bluuebunny/crossref_metadata_2025 huggingface dataset:
METHODS OF PIGMENTATION OF POLYSILOXANE RESIN AND HEAT-RESISTANT COATINGS ON THEIR BASIS
Authors: Kazhuro Irina P. , Koshewar Vasiliy D. , Shkadretsova Valentina G.
Published: February 2018

The purpose of the work is carrying out the comparative analysis of methods of receiving compositions on the basis of organic silicon resin for creation of a heat-resistant coating and a research of their physical, chemical s and serviceability properties. The method of a dispersion and influence of a dispersing agent and fillers on process of production and properties of heat-resistant paint on the basis of polyorganosiloxane resin was established. The grinding was carried out in two modes: dispersing mixer and beaded mixing. The mode of a beaded mill gives the increased lathering. It is established that adhesion of a film of paint to steel considerably worsens at a high thickness of a coating. Introduction of a disperser minimizes dependences of adhesion on coating thickness. Dependence of adhesion on the maintenance of an aluminum powder in composition and thickness of coating was established. Selection of components for composition of heat-resistant paint is experimentally reasonable and its compounding is developed. The carried-out assessment of properties of composition of paint and coating on its basis indicates compliance of their main serviceability properties. The received coating composition conforms to requirement for heat-resistant paint. The composition is recommended for applying heat-resistant anticorrosion coatings to the exhaust devices of cars, thermo-furnaces, external surfaces of chimneys, heaters exposed to temperatures in the range of 500-600 °C. properties. The received coating composition conforms to requirement for heat-resistant paint.Forcitation:Kazhuro I.P., Koshevar V.D., Shkadretsova V.G. Methods of pigmentation of polysiloxane resin and heat-resistant coatings on their basis. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 3. P. 77-82
OXIDATION OF PROPANE-BUTANE MIXTURE IN DIELECTRIC BARRIER DISCHARGE IN PRESENCE OF LIQUID OCTANE
Authors: Kudryashov Sergey V. , Ryabov Andrey Yu. , Ocheredko Andrey N.
Published: February 2018

The results of oxidation of a propane-butane mixture in a barrier discharge plasma in the presence of liquid octane are presented. The conversion of the gas-liquid mixture results in the formation of an oxygenate containing predominantly hydroxyl and carbonyl compounds with the same number of carbon atoms in a molecule as in the starting compounds. The presence of a liquid octane film flowing down the plasma-chemical reactor walls enables an effective removal of the reaction products from the discharge zone due to dissolution of the compounds formed therein. Alkyl radicals, atomic oxygen, and hydrogen are the main active particles. The formation of both oxygenated compounds and hydrocarbons with isomeric structure occurs as a result of their further chemical transformations. The mechanism of conversion of gaseous hydrocarbons is much like that for the conversion of liquid hydrocarbons in a barrier discharge plasma. They both are carried out under similar conditions. The change in the initial concentration of the propane-butane mixture in the gas phase from 10 to 75 % wt results in a decrease in the conversion of gaseous hydrocarbons from 4.1 to 0.9 % wt, while the conversion of octane decreases from 2.4 to 0.3% wt. in one pass through the reactor. The decrease in hydrocarbon conversion is due to decrease in the rate of formation of atomic oxygen in a discharge gap of the reactor. Theoretical calculations were performed using the software package Bolsig+ for the model oxygen-propane mixture. The results of calculations show that the rate constant of oxygen dissociation increases from 1.87·10-10 cm3/s to 6.71·10-9 cm3/s, due to an increase in the average electron energy from 3.4 to 4.1 eV. It was found out that the mass of products formed in result of oxidation of gaseous and liquid hydrocarbons depends on the initial concentration of the starting compounds in the vapor-gas mixture. A simple expression is proposed that allows one to evaluate the preferential direction of the plasma-chemical reaction as a function of the initial concentration of hydrocarbons in a discharge gap of the reactor.Forcitation:Kudryashov S.V., Ryabov A.Yu., Ocheredko A.N. Oxidation of propane-butane mixture in dielectric barrier discharge in presence of liquid octane. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 3. P. 88-92
ACID ORANGE 52 DYE DEGRADATION EFFICIENCY BY ELECTROCATALYTIC METHOD
Authors: Zhao Hui , Zhong Heng , Sun Lei , Xia Dongsheng , Nevsky Alexander V.
Published: February 2018

