bluuebunny/crossref_metadata_2025 huggingface dataset:
Highly selective and sensitive recognition of Zn(ii) by a novel coumarinyl scaffold following spectrofluorometric technique and its application in living cells
Authors: Dey Sunanda , Purkait Rakesh , Patra Chiranjit , Saha Moumita , Mondal Sanchaita , Das Saha Krishna , Sinha Chittaranjan
Published: August 2018

A biocompatible coumarinyl Schiff base scaffold (H2L), a nontoxic probe and a fluorescent sensor to Zn2+, with an LOD of 11 nM, was used for living cell imaging.
Grafting of porphyrin oligomers on single-walled carbon nanotubes by Hay coupling
Authors: Hijazi Ismail , Khedhiri Khaoula , Campidelli Stéphane
Published: August 2018

Two different Zn-porphyrin oligomers were synthesized on single-walled carbon nanotubes via Hay coupling and the formation of 1,3-butadiyne linkers.
Visible light-induced aerobic oxidative cross-coupling of glycine esters with α-angelicalactone: a facile pathway to γ-lactams
Authors: Zhou Huang , Yang Xiaorong , Li Shilin , Zhu Yin , Li Ying , Zhang Yuan
Published: August 2018

A rapid synthesis of substituted γ-lactams is achieved via metal-free photocatalyzed aerobic oxidative dehydrogenative formal [2 + 3] cyclization of glycine esters with α-angelicalactone.
Sequence-definition from controlled polymerization: the next generation of materials
Authors: De Neve Jeroen , Haven Joris J. , Maes Lowie , Junkers Tanja
Published: August 2018

An overview is given on the state-of-the-art in synthesis of sequence-controlled and sequence-defined oligomers and polymers.
Eco-friendly synthesis of CuInS2 and CuInS2@ZnS quantum dots and their effect on enzyme activity of lysozyme
Authors: Mir Irshad Ahmad , Das Kishan , Akhter Tabasum , Ranjan Rahul , Patel Rajan , Bohidar H. B.
Published: August 2018

Eco-friendly synthesis of CIS and CIS@ZnS quantum dots was carried out, and their interaction with lysozyme revealed spontaneous and hydrophobic binding. Lysozyme helicity and enzymatic activity increased upon complexation.
Gating the electron transfer at a monocopper centre through the supramolecular coordination of water molecules within a protein chamber mimic
Authors: Le Poul Nicolas , Colasson Benoit , Thiabaud Grégory , Dit Fouque Dany Jeanne , Iacobucci Claudio , Memboeuf Antony , Douziech Bénédicte , Řezáč Jan , Prangé Thierry , Lande Aurélien de la , Reinaud Olivia , Le Mest Yves
Published: August 2018

Functionality of enzymes is strongly related to water dynamic processes.
Nonequilibrium phase diagrams for actomyosin networks
Authors: Freedman Simon L. , Hocky Glen M. , Banerjee Shiladitya , Dinner Aaron R.
Published: August 2018

Simulations reveal diverse structural phases of the actomyosin cytoskeleton and their implications for network-scale properties.
Tuning of volume phase transition for poly(N-isopropylacrylamide) ionogels by copolymerization with solvatophilic monomers
Authors: Timothy Bernard , Kim Dowan , Yoo Seong Il , Yoon Jinhwan
Published: August 2018

Tuning of volume phase transition for PNIPAm based ionogels is achieved by incorporating solvatophilic monomers.
Biosynthesis and metabolic engineering of pseudo-oligosaccharides
Authors: Alanzi Abdullah R. , Demessie Ananiya A. , Mahmud Taifo
Published: August 2018

Pseudo-oligosaccharides are microbial-derived secondary metabolites whose chemical structures contain pseudosugars (glycomimetics). Owing to their high resemblance to the molecules of life (carbohydrates), most pseudo-oligosaccharides show significant biological activities. Some of them have been used as drugs to treat human and plant diseases. Because of their significant economic value, efforts have been put into understanding their biosynthesis, optimizing their fermentation conditions, and engineering their metabolic pathways to obtain better production yields. Many unusual enzymes participating in diverse biosynthetic pathways to pseudo-oligosaccharides have been reported. Various methods and conditions to improve the production yields of the target compounds and eliminate byproducts have also been developed. This review article describes recent studies on the biosynthesis, fermentation optimization, and metabolic engineering of high-value pseudo-oligosaccharides.
Node‐pair selection scheme based on modified PDOP for cooperative triangulation
Authors: Im C. , Lee C.
Published: August 2018

This Letter proposes a scheme to select a pair of nodes for cooperative triangulation‐based localisation. The authors select the pair of nodes by considering the position dilution of precision (PDOP) and the noise power of the measured distance error. The proposed scheme reduces the localisation error by considering the measured distance errors of the positioning user equipment (UE) and the cooperative UE at the same time in calculating PDOP. The simulation results show that the proposed scheme provides higher positioning accuracy than the conventional triangulation schemes.
Operation paradigm of an all converter interfaced generation bulk power system
Authors: Ramasubramanian Deepak , Farantatos Evangelos , Ziaeinejad Saleh , Mehrizi‐Sani Ali
Published: August 2018

