bluuebunny/crossref_metadata_2025 huggingface dataset:
Patients' priorities for treatment decision making during periods of incapacity: quantitative survey
Authors: Rid Annette , Wesley Robert , Pavlick Mark , Maynard Sharon , Roth Katalin , Wendler David
Published: October 2014

Objective:

Clinical practice aims to respect patient autonomy by basing treatment decisions for incapacitated patients on their own preferences. Yet many patients do not complete an advance directive, and those who do frequently just designate a family member to make decisions for them. This finding raises the concern that clinical practice may be based on a mistaken understanding of patient priorities. The present study aimed to collect systematic data on how patients prioritize the goals of treatment decision making.

Method:

We employed a self-administered, quantitative survey of patients in a tertiary care center.

Results:

Some 80% or more of the 1169 respondents (response rate = 59.8%) ranked six of eight listed goals for treatment decision making as important. When asked which goal was most important, 38.8% identified obtaining desired or avoiding unwanted treatments, 20.0% identified minimizing stress or financial burden on their family, and 14.6% identified having their family help to make treatment decisions. No single goal was designated as most important by 25.0% of participants.

Significance of Results:

Patients endorsed three primary goals with respect to decision making during periods of incapacity: being treated consistent with their own preferences; minimizing the burden on their family; and involving their family in the decision-making process. However, no single goal was prioritized by a clear majority of patients. These findings suggest that advance care planning should not be limited to documenting patients' treatment preferences. Clinicians should also discuss and document patients' priorities for how decisions are to be made. Moreover, future research should evaluate ways to modify current practice to promote all three of patients primary goals for treatment decision making.
‘The fugitive’: The figure of the judge in Coase's economics
Authors: BERTRAND ELODIE
Published: October 2014

‘The Problem of Social Cost’ (Coase, 1960) asserts a normative role for the common law judge, that of taking into account the economic consequences of his decisions in allocating property rights. This position is often accused of inconsistency: Coase sees the figure of the judge as willing and able to improve economic efficiency, but criticises the actors of public intervention, particularly regulators, for being fallible, vulnerable to political pressures, and lacking information. I shall show that Coase's giving this role to the judge stems precisely from his criticism of public intervention. This means that his figure of the judge escapes the tenets of the theoretical system that first rendered it necessary. Various reasons could explain this difference of treatment as between the judge and the other figures of public intervention in Coase's system, but Coase makes too strong an opposition between common law on one side and regulatory and statutory law on the other, and leaves unexplained the motivation of judges.
Planar compact dual-band monopole antenna with circular polarization for WLAN applications
Authors: Lu Jui-Han , Huang Hao-Shiang
Published: October 2014

A planar circularly polarized (CP) monopole antenna (MA) with dual-band operation for the IEEE 802.11a/b/g wireless local area network (WLAN) is proposed. By introducing dual strip-sleeves shorted at the ground plane, the excitation of dual-resonant modes can resemble the 2.4/5.2 GHz bands required for WLAN operations. The obtained impedance bandwidths (RL ≧10 dB) across the operating bands approach 260/988 MHz and the 3 dB axial-ratio bandwidth of about 103/710 MHz for 2.4/5.2 GHz bands, respectively. The model proposed in this study reflects more advantages in physical implementation as its overall volume is only 40 × 40 × 0.8 mm3, 22% smaller than other conventional CP MAs. The measured peak gain and radiation efficiency are about 4.1/3.3 dBic and 94/84%, respectively, and demonstrate nearly bidirectional patterns in the XZ- and YZ-planes.
Seizure activity results in calcium- and mitochondria-independent ROS production via NADPH and xanthine oxidase activation
Authors: Kovac S , Domijan A-M , Walker M C , Abramov A Y
Published: October 2014

Seizure activity has been proposed to result in the generation of reactive oxygen species (ROS), which then contribute to seizure-induced neuronal damage and eventually cell death. Although the mechanisms of seizure-induced ROS generation are unclear, mitochondria and cellular calcium overload have been proposed to have a crucial role. We aim to determine the sources of seizure-induced ROS and their contribution to seizure-induced cell death. Using live cell imaging techniques in glioneuronal cultures, we show that prolonged seizure-like activity increases ROS production in an NMDA receptor-dependent manner. Unexpectedly, however, mitochondria did not contribute to ROS production during seizure-like activity. ROS were generated primarily by NADPH oxidase and later by xanthine oxidase (XO) activity in a calcium-independent manner. This calcium-independent neuronal ROS production was accompanied by an increase in intracellular [Na+] through NMDA receptor activation. Inhibition of NADPH or XO markedly reduced seizure-like activity-induced neuronal apoptosis. These findings demonstrate a critical role for ROS in seizure-induced neuronal cell death and identify novel therapeutic targets.
The activation of G protein-coupled receptor 30 (GPR30) inhibits proliferation of estrogen receptor-negative breast cancer cells in vitro and in vivo
Authors: Wei W , Chen Z-J , Zhang K-S , Yang X-L , Wu Y-M , Chen X-H , Huang H-B , Liu H-L , Cai S-H , Du J , Wang H-S
Published: October 2014

