inputs of different forms of capital, and also the importance of human-environment relationships in the production of ecosystem goods and services. Third, the nature of different goods and services produced from land, and the sources of these goods as they relate to agricultural land systems and land management are reviewed, using examples based on farming in Scotland. This provides an understanding of ecosystem services that are based on land and land management, and emphasizes the roles of human activities in the delivery of ecosystem services.
Enhancing climate resilience of cropping systems.
Authors: Webber H. , Kahiluoto H. , Rötter R. , Ewert F.
Published: July 2014

This chapter examines how a resilience approach may be used to learn about, and ultimately support, adaptations to increasing climate variation and uncertainty for cropping systems. The potential contributions of several commonly mentioned crop and soil management adaptation options in improving the climate resilience of cropping systems are also discussed.
Shaping sustainable intensive production systems: improved crops and cropping systems in the developing world.
Authors: Stirling C. , Hellin J. , Cairns J. , Silverblatt-Buser E. , Tefera T. , Ngugi H. , Gbegbelegbe S. , Tesfaye K. , Chung U. , Sonder K. , Cox R. A. , Verhulst N. , Govaerts B. , Alderman P. , Reynolds M.
Published: July 2014

This chapter focuses on the impacts of climate change on intensive maize and wheat production systems. Some technologies to close the yield gap to achieve sustainable intensification are also discussed.
The role of modelling in adapting and building the climate resilience of cropping systems.
Authors: Kahiluoto H. , Rötter R. , Webber H. , Ewert F.
Published: July 2014

This chapter focuses on the current applications of modelling tools for cropping system (i.e. barley) assessment under climate change. The contributions of these modelling approaches in enhancing the resilience of cropping systems are also discussed.
Agroforestry solutions for buffering climate variability and adapting to change.
Authors: Noordwijk M. van , Bayala J. , Hairiah K. , Lusiana B. , Muthuri C. , Khasanah N. , Mulia R.
Published: July 2014

This chapter focuses on increasing the adaptive capacity of agricultural systems in tropical and subtropical regions through agroforestry. Agroforestry as a concept resists and tries to counteract the way agriculture has been segregated from forests and forestry. The chapter reviews the hypothesis that the presence of trees increases the degree of buffering of climate variability from the perspective of an annual food crop, and that retention and the increase of trees in agricultural landscapes can be a relevant art of climate change adaptation strategies.