bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and characterization of quantum dots for application in laser soft desorption/ionization mass spectrometry to detect labile metal–drug interactions and their antibacterial activity
Authors: Abdelhamid Hani Nasser , Wu Hui-Fen
Published: September 2015

Synthesis and characterization of quantum dot modified mercaptopropionic acid (CdS@MPA) and its application in laser soft desorption/ionization for labile metal–drug interactions is reported.
Physically crosslinked poly(vinyl alcohol)–carrageenan composite hydrogels: pore structure stability and cell adhesive ability
Authors: Zhang Yabin , Ye Lei , Cui Man , Yang Boguang , Li Junjie , Sun Hong , Yao Fanglian
Published: September 2015

Poly(vinyl alcohol) (PVA)–carrageenan (CAR) composite hydrogels can reduce pore collapse during lyophilization and enhance cell adhesion in comparison to pure PVA hydrogels.
Synthesis and electrochemical capacitance performance of polyaniline doped with lignosulfonate
Authors: Xu Hailing , Jiang Huang , Li Xingwei , Wang Gengchao
Published: September 2015

Polyaniline doped with lignosulfonate (PANI/LGS) was prepared by using a facile oxidative polymerization of aniline with (NH4)2S2O8as an oxidant, and its electrochemical capacitance performance was investigated.
Rationally developed core–shell polymeric-lipid hybrid nanoparticles as a delivery vehicle for cromolyn sodium: implications of lipid envelop on in vitro and in vivo behaviour of nanoparticles upon oral administration
Authors: Patel Ravi R. , Khan Gayasuddin , Chaurasia Sundeep , Kumar Nagendra , Mishra Brahmeshwar
Published: September 2015

In the present study, cromolyn sodium, a highly water soluble molecule was encapsulated into rationally designed, core–shell polymeric-lipid hybrid nanoparticles for enhancing its oral bioavailability, by improving its intestinal permeability.
Fabrication of SiO2 incorporated ordered mesoporous TiO2 composite films as functional Pt supports for photo-electrocatalytic methanol oxidation
Authors: Fan X. L. , Zhang C. X. , Xue H. R. , Guo H. , Song L. , He J. P.
Published: September 2015

SiO2 incorporated ordered mesoporous TiO2 composite films were fabricated as an active support for methanol oxidation and excellent photoelectrocatalytic activity was obtained, showing great potential application prospects.
Catalytic low-temperature combustion of dichloromethane over V–Ni/TiO2 catalyst
Authors: Zhang Xinhua , Pei Zhiying , Ning Xingjie , Lu Hanfeng , Huang Haifeng
Published: September 2015

A plausible pathway for DCM oxidation over V–Ni/TiO2.
Review on nanomaterials synthesized by vapor transport method: growth and their related applications
Authors: Xue X. , Zhou Z. , Peng B. , Zhu M. M. , Zhang Y. J. , Ren W. , Ye Z. G. , Chen X. , Liu M.
Published: September 2015

Nanostructures with different dimensions, including bulk crystals, thin films, nanowires, nanobelts and nanorods, have received considerable attention due to their novel functionalities and outstanding applications in various areas.
Electrokinetic remediation: challenging and optimization of electrolyte for sulfate removal in textile effluent-contaminated farming soil
Authors: Annamalai Sivasankar , Selvaraj Subbulakshmi , Selvaraj Hosimin , Santhanam Manikandan , Pazos Marta
Published: September 2015

In the current situation, soil salinity has increased due to the uncontrolled discharge of industrial effluent.
A direct approach for the expedient synthesis of unsymmetrical ethers by employing bromodimethylsulfonium bromide (BDMS) mediated C–S bond cleavage of naphthalene-2-ol sulfides
Authors: Islam Kobirul , Sidick Basha R. , Dar Ajaz A. , Das Deb K. , Khan Abu T.
Published: September 2015

Synthesis of unsymmetrical ether derivatives using 1-(aryl(alkyl/arylthio)methyl)-naphthalene-2-ol and alcohols in the presence of bromodimethylsulfonium bromide (BDMS).
Aqueous biphasic separation of97Ru and95,96Tc from yttrium
Authors: Maiti Moumita , Datta Arpita , Lahiri Susanta
Published: September 2015

An aqueous biphasic separation technique has been developed for the separation of97Ru, a potential candidate radionuclide in nuclear medicine, from its target matrix, yttrium.
Platinum-catalysed cinnamaldehyde hydrogenation in continuous flow
Authors: Durndell Lee J. , Wilson Karen , Lee Adam F.
Published: September 2015

Continuous flow operation provides significantly enhanced activity, selectivity and lifetime for the Pt catalysed selective hydrogenation of cinnamaldehyde to cinnamyl alcohol.
Co-delivery of doxorubicin hydrochloride and verapamil hydrochloride by pH-sensitive polymersomes for the reversal of multidrug resistance
Authors: Li Nuannuan , Zhang Pei , Huang Chunzhi , Song Yunmei , Garg Sanjay , Luan Yuxia
Published: September 2015

A promising co-delivery system was proposed for effectively reversing multidrug resistance of cancer cells and simultaneously improving the anticancer effect of the drug.
Stimuli-responsive protein-based micro/nano-waveguides
Authors: Hou Zhishan , Sun Siming , Zheng Boyuan , Yang Ruizhu , Li Aiwu
Published: September 2015

Protein-based single nano-wire waveguides constructed by FsLDW using BSA aqueous ink which might be applicable for uses as sensing probes.
A mechanistic study of the synthesis, single crystal X-ray data and anticarcinogenic potential of bis(2-pyridyl)selenides and -diselenides
Authors: Dhau Jaspreet S. , Singh Avtar , Singh Amritpal , Sharma Neha , Brandão Paula , Félix Vítor , Singh Baljinder , Sharma Vishal
Published: September 2015

