bluuebunny/crossref_metadata_2025 huggingface dataset:
The Growth of Dunes in Rivers
Authors: Bradley Ryan W. , Venditti Jeremy G.
Published: January 2019

Dune response to variable flow has been well documented, but there is no universal model to predict dune dimensions as they respond to imposed flows. Here we use a series of flume experiments to explore dune growth in response to constant flow to better understand the form of dune growth curves. Observations of dune growth from a flat sand bed were made at three flow depths, under five different constant transport stages in a laboratory flume. The transport stages ranged from the sediment entrainment threshold to suspension conditions. The bed was flattened before each run and topography was continually mapped, providing observations of dune growth and morphology at each distinct transport stage condition. The results show that dune growth curves exhibited three different behaviors: (1) exponential growth; (2) punctuated growth, when a period of initially linear growth was abruptly interrupted by exponential growth; and (3) instantaneous growth, when bed evolution happened so quickly that we were unable to take measurements of the phenomenon. Growth behavior is dependent on the applied transport stage, and the time for a growing dune field to reach equilibrium decreases nonlinearly with transport stage. Observations of evolving dunes and the time required to achieve an equilibrium bed state are used to propose a series of relations that can predict dune dimensions through time.
The Response of Fish Diversity in a Highly Modified Large River System to Multiple Anthropogenic Stressors
Authors: DeBoer Jason A. , Thoms Martin C. , Casper Andrew F. , Delong Michael D.
Published: January 2019

Large riverine landscapes are among the most productive ecosystems on earth, and the most affected by humans. Few studies explicitly explore the effects of, or responses to, multiple stressors in highly modified large river systems. Changes in fish assemblages in response to multiple anthropogenic stressors were explored from a 60‐year data set for the Illinois River (Illinois, USA). Despite a legacy of stressors, the highly modified Illinois River responded to additional multiple stressors, especially four distinct stressor phases, which included two policies to improve water quality and bigheaded carp invasion. The response in fish diversity (Shannon H′) was complex in terms of the number of thresholds in the pattern of fish diversity, the rate and direction of change between thresholds, and the variance of response at two spatial scales and two ecological levels of organization. Overall, nine response trajectories were observed. Changes in fish diversity in the Illinois River since 1959 do not conform to current ecosystem response models. Without long‐term and broad‐scale data, elucidating complex responses in large river ecosystems is unlikely. Expanding the spatial and temporal scale of investigation in modified large rivers will increase our ability to understand how these ecosystems respond to multiple stressors.
Orbital Forcing, Ice Volume, and CO2 Across the Oligocene‐Miocene Transition
Authors: Greenop Rosanna , Sosdian Sindia M. , Henehan Michael J. , Wilson Paul A. , Lear Caroline H. , Foster Gavin L.
Published: January 2019

Paleoclimate records suggest that a rapid major transient Antarctic glaciation occurred across the Oligocene‐Miocene transition (OMT; ca. 23 Ma; ~50‐m sea level equivalent in 200–300 kyr). Orbital forcing has long been cited as an important factor determining the timing of the OMT glacial event. A similar orbital configuration occurred 1.2 Myr prior to the OMT, however, and was not associated with a major climate event, suggesting that additional mechanisms play an important role in ice sheet growth and decay. To improve our understanding of the OMT, we present a boron isotope‐based CO2 record between 22 and 24 Ma. This new record shows that δ11B/CO2 was comparatively stable in the million years prior to the OMT glaciation and decreased by 0.7‰ (equivalent to a CO2 increase of ~65 ppm) over ~300 kyr during the subsequent deglaciation. More data are needed, but we propose that the OMT glaciation was triggered by the same forces that initiated sustained Antarctic glaciation at the Eocene‐Oligocene transition: long‐term decline in CO2 to a critical threshold and a superimposed orbital configuration favorable to glaciation (an eccentricity minimum and low‐amplitude obliquity change). When comparing the reconstructed CO2 increase with estimates of δ18Osw during the deglaciation phase of the OMT, we find that the sensitivity of the cryosphere to CO2 forcing is consistent with recent ice sheet modeling studies that incorporate retreat into subglacial basins via ice cliff collapse with modest CO2 increase, with clear implications for future sea level rise.
TTG‐Adakitic‐Like (Tonalitic‐Trondhjemitic) Magmas Resulting From Partial Melting of Metagabbro Under High‐Pressure Condition During Continental Collision in the North Qaidam UHP Terrane, Western China
Authors: Yu Shengyao , Zhang Jianxin , Li Sanzhong , Santosh M. , Li Yunshuai , Liu Yongjiang , Li Xiyao , Peng Yinbiao , Sun Deyou , Wang Zhengyi , Lv Pei
Published: January 2019

The tectonic regime and melting conditions of adakitic tonalitic‐trondhjemitic leucosomes and tonalite plutons from the North Qaidam terrane are evaluated through petrology, whole‐rock major, trace element and Sr‐Nd isotopic data and zircon U‐Pb data. Zircons from leucosomes and metabasites preserve distinct U‐Pb age populations: early Ordovician inherited zircon cores record a protolith age of ~470 Ma, whereas zircon rims preserve subsequent HP granulite facies metamorphism, anatexis, and magmatism between 437 and 433 Ma. Whole‐rock geochemistry suggests that three types of leucosomes and tonalite plutons have geochemical features similar to adakites. Type 1 leucosomes record high Sr contents and positive Eu anomalies representing an earlier period of plagioclase accumulation. The flat fractionated rare earth element patterns of type 2 leucosomes correspond to residues of HP mafic granulites, and the steep fractionated rare earth element patterns of type 3 leucosomes correspond to garnet‐ and clinopyroxene‐rich residues. Petrological observations with P‐T paths and experimentally constrained melting curves together infer that melting of the metagabbro were triggered by the breakdown of amphibole ± zoisite under high‐pressure conditions. Therefore, tonalite, trondhjemite, and granodiorite (TTG)‐adakitic magmas in the North Qaidam terrane were produced through partial melting of newly emplaced gabbroic rocks with an arc affinity under high‐pressure, granulite facies conditions in a thickened lower crust during continental collision. This model explains the origin of TTG‐adakitic rocks and related continental growth and crustal differentiation genetically associated with continental collision.
Seven New Awardees of Celebrate 100 Grants
Authors: McEntee Chris
Published: January 2019

