bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation behaviours and interchangeability of modulators for electrical machines
Authors: Wen Honghui , Cheng Ming , Wang Wei , Zhang Gan 
Published: March 2021

AbstractThe authors aimed to investigate the modulation behaviours and the interchangeability of three kinds of modulators in electrical machines, which are short circuited coil, salient pole reluctance and flux barriers, to understand the evolution of the modulator and reveal their individual action mechanism based on the general airgap field modulation theory. The modulation behaviours are systematically analysed and compared, including the modulation principles of the improved short circuited coil, the relationship between salient pole reluctance and pole arc together with slot opening depth etc., based on which the key rule of interchangeable modulators is summarised. Although different modulators possess different magnetic field modulation principles and magnetic conversion capabilities, they share the similar asynchronous behaviours and modulated harmonics distribution. In addition, the detailed topological analysis of traditional brushless doubly fed machine with interchangeable and combined modulators is presented to show the effectiveness of the theoretical investigation. Electromagnetic performances comparison, such as airgap flux density distribution, cross coupling ability, general torque performances and inductance characteristics, of a brushless doubly fed machine with different modulators are provided to reveal the relation between the machine performances and magnetic field conversion capability. Theoretical predictions are verified by 2‐D finite element analysis and experimental measurements.
Simple current sensor fault‐tolerant control strategy for switched reluctance motors in high‐reliability applications
Authors: Ali Nasir , Gao Qiang 
Published: March 2021

AbstractSwitched reluctance motors (SRMs) are considered as a potential candidate in many high‐reliability demanding applications, including electrical vehicles (EVs), hybrid EVs and more electric aircrafts. For precise and stable control performance, normally an SRM drive requires one current sensor for each phase winding. Failure of any of these sensors will inevitably degrade the system's performance. The behaviour of an SRM drive under current sensor failure is investigated and a fault‐tolerant control technique is proposed by changing the current sensor installation scheme without adding extra current sensors. Moreover, through the analysis of the detected currents by the phase current sensors and the dc‐link sensor, a diagnostic scheme for current sensors failure is presented. The excitation current in the faulty phase under postfault conditions is reconstructed through a simple calculation without injecting a high‐frequency signal or modifying the switching signals, thereby reducing the current distortion and avoiding voltage penalty issues. Motor drive can operate with satisfactory control performance even when all the phase current sensors are in fault conditions. Detailed analysis under both steady state and dynamic conditions through thorough simulations and experiments has been carried out on a three‐phase 12/8 SRM. The extensive results validate the effectiveness of the proposed technique.
Open‐phase fault tolerant driving operation of dual‐inverter‐based traction drive
Authors: Pathmanathan M. , Viana C.C.D. , Semsar S. , Lehn P.W. 
Published: March 2021

AbstractA method for achieving open‐phase fault tolerant operation of a dual‐inverter‐based traction drive with charging capability is presented. This method utilises a contactor to connect the switching nodes of the two half bridges which are normally used for AC charging in this dual inverter configuration. These half bridges are then modulated to provide a path for zero‐sequence current and enhance the available voltage vector space of the drive by injecting a controllable common‐mode voltage between the two inverters. A control method and five‐level modulator based on zero‐sequence voltage control and phase shifted carriers are introduced to accommodate this novel remedial method. Using this approach, the open‐phase faulted dual inverter drive is able to operate with twice the speed range of the conventional open‐phase fault tolerant approach, which is to provide a path for zero‐sequence current by connecting the negative DC rails of the two inverters with a contactor. Simulation and experimental results with a prototype dual inverter drive are presented to validate the theory of the new control and modulation method. The experimental results showcase the proposed algorithms performance by dynamically responding to an open‐phase fault and starting from standstill, thereby proving its validity for an electric vehicle application.
The effect of dynamic behaviours of the water droplet on DC/AC flashover performance on silicone rubber surface: Experiment, simulation and theoretical analysis
Authors: Cao Wen , Xue Hao , Shen Wei , Yang Hao , Zhao Long , Wang Yang 
Published: March 2021