A mechanistic study on LiAlH4 assisted scission of C–Se bond in bis(2-pyridyl)diselenides leading to bis(2-pyridyl)selenides generation has been presented.
Synthesis of Pt doped Mg–Al layered double oxide/graphene oxide hybrid as novel NOx storage–reduction catalyst
Authors: Mei Xueyi , Wang Junya , Yang Ruoyan , Yan Qinghua , Wang Qiang
Published: September 2015

We report the synthesis of Pt doped Mg–Al layered double oxide/graphene oxide (Pt–LDO/GO) hybrid as novel NOx storage and reduction (NSR) catalyst.
5-Phenyl-dipyrromethane and 5-(4-pyridyl)-dipyrromethane as modular building blocks for bio-inspired conductive molecularly imprinted polymer (cMIP). An electrochemical and piezoelectric investigation
Authors: Susmel S. , Comuzzi C.
Published: September 2015

5-Phenyl-dipyrromethane (5-ph-DP) and 5-(4-pyridyl)dipyrromethane (5-py-DP) are proposed, for the first time, as electroactive building blocks for the preparation of sensors based on molecularly imprinted conductive polymers (cMIP).
Shaping of bacterial community structure in microbial fuel cells by different inocula
Authors: Mei Xiaoxue , Guo Changhong , Liu Bingfeng , Tang Yu , Xing Defeng
Published: September 2015

Understanding how the community structure of anode biofilms is shaped is important for enhancing the performance of microbial fuel cells (MFCs).
Selecting analytical tools for characterization of polymersomes in aqueous solution
Authors: Habel Joachim , Ogbonna Anayo , Larsen Nanna , Cherré Solène , Kynde Søren , Midtgaard Søren Roi , Kinoshita Koji , Krabbe Simon , Jensen Grethe Vestergaard , Hansen Jesper Søndergaard , Almdal Kristoffer , Hèlix-Nielsen Claus
Published: September 2015

We present 17 techniques to analyze polymersomes, in terms of their size, bilayer properties, elastic properties or surface charge.
Dual functionalized task specific ionic liquid promoted in situ generation of palladium nanoparticles in water: synergic catalytic system for Suzuki–Miyaura cross coupling
Authors: Patil Jayavant D. , Korade Suyog N. , Patil Supriya A. , Gaikwad Dipak S. , Pore Dattaprasad M.
Published: September 2015

A new task specific ionic liquid with hydroxyl and prolinate functionalities acts as a reducing agent and serves as a ligand and stabilizer for in situ formed palladium nanoparticles. This system displays high catalytic activity for Suzuki–Miyaura cross-coupling in water.
Influence of silver grain size, roughness, and profile on the extraordinary fluorescence enhancement capabilities of grating coupled surface plasmon resonance
Authors: Wood A. J. , Chen B. , Pathan S. , Bok S. , Mathai C. J. , Gangopadhyay K. , Grant S. A. , Gangopadhyay S.
Published: September 2015

Silver gratings with different metal film properties and structures were examined to determine their effect on metal enhanced fluorescence.
Chemoselective calcium-catalysed direct amidation of carboxylic esters
Authors: Nguyen D. Thao , Lenstra Danny C. , Mecinović Jasmin
Published: September 2015

Cheap, non-toxic and environmentally benign CaI2 catalyses direct amide bond formation between unactivated carboxylic esters and primary amines in excellent yields.
The specificity of thioredoxins and glutaredoxins is determined by electrostatic and geometric complementarity
Authors: Berndt Carsten , Schwenn Jens-Dirk , Lillig Christopher Horst
Published: September 2015

Specific long- and short-range electrostatic interactions and not redox potentials determine the substrate specificity of Trx family proteins.
The high-performance and mechanism of P-doped activated carbon as a catalyst for air-cathode microbial fuel cells
Authors: Liu Yunting , Li Kexun , Liu Yi , Pu Liangtao , Chen Zhihao , Deng Shuguang
Published: September 2015

We report phosphorus (P)-doped activated carbon (AC) as a highly active catalyst for the oxygen reduction reaction (ORR) in air-cathode microbial fuel cells (MFCs).
Capture and electrochemical conversion of CO2to ultrathin graphite sheets in CaCl2-based melts
Authors: Hu Liwen , Song Yang , Ge Jianbang , Zhu Jun , Jiao Shuqiang
Published: September 2015

A novel method for capture and electrochemical conversion of CO2to graphite sheets in molten CaCl2with the utilization of renewable energy sources has been proposed. The reduction mechanism was investigated and the results indicate that two steps are involved.
The influence of spacer units on molecular properties and solar cell performance of non-fullerene acceptors
Authors: Zhao Jingbo , Li Yunke , Zhang Jianquan , Zhang Lu , Lai Joshua Yuk Lin , Jiang Kui , Mu Cheng , Li Zhengke , Chan Chun Lam Clement , Hunt Adrian , Mukherjee Subhrangsu , Ade Harald , Huang Xuhui , Yan He
Published: September 2015

The position of methyl groups causes a dramatic change in molecular properties and solar cell performance.
One-pot construction of three dimensional CoMoO4/Co3O4 hybrid nanostructures and their application in supercapacitors
Authors: Zhou Min , Lu Fei , Shen Xiaoshuang , Xia Weiwei , He Hui , Zeng Xianghua
Published: September 2015

