bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of feature-based attention on flanker interference processing: An fMRI-constrained source analysis
Authors: Siemann Julia , Herrmann Manfred , Galashan Daniela
Published: January 2018

The present study examined whether feature-based cueing affects early or late stages of flanker conflict processing using EEG and fMRI. Feature cues either directed participants’ attention to the upcoming colour of the target or were neutral. Validity-specific modulations during interference processing were investigated using the N200 event-related potential (ERP) component and BOLD signal differences. Additionally, both data sets were integrated using an fMRI-constrained source analysis. Finally, the results were compared with a previous study in which spatial instead of feature-based cueing was applied to an otherwise identical flanker task. Feature-based and spatial attention recruited a common fronto-parietal network during conflict processing. Irrespective of attention type (feature-based; spatial), this network responded to focussed attention (valid cueing) as well as context updating (invalid cueing), hinting at domain-general mechanisms. However, spatially and non-spatially directed attention also demonstrated domain-specific activation patterns for conflict processing that were observable in distinct EEG and fMRI data patterns as well as in the respective source analyses. Conflict-specific activity in visual brain regions was comparable between both attention types. We assume that the distinction between spatially and non-spatially directed attention types primarily applies to temporal differences (domain-specific dynamics) between signals originating in the same brain regions (domain-general localization).
Metasurfaced Reverberation Chamber
Authors: Sun Hengyi , Li Zhuo , Gu Changqing , Xu Qian , Chen Xinlei , Sun Yunhe , Lu Shengchen , Martin Ferran
Published: January 2018

The concept of metasurfaced reverberation chamber (RC) is introduced in this paper. It is shown that by coating the chamber wall with a rotating 1-bit random coding metasurface, it is possible to enlarge the test zone of the RC while maintaining the field uniformity as good as that in a traditional RC with mechanical stirrers. A 1-bit random coding diffusion metasurface is designed to obtain all-direction backscattering under normal incidence. Three specific cases are studied for comparisons, including a (traditional) mechanical stirrer RC, a mechanical stirrer RC with a fixed diffusion metasurface, and a RC with a rotating diffusion metasurface. Simulation results show that the compact rotating diffusion metasurface can act as a stirrer with good stirring efficiency. By using such rotating diffusion metasurface, the test region of the RC can be greatly extended.
Real-time TIRF observation of vinculin recruitment to stretched α-catenin by AFM
Authors: Maki Koichiro , Han Sung-Woong , Hirano Yoshinori , Yonemura Shigenobu , Hakoshima Toshio , Adachi Taiji
Published: January 2018

Adherens junctions (AJs) adaptively change their intensities in response to intercellular tension; therefore, they integrate tension generated by individual cells to drive multicellular dynamics, such as morphogenetic change in embryos. Under intercellular tension, α-catenin, which is a component protein of AJs, acts as a mechano-chemical transducer to recruit vinculin to promote actin remodeling. Although in vivo and in vitro studies have suggested that α-catenin-mediated mechanotransduction is a dynamic molecular process, which involves a conformational change of α-catenin under tension to expose a cryptic vinculin binding site, there are no suitable experimental methods to directly explore the process. Therefore, in this study, we developed a novel system by combining atomic force microscopy (AFM) and total internal reflection fluorescence (TIRF). In this system, α-catenin molecules (residues 276–634; the mechano-sensitive M1-M3 domain), modified on coverslips, were stretched by AFM and their recruitment of Alexa-labeled full-length vinculin molecules, dissolved in solution, were observed simultaneously, in real time, using TIRF. We applied a physiologically possible range of tensions and extensions to α-catenin and directly observed its vinculin recruitment. Our new system could be used in the fields of mechanobiology and biophysics to explore functions of proteins under tension by coupling biomechanical and biochemical information.
New insights into the plasmonic enhancement for photocatalytic H2 production by Cu–TiO2 upon visible light illumination
Authors: Nie J. , Patrocinio A. O. T. , Hamid S. , Sieland F. , Sann J. , Xia S. , Bahnemann D. W. , Schneider J.
Published: January 2018

Cu nanoparticles were deposited on the surface of commercial TiO2 nanoparticles (Cu–TiO2) using different methods aiming at the production of highly efficient visible light photocatalysts.
Monitoring the formation of PtNi nanoalloys supported on hollow graphitic spheres usingin situpair distribution function analysis
Authors: Ortatatlı Ş. , Knossalla J. , Schüth F. , Weidenthaler C.
Published: January 2018

Disorder/order transition in PtNi nanoalloys on hollow graphitic carbons for fuel cell applications depends strongly on heating and cooling protocols as conclusively shown usingin situXRD and PDF analyses.
Grain boundary dominated charge transport in Mg3Sb2-based compounds
Authors: Kuo Jimmy Jiahong , Kang Stephen Dongmin , Imasato Kazuki , Tamaki Hiromasa , Ohno Saneyuki , Kanno Tsutomu , Snyder G. Jeffrey
Published: January 2018

The influence of grain boundaries is modelled to show that there is much room for improvement in some thermoelectric materials.
Influence of pressure main pumping frequency on sulfide formation rates in sanitary sewers
Authors: Shypanski A. H. , Yuan Z. , Sharma K.
Published: January 2018

