bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel process and catalytic materials for converting CO2 and H2 containing mixtures to liquid fuels and chemicals
Authors: Meiri Nora , Dinburg Yakov , Amoyal Meital , Koukouliev Viatcheslav , Nehemya Roxana Vidruk , Landau Miron V. , Herskowitz Moti
Published: October 2015

Carbon dioxide and water are renewable and the most abundant feedstocks for the production of chemicals and fungible fuels. However, the current technologies for production of hydrogen from water are not competitive. Therefore, reacting carbon dioxide with hydrogen is not economically viable in the near future. Other alternatives include natural gas, biogas or biomass for the production of carbon dioxide, hydrogen and carbon monoxide mixtures that react to yield chemicals and fungible fuels. The latter process requires a high performance catalyst that enhances the reverse water-gas-shift (RWGS) reaction and Fischer–Tropsch synthesis (FTS) to higher hydrocarbons combined with an optimal reactor system. Important aspects of a novel catalyst, based on a Fe spinel and three-reactor system developed for this purpose published in our recent paper and patent, were investigated in this study. Potassium was found to be a key promoter that improves the reaction rates of the RWGS and FTS and increases the selectivity of higher hydrocarbons while producing mostly olefins. It changed the texture of the catalyst, stabilized the Fe–Al–O spinel, thus preventing decomposition into Fe3O4 and Al2O3. Potassium also increased the content of Fe5C2 while shifting Fe in the oxide and carbide phases to a more reduced state. In addition, it increased the relative exposure of carbide iron on the catalysts surface, the CO2 adsorption and the adsorption strength. A detailed kinetic model of the RWGS, FTS and methanation reactions was developed for the Fe spinel catalyst based on extensive experimental data measured over a range of operating conditions. Significant oligomerization activity of the catalyst was found. Testing the pelletized catalyst with CO2, CO and H2 mixtures over a range of operating conditions demonstrated its high productivity to higher hydrocarbons. The composition of the liquid (C5+) was found to be a function of the potassium content and the composition of the feedstock.
Size-tunable rhodium nanostructures for wavelength-tunable ultraviolet plasmonics
Authors: Zhang Xiao , Li Pan , Barreda Ángela , Gutiérrez Yael , González Francisco , Moreno Fernando , Everitt Henry O. , Liu Jie
Published: October 2015

The localized surface plasmon resonance of Rh nanocubes red-shifts in the UV region with increasing size.
Fungal phytotoxins with potential herbicidal activity: chemical and biological characterization
Authors: Cimmino Alessio , Masi Marco , Evidente Marco , Superchi Stefano , Evidente Antonio
Published: October 2015

Phytotoxins are an efficient tool to design natural safe bioherbicides for weed management. Agricultural products with low or nil risk to human and animal health could be obtained by avoiding the use of pesticides.
Spontaneous and specific myogenic differentiation of human mesenchymal stem cells on polyethylene glycol-linked multi-walled carbon nanotube films for skeletal muscle engineering
Authors: Zhao Chunyan , Andersen Henrik , Ozyilmaz Barbaros , Ramaprabhu Sundara , Pastorin Giorgia , Ho Han Kiat
Published: October 2015

PEG-CNT films spontaneously direct the skeletal myogenic differentiation of hMSCs in the absence of myogenic induction factors.
Electrical and thermal conduction in ultra-thin freestanding atomic layer deposited W nanobridges
Authors: Eigenfeld Nathan T. , Gertsch Jonas C. , Skidmore George D. , George Steven M. , Bright Victor M.
Published: October 2015

Electro/thermal conduction is reduced substantially in ultra-thin ALD W films. Evidence of phonon conduction appears in fabricated W structures.
Photoswitchable fluorescent nanoparticles and their emerging applications
Authors: Zhang Yuanlin , Zhang Kaiquan , Wang Jie , Tian Zhiyuan , Li Alexander D. Q.
Published: October 2015

This review summarizes the recent advances in photoswitchable nanoparticles and their novel applications in super resolution imaging, frequency domain imaging, and anti-phase dual color correlation imaging.
Stabilization of ultrafine metal nanocatalysts on thin carbon sheets
Authors: Liu Xiaofang , Cui Xinrui , Liu Yiding , Yin Yadong
Published: October 2015

A novel strategy was proposed to anchor ultrafine metal nanoparticles (NPs) on thin carbon sheets for highly stable and efficient heterogeneous catalysts.
Modeling of biosynthesized silver nanoparticles in Vitex negundo L. extract by artificial neural network
Authors: Shabanzadeh Parvaneh , Yusof Rubiyah , Shameli Kamyar
Published: October 2015

In this study silver nanoparticles (Ag-NPs) are biosynthesized from silver nitrate aqueous solution through a simple and eco-friendly route using water extract ofVitex negundoL. (V. negundo) which acted as a reductant and stabilizer simultaneously.
Synthesis of ZnO nanorods on a flexible Phynox alloy substrate: influence of growth temperature on their properties
Authors: Gaddam Venkateswarlu , Kumar R. Rakesh , Parmar Mitesh , Nayak M. M. , Rajanna K.
Published: October 2015

A novel flexible alloy substrate (Phynox, 50 μm thick) was used for the synthesis of zinc oxide (ZnO) nanorods via a low-temperature solution growth method.
Copper nanowires based current collector for light-weight and flexible composite silicon anode with high stability and specific capacity
Authors: Lin Ruoxu , Zhang Shichao , Du Zhijia , Fang Hua , Ren Yanbiao , Wu Xiaomeng
Published: October 2015

