bluuebunny/crossref_metadata_2025_split huggingface dataset:
Permanent Rabi oscillations in coupled exciton-photon systems with PT -symmetry
Authors: Chestnov Igor Yu. , Demirchyan Sevak S. , Alodjants Alexander P. , Rubo Yuri G. , Kavokin Alexey V. 
Published: January 2016

AbstractWe propose a physical mechanism which enables permanent Rabi oscillations in driven-dissipative condensates of exciton-polaritons in semiconductor microcavities subjected to external magnetic fields. The method is based on stimulated scattering of excitons from the incoherent reservoir. We demonstrate that permanent non-decaying oscillations may appear due to the parity-time symmetry of the coupled exciton-photon system realized in a specific regime of pumping to the exciton state and depletion of the reservoir. At non-zero exciton-photon detuning, robust permanent Rabi oscillations occur with unequal amplitudes of exciton and photon components. Our predictions pave way to realization of integrated circuits based on exciton-polariton Rabi oscillators.
A Simple Approach for Molecular Controlled Release based on Atomic Layer Deposition Hybridized Organic-Inorganic Layers
Authors: Boehler Christian , Güder Firat , Kücükbayrak Umut M. , Zacharias Margit , Asplund Maria 
Published: January 2016

AbstractOn-demand release of bioactive substances with high spatial and temporal control offers ground-breaking possibilities in the field of life sciences. However, available strategies for developing such release systems lack the possibility of combining efficient control over release with adequate storage capability in a reasonably compact system. In this study we present a new approach to target this deficiency by the introduction of a hybrid material. This organic-inorganic material was fabricated by atomic layer deposition of ZnO into thin films of polyethylene glycol, forming the carrier matrix for the substance to be released. Sub-surface growth mechanisms during this process converted the liquid polymer into a solid, yet water-soluble, phase. This layer permits extended storage for various substances within a single film of only a few micrometers in thickness and hence demands minimal space and complexity. Improved control over release of the model substance Fluorescein was achieved by coating the hybrid material with a conducting polymer film. Single dosage and repetitive dispensing from this system was demonstrated. Release was controlled by applying a bias potential of ±0.5 V to the polymer film enabling or respectively suppressing the expulsion of the model drug. In vitro tests showed excellent biocompatibility of the presented system.
Hypercarnivorous apex predator could provide ecosystem services by dispersing seeds
Authors: Sarasola José Hernán , Zanón-Martínez Juan Ignacio , Costán Andrea Silvina , Ripple William J. 
Published: January 2016

AbstractLarge “hypercarnivorous” felids are recognized for their role as apex predators and hence as key elements in food webs and ecosystem functioning through competition and depredation. Here we show that cougars (Puma concolor), one of the largest and the most widely ranging apex felid predators with a strictly carnivorous diet, could also be effective secondary long distance seed dispersers, potentially establishing direct and non-herbivore mediated interactions with plant species at the bottom of the food web. Cougars accidently ingest and disseminate large amounts of seeds (31,678 seeds in 123 scats) of plant species initially consumed by their main prey, the Eared Dove Zenaida auriculata. The germination potential of seeds for the three plant species most abundantly found in cougar scats (19,570 seeds) was not significantly different from that observed in seeds obtained from dove gizzards, indicating that seed passage through cougar guts did not affect seed germination. Considering the estimated cougar density in our study area, dispersal of seeds by cougars could allow a mean, annual seed spread of ~5,000 seeds per km2. Our results demonstrate that strictly carnivorous, felid predators could have broad and overlooked ecological functions related to ecosystem structuring and functioning.
Label-free SERS study of galvanic replacement reaction on silver nanorod surface and its application to detect trace mercury ion
Authors: Wang Yaohui , Wen Guiqing , Ye Lingling , Liang Aihui , Jiang Zhiliang 
Published: January 2016