The degradation process of Acid Orange 52 dye in aqueous solutions by electrocatalytic technique has been studied. Acid Orange 52 was chosen as a representative compound of azo dyes and one of the often used acid dyes in the textile industry. In the electrocatalytic reactor, the titanium plates with catalyst layer were used as anode, and the stainless steel plates worked as cathodes. The layers of catalyst were coated on titanium plates by electrochemical method followed by calcination. The effect of dye initial concentration (Cdye), catalyst nature on anode, initial voltage (Uin), electrolysis time (t), initial solution pHin and NaCl concentration on the rate of Acid Orange 52 degradation process was studied in the electrocatalytic process. It was determined that the optimal conditions of electrocatalytic treatment, in particular are: Cdye=100 mg/l, Uin=20 V, pHin = 6, t = 50 min. The experimental results show that when Acid Orange 52 simulated dye wastewater was treated under the optimal conditions, the treatment effect was 95 % in visible part of light spectrum (464 nm) and 38.6 % in ultraviolet part (270nm), respectively. The removal rate of chemical oxygen demand (COD) and total organic carbon (TOC) were 23.5 % and 47.7 %, respectively. It was found that electrocatalytic process can provide an effective decolorization rate of Acid Orange 52. However, not high values of COD removal rate most likely witness that there was no significant destruction of large fragments of the dye structure, such as the benzene ring.Forcitation:Hui Zhao, Heng Zhong, Lei Sun, Dongsheng Xia, Nevsky A.V. Acid Orange 52 dye degradation efficiency by electrocatalytic method. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 3. P. 64-69
Anmeldelse af: G. Clinton Godart, Darwin, Dharma, and the Divine. Evolutionary Theory and Religion in Modern Japan
Authors: Borup Jørn
Published: February 2018

Anmeldelse af: G. Clinton Godart, Darwin, Dharma, and the Divine. Evolutionary Theory and Religion in Modern Japan, University of Hawaii Press 2017, 301 s., $ 68.00
La relation entre les problèmes de comportement et le surplus de poids chez des enfants québécois d’âge préscolaire : une étude transversale
Authors: Leblanc Nancy , Drapeau Vicky
Published: February 2018

Cette étude transversale examine la relation entre les problèmes de comportement intériorisés et extériorisés et le surplus de poids chez des enfants québécois âgés de 3 à 5 ans. En tout, 330 parents ont rempli la version canadienne-française de la Child Behavior Checklist for Ages 1.5-5. Les enfants ont été classés dans la catégorie poids normal (3e au 85e centile) ou surplus de poids (> 85e centile). Les filles ayant un poids normal présentent des scores significativement plus élevés que les filles ayant un surplus de poids quant aux comportements intériorisés totaux ainsi qu’aux sous-échelles anxiété/dépression et retrait social. Pour les comportements extériorisés, aucune différence significative n’est observée parmi les enfants. Des études longitudinales sur la relation entre les problèmes comportementaux et le surplus de poids en bas âge sont nécessaires, afin de mieux documenter l’émergence et la direction de cette relation ainsi que les mécanismes impliqués.
L’anxiété des élèves en milieu scolaire telle que perçue par des enseignants du primaire
Authors: Lambert-Samson Véronique , Beaumont Claire
Published: February 2018

Cette étude exploratoire menée auprès de douze enseignants du primaire (1reà 6eannée) vise à vérifier leurs connaissances théoriques, leurs pratiques de même que les sources qui ont contribué à leurs savoirs actuels concernant l’anxiété des élèves. Des entrevues ont permis de relever les connaissances et les interventions déclarées par le personnel enseignant et d’explorer les fondements les soutenant. Les résultats révèlent que les connaissances des enseignants quant aux manifestations de l’anxiété, ses causes et les interventions à pratiquer sont limitées. Les principales sources de leurs connaissances sont issues de leurs expériences personnelles et professionnelles et très peu de leurs formations initiale ou continue. De nouvelles pistes d’intervention et de recherche sont proposées pour améliorer les formations initiale et continue des enseignants et contribuer au développement de leur compétence pour venir en aide aux élèves qui vivent de l’anxiété à l’école primaire.
Mandaic Incantation(s) on Lead Scrolls from the Schøyen Collection
Authors: Abudraham Ohad , Morgenstern Matthew
Published: February 2018

