bluuebunny/crossref_metadata_2025 huggingface dataset:
Coming across a novel copper oxide 2D framework during the oxidation of Cu(111)
Authors: Matencio Sonia , Barrena Esther , Ocal Carmen
Published: November 2016

This strategy creates diverse oxide structures described as the evolution by oxygen incorporation from a new highly porous 2D framework.
Effect of graphene support on large Pt nanoparticles
Authors: Verga L. G. , Aarons J. , Sarwar M. , Thompsett D. , Russell A. E. , Skylaris C.-K.
Published: November 2016

Large scale DFT calculations of Pt nanoparticles supported on graphene explore the non-trivial interplay of size and support effects.
A metastable cubic phase of sodium niobate nanoparticles stabilized by chemically bonded solvent molecules
Authors: Gu Qilin , Zhu Kongjun , Sun Qiaomei , Liu Jinsong , Wang Jing , Qiu Jinhao , Wang John
Published: November 2016

A facile and green alternative was provided to prepare a metastable phase of cubic NaNbO3 nanoparticles. A new insight into the stabilization of cubic NaNbO3 nanoparticles by chemically bonded organic molecules was proposed on the basis of systematic structural and surface analyses.
Z-scheme CdS–Au–BiVO4with enhanced photocatalytic activity for organic contaminant decomposition
Authors: Bao Shenyuan , Wu Qiangfang , Chang Shunzhou , Tian Baozhu , Zhang Jinlong
Published: November 2016

A Z-scheme heterogeneous photocatalyst CdS–Au–BiVO4was synthesized for the first time by photo-reduction and deposition–precipitation methods.
Redox trends in cyclometalated palladium(ii) complexes
Authors: Dudkina Yulia B. , Kholin Kirill V. , Gryaznova Tatyana V. , Islamov Daut R. , Kataeva Olga N. , Rizvanov Ildar Kh. , Levitskaya Alina I. , Fominykh Olga D. , Balakina Marina Yu. , Sinyashin Oleg G. , Budnikova Yulia H.
Published: November 2016

Electrochemical and DFT studies on palladacycles revealed an increase in the metal–metal distance in the complexes leads to higher oxidation potentials.
Exploring the potential of a hybrid device combining solar water heating and molecular solar thermal energy storage
Authors: Dreos Ambra , Börjesson Karl , Wang Zhihang , Roffey Anna , Norwood Zack , Kushnir Duncan , Moth-Poulsen Kasper
Published: November 2016

A hybrid solar energy system consisting of a molecular solar thermal energy storage system (MOST) combined with a solar water heating system (SWH) is presented.
NHC-based coordination polymers as solid molecular catalysts for reductive amination of biomass levulinic acid
Authors: Sun Zheming , Chen Jiangbo , Tu Tao
Published: November 2016

Novel NHC-Ru coordination polymer acts as a high activity solid molecular catalyst in the solvent-free reductive aminations of levulinic acid. Besides the catalyst could be reused for 37 runs, up to 6.7 × 104 TON could be achieved.
Expanding the reaction space of aldolases using hydroxypyruvate as a nucleophilic substrate
Authors: de Berardinis Véronique , Guérard-Hélaine Christine , Darii Ekaterina , Bastard Karine , Hélaine Virgil , Mariage Aline , Petit Jean-Louis , Poupard Nicolas , Sánchez-Moreno Israel , Stam Mark , Gefflaut Thierry , Salanoubat Marcel , Lemaire Marielle
Published: November 2016

Hydroxypyruvate was shown to be a nucleophile for class II pyruvate aldolases isolated from biodiversity, allowing unprecedented stereoselective cross-aldol reactions.
Quantitative optimization and assessments of supplemented fructooligosaccharides in dry dog food
Authors: Chen Maoshen , Yong Xiaolei , Nsor-Atindana John , Masamba Kingsley George , Ma Jianguo , Zhong Fang
Published: November 2016

The effects of supplementation of fructooligosaccharides (FOS) in dry dog food on the populations of microflora, short-chain fatty acid (SCFA) production, fecal protein catabolites and fecal quality in puppies were investigated.
Toughening modification of PLLA by combination of copolymerization and in situ reactive blending
Authors: Zhang Bao , Bian Xinchao , Zhou Dongdong , Feng Lidong , Li Gao , Chen Xuesi
Published: November 2016

PLLA/PLLA-b-PBAT-b-PLLA/(PLLA-b-PGMA)3 blends with different ratio.
Sn–P–F containing glass matrix for the fabrication of phosphor-in-glass for use in high power LEDs
Authors: Yoo Heeyeon , Kouhara Yoshihiro , Yoon Hee Chang , Park Sang Jun , Oh Ji Hye , Do Young Rag
Published: November 2016

In this study, we introduce a low-melting-point (MP) glass ceramic (GlaC) material which can be used to fabricate a phosphor-in-glass (PiG) with Y3Al5O12:Ce3+ (YAG) phosphor for the realization of high-power white-light-emitting diodes (WLEDs).
Mechanistic studies on the VO(acac)2-catalyzed oxidative cleavage of lignin model compounds in acetic acid
Authors: Ma Yangyang , Du Zhongtian , Xia Fei , Ma Jiping , Gao Jin , Xu Jie
Published: November 2016

Selective aerobic oxidation has provided a promising approach for breaking lignin into smaller aromatics. Here, the reaction pathway of VO(acac)2-catalyzed oxidation of lignin model 2-phenoxy-1-phenylethanol in acetic acid was studied.
A silver on 2D white-C3N4support photocatalyst for mechanistic insights: synergetic utilization of plasmonic effect for solar hydrogen evolution
Authors: Yi Jianjian , She Xiaojie , Song Yanhua , Xu Hui , Zhang Peng , Mo Zhao , Liu Liang , Du Daolin , Li Huaming
Published: November 2016