AbstractIt is usually seen that DC flashover voltage of the water droplet on the surface of silicone rubber (SIR) composite insulator is lower than AC flashover voltage. It is necessary to study the mechanisms and influencing factors of the surface properties. In this article, experiments are performed to study the moving processes of the water droplet and the influences of its dynamic behaviours on flashover voltage under DC/AC electric field. Besides, an electrohydrodynamic coupling method is employed to establish the simulating model. Moreover, the theoretical physical model is established to reveal the mechanisms of dynamic behaviours of a droplet. It is indicated that the simulation results are in good consistency with the experimental data. The elongation behaviours of a droplet on the surface of a composite insulator can influence the homogeneity of the electric field distribution along the sample's surface. It is shown that the different dynamic behaviours and flashover performances for a single water droplet on the SIR surface are both affected by the volume of the droplet and the type of voltage applied.
Active feedback supported CMOS LNA blended with coplanar waveguide‐fed antenna for Wi‐Fi networks
Authors: Roy Gunjan Mittal , Dwari Santanu , Kanaujia Binod Kumar , Kumar Sandeep , Song Hanjung 
Published: March 2021

AbstractThis study presents integration of complementary CMOS active feedback low noise amplifier with coplanar waveguide fed patch antenna for Wi‐Fi networks. The LNA design‐I, involves a cascode amplifier followed by active feedback common source amplifier offering wideband impedance matching with lowered parasitic losses. The inductor‐less feedback mechanism is used to nullify noise effect with extended bandwidth in the range of 2.2 to 5.8 GHz and a peak forward gain of 22.5 dB. It is implemented on agilent's advance design system using 45 nm CMOS process. The noise figure (NF) is approximately 2 dB while the stability factors µ and µ prime are well above 1 dB with IIP3 of about 15 dBm. The chip area is 0.57 x 0.57 mm2 under dc power supply of 1V while power consumption of 0.8 mW. A CPW fed antenna design‐II, achieves a wide band response similar to the bandwidth of LNA. The size of the fabricated antenna is calculated as 40 x 40 mm2. The peak gain is approximately 4.1 dBi at 3.9 GHz. The codesign‐III, proposes a receiver achieving a much wider band of 1.6 to 6 GHz with a gain of 16.5 dB and NF of 2.59 dB at 2.06 GHz. The codesign improves the system integration by reducing overall chip area and offers saving in the effective cost.
Field calculation of electric dipole excitation of a metafilm printed on a finite‐thickness dielectric slab using the susceptibility homogenization method
Authors: Azari A. , Firouzeh Z.H. , Bakhtafrouz A. 
Published: March 2021

AbstractHere, the authors calculate the fields due to the electric dipole that excites a homogenized metasurface which is printed on a finite thickness dielectric slab. The problem is solved by replacing the total parts below the periodic array which contain the dielectric slab and the half‐space under it, with an effective homogenous half‐space. Furthermore, the static interaction constants between dipoles which are located at two different materials’ interface are calculated. Then, with the help of the Lorentz method, the analytical formulae are presented to calculate the surface susceptibility densities of the homogenized metasurface located at two materials’ interface. These analytical formulae can be applied to arrays with both square and rectangular periodicity. An array of circular patches printed on dielectric slabs with different thicknesses is considered to verify the results. The results show good agreement compared to the fields calculated by commercial numerical software FEKO.
Prussian blue‐based inorganic flexible electrochromism glucose sensor
Authors: Chaudhary Anjali , Ghosh Tanushree , Pathak Devesh K , Kandpal Suchita , Tanwar Manushree , Rani Chanchal , Kumar Rajesh 
Published: March 2021

