bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic formation of stable current-driven plasma jets
Authors: Underwood Thomas C. , Loebner Keith T. K. , Miller Victor A. , Cappelli Mark A.
Published: February 2019

Instabilities play a prominent role in determining the inherent structure and properties of magnetized plasma jets spanning both laboratory and astrophysical settings. The manner in which prominent unstable modes dynamically evolve remains key to understanding plasma behavior and control. In astrophysical phenomena, self-similar jets are observed to propagate over vast distances while avoiding breakup caused by unstable mode growth. However, the production of stable dense plasma jets in the laboratory has been limited by the onset of unstable modes that restrict jet lifetime, collimation, and scalability. In this work, we visualize the formation of stable laboratory-generated, dense, super-magnetosonic plasma jets in real time, and we identify an underlying mechanism that contributes to this behavior. The current-driven plasma jets generated in our experiments form a flowing Z-pinch, which is generally unstable to the m = 1 kink instability. Our results indicate that a stable dense plasma jet can be maintained for timescales over which a steady pinch current can be sustained, even at levels which would otherwise lead to rapid unstable mode growth and resultant pinch disassembly.
A pH-based sensor array for the detection and identification of proteins using CdSe/ZnS quantum dots as an indicator
Authors: Yan Peng , Li Xizhe , Dong Yanhua , Li Bingyu , Wu Yayan
Published: February 2019

A novel and simple fluorescence sensor array was developed for the detection and identification of proteins using pH buffer solutions as sensing elements.
Probabilistic mapping of single molecule junction configurations as a tool to achieve the desired geometry of asymmetric tripodal molecules
Authors: Kolivoška Viliam , Šebera Jakub , Sebechlebská Táňa , Lindner Marcin , Gasior Jindřich , Mészáros Gábor , Mayor Marcel , Valášek Michal , Hromadová Magdaléna
Published: February 2019

Probabilistic mapping of asymmetric molecular junctions.
The influence of nanoparticles on the excitation energies of the photochromic dihydroazulene/vinylheptafulvene system
Authors: Hillers-Bendtsen Andreas Erbs , Hansen Mia Harring , Mikkelsen Kurt V.
Published: February 2019

This paper studies how nanoparticles affect photochromic systems, focusing on the influence of gold nanoparticles on the optical properties of the dihydroazulene/vinylheptafulvene (DHA/VHF) system.
Cyclization reaction dynamics of an inverse type diarylethene derivative as revealed by time-resolved absorption and fluorescence spectroscopies
Authors: Sotome Hikaru , Kitagawa Daichi , Nakahama Tatsumoto , Ito Syoji , Kobatake Seiya , Irie Masahiro , Miyasaka Hiroshi
Published: February 2019

Time-resolved absorption and fluorescence spectroscopies revealed the cyclization reaction dynamics of an inverse diarylethene derivative.
Complete catalog of ground-state diagrams for the general three-state lattice-gas model with nearest-neighbor interactions on a square lattice
Authors: Silva Daniel , Rikvold Per Arne
Published: February 2019

The fifteen topologically different zero-temperature phase diagrams in the model's full, five-dimensional parameter space provide a solid foundation for studies at finite temperatures.
Molecular water oxidation catalysis by zwitterionic carboxylate bridge-functionalized bis-NHC iridium complexes
Authors: Puerta-Oteo Raquel , Jiménez M. Victoria , Pérez-Torrente Jesús J.
Published: February 2019

Carboxylate functionalized bis-NHC ligands allow for the stabilization of high-valent iridium intermediate species involved in homogeneous water oxidation catalysis.
Ni/NiM2O4 (M = Mn or Fe) supported on N-doped carbon nanotubes as trifunctional electrocatalysts for ORR, OER and HER
Authors: Qin Qing , Chen Lulu , Wei Tao , Wang Yimeng , Liu Xien
Published: February 2019

The NCNT/Ni–NiM2O4 (M = Mn or Fe) exhibit excellent trifunctional electrocatalytic performance for ORR, OER and HER.
The impact of microstructural features of carbon supports on the electrocatalytic hydrogen evolution reaction
Authors: Suliman Munzir H. , Adam Alaaldin , Siddiqui Mohammad N. , Yamani Zain H. , Qamar Mohammad
Published: February 2019

The study evaluates the dependency of the HER performance on the microstructural attributes of carbon supports, and correlates the performance variation to crucial features of the as-prepared electrode.
Hydrogen-bonded organo-amino phosphonium halides: dielectric, piezoelectric and possible ferroelectric properties
Authors: Vijayakanth Thangavel , Pandey Richa , Kulkarni Priyangi , Praveenkumar Balu , Kabra Dinesh , Boomishankar Ramamoorthy
Published: February 2019

A series of hydrogen bonded binary salts of diphenyl diisopropylamino phosphonium halides of the formula [Ph2(iPrNH)2P]·X (X = Cl, Br, I) shows dielectric, piezoelectric and possible ferroelectric properties.
Outlier detection and gap filling methodologies for low-cost air quality measurements
Authors: Ottosen Thor-Bjørn , Kumar Prashant
Published: February 2019

Data processing offers a promising solution to alleviate artifacts from low-cost air quality sensors.
In situ fabrication of carbon dots-based lubricants using a facile ultrasonic approach
Authors: He Chuang , Yan Honghao , Li Xiaojie , Wang Xiaohong
Published: February 2019

