bluuebunny/crossref_metadata_2025 huggingface dataset:
Top-down fabrication of hierarchical nanocubes on nanosheets composite for high-rate lithium storage
Authors: Zhang Jian-Ping , Wu Xue-Yan , Wei Xiao , Xu Shu-Mao , Ma Chao , Shu Mou-Hai , Wang Kai-Xue , Chen Jie-Sheng
Published: October 2018

A top-down method was developed to synthesize a “nanocubes on nanosheets” hierarchical structure composite for high-rate lithium storage.
The protective effects of selenium-enriched spirulina on the reproductive system of male zebrafish (Danio rerio) exposed to beta-cypermethrin
Authors: Zhang Yi , Zhou Yuhang , Tang Qingyang , Hu Feng , Feng Lixue , Shen Jinglian , Huang Bei
Published: October 2018

Beta-cypermethrin (beta-CYP), which is widely used for the control of indoor and field pests, is a highly lipophilic insecticide with environmental estrogenic effects.
Thioredoxin silencing-induced cardiac supercontraction occurs through endoplasmic reticulum stress and calcium overload in chicken
Authors: Yang Jie , Gong Yafan , Liu Qi , Cai Jingzeng , Zhang Bo , Zhang Ziwei
Published: October 2018

The thioredoxin (Txn) system is the most crucial antioxidant defense mechanism in the myocardium, and hampering the Txn system may compromise cell survival.
Copper reduction and dioxygen activation in Cu–amyloid beta peptide complexes: insight from molecular modelling
Authors: Arrigoni Federica , Prosdocimi Tommaso , Mollica Luca , De Gioia Luca , Zampella Giuseppe , Bertini Luca
Published: October 2018

Alzheimer's disease (AD) involves a number of factors including an anomalous interaction of copper with the amyloid peptide (Aβ), inducing oxidative stress with radical oxygen species (ROS) production through a three-step cycle in which O2 is gradually reduced to superoxide, oxygen peroxide and finally OH radicals.
Unusual chirality transfer from silica to metallic nanoparticles with formation of distorted atomic array in crystal lattice structure
Authors: Tsunega Seiji , Tanabe Toyokazu , Jin Ren-Hua
Published: October 2018

Metal cations entrapped in chiral silica were transformed to chiral metallic nanoparticles with a distorted atomic array in their lattice structures.
A convenient method for isolating carbon quantum dots in high yield as an alternative to the dialysis process and the fabrication of a full-band UV blocking polymer film
Authors: Uthirakumar Periyayya , Devendiran M. , Kim Tae Hwan , Lee In-Hwan
Published: October 2018

A convenient method to isolate >80% CQD and the fabrication of a non-toxic CQD polymer film which could protect UV-sensitive foods.
2D molybdenum nitride nanosheets as anode materials for improved lithium storage
Authors: Wang Liangbiao , Zhang Kailong , Pan Honglin , Wang Li , Wang Di , Dai Weicheng , Qin Hengfei , Li Gaoran , Zhang Junhao
Published: October 2018

Two-dimensional (2D) molybdenum nitride (MoN) nanosheets are promising anode materials for improved lithium-ion batteries.
Thermoelectric fibers from well-dispersed carbon nanotube/poly(vinyliedene fluoride) pastes for fiber-based thermoelectric generators
Authors: Kim Jae-Yeop , Mo Jun-Hyun , Kang Young Hun , Cho Song Yun , Jang Kwang-Suk
Published: October 2018

The organic thermoelectric fibers with p- and n-type power factors of 378 ± 56 and 289 ± 98 μW m−1 K−2, respectively, were prepared via simple wet-spinning and post-treatment methods.
Multi-functional MnO2 nanomaterials for photo-activated applications by a plasma-assisted fabrication route
Authors: Barreca Davide , Gri Filippo , Gasparotto Alberto , Carraro Giorgio , Bigiani Lorenzo , Altantzis Thomas , Žener Boštjan , Lavrenčič Štangar Urška , Alessi Bruno , Padmanaban Dilli Babu , Mariotti Davide , Maccato Chiara
Published: October 2018

F-doped β-MnO2 nanomaterials fabricated using a one-step plasma-assisted route display attractive functional performances in view of photo-activated self-cleaning/antifogging applications and wastewater treatment.
Simultaneous edge and electronic control of MoS2 nanosheets through Fe doping for an efficient oxygen evolution reaction
Authors: Tang Baoshan , Yu Zhi Gen , Seng Hwee Leng , Zhang Nengduo , Liu Xixia , Zhang Yong-Wei , Yang Weifeng , Gong Hao
Published: October 2018

Electronic regulation and structural engineering at the atomic level of electrocatalysts is of vital importance to a highly efficient oxygen evolution reaction (OER).
Prediction of high-temperature Chern insulator with half-metallic edge states in asymmetry-functionalized stanene
Authors: Zhang Meng-han , Zhang Chang-wen , Wang Pei-ji , Li Sheng-shi
Published: October 2018

A great obstacle for the practical applications of the quantum anomalous Hall (QAH) effect is the lack of suitable two-dimensional (2D) materials with a sizable nontrivial band gap, high Curie temperature, and high carrier mobility.
A rapid hemostatic sponge based on large, mesoporous silica nanoparticles andN-alkylated chitosan
Authors: Chen Zihao , Han Lei , Liu Changjun , Du Yu , Hu Xiao , Du Ge , Shan Chao , Yang Kun , Wang Chunlai , Li Minggao , Li Fan , Tian Feng
Published: October 2018