Three dimensional CoMoO4/Co3O4 hybrid nanostructures were synthesized via one-pot hydrothermal method and displayed excellent performance as electrode material in supercapacitors.
Quantum-sized BiVO4 modified TiO2 microflower composite heterostructures: efficient production of hydroxyl radicals towards visible light-driven degradation of gaseous toluene
Authors: Sun Juanjuan , Li Xinyong , Zhao Qidong , Tadé Moses O. , Liu Shaomin
Published: September 2015

The enhanced photocatalytic activity of the quantum-BiVO4/TiO2 composite was mainly attributed to the high separation of photo-induced electron–hole pairs and the efficient production of hydroxyl radicals.
Critical advances for the iron molten air battery: a new lowest temperature, rechargeable, ternary electrolyte domain
Authors: Liu Shuzhi , Li Xin , Cui Baochen , Liu Xianjun , Hao Yulan , Guo Qi , Xu Peiqiang , Licht Stuart
Published: September 2015

The iron molten air battery cycled stably at 500 °C for 60 cycles using cost effective nickel and steel electrodes and KCl–LiCl–LiOH eutectic electrolyte with added NaOH.
Retracted Article:
In situ nano-coating on Li1.2Mn0.52Ni0.13Co0.13O2 with a layered@spinel@coating layer heterostructure for lithium-ion batteries
Authors: Li Bing , Li Chao , Cai Jijun , Zhao Jinbao
Published: September 2015

Lithium-rich manganese-based layered oxides with a composition of xLi2MnO3·(1 − x)LiMO2 (M = Mn, Co, Ni, etc.) are attractive, due to their high discharge capacity.
Improved molecular architecture of D–π–A carbazole dyes: 9% PCE with a cobalt redox shuttle in dye sensitized solar cells
Authors: Soni Saurabh S. , Fadadu Kishan B. , Vaghasiya Jayraj V. , Solanki Bharat G. , Sonigara Keval K. , Singh Ashish , Das Dipjyoti , Iyer Parameswar K.
Published: September 2015

DSSCs with >9% PCE based on a new D–π–A dye (SK3) having carbazole as a donor, vinylene-phenylene (π-bridge) and cyanoacrylic acid as electron withdrawing–injecting as well as anchoring groups are reported.
A shape- and morphology-controlled metal organic framework template for high-efficiency solid-state dye-sensitized solar cells
Authors: Chi Won Seok , Roh Dong Kyu , Lee Chang Soo , Kim Jong Hak
Published: September 2015

Deliberate calcination of shape- and morphology-controlled MIL-125(Ti) gave mesoporous hierarchical TiO2(hier-TiO2) with an anatase phase and a large surface area. DSSCs fabricated with the hier-TiO2photoanode and a solid electrolyte exhibited a high efficiency of 8.0%.
Glucose-induced decomposition of layer-by-layer films composed of phenylboronic acid-bearing poly(allylamine) and poly(vinyl alcohol) under physiological conditions
Authors: Sato Katsuhiko , Takahashi Mao , Ito Megumi , Abe Eiichi , Anzai Jun-Ichi
Published: September 2015

Phenylboronic acid-bearing poly(allylamine)/poly(vinyl alcohol) layer-by-layer films coupled with glucose oxidase decomposed in the presence of glucose under physiological conditions.
Efficient delivery of small interfering RNA into cancer cells using dodecylated dendrimers
Authors: Chang Hong , Zhang Yueming , Li Lei , Cheng Yiyun
Published: September 2015

Dodecylated dendrimers show significantly improved gene silencing efficacy after dodecylation. Among the dendrimers, G4-23C12 shows the highest gene knockdown efficacy.
A highly effective in vivo photothermal nanoplatform with dual imaging-guided therapy of cancer based on the charge reversal complex of dye and iron oxide
Authors: Chang Yulei , Li Xiaodan , Kong Xianggui , Li Ye , Liu Xiaomin , Zhang Youlin , Tu Langping , Xue Bin , Wu Fei , Cao Dianbo , Zhao Huiying , Zhang Hong
Published: September 2015

A new precision treatment strategy based on the dual photothermal agent of IR-806 NIR dye and iron oxide nanocomplex was constructed for efficient image-guidedin vivophotothermal therapy (PTT).
Biomolecular strategies to modulate the macrophage response to implanted materials
Authors: Kim Yoon Kyung , Chen Esther Y. , Liu Wendy F.
Published: September 2015

Materials engineered to display immunomodulatory molecules including adhesion ligands, cytokines, and self-proteins, target receptors on immune cells to modulate their response to biomaterial implants.
Phototransistors based on a donor–acceptor conjugated polymer with a high response speed
Authors: Wang Qinghe , Zhu Min , Wu Di , Zhang Guobing , Wang Xiaohong , Lu Hongbo , Wang Xianghua , Qiu Longzhen
Published: September 2015

A D–A polymer phototransistor shows both hole- and electron-carrier transport response to incident light with photoswitching speeds below 14 ms.
Acido-basic control of the thermoelectric properties of poly(3,4-ethylenedioxythiophene)tosylate (PEDOT-Tos) thin films
Authors: Khan Zia Ullah , Bubnova Olga , Jafari Mohammad Javad , Brooke Robert , Liu Xianjie , Gabrielsson Roger , Ederth Thomas , Evans Drew R. , Andreasen Jens W. , Fahlman Mats , Crispin Xavier
Published: September 2015

PEDOT-Tos is one of the conducting polymers that displays the most promising thermoelectric properties.
Heteroatom induced contrasting effects on the stimuli responsive properties of anthracene based donor–π–acceptor fluorophores
Authors: Naeem Karattu Chali , Subhakumari Akhila , Varughese Sunil , Nair Vijayakumar C.
Published: September 2015

