bluuebunny/crossref_metadata_2025 huggingface dataset:
Chronic Glutathione Depletion Confers Protection against Alcohol-induced Steatosis: Implication for Redox Activation of AMP-activated Protein Kinase Pathway
Authors: Chen Ying , Singh Surendra , Matsumoto Akiko , Manna Soumen K. , Abdelmegeed Mohamed A. , Golla Srujana , Murphy Robert C. , Dong Hongbin , Song Byoung-Joon , Gonzalez Frank J. , Thompson David C. , Vasiliou Vasilis
Published: July 2016

The pathogenesis of alcoholic liver disease (ALD) is not well established. However, oxidative stress and associated decreases in levels of glutathione (GSH) are known to play a central role in ALD. The present study examines the effect of GSH deficiency on alcohol-induced liver steatosis in Gclm knockout (KO) mice that constitutively have ≈15% normal hepatic levels of GSH. Following chronic (6 week) feeding with an ethanol-containing liquid diet, the Gclm KO mice were unexpectedly found to be protected against steatosis despite showing increased oxidative stress (as reflected in elevated levels of CYP2E1 and protein carbonyls). Gclm KO mice also exhibit constitutive activation of liver AMP-activated protein kinase (AMPK) pathway and nuclear factor-erythroid 2–related factor 2 target genes, and show enhanced ethanol clearance, altered hepatic lipid profiles in favor of increased levels of polyunsaturated fatty acids and concordant changes in expression of genes associated with lipogenesis and fatty acid oxidation. In summary, our data implicate a novel mechanism protecting against liver steatosis via an oxidative stress adaptive response that activates the AMPK pathway. We propose redox activation of the AMPK may represent a new therapeutic strategy for preventing ALD.
Effects of chronic variable stress on cognition and Bace1 expression among wild-type mice
Authors: Cordner Z A , Tamashiro K L K
Published: July 2016

Stressful life events, activation of the hypothalamic–pituitary–adrenal (HPA) axis and glucocorticoids are now thought to have a role in the development of several neurodegenerative and psychiatric disorders including Alzheimer’s disease (AD) through mechanisms that may include exacerbation of cognitive impairment, neuronal loss, and beta-amyloid (Aβ) and tau neuropathology. In the current study, we use a wild-type mouse model to demonstrate that chronic variable stress impairs cognitive function and that aged mice are particularly susceptible. We also find that stress exposure is associated with a 1.5- to 2-fold increase in the expression of Bace1 in the hippocampus of young adult mice and the hippocampus, prefrontal cortex and amygdala of aged mice. Further, the increased expression of Bace1 was associated with decreased methylation of several CpGs in the Bace1 promoter region. In a second series of experiments, exposure to environmental enrichment (EE) prevented the stress-related changes in cognition, gene expression and DNA methylation. Together, these findings re-affirm the adverse effects of stress on cognition and further suggest that aged individuals are especially susceptible. In addition, demonstrating that chronic stress results in decreased DNA methylation and increased expression of Bace1 in the brain may provide a novel link between stress, Aβ pathology and AD. Finally, understanding the mechanisms by which EE prevented the effects of stress on cognition and Bace1 expression will be an important area of future study that may provide insights into novel approaches to the treatment of AD.
Synthesis and characterization of pristine closo-[Ge10]2−
Authors: Bentlohner Manuel M. , Fischer Christina , Fässler Thomas F.
Published: July 2016

More than 25 years after the first report on a pristine anion [Ge10]2−, the cluster anion is now structurally and spectroscopically characterized.
Photothermally responsive gold nanoparticle conjugated polymer-grafted porous hollow silica nanocapsules
Authors: Paramelle David , Gorelik Sergey , Liu Ye , Kumar Jatin
Published: July 2016

A laser triggered release of encapsulated compounds from gold conjugated polymer-grafted porous hollow silica nanocapsules.
Neutral versus polycationic coordination cages: a comparison regarding neutral guest inclusion
Authors: Szalóki György , Croué Vincent , Allain Magali , Goeb Sébastien , Sallé Marc
Published: July 2016

A neutral self-assembled container synthesized from a concave π-extended tetrathiafulvalene (exTTF) ligand and the cis-Pd(dctfb)2(cod) complex (dctfb = 3,5-dichloro-2,4,6-trifluorobenzene; cod = 1,5-cyclooctadiene) is described.
Seed-mediated biomineralizaton toward the high yield production of gold nanoprisms
Authors: Geng Xi , Roth Kristina L. , Freyman Megan C. , Liu Jianzhao , Grove Tijana Z.
Published: July 2016

Biocompatible triangular gold nanoprisms with well-defined morphology, tailored plasmonic absorbance, and high colloidal stability are synthesized via seed-mediated biomineralizaton.
Theoretical insights into the promotion effect of subsurface boron for the selective hydrogenation of CO to methanol over Pd catalysts
Authors: Wu Panpan , Yang Bo
Published: July 2016

CO hydrogenation to methanol and methane on both Pd(211) and subsurface boron-modified Pd(211) are studied based on density functional theory calculations.
A molecular dynamics study of the effect of the substrate on the thermodynamic properties of bound Pt–Cu bimetallic nanoclusters
Authors: Akbarzadeh Hamed , Shamkhali Amir Nasser , Abbaspour Mohsen , Salemi Sirous , Attaran Zeinab
Published: July 2016