These latest creative and far-reaching projects chosen for AGU Centennial support range from a giant map of Mars for display on the U.S. National Mall to a climate science workshop in Puerto Rico.
Mayor Signs Landmark Clean Energy Law for D.C.
Authors: Showstack Randy
Published: January 2019

The new law, which gained widespread support, including in the environmental and business communities, requires that all electricity sold in the city come from renewable energy sources by 2032.
Repeated Seismic Slipping Events Recorded in a Fault Gouge Zone: Evidence From the Nojima Fault Drill Holes, SW Japan
Authors: Lin Aiming , Nishiwaki Takafumi
Published: January 2019

Drilling investigations and structural analysis of drill cores reveal that a fault gouge zone of 10–30 cm in width was observed at depths of ~260 to 900 m in nine drill holes that intersected the Nojima Fault (NF), on which the 1995 Mw 6.9 Kobe (Japan) earthquake occurred. Logging data and an analysis of mesostructures and microstructures in drill cores show that (i) a ~60‐m wide fault damage zone containing a 10‐ to 30‐cm‐thick fault gouge zone developed in the NF, (ii) the fault gouge zone can be divided into 11–20 thin layers of different color, and (iii) the individually colored layers contain different color breccias of fault gouge that are offset and/or cut by cracks and crack‐filled calcite and quartz veinlets. Our results reveal that the fault gouge zone probably records more than 11–20 paleoseismic faulting events along the NF during the late Pleistocene‐Holocene.
IFT80 is required for stem cell proliferation, differentiation, and odontoblast polarization during tooth development
Authors: Yuan Xue , Cao Xu , Yang Shuying
Published: January 2019

Primary cilia and intraflagellar transport (IFT) proteins control a wide variety of processes during tissue development and homeostasis. However, their role in regulation of stem cell properties during tooth development remains elusive. Here, we revealed that dental pulp stem cells (DPSCs) express IFT80, which is required for maintaining DPSC properties. Mice with deletion of IFT80 in odontoblast lineage show impaired molar root development and delayed incisor eruption through reduced DPSC proliferation and differentiation, and disrupted odontoblast polarization. Impaired odontoblast differentiation resulted from disrupted hedgehog (Hh) signaling pathways. Decreased DPSC proliferation is associated with impaired fibroblast growth factor 2 (FGF2) signaling caused by loss of IFT80, leading to the disruption of FGF2-FGFR1-PI3K-AKT signaling in IFT80-deficient DPSCs. The results provide the first evidence that IFT80 controls tooth development through influencing cell proliferation, differentiation, and polarization, and Hh and FGF/AKT signaling pathways, demonstrating that IFT proteins are likely to be the new therapeutic targets for tooth and other tissue repair and regeneration.
Chromosome conformation capture resolved near complete genome assembly of broomcorn millet
Authors: Shi Junpeng , Ma Xuxu , Zhang Jihong , Zhou Yingsi , Liu Minxuan , Huang Liangliang , Sun Silong , Zhang Xiangbo , Gao Xiang , Zhan Wei , Li Pinghua , Wang Lun , Lu Ping , Zhao Haiming , Song Weibin , Lai Jinsheng
Published: January 2019

Broomcorn millet (Panicum miliaceum L.) has strong tolerance to abiotic stresses, and is probably one of the oldest crops, with its earliest cultivation that dated back to ca. ~10,000 years. We report here its genome assembly through a combination of PacBio sequencing, BioNano, and Hi-C (in vivo) mapping. The 18 super scaffolds cover ~95.6% of the estimated genome (~887.8 Mb). There are 63,671 protein-coding genes annotated in this tetraploid genome. About ~86.2% of the syntenic genes in foxtail millet have two homologous copies in broomcorn millet, indicating rare gene loss after tetraploidization in broomcorn millet. Phylogenetic analysis reveals that broomcorn millet and foxtail millet diverged around ~13.1 Million years ago (Mya), while the lineage specific tetraploidization of broomcorn millet may be happened within ~5.91 million years. The genome is not only beneficial for the genome assisted breeding of broomcorn millet, but also an important resource for other Panicum species.
A natural in situ fabrication method of functional bacterial cellulose using a microorganism
Authors: Gao Minghong , Li Juan , Bao Zixian , Hu Moudong , Nian Rui , Feng Dexin , An Dong , Li Xing , Xian Mo , Zhang Haibo
Published: January 2019

The functionalization methods of materials based on bacterial cellulose (BC) mainly focus on the chemical modification or physical coating of fermentation products, which may cause several problems, such as environment pollution, low reaction efficiency and easy loss of functional moieties during application. Here, we develop a modification method utilizing the in situ microbial fermentation method combined with 6-carboxyfluorescein-modified glucose (6CF-Glc) as a substrate using Komagataeibacter sucrofermentans to produce functional BC with a nonnatural characteristic fluorescence. Our results indicate that the microbial synthesis method is more efficient, controllable and environmentally friendly than traditional modification methods. Therefore, this work confirms that BC can be functionalized by using a microbial synthesis system with functionalized glucose, which provides insights not only for the functionalization of BC but also for the in situ synthesis of other functional materials through microbial synthetic systems.
Cell phone based colorimetric analysis for point-of-care settings
Authors: Coleman Benjamin , Coarsey Chad , Asghar Waseem
Published: January 2019