AbstractIt is significant to explore a rapid and highly sensitive galvanic replacement reaction (GRR) surface enhanced Raman scattering (SERS) method for detection of trace mercury ions. This article was reported a new GRR SERS analytical platform for detecting Hg(II) with label-free molecular probe Victoria blue B (VBB). In HAc-NaCl-silver nanorod (AgNR) substrate, the molecular probe VBB exhibited a strong SERS peak at 1609 cm−1. Upon addition of Hg(II), the GRR occurred between the AgNR and Hg(II) and formed a weak SERS activity of Hg2Cl2that deposited on the AgNR surfaces to decrease the SERS intensity at 1609 cm−1. The decreased SERS intensity "Equation missing"was linear to Hg(II) concentration in the range of 1.25–125 nmol/L, with a detection limit of 0.2 nmol/L. The GRR was studied by SERS, transmission electron microscopy and other techniques and the GRR mechanism was discussed.
Effects of asymmetric nanostructures on the extinction difference properties of actin biomolecules and filaments
Authors: Khoo E. H. , Leong Eunice S. P. , Wu S. J. , Phua W. K. , Hor Y. L. , Liu Y. J. 
Published: January 2016

AbstractIn this paper, symmetric and asymmetric tapering on the arms of the gammadion nanostructure is proposed to enhance both local field distribution and extinction difference (ED). The asymmetric tapered gammadion with tapering fraction (TF) of 0.67 is seen to have the largest ED and spatial local field distribution, producing a large wavelength shift of more than 50 percent as compared to the untapered gammadion nanostructures when immersed in a solution of actin molecules and filaments. The optical chirality, ζ shows that the larger local field amplitudes produced by the asymmetric designs increases the rate of chiral molecules excitation. This enhanced field is strongly rotating and highly sensitive to single molecules and larger filaments. Here, we show that the ED, optical chirality, sensitivity and rate of chiral molecules excitation can be improved by incorporating asymmetric designs into chiral gammadion nanostructures through tapering.
Adaptive Strategies for Materials Design using Uncertainties
Authors: Balachandran Prasanna V. , Xue Dezhen , Theiler James , Hogden John , Lookman Turab 
Published: January 2016

AbstractWe compare several adaptive design strategies using a data set of 223 M2AX family of compounds for which the elastic properties [bulk (B), shear (G) and Young’s (E) modulus] have been computed using density functional theory. The design strategies are decomposed into an iterative loop with two main steps: machine learning is used to train a regressor that predicts elastic properties in terms of elementary orbital radii of the individual components of the materials; and a selector uses these predictions and their uncertainties to choose the next material to investigate. The ultimate goal is to obtain a material with desired elastic properties in as few iterations as possible. We examine how the choice of data set size, regressor and selector impact the design. We find that selectors that use information about the prediction uncertainty outperform those that don’t. Our work is a step in illustrating how adaptive design tools can guide the search for new materials with desired properties.
Toxicity of AMPA to the earthworm Eisenia andrei Bouché, 1972 in tropical artificial soil
Authors: Domínguez Anahí , Brown George Gardner , Sautter Klaus Dieter , Ribas de Oliveira Cintia Mara , de Vasconcelos Eliane Carvalho , Niva Cintia Carla , Bartz Marie Luise Carolina , Bedano José Camilo 
Published: January 2016

AbstractAminomethylphosphonic acid (AMPA) - one of glyphosate’s main metabolites - has been classified as persistent in soils, raising concern regarding the widespread use of glyphosate in agriculture and forestry. Glyphosate may have negative or neutral effects on soil biota, but no information is available on the toxicity of AMPA to soil invertebrates. Therefore our aim was to study the effect of AMPA on mortality and reproduction of the earthworm species Eisenia andrei using standard soil ecotoxicological methods (ISO). Field-relevant concentrations of AMPA had no significant effects on mortality in acute or chronic assays. Except at the highest concentration tested, a significant biomass loss was observed compared to controls in the chronic assay. The number of juveniles and cocoons increased with higher concentrations of AMPA applied, but their mean weights decreased. This mass loss indicates higher sensitivity of juveniles than adults to AMPA. Our results suggest that earthworms coming from parents grown in contaminated soils may have reduced growth, limiting their beneficial roles in key soil ecosystem functions. Nevertheless, further research is needed to better understand the mechanisms underlying the sublethal effects observed here.
Metallic conduction induced by direct anion site doping in layered SnSe2
Authors: Kim Sang Il , Hwang Sungwoo , Kim Se Yun , Lee Woo-Jin , Jung Doh Won , Moon Kyoung-Seok , Park Hee Jung , Cho Young-Jin , Cho Yong-Hee , Kim Jung-Hwa , Yun Dong-Jin , Lee Kyu Hyoung , Han In-taek , Lee Kimoon , Sohn Yoonchul 
Published: January 2016

