bluuebunny/crossref_metadata_2025 huggingface dataset:
Scalable single-step microfluidic production of single-core double emulsions with ultra-thin shells
Authors: Arriaga L. R. , Amstad E. , Weitz D. A.
Published: July 2015

We report a scalable single-step microfluidic technique for the production of monodisperse double emulsions with very thin shell thicknesses, of about 5% of the drop radius.
Three-dimensional structure and molecular dynamics studies of prorrenin/renin receptor: description of the active site
Authors: Sánchez-Guerrero E. , Hernández-Campos M. E. , Correa-Basurto J. , López-Sánchez P. , Tolentino-López L. E.
Published: July 2015

The recent finding of a specific receptor for prorrenin/renin (PRR) has brought new insights into the physiology of the renin–angiotensin–aldosterone system.
Synthesis and characterization of bifunctional dendrimers: preliminary use for the coating of gold surfaces and the proliferation of human osteoblasts (HOB)
Authors: de Jong Edwin R. , Deloch Nicole , Knoll Wolfgang , Turrin Cédric-Olivier , Majoral Jean-Pierre , Caminade Anne-Marie , Köper Ingo
Published: July 2015

Dendrimers having one dithiolane and ammonium or carboxylate functions have been synthesized for coating gold surfaces interacting with human osteoblasts.
One-dimensional CdS nanowires–CeO2 nanoparticles composites with boosted photocatalytic activity
Authors: Zhang Xin , Zhang Nan , Xu Yi-Jun , Tang Zi-Rong
Published: July 2015

The one-dimensional CdS nanowires–CeO2 nanoparticles composites exhibit enhanced visible-light-driven photoactivity toward selective reduction of nitroaromatics and water splitting to hydrogen.
Pyrimidinone: versatile Trojan horse in DNA photodamage?
Authors: Micheel Mathias , Ziegenbein Christian Torres , Gilch Peter , Ryseck Gerald
Published: July 2015

(6-4) Photolesions between adjacent pyrimidine DNA bases are prone to secondary photochemistry. It has been shown that singlet excited (6-4) moieties form Dewar valence isomers as well as triplet excitations. We here report on the triplet state of a minimal model for the (6-4) photolesion, 1-methyl-2(1H)-pyrimidinone. Emphasis is laid on its ability to abstract hydrogen atoms from alcohols and carbohydrates. Steady-state and time-resolved experiments consistently yield bimolecular rate constants of ∼104 M−1 s−1 for the hydrogen abstraction. The process also occurs intramolecularly as experiments on zebularine (1-(β-d-ribofuranosyl)-2(1H)-pyrimidinone) show.
Unveiling the hyperbolic thermal behaviour of poly(p-phenylene alkylene)s
Authors: Sauty Nicolas F. , Caire da Silva Lucas , Gallagher Caitlyn , Graf Robert , Wagener Kenneth B.
Published: July 2015

A series of poly(p-phenylene alkylene)s with methylene run lengths ranging from 8 to 40 were obtained by ADMET polymerization of symmetrical α,ω-diene monomers and subsequent exhaustive hydrogenation.
Improved hydrogen storage properties of MgH2by addition of Co2NiO nanoparticles
Authors: Juahir N. , Mustafa N. S. , Sinin A. M. , Ismail M.
Published: July 2015

The result showed that the addition of 10 wt% Co2NiO to the MgH2exhibits a lower onset desorption temperature. The dehydrogenation and rehydrogenation kinetics of MgH2+ 10 wt% Co2NiO were also improved compared to un-doped MgH2.
Growth of nano Ag@AgCl on (111) facets of Cu2O microcrystals with an enhanced photocatalytic activity
Authors: Liu Li , Lin Shuanglong , Hu Jinshan , Liang Yinghua , Cui Wenquan
Published: July 2015

A Ag@AgCl/Cu2O photocatalyst was prepared by directly growing Ag@AgCl nanoparticles on (111) facets of octahedral Cu2O via a facile precipitation in situ photoreduction method.
Cooling-induced formation of honeycomb patterns on pre-cast PMMA films at low temperatures
Authors: Sun Wei , Yang Fuqian
Published: July 2015

Surface patterns formed on pre-cast PMMA films. A typical AFM image shows the hexagon network.
Synthesis of 2-triazolyl-imidazo[1,2-a]pyridine through a one-pot three-component reaction using a nano copper oxide assisted click-catalyst
Authors: Bagdi Prasanta Ray , Basha R. Sidick , Khan Abu T.
Published: July 2015

The syntheses of 2-triazolyl imidazo[1,2-a]pyridine were accomplished through 5-exo dig cyclisation using 5 mol% nanocopper oxide together with 10 mol% sodium ascorbate as a click-catalyst in ethanol at 70 °C.
Hydrothermal synthesis of bimodal mesoporous MoS2 nanosheets and their hydrodeoxygenation properties
Authors: Wang Weiyan , Li Lu , Wu Kui , Zhu Guohua , Tan Song , Li Wensong , Yang Yunquan
Published: July 2015

Bimodal mesopore MoS2 nanosheets were successfully synthesized by adjusting the pH value and exhibited high HDO activity.
Structure characteristics and photoactivity of simultaneous luminescence and photocatalysis in CaV2O6 nanorods synthesized by the sol–gel Pechini method
Authors: Yu Ruijin , Xue Na , Huo Shuaidong , Li Junbo , Wang Jinyi
Published: July 2015