Mechanical friction and wear account for approximately one third of the present global energy consumption.
An integrated microfluidic system for rapid detection and multiple subtyping of influenza A viruses by using glycan-coated magnetic beads and RT-PCR
Authors: Shen Kao-Mai , Sabbavarapu Narayana Murthy , Fu Chien-Yu , Jan Jia-Tsrong , Wang Jen-Ren , Hung Shang-Cheng , Lee Gwo-Bin
Published: February 2019

A microfluidic chip featuring HA × NA arrayed reaction chambers for RT-PCR was developed for diagnosis and subtyping of influenza A viruses.
High-throughput screening and Bayesian machine learning for copper-dependent inhibitors of Staphylococcus aureus
Authors: Dalecki Alex G , Zorn Kimberley M , Clark Alex M , Ekins Sean , Narmore Whitney T , Tower Nichole , Rasmussen Lynn , Bostwick Robert , Kutsch Olaf , Wolschendorf Frank
Published: February 2019

One potential source of new antibacterials is through probing existing chemical libraries for copper-dependent inhibitors (CDIs), i.e., molecules with antibiotic activity only in the presence of copper. Recently, our group demonstrated that previously unknown staphylococcal CDIs were frequently present in a small pilot screen. Here, we report the outcome of a larger industrial anti-staphylococcal screen consisting of 40 771 compounds assayed in parallel, both in standard and in copper-supplemented media. Ultimately, 483 had confirmed copper-dependent IC50 values under 50 μM. Sphere-exclusion clustering revealed that these hits were largely dominated by sulfur-containing motifs, including benzimidazole-2-thiones, thiadiazines, thiazoline formamides, triazino-benzimidazoles, and pyridinyl thieno-pyrimidines. Structure–activity relationship analysis of the pyridinyl thieno-pyrimidines generated multiple improved CDIs, with activity likely dependent on ligand/ion coordination. Molecular fingerprint-based Bayesian classification models were built using Discovery Studio and Assay Central, a new platform for sharing and distributing cheminformatic models in a portable format, based on open-source tools. Finally, we used the latter model to evaluate a library of FDA-approved drugs for copper-dependent activity in silico. Two anti-helminths, albendazole and thiabendazole, scored highly and are known to coordinate copper ions, further validating the model's applicability.
Silicon substrate effects on ionic current blockade in solid-state nanopores
Authors: Tsutsui Makusu , Yokota Kazumichi , Nakada Tomoko , Arima Akihide , Tonomura Wataru , Taniguchi Masateru , Washio Takashi , Kawai Tomoji
Published: February 2019

Si compositions strongly affect the single-particle sensitivity of solid-state nanopore sensors by the capacitance effect to retard resistive pulse signals.
Selectively grown GaN nanowalls and nanogrids for photocatalysis: growth and optical properties
Authors: Winnerl Julia , Kraut Max , Artmeier Sabrina , Stutzmann Martin
Published: February 2019

Position-controlled growth of GaN nanowalls and nanogrids with predefined planes as sidewalls with high crystal quality for photocatalytic applications.
Base induced C–CN bond cleavage at room temperature: a convenient method for the activation of acetonitrile
Authors: Zhang Xiaofeng , Zhang Zilong , Xiang Shiqun , Zhu Yingzu , Chen Changneng , Huang Deguang
Published: February 2019

Acetonitrile was activated to form formaldehyde and cyanide in air. Utilization of the product [CuII–CN] for catalytic cyanation was investigated.
How do transition-metal-substituted POMs modify the photoanode of dye-sensitized solar cells? A DFT study
Authors: Gao Yu , Yan Li-Kai , Guan Wei , Su Zhong-Min
Published: February 2019

Herein, the electronic structures and absorption spectra of a series of transition-metal-substituted polyoxometalates (TMSPs) were systematically investigated to screen promising candidates for the POM/TiO2 nanocomposite film used in DSSCs using the density functional theory (DFT) and time-dependent DFT (TD-DFT) methods.
Identifying the location of Cu ions in nanostructured SAPO-5 molecular sieves and its impact on the redox properties
Authors: Radnik Jörg , Dang Thi Thuy Hanh , Gatla Suresh , Raghuwanshi Vikram Singh , Tatchev Dragomir , Hoell Armin
Published: February 2019

Where is the Cu located? Combining X-ray Absorption Fine Spectroscopy (XAFS) with Anomalous Small-Angle X-ray Scattering (ASAXS) can answer this question for Cu loaded molecular sieves.
Sidewall contact regulating the nanorod packing inside vesicles with relative volumes
Authors: Wu Zeming , Yuan Hongyan , Zhang Xinyun , Yi Xin
Published: February 2019

Contact between the nanorod sidewall and membrane protrusion regulates vesicle tubulation and the buckling and protrusion of encapsulated nanorods.
Lehmann rotation of cholesteric droplets driven by Marangoni convection
Authors: Oswald P. , Ignés-Mullol J. , Dequidt A.
Published: February 2019

We show experimentally and theoretically that the Lehmann effect recently observed by Yoshioka and Araoka (Nat. Commun., 2018,9, 432) in emulsified cholesteric liquid crystal droplets under temperature gradients is due to Marangoni flows rather than to the thermomechanical or chemomechanical couplings often invoked to explain the phenomenon.
Tuning self-healing properties of stiff, ion-conductive polymers
Authors: Qin Jiaxu , Lin Francis , Hubble Dion , Wang Yujia , Li Yun , Murphy Ian A. , Jang Sei-Hum , Yang Jihui , Jen Alex K.-Y.
Published: February 2019

