bluuebunny/crossref_metadata_2025 huggingface dataset:
Does Piracy Create Online Word of Mouth? An Empirical Analysis in the Movie Industry
Authors: Lu Shijie , Wang Xin (Shane) , Bendle Neil
Published: June 2019

Anecdotal evidence suggests that counterfeiting/piracy can help create online word of mouth (WOM) and through this boost demand, but how powerful is such WOM? To answer this question, we conduct a descriptive study with some attempts to establish near causality. We estimate the impact of piracy on WOM and ultimately revenue by applying a panel data method to all movies widely released in the United States from 2015 to 2017. In identifying the effects of piracy we make inventive use of Russian piracy data to construct instrument variables for piracy in the United States. This is possible because the key piracy site, The Pirate Bay, has been blocked in Russia since 2015. We find movies with prerelease piracy are associated with lower revenues despite the WOM effect. Critically, however, we show a positive correlation between postrelease piracy and WOM volume, and we extend the field by finding that the presence of postrelease piracy is associated with an approximately 3.0% increase in box office revenue. We also note the impact of a raid by the Swedish Police that temporarily took down The Pirate Bay website in December 2014. The period when the site was down experienced a decline in WOM volume and revenues, consistent with the effect of lower postrelease piracy predicted by our models. Our findings suggest approaches to target scarce antipiracy resources, such as focusing on tackling damaging prerelease piracy.

This paper was accepted by Juanjuan Zhang, marketing.
A CONSTRUÇÃO DO ANTAGONISTA EM OS MAGOS
Authors: Gonçalves Giuliane Moreira , Pierini Fábio Lucas
Published: June 2019

A construção das personagens e, em especial, a do antagonista é essencial para o desenvolvimento da narrativa. Diante disto, este trabalho analisa a construção das personagens de acordo com a visão de Candido (1968), Brait (1985) e Palmer (2004), além da noção de antagonista defendida por Propp (2001), Campbell (1997) e Prado (1968). Partindo desta análise, avalia-se também a construção deste antagonista como um agente do mal, como afirma Campbell (1997), e suas características maléficas e monstruosas pelas visões de Jeha (2007), Molino (1980) e Todorov (1981). Diante desta discussão teórica, analisou-se a trilogia de Grossman intitulada Os Magos, em especial o antagonista do primeiro livro, A Criatura. Concluiu-se, assim, que a construção desta personagem obedece à maioria os princípios de construção do antagonista discutidos pelas teorias mencionadas, com exceção ao discorrido por Jeha (2007) de que a maldade do antagonista é interior, uma vez que forças exteriores levam o antagonista de Grossman a agir vingativamente, demonstrando como a maldade e as noções de bem e mal são fixas, mas socialmente instituídas.
ABALOS NO CORPO, A IMINÊNCIA DE UM MONSTRO? O CIBORGUE EM NEUROMANCER, DE WILLIAN GIBSON
Authors: Lima George
Published: June 2019

No presente artigo investigamos de que modo o corpo das personagens funciona como condição de existência dos espaços que são dados a ver na obra literária Neuromancer, escrita por Willian Gibson. Por outro lado, notamos que o status dos espaços depende do corpo, que, por sua vez, é determinado por esses espaços, os quais fazem com que a esse corpo sejam associadas instâncias que fogem ao que trivialmente chamamos de natural. Nesse “entre lugares” dos espaços, vemos a iminência fantástica do corpo ciborgue, convergindo matéria orgânica com o maquínico, e, dessa forma, configura-se o que parece ser uma espécie de monstruosidade. Para realizarmos essa leitura, utilizamos algumas noções postuladas por Michel Foucault (2013b) em torno da literatura enquanto ser de linguagem, e outras postuladas também por Foucault (2001) e por Jacques Derrida (1971) sobre a monstruosidade de acordo com o domínio jurídico-biológico.
“TIRO NÃO O MATA, FOGO NÃO O QUEIMA, ÁGUA NÃO O AFOGA”: AS REFIGURAÇÕES DE MACOBEBA NO MODERNISMO BRASILEIRO
Authors: Verçosa Thayane , Araújo Nabil
Published: June 2019

Partindo das colunas assinadas por José Mathias no periódico A província, de abril a setembro de 1929, nas quais as peripécias e as atrocidades de Macobeba são narradas, pretendemos analisar, comparar e contrastar o modo como o monstro reaparece em diferentes contextos e obras do Modernismo brasileiro. Para tanto, o nosso corpus é composto também, em ordem cronológica, por “Macobeba” (1929), de Mário de Andrade; pelos textos “Macobeba pré-histórico” (1930) e “Macobeba antigo” (1930), de Graciliano Ramos; e pelo Manuscrito Holandês ou a peleja do caboclo Mitavaí com o Monstro Macobeba (1960), livro de Manuel Cavalcanti Proença. Desse modo, a partir do conceito de refiguração (REIS, 2018), buscaremos analisar como ocorrem as reelaborações monstro, atentando para os procedimentos retórico-estilísticos usados nas diferentes composições, e para o modo como elas dialogam, destacando eventuais aproximações e afastamentos.
ONZE HISTÓRIAS E UM SEGREDO: DESVENDANDO AS LENDAS AMAZÔNICAS. TAÍSA APARECIDA CARVALHO SALES. 2016
Authors: Santos Jamille Da Silva
Published: June 2019

Recebido em 24 mar 2019Aprovado em 04 abr 2019
Editorial
Authors: Mattos Amana , Jacó-Vilela Ana Maria , Mendes Deise Maria Fernandes , Quadros Laura Cristina de Toledo , Quitério Patrícia Lorena , Leme Vanessa Barbosa Romera , Darriba Vinicius Anciães
Published: June 2019

