bluuebunny/crossref_metadata_2025 huggingface dataset:
Hidden messages and revealing stories
Authors: Cresswell Jenni
Published: June 2019

In this article I explore my creative textile practice as an auto/ethnographical investigation into my work. I examine how my work methodologies have altered over the past few years as a result of research through practice and as I have attempted to hide, yet reveal stories through my pieces. I note how my work has become more concerned with finding ways to express my own personal story visually through the medium of second-hand garments, in particular dresses. I show how, as I attempt to illustrate narratives through my work, each dress also reveals a story of its own through its deconstruction or embellishment within the piece; the wear and tear of the dress hinting at its past lives and stories. In turn this multilayered medium allows me to hide my own stories in plain sight and also allows viewers of the pieces to draw their own narratives from the whole.
Managing hysteria: Exploring the writer’s voice through verbatim work
Authors: Jordan-Baker Craig
Published: June 2019

Verbatim work places a premium on the invisibility of the artist. This is in tension to Neo-Romantic conceptions of the ‘writer’s voice’, often characterized as the expression of the sovereign individual. Such a tension raises the question of to what extent an expression of self is desirable and what we can learn about artistic voice in verbatim work. This article discusses such questions through the lens of a commission to creatively respond to the National Archive’s material on mental health. This resulted in a piece of ‘contrapuntal radio’ that dramatized the voices of militant suffragettes (c. 1907–14). By consideration of the process of production, the article will argue that often, considerations of self-expression (where the artist is a unique voice transmitting their individuality), threatens a more productive self-expression, where an artist is a disinterested expresser of human feeling.
‘Getting over our selves’: Elegy and rhetoric in Ted Hughes’s Birthday Letters and Carrie Etter’s Imagined Sons
Authors: Dreyer Cathy
Published: June 2019

Critical analysis ofBirthday Lettersby Ted Hughes andImagined Sonsby Carrie Etter is illuminated by reading both texts against the rhetorical strategies and conventions of elegy.Birthday LettersandImagined Sonsare engaged in communicating strong feelings of grief following serious losses within lived experience, for which both construct first-person speakers. This article recognizes the presence of the conventions of elegy in both texts and suggests that despite thematic and structural similarities, there are significant differences in the ways the speakers in these texts are configured and how they address their audiences.
A base nacional comum curricular e a superação de conflitos em um projeto educativo
Authors: Augusti Rudinei Barichello
Published: June 2019

Este artigo compreende o estudo, revisão, investigação, sobre a Base Nacional Comum Curricular, bem como aborda a superação de conflitos para o desenvolvimento do projeto educativo. O mesmo apresenta a fundamentação legal da Base Nacional Comum Curricular, bem como, de que forma esses elementos legais foram se tornando legítimos no decorrer da história. Após a fundamentação dos aspectos legais, históricos, culturais e sociais da Base, apresenta-se duas barreiras e três conflitos que precisam ser superados na dinâmica da Base Nacional Comum Curricular. A primeira barreira imposta ao currículo escolar refere-se ao afastamento do professor, do aluno, do agente educacional e dos pais, do exercício político-pedagógico e educacional das escolas. A segunda, é consequência do veio da Pedagogia Tradicional, em que emprega a existência de um conhecimento exterior e prévio da escola que deve ser apreendido e aprendido por ela. Já os conflitos são a superação da racionalidade técnica, a superação da epistemologia reguladora e, a superação dos conflitos culturais. Nesse sentido, o que se busca é compreender a Base Nacional Comum Curricular a partir de seu contexto imbricado pedagógica e politicamente.
As TIC’s na Educação Infantil: contribuições do Facebook para a aprendizagem e para a integração família e escola
Authors: Costa Luciano Andreatta da , Steyer Silvana Castilhos , Ramos Maria Altina Silva
Published: June 2019

A revolução tecnológica a cada dia aumenta e transforma de forma significativa diversos setores da sociedade: econômicos, culturais, sociais e educacionais. Os meios tecnológicos, através da informática, se fazem presentes na sociedade moderna. As crianças pequenas não estão alheias a esta gama de informações que são disponibilizadas pelas TIC. As tecnologias promovem mudanças expressivas em toda a sociedade, e, consequentemente na educação, na qual devem estar presentes, pois instituem novas formas de comunicação e estimulam as já existentes. Neste contexto, este artigo, elaborado a partir da pesquisa de mestrado da autora, visa trazer uma contribuição para o campo educacional e analisar o interesse educativo do uso das TIC na Educação Infantil. Com isso busca-se lançar um olhar sobre as contribuições do grupo “Turminha Legal” no Facebook, para ligar família-escola em torno dos conteúdos escolares. Os resultados obtidos pelo presente estudo corroboram a importância da inserção das tecnologias no ambiente escolar, e, consequentemente na educação infantil.
ФУНКЦІЇ ПІДРУЧНИКА УКРАЇНСЬКОЇ МОВИ В КОМПЕТЕНТНІСНІЙ ПАРАДИГМІ
Authors: Горошкіна Олена
Published: June 2019

W artykule określono funkcje podręcznika do języka ukraińskiego, zwłaszcza światopoglądową, wartościująco-orientacyjną, rozwijającą, informacyjną, refl eksyjno-korekcyjną. Szczególną uwagę zwrócono na kwestię wprowadzenia podejścia kompetencyjnego do procesu kształcenia, co warunkuje przekształcenie funkcji podręcznika, wyodrębnienie nowych funkcji, które odpowiadają współczesnym wyzwaniom społecznym.
МЕТАФОРА В БІОЛОГІЧНІЙ ТЕРМІНОСИСТЕМІ (українсько-польські паралелі)
Authors: Кухарчишин Марія
Published: June 2019