Stiff polymers with tunable self-healing and mechanical properties show promising potential in electrochemical devices.
Exploring the potential of a urea derivative: an AIE-luminogen and its interaction with human serum albumin in aqueous medium
Authors: Halder Senjuti , Samanta Soham , Das Gopal
Published: February 2019

A simple AIE active urea molecule (L1) can selectively interact with HSAviaturn-on fluorescence response in aqueous medium.
A unified approach for investigating chemosensor properties – dynamic characteristics
Authors: Frankær Christian G. , Sørensen Thomas Just
Published: February 2019

The response is what makes a sensor. In this review the methods for characterizing the response are laid out.
An environment-friendly device for rapid determination of chemical oxygen demand in waters based on ozone-induced chemiluminescence technology
Authors: Zhao Youquan , Zhou Junpeng , Song Yang , Li Zhende , Liu Xiao , Zhang Mimi , Zang Hechao , Cao Xuan , Lv Chenxing
Published: February 2019

An environment-friendly device was developed and optimized for the rapid measurement of chemical oxygen demand (COD) in waters.
Prediction of ligand modulation patterns on membrane receptors via lysine reactivity profiling
Authors: Zhou Ye , Liu Zheyi , Zhang Jinbao , Dou Tongyi , Chen Jin , Ge Guangbo , Zhu Shujia , Wang Fangjun
Published: February 2019

A mass spectrometry-based lysine reactivity profiling strategy for the prediction of the ligand modulation patterns on neuronal membrane receptors.
A new ZIF molecular-sieving membrane for high-efficiency dye removal
Authors: Li Zhan , Yang Pingping , Gao Zhuangzhuang , Song Mingqiu , Fang Qianrong , Xue Ming , Qiu Shilun
Published: February 2019

A new and robust ZIF membrane was prepared and demonstrated excellent dye removal capacity due to its unique pore structure.
A novel strategy for the synthesis of hollow Pt–Cu tetradecahedrons as an efficient electrocatalyst toward methanol oxidation
Authors: Zhao Ruopeng , Fu Gengtao , Chen Zhijing , Tang Yawen , Wang Yi , Huang Shaoming
Published: February 2019

Pt–Cu TNs can be simply achieved within a few minutes by an H+-assisted disproportionation reaction using Cu2O tetradecahedrons as the template. Due to its unique structural advantages, these Pt–Cu TNs exhibit extraordinary electrocatalytic performance toward MOR.
Bayesian determination of the effect of a deep eutectic solvent on the structure of lipid monolayers
Authors: McCluskey Andrew R. , Sanchez-Fernandez Adrian , Edler Karen J. , Parker Stephen C. , Jackson Andrew J. , Campbell Richard A. , Arnold Thomas
Published: February 2019

A novel reflectometry analysis method reveals the structure of lipid monolayers at the air-DES interface.
Tuning of the gold work function by carborane films studied using density functional theory
Authors: Hladík Martin , Vetushka Aliaksei , Fejfar Antonín , Vázquez Héctor
Published: February 2019

Using density functional theory including van der Waals interactions, we calculate the adsorption and electronic properties of dithiol-dicarba-closo-dodecaboranes chemisorbed on Au(111) surfaces.
Gold substrates of controlled roughness and electrokinetic properties formed by nanoparticle deposition
Authors: Morga Maria , Nattich-Rak Małgorzata , Oćwieja Magdalena , Adamczyk Zbigniew
Published: February 2019

The formation of gold sensors via controlled nanoparticle self-assembly.
Organocatalytic cycloaddition of carbonyl sulfide with propargylic alcohols to 1,3-oxathiolan-2-ones
Authors: Zhou Hui , Zhang Rui , Zhang Hui , Mu Sen , Lu Xiao-Bing
Published: February 2019

Lewis base-COS adducts were firstly studied as organocatalysts for the cyclization of propargylic alcohols with carbonyl sulfide.
Computational insights into different chemoselectivities in Rh2(ii)-catalyzed N-aryl nitrene and analogous Rh2(ii)/Cu(i)-catalyzed aryl-substituted carbene involving reactions
Authors: Wu Xueli , Bao Xiaoguang
Published: February 2019

Computational studies were carried out to investigate the mechanisms and the origins of chemoselectivities among multiple reactive sites for Rh2(ii)-catalyzed N-aryl nitrene and analogous Rh2(ii)/Cu(i)-catalyzed aryl carbene involving reactions.
Charge-tuning of glycosaminoglycan-based hydrogels to program cytokine sequestration
Authors: Freudenberg Uwe , Atallah Passant , Limasale Yanuar Dwi Putra , Werner Carsten
Published: February 2019

Glycosaminoglycan (GAG)-based biohybrid hydrogels of varied GAG content and GAG sulfation pattern were prepared and applied to sequester cytokines.
Cross-linking of shrimp tropomyosin catalyzed by transglutaminase and tyrosinase produces hypoallergens for potential immunotherapy
Authors: Wang Yanbo , Ni Saiqiao , Wang Chong , Li Xiuting , Fu Linglin
Published: February 2019

Transglutaminase or tyrosinase treatment reduces tropomyosin allergenicity and produces potential hypoallergens for immunotherapy.
Coal analysis by laser-induced breakdown spectroscopy: a tutorial review
Authors: Sheta Sahar , Afgan Muhammad Sher , Hou Zongyu , Yao Shun-Chun , Zhang Lei , Li Zheng , Wang Zhe
Published: February 2019