Due to the designed, coagulation-promoting microstructure, a rapid and safe hemostat was developed and its hemostatic efficiency was evaluated byin vitroclotting tests andin vivohemostatic analyses.
Identification of a lysine 4-hydroxylase from the glidobactin biosynthesis and evaluation of its biocatalytic potential
Authors: Amatuni Alexander , Renata Hans
Published: October 2018

We present the functional characterization of GlbB, a lysine 4-hydroxylase from the glidobactin biosynthetic gene cluster.
Synthesis of benzimidazoles by CuI-catalyzed three-component reaction of 2-haloaniline, ammonia and aldehyde in water
Authors: Ke Fang , Zhang Peng , Lin Chen , Lin Xiaoyan , Xu Jianhua , Zhou Xiangge
Published: October 2018

An efficient three-component reaction of 2-haloaniline, aldehyde, and ammonia in water catalyzed by CuI afforded benzimidazole derivatives in good to excellent yields up to 95%.
Polynitroxide copolymers to reduce biofilm fouling on surfaces
Authors: Boase Nathan R. B. , Torres Marcelo D. T. , Fletcher Nicholas L. , de la Fuente-Nunez Cesar , Fairfull-Smith Kathryn E.
Published: October 2018

Polynitroxide films – the first example of surface tethered nitroxides reducing biofilm fouling.
Zwitterionic poly(sulfobetaine methacrylate)s in water: from upper critical solution temperature (UCST) to lower critical solution temperature (LCST) with increasing length of one alkyl substituent on the nitrogen atom
Authors: Wang Ning , Seymour Bryan T. , Lewoczko Evan M. , Kent Ethan W. , Chen Ming-Li , Wang Jian-Hua , Zhao Bin
Published: October 2018

Increasing the alkyl length on nitrogen of the polymer changes behaviour from UCST, to soluble, LCST, and insoluble.
Electro-interconverted thermogelling and thermothinning polymer solutions
Authors: He Jiaqing , Zhang Jian , Zhou Chengda , Peng Kang , Yang Haiyang , Hao Xiang
Published: October 2018

We report an intelligent electrothermal system exhibiting two remarkably different temperature response rheological behaviors: thermothinning versus thermogelling, which are controlled by voltage.
Rational design of a novel quaternary ZnO@ZnS/Ag@Ag2S nanojunction system for enhanced photocatalytic H2 production
Authors: Su Yiping , Zhao Zhicheng , Li Shun , Liu Fei , Zhang Zuotai
Published: October 2018

A novel ZnO@ZnS/Ag@Ag2S quaternary nanojunction photocatalyst has been designed for efficient solar water splitting.
Ni-modified Ti3C2MXene with enhanced microwave absorbing ability
Authors: Feng Wanlin , Luo Heng , Zeng Sifan , Chen Chen , Deng Lianwen , Tan Yongqiang , Zhou Xiaosong , Peng Shuming , Zhang Haibin
Published: October 2018

Ni-modification of Ti3C2MXene enables enhanced microwave absorption ability.
Simulation before fabrication: a case study on the utilization of simulators for the design of droplet microfluidic networks
Authors: Grimmer Andreas , Chen Xiaoming , Hamidović Medina , Haselmayr Werner , Ren Carolyn L. , Wille Robert
Published: October 2018

Simulating microfluidic networks allows to check a design even before first prototypes are realized.
Thermally controlled biotransformation of glycyrrhizic acidviaan asymmetric temperature-responsive polyurethane membrane
Authors: Wu Xiuhong , Wang Shaoyan , Zhang Lina , Wu Lidong , Chen Yi
Published: October 2018

A “smart” bioreaction system was developed by using the special characteristic of a temperature-responsive polyurethane (TRPU). This “smart” support material presents a potential benefit of separation for complex biotransformation reactions.
Effects of annealing temperature on properties of InSnZnO thin film transistors prepared by Co-sputtering
Authors: Zhong Wei , Li Guoyuan , Lan Linfeng , Li Bin , Chen Rongsheng
Published: October 2018

Indium-tin-zinc-oxide (ITZO) as the channel layer grown by co-sputtering of ZnO target and ITO target in the bottom gate thin-film transistors (TFTs) is proposed in this work.
Correction: Up-regulation of exosomal miR-125a in pneumoconiosis inhibits lung cancer development by suppressing expressions of EZH2 and hnRNPK
Authors: Zhang Lin , Li Jiangfeng , Hao Changfu , Guo Wei , Wang Di , Zhang Jianhui , Zhao Youliang , Duan Shuyin , Yao Wu
Published: October 2018

Correction for ‘Up-regulation of exosomal miR-125a in pneumoconiosis inhibits lung cancer development by suppressing expressions of EZH2 and hnRNPK’ by Lin Zhang et al., RSC Adv., 2018, 8, 26538–26548.
A cell membrane-anchored fluorescent probe for monitoring carbon monoxide release from living cells
Authors: Xu Shuai , Liu Hong-Wen , Yin Xia , Yuan Lin , Huan Shuang-Yan , Zhang Xiao-Bing
Published: October 2018

