bluuebunny/crossref_metadata_2025 huggingface dataset:
B(C6F5)3 catalysed 1,6-conjugate allylation of para-quinone methides: expedient access to allyl diarylmethanes
Authors: Mahesh Sriram , Kant Guddi , Anand Ramasamy Vijaya
Published: August 2016

An efficient protocol for the synthesis of unsymmetrical allyl diarylmethanes through a Lewis acid catalysed 1,6-conjugate addition of allylsilanes to para-quinone methides is described.
Enantioselective dearomatization of isoquinolines by anion-binding catalysis en route to cyclic α-aminophosphonates
Authors: Ray Choudhury Abhijnan , Mukherjee Santanu
Published: August 2016

An enantioselective dearomatization of isoquinolines has been developed using chiral anion-binding catalysis. This transformation makes use of silyl phosphite as a nucleophile and generates cyclic α-aminophosphonates.
Regioisomer effects of [70]fullerene mono-adduct acceptors in bulk heterojunction polymer solar cells
Authors: Umeyama Tomokazu , Miyata Tetsushi , Jakowetz Andreas C. , Shibata Sho , Kurotobi Kei , Higashino Tomohiro , Koganezawa Tomoyuki , Tsujimoto Masahiko , Gélinas Simon , Matsuda Wakana , Seki Shu , Friend Richard H. , Imahori Hiroshi
Published: August 2016

Regioisomer separations of [70]fullerene mono-adducts for polymer solar cell (PSC) applications were conducted for the first time.
On the syneresis of an OPV functionalised dipeptide hydrogel
Authors: Castilla Ana M. , Wallace Matthew , Mears Laura L. E. , Draper Emily R. , Doutch James , Rogers Sarah , Adams Dave J.
Published: August 2016

Contraction of a low molecular weight gel is not simply an effect of pH or charges on the gel fibre surface, but is related to the 3D arrangement of the self-assembled fibres in the gel network.
High-performance organic thermoelectric modules based on flexible films of a novel n-type single-walled carbon nanotube
Authors: Wu Guangbao , Gao Caiyan , Chen Guangming , Wang Xin , Wang Hanfu
Published: August 2016

A new strategy to realize p- to n-type conversion of a SWCNT is proposed by diethylenetriamine doping and subsequent CaH2 reduction. The module with a multilayered stacked structure reveals excellent thermoelectric performance.
Dual-defective strategy directing in situ assembly for effective interfacial contacts in MoS2 cocatalyst/In2S3 light harvester layered photocatalysts
Authors: Fang Zhibin , Huang Xueyan , Wang Yaozhu , Feng Wenhui , Zhang Yan , Weng Sunxian , Fu Xianzhi , Liu Ping
Published: August 2016

Directed by a novel strategy of dual-defective construction, both enhanced reactivity and considerable photostability are achieved in layered MoS2/In2S3 photocatalysts with intimate interfacial contact and rich active sites.
Integrated self-charging power unit with flexible supercapacitor and triboelectric nanogenerator
Authors: Song Yu , Cheng Xiaoliang , Chen Haotian , Huang Jiahuan , Chen Xuexian , Han Mengdi , Su Zongming , Meng Bo , Song Zijian , Zhang Haixia
Published: August 2016

A sandwich-shaped, self-charging power unit integrated with triboelectric nanogenerator and supercapacitor could be stably charged and drive an electrochromic device.
Highly efficient inverted organic light-emitting diodes using composite organic heterojunctions as electrode-independent injectors
Authors: Wang Xiaoli , Shi Changsheng , Guo Qingxun , Wu Zhongbin , Yang Dezhi , Qiao Xianfeng , Ahamad Tansir , Alshehri Saad M. , Chen Jiangshan , Ma Dongge
Published: August 2016

A p/bulk heterojunction/n junction not only enhances electron injection, but also makes device performances independent of work functions of the used cathode.
The pro-inflammatory cytokines IFNγ/TNFα increase chromogranin A-positive neuroendocrine cells in the colonic epithelium
Authors: Hernández-Trejo José Antonio , Suárez-Pérez Dimelza , Gutiérrez-Martínez Itzel Zenidel , Fernandez-Vargas Omar Eduardo , Serrano Carolina , Candelario-Martínez Aurora Antonia , Meraz-Ríos Marco Antonio , Citalán-Madrid Alí Francisco , Hernández-Ruíz Marcela , Reyes-Maldonado Elba , Valle-Rios Ricardo , Feintuch-Unger Jacobo H. , Schnoor Michael , Villegas-Sepúlveda Nicolás , Medina-Contreras Oscar , Nava Porfirio
Published: August 2016

The gastrointestinal tract is the largest hormone-producing organ in the body due to a specialized cell population called enteroendocrine cells (EECs). The number of EECs increases in the mucosa of inflammatory bowel disease patients; however, the mechanisms responsible for these changes remain unknown. Here, we show that the pro-inflammatory cytokines interferon γ (IFNγ) and tumor necrosis factor α (TNFα) or dextran sulfate sodium (DSS)-induced colitis increase the number of EECs producing chromogranin A (CgA) in the colonic mucosa of C57BL/6J mice. CgA-positive cells were non-proliferating cells enriched with inactive phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and autophagy markers. Moreover, inhibition of Akt and autophagy prevented the increase in CgA-positive cells after IFNγ/TNFα treatment. Similarly, we observed that CgA-positive cells in the colonic mucosa of patients with colitis expressed Akt and autophagy markers. These findings suggest that Akt signaling and autophagy control differentiation of the intestinal EEC lineage during inflammation.
Flow measurement method based on a fringing field capacitor structure
Authors: Liu Zhe , Wang WenLian
Published: August 2016