This review article forms a guideline for LIBS contribution in coal analysis, encompassing fundamental aspects, operation modes, data processing, and analytical results. LIBS applications related to coal utilization are also highlighted (fly ash analysis and combustion monitoring).
Quantification of amine functional groups on silica nanoparticles: a multi-method approach
Authors: Sun Ying , Kunc Filip , Balhara Vinod , Coleman Brian , Kodra Oltion , Raza Mohammad , Chen Maohui , Brinkmann Andreas , Lopinski Gregory P. , Johnston Linda J.
Published: February 2019

Surface chemistry is an important factor for quality control during production of nanomaterials and for controlling their behavior in applications and when released into the environment.
The top-down synthesis of single-layered Cs4CuSb2Cl12 halide perovskite nanocrystals for photoelectrochemical application
Authors: Wang Xu-Dong , Miao Nai-Hua , Liao Jin-Feng , Li Wen-Qian , Xie Yao , Chen Jian , Sun Zhi-Mei , Chen Hong-Yan , Kuang Dai-Bin
Published: February 2019

Herein, lead-free single-layered Cs4CuSb2Cl12 and Cs3M2X9 (X = Cl, Br, I; M = Sb, Bi) perovskite NCs have been prepared for the first time via a top-down liquid-phase ultrasonic exfoliation technique.
Understandingexo-selective Diels–Alder reactions involving Fischer-type carbene complexes
Authors: Cabrera-Trujillo Jorge Juan , Fernández Israel
Published: February 2019

Exo-selective Diels–Alder cycloaddition reactions can be successfully achieved by the proper selection of an initial Fischer carbene complex.
Diastereoselectivity in the boron aldol reaction of α-alkoxy and α,β-bis-alkoxy methyl ketones
Authors: Fernandes Alessandra A. G. , Leonarczyk Ives A. , Ferreira Marco A. B. , Dias Luiz Carlos
Published: February 2019

We investigated the asymmetric induction in boron enolate aldol reactions of α-alkoxy and α,β-bisalkoxy methyl ketones and elucidated the synergistic effect between the stereocenters.
An effective amino acid-assisted growth of ultrafine palladium nanocatalysts toward superior synergistic catalysis for hydrogen generation from formic acid
Authors: Hong Cheng-Bin , Zhu De-Jie , Ma Dong-Dong , Wu Xin-Tao , Zhu Qi-Long
Published: February 2019

An amino acid-assisted approach is developed to immobilize ultrafine Pd NPs onto mesoporous carbon, which exhibits remarkable catalytic activity for hydrogen generation.
Aggregation-induced emission lights up the swelling process: a new technique for swelling characterisation of hydrogels
Authors: Tavakoli Javad , Zhang Hong-ping , Tang Ben Zhong , Tang Youhong
Published: February 2019

The characterization of the swelling properties in hydrogels suffers uncertainty due to the limitations that occur during weight change measurement.
Palladium/copper-catalyzed decarbonylative heteroarylation of amides via C–N bond activation
Authors: Zhou Ping-Xin , Shi Shuai , Wang Jia , Zhang Yalei , Li Changzheng , Ge Chunpo
Published: February 2019

A novel strategy for the synthesis of 2-arylated oxazole derivatives via palladium/copper-catalyzed decarbonylative heteroarylation of amides via C–N bond activation by ground-state destabilization is reported.
Cryogenic wormlike micelles
Authors: Yin Hongyao , Feng Yujun , Li Peixun , Doutch James , Han Yixiu , Mei Yongjun
Published: February 2019

Cryogenic wormlike micellar solutions with a freezing point far below 0 °C and unique rheological behavior are fabricated from the self-assembly of a C22-tailed zwitterionic surfactant in a mixed solvent of ethylene glycol and water. Such fluids could find applications in areas where viscoelasticity is highly desired at subfreezing temperatures.
Natural rubber–SiO2 nanohybrids: interface structures and dynamics
Authors: Sattar Md. Abdul , Nair A. Sreekumaran , Xavier P. J. , Patnaik Archita
Published: February 2019

Homogeneous dispersion of silica nanoparticles (SiO2 NPs) in natural rubber (NR) is a key challenge for engineering high-performance nanocomposites and elucidation of their structure on a molecular basis.
Spatial engineering of a Co(OH)x encapsulated p-Cu2S/n-BiVO4 photoanode: simultaneously promoting charge separation and surface reaction kinetics in solar water splitting
Authors: He Bing , Wang Yang , Liu Xueqin , Li Yinchang , Hu Xiaoqin , Huang Jing , Yu Yongsheng , Shu Zhu , Li Zhen , Zhao Yanli
Published: February 2019

An ultrathin Co(OH)x coated p-Cu2S/n-BiVO4 heterojunction photoanode with improved charge separation efficiency was prepared, showing a photocurrent density of 3.51 mA cm−2.
Predictive fabrication of Ni phosphide embedded in carbon nanofibers as active and stable electrocatalysts
Authors: Kim Ji-Yong , Park Hwanyeol , Joo Wonhyo , Nam Dae-Hyun , Lee Sungwoo , Kim Hyoung Gyun , Ahn In-Kyoung , Kang Ho-Young , Lee Gi-Baek , Jung In-ho , Kim Mi-Young , Lee Gun-Do , Joo Young-Chang
Published: February 2019

With the combination of first principle calculations and thermodynamics, a predictive fabrication to modify structure and phase was developed.
Versatile antifouling coatings based on self-assembled oligopeptides for engineering and biological materials
Authors: Li Nan , Yue Xuanfeng , Zhang Li , Wang Ke , Zhang Jing , Zhang Zhiqi , Dang Fuquan
Published: February 2019