CaV2O6 nanorods show simultaneous luminescent and photocatalytic activities meaning that CaV2O6 could be a potential photoactive material with a layered structure constructed by line-arranged VO5 units.
Dual-shape memory effect in radiation crosslinked thermoplastic blends: fabrication, optimization and mechanisms
Authors: Shi Xiang , Wang Xuemei , Fu Chao , Ran Xianghai
Published: July 2015

Recently, as an important class of mechanically active smart materials, thermoplastic dual-shape memory polymers (SMPs) have attracted notable attention and can be fabricated in many different manufacturing techniques.
First-principles investigation of the structural and elastic properties of Be12Ti under high pressure
Authors: Liu X. K. , Zhou W. , Liu X. , Peng S. M.
Published: July 2015

The effects of pressure on the structural and elastic properties of Be12Ti were investigated by the generalized gradient approximation (GGA) with a Perdew–Burke–Ernzerhof (PBE) exchange-correlation function using density-functional theory.
Enhanced ferroelectric properties of electrospun poly(vinylidene fluoride) nanofibers by adjusting processing parameters
Authors: Abolhasani Mohammad Mahdi , Azimi Sara , Fashandi Hossein
Published: July 2015

This contribution investigates the ferroelectric properties and polymorphism evolution of poly(vinylidene fluoride) (PVDF) mats prepared through electrospinning solutions of PVDF in pure N,N-dimethylformamide (DMF) and DMF/acetone mixtures with different weight ratios.
Discovery of a series of 2-phenylnaphthalenes as firefly luciferase inhibitors
Authors: Bai Haixiu , Chen Wang , Wu Wenxiao , Ma Zhao , Zhang Huateng , Jiang Tianyu , Zhang Tianchao , Zhou Yubin , Du Lupei , Shen Yuemao , Li Minyong
Published: July 2015

A series of 2-phenylnaphthalenes as firefly luciferase inhibitors are reported. The most potent compound 5 showed good systemic inhibition in transgenic mice. Kinetic assay indicated 5 is competitive for aminoluciferin and noncompetitive for ATP.
Constructing real-time, wash-free, and reiterative sensors for cell surface proteins using binding-induced dynamic DNA assembly
Authors: Tang Yanan , Wang Zhixin , Yang Xiaolong , Chen Junbo , Liu Linan , Zhao Weian , Le X. Chris , Li Feng
Published: July 2015

A real-time, wash-free, and reiterative sensor is constructed for monitoring cell surface proteins using the principle of binding-induced DNA dynamic assembly.
Stepwise double excited-state proton transfer is not possible in 7-azaindole dimer
Authors: Crespo-Otero Rachel , Kungwan Nawee , Barbatti Mario
Published: July 2015

Topographical analysis of the dimer's excited state shows that internal conversion after first proton transfer blocks the stepwise process.
Three-dimensionally ordered porous TiNb2O7 nanotubes: a superior anode material for next generation hybrid supercapacitors
Authors: Li Hongsen , Shen Laifa , Wang Jie , Fang Shan , Zhang Yingxia , Dou Hui , Zhang Xiaogang
Published: July 2015

A novel hybrid supercapacitor is successfully constructed based on the 3D ordered porous TiNb2O7 electrode (anode) and graphene grass electrode (cathode). In combination with the advantages from the lithium ion batteries and supercapacitors, this device shows superior energy density and power density with improved cycling performances.
Carbon dot reduced bimetallic nanoparticles: size and surface plasmon resonance tunability for enhanced catalytic applications
Authors: Essner Jeremy B. , Laber Charles H. , Baker Gary A.
Published: July 2015

Carbon dots derived from citric acid pyrolysis were competent reductants and stabilizing agents in the eco-friendly preparation of Ag, Au, and bimetallic AuAg nanoparticles which presented plasmonic, size, and catalytic tunability.
The role of oxygen vacancies in improving the performance of CoO as a bifunctional cathode catalyst for rechargeable Li–O2 batteries
Authors: Gao Rui , Liu Lei , Hu Zhongbo , Zhang Peng , Cao Xingzhong , Wang Baoyi , Liu Xiangfeng
Published: July 2015

The effect of oxygen vacancies on the performance of CoO as a cathode catalyst for Li–O2 batteries has been investigated.
Retracted Article: Mesoporous amorphous FeOF nanococoons for high-rate and long-life rechargeable sodium-ion batteries
Authors: Fu Shi Yan , Li Yuan Zhi , Chu Wei , Yang Yi Mei , Tong Dong Ge , Le Zeng Qing
Published: July 2015

Mesoporous amorphous FeOF nanococoons exhibited high rate performance and long life as cathode materials for sodium-ion batteries.
Conjugated polymers with deep LUMO levels for field-effect transistors and polymer–polymer solar cells
Authors: Zhang Andong , Xiao Chengyi , Meng Dong , Wang Qiang , Zhang Xiaotao , Hu Wenping , Zhan Xiaowei , Wang Zhaohui , Janssen René A. J. , Li Weiwei
Published: July 2015

Three new diketopyrrolopyrrole-based conjugated polymers were developed with low-lying LUMO levels up to −4.4 eV for n-type field-effect transistors and polymer–polymer solar cells.
Examining the Echolalia Literature: Where Do Speech-Language Pathologists Stand?
Authors: Stiegler Lillian N.
Published: July 2015

Purpose

Echolalia is a common element in the communication of individuals with autism spectrum disorders. Recent contributions to the literature reflect significant disagreement regarding how echolalia should be defined, understood, and managed. The purpose of this review article is to give speech-language pathologists and others a comprehensive view of the available perspectives on echolalia.

Method

Published literature from the disciplines of behavioral intervention, linguistics, and speech-language intervention is discussed. Special areas of focus include operational definitions, rationales associated with various approaches, specific procedures used to treat or study echolalic behavior, and reported conclusions.