Controlling pumping frequency at sanitary pressure mains is an effective tool for reducing overall sulfide generation.
Biodegradability assessment of complex chemical mixtures using a carbon balance approach
Authors: Brillet F. , Cregut M. , Durand M. J. , Sweetlove C. , Chenèble J. C. , L'Haridon J. , Thouand G.
Published: January 2018

The assessment of complex mixture biodegradability can be limited by technical issues and/or difficulties to rule on ready or inherent biodegradability.
Closed cycle production of concentrated and dry redispersible colloidal lignin particles with a three solvent polarity exchange method
Authors: Lintinen Kalle , Xiao Yao , Bangalore Ashok Rahul , Leskinen Timo , Sakarinen Ekaterina , Sipponen Mika , Muhammad Farooq , Oinas Pekka , Österberg Monika , Kostiainen Mauri
Published: January 2018

An energy efficient closed cycle process converts lignin from pulping side stream into water-dispersible colloidal spheres and microclusters.
Microfluidic thread based electroanalytical system for green chromatographic separations
Authors: Agustini Deonir , Fedalto Lucas , Bergamini Márcio F. , Marcolino-Junior Luiz Humberto
Published: January 2018

The use of miniaturized chromatographic systems is an important strategy for reducing the consumption of supplies related to separations, allowing the development of more sustainable analytical methodologies.
Ultrahigh performance of novel energy-efficient capacitive deionization electrodes based on 3D nanotubular composites
Authors: Ramadan Mohamed , Hassan Hassan M. A. , Shahat Ahmed , Elshaarawy Reda F. M. , Allam Nageh K.
Published: January 2018

TiO2/CNT composites are energy-efficient capacitive deionization platforms with exceptional electrosorption capacity.
A “turn-on-and-off” pH sensitive BODIPY fluorescent probe for imaging E. coli cells
Authors: Prasannan Dijo , Arunkumar Chellaiah
Published: January 2018

Highly selective fluorescent BODIPY probes towards H+ ions displayed good photostability and reversibility and the utility of acid sensitive behavior to visualize extreme acidity in E. coli cells is also demonstrated.
Novel Fe3O4nanoparticles-based DGT device for dissolved reactive phosphate measurement
Authors: Zhang Ya , Song Jieyao , Zhou Hongjian , Zhang Yunxia , Wang Guozhong
Published: January 2018

The use of Fe3O4nanoparticles as a liquid binding phase in DGT is demonstrated for the sampling measurement of dissolved reactive phosphate in natural water.
Sensitive detection of Japanese encephalitis virus by surface molecularly imprinted technique based on fluorescent method
Authors: Feng Wenbao , Liang Caishuang , Gong Hang , Cai Changqun
Published: January 2018

A fluorescence method was used to detect Japanese encephalitis virus using surface molecularly imprinted technique. This method could selectively detect Japanese encephalitis virus with a picomolar detection limit.
Selective self-assembly and light emission tuning of layered hybrid perovskites on patterned graphene
Authors: Guerra Valentino L. P. , Kovaříček Petr , Valeš Václav , Drogowska Karolina , Verhagen Tim , Vejpravova Jana , Horák Lukáš , Listorti Andrea , Colella Silvia , Kalbáč Martin
Published: January 2018

Graphene is used as substrate for inducing selective self-assembly of hybrid perovskite with high spatial resolution.
Rapid construction of substituted 3-amino-1,5-benzothiazepin-4(5H)-one dipeptide scaffolds through an Ugi-4CR – Ullmann cross-coupling sequence
Authors: Van der Poorten O. , Van Den Hauwe R. , Hollanders K. , Maes B. U. W. , Tourwé D. , Jida M. , Ballet S.
Published: January 2018

A 3-step methodology afforded the title compounds in moderate to good yields, with in silico and NMR conformational studies showing that the lowest energy conformers stabilize γ- and β-turn structures.
A one-pot strategy to improve end-capping efficacy in Stille poly-condensations
Authors: Harris Jared D. , Carter Kenneth R.
Published: January 2018

A reproducible synthetic method affording end-functionalized conjugated polymers via Stille polycondensations based upon end-capping reagent relative kinetics is presented.
Multicomponent polysaccharide–protein bioconjugation in the development of antibacterial glycoconjugate vaccine candidates
Authors: Méndez Yanira , Chang Janoi , Humpierre Ana R. , Zanuy Abel , Garrido Raine , Vasco Aldrin V. , Pedroso Jessy , Santana Darielys , Rodríguez Laura M. , García-Rivera Dagmar , Valdés Yury , Vérez-Bencomo Vicente , Rivera Daniel G.
Published: January 2018

A multicomponent reaction enables the one-pot assembly of immunogenic multivalent glycoconjugates.
Sustainable one-step strategy towards low temperature curable superparamagnetic composite based on smartly designed iron nanoparticles and cardanol benzoxazine
Authors: Monisha Monisha , Yadav Nisha , Srivastava Shashi B. , Singh Samarendra P. , Lochab Bimlesh
Published: January 2018

