bluuebunny/crossref_metadata_2025 huggingface dataset:
Electric field energy harvesting under actual three‐phase 765 kV power transmission lines for wireless sensor node
Authors: Kang S. , Kim J. , Yang S. , Yun T. , Kim H.
Published: June 2017

For the first time, under the actual three‐phase 765 kV power transmission lines, electric field energy is harvested and Zigbee‐based sensor node powered by the harvested energy is operated autonomously. A conductor tube is placed between power lines and the earth surface for electric field energy harvesting. The voltage difference between conductor tube and the earth surface is rectified and the harvested electric energy is stored in a storage capacitor. A self‐sustaining power management circuit adopting low‐power comparator with hysteresis is devised to monitor the stored energy and to operate the sensor node autonomously according to the stored energy. Experimental results under the actual three‐phase 765 kV power lines show that the data transfer period is almost inversely proportional to the square of the height of the sensor module from the earth surface. The temperature data is transmitted in every 25 s when the conductor tube is located at 4 m from the earth surface. Since the presented non‐contact energy harvesting apparatus is very simple, robust and low‐cost, it is believed that the presented technology can be widely applied to power transmission, distribution and smart grid system.
Optimum and quasi‐optimum relaxation parameters for low‐complexity massive MIMO detector based on Richardson method
Authors: Minango J. , de Almeida C.
Published: June 2017

The low‐complexity minimum mean square error detector based on Richardson method for massive MIMO systems was proposed, where the very important relaxation parameter was obtained by intensive simulations for each given massive MIMO channel matrix. Thus, a simple approach is developed to determine the optimum relaxation parameter of Richardson method for any massive MIMO system configuration. Furthermore, by exploiting the massive MIMO channel property of asymptotic orthogonality, a simple way to obtain the quasi‐optimum relaxation parameter is proposed, which is given as a function of the number of users and the received base station antennas of a massive MIMO system.
Finite‐time robust fuzzy control for non‐linear Markov jump systems under aperiodic sampling and actuator constraints
Authors: Xu Shidong , Sun Guanghui , Li Zhan , Zheng Hui
Published: June 2017

This study investigates the fuzzy control problem for a class of non‐linear Markov jump systems with sampled‐data inputs and actuator constraints over a finite‐time interval. Takagi–Sugeno (T–S) fuzzy models are employed to approximate the non‐linearity. The partly known transition probability matrix consisting of known, uncertain, and unknown elements is considered. The asynchronous errors of the membership functions induced by aperiodic sampling are taken care of to avoid conservative results. The objective is to procure a sampled‐data fuzzy controller such that the resulting closed‐loop system is finite‐time bounded and a prescribed performance index is guaranteed simultaneously. By establishing a new piecewise Lyapunov–Krasovskii functional and utilising convex optimisation technique, a novel set of sufficient conditions for the existence of anticipated sampled‐data controller are developed. Finally, two illustrative examples are presented to prove the effectiveness of the proposed approaches.
Robust higher‐order ILC for non‐linear discrete‐time systems with varying trail lengths and random initial state shifts
Authors: Wei Yun‐Shan , Li Xiao‐Dong
Published: June 2017

This study addresses a robust iterative learning control (ILC) scheme for non‐linear discrete‐time systems in which both the trail lengths and the initial state shifts could be randomly variant in iteration domain. The proposed higher‐order ILC law guarantees that as the iteration number goes to infinity, the ILC tracking errors at the desired output trail period are bounded in mathematical expectation, and the bound of tracking errors is proportional to the random initial state shifts. Specifically, the ILC tracking errors in mathematical expectation can be driven to zero as the expectation of initial state shifts is zero. Two numerical examples are carried out to demonstrate the effectiveness of the proposed higher‐order ILC law.
Finite‐time event‐triggered consensus for non‐linear multi‐agent networks under directed network topology
Authors: Dong Yan , Xian Jin‐guo
Published: June 2017

This study investigates the finite‐time consensus problem for a class of first‐order non‐linear multi‐agent networks under directed network topology. A novel non‐linear consensus protocol is proposed based on event‐triggered strategy. By using the combinational measurement approach, two kinds of event triggers are designed, one depends on continuous communications between the agents, the other avoids the continuous communications. For such two classes of event‐triggers, sufficient conditions guaranteeing the finite‐time consensus are derived, respectively, provided that the coupling network topology contains at least a rooted directed spanning tree. Meanwhile, some numerical simulations are given to illustrate the effectiveness of the theoretical results.
Equivalent to represent inertial and primary frequency control effects of an external system
Authors: Weckesser Tilman , Van Cutsem Thierry
Published: June 2017

This study presents a novel equivalent, which is suitable for simulation of inertial and primary frequency control effects. In the model reduction procedure, dynamic power injectors are used to replace the external system and to mimic its dynamic behaviour. The parameters of the equivalents are tuned with a simple approach presented in this study. The effectiveness of the proposed method is demonstrated on a modified version of the European Network of Transmission System Operators for Electricity (ENTSO‐E) dynamic study model. The results show that the system frequency response of the unreduced system is retained and a speedup of the simulations of around 4.0 is achieved.
Inkjet‐printed cage‐dipole antennas for radio‐frequency applications
Authors: Mutlu Feza , Önol Can , Karaosmanoğlu Barışcan , Ergül Özgür
Published: June 2017