This study investigates the viability and the associated operational implications of an all converter interfaced generation system operating at constant frequency using grid forming converters. Grid‐forming converters set the frequency and voltage of the grid and enable its operation under constant frequency, thus creating a new paradigm for the frequency response of a power system. Power sharing between converters is addressed while assessing the implications of operating the bulk power system at a constant frequency. Case studies performed on a small 9‐bus system as well as a large 2000‐bus system, using a developed positive sequence as well as a detailed three‐phase point on wave models of a grid forming converter are discussed.
DG planning incorporating demand flexibility to promote renewable integration
Authors: Dang Can , Wang Xifan , Wang Xiuli , Li Furong , Zhou Baorong
Published: August 2018

The integration of demand flexibility in distributed generation (DG) planning either lacks accuracy or ignores the potential of the behaviour of consumers in promoting the integration of renewables. This study proposes a DG planning model coordinating demand flexibility, in which the DG expansion plan and the behaviour of consumers in demand response (DR) programmes are co‐optimised for the highest social welfare and the optimal utilisation of renewable generation. Consequently, the supply cost is reduced by utilising higher renewable generation instead of buying electricity from the grid. A share of the cost savings is allocated to the consumers to encourage their participation in DR programmes. Simulation results show that the expansion capacity of renewable generation is increased by 7.4% compared with no demand flexibility incorporation, and the social welfare is increased by up to 13.5% compared with no DG installation and 3.1% compared with no demand flexibility incorporation. Besides, the DR programmes carried out in the distribution system interact with the DG expansion plan, and higher subsidy rates in DR programmes could further promote the integration of renewables.
Sub‐synchronous oscillations caused by the control of LCC HVDC transmission line under the condition of open‐loop modal coupling
Authors: Du Wenjuan , Zhen Zijing , Wang Haifeng
Published: August 2018

This study examines the sub‐synchronous oscillations (SSOs) caused by the control of a line commutated converter high‐voltage, direct current (LCC HVDC) transmission line in a power system with a doubly fed induction generator for the wind power generation. The examination is based on a closed‐loop interconnected model consisted of an open‐loop HVDC subsystem and an open‐loop subsystem of power generation. The open‐loop modal coupling is the modal condition that an SSO mode of the open‐loop HVDC subsystem is close to an open‐loop SSO mode of the power generation subsystem on the complex plane. Analysis in the study indicates that under the condition of open‐loop modal coupling, the LCC HVDC line may induce strong dynamic interactions which degrade the damping of power system SSOs. An SSO index is derived to assess the degree of damping degradation of the SSOs, which can be used to identify the SSO instability risk brought about by the control of LCC HVDC transmission line. Hence, the mechanism of why the control of LCC HVDC transmission line may cause power system SSOs is revealed from the perspective of open‐loop modal coupling. Study cases are presented to demonstrate and validate the analysis and conclusions made in the study.
Dual‐band sensor–antenna design for low energy consumption/cost wireless sensor nodes
Authors: Khelladi Rafik , Ghanem Farid , Djeddou Mustapha , Nedil Mourad
Published: August 2018

Wireless sensor networks (WSNs) consist of nodes with a limited power source. Reducing the energy consumption is an effective way to extend the lifespan of the sensor node. In this contribution, a new approach of designing of a new class radio frequency sensor–antenna for low energy consumption and low‐cost wireless sensor nodes is proposed. Unlike the architecture of a conventional wireless sensor node, the proposed approach does not require any processor device that consumes power. It consists of integrating a capacitive sensor in a narrowband antenna that can send raw information, through its operating frequency which can be tuned depending on the value of the physical parameter to measure. As a result, a corresponding table between the resonant frequency of the sensor–antenna and the measured physical parameter is obtained. Furthermore, by using a dual‐band antenna, the proposed configuration is able to measure, simultaneously, two physical parameters. A prototype of the sensor–antenna has been simulated and its behaviour has been validated with measurements. From the obtained results, it can be noted that the use of the proposed sensor–antenna can be a good alternative to reduce considerably the complexity and hence the cost of wireless sensor nodes for WSN applications.
Design of multiband multipolarised single feed patch antenna
Authors: Dabas Tanvi , Kanaujia Binod Kumar , Gangwar Deepak , Gautam Anil Kumar , Rambabu Karumudi
Published: August 2018

A new low profile, multiband, multipolarised single feed antenna is designed. A corner truncated patch loaded with slots and a complementary split ring resonator is used to achieve three frequency bands with different polarisations. The antenna exhibits right‐hand circular, linear, and left‐hand circular polarisation at three different bands, respectively. To obtain circular polarisation, orthogonal modes are excited by truncating corners of the patch and etching slits. Single feed, single layer geometry with Y‐shaped feed structure is employed. The antenna is fabricated on a low‐cost FR4 substrate with an overall size of , and the proposed design has been verified experimentally. The selected frequency bands are centred at 2.313, 2.396, and 2.478 GHz, and they have −10 dB impedance bandwidths of 2.14, 2.50, and 2.42%, respectively. The first frequency band exhibits right‐hand circular polarisation with a 3 dB axial ratio bandwidth of 0.85%. The second frequency band exhibits linear polarisation, whereas the third frequency band exhibits left‐hand circular polarisation with a 3 dB axial ratio bandwidth of 0.81%.
Analysis of drain current saturation behaviour in GaN polarisation super junction HFETs
Authors: Unni Vineet , Long Hong Yao , Yan Hongyang , Nakajima Akira , Kawai Hiroji , Sankara Narayanan Ekkanath Madathil
Published: August 2018