A flow measurement method based on fringing field capacitors is proposed. Alternate annular electrodes are fabricated on the surface of the tube to constitute the capacitor structure, and the fringing field penetrates the wall to achieve the detection of fluid. The electric field between two electrodes distributes along the annular wall, which is conducive to analyse the relationship of the capacitance and the flow. The proposed measurement method is suitable for the industrial applications due to the simple structure and low cost. A water flow measurement experiment was implemented by making foil capacitor on the surface of a plastic tube.
Optimum reference element selection for GNSS power‐inversion adaptive arrays
Authors: Wan Youda , Chen Feiqiang , Nie Junwei , Sun Guangfu
Published: August 2016

An improved algorithm for power‐inversion adaptive antenna arrays used in global navigation satellite systems (GNSS) receivers is proposed. Compared with traditional methods which select the reference element arbitrarily, the proposed method is capable of selecting the optimum reference element at signal acquisition stage. The criterion of the reference element selection is to maximise the acquisition test statistic results by developing the generalised likelihood ratio test detector. Monte Carlo simulation results show that the proposed method can improve the array performance significantly.
State estimation strategy for fractional order systems with noises and multiple time delayed measurements
Authors: Azami Ali , Naghavi Seyed Vahid , Dadkhah Tehrani Reza , Khooban Mohammad Hassan , Shabaninia Faridoon
Published: August 2016

The fractional order calculus can represent systems with high‐order dynamics and complex non‐linear phenomena using fewer coefficients. In this study the extended fractional Kalman filter is developed for the class of non‐linear discrete‐time fractional order systems using observations with multiple delays contaminated by additive white noise. For a wide class of practical applications, the time delay cannot be neglected. In the time delay integer order systems, a common approach is partial differential equation. This method is very difficult to solve. The authors’ approach is applied the reorganised innovation technique. As a result of the reorganised innovation sequence, the Kalman filtering problem with multiple delayed measurements is converted to filter of a delay‐free system. In the rest of paper, the covariance matrix of the prediction error of the states is presented in the form of the novel Riccati equations. Finally, the solution of the Kalman filtering problem is obtained by applying the re‐organised innovation sequence and Riccati equations. A numerical example is given to illustrate the effectiveness of the proposed scheme.
Capacitive micromachined ultrasonic transducer arrays incorporating anodically bondable low temperature co‐fired ceramic for small diameter ultrasonic endoscope
Authors: Yildiz Fikret , Matsunaga Tadao , Haga Yoichi
Published: August 2016

A process for the fabrication of a capacitive micromachined ultrasonic transducer (CMUT), with a resonance frequency of 2.88 MHz, using an anodically bondable custom‐designed low temperature co‐fired ceramic (LTCC) substrate with a 60 μm via diameter made of Au is presented. Fabrication of CMUTs with a high fill factor on the LTCC via with a pitch distance of 150 μm is good candidate for medical applications of a miniaturised ring shape CMUT endoscope. Electrical connection between the front side where the device is fabricated and the backside of the LTCC can be achieved with horizontal and vertical interconnects. Investigation of limitations with respect to the device dimensions and experimental fabrication results are discussed. CMUT arrays on LTCC provide a simplified fabrication process with advantages of LTCC architecture compared with typical glass counterparts used in the microelectromechanical systems field.
MEMS oxygen transport device for islet transplantation in the subcutaneous site
Authors: Komatsu Hirotake , Kang Dongyang , Lin Henry , Cook Colin A. , Mendez Daniel , Rawson Jeffrey , Mullen Yoko , Kandeel Fouad , Tai Yu‐Chong
Published: August 2016

A new microelectromechanical systems (MEMS) oxygen transporter device to improve the efficacy of islet transplantation to treat type 1 diabetes is described here. The device is fabricated for biocompatibility and designed to maintain islet oxygenation levels throughout the normally hypoxic subcutaneous transplant site. Transplantation of the islets and the device to the subcutaneous location is minimally invasive. Bench‐top testing and computational modelling of the device demonstrate that the device can provide sufficient oxygen to prevent hypoxia‐induced islet death transplanted subcutaneously. In vitro studies show that the partial oxygen tension is well‐maintained using the oxygen transporter in an anoxic environment. In vivo studies using a rat subcutaneous transplant model demonstrate that transplanted islets have more than three‐times higher survival using the oxygen transporter compared with transplants not using the transporter, two weeks post‐transplant. In addition, histology sections show well‐maintained islet structures one month after transplantation for islets transplanted in the presence of the device. Our MEMS oxygen transporter is a novel and promising device to support the efficacy of subcutaneous islet transplantation as a potential cure for type 1 diabetes.
Effects of magnesium and chlorine co‐doping on the structural and electrochemical performance of the spinel LiMn2O4 cathode materials
Authors: Zeng Xiaoxiong , Wu Jinghe , Hu Qishan
Published: August 2016