Amana Mattos, Ana Maria Jacó Vilela, Deise Maria Fernandes Mendes, Laura Cristina de Toledo Quadros, Patrícia Lorena Quitério, Vanessa Barbosa Romera Leme, Vinicius Anciães Darriba
We support Unicef … up to a point
Authors: Allen Mark
Published: June 2019

Unicef's Baby Friendly Initiative has been formally incorporated into the NHS Long Term Plan, but as Mark Allen writes, this could limit midwives' professional autonomy
Interplay between Politics and Institution in Higher Education Reform
Authors: Khelifi Saber
Published: June 2019

The advent of the new economy brought university reforms to the limelight, and higher education research concentrated on the study of interactions of multi-level, multi-actor policy reforms, to the detriment of studying policy implementation. The ebbing of implementation analysis in the mid-1980s has probably put researchers off following up policies to the point of delivery, resulting in what critics dubbed a 'missing link'. Policymakers more pronounced need to evaluate the impact of the policies they adopt, inter alia, has led to a renewed interest in bottom-up implementation in other public policy fields, but not as much in higher education research. The article builds on a Network Governance-informed approach for studying policy reform in higher education and adapts it to study of policy implementation with a focus on transition systems. Witte's actor-centered new institutional framework is taken as a springboard, and some of its underlying assumptions are reviewed for that purpose, adding insights from public administration literature (NPM) and Lipsky's street-level bureaucracy (SLBy). Ultimately, it proposes a politics-institutions framework to account for the institutional change entailed to the reforms.
Individual weakness to collective strength: (Re)creating the self as a ‘working-class academic’
Authors: Byrne George
Published: June 2019

This article is an autoethnographic account of my experience of becoming a working-class academic. I have found that, in addition to overcoming structural inequalities, ‘escaping’ a working-class home to seek a new life in a strange world has required the construction of a new identity that is neither entirely ‘academic’ nor entirely ‘working-class’. I discuss my perspective on class privilege and inequality through my experience of being part of a group of people who tend to exist in academia as invisible individuals. I have written this article as a practical exercise that contributes to increasing this visibility because, by becoming a more visible and collective community, it is possible to challenge existing notions of what it means to be working-class, to be an academic or to be both.
Provocações feministas no sistema socioeducativo: pensando educação para/com homens jovens homens
Authors: Hernández Jimena De Garay , Uziel Anna Paula
Published: June 2019

O presente trabalho apresenta algumas reflexões que surgiram em uma pesquisa-intervenção realizada em uma unidade masculina de internação do Sistema Socioeducativo do Rio de Janeiro. A partir de uma cartografia feminista e através de diversas propostas, atividades e parcerias, foi possível provocar as noções sobre socioeducação e educação, bem como a forma em que elas poderiam considerar gênero e sexualidade como eixos fundamentais de ação tanto em estabelecimentos de privação de liberdade, quanto na fundamentação de uma transformação social mais ampla. Para isso, foi fundamental um olhar crítico que permanentemente articulasse os dispositivos de gênero, raça, classe social, geração, sexualidade, escolaridade e localidade, como forças que compõem os processos de subjetivação e os mecanismos institucionais que os circunscrevem.
A educação e o seu investimento heteronormativo curricular
Authors: Braga Keith Daiani da Silva , Caetano Marcio , Ribeiro Arilda Ines Miranda
Published: June 2019

Há quem defenda que a sexualidade e o gênero não se configuram nos currículos escolares e que estas categorias não orientam as prioridades da escola. Essa afirmação nos revela duas situações iniciais: o desconhecimento das relações e práticas pedagógicas cotidianas das escolas e o conceito enrijecido de gênero e sexualidade. Historicamente, as práticas educativas, mesmo quando não-verbalizadas, preocuparam-se em estabelecer, por meio de seus discursos e práticas curriculares, determinados modelos de mulheres e homens. Ao considerar este cenário, neste ensaio, balizado pelas contribuições feministas e foucaultianas, interessa-nos refletir sobre a pedagogização de gênero e da sexualidade por meio dos currículos escolares. Partimos do pressuposto que a sexualidade e o gênero não são desinteressantes às instituições de ensino, mas produzidos com caráter fortemente heteronormativo.
Tipologias de funcionamento familiar: Do desenvolvimento identitário à perturbação emocional na adolescência e adultez emergente
Authors: Prioste Ana , Tavares Petra , Magalhães Eunice
Published: June 2019

O funcionamento familiar contribui diferentemente para ajustamento psicológico, de acordo com as etapas de desenvolvimento e com as tarefas que lhes estão subjacentes. Através de um desenho quantitativo transversal, e com recurso a uma amostra de 387 participantes com idades compreendidas entre os 15 e os 25 anos (M=20.06, DP=3.21), este estudo pretendeu: identificar as tipologias de funcionamento familiar, a partir das dimensões coesão e conflito; e analisar a associação entre as tipologias de funcionamento familiar, os processos de desenvolvimento da identidade, a etapa desenvolvimental (adolescência e adultez emergente) e a perturbação emocional. Foram identificadas cinco tipologias de funcionamento familiar, correspondentes a famílias: Coesas, Desligadas, Equilibradas, Conflituosas e Emaranhadas. Tendo em conta a literatura, os participantes foram divididos em grupos, consoante a idade (adolescentes e adultos emergentes) e o nível de perturbação emocional (com e sem perturbação emocional). Os resultados mostram associações estatisticamente significativas entre as tipologias de funcionamento familiar, a etapa desenvolvimental, os processos de desenvolvimento da identidade e os grupos com e sem perturbação emocional. Especificamente, os resultados indicam que os adultos emergentes percepcionam o funcionamento das suas famílias como mais Coeso ou Emaranhado, em comparação com os adolescentes; e que o grupo com perturbação emocional percepcionou, maioritariamente, o funcionamento da sua família como Emaranhado. São discutidas as implicações para a prática e para a literatura nas áreas da Psicopatologia do Desenvolvimento e Psicologia da Família.
ДОСЛІДЖЕННЯ УКРАЇНСЬКО-НІМЕЦЬКИХ ЛЕКСИЧНИХ ПАРАЛЕЛЕЙ У СЛОВНИКОВОМУ ФОРМАТІ
Authors: Дубічинський Володимир , Reuther Tilmann
Published: June 2019