AbstractThe emergence of metallic conduction in layered dichalcogenide semiconductor materials by chemical doping is one of key issues for two-dimensional (2D) materials engineering. At present, doping methods for layered dichalcogenide materials have been limited to an ion intercalation between layer units or electrostatic carrier doping by electrical bias owing to the absence of appropriate substitutional dopant for increasing the carrier concentration. Here, we report the occurrence of metallic conduction in the layered dichalcogenide of SnSe2 by the direct Se-site doping with Cl as a shallow electron donor. The total carrier concentration up to ~1020 cm−3 is achieved by Cl substitutional doping, resulting in the improved conductivity value of ~170 S·cm−1 from ~1.7 S·cm−1 for non-doped SnSe2. When the carrier concentration exceeds ~1019 cm−3, the conduction mechanism is changed from hopping to degenerate conduction, exhibiting metal-insulator transition behavior. Detailed band structure calculation reveals that the hybridized s-p orbital from Sn 5s and Se 4p states is responsible for the degenerate metallic conduction in electron-doped SnSe2.
Role of Ag2S coupling on enhancing the visible-light-induced catalytic property of TiO2 nanorod arrays
Authors: Li Zhengcao , Xiong Shan , Wang Guojing , Xie Zheng , Zhang Zhengjun 
Published: January 2016

AbstractIn order to obtain a better photocatalytic performance under visible light, Ag2S-coupled TiO2 nanorod arrays (NRAs) were prepared through the electron beam deposition with glancing angle deposition (GLAD) technique, annealing in air, followed by the successive ionic layer absorption and reaction (SILAR) method. The properties of the photoelectrochemical and photocatalytic degradation of methyl orange (MO) were thus conducted. The presence of Ag2S on TiO2 NRAs was observed to have a significant improvement on the response to visible light. It’s resulted from that Ag2S coupling can improve the short circuit photocurrent density and enhance the photocatalytic activity remarkably.
Lifetime of Ionic Vacancy Created in Redox Electrode Reaction Measured by Cyclotron MHD Electrode
Authors: Sugiyama Atsushi , Morimoto Ryoichi , Osaka Tetsuya , Mogi Iwao , Asanuma Miki , Miura Makoto , Oshikiri Yoshinobu , Yamauchi Yusuke , Aogaki Ryoichi 
Published: January 2016

AbstractThe lifetimes of ionic vacancies created in ferricyanide-ferrocyanide redox reaction have been first measured by means of cyclotron magnetohydrodynamic electrode, which is composed of coaxial cylinders partly exposed as electrodes and placed vertically in an electrolytic solution under a vertical magnetic field, so that induced Lorentz force makes ionic vacancies circulate together with the solution along the circumferences. At low magnetic fields, due to low velocities, ionic vacancies once created become extinct on the way of returning, whereas at high magnetic fields, in enhanced velocities, they can come back to their initial birthplaces. Detecting the difference between these two states, we can measure the lifetime of ionic vacancy. As a result, the lifetimes of ionic vacancies created in the oxidation and reduction are the same and the intrinsic lifetime is 1.25 s and the formation time of nanobubble from the collision of ionic vacancies is 6.5 ms.
Points of Departure
Authors: Newitt Malyn 
Published: January 2016

Abstract
This chapter examines the reasons for emigration from Portugal and the scale of migration over the centuries. It looks at land tenure and the rural economy; the origins of Portuguese overseas expansion and the role of the royal family and nobility; the long term structures of the Portuguese economy and society and the importance of emigrant remittances; official emigration schemes; and the exile of convicts and gipsies and the placement of orphans.
The Portuguese in Brazil
Authors: Newitt Malyn 
Published: January 2016