There is an urgent clinical need for safe and effective treatment agents and therapy targets for estrogen receptor negative (ER−) breast cancer. G protein-coupled receptor 30 (GPR30), which mediates non-genomic signaling of estrogen to regulate cell growth, is highly expressed in ER− breast cancer cells. We here showed that activation of GPR30 by the receptor-specific agonist G-1 inhibited the growth of ER− breast cancer cells in vitro. Treatment of ER− breast cancer cells with G-1 resulted in G2/M-phase arrest, downregulation of G2-checkpoint regulator cyclin B, and induction of mitochondrial-related apoptosis. The G-1 treatment increased expression of p53 and its phosphorylation levels at Serine 15, promoted its nuclear translocation, and inhibited its ubiquitylation, which mediated the growth arrest effects on cell proliferation. Further, the G-1 induced sustained activation and nuclear translocation of ERK1/2, which was mediated by GPR30/epidermal growth factor receptor (EGFR) signals, also mediated its inhibition effects of G-1. With extensive use of siRNA-knockdown experiments and inhibitors, we found that upregulation of p21 by the cross-talk of GPR30/EGFR and p53 was also involved in G-1-induced cell growth arrest. In vivo experiments showed that G-1 treatment significantly suppressed the growth of SkBr3 xenograft tumors and increased the survival rate, associated with proliferation suppression and upregulation of p53, p21 while downregulation of cyclin B. The discovery of multiple signal pathways mediated the suppression effects of G-1 makes it a promising candidate drug and lays the foundation for future development of GPR30-based therapies for ER− breast cancer treatment.
Histone deacetylase inhibitors promote glioma cell death by G2 checkpoint abrogation leading to mitotic catastrophe
Authors: Cornago M , Garcia-Alberich C , Blasco-Angulo N , Vall-llaura N , Nager M , Herreros J , Comella J X , Sanchis D , Llovera M
Published: October 2014

Glioblastoma multiforme is resistant to conventional anti-tumoral treatments due to its infiltrative nature and capability of relapse; therefore, research efforts focus on characterizing gliomagenesis and identifying molecular targets useful on therapy. New therapeutic strategies are being tested in patients, such as Histone deacetylase inhibitors (HDACi) either alone or in combination with other therapies. Here two HDACi included in clinical trials have been tested, suberanilohydroxamic acid (SAHA) and valproic acid (VPA), to characterize their effects on glioma cell growth in vitro and to determine the molecular changes that promote cancer cell death. We found that both HDACi reduce glioma cell viability, proliferation and clonogenicity. They have multiple effects, such as inducing the production of reactive oxygen species (ROS) and activating the mitochondrial apoptotic pathway, nevertheless cell death is not prevented by the pan-caspase inhibitor Q-VD-OPh. Importantly, we found that HDACi alter cell cycle progression by decreasing the expression of G2 checkpoint kinases Wee1 and checkpoint kinase 1 (Chk1). In addition, HDACi reduce the expression of proteins involved in DNA repair (Rad51), mitotic spindle formation (TPX2) and chromosome segregation (Survivin) in glioma cells and in human glioblastoma multiforme primary cultures. Therefore, HDACi treatment causes glioma cell entry into mitosis before DNA damage could be repaired and to the formation of an aberrant mitotic spindle that results in glioma cell death through mitotic catastrophe-induced apoptosis.
The bifunctional regulation of interconnected Zn-incorporated ZrO2nanoarrays in antibiosis and osteogenesis
Authors: Cheng Haoyan , Mao Lin , Xu Xing , Zeng Yan , Lan Danni , Hu Hao , Wu Xu , You Huihui , Yang Xu , Li Rui , Zhu Zhihong
Published: October 2014

Bifunctional regulation in antibiosis and osteogenesis is obtained using well-organized Zn-incorporated ZrO2nanoarrays with interconnected internal space.
Label-free detection and discrimination of poly-brominated diphenylethers using molecularly imprinted photonic cross-reactive sensor arrays
Authors: Xu Dan , Zhu Wei , Wang Chen , Tian Tian , Li Jian , Lan Yue , Zhang Guanxin , Zhang Deqing , Li Guangtao
Published: October 2014

Molecularly imprinted photonic polymers were used as sensing elements for efficiently creating a cross-reactive sensor array, as well as the sensitive and label-free detection of trace PBDEs was realized.
MnO2 grafted V2O5 nanostructures: formation mechanism, morphology and supercapacitive features
Authors: Saravanakumar Balakrishnan , Purushothaman Kamatchi Kamaraj , Muralidharan Gopalan
Published: October 2014

The network structured MnO2 grafted V2O5 exhibits higher performance as a smart electrode material for supercapacitor applications.
Flexibility transition and guest-driven reconstruction in a ferroelastic metal–organic framework
Authors: Hunt Sarah J. , Cliffe Matthew J. , Hill Joshua A. , Cairns Andrew B. , Funnell Nicholas P. , Goodwin Andrew L.
Published: October 2014

Copper(i) tricyanomethanide shows exceptional mechanical and coordination flexibility in response to temperature and guest sorption.
Multi-stage decomposition of 5-aminotetrazole derivatives: kinetics and reaction channels for the rate-limiting steps
Authors: Yan Qi-Long , Zeman Svatopluk , Zhang Jian-Guo , He Piao , Musil Tomáš , Bartošková Monika
Published: October 2014

Three-step decomposition was observed for both tetrazene and MTX-1, and the peaks are well separated by the Fraser–Suzuki function before kinetic evaluation.
Uniaxial tension-induced fracture in gold nanowires with the dependence on size and atomic vacancies
Authors: Wang Fenying , Dai Yanfeng , Zhao Jianwei , Li Qianjin
Published: October 2014

The size effect dominates the rupture of gold nanowires, which is also related to atomic vacancies in a single-layer crystalline plane.
Computational Raman spectroscopy of organometallic reaction products in lithium and sodium-based battery systems
Authors: Sánchez-Carrera Roel S. , Kozinsky Boris
Published: October 2014