The photocatalytic activity of Ag/2D white-C3N4is enhancedviasynergetic utilization of plasma effects from Ag and visible-light excitation of the semiconductor.
Host–guest interaction between corannulene and γ-cyclodextrin: mass spectrometric evidence of a 1 : 1 inclusion complex formation
Authors: Joshi Hrishikesh , Sreejith Sivaramapanicker , Dey Ranjan , Stuparu Mihaiela C.
Published: November 2016

The toroidal cavity of γ-cyclodextrin is shown to interact with a bowl-shaped polycyclic aromatic hydrocarbon, corannulene, through host–guest interactions.
PdII2L4-type coordination cages up to three nanometers in size
Authors: Jansze Suzanne M. , Wise Matthew D. , Vologzhanina Anna V. , Scopelliti Rosario , Severin Kay
Published: November 2016

The utilization of easily accessible metalloligands allows the construction of PdII2L4-type coordination cages of unprecedented size.
Surface charge transfer doping induced inversion layer for high-performance graphene/silicon heterojunction solar cells
Authors: Ding Ke , Zhang Xiujuan , Xia Feifei , Wang Rongbin , Kuang Yawei , Duhm Steffen , Jie Jiansheng , Zhang Xiaohong
Published: November 2016

Surface charge transfer doping (SCTD) induced p-type inversion layer was implemented in the graphene/silicon heterojunction solar cells, leading to significant improvement of device efficiency.
Fabrication of robust and durable superhydrophobic fiberglass fabrics for oil–water separation based on self-assembly of novel N-TESPO and N-TESPS reagents
Authors: Rostami A. , Sharifnia S.
Published: November 2016

Novel robust and durable self-assembled fiberglass fabrics were prepared by immersing the OH-functionalized fiberglass fabrics into N-(3-triethoxysilylpropyl)oleamide (N-TESPO) and N-(3-triethoxysilylpropyl)stearamide (N-TESPS) reagent solutions.
Integration of MCMBs/MWCNTs with Fe3O4in a flexible and light weight composite paper for promising EMI shielding applications
Authors: Chaudhary Anisha , Kumar Rajeev , Teotia Satish , Dhawan S. K. , Dhakate Sanjay R. , Kumari Saroj
Published: November 2016

A hybrid three phase system containing MCMBs/MWCNTs/Fe3O4in the form of a highly flexible and light weight composite paper is fabricated by simple cost effective strategies and is promising EMI shielding applications.
HR-COSMOS: Kinematics of star-forming galaxies at z ~ 0.9
Authors: Pelliccia D. , Tresse L. , Epinat B. , Ilbert O. , Scoville N. , Amram P. , Lemaux B. C. , Zamorani G.
Published: November 2016

We present the kinematic analysis of a sub-sample of 82 galaxies at 0.75 < z < 1.2 from our new survey HR-COSMOS aimed to obtain the first statistical sample to study the kinematics of star-forming galaxies in the treasury COSMOS field at 0 < z < 1.2. We observed 766 emission line galaxies using the multi-slit spectrograph ESO-VLT/VIMOS in high-resolution mode (R = 2500). To better extract galaxy kinematics, VIMOS spectral slits have been carefully tilted along the major axis orientation of the galaxies, making use of the position angle measurements from the high spatial resolution HST/ACS COSMOS images. We constrained the kinematics of the sub-sample at 0.75 < z < 1.2 by creating high-resolution semi-analytical models. We established the stellar-mass Tully-Fisher relation at z ≃ 0.9 with high-quality stellar mass measurements derived using the latest COSMOS photometric catalog, which includes the latest data releases of UltraVISTA and Spitzer. In doubling the sample at these redshifts compared with the literature, we estimated the relation without setting its slope, and found it consistent with previous studies in other deep extragalactic fields assuming no significant evolution of the relation with redshift at z ≲ 1. We computed dynamical masses within the radius R2.2 and found a median stellar-to-dynamical mass fraction equal to 0.2 (assuming Chabrier IMF), which implies a contribution of gas and dark matter masses of 80% of the total mass within R2.2, in agreement with recent integral field spectroscopy surveys. We find no dependence of the stellar-mass Tully-Fisher relation with environment probing up to group scale masses. This study shows that multi-slit galaxy surveys remain a powerful tool to derive kinematics for large numbers of galaxies at both high and low redshift.
Akzeptanz von Handlungsempfehlungen des Netzwerks „Gesund ins Leben – Netzwerk Junge Familie“ zur Säuglingsernährung und Ernährung der stillenden Mutter. Befragung unterschiedlicher Berufsgruppen
Authors: Reiss K. , Flothkötter M. , Greif N. , Kolip P.
Published: November 2016

Ziel der Studie: Das Ziel dieser Untersuchung liegt in der Ermittlung der Akzeptanz der einheitlichen Handlungsempfehlungen des Netzwerks „Gesund ins Leben – Netzwerk Junge Familie“ zu den Themen Säuglingsernährung und Ernährung der stillendenden Mutter bei unterschiedlichen Berufsgruppen.

Methodik: Webbasierte Befragung u. a. unter Frauenärzten/-innen, Kinder- und Jugendärzten/-innen und Hebammen/Entbindungspflegern sowie eine zweite webbasierte Befragung unter Kinder- und Jugendärzten/-innen. Die Zustimmung wurde dichotom erfasst. Der prozentuale Zustimmungsgrad wurde als gering (<75%), mäßig (75–89%), stark (90–94%), sehr stark (95–99%) und absolut (100%) kategorisiert.