Conclusions

Dissimilarities in the definition and understanding of echolalia have led to vastly different approaches to management. Evidence-based practice protocols are available to guide speech-language interventionists in their work with individuals with autism spectrum disorders.
Design of optical multi/demultiplexers composed of bidirectional 2 × 2 switch elements for reducing component count
Authors: Obara H.
Published: July 2015

A component‐efficient design for optical multi/demultiplexers (OMDPXs) relying on 2 × 2 switch elements (SEs) with a bidirectional property is described for the first time. First, the observation is made that some 2 × 1 or 1 × 2 SEs used in conventional OMDPXs have been implemented with part of a 2 × 2 SE. A novel design of OMDPXs fully utilising the connection capability of 2 × 2 SEs is presented. The SE count in the design becomes virtually half of that in the conventional design because a 2 × 2 SE is equivalent to a pair of 2 × 1 and/or 1 × 2 SEs. Other basic characteristics such as insertion loss and cross‐talk are also approximated. Finally, the design provides an N × N optical switch composed of N(N − 1)/2 2 × 2 SEs instead of N2 for conventional optical cross‐bar switches, keeping the strictly non‐blocking capability unlike N‐stage planar switches, which are rearrangeably non‐blocking while composed of the same number of SEs as the design.
Folded meander line antenna for wireless M‐Bus in the VHF and UHF bands
Authors: Loutridis A. , John M. , Ammann M.J.
Published: July 2015

The first dual‐band printed monopole antenna for wireless M‐Bus and M2M applications with operation in the VHF and lower UHF bands is presented. The antenna operates at 169 and 433 MHz. The miniaturisation of the proposed compact antenna is based on a double‐sided meandering structure offering an easily controlled large frequency ratio. The antenna provides high total efficiency and gain in both bands. Measured and simulated results are reported.
Prognostic and health management for engineering systems: a review of the data‐driven approach and algorithms
Authors: Sutharssan Thamo , Stoyanov Stoyan , Bailey Chris , Yin Chunyan
Published: July 2015

Prognostics and health management (PHM) has become an important component of many engineering systems and products, where algorithms are used to detect anomalies, diagnose faults and predict remaining useful lifetime (RUL). PHM can provide many advantages to users and maintainers. Although primary goals are to ensure the safety, provide state of the health and estimate RUL of the components and systems, there are also financial benefits such as operational and maintenance cost reductions and extended lifetime. This study aims at reviewing the current status of algorithms and methods used to underpin different existing PHM approaches. The focus is on providing a structured and comprehensive classification of the existing state‐of‐the‐art PHM approaches, data‐driven approaches and algorithms.
Können psychometrische Tests den Erfolg im Auswahlgespräch zum Medizinstudium vorhersagen? Eine Querschnittsstudie an einer deutschen Hochschule
Authors: Kötter T. , Obst K. , Brüheim L. , Eisemann N. , Voltmer E. , Katalinic A.
Published: July 2015

Ziel der Studie Die Abiturnote ist bei der Vergabe von Medizinstudienplätzen das Hauptauswahlkriterium. Für den Studienerfolg scheint sie ein zuverlässiger Prädiktor zu sein. Ihr Einsatz als alleiniges Auswahlkriterium steht jedoch in der Kritik. An einigen Hochschulen sind Auswahlgespräche Teil des Auswahlverfahrens (AdH). Diese sind jedoch zeitaufwändig und von unklarer Validität. Der (zusätzliche) Einsatz geeigneter psychometrischer Instrumente könnte den Aufwand verringern und die Validität erhöhen. Mit dieser Studie soll untersucht werden, inwieweit psychometrische Instrumente das Ergebnis des Auswahlgespräches vorhersagen bzw. unabhängige Information beinhalten.

Methodik Es handelt sich um eine Querschnittstudie zum Zusammenhang der Ergebnisse psychometrischer Testungen mit denen des Auswahlgespräches im Rahmen des AdH. Als Zielgröße wurde die Punktzahl des Auswahlgespräches verwendet. An Instrumenten wurden das NEO-Fünf-Faktoren-Inventar, die Hospital Anxiety and Depression Scale (HADS) und der Fragebogen zur Ermittlung arbeitsbezogener Verhaltens- und Erlebensmuster (AVEM) verwendet.

Ergebnisse Es zeigte sich ein statistisch signifikanter Zusammenhang mit dem Ergebnis des mündlichen Auswahlgespräches für die Dimension Lebenszufriedenheit des AVEM und den Summenscore der Subskala Depressivität der HADS. Zudem erzielten diejenigen TeilnehmerInnen ein besseres Ergebnis im Auswahlgespräch, die vorher kein Bewerbungstraining absolviert hatten.

Schlussfolgerung Die verwendeten Instrumente können Auswahlgespräche nicht ersetzen, da sie etwas anderes messen. Abzuwarten bleibt, ob die gewählten Parameter Studienerfolg vorhersagen.
Modeling the dark current histogram induced by gold contamination in complementary-metal-oxide-semiconductor image sensors
Authors: Domengie F. , Morin P. , Bauza D.
Published: July 2015