We demonstrate that small molecular dimers of Li/Na organometallic compounds can provide relevant information about the inter- and intramolecular interactions of their respective crystallographic configurations, which in turn leads to an improved description of their respective Raman spectra.
A computational study on the hydrogenation of CO2 catalyzed by a tetraphos-ligated cobalt complex: monohydride vs. dihydride
Authors: Gao Hui , Chen Limin , Chen Jinzhu , Guo Yuanyuan , Ye Daiqi
Published: October 2014

Compared with the monohydride catalytic pathway, the dihydride catalytic pathway for the hydrogenation of CO2 is much more favoured.
Amidinate group 4 complexes in the polymerization of olefins
Authors: Elkin Tatyana , Eisen Moris S.
Published: October 2014

The current perspective will present the use of amidinate group 4 complexes in α-olefin polymerizations.
Molecular structure and spectroscopic properties of a nickel-bridged {Ni(Ph3P)}2(μ2–η2, η2-C60)2 dimer
Authors: Konarev Dmitri V. , Troyanov Sergey I. , Nakano Yoshiaki , Otsuka Akihiro , Yamochi Hideki , Saito Gunzi , Lyubovskaya Rimma N.
Published: October 2014

A nickel-bridged fullerene dimer, {Ni(Ph3P)}2(μ2–η2, η2-C60)2, was obtained and studied by X-ray crystallography. Optical and EPR spectra indicated a zero-valent state of Ni and no charge transfer from Ni to C60.
N-doped TiO2 nanotubes coated with a thin TaOxNy layer for photoelectrochemical water splitting: dual bulk and surface modification of photoanodes
Authors: Kim Hyoung-il , Monllor-Satoca Damián , Kim Wooyul , Choi Wonyong
Published: October 2014

Thin amorphous TaOxNy layer-coated N-doped TiO2 nanotubes successfully serve as a water splitting photoanode.
Pt–Ru catalyzed hydrogen oxidation in alkaline media: oxophilic effect or electronic effect?
Authors: Wang Ying , Wang Gongwei , Li Guangwei , Huang Bing , Pan Jing , Liu Qiong , Han Juanjuan , Xiao Li , Lu Juntao , Zhuang Lin
Published: October 2014

The PtRu/C HOR catalyst weakens the metal–H interaction and boosts the cell performance of the APEFC to 1 W cm−2.
Development of a fast laser ablation-inductively coupled plasma-mass spectrometry cell for sub-μm scanning of layered materials
Authors: Van Malderen Stijn J. M. , van Elteren Johannes T. , Vanhaecke Frank
Published: October 2014

A deconvolution algorithm complemented by a low dispersion cell unlocks lateral resolutions of 0.3 ± 0.1 μm at 200–300 Hz in LA-ICP-MS.
Network motif frequency vectors reveal evolving metabolic network organisation
Authors: Pearcy Nicole , Crofts Jonathan J. , Chuzhanova Nadia
Published: October 2014

At the systems level many organisms of interest may be described by their patterns of interaction, and as such, are perhaps best characterised via network or graph models.
Affinity proteomics led identification of vimentin as a potential biomarker in colon cancers: insights from serological screening and computational modelling
Authors: Bukhari Shoiab , Mokhdomi Taseem A. , Chikan Naveed A. , Amin Asif , Qazi Hilal , Wani Sajad H. , Wafai Asrar H. , Tyub Sumira , Mustafa Farhat , Mir Masood S. , Chowdri Nisar A. , Qadri Raies A.
Published: October 2014

Utilizing immunogenic property of antigens, an in-house affinity-reagent was developed to capture tumor associated antigens
A mononuclear cobalt(iii) complex and its catecholase activity
Authors: Mitra Merry , Raghavaiah Pallepogu , Ghosh Rajarshi
Published: October 2014

A mononuclear Co(iii) complex mimics the catechol oxidase enzyme with appreciably high turnover numbers in different solvents.
Diterpenoids of terrestrial origin
Authors: Hanson James R.
Published: October 2014

This review covers the isolation and chemistry of diterpenoids from terrestrial as opposed to marine sources and includes labdanes, clerodanes, pimaranes, abietanes, kauranes, gibberellins, cembranes and their cyclization products. The literature from January to December 2013 is reviewed.
Anomalous optical and magnetic behavior of multi-phase Mn doped Zn2SiO4 nanowires: a new class of dilute magnetic semiconductors
Authors: Hafeez Muhammad , Ali Awais , Manzoor Sadia , Bhatti Arshad S.
Published: October 2014

We present the synthesis of Mn doped Zn2SiO4 dense nanowire bundles using the VLS mode of growth with unusual optical and magnetic properties.
ANG-2 for quantitative Na+ determination in living cells by time-resolved fluorescence microscopy
Authors: Roder Phillip , Hille Carsten
Published: October 2014