A sustainable method for PBz:iron NPs composite based on cardanol, an agro-waste, exhibiting a versatile crosslinked network with superparamagnetic properties.
Monolayer InP3 as a reversible anode material for ultrafast charging lithium- and sodium-ion batteries: a theoretical study
Authors: Liu Jin , Liu Chun-Sheng , Ye Xiao-Juan , Yan Xiao-Hong
Published: January 2018

Monolayer InP3 as a reversible anode material for ultrafast charging lithium- and sodium-ion batteries.
Plasmonic CuS nanodisk assembly based composite nanocapsules for NIR-laser-driven synergistic chemo-photothermal cancer therapy
Authors: He Jian , Ai Lisha , Liu Xin , Huang Hao , Li Yuebin , Zhang Mingguang , Zhao Qianru , Wang Xingguo , Chen Wei , Gu Haoshuang
Published: January 2018

The NIR-laser-driven plasmonic photothermal and sustained drug release behavior of CuS–PTX/SiO2 nanocapsules show great synergistic chemo-photothermal therapeutic effects on cancer cells in vitro and in vivo.
Thiol–ene click chemistry: a modular approach to solid-state triplet–triplet annihilation upconversion
Authors: Williams Abagail K. , Davis Brad J. , Crater Erin R. , Lott Joseph R. , Simon Yoan C. , Azoulay Jason D.
Published: January 2018

Thiol–ene click chemistry can be used as a facile cure-on-demand synthetic route to access robust host materials for solid-state upconversion.
The Contributions of Phonological Awareness, Alphabet Knowledge, and Letter Writing to Name Writing in Children With Specific Language Impairment and Typically Developing Children
Authors: Pavelko Stacey L. , Lieberman R. Jane , Schwartz Jamie , Hahs-Vaughn Debbie
Published: January 2018

Purpose

Name writing is one aspect of emergent writing that has been used to understand emergent literacy development. Name-writing skills and the relationship of name writing to other emergent literacy skills have not been studied extensively in children with specific language impairment (SLI). Children with SLI consistently demonstrate delays in phonological awareness (PA), alphabet knowledge (AK), print awareness, and emergent writing. The purpose of this study was to examine the contributions of PA, AK, and letter writing to name writing in children with SLI and typically developing (TD) children.

Method

Participants were 65 children (22 SLI, 43 TD) with an average age of 53 months. Participants completed the Assessment of Literacy and Language (Lombardino, Lieberman, & Brown, 2005), a letter-writing task, and a name-writing task.

Results

Data were analyzed using correlation and mediation modeling. Mediation modeling, a more sophisticated analysis, revealed that PA, AK, and letter writing, in serial, were mediating variables for language status on name writing.

Conclusion

Phonemic awareness, AK, and letter writing help to explain the relationship between language status and name writing. These skills should be integrated during treatment, using a horizontal approach with developmentally appropriate activities, particularly for children with SLI.
Control strategy of traction rectifier based on virtual synchronous machine
Authors: Chen XuDong , Ge XingLai , Diao Fei
Published: January 2018

Based on the idea of virtual synchronous machine, a control strategy of traction rectifier is proposed. The proposed strategy provides the voltage and frequency support for the traction grid, damps oscillation, which helps to improve the stability of the power system. In this way, the electrical energy can be fed back to the traction grid more friendly in the regenerative braking condition. The experiment proves that the control strategy has good control effect both on traction and regeneration braking conditions.
Microwave frequency doubling by synchronising and polarisation multiplexing the optical signals from a dual‐output Mach–Zehnder modulator
Authors: Maafa M.R. , Pham S.K. , Ravichandran M. , Maywar D.N.
Published: January 2018

A technique is experimentally demonstrated to double the frequency of a microwave signal by synchronising and polarisation multiplexing the optical signals from a dual‐output Mach–Zehnder modulator. The frequency‐doubled tone at 4 GHz is 41.2 dB stronger than the residual fundamental‐frequency tone. The strongest side tone is found at 12 GHz (sixth order) and is suppressed by 32.7 dB. The phase noise of the frequency‐doubled signal is −104.1 dBc/Hz at an offset of 10 kHz, an increase of 6.7 dB over that of the initial signal. This technique does not rely on electronic or optical filters or amplifiers and is demonstrated using commercial off‐the‐shelf components.
Variational total curvature model for multiplicative noise removal
Authors: Xu Xinli , Yu Teng , Xu Xinmei , Hou Guojia , Liu Ryan Wen , Pan Huizhu
Published: January 2018

The multiplicative noise removal problem has received considerable attention recently. To solve this problem, various variational models have been proposed, which minimise an energy functional composed of the data term and the regularisation term. Regarding the regularisation term, a first‐order model is frequently used to remove multiplicative noise, which may cause staircase effect and loss of contrast in the output image. In this study, the authors use a second‐order model, the total curvature (TC), to solve the above problem. The TC model has the benefit of removing the staircase effect and maintaining image edges, contrasts and corners. The augmented Lagrange method is utilised to solve the proposed TC model by introducing auxiliary variables, Lagrange multipliers and using alternating optimisation strategy. In each loop of optimisation, the fast Fourier transform, generalised soft threshold formulas, projection method and gradient descent method are integrated effectively. The experimental results show that the TC model can effectively remove staircase effect and preserve smoothness, via comparison with the first‐order model (total variation regularisation and Perona–Malik regularisation). Furthermore, the TC model is better than another second‐order model based on bounded Hessian regularisation in preserving contrast and corner.
FS electromagnetic characterisation of a flexible and scalable X‐band RAM
Authors: Aguirre Anibal , Torres de Pedro Cristian , Plaza Gallardo Borja , Poyatos Martínez David , Escot Bocanegra David
Published: January 2018