Ergebnisse: An der ersten Befragung nahmen 1 311 Personen teil (n=908 Hebammen/Entbindungspfleger), wovon 77,6% angaben, die Handlungsempfehlungen zu kennen. Der durchschnittliche Zustimmungsgrad war bei Hebammen/Entbindungspflegern mit 67,5% am geringsten. An der zweiten Befragung nahmen 119 Kinder- und Jugendärzte/-innen teil, wobei 86,5% Kenntnis von der Existenz der Empfehlungen hatten. Geringe Akzeptanz wiesen bei allen Berufsgruppen insbesondere die Empfehlungen zu den Nährstoffsupplementen Iod und Fluorid auf. Als Ablehnungsgründe wurden eine Orientierung an der individuellen Situation der jungen Familie, an anderen Empfehlungen oder an eigenen Erfahrungen angeführt.

Schlussfolgerung: Die Übertragung der Handlungsempfehlungen in die Hebammenpraxis scheint noch nicht gelungen. Aufgrund der überproportionalen Beteiligung von Hebammen/Entbindungspflegern sind die Ergebnisse aber nicht auf andere Berufsgruppen übertragbar. Die Integration der Empfehlungen in die Aus-, Fort- und Weiterbildung der Berufsgruppen, die Überarbeitung eventuell missverständlicher Formulierungen sowie die Kommunikation der wissenschaftlichen Hintergründe sind sinnvolle Ansatzpunkte für eine Akzeptanzsteigerung.
The Paradigm Shift: Disruption, Creativity, and Innovation in Kenya
Authors: Ndemo Bitange
Published: November 2016

A paradigm shift is underway in Kenya. New innovations are destroying old ways of doing business, and smart young start-up entrepreneurs are at the forefront of this quiet but historic transformation. Teams of skilled developers and programmers have sprung up in innovation hubs, incubators, and accelerators across the country to build information and telecom solutions that capitalize on the country’s mix of challenges and opportunities. At the same time, we have seen a number of spinoffs of Kenya’s unique entrepreneurial revolution reach across Africa and into other corners of the world, attracting global recognition for the country.
Developing Strategies to Harness the Power of Parallel Entrepreneurship in Africa
Authors: John Eskor
Published: November 2016

The study of entrepreneurship in general has drawn large interest over the last decade, and the specific subject of parallel entrepreneurship is no exception. Parallel entrepreneurship, or concurrent entrepreneurship, is the simultaneous ownership of at least two business ventures. It is found all over the world but is particularly evident at the international level, in the form of conglomerates. It has been argued that entrepreneurs owning several enterprises at the same time are more experienced than their peers operating single businesses and that studying this particular business model can enhance understanding of entrepreneurship more generally. This chapter identifies some of the most salient factors related to parallel entrepreneurship—factors that, if better understood and supported, have the potential to make a significant contribution to the economic transformation of developing economies. It also explores the contextual factors contributing to the growth of entrepreneurship in Africa and the prevalence and implications of parallel entrepreneurship. It concludes with a number of recommendations on how to support and develop parallel entrepreneurship in the future.
Entrepreneuring for Society: What Is Next for Africa?
Authors: Weiss Tim
Published: November 2016

Digital Kenya is a modest representation of the powerful space and time in which an inspiring generation of entrepreneurs finds itself at the present moment—a generation that is working actively to bring the benefits of the digital age to every citizen and organization of Africa, unleashing the power of modern-day technology for the benefit of society. Above all, it is a generation that seeks to help create a brighter future full of opportunities and possibilities for the many generations to come. The book has sought to capture this intriguing moment and—like the snap of a camera’s shutter—permanently conserve and document its uniqueness.
The Internet Journey for Kenya: The Interplay of Disruptive Innovation and Entrepreneurship in Fueling Rapid Growth
Authors: Mureithi Muriuki
Published: November 2016

The Internet has witnessed a dramatic evolution since its launch in 1995, presenting a myriad of opportunities to society and to enterprises, in particular, through access to information. This evolution has also presented significant challenges, including new competition, changing customer engagement and business models, unprecedented transparency, privacy concerns, and cybersecurity threats. This chapter draws on the theory of disruptive innovation pioneered by Christensen (“Executive Forum, 81(2), 27–37”, 2001) in exploring the interplay of disruptive innovation and entrepreneurship in fueling rapid ICT growth in Kenya. The theory explained how a business model is likely to succeed by coming from the lower end of the market and eventually disrupting and taking over the market as the pioneers of each new technology or business process attempt to dominate their competitors. The theory is used to explain these phenomena and is adapted to examine not just the success of the business model, but also to explain the sustaining disruptive effects on the entire market by entrants as challengers of the incumbents. This provides a theoretical lens through which to view the market experience acquired through continuous market engagement by the author in a consultancy practice in Kenya over the last 20 years.
I-Entrepreneurship: Changing Lives Through Technology
Authors: Wamukoya Carmen Merab , Ng’weno Amolo
Published: November 2016