Artykuł poświęcony jest analizie metafory jako środka tworzenia terminów w terminologii biologicznej. Оkreślonа została rola metafory w naukowym obrazie świata w języku ukraińskim i polskim. Оpisano skojarzenia, które stały się podstawą przeniesienia metaforycznego.
ВЕРБАЛІЗАЦІЯ НЕВЕРБАЛІКИ: КОМПАРАТИВНО-ЗІСТАВНИЙ АНАЛІЗ НАЦІОНАЛЬНОЇ ПОВЕДІНКИ (на матеріалі української, російської, польської фразеології)
Authors: Осіпова Тетяна
Published: June 2019

W artykule przeanalizowano metodykę badań nad parametrami komunikacji niewerbalnej, werbalizowanymi poprzez jednostki frazeologiczne ukraińskiego, polskiego, rosyjskiego etnosu, które łączą wspólne wschodniosłowiańskie korzenie. Zastosowanie komparatywno-porównawczej metody analizy sprzyja ujawnieniu pragmatycznych mechanizmów tworzenia komunikacyjnych znaczeń frazeologizmów z komponentami niewerbalnymi.
ЗАСОБИ ВИРАЖЕННЯ НЕГАТИВНИХ ЕМОЦІЙ У СУЧАСНИХ ПУБЛІЦИСТИЧНИХ ТЕКСТАХ (на матеріалі статей, опублікованих у журналі New Yorker та газеті Українська правда)
Authors: Сліпецька Віра
Published: June 2019

W artykule dokonano analizy sposobów wyrażania negatywnych emocji gniewu, nienawiści, oburzenia we współczesnych ukraińskich oraz angielskich tekstach publicystycznych. Bezpośrednia nominacja emocji, wyrazy-wykrzykniki, brutalna leksyka, znaki wykrzyknienia, metaforyczne przeniesienia, negatywnie zabarwione partykuły to środki wyrażenia negatywnych emocji.
МОВНОСОЦІУМНА ОБ’ЄКТИВНА ГРАМАТИКА: КАТЕГОРІЇ, РІВНІ, АСПЕКТИ
Authors: Загнітко Анатолій
Published: June 2019

W skład obiektywnej gramatyki językowo-społecznej wchodzą, m.in. kategoria językowa, kategoria mówienia czy kategoria komunikacyjna z poziomami werbalno-semantycznym, kognitywnym czy pragmatycznym, a także kategorie językowego/ kognitywno-językowego, narodowo-kognitywnego obrazu świata i in. Podstawowymi jednostkami są wyraz morfologiczny i wyraz syntaktyczny, związek wyrazowy, zdanie, wypowiedzenie, tekst z uwzględnieniem różnorodnych dyskursów, ich organizacji, dyskursywnych praktyk. Obiektywna gramatyka językowo-społeczna opiera się na rozróżnieniu poziomów morfologicznego i syntaktycznego, ich różnych aspektów.
Hot Deformation Behavior and Microstructural Characterization of CoCrFeNiNb0.45 Eutectic High Entropy Alloy
Authors: Rahul M. R. , Samal Sumanta , Phanikumar Gandham
Published: June 2019

In recent years, several multicomponent alloys of near equiatomic composition (also known as high-entropy alloys) with excellent mechanical properties have been developed. In this study, a eutectic high entropy alloy, CoCrFeNiNb0.45, was chosen for a hot deformation study. The alloy consists of a primary face-centered cubic (FCC) phase (CoCrFeNi rich) and a eutectic region between the FCC and Laves phase (Co2Nb type). The combination of FCC and eutectic region is expected to provide better strength and ductility. Hot compression tests were carried out at different strain rates of 0.001, 0.1, 1, and 10 s−1 with varying temperatures of 1,073, 1,173, 1,273, and 1,323 K. The optimum processing window was identified by plotting processing maps, and the instability region was verified using multiple parameters. Constitutive equation relating stress, strain rate, and temperature is established. The optimum processing condition was correlated with the microstructural characterization, and instability was characterized with cracks on the specimen. Finite element simulation was carried out, taking the flow curve as input and correlating the strain field distribution with the microhardness variation. These studies are intended to contribute to an integrated computational materials engineering approach to developing these alloys toward a product.
Los Basurales a Cielo Abierto y Su Invisibilización: ¿Un Traspaso de Costos a Futuro?
Authors: D'hers Victoria
Published: June 2019

En este escrito se plantea un análisis de los basurales a cielo abierto tomando nociones de la Economía Ecológica, considerando dos aspectos complementarios: por una parte, los “lenguajes de valoración” implicados en las conceptualizaciones del ambiente; y por otra, la posibilidad de evaluarlos como pasivos ambientales. Ambos aspectos vinculados estrechamente con su valorización económica. Se despliega brevemente la dinámica de la gestión de los residuos en el Área Metropolitana de Buenos Aires, re-situándolos en el metabolismo de la ciudad capitalista para problematizar el modo en que estos espacios funcionan como traspaso de costos a sectores invisibilizados. ¿Cómo cuantificar las consecuencias de la exposición a contaminantes? ¿Cómo reconocer la deuda ecológica al interior de una sociedad que deposita en sectores subalternos la carga de la omisión estatal? Finalmente, ¿de qué modo este traspaso de costos es funcional tanto a nivel de la gestión de los residuos, como en la forma de una solución del déficit habitacional actual?
Sociedade Civil: Considerações Acerca de sua Concepção e Empoderamento no Século XXI
Authors: Gimenes Éder Rodrigo
Published: June 2019

Resenha do livro: LUIZ, Danuta E. Cantoia. (Org.). Sociedade civil e democracia: expressões contemporâneas. São Paulo: Veras, 2010. 303 p.
Crisis ambiental – Crisis civilizatoria: el giro ambiental de lo humano en tiempos de crisis civilizatoria
Authors: De Echeverri Ana Patricia Noguera
Published: June 2019