Along the years, RADAR absorbing materials (RAM's) have been widely introduced in aeronautic applications and platforms. However, this kind of materials presents three main problems for certain applications when they are intended to be used in real operations. First, they must be scalable from a laboratory sample to actual size, at a reasonable cost. Second, they must be able to work without metal backing for applications in non‐metallic vehicles or other objects which surface might not be flat. Indeed, they should also be flexible and surface adaptable. Finally, their absorbing properties against electromagnetic fields should be preferably characterised under real conditions, that is, in free space (FS), in order to design and fabricate an appropriate material for the intended application. In this study, a self‐developed, low‐cost, bilayer, X‐band RAM, composed of a lower layer of polyaniline silicon rubber and a top layer of silicon rubber with graphite was characterised in a bistatic anechoic chamber called BIANCHA, and the results are presented, analysed and compared with software simulation and with the typical single polarisation waveguide measurement method, showing the adequacy of FS measurements for the development of this type of RAM.
Characterising THz propagation and intrabody thermal absorption in iWNSNs
Authors: Elayan Hadeel , Shubair Raed M. , Jornet Josep M.
Published: January 2018

Nanosized devices operating inside the human body will eventually facilitate transformative health monitoring and diagnosis systems. The interconnection of these implantable nanosensors forms an in vivo wireless nanosensor network (iWNSN), which allows autonomous data transmission and enables sensing, coordination, and control among its entities. In specific, with the development of miniature plasmonic signal sources, antennas and detectors, wireless communications among nanodevices points towards the terahertz band (0.1–10 THz) as a suitable platform and feasible wireless range to initiate intrabody communication. In this study, a rigorous channel model for intrabody communication in iWNSNs is developed. The total path loss is computed by taking into account the contribution of the spreading of the propagating wave, molecular absorption from human tissues, as well as scattering from both small and large body particles. The presented model is further complemented by investigating the photo‐thermal interactions which arise from absorption at the THz frequency band. The aforementioned study which analyzes the propagation of electromagnetic signals inside the human body is fundamental to assess the feasibility of the THz frequency band, determine the requirements and controlling parameters of a THz intrabody system as well as highlight the health issues correlated with operating at such frequencies.
Short‐term power‐forecasting method of distributed PV power system for consideration of its effects on load forecasting
Authors: Liu Yu , Li Zhi , Bai Kai , Zhang Zhaoguang , Lu Xining , Zhang Xiaomeng
Published: January 2018

This study analyses the distributed photovoltaic (PV) power system effects on common short‐term load forecasting, based on the proposed power penetration index, and load data reconfiguration method, by using common short‐term load‐forecasting algorithm under conditions of the distributed PV power system and the power penetration index as 0, 5, 10, 15, 20, 24.46, 30, 35, 40, 50, 60 and 75%, the short‐term load‐forecasting accuracy obviously decreases. In this research study, the short‐term power‐forecasting method is proposed in order to offset the power output of distributed PV power systems, and transfer to the original load without the effects of distributed PV power systems or treated as the input information for updated load‐forecasting model, this study proposes the short‐term power‐forecasting algorithm based on the BP neutral network for the typical distributed PV power system through training and validation of the proposed model. The power‐forecasting accuracy is analysed and verified for a typical distributed PV power system, and the proposed method is effective in improving the accuracy for load forecasting.
Frequency characteristics of East China Power Grid after bipolar locking of ultra‐high voltage direct current (UHVDC)
Authors: WU Xuelian , LAN Qiang , LI Zhaowei , ZHUANG Kanqin , MIAO Yuancheng , LI Wei
Published: January 2018

With the increasing capacity of multi‐infeed DC for East China Power Grid, the risk of losing large‐capacity power supply is increasing, and the frequency security and stability situation in low load mode is worsening. Since the ‘9·19’ incident, the frequency characteristics of East China Power Grid have aroused wide concern. Actually, there is a big gap between simulation results and the actual measured values. This study analysed the key factors that affect the frequency response from the point of view of the turbine‐governor and drum boiler. On the basis of measured values, the parameters of primary frequency modulation and main steam pressure are identified. The results reflect the dynamic frequency response of ‘9·19’ incident successfully. According to the recognition results, recommendations are put forward to give the backbone to the security and stability of East China Power Grid.
Method to evaluate comprehensive economic benefit of hybrid wind power–pumped hydro storage considering the carbon emission trade
Authors: Ya Liu , Conggan Ma , Yi Wang
Published: January 2018