The existence of nonspecific protein adsorption often results in significant challenges for microfluidic devices and laboratory cultureware used in biological experiments.
Polyrotaxane-based biointerfaces with dynamic biomaterial functions
Authors: Arisaka Yoshinori , Yui Nobuhiko
Published: February 2019

Regulating protein adsorption and cell response by dynamic biomaterial functions.
Engineering Innovation in Speech Science: Data and Technologies
Authors: Hagedorn Christina , Sorensen Tanner , Lammert Adam , Toutios Asterios , Goldstein Louis , Byrd Dani , Narayanan Shrikanth
Published: February 2019

Purpose

As increasing amounts and types of speech data become accessible, health care and technology industries increasingly demand quantitative insight into speech content. The potential for speech data to provide insight into cognitive, affective, and psychological health states and behavior crucially depends on the ability to integrate speech data into the scientific process. Current engineering methods for acquiring, analyzing, and modeling speech data present the opportunity to integrate speech data into the scientific process. Additionally, machine learning systems recognize patterns in data that can facilitate hypothesis generation, data analysis, and statistical modeling. The goals of the present article are (a) to review developments across these domains that have allowed real-time magnetic resonance imaging to shed light on aspects of atypical speech articulation; (b) in a parallel vein, to discuss how advancements in signal processing have allowed for an improved understanding of communication markers associated with autism spectrum disorder; and (c) to highlight the clinical significance and implications of the application of these technological advancements to each of these areas.

Conclusion

The collaboration of engineers, speech scientists, and clinicians has resulted in (a) the development of biologically inspired technology that has been proven useful for both small- and large-scale analyses, (b) a deepened practical and theoretical understanding of both typical and impaired speech production, and (c) the establishment and enhancement of diagnostic and therapeutic tools, all having far-reaching, interdisciplinary significance.

Supplemental Material

https://doi.org/10.23641/asha.7740191
Programmable metasurface‐based RF chain‐free 8PSK wireless transmitter
Authors: Tang Wankai , Dai Jun Yan , Chen Mingzheng , Li Xiang , Cheng Qiang , Jin Shi , Wong Kai‐Kit , Cui Tie Jun
Published: February 2019

In this Letter, a wireless transmitter using the new architecture of programmable metasurface is presented. The proposed transmitter does not require any filter, nor wideband mixer or wideband power amplifier, thereby making it a promising hardware architecture for cost‐effective wireless communications systems in the future. Using experimental results, the authors demonstrate that a programmable metasurface‐based 8‐phase shift‐keying (8PSK) transmitter with 8 × 32 phase adjustable unit cells can achieve 6.144 Mbps data rate over the air at 4.25 GHz with a comparable bit error rate performance as the conventional approach without channel coding, but with less hardware complexity.
Energy‐efficient computation offloading in 5G cellular networks with edge computing and D2D communications
Authors: Jia Qingmin , Xie Renchao , Tang Qinqin , Li Xiaolu , Huang Tao , Liu Jiang , Liu Yunjie
Published: February 2019

Computation offloading has been considered as one of the key research issues in edge computing fields. In order to reduce the energy consumption of the mobile terminal, the energy efficiency issue of computation offloading has attracted a lot of attention from academia and industry. In this study, the authors propose an energy‐efficient computation offloading scheme in 5G cellular networks with edge computing and device‐to‐device (D2D) communications. They consider the computation offloading to fog computing devices via D2D communications and mobile edge computing (MEC) servers via cellular networks. And thus the computation task execution model can be composed of local execution, fog computing device execution and MEC server execution. Then, they formulate the computation offloading issue as stochastic optimisation problem, and use the Lyapunov optimisation technology framework to solve this problem. Finally, extensive simulation results are presented to illustrate the effectiveness of the proposed scheme.
Position sensorless direct torque control for six‐phase permanent magnet synchronous motor under two‐phase open circuit
Authors: Lin Xiaogang , Huang Wenxin , Jiang Wen , Zhao Yong , Dong Dingfeng , Liu Saide
Published: February 2019

A position sensor is usually required in the existing fault‐tolerant direct torque control (FT‐DTC) system for the multiphase permanent magnet synchronous motor (PMSM). Thus, the volume, weight, and cost of the system is increased, and the reliability is decreased. The conventional high‐performance position sensorless strategies for the multiphase motor under fault‐free condition cannot be directly applied to FT‐DTC system. To improve this situation, a high‐speed position sensorless FT‐DTC strategy for a six‐phase symmetrical winding PMSM with two opened phases is proposed in this study. Firstly, modified variables and a new rotating coordinate system are defined to achieve the symmetrical and decoupled mathematical model. Secondly, a stator flux observer based on the modified variables and a new coordinate system is proposed. According to the current model of modified stator flux, the estimated modified stator current can be achieved. Then, the estimated error of the modified stator current is sent to the integrator of the modified stator flux observer to correct the voltage model. Finally, the proposed stator flux observer is applied in FT‐DTC for six‐phase PMSM with two opened phases to realize the position sensorless operation at high speed. The experimental results verify the feasibility and effectiveness of the proposed strategy.
Design of miniaturised meandered loop on‐chip antenna with enhanced gain using shorted partially shield layer for communication at 9.45 GHz
Authors: Singh Harshavardhan , Mandal Sanjukta , Mandal Sujit Kr. , Karmakar Ayan
Published: February 2019