This article presents a first edition of three Mandaic lamellae from the Schøyen Collection, MS 2087/10, 2087/11, and 2087/18, which are the product of the same scribe and probably constituted a single amulet. The language of the amulet differs from that of other Mandaic texts, and demonstrates unknown or rare phonetic and morphological features. In addition, several lexemes that were hitherto unattested in Mandaic have been identified. Some of the amulet’s formulae are familiar from previously published texts, but in several cases the new textual evidence allows us to improve upon their readings.
Digital Humanities and Islamic and Middle Eastern Studies. Edited by Elias Muhanna
Authors: Lit L. W. Cornelis van
Published: February 2018

The Digital Humanities and Islamic and Middle Eastern Studies. Edited by Elias Muhanna. Berlin: de Gruyter, 2016. Pp. vi + 271. $140, £74.99, €99.95.
Archaeology of Cyprus: From Earliest Prehistory through the Bronze Age. By A. Bernard Knapp
Authors: Keswani Priscilla
Published: February 2018

The Archaeology of Cyprus: From Earliest Prehistory through the Bronze Age. By A. Bernard Knapp. Cambridge World Archaeology. Cambridge: Cambridge University Press, 2013. Pp. xx + 640 (illus.). $38.99 (paper).
Rethinking Biblical Scholarship. By Philip R. Davies, Copenhagen International Seminar
Authors: Van Seters John
Published: February 2018

Rethinking Biblical Scholarship. By Philip R. Davies, Copenhagen International Seminar. Changing Perspectives, vol. 4. Durham, UK: Acumen Publishing, 2014. Pp. xv + 253. $99.95. [Distributed by ISD, Bristol, Conn.]
Ebolição frente ao ajuste na Argentina: a cleptocracia desafiada
Authors: Katz Claudio
Published: February 2018

Na Argentina, cresce a resistência contra as reformas de Macri e os professoresprotagonizam asbatalhasprincipais. Concomitantemente, também aumenta a revolta contra a complacência das liderançassindicais. Por diferentes formas, o governoreforça a agenda neoliberal. Mas enfrenta a persistente estagnação da economia e se depara comgraves acusações de corrupção. De um lado, nãoconsegueimporsua agenda e, de outro,vaiperdendo a homogeneidade. Paralelamente, há grandes mudanças no nível de organização e conscientização popular.
Mecanismos institucionais de participação social e barreiras estruturais: o caso do Equador
Authors: Ribeiro Agatha Justen Gonçalves , Gurgel Claudio Roberto Marques
Published: February 2018

A América Latina conta hoje com países onde se busca transformações pelo empoderamento do cidadão por via constitucional e institucional. O Equador é um exemplo disso pelo que anuncia como uma revolución ciudadana. Seu processo chama atenção pela série de mecanismos de participação social construídos, a partir da Constituição de 2008.  O objetivo deste trabalho é expor a proposta revolucionária em curso no Equador e examiná-la em face do modo de produção capitalista que subsiste nesse país. Indagamos o que se pode ter como expectativa e como avanços nessa experiência. Para isto, mobilizamos a bibliografia sobre o Equador recente e os documentos constitucionais e institucionais que definem o processo, além dos sites que integram os mecanismos de participação e controle social adotados. 
A educação paraguaia: quatro marcos históricos decisivos
Authors: Roesler Patricia Simone
Published: February 2018

O propósito deste artigo é registrar a trajetória da educação do Paraguai destacando seus principais marcos históricos, assim organizado em quatro partes, a saber. Na primeira, tecemos considerações sobre a educação no período colonial, entendido como uma das primeiras iniciativas educacionais estabelecidas no país. Na segunda, apresentamos ponderações acerca da realidade educacional da nação mediante o advento da república em 1811, que estabelece o período independente, até a guerra do Paraguai iniciada em 1864. Na terceira, registramos o processo de reconstrução nacional e as iniciativas estabelecidas para a materialização das escolas públicas e privadas no contexto do pós-guerra do Paraguai. Para finalizar, abordamos o processo de democratização que culmina, no setor educacional, com a reforma de 1994, que por sua vez, materializou-se na Lei 12.64/98, assim, organizando os princípios meios e fins da educação nacional. A elaboração do trabalho está fundamentada em fontes primárias, constituídas pelos documentos legais característicos dos momentos indicados e nas fontes secundárias representadas pelas bibliografias já produzidas sobre a história da educação paraguaia. 
O Brasil, a Venezuela e os movimentos sociais no contexto da América Latina e do Império
Authors: Camargo Paola Claudia Carolina Estrada , Stédile João Pedro , Giordani Jorde
Published: February 2018