The magnitude of saturation current in a power device significantly impacts its short‐circuit capability. In conjunction with the unprecedented miniaturisation that gallium nitride (GaN) offers, there is a compelling rationale to examine this critical parameter in GaN transistors for thermally stable and reliable power converter applications. This study presents a comprehensive analysis of the physical behaviour that yields intrinsically low drain current saturation in GaN polarisation super junction heterojunction field‐effect transistors (PSJ HFETs). The analysis in this work has been performed using electrical characterisation data of conventional and PSJ HFETs, supported by physics‐based two‐dimensional device simulations. Insight is gained on the differing device architecture‐dependent mechanisms that determine the magnitude of drain current density in both types of devices when biased in the saturation region.
Jiamusi pulsar observations
Authors: Wang P. F. , Han J. L. , Han L. , Zhang J. H. , Li J. Q. , Wang C. , Han J. , Wang T. , Gao X. Y.
Published: August 2018

Context. Pulsars scintillate. Dynamic spectra show brightness variation of pulsars in the time and frequency domain. Secondary spectra demonstrate the distribution of fluctuation power in the dynamic spectra.

Aims. Dynamic spectra strongly depend on observational frequencies, but were often observed at frequencies lower than 1.5 GHz. Scintillation observations at higher frequencies help to constrain the turbulence feature of the interstellar medium over a wide frequency range and can detect the scintillations of more distant pulsars.

Methods. Ten pulsars were observed at 2250 MHz (S-band) with the Jiamusi 66 m telescope to study their scintillations. Their dynamic spectra were first obtained, from which the decorrelation bandwidths and timescales of diffractive scintillation were then derived by autocorrelation. Secondary spectra were calculated by forming the Fourier power spectra of the dynamic spectra.

Results. Most of the newly obtained dynamic spectra are at the highest frequency or have the longest time span of any published data for these pulsars. For PSRs B0540 + 23, B2324 + 60, and B2351 + 61, these were the first dynamic spectra ever reported. The frequency dependence of the scintillation parameters indicates that the intervening medium can rarely be ideally turbulent with a Kolmogorov spectrum. The thin-screen model worked well at S-band for the scintillation of PSR B1933 + 16. Parabolic arcs were detected in the secondary spectra of three pulsars, PSRs B0355 + 54, B0540 + 23, and B2154 + 40, all of which were asymmetrically distributed. The inverted arclets of PSR B0355 + 54 were seen to evolve along the main parabola within a continuous observing session of 12 h, from which the angular velocity of the pulsar was estimated. This was consistent with the measurement by very long baseline interferometry.
Recent Progress in σ-Bond Cross-Exchange Reactions to Access Diverse Silacycles
Authors: Zhao Dongbing , Zhao Wen-Tao , Gao Fang
Published: August 2018

The σ-bond cross-exchange reaction, which involves cleavage and subsequent exchange between different nonpolar σ-bonds, constitutes an attractive protocol for rapid access to organic skeletons with 100% atom economy. Herein, we give a brief summary of recent achievements in this approach for the synthesis of diverse silacycles, highlighting our recent advances in the first intermolecular σ-bond exchange between C–C bonds of cyclopropenones and C–Si bonds of (benzo)silacyclobutanes.

1 Introduction

2 σ-Bond Exchange-Reaction of Benzocyclobutanones to Silacycles

3 σ-Bond Exchange-Reaction of Ethyl Cyclopropylideneacetates to Silacycles

4 σ-Bond Exchange-Reaction of Cyclopropenones to Silacycles

5 Conclusion
Characterization of pulsed ultrasound using optical detection in Raman-Nath regime
Authors: Jia Lecheng , Xue Bin , Chen Shili , Wu Hanzhong , Yang Xiaoxia , Zhai Jingsheng , Zeng Zhoumo
Published: August 2018

In this paper, we describe an optical detection method for the characterization of pulsed ultrasound based on acousto-optic interaction. We deduce the relationship between the ultrasound and the diffracted light from the principle of acousto-optic diffraction in the Raman-Nath regime, which is verified experimentally. Five ultrasonic transducers with different central frequencies and different focusing types are measured to show the method’s performance regarding linearity, sound pressure measurement, phase measurement, frequency response, and spatial resolution. The experimental results show a good agreement with simulation data by CIVA (ultrasonic simulation software, M2M NDT, Inc.) and the pulse-echo method.
A laboratory X-ray microscopy study of cracks in on-chip interconnect stacks of integrated circuits
Authors: Kutukova K. , Niese S. , Sander C. , Standke Y. , Gluch J. , Gall M. , Zschech E.
Published: August 2018

Laboratory transmission X-ray microscopy with a spatial resolution of about 100 nm was used to image 3D interconnect structures and failures in microchips during mechanical loading, applied by a microDouble Cantilever Beam (micro-DCB) test. High-resolution 3D image sequences based on nano X-ray computed tomography (nano-XCT) are used to visualize crack opening and propagation in fully integrated multilevel on-chip interconnect structures of integrated circuits. The nondestructive investigation of sub-micron cracks during the in-situ micro-DCB test allows one to identify the weakest layers and interfaces, to image delamination along Cu/dielectric interfaces (adhesive failure) and fracture in dielectrics (cohesive failure), as well as to evaluate the robustness of Backend-of-Line stacks against process-induced thermomechanical stress.
Irregular conformal blocks and connection formulae for Painlevé V functions
Authors: Lisovyy O. , Nagoya H. , Roussillon J.
Published: August 2018

