bluuebunny/crossref_metadata_2025 huggingface dataset:
The challenges of solar hydrogen in chemical industry: how to provide, and how to apply?
Authors: Setoyama Tohru , Takewaki Takahiko , Domen Kazunari , Tatsumi Takashi
Published: October 2016

Curbing anthropogenic CO2 emissions is one of the most important issues in the 21st century in order to mitigate climate change. Although the installation of solar cells for energy supply is in progress and these are becoming popular as an efficient use of sunlight, they are mostly used by energy-related industrial sectors. In the common chemical industry, various fossil resources are used to emit a huge amount of CO2. We believe that the chemical industry can make an effort to curb CO2 emissions by changing its resources to more environmentally benign ones. Solar hydrogen (hydrogen obtained by catalytic water splitting under sunlight) is an ideal sustainable resource and can be utilized as a chemical resource via combination with CO2. The 10 year program named “Artificial Photo Synthetic Chemical Process (ARPChem)” has been in progress under the support of the New Energy and Industrial Technology Development Organization (NEDO) in Japan since 2012. We introduce the strategy of ARPChem and the progress of the investigations including water splitting, hydrogen/oxygen separation, and olefin synthesis from solar hydrogen and CO2. We also argue that a realistic strategy to actualize “ARPChem” technologies in the society would be their combination with better fossil resources such as lower alkanes from a Life Cycle Assessment (LCA) point of view.
Novel yttrium and zirconium catalysts featuring reduced Ar-BIANH2 ligands for olefin hydroamination (Ar-BIANH2 = bis-arylaminoacenaphthylene)
Authors: Cimino Alessandro , Moscatelli Filippo , Ferretti Francesco , Ragaini Fabio , Germain Stéphane , Hannedouche Jérôme , Schulz Emmanuelle , Luconi Lapo , Rossin Andrea , Giambastiani Giuliano
Published: October 2016

Even demanding aminoalkenes can be cyclized by Ar-BIANH2 yttrium complexes; a related zirconium complex has been crystallographically characterized.
A high quantum yield two-way conversion luminescent oligomer: 1,4-butanediol-bis(5-carbonyl-3-carbethoxy-2-pyrazoline)
Authors: Chen Cheng , Li Yan , Liu Lijian
Published: October 2016

Oligomers as fluorescent macromolecules exhibit excellent efficiency of a two-way conversion fluorescence process which makes them potentially attractive for biological applications.
A porous magnesium metal–organic framework showing selective adsorption and separation of nitrile guest molecules
Authors: Xu Jin , Yu Yang , Li Guanghua , Wang Shanshan , Liu Yongxin , Liu Dan , Wang Cheng
Published: October 2016

Selective and reversible adsorption of nitrile guest molecules including MeCN, ACN, AN and CTN on a Mg-based MOF were reported. Interestingly, the Mg-based MOF selectively captured cis-CTN into its cavity from a mixture of cis- and trans-isomers.
Exploration of biological activities of alkyne arms containing Cu(ii) and Ni(ii) complexes: syntheses, crystal structures and DFT calculations
Authors: Balakrishnan Chithiraivel , Natarajan Satheesh , Neelakantan M. A.
Published: October 2016

Several mononuclear Cu(ii) and Ni(ii) Schiff base (N,O-donor) complexes were synthesized and characterized. The binding ability with DNA and BSA and catecholase activity of the complexes were investigated.
One-step synthesis and applications of highly concentrated silver nanoparticles with an ultra-thin silica shell
Authors: Willett Daniel R. , Chumanov George
Published: October 2016

One-step synthesis resulting in highly concentrated silver nanoparticles with ultra-thin silica shell that were used for SERS & chemiresistor applications.
CuO nanostructures of variable shapes as an efficient catalyst for [3 + 2] cycloaddition of azides with terminal alkyne
Authors: Kaur Anupamjeet , Mann Sukhmani , Goyal Bhupesh , Pal Bhupender , Goyal Deepti
Published: October 2016

CuO nanowires exhibited highest catalytic efficiency for the cycloaddition reaction between azide and terminal alkyne, featuring short reaction time, soft reaction conditions and complete regioselectivity.
Anomalous red emission with competition and coexistence of defect and band edge emission in photo-electrochemically active (Zn0.97Ga0.03)(O0.95N0.05) solid solution
Authors: Menon Sumithra Sivadas , Sen Sayantani , Pramanik Pallabi , Bhattacharyya Anirban , Gupta Bhavana , Tiwari Brajesh , Baskar K. , Singh Shubra
Published: October 2016

Photo-electrochemically active nanostructured (Zn0.97Ga0.03)(O0.95N0.05) synthesized by solution combustion technique exhibiting anomalous red emission in room temperature.
Carbon dots-based ratiometric nanosensor for highly sensitive and selective detection of mercury(ii) ions and glutathione
Authors: Lu Shuaimin , Wu Di , Li Guoliang , Lv Zhengxian , Chen Zilin , Chen Lu , Chen Guang , Xia Lian , You Jinmao , Wu Yongning
Published: October 2016

Ratiometric fluorescent nanohybrid system for detection of Hg2+ and GSH.
Development, optimization and evaluation of tinidazole functionalized electrospun poly(ε-caprolactone) nanofiber membranes for the treatment of periodontitis
Authors: Khan Gayasuddin , Patel Ravi R. , Yadav Sarita K. , Kumar Nagendra , Chaurasia Sundeep , Ajmal Gufran , Mishra Pradeep K. , Mishra Brahmeshwar
Published: October 2016