Palestra realizada em 29/10/2013Local: Instituto de Filosofia, Sociologia e Política, Sala 309, 3o andarAna Patricia Noguera de Echeverri,PhD Grupo de Pensamiento Ambiental Universidad Nacional Sede Manizales
TECNOLOGIA E AMBIENTE: AS ESCOLHAS TÉCNICAS E SEUS EFEITOS “SOCIAIS”
Authors: Prates Camila Dellagnese
Published: June 2019

Este trabalho está amparado nas incursões teóricas da Sociologia da Ciência e da Tecnologia e visa problematizar as transformações ambientais e os efeitos “sociais” que resultam da inserção de um artefato tecnocientífico em dada localidade. O empírico delimitado (os estudos altimétricos que delimitam a cota 100) faz parte de um universo mais amplo que compreende a construção da Usina Hidrelétrica de Belo Monte (UHEBM) situada nas proximidades de Altamira, Pará. Neste trabalho, reforça-se o papel de atores externos (pesquisadores universitários e procuradores) à construção da usina enquanto agenciadores da controvérsia tecnocientífica que envolve o cálculo da cota 100, responsável por delimitar a quantidade de pessoas afetadas e indenizadas na cidade de Altamira. A hipótese norteadora do trabalho considera que os consultores responsáveis pelos “estudos oficiais” estipulam o cálculo da cota com um grau menor de certeza, ampliando a margem de riscos ambientais na região. Nesse sentido, busca-se explorar os argumentos e a rede de sustentação que defendem a cota 100, mobilizados pelo empreendedor, a Norte Energia, e também os contraargumentos, e a rede de sustentação agenciada pelo Ministério Público Federal (MPF). A controvérsia é considerada como pano de fundo para evidenciar o modo como os conhecimentos aplicados na usina são justificados e legitimados como modificadores do ambiente e problematiza as implicações da aceitação desse conhecimento. Este trabalho contribui para pensar sobre a atuação do MPF como um ator que formata uma controvérsia tecnocientífica, a mantém aberta e promove diferenciações na compreensão das modificações tecnocientíficas no ambiente. Teoricamente, este estudo está amparado nas provocações epistêmicas e metodológicas da Teoria do Ator-Rede (TAR) de Bruno Latour, Michel Callon e Annemarie Mol. A pesquisa empírica que sustenta a discussão foi realizada entre Março e Maio de 2014 em Altamira, Pará.Palavras-Chaves: Controvérsia; Tecnociência; Usina Hidrelétrica Belo Monte.
UNA PERSPECTIVA SOCIOLÓGICA DE LA CAPACITACIÓN DOCENTE EN EDUCACIÓN AMBIENTAL: UN DISPOSITIVO DE ESCOLARIZACIÓN NEOLIBERAL
Authors: Humacata Vanesa Victoria
Published: June 2019

Se presenta un ensayo teórico que reconoce a partir de la noción conceptual de “escolarización”, los factores que inciden en la conformación de políticas de capacitación docente de Educación Ambiental (EA) en un contexto de neoliberalismo y reformas educativas. La guía empírica de este recorrido teórico es un decreto ministerial, este decreto institucionaliza la EA mediante la creación de un espacio en la estructura organizacional del Ministerio de Educación (Jujuy-Argentina). Desde el Análisis Político del Discurso (APD), se comprende cómo la política de “capacitación docente” adquiere protagonismo. La contextualización del marco socio-económico de las últimas dos décadas, el rol de las reformas educativas y su vinculación con el mercado, los organismos internacionales, el financiamiento multilateral, son parte del análisis teórico; un análisis clave que permite reconocer las condiciones simbólicas de la formación y el trabajo docente, que configuran una posición docente particular.El ensayo teórico que posiciona a la capacitación docente en el marco de las coordenadas de un análisis macroestructural, evidencia que las Políticas de EA y la capacitación docente tienen que negociar con tradiciones y prácticas con las que se construyen híbridos, finalmente, se trata de resituar el valor de la capacitación docente.Se cuestiona aquella idea establecida de vincular la capacitación docente con políticas puntuales. Los binomios “Capacitación docente en…” operan en un nivel de reduccionismo que evade la discusión políticoeducativa, un reduccionismo que opera como la principal forma de escolarización neoliberal. El ensayo concluye en resignificar los fines de la EA y la formación docente, una discusión sobre como renovar la significatividad de la escuela, no desde un reduccionismo disciplinar, sino desde la perspectiva teleológica, que reconoce las reflexiones de Philippe Meirieu.Palabras Clave: Políticas de capacitación docente; Educación Ambiental; Dispositivos de escolarización.
CONFLITO AMBIENTAL RELACIONADO A PROCESSOS ESPECULATIVOS E IMOBILIÁRIOS NO PONTAL DA BARRA, PELOTAS/RS
Authors: Da Silveira Nebel Gitana Cardoso
Published: June 2019