Cell phone imaging based method for bioanalytical applications under various operating field conditions.
Characterization of a novel decellularized bone marrow scaffold as an inductive environment for hematopoietic stem cells
Authors: Bianco Juares E. Romero , Rosa Renata Giardini , Congrains-Castillo Ada , Joazeiro Paulo P. , Waldman Stephen D. , Weber Joanna F. , Saad Sara Teresinha Olalla
Published: January 2019

Due to the increasing demand for a bone marrow study model, we developed a natural scaffold from decellularized bovine bone marrow (DeBM).
BINOPtimal: a web tool for optimal chiral phosphoric acid catalyst selection
Authors: Reid Jolene P. , Ermanis Kristaps , Goodman Jonathan M.
Published: January 2019

A catalyst selection program, BINOPtimal, has been developed.
Naphtho[2,3-b]furan-4,9-dione synthesisviapalladium-catalyzed reverse hydrogenolysis
Authors: Li Jimei , Zhang Jie , Li Mingfei , Zhang Chenyang , Yuan Yongkun , Liu Renhua
Published: January 2019

A reverse hydrogenolysis process has been developed for two-site coupling of 2-hydroxy-1,4-naphthoquinones with olefins to produce naphtha[2,3-b]furan-4,9-diones and hydrogen (H2).
A cobalt arylphosphonate MOF – superior stability, sorption and magnetism
Authors: Zorlu Yunus , Erbahar Doğan , Çetinkaya Ahmet , Bulut Aysun , Erkal Turan S. , Yazaydin A. Ozgur , Beckmann Jens , Yücesan Gündoğ
Published: January 2019

We report a novel metal organic framework (MOF) based on a cobalt arylphosphonate, namely, [Co2(H4-MTPPA)]·3NMP·H2O (1·3NMP·H2O), which was prepared solvothermically from the tetrahedral linker tetraphenylmethane tetrakis-4-phosphonic acid (H8-MTPPA) and CoSO4·7H2O in N-methyl-2-pyrrolidone (NMP).
Confining Al–Li alloys between pre-constructed conductive buffers for advanced aluminum anodes
Authors: Dong Ning , Luo Hao , Xia Yonggao , Guo Haocheng , Fu Rusheng , Liu Zhaoping
Published: January 2019

A one-step facile synthesis of pre-constructed two-layer conductive buffers for Al anodes with enhanced electrochemical performance in lithium-ion batteries.
Selective synthesis of single layer translucent cobalt hydroxide for the efficient oxygen evolution reaction
Authors: Jash Priyajit , Srivastava Pradhi , Paul Amit
Published: January 2019

Remarkable water oxidation reactivity exhibited by a translucent single layer Co(OH)2 nanosheet synthesized from α-Co(OH)2 by liquid phase exfoliation.
Solution properties of imidazolium-based amphiphilic polyelectrolyte in pure- and mixed-solvent media
Authors: Su Chien-You , Yi Han-Liou , Tsai Li-Duan , Chen Ming-Chou , Hua Chi-Chung
Published: January 2019

Mixed solvents that are selectively attractive to different parts of an amphiphilic polyelectrolyte lead to exceptional and promoted solution properties.
Physical–chemical properties of M@Fe3O4core@shell nanowires (M = Cu, Co, CoO)
Authors: Mejía-López J. , Tangarife E. , Mazo-Zuluaga J.
Published: January 2019

Modifications of the magnetic, elastic and thermal behaviors of Fe3O4@M core@shell nanowires (M: Cu, Co, CoO) are observed as result of sp and spd hybridization processes.
The role of H2S addition on Pt/Al2O3 catalyzed propane dehydrogenation: a mechanistic study
Authors: Wang Hai-Zhi , Zhang Wei , Jiang Jia-Wei , Sui Zhi-Jun , Zhu Yi-An , Ye Guang-Hua , Chen De , Zhou Xing-Gui , Yuan Wei-Kang
Published: January 2019

Effects of H2S addition on the Pt/Al2O3 catalyzed propane dehydrogenation.
Effect of Ce and La dopants in Co3O4 nanorods on the catalytic activity of CO and C3H6 oxidation
Authors: Li Ping , Chen Xiaoyin , Ma Lei , Bhat Adarsh , Li Yongdan , Schwank Johannes W.
Published: January 2019

The catalytic activity is enhanced by Ce but inhibited by La dopant. The catalysts have been characterized in light of structural properties, reducibility, mobility of adsorbed oxygen and lattice oxygen, and surface reaction intermediates.
Molecular-scale structures of uranyl surface complexes on hematite facets
Authors: Huang Xiaopeng , Hou Xiaojing , Wang Fan , Guo Binghuang , Song Fahui , Ling Lan , Zhao Jincai , Zhang Lizhi
Published: January 2019

The2E uranyl coordination was preferred on hematite {001} facets, but the2C uranyl coordination was preferred on both {012} and {110} hematite facets.
Role of Al-based coagulants on a hybrid ozonation–coagulation (HOC) process for WWTP effluent organic matter and ibuprofen removal
Authors: Jin Xin , Shi Yong , Hou Rui , Zhang Weijie , Jin Pengkang , Wang Xiaochang
Published: January 2019