The proposed work is focused to alleviate shortcomings in the treatment of periodontitis by electrospinning of a novel biodegradable poly(ε-caprolactone) based nanofiber membrane functionalized with tinidazole.
An investigation on the aqueous-phase hydrodeoxygenation of various methoxy-substituted lignin monomers on Pd/C and HZSM-5 catalysts
Authors: Zhang Cong , Qi Jingbo , Xing Jing , Tang Si-Fu , Song Liang , Sun Yuanyuan , Zhang Chuanhui , Xin Hongchuan , Li Xuebing
Published: October 2016

Aqueous phase catalytic upgrading of lignin monomers to hydrocarbons via hydrodeoxygenation (HDO) has been explored using a combination of Pd/C and HZSM-5 catalysts under 2 MPa of H2 (ambient temperature).
Selective oxidative degradation of azo dyes by hydrogen peroxide catalysed by manganese(ii) ions
Authors: Bennett Jevan , Miah Yusuf A. , Varsani Dhimal S. , Salvadori Enrico , Sheriff Tippu S.
Published: October 2016

Calmagite, Orange II and Orange G exhibit pH/buffer selective bleaching using MnCl2·4H2O as catalyst with added H2O2 as terminal oxidant.
Synthesis of Co-doped MoS2/graphene hybrids as enhanced electrocatalysts for the hydrogen evolution reaction
Authors: Ye Jianbo , Chen Weixiang , Xu Shurui , Yu Zheting , Hou Shicheng
Published: October 2016

Co-Doped MoS2/graphene hybrids with more exposed active sites and a Tafel slope of 44.3 mV dec−1 for HER were prepared.
Preparation and characterization of antiglare waterborne polyurethane
Authors: Zhu Jiaqi , Huang Huihua , Peng Xiaohong
Published: October 2016

An antiglare coating was prepared by controlling the content of 2-[(2-aminoethyl)amino] ethyl sulfonic acid sodium and hydrazine hydrate in waterborne polyurethane. It possessed low gloss and high light transmission in the presence of nano-spheres.
The release of hydrogen from ammonia borane over copper/hexagonal boron nitride composites
Authors: Qiu Xiaoqing , Wu Xin , Wu Yawei , Liu Qiuwen , Huang Caijin
Published: October 2016

Facile solution-phase synthesis of copper nanoparticles dispersed on h-BNviaa solvothermal method is proposed for hydrolytic dehydrogenation of ammonia borane.
Transfer hydrodehalogenation of aryl halides accelerated by a saturated sodium acetate aqueous solution
Authors: Xue Zhimin , Zhao Xinhui , Wang Jinfang , Mu Tiancheng
Published: October 2016

A saturated sodium acetate aqueous solution could be applied as an efficient and environmentally-friendly reaction medium to accelerate transfer hydrodehalogenation of various aryl halides.
Saccharification of thermochemically pretreated cellulosic biomass using native and engineered cellulosomal enzyme systems
Authors: Chundawat Shishir P. S. , Paavola Chad D. , Raman Babu , Nouailler Matthieu , Chan Suzanne L. , Mielenz Jonathan R. , Receveur-Brechot Veronique , Trent Jonathan D. , Dale Bruce E.
Published: October 2016

Tethering hydrolytic enzymes (e.g., cellulases) to protein scaffolds enhances biomass saccharification to sugars.
Linker-free incorporation of carbohydrates into in vitro displayed macrocyclic peptides
Authors: Jongkees S. A. K. , Umemoto S. , Suga H.
Published: October 2016

We report a strategy for efficient post-translational modification of a library of ribosomally-translated peptides by activation and elimination of cysteine to dehydroalanine then conjugate addition of a range of exogenous thiols, with an emphasis on carbohydrates.
Anion-exchange membranes with polycationic alkyl side chains attached via spacer units
Authors: Dang Hai-Son , Jannasch Patric
Published: October 2016

Poly(phenylene oxide)s carrying pendant polycationic alkyl side chains with a suitable configuration show high hydroxide ion conductivity and excellent alkaline stability.
Variation in surface energy and reduction drive of a metal oxide lithium-ion anode with stoichiometry: a DFT study of lithium titanate spinel surfaces
Authors: Morgan Benjamin J. , Carrasco Javier , Teobaldi Gilberto
Published: October 2016

Computational screening of lithium-titanate–spinel surfaces reveals how stoichiometry can strongly affect the thermodynamic drive for reduction at metal-oxide-electrode surfaces.
Direct application of cobaltite-based perovskite cathodes on the yttria-stabilized zirconia electrolyte for intermediate temperature solid oxide fuel cells
Authors: Chen Kongfa , Li Na , Ai Na , Li Meng , Cheng Yi , Rickard William D. A. , Li Jian , Jiang San Ping
Published: October 2016

Cobaltite based perovskites can be directly applied on the YSZ electrolyte via an in situ polarization induced electrode/electrolyte interface.
Nb2O5 quantum dots embedded in MOF derived nitrogen-doped porous carbon for advanced hybrid supercapacitor applications
Authors: Liu Sainan , Zhou Jiang , Cai Zhenyang , Fang Guozhao , Cai Yangsheng , Pan Anqiang , Liang Shuquan
Published: October 2016