The development of wind power (WP) is the important aspect of promoting energy transition of our country; however, because of the intermittent fluctuation of WP, the phenomenon of abandoning WP is very severe. The construction of pumped storage power station is one of the most important measures to solve the problem of WP taken by the State Grid. The overall efficiency evaluation of the combination of WP and pumped storage power station is necessary to solve the problem. By the end of 2016, the NEA issued the ‘13th five‐year work plan for controlling greenhouse gas emissions requirements,’ which starts carbon emission trading in 2016 to reduce carbon emissions. The reduction of carbon emission is not only conducive to environmental protection but also beneficial to increasing economic benefits. This study analyses eight aspects of economic efficiency and low carbon benefits of the impact on the combined system, including the WP and pumped hydro storage system (PHS) construction, operation and maintenance, system back‐up cost, WP acceptance cost, generation benefit, spare admission generation benefit, peak‐load following benefit and network loss improvement benefit, and then optimise the operation mode of WP–PHS with the maximum comprehensive economic benefit as the goal. Taken low carbon trading regulations as the basis, the study comes up with the establishment of a comprehensive economic benefit model in the carbon emission trading mechanism with comprehensive economic benefits of the combined system. The overall test system is quantified through calculation, which proves the validity of the evaluation method.
Improved maximum power point tracking algorithm with cuk converter for PV systems
Authors: Sun Zongchang , Yang Zhoujun
Published: January 2018

The maximum power point tracking (MPPT) techniques are essential for the optimisation of the efficiency in the photovoltaic (PV) systems. Here, a practical PV model is discussed and employed, and cuk converter is selected as MPPT's DC–DC converter for PV systems. Then, on the basis of the power–current (P –I) characteristics curve of a PV cell, an improved MPPT algorithm with direct control by using the fuzzy controller is proposed. Compared with some algorithms mentioned here, the proposed algorithm is able to track a more accurate MPP quickly and have a smaller steady‐state oscillation. To validate its correctness and good performance under the varying environmental conditions, simulation study on it is carried out in MATLAB/Simulink. Also, simulation results demonstrate the proposed algorithm here is feasible and in contrast, it has a faster dynamic and more robust steady‐state performance.
Joint maintenance scheduling of the municipal solid waste incineration power plant and connected power system devices
Authors: Liu Yangyang , Shen Zhongqi , Tang Xiaowei , Lian Hongbo , Li Jiarui
Published: January 2018

Municipal solid waste (MSW) incineration power plant is an environmentally friendly way to deal with the increasing MSW. The generation of the MSW incineration plant is affected by the solid waste quantities, heating value, and maintenance scheduling. Both of the maintenance scheduling for generators and connected power system devices define the MSW power plant's operating states. Thus, their maintenance scheduling should be jointly elaborated, considering local MSW conditions. This study built a model of the MSW power plant in the view of power systems, taking full consider of its generation procedures. Then, this study proposed a joint maintenance scheduling model for the MSW power plant and connected power system devices, maximising the MSW power plant's monthly generations. This maintenance scheduling model was illustrated and compared in the case study. The MSW power plant can obtain the optimal maintenance scheduling by the proposed model, considering the interaction with power systems.
Study on online under‐frequency load shedding strategy with virtual inertia control of wind turbines
Authors: Huang BingXiang , Du ZhaoBin , Liu YuanJun , Zhao Fang
Published: January 2018

Under‐frequency load shedding (UFLS) is one of the most effective methods to prevent frequency collapse. At present, more hybrid AC/DC lines and increasing wind turbines have been connected to the power system. The fluctuation and randomness of the renewable energy bring many challenges to the frequency stability of power systems. In this study, a new online UFLS strategy considering the virtual inertia control of wind turbines is proposed. The virtual inertia control of the wind turbine can be used to release the kinetic energy stored in the wind turbine to support the power system when power deficiency occurs. An online control strategy based on fuzzy control is applied in the UFLS strategy in order to reduce the load shedding value. Tests in the four‐machine two‐area containing the wind farm model were carried out; the simulation results show that it is feasible to achieve the goal of less load shedding and faster frequency recovery based on this strategy.
Planning of electric vehicle charging station based on queuing theory
Authors: Zhu Jie , Li Yixin , Yang Jun , Li Xianglong , Zeng Shuang , Chen Yanxie
Published: January 2018

EV charging station is a very important link in urban planning, and the design of the position and capacity of charging stations are not only to meet the public demand for traveling, but also to maintain the stability of operation and management in power grid. Considering the non‐simultaneity and randomness of the EVs arriving at the charging station, the capacity of EV charging stations is calculated by using queuing theory in this study. This study proposes a model which has considered the EVs' charging requirement, economy, and power grid safety to solve the problem of planning EV charging station. Firstly, determine the location of charging station by traffic satisfaction. Secondly, the EV charging stations' charging capacity is optimized with the minimum cost as the optimization target, with the EV user' waiting time patience limit and the distribution network running safety as the constraint condition. Finally, the service area of charging station is divided by the Voronoi diagram. In this study, a 25_nodes traffic network with 24_nodes distribution network underground is modelled in the MATLAB environment to demonstrate the effectiveness of the proposed method. In addition the authors solve the model by the genetic algorithm in MATLAB.
Research on VSC–HVDC control strategy based on large offshore wind power system
Authors: Qiu Sun , Chunju Fan , Cheng Lv , Linyue Qiao
Published: January 2018