The electrodeposition process makes good progress to reduce the sheet resistance, which ensures the effective diffusion of Li-ions and electrons.
Computational insight into the mechanism of the Pd(0)–Brønsted acid cooperatively catalysed head-to-tail dimerization of terminal alkynes
Authors: Zhang Hao , Bao Xiaoguang
Published: October 2015

The Pd(0)–Brønsted acid cooperatively catalysed head-to-tail dimerization of terminal alkynes was computationally studied to gain a mechanistic insight.
Self-assembly of thioether functionalized fullerenes on gold and their activity in electropolymerization of styrene
Authors: Piotrowski P. , Pawłowska J. , Pawłowski J. , Czerwonka A. M. , Bilewicz R. , Kaim A.
Published: October 2015

Fulleropyrrolidine alkylaromatic sulphides were found to form uniform coating on the gold surface through the thioether sulphur anchoring group and can initiate the anionic polymerization of styrene under electrochemical conditions.
Controllable synthesis of uniform BiOF nanosheets and their improved photocatalytic activity by an exposed high-energy (002) facet and internal electric field
Authors: Zou Sijia , Teng Fei , Chang Chao , Liu Zailun , Wang Shurong
Published: October 2015

Uniform BiOF nanosheets show an improved photocatalytic activity for the degradation of RhB dye.
Application of gas chromatography-mass spectrometry and chemometrics methods for assessing volatile profiles of Pu-erh tea with different processing methods and ageing years
Authors: Lv Shidong , Wu Yuanshuang , Wei Jifu , Lian Ming , Wang Chen , Gao Xuemei , Meng Qingxiong
Published: October 2015

A method was developed based on head-space solid phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS) combined with multivariate statistical methods to assess volatile profiles in different types of Pu-erh teas.
Synthesis, optical, electrochemical properties and photovoltaic performance of novel panchromatic meso-thiophene BODIPY dyes with a variety of electron-donating groups at the 3,5-positions
Authors: Liao Junxu , Xu Yongjun , Zhao Hongbin , Wang Yucai , Zhang Wentao , Peng Fei , Xie Shengjie , Yang Xiaoxi
Published: October 2015

A series of novel BODIPY derivatives (BDP1–5) containing a thiophene motif at the meso-position and various electron-donating units at the 3,5-positions were designed and synthesized.
Construction of g-C3N4/S-g-C3N4 metal-free isotype heterojunctions with an enhanced charge driving force and their photocatalytic performance under anoxic conditions
Authors: Hu Shaozheng , Ma Lin , Li Fayun , Fan Zhiping , Wang Qiong , Bai Jin , Kang Xiaoxue , Wu Guang
Published: October 2015

g-C3N4/S-g-C3N4 metal-free isotype heterojunction catalysts with an enhanced charge driving force were prepared by a two step calcination method. The results indicate that this method can lead to a more efficient charge-carrier migration.
Performance and mechanisms for removal of perfluorooctanoate (PFOA) from aqueous solution by activated carbon fiber
Authors: Wang Yujuan , Niu Junfeng , Li Yang , Zheng Taojie , Xu Yi , Liu Ye
Published: October 2015

The sorption behavior of perfluorooctanoate (PFOA) by activated carbon fiber (ACF) in aqueous solution was investigated.
Evaluation of a quercetin–gadolinium complex as an efficient positive contrast enhancer for magnetic resonance imaging
Authors: Muthurajan Thenmozhi , Rammanohar Pooja , Rajendran Nisha Palanisamy , Sethuraman Swaminathan , Krishnan Uma Maheswari
Published: October 2015

The quercetin–gadolinium complex showing superior contrast than the commercially used gadopentetate dimeglumine.
A label-free electrochemical immunosensor for carcinoembryonic antigen detection on a graphene platform doped with poly(3,4-ethylenedioxythiophene)/Au nanoparticles
Authors: Gao Yan-Sha , Xu Jing-Kun , Lu Li-Min , Zhu Xiao-Fei , Wang Wen-Min , Yang Tao-Tao , Zhang Kai-Xin , Yu Yong-Fang
Published: October 2015

In this work, a two-step method was developed for the fabrication of a graphene sensing platform doped with poly(3,4-ethylenedioxythiophene)/Au nanoparticles (AuNPs/PEDOT/GR).
Surface-modification of SnO2 nanoparticles by incorporation of Al for the detection of combustible gases in a humid atmosphere
Authors: Suematsu Koichi , Ma Nan , Yuasa Masayoshi , Kida Tetsuya , Shimanoe Kengo
Published: October 2015

Aluminium-doped SnO2 nanoparticles inhibited hydroxyl poisoning and enhanced the sensor response in a humid atmosphere.
Effects of functional groups of graphene oxide on the electrochemical performance of lithium-ion batteries
Authors: Xie Zhengwei , Yu Zuolong , Fan Weifeng , Peng Gongchang , Qu Meizhen
Published: October 2015

Graphene oxide (GO) with different ratios of functional groups is prepared via low temperature directional thermal reduction and re-oxidization by nitric acid.
Tunable ternary (P, S, N)-doped graphene as an efficient electrocatalyst for oxygen reduction reaction in an alkaline medium
Authors: Wang Yishu , Zhang Bowen , Xu Minghui , He Xingquan
Published: October 2015