The authors present cage‐dipole antennas that are suitable for inkjet printing. The antennas involve hard‐coded switches, i.e. open and closed gaps, for providing desired antenna characteristics at radio frequencies. Optimisations are performed rigorously using the method of moments (MOM) or the multilevel fast multipole algorithm (MLFMA) combined with genetic algorithms to find the most suitable switch configurations. Thousands of trials required for the optimisations are performed accurately and efficiently using MOM/MLFMA without resorting to alternative representations of the antennas. Optimised antennas are further fabricated via low‐cost inkjet printing. Inkjet‐printed cage‐dipole antennas, as well as the overall design and fabrication procedure, are suitable for radio‐frequency applications that require inexpensive and easy‐to‐produce antennas.
New broad angle frequency scanning antenna with narrow bandwidth based on a CRLH structure
Authors: Siaka Francis , Laurin Jean‐Jacques , Deban Ramin
Published: June 2017

A new type of frequency scanning slot array antenna using composite right/left‐handed (CRLH) waveguide as a feeding structure is presented in this study. The waveguide is loaded periodically with short‐circuited air‐filled double‐ridge stubs, which permit the CRLH propagation. The feeding structure is highly dispersive in order to scan a wide angular sector with a narrow frequency sweep. It also easily allows amplitude tapering of the array elements. An eight‐element longitudinal slot array designed for X‐band operation with −22 dB sidelobe level has been built and tested. Good agreement between simulations and measurements was obtained. The structure exhibits 31° of scanning over a frequency bandwidth of only 6%, and low return loss in its band of operation.
Investigation of stimulus signals for a time domain microwave imaging system
Authors: Zeng Xuezhi , Monteith Albert , Fhager Andreas , Persson Mikael , Zirath Herbert
Published: June 2017

Two different types of time domain signals, pulse and pseudo random noise (PN) sequence, were investigated for a time domain microwave imaging system in order to study the effect of stimulus signals on the system performance. The system's measurement accuracy was investigated when the two different stimulus signals were used, respectively. An imaging test was performed in order to show the effect of transmitted waveforms on the imaging quality. The results suggest that the PN sequence in general gives higher measurement accuracy than the pulse. Better imaging results, although not significant, were also obtained when the pseudo random sequence was employed.
Direct metal laser sintering process investigation: application to 3D slotted waveguide antennas
Authors: Martin‐Guennou Annaig , Quéré Yves , Rius Eric , Person Christian , Enouz‐Vedrenne Shaima , Lesueur Guillaume , Merlet Thomas
Published: June 2017

Increasing demand for the development of multifunction radio‐frequency‐systems requires the fabrication of complex architectures. Three‐dimensional (3D) direct metal printing direct metal laser sintering (DMLS) has the required properties to build complex and robust parts. To determine whether this technology is able to replace traditional machining methods, it needs to be extensively examined. In the present study, several waveguides operating in a wide‐frequency range, and slotted waveguide antennas with relevant details and shape, operating in the Ku‐band, were designed, machined, assessed and measured. Measurements show that the degradation of component performances are related to the fabrication strategy used. Deterministic defects were observed that make it possible to conceive ways of enhancing manufactured parts. Through this analysis, the authors demonstrate the potential of the DMLS process to construct finely detailed complex and conformal structures.
Hybrid converter topology for reducing torque ripple of BLDC motor
Authors: Viswanathan Vaiyapuri , Jeevananthan Seenithangom
Published: June 2017

This study investigates the torque ripple performance of brushless DC (BLDC) motor drive system by integrating both modified single‐ended primary inductor converter (SEPIC) and silicon carbide metal–oxide–semiconductor field‐effect transistor based three‐level neutral‐point‐clamped (NPC) inverter. In BLDC motor, the high commutation torque ripple is an important origin of vibration, speed ripple and prevents the use of the BLDC motor drive system in high‐performance and high‐precision applications. For torque ripple reduction, the modified SEPIC converter is employed at the entrance of the three‐level NPC inverter, which regulates the DC‐link voltage according to the motor speed. Moreover, the three‐level NPC inverter is employed as a second‐stage converter to suppress current ripple for further torque ripple reduction. Finally, the performance of the proposed hybrid converter topology is verified by simulation and laboratory experimental results.
Design of auto frequency tuning capacitive power transfer system based on class‐E2 dc/dc converter
Authors: Lu Kai , Nguang Sing Kiong , Ji Shengkai , Wei Lei
Published: June 2017