An advanced hybrid material based on Nb2O5 quantum dots embedded in ZIF-8 derived N-doped porous carbon is demonstrated. The resulting hybrid material exhibits superior electrochemical performance for lithium-ion battery and hybrid supercapacitor applications.
A highly hindered bithiophene-functionalized dispiro-oxepine derivative as an efficient hole transporting material for perovskite solar cells
Authors: Rakstys Kasparas , Paek Sanghyun , Sohail Muhammad , Gao Peng , Cho Kyung Taek , Gratia Paul , Lee Yonghui , Dahmen Klaus H. , Nazeeruddin Mohammad Khaja
Published: October 2016

Dimethoxydiphenylamine-substituted dispiro-oxepine derivative DDOF has been synthesized using a facile synthetic route and tested in perovskite solar cells as a hole transporting material exhibiting a remarkable PCE of 19.4%.
Intrinsic superoxide dismutase activity of MnO nanoparticles enhances the magnetic resonance imaging contrast
Authors: Ragg R. , Schilmann A. M. , Korschelt K. , Wieseotte C. , Kluenker M. , Viel M. , Völker L. , Preiß S. , Herzberger J. , Frey H. , Heinze K. , Blümler P. , Tahir M. N. , Natalio F. , Tremel W.
Published: October 2016

MnO nanoparticles decompose superoxide and hydrogen peroxide in an enzyme-like manner leading to enhanced MRI contrast.
Low-temperature, nontoxic water-induced high-k zirconium oxide dielectrics for low-voltage, high-performance oxide thin-film transistors
Authors: Zhu Chundan , Liu Ao , Liu Guoxia , Jiang Guixia , Meng You , Fortunato Elvira , Martins Rodrigo , Shan Fukai
Published: October 2016

High-performance n- and p-type metal-oxide thin-film transistors are fabricated on ZrOx high-k dielectrics via a nontoxic water-inducement method.
Spectroscopic characterization of charge carriers of the organic semiconductor quinacridone compared with pentacene during redox reactions
Authors: Enengl Sandra , Enengl Christina , Pluczyk Sandra , Glowacki Eric D. , Lapkowski Mieczyslaw , Ehrenfreund Eitan , Neugebauer Helmut , Sariciftci Niyazi Serdar
Published: October 2016

The molecular-scale changes of the pigment quinacridone, a hydrogen-bonded organic semiconductor, are evaluated during redox reactions.
Formation mechanism of graphene quantum dots and their edge state conversion probed by photoluminescence and Raman spectroscopy
Authors: Rajender Gone , Giri P. K.
Published: October 2016

The formation mechanism of graphene quantum dots (GQDs) from a graphene oxide (GO) precursor is elucidated and the inter-conversion of edge states in GQDs by annealing under a controlled gas environment is studied by various microscopic and spectroscopic tools.
A mechanistic study on graphene-based nonvolatile ReRAM devices
Authors: Rani Adila , Kim Dong Ha
Published: October 2016

An overview of the switching mechanism of ReRAM devices employing graphene oxide (GO), reduced graphene oxide (rGO), hybrid GO, hybrid rGO, and graphene as dielectric layers or electrodes.
Subjective Reports of Trouble Tolerating Sound in Daily Life versus Loudness Discomfort Levels
Authors: Zaugg Tara L. , Thielman Emily J. , Griest Susan , Henry James A.
Published: October 2016

Purpose

A retrospective analysis of tonal and speech loudness discomfort levels (LDLs) relative to a subjective report of sound tolerance (SRST) was performed to explore the relation between the 2 commonly used clinical measures.

Method

Tonal LDLs and SRST were measured for 139 U.S. military veterans who were recruited into a study providing intervention for tinnitus. Spearman's rank correlation coefficients were computed to assess the relation between the tonal and speech LDLs and the SRST.

Results

Only weak correlations were found between tonal LDLs and SRST and between speech LDLs and SRST.

Conclusion

If LDLs ratings of SRST measured the same phenomenon, the measures would be strongly negatively correlated. The weak correlations found between the measures suggest that LDLs do not accurately represent a patient's ability to tolerate sound in daily life.
Improvements of femto‐base station resource utilisation and ABS assignment convergence for dynamic ABS assignment
Authors: Ozawa Masayoshi , Ohtsuki Tomoaki
Published: October 2016

Almost blank subframe (ABS) techniques emerge as inter‐cell interference mitigation techniques in time region. One of the conventional ABS techniques is dynamic ABS assignment, which is able to adapt to interference state to protect the outage users more. However, the number of ABS assignments increases to protect a lot of outage users in the dense BS deployment. Therefore, the resource utilisation of base stations (BSs) decreases. Moreover, the convergence time of subframe assignment should be short enough to adapt to the change of environments. In this study, the authors propose a dynamic ABS assignment method to improve the resource utilisation of BSs and the convergence time of subframe assignment. Each BS receives feedback from surrounding BSs and users, and selects its subframe assignment based on the received feedback. Simulation results show that the proposed method improves the resource utilisation of BSs and the convergence time of subframe assignment compared with the conventional dynamic ABS assignment one, while achieving a similar user outage ratio.
Weighted compressive sensing based uplink channel estimation for time division duplex massive multi‐input multi‐output systems
Authors: Nan Yang , Zhang Li , Sun Xin
Published: October 2016