A novel nitrogen, phosphorus and sulfur ternary-doped graphene (PSNG) was synthesized by a one-step pyrolysis method, which was used as a low-cost and high-efficient catalyst for the oxygen reduction reaction.
Access to a new class of synthetic building blocks via trifluoromethoxylation of pyridines and pyrimidines
Authors: Feng Pengju , Lee Katarzyna N. , Lee Johnny W. , Zhan Chengbo , Ngai Ming-Yu
Published: October 2015

One-pot trifluoromethoxylation of functionalized pyridines and pyrimidines via OCF3-migraion.
Harnessing isomerization-mediated manipulation of nonspecific cell/matrix interactions to reversibly trigger and suspend stem cell differentiation
Authors: Bai Tao , Sinclair Andrew , Sun Fang , Jain Priyesh , Hung Hsiang-Chieh , Zhang Peng , Ella-Menye Jean-Rene , Liu Wenguang , Jiang Shaoyi
Published: October 2015

Spiropyran-decorated zwitterionic hydrogel realizes reversible manipulation of mesenchymal stem cell fate through programmed light exposure.
π-extended anthracenes as sensitive probes for mechanical stress
Authors: Göstl R. , Sijbesma R. P.
Published: October 2015

Diels–Alder adducts of π-extended anthracenes have been synthesised, employed as mechanophores in polymeric materials and show unprecedented detection sensitivity for mechanical stress.
A terminally protected dipeptide: from crystal structure and self-assembly, through co-assembly with carbon-based materials, to a ternary catalyst for reduction chemistry in water
Authors: Mazzier Daniela , Carraro Francesco , Crisma Marco , Rancan Marzio , Toniolo Claudio , Moretto Alessandro
Published: October 2015

An efficient catalyst for reduction chemistry in water was prepared by the co-assembly of a hydrophobic dipeptide, multiwalled carbon nanotubes, and C60.
Joint quantisation levels and power optimisation in uplink network multiple‐input and multiple‐output under constraint backhaul
Authors: Wang Shipeng , Chen Li , Chen Xiaohui , Wei Guo
Published: October 2015

This article studies the performance of the cooperative system where each base station (BS) is connected to a central processor (CP) via a noiseless and rate‐limited backhaul link. The single‐user compress‐and‐forward scheme is deployed at the BSs, and the problem for jointly setting the quantisation noise and the transmit power levels is left open. The authors formulate the weighted sum‐rate (WSR) problem of optimising quantisation and transmit power levels for K‐users and B‐BSs situation. However, the problem is non‐convex and difficult to be solved directly by conventional convex methods. In this work, an algorithm is proposed to solve the optimisation problem and achieve its global optimality. More importantly, the authors reveal the reason for the effect of the quantisation levels on the performance of cooperative system. Lower and upper bounds of quantisation levels are derived under the given signal to interference noise ratio (SINR) requirements. The lower and upper bounds are then demonstrated to be rather close to the numerical results. It is also numerically shown that the proposed algorithm can achieve the global optimality and is robust with respect to different multi‐user situations.
Quantised consensus of heterogeneous multi‐agent systems
Authors: Zhu Yunru , Zheng Yuanshi , Wang Long
Published: October 2015

In this study, the consensus problem of heterogeneous multi‐agent systems with quantised interactions is investigated. Distributed control laws are proposed for heterogeneous multi‐agent systems by using uniform and logarithmic quantisers, respectively. Based on graph theory and non‐smooth analysis, it is shown that the heterogeneous multi‐agent system can reach consensus with logarithmic quantisers. For uniform quantisers, some convergence results are also derived. Simulation examples are presented to illustrate the effectiveness of the theoretical results.
Adaptive stabilisation of random systems with arbitrary switchings
Authors: Jiao Ticao , Xu Shengyuan , Li Yongmin , Li Ze
Published: October 2015

This study is concerned with the global stabilisation problem for a class of random non‐linear systems with arbitrary switchings and parameter uncertainties. Under some milder assumptions and by constructing a Lyapunov function, a common adaptive state feedback controller is designed such that the resulting closed‐loop system has a globally unique and almost surely bounded solution. Furthermore, the system states are exponentially noise‐to‐state stable in mean square. Finally, the efficiency of the proposed design approach is demonstrated by a numerical example.
Robust design methodology for simultaneous feedforward and feedback tuning
Authors: Rodríguez Carlos , Normey‐Rico Julio E. , Luis Guzmán José , Berenguel Manuel
Published: October 2015

This study presents a control design methodology to address simultaneous robust feedforward and feedback tuning. A tuning guideline including tuning rules based on the time‐domain response is introduced. Then, an optimisation algorithm is used in the frequency domain to find the optimal feedback–feedforward controller. Detailed simulations covering a wide range of industrial process models are carried out to demonstrate the validity of the proposed methodology and its advantages over other approaches.
Distributed state estimation for stochastic non‐linear systems with random delays and packet dropouts
Authors: Wang Shaoying , Fang Huajing , Liu Xiaoyong
Published: October 2015