This study presents the design of capacitive wireless power transfer systems based on a suboptimal Class‐E2 converter approach. The main reason for selecting the suboptimal Class‐E2 converter is due to its ability of maintaining its high efficiency over a wide bandwidth of operation frequency. However, Class‐E2 converters in general are sensitive to its load's variation. This variation greatly affects the output voltage and increases the switching loss of the system. Motivated by this drawback, the authors develop an auto‐frequency tuning mechanism based on a PI approach for the suboptimal Class‐E2 converter to regulate the output voltage and minimise the switching loss. A non‐contact communication mechanism is also developed to transmit the secondary side's measurements to the primary side. Finally, simulation and experiment are carried out to verify the effectiveness of the auto‐frequency tuning mechanism.
Reverse voltage generating circuit for rapid commutation of output current polarity in variable polarity arc welding power supply
Authors: Zhong‐Yu Yang , Zhi‐Ming Zhu , Bo Liu
Published: June 2017

The topology of variable polarity (VP) arc welding power supply is composed of a first inverting stage responsible for the adjustment of output current amplitude and a second inverting stage used for the commutation of output current polarity. A reverse voltage generating (RVG) circuit is proposed, which could be applied in the second inverting stage of a VP arc welding power supply to generate a stable reverse voltage with fixed amplitude during the commutation procedure and to make the commutation rate of output current more rapidly. First, a basic circuit unit is designed to illustrate the operating principle of the RVG circuit. Then, the Pspice simulations for the comparison between the RVG circuit and the conventional RC resonant circuit in the half‐bridge applications of second inverting stage are carried out to illustrate the superiority of RVG circuit. Finally, an experimental prototype of VP arc welding power supply is established to test and verify the proposed RVG circuit. The experimental waveforms of output current and voltage demonstrate that the RVG circuit is effective and suitable for generating a stable reverse voltage with fixed amplitude, and realizing a rapid commutation of the output current polarity in VP arc welding power supply.
Single‐phase ac–dc–ac topology for grid overvoltage and voltage harmonic mitigation
Authors: Maia Ayslan Caisson Norões , Jacobina Cursino Brandão
Published: June 2017

A single‐phase ac–dc–ac topology to improve power quality is proposed in this study. This configuration is obtained from the addition of a floating capacitor H‐bridge converter on the grid side of the conventional ac–dc–ac three‐leg topology. The role of the structure is not only to ensure regulated load voltage with fixed amplitude and frequency, grid current with low harmonic content and unitary power factor, but also to mitigate fundamental overvoltage and voltage harmonics at the grid. As a consequence, the proposed topology is suitable to operate as unified power quality compensator or uninterrupted power supply. It does not use isolation transformer and is capable of generating multilevel input voltages due to the cascaded H‐bridge. The operation with asymmetrical dc‐link voltages is considered to increase the number of voltage levels and reduce the harmonic content of the generated input voltages. Two pulse‐width modulation techniques and a control system are developed to regulate the dc‐link voltages and to decrease the harmonic distortion (HD), lowering the switching stress and also the power losses. The proposed configuration is compared with the conventional one with respect to HD and semiconductor losses. Simulated and experimental results are presented for validation purposes.
Model following average‐current‐mode control with 1/∛s compensator for interleaved boost converters with improved dynamic response
Authors: Liu He , Zhang Donglai
Published: June 2017

This study presents a model following average‐current‐mode (MFACM) control using a 1/∛s compensator to improve robustness and dynamic response for multiphase boost converters. The proposed 1/∛s compensator can maintain a constant phase boost of about 60° over two decades, which is attractive from the point of view of stability design when phase margin, gain margin, delay margin and modulus margin are taken into consideration. In addition, the MFACM control is shown to elevate perturbation rejection ability of converters by reducing closed‐loop output impedance and closed‐loop audio susceptibility, relative to traditional average‐current‐mode control methods with the almost same crossover frequency. Computer simulations and experimental results using a three‐phase interleaved boost converter are shown close agreement between modelled estimates and measured values.
NBP‐based control strategy for DSTATCOM
Authors: Mangaraj Mrutyunjaya , Panda Anup Kumar
Published: June 2017

A propounded control strategy called naive back propagation (NBP)‐based is implemented in designing of distribution static compensator (DSTATCOM) in this study. The performance of the DSTATCOM using both the proposed and control technique are compared under varying load condition in the three‐phase three‐wire (3P3W) distribution system. The extraction of both tuned active as well as reactive weighting components are obtained from the accuracy of the control algorithm with respect to proportional–integral controllers. The comparative study reveals with source current harmonics reduction, voltage regulation, load balancing, power factor correction and sizing of VSC. The results demonstrate the robustness of the DSTATCOM in order to show the superiority, reliability, robustness and effectiveness of the proposed approach compared with the conventional one. The effectiveness of both the algorithms are validated through the simulation using MATLAB and real‐time implementation conducted in real time digital simulator (RTDS) environment, showing the power quality indices.
Handshaking V2G strategy for grid connected PV assisted charging station
Authors: Sahoo Subham , Prakash Surya , Mishra Sukumar
Published: June 2017