Artykuł dotyczy kwestii opisu leksykografi cznego ukraińskoniemieckich paraleli leksykalnych, których cechą charakterystyczną jest podobieństwo pod względem brzmienia i pisowni oraz niezupełne podobieństwo bądź jego brak pod względem znaczenia. Przytoczono przykłady opisu słownikowego homonimów i paronimów międzyjęzykowych.
КОМПАРАТИВНІ КОНСТРУКЦІЇ ЯК ВЕРБАЛІЗАТОРИ КОНЦЕПТІВ УЧИТЕЛЬ ТА УЧЕНЬ (на матеріалі творів Івана Франка та Чарльза Діккенса)
Authors: Дзюбенко Оксана
Published: June 2019

Artykuł poświęcono wyjaśnieniu konceptów NAUCZYCIEL i UCZEŃ na podstawie analizy struktur porównawczych w twórczości Iwana Franki i Charlesa Dickensa. Aparat terminologiczny w analizie porównawczej stanowią obrazy-etalony, strefy dawcy i biorcy. Dzięki zestawieniu jednostek porównawczych wydzielono uniwersalne i etnokulturowe składniki ukraińskiej i angielskiej kultury językowej.
ПРАГМАТИКА ГАСЕЛ У ПРЕСІ ПІДРАДЯНСЬКОЇ УКРАЇНИ
Authors: Коротич Катерина
Published: June 2019

Artykuł poświęcony jest funkcjonowaniu i pragmatyce haseł w ukraińskiej prasie radzieckiej. Wyróżniono najczęstsze grupy haseł ze względu na ich cel illokucyjny: konstatywne, dyrektywne, komisywne. Zaproponowano nowy rodzaj haseł — slogany gloryﬁkacyjne, których celem było wyrażenie przychylności przedstawicieli władzy i gloryﬁkacja. Okazało się, że bardzo duże spektrum sloganów  adresowanych do różnych grup odbiorców stanowi ważną rolę hasła jako przejawu języka władzy.
ПРОБЛЕМА МІЖОСОБИСТІСНИХ ВЗАЄМИН В УКРАЇНСЬКІЙ ДРАМАТУРГІЇ 1920–1930-х рр.
Authors: Суховєєнко Катерина
Published: June 2019

Niniejszy artykuł poświęcony jest analizie relacji interpersonalnych w ukraińskiej dramaturgii w latach 1920–1930. Zwrócono uwagę na dwa aspekty — walkę pokoleń w rodzinie i związek między mężczyzną a kobietą. Powyższe kwestie przeanalizowano w kontekście procesów społecznych i politycznych owego okresu.
Random Forest–Based Pavement Surface Friction Prediction Using High-Resolution 3D Image Data
Authors: Yang Guangwei , Yu Wenying , Li Qiang Joshua , Wang Kelvin , Peng Yi , Zhang Aonan
Published: June 2019

Many studies have concluded that pavement micro- and macro- texture characteristics have significant contributions to pavement friction and thus roadway safety. This study explores novel three-dimensional (3D) areal texture parameters to represent pavement texture characteristics at both micro- and macroscales and their usage for friction prediction. Three rounds of pavement friction and texture data were collected from 2015 to 2017 at a testing site in Oklahoma with six different mixture designs. Pavement friction was acquired by a Dynamic Friction Tester, and the corresponding texture data were collected by a portable ultrahigh-resolution 3D laser scanner. Each 3D texture datum is decomposed into micro- and macroscales with predesigned Butterworth filters. Twenty-seven 3D texture parameters falling into five categories are calculated at both texture levels. Subsequently, the random forest algorithm is implemented to determine the most important texture parameters for friction predictive model development. The selected macro- and micro-texture parameters account for 48.8 % and 39.6 % contributions to high-speed friction and 50.0 % and 14.1 % contributions to low-speed friction. The temperature during testing also exhibits a significant impact, with 11.6 % and 35.9 % contributions to high- and low-speed friction, respectively.
¿CÓMO A PARTIR DE UN MOVIMIENTO SOCIAL, SURGE LA REVITALIZACIÓN DE LA IDENTIDAD-TERRITORIAL DENTRO DE UNA COMUNIDAD?
Authors: Montecinos Nicolas
Published: June 2019

El siguiente artículo quiere exponer cómo la re-organización de comunidades y la re-apropiación de la identidad-lafkenche dentro de un sector costero del sur de Chile detonan en el ethos de la población, a partir de un movimiento de resistencia territorial-ambiental. Esto gatillado por los conflictos internos en la propia organización que nace al arribar a la zona costera de Mehuín, XIV Región de los Ríos, la empresa multinacional Celulosa Arauco y Constitución, (CELCO, actualmente con el nombre de Arauco), del grupo económico de la familia Angelini1. Para esto se buscará describir los procesos por los que transitó el movimiento social que allí surgió, como consecuencia de la amenaza ambiental, social, económica y cultural que implica para los habitantes vernáculos de este territorio, la instauración de una empresa de esa envergadura.Palabras claves: Movimiento Social; Identidad territorial; revitalización cultural.
AGRICULTURA DE BASE ECOLÓGICA E SUSTENTABILIDADE - ENTREVISTA COM NILO SCHIAVON
Authors: Schiavon Nilo
Published: June 2019