The lithium‐ion battery cathode materials spinel LiMn2O4 and LiMg0.05Mn1.95O3.9Cl0.1 samples are synthesised by solid state reaction route, the effects of magnesium and chlorine co‐doping on the structure, morphology and electrochemical performance of material LiMn2O4 are studied by X‐ray diffraction, scanning electron microscope, electron diffraction spectroscope and galvanostatic charge–discharge, respectively. The results indicate that appropriate amount doping of magnesium and chlorine does not change the spinel structure of LiMn2O4, and the results reveal that the LiMg0.05Mn1.95O3.9Cl0.1 has an initial discharge capacity of 125.2 mAh/g at 0.2C, and the capacity retention is still as high as 89.3% even after 100 cycles, which is significantly higher than 79.6% of LiMn2O4. Especially, the LiMg0.05Mn1.95O3.9Cl0.1 shows the discharge capacity of 91.2 mAh/g at 10C, which higher than that of LiMn2O4 (64.3 mAh/g). The LiMg0.05Mn1.95O3.9Cl0.1 exhibits excellent cycling performance and rate capability than that of LiMn2O4. Thus, this is a very effective way for comprehensive improving LiMn2O4 electrochemical performance.
Effects of neoclassical toroidal viscosity induced by the intrinsic error fields and toroidal field ripple on the toroidal rotation in tokamaks
Authors: Lee H. H. , Seol J. , Ko W. H. , Terzolo L. , Aydemir A. Y. , In Y. , Ghim Y.-c. , Lee S. G.
Published: August 2016

Effects of neoclassical toroidal viscosity (NTV) induced by intrinsic error fields and toroidal field ripple on cocurrent toroidal rotation in H-mode tokamak plasmas are investigated. It is expected that large NTV torque can be localized at the edge region through the 1/ν-regime in the vicinity of Er∼0 in the cocurrent rotating H-mode plasma. Numerical simulation on toroidal rotation demonstrates that the edge localized NTV torque determined by the intrinsic error fields and toroidal field ripples in the level of most tokamaks can damp the toroidal rotation velocity over the whole region while reducing the toroidal rotation pedestal which is clearly observed in Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. It is found that the NTV torque changes the toroidal rotation gradient in the pedestal region dramatically, but the toroidal rotation profile in the core region responds rigidly without a change in the gradient. On the other hand, it shows that the NTV torque induced by the intrinsic error fields and toroidal field ripple in the level of the KSTAR tokamak, which are expected to be smaller than most tokamaks by at least one order of magnitude, is negligible in determining the toroidal rotation velocity profile. Experimental observation on the toroidal rotation change by the externally applied nonaxisymmetric magnetic fields on KSTAR also suggests that NTV torque arising from nonaxisymmetric magnetic fields can damp the toroidal rotation over the whole region while diminishing the toroidal rotation pedestal.
Determination of ν2 fundamental band origin for BeH2 and BeD2 from deperturbation analysis of hot bands
Authors: Motallebipour Maryam S. , Shayesteh Alireza
Published: August 2016

New vibration-rotation hot bands, i.e., 031 → 030 and 041 → 040, have been assigned and rotationally analyzed for the gaseous BeH2 molecule. The 0310 (Πu), 0311 (Πg), 0420 (Δg), and 0421 (Δu) states are locally perturbed by the nearby 001 (Σu+), 002 (Σg+), 0111 (Πg), and 0112 (Πu) states, respectively [A. Shayesteh et al., J. Chem. Phys. 118, 3622 (2003)]. Appropriate Hamiltonian matrices have been constructed to take the effects of rotational ℓ-type doubling, ℓ-type resonance, and third order Coriolis interactions into account, and used in deperturbation analyses. From nonlinear least squares fits of all the data, relative energies and unperturbed rotational constants have been determined for the 030, 031, 040, and 041 vibrational levels of BeH2. Similar deperturbation fits were performed for the 001 → 000 and 011 → 010 bands of the BeD2 isotopologue, while the 030 and 040 vibrational levels were treated as dark states. From relative vibrational energies of the 030 and 040 levels, the ν2 fundamental band origins were determined to be 711.48 ± 0.05 cm−1 and 548.21 ± 0.1 cm−1 for BeH2 and BeD2, respectively.
Particle-in-cell simulation of two-dimensional electron velocity shear driven instability in relativistic domain
Authors: Shukla Chandrasekhar , Das Amita , Patel Kartik
Published: August 2016

We carry out particle-in-cell simulations to study the instabilities associated with a 2-D sheared electron flow configuration against a neutralizing background of ions. Both weak and strong relativistic flow velocities are considered. In the weakly relativistic case, we observe the development of electromagnetic Kelvin-Helmholtz instability with similar characteristics as that predicted by the electron Magnetohydrodynamic (EMHD) model. On the contrary, in a strong relativistic case, the compressibility effects of electron fluid dominate and introduce upper hybrid electrostatic oscillations transverse to the flow which are very distinct from EMHD fluid behavior. In the nonlinear regime, both weak and strong relativistic cases lead to turbulence with broad power law spectrum.
The impact of electron correlations on the energetics and stability of silicon nanoclusters
Authors: Matsko N. L. , Tikhonov E. V. , Baturin V. S. , Lepeshkin S. V. , Oganov Artem R.
Published: August 2016