The hydrolysing Al-based coagulants acted more like promoters for the generation of ˙O2−to propagate the ˙OH chain reactions.
Characterization of natural melanin fromAuricularia auriculaand its hepatoprotective effect on acute alcohol liver injury in mice
Authors: Hou Ruolin , Liu Xin , Yan Junjie , Xiang Kaikai , Wu Xiaoping , Lin Wenxiong , Chen Guanshui , Zheng Mingfeng , Fu Junsheng
Published: January 2019

Auricularia auriculamelanin could attenuate alcohol-induced liver injury in mice by enhancing their antioxidant capacity.
Cleaning carbohydrate impurities from lignin usingPseudomonas fluorescens
Authors: Ghosh Tanushree , Ngo Tri-Dung , Kumar Aloke , Ayranci Cagri , Tang Tian
Published: January 2019

A bio-based process for selective degradation of carbohydrate impurities from waste lignin was achieved usingPseudomonas fluorescensas a green cleaner.
Conversion of levulinic acid to γ-valerolactone over ultra-thin TiO2 nanosheets decorated with ultrasmall Ru nanoparticle catalysts under mild conditions
Authors: Li Shaopeng , Wang Yanyan , Yang Youdi , Chen Bingfeng , Tai Jing , Liu Huizhen , Han Buxing
Published: January 2019

Herein, we successfully loaded Ru nanoparticles onto TiO2 nanosheet catalyst, which could exhibit highly efficient catalytic activity during the conversion of levulinic acid to γ-valerolactone at mild condition.
Synergetic conversion of microalgae and CO2into value-added chemicals under hydrothermal conditions
Authors: Yang Yang , Zhong Heng , He Runtian , Wang Xiaoguang , Cheng Jiong , Yao Guodong , Jin Fangming
Published: January 2019

CO2(or HCO3−) is selectively reduced into formate with microalgae as the reductant, and simultaneously HCO3−significantly enhances the conversion of microalgae into organic acids andN-substituted lactam as the oxidant.
Chemometric sorting based on laser-induced plume fluorescence: characterization of spectral noise for effective preprocessing
Authors: Cheung Nai-Ho
Published: January 2019

Single-shot laser-induced plume fluorescence spectra can be effectively denoised for clean unsupervised PCA sorting.
Hollow core–shell NiCo2S4@MoS2 dodecahedrons with enhanced performance for supercapacitors and hydrogen evolution reaction
Authors: Song Xue-Zhi , Sun Fei-Fei , Meng Yu-Lan , Wang Zi-Wei , Su Qiao-Feng , Tan Zhenquan
Published: January 2019

Hollow core–shell NiCo2S4@MoS2 heterostructures were fabricated using zeolitic imidazolate frameworks as templates and exhibited enhanced electrochemical performance for supercapacitors and hydrogen evolution reaction.
Potential impact of organic ligands on the antibacterial activity of silver nanoparticles
Authors: Xue Peng , Shan Yixuan , Shen Qihui , Li Yingdi , Jiang Jiayu , Liu Yan , Liu Xiaoyang
Published: January 2019

Organic functional group ligands were connected to silica submicrospheres, and the antibacterial activity of AgNPs with ligands was compared with that of bare AgNPs.
Nickel-catalyzed regioselective C–H halogenation of electron-deficient arenes
Authors: Li Ze-Lin , Wu Peng-Yu , Cai Chun
Published: January 2019

A straightforward Ni(ii)-catalyzed general strategy was developed for the ortho-halogenation of electron-deficient arenes with easily available halogenating reagents N-halosuccinimides (NXS; X = Br, Cl and I).
Synergistic promotion by intramolecular hydrogen bonding: a bi-functionally catalyzed cascade reaction for the synthesis of enantiopure chromenopyrrolidines
Authors: Cao Jian , Liu Jin-Yu , Zhang Yi-Ming , Wang Zhu-Yin , Xu Peng-Fei
Published: January 2019

An effective organocatalytic asymmetric cascade reaction of o-hydroxy aromatic aldimines and β,γ-unsaturated-α-ketoesters was developed.
Ultralow-temperature photochemical synthesis of atomically dispersed Pt catalysts for the hydrogen evolution reaction
Authors: Wei Hehe , Wu Hongbo , Huang Kai , Ge Binghui , Ma Jingyuan , Lang Jialiang , Zu Di , Lei Ming , Yao Yugui , Guo Wei , Wu Hui
Published: January 2019

Atomically dispersed Pt is prepared by photochemical synthesis at a record-low temperature of −60 °C, which exhibits ultrahigh catalytic activity.
TiO2-B nanowires via topological conversion with enhanced lithium-ion intercalation properties
Authors: Zhang Weifeng , Zhang Ying , Yu Ling , Wu Nae-Lih , Huang Haitao , Wei Mingdeng
Published: January 2019

TiO2-B nanowires were synthesized via a topological transformation route for the first time and showed long-term cycling stability.
Chalcogenide solution-mediated activation protocol for scalable and ultrafast synthesis of single-crystalline 1-D copper sulfide for supercapacitors
Authors: Hong John , Kim Byung-Sung , Yang Seungmo , Jang A-Rang , Lee Young-Woo , Pak Sangyeon , Lee Sanghyo , Cho Yuljae , Kang Dongwoo , Shin Hyeon Suk , Hong Jin Pyo , Morris Stephen M. , Cha SeungNam , Sohn Jung Inn , Kim Jong Min
Published: January 2019