A novel cell membrane-anchored probe (ANRP) was constructed to monitor CO release from living cells for the first time.
Rational design of a super-contrast NIR-II fluorophore affords high-performance NIR-II molecular imaging guided microsurgery
Authors: Tian Rui , Ma Huilong , Yang Qinglai , Wan Hao , Zhu Shoujun , Chandra Swati , Sun Haitao , Kiesewetter Dale O. , Niu Gang , Liang Yongye , Chen Xiaoyuan
Published: October 2018

A super-contrast NIR-II fluorophore IR-BEMC6P with enhanced quantum yield is developed and the excretion mechanism is identified.
Structure–property relationships describing the buried interface between silicon oxide overlayers and electrocatalytic platinum thin films
Authors: Beatty Marissa E. S. , Chen Han , Labrador Natalie Y. , Lee Brice J. , Esposito Daniel V.
Published: October 2018

This article identifies Pt-oxide interlayers at the buried interface of Si-oxide/Pt thin films and explores their implications for electrocatalysis.
Tailoring the porosity of MOF-derived N-doped carbon electrocatalysts for highly efficient solar energy conversion
Authors: Kang Jin Soo , Kang Jiho , Chung Dong Young , Son Yoon Jun , Kim Seoni , Kim Sungjun , Kim Jin , Jeong Juwon , Lee Myeong Jae , Shin Heejong , Park Subin , Yoo Sung Jong , Ko Min Jae , Yoon Jeyong , Sung Yung-Eun
Published: October 2018

Pore sizes of MOF-derived N-doped carbons were tailored for mesoscopic solar cell applications.
Synergic TiO2 photocatalysis and guanine photoreduction for silver deposition amplification: an ultrasensitive and high-throughput visualized colorimetric analysis strategy for anthrax DNAs in blood using a wettable microwells array
Authors: Liu Huan , Feng Luping , Cai Yuanyuan , Hua Yue , Liu Min , Yin Mengyuan , Li Shuai , Lv Xiaoxia , Wen Jiangwei , Wang Hua
Published: October 2018

A colorimetric strategy was developed for probing anthrax DNAs by photocatalytic silver deposition on wettable microwells array.
Concatenation of the Moving Window Technique for Auditory-Perceptual Analysis of Voice Quality
Authors: Ehrlich Benjamin , Lin Liyu , Jiang Jack
Published: October 2018

Purpose

The purpose of this study is to develop a program to concatenate acoustic vowel segments that were selected with the moving window technique, a previously developed technique used to segment and select the least perturbed segment from a sustained vowel segment. The concatenated acoustic segments were compared with the nonconcatenated, short, individual acoustic segments for their ability to differentiate normal and pathological voices. The concatenation process sometimes created a clicking noise or beat, which was also analyzed to determine any confounding effects.

Method

A program was developed to concatenate the moving window segments. Listeners with no previous rating experience were trained and, then, rated 20 normal and 20 pathological voice segments, both concatenated (2 s) and short (0.2 s) for a total of 80 segments. Listeners evaluated these segments on both the Grade, Roughness, Breathiness, Asthenia, and Strain scale (GRBAS; 8 listeners) and the Consensus Auditory-Perceptual Evaluation of Voice (Kempster, Gerratt, Abbott, Barkmeier-Kraemer, & Hillman, 2009) scale (7 listeners). The sensitivity and specificity of these ratings were analyzed using a receiver-operating characteristic curve. To evaluate if there were increases in particular criteria due to the beat, differences between beat and nonbeat ratings were compared using a 2-tailed analysis of variance.

Results

Concatenated segments had a higher sensitivity and specificity for distinguishing pathological and normal voices than short segments. Compared with nonbeat segments, the beat had statistically similar increases for all criteria across Consensus Auditory-Perceptual Evaluation of Voice and GRBAS scales, except pitch and loudness.

Conclusions

The concatenated moving window method showed improved sensitivity and specificity for detecting voice disorders using auditory-perceptual analysis, compared with the short moving window segment. It is a helpful tool for perceptual analytic protocols, allowing for voice evaluation using standardized and automated voice-segmenting procedures.

Supplemental Material

https://doi.org/10.23641/asha.7100951
Ultra‐low‐voltage low‐power dynamic comparator with forward body bias scheme for SAR ADC
Authors: Hwang Young‐Ha , Jeong Deog‐Kyoon
Published: October 2018

An ultra‐low‐voltage two‐stage dynamic comparator is proposed with a forward body bias (FBB) scheme for successive approximation register (SAR) analogue‐to‐digital converters (ADCs). The proposed FBB scheme for a preamplifier and latch stage reduces the delay time remarkably under a low supply voltage. At 0.4 V, the power consumption is 4.48 nW, and the delay can be decreased to 593.9 ns for ΔVin = 0.1 mV and fclk = 100 kHz. The RMS equivalent input‐referred noise of the comparator is 0.136 mV. The total offset is 13.7 mV, and offset fluctuation is 0.183 mV with the proposed structure. Both the input‐referred noise and offset fluctuation are <0.5 least‐significant bit for a 10‐bit SAR ADC at 0.4 V.
Forecasting of commodities prices using a multi‐factor PDE model and Kalman filtering
Authors: Rigatos Gerasimos , Siano Pierluigi , Ghosh Taniya , Ding Yi
Published: October 2018