The first-principles prediction of stable nanocluster structure is often hampered by the existence of many isomer configurations with energies close to the ground state. This fact attaches additional importance to many-electron effects beyond density functional theory (DFT), because their contributions can change a subtle energy order of competitive structures. To analyze this problem, we consider, as an example, the energetics of silicon nanoclusters passivated by hydrogen Si10H2n (0 ≤ n ≤ 11), where passivation changes the structure from compact to loosely packed and branched. Our calculations performed with DFT, hybrid functionals, and Hartree-Fock methods, as well as by the GW approximation, confirm a considerable sensitivity of isomer energy ordering to many-electron effects.
Characterization of perovskite solar cells: Towards a reliable measurement protocol
Authors: Zimmermann Eugen , Wong Ka Kan , Müller Michael , Hu Hao , Ehrenreich Philipp , Kohlstädt Markus , Würfel Uli , Mastroianni Simone , Mathiazhagan Gayathri , Hinsch Andreas , Gujar Tanaji P. , Thelakkat Mukundan , Pfadler Thomas , Schmidt-Mende Lukas
Published: August 2016

Lead halide perovskite solar cells have shown a tremendous rise in power conversion efficiency with reported record efficiencies of over 20% making this material very promising as a low cost alternative to conventional inorganic solar cells. However, due to a differently severe “hysteretic” behaviour during current density-voltage measurements, which strongly depends on scan rate, device and measurement history, preparation method, device architecture, etc., commonly used solar cell measurements do not give reliable or even reproducible results. For the aspect of commercialization and the possibility to compare results of different devices among different laboratories, it is necessary to establish a measurement protocol which gives reproducible results. Therefore, we compare device characteristics derived from standard current density-voltage measurements with stabilized values obtained from an adaptive tracking of the maximum power point and the open circuit voltage as well as characteristics extracted from time resolved current density-voltage measurements. Our results provide insight into the challenges of a correct determination of device performance and propose a measurement protocol for a reliable characterisation which is easy to implement and has been tested on varying perovskite solar cells fabricated in different laboratories.
Preface: Recent Advances in Fractional Dynamics
Authors: Srivastava H. M. , Baleanu Dumitru , Li Changpin
Published: August 2016

This Special Focus Issue contains several recent developments and advances on the subject of Fractional Dynamics and its widespread applications in various areas of the mathematical, physical, and engineering sciences.
Flue gas adsorption by single-wall carbon nanotubes: A Monte Carlo study
Authors: Romero-Hermida M. I. , Romero-Enrique J. M. , Morales-Flórez V. , Esquivias L.
Published: August 2016

Adsorption of flue gases by single-wall carbon nanotubes (SWCNT) has been studied by means of Monte Carlo simulations. The flue gas is modeled as a ternary mixture of N2, CO2, and O2, emulating realistic compositions of the emissions from power plants. The adsorbed flue gas is in equilibrium with a bulk gas characterized by temperature T, pressure p, and mixture composition. We have considered different SWCNTs with different chiralities and diameters in a range between 7 and 20 Å. Our results show that the CO2 adsorption properties depend mainly on the bulk flue gas thermodynamic conditions and the SWCNT diameter. Narrow SWCNTs with diameter around 7 Å show high CO2 adsorption capacity and selectivity, but they decrease abruptly as the SWCNT diameter is increased. For wide SWCNT, CO2 adsorption capacity and selectivity, much smaller in value than for the narrow case, decrease mildly with the SWCNT diameter. In the intermediate range of SWCNT diameters, the CO2 adsorption properties may show a peculiar behavior, which depend strongly on the bulk flue gas conditions. Thus, for high bulk CO2 concentrations and low temperatures, the CO2 adsorption capacity remains high in a wide range of SWCNT diameters, although the corresponding selectivity is moderate. We correlate these findings with the microscopic structure of the adsorbed gas inside the SWCNTs.
Spacetime and observer space symmetries in the language of Cartan geometry
Authors: Hohmann Manuel
Published: August 2016

We introduce a definition of symmetry generating vector fields on manifolds which are equipped with a first-order reductive Cartan geometry. We apply this definition to a number of physically motivated examples and show that our newly introduced notion of symmetry agrees with the usual notions of symmetry of affine, Riemann-Cartan, Riemannian, and Weizenböck geometries, which are conventionally used as spacetime models. Further, we discuss the case of Cartan geometries which can be used to model observer space instead of spacetime. We show which vector fields on an observer space can be interpreted as symmetry generators of an underlying spacetime manifold, and may hence be called “spatio-temporal.” We finally apply this construction to Finsler spacetimes and show that symmetry generating vector fields on a Finsler spacetime are indeed in a one-to-one correspondence with spatio-temporal vector fields on its observer space.
Discrete solitons of the focusing Ablowitz-Ladik equation with nonzero boundary conditions via inverse scattering
Authors: Prinari Barbara
Published: August 2016

Soliton solutions of the focusing Ablowitz-Ladik equation with nonzero boundary conditions at infinity are derived within the framework of the inverse scattering transform (IST). After reviewing the relevant aspects of the direct and inverse problems, explicit soliton solutions are obtained which are the discrete analog of the Tajiri-Watanabe and Kuznetsov-Ma solutions to the focusing nonlinear Schrödinger equation on a finite background. Then, by performing suitable limits of the above solutions, discrete analogs of the celebrated Akhmediev and Peregrine solutions are also presented. The latter, which can be thought of as a discrete “rogue” wave, is expressed as a family of rational functions of the discrete spatial variable n ∈ ℤ and time τ ∈ ℝ, parametrically depending on the amplitude Qo of the background. These solutions, which had been recently derived by direct methods, are obtained for the first time within the framework of the IST, thus also providing a spectral characterization of the solutions and a description of the singular limit process.
Studies on dispersive stabilization of porous media flows
Authors: Daripa Prabir , Gin Craig
Published: August 2016