In this work confinement of the Pt708Cu707 bimetallic nanocluster in single-walled carbon, boron nitride, and silicon carbide nanotubes was investigated using molecular dynamics simulation.
Organotemplate-free synthesis of hollow Beta zeolite supported Pt-based catalysts for low-temperature ethanol steam reforming
Authors: Zheng Ziliang , Sun Chen , Dai Rong , Wang Shiyao , Wu Xu , An Xia , Xie Xianmei
Published: July 2016

A novel platinum-encapsulated hollow Beta zeolite (Pt@HBS) catalyst was successfully fabricated through an organotemplate-free and seed-directed route, with carbon spheres as a hard template.
Light-triggered CO delivery by a water-soluble and biocompatible manganese photoCORM
Authors: Jimenez Jorge , Chakraborty Indranil , Carrington Samantha J. , Mascharak Pradip K.
Published: July 2016

Careful design of the coligand of the photoCORM [MnBr(CO)3(pyTAm)] makes it highly stable and soluble in aqueous media and allows light-induced CO release to biological targets.
hsDNA groove binding, photocatalytic activity, and in vitro breast and colon cancer cell reducing function of greener SeNPs
Authors: Pansare Amol V. , Kulal Dnyaneshwar K. , Shedge Amol A. , Patil Vishwanath R.
Published: July 2016

Selenium nanoparticles (SeNPs) have attracted great attention because of their superior optical properties and wide utilization in biological and biomedical studies.
Coordination structure and extraction behavior of a silver ion with N-substituted-9-aza-3,6,12,15-tetrathiaheptadecanes: significant effect of Ph–C–N framework on the extractability
Authors: Iwatsuki Satoshi , Ichiyama Atsushi , Tanooka Syogo , Toyama Mari , Katagiri Kosuke , Kawahata Masatoshi , Yamaguchi Kentaro , Danjo Hiroshi , Chayama Kenji
Published: July 2016

The N-substituent having a Ph–C–N framework on monoazatetrathioethers significantly enhanced the Ag(i) extractability due to its “hydrophobic cover” effect.
CuFe2O4 magnetic nanoparticle catalyzed odorless synthesis of sulfides using phenylboronic acid and aryl halides in the presence of S8
Authors: Amiri Kamran , Rostami Amin , Rostami Abed
Published: July 2016

The ligand-free synthesis of sulfides is reported in the presence of CuFe2O4 as a magnetically reusable nanocatalyst in PEG.
Synthesis of enantiopure cyclopropyl esters from (−)-levoglucosenone
Authors: Stockton Kieran P. , Greatrex Ben W.
Published: July 2016

Levoglucosenone was converted into the GABAC agonists (−)-TAMP, (+)-TAMP and an advanced intermediate used for the synthesis of the selective glutamate receptor antagonist PCCG-4.
Chemoselective acylation of benzimidazoles with phenylacetic acids under different Cu catalysts to give fused five-membered N-heterocycles or tertiary amides
Authors: Mai Shaoyu , Zhao Yingwei , Song Qiuling
Published: July 2016

Chemoselective C–N bond formationsviaaerobic oxidative decarboxylative tandem protocols under different Cu catalysts were realized.
Efficient and scalable synthesis of α,α-disubstituted β-amino amides
Authors: Paulsen Marianne Hagensen , Engqvist Magnus , Ausbacher Dominik , Strøm Morten Bøhmer , Bayer Annette
Published: July 2016

A scalable synthesis of α,α-disubstituted β-amino amides comprising the chemoselective reduction of a nitrile group in presence of amides and aryl halides is described.
Approach to the synthesis of the C1–C11 and C14–C18 portion of Leucascandrolide A
Authors: Hunter T. J. , Zheng J. , O'Doherty G. A.
Published: July 2016

An iterative asymmetric hydration of dienoates approach to Leucasndrolide A was explored.
Efficient and “green” fabrication of pH-responsive poly(methacrylic acid) nano-hydrogels in water
Authors: Zhang You-Wei , Guan Wen-Juan , Lu Ya-Ming , Zhao Jiong-Xin
Published: July 2016

PMAA nano-hydrogels are fabricated efficiently in water with the help of a hydrophobic initiator, a nonionic surfactant and nanolatex seeds.
Nanotechnology promotes the R&D of new-generation micronutrient foliar fertilizers
Authors: Li Peng , Du Yumei , Huang Longbin , Mitter Neena , Xu Zhi Ping
Published: July 2016

New generation foliar fertilizers are expected to be sheet-like nanocrystals and provide a sustainable supply of metal ions at a suitable concentration.
Eco-friendly microwave synthesis of Mg(ii) phenoxy carboxylic acid coordination compounds with specific motifs driven by multiple hydrogen bonding
Authors: Xu Xiuling , Hu Fan , Yan Saisai , Lin Jianguang , Li Qing , Shuai Qi
Published: July 2016

Four magnesium complexes with specific motifs driven by multiple hydrogen bonding were synthesized by microwave method. The design strategy presented here gave an insight into the further structural prediction of magnesium supramolecular assemblies.
Dipole-induced asymmetric conduction in tunneling junctions comprising self-assembled monolayers
Authors: Kovalchuk Andrii , Egger David A. , Abu-Husein Tarek , Zojer Egbert , Terfort Andreas , Chiechi Ryan C.
Published: July 2016

The collective action of embedded dipoles causes asymmetric tunneling charge-transport through self-assembled monolayers.
Synthesis of nanostructured calcium carbonate/methotrexate@silica and its application in cancer therapy
Authors: Dai Chao-Fan , Wang Wei-Yuan , -Wang Lin , -Zhou Lei , Li Shu-Ping , Li Xiao-Dong
Published: July 2016