This study proposes a method for forecasting commodities prices using Schwartz partial differential equation (PDE) and Kalman filtering. The method is applicable to both the single‐factor and the multi‐factor Schwartz PDE. Using semi‐discretisation and the finite differences method, the Schwartz PDE is transformed into an equivalent state‐space description. This latter representation is finally written in a linear matrix form in which the Kalman filter's recursion is applicable. By redesigning the Kalman filter as a m‐step ahead predictor it becomes possible to obtain accurate estimates of the future commodities’ price. The prediction scheme analysed in this study can contribute to maximising profits in commodities trading, including also the trading of electric power.
Robust observer synthesis for the uncertain large‐scale T–S fuzzy system
Authors: Vu Van‐Phong , Wang Wen‐June
Published: October 2018

This work studies a new method to synthesise a robust observer to estimate the immeasurable state variables for an uncertain large‐scale Takagi–Sugeno (T–S) fuzzy system, which has not been considered in the previous studies. This system consists of a set of T–S fuzzy subsystems that are interconnected, but these systems have certain uncertainties. An observer relying on the unknown input method is synthesised such that not only the unknown states are estimated but also the effects of the uncertainties are eliminated completely, even though the upper bounds of the uncertainties are not known. The conditions to design the observer are obtained in the main theorems by employing Lyapunov methodology, S‐procedure, and linear matrix inequalities technique. Finally, the illustrative examples are provided to illustrate the advantages and success of the proposed method.
Switched control strategy including time optimal control and robust dynamic output feedback for anaesthesia
Authors: Queinnec Isabelle , Tarbouriech Sophie , Zabi Saïd , Garcia Germain , Mazerolles Michel
Published: October 2018

Mimicking the medical practice, this study deals with the control of hypnosis during a surgical intervention thanks to a switched control strategy. The key idea consists in starting with an initial minimum time control for the induction phase followed by a dynamic output feedback for the maintenance phase. The objective during the first phase is to bring the patient from its awake state to a final state corresponding to some given depth of hypnosis, measured by the BIS (Bispectral index), within a minimum time. Then, once the patient state is close to the desired target, the control is switched to a dynamic output feedback ensuring that the BIS stays in a given interval taking into account the saturation of the actuator and the multi‐time scale dynamics in the anaesthesia model. The positivity of the system is also preserved thanks to the use of input saturation and state constraints. The stability of the switched control strategy is addressed and the theoretical conditions are evaluated on different case studies.
Bounded‐input prescribed performance control of uncertain Euler–Lagrange systems
Authors: Jabbari Asl Hamed , Narikiyo Tatsuo , Kawanishi Michihiro
Published: October 2018

This study proposes a novel saturated prescribed performance (PP) controller for Euler–Lagrange dynamic systems. The design of bounded‐input controller is facilitated by means of introduction of auxiliary dynamics in the closed‐loop system. The controller takes advantages of using an adaptive multilayer neural network and a robust term to deal with uncertainties of the system. Through the stability analysis, it is shown that PPwith saturated control command is feasible having certain constraints on initial conditions and external disturbances. The proposed controller is validated through experimental and simulation studies conducted on a lower‐limb robotic exoskeleton.
Arterial link travel time estimation considering traffic signal delays using cellular handoff data
Authors: Yang Fei , Yao Zhenxing , Jin Peter J. , Xiong Yaohua
Published: October 2018

Link travel time is an important evaluation index of urban arterial traffic condition. It is traditionally estimated from loop detector data and GPS probe vehicle data. The former suffers from the coverage and maintenance issues. The latter has issues related to low penetration rate. Cellphone handoff data is one alternative that may address those deficiencies with its large coverage areas and continuous detection capabilities at low cost. Existing cellular probe vehicle based travel time estimation methods are primarily designed for freeway. Limited studies have been conducted for signalised arterials. Cellular handoff data detects the time lapse between two consecutive wireless handoff points. When vehicles with on‐call cellphones traverse between two handoff points, their space mean speeds can be calculated by dividing the pre‐calibrated distances by the time lapses. In this study, a new cellular handoff data based arterial travel time estimation model is proposed and compared with existing models. A hybrid traffic‐and‐wireless simulation network is built to simulate the handoff data generation and processing. Field data are collected at an arterial corridor in Chengdu, China to establish the baseline condition. The results from the proposed model show promising performance with detection errors of link travel times mostly within 10%.
S‐PS resonant topology of WPT system for implantable spinal cord stimulator
Authors: Lu Yuehai , Qiu Dongyuan , Meng Xiantian , Zhang Bo , Chun Tang Sai
Published: October 2018

Magnetic resonance‐based wireless power transfer (WPT) system offers a promising solution to provide power for implantable spinal cord stimulator (SCS). To meet with the clinical requirements, the SCS‐WPT system should have high transfer efficiency and long transfer distance. As the topology of the resonant network will directly affect the transfer efficiency and output power of the WPT system, a new resonant network, series‐parallel and series (S‐PS), is selected in this work. The performance of WPT system with S‐PS resonant network has been compared with those with the classic resonance networks, it is concluded that S‐PS is the suitable resonant network for the WPT system in a wide range of load. Finally, an SCS‐WPT prototype with S‐PS resonant network is built with detailed parameter design to verify the correctness of theoretical analysis. The system efficiency is up to 68.4% at a coil separation of 50 mm.
Controllable regenerative braking process for hybrid battery–ultracapacitor electric drive systems
Authors: Peng Hui , Wang Junzheng , Shen Wei , Shi Dawei , Huang Yuan
Published: October 2018