Nilo traz em seu relato a experiência de se sentir “na contramão do mundo”, que significou se posicionar de modo contrário ao amplo processo denominado de modernização conservadora da agricultura, que implicava em seguir preceitos e receituários que levavam à intensificação da produtividade e ao uso de alto grau de insumos externos para continuidade da produção. Esse posicionamento é marcado pela lembrança de uma grave intoxicação quando ainda utilizava agrotóxicos, situação que de modo recorrente é indicada como um marco para os agricultores que optam por uma produção sem “o químico”, além do desgaste dos solos e o desequilíbrio de fauna e flora gerado por esse manejo produtivista.
EDITORIAL
Authors: Revista Norus Equipe Editorial
Published: June 2019

É com satisfação que a Revista Novos Rumos Sociológicos (NORUS) do Programa de Pós-Graduação em Sociologia (PPGS) da Universidade Federal de Pelotas (UFPel) em seu quinto número publica o Dossiê “A dinâmica das relações raciais: dados, abordagens e intersecções”.
Apresentação
Authors: Soto William Héctor Gómez , Machado Carlos Roberto Da Silva
Published: June 2019

Henri Lefebvre é um autor pouco conhecido pela sociologia brasileira, e é até certo ponto, considerado um herege, assim como outros, que em dimensões distintas tem questionado os paradigmas dominantes. Pensamos, por exemplo, em Nicholas GeorgescuRoegen que introduziu a física na teoria econômica e mostrou a partir da Lei da Entropia, que os processos econômicos, de forma irreversível, utilizam energia disponível para transformála em energia que não pode ser mais utilizada.
PERCURSOS ENTRE A PRODUÇÃO DO ESPAÇO E AS PRÁTICAS MICROBIANAS: REFLEXÕES A PARTIR DA ARTICULAÇÃO ENTRE AS CONCEPÇÕES TEÓRICAS DE HENRI LEFEBVRE E MICHEL DE CERTEAU
Authors: Gamalho Nola Patrícia
Published: June 2019

O diálogo entre as perspectivas teóricas de Lefebvre e Certeau possuem não apenas convergências possíveis, mas também correspondem à potencialidade de analisar as espacialidades contemporâneas na articulação de escalas, normas, lógicas e sujeitos.  As inquietações teóricas dos autores  implicaram na diversidade e complexidade de suas produções textuais. Logo, correspondem a inspirações conceituais, que instrumentalizam formas de desvendar o mundo contemporâneo em sua complexidade. A produção teórica abrange desde os sistemas ordenadores, como o espaço concebido ou as estruturas tecnocráticas, até a escala do sujeito comum, ordinário, cujas práticas correspondem aos espaços vividos e percebidos, configurando-se como astúcias e subversões ao sistema ordenador. Essa análise propõe uma reflexão teórica de articulação dos autores a  partir dos livros “A produção do espaço” (LEFEBVRE, 2013) e “A invenção do cotidiano” (CERTEAU, 2009). Considera-se essa aproximação como um profícuo avanço na construção de interpretações de espacialidades complexas, envolendo tanto os sistemas normativos e ordenadores, quanto as pequenas e constantes formas de  driblar a norma.
Genome-Wide Association Study and Cost-Efficient Genomic Predictions for Growth and Fillet Yield in Nile Tilapia (Oreochromis niloticus)
Authors: Yoshida Grazyella M , Lhorente Jean P , Correa Katharina , Soto Jose , Salas Diego , Yáñez José M
Published: June 2019

Fillet yield (FY) and harvest weight (HW) are economically important traits in Nile tilapia production. Genetic improvement of these traits, especially for FY, are lacking, due to the absence of efficient methods to measure the traits without sacrificing fish and the use of information from relatives to selection. However, genomic information could be used by genomic selection to improve traits that are difficult to measure directly in selection candidates, as in the case of FY. The objectives of this study were: (i) to perform genome-wide association studies (GWAS) to dissect the genetic architecture of FY and HW, (ii) to evaluate the accuracy of genotype imputation and (iii) to assess the accuracy of genomic selection using true and imputed low-density (LD) single nucleotide polymorphism (SNP) panels to determine a cost-effective strategy for practical implementation of genomic information in tilapia breeding programs. The data set consisted of 5,866 phenotyped animals and 1,238 genotyped animals (108 parents and 1,130 offspring) using a 50K SNP panel. The GWAS were performed using all genotyped and phenotyped animals. The genotyped imputation was performed from LD panels (LD0.5K, LD1K and LD3K) to high-density panel (HD), using information from parents and 20% of offspring in the reference set and the remaining 80% in the validation set. In addition, we tested the accuracy of genomic selection using true and imputed genotypes comparing the accuracy obtained from pedigree-based best linear unbiased prediction (PBLUP) and genomic predictions. The results from GWAS supports evidence of the polygenic nature of FY and HW. The accuracy of imputation ranged from 0.90 to 0.98 for LD0.5K and LD3K, respectively. The accuracy of genomic prediction outperformed the estimated breeding value from PBLUP. The use of imputation for genomic selection resulted in an increased relative accuracy independent of the trait and LD panel analyzed. The present results suggest that genotype imputation could be a cost-effective strategy for genomic selection in Nile tilapia breeding programs.
Variations of anterior and posterior division of internal iliac artery: A systematic review and clinical implications
Authors: Mohammadbaigi Hadis , Darvishi Marzieh , Moayeri Ardeshir
Published: June 2019