Both ACC-MTX@SiO2 and vaterite-MTX@SiO2 nanospheres were synthesized at different pH values. The results indicated that ACC-MTX@SiO2 nanospheres presented better controlled release and results in efficient death of cancer cells.
Kinetic study of the alkaline degradation of imidapril hydrochloride using a validated stability indicating HPLC method
Authors: Abdulla Shabaan A. , Frag Eman Y. , Ahmed Heba E.
Published: July 2016

An aqueous alkaline degradation study was performed for imidapril hydrochloride (IMD) drug in the presence of its degradation products and an isocratic stability indicating method was presented using HPLC.
Effects of a SiO2 sub-supporting layer on the structure of a Al2O3 supporting layer, formation of Fe catalyst particles, and growth of carbon nanotube forests
Authors: Lee Jaegeun , Lee Cheol Hun , Park Junbeom , Lee Dong-Myeong , Lee Kun-Hong , Jo Sae Byeok , Cho Kilwon , Maruyama Benji , Kim Seung Min
Published: July 2016

We investigate the effects of a SiO2 sub-supporting layer on the growth of carbon nanotube (CNT) forests, especially on the spinnability of the CNT forest into a CNT yarn, which is one of the most promising application areas.
A neural network learning approach for improving the prediction of residue depth based on sequence-derived features
Authors: Yan Renxiang , Wang Xiaofeng , Xu Weiming , Cai Weiwen , Lin Juan , Li Jian , Song Jiangning
Published: July 2016

Residue depth is a solvent exposure measure that quantitatively describes the depth of a residue from the protein surface.
Electrochemical performance of polypyrrole derived porous activated carbon-based symmetric supercapacitors in various electrolytes
Authors: Bello A. , Barzegar F. , Madito M. J. , Momodu D. Y. , Khaleed A. A. , Masikhwa T. M. , Dangbegnon J. K. , Manyala N.
Published: July 2016

The electrochemical performance of porous carbon prepared from the polymerization and carbonization of pyrrole is presented in this work.
Investigation of thermal, structural and dynamical properties of (Aux–Cuy–Niy)N=32,108,256 ternary nanosystems: effect of Au addition to Cu–Ni bimetallic nanoclusters via MD simulation
Authors: Akbarzadeh Hamed , Abbaspour Mohsen , Mehrjouei Esmat
Published: July 2016

In this work, we have investigated the heating and cooling processes for ternary metallic nanoclusters with different Au mole fractions using molecular dynamics simulation.
Titanate nanowire/NiO nanoflake core/shell heterostructured nanonanocomposite catalyst for methylene blue photodegradation
Authors: Chen W. X. , Yu J. S. , Hu W. , Chen Z. L. , Memon H. , Chen G. L.
Published: July 2016

A core/shell heterostructured nanonanocomposite catalyst based on NiO nanoflakes and titanate nanowires (TNWs) was fabricated.
Porphyrinic MOFs for reversible fluorescent and colorimetric sensing of mercury(ii) ions in aqueous phase
Authors: Yang Jian , Wang Zhe , Li Yongsheng , Zhuang Qixin , Zhao Wenru , Gu Jinlou
Published: July 2016

A simple, rapid and visual assay for Hg2+ detection is designed based on assembling Zr–O clusters and porphyrin ligands.
Polymer functionalized magnetic nanoconstructs for immunomagnetic separation of analytes
Authors: Chattopadhyay Sruti , Kaur Avneet , Jain Swati , Sabharwal Prabhjot K. , Singh Harpal
Published: July 2016

Core–shell polymer functionalized magnetic nanoparticles are promising material for rapid immunomagnetic separation and detection of analyte.
Facile synthesis of three-dimensional NiCo2O4 with different morphology for supercapacitors
Authors: Wang Jinxing , Zhang Yangyang , Ye Junhua , Wei Hongmei , Hao Jinghua , Mu Juyi , Zhao Shuoqing , Hussain Shahid
Published: July 2016

The morphology of NiCo2O4 can be controlled by changing the kinds of alkali source and the addition of NH4F, influencing its electrochemical properties.
The direct growth of highly dispersed CoO nanoparticles on mesoporous carbon as a high-performance electrocatalyst for the oxygen reduction reaction
Authors: Li Pengxi , Ma Ruguang , Zhou Yao , Chen Yongfang , Liu Qian , Peng Guihua , Wang Jiacheng
Published: July 2016

Highly dispersed CoO nanoparticles on mesoporous carbon show the excellent activity and stability toward the electrocatalytic oxygen reduction reaction with a four-electron reaction path, compared to commercial Pt/C.
Brönsted acid-mediated annulations of 1-cyanocyclopropane-1-carboxylates with arylhydrazines: efficient strategy for the synthesis of 1,3,5-trisubstituted pyrazoles
Authors: Xue Shuwen , Liu Jiaming , Qing Xushun , Wang Cunde
Published: July 2016

A diversity-oriented synthesis of 1H-pyrazole derivativesviaBrönsted acid-promoted annulations of 1-cyanocyclopropane-1-carboxylates with arylhydrazines has been developed.
A high performance soy protein-based bio-adhesive enhanced with a melamine/epichlorohydrin prepolymer and its application on plywood
Authors: Luo Jing , Luo Jianlin , Bai Yuanyuan , Gao Qiang , Li Jianzhang
Published: July 2016

The aim of this study was to improve the water resistance of a soy protein-based bio-adhesive using a melamine/epichlorohydrin prepolymer (MEP).
Enhanced metal–support interactions between Pd NPs and ZrSBA-15 for efficient aerobic benzyl alcohol oxidation
Authors: Ji Ran , Zhai Shangru , Zheng Wei , Xiao Zuoyi , An Qingda , Zhang Feng
Published: July 2016