Motivated by a need to improve the performance of chemical enhanced oil recovery (EOR) processes, we investigate dispersive effects on the linear stability of three-layer porous media flow models of EOR for two different types of interfaces: permeable and impermeable interfaces. Results presented are relevant for the design of smarter interfaces in the available parameter space of capillary number, Peclet number, longitudinal and transverse dispersion, and the viscous profile of the middle layer. The stabilization capacity of each of these two interfaces is explored numerically and conditions for complete dispersive stabilization are identified for each of these two types of interfaces. Key results obtained are (i) three-layer porous media flows with permeable interfaces can be almost completely stabilized by diffusion if the optimal viscous profile is chosen, (ii) flows with impermeable interfaces can also be almost completely stabilized for short time, but become more unstable at later times because diffusion flattens out the basic viscous profile, (iii) diffusion stabilizes short waves more than long waves which leads to a “turning point” Peclet number at which short and long waves have the same growth rate, and (iv) mechanical dispersion further stabilizes flows with permeable interfaces but in some cases has a destabilizing effect for flows with impermeable interfaces, which is a surprising result. These results are then used to give a comparison of the two types of interfaces. It is found that for most values of the flow parameters, permeable interfaces suppress flow instability more than impermeable interfaces.
A mixing surface acoustic wave device for liquid sensing applications: Design, simulation, and analysis
Authors: Bui ThuHang , Morana Bruno , Scholtes Tom , Chu Duc Trinh , Sarro Pasqualina M.
Published: August 2016

This work presents the mixing wave generation of a novel surface acoustic wave (M-SAW) device for sensing in liquids. Two structures are investigated: One including two input and output interdigital transducer (IDT) layers and the other including two input and one output IDT layers. In both cases, a thin (1 μm) piezoelectric AlN layer is in between the two patterned IDT layers. These structures generate longitudinal and transverse acoustic waves with opposite phase which are separated by the film thickness. A 3-dimensional M-SAW device coupled to the finite element method is designed to study the mixing acoustic wave generation propagating through a delay line. The investigated configuration parameters include the number of finger pairs, the piezoelectric cut profile, the thickness of the piezoelectric substrate, and the operating frequency. The proposed structures are evaluated and compared with the conventional SAW structure with the single IDT layer patterned on the piezoelectric surface. The wave displacement along the propagation path is used to evaluate the amplitude field of the mixing longitudinal waves. The wave displacement along the AlN depth is used to investigate the effect of the bottom IDT layer on the transverse component generated by the top IDT layer. The corresponding frequency response, both in simulations and experiments, is an additive function, consisting of sinc(X) and uniform harmonics. The M-SAW devices are tested to assess their potential for liquid sensing, by dropping liquid medium in volumes between 0.05 and 0.13 μl on the propagation path. The interaction with the liquid medium provides information about the liquid, based on the phase attenuation change. The larger the droplet volume is, the longer the duration of the phase shift to reach stability is. The resolution that the output change of the sensor can measure is 0.03 μl.
Enhancement of thermoelectric properties in the Nb–Co–Sn half-Heusler/Heusler system through spontaneous inclusion of a coherent second phase
Authors: Buffon Malinda L. C. , Laurita Geneva , Verma Nisha , Lamontagne Leo , Ghadbeigi Leila , Lloyd Demetrious L. , Sparks Taylor D. , Pollock Tresa M. , Seshadri Ram
Published: August 2016

Half-Heusler XYZ compounds with an 18 valence electron count are promising thermoelectric materials, being thermally and chemically stable, deriving from relatively earth-abundant components, and possessing appropriate electrical transport properties. The typical drawback with this family of compounds is their high thermal conductivity. A strategy for reducing thermal conductivity is through the inclusion of secondary phases designed to minimize negative impact on other properties. Here, we achieve this through the addition of excess Co to half-Heusler NbCoSn, which introduces precipitates of a semi-coherent NbCo2Sn Heusler phase. A series of NbCo1+xSn materials are characterized here using X-ray and neutron diffraction studies and electron microscopy. Electrical and thermal transport measurements and electronic structure calculations are used to understand property evolution. We find that annealing has an important role to play in determining antisite ordering and properties. Antisite disorder in the as-prepared samples improves thermoelectric performance through the reduction of thermal conductivity, but annealing during the measurement degrades properties to resemble those of the annealed samples. Similar to the more widely studied TiNi1+xSn system, Co addition to the NbCoSn phase results in improved thermoelectric performance through a decrease in thermal conductivity which results in a 20% improvement in the thermoelectric figure of merit, zT.
Joule heating induced thermomigration failure in un-powered microbumps due to thermal crosstalk in 2.5D IC technology
Authors: Li Menglu , Kim Dong Wook , Gu Sam , Parkinson Dilworth Y. , Barnard Harold , Tu K. N.
Published: August 2016