The distribution pattern of internal iliac artery (IIA) implies its bifurcation to two branches, the anterior and the posterior trunks. According to previous research, IIA indicates several anatomical variations. The purpose of this study is to evaluate the types of these variations. The presence of these variations in the arteries is an important topic to urologists, gynecologists, radiologists, and general surgeons because they can be ruptured during surgical procedures in the perineal and pelvis region. Three databases were searched for the period from 1810 to January 2018 and a total of 75 studies were investigated. This study evaluated the branching of the internal iliac artery in several literatures and compared it with Adachi's classification. This finding can lead to improve surgical technique and safety in medical practice.
Nano-scale Chemistry of Complex Self-Assembled Nanostructures in Epitaxial SiGe Films
Authors: Balasubramanian Prabhu , Floro Jerrold A. , Gray Jennifer L. , Hull Robert
Published: June 2019

Heteroepitaxy of SiGe alloys on Si (001) under certain growth conditions has previously been shown to cause self-assembly of nanostructures called Quantum Dot Molecules, QDMs, where pyramidal pits and 3D islands cooperatively form. QDMs have potential applications to nanologic device architectures such as Quantum Cellular Automata that relies on localization of charges inside islands to create bi-stable logic states. In order to determine the applicability of QDMs to such structures it is necessary to understand the nano-scale chemistry of QDMs because the chemistry affects local bandgap which in turn affects a QDM’s charge confinement property. We investigate the nanoscale chemistry of QDMs in the Si0.7Ge0.3/Si (100) system using Auger Electron Spectroscopy (AES). Our AES analysis indicates that compressively strained QDM pit bases are the most Ge rich regions in a QDM. The segregation of Ge to these locations cannot be explained by strain energy minimization.
In-Situ Diffraction Studies of Gas Storage Materials on a Laboratory X-Ray System
Authors: Sommariva Marco , van Weeren Harald , Narygina Olga , Gertenbach Jan-André , Resch Christian , Pein Andreas , Smith Vincent J. , Barbour Leonard J.
Published: June 2019

The sorption processes for hydrogen and carbon dioxide are of considerable, and growing interest, particularly due to their relevance to a society that seeks to replace fossil fuels with a more sustainable energy source. X-ray diffraction allows a unique perspective for studying structural modifications and reaction mechanisms that occur when gas and solid interact. The fundamental challenge associated with such a study is that experiments are conducted while the solid sample is held under a gas pressure. To date in-situ high gas pressure studies of this nature have typically been undertaken at large-scale facilities such as synchrotrons or on dedicated laboratory instruments. Here we report high-pressure XRD studies carried out on a multi-purpose diffractometer. To demonstrate the suitability of the equipment, two model studies were carried out, firstly the reversible hydrogen cycling over LaNi5, and secondly the structural change that occurs during the decomposition of ammonia borane that results in the generation of hydrogen gas in the reaction chamber. The results have been finally compared to the literature. The study has been made possible by the combination of rapid X-ray detectors with a reaction chamber capable of withstanding gas pressures up to 100 bar and temperatures up to 900 °C.
Triboemission phenomena: electronic and photonic outputs from surface modification, and their use as novel probes
Authors: Molina Gustavo J. , Kajdas Czeslaw
Published: June 2019

Triboemission comprises the emission of low energy electrons and photons, the eventual formation of micro-triboplasmas, and the possible charge-initiated tribochemical reactions on the surfaces under contact. Electron triboemission is often seen as a case of electron exoemission, but such low-energy output may be just a fraction of the total electronic excitation on the surface, the majority of which may proceed as internal currents. The dynamics of these related surface phenomena have been investigated by different techniques, which are discussed in this work; in particular, the authors have obtained extensive data indicating that electrons and photons are produced from mechanical surface work, particularly from surface oxides and semiconductors under contact sliding in vacuum. This paper also discusses the existing body of work on triboemission, and the possible use of the developed measurement techniques as novel probes for surface processes.
Nanofluidic Cells with Controlled Path Length and Liquid Flow for Rapid, High-Resolution In Situ Electron Microscopy
Authors: Mueller C. , Harb M. , Dwyer J.R. , Miller R.J.D.
Published: June 2019

In situ imaging using (scanning) transmission electron microscopy has proven to be an extremely important and powerful cross-disciplinary scientific technique. In particular nanotechnology and materials sciences have special interest in assembly and disintegration processes, in growth and shape-tuning of (nano)-particles, and, furthermore in mechanistic studies of chemical reactions underlying these processes. However, limitations for in liquid and in situ imaging using electron microscopy arise from the stringent experimental conditions required with respect to electron scattering.