This study proposes a controllable regenerative braking process for hybrid battery–ultracapacitor electric drive systems. The motor in the system is controlled to brake with a constant torque. To this end, a control framework is proposed which includes a circuit topology, decentralised active disturbance rejection controllers (ADRCs) and an operational modes switch controller (OMSC). The motor brakes with ultracapacitor when its speed is fast, and brakes with a dissipative resistor when its speed is slow. Decentralised ADRCs guarantee that ultracapacitor‐based braking mode and dissipative resistor‐based braking mode can be controlled individually. OMSC coordinates the decentralised ADRCs working cooperatively. Modified ADRC is proposed to implement bumpless transfer when the operational mode or braking mode is switched. The advantages of the proposed control system are as follows: (i) the control of the regenerative braking process based on ultracapacitor and dissipative resistor is linked with the control of the motor; (ii) speed of the motor in the electric drive system is controllable during the regenerative braking process; and (iii) bumpless transfer is guaranteed when braking mode changes from ultracapacitor‐based braking mode to dissipative resistor‐based braking mode. The following experimental results validate the proposed control framework for the controllable regenerative braking process.
Design of coils on printed circuit board for inductive power transfer system
Authors: Li Zhenning , He Xiaoqiong , Shu Zeliang
Published: October 2018

Due to the different application prospects, the coils of inductive power transfer (IPT) systemvaries. The coils on printed circuit boards (PCB) have drawn considerableattention gradually. However, the applications mainly involve portable equipmentand implantable medical devices operating at a high frequency, not fit for IPTsystem. In this paper, an IPT system based on PCB coils were designed. All thecharacteristics of single turn coils on a single‐layer, multi turns coils on asingle‐layer and multi turns coils on multi‐layers of printed spiral coils(PSCs) were analysed and calculated. The self‐inductance and mutual inductanceof the series windings on PSCs were modeled and calculated firstly. Anequivalent circuit of coils were proposed to simplify the calculation andfacilitate the analysis. Furthermore, in order to increase mutual inductance andtransfer more power, the multi‐layer coils connecting in series were designedfor the first time and the inductance parameters can be acquired by the means ofproposed method. The analyses on coils model were verified by simulations usingfinite element method and measuring. Finally, the coil characteristics on IPTsystem were verified by the circuit simulation and experiment results and thedesigned coils can meet the desired requirements.
Comprehensive review on enhancement of stability in multimachine power system with conventional and distributed generations
Authors: Paital Shiba R. , Ray Prakash K. , Mohanty Asit
Published: October 2018

A comprehensive review on stability analysis in multimachine power system is presented in this study. The increasing demand of power has led to the expansion of power system and complexity in design as well as operation. This threatens to deteriorate the stability and reliability in the power network. However, with the advances in semiconductor and power electronic control technology, various flexible AC transmission systems (FACTS) are designed to enhance the power system stability. Different power system configurations with the incorporation of conventional and distributed generations (DGs) are proposed whose stability is being tested in the presence of the FACTS controllers. The optimal damping of power system oscillations under transient operating conditions are studied in presence of HVAC and HVDC links with conventional as well as DG systems and energy storage options like battery, supercapacitors and so on. Different control approaches such as classical control, robust control, wide‐area control along with soft computing approaches like neural networks, fuzzy logic control, adaptive neuro‐fuzzy inference system, genetic algorithm, particle swarm optimisation and so on are broadly discussed. A comparative analysis of different methodologies is presented to establish a quick survey of the proposed solutions for stability enhancement.
LCO‐FLL control for single‐phase utility integrated single‐stage solar PV system
Authors: Pandey Sunil Kumar , Kumar Shailendra , Singh Bhim
Published: October 2018

This study presents a limit cycle oscillator‐frequency locked loop (LCO‐FLL) control for single‐phase utility integrated single‐stage photovoltaic (PV) system. The proposed topology increases the utility of the voltage‐source converter (VSC), particularly in the absence of PV generation. It has the potential to load harmonics current mitigation. It estimates harmonic free load current accurately with low computational requirement due to the absence of cumbersome mathematical algorithm and transformation techniques. It provides reactive power compensation, both in the absence and the presence of PV generation, improves transient response during dynamics in load and varying irradiance conditions. The total harmonic distortions of utility current and utility voltage, compliance the limit of the IEEE‐519 standard. The proportional–integral (PI) regulator regulates the DC‐link voltage of VSC input to the reference DC‐link voltage. The incremental conductance‐based technique derives the reference DC‐link voltage. The dynamic behaviour of the LCO‐FLL‐based control is improved using a feed‐forward loop for the PV power sharing. It also reduces loading on the PI controller. Test results demonstrate satisfactory performance of LCO‐FLL‐based control.
Effects of waveform parameters on the breakdown characteristics of OIP subjected to impulse voltages and evaluation method for waveform equivalence
Authors: Sima Wenxia , Ye Lian , Sun Potao , Chen Qiulin , Zhang Huangjing , Chen Jiaqi
Published: October 2018