Na seção Entrevista sob o título O Brasil, a Venezuela e os movimentos sociais no contexto da América Latina e do império, reunimos três entrevistas. Uma, feita com Paola Claudia Carolina Estrada Camargo, intitulada: O Brasil no contexto das mudanças na América Latina e no império, outra, com Jorge Giordani, que trata da Venezuela, com o título: A Venezuela e desafios do tempo presente, ambas semiestruturadas por Paulino José Orso e uma terceira, com  João Pedro Stedile, primeiramente elaborada para o livro PENSAR, das editoras SUDESTADA (Argentina)/La FOGATA (México)/ EL PERO Y LA RANA (Venezuela), cedida pelo autor, para publicar no Brasil, pela Revista Germinal, em que faz uma Análise da situação política e dos movimentos populares da América Latina. As mesmas analisam os ataques impetrados pelo imperialismo sobre a América Latina, em especial, sobre a Venezuela e o Brasil, ricos em riquezas naturais, minerais e petrolíferos, centrais do ponto de vista do projeto político e geoestratégico de dominação estadunidenses para o século XXI, bem como, analisam os impactos desses ataques sobre os movimentos sociais populares.
A Revolução Russa e os desafios à pedagogia histórico-crítica
Authors: Lombardi José Claudinei
Published: February 2018

O artigo traça as linhas gerais da educação nas condições históricas em que se deu a Revolução Russa. O texto está organizado em três pontos: 1º. É apresentado o significado histórico da Revolução Russa que não pode ser separada das revolução burguesas, no interior das quais se deu o surgimento das classes fundamentais do capitalismo, a partir de onde se forjaram as lutas do proletariado contra a exploração capitalista. O texto compartilha do entendimento de que a Revolução Bolchevique foi um fato fundamental para história do Século XX, notadamente como referência ao proletariado, tal qual o foi a Revolução Francesa para demarcar o fim do antigo regime e a vitória política da burguesia revolucionária. 2º. Faz uma leitura da educação na primeira fase da Revolução de Outubro, estudando-se o relatório apresentado no I Congresso de Toda a Rússia para a Instrução Pública, denominado “A Educação na Rússia Revolucionária”, ocorrido em 1922, pelo Presidente do Comissariado do Povo para a Instrução Pública, Anatóli Lunatcharski, que descreveu as questões fundamentais da educação no contexto da revolução. 3º. São feitas algumas observações sobre as possíveis contribuições da educação na Rússia revolucionária no processo de construção da Pedagogia Histórico-Crítica.
A gramática do chavismo: entre a pulsão socialista e o redentorismo popular. notas de investigação
Authors: Casanova Mattera Ramon
Published: February 2018

O texto reúne notas de uma investigação em curso em torno do significado do chavismo no ciclo político aberto na sociedade venezuelana desde o final dos anos 90. Esboça hipóteses, linhas de análise e campo de observação para uma interpretação sociológica do mesmo, valorizando o sujeito coletivo que mobiliza, os imaginários sociais e as tradições intelectuais que lhes conferem identidade política. Assim, o considera como uma expressão da crise histórica do padrão de modernização capitalista ligado as lógicas sociais que produzem a economia rentista do petróleo. Contextualizado, dessa maneira, avalia-se como uma condensação política das contradições de tal padrão, registrando sua evolução no interior da tensão entre uma pulsão socialista e um redentorismo popular. Conclui perguntando se o chavismo mais do que uma alternativa não segue sendo parte do tempo deste padrão de desenvolvimento, correspondendo simplesmente ao momento da crise dos meios institucionais que controlavam as classes subalternas e neutralizavam sua potencialidade conflitiva, atualizando, além de tudo, o patrimonialismo latinoamericano.
Fidel Castro: algumas de suas contribuições teórico-práticas para as inconclusas lutas pela emancipação de nossa América
Authors: Suárez Salazar Luis
Published: February 2018