Abstract
This chapter traces Portuguese settlement in Brazil, which began in the early sixteenth century and grew with the expansion of the Brazilian economy. The production of sugar and tobacco was followed by the settlement of the interior after the discovery of gold at the end of the seventeenth century. The expanding frontier took Portuguese settlers to Amazonia, to the Rio de la Plata and as far as the Andes, settlements characterized by slaving, cattle ranching and the planting of missions in the backlands. After the independence of Brazil from Portugal in 1822 emigration continued with Portuguese joining families already established in the commercial sector of the cities or seeking work on the plantations after the end of the slave trade in 1851. Brazil remained the principal destination of Portuguese emigrants until after the Second World War.
Portuguese Emigration in the Twentieth Century
Authors: Newitt Malyn 
Published: January 2016

Abstract
Emigration in the twentieth century became a politically contentious topic in Portugal. This chapter looks at the numbers involved and the difficulty of establishing exact figures, the geographical and social distribution of emigrants, their destinations, the factors that led to continued migration and the balance sheet of benefits and problems caused by emigration. Remittances remained a key factor in Portugal’s balance of payments. Differences emerged between islanders who looked towards the Americas and mainland Portuguese who increasingly emigrated to northern Europe, especially France and Germany.
The Caribbean, Canada and South America
Authors: Newitt Malyn 
Published: January 2016

Abstract
In the nineteenth century Portuguese from Madeira emigrated in large numbers to the British Caribbean islands, especially British Guiana where they established themselves first as plantation workers and then in the commercial sectors. There they were treated as a separate racial category from other European settlers. At the end of the nineteenth century emigration also began to Argentina, especially from southern Portugal. Integration into the Spanish-speaking population was relatively swift, as it was in neighbouring Uruguay. After World War II large-scale emigration also took place to Venezuela. Emigration to Canada began in the 1950s and large Portuguese emigrant populations settled in Toronto and Montreal. The chapter follows the trajectory of emigrants from the earliest unskilled arrivals to second and third generations of settled Portuguese Canadians.
The Portuguese Diaspora in the United States
Authors: Newitt Malyn 
Published: January 2016

Abstract
Portuguese emigration to the United States began with whalers from the Azores and Cape Verde islands. Most settled in New England where significant communities grew up in Massachusetts and Rhode Island. The chapter looks in detail at the community in Gloucester, Mass. Madeirans also went to Hawaii to work in the sugar industry. Later, many moved on to California where they became well established in the dairy industry. This chapter looks at the way Portuguese have been represented by American writers from Bullen in the nineteenth century to Jack London, Steinbeck, Ross and the recent generation of Azorean writers like Lewis, Fagundes and Gaspar.
Electromagnetic Theory
Authors: Guenther B. D. 
Published: January 2016

Abstract
Electromagnetic theory, Maxwell’s equations, and Poynting’s theorem are used to derive the following properties of light waves: (1) the wave nature of light; (2) the fact that light is a transverse wave; (3) the velocity of light in terms of fundamental electromagnetic properties of materials; (4) the relative magnitude of the electric and magnetic fields and relationships between the two fields; and finally (5) the energy associated with a light wave. The concept of polarized light and a geometrical construction used to visualize its behavior are introduced.
Diffraction and Gaussian Beams
Authors: Guenther B. D. 
Published: January 2016

Abstract
A descriptive scalar theory, based on Huygens’ principle is used to derive an integral called the Huygens–Fresnel integral. Two more rigorous mathematical treatments of scalar diffraction theory: Fresnel–Kirchhoff diffraction and the Rayleigh–Sommerfeld formula, are given in appendices. To justify the use of Huygens’ principle, the principle is used to derive the laws of reflection and refraction. Another approach to determining the propagation of light through an optical system is the solution of the Helmholtz equation. A particular solution is shown to be a Gaussian wave. The Gaussian wave can be characterized by a beam waist (the diameter of the beam of light at the half-power points of the Gaussian distribution) and the radius of curvature of the wave’s phase front. The ABCD law for Gaussian waves is derived and used to design a laser cavity.
Fresnel Diffraction
Authors: Guenther B. D. 
Published: January 2016