Heteroatom induced differences in mechanochromism and acidochromism of anthracene based fluorophores are described.
Achieving hierarchical hollow carbon@Fe@Fe3O4 nanospheres with superior microwave absorption properties and lightweight features
Authors: Lv Hualiang , Ji Guangbin , Liu Wei , Zhang Haiqian , Du Youwei
Published: September 2015

Hierarchical hollow carbon@Fe@Fe3O4 nanospheres were synthesized by a simple template method and another pyrolysis process.
Design, validation and efficacy of bisubstrate inhibitors specifically affecting ecto-CK2 kinase activity
Authors: Cozza Giorgio , Zanin Sofia , Sarno Stefania , Costa Elena , Girardi Cristina , Ribaudo Giovanni , Salvi Mauro , Zagotto Giuseppe , Ruzzene Maria , Pinna Lorenzo A.
Published: September 2015

By derivatizing the purely competitive CK2 inhibitor N1-(4,5,6,7-tetrabromo-1H-benzimidazol-2-yl)-propane-1,3-diamine (K137) at its 3-amino position with a peptidic fragment composed of three or four glutamic or aspartic acid residues, a new family of bisubstrate inhibitors has been generated whose ability to simultaneously interact with both the ATP and the phosphoacceptor substrate-binding sites has been probed by running mixed competition kinetics and by mutational mapping of the kinase residues implicated in substrate recognition. The most effective bisubstrate inhibitor, K137-E4, interacts with three functional regions of the kinase: the hydrophobic pocket close to the ATP-binding site, the basic residues of the p+1 loop that recognizes the acidic determinant at position n+1 and the basic residues of α-helixC that recognize the acidic determinant at position n+3. Compared with the parent inhibitor (K137), K137-E4 is severalfold more potent (IC50 25 compared with 130 nM) and more selective, failing to inhibit any other kinase as drastically as CK2 out of 140 enzymes, whereas 35 kinases are inhibited more potently than CK2 by K137. K137-E4 is unable to penetrate the cell and to inhibit endogenous CK2, its pro-apoptotic efficacy being negligible compared with cell-permeant inhibitors; however, it readily inhibits ecto-CK2 on the outer cell surface, reducing the phosphorylation of several external phosphoproteins. Inhibition of ecto-CK2 by K137-E4 is accompanied by a slower migration of cancer cells as judged by wound healing assays. On the basis of the cellular responses to K137-E4, we conclude that ecto-CK2 is implicated in cell motility, whereas its contribution to the pro-survival role of CK2 is negligible.
Involvement of selective autophagy mediated by p62/SQSTM1 in KLHL3-dependent WNK4 degradation
Authors: Mori Yutaro , Mori Takayasu , Wakabayashi Mai , Yoshizaki Yuki , Zeniya Moko , Sohara Eisei , Rai Tatemitsu , Uchida Shinichi
Published: September 2015

We reported that kelch-like protein 3 (KLHL3)–Cullin3 E3 ligase ubiquitinates with-no-lysine kinase 4 (WNK4) and that impaired WNK4 ubiquitination causes pseudohypoaldosteronism type II, a hereditary hypertensive disease. However, we also found that KLHL3-induced WNK4 degradation could not be inhibited completely by a proteasome inhibitor. Rather, on exposure, for 24 h, of HEK293T cells expressing WNK4 and KLHL3 to a proteasome inhibitor, epoxomicin, the WNK4 protein level was further decreased. As proteasome inhibition is known to activate p62-mediated selective autophagy, we investigated whether WNK4 degradation induced by KLHL3 is also mediated by such an autophagic mechanism. 3-Methyladenine, an autophagy inhibitor, blocked the epoxomicin-induced decrease in WNK4. Co-immunoprecipitation assays revealed that KLHL3 formed a complex not only with WNK4 but also with p62 via its kelch repeat domain. Under proteasome inhibition, p62 overexpression decreased KLHL3 and WNK4 protein levels, and p62 knockdown dramatically increased KLHL3 and WNK4 protein levels. Based on immunofluorescent staining, transiently overexpressed WNK4 showed punctate localization in the cytoplasm where it co-localized with KLHL3, p62 and light chain 3, a marker of autophagosomes. Thus, WNK4 was degraded not only by proteasomes but also by p62–KLHL3-mediated selective autophagy, which may be involved in WNK regulation under certain pathophysiological conditions.
Manipulating Cx43 expression triggers gene reprogramming events in dermal fibroblasts from oculodentodigital dysplasia patients
Authors: Esseltine Jessica L. , Shao Qing , Huang Tao , Kelly John J. , Sampson Jacinda , Laird Dale W.
Published: September 2015

Oculodentodigital dysplasia (ODDD) is primarily an autosomal dominant disorder linked to over 70 GJA1 gene [connexin43 (Cx43)] mutations. For nearly a decade, our laboratory has been investigating the relationship between Cx43 and ODDD by expressing disease-linked mutants in reference cells, tissue-relevant cell lines, 3D organ cultures and by using genetically modified mouse models of human disease. Although salient features of Cx43 mutants have been revealed, these models do not necessarily reflect the complexity of the human context. To further overcome these limitations, we have acquired dermal fibroblasts from two ODDD-affected individuals harbouring D3N and V216L mutations in Cx43, along with familial controls. Using these ODDD patient dermal fibroblasts, which naturally produce less GJA1 gene product, along with RNAi and RNA activation (RNAa) approaches, we show that manipulating Cx43 expression triggers cellular gene reprogramming. Quantitative RT-PCR, Western blot and immunofluorescent analysis of ODDD patient fibroblasts show unusually high levels of extracellular matrix (ECM)-interacting proteins, including integrin α5β1, matrix metalloproteinases as well as secreted ECM proteins collagen-I and laminin. Cx43 knockdown in familial control cells produces similar effects on ECM expression, whereas Cx43 transcriptional up-regulation using RNAa decreases production of collagen-I. Interestingly, the enhanced levels of ECM-associated proteins in ODDD V216L fibroblasts is not only a consequence of increased ECM gene expression, but also due to an apparent deficit in collagen-I secretion which may further contribute to impaired collagen gel contraction in ODDD fibroblasts. These findings further illuminate the altered function of Cx43 in ODDD-affected individuals and highlight the impact of manipulating Cx43 expression in human cells.
In vitro translation of mRNAs that are in their native ribonucleoprotein complexes
Authors: Panthu Baptiste , Mure Fabrice , Gruffat Henri , Ohlmann Theophile
Published: September 2015