We prove a Fredholm determinant and short-distance series representation of the Painlevé V tau function τt associated with generic monodromy data. Using a relation of τt to two different types of irregular c = 1 Virasoro conformal blocks and the confluence from Painlevé VI equation, connection formulas between the parameters of asymptotic expansions at 0 and i∞ are conjectured. Explicit evaluations of the connection constants relating the tau function asymptotics as t → 0, +∞, i∞ are obtained. We also show that irregular conformal blocks of rank 1, for arbitrary central charge, are obtained as confluent limits of the regular conformal blocks.
Nonlinear shear flow-modified dust ion acoustic waves
Authors: Saleem H.
Published: August 2018

Nonlinear equations for the modified dust ion acoustic waves are solved analytically in the small amplitude limit in a plasma having field-aligned shear flow of ions relative to electrons, while the heavy dust fluid is assumed to be stationary. Landau damping is negligibly small in this case because ion number density is larger than that of the electrons, and hence parallel phase speed of dust ion acoustic waves becomes greater than ion thermal speed. As a result, the non-resonant unstable electrostatic mode grows rapidly when the instability condition is satisfied. On the other hand in the nonlinear regime, the waves can produce dipolar vortices whose size will depend upon the scale size of the shear in the zero order flow velocity and density ratios of the species. Here, a general theoretical model is presented, which is applicable to dusty plasmas of planetary magnetospheres, comets, and inter-stellar clouds.
Upgrades to the in-vessel calibration light source on JET
Authors: Conway N. J. , Cackett A. J. , Maggi C. F. , Meigs A. G. , Zastrow K.-D. , Biewer T. M. , Hillis D. L.
Published: August 2018

Since 2010, an in-vessel calibration light source (ICLS) has been used periodically on JET to calibrate a range of diagnostics at UV, visible, and IR wavelengths. During shutdowns, the ICLS (which is essentially an integrating sphere) is positioned within the vacuum vessel by the remote handling (RH) system. Following the 2013 calibration runs, several changes were made to improve the efficiency and quality of the calibrations. Among these was the replacement of a 20 m “umbilical” cable which carried power and other electrical signals through a vessel port to/from a control cubicle. A lightweight 2 m cable now plugs directly into a single connector on the RH manipulator system, greatly reducing the time required for deployment and improving operational flexibility; e.g., the vessel access “floor” no longer needs to be installed. This change also means the system would be compatible with calibrations after a high neutron-fluence period of operation. An on-board micro-spectrometer now allows for real-time verification of the emitted spectrum. Finally, new “baffles” were designed and installed within the integrating sphere itself, greatly improving the spectral radiance uniformity at non-normal viewing angles (necessary due to orientation uncertainties with the RH system).
Temperature dependence of the Dzyaloshinskii-Moriya interaction in Pt/Co/Cu thin film heterostructures
Authors: Schlotter Sarah , Agrawal Parnika , Beach Geoffrey S. D.
Published: August 2018

Magnetic materials that exhibit chiral domain walls are of great interest for spintronic devices. In this work, we examine the temperature-dependent behavior of the Dzyaloshinskii-Moriya interaction (DMI) in Pt/Co/Cu thin film heterostructures. We extract the DMI strength, D, from static domain spacing analysis between 300 K and 500 K and compare its temperature dependence to that of the magnetic anisotropy, Ku, and saturation magnetization, Ms. Consistent with expected scaling in thin films, Ms exhibits Bloch-law temperature scaling and Ku scales as Ms2.1±0.1. However, D varies more strongly with temperature than expected, scaling as D∝Ms4.9±0.7, indicating that interfacial DMI is more sensitive to thermal fluctuations than bulk magnetic properties. We suggest that this may be related to the temperature dependence of locally induced magnetic moments in the Pt underlayer and the 3d-5d orbital interactions at the interface. While we observe stable domain widths in the studied temperature range, a strongly temperature dependent DMI may have significant consequences for potential devices based on the chiral domain wall or skyrmion motion.
Shedding of multiple sessile droplets by an airflow
Authors: Razzaghi A. , Banitabaei S. A. , Amirfazli A.
Published: August 2018

Shedding of multiple sessile droplets by an airflow in triangle, square, reversed triangle, and diamond arrangements is examined. The interaction of the flow around the sessile droplets is found to be influenced by the type of the arrangement and the spacing of the sessile droplets in each arrangement. Consequently, the minimum airflow velocity required to shed the droplet (Ucr) also changes. Water droplets of 5 and 10 μl were used on both hydrophilic and hydrophobic surfaces in a laminar airflow. In general, at the minimum spacing, the highest increase in Ucr for the upstream droplet(s) (compared with that for a single droplet) was observed for the triangle arrangement (∼40%), followed by the diamond, reversed triangle, and square arrangements. Increasing the spacing resulted in a reduction of the Ucr for all the arrangements, except for the square arrangement where increasing the spacing does not show a substantial change in Ucr. Neither the size of the droplets nor the wettability of the substrate was found to significantly affect the amount of the change in the Ucr.
An ultra-broadband single-component fractional-order capacitor using MoS2-ferroelectric polymer composite
Authors: Agambayev Agamyrat , Farhat Mohamed , Patole Shashikant P. , Hassan Ali H. , Bagci Hakan , Salama Khaled N.
Published: August 2018