A significantly miniaturised meandered loop on‐chip antenna (MeLOCA) for communication at 9.45 GHz has been proposed. First, a meandered loop antenna size is reduced and its gain is enhanced by introducing a partially shield layer (PSL). Then, the antenna size is further reduced with a shorted conical pin connecting the antenna and PSL. The PSL provides capacitive loading and shifts resonating frequency of the reference antenna from 23 to 11.07 GHz. Also, it reduces substrate loss by obstructing EM wave propagation towards the lossy Silicon substrate and offers gain enhancement. Moreover, shorting to PSL offers an enhanced electrical length and shifts resonating frequency at 9.45 GHz. Thus, combination of PSL and shorting pin leads to realise the optimally designed MeLOCA size of 2.1 × 2 mm2 with reduction up to λ0/15.11. Simulated maximum gain and efficiency of −29 dB and 21.07%, respectively, make the antenna a suitable candidate for short range communication. Also, maximum of 16 and 20 dB and minimum of 3 and 5.6 dB isolations between co‐polarisation and cross‐polarisation components are achieved, respectively, in E and H planes. A prototype has been fabricated using 0.18 μm CMOS technology and good agreement between simulated and measured return loss characteristics is observed.
Influence of spatial‐wideband effects in evaluation of mm‐wave communications
Authors: Dupleich Diego , Schäfer Eric , Del Galdo Giovanni , Thomä Reiner
Published: February 2019

Hybrid, mixed analogue/digital beam‐forming architectures are a central research topic for the development of mm‐wave communication for fifth generation. Most approaches are based on phase shifters in the analogue part, which are inherently narrowband. In this study, the authors evaluate the effects and performance of narrowband beam‐steering on wideband signals using two different modelling approaches: spatial‐narrowband model, in which the inter‐antenna element delays are neglected, and spatial‐wideband model, in which the inter‐antenna element delays are considered. They show that neglecting the spatial‐wideband effects on channel models overestimates the focusing of beam‐forming, the expected delay spread reduction, and achievable data‐rate with an increasing number of antennas and bandwidth. These effects are quantised by simulations using a realistic ray‐tracing scenario at 60 GHz.
New topology of a switched‐capacitor‐based multilevel inverter with a single DC power supply
Authors: Taheri Asghar , Samsami Hosein
Published: February 2019

The utilisation and importance of multilevel inverters, as one of the key component of new electrical systems, are ever‐increasing. As a result, many works and evolutions have been carried out, which lead to improvements of topologies and control strategies. Newly introduced topologies can generate output voltage with maximum level number, minimum switching components and power supplies. This study introduces a multilevel inverter with minimum number of DC power supply and optimum number of semiconductors based on the switched‐capacitor method. One of the best features of the proposed topology is its voltage generation with boost capability without any need for H‐bridge. Moreover, the proposed topology has modular extension capability in order to increase the number of output levels. The comparison between the proposed converter and some previous topologies shows that it has better conditions with respect to the used semiconductor count, switches and capacitors losses. The operation and performance of the proposed multilevel converter have been ascertained through simulations and verified experimentally for a single‐phase 17‐level inverter. All results are illustrated to show the proposed converter's ability in smooth sinusoidal output voltage generation with boosting the input voltage without any transformer.
Design and implementation of a SIMO DC–DC converter
Authors: Dhananjaya Mudadla , Pattnaik Swapnajit
Published: February 2019

Multiport converters have tremendous performance over conventional solutions that employ multiple single converters in multi‐input and multi‐output applications. Furthermore, they provide the most economic operation and improve the performance of the system. Hence, in the recent past, a lot of development and research have been carried out for developing the single‐input–multi‐output (SIMO) converters in various aspects which are presented in the study. These topologies have some assumptions which are made on the charging of inductor current and design of duty cycle for achieving multiple outputs. In this study, an SIMO DC–DC converter is proposed. It independently regulates both the outputs at different voltage levels and none of the assumptions are made on the basis of inductor charging currents (iL1 > iL2 or iL1 < iL2). Cross‐regulation problems do not exist, so the output voltage V01 (V02) is not influenced by the variation of load current i02 (i01), also the proposed converter has the ability to avoid the common grounding problems between the outputs. Low‐power (200 W) prototype circuit is developed to verify the feasibility of the proposed converter and the experimental results are validated with simulation results.
Automatic modulation classification based on joint feature map and convolutional neural network
Authors: Wang Feng , Yang Chenlu , Huang Shanshan , Wang Hao
Published: February 2019

The authors propose an automatic modulation classification algorithm to discriminate the radar emitter signals exploiting deep learning of convolutional neural network (CNN) based on a joint feature map. The joint feature map including time‐frequency map and instantaneous autocorrelation (IA) map is generated to achieve superior classification performance on the identification of both phase modulated signals and frequency modulated signals. Afterwards, a CNN is designed to extract the features of the joint feature map. Training and test samples are designed to evaluate the recognition rate of the CNN. Simulation results show that the joint feature map makes up for the weakness of a single feature map for the classification of frequency modulated signals and phase modulated signals simultaneously, and superior classification accuracy is obtained.
Dynamic charging of electric vehicles integrating renewable energy: a multi‐objective optimisation problem
Authors: Humfrey Harry , Sun Hongjian , Jiang Jing
Published: February 2019