Towards the aerobic oxidation of alcohols, palladium nanoparticle immobilized mesoporous catalysts have been extensively investigated; however, the preparation of efficient catalytic materials without using complexing moieties remains a challenge.
Teaching of chemical bonding: a study of Swedish and South African students' conceptions of bonding
Authors: Nimmermark Anders , Öhrström Lars , Mårtensson Jerker , Davidowitz Bette
Published: July 2016

Almost 700 Swedish and South African students from the upper secondary school and first-term chemistry university level responded to our survey on concepts of chemical bonding. The national secondary school curricula and most common textbooks for both countries were also surveyed and compared for their content on chemical bonding. Notable differences between the countries were found in textbooks and in the curriculum regarding the topics of ionic bonding, bond energetics and use of the VSEPR model, the latter being absent in the Swedish curriculum and ionic bonding not explicitly mentioned in the South African curriculum. To some extent these differences are reflected in the students’ responses to the survey. It is also clear that university teachers in both countries must prepare effective counter-measures against deep rooted misunderstandings. For the upper secondary school level it is suggested that the bond energetics and exothermic and endothermic reactions be clearly and carefully presented and separated as the study indicates that mixing of these two concepts is a major cause of confusion.
Argument construction in understanding noncovalent interactions: a comparison of two argumentation frameworks
Authors: Kat Cooper A. , Oliver-Hoyo M. T.
Published: July 2016

Argument construction is a valuable ability for explaining scientific phenomena and introducing argumentation skills as part of a curriculum can greatly enhance student understanding by promoting self-reflection on the topic under investigation. This article aims to use argument construction as a technique to support an activity designed to improve student understanding of noncovalent interactions. Two theoretical argumentation frameworks were used and compared in order to determine the most effective for use in the developed activity.
Specific inhibition of CK2α from an anchor outside the active site
Authors: Brear Paul , De Fusco Claudia , Hadje Georgiou Kathy , Francis-Newton Nicola J. , Stubbs Christopher J. , Sore Hannah F. , Venkitaraman Ashok R. , Abell Chris , Spring David R. , Hyvönen Marko
Published: July 2016

CAM4066, a specific CK2α kinase inhibitor, is anchored in the cryptic αD pocket outside the active site and inserts a “warhead” into the active site, blocking ATP binding and thereby inhibiting the kinase.
Foldable glycoprobes capable of fluorogenic crosslinking of biomacromolecules
Authors: Li Kai-Bin , Li Na , Zang Yi , Chen Guo-Rong , Li Jia , James Tony D. , He Xiao-Peng , Tian He
Published: July 2016

We demonstrate a foldable, fluorogenic glycoprobe that can recognize and simultaneously crosslink a receptor protein to form unique supramolecular bio-ensembles.
A durable luminescent ionic polymer for rapid detection and efficient removal of toxic Cr2O72−
Authors: Wang Yangxin , Zhao Huaixia , Li Xinxiong , Wang Ruihu
Published: July 2016

A durable imidazolium-based main-chain ionic polymer for rapid luminescence detection and removal of toxic Cr2O72− was prepared. The separation and recycling procedures are simplified by the integration of Fe3O4 particles and the polymer.
High-performance blue organic light-emitting diodes with 20% external electroluminescence quantum efficiency based on pyrimidine-containing thermally activated delayed fluorescence emitters
Authors: Park In Seob , Lee Jiyoung , Yasuda Takuma
Published: July 2016

High-performance pure blue thermally activated delayed fluorescence (TADF) emitters consisting of pyrimidine and diphenylacridan units are developed.
Isoform-specific function of calpains in cell adhesion disruption: studies in postlactational mammary gland and breast cancer
Authors: Rodríguez-Fernández Lucía , Ferrer-Vicens Iván , García Concha , Oltra Sara S. , Zaragozá Rosa , Viña Juan R. , García-Trevijano Elena R.
Published: July 2016

Cleavage of adhesion proteins is the first step for physiological clearance of undesired cells during postlactational regression of the mammary gland, but also for cell migration in pathological states such as breast cancer. The intracellular Ca2+-dependent proteases, calpains (CAPNs), are known to cleave adhesion proteins. The isoform-specific function of CAPN1 and CAPN2 was explored and compared in two models of cell adhesion disruption: mice mammary gland during weaning-induced involution and breast cancer cell lines according to tumor subtype classification. In both models, E-cadherin, β-catenin, p-120, and talin-1 were cleaved as assessed by western blot analysis. Both CAPNs were able to cleave adhesion proteins from lactating mammary gland in vitro. Nevertheless, CAPN2 was the only isoform found to co-localize with E-cadherin in cell junctions at the peak of lactation. CAPN2/E-cadherin in vivo interaction, analyzed by proximity ligation assay, was dramatically increased during involution. Calpain inhibitor administration prevented the cytosolic accumulation of truncated E-cadherin cleaved by CAPN2. Conversely, in breast cancer cells, CAPN2 was restricted to the nuclear compartment. The isoform-specific expression of CAPNs and CAPN activity was dependent on the breast cancer subtype. However, CAPN1 and CAPN2 knockdown cells showed that cleavage of adhesion proteins and cell migration was mediated by CAPN1, independently of the breast cancer cell line used. Data presented here suggest that the subcellular distribution of CAPN1 and CAPN2 is a major issue in target-substrate recognition; therefore, it determines the isoform-specific role of CAPNs during disruption of cell adhesion in either a physiological or a pathological context.
APC/C and retinoblastoma interaction: cross-talk of retinoblastoma protein with the ubiquitin proteasome pathway
Authors: Ramanujan Ajeena , Tiwari Swati
Published: July 2016