This study presents a novel handshaking approach to reduce transformer and line overloading using plug‐in electric vehicles (PEVs) connected to a photovoltaic (PV) assisted charging station (CS) via vehicle‐to‐grid (V2G) control strategy. The discharging behaviour of PEVs on receiving an aggregator command is carried out using a priority index function under two variant of customer command: (i) normal charging; and (ii) fast charging. Moreover, it is carried out to maximise aggregator profit in an optimal fashion by broadcasting to each CS and scheduling their dispatch based on the available power feedback from each CS. The energy command compliance for handshaking is ensured in a sturdy manner using a contingency approach considering the uncertain mobile behaviour of PEVs. Owing to the highly unlikely travelling behaviour of PEVs, a novel distributed consensus‐based power restoration between a fleet of CSs is proposed to endure handshaking using average power contribution from the rest of the CS if contingency fails for any CS. The proposed strategy has been tested on a 1 kVA FPGA‐based experimental setup to validate the proposed control scheme under different scenarios.
Diagnosis of non‐linear mixed multiple faults based on underdetermined blind source separation for wind turbine gearbox: simulation, testbed and realistic scenarios
Authors: Hu Chun‐zhi , Yang Qiang , Huang Miao‐ying , Yan Wen‐jun
Published: June 2017

The diagnosis of multi‐fault in wind turbine gearbox based on vibration signal processing is considered challenging as the collected measurements from acceleration transducers are often a non‐linear mixture of signals induced from an unknown number of sources, i.e. an underdetermined blind source separation (UBSS) problem. In this study, a novel UBSS‐based algorithmic solution is proposed to address this technical challenge from two aspects: source number estimation and source signal recovery. The former is realised based on the empirical mode decomposition and singular value decomposition (SVD) joint approach; and for the latter, the observed vibration signals are transformed to the time‐frequency domain using short‐time Fourier transform to obtain the sparse representation of the signals. The fuzzy C‐means clustering and l1 norm decomposition are carried out to estimate the mixing matrix and recover the source signals, respectively. The performance of proposed solution is extensively assessed through experiments based on simulation, testbed and realistic wind farm measurements for a range of fault scenarios for both linear and non‐linear scenarios. The numerical result clearly confirms the effectiveness of the proposed algorithmic solution for non‐linear multi‐fault diagnosis of wind turbines.
Evaluating the effectiveness of a machine learning approach based on response time and reliability for islanding detection of distributed generation
Authors: Alam Mollah Rezaul , Muttaqi Kashem M. , Bouzerdoum Abdesselam
Published: June 2017

Conventional relays, such as vector surge relay, frequency relay and rate‐of‐change‐of‐frequency relay, are usually employed for islanding detection; however, these conventional relays fail to detect islanding incidents in the presence of small power imbalance inside the islanded system. This study presents an islanding detection approach for synchronous type distributed generation using multiple features extracted from network variables and a support vector machine (SVM) classifier. Features are extracted from a sliding temporal window, whose width is selected so as to achieve the highest detection rate at a fixed false alarm rate. The SVM classifier is trained with linear, polynomial and Gaussian radial basis function kernels, and the parameters of the kernels are tuned to improve the classification performance. The application of the proposed method is illustrated for islanding cases associated with different power imbalance conditions, including small power imbalance conditions associated with the non‐detection zone of conventional relays. Furthermore, variation of detection time as a function of power imbalance scenarios, which involve all probable combinations of deficit of active/reactive and excess of active/reactive power imbalance, is assessed in the testing phase. The performance of the proposed approach is evaluated and compared with those of conventional relays in terms of reliability and response time of islanding detection.
Smart load management of water injection systems in offshore oil and gas platforms integrating wind power
Authors: Sanchez Santiago , Tedeschi Elisabetta , Silva Jesus , Jafar Muhammad , Marichalar Alexandra
Published: June 2017

The pollution coming from the use of gas turbines (GTs) in oil and gas (O&G) platforms requires greener solutions. One option is to use wind turbines (WTs) to supply the water injection systems (WISs) and explore smart energy management to make the O&G sector more sustainable. The effect of WT integration, and their the coordination with the local GTs, needs to be carefully analysed since the intermittency of the wind can jeopardise the stability of the offshore grid. The existence of flexible loads (FLEX) interfaced by variable speed drives (VSD), such as WISs, can help overcome the challenges related to wind intermittency and rotor angle stability: suitable control of such non‐essential loads can be implemented to reduce the effect of wind power fluctuations, balance power generation and consumption and contribute to the optimal efficiency of the GT adjusting its loading conditions. This work investigates the system dynamics under short‐term wind‐induced power fluctuations, analysing the evolution of electrical variables, such as active power and generator rotor speed, to evaluate the possible arise of low‐frequency oscillations. The impact of an adequate WIS load control to increase the system damping is also explored and an algorithm for system damping estimation is proposed.
Weather forecasting error in solar energy forecasting
Authors: Sangrody Hossein , Sarailoo Morteza , Zhou Ning , Tran Nhu , Motalleb Mahdi , Foruzan Elham
Published: June 2017