We propose a model for dark current induced by metallic contamination in a CMOS image sensor. Based on Shockley-Read-Hall kinetics, the expression of dark current proposed accounts for the electric field enhanced emission factor due to the Poole-Frenkel barrier lowering and phonon-assisted tunneling mechanisms. To that aim, we considered the distribution of the electric field magnitude and metal atoms in the depth of the pixel. Poisson statistics were used to estimate the random distribution of metal atoms in each pixel for a given contamination dose. Then, we performed a Monte-Carlo-based simulation for each pixel to set the number of metal atoms the pixel contained and the enhancement factor each atom underwent, and obtained a histogram of the number of pixels versus dark current for the full sensor. Excellent agreement with the dark current histogram measured on an ion-implanted gold-contaminated imager has been achieved, in particular, for the description of the distribution tails due to the pixel regions in which the contaminant atoms undergo a large electric field. The agreement remains very good when increasing the temperature by 15 °C. We demonstrated that the amplification of the dark current generated for the typical electric fields encountered in the CMOS image sensors, which depends on the nature of the metal contaminant, may become very large at high electric field. The electron and hole emissions and the resulting enhancement factor are described as a function of the trap characteristics, electric field, and temperature.
Ionic gel as gate dielectric for the easy characterization of graphene and polymer field-effect transistors and electrochemical resistance modification of graphene
Authors: Kettner Michel , Vladimirov Ilja , Strudwick Andrew J. , Schwab Matthias Georg , Weitz R. Thomas
Published: July 2015

In order to judge the usability of novel semiconductors for field-effect transistors (FETs), fast tools for the assessment of relevant electrical transistor parameters are necessary. We discuss here the use of an ionic gel (IG) as gate material that allows the quick fabrication of, for example, graphene FETs. Our IG-FETs show excellent performance. For example, IG-gated FETs have a charge carrier mobility of 2000 cm2/Vs, which is 5 times larger than that previously reported in similar devices. Using cyclic voltammetry and electrochemical impedance spectroscopy in a detail previously not shown, we furthermore investigate the gating mechanism of as-fabricated CVD-grown graphene FETs and compare it with IG gated FETs based on regioregular poly(3-hexylthiophene) (rr-P3HT). Consistent with literature, we find that, while IG-based graphene transistors are gated electrostatically, IG-gated rr-P3HT transistors work via electrochemical doping. IGs and our presented electrical measurements will allow to judge the electrical quality and gating mechanism also of novel semiconductors. Finally, to the best of our knowledge, we are the first to show that with the aid of IGs, graphene can be functionalized electrochemically with a concomitant variation in conductance of more than an order of magnitude.
Driven assembly with multiaxial fields: Creating a soft mode in assemblies of anisometric induced dipoles
Authors: Martin James E. , van Swol Frank
Published: July 2015

In this paper, we show that multiaxial fields can induce time-averaged, noncentrosymmetric interactions between particles having polarization anisotropy, yet the multiaxial field itself does not exert either a force or a torque on an isolated particle. These induced interactions lead to particle assemblies whose energy is strongly dependent on both the translational and orientational degrees of freedom of the system. The situation is similar to a collection of permanent dipoles, but the symmetry of the time-averaged interaction is quite distinct, and the scale of the system energy can be dynamically controlled by the magnitude of the applied multiaxial field. In this paper, the case of polarizable rods is considered in detail, and it is suggested that collections of rods embedded in spheres can be used to create a material with a dynamically tunable magnetic permeability or dielectric permittivity. We report on Monte Carlo simulations performed to investigate the behavior of assemblies of both multiaxial-field induced dipoles and permanent dipoles arranged onto two-dimensional lattices. The ground state of the induced dipoles is an orientational soft mode of aligned dipoles, whereas that of the permanent dipoles is a vortex state.
On the isotropic Raman spectrum of Ar2 and how to benchmark ab initio calculations of small atomic clusters: Paradox lost
Authors: Chrysos Michael , Dixneuf Sophie , Rachet Florent
Published: July 2015

This is the long-overdue answer to the discrepancies observed between theory and experiment in Ar2 regarding both the isotropic Raman spectrum and the second refractivity virial coefficient, BR [Gaye et al., Phys. Rev. A 55, 3484 (1997)]. At the origin of this progress is the advent (posterior to 1997) of advanced computational methods for weakly interconnected neutral species at close separations. Here, we report agreement between the previously taken Raman measurements and quantum lineshapes now computed with the employ of large-scale CCSD or smartly constructed MP2 induced-polarizability data. By using these measurements as a benchmark tool, we assess the degree of performance of various other ab initio computed data for the mean polarizability α, and we show that an excellent agreement with the most recently measured value of BR is reached. We propose an even more refined model for α, which is solution of the inverse-scattering problem and whose lineshape matches exactly the measured spectrum over the entire frequency-shift range probed.
Simple scalings for various regimes of electron acceleration in surface plasma waves
Authors: Riconda C. , Raynaud M. , Vialis T. , Grech M.
Published: July 2015

Different electron acceleration regimes in the evanescent field of a surface plasma wave are studied by considering the interaction of a test electron with the high-frequency electromagnetic field of a surface wave. The non-relativistic and relativistic limits are investigated. Simple scalings are found demonstrating the possibility to achieve an efficient conversion of the surface wave field energy into electron kinetic energy. This mechanism of electron acceleration can provide a high-frequency pulsed source of relativistic electrons with a well defined energy. In the relativistic limit, the most energetic electrons are obtained in the so-called electromagnetic regime for surface waves. In this regime, the particles are accelerated to velocities larger than the wave phase velocity, mainly in the direction parallel to the plasma-vacuum interface.
Mapping the magnetic and crystal structure in cobalt nanowires
Authors: Cantu-Valle Jesus , Betancourt Israel , Sanchez John E. , Ruiz-Zepeda Francisco , Maqableh Mazin M. , Mendoza-Santoyo Fernando , Stadler Bethanie J. H. , Ponce Arturo
Published: July 2015