Thermal-crosstalk induced thermomigration failure in un-powered microbumps has been found in 2.5D integrated circuit (IC) circuit. In 2.5D IC, a Si interposer was used between a polymer substrate and a device chip which has transistors. The interposer has no transistors. If transistors are added to the interposer chip, it becomes 3D IC. In our test structure, there are two Si chips placed horizontally on a Si interposer. The vertical connections between the interposer and the Si chips are through microbumps. We powered one daisy chain of the microbumps under one Si chip; however, the un-powered microbumps in the neighboring chip are failed with big holes in the solder layer. We find that Joule heating from the powered microbumps is transferred horizontally to the bottom of the neighboring un-powered microbumps, and creates a large temperature gradient, in the order of 1000 °C/cm, through the un-powered microbumps in the neighboring chip, so the latter failed by thermomigration. In addition, we used synchrotron radiation tomography to compare three sets of microbumps in the test structure: microbumps under electromigration, microbumps under thermomigration, and microbumps under a constant temperature thermal annealing. The results show that the microbumps under thermomigration have the largest damage. Furthermore, simulation of temperature distribution in the test structure supports the finding of thermomigration.
A multiscale transport model for Lennard-Jones binary mixtures based on interfacial friction
Authors: Bhadauria Ravi , Aluru N. R.
Published: August 2016

We propose a one-dimensional isothermal hydrodynamic transport model for non-reacting binary mixtures in slit shaped nanochannels. The coupled species momentum equations contain viscous dissipation and interspecies friction term of Maxwell-Stefan form. Species partial viscosity variations in the confinement are modeled using the van der Waals one fluid approximation and the local average density method. Species specific macroscopic friction coefficient based Robin boundary conditions are provided to capture the species wall slip effects. The value of this friction coefficient is computed using a species specific generalized Langevin formulation. Gravity driven flow of methane-hydrogen and methane-argon mixtures confined between graphene slit shaped nanochannels are considered as examples. The proposed model yields good quantitative agreement with the velocity profiles obtained from the non-equilibrium molecular dynamics simulations. The mixtures considered are observed to behave as single species pseudo fluid, with the interfacial friction displaying linear dependence on molar composition of the mixture. The results also indicate that the different species have different slip lengths, which remain unchanged with the channel width.
Crossover phenomena of percolation transition in evolution networks with hybrid attachment
Authors: Chen Xiaolong , Yang Chun , Zhong Linfeng , Tang Ming
Published: August 2016

A first-order percolation transition, called explosive percolation, was recently discovered in evolution networks with random edge selection under a certain restriction. For many real world networks, the mechanism of preferential attachment plays a significant role in the formation of heterogeneous structures, but the network percolation in evolution process with preferential attachment has not yet been concerned. We propose a tunable network percolation model by introducing a hybrid mechanism of edge selection into the Bohman-Frieze-Wormald model, in which a parameter adjusts the relative weights between random and preferential selections. A large number of simulations indicate that there exist crossover phenomena of percolation transition by adjusting the parameter in the evolution processes. When the strategy of selecting a candidate edge is dominated by random selection, a single discontinuous percolation transition occurs. When a candidate edge is selected more preferentially based on nodes degree, the size of the largest component undergoes multiple discontinuous jumps, which exhibits a peculiar difference from the network percolation of random selection with a certain restriction. Besides, the percolation transition becomes continuous when the candidate edge is selected completely preferentially.
One-dimensional Coulomb-like problem in general case of deformed space with minimal length
Authors: Samar M. I. , Tkachuk V. M.
Published: August 2016

In general case of deformed Heisenberg algebra leading to the minimal length, we present a definition of the inverse of position operator which is linear and two-sided. Our proposal is based on the functional analysis of the position operator. Using this definition, 1D Coulomb-like problem is studied. We find exactly the energy spectrum and the eigenfunctions for the 1D Coulomb-like potential in deformed space with arbitrary function of deformation. We analyze the energy spectrum for different partial cases of deformation function and find that the correction caused by the deformation highly depends on the type of the deformation function.
Confined states in photonic-magnonic crystals with complex unit cell
Authors: Dadoenkova Yu. S. , Dadoenkova N. N. , Lyubchanskii I. L. , Kłos J. W. , Krawczyk M.
Published: August 2016

We have investigated multifunctional periodic structures in which electromagnetic waves and spin waves can be confined in the same areas. Such simultaneous localization of both sorts of excitations can potentially enhance the interaction between electromagnetic waves and spin waves. The system we considered has a form of one dimensional photonic-magnonic crystal with two types of magnetic layers (thicker and thinner ones) separated by sections of the dielectric photonic crystals. We focused on the electromagnetic defect modes localized in the magnetic layers (areas where spin waves can be excited) and decaying in the sections of conventional (nonmagnetic) photonic crystals. We showed how the change of relative thickness of two types of the magnetic layers can influence on the spectrum of spin waves and electromagnetic defect modes, both localized in magnetic parts of the system.
Magnetoelectric studies on CoFe2O4/0.5(BaTi0.8Zr0.2O3)-0.5(Ba0.7Ca0.3TiO3) lead-free bilayer thin films derived by the chemical solution deposition
Authors: Venkata Ramana E. , Zavašnik Janez , Graça M. P. F. , Valente M. A.
Published: August 2016