Sodium ions (Na+) play an important role in a plethora of cellular processes, which are complex and partly still unexplored. For the investigation of these processes and quantification of intracellular Na+concentrations ([Na+]i), two-photon coupled fluorescence lifetime imaging microscopy (2P-FLIM) was performed in the salivary glands of the cockroachPeriplaneta americana. For this, the novel Na+-sensitive fluorescent dye Asante NaTRIUM Green-2 (ANG-2) was evaluated, bothin vitroandin situ. In this context, absorption coefficients, fluorescence quantum yields and 2P action cross-sections were determined for the first time. ANG-2 was 2P-excitable over a broad spectral range and displayed fluorescence in the visible spectral range. Although the fluorescence decay behaviour of ANG-2 was triexponentialin vitro, its analysis indicates a Na+-sensitivity appropriate for recordings in living cells. The Na+-sensitivity was reducedin situ, but the biexponential fluorescence decay behaviour could be successfully analysed in terms of quantitative [Na+]irecordings. Thus, physiological 2P-FLIM measurements revealed a dopamine-induced [Na+]irise in cockroach salivary gland cells, which was dependent on a Na+-K+-2Cl−cotransporter (NKCC) activity. It was concluded that ANG-2 is a promising new sodium indicator applicable for diverse biological systems.
Li2FePO4F and its metal-doping for Li-ion batteries: an ab initio study
Authors: Yang Fengmei , Sun Weiwei , Li Yuhan , Yuan Haiyan , Dong Zhiyong , Li Huanhuan , Tian Jumei , Zheng Yiying , Zhang Jingping
Published: October 2014

The substitution of Co for Fe in Pnma-Li2FePO4F i.e. Li2Fe1−xCoxPO4F (x = 1/8, 2/8, 3/8, 4/8, 5/8, 6/8, 7/8) are stable enough as new cathode materials and with the concentration of Co increases the discharge potential of the materials can increase.
Polymethylmethacrylate doped with porphyrin and silver nanoparticles as light-activated antimicrobial material
Authors: Lyutakov O. , Hejna O. , Solovyev A. , Kalachyova Y. , Svorcik V.
Published: October 2014

Light-activated antimicrobial materials based on polymethylmethactylate doped with porphyrin and silver nanoparticles were prepared and studied.
The antibacterial properties of light-activated polydimethylsiloxane containing crystal violet
Authors: Ozkan Ekrem , Allan Elaine , Parkin Ivan P.
Published: October 2014

Crystal violet was incorporated into polydimethylsiloxane (PDMS) by a swell–encapsulation–shrink method using chloroform as a swelling solvent.
Reversible-deactivation radical polymerization of chloroprene and the synthesis of novel polychloroprene-based block copolymers by the RAFT approach
Authors: Hui Jia , Dong Zhijiao , Shi Yan , Fu Zhifeng , Yang Wantai
Published: October 2014

Novel, well-defined PCP-based block copolymers (PSt-b-PCP and PMMA-b-PCP) with controlled number averaged molecular weights and molecular weight distributions can be prepared, employing EPDTB and CPDB, respectively, as the initial RAFT agent.
Rational synthesis of F-doped iron oxides on Al2O3(0001) single crystals
Authors: Carraro G. , Gasparotto A. , Maccato C. , Bontempi E. , Lebedev O. I. , Sada C. , Turner S. , Van Tendeloo G. , Barreca D.
Published: October 2014

F-doped α- and γ-Fe2O3nanostructures are grown on Al2O3(0001) by PE-CVD tailoring fluorine content, nano-organization and optical properties as a function of processing conditions.
Resonant detection of the signature of control of a resonance state lifetime using a pump–probe scheme
Authors: García-Vela A.
Published: October 2014

Realistic wave packet simulations demonstrate that the signature of control of the survival probability and lifetime of a specific resonance state can be observed and probed in typical time-resolved pump–probe experiments.
K2CO3-mediated, direct C–H bond selenation and thiolation of 1,3,4-oxadiazoles in the absence of metal catalyst: an eco-friendly approach
Authors: Rafique Jamal , Saba Sumbal , Rosário Alisson R. , Zeni Gilson , Braga Antonio L.
Published: October 2014

An eco-friendly, straightforward and high-yielding methodology for the synthesis of chalcogenyl oxadiazoles via the K2CO3-promoted direct C–H bond chalcogenation of 2-substituted-1,3,4-oxadiazoles is described herein.
Pyrene based materials for exceptionally deep blue OLEDs
Authors: Chercka Dennis , Yoo Seung-Jun , Baumgarten Martin , Kim Jang-Joo , Müllen Klaus
Published: October 2014

A 2,7-functionalized pyrene-based emitter for highly efficient OLEDs has been developed. It offers an exceptional deep blue photoluminescence (CIE: x = 0.16, y = 0.024) and good external quantum efficiency (EQE) of 3.1% when employed in a guest–host system OLED.
Synthesis of Na2SiF6:Mn4+ red phosphors for white LED applications by co-precipitation
Authors: Nguyen Hoang-Duy , Lin Chun Che , Fang Mu-Huai , Liu Ru-Shi
Published: October 2014

A one-step approach to synthesize Na2SiF6:Mn4+and K2SiF6:Mn4+ red phosphors by co-precipitation is reported in this paper.
In‐the‐ear spiral monopole antenna for hearing instruments
Authors: Kammersgaard N.P.I. , Kvist S.H. , Thaysen J. , Jakobsen K.B.
Published: October 2014

A novel in‐the‐ear (ITE) antenna solution for hearing instruments that operates at 2.45 GHz is presented. The antenna consists of a quarter wave monopole and a ground plane that are placed in the ear. The simulated path gain |S21| is −86 dB and the measured path gain is −80 dB. Simulations and measurements show that the antenna covers the entire 2.40–2.48 GHz industrial, scientific and medical (ISM) band. It is the first ever ITE‐antenna solution that demonstrates the possibility of establishing an ear‐to‐ear link by using a standard Bluetooth chip.
Towards 1 Tbit/s SOA‐based 1310 nm transmission for local area network/data centre applications
Authors: Mazurek Paweł , de Waardt Huug , Turkiewicz Jarosław Piotr
Published: October 2014