Here, we present a nanofluidic sample cell allowing for controlled fluidic conditions which preserve the highest possible spatial resolution for in-liquid electron microscopy. The nanocell allows for liquid flow with a flow control mechanism operated external to the microscope column enabling on-the-fly sample exchange within the imaging area. A well-defined flow path allows us to direct the motion of gold nanorods through fluid flow. Further a particle’s Brownian motion becomes evident once the external flow is terminated. In addition to quantitatively showing the resolution capabilities of our nanofluidic design, we show preliminary results of in situ imaging of gold nanorods and unstained amyloid fibrils to emphasize the significance of this imaging modality for both material sciences and biology.
Scanning Photocurrent Microscopy of as-Grown Silicon Nanowire Metallurgical Junctions
Authors: Triplett Mark , Saif Islam M. , Yu Dong
Published: June 2019

During the epitaxial bottom up growth of nanowire (NW) arrays, occasional kinks in growth direction can lead to intersecting and consequently self-welded crystalline connections between NWs. In order to study these self-welded metallurgical NW junctions, a NW bridge device architecture which requires no post-growth processing was used to grow and stabilize Si NW junctions. Scanning Photocurrent Microscopy (SPCM) was used to study the optoelectronic properties of the NW junctions as well as the characteristics of the NW bridge devices. SPCM measurements show a bias dependent photocurrent (PC) response at the NW junction indicating local band bending at this location. A decay of the PC response away from the junction is also seen in the secondary NW channel ensuring an electrical connection. These junction properties may be important for ensemble NW optical devices.
The Synthesis of Metastable Skutterudites and Crystalline Superlattices
Authors: Sellinschegg Heike , Williams Joshua R. , Yoon Gene , Johnson David C. , Kaeser Mike , Tritt Terry , Nolas George , Nelson E.
Published: June 2019

We have used controlled crystallization of elementally modulated reactants to prepare a series of kinetically stable, crystalline skutterudites (M'xM4Sb12 where M' = vacancy, RE, Hf,…; M = Ni, Fe, Co) and crystalline superlattices composed of promising thermoelectric materials. For the bulk synthesis of skutterudites, low angle diffraction data demonstrates that the elemental layers interdiffuse at temperatures below 150°C. Nucleation of the skutterudite structure occurs with at large exotherm on annealing at temperatures below 200°C regardless of the ternary metal. All of the metastable ternary compounds and the new metastable binary compounds were found to decompose exothermically on higher temperature annealing. The decomposition temperature ranged from 250°C for the binary compound NiSb3 to above 550°C for the rare earth containing cobalt compounds. The occupation of the ternary site was found to depend on the composition of the initial reactant and was varied from 0 to 1. Full occupancy typically required an excess of the filling cation. The lattice parameters of the compounds prepared at low temperatures are distinctly smaller than those prepared using traditional synthetic approaches. High temperature annealing converts the lattice parameters of the low temperature compounds to those prepared at higher temperatures using traditional synthetic approaches. Diffraction patterns of crystalline superlattices containing skutterudites prepared using elementally modulated reactants show splitting of high angle diffraction maxima as well as the presence of the expected low angle diffraction pattern from a supperlattice. The skutterudite superlattices are stable with respect to low temperature annealing.
Electrochemical Deposition of (Bi,Sb)2Te3 for Thermoelectric Microdevices
Authors: Fleurial Jean-Pierre , Herman Jennifer A. , Jeffrey Snyder G. , Ryan Margaret A. , Borshchevsky Alexander , Huang Chen-Kuo
Published: June 2019

New experimental methods have been developed to electrochemically deposit p-type Sb-rich Bi2-xSbxTe3, Pb-doped and Bi-doped Bi2Te3, and PbTe thick films. Some of the deposited films were dense and had a smooth surface morphology. These films were deposited potentiostatically at room temperature in an acidic aqueous electrolyte. Experimental deposition of Bi2Te3 alloys into various thick nanoporous templates made out of anodized alumina has also been achieved. Miniaturized thermoelements for microdevices (25 μm tall, 60 μm diameter) were grown by plating through thick photoresist templates. The experimental techniques developed, as well as the transport properties of some of the films and filled templates, will be presented.
P-type SiGe/Si Superlattice Cooler
Authors: Fan Xiaofeng , Zeng Gehong , Croke Edward , Robinson Gerry , LaBounty Chris , Ahn Channing C. , Shakouri Ali , Bowers John E.
Published: June 2019

The fabrication and characterization of single element p-type SiGe/Si superlattice coolers are described. Superlattice structures were used to enhance the device performance by reducing the thermal conductivity between the hot and the cold junctions, and by providing selective emission of hot carriers through thermionic emission. The structure of the samples consisted of a 3 μm thick symmetrically strained Si0.7Ge0.3/Si superlattice grown on a buffer layer designed so that the in-plane lattice constant is approximately that of relaxed Si0.9Ge0.1. Cooling up to 2.7 K at 25 °C and 7.2 K at 150 °C were measured. These p-type coolers can be combined with n-type devices that were demonstrated in our previous work. This is similar to conventional multi element thermoelectric devices, and it will enable us to achieve large cooling capacities with relatively small currents.
Thermoelectric Properties of Selenide Spinels
Authors: Jeffrey Snyder G. , Caillat T. , Fleurial J. -P.
Published: June 2019

Many compounds with the spinel structure type have been analyzed for their thermoelectric properties. Published data was used to augment experimental results presented here and to select promising thermoelectric spinels. Compounds studied here include Cu0.5Al0.5Cr2Se4, Cu0.5Co0.5Cr2Se4, Cu0.5In0.5Cr2Se4, and CuIr2Se4. Many exhibit low lattice thermal conductivity of about 20 mW/cmK, independent of temperature. Preliminary results are given for two series of compounds that were selected for further study: GaxCu1-xCr2Se4 and ZnxCu1-xCr2Se4.
Carrier Pocket Engineering for the Design of Low Dimensional Thermoelectrics with High Z3DT
Authors: Koga Takaaki , Cronin Stephen B. , Dresselhaus Mildred S.
Published: June 2019