mRNA is bound to a complex network of hundreds of RNA-binding proteins (RBPs) which constitute the mature ribonucleoprotein (mRNP). Such a complex particle is initially scaffolded in the nucleus and stays associated throughout mRNA's journey to the cytoplasm, where it participates in translation. However, due to the size, complexity and variability of the mRNP, it remains technically challenging to assess its impact on translation. By designing a novel in vitro translational assay, we have been able to compare the translational efficiency of reporter mRNAs that are, or are not, associated with their cognate RBPs. This showed the strong impact of these RBPs on translational efficiency, and revealed intrinsic variations according to the structure of both the mRNA and its nuclear history, e.g. the use of intron-containing mRNA constructs showed that splicing strongly enhanced translation. The present study shows that nuclear and cytoplasmic gene expression steps in vitro are coupled in eukaryotes and this is determined from the very birth of the mRNA in the nucleus by a network of hundreds of RBPs.
Capacity optimisation method of distribution static synchronous compensator considering the risk of voltage sag in high‐voltage distribution networks
Authors: Li Shuaihu , Li Yong , Cao Yijia , Tan Yi , Keune Björn
Published: September 2015

Unlike the traditional methods that only take static voltage stability or minimum network loss into consideration when optimising capacity of distribution static synchronous compensator (D‐STATCOM), a new approach is proposed with considering the risk of voltage sag as well as the network loss and the investment cost of D‐STATCOM. This approach can balance the investment cost and technical performance. Monte Carlo method is used for the random setting of fault types and locations to obtain the original probability of voltage sag under some given configuration schemes. Moreover, through revealing the hidden relationship between the original probability and the real‐time load, the converted probability is presented to fit the expression for calculating the original probability of voltage sag with respect to the size of additional D‐STATCOM. Finally, a single‐objective capacity optimisation model is established to obtain the optimum size of additional D‐STATCOM, which is based on the economic assessment method of risk. The proposed method is validated in Chinese Dongguang Distribution Networks. The result confirms this method can not only reduce the loss of voltage sag, but also significantly improve the efficiency of D‐STATCOM.
Modelling hierarchical decision making framework for operation of active distribution grids
Authors: Bahramara Salah , Parsa Moghaddam Mohsen , Haghifam Mahmoud Reza
Published: September 2015

In this study, a hierarchical decision making framework for operation of active distribution grids (ADGs) in which distribution company (Disco) and microgrids (MGs) cooperate with each other is modelled. Since there are several MGs, which may have independent decision makers, in ADGs, two levels of decision makers are considered in this framework. The mentioned framework is modelled as a bi‐level optimisation problem in which Disco and MGs are considered as the leader and the followers, respectively. The resulting model is a non‐linear bi‐level problem which is transformed into a linear single‐level problem through Karush–Kuhn–Tucker conditions and dual theory. To evaluate the effectiveness of the model, a hypothetical distribution grid is considered as the case study.
Transient stability improvement of doubly fed induction generator based variable speed wind generator using DC resistive fault current limiter
Authors: Hossain Md Maruf , Ali Mohd. Hasan
Published: September 2015

Currently, the doubly fed induction generator (DFIG) is getting wider popularity due to its ability to adapt with variable wind speed and to capture more wind energy. According to the grid code, transient stability enhancement of the DFIG system is very important. Though DFIG has a salient feature of the fault ride through capability, this is not sufficient to preserve the necessity of the grid code when the DFIG system is connected with the grid. To accomplish this goal, a DC resistive superconducting fault current limiter (SFCL) is proposed, as it reduces the system power losses during stable operation of the network with improved system efficiency, in comparison with the conventional SFCL. To verify the performance of the transient stability of the DFIG based wind power system with the DC resistive SFCL, both the symmetrical and asymmetrical faults are considered. The performance of the DC resistive SFCL is compared with that of the series dynamic braking resistor (SDBR) and the crowbar system. Simulations are carried out by using the Matlab/Simulink software. Simulation results clearly indicate that the proposed DC resistive SFCL improves the transient stability of DFIG based variable speed wind generator well. Moreover, the overall performance of the proposed method is better than that of the SDBR, as well as the crowbar system.
Radar high‐resolution range profiles target recognition based on stable dictionary learning
Authors: Liu Hong‐wei , Feng Bo , Chen Bo , Du Lan
Published: September 2015

Sparse representation models based on dictionary learning have led to interesting results in signal restoration and target recognition. However, due to the redundancy defined by overcomplete dictionary atoms in new space, finding sparse representations from inaccurate measurements may cause uncertainty and ambiguity. Especially for radar automatic target recognition using high‐resolution range profiles (HRRP), the target‐aspect sensitivity, amplitude fluctuation and outliers in HRRPs could result in mismatch among the sparse representations of the same class and thus deteriorate the recognition performance. This article proposes a novel stable dictionary learning method to deal with this problem and improve the pattern recognition performance. The proposed method relies on the constraints that the sparse representations of adjacent HRRPs without scatterers’ motion through range cells should have the same support and lower variance. The structured sparse regularisation is then used to automatically select the optimal dictionary basis vectors for stable sparse coding. Experiments based on the measured HRRP dataset validate the performance of the proposed method. Moreover, encouraging results are reported with small training data size and under different signal‐to‐noise ratio conditions.
Radar micro‐Doppler signatures of various human activities
Authors: Narayanan Ram M. , Zenaldin Matthew
Published: September 2015