The ubiquitin (Ub) ligase anaphase promoting complex/cyclosome (APC/C) and the tumour suppressor retinoblastoma protein (pRB) play key roles in cell cycle regulation. APC/C is a critical regulator of mitosis and G1-phase of the cell cycle whereas pRB keeps a check on proliferation by inhibiting transition to the S-phase. APC/C and pRB interact with each other via the co-activator of APC/C, FZR1, providing an alternative pathway of regulation of G1 to S transition by pRB using a post-translational mechanism. Both pRB and FZR1 have complex roles and are implicated not only in regulation of cell proliferation but also in differentiation, quiescence, apoptosis, maintenance of chromosomal integrity and metabolism. Both are also targeted by transforming viruses. We discuss recent advances in our understanding of the involvement of APC/C and pRB in cell cycle based decisions and how these insights will be useful for development of anti-cancer and anti-viral drugs.
Figurative Language Deficits Associated With Right Hemisphere Disorder
Authors: Lundgren Kristine , Brownell Hiram
Published: July 2016

Purpose

To describe the nonliteral language deficits associated with right hemisphere disorder (RHD), discuss the neuroimaging data associated with the processing of nonliteral language, and to offer some suggestions for treating this type of cognitive-linguistic disorder.

Method

In this discussion, we review literature on comprehension of metaphor, idioms, proverbs, and sarcasm and provide some treatment options.

Conclusion

The evidence-based treatment options for the remediation of figurative language deficits are extremely limited, not only for those individuals with RHD, but for all populations of children and adults with figurative language comprehension impairments.
Thermal noise limit for time‐domain analogue signal processing in CMOS technologies
Authors: Pathan A. , Liscidini A.
Published: July 2016

The impact of thermal noise in voltage‐ and time‐domain analogue signal processing is discussed. Despite the technology scaling allows to resolve smaller time differences, it will be shown that in CMOS technologies voltage signal processing have a better fundamental limit compared with its time counterpart.
Compact dual polarised V slit, stub and slot embedded circular patch antenna for UMTS/WiMAX/WLAN applications
Authors: Mathew S. , Ameen M. , Jayakrishnan M.P. , Mohanan P. , Vasudevan K.
Published: July 2016

A single probe‐fed novel V slit, stub and slot embedded circular microstrip antenna with resonances in the three bands of UMTS, worldwide interoperability for microwave access (WiMAX) and WLAN is presented. The polarisation is circular in the UMTS band and linear in the other two bands. Asymmetrical V slits in the patch boundary along with an embedded circular slot in the patch centre are employed to introduce the perturbation necessary for circular polarisation. Impedance bandwidths (BWs) of 4.2, 2 and 6.2%, respectively, in the three bands centred at 2, 3.5 and 5.6 GHz are obtained. The axial ratio BW is 2.3% in the UMTS band. Moderate gains of 4.4, 3.5 and 2.8 dBi are obtained in the three bands. There is a patch size reduction of about 48% when compared with the conventional circular patch antenna at a fixed operating frequency. The radiation pattern is directional in the WiMAX band and nearly omnidirectional in the WLAN band.
A modified‐secant iterative method for solving the Hamilton–Jacobi–Bellman–Isaac equations in non‐linear optimal control
Authors: Aliyu M.D.S.
Published: July 2016

In this study, a gradient‐free iterative secant method approach for solving the Hamilton–Jacobi–Bellman–Isaacs equations arising in the optimal control of affine non‐linear systems is discussed. Local convergence of the method is established under fairly mild assumptions, and some examples are solved to demonstrate the utility of the method. However, the results presented here are preliminary, and it will need several experimentations to establish the computational efficiency of the method.
Global stabilisation of complicated feedforward non‐linear systems by constructing state‐dependent saturation levels
Authors: Ye Huawen
Published: July 2016

It remains a significant issue to globally stabilise structure‐complicated non‐linear systems. For a class of non‐strict feedforward non‐linear systems – the chain of integrators subject to a vector field that is homogeneous of at least order one, the authors construct a class of new state‐dependent saturation levels for achieving global stabilisation. However, the authors provide the second class of saturation level functions for the case where the perturbed vector field is in a strict upper‐triangular form but does not satisfy the usual growth condition. Examples including the frictionless ball‐and‐beam model are analysed to illustrate the algorithms.
Boundedness of discretised non‐linear systems under fast terminal sliding mode control
Authors: Xiong Junlin , Gan Quanhongbo , Ren Wei
Published: July 2016

This study analyses the steady‐state boundedness property of discretised non‐linear systems under fast terminal sliding mode (FTSM) control. First, the recursive FTSM variables and surfaces are introduced. Then, the FTSM control law is designed by enforcing the system trajectory to reach the last FTSM surface after one sample period. The boundedness of the FTSM variables and the system steady states are established and the corresponding bounds are provided. Finally, the theoretical results are illustrated by a numerical example and a comparison with terminal sliding mode control is presented.
Flatness‐based deformation control of an Euler–Bernoulli beam with in‐domain actuation
Authors: Badkoubeh Amir , Zheng Jun , Zhu Guchuan
Published: July 2016