O propósito deste artigo consiste em explicitar as controvérsias entre atores sociais com distintos modos de significação, uso e apropriação territorial no contexto de conflito ambiental em torno do Pontal da Barra, Laranjal, Pelotas/RS. As reflexões procedem da dissertação de mestrado da autora (NEBEL, 2014), cujo objetivo consistiu em incorporar a dimensão do conflito enquanto elemento central de análise desde uma perspectiva etnográfica. Para isso, partiu-se da proposta analítica de explicitação do conflito como forma de mapeamento dos diferentes atores sociais, contemplando suas visões, posições, interesses, discursos e estratégias de disputa e legitimação no campo ambiental. De modo mais específico, o presente artigo busca problematizar o modelo dominante e hegemônico de “desenvolvimento” na região, e como essas posturas de homogeneização e exclusão podem silenciar as controvérsias públicas, subsumindo os complexos processos sociais e os diversos atores neles envolvidos. Mediante esses conflitos revelam-se as contradições e as assimetrias no agenciamento de atividades e de formas sociais de apropriação e uso dos territórios que, em última análise, são reprodutoras de “injustiças ambientais”.Palavras-chave: Conflito ambiental; Etnografía; Pontal da Barra.
A Novel Gene Underlies Bleomycin-Response Variation inCaenorhabditis elegans
Authors: Brady Shannon C , Zdraljevic Stefan , Bisaga Karol W , Tanny Robyn E , Cook Daniel E , Lee Daehan , Wang Ye , Andersen Erik C
Published: June 2019

Bleomycin is a powerful chemotherapeutic drug used to treat a variety of cancers. However, individual patients vary in their responses to bleomycin. The identification of genetic differences that underlie this response variation could improve treatment outcomes by tailoring bleomycin dosages to each patient. We used the model organism Caenorhabditis elegans to identify genetic determinants of bleomycin-response differences by performing linkage mapping on recombinants derived from a cross between the laboratory strain (N2) and a wild strain (CB4856). This approach identified a small genomic region on chromosome V that underlies bleomycin-response variation. Using near-isogenic lines, and strains with CRISPR-Cas9 mediated deletions and allele replacements, we discovered that a novel nematode-specific gene (scb-1) is required for bleomycin resistance. Although the mechanism by which this gene causes variation in bleomycin responses is unknown, we suggest that a rare variant present in the CB4856 strain might cause differences in the potential stress-response function of scb-1 between the N2 and CB4856 strains, thereby leading to differences in bleomycin resistance.
Silent pirates: Anolis sagrei Duméril & Bibron, 1837 (Squamata, Dactyloidae) taking over Panama City, Panama
Authors: Batista Abel , Ponce Marcos , Garcés Orlando , Lassiter Elliot , Miranda Madian
Published: June 2019

Anolis sagrei Duméril & Bibron, 1837 is one of the most widespread reptiles in the world, having colonized more than 15 countries on 2 continents. It inhabits open areas and is commonly found around big cities. We noticed the presence of an unreported, nonnative population in Panama City, Panama, which has been established since at least 5 years. We report A. sagrei for the first time in Panama based on collected specimens. We argue that the species is currently abundant in some areas and it could be a threat for native species.
New records of the Mountain Mullet, Dajaus monticola (Bancroft, 1834), and an overview of historical records in Texas
Authors: Kubicek Kole M. , Pinion Amanda K. , Conway Kevin W.
Published: June 2019

Dajaus monticola (Bancroft, 1834) is an amphidromous species of mugilid known from South and Central America and the islands of the Caribbean but is rarely collected in Gulf coast states of the United States. Two new records of D. monticola collected from the Gulf of Mexico (Brazoria Co.) and the Brazos River (Washington Co.) are reported from Texas. The rare occurrence of D. monticola in Texas is discussed and diagnostic characters used to distinguish this species from other mugilids found in Texas are reevaluated.
Probing the thermal collapse of PNIPAM grafts by quantitative in situ ellipsometry
Authors: Kooij E.S. , Sui X.F. , Hempenius M.A. , Zandvliet H.J.W. , Vancso G.J.
Published: June 2019

We demonstrate the potential of spectroscopic ellipsometry for the investigation of the chain segment density profile and layer thickness during the temperature-induced, reversible collapse−expansion transition of poly(N-isopropylacrylamide) (PNIPAM) grafted layers with variable grafting densities in aqueous systems. To obtain a quantitative description of the thickness of our swollen PNIPAM layers, various models were implemented to fit the ellipsometric data. From the ellipsometry results, the density and thickness variation accompanying the collapse transition across the lower critical solution temperature (LCST) was characterized. The collapse can be adequately explained by considering the PNIPAM film to consist of two layers: (i) a dense layer near the surface and (ii) a more diluted layer with a gradient density profile on the side of the film exposed to the solvent.
Effect of Crystal Size on the Structural and Functional Properties of Water-Stable Monodisperse ZnO Nanoparticles Synthesized Via a Polyol-Route
Authors: Collantes Yesusa , Perales-Perez Oscar
Published: June 2019

Highly monodispersed ZnO nanoparticles (NPs) have been synthesized in polyol medium. The control on crystal size was attempted at 180°C by monitoring the heating rate of reacting solutions and the cooling rate (quenching) at the end of the reaction time. The possibility to promote crystal growth by heterogeneous nucleation was also evaluated; in this approach, pre-synthesized 5-nm pure ZnO nanocrystals were used as seeds in fresh Zn-polyol solutions at suitable seeds/ZnO w/w ratios. As-synthesized samples were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier Transform Infrared spectroscopy (FT-IR), Absorbance (UV-vis) and Photoluminescence spectroscopy (PL). XRD measurements confirmed the formation of well crystallized ZnO-wurtzite with absence of secondary phases in both seeds and grown crystals. FT-IR analyses evidenced the presence of organic moieties on the surface of the nanoparticles that are associated to the functional groups of polyol by-products; these adsorbed species would have prevented particles from aggregation. PL measurements (excitation wavelength 345 nm) reveled that a tuning in the emission bands of ZnO NPs can be achieved through synthesis conditions and crystal size. HRTEM measurements evidenced the formation of bare ZnO NPs of 2 nm, 6 nm, 20 nm and clusters of small nanocrystals.
Needles and Haystacks: Influence of Catalytic Metal Nanoparticles on Structural and Vibrational Properties and Morphology of Silicon Nanowires Synthesized by Metal-Assisted Chemical Etching
Authors: Dawood M. K. , Tripathy S. , Dolmanan S. B. , Ng T. H. , Hao T. , Lam J.
Published: June 2019