The impulse voltage wave invading a transformer is not the double exponential impulse wave (DEIW) specified by the IEC but a non‐standard waveform with oscillation attenuation characteristics, and this fact leads to doubts about the scientificity and optimality of insulation coordination. A key solution for this issue is the establishment of an equivalent relationship between the measured non‐standard impulse voltage wave and the DEIW. In this study, a test platform of multiparameter impulse voltage was set up. Then, the authors obtained the 50% breakdown voltage (U50%) of the oil‐impregnated paper (OIP) for transformer under the bipolar oscillatory attenuated impulse wave (BOAIW) and the DEIW with different waveform parameters. The effects of waveform parameters on the breakdown characteristics of the OIP were finally revealed. On the basis of experimental data and several mathematical methods, the authors established the U50% prediction mathematical models for the OIP under the BOAIW and DEIW. Based on the prediction models and the microfluctuation characteristics of measured overvoltage's waveform parameters, the authors proposed a method for evaluating the waveform equivalence. The characteristics of voltage amplitude and change rate were regarded as the two key factors for the waveform equivalence of this method.
Quantifying colorimetric assays in µPAD for milk adulterants detection using colorimetric android application
Authors: Salve Mary , Wadafale Ashwini , Dindorkar Gurushree , Kalambe Jayu
Published: October 2018

A microfluidic paper‐based analytical device (μ‐PAD) and handheld colorimeter android application for quantifying the precise concentration of adulterants in milk are developed. A simple method to pattern polydimethylsiloxane for creating a hydrophobic barrier on filter paper using custom‐designed rubber stamp containing the design of μ‐PAD was used. The experiments were performed for the detection of urea, starch, salt and detergent ranging from 1 to 100 mg in 10 ml of milk. The user just needs to pipette drops of adulterated milk on a test spot and the results are obtained instantly. The authors believe that the developed platform can be used as a basis for low‐cost, portable system for various fluid adulterants’ tests. The experimental database was used for the development of a colorimetric android application to calibrate the colour range for adulterants’ concentration detection. The limit of detection of colorimetric android application for adulterants urea is 5 mg, starch is 17 mg, salt is 29 mg and for detergent is 20 mg in 10 ml of milk. This kind of system is attractive for use in developing countries, in the field, or as an inexpensive alternative as compared with other methods for water and food safety.
Economic aspects of ensuring the capacity adequacy of electric power systems
Authors: Belyaev Nikolay , Egorov Andrey , Korovkin Nikolay , Chudny Vladimir
Published: October 2018

The present report deals with economic issues of selecting means ensuring the capacity adequacy of electric power systems. Cost analysis of various engineering measures ensuring the capacity adequacy has been performed, they are as follows: construction of margin generating capacities, erection of new power transmission lines or increase of transmission capacity of existing power lines. The cost-based analysis has been conducted following investment programs and regulatory acts in place. Recommendations on developing computational models of power systems have been given based on the results obtained in order to assess the capacity adequacy indices with account made for the cost of various engineering measures to be taken for their improvement.
Transformation of the model of estimation of balance reliability UPS of the Russia in the account of correlation of the consumption regime
Authors: Chukreyev Yuri
Published: October 2018

The characteristics of the electric power consumption regime are used when determining the indicators of adequacy in the management of the development of the UPS of Russia. The influence of the changed conditions of their representation on the probabilistic indicators of the balance reliability of system-forming links between the territorial zones (UPS) of the computational model of the UPS of Russia is shown. On this basis, we proposed the transformation of the model of estimating the balance reliability indicators, which allows to increase the computational efficiency.
Search of critically important combinations of objects of the gas industry from the positions of the system operability
Authors: Vorobev Sergey , Senderov Sergey , Edelev Alexey
Published: October 2018

The paper is devoted to the search for critical combinations of gas industry objects from the standpoint of system operability. Critically important is the object partial or complete failure which can cause significant damage to the country from the fuel and energy complex in general or within the framework of a separate energy system. It is possible to failure of a critical and other object of the system. The paper presents the main major critical combinations of gas industry objects. Their significance and impact on the efficiency of the gas industry in Russia is shown. Conclusions are made about the expediency of searching for critical combinations of gas industry objects from the standpoint of system operability.
Renewable energy sources in future energy balance of the republic of Kazakhstan
Authors: Mukatov Bekzhan , Khabibullin Ravil
Published: October 2018

The article describes the main factors determining the development of renewable energy sources in the world. The assessment of the applicability of foreign RES development strategies to Kazakhstan’s energy system has been made. The main tasks facing Kazakhstan’s energy system with large-scale implementation of renewable energy were formulated. On the basis of the analysis and performed calculations recommendations and basic principles have been made on development strategy of renewable energy sources in the Republic of Kazakhstan.
Methods of linear and nonlinear state estimation of distribution network
Authors: Golub Irina , Boloev Evgeny
Published: October 2018

The paper proposes a new approach to the problem of state estimation of a low voltage distribution network by the measurements coming from smart meters. The problem of nonlinear state estimation based on the measurements of nodal powers and voltages is solved by the method of simple iteration which minimizes the quadratic function of the residues with and without the consideration of the constraint on the zero currents in the transit nodes. The same algorithms are proposed to use for linear state estimation based on the measurements of nodal currents and voltages. The effectiveness of the proposed methods for linear and nonlinear state estimation is illustrated on the 33 nodes three-phase four-wire low-voltage network.
Determination of optimal location for installation of symmetry facilities in 0.4 kV power supply systems with motor-drive load
Authors: Romanova Victoria
Published: October 2018