The growing data traffic in the local area networks is driving development of the cost‐effective transmission systems that can carry it effectively. In this study, firstly, we investigate the influence of a semiconductor optical amplifier (SOA) on the transmission quality in the 1310 nm wavelength‐division‐multiplexed system. We examine the differences in the channels gain and power penalty depending on the applied channel spacing. Moreover, we analyse the transmission‐related power penalty suffered during the transmission over the link consisting of the standard single‐mode fibre (SSMF) and a SOA. Furthermore, we propose the 1310 nm dense‐wavelength‐division multiplexed and polarisation multiplexed transmission system architecture which counteracts the key performance limitation that can be encountered in the 1310 nm window transmission systems. The demonstrated n × 2 × 40 Gbit/s transmission system is based exclusively on semiconductor components without any form of the chromatic dispersion compensation or error correction. Results of the conducted experiments show the excellent error‐free 8 × 2 × 40 Gbit/s all‐semiconductor transmission over 25 km of SSMF. The demonstrated transmission system can be utilised to realise ultra‐high‐speed connections like the next generation 400 Gbit/s and 1 Tbit/s Ethernet.
Appropriate structural parameters of biogas SI engine converted from diesel engine
Authors: Van Ga Bui , Van Nam Tran
Published: October 2014

A simulation of effects of combustion chamber shape, compression ratio, and spark timing advance to the performance of a biogas spark‐ignition (SI) engine converted from a diesel engine is presented. It is a comparative research which uses computational fluid dynamics (CFD) software FLUENT for identifying basic structural parameters of the diesel engine that could be modified in order to obtain a high performance biogas engine. The presence of CO2 in biogas fuel slows down the burning velocity of the mixture, thus any mechanisms speeding up the combustion would be desirable. Under the same operating conditions of biogas engine, an increase of indicated cycle work is observed as replacing flat combustion chamber shape by omega combustion chamber shape. Optimal spark timing advance of a biogas engine is greater than that of a gasoline engine and it depends on engine speed and/or on CH4 fraction in the biogas. At rated regime of engine fueled with normal biogas, the results pointed out an optimal value of compression ratio. The research is successfully applied to convert a typical ZH1115 diesel engine to a biogas SI engine. The evidence developed from this research can be applied to any other diesel engine.
Grid‐connected photovoltaic power plants for helping node voltage regulation
Authors: Miñambres‐Marcos Víctor , Guerrero‐Martínez Miguel Ángel , Romero‐Cadaval Enrique , González‐Castrillo Pedro
Published: October 2014

This study presents a way of using the photovoltaic power plants for helping the grid to regulate the point of common coupling voltage, not only for injecting active power. This functionality of the photovoltaic resources has become a need as some countries’ standards propose renewable energy to increase the voltage when a sag happens. In addition, this philosophy could also be applied in smart grids where the power must be controlled by the distributed generation. In this study, active power injection is developed by a reference power point tracking and reactive power regulation is carried out by controlling the node voltage, both with dq current control under different power priority possibilities. The generic flow diagram of the control algorithm was implemented on a single‐stage traditional inverter topology. The whole system has been checked with a simulation model, including the control algorithm, in order to tune the controller for obtaining the best performance. Finally, an experimental prototype was implemented for validating the proposed node voltage regulating method.
Tunable lens driven by dielectric elastomer actuator with ionic electrodes
Authors: Liang Dao , Lin Zi‐Fang , Huang Cheng‐Chun , Shih Wen‐Pin
Published: October 2014

A tunable lens driven by a dielectric elastomer actuator is developed. A solution of NaCl was used as the deformable lens and one of the electrodes for applying a bias voltage across the actuator. The dielectric elastomer actuator was made of a curved polydimethylsiloxane (PDMS) thin film sandwiched between a gold electrode and the NaCl solution. When a bias voltage was applied, the electrostatic force induced a radial compression, causing a lateral deflection of the PDMS. The radius of the curvature of the NaCl lens was consequently changed. The variation of the focal length under different bias voltages was characterised separately using two different approaches, and consistent results were obtained. The lens diameter was 4 mm. The focus lens can be tuned from 16.1 to 13.1 mm when the bias voltage is increased from 0 to 900 V.
Discotic columnar liquid crystal studied in the bulk and nanoconfined states by molecular dynamics simulation
Authors: Busselez Rémi , Cerclier Carole V. , Ndao Makha , Ghoufi Aziz , Lefort Ronan , Morineau Denis
Published: October 2014

A prototypical Gay Berne discotic liquid crystal was studied by means of molecular dynamics simulations both in the bulk state and under confinement in a nanoporous channel. The phase behavior of the confined system strongly differs from its bulk counterpart: the bulk isotropic-to-columnar transition is replaced by a continuous ordering from a paranematic to a columnar phase. Moreover, a new transition is observed at a lower temperature in the confined state, which corresponds to a reorganization of the intercolumnar order. It reflects the competing effects of pore surface interaction and genuine hexagonal packing of the columns. The translational molecular dynamics in the different phases has been thoroughly studied and discussed in terms of collective relaxation modes, non-Gaussian behavior, and hopping processes.
Measuring thermal conductivity of polystyrene nanowires using the dual-cantilever technique
Authors: Canetta Carlo , Guo Samuel , Narayanaswamy Arvind
Published: October 2014