Using off-axis electron holography under Lorentz microscopy conditions to experimentally determine the magnetization distribution in individual cobalt (Co) nanowires, and scanning precession-electron diffraction to obtain their crystalline orientation phase map, allowed us to directly visualize with high accuracy the effect of crystallographic texture on the magnetization of nanowires. The influence of grain boundaries and disorientations on the magnetic structure is correlated on the basis of micromagnetic analysis in order to establish the detailed relationship between magnetic and crystalline structure. This approach demonstrates the applicability of the method employed and provides further understanding on the effect of crystalline structure on magnetic properties at the nanometric scale.
The electronic structure of VO in its ground and electronically excited states: A combined matrix isolation and quantum chemical (MRCI) study
Authors: Hübner Olaf , Hornung Julius , Himmel Hans-Jörg
Published: July 2015

The electronic ground and excited states of the vanadium monoxide (VO) molecule were studied in detail. Electronic absorption spectra for the molecule isolated in Ne matrices complement the previous gas-phase spectra. A thorough quantum chemical (multi-reference configuration interaction) study essentially confirms the assignment and characterization of the electronic excitations observed for VO in the gas-phase and in Ne matrices and allows the clarification of open issues. It provides a complete overview over the electronically excited states up to about 3 eV of this archetypical compound.
Exponential stability of spherically symmetric solutions for compressible viscous micropolar fluid
Authors: Huang Lan , Lian Ruxu
Published: July 2015

This paper is concerned with the dynamics for the Navier-Stokes for a viscous micropolar fluid in bounded annular domains in R3. We prove that spherically symmetric solutions decay to a constant state exponentially as time goes to infinity.
The influence of different mask aperture on the open-circuit voltage measurement of perovskite solar cells
Authors: Xu Xin , Shi Jiangjian , Wu Huijue , Yang Yueyong , Xiao Junyan , Luo Yanhong , Li Dongmei , Meng Qingbo
Published: July 2015

We studied the influence of different mask apertures on the open-circuit voltage measurement of perovskite solar cells. Aperture masks with different sizes were equipped to control the proportion of dark-state region. Statistical results of photovoltaic parameters, ideality factor, and reverse saturation current density revealed that different mask apertures would affect the J-V measurement results, especially the open-circuit voltage. A double diode model simulation together with the impedance spectroscopy and transient photovoltage decay measurement has been further employed to analyze the reasons and found that the mask with inappropriate shading, which is smaller than the cells active area, will introduce excess charge transfer and recombination pathways, thus lead to an underestimate of open-circuit voltage. This work provides a promising route towards a more accurate J-V measurement of perovskite solar cells.
Plasma column and nano-powder generation from solid titanium by localized microwaves in air
Authors: Popescu Simona , Jerby Eli , Meir Yehuda , Barkay Zahava , Ashkenazi Dana , Mitchell J. Brian A. , Le Garrec Jean-Luc , Narayanan Theyencheri
Published: July 2015

This paper studies the effect of a plasma column ejected from solid titanium by localized microwaves in an ambient air atmosphere. Nanoparticles of titanium dioxide (titania) are found to be directly synthesized in this plasma column maintained by the microwave energy in the cavity. The process is initiated by a hotspot induced by localized microwaves, which melts the titanium substrate locally. The molten hotspot emits ionized titanium vapors continuously into the stable plasma column, which may last for more than a minute duration. The characterization of the dusty plasma obtained is performed in-situ by small-angle X-ray scattering (SAXS), optical spectroscopy, and microwave reflection analyses. The deposited titania nanoparticles are structurally and morphologically analyzed by ex-situ optical and scanning-electron microscope observations, and also by X-ray diffraction. Using the Boltzmann plot method combined with the SAXS results, the electron temperature and density in the dusty plasma are estimated as ∼0.4 eV and ∼1019 m−3, respectively. The analysis of the plasma product reveals nanoparticles of titania in crystalline phases of anatase, brookite, and rutile. These are spatially arranged in various spherical, cubic, lamellar, and network forms. Several applications are considered for this process of titania nano-powder production.
Nature of radiation-induced defects in quartz
Authors: Wang Bu , Yu Yingtian , Pignatelli Isabella , Sant Gaurav , Bauchy Mathieu
Published: July 2015

Although quartz (α-form) is a mineral used in numerous applications wherein radiation exposure is an issue, the nature of the atomistic defects formed during radiation-induced damage has not been fully clarified. Especially, the extent of oxygen vacancy formation is still debated, which is an issue of primary importance as optical techniques based on charged oxygen vacancies have been utilized to assess the level of radiation damage in quartz. In this paper, molecular dynamics simulations are applied to study the effects of ballistic impacts on the atomic network of quartz. We show that the defects that are formed mainly consist of over-coordinated Si and O, as well as Si–O connectivity defects, e.g., small Si–O rings and edge-sharing Si tetrahedra. Oxygen vacancies, on the contrary, are found in relatively low abundance, suggesting that characterizations based on E′ centers do not adequately capture radiation-induced structural damage in quartz. Finally, we evaluate the dependence on the incident energy, of the amount of each type of the point defects formed, and quantify unambiguously the threshold displacement energies for both O and Si atoms. These results provide a comprehensive basis to assess the nature and extent of radiation damage in quartz.
Femtosecond upconverted photocurrent spectroscopy of InAs quantum nanostructures
Authors: Yamada Yasuhiro , Tex David M. , Kamiya Itaru , Kanemitsu Yoshihiko
Published: July 2015