Dynamically charging electric vehicles (EVs) have the potential to significantly reduce range anxiety and decrease the size of battery required for acceptable range. However, with the main driver for progressing EV technology being the reduction of carbon emissions, consideration of how a dynamic charging system would impact these emissions is required. This study presents a demand‐side management method for allocating resources to charge EVs dynamically considering the integration of local renewable generation. A multi‐objective optimisation problem is formulated to consider individual users, an energy retailer and a regulator as players with conflicting interests. A 19% reduction in the energy drawn from the power grid is observed over the course of a 24 h period when compared with a first‐come‐first‐served allocation method. This results in a greater reduction in CO2 emissions of 22% by considering the power grid's make‐up at each time interval. Furthermore, a 42% reduction in CO2 emissions is achieved compared to a system without local renewable energy integration. By varying the weights assigned to the players’ goals, the method can reduce overall demand at peak times and produce a smoother demand profile. System fairness is shown to improve with an average Gini coefficient reduction of 4.32%.
Warm and cool starspots with opposite polarities
Authors: Strassmeier K. G. , Carroll T. A. , Ilyin I. V.
Published: February 2019

Aims. We present a temperature and a magnetic-field surface map of the K2 subgiant of the active binary II Peg. Employed are high resolution Stokes IV spectra obtained with the new Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT).

Methods. Fourteen average line profiles are inverted using our iMap code. We have employed an iterative regularization scheme without the need of a penalty function and incorporate a physical 3D description of the surface field vector. The spectral resolution of our data is 130 000 which converts to 20 resolution elements across the disk of II Peg.

Results. Our main result is that the temperature features on II Peg closely correlate with its magnetic field topology. We find a warm spot (350 K warmer with respect to the effective temperature) of positive polarity and radial field density of 1.1 kG coexisting with a cool spot (780 K cooler) of negative polarity of 2 kG. Several other cool features are reconstructed containing both polarities and with (radial) field densities of up to 2 kG. The largest cool spot is reconstructed with a temperature contrast of 550 K, an area of almost 10% of the visible hemisphere, and with a multipolar magnetic morphology. A meridional and an azimuthal component of the field of up to ±500 G is detected in two surface regions between spots with strong radial fields but different polarities. A force-free magnetic-field extrapolation suggests that the different polarities of cool spots and the positive polarity of warm spots are physically related through a system of coronal loops of typical height of ≈2 R⋆. While the Hα line core and its red-side wing exhibit variations throughout all rotational phases, a major increase of blue-shifted Hα emission was seen for the phases when the warm spot is approaching the stellar central meridian indicating high-velocity mass motion within its loop.

Conclusions. Active stars such as II Peg can show coexisting cool and warm spots on the surface that we interpret resulting from two different formation mechanisms. We explain the warm spots due to photospheric heating by a shock front from a siphon-type flow between regions of different polarities while the majority of the cool spots is likely formed due to the expected convective suppression like on the Sun.
Simulation and modelling of microclimate in a building with high thermal mass during the winter season
Authors: Ţurcanu Florin Emilian , Verdeş Marina , Ciocan Vasilică , Burlacu Andrei , Bălan Marius Costel , Luciu Răzvan Silviu , Vizitiu Robert Ştefan
Published: February 2019

This paper presents the simulation method for evaluating the heating system from a church. The inside climate has been evaluated by measures of temperature and humidity taken in the winter season. The aim of the paper is to model and validate the indoor climate measures thought numerical analysis and to evaluate the heating system performance. The paper include a case study over and representative category of buildings, used as worship place that can contain heritage values. Nowadays, to conserve the historical heritage is a fact studied in many countries of Europe.
Numerical study and design of a dew point evaporative cooler for buildings
Authors: Maalouf Chadi , Moussa Tala , Ferial Boudjabi Amel , Abada Djallel , Polidori Guillaume , Rouag Saffidine Djamila , Wurtz Etienne
Published: February 2019

Refreshing air remains a crucial problem in warm climates where electricity consumption for air conditioning has become excessive and irrational for several years, notably in Algeria. Research in this field is increasingly oriented towards new techniques that can reduce costs and environmental impacts. Among these techniques, the evaporative dew point cooling technology is the most promising as it can cool outdoor air to temperatures below its wet bulb temperature. The aim of this work is to model and design a dew point cooler for french and algerian climates. This model is used to study the effect of the cooler parameters such as its length, water temperature and working air ratio on its cooling effectiveness and supply temperature.
Numerical modelling and experimental study of heat and moisture properties of a wall based on date palm fibers concrete
Authors: Alioua Tarek , Agoudjil Boudjemaa , Boudenne Abderrahim
Published: February 2019

In the present paper, we study with both experimental and numerical aspect the heat and moisture transfer properties of a wall based on concrete filled with the natural fibers. The wall was placed in climatic chamber and temperature and relative humidity were monitored at different depths. A developed model describing heat and moisture transfers in porous building materials was implemented in COMSOL Multiphysics and solved with the finite element method. The obtained results are compared with experimental data. A relatively good agreement was obtained for both temperature and relative humidity variation at different depths. Finally, the developed model gives almost a good prediction despite the classical difficulties encountered at the experiment, which is very promising for the prediction of the hygrothermal behavior of bio-based building materials at different conditions.
Numerical model of a solar ventilated facade element: experimental validation, final parameters and results
Authors: Bejan Andrei-Stelian , Bode Florin , Teodosiu Cătalin , Croitoru Cristiana Verona , Năstase Ilinca
Published: February 2019