Thermal conductance measurements are performed on individual polystyrene nanowires using a novel measurement technique in which the wires are suspended between two bi-material microcantilever sensors. The nanowires are fabricated via electrospinning process. Thermal conductivity of the nanowire samples is found to be between 6.6 and 14.4 W m−1 K−1 depending on sample, a significant increase above typical bulk conductivity values for polystyrene. The high strain rates characteristic of electrospinning are believed to lead to alignment of molecular polymer chains, and hence the increase in thermal conductivity, along the axis of the nanowire.
Equilibrium reconstruction based on core magnetic measurement and its applications on equilibrium transition in Joint-TEXT tokamak
Authors: Chen J. , Zhuang G. , Jian X. , Li Q. , Liu Y. , Gao L. , Wang Z. J.
Published: October 2014

Evaluation and reconstruction of plasma equilibrium, especially to resolve the safety factor profile, is imperative for advanced tokamak operation and physics study. Based on core magnetic measurement by the high resolution laser polarimeter-interferometer system (POLARIS), the equilibrium of Joint-TEXT (J-TEXT) plasma is reconstructed and profiles of safety factor, current density, and electron density are, therefore, obtained with high accuracy and temporal resolution. The equilibrium reconstruction procedure determines the equilibrium flux surfaces essentially from the data of POLARIS. Refraction of laser probe beam, a major error source of the reconstruction, has been considered and corrected, which leads to improvement of accuracy more than 10%. The error of reconstruction has been systematically assessed with consideration of realistic diagnostic performance and scrape-off layer region of plasma, and its accuracy has been verified. Fast equilibrium transitions both within a single sawtooth cycle and during the penetration of resonant magnetic perturbation have been investigated.
Integral constraints in the study of Richtmyer-Meshkov turbulent mixing
Authors: Likhachev Oleg A. , Tsiklashvili Vladimer
Published: October 2014

An experimental study of the temporal evolution of the shock-induced Richtmyer-Meshkov instability in the turbulent regime with three-dimensional random interfacial perturbations is carried out. The primary interest is the growth rate of the turbulent mixing layer that develops after an impulsive acceleration of the perturbed interface between two gases (air/SF6) by a weak Ma = 1.2 incident shock wave. Planar Mie scattering is used to visualize the flow, and image sequences are captured using a high-speed video camera. The analysis of the total mixing width has been extended to study the growth behaviors of the bubbles and spikes, separately. A novel definition of the bubble and spike widths is introduced using the mass and linear momentum conservation laws. For the planar incident shock wave the newly defined bubble and spike widths increase in time as hb.s ∝ tθ, with a growth exponent θ = 1/2 that does not depend on either the initial conditions or the physical properties of the gases composing the interface.
Ablowitz-Ladik hierarchy of integrable equations on a time-space scale
Authors: Hovhannisyan Gro
Published: October 2014

We derive the Toda's lattice, the Hirota's network, and the nonlinear Schrodinger dynamic equations on a time-space scale by extension on a time-space scale the Ablowitz-Ladik hierarchy of integrable dynamic systems.
Transport of hydrogen in metals with occupancy dependent trap energies
Authors: Schmid K. , von Toussaint U. , Schwarz-Selinger T.
Published: October 2014

Common diffusion trapping models for modeling hydrogen transport in metals are limited to traps with single de-trapping energies and a saturation occupancy of one. While they are successful in predicting typical mono isotopic ion implantation and thermal degassing experiments, they fail at describing recent experiments on isotope exchange at low temperatures. This paper presents a new modified diffusion trapping model with fill level dependent de-trapping energies that can also explain these new isotope exchange experiments. Density function theory (DFT) calculations predict that even mono vacancies can store between 6 and 12 H atoms with de-trapping energies that depend on the fill level of the mono vacancy. The new fill level dependent diffusion trapping model allows to test these DFT results by bridging the gap in length and time scale between DFT calculations and experiment.
Stopbands in the existence domains of acoustic solitons
Authors: Nsengiyumva F. , Hellberg M. A. , Verheest F. , Mace R. L.
Published: October 2014

A fully nonlinear Sagdeev pseudopotential approach is used to study the existence domain of fast mode ion-acoustic solitons in a three-species plasma composed of cold and warm adiabatic positive ion species and Boltzmann electrons. It is shown that for appropriate values of the cold-to-warm ion charge-to-mass ratio, μ, and the effective warm ion-to-electron temperature ratio, τ, there is a range in cold to warm ion charge density ratio, f, over which a stopband in soliton speed exists. Solitons do not propagate in the stopband, although they can occur for both higher and lower speeds. The stopbands are associated with a limiting curve of the existence domain that is double-valued in speed for a range of values of f. Analytical estimates of the upper and lower limits of τ and μ that support stopbands are found. It is suggested that, inter alia, the analysis should be applicable to the solar wind plasma.
Nonlinear features of ion acoustic shock waves in dissipative magnetized dusty plasma
Authors: Sahu Biswajit , Sinha Anjana , Roychoudhury Rajkumar
Published: October 2014

The nonlinear propagation of small as well as arbitrary amplitude shocks is investigated in a magnetized dusty plasma consisting of inertia-less Boltzmann distributed electrons, inertial viscous cold ions, and stationary dust grains without dust-charge fluctuations. The effects of dissipation due to viscosity of ions and external magnetic field, on the properties of ion acoustic shock structure, are investigated. It is found that for small amplitude waves, the Korteweg-de Vries-Burgers (KdVB) equation, derived using Reductive Perturbation Method, gives a qualitative behaviour of the transition from oscillatory wave to shock structure. The exact numerical solution for arbitrary amplitude wave differs somehow in the details from the results obtained from KdVB equation. However, the qualitative nature of the two solutions is similar in the sense that a gradual transition from KdV oscillation to shock structure is observed with the increase of the dissipative parameter.
Dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons
Authors: Saha Asit , Pal Nikhil , Chatterjee Prasanta
Published: October 2014