The phase angle of a fractional-order capacitor's (FOC) impedance has a constant value between −90° and 0°. Maintaining this value over a broad frequency band is of utmost importance since it increases the applicability of the electrical circuit that employs the fractional-order capacitor (FOC). In this work, a molybdenum disulfide (MoS2)-ferroelectric polymer composite is used to design/fabricate an FOC. The resulting FOC's bandwidth of operation, which is defined as the frequency band where the variation in the phase angle is no more than ±4°, is five decades between 100 Hz and 10 MHz, a 3 decades improvement over the best reported state of the art. The value of the constant phase angle can be tuned from −80° to −58° by changing the type of the ferroelectric polymer in the composite and the volume ratio of MoS2. The results presented in this work demonstrate the potential of the FOCs fabricated using MoS2-ferroelectric polymer composites in robust and accurate realization of various electrical systems.
Optimizing co-operative multi-environment dynamics in a dark-state-enhanced photosynthetic heat engine
Authors: Wertnik Melina , Chin Alex , Nori Franco , Lambert Neill
Published: August 2018

We analyze the role of coherent, non-perturbative system-bath interactions in a photosynthetic heat engine. Using the reaction-coordinate formalism to describe the vibrational phonon-environment in the engine, we analyze the efficiency around an optimal parameter regime predicted in earlier studies. We show that, in the limit of high-temperature photon irradiation, the phonon-assisted population transfer between bright and dark states is suppressed due to dephasing from the photon environment, even in the Markov limit where we expect the influence of each bath to have an independent and additive effect on the dynamics. Manipulating the phonon bath properties via its spectral density enables us to identify both optimal low- and high-frequency regimes where the suppression can be removed. This suppression of transfer and its removal suggests that it is important to consider carefully the non-perturbative and cooperative effects of system-bath environments in designing artificial photosynthetic systems and also that manipulating inter-environmental interactions could provide a new multidimensional “lever” by which photocells and other types of quantum devices can be optimized.
Magnetic and martensitic transformations in Ni48Co2Mn35In15 melt-spun ribbons
Authors: Pandey Sudip , Quetz Abdiel , Ibarra-Gaytan P. J. , Sanchez-Valdes C. F. , Aryal Anil , Dubenko Igor , Sanchez Llamazares J. L. , Stadler Shane , Ali Naushad
Published: August 2018

As-solidified Ni48Co2Mn35In15 ribbons were prepared through the melt-spinning method, and their structural, magnetic, magnetocaloric properties, and martensitic transformations were investigated. The inverse martensitic transformation temperature (TA=325 K) for the melt spun ribbons shifted by 55 K to higher temperature relative to that of the bulk material (TA = 270 K). The working temperature range of the magnetic entropy change (ΔSM) in Ni48Co2Mn35In15 ribbons has been significantly expanded relative to that of bulk. The roles of the magnetostructural transitions on the magneto-responsive properties of the ribbons are discussed.
Investigation of the tricritical point of the ising ferromagnet URhGe by angle-resolved measurements
Authors: Nakamura Shota , Kittaka Shunichiro , Sakakibara Toshiro , Shimizu Yusei , Kono Yohei , Haga Yoshinori , Pospíšil Jiří , Yamamoto Etsuji
Published: August 2018

Magneto-caloric effect and specific heat measurements have been performed on a single-crystalline sample of URhGe, an orthorhombic Ising ferromagnet with a magnetization easy axis c, in high-precision in-situ magnetic field along the b axis. In this compound, first order planes (ferromagnetic wing structure) appear below tri-critical point in the T-Hc-Hb phase diagram. In the present study, we have succeeded in observing a peak of magneto-caloric effect up to 2-3 K, indicating that the tri-critical point is above 2-3 K at least. The result of the specific heat measurements, however, suggests the behavior of the transition does not quantitatively change in wide temperature range between 1.5 and 10 K. The lack of the change makes it difficult to decide the position of TCP, which may locate above 2-3 K at least, clearly from the specific heat measurements.
Magnetoelectric spin-glass transition(s) in pure and disordered BiFeO3
Authors: Kumar Arun , Pandey Dhananjai
Published: August 2018

We present here the results of a comparative study of the spin glass (SG) transition in pure and disordered (0.80BiFeO3-0.20BaTiO3 or 0.80BF-0.20BT) BiFeO3. It is shown that the anomalous frequency dependence of ac susceptibility in the SG phase of BF is not linked with the spin cycloid as it is present even after its destruction in 0.80BF-0.20BT solid solution. Our neutron scattering studies on disordered BF reveal the presence of long-range ordered (LRO) antiferromagnetic (AFM) peak and decrease in the ordered magnetic moment from the overall Brillouin function behaviour around the SG transition suggesting that some spin components are getting detached from the AFM phase. Further, the SG transition is accompanied with anomalies in the unit cell volume and ferroelectric polarization around the SG transition temperature, highlighting the presence of magnetoelastic and magnetoelectric couplings, respectively. All these results suggest that the SG phase of BF is intrinsic to the system and is not due to nano-sized impurities.
Pressure effects on Ce-based Kondo approximant crystal
Authors: Sawano Takuya , Shinagawa Yuta , Shiino Takayuki , Imura Keiichiro , Deguchi Kazuhiko , Sato Noriaki K.
Published: August 2018