The concept of carrier pocket engineering applied to Si/Ge superlattices is tested experimentally. A set of strain-symmetrized Si(20Å)/Ge(20Å) superlattice samples were grown by MBE and the Seebeck coefficient S, electrical conductivity σ, and Hall coefficient were measured in the temperature range between 4K and 400K for these samples. The experimental results are in good agreement with the carrier pocket engineering model for temperatures below 300K. The thermoelectric figure of merit for the entire superlattice, Z3DT, is estimated from the measured S and σ, and using an estimated value for the thermal conductivity of the superlattice. Based on the measurements of these homogeneously doped samples and on model calculations, including the detailed scattering mechanisms of the samples, projections are made for δ-doped and modulation-doped samples [(001) oriented Si(20Å)/Ge(20Å) superlattices] to yield Z3DT ≈ 0.49 at 300K.
Where Should We Look For High Zt Materials: Suggestions From Theory.
Authors: Fornari M. , Singh D. J. , Mazin I. I. , Feldman J. L.
Published: June 2019

The key challenges in discovering new high ZT thermoelectrics are understanding how the nearly contradictory requirements of high electrical conductivity, high thermopower and low thermal conductivity can be achieved in a single material and based on this identifying suitable compounds. First principles calculations provide a material specific microscopic window into the relevant properties and their origins. We illustrate the utility of the approach by presenting specific examples of compounds belonging to the class of skutterudites that are or are not good thermoelectrics along with the microscopic reasons. Based on our computational exploration we make a suggestion for achieving higher values of ZT at room temperature in bulk materials, namely n-type La(Ru,Rh)4Sb12 with high La-filling.
Granular Flows in the Elastic Limit
Authors: Campbell Charles S.
Published: June 2019

This paper describes recent computer simulation studies into the rheological behavior of granular materials in the regime that lies between the quasistatic and rapid-flow regime. This investigation was prompted by studies of landslides, hopper flows and the “phase change” (i.e. the change between solidlike and fluid-like behavior) all of which indicated that the shear-to-normal stress ratio (the effective friction coefficient for the material) increased with shear rate. The results presented herein do demonstrate that the stress ratio varies with a dimensionless parameter created by scaling the shear rate with the stiffness of the interparticle contacts. In dense regimes, the stresses themselves scale with the stiffness indicating that they are generated by the elastic response of particle networks. Such speculation is supported by studies that show that the normal stresses are strongly dependent on the interparticle friction coefficient which affects the ability of internal elastic particle structures to support load and by the time variation of stress, which shows a spiky behavior as the structures form and break. However, analyses also indicate that these observations cannot explain the hopper, landslide and phase-change as these systems operate in regimes different from those in which the effect was observed. Finally, the effects of non-linear contacts are investigated and an appropriate scaling that takes the non-linearity into account is proposed.
A Nonequilibrium Approach for Self-Diffusion in Unbounded Rapid Granular Flows
Authors: Jalali Payman , Zamankhan Piroz , Polashenski William
Published: June 2019

A nonequilibrium simulation scheme is introduced to investigate the transverse diffusive motion in unbounded shear flows of smooth, monodisperse, inelastic spherical particles. A certain labeling algorithm is used in this scheme to extract a one-way particle mass flux which results a concentration gradient for the labeled particles. The self-diffusion coefficient can then be obtained from Fick's law. Using this scheme, one may find that the self-diffusion phenomenon across any layer inside the granular shear flow is analogous to the classic diffusion problem across a membrane. Under steady conditions, the current simulation results revealed that the particle diffusivity can be described by a linear law. This finding justifies the assumption of a linear law relationship in the kinetic theory type derivation of an expression for self-diffusivity. Moreover, it is shown that the results of self-diffusion coefficient obtained from the computer simulations are in agreement with the predictions of kinetic theory formulations in the range of solid volume fractions less than 0.5.
An Experimental Study of the Fluctuations in Granular Drag
Authors: Albert István , Tegzes Pál , Albert Réka , Sample John , Barabási Albert-László , Vicsek Tamás , Kahng B. , Schiffer Peter
Published: June 2019

We study fluctuations in the drag force resisting the motion of an object being pulled through a dense spherical granular medium. These fluctuations are stick-slip in nature due to the jamming and reorganization of the grains. The fluctuations in the force are periodic at small depths, but they become “stepped” at large depths. We interpret this transition as a consequence of the long-range nature of the force chains.
Multiscale Modeling of Dislocation Processes in Bcc Tantalum: Bridging Atomistic and Mesoscale Simulations
Authors: Yang L. H. , Tang Meijie , Moriarty John A.
Published: June 2019

Plastic deformation in bcc metals at low temperatures and high-strain rates is controlled by the motion of a/2<111> screw dislocations, and understanding the fundamental atomistic processes of this motion is essential to develop predictive multiscale models of crystal plasticity. The multiscale modeling approach presented here for bcc Ta is based on information passing, where results of simulations at the atomic scale are used in simulations of plastic deformation at mesoscopic length scales via dislocation dynamics (DD). The relevant core properties of a/2<111> screw dislocations in Ta have been obtained using quantum-based interatomic potentials derived from model generalized pseudopotential theory and an ab-initio data base together with an accurate Green's-function simulation method that implements flexible boundary conditions. In particular, the stress-dependent activation enthalpy for the lowest-energy kink-pair mechanism has been calculated and fitted to a revealing analytic form. This is the critical quantity determining dislocation mobility in the DD simulations, and the present activation enthalpy is found to be in good agreement with the previous empirical form used to explain the temperature dependence of the yield stress.
Stresses in Thin Coatings from Curvature Measurements on Non-Planar Substrates
Authors: Wikström A. , Gudmundson P.
Published: June 2019