A novel distributed fusion Kalman filter is proposed for a class of stochastic non‐linear systems with multi‐step transmission delays and packet dropouts. The stochastic non‐linearities described by statistical means enter into both state equation and measurement equation, and some Bernoulli distributed random variables are introduced to model the delayed measurements. Using the measurement reorganisation approach instead of state augmentation, the addressed system is transformed into a delay‐free one. For each subsystem, the optimal local estimators are designed via the innovation analysis method. The filtering error cross‐covariance matrices between any two local filters are then obtained. On this basis, a distributed fusion filter is derived by means of matrix‐weighted fusion estimation criterion. The effects of stochastic non‐linearities, random delays and packet dropouts on the performance of the filter are all considered in the proposed algorithms. Moreover, some sufficient conditions that guarantee the convergence of the estimation error covariance matrices are established. Finally, a numerical example is given to illustrate the effectiveness of the developed algorithms.
Reliable guaranteed‐cost control of delta operator switched systems with actuator faults: mode‐dependent average dwell‐time approach
Authors: Hu Hao , Jiang Bin , Yang Hao
Published: October 2015

This study deals with the reliable guaranteed‐cost control problem for a class of delta operator switched linear systems, in terms of mode‐dependent average dwell‐time (MDADT) approach. Firstly, based on MDADT approach, asymptotical and exponential stabilities of delta operator non‐linear switched systems are analysed. Then, the reliable controller and the minimum MDADT are designed to stabilise the considered delta operator linear switched system with actuator faults and to determine an upper bound of the given cost function. A flight control switched system is given to show the validity and potential of the proposed method.
Model predictive control allocation for stability improvement of four‐wheel drive electric vehicles in critical driving condition
Authors: Zhao Haiyan , Ren Bingtao , Chen Hong , Deng Weiwen
Published: October 2015

To improve the vehicle stability of an electric vehicle (EV) with four in‐wheel motors, the authors investigate the use of a non‐linear control allocation scheme based on model predictive control (MPC) for EVs. Such a strategy is useful in yaw stabilisation of the vehicle. The proposed allocation strategy allows a modularisation of the control task, such that an upper level control system specifies a desired yaw moment to work on the EVs, while the control allocation is used to determine control inputs for four driving motors by commanding appropriate wheel slips. To avoid unintended side effects, skidding or discomforting the driver in critical driving condition, the MPC method, which permits us to consider constraints of actuating motors and slip ratio, is proposed to deal with this challenging problem. An analytical approach for the proposed controller is given and applied to evaluate the handing and stability of EVs. The experimental results show that the designed MPC allocation algorithm for motor torque has better performance in real time, and the control performance can be guaranteed in the real‐time environment.
Discrete Fourier transform‐based parametric modal identification from ambient data of the power system frequency
Authors: Hwang Jin Kwon , Liu Yilu
Published: October 2015

This study proposes a discrete Fourier transform (DFT)‐based parametric identification method by using a difference sequence between two sets of frequency data. An autocorrelation function of the frequency difference sequence can be represented as a linear combination of exponentially decaying sinusoidal functions, whose natural frequencies and damping ratios are equal to those of interarea modes. These modal parameters are calculated from the Laplace transform coefficients of the autocorrelation function. The coefficients are estimated by curve‐fitting the DFT values of the autocorrelation function. The proposed method is compared with the modified extended Yule Walker method through simulations on signal‐to‐noise ratio. Finally, the feasibility of the proposed method is shown by identifying real power systems from frequency data of the frequency monitoring network system.
Optimal placement of underground cables to maximise total ampacity considering cable lifetime
Authors: Abootorabi Zarchi Davoud , Vahidi Behrooz
Published: October 2015

This study presents a novel algorithm for the optimum placement for underground cable in a concrete duct bank to maximise ampacity and also the lifetime of the cable and fluctuation in the input variables. Fluctuations in the operating temperature cable result from variations in factors such as the ambient temperature, the thermal resistivity of the soil and back fill, as well as the loading of the cable. Operating the cable near or above its thermal rating could have an adverse effect on the aging of the cable insulation subsequently reducing the lifetime of the cable. The algorithm reported in this study considers the factors mentioned above and computes the optimum cable placement in the duct bank by calculating simulated lifetimes for the cables. It makes use of an Arrhenius thermal model to calculate the lifetime of the cable as well as the vector immune system algorithm and interior point method to optimise the placement of the cables in the duct bank. The proposed method has been used in a test case to show how cable placement affects the lifetime of the cables in the duct bank.
Fuzzy logic inference system‐based hybrid quality prediction model for wireless 4kUHD H.265‐coded video streaming
Authors: Alreshoodi Mohammed , Adeyemi‐Ejeye Anthony Olufemi , Woods John , Walker Stuart D.
Published: October 2015

Networked visual applications such video streaming have grown exponentially in recent years, yet are known to be sensitive to network impairments. However, available measurement techniques that adopt a full reference model are impractical in real‐time streaming because they require the original video sequence available at the receivers side. The primary aim of this study is to present a hybrid no‐reference prediction model for the perceptual quality of 4kUHD H.265‐coded video in the wireless domain. The contributions of this paper are two‐fold: first, an investigation of the impact of quality of service (QoS) parameters on 4kUHD H.265‐coded video transmission in an experimental environment; second, objective model based on fuzzy logic inference system is developed to predict the visual quality by mapping QoS parameters to the measured quality of experience. The model is evaluated in contrast to random neural networks. The results show that good prediction accuracy was obtained from the proposed hybrid prediction model. This study will help in the development of a reference‐free video quality prediction model and QoS control methods for 4kUHD video streaming.
DC‐link capacitor voltage control for single‐phase shunt active power filter with step size error cancellation in self‐charging algorithm
Authors: Zainuri Muhammad Ammirrul Atiqi Mohd , Radzi Mohd Amran Mohd , Soh Azura Che , Mariun Norman , Rahim Nasrudin Abd.
Published: October 2015