The Ag–In–Ce alloy is an approximant crystal to a Tsai-type quasicrystal and exhibits heavy-fermion (Kondo) physics. This new type of Kondo material exhibits spin-glass ordering below the freezing temperature Tf ∼ 0.3 K at ambient pressure. Here we investigated the effect of hydrostatic pressure on the Ag–In–Ce alloy. Spin-glass features, such as the frequency-dependent cusp near Tf in the ac magnetic susceptibility curve, were observed even under external pressure. In addition, the C/T value (where C is the specific heat) increased with decreasing temperature and exhibited a broad peak above Tf. The Tf increased as the pressure increased up to its highest value in the experiment (approximately 2.6 GPa).
Metal-insulator transition in Mott-insulator FePS3
Authors: Tsurubayashi M. , Kodama K. , Kano M. , Ishigaki K. , Uwatoko Y. , Watanabe T. , Takase K. , Takano Y.
Published: August 2018

We have prepared single crystal of layered Mott-insulator FePS3 and investigated the pressure dependence of the electrical resistivity. FePS3 shows a metal-insulator transition between 10 and 11 GPa. In the insulating region, the activation energy increases continuously with decreasing the pressure and it is well extrapolated to the ambient pressure value. In the metallic region, the electrical resistivity is propotional to the square of the temperature within 50 to 100 K.
Monitoring the effect of asymmetrical vertical strain on Janus single layers of MoSSe via vibrational spectrum
Authors: Kandemir A. , Peeters F. M. , Sahin H.
Published: August 2018

Using first principles calculations, we study the structural and phononic properties of the recently synthesized Janus type single layers of molybdenum dichalcogenides. The Janus MoSSe single layer possesses 2H crystal structure with two different chalcogenide sides that lead to out-of-plane anisotropy. By virtue of the asymmetric structure of the ultra-thin Janus type crystal, we induced the out-of-plane anisotropy to show the distinctive vertical pressure effect on the vibrational properties of the Janus material. It is proposed that for the corresponding Raman active optical mode of the Janus structure, the phase modulation and the magnitude ratio of the strained atom and its first neighbor atom adjust the distinctive change in the eigen-frequencies and Raman activity. Moreover, a strong variation in the Raman activity of the Janus structure is obtained under bivertical and univertical strains. Not only eigen-frequency shifts but also Raman activities of the optical modes of the Janus structure exhibit distinguishable features. This study reveals that the vertical anisotropic feature of the Janus structure under Raman measurement allows us to distinguish which side of the Janus crystal interacts with the externals (substrate, functional adlayers, or dopants).
Boundary layer flow interaction with a permeable wall
Authors: Showkat Ali Syamir Alihan , Azarpeyvand Mahdi , Szőke Máté , Ilário da Silva Carlos Roberto
Published: August 2018

The interaction of a zero pressure gradient turbulent boundary layer flow with a rough permeable surface has been investigated experimentally. The flow interaction characteristics have been examined using a long flat plate equipped with several surface pressure transducers and pressure taps. Three types of porous materials with different porosities and permeability constants were used in these investigations. To reveal the behavior of turbulent flows over porous surfaces, measurements were performed for the boundary layer growth, energy content of the turbulent structure within the boundary layer, and surface pressure fluctuations, before, over, and after the porous test-section. The interaction of the flow with the porous substrate was found to significantly alter the energy cascade within the boundary layer. Results have also shown that the boundary layer interaction with the rough porous surfaces leads to an increase in the pressure fluctuations exerted on the wall, particularly at low frequencies. The near-field investigations have shown that the penetration of the boundary layer flow into the porous medium can generate an internal hydrodynamic field within the porous medium. This, in turn, reduces the frequency-energy content of the large boundary layer coherent structures and their spanwise correlation length. This study paves the way for further investigation into the interaction of the porous media with different flow fields and development of tailored porous treatments for improving the aerodynamic and aeroacoustic performance of different aero- and hydro-components.
A direct numerical simulation analysis of spherically expanding turbulent flames in fuel droplet-mists for an overall equivalence ratio of unity
Authors: Ozel Erol Gulcan , Hasslberger Josef , Klein Markus , Chakraborty Nilanjan
Published: August 2018