One-dimensional Cu2S nanostructuresviaa facile and room-temperature sulfur activation for supercapacitors.
Enhanced fluorescence sensing of hypochlorous acid using serum albumin as a signal amplifier
Authors: Zhang Peng , Zhang Qian , Li Shasha , Chen Wenhui , Guo Xinjie , Ding Caifeng
Published: January 2019

A mitochondria-targeting fluorescent probe for ClO−was developed and a signal amplifier BSA was utilized to promote the fluorescent signal.
Regio-asymmetric polymers based on fluorinated benzothiadiazole–benzodithiophene for polymer solar cells with a high open-circuit voltage
Authors: Li Zhanfeng , Liu Caijun , Gan Guoyue , Sun Na , Li Xueqiao , Tong Yahui , Wang Hua , Hao Yuying
Published: January 2019

Regio-asymmetric polymer PR2F-based devices with SVA exhibited an appreciable PCE of 4.73% with a high VOC of 0.98 V.
Modulation of miR-10a-mediated TGF-β1/Smads signaling affects atrial fibrillation-induced cardiac fibrosis and cardiac fibroblast proliferation
Authors: Li Peng-Fei , He Rong-Hua , Shi Shao-Bo , Li Rui , Wang Qiong-Tao , Rao Guo-Tao , Yang Bo
Published: January 2019

Atrial fibrillation (AF) rat models and rat cardiac fibroblasts (CFs) with overexpressed or inhibited miR-10a were used to investigate the possible role of miR-10a-mediated transforming growth factor-β (TGF-β1)/Smads signaling in cardiac fibrosis and fibroblast proliferation in rats with AF. Gene ontology and pathway enrichment analyses were used to identify the possible function of miR-10a in cardiac fibrosis. The results showed that overexpressed miR-10a significantly prolonged the duration of AF, further elevated the collagen volume fraction (CVF), and increased the viability of CFs in AF rats; these findings were in contrast with the findings for rats with inhibition of miR-10a (all P<0.05). Moreover, miR-10a overexpression could promote miR-10a, collagen-I, collagen III, α-SMA, and TGF-β1 protein expression and increase the levels of hydroxyproline but reduced Smad7 protein expression in atrial tissues and CFs in AF rats. Not surprisingly, inhibiting miR-10a led to completely contrasting results (all P<0.05). Moreover, TGF-β1 treatment could reverse the inhibitory effect of miR-10a down-regulation on cardiac fibrosis in CFs. Bioinformatics analysis and luciferase reporter assay results demonstrated that miR-10a bound directly to the 3′-UTR of BCL6, which is involved in cell growth and proliferation. Thus, our study indicate that down-regulation of miR-10a may inhibit collagen formation, reduce atrial structure remodeling, and decrease proliferation of CFs, eventually suppressing cardiac fibrosis in AF rats via inhibition of the TGF-β1/Smads signaling pathway.
Biomimetic artificial cartilage: fibre‐reinforcement of PVA hydrogel to promote biphasic lubrication mechanism
Authors: Sakai Nobuo , Yarimitsu Seido , Sawae Yoshinori , Komori Mochimitsu , Murakami Teruo
Published: January 2019

The fibre‐reinforced structure in synovial articular cartilage plays an important role in enhancing the fluid load support in the biphasic lubrication mechanism. Poly(vinyl alcohol) (PVA) hydrogel is a potential biomimetic articular cartilage material. In this study, PVA hydrogel was reinforced with PVA fibres to improve its frictional properties. By computational analysis, the position of the PVA fibre layer was examined with a migrating contact condition to reduce the friction coefficient. To improve the fibre reinforcement, a method for fibre placement was developed to retain the initial strain of the fibre in the hydrogel matrix. The experimental results showed that the fibre‐reinforced PVA hydrogel with a surface fibre layer had a low friction coefficient of 0.031 in pure water. The fibre‐reinforced PVA hydrogel successfully reduced friction coefficient.
Evaluation of local B1 field as dosimeter of RF heating for implant in MRI
Authors: Wan Sen , Jiang Changqing , Ding Jianqi , Li Luming
Published: January 2019

Radio frequency (RF) heating is a serious risk for a patient with an elongated implant during MRI scan. The conventional dosimeter of specific absorption rate (SAR) and the recently proposed B1+rms may not accurately indicate the implant heating. The local B1 field around the tip of a lead and its relationship with the RF heating were studied by numerical simulations. It was found that regardless of the route of the lead, the angle or position of placement, there was a strong linear correlation between the averaged square of local B1 field and the rise in temperature. The evaluation range had an effect on the linearity. Generally, the local B1 field performed better as a dosimeter of RF heating than SAR or B1+rms at the isocentre.
Numerical demonstration of non‐reciprocal waveform‐selective metasurfaces
Authors: Wakatsuchi H.
Published: January 2019

The authors demonstrate two types of non‐reciprocal waveform‐selective metasurfaces that control the level of reflectance, depending not only on the direction of the incident wave but also on the waveform, namely, on the pulse width. A capacitor‐based waveform‐selective metasurface exhibits strong reflectance for a short pulse compared to that for a continuous wave (CW) at the same frequency. In contrast, an inductor‐based waveform‐selective metasurface more strongly reflects a CW than a pulse. The difference between them is demonstrated to be more than 50% but is reduced for a wave propagating in the other direction. The concept of the authors' structures is expected to offer an additional degree of freedom with which to design non‐reciprocal devices and applications.
Analysis of Variable Bit Rate WH/CI‐Spread OFDM based Integrated Satellite‐Terrestrial Broadcast System
Authors: Agarwal Akash , Kumar Preetam
Published: January 2019