In this study, the channel estimation problem for the uplink massive multi‐input multi‐output (MIMO) system is considered. Motivated by the observations that the channels in massive MIMO systems may exhibit sparsity and the channel support changes slowly over time, the authors propose one efficient channel estimation method under the framework of compressive sensing (CS). By exploiting the channel impulse response (CIR) estimated from the previous orthogonal frequency division multiplexing symbol, they firstly estimate the probabilities that the elements in the current CIR are non‐zero. Then, they propose the probability‐weighted subspace pursuit algorithm exploiting these probability information to efficiently reconstruct the uplink massive MIMO channel. Moreover, noting that the massive MIMO systems also share a common support within one channel matrix due to the shared local scatterers in the physical propagation environment, an antenna collaborating method is exploited for the proposed method to further enhance the channel estimation performance. Simulation results show that compared to the existing CS methods, the proposed methods could achieve higher spectral efficiency as well as more reliable performance over time‐varying channel.
Frequency droop control with scheduled charging of electric vehicles
Authors: Liu Hui , Yang Yude , Qi Junjian , Li Jinghua , Wei Hua , Li Peijie
Published: October 2016

Vehicle‐to‐grid (V2G) control of electric vehicles (EVs) has the potential to provide frequency regulation for power system operation. The authors study the frequency droop control with EVs’ participation. The challenge is to simultaneously suppress frequency fluctuation and satisfy transportation usages of EV owners. A V2G control consisting of frequency droop control and scheduled charging is developed to overcome this challenge. Frequency droop control can suppress frequency fluctuation by responding to frequency deviation signal, while scheduled charging can achieve the charging demands of EV owners. Although uncertain regulation may result in deviation of the battery energy levels from the expected, the scheduled charging made based on the departure time, the real‐time, the real‐time battery energy levels, and the expected battery energy levels can compensate this change in real time. The proposed V2G control can ensure different types of charging demands such as holding battery energy levels and elevating battery energy levels, unlike existing methods in which different V2G control strategies have to be developed. Simulations on a two‐area interconnected power grid using real power grid data in China validate the effectiveness of the proposed V2G control in suppressing frequency fluctuation and achieving the charging demands of EV owners.
Risk‐based framework for the planning of low‐voltage networks incorporating severe uncertainty
Authors: Nijhuis Michiel , Gibescu Madeleine , Cobben Sjef
Published: October 2016

Current low‐voltage (LV) network planning methods consist mostly of a static deterministic assessment of radial network alternatives. This straightforward approach does not take into account the uncertainty which comes with the introduction of photovoltaic generation, electric vehicles and other new technologies into the LV network. Moreover, these technologies may call for a change in network topology, from radially oriented networks to more meshed variants. The focus on cost‐efficiency requires the implementation of risk‐based asset management into the LV planning approach. The complete implementation of these two aspects into LV network planning methods would result in a too complex network planning formulation. By using heuristic optimisation methods to reduce the number of network alternatives and scenarios which need to be assessed in combination with simplifications on the risk‐based assessment of power quality, losses and service availability, a computationally feasible LV network planning approach is developed in this work. A Greenfield case study based on an existing Dutch neighbourhood shows how this approach can be applied in practice to yield the optimal network structure. Though the initial investments and availability of a meshed network are worse, the meshed network structure generates a 10% lower overall cost, due to reduced losses and improved power quality.
Adaptive fuzzy critic based control design for AGC of power system connected via AC/DC tie‐lines
Authors: Sharma Gulshan , Ibraheem  , Niazi Khaleequr Rehman , Bansal Ramesh C.
Published: October 2016

This study presents the design of adaptive fuzzy critic based emotional learning control design for automatic generation control (AGC) of a two‐area power system interconnected via parallel AC/DC tie‐lines. The adaptive fuzzy critic evaluates the current system situation and provides the emotional signal so that the artificial neuro fuzzy regulator to modify its characteristic and reduce the critic stress. The adaptive fuzzy critic based emotional learning control design are implemented and the system dynamic responses are obtained considering 1% load disturbance in area‐1. A comparative study of performance of proposed control, fuzzy logic and conventional integral based control is carried out and presented with and without considering the system non‐linearities such as governor dead‐band and generation rate constraint. The proposed control design technique has been demonstrated as a superior one as compared with other techniques used for the AGC design in the study. Furthermore, the sensitivity analysis of the proposed control is also examined by varying the system parameters over the wide range from the nominal system values.
Revised look at the effects of the channel model on molecular communication systems
Authors: Lu Yi , Higgins Matthew D. , Leeson Mark S. , Chen Yunfei , Jennings Paul A.
Published: October 2016

Molecular communications, where information is passed between the transmitter (TX) and the receiver (RX) via molecules is a promising area with vast potential applications. However, the infancy of the topic within the overall taxonomy of communications has meant that to date, several channel models are in press, each of which is applied under various constraints and/or assumptions. Amongst them is that the arrival of molecules in different time slots can be, or is, considered as independent events. In practice, this assumption is not accurate, as the molecules arriving in the previous slot reduce the possible number of molecules in the next slot and hence make them correlated. A more realistic performance of a molecular communication is analysed assuming correlated events. The key result shown is that the widely used model assuming independent events significantly overestimates the error rates in the channel. This result is thus critical to researchers who focus on energy use at the nanoscale, as the new analysis provides a more realistic prediction, and therefore less energy will be needed to attain a desired error rate, increasing system feasibility.
One‐pot synthesis of flake Cu1.81S/C composite for high‐performance supercapactiors electrodes
Authors: Hu Haihua , Sui Yanwei , Zhou Yaoyao , Qi Jiqiu , Wei Fuxiang , He Yezeng , Meng Qingkun , Sun Zhi , Zhao Yulong
Published: October 2016