This study addresses the problem of deformation control of an Euler–Bernoulli beam with in‐domain actuation. The proposed control scheme consists in first relating the system model described by an inhomogeneous partial differential equation to a system under a standard boundary control form. Then, a combination of closed‐loop feedback control and flatness‐based motion planning is used for stabilising the closed‐loop system around reference trajectories. The validity of the proposed method is assessed through well‐posedness and stability analysis of the considered systems. The performance of the developed control scheme is demonstrated through numerical simulations of a representative micro‐beam.
Adaptive Lyapunov‐based backstepping control for an axially moving system with input saturation
Authors: Liu Yu , Zhao Zhijia , Guo Fang
Published: July 2016

This study presents an adaptive boundary control to suppress the vibration of an axially moving accelerated/decelerated belt system with input saturation. The dynamic model of the belt system is represented by a non‐homogeneous hyperbolic partial differential equation and two ordinary differential equations with the consideration of the high acceleration/deceleration. By utilising backstepping technique and adaptive technique, an adaptive boundary control is developed based on Lyapunov's direct method to stabilise the presented belt system. An auxiliary system is introduced to handle the effects of the input saturation, an adaptive law is designed to compensate for the system parametric uncertainties, a disturbance adaptation law is proposed to cancel out the effects of the boundary disturbance and the S‐curve acceleration/deceleration method is adopted to plan the speed of the belt system. With the proposed control scheme, the system states are guaranteed to be uniformly bounded and converged to a small neighbourhood of its equilibrium position, and the spillover instability problems are also avoided. Numerical simulations are provided to illustrate the validity of the proposed control scheme.
Multi‐objective design and prototyping of a low cogging torque axial‐flux PM generator with segmented stator for small‐scale direct‐drive wind turbines
Authors: Jamali Arand Saadat , Ardebili Mohammad
Published: July 2016

The multi‐objective design of an axial‐flux permanent magnet (PM) generator with the yokeless and segmented armature is done, for use in the small‐scale direct‐drive wind turbines. Using the multi‐objective genetic algorithm technique, an optimisation process is performed for maximising the efficiency and minimising the cost, size, and mass of active materials, considering the practical constraints of the wind generator. The Pareto optimal fronts are used to find the best solutions. Also, a comparative study is performed to determine the most appropriate configuration among 12 configurations with the different combinations of poles and stator segments. Then, the selected optimal configuration is analysed using the three‐dimensional (3D) finite element analysis (FEA). The inherent cogging torque of the PM wind generator affects the cut‐in speed and start‐up of the turbine. Thus, to improve the turbine performance, especially at low starting speeds, the generator cogging torque should be reduced to an acceptable level. In this study, using a new and practical approach, the peak‐to‐peak value of the cogging torque is reduced largely (81.4%), without notable reduction in the generator loadability. A prototype of the designed generator is fabricated and tested. The experimental results show good agreement with the 3D FEA simulation results.
Planning process for distribution grids based on flexibly generated time series considering RES, DSM and storages
Authors: Kays Jan , Rehtanz Christian
Published: July 2016

The volatile feed‐in of distributed generation based on renewable energy sources as well as new and intelligent loads and storages require an appropriate consideration in the distribution grid planning process. With the conventional planning method being dependent on extreme scenarios, the consideration is very limited. Therefore, a new planning tool based on the concept of a multi‐agent system is presented. In this system, every network user is represented by an agent, allowing not only the consideration of the volatile feed‐in characteristics of renewable energy sources but also of the dependencies between the grid users and their environment. Within this contribution, a system overview is given and the agent design process demonstrated on the example of the storage agent, including negotiations. This multi‐agent system generates time series for all relevant system variables, defining detailed input parameters in the distribution grid planning process. For the first time, this allows for a detailed determination of the conditions in the up to now rarely measured medium‐ and low‐voltage grids. As a consequence, new assumptions for the planning process are derivable, permitting a demand‐ and future‐oriented grid planning and avoiding over‐dimensioning of the grids.
Frequency regulation of multi‐area power systems with plug‐in electric vehicles considering communication delays
Authors: Fan Hua , Jiang Lin , Zhang Chuan‐Ke , Mao Chengxiong
Published: July 2016

Dynamics of vehicle‐to‐grid service to frequency regulation may suffer from the uncertainties arising from the spatial and temporal diversities of the large‐scale plug‐in vehicles (PEVs). Communication delays incurred both in the aggregation of the PEVs and in load frequency control (LFC) loop also degrade the dynamics and even destabilise the system. This study designs the LFC scheme considering those uncertainties. First, a dynamic model of individual PEV based on equivalent circuit and an aggregated model for PEVs group considering driving behaviours, battery characteristics, and delays are developed. Then, a state‐space model with time delays and uncertainties is constructed to model the closed‐loop LFC scheme with PEVs in primary control loop. After constructing the relationships among control gains, robust performances, and delays, a robust proportional–integral–derivative‐type LFC scheme design method is developed by using linear matrix inequality and particle swarm optimisation algorithm. Case studies based on a three‐area LFC system demonstrate that the PEVs contribute to the frequency regulation under different load disturbances and that the proposed LFC scheme successfully suppresses frequency fluctuations in the presence of delays and provides robustness against the uncertainties arising from the PEVs.
Image denoising via bidirectional low rank representation with cluster adaptive dictionary
Authors: Li Xiaoping , Wang Weiwei , Feng Xiangchu , Liu Xiaoyan , Luo Liang
Published: July 2016