The dynamic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas with superthermal electrons and positrons has been investigated in the framework of perturbed and non-perturbed Kadomtsev-Petviashili (KP) equations. Applying the reductive perturbation technique, we have derived the KP equation in electron-positron-ion magnetoplasma with kappa distributed electrons and positrons. Bifurcations of ion acoustic traveling waves of the KP equation are presented. Using the bifurcation theory of planar dynamical systems, the existence of the solitary wave solutions and the periodic traveling wave solutions has been established. Two exact solutions of these waves have been derived depending on the system parameters. Then, using the Hirota's direct method, we have obtained two-soliton and three-soliton solutions of the KP equation. The effect of the spectral index κ on propagations of the two-soliton and the three-soliton has been shown. Considering an external periodic perturbation, we have presented the quasi periodic behavior of ion acoustic waves in electron-positron-ion magnetoplasmas.
Interfacial thermal resistance and thermal rectification between suspended and encased single layer graphene
Authors: Xu Wen , Zhang Gang , Li Baowen
Published: October 2014

With molecular dynamics simulations, we systematically investigate interfacial thermal resistance between suspended and encased single layer graphene. Combining with lattice dynamics analysis, we demonstrate that induced by substrate coupling which serves as perturbation, the long wavelength flexural phonon mode in the encased graphene is significantly suppressed when compared with that in the suspended graphene. Therefore, at the interface between suspended and encased graphene, in-plane phonon modes can transmit well, whereas low frequency flexural phonon modes are reflected, leading to this nontrivial interfacial thermal resistance. The impacts of coupling strength, temperature, and size of the system on this type of interfacial thermal resistance are explored. More interesting, we find that thermal rectification can be realized in this inhomogeneous encased graphene structures with a thermal rectification efficiency of 40% at 50 K temperature difference. Our study provides insight to better understand thermal transport in two-dimensional materials and promising structures for practical thermal rectification devices.
Measurement of defect densities and Urbach energies of tail states in PTB7 solar cells
Authors: Samiee Mehran , Joshi Pranav , Aidarkhanov Damir , Dalal Vikram
Published: October 2014

Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl) carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7) is an important material for solar cells. We report on measurement of bulk and interfacial defects in PTB7 devices and measurement of Urbach energies of tail states near the HOMO and LUMO levels. The bulk defects and Urbach energies were measured using sub-gap quantum efficiency techniques and the donor/acceptor interfacial defects using capacitance techniques. Interfacial defects were found to peak at ∼0.7 eV above the HOMO level. Dark current-voltage curve indicated both interfacial and bulk recombination. Urbach energy for tail states near the HOMO level of PTB7 is 33 meV and near the LUMO level 55 meV.
Effectiveness of plasma diagnostic in ultra high frequency and radio frequency hybrid plasmas for synthesis of silicon nitride film at low temperature
Authors: Sahu B. B. , Shin Kyung Sik , Jin Su. B. , Han Jeon G. , Ishikawa K. , Hori M.
Published: October 2014

This work presents a systematic plasma diagnostic approach for plasma processing using radio frequency (RF) and RF/UHF (ultra high frequency) hybrid plasmas. The present work also studies the influence of frequency on the deposition of Hydrogenated silicon nitride (SiNx: H) film using N2/SiH4/NH3 discharges. Analysis of data reveals that the UHF power addition to RF is quite effective in the plasma and radicals formation in different operating conditions. For the diagnostics, we have used optical emission spectroscopy, vacuum ultraviolet absorption spectroscopy, and RF compensated Langmuir probe. The presented diagnostic method directly exploits the optimized condition for fabricating high-quality silicon rich nitride (SiNx: H) thin film, at low temperature. With the help of hybrid plasmas, it is possible to fabricate SiNx: H film with high transparency ∼90%.
Effect of crystallographic orientation in textured Ba0.92Ca0.08TiO3 piezoelectric ceramics
Authors: Haugen Astri Bjørnetun , Morozov Maxim I. , Johnsson Mats , Grande Tor , Einarsrud Mari-Ann
Published: October 2014

Strongly textured lead-free Ba0.92Ca0.08TiO3 piezoelectric ceramics were fabricated by tape casting and templated grain growth. Dense ceramics with both favorable ⟨100⟩ and unfavorable ⟨111⟩ texture were successfully prepared. Enhanced piezoelectric performance was demonstrated for ceramics with ⟨100⟩ texture, in line with the predictions based on reported piezoelectric coefficients of tetragonal BaTiO3. Due to the expanded tetragonal range through Ca-substitution, ⟨100⟩ texture is favorable over a wide temperature range. The ⟨100⟩ texture also results in the enhanced piezoelectric performance being temperature-independent. In addition to engineering of stable, high-performance lead-free piezoelectric ceramics, this study has demonstrated that consideration of the extender/rotator nature of piezoelectric properties is imperative for improving the piezoelectric response through texturing.
Specific heat of Nb3Sn: The case for a single gap
Authors: Jo Y. J. , Zhou Jian , Sung Zu Hawn , Lee Peter J. , Larbalestier D. C.
Published: October 2014