Abstract
Fresnel diffraction is an approximate solution of the Huygens–Fresnel integral assuming the phase of the wavefront in the aperture has a quadratic dependence upon aperture coordinates. Only that portion of the aperture near the line connecting source and observation points contributes to Fresnel diffraction. For different symmetries, the integral is solved using different mathematical techniques. With separable rectangular coordinates, a table of Fresnel integrals or a graphical technique based on a plot of the Fresnel integral called the Cornu spiral is used. For circular symmetric apertures, a geometrical construction called Fresnel zones is used. The impact of the obliquity factor in calculating the contribution of Fresnel zones is discussed. The existence of Poisson’s spot behind an opaque screen and the performance of a pinhole camera are derived. The design of a zone plate is discussed. The Fresnel zone construction is used to provide additional physical insight into Fermat’s principle.
Optical Modulation
Authors: Guenther B. D. 
Published: January 2016

Abstract
The use of an electric, magnetic, or stress field to modify the optical properties of a medium is examined. The application of one of these disturbances produces an anisotropy in the medium that requires a tensor description and generates a birefringence. The technique used to convert the modification of the polarization by the birefringence to an intensity modulation is described and its implementation in the design of an electro-optic modulator is discussed. Application of a stress to a material modifies its optical properties by producing an anisotropy in its density. The spatial density variation produces a birefringence in the material, and both phenomenological and scattering theories are described that explain the operation of an acousto-optic modulator.
A Cognitive Approach to Greek Metre: Hermann’s Bridge in the Homeric Hexameter and the Interpretation of Iliad 24
Authors: Schein Seth L. 
Published: January 2016

Abstract
A study of violations of Hermann’s Bridge in the Homeric hexameter, grounded in cognitive studies of ‘Event-related Brain Potentials’, complements Russian formalist and structuralist theory in suggesting that such violations are often associated with other deviations from normal hexameter colometry and that they often are, by a process of defamiliarization, marked and mimetically or semantically meaningful. Detailed analysis of violations of Hermann’s Bridge, whether or not they involve enclitics, illustrates the kinds of meaning that can be produced by such metrical anomalies. Close attention to the first 73 lines of Iliad 24, in which there are violations of Hermann’s Bridge in lines 35 and 60 in the speeches of Apollo and Hera, suggests parallels between significant non-normative metrical phenomena and significant mythological allusion and demonstrates how detailed study of the violation of metrical form and of mythological allusion opens pathways into literary interpretation.
Milman Parry and the Literary Interpretation of Homeric Poetry
Authors: Schein Seth L. 
Published: January 2016

Abstract
Milman Parry’s ‘The Historical Method in Literary Criticism’ reflects his insistence on exact scholarship and rigorous analysis and his belief that an empathetic reader of Homeric epic can, like an anthropologist, become part of a culture he or she is studying. Committed to both principles, Parry did not fully appreciate the difficulties raised when they are in conflict. Parry’s ‘fieldwork’ in both Homeric and Yugoslav cultures led him to attach moral significance to the study of literature as he himself practised it: he identified with the men of the heroic past and argued that through such identification, readers could ‘gain through their literature an understanding of men and life and a power for effective and noble action…’. Parry, however, though he spoke of readers, was committed to his own ways of reading and identification; he did not appreciate how other readers and audiences might approach and understand Homer differently.
Ioannis Kakridis and Neoanalysis
Authors: Schein Seth L. 
Published: January 2016

Abstract
Ioannis Kakridis created the method of Homeric scholarship known as Neoanalysis. Starting from the Unitarian belief that the Iliad is the work of one great poet, he also drew on Analytical scholarship. Where, however, Analysts detected inartistic clumsiness and signs of multiple authorship, Kakridis saw poetic creativity and Homeric artistry in the appropriation and adaptation of motifs, speeches, and scenes present in pre-Homeric epic, folklore, and popular song, often by transferring material from one character or myth to another. Kakridis discovered in Homeric epic structural motifs and narrative techniques familiar from medieval and modern Greek folktales and popular songs. He suggested that there had been analogous, pre-Homeric folktales and songs on which the poet drew for his own artistic purposes. Kakridis shared with M. Parry an understanding of poetic tradition based not only on philological scholarship, but on a somewhat romanticizing approach to the heroic world of Homeric epic.