Three-dimensional direct numerical simulations with a modified single-step Arrhenius chemistry have been used to analyze spherically expanding n-heptane flames propagating into mono-sized fuel droplet mists for different droplet diameters and an overall equivalence ratio of unity. The evolutions of flame surface area and burned gas volume for both laminar and turbulent spherically expanding droplet flames have been compared to the corresponding gaseous stoichiometric premixed spherically expanding flames with the same initial burned gas radius. It has been found that the initial droplet diameter significantly affects the burned gas volume and flame area generation, which increase with decreasing droplet diameter for both laminar and turbulent cases. The droplet-flame interaction plays a key role in determining flame wrinkling under laminar conditions, which is reflected in a range of local curvatures for a given reaction progress variable isosurface, whereas each progress variable isosurface in spherically expanding laminar premixed flames exhibits a single value of curvature. The effect of droplet-induced curvature becomes less distinguishable from the flow-induced wrinkling for the turbulent cases considered here, but the reaction progress variable isosurfaces in droplet cases exhibit wider curvature probability density functions than in the corresponding turbulent premixed flame cases. It has been found that the heat release rate arises principally from premixed mode in small droplet cases, whereas the contribution of the non-premixed mode to the overall heat release rate increases with increasing droplet diameter and turbulence intensity.
Energy of dendritic avalanches in thin-film superconductors
Authors: Qureishy T. , Vestgården J. I. , Qviller A. J. , Fjellvåg A. S. , Meckbach J. M. , Torgovkin A. , Johansen T. H. , Ilin K. , Siegel M. , Maasilta I. , Mikheenko P.
Published: August 2018

A method for calculating stored magnetic energy in a thin superconducting film based on quantitative magneto-optical imaging is developed. Energy and magnetic moment are determined with these calculations for full hysteresis loops in a thin film of the superconductor NbN. Huge losses in energy are observed when dendritic avalanches occur. Magnetic energy, magnetic moment, sheet current and magnetic flux distributions, all extracted from the same calibrated magneto-optical images, are analyzed and discussed. Dissipated energy and the loss in moment when dendritic avalanches occur are related to each other. Calculating these losses for specific spatially-resolved flux avalanches is a great advantage, because of their unpredictable and non-reproducible nature. The relative losses in energy are much higher than the relative losses in moment.
Apparatus for dosing liquid water in ultrahigh vacuum
Authors: Balajka Jan , Pavelec Jiri , Komora Mojmir , Schmid Michael , Diebold Ulrike
Published: August 2018

The structure of the solid-liquid interface often defines the function and performance of materials in applications. To study this interface at the atomic scale, we extended an ultrahigh vacuum (UHV) surface-science chamber with an apparatus that allows bringing a surface in contact with ultrapure liquid water without exposure to air. In this process, a sample, typically a single crystal prepared and characterized in UHV, is transferred into a separate, small chamber. This chamber already contains a volume of ultrapure water ice. The ice is at cryogenic temperature, which reduces its vapor pressure to the UHV range. Upon warming, the ice melts and forms a liquid droplet, which is deposited on the sample. In test experiments, a rutile TiO2(110) single crystal exposed to liquid water showed unprecedented surface purity, as established by X-ray photoelectron spectroscopy and scanning tunneling microscopy. These results enabled us to separate the effect of pure water from the effect of low-level impurities present in the air. Other possible uses of the setup are discussed.
Four drug-sensitive subunits are required for maximal effect of a voltage sensor–targeted KCNQ opener
Authors: Wang Alice W. , Yau Michael C. , Wang Caroline K. , Sharmin Nazlee , Yang Runying Y. , Pless Stephan A. , Kurata Harley T.
Published: August 2018

KCNQ2-5 (Kv7.2–Kv7.5) channels are strongly influenced by an emerging class of small-molecule channel activators. Retigabine is the prototypical KCNQ activator that is thought to bind within the pore. It requires the presence of a Trp side chain that is conserved among retigabine-sensitive channels but absent in the retigabine-insensitive KCNQ1 subtype. Recent work has demonstrated that certain KCNQ openers are insensitive to mutations of this conserved Trp, and that their effects are instead abolished or attenuated by mutations in the voltage-sensing domain (VSD). In this study, we investigate the stoichiometry of a VSD-targeted KCNQ2 channel activator, ICA-069673, by forming concatenated channel constructs with varying numbers of drug-insensitive subunits. In homomeric WT KCNQ2 channels, ICA-069673 strongly stabilizes an activated channel conformation, which is reflected in the pronounced deceleration of deactivation and leftward shift of the conductance–voltage relationship. A full complement of four drug-sensitive subunits is required for maximal sensitivity to ICA-069673—even a single drug-insensitive subunit leads to significantly weakened effects. In a companion article (see Yau et al. in this issue), we demonstrate very different stoichiometry for the action of retigabine on KCNQ3, for which a single retigabine-sensitive subunit enables near-maximal effect. Together, these studies highlight fundamental differences in the site and mechanism of activation between retigabine and voltage sensor–targeted KCNQ openers.
Career Development and Organizational Support
Authors: Coetzee Melinde
Published: August 2018

The complexity of modern careers requires personal agency in managing career development and employability capital as personal resources for career success. Individuals’ employability capital also serves as a valuable resource for the sustainable performance of organizations. Individuals’ ability to proactively engage in career self-management behaviors through the use of a comprehensive range of self-regulatory capabilities, known as career metacapacities, contributes to their employability capital. Organizational career development supports initiatives that consider individuals’ proactivity in light of conditions that influence their motivational states, and availability of personal resources helps organizations benefit from individuals who bring information, knowledge, capacities, and relationship networks (i.e., employability capital) into their work that ultimately contribute to the organization’s capability to sustain performance in uncertain, highly competitive business markets. Career development support practices should embrace the individualization of modern-day careers, the need for whole-life management, and the multiple meanings that career success has for individuals.
Electronic Monitoring
Authors: Brancale Julie , Blomberg Thomas G. , Bales William D.
Published: August 2018