One‐pot fabrication of flake Cu1.81S/C composite with size of 300 nm was successfully demonstrated in this work. As the supercapacitor electrode material, the obtained Cu1.81S/C composite sample displayed good cycling stability of 83.6% capacitance retention after 1000 cycles and high specific capacitance of 617 F g−1 at current density of 0.5 A g−1. The excellent electrochemical performance is mainly attributed to flake nanostructure, which provides large electrode‐electrolyte contact area and facilitates an easy access of electrolyte ions to the electrode surface. This result provides a new pathway for the fabrication of high‐performance electrode material for supercapacitors.
Improved slicing strategy for digital micromirror device‐based three‐dimensional lithography with a single scan
Authors: Huang Shengzhou , Li Mujun , Shen Lianguan , Qiu Jinfeng , Zhou Youquan
Published: October 2016

To improve the profile quality of three‐dimensional microstructures, an improved method was proposed in real‐time maskless lithography based on digital micromirror device. First, to calculate the spatial distribution of exposure dose for the target profile in design, the relations of the exposure dose and the development depth were investigated. Moreover, a suitable development time was obtained. Second, an improved slicing strategy based on equal‐arc algorithm was proposed to reduce the profile error. Different from traditional equal‐expose‐dose method, this method generated slicing layers with equal arc‐length instead of equal‐exposure dose. Such an approach has advantages in obtaining a series of suitable section patterns adapting to the curvature variation of the design profile. Finally, an aspheric microlens array was fabricated with this method and the equal‐exposure‐dose method. Results showed that the resulting microstructure profile by their method was more consistent with the design profile with the same slicing numbers. Moreover, results also showed that the method used can obtain as good profile quality as that of the equal‐exposure‐dose method with only a half of slicing numbers. This indicated that the proposed method is feasible for achieving good profile quality with slicing efficiency improved remarkably.
On pseudo-hyperkähler prepotentials
Authors: Devchand Chandrashekar , Spiro Andrea
Published: October 2016

An explicit surjection from a set of (locally defined) unconstrained holomorphic functions on a certain submanifold of Sp1(ℂ) × ℂ4n onto the set HKp,q of local isometry classes of real analytic pseudo-hyperkähler metrics of signature (4p, 4q) in dimension 4n is constructed. The holomorphic functions, called prepotentials, are analogues of Kähler potentials for Kähler metrics and provide a complete parameterisation of HKp,q. In particular, there exists a bijection between HKp,q and the set of equivalence classes of prepotentials. This affords the explicit construction of pseudo-hyperkähler metrics from specified prepotentials. The construction generalises one due to Galperin, Ivanov, Ogievetsky, and Sokatchev. Their work is given a coordinate-free formulation and complete, self-contained proofs are provided. The Appendix provides a vital tool for this construction: a reformulation of real analytic G-structures in terms of holomorphic frame fields on complex manifolds.
Iron as a source of efficient Shockley-Read-Hall recombination in GaN
Authors: Wickramaratne Darshana , Shen Jimmy-Xuan , Dreyer Cyrus E. , Engel Manuel , Marsman Martijn , Kresse Georg , Marcinkevičius Saulius , Alkauskas Audrius , Van de Walle Chris G.
Published: October 2016

Transition metal impurities are known to adversely affect the efficiency of electronic and optoelectronic devices by introducing midgap defect levels that can act as efficient Shockley-Read-Hall centers. Iron impurities in GaN do not follow this pattern: their defect level is close to the conduction band and hence far from midgap. Using hybrid functional first-principles calculations, we uncover the electronic properties of Fe and we demonstrate that its high efficiency as a nonradiative center is due to a recombination cycle involving excited states. Unintentional incorporation of iron impurities at modest concentrations (1015 cm–3) leads to nanosecond nonradiative recombination lifetimes, which can be detrimental for the efficiency of electronic and optoelectronic devices.
Ab initio investigation of structure, stability, thermal behavior, bonding, and infrared spectra of ionized water cluster (H2O)6+
Authors: Liu Lei , Hu Cui-E , Tang Mei , Chen Xiang-Rong , Cai Ling-Cang
Published: October 2016

The low-lying isomers of cationic water cluster (H2O)6+ have been globally explored by using particle swarm optimization algorithm in conjunction with quantum chemical calculations. Compared with previous results, our searching method covers a wide range of structural isomers of (H2O)6+ and therefore turns out to be more effective. With these local minima, geometry optimization and vibrational analysis are performed for the most interesting clusters at second-order Møller-Plesset (MP2)/aug-cc-pVDZ level, and their energies are further refined at MP2/aug-cc-pVTZ and coupled-cluster theory with single, double, and perturbative triple excitations/aug-cc-pVDZ level. The interaction energies using the complete basis set limits at MP2 level are also reported. The relationships between their structure arrangement and their energies are discussed. Based on the results of thermal simulation, structural change from a four-numbered ring to a tree-like structure occurs at T ≈ 45 K, and the relative population of six lowest-free-energy isomers is found to exceed 4% at some point within the studied temperature range. Studies reveal that, among these six isomers, two new-found isomers constitute 10% of isomer population at 180 K, and the experimental spectra can be better explained with inclusions of the two isomers. The molecular orbitals for six representative cationic water clusters are also studied. Through topological and reduced density gradient analysis, we investigated the structural characteristics and the bonding strengths of these water cluster radical cations.
Hamiltonian magnetohydrodynamics: Lagrangian, Eulerian, and dynamically accessible stability—Examples with translation symmetry
Authors: Andreussi T. , Morrison P. J. , Pegoraro F.
Published: October 2016