Depois de narrar os diversos compromissos que tinha estabelecido com as lutas pela emancipação da América Latina e do Caribe antes 01 de janeiro de 1959, o autor deste artigo se ocupa dos vários momentos que, desde os primeiros dias desse ano, o líder histórico da Revolução cubana, Fidel Castro, agora desaparecido fisicamente, convocou à "unidade anti-imperialista" e expressou sua utopia de que todos os estados do continente pudessem se integrar económica e politicamente como uma condição necessária, mas não suficiente para que suas nações e seus povos pudessem transformar em realidade os ideais dos fundadores das lutas pela independência contra o colonialismo ibérico, de igual modo que o chamado que José Martí havia feito até o final do século XIX, para as lutas que havia denominado de "segunda independência" de Nossa América, frente ao então nascente e hoje decadente imperialismo norte-americano. Daí, acrescenta o autor deste artículo, a consistente solidariedade da Revolução Cubana com a luta pela descolonização do Caribe, bem como, com todos os processos revolucionários, reformadores e reformistas ou favoráveis aos interesses populares e nacionais que foram implantados (e estão sendo implantados) no “sul político do continente americano". Também, o apoio dado pelas lideranças políticas do Estado cubano e pelos próprios cubanos aos vários processos de diálogo político, de cooperação económica e de integração na América Latina e no Caribe. Em especial, à Associação de Estados do Caribe (AEC), à agora chamada Aliança Bolivariana para os Povos de Nossa América – Acordo de Comércio entre os Povos (ALBA-TCP) e, mais recentemente, à Comunidade Latino-americana e Caraibenha (CELAC).
A pedagogia de Makarenko: aproximações de um modelo socioeducativo na Revolução Russa
Authors: Pinel Walace Roza , Reses Erlando da Silva
Published: February 2018

Destacamos a obrigatoriedade histórica no resgate das ideias do educador socialista Anton Makarenko, procurando destacar seu relevante trabalho na luta em favor da educação, como projeto social dirigida aos excluídos. Dedicou a sua vida a construir e elaborar um processo educativo balizado na perspectiva de uma práxis social transformadora. Destaca-se no Brasil sua influência, junto aos Movimentos Sociais e Populares, na formação sindical e nas Comunidades Eclesiais de Base vinculados às tendências progressistas da Igreja Católica. Reafirma-se, a perspectiva socialista desta pesquisa reconhecendo as contradições da Pedagogia Socialista de Makarenko como pioneira e fundamental à discussão de instituições de “reforma” de infratores (as) por meio da educação e trabalho especialmente na perspectiva: coletivista e autogestionária.
Local Infrasound Variability Related to In Situ Atmospheric Observation
Authors: Kim Keehoon , Rodgers Arthur , Seastrand Douglas
Published: February 2018

Local infrasound is widely used to constrain source parameters of near‐surface events (e.g., chemical explosions and volcanic eruptions). While atmospheric conditions are critical to infrasound propagation and source parameter inversion, local atmospheric variability is often ignored by assuming homogeneous atmospheres, and their impact on the source inversion uncertainty has never been accounted for due to the lack of quantitative understanding of infrasound variability. We investigate atmospheric impacts on local infrasound propagation by repeated explosion experiments with a dense acoustic network and in situ atmospheric measurement. We perform full 3‐D waveform simulations with local atmospheric data and numerical weather forecast model to quantify atmosphere‐dependent infrasound variability and address the advantage and restriction of local weather data/numerical weather model for sound propagation simulation. Numerical simulations with stochastic atmosphere models also showed nonnegligible influence of atmospheric heterogeneity on infrasound amplitude, suggesting an important role of local turbulence.
Life history (nonhuman primates)
Authors: Lee Phyllis C.
Published: February 2018

Primate life histories represent a general description of the pace of living and dying in this diverse group of mammals. Life histories represent evolved mechanisms for trading the energy and time costs of each life event (e.g., pregnancy) against other such events (e.g., living to old age) on at least two independent dimensions. Originally life histories were differentiated along a single axis into species with rapid rates of living and dying (
r
‐strategists), and species living at their population maxima and therefore investing in high individual quality and competitive ability (K‐strategists). Current theory suggests that there are two separate dimensions: (1) production or the balance of offspring size against offspring numbers; and (2) timing or rates of reproduction. Primate life histories are distinct from those of many mammals, specifically in their strategy of trading time against energy, resulting in slow rates of reproduction, at low costs, associated with early survival and greater longevity. Factors affecting primate life histories are complex, ranging from the stability or unpredictability of foods (energy capture) to social context and strength of social networks, and include body and brain size as correlated traits. This complexity makes their study both rewarding and difficult.
Molecular clock
Authors: Cox Murray P.
Published: February 2018