This article considers the issue for creation of computer-aided program designed for determination of optimal location for installation of symmetry facilities in 0.4 kV power supply systems with motor-drive load in conditions of asymmetry of voltages. The developed program is implemented by means of C# programing language in Microsoft Visual Studio 2012 programming environment using the embedded cross-platform data base SQLite. The program is designed for making electrotechnical calculations during designing, modernization and operation of electrical grids with available motor drive load. It ensures plotting of schematic circuits for 0.4 kV power supply system sections with installed symmetry facilities. The program will enable quick and exact calculation of power capacity loss, determination of economic feasibility for taking special measures to eliminate the asymmetry of voltages, and to determine optimal application and location of symmetry facilities. Using the program in motor-drive load power supply systems will enhance the asynchronous motor reliability and efficiency.
Projection methods for stochastic structural dynamics
Authors: Pryse Sion Eilir , Adhikari Sondipon , Kundu Abhishek
Published: October 2018

A set of novel hybrid projection approaches are proposed for approximating the response of stochastic partial differential equations which describe structural dynamic systems. An optimal basis for the response of a stochastic system has been computed from the eigen modes of the parametrized structural dynamic system. The hybrid projection methods are obtained by applying appropriate approximations and by reducing the modal basis. These methods have been further improved by an implementation of a sample based Galerkin error minimization approach. In total four methods are presented and compared for numerical accuracy and efficiency by analysing the bending of a Euler-Bernoulli cantilever beam.
An overview of PST for vibration based fault diagnostics in rotating machinery
Authors: Mohamad T. Haj , Nataraj C.
Published: October 2018

In general, diagnostics can be defined as the procedure of mapping the information obtained in the measurement space to the presence and magnitude of faults in the fault space. These measurements, and especially their nonlinear features, have the potential to be exploited to detect changes in dynamics due to the faults. We have been developing some interesting techniques for fault diagnostics with gratifying results. These techniques are fundamentally based on extracting appropriate features of nonlinear dynamical behavior of dynamic systems. In particular, this paper provides an overview of a technique we have developed called Phase Space Topology (PST), which has so far displayed remarkable effectiveness in unearthing faults in machinery. Applications to bearing, gear and crack diagnostics are briefly discussed.
Geometrically nonlinear free and forced vibrations of Euler-Bernoulli multi-span beams
Authors: Fakhreddine Hatim , Adri Ahmed , Rifai Saïd , Benamar Rhali
Published: October 2018

The objective of this paper is to establish the formulation of the problem of nonlinear transverse forced vibrations of uniform multi-span beams, with several intermediate simple supports and general end conditions, including use of translational and rotational springs at the ends. The beam bending vibration equation is first written at each span and then the continuity requirements at each simple support are stated, in addition to the beam end conditions. This leads to a homogeneous linear system whose determinant must vanish in order to allow nontrivial solutions to be obtained. The formulation is based on the application of Hamilton’s principle and spectral analysis to the problem of nonlinear forced vibrations occurring at large displacement amplitudes, leading to the solution of a nonlinear algebraic system using numerical or analytical methods. The nonlinear algebraic system has been solved here in the case of a four span beam in the free regime using an approximate method developed previously (second formulation) leading to the amplitude dependent fundamental nonlinear mode of the multi-span beam and to the corresponding backbone curves. Considering the nonlinear regime, under a uniformly distributed excitation harmonic force, the calculation of the corresponding generalised forces has led to the conclusion that the nonlinear response involves predominately the fourth mode. Consequently, an analysis has been performed in the neighbourhood of this mode, based on the single mode approach, to obtain the multi-span beam nonlinear frequency response functions for various excitation levels.
On the dynamic buckling of very slender structures to self-weight
Authors: Brasil Reyolando , Orbolato Leandro , Pádua Eduardo
Published: October 2018

We present a mathematical and experimental study of the dynamic buckling of very slender structures due to their self-weight. Modern materials and powerful new analysis methods are leading to the design of very slender tall structures that may be prone to instability issues. Elastic stability of such structures is a problem inside the scope of the Non-Linear Dynamics Analysis Methods. An indicator of instability is when the structure’s free vibration frequency approaches null value. Two main factors affect these frequency results. First the stiffness, composed of elastic stiffness, always positive and non-zero, that diminishes rapidly with height, and the geometric stiffness, negative for compressive forces, whose absolute value grows as the structure gets taller and heavier. Second, the mass, that also grows with the height of the structures. To access this behaviour, we first present a simple one-degree-of-freedom mathematical model derived with Rayleigh’s Method, adopting a cubic polynomial as shape function. Next, comparisons are made with results of an experimental set up composed of a variable length cantilever vertical aluminium bar. These models reasonably agree with analytical close solutions available in the literature.
Integration of maintenance systems
Authors: Sarje S H
Published: October 2018