A control strategy has been proposed based on five terminals voltage source converter (VSC)–HVDC typical topological structure of large grid‐connected offshore wind power system, which means that VSCs on the wind farm side are controlled with AC voltage control method and VSCs on the grid side are controlled with DC voltage droop control method. A simulation model has been built on power systems computer aided design (PSCAD)/electromagnetic transients including DC (EMTDC) platform, and with it, several simulations have been conducted such as start‐stop of wind farm, power fluctuation and suspension of converter station. In the end, the control strategy is proved out to have coordination control capability and flexibility.
Robust optimisation for AC–DC power flow based on second‐order cone programming
Authors: Zhou Ye , Tian Yuan , Wang Keyou , Ghandhari Mehrdad
Published: January 2018

This study presents an adjustable robust optimisation method for AC–DC optimal power flow (OPF) considering the uncertainty of renewable energy source (RESs). The optimal power flow of AC–DC system is modelled as a second‐order cone (SOC) problem, and the affinely adjustable robust OPF (AAROPF) formulation is proposed. To apply AAROPF, the base‐point generation is calculated and determined to match the power with forecasted RES output before the realisation of the uncertainty. Also once the uncertainty is revealed, generators reschedule its output through participation factors responding to the uncertain fluctuation of RES output to ensure a feasible solution for all realisations of RES output within a prescribed uncertainty set. Numerical results are obtained on a modified AC–DC IEEE 30‐bus to minimise the expected operational cost. Results reveal a higher cost using AAROPF than the deterministic case, but it obtains a more robust solution with higher successful rates.
Stability of grid connected system of two types of wind turbines with UPFC
Authors: Liu Haitao , Li Xu , Qin Gaofeng , Hao Sipeng
Published: January 2018

With the rapid development of wind power generation, large‐scale grid connected wind power system brings challenges to the stable operation of power system. Unified power flow controller (UPFC) with capability of voltage support and power control is going to have general application. It will have different impacts on different types of wind turbines (WTs) grid‐connected system. In this study, the authors will compare and analyse the structure, principle, and mathematical model of doubly fed induction generator (DFIG) and direct drive permanent magnet synchronous generator (DDPMSG) and built simulation models of them. Through the change of the operation mode and the setting of the disturbance, the authors will analyse the operation status of the system of two different types of WTs with UPFC in detail. The results show that UPFC improves the stability of the system in the grid‐connected system of DDPMSG, which is superior to that of DFIG.
Wind power fluctuation characteristics of Three North regions based on clustering algorithm
Authors: Yang Shuo , Li Chi , Li Xiaofei , Huang Yuehui , Liu Chun , Wang Weisheng
Published: January 2018

Limited by some restricted conditions, such as the grid structure and the power source type, the security of the grid and the consumption of the clean energy have faced the challenge from the random and intermittent characteristics of wind power. Firstly, an analyzing method to divide and express different types of wind power fluctuation process is proposed by utilizing the self‐organizing map clustering algorithm in this paper. The research framework of wind power fluctuations characteristics considering multiple space and time scales is also proposed. Furthermore, on the basis of the actual operation data of the north, northeast and northwest parts of China (Three North regions for short), and different time characteristics of the wind power fluctuations have been researched from three different spatial scales such as the wind power plant, the provincial grid and the regional grid. From the actual data analysis results, it can be seen that the wind power fluctuations categories can be efficiently identified by the self‐organizing map clustering algorithm. The results also show that, the time and spatial scale analysis of wind power fluctuations characteristics can support the quantitative evidences for the scheduling decision of the wind power enrichment regions.
Solution of voltage stability assessment for complicated power system incorporating wind power
Authors: Chen Hao , Shi Libao , Ni Yixin
Published: January 2018

With the power system becoming increasingly complex, it introduces more challenge for the assessment of voltage stability. An analytical solution of static voltage stability assessment for complex power system incorporating wind farm equipped with permanent magnet synchronous generator is presented. It is based on the PQ ‐plane analysis method with meticulously selected voltage stability indices and system equivalent method which introduces the concept of ‘coupled single‐port circuit’. Case studies are performed on the IEEE 30‐bus test system, and the corresponding simulation results verify the validity of the proposed evaluation method with the low computational burden.
Maximum energy yield oriented turbine control in PMSG‐based wind farm
Authors: Tian Jie , Zhou Dao , Su Chi , Blaabjerg Frede , Chen Zhe
Published: January 2018

In the modern power systems, with the fast integration of the wind power into the grid, it turns to develop large‐scale offshore wind farms equipped with the permanent magnet synchronous generator (PMSG) wind turbine. In large‐scale offshore wind farms, the wind turbine operating reliability and the wake effect in the wind farm became important issues. The pitch angle and tip speed ratio are the two degrees of freedom for the PMSG wind turbine active power control, which are also the determining factors of the wind turbine lifetime. As the energy production of the wind turbine is the product of its active power and lifetime, the energy production can be maximised by optimising its pitch angle and tip speed ratio. In this study, the energy production of a 2 MW PMSG wind turbine is maximised by optimising its pitch angle and tip speed ratio. Moreover, taking into account the wake effect, the energy production of a wind farm equipped with two 2 MW PMSG wind turbines is maximised by optimising the pitch angle and tip speed ratio of each wind turbine.
Model predictive control considering scenario optimisation for microgrid dispatching with wind power and electric vehicle
Authors: Guo Xiaogang , Bao Zhejing , Lai Hongji , Yan Wenjun
Published: January 2018