Lead-free multiferroic bilayer thin films were fabricated on (111)Pt/Si substrate via a simple sol-gel chemical solution deposition, by altering the position of piezoelectric (Ba0.85Ca0.15) (Ti0.9Zr0.1)O3 (BCTZO) and ferromagnetic CoFe2O4 (CFO). Single layer BCTZO experiences the out-of-plane compressive stress, while this layer is under tensile strain in both the bilayers. The microstructural study confirms the formation of bilayers with expected chemical composition composed of multiple well-developed crystallites having no crystallographic dependencies. Thin films of BCTZO and CFO/BCTZO exhibited saturated ferroelectric hysteresis loops at room temperature with a Pr of 7.2 and 5.6 μC/cm2. The magnetic field induced shift in phonon vibrations coupled with direct magnetoelectric (ME) measurements demonstrated a stress-mediated coupling mechanism in the bilayers. We found a superior ME coefficient (105 MV/cm Oe) and dielectric tunability (∼52%) for CFO/BCTZO bilayer compared to the BCTZO/CFO bilayer, which demonstrates that the modification of strain state in bilayers is useful for the desired ME coupling. The BCTZO having piezoelectricity on par with that of lead-based ones can be useful to tailor lead-free ME applications.
Fermi-level unpinning in Pt/Al2O3/GaSb PMOS capacitors by sulphurization and rapid thermal annealing of GaSb surfaces
Authors: Kim Seongkyung , Yoo Sijung , Lim Hajin , Kim Joon-Rae , Jeong Jae Kyeong , Kim Hyeong Joon
Published: August 2016

A facile route to mitigate the Fermi-level pinning between a p-type GaSb semiconductor and an Al2O3 dielectric is proposed. Combination of the sulphurization of the GaSb surface and the subsequent rapid thermal annealing allowed for high quality GaSb/Al2O3 interfacial characteristics; the interfacial trap density value was ≤2.0 × 1012 cm−2 eV−1 in an energy range of 0.05 ≤ ET − Ev ≤ 0.45 eV for the PMOS capacitor via rapid thermal annealing at 575 °C. A physical rationale was given on the basis of the thermo-chemical conversion of Ga2O into Ga2O3 and the conformal elimination of Sb related elements and oxides on the GaSb surface.
Piezoelectric energy harvesting in coupling-chamber excited by the vortex-induced pressure
Authors: Cheng Tinghai , Wang Yingting , Qin Feng , Song Zhaoyang , Lu Xiaohui , Bao Gang , Zhao Xilu
Published: August 2016

The performance of a piezoelectric energy harvester with a coupling chamber was investigated under vortex-induced pressure. The harvester consisted of a power chamber, a buffer, and a storage chamber. Different types of vortex (i.e., clockwise or counter-clockwise) could be induced by changing the volume ratio between the power chamber and the storage chamber. The peak voltage of the harvester could be tuned by changing the volume ratio. For example, under a pressure of 0.30 MPa, input cycle of 2.0 s, and flow rate of 200 l/min, the peak voltage decreased from 79.20 to 70.80 V with increasing volume ratio. The optimal volume ratio was 2.03, which resulted in the formation of a clockwise vortex. The corresponding effective power through a 600 kΩ resistor was 1.97 mW.
An easily fabricated high performance ionic polymer based sensor network
Authors: Zhu Zicai , Wang Yanjie , Hu Xiaopin , Sun Xiaofei , Chang Longfei , Lu Pin
Published: August 2016

Ionic polymer materials can generate an electrical potential from ion migration under an external force. For traditional ionic polymer metal composite sensors, the output voltage is very small (a few millivolts), and the fabrication process is complex and time-consuming. This letter presents an ionic polymer based network of pressure sensors which is easily and quickly constructed, and which can generate high voltage. A 3 × 3 sensor array was prepared by casting Nafion solution directly over copper wires. Under applied pressure, two different levels of voltage response were observed among the nine nodes in the array. For the group producing the higher level, peak voltages reached as high as 25 mV. Computational stress analysis revealed the physical origin of the different responses. High voltages resulting from the stress concentration and asymmetric structure can be further utilized to modify subsequent designs to improve the performance of similar sensors.
An analytical description for the elastic compression of metallic polyhedral nanoparticles
Authors: Yang L. , Feng J. , Ding Y. , Bian J. J. , Wang G. F.
Published: August 2016

Metallic nanoparticles are usually polyhedrons instead of perfect spheres, which presents a challenge to characterize their elastic response. In the present paper, the elastic compression of truncated octahedral nanoparticles is investigated through finite element calculations and atomic simulations. An analytical expression of load is obtained for octahedral particles, which is linearly proportional to indent depth, instead of the 3/2 power law relation predicted by Hertzian model for elastic sphere. Comparisons with molecular dynamics simulations demonstrate that the obtained relation can predict the elastic response of polyhedral nanoparticles. This study is helpful to measure the elastic properties of polyhedral nanoparticles, and characterize their elastic response.
Comparison of Electrofishing and Gill Nets for Sampling Cichlid Species
Authors: Bies Jason M. , Fox Cynthia N. , Neal J. Wesley
Published: August 2016

Introduced cichlid species are increasingly more common in tropical freshwater systems and expanding in range, often with negative consequences to receiving systems. To better understand, monitor, and manage these populations, investigators need improved cichlid sampling protocols. In this study, electrofishing and gill nets were compared for their effectiveness at collecting cichlid species during diel sampling in a Puerto Rico reservoir containing five cichlid species. Both gears were fished simultaneously during day and night periods in January and July. Species composition, species length frequencies, and overall cichlid catch per person-hour were compared. This study suggests that electrofishing, particularly at night, may be a more appropriate gear for sampling cichlid species in the littoral zone of reservoirs, as gill nets were more time intensive, had more variable catch rates, and exhibited considerable selectivity. Gill nets were highly selective for Red Devil Cichlid Amphilophus labiatus and Butterfly Peacock Bass Cichla ocellaris and were size-selective for Butterfly Peacock Bass. Electrofishing captured 37.7 cichlids/person-hour, compared with 13.7 cichlids/person-hour for gill nets. However, cichlid capture efficiency was low and variable, and therefore electrofishing catch rate should not be used as a measure of relative abundance.