As renewable distributed energy resources (DERs) penetrate the power grid at an accelerating speed, it is essential for operators to have accurate solar photovoltaic (PV) energy forecasting for efficient operations and planning. Generally, observed weather data are applied in the solar PV generation forecasting model while in practice the energy forecasting is based on forecasted weather data. A study on the uncertainty in weather forecasting for the most commonly used weather variables is presented. The forecasted weather data for 6 days ahead is compared with the observed data and the results of analysis are quantified by statistical metrics. In addition, the most influential weather predictors in energy forecasting model are selected. The performance of historical and observed weather data errors is assessed using a solar PV generation forecasting model. Finally, a sensitivity test is performed to identify the influential weather variables whose accurate values can significantly improve the results of energy forecasting.
Optimisation of controller parameters for grid‐tied photovoltaic system at faulty network using artificial neural network‐based cuckoo search algorithm
Authors: Kalaam Rahila N. , Muyeen S.M. , Al‐Durra Ahmed , Hasanien Hany M. , Al‐Wahedi Khaled
Published: June 2017

This study exhibits the optimum design procedure to tune controller parameters for grid‐connected distributed generation system based on cuckoo search algorithm (CSA). To investigate the effectiveness of proposed algorithm, a grid‐tied photovoltaic (PV) system consisting of two power electronic converters controlled by five proportional integral (PI) controllers is chosen. Setting proper values for all the PI controllers is a complicated task, notably when the system is non‐linear. In this study, response surface methodology (RSM) is used to develop the mathematical design of the PV system which is required to apply the optimisation algorithm. To minimise the design efforts of RSM, an alternate approach based on artificial neural network is introduced to develop the mathematical model of the PV system which is another salient feature of this research. Moreover, two modifications in the CSA are proposed to extract optimum parameters for the controllers which are found suitable in power system applications. Both the transient and dynamic performances of the system with the optimum values obtained through CSA are studied for different types of grid fault conditions using PSCAD/EMTDC. The design values are compared with values obtained through genetic algorithm and bacterial foraging optimisation. Experimental validation is also given for the proposed method.
Design methodology for a special single winding based bearingless switched reluctance motor
Authors: Choudhury Madhurjya Dev , Ahmed Firdausa , Kumar Gaurav , Kalita Karuna , Tammi Kari
Published: June 2017

Bearingless switched reluctance motors (BSRMs) have both magnetic bearing as well as conventional motor characteristics which make them suitable for diverse industrial applications. This study proposes a design methodology for a BSRM in order to calculate the appropriate geometrical dimensions essential for realising a minimum levitation force at every orientation of rotor. It is based on the stator–rotor overlap angle and helps in reducing the complexities associated with the self‐bearing operation of a switched reluctance motor (SRM). Different from a conventional SRM, the motor under study deploys a special single set parallel winding scheme for simultaneous production of torque as well as radial force. An analytical model incorporating this single set winding is developed for calculating the torque and the radial force. The proposed bearingless design is verified by developing a two‐dimensional finite‐element model of a 12/8 SRM in ANSYS Maxwell.
Development of interharmonics identification using enhanced‐FFT algorithm
Authors: Lin Hsiung Cheng
Published: June 2017

The fast Fourier transform (FFT) is a mostly used tool to measure power system harmonics. FFT, however, is not applicable to analyse interharmonics due to spectral leakage effect. Although International Electrotechnical Commission (IEC) standard is recommended for interharmonic measurement, the individual interharmonic frequency and respective amplitude cannot be worked out under this framework. For this reason, this paper proposes an enhanced‐FFT model to build up the relationship between interharmonic frequency and dispersed leakage energy. The mathematical equation is thus established to find actual value of interharmonic frequency. Moreover, the true interharmonic amplitude can be retrieved from the dispersed energy collection. In other words, the sampling window length is no longer required to match the interharmonic period and the correct measurement results can be achieved. The proposed model is developed using a simple arithmetic equation so that it is feasible for more efficient calculation for interharmonic analysis. Performance results verify that the proposed scheme can achieve accurate, rapid and reliable outcomes.
Laser‐assisted bending by magnetic force
Authors: Fetene Besufekad N. , Dixit Uday S. , Davim João Paulo
Published: June 2017

In this study, a laser‐assisted bending process is proposed, in which the external force is applied by magnets. The process can be used for bending the magnetic and non‐magnetic materials. The experiments indicated that a large bend angle with reduced edge effect can be obtained by this process. The process was simulated by finite element method and a reasonable agreement was obtained between the experimental and simulated bend angles. It was experimentally observed that the micro‐hardness after bending was greater than the original micro‐hardness for mild steel as well as stainless steel work plates. In all the cases, micro‐hardness reduced from laser‐irradiated surface to opposite surface. Performance of the process as well as its ability to get accurately simulated bring out its potential of adaptability in industries.
Development of water surface mobile robot inspired by water striders
Authors: Suzuki Kenji , Ichinose Richard Waki , Takanobu Hideaki , Miura Hirofumi
Published: June 2017