In this study, the exact closed‐form signal‐to‐interference‐noise ratio (SINR) expression, for the impact of Doppler frequency shift on minimum mean square error receiver is derived for Walsh Hadamard (WH) and polyphase carrier interferometry (CI) code based multicarrier spread orthogonal frequency division multiplexing (SOFDM) transmission scheme over integrated satellite–terrestrial broadcast system. Additionally, bit error rate and spectral efficiency are analysed based on the obtained SINR expression. To examine that, three‐state Fontan land mobile satellite, and six‐path typical urban and rural area terrestrial channel models are employed. This analysis is performed to substantiate variable bit rate (VBR) quality of service at the physical layer of digital video broadcast satellite handheld (DVB‐SH)‐A architecture, the provision of which is absent in DVB‐SH standard. VBR is assumed for SOFDM. The results illustrate that WH‐SOFDM outperforms CI‐SOFDM under both performance measures in all the three channel environments. Further, pilot‐based channel estimation technique is performed and the estimated error variance is evaluated for VBR WH/CI‐SOFDM. Later, block‐wise system computational complexity of WH/CI‐SOFDM schemes is evaluated. It is shown that, CI‐SOFDM is a relatively more complex system than WH‐SOFDM. Thus, a trade‐off is present between the achieved performance gain and system complexity.
Disturbance observer based robust backstepping control design of flexible air‐breathing hypersonic vehicle
Authors: Wang Fang , Guo Ying , Wang Kun , Zhang Zheng , Hua Changchun , Zong Qun
Published: January 2019

This study presents a new controller that is integrating sliding mode control method, a backstepping technique with disturbance observer (DO) for the flexible air‐breathing hypersonic vehicle (FAHV). A control‐oriented model (COM) is firstly established based on the engineering background of FAHV, and the COM is decomposed into a velocity subsystem and an altitude subsystem, then controllers and the DO are designed for them. The developed sliding mode surface with exponential form can accelerate the convergence speed of the sliding mode state. Furthermore, the time derivative of the virtual control inputs is seen as uncertainty, and the DO is used to estimate it, so the problem of ‘explosion of terms’ is avoided. Then the stability of the closed‐loop system is proved by Lyapunov theory, the tracking error of velocity converges to the random neighbourhood around zero, and the tracking error of altitude is asymptotic stable. Lastly, the compared simulation result is shown to verify that the proposed control method has better tracking performance than that of an adaptive backstepping controller.
Sampled‐data leader–follower algorithm for flocking of multi‐agent systems
Authors: Yazdani Sahar , Haeri Mohammad , Su Housheng
Published: January 2019

In this study, the authors propose a new algorithm for the flocking problem of multi‐agent systems with the dynamic virtual leader under the sampled‐data frameworks. A necessary time‐varying condition is derived on the sampling period for preserving connectivity of the network and avoiding collision among agents. Then, defining a new energy function, it is proved that using a connectivity‐preserving potential function and under the sampling period which satisfies the necessary condition, an asymptotic flocking motion is achievable. Under the proposed sampled‐data flocking algorithm, the connectivity preservation of the network and collision avoidance among agents are guaranteed as well as the velocity convergence of all agents to that of the virtual leader is ensured. Moreover, employing the upper bound of the energy function, they specify an upper bound of the sampling period which could satisfy the time‐varying necessary condition. Finally, they present a numerical simulation to illustrate the theoretical results.
Outer rotor wound field flux switching machine for In‐wheel direct drive application
Authors: Ahmad Naseer , Khan Faisal , Ali Hazrat , Ishaq Samra , Sulaiman Erwan
Published: January 2019

Nowadays the flux switching machines offer pivotal role in high speed applications. The flux sources (field excitation coil and armature winding or permanent magnet) are confined to the stator leaving rotor completely passive, and thus making the flux switching machine (FSM) more suitable for industrial applications. This paper emphasizes salient rotor pole and non‐overlapping windings embedded in electrical machine design possess some pertinent features such as reduced copper losses, low‐cost, and usage in high speed applications. The proposed design is analyzed for coil test analysis and flux linkage and torque. On the basis of the analysis performed, it is clear that 12‐slot/13‐pole has low cogging torque, high flux linkage, and maximum torque, compared with other topologies of outer rotor field excitation FSM. A deterministic optimization technique is adopted to enhance the performance of 12‐slot/13‐pole design. Further, finite element analysis (FEA) results are verified through Global Reluctance Network (GRN) methodology, which show close resemblance with error less than 1.2%. Hence, it validates the proposed design for outer rotor field excitation FSM direct drive application. The proposed design for hybrid electric vehicle torque characteristic is compared with existing interior permanent magnet synchronous machine (IPMSM) and 6‐slot/7‐pole wound field flux switching machine (WFFSM).
New method for simultaneous moderate bias correction and image segmentation
Authors: Yang Yunyun , Wang Ruofan , Feng Chong
Published: January 2019

This study proposes a new method for simultaneous image segmentation and moderate bias correction. Though many methods are proposed to deal with the image intensity inhomogeneity, some problems still exist and have influenced the segmentation results a lot. In this study, a new model is proposed for image segmentation and correction based on the multiplicative intrinsic component optimization (MICO) model. First, the new model in the level set formulation for gray images has been presented and the split Bregman method for fast minimization has been applied. The proposed model is tested with lots of magnetic resonance images and some medical colour images with promising results. Experimental results show that the proposed model can simultaneously segment images and correct bias field moderately. In the experimental part for gray images, a qualitative comparison between the proposed model and the MICO model in both segmentation and bias‐correction results is made. Besides, the proposed model with the Chan‐Vese model and the illumination and reflectance estimation model in the experimental part for colour images are compared. Moreover, the proposed model can segment nature colour images successfully. It is clear that the proposed model has a good performance on many characteristics such as accuracy, efficiency, and robustness.
Gabor phase response based scheme for accurate pectoral muscle boundary detection
Authors: Rahman Mohammad Akhlaqur , Jha Rajib Kumar , Gupta Abhishek Kumar
Published: January 2019