AbstractFlexible inorganic Prussian blue (PB) containing electrode hcas been synthesised using a simple electrodeposition technique for dual functions in electronics (electrochromism) and biology (glucose sensing) applications. Structural and spectroscopic characterisations of the fabricated film have been done using electron microscopy and Raman spectroscopy. Flexible inorganic electrochromic device is one of its kind having promising features with colour contrast (50%), coloration efficiency (80 cm2/C) and robust stability for more than 400 s. The prototype device contains only PB electrode as active electrochromic material with gel electrolyte in a pre‐designed device geometry that exhibits two primary colours, blue and green, with little amount of bias switching. Reversible redox processes have been found to be responsible for the electrochromism in PB containing flexible device. The same has been experimentally verified using spectroscopic and electrochemical techniques during device’s operation. Its additional use for glucose sensing purpose can be exploited for wearable electronics application. It is a first fully developed inorganic flexible device with superior electrochromic performance.
Orchestration‐based mechanism for sampling adaptation in sensing‐based applications
Authors: Harb H. , Baalbaki H. , Jaoude C. Abou , Jaber A. 
Published: March 2021

AbstractCurrently, the world witnesses a boom in the sensing‐based applications where the number of connected devices is becoming higher than the people. Such small sensing devices are now deployed in billions around the world, collecting data about the surroundings and reporting them to the data analysis centres. This fact allows a better understanding of the world and helps to reduce the effects of potential risks. However, while the benefits of such devices are real and significant, sensing‐based applications face two major challenges: big data collection and restricted power of sensor battery. In order to overcome these challenges, data reduction and sampling sensor adaptation techniques have been proposed to reduce data collection and to save the sensor energy. The authors propose an orchestration‐based mechanism (OM) for adapting the sampling rate of the sensors in the network. OM is two‐fold: first, it proposes a data transmission model at the sensor level, based on the clustering and Spearman coefficient, in order to reduce the amount of data transmitted to the sink; second, it proposes a sampling rate mechanism at the cluster‐head level that allows searching the similarity between data collected by the neighbouring sensors, and then to adapt their sensing frequencies accordingly. A set of simulations on real sensor data have been conducted to evaluate the efficiency of OM, in terms of data reduction and energy conservation, compared to other exiting techniques.
Closest Energy Matching: Improving peer‐to‐peer energy trading auctions for EV owners
Authors: Thomas Huw , Sun Hongjian , Kazemtabrizi Behzad 
Published: March 2021

AbstractHerein, a novel approach to conduct peer‐to‐peer energy auctions for electric vehicles (EVs) to benefit both buyers and sellers is presented. It considers a scenario where households can sell their surplus solar energy to visiting EVs that make use of the households' vacant charge points during the day. The aim of the energy trading is to maximise the amount of charge EVs receive from the solar energy, and increase the revenue for sellers. The novel Closest Energy Matching (CEM) double auction mechanism is proposed and it is compared with four other mechanisms. CEM allows the auction to take into account current energy requests as well as the potential future demand without requiring additional information. A novel algorithm, MARMES (MAtrix Ranking for Maximising Element Selection), is also presented to solve the optimisation problem that forms the basis of the CEM mechanism. The CEM mechanism on average results in 21.5% more solar energy used, lower cost to the consumer, a 24.9% increase in profits for sellers and a 71.4% reduction in required grid energy compared with the traditional double auction mechanism.
Design and optimization of printed spiral coils for wireless passive sensors
Authors: Noroozi Babak , Morshed Bashir I. 
Published: March 2021

AbstractMonitoring physiological signals during regular life might provide many benefits including early detection of abnormalities and tracking the severities of diseases. A wireless connection between the passive sensor and the scanner eliminates the obtrusive wires, resolves battery‐related issues, and makes it easy‐to‐use. We have previously proposed a wireless resistive analogue passive sensor technique that operates with the help of inductive coupling. The variation of resistive physiological transducer (secondary side) leads to amplitude modulation on the scanner coil (primary side). The design of printed spiral coil (PSC) on printed circuit board, significantly affects the performance of the overall system in terms of sensitivity, the output voltage change as a reflection of the transducer change. To optimize the PSC's profile and maximize the sensitivity, we employ three methods: iterative, analytical, and genetic algorithm (GA). The GA optimized PSCs, as the best result, have been fabricated and the measurement showed a sensitivity of 0.72 mƱ which has 5% (8.8%) deviation from the simulation (theoretical) results. This method can be utilized to design a PSC pair in near‐field applications to transfer amplitude modulation with various sizes and fabrication constraints.
Thia-Bridged Triarylamine[4]helicene-Functionalized Polynorbor­nenes as Redox-Active pH-Sensitive Polymers
Authors: Viglianisi Caterina , Lupi Michela , Menichetti Stefano , Stagnaro Paola , Utzeri Roberto 
Published: March 2021