This study presents the results of the authors’ experimental investigation into the radar micro‐Doppler signatures (MDS) of various human activities both in free‐space and through‐wall environments. The collection of MDS signatures was divided into three categories: stationary, forward‐moving, and multi‐target. Each category of MDS signatures encompassed a variety of movements associated with it, adding up to a total of 18 human movements. Using a 6.5‐GHz C‐band coherent radar, the MDS of six human subjects were gathered in free‐space and through‐wall environments. The MDS for these cases were analysed in detail and the general properties of the signatures were related to their associated phenomenological characteristics. Based upon the MDS, features for designing detectors and classifiers of human targets performing such movements are recommended. In the case of multiple human targets in the radar field of view, it was found that it is possible to distinguish these targets from the MDS under certain circumstances, but not under others.
High Strain‐Rate Material Model Validation for Laser Peening Simulation
Authors: Langer Kristina , Olson Steven , Brockman Robert , Braisted William , Spradlin Thomas , Fitzpatrick Michael E.
Published: September 2015

Finite element modeling can be a powerful tool for predicting residual stresses induced by laser peening; however the sign and magnitude of the stress predictions depend strongly on how the material model captures the high strain rate response. Although a Johnson‐Cook formulation is often employed, its suitability for modeling phenomena at very high strain rates has not been rigorously evaluated. In this paper, we address the effectiveness of the Johnson‐Cook model, with parameters developed from lower strain rate material data (∼103 s–1), to capture the higher strain rate response (∼105 –106 s–1) encountered during the laser peening process. Published Johnson‐Cook parameters extracted from split Hopkinson bar testing were used to predict the shock response of aluminum samples during high‐impact flyer plate tests. Additional quasi‐static and split Hopkinson bar tests were also conducted to study the model response in the lower strain rate regime. The overall objective of the research was to ascertain whether a material model based on conventional test data (quasi‐static compression testing and split Hopkinson bar measurements) can credibly be used in FE simulations to predict laser peen‐induced stresses.
Line segments in homogeneous scalar turbulence
Authors: Gauding Michael , Goebbert Jens Henrik , Hasse Christian , Peters Norbert
Published: September 2015

The local structure of a turbulent scalar field in homogeneous isotropic turbulence is analyzed by direct numerical simulations (DNS) with different Taylor micro-scale based Reynolds numbers between 119 and 529. A novel signal decomposition approach is introduced where the signal of the scalar along a straight line is partitioned into segments based on the local extremal points of the scalar field. These segments are then parameterized by the distance ℓ between adjacent extremal points and the scalar difference Δϕ at the extrema. Both variables are statistical quantities and a joint distribution function of these quantities contains most information to statistically describe the scalar field. It is highlighted that the marginal distribution function of the length becomes independent of Reynolds number when normalized by the mean length ℓm. From a statistical approach, it is further shown that the mean length scales with the Kolmogorov length, which is also confirmed by DNS. For turbulent mixing, the scalar gradient plays a paramount role. Turbulent scalar fields are characterized by cliff-ramp-like structures manifesting the occurrence of localized large scalar gradients. To study turbulent mixing, a segment-based gradient is defined as Δϕ/ℓ. Joint statistics of the length and the segment-based gradient provide novel understanding of cliff-ramp-like structures. Ramp-like structures are unveiled by the asymmetry of the joint distribution function of the segment-based gradient and the length. Cliff-like structures are further analyzed by conditional statistics and it is shown from DNS that the width of cliffs scales with the Kolmogorov length scale.
Demonstration of the high collection efficiency of a broadband Mo/Si multilayer mirror with a graded multilayer coating on an ellipsoidal substrate
Authors: Ichimaru S. , Takenaka H. , Namikawa K. , Gullikson E. M. , Maruyama M. , Oku S.
Published: September 2015

A graded and broadband Mo/Si multilayer mirror for EUV spectroscopy is demonstrated. This mirror has an average reflectivity profile of 16% in the wavelength region from 15 nm to 17 nm and an effective area of 1100–1500 mm2. This reflectivity is about 4 times larger than that of a standard Mo/Si multilayer mirror on a 1 in. diameter substrate, showing that the mirror can be used for measuring EUV fluorescence at wavelengths in the region around 15 nm to 17 nm.
A tunable amorphous p-type ternary oxide system: The highly mismatched alloy of copper tin oxide
Authors: Isherwood Patrick J. M. , Butler Keith T. , Walsh Aron , Walls John M.
Published: September 2015

The approach of combining two mismatched materials to form an amorphous alloy was used to synthesise ternary oxides of CuO and SnO2. These materials were analysed across a range of compositions, and the electronic structure was modelled using density functional theory. In contrast to the gradual reduction in optical band gap, the films show a sharp reduction in both transparency and electrical resistivity with copper contents greater than 50%. Simulations indicate that this change is caused by a transition from a dominant Sn 5s to Cu 3d contribution to the upper valence band. A corresponding decrease in energetic disorder results in increased charge percolation pathways: a “compositional mobility edge.” Contributions from Cu(II) sub band-gap states are responsible for the reduction in optical transparency.
The transitional wake behind an inclined prolate spheroid
Authors: Jiang Fengjian , Gallardo José P. , Andersson Helge I. , Zhang Zhiguo
Published: September 2015