This study presents an improved self‐charging algorithm by introducing a new feature known as step size error cancellation for better performance of DC‐link capacitor voltage control in single‐phase shunt active power filter (SAPF). Previous works of self‐charging algorithms were focused only for steady‐state operation by using either proportional–integral (PI) or fuzzy logic control (FLC). However, in a certain operation of any power system, dynamic operation may also happen. Thus, by introducing step size error cancellation as an additional feature to the self‐charging algorithm, both steady state and dynamic operations can be covered. For evaluation and comparison analysis, self‐charging with PI and FLC algorithms have been developed too. All the algorithms were simulated in MATLAB–Simulink, respectively, together with the single‐phase SAPF. For hardware implementation, the proposed algorithm was programmed in TMS320F28335 digital signal processing board. The other two conventional self‐charging algorithms were also programmed for comparison purposes. From the results and analysis, the proposed self‐charging with step size error cancellation shows the best performance with high accuracy, fast response time and less overshoot and undershoot. It performs well in both steady state and dynamic operations as compared with both previous self‐charging techniques which only work well in steady‐state operation.
Turbulent structure at the midsection of an annular flow
Authors: Ghaemi S. , Rafati S. , Bizhani M. , Kuru E.
Published: October 2015

The turbulent flow in the midsection of an annular gap between two concentric tubes at Reynolds number of 59 200–90 800 based on hydraulic diameter (dh = 57 mm) and average velocity is experimentally investigated. Measurements are carried out using particle tracking velocimetry (PTV) and planar particle image velocimetry (PIV) with spatial resolution of 0.0068dh (size of the binning window) and 0.0129dh (size of the interrogation window), respectively. Both PTV and PIV results show that the location of maximum mean streamwise velocity (yU) does not coincide with the locations of zero shear stress (yuv), minimum streamwise velocity fluctuation (yu2), and minimum radial velocity fluctuation (yv2). The separation between yU and yuv is 0.013dh based on PTV while PIV underestimates the separation distance as 0.0063dh. Conditional averages of turbulent fluctuations based on the four quadrants across the annulus demonstrate that the inner and outer wall flows overlap in the midsection. In the midsection, the flow is subject to opposing sweep/ejection events originating from both the inner and outer walls. The opposite quadrant events of the two boundary layers cancel out at yuv while the local minimum of spatial correlation of u (maximum mixing of the two wall flows) occurs at yU. Investigation of the budget of Reynolds shear stress showed that production and advection terms act towards the coincidence of the yU and yuv while the dissipation term works against the coincidence of the two points. The location of 〈U〉max also overlaps with zero dissipation of 〈uv〉. The production of turbulent kinetic energy is slightly negative in the narrow region between yU and yuv. This negative production acts towards smoothing the mean velocity profile at the joint of the two wall flows by equalizing its curvature (∂2〈U〉/∂y2) on the two sides of yU. The small separation distance of the yU and yuv is associated with slight deviation from the fully developed condition.
Effects of magnetic fields on magnetohydrodynamic cylindrical and spherical Richtmyer-Meshkov instability
Authors: Mostert W. , Wheatley V. , Samtaney R. , Pullin D. I.
Published: October 2015

The effects of seed magnetic fields on the Richtmyer-Meshkov instability driven by converging cylindrical and spherical implosions in ideal magnetohydrodynamics are investigated. Two different seed field configurations at various strengths are applied over a cylindrical or spherical density interface which has a single-dominant-mode perturbation. The shocks that excite the instability are generated with appropriate Riemann problems in a numerical formulation and the effect of the seed field on the growth rate and symmetry of the perturbations on the density interface is examined. We find reduced perturbation growth for both field configurations and all tested strengths. The extent of growth suppression increases with seed field strength but varies with the angle of the field to interface. The seed field configuration does not significantly affect extent of suppression of the instability, allowing it to be chosen to minimize its effect on implosion distortion. However, stronger seed fields are required in three dimensions to suppress the instability effectively.
Linear stability of optimal streaks in the log-layer of turbulent channel flows
Authors: Alizard Frédéric
Published: October 2015