AbstractA series of thia-bridged triarylamine[4]helicene-functionalized polynorbornenes P1, P2, and P3 were synthesized via ring-opening metathesis polymerization (ROMP). The polymers obtained undergo a reversible one-electron oxidation, in both solution and solid state, responding to the pH changes in the surrounding medium showing a clear reversible electrochromic behavior.
Stents as Bridge to Arterial Switch Operation for D-Transposition of Great Arteries Late Presenter
Authors: Liman Novita Gemalasari , Prakoso Radityo 
Published: March 2021

AbstractWe report a 5-month-old infant with dextro-transposition of great arteries (D-TGA) with intact ventricular septum (IVS) who had low left ventricular mass index, small patent ductus arteriosus (PDA), and stretched patent foramen ovale. The patient had respiratory failure due to pneumonia. The surgical intervention was considered very high risk. Thus, the patient underwent PDA stenting with balloon predilation technique followed by atrial septal stenting with false impression of dislodgement—“pseudo-dislodgement” because of inadvertent retraction of patent foramen ovale that was confirmed by transthoracic echocardiography guidance. After the procedure, the left ventricular mass index improved and patient was planned for arterial switch operation. The combined approach of PDA and atrial septal stenting may provide potential nonsurgical method of ventricular preparation for D-TGA/IVS late presenter, acting as a bridge to arterial switch operation especially those living in remote areas.
Are gender stereotypes changing over time? A cross-temporal analysis of perceptions about gender stereotypes in Spain (¿Están cambiando los estereotipos de género con el tiempo? Un análisis transtemporal de las percepciones sobre los estereotipos de género en España)
Authors: Lopez-Zafra Esther , Garcia-Retamero Rocio 
Published: March 2021

The evolution of societal gender roles over time changes perceptions about the characteristics of men and women and how they behave. Previous studies on the dynamics of gender stereotypes have investigated people’s perceptions about men and women at specific time points (i.e., thinking in the past, present and future). However, studies comparing results of present perceptions of men and women measured at a lapse of time could clarify whether there have been real changes in gender stereotypes or just a desired perception for change. In the current research, we investigate whether perceptions about gender stereotypes evolve over time by comparing 453 Spanish participants’ perceptions of men and women over a 10-year period based on data collected at two time points: 2006 ( n = 199) and 2016 ( n = 254). In line with the conclusions of previous research, our results indicate that perceptions of gender stereotypes evolved over time from 2006 to 2016. Interestingly, over 10 years, men and women are perceived to be more similar on feminine characteristics but diverge on masculine characteristics. We discuss the dynamic of stereotypes in light of social constraints that may influence gender characteristics adscription.
Revisiting Marxism and decolonisation through the legacy of Samir Amin
Authors: Ndlovu-Gatsheni Sabelo J. 
Published: March 2021

ABSTRACT
Samir Amin’s legacy of deployment of Marxist science, dedication to pan-Africanism and commitment to revolutionary liberation of the global South from imperialism and capitalism is re-evaluated from an epistemological vantage point. This is necessary because Amin raised fundamental epistemological issues as he challenged the discipline of economics, built institutions which advanced alternative thinking, and consistently created concepts and theories from concrete situations in the global South in general and Africa in particular. Three main issues stand out. The first is how epistemology shaped modern patterns of domination and subordination within modern Euro–North American-centric internationalism. The second is how intersections of Marxism and decoloniality reinforce a robust critique of modern racial capitalism. The third is how the legacy of Amin enabled a synthesis of Marxism (democratic Marxism of the 21st century), pan-Africanism, and decolonisation (planetary decoloniality of the 21st century) to consistently challenge and oppose the dominant and current imperial/colonial/capitalist internationalism.
Effects of magnetic field and particles content on rheology and resistivity behavior of magnetorheological elastomer with embedded cobalt particles
Authors: Zainudin Afiq Azri , Mazlan Saiful Amri , Shabdin Muhammad Kashfi , Abdul Aziz Siti Aishah , Homma Koji , Nazmi Nurhazimah , Nordin Nur Azmah , Noordin Ahmad Faiz , Rambat Shuib 
Published: March 2021