Because different constraints are imposed, stability conditions for dissipationless fluids and magnetofluids may take different forms when derived within the Lagrangian, Eulerian (energy-Casimir), or dynamically accessible frameworks. This is in particular the case when flows are present. These differences are explored explicitly by working out in detail two magnetohydrodynamic examples: convection against gravity in a stratified fluid and translationally invariant perturbations of a rotating magnetized plasma pinch. In this second example, we show in explicit form how to perform the time-dependent relabeling introduced in Andreussi et al. [Phys. Plasmas 20, 092104 (2013)] that makes it possible to reformulate Eulerian equilibria with flows as Lagrangian equilibria in the relabeled variables. The procedures detailed in the present article provide a paradigm that can be applied to more general plasma configurations and in addition extended to more general plasma descriptions where dissipation is absent.
Nonlinear Landau damping of wave envelopes in a quantum plasma
Authors: Chatterjee Debjani , Misra A. P.
Published: October 2016

The nonlinear theory of Landau damping of electrostatic wave envelopes (WEs) is revisited in a quantum electron-positron pair plasma. Starting from a Wigner-Moyal equation coupled to the Poisson equation and applying the multiple scale technique, we derive a nonlinear Schrödinger (NLS) equation which governs the evolution of electrostatic WEs. It is shown that the coefficients of the NLS equation, including the nonlocal nonlinear term, which appears due to the resonant particles having a group velocity of the WEs, are significantly modified by the particle dispersion. The effects of the quantum parameter H (the ratio of the plasmon energy to the thermal energy densities), associated with the particle dispersion, are examined on the Landau damping rate of carrier waves, as well as on the modulational instability of WEs. It is found that the Landau damping rate and the decay rate of the solitary wave amplitude are greatly reduced compared to their classical values (H = 0).
Parametric instabilities in strongly correlated plasma
Authors: Sharma Prerana , Avinash K. , Gupta D. N.
Published: October 2016

Parametric instabilities (Stimulated Brillouin Scattering, parametric decay instability, and Langmuir decay instability) in laser plasmas with strongly correlated/coupled ions are examined. It is shown that strong correlation/coupling effects lead to a slowing down of the ion acoustic wave which, in turn, leads to a significant destabilization of parametric instabilities and concomitant enhancement of the scattered light. Applications of these results to inertial confinement fusion experiments are discussed.
Frequency-wavenumber spectrum of the free surface of shallow turbulent flows over a rough boundary
Authors: Dolcetti G. , Horoshenkov K. V. , Krynkin A. , Tait S. J.
Published: October 2016

Data on the frequency-wavenumber spectra and dispersion relation of the dynamic water surface in an open channel flow are very scarce. In this work, new data on the frequency-wavenumber spectra were obtained in a rectangular laboratory flume with a rough bottom boundary, over a range of subcritical Froude numbers. These data were used to study the dispersion relation of the surface waves in such shallow turbulent water flows. The results show a complex pattern of surface waves, with a range of scales and velocities. When the mean surface velocity is faster than the minimum phase velocity of gravity-capillary waves, the wave pattern is dominated by stationary waves that interact with the static rough bed. There is a coherent three-dimensional pattern of radially propagating waves with the wavelength approximately equal to the wavelength of the stationary waves. Alongside these waves, there are freely propagating gravity-capillary waves that propagate mainly parallel to the mean flow, both upstream and downstream. In the flow conditions where the mean surface velocity is slower than the minimum phase velocity of gravity-capillary waves, patterns of non-dispersive waves are observed. It is suggested that these waves are forced by turbulence. The results demonstrate that the free surface carries information about the underlying turbulent flow. The knowledge obtained in this study paves the way for the development of novel airborne methods of non-invasive flow monitoring.
Sampled-data-based consensus and containment control of multiple harmonic oscillators: A motion-planning approach
Authors: Liu Yongfang , Zhao Yu , Chen Guanrong
Published: October 2016

This paper studies the distributed consensus and containment problems for a group of harmonic oscillators with a directed communication topology. First, for consensus without a leader, a class of distributed consensus protocols is designed by using motion planning and Pontryagin's principle. The proposed protocol only requires relative information measurements at the sampling instants, without requiring information exchange over the sampled interval. By using stability theory and the properties of stochastic matrices, it is proved that the distributed consensus problem can be solved in the motion planning framework. Second, for the case with multiple leaders, a class of distributed containment protocols is developed for followers such that their positions and velocities can ultimately converge to the convex hull formed by those of the leaders. Compared with the existing consensus algorithms, a remarkable advantage of the proposed sampled-data-based protocols is that the sampling periods, communication topologies and control gains are all decoupled and can be separately designed, which relaxes many restrictions in controllers design. Finally, some numerical examples are given to illustrate the effectiveness of the analytical results.
Generalized quantum nonlinear oscillators: Exact solutions and rational extensions
Authors: Schulze-Halberg Axel , Roy Barnana
Published: October 2016

We construct exact solutions and rational extensions to quantum systems of generalized nonlinear oscillators. Our method is based on a connection between nonlinear oscillator systems and Schrödinger models for certain hyperbolic potentials. The rationally extended models admit discrete spectrums and corresponding closed form solutions are expressed through Jacobi type Xm exceptional orthogonal polynomials.
Investigating the effect of adding an on-axis jet to Ar gas puff Z pinches on Z
Authors: Harvey-Thompson A. J. , Jennings C. A. , Jones B. , Apruzese J. P. , Ampleford D. J. , Lamppa D. C. , Coverdale C. A. , Cuneo M. E. , Giuliani J. L. , Hansen S. B. , Jones M. C. , Moore N. W. , Rochau G. A. , Thornhill J. W.
Published: October 2016