In this study, the authors propose a new image representation model that fully exploits the similarity inherent in natural images. The idea is based on an observation of similar patches. For a clean image, when a cluster of similar patches are collected to form the similar patch matrix (SPM), there exists high correlation among columns/rows of the SPM. This implies that, when the column/row vectors are linearly expressed by a dictionary, their coefficients of columns/rows should have high correlation, which leads to the coefficient matrixes of column/row representation are low‐ranked. This observation inspires them to propose a novel image denoising model named bidirectional low rank representation (BiLRR) with cluster adaptive dictionary. Specifically, they use low rank penalties simultaneously on the coefficient matrixes of column and row representations to recover the correlation structure of the SPM. Meanwhile, a cluster adaptive dictionary is learned to represent each SPM so as to well preserve the fine structure of image. By applying variable splitting and penalty technique, they present an efficient alternative minimisation algorithm to solve the proposed BiLRR model. Experimental results indicate the authors’ method achieves a competitive denoising performance in comparison with state‐of‐the‐art algorithms in terms of subjective and objective qualities.
Dual‐band MIMO dielectric resonator antenna for WiMAX/WLAN applications
Authors: Khan Aftab Ahmad , Jamaluddin Mohd Haizal , Aqeel Sajid , Nasir Jamal , Kazim Jalil ur Rehman , Owais Owais
Published: July 2016

In this study, a novel dual‐band multiple‐input multiple‐output (MIMO) rectangular dielectric resonator antenna (DRA) for Worldwide interoperability for microwave access (WiMAX) (3.4–3.7) GHz and wireless local area network (WLAN) (5.15–5.35) GHz applications is proposed and investigated. The design operates at fundamental TEδ11x, TE1δ1y and higher order TEδ21x, TE2δ1y modes, excited through two coaxial probes, symmetrically placed adjacent to the DRA. A compact design is achieved by stacking a high permittivity material. The obtained impedance bandwidth at 3.6 GHz is 9.97% and at 5.2 GHz is 8.88%. Measured antenna gain through both ports at 3.6 GHz is 5.7 dBi and at 5.2 GHz is 6.61 dBi, respectively. Isolation achieved at 3.6 GHz is −13 dB and at 5.2 GHz is −16 dB, respectively. Co‐ and cross‐polarisation, radiation efficiency, diversity gain, envelope correlation and mean effective gain of the proposed design are measured. Results show that the proposed design is suitable for use in MIMO WiMAX/WLAN applications.
Simplified RET model derived from path loss and directional spectrum measurements in vegetation media at 11.2 and 20 GHz
Authors: Caldeirinha Rafael F.S. , Fernandes Telmo R. , Richter Jürgen , Al‐Nuaimi Miqdad O.
Published: July 2016

This study presents a simplified radiative energy transfer (RET) model derived from path loss and directional spectrum measurements in vegetation media at 11 and 20 GHz. Thus, a simplified extraction procedure for the inputs parameters based on the method foreseen by the international telecommunications union ‐ recommendation (ITU‐R) P.833‐8, however for isolated vegetation volumes, is proposed. Results for specific measurements aimed at the extraction of the RET model parameters are subsequently presented and discussed. The extraction method relies on a limited set of propagation measurements to find and optimise the RET input parameters. Specific measurements of the received signal directional profile are used to show the applicability of the method. This parameter evaluation method is tested and assessed based on the received signal directional profile measurements performed in Populous trees at 11.2 and 20 GHz.
Fundamental even leaky mode in microstrip line loaded with shorting vias
Authors: Liu Juhua , Li Yuanxin , Long Yunliang
Published: July 2016

An even leaky mode in a microstrip line loaded with periodic shorting vias at the centre is investigated. The even leaky mode has a lower cutoff frequency than that of the first higher mode (odd mode). Thus, it is a fundamental leaky mode. The even leaky mode can generate dual symmetrical side beams that scan with frequency, similar to the second higher mode (even mode) in a non‐loaded microstrip line. The dispersion characteristic of the even leaky mode is analysed efficiently with the method of auxiliary sources and validated with HFSS. Based on the leaky even mode, two leaky‐wave antennas with different feeding structures are designed. Measured results for the two antennas are consistent with simulated and theoretical results.
Synthesis design of a wideband impedance transformer consisting of two‐section coupled lines
Authors: Wu Qiongsen , Zhu Lei
Published: July 2016

An impedance transformer employing two‐section coupled lines is presented in this study, which can achieve a wide operating band or passband with three reflection zeros. A direct synthesis approach is proposed and applied to the design of this transformer with the prescribed Chebyshev‐function frequency response. If the impedance–transformation ratio, passband return loss (RL), and operating bandwidth are properly specified, all the required design parameters of this transformer can be explicitly gained. Furthermore, a special region for realisable impedance–transformation ratio and operating bandwidth with respect to the passband equal‐ripple RL is extensively investigated. As such, various sets of design curves are numerically derived and graphically demonstrated for synthesis design of authors’ proposed impedance transformer. As an example, a 50–25 Ω impedance transformer with the 50% fractional bandwidth and 20 dB passband RL is designed, fabricated, and measured to confirm the theoretical predictions in the experiment.
Timely and reliable packets delivery over internet of vehicles for road accidents prevention: a cross‐layer approach
Authors: Eze Elias C. , Zhang Sijing , Liu Enjie , Nweso Emmanuel N. , Eze Joy C.
Published: July 2016