The wake behind a 6:1 prolate spheroid at 45° incidence has been studied by means of direct numerical simulations (DNSs). The Reynolds number based on the minor axis of the spheroid was 3000 as compared to 1000 in our preceding study [Jiang et al., “The laminar wake behind a 6:1 prolate spheroid at 45° incidence angle,” Phys. Fluids 26, 113602 (2014)]. The resulting wake is no longer laminar and the transitional wake is fundamentally unsteady and highly asymmetric from the very beginning. A substantial side force resulted from the asymmetric pressure field. No signs of vortex shedding could be observed. The forces and the flow field around the spheroid exhibited a dominant periodicity with a surprisingly low Strouhal number of 0.0733. One part of the counter-rotating vortex pair which dominated the near-wake broke down into small-scale vortices as soon as the vortex left the shadow behind the spheroid. The other part appeared as a helical vortex inside which the mechanical energy was conserved over a substantial length. The axial flow within this vortex tube experienced a sudden change from having maximum to minimum at the vortex center while maintaining the sign of the circulation. The severe asymmetry of the wake is ascribed to a global instability and may impact on submarine maneuverability.
Parallel momentum input by tangential neutral beam injections in stellarator and heliotron plasmas
Authors: Nishimura S. , Nakamura Y. , Nishioka K.
Published: September 2015

The configuration dependence of parallel momentum inputs to target plasma particle species by tangentially injected neutral beams is investigated in non-axisymmetric stellarator/heliotron model magnetic fields by assuming the existence of magnetic flux-surfaces. In parallel friction integrals of the full Rosenbluth-MacDonald-Judd collision operator in thermal particles' kinetic equations, numerically obtained eigenfunctions are used for excluding trapped fast ions that cannot contribute to the friction integrals. It is found that the momentum inputs to thermal ions strongly depend on magnetic field strength modulations on the flux-surfaces, while the input to electrons is insensitive to the modulation. In future plasma flow studies requiring flow calculations of all particle species in more general non-symmetric toroidal configurations, the eigenfunction method investigated here will be useful.
Photo-acoustic spectroscopy and quantum efficiency of Yb3+ doped alumino silicate glasses
Authors: Kuhn Stefan , Tiegel Mirko , Herrmann Andreas , Rüssel Christian , Engel Sebastian , Wenisch Christoph , Gräf Stephan , Müller Frank A. , Körner Jörg , Seifert Reinhard , Yue Fangxin , Klöpfel Diethardt , Hein Joachim , Kaluza Malte C.
Published: September 2015

In this contribution, we analyze the effect of several preparation methods of Yb3+ doped alumino silicate glasses on their quantum efficiency by using photo-acoustic measurements in comparison to standard measurement methods including the determination via the fluorescence lifetime and an integrating sphere setup. The preparation methods focused on decreasing the OH concentration by means of fluorine-substitution and/or applying dry melting atmospheres, which led to an increase in the measured fluorescence lifetime. However, it was found that the influence of these methods on radiative properties such as the measured fluorescence lifetime alone does not per se give exact information about the actual quantum efficiency of the sample. The determination of the quantum efficiency by means of fluorescence lifetime shows inaccuracies when refractive index changing elements such as fluorine are incorporated into the glass. Since fluorine not only eliminates OH from the glass but also increases the “intrinsic” radiative fluorescence lifetime, which is needed to calculate the quantum efficiency, it is difficult to separate lifetime quenching from purely radiative effects. The approach used in this contribution offers a possibility to disentangle radiative from non-radiative properties which is not possible by using fluorescence lifetime measurements alone and allows an accurate determination of the quantum efficiency of a given sample. The comparative determination by an integrating sphere setup leads to the well-known problem of reabsorption which embodies itself in the measurement of too low quantum efficiencies, especially for samples with small quantum efficiencies.
Determining the band gap and mean kinetic energy of atoms from reflection electron energy loss spectra
Authors: Vos M. , Marmitt G. G. , Finkelstein Y. , Moreh R.
Published: September 2015

Reflection electron energy loss spectra from some insulating materials (CaCO3, Li2CO3, and SiO2) taken at relatively high incoming electron energies (5–40 keV) are analyzed. Here, one is bulk sensitive and a well-defined onset of inelastic excitations is observed from which one can infer the value of the band gap. An estimate of the band gap was obtained by fitting the spectra with a procedure that includes the recoil shift and recoil broadening affecting these measurements. The width of the elastic peak is directly connected to the mean kinetic energy of the atom in the material (Doppler broadening). The experimentally obtained mean kinetic energies of the O, C, Li, Ca, and Si atoms are compared with the calculated ones, and good agreement is found, especially if the effect of multiple scattering is taken into account. It is demonstrated experimentally that the onset of the inelastic excitation is also affected by Doppler broadening. Aided by this understanding, we can obtain a good fit of the elastic peak and the onset of inelastic excitations. For SiO2, good agreement is obtained with the well-established value of the band gap (8.9 eV) only if it is assumed that the intensity near the edge scales as (E − Egap)1.5. For CaCO3, the band gap obtained here (7 eV) is about 1 eV larger than the previous experimental value, whereas the value for Li2CO3 (7.5 eV) is the first experimental estimate.
Silicon junctionless field effect transistors as room temperature terahertz detectors
Authors: Marczewski J. , Knap W. , Tomaszewski D. , Zaborowski M. , Zagrajek P.
Published: September 2015