Double-shell Ar gas puff implosions driven by 16.5 ± 0.5 MA on the Z generator at Sandia National Laboratories are very effective emitters of Ar K-shell radiation (photon energy >3 keV), producing yields of 330 ± 9% kJ [B. Jones et al., Phys. Plasmas 22, 020706 (2015)]. Previous simulations and experiments have reported dramatic increases in K-shell yields when adding an on-axis jet to double shell gas puffs for some configurations. We report on a series of experiments on Z testing Ar gas puff configurations with and without an on-axis jet guided by 3D magneto-hydrodynamic (MHD) simulations. Adding an on-axis jet was found to significantly improve the performance of some, but not all, configurations. The maximum observed K-shell yield of 375 ± 9% kJ was produced with a configuration that rapidly imploded onto an on-axis jet. A dramatic difference was observed in the plasma conditions at stagnation when a jet was used, producing a narrower stagnation column in experiments with a higher density but relatively lower electron temperature. The MHD simulations accurately reproduce the experimental measurements. The conversion efficiency for electrical energy delivered to the load to K-shell x-rays is estimated to be ∼12.5% for the best-performing configuration, similar to the best results from experiments at smaller facilities.
Simulation study of enhancing laser driven multi-keV line-radiation through application of external magnetic fields
Authors: Kemp G. E. , Colvin J. D. , Blue B. E. , Fournier K. B.
Published: October 2016

We present a path forward for enhancing laser driven, multi-keV line-radiation from mid- to high-Z, sub-quarter-critical density, non-equilibrium plasmas through inhibited thermal transport in the presence of an externally generated magnetic field. Preliminary simulations with Kr and Ag suggest that as much as 50%–100% increases in peak electron temperatures are possible—without any changes in laser drive conditions—with magnetized interactions. The increase in temperature results in ∼2−3× enhancements in laser-to-x-ray conversion efficiency for K-shell emission with simultaneous ≲4× reduction in L-shell emission using current field generation capabilities on the Omega laser and near-term capabilities on the National Ignition Facility laser. Increased plasma temperatures and enhanced K-shell emission are observed to come at the cost of degraded volumetric heating. Such enhancements in high-photon-energy x-ray sources could expand the existing laser platforms for increasingly penetrating x-ray radiography.
Seeded and unseeded helical modes in magnetized, non-imploding cylindrical liner-plasmas
Authors: Yager-Elorriaga D. A. , Zhang P. , Steiner A. M. , Jordan N. M. , Lau Y. Y. , Gilgenbach R. M.
Published: October 2016

In this research, we generated helical instability modes using unseeded and kink-seeded, non-imploding liner-plasmas at the 1 MA Linear Transformer Driver facility at the University of Michigan in order to determine the effects of externally applied, axial magnetic fields. In order to minimize the coupling of sausage and helical modes to the magneto Rayleigh-Taylor instability, the 400 nm-thick aluminum liners were placed directly around straight-cylindrical (unseeded) or threaded-cylindrical (kink-seeded) support structures to prevent implosion. The evolution of the instabilities was imaged using a combination of laser shadowgraphy and visible self-emission, collected by a 12-frame fast intensified CCD camera. With no axial magnetic field, the unseeded liners developed an azimuthally correlated m = 0 sausage instability (m is the azimuthal mode number). Applying a small external axial magnetic field of 1.1 T (compared to peak azimuthal field of 30 T) generated a smaller amplitude, helically oriented instability structure that is interpreted as an m = +2 helical mode. The kink-seeded liners showed highly developed helical structures growing at the seeded wavelength of λ = 1.27 mm. It was found that the direction of the axial magnetic field played an important role in determining the overall stabilization effects; modes with helices spiraling in the opposite direction of the global magnetic field showed the strongest stabilization. Finally, the Weis-Zhang analytic theory [Weis et al., Phys. Plasmas 22, 032706 (2015)] is used to calculate sausage and helical growth rates for experimental parameters in order to study the effects of axial magnetic fields.
Experimental realization of Talbot array illumination for a 2-dimensional phase grating
Authors: Mondal Puspen , Kumar Mukund , Tiwari Pragya , Srivastava A. K. , Chakera J. A. , Naik P. A.
Published: October 2016

We present the result of a multiple phase level Talbot array illuminator (TAI) based on two dimensional phase grating. The grating was fabricated on glass by a Deep Reactive Ion Etching (DRIE) system with optimized gas combination recipe. The opening ratio of the grating is ∼0.71 with a phase step of 11π. The experimental study on Talbot array illuminations (TAI's) of this fabricated device in near-field region was carried out using a He-Ne laser. The TAI's were observed at the positions 2.81 mm, 8.59 mm, 14.28 mm, and 20.57 mm along the light propagation direction. The computer simulations of wave field distribution in near field region at different fractional Talbot distances have been generated. These simulated results are in reasonably good agreement with our experimental observed results. Our analysis on Talbot array illumination (TAI's) shows that the multiple harmonic phase modulations are transformed into intensity modulations at 1/8, 3/8, 5/8, and 7/8 fractional Talbot position. We have observed three different grating images, viz., attenuated, phase contrast, and diffraction contrast images. We also show the presence of a considerable amount of phase change at the edge of each phase sublevel that enhances the contrast of differential phase contrast imaging. Therefore, the phase contrast signal can be detected at a fractional position using single phase grating without the need of phase stepping.
Sensitivity study of multilayer thin-film bulk acoustic resonator for mass sensor application
Authors: Liu Haiqiang , Li Fang , Qin Lifeng , Wang Qing-Ming
Published: October 2016