As information and communications technologies (ICTs) and social enterprises are increasingly recognized for their role as drivers of economic growth, opportunities are continuously arising for new business models to address socioeconomic challenges and encourage innovation. This chapter examines the growth of social entrepreneurship in Kenya and demonstrates how businesses can create shared value in the field of technology. It illustrates the role of impact sourcing as a means of generating employment through an examination of Digital Divide Data (DDD) Kenya, the country’s innovative ICT program for the training and education of disadvantaged youth. The DDD case study sheds light on the potential of ICTs to transform businesses and provide an enabling environment for the development of technology-based social enterprise. The impact sourcing model used by DDD Kenya, it will be shown, provides opportunities for youth from low-income and disadvantaged backgrounds to acquire practical, hands-on professional training while pursuing higher education. It also highlights the challenges of setting up a social enterprise and casts light on a number of the lessons and best practices that can be taken up by other entrepreneurs.
From Cyber Café to Smartphone: Kenya’s Social Media Lens Zooms In on the Country and Out to the World
Authors: Kaigwa Mark
Published: November 2016

This chapter investigates Global North paradigms of connectivity contrasted with those of Kenya. It examines the age of the cyber café and the transition into the mobile age that has defined Kenya’s ascent as a technology powerhouse—specifically, the ascent of mobile connectivity as a tool for Internet connectivity, and in particular, for social networking (and the factors of availability, affordability, and accessibility that have proved pivotal). The social networking service Twitter is the focus when it comes to social media. The microblogging network, in addition, is highlighted through initiatives, movements, and various hashtags inspired by online conversations and resulting in real-world outcomes. Before the adoption of localized trending topics, Kenyans on Twitter had their trends set on default to “Worldwide.” From 2010, when a fictional character in a Kenyan music video went viral, creating a global Internet sensation, the wheels were set in motion to see Kenyans discover their identity online and carve a niche as a globally respectable digital citizenry that was worthy of greater understanding and inspection.
Plasma kinetic effects on interfacial mix
Authors: Yin L. , Albright B. J. , Taitano W. , Vold E. L. , Chacon L. , Simakov A. N.
Published: November 2016

Mixing at interfaces in dense plasma media is a problem central to inertial confinement fusion and high energy density laboratory experiments. In this work, collisional particle-in-cell simulations are used to explore kinetic effects arising during the mixing of unmagnetized plasma media. Comparisons are made to the results of recent analytical theory in the small Knudsen number limit and while the bulk mixing properties of interfaces are in general agreement, some differences arise. In particular, “super-diffusive” behavior, large diffusion velocity, and large Knudsen number are observed in the low density regions of the species mixing fronts during the early evolution of a sharp interface prior to the transition to a slow diffusive process in the small-Knudsen-number limit predicted by analytical theory. A center-of-mass velocity profile develops as a result of the diffusion process and conservation of momentum.
Studies of electron diffusion in photo-excited Ni using time-resolved X-ray diffraction
Authors: Persson A. I. H. , Jarnac A. , Wang Xiaocui , Enquist H. , Jurgilaitis A. , Larsson J.
Published: November 2016

We show that the heat deposition profile in a laser-excited metal can be determined by time-resolved X-ray diffraction. In this study, we investigated the electron diffusion in a 150 nm thick nickel film deposited on an indium antimonide substrate. A strain wave that mimics the heat deposition profile is generated in the metal and propagates into the InSb, where it influences the temporal profile of X-rays diffracted from InSb. We found that the strain pulse significantly deviated from a simple exponential profile, and that the two-temperature model was needed to reproduce the measured heat deposition profile. Experimental results were compared to simulations based on the two-temperature model carried out using commercial finite-element software packages and on-line dynamical diffraction tools. To reproduce the experimental data, the electron–phonon coupling factor was lowered compared to previously measured values. The experiment was carried out at a third-generation synchrotron radiation source using a high-brightness beam and an ultrafast X-ray streak camera with a temporal resolution of 3 ps.
Geometries of H2S⋯MI (M = Cu, Ag, Au) complexes studied by rotational spectroscopy: The effect of the metal atom
Authors: Medcraft Chris , Bittner Dror M. , Tew David P. , Walker Nicholas R. , Legon Anthony C.
Published: November 2016

Complexes formed between H2S and each of CuI, AgI, and AuI have been isolated and structurally characterised in the gas phase. The H2S⋯MI complexes (where M is the metal atom) are generated through laser vaporisation of a metal rod in the presence of a low concentration of H2S and CF3I in a buffer gas of argon undergoing supersonic expansion. The microwave spectra of six isotopologues of each of H2S⋯CuI, H2S⋯AgI and three isotopologues of H2S⋯AuI have been measured by chirped-pulse Fourier transform microwave spectroscopy. The spectra are interpreted to determine geometries for the complexes and to establish the values of structural parameters. The complexes have Cs symmetry at equilibrium and have a pyramidal configuration about the sulfur atom. The local C2 axis of the hydrogen sulfide molecule intersects the linear axis defined by the three heavy atoms at an angle, ϕ = 75.00(47)° for M = Cu, ϕ = 78.43(76)° for M = Ag, and ϕ = 71.587(13)° for M = Au. The trend in the molecular geometries is consistent with significant relativistic effects in the gold-containing complex. The force constant describing the interaction between the H2S and MI sub-units is determined from the measured centrifugal distortion constant, ΔJ, of each complex. Nuclear quadrupole coupling constants, χaa(M) and χaa(I) (where M denotes the metal atom), are determined for H2S⋯CuI and H2S⋯AuI for the first time.
Subwavelength diffractive acoustics and wavefront manipulation with a reflective acoustic metasurface
Authors: Wang Wenqi , Xie Yangbo , Popa Bogdan-Ioan , Cummer Steven A.
Published: November 2016