This work describes a water surface mobile robot utilising surface tension forces. Recent biological studies on water striders revealed how they stay afloat and move on the surface of water. By using their hairy legs coated with hydrophobic substance produced, they increase the water repellency and float by the surface tension. This work focuses on understanding the static and dynamic interactions between supporting legs and the surface of water. First, microstructured wire legs were fabricated by using femtosecond laser machining to enhance the water repellency. Then the supporting force, the pull‐off force and the drag force were measured to find the suitable legs for water strider robot. Finally, by assembling the legs optimised for supporting load and propulsion, a water strider robot weighing 4.39 g was developed. The robot successfully moved on the surface of water at a speed of 59.2 mm/s.
Synthesis of carbon nanoparticles from mustard oil and evaluation of their antibacterial activity against dental caries
Authors: Gautam Gorika , Jha Diksha , Gaurav Shailendra S. , Sharma Ashwani K. , Kumar Pradeep , Gautam Hemant K.
Published: June 2017

Dental infections are thorny since time immemorial mainly due to the accumulation of plaque on the teeth surface. Antibiotics are slowly losing their capability to degrade bacteria due to development of resistance in them which necessitates the need of new drug formulations. The role of carbon for tartar and plaque removal in the form of charcoal powder is seen for ages. Hence, in this study, nanotised form of carbon has been exploited for their role against resistant bacteria. Green synthesis of carbon nanoparticles (CNPs) was accomplished from the soot of the burning mustard oil which was collected on clay pots. The synthesised particles were characterised by UV spectroscopy, dynamic light scattering and transmission electron microscopy. Antibiotic sensitivity test of the isolated oral bacteria from dental cavity, post cavity and cavity‐free patients was done in order to find out the antibiotic resistant bacteria. Antimicrobial efficiency (minimum inhibitory concentration) of CNPs was carried out on these antibiotic resistant bacteria and observed their microbial killing potential. Hemolysis assay was conducted to comprehend the toxicity of these nanoparticles on human cells. Cell viability study on MRC‐5 cell line showed that nanoparticles are safe to use.
Nanoscale electric discharge‐induced FLG peeling off during the STM electric lithography
Authors: Yang Ye , Fang Zuhua
Published: June 2017

Scanning tunnelling microscope (STM) electric lithography exhibits its unique advantages in the nanoscale positioning accuracy, in situ measurement, atomic manipulation and ultra‐precise fabrication. Nowadays various nanoscale structures and devices have been delivered from STM electric lithography by versatile means of the local mechanical force, the chemical reaction and the thermal effects. In this paper, the authors have innovatively utilised the nanoscale electric discharge effect induced by the STM electric lithography to peel off the site‐specific few layer graphene (FLG) flakes on the highly oriented pyrolytic graphite sample. The piece number, distribution, area and thickness of the exfoliated graphene flakes generated under the different machining parameter settings were quantitatively analysed. It has been found out that both of the machining gap distance and the bias voltage amplitude play the decisive roles in the exfoliation of the FLG flakes. Moreover, the machining current was measured to validate the occurrence of the nanoscale electric discharge during the STM electric lithography processes. It directly proves the relevance of FLG flakes peeling off to the electric discharge. This work has confirmed the processing capability of the STM electric lithography for the FLG flakes peeling off, which is desired in the fabrication of graphene‐based nanodevices.
“How my hair look?”
Authors: Lopez Qiuana , Bucholtz Mary
Published: June 2017

This article builds on research in queer linguistics and linguistic scholarship on race in the media to examine the semiotic representation of race, gender, and sexuality inThe Wire, often considered one of the most “authentic” media representations of Blackness. Based on an analysis of the entire series, the article argues that this authenticity effect is partly due to the show’s complex African American characters, who reflect a range of gendered and sexual subjectivities. The analysis focuses on three queer Black characters onThe Wirewho are represented as both “authentically queer” in their social worlds and “authentically Black” in their language. However, the semiotic authenticity of the series is linked to its reification of familiar stereotypes of Blackness, especially hyperviolence and hypermasculinity. Thus, these characters both contest and complicate traditional representations of queerness and gender while reinforcing problematic representations of Blackness for its largely white, affluent target audience.
Unnatural acts lead to unconsummated marriages
Authors: Findlay Jamie Y.
Published: June 2017

In June and July 2013, the UK House of Lords debated, and ultimately accepted, a Bill to legalise same-sex marriage. Following the model of Baker’s (2004) work on a set of earlier Lords debates relating to homosexuality, this study uses a corpus-based keywords analysis to assess the main lexical differences between those arguing in favour and those arguing against a change to the marriage laws. In so doing, it sheds light on the ways in which discourses relating to homosexuality are constructed and accessed by the Lords. In general, it is shown that supporters of reform take advantage of their hegemonic liberal position to construct a simple line of argument in contrast to the opponents, who are forced to use more subtle and elaborate lines of reasoning by the limited discursive space available to those espousing anti-LGBT sentiments.
The legal hypothesis of creole genesis
Authors: Sessarego Sandro
Published: June 2017