The importance of secondary instability of streaks for the generation of vortical structures attached to the wall in the logarithmic region of turbulent channels is studied. The streaks and their linear instability are computed by solving equations associated with the organized motion that include an eddy-viscosity modeling the effect of incoherent fluctuations. Three friction Reynolds numbers, Reτ = 2000, 3000, and 5000, are investigated. For all flow cases, optimal streamwise vortices (i.e., having the highest potential for linear transient energy amplification) are used as initial conditions. Due to the lift-up mechanism, these optimal perturbations lead to the nonlinear growth of streaks. Based on a Floquet theory along the spanwise direction, we observe the onset of streak secondary instability for a wide range of spanwise wavelengths when the streak amplitude exceeds a critical value. Under neutral conditions, it is shown that streak instability modes have their energy mainly concentrated in the overlap layer and propagate with a phase velocity equal to the mean streamwise velocity of the log-layer. These neutral log-layer modes exhibit a sinuous pattern and have characteristic sizes that are proportional to the wall distance in both streamwise and spanwise directions, in agreement with the Townsend’s attached eddy hypothesis (A. Townsend, the structure of turbulent shear flow, Cambridge university press, 1976 2nd edition). In particular, for a distance from the wall varying from y+ ≈ 100 (in wall units) to y ≈ 0.3h, where h is half the height of the channel, the neutral log-layer modes are self-similar with a spanwise width of λz ≈ y/0.3 and a streamwise length of λx ≈ 3λz, independently of the Reynolds number. Based on this observation, it is suggested that compact vortical structures attached to the wall can be ascribed to streak secondary instabilities. In addition, spatial distributions of fluctuating vorticity components show that the onset of secondary instability is associated with the roll-up of the shear layer at the edge of the low-speed streak, similarly to a three-dimensional mixing layer.
Calcineurin mediates homeostatic synaptic plasticity by regulating retinoic acid synthesis
Authors: Arendt Kristin L. , Zhang Zhenjie , Ganesan Subhashree , Hintze Maik , Shin Maggie M. , Tang Yitai , Cho Ahryon , Graef Isabella A. , Chen Lu
Published: October 2015

Significance

Chronic reduction of synaptic activity in neural networks leads to compensatory changes at both excitatory and inhibitory synapses, a phenomenon known as homeostatic synaptic plasticity. Postsynaptic activity/Ca2+-dependent regulation of retinoic acid (RA) synthesis is critically involved in homeostatic synaptic plasticity; however, the signaling molecule that gates RA synthesis in response to Ca2+level changes remains unknown. Using pharmacologic and genetic manipulations, we show that calcineurin (CaN) activity, which is regulated by postsynaptic Ca2+levels, directly controls RA synthesis. Inhibiting CaN activity or genetic ablation of CaN leads to homeostatic modulation of synaptic transmission in an RA signaling-dependent manner. These findings uncover the molecular mechanism by which activity regulates synaptic strength through RA synthesis.
Selective optogenetic activation of arcuate kisspeptin neurons generates pulsatile luteinizing hormone secretion
Authors: Han Su Young , McLennan Timothy , Czieselsky Katja , Herbison Allan E.
Published: October 2015

Significance

The mammalian reproductive system is critically dependent upon pulsatile gonadotropin hormone release driven by a small population of gonadotropin-releasing hormone neurons in the brain. However, the mechanisms underlying the episodic activation of the gonadotropin-releasing hormone neurons to drive pulsatile hormone release are unknown. We report here that, using optogenetics in vivo, the synchronous activation of a population of kisspeptin neurons located in the hypothalamic arcuate nucleus is remarkably potent at generating pulsatile gonadotropin secretion. This system exhibits major sex differences and is modulated by the gonadal steroid environment of the organism. These results provide an important insight into the brain mechanism underlying gonadotropin pulsatility in mammalian reproductive biology.
Disowning the Self: The Cultural Value of Modesty can Attenuate Self-Positivity
Authors: Shi Yuanyuan , Sedikides Constantine , Cai Huajian , Liu Yunzhi , Yang Ziyan
Published: October 2015

Western participants endorse a higher number of positive traits as self-descriptive, but endorse a lower number of negative traits as self-descriptive. They also respond quicker to categorize positive traits as self-descriptive, but respond slower to categorize negative traits as self-descriptive. Is this self-positivity bias qualified by the cultural value of modesty? We induced modesty (vs. punctuality) and assessed self-descriptiveness judgments and response times among Chinese participants. We replicated the self-positivity bias in regards to both self-descriptiveness judgments and response times. In the case of self-descriptiveness judgments, however, the bias was partially qualified by modesty. Relative to control participants, those in the modesty condition endorsed fewer positive traits as self-descriptive and manifested a tendency toward endorsing more negative traits as self-descriptive. In the case of response times, the self-positivity bias was unqualified by modesty. Within both conditions, participants were quicker to categorize positive traits as self-descriptive and were slower to categorize negative traits as self-descriptive. The results speak to the relation between the self-positivity bias and the self-reference effect and illustrate the malleability of self-processing.
Effects of self-generated versus experimenter-provided cues on the representation of future events
Authors: Neroni Maria Adriana , Gamboz Nadia , de Vito Stefania , Brandimonte Maria Antonella
Published: October 2015

Most experimental studies of prospection focused on episodic forms of future events prompted by means of verbal cues. However, there is evidence suggesting that future events differ considerably according to whether they are produced in response to external, experimenter-provided verbal cues or they are self-generated. In the present study, we compared the quality, the phenomenal characteristics, the temporal distribution, and the content of imagined events prompted by experimenter-provided cues (i.e., cue-words and short verbal sentences) or elicited by means of verbal cues that were self-generated in an autobiographical fluency task. The results showed that future events prompted by means of self-generated cues contained fewer event-specific details than future events prompted by experimenter-provided cues. However, future events elicited by means of self-generated and by experimenter-provided cues did not differ with respect to their phenomenal characteristics. The temporal distribution and the thematic content of future representations were also affected by the type of cue used to elicit prospection. These results offer a holistic view of the properties of future thinking and suggest that the content and the characteristics of envisioned future events may be affected by the method used to elicit prospection.
The effects of direction similarity in visual working memory: Behavioural and event-related potential studies
Authors: Zhang Qian , Li Shouxin , Wang Xiusong , Che Xiaowei
Published: October 2015