Received November 10, 2015; accepted April 20, 2016Published online August 19, 2016
Different Dietary Lipid Sources Affect Plasma Lipid Composition but Not Stress Tolerance or Growth of Hybrid Striped Bass
Authors: Trushenski Jesse , Aardsma Matthew
Published: August 2016

To determine whether dietary lipid sources used in regimens to replace fish oil differentially impact the production performance and physiological status of hybrid Striped Bass (White Bass Morone chrysops × Striped Bass M. saxatilis), the growth performance and stress response of fish raised on diets containing oil from fish, canola, corn, or flaxseed were evaluated. Production performance was unaffected by diet. Net-chasing and handling stress challenges elicited changes in hematology consistent with the generalized stress response, and there was a significant main effect of stressor exposure (P < 0.01) on both plasma cortisol and osmolality, as well as a main effect of lipid source (P < 0.05) on plasma osmolality. Across diets, cortisol and osmolality levels were highest 1 h after stressor exposure (411 ng/mL and 385 mOsm/kg, respectively) but decreased significantly by 4 h poststressor (169 ng/mL and 332 mOsm/kg, respectively). The plasma lipid fatty acid (FA) profile was influenced by diet and generally reflected the FA profile in the feed. However, higher levels of saturated and monounsaturated FAs and lower levels of polyunsaturated FAs were typically observed shortly after stressor exposure. Although differences in hematology were associated with differences in lipid source and stressor exposure, neither obvious impairment of physiological function nor gross effects (i.e., morbidity and mortality) were observed.
Study of NBI-driven chirping mode properties and radial location by the heavy ion beam probe in the TJ-II stellarator
Authors: Melnikov A.V. , Eliseev L.G. , Castejón F. , Hidalgo C. , Khabanov P.O. , Kozachek A.S. , Krupnik L.I. , Liniers M. , Lysenko S.E. , de Pablos J.L. , Sharapov S.E. , Ufimtsev M.V. , Zenin V.N.
Published: August 2016

Alfvén eigenmodes (AEs) were studied in low magnetic shear flexible heliac TJ-II (B
0  =  0.95 T, R
0  =  1.5 m,

〈
a
〉

  =  0.22 m) neutral beam injection (NBI) heated plasmas (P
NBI  ⩽  1.1 MW, E
NBI  =  32 keV) using the heavy ion beam probe (HIBP). L-mode hydrogen plasmas heated with co-, counter- and balanced-NBI and electron cyclotron resonance heating (ECRH) were investigated in various magnetic configurations with rotational transform ι(a)/2π  =  1/q ~ 1.5–1.6. The HIBP diagnostic is capable of simultaneously measuring the oscillations of the plasma electric potential, density and poloidal magnetic field. In earlier studies chirping modes have been observed with 250 kHz  <  f
AE  <  380 kHz in combined ECR and NBI heated plasmas at low density

n
¯

e

  =  (0.3–1.5)  ×  1019 m−3. In this paper we report the observation of chirping modes obtained with NBI only in plasmas with densities similar to those of earlier studies and obtained after lithium evaporation in the vacuum vessel. The absence of ECRH in the discharges studied here shows that ECRH is not a necessary ingredient to obtain chirping modes in TJ-II but rather a tool for obtaining low-density discharges. Using the HIBP we deduce that the location of the AE chirping mode is  −0.8  <  ρ  <  0.8. Chirping modes have a specific spatial structure: electric potential perturbations have a ballooning character, while the density and B
pol perturbations are nearly symmetric for both ECRH  +  NBI and NBI-only plasmas. On TJ-II, the dominant effect on the nonlinear evolution of the AE from the chirping state to the steady-frequency state is the magnetic configuration, determined by the vacuum ι and plasma current I
pl.
Nash equilibrium can resolve conflicting maximum sustainable yields in multi-species fisheries management
Authors: Norrström Niclas , Casini Michele , Holmgren Noél M. A.
Published: August 2016

The current fisheries management goals set by the European Commission states that fish stocks should be harvested to deliver maximum sustainable yields (MSY) and simultaneously, management should take ecosystem considerations into account. This creates unsolved trade-offs for the management of the stocks. We suggest a definition of a multi-species-MSY (MS-MSY) where no alternative fishing mortality (F) can increase yield (long term) for any ecologically interacting stock, given that the other stocks are fished at constant efforts (Fs). Such a MS-MSY can be solved through the game theoretic concept of a Nash equilibrium and here we explore two solutions to this conflict in the Baltic Sea. We maximize the sustainable yield of each stock under two constraints: first, we harvest the other stocks at a fixed F (FNE); second, we keep the spawning stock biomasses of the other stocks fixed [biomass Nash equilibrium (BNE)]. As a case study, we have developed a multi-species interaction stochastic operative model (MSI-SOM), which contains a SOM for each of the three dominant species of the Baltic Sea, the predator cod (Gadus morhua), and its prey herring (Clupea harengus), and sprat (Sprattus sprattus). For our Baltic Sea case, MS-MSYs exist under both the FNE and the BNE, but there is no guarantee that point solutions exists. We found that the prey species’ spawning stock biomasses are additive in the cod growth function, which allowed for a point solution in BNE. In the FNE, the herring MSY was found to be relatively insensitive to the other species’ fishing mortalities (F), which facilitated a point solution. The MSY targets of the BNE and the FNE differ slightly where the BNE gives higher predator yields and lower prey yields.