The origins of the Afro-Hispanic Languages of the Americas (AHLAs), the languages that developed in Latin America from the contact of African languages and Spanish in colonial times, are extremely intriguing, since it still has to be explained why we do not find creole languages in certain regions of Spanish America, where the socio-demographic conditions for creole languages to emerge appear to have been in place in colonial times. Nowadays, in contrast, we can find such contact varieties in similar former colonies, which were ruled by the British, the French or the Dutch (McWhorter 2000). Despite the fascinating implications of this phenomenon, our knowledge of the AHLAs remains extremely limited. Several hypotheses have been proposed to account for this situation, but no common consensus has yet been achieved (Chaudenson 2001;Mintz 1971;Laurence 1974;Granda 1968;Schwegler 1993,2014;Lipski 1993; etc.). The pull of different views on the issue has been labelled in the literature as the ‘Spanish creole debate’ (Lipski 2005: ch.9).

The current study is aimed at casting new light on the Spanish creole debate by relying on a comparative analysis of slave laws in the Americas. This article highlights the role that legal differences played in shaping colonial societies and the Afro-European languages that developed in the New World.
Engsh, a Kenyan middle class youth language parallel to Sheng
Authors: Barasa Sandra Nekesa , Mous Maarten
Published: June 2017

Youth ‘languages’ are an important topic of research in the domain of linguistic change through language contact because the change is rapid and observable and also because the social dimension of change is inevitably present. Engsh, as a youth language in Kenya expresses not only modernity and Kenyan identity but also, the status of being educated, and it differs in this respect from Sheng, the dominant Kenyan youth language. The element of Engsh that expresses this aspect most directly is the use of a grammatical system from English whereas Sheng uses Swahili. In lexicon, Engsh draws upon Sheng and urban English slang. This is a first extensive description of Engsh. The social function of Engsh is interesting in that class is expressed in it, which is not often reported in African urban youth codes. Also the fact that Engsh is a non-exclusive register, which expands through its use in (social) media and most of all in computer mediated communication.
Afro-Brazilian Cupópia
Authors: Álvarez López Laura , Jon-and Anna
Published: June 2017

The present paper focuses on the speech of a rural Afro-Brazilian community called Cafundó, situated 150 km from São Paulo. In 1978, when linguistic data were collected, the community constituted approximately eighty individuals, descendants of two slave women who inherited their owners’ proprieties. According to earlier studies, when the inhabitants of Cafundó spoke in their supposed ‘African language’, Cupópia, they used structures borrowed from Portuguese and a vocabulary of possible African origin. A lexical analysis shows that the etymologies match historical and demographical data, indicating that speakers of varieties of Kimbundu, Kikongo, and Umbundu dominated in the community. Through a morphosyntactic analysis, specific features were found in the data, such as copula absence and variable agreement patterns. By showing that some of Cupópia’s specific grammatical features are not derived from the Portuguese spoken by the same speakers but are instead shared with more restructured varieties, this paper defends the hypothesis that this lexically driven in-group code is not simply a regional variety of Portuguese with a number of African-derived words.
Analyzing online suicide prevention chats
Authors: Cooren François , Higham Lise , Huët Romain
Published: June 2017

In this article, we propose to mobilize a communicative constitutive approach to analyze sessions that took place in the context of online suicide prevention chats in France. By analyzing the detail of a specific excerpt, we propose, more precisely, to draw a portrait of various figures that appear to express themselves in what could be called online help in action (see alsoBartesaghi, 2014). Beyond the various psychotherapeutic approaches that are supposed to inform what volunteers are saying and doing, our goal is to start with their practices to determine the figures that they implicitly or explicitly stage in their turns of talk to help out the callers. By analyzing the relational aspects of these conversations, we thus show that these sessions can be compared to a form of modern exorcism, where the callers’ distress, uneasiness or suffering is meant to pass in and through the conversations. It is the conditions of these passages that we are exploring, especially regarding the tensions that they generate.
Rhetoric, ethics, and the principle of charity
Authors: Stroud Scott R.
Published: June 2017

This article examines the challenge of partisanship to the free and open communication entailed by rich notions of democracy. Exploring the vexing riddle of how democratic citizens can balance openness and assertiveness in their dialogic interactions, I turn to the American pragmatist tradition for two important starting points. Drawing from William James and John Dewey, I highlight how the pragmatist tradition provides a nuanced reading of charity, both towards individuals and to situations. Charity is a choice of disposition, and it has vital implications for pragmatist rhetoric’s drive to instantiate a deep sense of democratic communication.
The speech we do not speak
Authors: Lipari Lisbeth A.
Published: June 2017