Metal-assisted chemical etching (MACE) of silicon (Si) is a simple and low-cost process to fabricate Si nanostructures with varying aspect ratio and properties. In this work, we report on the structural and vibrational properties of Si nanostructures synthesized with varying metal catalyst. The morphology of the synthesized nanowires was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The optical and vibrational properties of the Si nanostructures were studied by photoluminescence and Raman spectroscopy using three different excitation sources (UV, visible and near-infrared) and are correlated to their microstructures. We propose that the excessive injection of holes into Si at the metal-Si interface and its diffusion to the nanowire surfaces facilitate the etching of Si on these surfaces, leading to a mesoporous network of Si nanocrystallites. When etched with catalytic Au nanoparticles, “hay-stacked” mesoporous Si nanowires were obtained. The straighter nanowires etched with Ag nanoparticles, consisted of a single crystalline core with a thin porous layer that decreased in thickness towards the base of the nanowire. This difference is due to the higher catalytic activity of Au compared to Ag for H2O2 decomposition. The SERRS observed during UV and visible Raman with Ag-etched Si nanowires and near-infrared Raman with Au-etched Si nanowires is due to the presence of the sunken metal nanoparticles. In addition, we explored the influence of varying H2O2 and HF concentration as well as the influence of increased etching temperature on the resultant nanostructured Si morphology. Such Si nanostructures may be useful for a wide range of applications such as photovoltaic and biological and chemical sensing.
Electron Localization, Tunneling and Energy Spectrum for Systems of Double Quantum Dots
Authors: Filikhin Igor , Matinyan Sergei , Vlahovic Branislav
Published: June 2019

Semiconductor heterostructures as quantum dots demonstrate discrete atom-like energy level structure based on several hundred of electron confinement states. In the case of double QD (DQD) or double QR (DQR), there is a single electron spectrum composed of a set of quasi-doublets. We study these specific spectrum properties with their relation to the electron tunneling in DQD (DCQR) when the wave function of electron localized initially in one of the double quantum object is spread into whole system. The double InAs/GaAs quantum dots are considered within the effective approach. Tunneling in DQD is studied in connection with change of inter-dot distance and QD geometry. There are two types of such tunneling in DQD. The first is related to tunneling in the system of two identical QDs; the second one occurs in the system of non-identical QDs. The tunneling in the DQR is a tunneling in the system with non-identical quantum objects. The quasi-doublets of the DQD spectrum play an important role in the tunneling. We study effect of violation of symmetry of DQD geometry on the tunneling and show that the violation of symmetry makes difficulties for such tunneling.
Structural and Electrical Characterization of Shaped Beam Laser Recrystallized Polysilicon on Amorphous Substrates
Authors: Stultz T. J. , Gibbons J. F.
Published: June 2019

Structural and electrical characterization of laser recrystallized LPCVD silicon films on amorphous substrates using a shaped cw laser beam have been performed. In comparing the results to data obtained using a circular beam, it was found that a significant increase in grain size can be achieved and that the surface morphology of the shaped beam recrystallized material was much smoother. It was also found that whereas circular beam recrystallized material has a random grain structure, shaped beam material is highly oriented with a <100> texture. Finally the electrical characteristics of the recrystallized film were very good when measured in directions parallel to the grain boundaries.
How cerium filling fraction influences thermal factors and magnetism in CeyFe4-xNixSb12.
Authors: Chapon L. , Ravot D. , Tedenac J.C. , Bouree-Vigneron F.
Published: June 2019

Since few years, cerium filled and partially filled skutterudites are intensively studied because they show a wide variety of fundamental and applied properties. One of them consists in high values of thermal factors for rare earth atom in antimony skutterudites [1,2]. Slack suggests [3,4] a incoherent rattling of this ion in the oversized cage “Sb12” surrounding the cerium which affects highly the phonon motion and thus lowers the lattice thermal conductivity (kl). As a rule, the lattice thermal conductivity is decreased by a factor of 5 or greater by filling entirely the voids of the binary filled skutterudites with rare earth atoms [5]. Besides, kl decreases for partially filled compounds in respect with totally filled ones [6,7]. Mass fluctuation mechanism between cerium atom and vacancy is obviously involved as the origin of this last reduction. On that purpose, theoretical calculations [7] demonstrate that the reduction belonging to mass fluctuation mechanism is an order of magnitude lower than the measured decrease. As the mass fluctuation added to the “rattling” on the cerium site is not sufficient to explain such low values of thermal conductivity, another phonon scattering mechanism must exist. In order to find another mechanism we present the influence of the filling fraction of cerium on thermal factors and the temperature dependence of this factor for a partially filled compound.
Structural Defects in a Partially-Filled Skutterudite
Authors: Harper Jennifer S. , Gronsky Ronald
Published: June 2019

The partially filled skutterudite structure is a candidate thermoelectric material with the capacity for phonon scattering by the decoupled rattling of filling ions. In this transmission electron microscopy investigation of a 1.6%Ce, 1.6%Ni, 4.9%Ge, 22.8%Co, and 69.1%Sb alloy, the structure is found to be that expected of a partially-filled skutterudite, but with a varied assortment of structural defects. These defects are characterized and their effect on thermoelectric properties is discussed.
Optimization of Bismuth Nanowire Arrays by Electrochemical Deposition
Authors: Barkyoumb J. H. , Price J. L. , Guardala N. A. , Lindsey N. , Demske D. L. , Sharma J. , Kang H. H. , Salamanca-Riba L.
Published: June 2019