Abstract
In most studies, carbonyl iron particles were merged with carbon-based particles such as graphite or carbon black particles as fillers to enhance the electrical properties of magnetorheological elastomers (MREs). These combined fillers can be replaced by using a single material in order to reduce brittleness due to the high amount of composition. Therefore, in this research, cobalt particles having dual properties, magnetic and electrical, have been employed as a filler in MRE. A total of three anisotropic MREs containing 53, 60, and 67 wt% of cobalt were fabricated through the mixing process method. The characterization related to morphological and magnetic properties of MRE samples was analyzed by using field emission scanning electron microscopy and vibrating sample magnetometer. Then, the rheological properties of the MRE in various strengths of magnetic field intensity between 0 and 0.8 T were conducted by using a rheometer. Afterward, the effect of the cobalt on the electrical properties was investigated and compared with different applied forces towards the MRE. The outcome showed that the rheological and electrical properties of MRE were improved with the increase of cobalt content embedded in the silicone matrix. Higher cobalt content in MRE contributed to a higher magnetorheological (MR) effect and simultaneously lower the electrical resistivity. Therefore, the addition of cobalt particles as a filler in MRE is a great potential to be applied as sensors.
Unraveling excitation energy transfer assisted by collective behaviors of vibrations
Authors: Li Zeng-Zhao , Ko Liwen , Yang Zhibo , Sarovar Mohan , Whaley K Birgitta 
Published: March 2021

Abstract
We investigate how collective behaviors of vibrations such as cooperativity and interference can enhance energy transfer in a nontrivial way, focusing on an example of a donor–bridge–acceptor trimeric chromophore system coupled to two vibrational degrees of freedom. Employing parameters selected to provide an overall uphill energy transfer from donor to acceptor, we use numerical calculations of dynamics in a coupled exciton–vibration basis, together with perturbation-based analytics and calculation of vibronic spectra, to identify clear spectral features of single- and multi-phonon vibrationally-assisted energy transfer (VAET) dynamics, where the latter include up to six-phonon contributions. We identify signatures of vibrational cooperation and interference that provide enhancement of energy transfer relative to that obtained from VAET with a single vibrational mode. We observe a phononic analogue of two-photon absorption, as well as a novel heteroexcitation mechanism in which a single phonon gives rise to simultaneous excitation of both the trimeric system and the vibrational degrees of freedom. The impacts of vibrations and of the one- and two-phonon VAET processes on the energy transfer are seen to be quite different in the weak and strong site–vibration coupling regimes. In the weak coupling regime, two-phonon processes dominate, whereas in the strong coupling regime up to six-phonon VAET processes can be induced. The VAET features are seen to be enhanced with increasing temperature and site–vibration coupling strength, and are reduced in the presence of dissipation. We analyze the dependence of these phenomena on the explicit form of the chromophore–vibration couplings, with comparison of VAET spectra for local and non-local couplings.
Graphene phonons lifetime and mean free path using ab initio molecular dynamics and spectral energy density analysis
Authors: Mafakheri Morteza , Dodaran Amir Abbas Sabouri 
Published: March 2021

Abstract
In this study, simulation of ab initio molecular dynamics with phonon spectral analysis was performed with the aim of understanding the two-dimensional thermal conductivity in graphene. Using the atomic velocities obtained from the simulation of ab initio molecular dynamics, and the analysis of spectral energy density, we calculated the lifetime of phonons in each mode. The calculations show that acoustical phonons ZA, LA and TA phonons have larger lifetimes and mean free path so they have more contribution in thermal conductivity. Among optical phonons, ZO-mode phonons, i.e. vibrations perpendicular to the graphene layer, have a longer lifetime than LO, TO models, but due to the low group velocity, their role in thermal vesting is negligible.