Pectoral muscle segmentation is a very important step in any Computer Aided Detection (CAD) system, for automatic detection of different possible signs of malignancy in the mammographic image. Presence of high‐density glandular tissues overlapping pectoral muscle boundary, presence of pectoral muscle of small size and low density, presence of pectoralis minor etc., poses a great challenge for researchers working on the problem of automatic pectoral muscle boundary detection. Gabor filter has been used by many researchers to detect textural edges. The ability that it can be tuned along a particular direction, makes it a very important image processing tool. In the proposed research work a Gabor filter tuned in the direction of pectoral muscle boundary is applied on the region of interest (ROI) containing pectoral muscle. Finally, the magnitude and phase response of Gabor filtered ROI image along with an edge‐connect and region merge algorithm is used to detect pectoral muscle boundary. The proposed method is validated using 200 mammograms from the miniMIAS database and 200 mammograms from INbreast database. With an accuracy of 97.50% for miniMIAS database and 94.50% for INbreast database, the proposed method outperforms many state‐of‐the‐art methods which show its suitability for CAD Systems.
Transfer metric learning for unsupervised domain adaptation
Authors: Huang Junchu , Zhou Zhiheng
Published: January 2019

Domain adaptation is still a challenging task due to the fact that the distribution discrepancy between source domain and target domain weakens the transfer ability. Intuitively, it is crucial to discover a more discriminative feature representation across domains. However, previous methods do not take the target discriminative information into account since (most) target data are unlabelled. Here, the authors propose a transfer metric learning method which decreases intra‐class distance and increases inter‐class distance simultaneously even in the case of target data are unlabelled. The shared features are more discriminative, hence the model could be more robust for target data. Specially, the global optimal solution can be obtained by solving a generalised eigen‐decomposition problem. Extensive experiments on image datasets demonstrate that compared to several state‐of‐the‐art methods, authors’ method achieves significant improvement of 9.0% in average classification accuracy.
Design and implementation of a novel low complexity symmetric orthogonal wavelet filter‐bank
Authors: Edavoor Pranose J. , Rahulkar Amol D.
Published: January 2019

The design of wavelet filter‐bank in real continuum domain demands infinite precision to achieve perfect reconstruction (PR). The computations with irrational coefficients in orthogonal filters require a large amount of hardware that result in increased power dissipation, huge memory requirements and reduction in speed of operation. This paper presents a new approach to obtain a complete dyadic (low complexity) 6‐tap orthogonal symmetric wavelet filter‐bank (FB) with near perfect reconstruction. This is achieved by slightly altering the PR conditions to make orthogonal filters symmetric and to obtain complete dyadic filter coefficients. The proposed wavelet FB has reduced dynamic power dissipation and significantly reduced adder and shifter count. The VLSI architecture of the proposed FB is designed and implemented on Kintex‐7 FPGA. The architectural design is carried out using Verilog and functional simulation and synthesis are executed using Vivado 2016.4 software. The proposed FB dissipates 114mW dynamic power and requires only 5 adders and 3 shifters. The effectiveness of the proposed wavelet is verified in three different applications namely image compression, iris recognition system and orthogonal frequency division multiplexing (OFDM). The proposed wavelet FB gives comparable performance in image compression and attains superior performance in iris recognition system (feature extraction) and OFDM.
Efficient level‐set segmentation model driven by the local GMM and split Bregman method
Authors: Wang Dengwei
Published: January 2019

An efficient level‐set model driven by the local Gaussian mixture model (GMM) and split Bregman method is proposed for image segmentation. Firstly, the two intensity fitting functions in the original local binary fitting (LBF) model are pre‐estimated by using a local GMM‐based intensity distribution estimator before curve evolution. The benefit of this pre‐computation strategy is to avoid updating the fitting functions at each step of the curve evolution, and it also overcomes the initialisation problem of common gradient descent‐based active contour models, i.e. the level‐set function can be initialised as an arbitrary random matrix instead of a signed distance function in the proposed processing framework. Secondly, two processing ideas named global convex segmentation (GCS) method and split Bregman are introduced into the numerical implementation, where the role of GCS is to transform the proposed model into a simplified convex segmentation model, and the purpose of the split Bregman is to quickly output a convergent solution of the newly derived convex segmentation model in an alternate iterative format. Experimental results for synthetic and real images of different modalities with inhomogeneity or homogeneity validate the desired performances of the proposed method in terms of accuracy, robustness, and rapidity.
Truck active reversing control strategy based on modified particle filter and multi‐sensors environment perception
Authors: Zhu Miankuan , Xi Chaoxing , Li Yanjun , Bano Shehar , Zhang Zutao , Liu Yugang , Yagubov Rasim
Published: January 2019