Bismuth nanowires for thermoelectric applications have been made by electrochemical deposition from an aqueous Bi solution into nanoporous mica substrates, and Anopore (Al2O3) filters. The nanoporous substrates are created by acid etching damage tracks that are produced in the mica using heavy-ion irradiation. In this work, further improvements in the fabrication process are made by investigating the electrochemical growth at the 1-d to 2-d transition region at the nanochannel-substrate surface interface as a function of deposition time and electrochemistry. Issues related to doping of the Bi wires with Te along with the problem of electrochemical growth of contacts to the nanowires as compared to vacuum deposition of contacts will be discussed.
Crystal Growth of Ternary and Quaternary Alkali Metal Bismuth Chalcogenides Using Bridgman Technique
Authors: Kyratsi Theodora , Chung Duck-Young , Choi Kyoung-Shin , Dick Jeffrey S. , Chen Wei , Uher Ctirad , Kanatzidis Mercouri
Published: June 2019

Our exploratory research in new thermoelectric materials has identified the ternary and quaternary bismuth chalcogenides β-K2Bi8Se13, K2.5Bi8.5Se14 and K1+xPb4-2xBi7+xSe15, to have promising properties for thermoelectric applications. These materials have needlelike morphology so they are highly anisotropic in their electrical and thermal properties. In order to achieve long and well-oriented needles for which, consequently, the best thermoelectric performance is expected, we developed a modified Bridgman technique for their bulk crystal growth. The preliminary results of our crystal growth experiments as well as electrical conductivity, Seebeck coefficient and thermal conductivity for the compounds obtained from this technique are presented.
Avalanche Stratification - Experimental Tests of the “Metastable Wedge” and “Continuous Flow” Models
Authors: Swanson M. E. , Landreman M. , Michel J. , Kakalios J.
Published: June 2019

When an initially homogeneous binary mixture of granular media such as fine and coarse sand is poured near the closed edge of a “quasi-two-dimensional” Hele-Shaw cell consisting of two vertical transparent plates held a narrow distance apart, the mixture spontaneously forms alternating segregated layers. Experimental measurements of this stratification effect are reported in order to determine which model, one which suggests that segregation only occurs when the granular material contained within a metastable heap between the critical and maximum angle of repose avalanches down the free surface, or one for which the segregation results from smaller particles becoming trapped in the top surface and being removed from the moving layer during continuous flow. The result reported here indicate that the Metastable Wedge model provides a natural explanation for the initial mixed zone which precedes the formation of the layers, while the Continuous Flow model explains the observed upward moving kink of segregated material for higher granular flux rates, and that both mechansims are necessary in order to understand the observed pairing of segregated layersfor intermediate flow rates and cell separations.
Mixing and Segregation Processes in Turbula Blender
Authors: Sommier Nathalie , Porion Patrice , Evesque Pierre
Published: June 2019

Magnetic Resonance Imaging (MRI) technique was used to study the mixing and segregation processes of granular materials in a sophisticated tumbling blender (Turbula® mixer) using binary mixtures of sugar beads of different diameters d. Its motion generates mixtures with complex patterns. Effects of some parameters (beads diameter ratio, rotation speed, mixing time) were checked on segregation and mixing processes. We report in this paper, a qualitative and quantitative analysis of these phenomena. A segregation index S was defined to study the homogeneity and the kinetics of the mixing/segregation processes. When the ratio of bead diametersdmax/dmin is approximately 1, mixing process is observed but segregation occurs as soon asdmax/dmin is greater than 1.1.
Dem Application to Mixing and Segregation Model in Industrial Blending System
Authors: Yamane Kenji
Published: June 2019

To predict the motion of powders and grains is important in pharmaceutical industries. Many pharmaceutical engineers have studied granular flows related to powder mixing. In this study, DEM (Discrete Element Method) approach is presented as an industrial application to investigate the behavior of granular flows. The granular motion in a rotating cylinder was focused on the basic study of DEM for industrial application. Rotating cylinder is a fundamental system for commercial blenders widely used in many industrial process. In addition, segregation of particles in a rotating cylinder is very interesting phenomena. Not only industrial engineers but also physicists research this segregation mechanism. DEM simulation showed radial segregation of two different size particles in a rotating cylinder. From the viewpoint of calculated granular temperature, radial segregation system was analyzed. Particle migration in axial direction, which is the source for axial segregation, was also shown by DEM simulation.
Effective Determination of Coexistence Curves using Reversible-Scaling Molecular Dynamics Simulations
Authors: Koning Maurice de , Antonelli Alex , Yip Sidney
Published: June 2019

We present a simulation technique that allows the calculation of a phase coexistence curve from a single nonequilibrium molecular dynamics (MD) simulation. The approach is based on the simultaneous simulation of two coexisting phases, each in its own computational cell, and the integration of the relevant Clausius-Clapeyron equation starting from a known coexistence point. As an illustration of the effectiveness of our approach we apply the method to explore the melting curve in the Lennard-Jones phase diagram.
Mechanics Of Crack Bridging Under Dynamic Loads
Authors: Sridhar N. , Cox B.N. , Dunn C.L. , Beyerlein I.J.
Published: June 2019

A bridging law for fiber reinforced composites under dynamic crack propagation conditions has been derived. Inertial effects in the mechanism of fibre pullout during dynamic propagation of a bridged crack are critically examined for the first time. By reposing simple shear lag models of pullout as problems of dynamic wave propagation, the effect of the frictional coupling between the fibres and the matrix is accounted for in a fairly straightforward way. The solutions yield the time-dependent relationship between the crack opening displacement and the bridging traction. Engineering criteria and the role of material and geometrical parameters for significant inertial effects are identified.
Bond-Order Potentials with Analytic Environment-Dependent Tight-Binding Integrals: Application to BCC Molybdenum
Authors: Mrovec Matous , Nguyen-Manh Duc , Pettifor David G. , Vitek Vaclav
Published: June 2019