Acoustic metasurfaces provide useful wavefront shaping capabilities, such as beam steering, acoustic focusing, and asymmetric transmission, in a compact structure. Most acoustic metasurfaces described in the literature are transmissive devices and focus their performance on steering sound beam of the fundamental diffractive order. In addition, the range of incident angles studied is usually below the critical incidence predicted by generalized Snell's law of reflection. In this work, we comprehensively analyze the wave interaction with a generic periodic phase-modulating structure in order to predict the behavior of all diffractive orders, especially for cases beyond critical incidence. Under the guidance of the presented analysis, a broadband reflective metasurface is designed based on an expanded library of labyrinthine acoustic metamaterials. Various local and nonlocal wavefront shaping properties are experimentally demonstrated, and enhanced absorption of higher order diffractive waves is experimentally shown for the first time. The proposed methodology provides an accurate approach for predicting practical diffracted wave behaviors and opens a new perspective for the study of acoustic periodic structures. The designed metasurface extends the functionalities of acoustic metasurfaces and paves the way for the design of thin planar reflective structures for broadband acoustic wave manipulation and extraordinary absorption.
Effects of antenna coil turns on plasma density and antenna voltage in solenoidal inductively coupled plasmas
Authors: Moon Jun-Hyeon , Kim Kyung-Hyun , Lin Ming-Chieh , Chung Chin-Wook
Published: November 2016

The number of antenna coil turns, N, that affects the plasma density is a significant factor to design an inductively coupled plasma source. The equivalent resistance and inductance of a transformer circuit seen at the antenna coil are known to increase with N. This can enhance the power transfer efficiency. However, there is an undesired capacitive coupling between the antenna coil and the plasma. The antenna voltage related to the capacitive coupling is known to be proportional to N. In this work, to investigate the effects of N, the plasma density and the antenna coil voltage are measured by a floating probe and high-voltage probes, respectively. A terminal capacitor is used to suppress the capacitive coupling. As a result, the effects of N are clearly observed on the plasma densities and the voltages of the antenna coil. The plasma density was found to dramatically increase with N while the capacitive coupling is suppressed. The antenna voltage was not increased with N, and it was investigated by the ratio of the antenna voltage to the total voltage.
Investigation of pitting corrosion of diamond-like carbon films using synchrotron-based spectromicroscopy
Authors: Tunmee Sarayut , Photongkam Pat , Euaruksakul Chanan , Takamatsu Hiroki , Zhou XiaoLong , Wongpanya Pornwasa , Komatsu Keiji , Kanda Kazuhiro , Ito Haruhiko , Saitoh Hidetoshi
Published: November 2016

Corrosion behavior of diamond-like carbon (DLC) films was evaluated via potentiodynamic polarization in a 3.5 wt. % NaCl solution with pH 2 at room temperature. The polarization results elucidated that the corrosion resistance of the films was enhanced with the variation of the chemical compositions and film thicknesses. The use of the spectromicroscopy method in the investigation of the pitting corrosion was a success in this study. Formation of orbital mapping, bonding state, and composition of the DLC films at non-corrosion and corrosion areas indicate the different structures between DLC and graphite oxide. Also, the π* (C=C) and π* (C=O) bonding states were found to increase in the corrosion areas. This finding not only exhibited the increase of sp2 content but also promoted the rise of oxygen atoms in corrosion zones. Consequently, the present results indicate that the synchrotron–based spectromicroscopy plays an important role in the characterization of the corrosion on DLC films.
Resonance phenomena in a two-layer two-vortex shear flow
Authors: Ryzhov Eugene A. , Koshel Konstantin V.
Published: November 2016

The paper deals with a dynamical system governing the motion of two point vortices embedded in the bottom layer of a two-layer rotating flow experiencing linear deformation and their influence on fluid particle advection. The linear deformation consists of shear and rotational components. If the deformation is stationary, the vortices can move periodically in a bounded region. The vortex periodic motion induces stirring patterns of passive fluid particles in the both layers. We focus our attention on the upper layer where the bottom-layer singular point vortices induce a regular velocity field with no singularities. In the upper layer, we determine a steady-state regime featuring no closed fluid particle trajectories associated with the vortex motion. Thus, in the upper layer, the flow's streamlines look like there is only external linear deformation and no vortices. In this case, fluid particles move along trajectories of almost regular elliptic shapes. However, the system dynamics changes drastically if the underlying vortices cease to be stationary and instead start moving periodically generating a nonstationary perturbation for the fluid particle advection. Then, we demonstrate that this steady-state regime transits to a perturbed state with a rich phase portrait structure featuring both periodic and chaotic fluid particle trajectories. Thus, the perturbed state clearly manifests the impact of the underlying vortex motion. An analysis, based on comparing the eigenfrequencies of the steady-state fluid particle rotation with the ones of the vortex rotation, is carried out, and parameters ensuring effective fluid particle stirring are determined. The process of separatrix reconnection of close stability islands leading to an enhanced chaotic region is reported and analyzed.
Guided ion beam and theoretical studies of the reactions of Re+, Os+, and Ir+ with CO
Authors: Kim JungSoo , Cox Richard M , Armentrout P. B.
Published: November 2016