The carrier upconversion dynamics in InAs quantum nanostructures are studied for intermediate-band solar-cell applications via ultrafast photoluminescence and photocurrent (PC) spectroscopy based on femtosecond excitation correlation (FEC) techniques. Strong upconverted PC-FEC signals are observed under resonant excitation of quantum well islands (QWIs), which are a few monolayer-thick InAs quantum nanostructures. The PC-FEC signal typically decays within a few hundred picoseconds at room temperature, which corresponds to the carrier lifetime in QWIs. The photoexcited electron and hole lifetimes in InAs QWIs are evaluated as functions of temperature and laser fluence. Our results provide solid evidence for electron–hole–hole Auger process, dominating the carrier upconversion in InAs QWIs at room temperature.
Dependence of device performance on the thickness of compact TiO2 layer in perovskite/TiO2 planar heterojunction solar cells
Authors: Wu Runsheng , Yang Bingchu , Xiong Jian , Cao Chenghao , Huang Yulan , Wu Fanying , Sun Jia , Zhou Conghua , Huang Han , Yang Junliang
Published: July 2015

Planar heterojunction perovskite solar cells (PHJ-PSCs) based on CH3NH3PbI3/TiO2 with high-quality CH3NH3PbI3 films were fabricated by two-step interdiffusion technology. The photovoltaic performance of PHJ-PSCs, including short-circuit-current (Jsc) and open-circuit-voltage (Voc), was found to be strongly dependent on the thickness of TiO2 layer. The largest Jsc was obtained at an optimized TiO2 thickness of 65 nm, resulting in a moderate power conversion efficiency (PCE) of 8.40% with a device structure of fluorine doped SnO2/compact TiO2/CH3NH3PbI3/Spiro-MeOTAD/Ag. A thicker compact TiO2 film could lead to a lower Voc, and the physical mechanism between the Voc and the thickness of compact TiO2 layer was disclosed.
Confocal fluorescence microscopy: An ultra-sensitive tool used to evaluate intracellular antiretroviral nano-drug delivery in HeLa cells
Authors: Mandal Subhra , Zhou You , Shibata Annemarie , Destache Christopher J.
Published: July 2015

In the last decade, confocal fluorescence microscopy has emerged as an ultra-sensitive tool for real-time study of nanoparticles (NPs) fate at the cellular-level. According to WHO 2007 report, Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) is still one of the world’s major health threats by claiming approximately 7,000 new infections daily worldwide. Although combination antiretroviral drugs (cARV) therapy has improved the life-expectancy of HIV-infected patients, routine use of high doses of cARV has serious health consequences and requires complete adherence to the regimen for success. Thus, our research goal is to fabricate long-acting novel cARV loaded poly(lactide-co-glycolic acid) (PLGA) nanoparticles (cARV-NPs) as drug delivery system. However, important aspects of cARV-NPs that require special emphasis are their cellular-uptake, potency, and sustained drug release efficiency over-time. In this article, ultra-sensitive confocal microscopy is been used to evaluate the uptake and sustained drug release kinetics of cARV-NPs in HeLa cells. To evaluate with the above goal, instead of cARV-drug, Rhodamine6G dye (fluorescent dye) loaded NPs (Rho6G NPs) have been formulated. To correlate the Rhodamin6G release kinetics with the ARV release from NPs, a parallel HPLC study was also performed. The results obtained indicate that Rho6G NPs were efficiently taken up at low concentration (<500 ng/ml) and that release was sustained for a minimum of 4 days of treatment. Therefore, high drug assimilation and sustained release properties of PLGA-NPs make them an attractive vehicle for cARV nano-drug delivery with the potential to reduce drug dosage as well as the number of drug administrations per month.
Tailoring of magnetic properties of ultrathin epitaxial Fe films by Dy doping
Authors: Baker A. A. , Figueroa A. I. , van der Laan G. , Hesjedal T.
Published: July 2015

We report on the controlled modification of relaxation parameters and magnetic moments of epitaxial Fe thin films through Dy doping. Ferromagnetic resonance measurements show that an increase of Dy doping from 0.1% to 5% gives a tripling in Gilbert damping, and more importantly a strongly enhanced anisotropic damping that can be qualitatively understood through the slow-relaxing impurity model. X-ray magnetic circular dichroism measurements show a pronounced suppression of the orbital moment of the Fe with Dy doping, leading to an almost threefold drop in the orbital to spin moment ratio, ml/ms. Doping with Dy can therefore be used to control both dynamic and static properties of thin ferromagnetic films for improved performance in spintronics device applications, mediated through the antiferromagnetic interaction of the 4f and 3d states.
52.7 kOe high coercivity in Sm(Co0.9Cu0.1)4.8 melt-spun ribbons
Authors: Koppoju Suresh , Chandrasekaran V. , Gopalan R.
Published: July 2015

Fine grained Cu substituted melt-spun Sm(Co0.9Cu0.1)4.8 ribbons prepared with a wheel speed of 50 m/s exhibit a high coercivity of 52.7 kOe. Detailed magnetic studies like I and II quadrant magnetization-demagnetization characteristics, minor-loop measurement with increasing field and recoil behaviour have been carried out in combination with TEM studies. Fine spots of size ∼3 nm having different crystallographic orientations within the grains have been observed, and the high coercivity of the sample is attributed to complex domain wall interactions with the fine grain (∼55 nm) microstructure containing nanoscale heterogeneities.
DNA-library assembly programmed by on-demand nano-liter droplets from a custom microfluidic chip
Authors: Tangen Uwe , Minero Gabriel Antonio S. , Sharma Abhishek , Wagler Patrick F. , Cohen Rafael , Raz Ofir , Marx Tzipy , Ben-Yehezkel Tuval , McCaskill John S.
Published: July 2015