Terahertz (THz) radiation detection by junctionless metal-oxide-semiconductor field-effect transistors (JL MOSFETs) was studied and compared with THz detection using conventional MOSFETs. It has been shown that in contrast to the behavior of standard transistors, the junctionless devices have a significant responsivity also in the open channel (low resistance) state. The responsivity for a photolithographically defined JL FET was 70 V/W and the noise equivalent power 460 pW/√Hz. Working in the open channel state may be advantageous for THz wireless and imaging applications because of its low thermal noise and possible high operating speed or large bandwidth. It has been proven that the junctionless MOSFETs can also operate in a zero gate bias mode, which enables simplification of the THz array circuitry. Existing models of THz detection by MOSFETs were considered and it has been demonstrated that the process of detection by these junctionless devices cannot be explained within the framework of the commonly accepted models and therefore requires a new theoretical approach.
Dynamics of glass-forming liquids. XIX. Rise and decay of field induced anisotropy in the non-linear regime
Authors: Young-Gonzales Amanda R. , Samanta Subarna , Richert Ranko
Published: September 2015

For glycerol and three monohydroxy alcohols, we have measured the non-linear dielectric effects resulting from the application and removal of a high dc bias electric field. The field effects are detected by virtue of a small amplitude harmonic field, from which time resolved changes in the dielectric loss are derived. The changes in permittivity are dominated by modifications of the time constants (rather than amplitudes) which display two contributions: a heating-like decrease of relaxation times that originates from the time dependent field when the bias is switched on and off and a slowing down of the dynamics resulting from the field induced reduction of configurational entropy. As observed for the electro-optical Kerr effect, the rise of the entropy change is slower than its decay, a feature that we rationalize on the basis of the quadratic dependence of the entropy change on polarization. For glycerol, the observed steady state level of the field induced shift of the glass transition temperature (+84 mK) matches the expectation based on the entropy change and its impact on dynamics via the Adam-Gibbs relation (+88 mK). For the alcohols, these non-linear effects rise and decay on the time scales of the prominent dielectric Debye process, underscoring the relation of these features to polarization anisotropy, opposed to mechanical or enthalpy relaxation which are orders of magnitude faster in these systems. A model is discussed which captures the observed magnitudes as well as time dependences in a near quantitative fashion. It is demonstrated that the high bias field modifies the response of polarization to the ac field, including a temporary change in the low field susceptibility.
Dynamics of dipole- and valence bound anions in iodide-adenine binary complexes: A time-resolved photoelectron imaging and quantum mechanical investigation
Authors: Stephansen Anne B. , King Sarah B. , Yokoi Yuki , Minoshima Yusuke , Li Wei-Li , Kunin Alice , Takayanagi Toshiyuki , Neumark Daniel M.
Published: September 2015

Dipole bound (DB) and valence bound (VB) anions of binary iodide-adenine complexes have been studied using one-color and time-resolved photoelectron imaging at excitation energies near the vertical detachment energy. The experiments are complemented by quantum chemical calculations. One-color spectra show evidence for two adenine tautomers, the canonical, biologically relevant A9 tautomer and the A3 tautomer. In the UV-pump/IR-probe time-resolved experiments, transient adenine anions can be formed by electron transfer from the iodide. These experiments show signals from both DB and VB states of adenine anions formed on femto- and picosecond time scales, respectively. Analysis of the spectra and comparison with calculations suggest that while both the A9 and A3 tautomers contribute to the DB signal, only the DB state of the A3 tautomer undergoes a transition to the VB anion. The VB anion of A9 is higher in energy than both the DB anion and the neutral, and the VB anion is therefore not accessible through the DB state. Experimental evidence of the metastable A9 VB anion is instead observed as a shape resonance in the one-color photoelectron spectra, as a result of UV absorption by A9 and subsequent electron transfer from iodide into the empty π-orbital. In contrast, the iodide-A3 complex constitutes an excellent example of how DB states can act as doorway state for VB anion formation when the VB state is energetically available.
Gate-controlled terahertz single electron photovoltaic effect in self-assembled InAs quantum dots
Authors: Zhang Y. , Shibata K. , Nagai N. , Ndebeka-Bandou C. , Bastard G. , Hirakawa K.
Published: September 2015

We have observed a terahertz (THz) induced single electron photovoltaic effect in self-assembled InAs quantum dots (QDs). We used a single electron transistor (SET) geometry that consists of a single InAs QD and nanogap electrodes coupled with a bowtie antenna. Under a weak, broadband THz radiation, a photocurrent induced by THz intersublevel transitions in the QD is generated even when no bias voltage is applied to the SET. The observed single electron photovoltaic effect is due to an energy-dependent tunneling asymmetry in the QD-SET. Moreover, the tunneling asymmetry changes not only with the shell but also with the electron number in the QD, suggesting the manybody nature of the electron wavefunctions. The THz photovoltaic effect observed in the present QD-SET system may have potential applications to nanoscale energy harvesting.
Variational symplectic particle-in-cell simulation of nonlinear mode conversion from extraordinary waves to Bernstein waves
Authors: Xiao Jianyuan , Liu Jian , Qin Hong , Yu Zhi , Xiang Nong
Published: September 2015

In this paper, the nonlinear mode conversion of extraordinary waves in nonuniform magnetized plasmas is studied using the variational symplectic particle-in-cell simulation. The accuracy of the nonlinear simulation is guaranteed by the long-term accuracy and conservativeness of the symplectic algorithm. The spectra of the electromagnetic wave, the evolution of the wave reflectivity, the energy deposition profile, and the parameter-dependent properties of radio-frequency waves during the nonlinear mode conversion are investigated. It is illustrated that nonlinear effects significantly modify the physics of the radio-frequency injection in magnetized plasmas. The evolutions of the radio-frequency wave reflectivity and the energy deposition are observed, as well as the self-interaction of the Bernstein waves and mode excitations. Even for waves with small magnitude, nonlinear effects can also become important after continuous wave injections, which are common in the realistic radio-frequency wave heating and current drive experiments.