The movements of accused and convicted offenders in many countries around the world are increasingly being monitored with electronic supervision tools. Individuals can be placed on electronic monitoring (EM) by the justice system for numerous reasons and can be of varying risk levels. Currently, individuals are placed on EM as conditions of pretrial release, probation, and parole. EM is a versatile tool designed to aid correctional officers in their supervision of offenders sentenced to confinement or house arrest. There are many forms of EM devices that are designed to limit the freedom and monitor the movements of individuals to ensure they are in compliance with court-mandated restrictions. In general, EM is intended to be an alternative to detention in either jails or prisons and is an intermediate sanction that is more punitive than traditional probation but less punitive than imprisonment. The expanded use of EM in recent years is largely attributable to financial constraints and overcrowding experienced by many jails and prisons. However, the empirical research of the effectiveness and unintended consequences is limited. There are serious concerns that have yet to be addressed about possible net-widening associated with EM use and whether it truly is an effective alternative to incarceration.
The Magnetosphere of Saturn
Authors: Badman Sarah
Published: August 2018

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Planetary Science. Please check back later for the full article.

Saturn’s magnetosphere is the region of space surrounding Saturn that is controlled by the planetary magnetic field. Saturn’s magnetic field is aligned to within 1 degree of the rotation axis and rotates with a period of ~10.7 h. The magnetosphere is compressed on the dayside by the impinging solar wind, and stretched into a long magnetotail on the nightside. Its surface, the magnetopause, is located where the internal and external plasma and magnetic pressures balance. As a result of the pressure distributions, the magnetopause has a bimodal distribution of standoff distance at the sub-solar point and is flattened over the poles relative to the equator.

Radiation belts composed of trapped energetic electrons and protons are present in the inner magnetosphere. Their intensity is limited by the moons and rings that can absorb the energetic particles. The icy moons and rings, particularly the cryovolcanic moon Enceladus, are the main sources of mass in the form of water. When the water molecules are ionized they are confined to the equatorial plane by the rapidly rotating magnetic field. This mass-loading acts to distend the magnetic field lines from a dipolar configuration into a radially stretched magnetodisk, with an associated eastward-directed current. In situ measurements of plasma velocity indicate it generally lags behind the planetary rotation, introducing an azimuthal component of the magnetic field. Despite the alignment of the magnetic and rotation axes, so-called planetary period oscillations are ubiquitous in field and plasma measurements in the magnetosphere.

Radial transport of plasma involves the centrifugal interchange instability in the inner magnetosphere and magnetic reconnection in the middle and outer magnetosphere. This allows mass from the moons and rings to be lost from the system. The outermost regions of the magnetosphere are also influenced by the surrounding solar wind through magnetic reconnection and viscous interactions. Acceleration via reconnection or other processes, or scattering of plasma into the atmosphere leads to auroral emissions detected at radio, infrared, visible, and ultraviolet wavelengths.
Postdevelopment Theory
Authors: Matthews Sally J.
Published: August 2018

Postdevelopment theory is a compelling and controversial field of thought in contemporary development studies. It gained prominence during the 1990s, when it sparked fierce debate, but its influence has since waned somewhat. This chapter summarizes the contribution of postdevelopment theory to development studies and, more generally, to international studies. Postdevelopment theory’s key contribution was a stringent and multifaceted critique of the idea of development. The critique offered by postdevelopment thinkers went beyond other critical engagements with development theory, in that it sought to reject, rather than reform, development. The critique was strongly informed by concerns about Westernization and by an associated desire to validate, protect, and revive non-Western ways of life. Furthermore, postdevelopment theorists adopt a critical stance toward globalization, seeking to defend the local against the global. After reviewing postdevelopment theory’s radical critique of development, the article provides an overview of critical engagements with postdevelopment theory. Critics have been particularly concerned about postdevelopment theorists’ reluctance or inability to move beyond critique in order to clearly outline possible alternatives to development. While this critique is well founded, the article does describe the ways in which some of the recent work by postdevelopment writers has begun to take on a more constructive character. The chapter concludes that post-development theory is relevant not only to those interested in development theory, but also to all those interested in thinking of alternatives to the capitalist, industrialized way of life that has for so long been held up as an ideal toward which all should strive.
Effects of Illiteracy on the European Cross-Cultural Neuropsychological Test Battery (CNTB)
Authors: Nielsen T Rune
Published: August 2018

Objectives

Test performances of illiterate and literate immigrants were compared to investigate the effects of illiteracy on the European Cross-cultural Neuropsychological Test Battery (CNTB), and associations between test performance and participant characteristics were examined.

Method

Participants were 20 illiterate and 21 literate middle-aged and older Turkish immigrants (50–85 years) matched by age and gender that completed the CNTB as well as a number of demographic and medical questionnaires.

Results

No significant group differences or correlations between education, acculturation or health characteristics and test performances were found on 10 of 16 measures. Illiteracy status and participant characteristics affected measures of mental processing speed, executive function, and visuoconstruction.

Conclusions

The preliminary findings suggest that several of the measures in the CNTB may be valid for assessment of cognitive functioning in people who are illiterate when applied using available normative data. However, these findings need to be replicated in larger samples.