This essay investigates three distinct modalities of the dialogic: dialogic mind, dialogic praxis, and dialogic ethics. Although each modality shares central dialogic characteristics of polyphony, polymodality, and polychronicity (Bakhtin, 1981, 1984, 1986; Lipari, 2014), each also differs in important ways, some of which are lost by using the single word ‘dialogue’ to refer to them. Rather, I will here explore how the dialogic is not merely a mode of communicative praxis, but it is also a mode of communicative consciousness and a mode of communicative ethics. Each dialogic modality describes different manifestations of what might otherwise be called the dialogic; each mode differs from the others in important ways while also sharing similar attributes.
Communicative Ethics
Authors: Arnett Ronald C.
Published: June 2017

This essay examines the importance of semioethics in relationship to the work of Levinas. The interplay of semioethics and Levinas’s commitment to “ethics as first philosophy” announces the communicative height and weight of a semiotic signification that demands responsive human action. Semioethics is a communicative act that wades through the plethora of signs in the global communication production system with the objective of discerning signs of ill health that curtail care of life. Semioethics necessitates attentiveness and responsiveness to Otherness and difference. Semioethics functions as resistance, the unwillingness to accept and abide within an unreflective communication production system composed of taken-for-granted sameness of process and procedure.
A prelude to a semioethics of dialogue
Authors: Eicher-Catt Deborah
Published: June 2017

This paper interrogates the phenomenological experience of enchantment as a sign process. I argue that our ethical intentionality in the world is significantly enhanced when we understand how the aesthetics of enchantment conditions the very possibility of such an ethic as a semiotic phenomenological event of dialogue. First, I discuss a key problematic of contemporary life – our culture of distraction and its impact on our dialogic relations. Next, I outline my thematic – enchantment as consequence of sign actions, both in what I call its “inauthentic” and “authentic” forms. Third, I interpret each form and their impact on the ethics of dialogic relations. Finally, I contend that authentic enchantment, as a semiotic interpretant, signifies an “answering comprehension” or unique expression that resonates with the greater whole, the greater good – demonstrating what Susan Petrilli describes as a productive or pragmatic semioethic.
Owning one’s past
Authors: Ritivoi Andreea Deciu
Published: June 2017

In this paper, I engage with the question of historical interpretation as a form of dialogue that can face an individual conscience with disturbing choices and decisions made at an earlier time, and the expectations we might have about a proper response. My paper draws on Paul Ricoeur’s philosophical ideas, as well as on a controversial part of his biography – his alleged involvement in the Petain circle in France in the early 1940s – to propose that instead of thinking about historical knowledge as reconstruction of another time, revelation of beliefs, or even exposure of intentions, we should consider it as a form of dialogical remembering that marks two joint features of subjectivity: fallibility and attestation. My paper does articulate a defense of Ricoeur’s philosophical conception of forgiveness, but offers neither an apology for nor an accusation on moral and political grounds.
Representation and videography in linguistic landscape studies
Authors: Troyer Robert A. , Szabó Tamás Péter
Published: June 2017

Much Linguistic Landscape scholarship relies on visual data collection, primarily the use of still photography; however, the field has yet to address the theoretical underpinning of such visual and spatial representation. Furthermore, digital video is currently as easy to capture and share as digital photographs were when Linguistic Landscape studies first became prominent in the early 2000s. With these two points in mind, this article first grounds the documentation and analysis of the Linguistic Landscape in a theory of visual representation; it then provides a framework for videographic methodologies drawing on recent work in the related fields of anthropology and cultural geography. An example study utilizing non-participatory videography is summarized in which digital video recordings were used to capture and convey the Linguistic Landscape.
Language contact in Mesoamerica and beyond
Authors: Dakin Karen , Operstein Natalie
Published: June 2017

The purpose of this introductory chapter is to provide an overview of the volume by outlining some of the major threads in the published literature on language contact and contact-induced change in Mesoamerica and adjacent areas, and by situating the volume and its individual chapters in the context of this research.
Spanish infinitives borrowed into Zapotec light verb constructions
Authors: de Azcona Rosemary G. Beam
Published: June 2017

Spanish infinitives are commonly borrowed into Zapotec languages. The borrowed infinitive construction is here analyzed as a special type of light verb construction. In Southern Zapotec languages the construction occurs in a transitive version using ‘do’ and an intransitive version using ‘become’. This chapter analyzes the syntax of these constructions in Southern Zapotec, including the lexical status of the borrowed infinitives and the argument structure of the different forms of the construction.
The effect of external factors on the perception of sounds in Meꞌphaa
Authors: Marlett Stephen A.
Published: June 2017

The Meꞌphaa (Tlapanec) language genus, which displays some interesting internal diversification, has been in contact with other languages of southern Mexico, including those with which it is not genetically related, and with Spanish. This chapter examines various specific areas of the phonology of Meꞌphaa and discusses different factors – both internal to the genus and external – that seem to be affecting how the sounds of the language are perceived by the speakers of the language today. The primary evidence is based on the on-going development of an alphabetic representation of the language. The discussion of these facts leads to a new assessment of the value of traditional methods, based on a closed corpus, for analyzing the sound system of a language. The effects of external factors need to be taken into consideration.