With the envisioned era of internet of things, all aspects of Intelligent Transportation Systems will be connected to improve transport safety, relieve traffic congestion, reduce air pollution, enhance the comfort of transportation and significantly reduce road accidents. In internet of vehicles, regular exchange of current position, direction, velocity and so on, enables mobile vehicles to predict an upcoming accident and alert the human drivers in time or proactively take precautionary actions to avoid the accident. The actualisation of this concept requires the use of channel access protocols that can guarantee reliable and timely broadcast of safety messages. This study investigates the application of network coding concept to increase content of every transmission and achieve improved broadcast reliability with less number of retransmissions. In particular, the authors proposed Code Aided Retransmission‐based Error Recovery (CARER) scheme, introduced a request‐to‐broadcast/clear‐to‐broadcast (RTB/CTB) handshake to overcome hidden node problem and reduce packets collision rate. In order to avoid broadcast storm problem associated with the use of RTB/CTB packet in a broadcast transmission, they developed a rebroadcasting metric used to successfully select a vehicle to rebroadcast the encoded message. The performance of CARER protocol is clearly shown with detailed theoretical analysis and further validated with simulation experiments.
Cluster‐based networks for cooperative localisation
Authors: Tseng Po‐Hsuan
Published: July 2016

Cooperative localisation (CL) is an effective way to enhance the position estimate by cooperation among agents, especially under insufficient signal source conditions. In centralised CL (C‐CL), all the information is transmitted to a data centre to find a globally optimal solution for all agents. However, the centralised network is not scalable since the collection of all the measurements requires higher communication overhead. In distributed CL (D‐CL), each agent iteratively estimates its position by exchanging this estimate with its neighbours, which require proper initial positions. In this study, cluster‐based networks are adopted to solve the scalability issue of C‐CL and the initial position issue of D‐CL. Analysis of performance limit for D‐CL is derived based on Cramér–Rao lower bound. The theoretical foundation supports the utilisation of the proposed cluster‐based CL (CbCL) to decouple C‐CL problem into intra‐cluster CL problem for a reliable initial position first. After the proposed N‐anchors cluster formation, the clusterhead estimates the cluster members’ initial positions based on intra‐cluster measurements. The cluster gateway further iteratively refines its position estimate with other cluster gateways based on inter‐cluster measurements. Simulation results validate that the CbCL achieves a tradeoff between the communication overhead and the localisation performance for a scalable implementation.
Tracking with MIMO sonar systems: applications to harbour surveillance
Authors: Pailhas Yan , Houssineau Jeremie , Petillot Yvan René , Clark Daniel Edward
Published: July 2016

Multiple‐input multiple‐output (MIMO) sonar systems offer new perspectives for area surveillance especially in complex environments where strong multipath and dense clutter can become very challenging. This study proposes a MIMO sonar system based scheme to tackle the difficult problem of harbour surveillance. An emphasis is put on recognition and tracking on low‐profile mid‐water targets. First, a MIMO simulator which can compute synthetic raw data for any transmitter/ receiver pair in a multipath, cluttered and dynamic environment is presented. The study then proposes two radically different methods for the underwater target tracking problem in complex environment: a digital tracker and an analogue tracker. On the digital side, an implementation of the recently developed hypothesised filter for independent stochastic populations is presented. This filter enables robust multi‐object tracking as well as track classification capabilities without the use of heuristics. An analogue filter based on acoustical time reversal techniques is also introduced. This filter directly uses the returned acoustic field from the scene to focus the sound on the expected target position, hence improving the signal‐to‐noise ratio on the target in complex environments and taking full advantage of the MIMO architecture.
Method of sparse design based on the dimension reduction technology and the double partial discharge sources positioning test
Authors: Xie Qing , Huang He , Liu Dan , Zhang Ying , Tao Junhan , Wang Xinjie , Lü Fangcheng
Published: July 2016

The detection method of partial discharge (PD) ultrasonic array signals is a new method that applies array sensors and array signals process technique to the PD detection. Moreover, the technique has high signal‐to‐noise ratio and high reliability. Compared with a full array sensor, degree reduction array sensor is a sparse array detection system, which has advantages of simple structure, low cost, and meeting most needs of engineering. However, these existed degree reduction algorithms of sparse optimal design are relatively complicated, affecting the success rate and the accuracy of detection. Therefore, this study proposes a method, which is the optimal design of the PD ultrasonic array sensor based on genetic algorithm dimension reduction technique. First, a two‐dimensional (2D) plane circular array search is changed into a corresponding 1D linear search, and the genetic algorithm performs the linear search. Then, a circular array structure is restored to calculate the array performance. Finally, an optimal sparse structure of the circular PD ultrasonic array sensor is obtained under multiple constraints. The simulated results and the experimental studies are carried out to verify the validity and effectiveness of the proposed approach.
One‐pot modification of Fe3O4 to prepare Fe3O4/SiO2/C nanoparticles and their catalytic activity in Fenton‐like process for dye decolouration
Authors: Xue Fumin , Yang Sheng‐Tao , Jin Xinyan , Li Tongtong , Wang Ruijue , Liu Xiaoyang , Bai Yitong , Chen Lingyun , Ming Zhu , Yang Hua
Published: July 2016

Heterogeneous catalysis of Fenton‐like process provides new alternatives to overcome the drawbacks of traditional Fe2+‐H2O2 system. Herein, the modification of Fe3O4 with SiO2/C in one‐pot hydrothermal reaction to prepare Fe3O4/SiO2/C nanoparticles (FSCNP) for the Fenton‐like catalysis in neutral environment is reported. FSCNP could catalyse the decomposition of H2O2 at various pH values to decolourise methylene blue (MB), in particular the neutral pH 7.5. Correspondingly, the chemical oxygen demanding of MB solution was significantly removed. FSCNP‐H2O2 system was resistant to radical scavengers. Higher H2O2 concentration and temperature would accelerate the decolouration of MB in FSCNP‐H2O2 system. The implications to the future applications of FSCNP in dye decolouration and water treatment are discussed.