The sensitivity of multilayer thin-film bulk acoustic resonators (MTFBARs) used as mass sensors is investigated. MTFBAR sensors with the structure of a mass-sensitive layer/electrode layer/piezo layer/electrode layer were used. Two methods, one using electric impedance and the other displacement, were adopted for the determination of sensitivity. Simulation results show that the two methods agree well, and the characteristic acoustic impedance and thickness of the non-piezo layers strongly affect mass sensitivity. It was found that high acoustic impedance in the non-piezo layer is not helpful for sensitivity improvement. Sensitivity is improved by choosing an appropriate thickness for the low acoustic impedance non-piezo layer, and the maximum sensitivity can be obtained by choosing suitable thickness combinations for the layers. Moreover, it was found that MTFBAR quality factor and sensitivity are simultaneously improved by adopting a high-quality-factor non-piezo layer with low acoustic impedance for an air working environment, whereas a balance between quality factor and sensitivity is found through optimization of the non-piezo layers for a water working environment. These results can be used for the design and application of MTFBAR mass sensors.
Summer drought survival and recovery in Microlaena stipoides
Authors: Mitchell M. L. , Virgona J. M. , Jacobs J. L. , Kemp D. R.
Published: October 2016

Microlaena stipoides (microlaena) is an important perennial grass in over 7 million hectares of native pastures in southern Australia and can survive and persist despite severe soil water deficits during summer. Many other pasture species survive similar conditions by relying on summer dormancy, which raises the possibility that microlaena may behave similarly. A field experiment using rainout shelters was conducted on an existing microlaena pasture in north-east Victoria. The experiment was a split-plot design with two watering treatments (‘summer storm’ or ‘summer dry’) as main plots and three defoliation treatments (nil, intense defoliation, strategic defoliation) as subplots. The ‘summer storm’ treatment resulted in the formation of new buds and tillers and increased basal cover from 1% in February to 18% in March. A glasshouse pot experiment examined the recovery of microlaena after different periods of drought and subsequent rewatering. In the pot experiment, microlaena withstood relatively short (up to 30 days) dry periods and then recovered when rewatered. Thus, it appears that microlaena is a persistent, perennial pasture plant that, although it survives very dry summers in Mediterranean areas, is not summer dormant. Microlaena does not exhibit summer dormancy in response to moisture stress and enter a quiescent stage, because normal growth is prevented by the lack of water, but it quickly recommences growth when soil water becomes available. The ability of microlaena to withstand summer soil water deficits and to recruit from seedlings make it a valuable pasture species across drought-prone environments, and this undoubtedly partly explains its very broad adaptation across eastern Australia.
Evaluation of decision support system for agrotechnology transfer SUBSTOR potato model (v4.5) under tropical conditions
Authors: Nand Moleen Monita , Iese Viliamu , Singh Upendra , Wairiu Morgan , Jokhan Anjeela , Prakash Reema
Published: October 2016

Decision Support System for Agrotechnology Transfer (DSSAT) SUBSTOR Potato model (v4.5) was calibrated using Desiree variety. DSSAT SUBSTOR Potato model simulates on a daily basis the development and growth of potatoes using inputs such as climate, soil and crop management. The experiment was conducted in Banisogosogo, Fiji Islands, during the potato growing season of 2012. Fresh and dry weights of belowground plant component (tubers) were taken during progressive harvests. The DSSAT SUBSTOR Potato model was calibrated using experimental field data, soil and weather data of the growing season. The manual calibration steps involved recalculation of soil water content and the adjustments of genetic co-efficient to suit the temperature and daylength regime similar to the experimental conditions. Tuber dry weight was used as the main parameter to evaluate the model. The R2 values of the observed and simulated model outputs before calibration for replicate plot 1, replicate plot 2 and replicate plot 3 were 0.52, 0.49 and 0.61 respectively. After calibration, the R2 values for tuber dry yield for replicate plot 1, replicate plot 2 and replicate plot 3 were 0.88, 0.66 and 0.92 respectively indicating a strong positive relationship between the simulated and the observed yield.
Doing ‘understanding’ in dialogue interpreting
Authors: Turner Graham H. , Merrison Andrew J.
Published: October 2016

This paper asks what ‘understanding’ looks like in the presence of an interpreter. Much investigation of understanding in Interpreting Studies explores claims which treat it as axiomatic, rather than exploring the occurrence of comprehension itself (how participants come to accept that it is occurring, what form it takes, what its consequences are). Here we re-purpose a well-established research tool — the Map Task — to illustrate a robustly empirical approach to this issue, using complex multimodal and multilingual data. The Map Task, we contend, can play a potentially groundbreaking role in Interpreting Studies, mitigating the constraint created by the uniqueness of each interpreted exchange which otherwise hinders generalisability and theoretical expansion. In particular, we argue that the way interpreters and service users, through their talk, bring themselvescollectivelyto points of assumed shared understanding is illuminated with particular clarity through the Map Task lens. Research within this paradigm, we suggest, may help to enable further development of Interpreting Studies, affording an opportunity to deepen our communal understanding of thecollaborativeandinteractivenature of meaning-making in interpreted exchanges, starting with the recognition that what understanding consists of is, in essence, what interlocutorstreatas understanding.