Due to the limit of the drivers' sight sheltered by the large body and the complexity of driving, heavy‐duty trucks usually cause serious reversing traffic accidents. In this study, the authors present a new strategy to settle this problem by using the multi‐sensors system, modified unscented particle filter, and an active safety control strategy. First, multi‐sensors including binocular cameras, ultrasonic sensors, and laser rangefinders are used to perceive the environmental information to help drivers to decrease the blind area and obtain the distance between obstacles and the truck. Second, a federal information fusion mechanism based on the unscented Kalman filter is used to fuse the information so that the proposed system can eliminate spurious data and improve the robustness. Next, a framework combining low‐rank representation with unscented particle filter that is used for target tracking is proposed. Third, a speed control method is introduced to realise the active speed control of a truck. Lastly, the experiment and the results prove that the proposed algorithm has higher accuracy than others. Moreover, the proposed system can not only help drivers decrease the burden while reversing but also increase the active safety ability to reverse, which has great significance for heavy‐duty trucks.
Wideband RCS reduction using three different implementations of AMC structures
Authors: Zaki Bahare , Firouzeh Zaker‐Hossein , Zeidaabadi‐Nezhad Abolgasem , Maddahali Mojtaba
Published: January 2019

Here, two new AMC structures are presented with phase difference in wideband frequency of 4.97–17.15 GHz. Three implementations of two AMC structures are presented, which include periodic checkerboard structure, aperiodic checkerboard structure, and randomised structure. The periodic checkerboard structure is presented in two models. In the first model, the RCS is reduced > 9.6 dB in the frequency range of 9.3–16.9 GHz, which is equivalent to 58.02%. In the second model, the RCS is reduced >7.8 dB in the frequency range of 8.1–16.9 GHz, which is equivalent to 70.4%. The second model is analysed through FMB parameter, bistatic and monostatic RCS. For improving the RCS reduction bandwidth, the new aperiodic checkerboard structure and the optimal randomised structure are presented with bandwidth of 81.67 and 98.69%, respectively. In aperiodic and randomised structure, the reflected field is scattered more uniformly in many direction. Therefore, the 3D bistatic RCS pattern is improved greatly. For validating the result of simulation, the second model of periodic checkerboard structure is fabricated and RCS reduction is measured, which are in good agreement with simulation results.
Flexible conductive fabric/E‐glass fibre composite ultra‐wideband antenna for future wireless networks
Authors: Elmobarak Husameldin Abdelrahman , Rahim Sharul Kamal Abdul , Castel Xavier , Himdi Mohamed
Published: January 2019

This study highlights the integration potential of a highly conductive fabric into composite materials based on an efficient fabrication technology for coplanar waveguide flexible composite ultra‐wideband antenna radiating from 3.3 to 12 GHz. A thin sheet of a highly conductive fabric has been embedded by infusion process in a thin composite laminate made of E‐glass fibre mat and epoxy resin to fabricate a flexible conductive composite laminate. The antenna elements have been machined precisely by laser etching. The measured radiation efficiency reaches over 70% throughout the antenna operating frequency band with satisfactory radiation patterns and gain. The composite antenna exhibits reliable performance under different bending conditions as presented by the measurements. The high radiation performance, the seamless integration process and flexible mechanical properties of such composite antennas pave the way for their promising potential for integrating efficient antennas into various devices and objects made of composite laminate materials.
Impedance tuning with photoconductors to 40 GHz
Authors: Drisko Jasper A. , Feldman Ari D. , Quinlan Franklyn , Booth James C. , Orloff Nathan D. , Long Christian J.
Published: January 2019

Light is widely used to control a variety of microwave devices, including switches, antennas, and detectors. Here, the authors present a photoconductive device integrated into a coplanar waveguide to tune complex impedances at microwave frequencies with applied light. The authors measured the current–voltage characteristics of the device as a function of the applied light intensity and fit the behavior to a known metal‐semiconductor‐metal junction model with two Schottky barriers. The authors also measured the frequency‐dependent scattering parameters and extracted the device impedances in a Pi‐network model. The devices showed three orders of magnitude impedance tunability from 100 MHz to 40 GHz, and the authors developed a circuit model to fit the frequency‐dependent impedances. This simple device has applications in microwave electronics, microwave metrology, and multi‐state calibrations.
Simple time‐domain analysis of a multilevel DC–DC flying capacitor converter average aperiodic natural balancing dynamics
Authors: Penczek Adam , Mondzik Andrzej , Stala Robert , Ruderman Alex
Published: January 2019

Reported capacitor average natural voltage balancing dynamics analysis methods are mostly based on frequency‐domain Fourier transformations that involve infinite series. Therefore, these methods require high mathematical skills, are not truly analytical and difficult to use in engineering practise. This study suggests a time‐domain power averaging‐based approach to the analysis of a multilevel DC–DC flying capacitor converter (or, more generally, switched capacitive converter) aperiodic (non‐oscillating) average voltage balancing dynamics. Simple analytical solutions are illustrated by single and dual capacitor converter examples that include pure resistive load and balance booster circuit. Theoretical results are supported by simulations and experimental verification.
Hybrid multi‐DC–AC MG based on multilevel interlinking converter
Authors: Sadeghi Meisam , Khederzadeh Mojtaba
Published: January 2019

This study presents a multilevel interlinking converter (IC) topology to form a hybrid multi‐DC–AC microgrid (MG) with an improved control system. The proposed topology provides stable DC voltage levels to link different DC MGs. Furthermore, without using any additional DC–DC converters to establish multi‐DC–AC MG, the number and rating of required components are reduced. The IC performs multi‐task operations including inverter‐based, rectifier‐based and DC–DC buck–boost‐based roles in hybrid multi‐DC–AC system, using a modified control strategy. A simple complementary control has been applied to keep the voltage of DC links stable instead of using other components. The proposed system improves the quality of AC‐side waveforms with the lower size of filters and reduces the DC‐side voltage transients compared with conventional bridge‐type converters. Simulation results using PSCAD/EMTDC software and experimental result are presented to validate the effectiveness and advantages of the proposed configuration in the grid‐connected mode.