One of the central goals of biological anthropology is to use genetic information to date past events. Today, even basic questions, such as ascertaining human mutation rates, remain surprisingly active areas of research, despite extensive advances since the first attempts at molecular dating during the 1960s. With new methods and genetic data now leading to increased accuracy, molecular dating is playing a growing role in genetic reconstructions of prehistoric events by placing them on a firmer temporal footing.
FirstPunicWar (264–241bce)
Authors: Burton Paul J.
Published: February 2018

The First Punic War began in 264 BCE as a minor diplomatic scuffle between two major western Mediterranean powers, Carthage and Rome, over which one of them should aid a much smaller power, the Sicilian city of Messana, against a mid‐sized, regional power, Syracuse. Through a complicated series of diplomatic incidents and political maneuverings by all parties, Carthage and Rome found themselves locked in a 23‐year‐long struggle for possession of a large portion of the island of Sicily and naval supremacy in the western Mediterranean. The war ended in 241 BCE with the Carthaginian defeat at the battle of the Aegates Islands. The treaty that ended the war, the Treaty of Lutatius, mandated the Carthaginian evacuation of Sicily and the payment of an indemnity of 3200 silver talents.
Microstructural Evolution and Texture Analysis in a Thermomechanically Processed Low SFE Super‐Austenitic Steel (Alloy‐28)
Authors: Eftekhari Niloofar , Zarei‐Hanzaki Abbas , Shamsolhodaei Amirali , Helbert Anne‐Laure , Baudin Thierry
Published: February 2018

Microstructural evolution and texture analysis after 80% cold rolling and subsequent annealing in the temperature range of 750–1050 °C is surveyed in Alloy‐28. This is precisely studied through electron back scattered diffraction and also is declared through elaborating the hardness map. The occurrence of partially recrystallization is clearly evident in the microstructure which was treated 850 °C annealing for 30 min. The recrystallization process is completed at 950 °C even after 3 min, but in an inhomogeneous manner, that is, coexistence of relatively large and fine recrystallized grains. This microstructure contains a high volume of special grain boundaries ended to the complete and homogenous recrystallization at 1050 °C, where further grain growth is occurred with increasing time. Texture analysis shows the retaining of Goss texture after annealing at 850 °C and this component is introduced as the main reason for retarding recrystallization and, therefore, creation of inhomogeneous microstructure. Finally, the specimens processed at 1050 °C indicate the α‐fiber texture due to occurrence of grain growth. The mechanical properties improvement is mainly attributed to the development of S component and also formation of high fraction of annealing twin. Although, predominant the appearance of Goss texture and grain growth are also known as the main reason for deteriorating strength.
Effects of Nb on Microstructure and Mechanical Properties of Ti42Al2.6C Alloys
Authors: Fang Hongze , Chen Ruirun , Gong Xue , Su Yanqing , Ding Hongsheng , Guo Jingjie , Fu Hengzhi
Published: February 2018

Ti42Al2.6C–xNb (x = 0, 2, 4, 6, and 8 at%, similarly hereinafter) alloys are synthesized by melting to investigate the effects of Nb on microstructure and mechanical properties, especially the formation of B2 phase and high temperature tensile properties. The results show that lamellar colony size decreases from 33.3 to 13.2 µm and lamellar space decreases from 193.4 to 139.6 nm with increasing Nb from 0 to 8%. Lattice parameters of γ and α2 phase change and B2 phase forms among lamellar colonies with the addition of Nb. The volume fraction of B2 phases and content of Nb in Ti2AlC phases increase with increasing Nb. B2 phases form between lamellar colonies because of Nb segregation. As high‐melting‐point element, Nb increases heterogenous nucleation particles and impedes grain growing. Compressive strength increases from 1568 to 1912 MPa with increasing Nb from 0 to 6% and then decreases at 8% Nb. Tensile strength at 750 °C can reach 465 MPa and the strain is only 2.4% when the Nb content is 6%. The increased strength is resulted from refined microstructure and solid solution of Nb. And the decreased strength is because many B2 phases acts as crack source.
Thermally Carbonized Porous Silicon and Its Recent Applications
Authors: Salonen Jarno , Mäkilä Ermei
Published: February 2018