Nanoscale synthetic biology can benefit from programmable nanoliter-scale processing of DNA in microfluidic chips if they are interfaced effectively to biochemical arrays such as microwell plates. Whereas active microvalve chips require complex fabrication and operation, we show here how a passive and readily fabricated microchip can be employed for customizable nanoliter scale pipetting and reaction control involving DNA. This recently developed passive microfluidic device, supporting nanoliter scale combinatorial droplet generation and mixing, is here used to generate a DNA test library with one member per droplet exported to addressed locations on microwell plates. Standard DNA assembly techniques, such as Gibson assembly, compatible with isothermal on-chip operation, are employed and checked using off-chip PCR and assembly PCR. The control of output droplet sequences and mixing performance was verified using dyes and fluorescently labeled DNA solutions, both on-chip and in external capillary channels. Gel electrophoresis of products and DNA sequencing were employed to further verify controlled combination and functional enzymatic assembly. The scalability of the results to larger DNA libraries is also addressed by combinatorial input expansion using sequential injection plugs from a multiwell plate. Hence, the paper establishes a proof of principle of the production of functional combinatorial mixtures at the nanoliter scale for one sequence per well DNA libraries.
Gate-tunable coherent transport in Se-capped Bi2Se3 grown on amorphous SiO2/Si
Authors: Liu Y. H. , Chong C. W. , Jheng J. L. , Huang S. Y. , Huang J. C. A. , Li Z. , Qiu H. , Huang S. M. , Marchenkov V. V.
Published: July 2015

A topological insulator (TI) is an exotic material that has a bulk insulating gap and metallic surface states with unique spin-momentum locking characteristics. Despite its various important applications, large scale integration of TI into MOSFET technologies and its coherent transport study are still rarely explored. Here, we report the growth of high quality Bi2Se3 thin film on amorphous SiO2/Si substrate using MBE. By controlling the thickness of the film at ∼7 nm and capping the as grown film in situ with a 2 nm-thick Se layer, largest electrostatic field effect is obtained and the resistance is changed by almost 300%. More importantly, pronounced gate-tunable weak antilocalization (WAL) is observed, which refers to modulation of α from ∼−0.55 to ∼−0.2 by applying a back gate voltage. The analysis herein suggests that the significant gate-tunable WAL is attributable to the transition from weak disorder into intermediate disorder regime when the Fermi level is shifted downward by increasing the negative back gate voltage. Our findings may pave the ways towards the development of TI-based MOSFET and are promising for the applications of electric-field controlled spintronic and magnetic device.
Negative space charge effects in photon-enhanced thermionic emission solar converters
Authors: Segev G. , Weisman D. , Rosenwaks Y. , Kribus A.
Published: July 2015

In thermionic energy converters, electrons in the gap between electrodes form a negative space charge and inhibit the emission of additional electrons, causing a significant reduction in conversion efficiency. However, in Photon Enhanced Thermionic Emission (PETE) solar energy converters, electrons that are reflected by the electric field in the gap return to the cathode with energy above the conduction band minimum. These electrons first occupy the conduction band from which they can be reemitted. This form of electron recycling makes PETE converters less susceptible to negative space charge loss. While the negative space charge effect was studied extensively in thermionic converters, modeling its effect in PETE converters does not account for important issues such as this form of electron recycling, nor the cathode thermal energy balance. Here, we investigate the space charge effect in PETE solar converters accounting for electron recycling, with full coupling of the cathode and gap models, and addressing conservation of both electric and thermal energy. The analysis shows that the negative space charge loss is lower than previously reported, allowing somewhat larger gaps compared to previous predictions. For a converter with a specific gap, there is an optimal solar flux concentration. The optimal solar flux concentration, the cathode temperature, and the efficiency all increase with smaller gaps. For example, for a gap of 3 μm the maximum efficiency is 38% and the optimal flux concentration is 628, while for a gap of 5 μm the maximum efficiency is 31% and optimal flux concentration is 163.
Nonmagnetic particles enhance magnetoelastic response of magnetic elastomers
Authors: Nagashima Kazushi , Kanauchi Shunta , Kawai Mika , Mitsumata Tetsu , Tamesue Shingo , Yamauchi Takeshi
Published: July 2015

The elastic modulus for bimodal magnetic elastomers has been investigated by compression measurements under large deformation. The bimodal magnetic elastomers consist of carbonyl iron magnetic particles and zinc oxide nonmagnetic particles. The Young's modulus for monomodal magnetic elastomers was 8.94 × 104 Pa at 0 mT and 1.65 × 105 Pa at 320 mT, respectively. The relative change in the Young's modulus for monomodal magnetic elastomer was 1.8, and it was raised to 5.8 only by mixing with the nonmagnetic particles of 9.6 vol. %. It is considered that the modulus enhancement originates from the stress transfer by the additional chains of magnetic particles via nonmagnetic particles. The electric resistivity analysis revealed that 27% of magnetic particles in a strand of chains were replaced by nonmagnetic particles. It was shown in the present study that the bimodal magnetic elastomers endured against a compression load of 30 N.
Lateral damage in graphene carved by high energy focused gallium ion beams
Authors: Liao Zhongquan , Zhang Tao , Gall Martin , Dianat Arezoo , Rosenkranz Rüdiger , Jordan Rainer , Cuniberti Gianaurelio , Zschech Ehrenfried
Published: July 2015