For optimal microgrid (MG) operation, one significant challenge is the inherent randomness of renewable energy sources (RESs) within MG should be accommodated by it itself. Here, a robust model predictive control (MPC) by considering scenario optimisation is proposed for MG dispatching to achieve the accommodation of uncertain RES and electricity demand by utilising discharging/charging of electric vehicle (EV) with a certain constraints violation probability of EV allowed. The method is based on the iterated solution, at each step, of a finite‐horizon optimal control that takes into account a suitable number of randomly extracted scenarios of uncertain RES and electricity demand while the economic objective and operational constraints are included. The optimisation of a number of uncertain scenarios embedded in a receding horizon of MPC can provide a probabilistic guarantee of EV constraints satisfaction. Simulation on an MG case is implemented and the results demonstrate that with the proposed control strategy, the coordination between uncertain RES and EV can be achieved to make the MG be controllable as seen from the main grid.
Improved droop control strategy for stability enhancement of VSC–MTDC systems with DC reactors
Authors: Zhang Ming , Xu Yin , Wang Zhenji , Wu Xiaoyu , He Jinghan
Published: January 2018

DC reactors installed in voltage source converter based multi‐terminal direct current (VSC–MTDC) systems will benefit the protection while degrading system stability. This study firstly analyses the protection method for VSC–MTDC systems with DC reactors. Then the small‐signal model of VSC–MTDC systems is built for stability analysis. An improved droop control strategy using the linear combination of the voltages at the two terminals of DC reactors as inputs is proposed to enhance the stability of VSC–MTDC systems. Small‐signal analysis and transient simulations are performed on a four‐terminal VSC–MTDC network to validate the effectiveness of the proposed protection and control strategy.
Key techniques for phased and multi‐mode hybrid simulation of multi‐energy flow systems
Authors: Yu Siqi , Zhang Shuqing , Sun Yubo , Zhu Yaping
Published: January 2018

A micro energy internet is a multi‐energy flow (MEF) system, containing different types of energy systems. However, the existing modelling and simulation methods for various energy systems only aim at an individual system. Thus, they can neither simulate the coupling and interaction of different energy forms nor be used for analysing operation and control characteristics of MEF systems. This study summarises the essential features of MEF systems and analyses the key points and difficulties to implement modelling and simulation. Furthermore, a phased multi‐mode hybrid simulation method is proposed, with its basic idea and key techniques illustrated. Two demonstrated test cases support the feasibility of the proposed method. The method can be used for developing an integrated device‐system level simulation platform for MEF systems.
Nano3YSZ electrophoretic deposition from acetylacetone + ethanol solvent on the surface of AZ91 magnesium alloy
Authors: Behrangi Sahand , Aghajani Hossein
Published: January 2018

In the present work, the conditions for electrophoretic deposition of yttria‐stabilised zirconia (YSZ) nanopowder have been investigated. For this purpose, the mixture of acetyl acetone and ethanol with different mixing ratios was used as solvent with iodine as a dispersant. To achieve a smooth, homogeneous and crack‐free coatings, the following parameters were chosen to be optimised: the mixing ratio of acetyl acetone and ethanol, voltage and duration of deposition. The obtained coatings were observed by scanning electron microscope and optical microscope. The weight of deposits was also measured in different deposition conditions to observe the effects of above‐mentioned parameters on the weight and consequently the quality of green coatings. All in all, the suspensions which composed of 50 vol% acetylacetone + 50 vol% ethanol led to more uniformity and fewer cracks/pores in deposits. The other parameters were optimised as follows: deposition voltage of 40 V and deposition time of 3 min. The results of polarisation test showed an improved corrosion resistance of the magnesium alloy with the application of YSZ coating, so that the Icorr value decreased from 1.16 to 0.088 mA.
Roles of Transit-Time Flow Measurement for Coronary Artery Bypass Surgery
Authors: Takagi Yasushi , Takami Yoshiyuki
Published: January 2018

Transit-time flow measurement (TTFM) has been increasingly applied to detect graft failure during coronary artery bypass grafting (CABG), because TTFM is less invasive, more reproducible, and less time consuming. Many authors have attempted to validate TTFM and to gain the clear cutoff values and algorithm in TTFM to predict graft failure. The TTFM technology has also been shown to be a useful tool to investigate CABG graft flow characteristics and coronary circulation physiology. It is important to recognize the practical roles of TTFM in the cardiac operating room by review and summarize the literatures.
Risk of Primary Spontaneous Pneumothorax According to Chest Configuration
Authors: Lee Geun , Do Young , Park Hee , Kim Junu , Hur Jin , Han Kyunghwa , Kim Tae , Song Jason , Park Chul , Sung MinDong , Lee Sungsoo
Published: January 2018

Background We compared the chest configurations of patients with primary spontaneous pneumothorax (PSP) and age-sex-matched controls to determine the presence of chest wall deformities in patients with PSP.

Methods We retrospectively enrolled 166 male patients with PSP (age, 18–19 years) and 85 age-sex-matched controls without PSP, who simultaneously underwent chest computed tomography (CT) and radiography at one of two institutes. After correcting for height, the following thoracic parameters were comparatively evaluated between the two groups: maximal internal transverse (T) and anteroposterior (W) diameters of the chest, maximal internal lung height (H), Haller index (T/W), and T/Height, T/H, W/Height, W/H, and H/Height ratios.