The important influence of multiple gaps in the superconductivity of MgB2 and Fe-based compounds, especially because of the possibility that manipulation of a second gap can significantly raise the upper critical field Hc2, has refocused attention on Nb3Sn because anomalies in both specific heat and point-contact tunneling studies have led to the proposal that Nb3Sn is also a two-gap superconductor. Here, we search for evidence of the second gap in a careful study of the influence of the homogenization temperature on the sample uniformity. We show that it is very difficult to fabricate samples that are both homogeneous and stoichiometric. We find so-called “second-gap” anomalies disappear only after high temperature and long-term annealing. Such a well-annealed sample shows only a strong, electron-phonon-coupled, single-gap behavior. In contrast, samples reacted and annealed at lower temperatures, as in the earlier two-gap studies, show small chemical composition variations of the A15 phase. We propose that the second gap sightings are actually due to variation of Tc within very difficult-to-fully homogenize samples. A curiosity of the A15 Nb3Sn phase is that almost any mixture of Nb and Sn tries to form a stoichiometric A15 composition, but the residue of course contains off-stoichiometric A15, Nb, and other phases when the Nb:Sn ratio departs from the true 3:1 stoichiometry.
Molecular beam epitaxial growth of Bi2Se3 nanowires and nanoflakes
Authors: Knebl G. M. , Gessler J. R. , Kamp M. , Höfling S.
Published: October 2014

Topological Insulators are in focus of immense research efforts and rapid scientific progress is obtained in that field. Bi2Se3 has proven to be a topological insulator material that provides a large band gap and a band structure with a single Dirac cone at the Γ-point. This makes Bi2Se3 one of the most promising three dimensional topological insulator materials. While Bi2Se3 nanowires and nanoflakes so far were fabricated with different methods and for different purposes, we here present the first Bi2Se3 nanowires as well as nanoflakes grown by molecular beam epitaxy. The nanostructures were nucleated on pretreated, silicon (100) wafers. Altering the growth conditions nanoflakes could be fabricated instead of nanowires; both with high crystalline quality, confirmed by scanning electron microscopy as well as transmission electron microscopy. These nanostructures have promise for spintronic devices and Majorana fermion observation in contact to superconductor materials.
Influence of stray fields on the switching-field distribution for bit-patterned media based on pre-patterned substrates
Authors: Pfau B. , Günther C. M. , Guehrs E. , Hauet T. , Hennen T. , Eisebitt S. , Hellwig O.
Published: October 2014

Using a direct imaging method, we experimentally investigate the reversal of magnetic islands in a bit-patterned media sample based on a pre-patterned substrate. Due to systematic variation of the island distances in the media, we are able to study the influence of the dipolar interaction on the switching-field distribution of the island ensemble. The experimental findings are explained by an analytical magnetostatic model that allows us to quantify the different components of the demagnetizing field in the system and to distinguish intrinsic and dipolar broadening of the switching-field distribution. Besides the well-known dipolar broadening due to stray fields from neighboring islands, we find strong influence from the magnetized trench material on the island switching.
In situ study of an oxidation reaction on a Pt/C electrode by ambient pressure hard X-ray photoelectron spectroscopy
Authors: Takagi Yasumasa , Wang Heng , Uemura Yohei , Ikenaga Eiji , Sekizawa Oki , Uruga Tomoya , Ohashi Haruhiko , Senba Yasunori , Yumoto Hirokatsu , Yamazaki Hiroshi , Goto Shunji , Tada Mizuki , Iwasawa Yasuhiro , Yokoyama Toshihiko
Published: October 2014

We have constructed an ambient pressure X-ray photoelectron spectroscopy instrument that uses hard X-ray radiation at the high-performance undulator beamline BL36XU of SPring-8. The dependence of the Au 4f peak intensity from Au foil on the ambient N2 pressure was measured. At a photon energy of 7.94 keV, the Au 4f peak intensity maintained 40% at 3000 Pa compared with that at high vacuum. We designed a polymer electrolyte fuel cell that allows us to perform X-ray photoelectron spectroscopy measurements of an electrode under working conditions. The oxidized Pt peaks were observed in the Pt 3d5/2 level of Pt nanoparticles in the cathode, and the peaks clearly depended on the applied voltage between the anode and cathode. Our apparatus can be applied as a valuable in situ tool for the investigation of the electronic states and adsorbed species of polymer electrolyte fuel cell electrode catalysts under the reaction conditions.
High temperature study of flexible silicon-on-insulator fin field-effect transistors
Authors: Diab Amer , Torres Sevilla Galo A. , Ghoneim Mohamed T. , Hussain Muhammad M.
Published: October 2014

We report high temperature electrical transport characteristics of a flexible version of the semiconductor industry's most advanced architecture: fin field-effect transistor on silicon-on-insulator with sub-20 nm fins and high-κ/metal gate stacks. Characterization from room to high temperature (150 °C) was completed to determine temperature dependence of drain current (Ids), gate leakage current (Igs), transconductance (gm), and extracted low-field mobility (μ0). Mobility degradation with temperature is mainly caused by phonon scattering. The other device characteristics show insignificant difference at high temperature which proves the suitability of inorganic flexible electronics with advanced device architecture.
Network histograms and universality of blockmodel approximation
Authors: Olhede Sofia C. , Wolfe Patrick J.
Published: October 2014

Significance

Representing and understanding large networks remains a major challenge across the sciences, with a strong focus on communities: groups of network nodes whose connectivity properties are similar. Here we argue that, independently of the presence or absence of actual communities in the data, this notion leads to something stronger: a histogram representation, in which blocks of network edges that result from community groupings can be interpreted as two-dimensional histogram bins. We provide an automatic procedure to determine bin widths for any given network and illustrate our methodology using two publicly available network datasets.