Object similarity can improve visual working memory (VWM) performance in the change-detection task, but impair the recognition performance when it occurs at retrieval of VWM in the recognition task. The effect of direction similarity is an issue that has not been well resolved. Furthermore, electrophysiological evidence in support of the mechanisms that underlie the effects of similarity is still scarce. In the current study, we conducted three behavioural experiments to examine the effects of direction similarity on memory performance with regard to both the encoding and retrieval phases of VWM and one event-related potential (ERP) experiment to explore the neural signatures of direction similarity in VWM. Our behavioural studies indicated that direction similarity improved performance when it occurred at the encoding phase but impaired performance when it occurred at the retrieval phase. Moreover, the ERP experiment showed that the amplitude of the contralateral delay activity (CDA) increased with the increasing set size for similar but not dissimilar directions. In addition, the CDA amplitude for similar directions was lower than that for dissimilar directions at set size 2. Taken together, these findings suggest that direction similarity at encoding has a positive effect on VWM performance and at retrieval has a negative effect. Given that VWM capacity depends on information load and the number of objects, the positive effect of similarity may be attributed to reduced information load of memory objects.
CCN1 Suppresses Pulmonary Vascular Smooth Muscle Contraction in Response to Hypoxia
Authors: Lee Seon‐jin , Zhang Meng , Hu Kebin , Lin Ling , Zhang Duo , Jin Yang
Published: October 2015

Pulmonary vasoconstriction and increased vascular resistance are common features in pulmonary hypertension (PH). One of the contributing factors in the development of pulmonary vasoconstriction is increased pulmonary artery smooth muscle cell (PASMC) contraction. Here we report that CCN1, an extracellular matrix molecule, suppressed PASMC contraction in response to hypoxia. CCN1 (Cyr61), discovered in past decade, belongs to the Cyr61‐CTGF‐Nov (CCN) family. It carries a variety of cellular functions, including angiogenesis and cell adhesion, death, and proliferation. Hypoxia robustly upregulated the expression of CCN1 in the pulmonary vessels and lung parenchyma. Given that CCN1 is a secreted protein and functions in a paracine manner, we examined the potential effects of CCN1 on the adjacent smooth muscle cells. Interestingly, bioactive recombinant CCN1 significantly suppressed hypoxia‐induced contraction in human PASMCs in vitro. Consistently, in the in vivo functional studies, administration of bioactive CCN1 protein significantly decreased right ventricular pressure in three different PH animal models. Mechanistically, protein kinase A–pathway inhibitors abolished the effects of CCN1 in suppressing PASMC contraction. Furthermore, CCN1‐inhibited smooth muscle contraction was independent of the known vasodilators, such as nitric oxide. Taken together, our studies indicated a novel cellular function of CCN1, potentially regulating the pathogenesis of PH.
Final Report Key Comparison COOMET.EM.BIPM-K10.b Comparison of the 10 V Josephson Voltage Standards COOMET 542/RU/11
Authors: Katkov A S , Chernyaev P A
Published: October 2015

The 10 V Josephson voltage standard of BelGIM was compared with the similar standard of VNIIM in August-November 2014 in accordance with the option B of the BIPM.EM-K10.b comparison protocol. The standard of VNIIM based upon the Josephson effect was used as a transfer standard to measure the output voltage by BelGIM. The final results are in very good agreement with the reference value supplied by the BIPM voltage standard: the relative voltage difference was 6·10-12 at the combined relative standard uncertainty of 2.8·10-10 for the nominal voltage of 10 V.

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Improved existence results of solutions to the gravitational Maxwell gauged 𝑂(3) sigma model
Authors: Song Kyungwoo
Published: October 2015

We improve the existence result of finite energy solutions to the self-dual equations of the gravitational Maxwell gauged

O
(
3
)

O(3)

sigma model in

(
2
+
1
)

(2+1)

-dimensional Minkowski space for arbitrary location of strings for a small gravitational constant using the standard super- and subsolution method. We construct an explicit supersolution and use the weighted Sobolev space for a subsolution.
On the size of the polynomials orthonormal on the unit circle with respect to a measure which is a sum of the Lebesgue measure and 𝑃 point masses
Authors: Denisov S.
Published: October 2015

For the measures on the unit circle that are equal to the sum of Lebesgue measure and

p
p

point masses, we give an estimate on the size of the corresponding orthonormal polynomials. As a simple corollary of the method, we obtain a bound for some exponential polynomials.
Hausdorff dimension, intersections of projections and exceptional plane sections
Authors: Mattila Pertti , Orponen Tuomas
Published: October 2015

This paper contains new results on two classical topics in fractal geometry: projections, and intersections with affine planes. To keep the notation of the abstract simple, we restrict the discussion to the planar cases of our theorems.