Excellence in maintenance is imperative in highly competitive market because it resulted into minimum maintenance cost, high equipment effectiveness, maximum reliability of the system, high quality of the products, low delivery time, high flexibility, safety etc. Any maintenance system such as Total Productive Maintenance (TPM) or Reliability Centered Maintenance (RCM) or Condition Based Maintenance (CBM) alone cannot achieve the excellence in maintenance but its integration may do. In this paper, an integration of TPM, RCM and CBM is proposed with a maintenance policy to take advantage of their respective strengths. A continuously monitored system subject to degradation due to the imperfect maintenance, where a hybrid hazard rate based on the concept of age reduction factor and hazard rate increase factor to predict the evolution of the system reliability in different maintenance cycles has been assumed.A quantitative decision making model for an integrated maintenance system is derived in order to assess the performance of the proposed maintenance policy. Numerical examples of calculation of optimal preventive maintenance age x and preventive maintenance number N* for the given cost ratio of corrective replacement and predictive preventive maintenance are given.
In-plane vibration of rotating rings using a high order theory
Authors: Lu Tao , Tsouvalas Apostolos , Metrikine Andrei
Published: October 2018

In-plane dynamics of rotating rings on elastic foundation is a topic of continuous research, especially in the field of tire dynamics. When the inner surface of a ring is connected to a stiff foundation, the through-thickness variation of radial and shear stress needs to be accounted for. This effect is often overlooked in the ring models proposed in the literature. In this paper, a new high order theory is developed for the in-plane vibration of rotating rings whose inner surface is connected to an immovable hub by distributed springs while the outer surface is stress-free. The high-order terms are chosen such that the boundary conditions at the inner and outer surfaces are satisfied at all times. Instability, which is usually overlooked in the literature, is predicted using the present model. Resonant speeds are investigated, at which modes appear as a stationary displacement pattern to a space-fixed observer. The exact satisfaction of boundary conditions at the inner and outer ring surfaces together with the through-thickness variation of the radial and shear stresses are shown to be of significant importance when the ring rotates at high speeds or is supported by relatively stiff foundation.
Singular solutions of a non-holonomic system as limits separating solution groups of particular type
Authors: Náprstek Jiří , Fischer Cyril
Published: October 2018

The non-holonomic system represents a model of the ball tuned mass damper (TMD), as used to absorb vibration of selected engineering structures, where conventional absorber types are inapplicable. The device consists of a ball moving within a spherical cavity fixed with the structure. To deduce a governing differential system the Appel-Gibbs formulation has been employed. The non-linear mathematical model includes six degrees of freedom and three non-holonomic constraints. The system has an auto-parametric character. The homogeneous differential system in the normal form is formulated. Its general properties are investigated for various settings of non-homogeneous initial conditions. Several singular solutions are extracted and physically interpreted. In principal, they represent limits separating solution groups of a certain character. The shape and general character of regular solutions within individual domains staked out by these limits are analyzed in order to facilitate a practical application of this theoretical background.
Special discontinuities in models of continuum mechanics
Authors: Chugaynova Anna
Published: October 2018

Some models of continuum mechanics with possible special discontinuities are analyzed. It is of interest to study such discontinuities since they can generate the non-uniqueness of solutions in a problem of arbitrary discontinuity disintegration.
A new simple method for determining the sound absorption coefficient
Authors: Chelidze Merab
Published: October 2018

Taking into account the influence of the length and diameter of the impedance tube on the process of decay of sound waves, a new study of sound propagation in an impedance tube is presented, on the basis of which it is easier to determine the sound absorption coefficient. The new simple method of determining the absorption coefficient, based on the decay of reverberating waves, is fairly stable and demonstrates a low sensitivity for all errors made in the measurement. The presented method makes it possible to measure the sound absorption coefficient without laboratories and precision measuring instruments in a wide range at the level of separate consumers.
Analysis of pendulums coupled by torsional springs for energy harvesting
Authors: Malaji P V , Doddi Suresh , Friswell Michael I. , Adhikari Sondipon
Published: October 2018

Harvesting energy from ambient sources has been a recent topic of interest. A typical linear harvester is effective only near resonance, limiting its frequency bandwidth. In order to increase the efficiency and bandwidth of harvesters, various strategies have been proposed. Using multiple harvesters in a single device can harvest enough power over wider frequency band. In the present work, the effect of torsional coupling of the harvesters for low frequency vibration energy harvesting is investigated. Two pendulums with electromagnetic induction as the energy conversion mechanism is proposed. The performance of the device is studied theoretically and numerically. Cubic polynomials are used to model the pendulum nonlinearity. Fundamental harmonic oscillation are assumed to obtain the analytical solution. The effect of torsional coupling and pendulum length on the power harvested are reported.
Coupling of structures using frequency response functions
Authors: Silva Tiago , Pereira João
Published: October 2018

In the field of structural dynamics is common to predict the behaviour of a structure regarding structural modifications. In this context, the frequency based substructuring method is well-known to perform structural modifications based on the coupling of structures. This process gives the possibility to perform the study of a structure at the level of its components and then assess the response of the coupled system. In practice, it is impossible to attain an experimental complete response model, although one can simulate all the responses of a structure using numerical models. Hence, the substructuring process can be enhanced by the combined use of experimental and numerical responses, as it was demonstrated using numerically obtained frequency response functions. This work presents the enhancement of the frequency based substructuring method using a method to expand experimental frequency response functions over the entire set of degrees of freedom in a finite element model. This expansion process, known as modified Kidder’s method, considers that if one can only measure translations due to exciting force, it is possible to obtain the complete response model, including the rotational frequency response functions due to exciting moments. The combined use of the frequency based substructuring and the modified Kidder’s methods has several advantages, as it avoids modal identification or residual compensation. To evaluate the performance of the proposed procedure a numerical example of a beam structure is presented, and its results are discussed.