Results Patients were taller than the control subjects (176.5 cm ± 5.9 cm versus 174.4 cm ± 5.6 cm; p = 0.007). After controlling for height, the patient group exhibited lower T and W and greater H and Haller index values than the control group (T: 95% confidence interval [CI], 24.8–25.2 cm versus 25.9–26.5; W: 95% CI, 8.9–9.2 cm versus 10.1–10.6 cm; H: 95% CI, 25.2–25.9 cm versus 23.4–24.4 cm; and Haller index, 95% CI, 2.7–2.9 versus 2.4–2.6; all, p < 0.001). The patient group also exhibited lower T/Height, T/H, W/Height, and W/H ratios and greater H/Height ratio than the control group.

Conclusions Patients with PSP have an anteroposteriorly flatter, laterally narrower, and craniocaudally taller thorax than subjects without PSP, suggesting that chest configuration is associated with the development of pneumothorax.
Reasons for Failure of Systemic-to-Pulmonary Artery Shunts in Neonates
Authors: Leopold Cornelius , von Ohain Jelena , Wolf Cordula , Beran Elisabeth , Lange Rüdiger , Cleuziou Julie , Vitanova Keti
Published: January 2018

Background Systemic-to-pulmonary artery shunt placement is an established palliative procedure for congenital heart disease. Although it is thought to be a simple operation, it is associated with significant morbidity and mortality.

Methods Data for all neonates who underwent surgery for a systemic-to-pulmonary artery shunt between 2000 and 2016 were reviewed. The study endpoints were shunt failure and shunt-related mortality. Shunt failure was defined as a shunt dysfunction because of thrombosis or stenosis requiring intervention or reoperation; shunt mortality was defined as death because of a shunt dysfunction.

Results A total of 305 shunts (central shunt, n = 135; Blalock–Taussig shunt, n = 170) were implanted in 280 patients. The median patients' age at the time of surgery was 9 days (1–31 days). The median shunt size was 3.5 mm (3–4 mm). Twenty-four patients (8%) were diagnosed with a shunt failure, with a median time of 7 days (0–438 days). Freedom from shunt failure at 1 year was 91.6% ± 2%. A shunt-related mortality was ascertained for 12 patients (4%). Freedom from shunt-related mortality at 1 year was 96% ± 1%. Perioperative platelet transfusion (p = 0.01), central shunt (p = 0.02), 3-mm shunt size (p = 0.02), and postoperative extra corporeal membrane oxygenation (ECMO) (p < 0.01) were identified as risk factors for shunt failure. Platelet transfusion (p = 0.04) and postoperative ECMO (p < 0.01) were further identified as risk factors for shunt mortality.

Conclusion Based on these data, we recommend implanting a modified Blalock–Taussig shunt of at least 3.5 mm in neonates. Perioperative platelet transfusion and postoperative ECMO increase the risk of shunt failure.
Pediatric Craniopharyngiomas: A Primer for the Skull Base Surgeon
Authors: Graffeo Christopher , Perry Avital , Link Michael , Daniels David
Published: January 2018

Pediatric craniopharyngioma is a rare sellar-region epithelial tumor that, in spite of its typically benign pathology, has the potential to be clinically devastating, and presents a host of formidable management challenges for the skull base surgeon. Strategies in craniopharyngioma care have been the cause of considerable controversy, with respect to both philosophical and technical issues. Key questions remain unresolved, and include optimizing extent-of-resection goals; the ideal radiation modality and its role as an alternative, adjuvant, or salvage treatment; appropriate indications for expanded endoscopic endonasal surgery as an alternative to transcranial microsurgery; risks and benefits of skull base techniques in a pediatric population; benefits of and indications for intracavitary therapies; and the preferred management of common treatment complications. Correspondingly, we sought to review the preceding basic science and clinical outcomes literature on pediatric craniopharyngioma, so as to synthesize overarching recommendations, highlight major points of evidence and their conflicts, and assemble a general algorithm for skull base surgeons to use in tailoring treatment plans to the individual patient, tumor, and clinical course. In general terms, we concluded that safe, maximal, hypothalamic-sparing resection provides very good tumor control while minimizing severe deficits. Endoscopic endonasal, intraventricular, and transcranial skull base technique all have clear roles in the armamentarium, alongside standard craniotomies; these roles frequently overlap, and may be further optimized by using the approaches in adaptive combinations. Where aggressive subtotal resection is achieved, patients should be closely followed, with radiation initiated at the time of progression or recurrence—ideally via proton beam therapy, although three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and stereotactic radiosurgery are very appropriate in a range of circumstances, governed by access, patient age, disease architecture, and character of the recurrence. Perhaps most importantly, outcomes appear to be optimized by consolidated, multidisciplinary care. As such, we recommend treatment in highly experienced centers wherever possible, and emphasize the importance of longitudinal follow-up—particularly given the high incidence of recurrences and complications in a benign disease that effects a young patient population at risk of severe morbidity from hypothalamic or pituitary injury in childhood.