Our first main result considers the orthogonal projections of two Borel sets

A
,
B
⊂

R

2

A,B \subset \mathbb {R}^{2}

into one-dimensional subspaces. Under the assumptions

dim
⁡
A
≤
1
>
dim
⁡
B

\dim A \leq 1 > \dim B

and

dim
⁡
A
+
dim
⁡
B
>
2

\dim A + \dim B > 2

, we prove that the intersection of the projections

P

L

(
A
)

P_{L}(A)

and

P

L

(
B
)

P_{L}(B)

has dimension at least

dim
⁡
A
−
ϵ

\dim A - \epsilon

for positively many lines

L
L

, and for any

ϵ
>
0

\epsilon > 0

. This is quite sharp: given

s
,
t
∈
[
0
,
2
]

s,t \in [0,2]

with

s
+
t
=
2

s + t = 2

, we construct compact sets

A
,
B
⊂

R

2

A,B \subset \mathbb {R}^{2}

with

dim
⁡
A
=
s

\dim A = s

and

dim
⁡
B
=
t

\dim B = t

such that almost all intersections

P

L

(
A
)
∩

P

L

(
B
)

P_{L}(A) \cap P_{L}(B)

are empty. In case both

dim
⁡
A
>
1

\dim A > 1

and

dim
⁡
B
>
1

\dim B > 1

, we prove that the intersections

P

L

(
A
)
∩

P

L

(
B
)

P_{L}(A) \cap P_{L}(B)

have positive length for positively many

L
L

.

If

A
⊂

R

2

A \subset \mathbb {R}^{2}

is a Borel set with

0
>

H

s

(
A
)
>
∞

0 > \mathcal {H}^{s}(A) > \infty

for some

s
>
1

s > 1

, it is known that

A
A

is “visible” from almost all points

x
∈

R

2

x \in \mathbb {R}^{2}

in the sense that

A
A

intersects a positive fraction of all lines passing through

x
x

. In fact, a result of Marstrand says that such non-empty intersections typically have dimension

s
−
1

s - 1

. Our second main result strengthens this by showing that the set of exceptional points

x
∈

R

2

x \in \mathbb {R}^{2}

, for which Marstrand’s assertion fails, has Hausdorff dimension at most one.
The mitochondrial fission receptor Mff selectively recruits oligomerized Drp1
Authors: Liu Raymond , Chan David C.
Published: October 2015

Dynamin-related protein 1 (Drp1) is the GTP-hydrolyzing mechanoenzyme that catalyzes mitochondrial fission in the cell. Residing in the cytosol as dimers and tetramers, Drp1 is recruited by receptors on the mitochondrial outer membrane, where it further assembles into a helical ring that drives division via GTP-dependent constriction. The Drp1 receptor Mff is a major regulator of mitochondrial fission, and its overexpression results in increased fission. In contrast, the alternative Drp1 receptors MiD51 and MiD49 appear to recruit inactive forms of Drp1, because their overexpression inhibits fission. Using genetic and biochemical assays, we studied the interaction of Drp1 with Mff. We show that the insert B region of Drp1 inhibits Mff–Drp1 interactions, such that recombinant Drp1 mutants lacking insert B form a stable complex with Mff. Mff cannot bind to assembly-deficient mutants of Drp1, suggesting that Mff selectively interacts with higher-order complexes of Drp1. In contrast, the alternative Drp1 receptors MiD51 and MiD49 can recruit Drp1 dimers. Therefore Drp1 recruitment by Mff versus MiD51 and MiD49 may result in different outcomes because they recruit different subpopulations of Drp1 from the cytosol.
Greek Law under the Romans
Authors: Kantor Georgy
Published: October 2015

This chapter deals with the impact of Roman legal institutions and political realities of Roman dominance on legal institutions in the Greek world, and with developments of Greek law within the imperial framework from the fall of Corinth to its last traces in late imperial legislation. It addresses in particular the specific characteristics of sources for Greek law in the Roman period, conflicts of jurisdiction between Greek poleis and imperial authorities, the law of personal status in the new imperial context and new developments in the law of property and obligation. The concluding sections deals with the demise of Greek law in late antiquity and its afterlife in late imperial legislation.
Acquired Dysgraphias: Mechanisms of Writing
Authors: Beeson Pélagie M. , Rising Kindle
Published: October 2015

Acquired dysgraphia refers to disorders of spelling or writing due to neurological damage in individuals with normal premorbid literacy skills. Dysgraphia can result from the disruption of central cognitive processes that also support spoken language and reading, so that spelling impairments frequently co-occur with aphasia and acquired alexia. The ability to produce written words can also be affected by damage to peripheral processes necessary to plan and execute the appropriate hand movements for letter generation or typing. In this chapter, we review the cognitive processes that support spelling and writing, and the characteristic dysgraphia syndromes that reflect differential impairment to specific central and peripheral components. We also review assessment procedures for writing and spelling that are structured to clarify the status of component processes and to guide rehabilitation planning. Treatment procedures and sequences are described with a focus on lexical-semantic, phonological, and interactive treatments. The nature and treatment of dysgraphia are illustrated by case examples of global dysgraphia, phonological dysgraphia, and surface dysgraphia.
Concussion and the College Athlete
Authors: Comper Paul , Hutchison Mike
Published: October 2015

Concussion is a common and serious injury among college/university level athletes. Similar to professional athletes, a central theme for most college level athletes is to be able to quickly but safely return to play following concussion. However, unlike professional athletes who earn their living playing sports, most college level athletes will move into other careers or professions once their playing career ends. College athletes therefore have a dual role, with academics and “returning to learn” being a component equally important as return to play in the concussion recovery process. This article describes some of the issues in developing and implementing a university concussion program, as well as issues and common difficulties facing college level athletes as they encounter the acute physical, neuropsychological, and psychosocial challenges related to concussive injuries.