Recent progress in research on thermally carbonized porous silicon (TCPSi) and its applications is reported. Despite a slow start, thermal carbonization has now started to gain interest mainly due to new emerging areas for applications. These new areas, such as optical sensing, drug delivery, and energy storage, require stable surface chemistry and physical properties. TCPSi is known to have all of these desired properties. Herein, the above‐listed properties of TCPSi are summarized, and the carbonization processes, functionalization, and characterization of TCPSi are reviewed. Moreover, some of the emerging fields of TCPSi applications are discussed and recent advances in the fields are introduced.
Low Thermal Conductivity through Dense Particle Packings with Optimum Disorder
Authors: Nutz Fabian A. , Philipp Alexandra , Kopera Bernd A. F. , Dulle Martin , Retsch Markus
Published: February 2018

Heat transport plays a critical role in modern batteries, electrodes, and capacitors. This is caused by the ongoing miniaturization of such nanotechnological devices, which increases the local power density and hence temperature. Even worse, the introduction of heterostructures and interfaces is often accompanied by a reduction in thermal conductivity, which can ultimately lead to the failure of the entire device. Surprisingly, a fundamental understanding of the governing heat transport processes even in simple systems, such as binary particle mixtures is still missing. This contribution closes this gap and elucidates how strongly the polydispersity of a model particulate system influences the effective thermal conductivity across such a heterogeneous system. In a combined experimental and modeling approach, well‐defined mixtures of monodisperse particles with varying size ratios are investigated. The transition from order to disorder can reduce the effective thermal conductivity by as much as ≈50%. This is caused by an increase in the thermal transport path length and is governed by the number of interparticle contact points. These results are of general importance for many particulate and heterostructured materials and will help to conceive improved device layouts with more reliable heat dissipation or conservation properties in the future.
Necklace‐Like Microfibers with Variable Knots and Perfusable Channels Fabricated by an Oil‐Free Microfluidic Spinning Process
Authors: Xie Ruoxiao , Xu Peidi , Liu Yupeng , Li Lili , Luo Guoan , Ding Mingyu , Liang Qionglin
Published: February 2018

Fiber materials with different structural features, which in many cases endow the fibers extraordinary functions, are drawing considerable attention from biomedical and material researchers. Here, perfusable necklace‐like knotted microfibers are presented for the first time. Additionally, a novel microfluidic spinning method facilitates the production of variable knots and channels. Not only spindle‐, but also hemisphere‐ and petal‐knotted microfibers can be controllably fabricated. Generation and perfusion of both Janus channels and helical channel in the knotted microfibers are also shown. With no need of oil and surfactant, the spinning process is highly cytocompatible. The potential bioengineering and biomedical application of the knotted hollow microfiber is demonstrated by its cell‐encapsulation feasibility and the unique liver acinus‐like diffusion gradient in the knot. The merits of perfusability, cytocompatibility, and structural diversity of the microfibers may open more avenues for further material and biomedical investigation.
CMOS Enabled Microfluidic Systems for Healthcare Based Applications
Authors: Khan Sherjeel M. , Gumus Abdurrahman , Nassar Joanna M. , Hussain Muhammad M.
Published: February 2018

With the increased global population, it is more important than ever to expand accessibility to affordable personalized healthcare. In this context, a seamless integration of microfluidic technology for bioanalysis and drug delivery and complementary metal oxide semiconductor (CMOS) technology enabled data‐management circuitry is critical. Therefore, here, the fundamentals, integration aspects, and applications of CMOS‐enabled microfluidic systems for affordable personalized healthcare systems are presented. Critical components, like sensors, actuators, and their fabrication and packaging, are discussed and reviewed in detail. With the emergence of the Internet‐of‐Things and the upcoming Internet‐of‐Everything for a people–process–data–device connected world, now is the time to take CMOS‐enabled microfluidics technology to as many people as possible. There is enormous potential for microfluidic technologies in affordable healthcare for everyone, and CMOS technology will play a major role in making that happen.
Effective Carrier‐Concentration Tuning of SnO2 Quantum Dot Electron‐Selective Layers for High‐Performance Planar Perovskite Solar Cells
Authors: Yang Guang , Chen Cong , Yao Fang , Chen Zhiliang , Zhang Qi , Zheng Xiaolu , Ma Junjie , Lei Hongwei , Qin Pingli , Xiong Liangbin , Ke Weijun , Li Gang , Yan Yanfa , Fang Guojia
Published: February 2018