Raman mapping is performed to study the lateral damage in supported monolayer graphene carved by 30 keV focused Ga+ beams. The evolution of the lateral damage is tracked based on the profiles of the intensity ratio between the D (1341 cm−1) and G (1582 cm−1) peaks (ID/IG) of the Raman spectra. The ID/IG profile clearly reveals the transition from stage 2 disorder into stage 1 disorder in graphene along the direction away from the carved area. The critical lateral damage distance spans from <1 μm up to more than 30 μm in the experiment, depending on the parameters used for carving the graphene. The wide damage in the lateral direction is attributed to the deleterious tail of unfocused ions in the ion beam probe. The study raises the attention on potential sample damage during direct patterning of graphene nanostructures using the focused ion beam technique. Minimizing the total carving time is recommended to mitigate the lateral damage.
Production and physiological effects of perennial ryegrass alkaloids under thermoneutral conditions in Merinos
Authors: Henry M. L. E. , Kemp S. , Clarke I. J. , Dunshea F. R. , Leury B. J.
Published: July 2015

A confined feeding study was conducted to compare the production and physiological effects of feeding three doses of wild-type perennial ryegrass alkaloids via whole seed to Merino sheep housed under thermoneutral conditions (21°C, 50% relative humidity). Eighteen Merino ewe weaners (16 months; initial bodyweight 47 ± 1.94 kg) were offered Nil, Low (50 µg/kg liveweight ergovaline, 22 µg/kg liveweight lolitrem B) or High (100 µg/kg liveweight ergovaline, 44 µg/kg liveweight lolitrem B) doses of alkaloids for 21 days. Dry matter intake tended (P = 0.072) to decrease in a linear manner with increasing dietary alkaloid concentration. Rectal temperature and respiration rate increased (P = 0.002 for both) in a linear manner with increasing dietary alkaloid concentration. Oxygen consumption increased linearly (P = 0.064) and quadratically (P = 0.015) with increasing alkaloid concentration, being highest in the Low dose and intermediate in the High dose group. Plasma prolactin decreased linearly (P = 0.002) with increasing dietary alkaloids. These data clearly show that animal production and efficiency are compromised when sheep consume perennial ryegrass alkaloids, even over a short period of time. This study indicates that a pyrogenic response can occur when alkaloids are consumed, even under thermoneutral conditions.
Dietary supplementation of a novel phytogenic feed additive: effects on nutrient metabolism, antioxidant status and immune response of goats
Authors: Choubey Mahipal , Pattanaik Ashok Kumar , Baliyan Shalini , Dutta Narayan , Jadhav Sunil E. , Sharma Kusumakar
Published: July 2015

Fifteen adult Jamunapari goats (12–14 months; 18.83 ± 0.83 kg) were used to ascertain the effect of a phytogenic feed additive (PFA) on nutrient utilisation, metabolic profile, antioxidant status and immune response. The goats, randomly assigned to three groups, were fed a standard diet supplemented with the PFA at 0 (CON), 2 (PFA-2) and 3 (PFA-3) % of feed intake for a period of 60 days. Bodyweight and feed intake were recorded. At the end of the experiment, a metabolism trial was conducted. Blood was collected at fortnightly intervals and used to assess blood metabolites, select hormones and erythrocytic antioxidant status. Humoral and cell-mediated immune responses were also assessed. Although dietary use of PFA improved (P < 0.05) the digestibility of all the nutrients, supplementation of PFA did not impart any significant effect (P < 0.05) on dry matter intake or bodyweight changes. Nitrogen balance was higher (P < 0.05) in both the PFA groups compared with the CON. Most of the blood metabolites showed comparable values except for a lower (P < 0.05) aspartate aminotransferase activity in PFA-3. Serum cortisol reduced (P < 0.05) with PFA supplementation in a dose-dependent manner. The supplementation of PFA increased (P < 0.05) the activity of antioxidant enzymes viz. glutathione peroxidase, catalase and glutathione-S-transferase at higher doses (PFA-3), but did not alter the non-enzymatic antioxidant indices. There was no influence of PFA on the cell-mediated or humoral immune responses. Overall, the results indicated the potential of the PFA for improvement in nutrient utilisation and antioxidant status in adult goats.
Effects of divergent selection for growth on egg quality traits in Japanese quail
Authors: Nasr Mohammed A. F. , El-Tarabany Mahmoud S. , Toscano Michael J.
Published: July 2015

The experiment was designed to investigate the impact of selection for increased body mass on external and internal egg quality traits of Japanese quail. Three hundred and sixty Japanese quail, divergently selected over three generations for different body mass at 4 weeks of age, were used. Quail were homogeneously divided into three groups each consisting of 120 birds: high body mass (HBM), low body mass (LBM) and Control. ANOVA was used to detect the effect of selection on egg quality. In addition, correlation between external and internal egg quality traits was measured. Our results revealed that HBM quail laid heavier eggs (P = 0.03 compared with LBM but not significantly different with Control quail) with a higher external (shell thickness, shell weight, eggshell ratio and eggshell density, P = 0.0001) and internal egg quality score (albumen weight, P = 0.003; albumen ratio, P = 0.01; albumen height, yolk height, yolk index and Haugh unit, P = 0.0001) when compared with both the Control and LBM. The egg surface area and yolk diameter were significantly higher in HBM when compared with the LBM but not with the Control line. Egg weight was positively correlated with albumen weight (r = 0.54, P = 0.0001), albumen ratio (r = 0.14, P = 0.05), yolk height (r = 0.27, P = 0.0001), yolk weight (r = 0.23, P = 0.002), yolk diameter (r = 0.14, P = 0.05) and yolk index (r = 0.21, P = 0.005) but was negatively correlated with yolk ratio (r = –0.16, P = 0.03). Our results indicate that selection for higher body mass might result in heavier eggs and superior egg quality.