The present paper analyses the airflow through the lobed orifices of a transpired solar collector which acts as a solar ventilated facade element through numerical simulation. This study is part of a complex research project which analyses the implementation of phase changing materials within air solar collectors. We decided to study an elementary part of the collectors' absorbent plate with four equivalent orifices in order to obtain the velocity and temperature field at the outlet of the computing domain since the numerical simulation of the entire solar collector (more than 5000 orifices) is not feasible due to the big amount of computational resources and time needed. This paper presents the experimental validation of the numerical model, its final parameters and preliminary results. The numerical simulation was conducted using Ansys Fluent CFD software and the results were processed via Tecplot. The boundary conditions imposed were emphasised and k-ε RNG turbulence model was used according to the literature. After comparing the velocity profiles and temperature fields obtained with both experimental and numerical approaches we concluded that the numerical model reproduces real flow phenomena within acceptable limits. The numerical model thus obtained will be used in further studies in order to optimise the collectors' geometry and characteristics by means of parametrical analyses.
Experimental and numerical study of the air distribution inside a car cabin
Authors: Dancă Paul , Bode Florin , Năstase Ilinca , Croitoru Cristiana Verona , Meslem Amina
Published: February 2019

The main declared goal of all car manufacturers is to ensure high comfort inside the cabin and to reduce the fossil fuel. It is well-known that the time spent by the people indoor has raised in the last decade. The distance between the home and the workplace increased due to diversity of activities and hence job diversity. The thermal comfort during the travel must to be ensured to reduce the occupant’s thermal stress. The present study is investigating a comparison between the measured data and the numerical simulation results in the case when the ventilation system is functioning. It was evaluated the effect of the boundary conditions air flow and air velocity distribution in a passenger compartment in two cases: first is the general used constant inlet flow and the second is a new approach of importing the measured data obtained during the experimental measurement session as a boundary condition.CFD simulations were made taking as input the measured data obtained during experimental session. We have observed differences between initial simulation results and the measured data, therefore, for more accurate results, a new approach is needed, to impose as boundary conditions the measured data.
A TOPSIS-based approach for wind turbines ranking with negative performance ratings and different weighting strategies
Authors: Zahariea Dănuţ , Husaru Dorin Emil , Pavăl Mihai Silviu
Published: February 2019

This paper presents an application of TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) multi-dimensional criteria decision-making method for a case study related with a wind turbine based on-grid power supply system with negative performance ratings and different weighting strategies. Two wind turbines (XZ and XL) are comparatively analysed with respect to a power supply system for an industrial consumer and a given site. The site wind potential has been obtained from NASA Surface meteorology and Solar Energy database. The on-grid power supply system has been modelled and simulated using HOMER Pro software. Ten attributes have been considered: five technical criteria, four financial criteria and one environmental criterion. Eleven different weighting strategies have been considered. From all these weighting strategies, the XZ wind turbine has been selected in 8 cases while the XL wind turbine has been selected in 2 cases. For two particular weighting strategies, the most suitable alternative (XZ) coincides with the ideal solution, while the other alternative (XL) coincides with the negative ideal solution.
Simple vs complex models for solar cells
Authors: Săbăduş Andreea , Paulescu Marius
Published: February 2019

In this paper three different procedures for extracting the current-voltage characteristics of a crystalline photovoltaic module are studied. Each procedure is associated to a solar cell model characterized by a well-defined degree of complexity. The results emphasize that the simple models approximate the current-voltage characteristics of a solar cell as good as the more complex models. Even if all the procedures analysed in this paper approximate well the measured characteristics, the specific model parameters experience a large dispersion. From a broader perspective, the results raise a question mark on the ability of the current procedures to accurately extract the solar cell parameters.
A peculiar behaviour of liquid jet impact
Authors: Pătraşcu Claudiu , Bălan Corneliu
Published: February 2019

Coalescent masses of fluid, formed upon liquid jet impact, should exhibit either dripping or jetting regardless of the distance between the nozzles. The study reveals that above a certain flow rate, by increasing this distance, the coalescent mass enters a dripping state, when only a jetting regime is previously present. This is followed again by a jetting regime before breakup which occurs at a critical distance. The upper limit of this dripping state is achieved when Bond number is equal to unity, this result being valid below a certain critical Reynolds number.
Analogy in the processes of heat exchange of capillary-porous coatings in energy installations
Authors: Genbach Alexander , Bondartsev David , Iliev Iliya , Terziev Angel
Published: February 2019

A model of the dynamics of steam bubbles generating on a solid surface in porous structures and a steam-generating wall (substrate) is developed. The model is based on the filming and photography with speed camera SKS-1M. The removal of high heat fluxes (up to 2х106 W/m2) is provided by the combined action of capillary and mass forces with application of intensifiers. An analytical model is developed based on the theory of thermoelasticity. The limiting state of a poorly heat-conducting porous coating and a metal substrate has been determined. The heat fluxes were calculated from the time of spontaneous appearance of the steam nucleation (10-8) up to the time of material destruction (102 ÷ 103 s). The destruction of the coating under the action of compression forces occurs in much earlier time than the tension forces. The intervals of the heat flux within which such destruction occurs are different for the quartz coating qmax ≈ 7х107 W/m2, qmin ≈ 8х104 W/m2 and for granite coating qmax ≈ 1х107 W/m2, qmin ≈ 21х104 W/m2. Experimental units, experimental conditions, the results of the heat exchange crisis and the limiting state of the surface are presented, and critical heat fluxes are calculated. The investigated capillary-porous system, operating under the combined action of capillary and mass forces, has the advantage over pool boiling, thin-film evaporators and heat pipes.