We present a new Screened Bond-Order Potential (SBOP) for molybdenum in which the environmental dependence of two-center tight-binding bond integrals has been implemented via a recently developed analytic expression. These bond integrals reproduce very well the numerical ab-intio values of screened LMTO bond integrals. In particular, they display the large discontinuity in ddπ between the first and second nearest neighbor of the bcc lattice whereas they do not show any discontinuity in ddσ. This dependence can be traced directly to the angular character of the analytic screening function and is shown to be critical for the behavior of the second nearest neighbor force constants. The new BOP eliminates the problem of the very soft T2 phonon mode at the N point that is found in most two-center tight-binding models. Preliminary study of the core structure of 1/2<111> screw dislocations performed using SBOP indicates that the core is narrower and less asymmetric than structures found in previous studies, in agreement with recent ab-initio calculations.
Efficient Treatment of Fixed and Induced Dipolar Interactions
Authors: Sagui Celeste , Darden Thoma
Published: June 2019

Fixed and induced point dipoles have been implemented in the Ewald and Particle-Mesh Ewald (PME) formalisms. During molecular dynamics (MD) the induced dipoles can be propagated along with the atomic positions either by interation to self-consistency at each time step, or by a Car-Parrinello (CP) technique using an extended Lagrangian formalism. The use of PME for electrostatics of fixed charges and induced dipoles together with a CP treatment of dipole propagation in MD simulations leads to a cost overhead of only 33% above that of MD simulations using standard PME with fixed charges, allowing the study of polarizability in largemacromolecular systems.
Multiple Donors in Zinc Oxide Substrates
Authors: Thonke K. , Kerwien N. , Wysmolek A. , Potemski M. , Waag A. , Sauer R.
Published: June 2019

We investigate by photoluminescence (PL) nominally undoped, commercially available Zinc Oxide substrates (from Eagle Picher) grown by seeded chemical vapor transport technique in order to identify residual donors and acceptors. In low temperature PL spectra the dominant emission comes from the decay of bound exciton lines at around 3.36 eV. Zeeman measurements allow the identification of the two strongest lines and some weaker lines in-between as donorrelated. From the associated two-electron satellite lines binding energies of the major donors of 48 meV and 55 meV, respectively, can be deduced.
Electrical Characterization of Laser-Irradiated 4H-SiC Wafer
Authors: Salama I. , Quick N. R , Kar A. , Chung Gilyong
Published: June 2019

Highly conductive tracks are generated in low-doped epilayers on 4H-SiC wafers using a laserdirect write technique. The current-voltage characteristics are measured to study the effect of the applied voltage on the electric resistance and the surface contact of the irradiated tracks. The effect of multiple irradiations on the electronic properties of the fabricated tracks was investigated and compared with the effect of the conventional annealing process. A laser doping process was used to achieve n-type as well as p-type impurity doping in the substrate. The electronic properties of the doped tracks are measured and compared with those of the untreated wafers. Microstructural observation and surface analysis of the irradiated tracks are studied. Laser fabrication of rectifying contact on SiC substrates is demonstrated.
Correlation of Surface Morphologies with Mn Compositions of Ga1-xMnxAs Epilayers Grown by Liquid Phase Epitaxy
Authors: Kim Hwa-Mok , Leem Jae-Hyeon , Choi Sung Woo , Kim Deuk Young , Kang Tae-Won
Published: June 2019

In this letter, we investigated the correlation between as-grown surface morphologies and Mn compositions of Ga1-xMnxAs epilayers - a III-V diluted magnetic semiconductor - grown by liquid phase epitaxy (LPE). Ga1-xMnxAs epilayers were grown at 595 °C from 50 % Ga + 50 % Bi mixed solvent. The grown layers were characterized by energy dispersive x-ray analysis (EDS) and atomic forced microscopy (AFM). The Mn composition measured by EDS after growth process was varied from 1 to 7 %. As increasing Mn composition surface morphologies of as-grown Ga1-xMnxAs epilayers were varied. At higher Mn compositions, the morphology of the surface layers degrades strongly, preventing removal of the solution-melt from it. Key words: LPE, as-grown, surface morphology, Mn composition, Ga1-xMnxAs, energy-dispersive x-ray analysis (EDS), atomic forced microscopy (AFM).
Behavior of copper in CdGeAs2 crystals
Authors: Voevodin Valeriy G. , Voevodina Olga V. , Bereznaya Svetlana A. , Korotchenko Zoya V. , Ohmer Melvin C. , Goldstein Jonathan T. , Fernelius Nils C.
Published: June 2019

We present an investigation of the diffusion and melt doping of Cu in CdGeAs2. Cu was found to be an acceptor, its introduction in the melt allowed the controlled introduction of holes from ∼8·1016 cm-3 to ∼1·1018 cm -3. Introduction of Cu from the melt was also found to improve the homogeneity of the crystal. The saturation solubility of Cu introduced via diffusion doping was found to have an exponential dependence on the diffusion temperature, from 723 K to 873 K, obeying the equation N = N0 exp (- δH / kT) with the parameters N0 = 6.10+19 cm-3, δH = 0.3 eV, and k equal to Boltzman's constant. From 873 K to 923 K, the saturation solubility was found to decrease exponentially with temperature.
Electron-beam-induced reactivation of Si dopants in hydrogenated and deuterated 2D AlGaAs heterostructures. Application to the fabrication of nanostructures
Authors: Kurowski L. , Silvestre S. , Loridant-Bernard D. , Constant E. , Barbe M. , Chevallier J. , Constant M.
Published: June 2019

Hydrogen incorporation in n-type Si-doped GaAs epilayers is now a well-known process. This paper is devoted to the study of the stability of SiH (SiD) complexes when submitted to an electron beam in n-type Si-doped GaAs epilayer and also in 2D-AlGaAs heterostructures exposed to a hydrogen or deuterium plasma.