The kinetic-energy dependences of the reactions M+ + CO where M+ = Re+, Os+, and Ir+ are studied using guided ion-beam tandem mass spectrometry. Formation of both MO+ and MC+ was observed in endothermic processes for all three metals. Modeling of the data provides thresholds that yield 0 K bond dissociation energies (BDEs, in eV) of 4.67 ± 0.09 (Re+–O), 4.82 ± 0.14 (Os+–O), 4.25 ± 0.11 (Ir+–O), 5.13 ± 0.12 (Re+–C), 6.14 ± 0.14 (Os+–C), and 6.58 ± 0.12 (Ir+–C). These BDEs agree well with literature values within experimental uncertainties demonstrating that ground state products are formed for all cases even though some of the reactions are formally spin forbidden. Quantum mechanical calculations at several levels of theory and using several basis sets were performed for MC+ and MO+ (with comparable results taken from the literature in some cases). B3LYP and CCSD(T) calculated ground state BDEs agree reasonably well with experimental values. The ground states in B3LYP and CCSD(T)/CBS calculations are Σ−3 (ReC+), Δ2 (OsC+), and Σ+1 or Δ3 (IrC+) after including spin-orbit considerations. Relaxed potential energy surfaces (PESs) for the M+ + CO reactions show crossings between surfaces of different spin states such that products can be formed with no barriers in excess of the substantial endothermicities. Unlike results for these metal cations reacting with O2, the kinetic energy dependent cross sections for the formation of MO+ in the M+ + CO reactions exhibit only one feature. Reasons for this differential behavior are discussed in detail.
Grain growth behavior of Ba1.5Sr1.5Co2Fe24O41 flakes in molten salt synthesis and the magnetic properties of flake/polymer composites
Authors: Moon Kyoung-Seok , Kang Young-Min , Han InTaek , Lee Sang-Eui
Published: November 2016

Single-phase Ba1.5Sr1.5Co2Fe24O41 (Ba1.5Sr1.5Z) hexaferrite flakes were synthesized using a two-step grain growth process, involving a calcination process and molten salt synthesis. Geometric parameters such as aspect ratio and the degree of agglomeration can be controlled by tuning this calcination-molten salt method. The morphological evolution of the flakes was explained using the concept of mixed-control grain growth, i.e., a combination of diffusion for growth and interface reactions, which is a growth mechanism for a faceted interface. The single-phase Ba1.5Sr1.5Z flake particle with high aspect ratio turned out to be a good candidate of soft magnetic inclusion, through an investigation of the correlation between material composition, magnetic behavior, and particle morphology.
Gettering of interstitial iron in silicon by plasma-enhanced chemical vapour deposited silicon nitride films
Authors: Liu A. Y. , Sun C. , Markevich V. P. , Peaker A. R. , Murphy J. D. , Macdonald D.
Published: November 2016

It is known that the interstitial iron concentration in silicon is reduced after annealing silicon wafers coated with plasma-enhanced chemical vapour deposited (PECVD) silicon nitride films. The underlying mechanism for the significant iron reduction has remained unclear and is investigated in this work. Secondary ion mass spectrometry (SIMS) depth profiling of iron is performed on annealed iron-contaminated single-crystalline silicon wafers passivated with PECVD silicon nitride films. SIMS measurements reveal a high concentration of iron uniformly distributed in the annealed silicon nitride films. This accumulation of iron in the silicon nitride film matches the interstitial iron loss in the silicon bulk. This finding conclusively shows that the interstitial iron is gettered by the silicon nitride films during annealing over a wide temperature range from 250 °C to 900 °C, via a segregation gettering effect. Further experimental evidence is presented to support this finding. Deep-level transient spectroscopy analysis shows that no new electrically active defects are formed in the silicon bulk after annealing iron-containing silicon with silicon nitride films, confirming that the interstitial iron loss is not due to a change in the chemical structure of iron related defects in the silicon bulk. In addition, once the annealed silicon nitride films are removed, subsequent high temperature processes do not result in any reappearance of iron. Finally, the experimentally measured iron decay kinetics are shown to agree with a model of iron diffusion to the surface gettering sites, indicating a diffusion-limited iron gettering process for temperatures below 700 °C. The gettering process is found to become reaction-limited at higher temperatures.
Charge blocking layers in thin-film/amorphous photovoltaics
Authors: Magen Osnat , Tessler Nir
Published: November 2016

The open circuit voltage of solar cells is a critical property which, in many thin film devices, is found to be much lower than the theoretical limit associated with the material's absorption energy gap. A known method for improving the open circuit voltage is that of adding charge blocking layers (a.k.a. charge selective or charge transport layers). However, such interfacial layers are often found to decrease the fill factor or even cause undesired S-shape in J-V curves. In the current work, we revisit the blocking-layer method through detailed device simulations, explain how such layers enable significant Voc increase (even above the built-in voltage), and show that the layers' resistance is responsible for the problematic behavior observed. Having identified the source of reduced fill factor, we suggest methods of reducing the resistivity and recovering the fill factor.
Integrated experimental and computational approach for residual stress investigation near through-silicon vias
Authors: Deluca Marco , Hammer René , Keckes Jozef , Kraft Jochen , Schrank Franz , Todt Juraj , Robach Odile , Micha Jean-Sébastien , Defregger Stefan
Published: November 2016

The performance of three-dimensional integrated circuits is decisively influenced by the thermo-mechanical behavior of through-silicon vias (TSVs), which are subjected to stresses formed during fabrication process as well as cyclic operation as a result of coefficients of thermal expansion (CTEs) mismatch between the silicon substrate, passivation layers, and metallic conduction paths. In this work, we adopted an integrated approach combining micro-Raman, wafer curvature experiments, and finite element (FE) modeling to study the triaxial residual stresses in silicon in the vicinity of W-coated hollow TSVs. A comparison of the experimental and calculated Raman shifts from a TSV cross section allowed a validation of the FE model, which was then extended to a non-sliced TSV. In the next step, the calculated bulk strains were compared with the ones measured using synchrotron X-ray micro-diffraction in order to specifically assess the stress decrease in Si as a function of the distance from the TSV wall within ∼25 μm. The experimental verification of the FE model demonstrates the importance of combined experimental-computational approaches to study stresses in micro-scale devices with complex morphology.
Detailed investigation of thermal and electron transport properties in strongly correlated compound Ce6Pd12In5 and its nonmagnetic analog La6Pd12In5
Authors: Falkowski M. , Krychowski D. , Strydom A. M.
Published: November 2016