Mechanical elastic and inelastic properties of thin coatings are often studied by means of the curvature measurement technique in combination with the Stoney formula. It is then implicitly assumed that the elastic substrate is initially flat which implies that the curvatures theoretically remain constant over the substrate. If the substrate has a slight initial curvature, a different situation arises. In this case, the curvatures will vary over the substrate. It has recently been shown that in spite of this, the stresses that appear in the thin coating will remain constant over the surface of the substrate. Therefore, measured curvatures can generally not be used to extract layer stresses without a proper compensation for the initial curvature. A general method for the extraction of mechanical properties from curvature measurements on non-planar substrates is outlined. The method is valid for linear as well as non-linear shell theories. The compensation needed to evaluate a coating on a circular substrate with spherical initial curvature is studied for all relevant parameters. The results are particularly discussed in relation to curvature measurements on silicon wafers.
Hybrid Electronic-density-functional/molecular-dynamics Simulation on Parallel Computers: Oxidation of Si Surface
Authors: Ogata Shuji , Shimojo Fuyuki , Nakano Aiichiro , Vashishta Priya , Kalia Rajiv K.
Published: June 2019

A hybrid quantum mechanical/molecular dynamics simulation scheme is developed by embedding a quantum mechanical system described by the real-space density-functional theory in a classical system of atoms interacting via an empirical interatomic potential. A novel scaled position method for handshake atoms coupling the quantum and the classical systems is introduced. Hybrid simulation run for oxidation of Si (100) surface is performed to demonstrate seamless coupling of the quantum and the classical systems.
Features of Vacancy Interaction with Interstitial Clusters in BCC Metals
Authors: Pelfort Marta , Osetsky Yuri N. , Serra Anna
Published: June 2019

Recent theoretical calculations and atomistic computer simulations have shown that one-dimensional (1D) glissile clusters of self-interstitial atoms (SIAs) play an important role in the evolution of the microstructure in metals and alloys under cascade damage conditions. Theoretical treatments based on the production bias model (PBM)and cascade-induced source hardening clarify many features of materials behaviour under irradiation by considering 1D glissile SIA clusters. However, further progress in understanding irradiation phenomena demands a detailed knowledge of different reactions where glissile SIA clusters take part. The latest version of the PBM has demonstrated that there is a significant lack of knowledge on mechanisms such as the interaction between mobile clusters and other microstructure components, changes on glide directions or the reduction of cluster mobility. Some aspects of interactions have been recently studied and the formation of immobile complexes of glissile clusters in the bulk and near dislocations has been shown. However, in addition to the cluster - clusters and cluster – dislocation interactions, the interactions of clusters with point defects should be considered. Here we present the first results on interaction between a SIA cluster and vacancy in bcc-iron. The interactions were studied by both atomistic simulations and elasticity theory. Some qualitative differences between the results obtained by these two methods were found, thereby demonstrating the need for the atomistic approach. It is shown that the interaction with vacancies can reduce and, in some cases, suppress the mobility of SIA clusters. The results are discussed in the light of both experimental data and theoretical predictions.
Fabrication of p-Type Zns with Blue-Ag Emission by Triple-Codoping Method
Authors: Kishimoto S. , Yamamoto T. , Iida S.
Published: June 2019

We have succeeded in the fabrication of low-resistivity p-type ZnS with blue -Ag emission by triple-codoping using Ag, a Zn-substituting species, In, a Zn-substituting species, and N, a S-substituting species. For the realization of blue-Ag emission at 436 nm, we use In species as co-activators with Ag activators. For the control of conduction type to obtain p-type ZnS thin films, we introduce N species as acceptors into ZnS codoped with the Ag and In. On the basis of the analysis of the experimental data and calculated results, we proposed a model for ZnS:(Ag, In, and N), in which some of the In species act as coactivators with Ag activators and other In species act as reactive codopants with N acceptors.
Optical Methods for Defect Characterization in Light-Ion Implanted Silicon Carbide
Authors: Muntele Claudiu I. , Muntele Iulia C. , Ila Daryush , Poker David B. , Hensley Dale K.
Published: June 2019

The work reported here deals with studying the defects induced by light ion (Al, N) implantation in 4H and 6H silicon carbide, both p-type (Al-doped) and n-type (N-doped). Confocal Micro-Raman (MR) was used for monitoring the (480 – 540) cm-1 spectral region of amorphous silicon. A broad peak forms in this region because of silicon atoms relocated as interstitials, translating into a locally stressed crystalline lattice. The locally relaxed lattice at these atoms' locations of origin also gives a broadening of the characteristic Raman peaks of each type of material. UV/Vis Optical Absorption (OA) Spectroscopy has also been employed as a good tool for dopant and carrier trapping levels embedded in the band gap of the silicon carbide material. MR and OA data collected from virgin samples, as implanted, and after annealing at two different temperatures (1100 and 1600 °C) are discussed in this paper.
Raman Scattering Spectra in Be-Implanted GaN Epilayers
Authors: Wang L. S. , Sun W. H. , Chua S. J.
Published: June 2019

Ion-implantation has been an interesting topic on impurity-doping in GaN. Raman measurement is a strong tool for the characterization of semiconductors. We have investigated the Raman scattering spectra in Be-implanted GaN epilayers. In as-implanted GaN, new Raman bands at ∼310, ∼360, 669 cm-1 appeared. From phonon-dispersion curves for hexagonal GaN, the ∼300 cm-1 and 669 cm-1 bands were assigned to the highest acoustic-phonon branch and the optical-phonon branch at the Brillouin zone boundaries, respectively. Two sharp bands at 168 and 199 cm-1 were observed in the Raman spectra of Be-implanted GaN after post-implantation annealing treatments. We tentatively assign these two bands to Be-related local vibrational modes.