The results obtained by Hall effect measurements on hydrogenated and deuterated GaAs epilayers with different thicknesses (0.2 and 0.35νm) and Si planar-doped AlGaAs/GaAs/InGaAs heterostructures exposed to an electron beam with different injection energies (10 to 50 keV) are presented. On one hand, the reactivation of Si dopants strongly decreases when deuterium is used. On the other hand, the study of this reactivation versus injection energies of electrons suggests an energetic electron excitation effect rather than a minority carrier generation effect. In addition, for the 0.2νm thick GaAs epilayer and the 2D heterostructures, the free carrier density does not vary significantly for low electron densities, and as a consequence, the reactivation of the Si dopants occurs above an electron dose threshold. This phenomenon might be attributed to the filling of surface states as the dopants are progressively reactivated.

As a result, due to the electron dose threshold as well as their high electron mobility properties, Si planar-doped AlGaAs/GaAs/InGaAs heterostructures are particularly interesting to reactivate dopants, with a good spatial contrast, using an electron beam irradiation and the effects described in this paper could open the fabrication of high mobility 1D or 2D mesoscopic structures for electronic or optoelectronic applications.
Energy Storage Materials Based on Iron Phosphate
Authors: Prosini Pier Paolo , Carewska Maria , Lisi Marida , Passerini Stefano , Scaccia Silvera , Pasquali Mauro
Published: June 2019

Several iron phosphates were synthesized by solution-based techniques and tested as cathodes in non aqueous lithium cells. The addition of phosphate ions to a solution of iron (II) produced crystalline Fe3(PO4)2. This material is easily oxidized by air to form an amorphous phase that is able to reversibly intercalate lithium. The amorphous compound was identified to be a mixture of FePO4 and Fe2O3. A new synthetic route was developed to prepare pure amorphous FePO4. Amorphous LiFePO4 was obtained by chemical lithiation of FePO4. The material was heated at 500°C under reducing atmosphere to obtain nano-crystalline LiFePO4. This latter material showed excellent electrochemical performance when used as cathode of lithium cells.
Metal-Organic Chemical Vapour Deposition of II-VI Semiconductor Thin Films Using Single-Source Approach
Authors: Afzaal Mohammad , Crouch David , O'Brien Paul , Park Jin-Ho
Published: June 2019

Thin films of CdS and CdSe have been deposited on glass substrates by low pressure metal-organic chemical vapour deposition (LP-MOCVD) using Cd[(EPiPr2)2N]2 (E = S, Se) as single-source precursors. These air-stable precursors are volatile, making them suitable for the deposition of thin films. As-deposited films were crystalline metal chalcogenides, as confirmed by X-ray powder diffraction (XRD), and their morphologies were studied by scanning electron microscopy (SEM).
Preparation of Doped Lanthanum Gallate Electrolyte for SOFC by Pulsed Laser Deposition
Authors: Kanazawa Seiji , Ito Takeshi , Yamada Kenji , Ohkubo Toshikazu , Nomoto Yukiharu , Ishihara Tatsumi , Takita Yusaku
Published: June 2019

In this study, doped lanthanum gallate (LSGM with the composition La0.9Sr0.1Ga0.8Mg0.2O3-δ, LSGMC with the composition La0.8Sr0.2Ga0.8Mg0.15Co0.05O3-δ) films for an electrolyte of the solid oxide fuel cell (SOFC) were prepared by pulsed laser deposition (PLD) technique. In the vacuum chamber, LSGM or LSGMC targets were set on the rotating target holder. A KrF excimer laser was introduced into the chamber at an incident angle of about 45 degree. The doped LaGaO3 film was deposited onto NiO substrates without heating in argon ambient gas. The NiO substrate can be used directly as an electrode in the fabrication of the SOFC. The deposited LSGM films were characterized by X-ray diffraction (XRD), secondary ion mass spectroscopy (SIMS) and scanning electron microscopy (SEM). As-deposited films were amorphous. After post annealing at 1273K for 6-10 hours, crystalline LaGaO3 was obtained. Films with thickness greater than several 10 μm showed an uniform and dense morphology. No gas leakage was found using thick films, which is an important characteristic for an electrolyte in fuel cells. The composition of the deposited films was slightly different to that of the target.
Synthesis and Thermoelectric Properties of Bi2 S3 Nanobeads
Authors: Fang Jiye , Chen Feng , Stokes Kevin L. , He Jibao , Tang Jinke , O'Connor Charles J.
Published: June 2019

Bismuth sulfide (Bi2S3), a direct band gap material with Eg ñ 1.3 eV, attracts high interest in thermoelectric investigations. In this work, nanometer-sized bismuth sulfide with unique morphology has been successfully prepared by a precipitation between bismuth 2-ethylhexanoate and thioacetamide in high-temperature organic solution with presence of proper capping/ stabilizing agents. By employing this technique, we are able to produce nanobeads of bismuth sulfide with an aspect ratio of ∼ 5, typically ~10 nm wide and ∼50 nm long according to the TEM observation. Characterization of XRD and TEM/HRTEM reveals that the as-prepared particles exist in single orthorhombic phase and possess high crystallinity. The composite ratio between Bi and S can be adjusted by varying the ratio between two precursors and was determined by using EDS (TEM) technique. Thermoelectric properties of these bismuth sulfide nanobeads were also investigated and will be discussed comparatively with those from commercial bulk materials.