An in-depth study of thermal and electron transport properties including thermal conductivity κ(T), thermoelectric power S(T), and electrical resistivity ρ(T) of the heavy fermion Kondo lattice Ce6Pd12In5 and its nonmagnetic reference compound La6Pd12In5 is presented. The absolute κ(T) value of Ce6Pd12In5 is smaller that than of La6Pd12In5, which indicates that conduction electron–4f electron scattering has a large impact on the reduction of thermal conductivity. The isolated 4f electron contributions to the electrical resistivity ρ4f(T), electronic thermal resistivity displayed in the form Wel,4f(T)·T, and thermoelectric power S4f(T) reveal a low- and high-temperature –lnT behaviour characteristic of Kondo systems with strong crystal-electric field (CEF) interactions. The analysis of phonon scattering processes of lattice thermal conductivity κph(T) in (Ce, La)6Pd12In5 was performed over the whole accessible temperature range according to the Callaway model. In the scope of a theoretical approach based on the perturbation type calculation, we were able to describe our experimental data of ρ4f(T) and Wel,4f(T)·T by using the model incorporating simultaneously the Kondo effect in the presence of the CEF splitting, as it is foreseen in the framework of the Cornut-Coqblin and Bhattacharjee-Coqblin theory. Considering the fact that there are not many cases of similar studies at all, we also show the numerical calculations of temperature-dependent behaviour of spin-disorder resistivity ρs(T), magnetic resistivity ρ4f(T), and occupation number ⟨Ni⟩ due to the various types of degeneracy of the ground state multiplet of Ce3+ (J = 5/2).
Improvement of optical and electric characteristics of MoO3/Ag film/MoO3 flexible transparent electrode with metallic grid
Authors: Wang Chen-Tao , Ting Chu-Chi , Kao Po-Ching , Li Shan-Rong , Chu Sheng-Yuan
Published: November 2016

In this paper, the authors report rationally designed, innovative tri-layer flexible transparent conductive electrodes (TCEs) fabricated via thermal deposition. The proposed structure improves transparency compared with that of the traditional tri-layer electrode (dielectric/metal film/dielectric) by using metallic grid patterns (dielectric/metal grids/dielectric). The obtained MoO3/Ag grids/MoO3 TCEs show low sheet resistance and good mechanical properties. The sheet resistance of the proposed electrodes is 5.88 Ω/square and the transmittance reaches 76.5%, which are better than those of conventional MoO3/Ag film/MoO3 electrodes (6.12 Ω/square, <70%). The mechanical properties are significantly improved compared with those of MoO3/Ag film/MoO3 in the bending test under both tensile and compressive stress. The surface features of the MoO3/Ag grids/MoO3 TCEs were measured using the contact angle method to calculate the surface energy and polarity. The polarity is 0.5–0.26, which is better than those of indium tin oxide (0.35) and MoO3/Ag film/MoO3 (0.5–0.0058) electrodes for 0–800 bending cycles. The proposed flexible transparent electrodes show good optical, electrical, and mechanical characteristics and have potential for application in optoelectronics.
Atomic scale analysis of phase formation and diffusion kinetics in Ag/Al multilayer thin films
Authors: Aboulfadl Hisham , Gallino Isabella , Busch Ralf , Mücklich Frank
Published: November 2016

Thin films generally exhibit unusual kinetics leading to chemical reactions far from equilibrium conditions. Binary metallic multilayer thin films with miscible elements show some similar behaviors with respect to interdiffusion and phase formation mechanisms. Interfacial density, lattice defects, internal stresses, layer morphologies and deposition conditions strongly control the mass transport between the individual layers. In the present work, Ag/Al multilayer thin films are used as a simple model system, in which the effects of the sputtering power and the bilayer period thickness on the interdiffusion and film reactions are investigated. Multilayers deposited by DC magnetron sputtering undergo calorimetric and microstructural analyses. In particular, atom probe tomography is extensively used to provide quantitative information on concentration gradients, grain boundary segregations, and reaction mechanisms. The magnitude of interdiffusion was found to be inversely proportional to the period thickness for the films deposited under the same conditions, and was reduced using low sputtering power. Both the local segregation at grain boundaries as well as pronounced non-equilibrium supersaturation effects play crucial roles during the early stages of the film reactions. For multilayers with small periods of 10 nm supersaturation of the Al layers with Ag precedes the polymorphic nucleation and growth of the hcp γ-Ag2Al phase. In larger periods the γ phase formation is triggered at junctions between grain boundaries and layers interfaces, where the pathway to heterogeneous nucleation is local supersaturation. Other Ag-rich phases also form as intermediate phases due to asymmetric diffusion rates of parent phases in the γ phase during annealing.
Optical properties of mesoporous 4H-SiC prepared by anodic electrochemical etching
Authors: Rashid Marzaini , Horrocks B. R. , Healy N. , Goss J. P. , Horsfall A. B.
Published: November 2016

Porous silicon carbide was fabricated from n-type 4H-SiC substrates via anodic electrochemical etching in HF/ethanol solution and suspended in ethanol after ultrasonication. We observed three photoluminescence bands: two at wavelengths of 303 nm and 345 nm were above the bulk bandgap and one at 455 nm was below the bulk bandgap. These blue-shifted and red-shifted emission processes reveal the interplay between quantum confinement, surface states, and band edge related optical transitions. We propose a model to explain the frequently observed deviation from the quantum confinement in the photoluminesence trends for SiC-derived nanoparticles suspended in solvents. The quantum confined properties of the SiC structures provide a route for optical tunability in the UV-blue spectrum for use in novel photonic and biomedical applications.
Experimental study on the relationship between the frequency-dependent shear viscosity and the intermediate scattering function of representative viscous liquids
Authors: Yamaguchi Tsuyoshi
Published: November 2016

The frequency-dependent shear viscosity of two representative viscous liquids, o-terphenyl and glycerin, was experimentally determined at several temperatures and compared with the intermediate scattering functions reported in the literature. A comparison based on mode-coupling theory succeeded in relating the frequency-dependent shear viscosity with the intermediate scattering function at the main peak of the static structure factor. It suggests that the slow relaxation mode of the shear viscosity of both liquids is governed by the density fluctuation at the main peak of the static structure factor, in spite of the differences in the details of their intermolecular interactions.
Asymmetry of velocity distribution function and inhomogeneity-induced flow associated with neutral depletion structure in an ECR plasma
Authors: Terasaka K. , Hattori M. , Ogiwara K. , Yoshimura S. , Aramaki M. , Okamoto A. , Tanaka M. Y.
Published: November 2016

A neutral depletion structure with strong inhomogeneity in the radial direction has been observed in an electron cyclotron resonance plasma. We have measured the velocity distribution function of neutrals with a high resolution laser-induced fluorescence system and examined the relationship between asymmetry of distribution function and flow induced by inhomogeneity. It has been revealed that the third order moment of distribution function, that is, skewness, is proportional to the inhomogeneity-induced flow, and a simple relation between the skewness and the normalized flow velocity has been obtained and confirmed in the experiment.
Monitoring coherent electron wave packet excitation dynamics by two-color attosecond laser pulses
Authors: Yuan Kai-Jun , Bandrauk André D.
Published: November 2016

We propose a method to monitor coherent electron wave packet (CEWP) excitation dynamics with two-color attosecond laser pulses. Simulations are performed on aligned H2+ by numerically solving the three-dimensional time-dependent Schrödinger equation with combinations of a resonant linearly polarized λl= 100/70 nm pump pulse and a circularly polarized λc=5 nm attosecond probe pulse. It is found that time dependent diffraction patterns in molecular frame photoelectron angular distributions (MFPADs) produced by the circular probe pulse exhibit sensitivity to the molecular alignments and time-dependent geometry of the CEWPs during and after the coherent excitation between the ground and excited states induced by the linear pump pulse. The time dependent MFPADs are described by an ultrafast diffraction model for the ionization of the bound CEWPs.
Note: Wide-range and high-resolution on-chip delay measurement circuit with low supply-voltage sensitivity for SoC applications
Authors: Sheng Duo , Hung Yu-Chan
Published: November 2016

This paper presents an on-chip delay measurement (OCDM) circuit with a wide delay-measurement range, a high delay-measurement resolution and low supply-voltage sensitivity for efficient detection, and diagnosis in the high-performance system-on-chip (SoC). The proposed cascade-stage measurement structure can simultaneously achieve a delay-measurement range of several nanoseconds and a quantization resolution of several picoseconds. The proposed delay-measurement circuit has a high immunity to supply voltage variations without any additional calibration or self-biasing circuit. The delay-measurement range is 5.25 ns with 6 ps resolution; and the average delay resolution variation is 0.41% with ±10% supply voltage variations.
Fermi liquid behavior of the in-plane resistivity in the pseudogap state of YBa
2
Cu
4
O
8
Authors: Proust Cyril , Vignolle Baptiste , Levallois Julien , Adachi S. , Hussey Nigel E.
Published: November 2016

Significance

High-temperature superconductivity evolves out of a metallic state that undergoes profound changes as a function of carrier concentration, changes that are often obscured by the high upper critical fields. In the more disordered cuprate families, field suppression of superconductivity has uncovered an underlying ground state that exhibits unusual localization behavior. Here, we reveal that, in stoichiometric YBa
2
Cu
4
O
8
, the field-induced ground state is both metallic and Fermi liquid-like. The manuscript also demonstrates the potential for using the absolute magnitude of the electrical resistivity to constrain the Fermi surface topology of correlated metals and, in the case of YBa
2
Cu
4
O
8
, reveals that the current picture of the reconstructed Fermi surface in underdoped cuprates as a single, isotropic electron-like pocket may be incomplete.
In vivo amelioration of endogenous antitumor autoantibodies via low-dose P4N through the LTA4H/activin A/BAFF pathway
Authors: Lin Yu-Ling , Tsai Nu-Man , Hsieh Cheng-Hao , Ho Shu-Yi , Chang Jung , Wu Hsin-Yi , Hsu Ming-Hua , Chang Chia-Ching , Liao Kuang-Wen , Jackson Tiffany L. B. , Mold David E. , Huang Ru Chih C.
Published: November 2016

Significance

This study finds that a small-molecule drug (P4N) is able to inhibit tumor growth by augmentation of endogenous antitumor autoantibodies (EAAs). We show that the enhancement of EAA activity by P4N is mediated through activation of the leukotriene A4 hydrolase (LTA4H)/activin A/B-cell activating factor (BAFF) pathway, revealing a valuable method for developing new immune modulators of tumor growth via humoral immunity. Typically, the effects of the humoral response on tumor inhibition are modest; however, the results of this study demonstrate that by removing the impediment to cancer cell destruction posed by low-activity autoantibodies, the realization of new, more potent immunotherapies for cancer treatment may be possible.