The carrier concentration of the electron‐selective layer (ESL) and hole‐selective layer can significantly affect the performance of organic–inorganic lead halide perovskite solar cells (PSCs). Herein, a facile yet effective two‐step method, i.e., room‐temperature colloidal synthesis and low‐temperature removal of additive (thiourea), to control the carrier concentration of SnO2 quantum dot (QD) ESLs to achieve high‐performance PSCs is developed. By optimizing the electron density of SnO2 QD ESLs, a champion stabilized power output of 20.32% for the planar PSCs using triple cation perovskite absorber and 19.73% for those using CH3NH3PbI3 absorber is achieved. The superior uniformity of low‐temperature processed SnO2 QD ESLs also enables the fabrication of ≈19% efficiency PSCs with an aperture area of 1.0 cm2 and 16.97% efficiency flexible device. The results demonstrate the promise of carrier‐concentration‐controlled SnO2 QD ESLs for fabricating stable, efficient, reproducible, large‐scale, and flexible planar PSCs.
A Bioinspired Interface Design for Improving the Strength and Electrical Conductivity of Graphene‐Based Fibers
Authors: Ma Tao , Gao Huai‐Ling , Cong Huai‐Ping , Yao Hong‐Bin , Wu Liang , Yu Zi‐You , Chen Si‐Ming , Yu Shu‐Hong
Published: February 2018

Graphene‐based fibers (GBFs) are attractive for next‐generation wearable electronics due to their potentially high mechanical strength, superior flexibility, and excellent electrical and thermal conductivity. Many efforts have been devoted to improving these properties of GBFs in the past few years. However, fabricating GBFs with high strength and electrical conductivity simultaneously remains as a great challenge. Herein, inspired by nacre‐like multilevel structural design, an interface‐reinforced method is developed to improve both the mechanical property and electrical conductivity of the GBFs by introducing polydopamine‐derived N‐doped carbon species as resistance enhancers, binding agents, and conductive connection “bridges.” Remarkably, both the tensile strength and electrical conductivity of the obtained GBFs are significantly improved to ≈724 MPa and ≈6.6 × 104 S m−1, respectively, demonstrating great superiority compared to previously reported similar GBFs. These outstanding integrated performances of the GBFs provide it with great application potential in the fields of flexible and wearable microdevices such as sensors, actuators, supercapacitors, and batteries.
Ultrafast Processing of Hierarchical Nanotexture for a Transparent Superamphiphobic Coating with Extremely Low Roll‐Off Angle and High Impalement Pressure
Authors: Teisala Hannu , Geyer Florian , Haapanen Janne , Juuti Paxton , Mäkelä Jyrki M. , Vollmer Doris , Butt Hans‐Jürgen
Published: February 2018

Low roll‐off angle, high impalement pressure, and mechanical robustness are key requirements for super‐liquid‐repellent surfaces to realize their potential in applications ranging from gas exchange membranes to protective and self‐cleaning materials. Achieving these properties is still a challenge with superamphiphobic surfaces, which can repel both water and low‐surface‐tension liquids. In addition, fabrication procedures of superamphiphobic surfaces are typically slow and expensive. Here, by making use of liquid flame spray, a silicon dioxide–titanium dioxide nanostructured coating is fabricated at a high velocity up to 0.8 m s−1. After fluorosilanization, the coating is superamphiphobic with excellent transparency and an extremely low roll‐off angle; 10 µL drops of n‐hexadecane roll off the surface at inclination angles even below 1°. Falling drops bounce off when impacting from a height of 50 cm, demonstrating the high impalement pressure of the coating. The extraordinary properties are due to a pronounced hierarchical nanotexture of the coating.
Micropatterning of Nonplanar Surfaces on 3D Devices Using Conformal Template Vacuum Bagging
Authors: Alaie Seyedhamidreza , Robinson Sanlin S. , Amiri Moghadam Amir Ali , Auge Jordyn , Datye Amit , Sidoti Hannah , Doshi Tejas , Gharaie Saleh Hassanzadeh , Min James K. , Mosadegh Bobak , Dunham Simon
Published: February 2018

Micropatterning provides a powerful means for engineering surface properties, such as friction, adhesion, and biocompatibility, with promise for medical device applications. While soft lithography allows for micropatterning on curved surfaces, there are limitations to the level of curvature and object complexity achievable. A cost effective and simple method is realized for micropatterning complex 3D objects and is demonstrated for a variety of micropatterns, materials, and devices. The technique integrates the simple principles of soft lithography for fabrication of flexible templates, and vacuum bagging, for transfer of the patterns on arbitrary shaped nonplanar objects. The technique is demonstrated with silicones, polyurethanes, and nitinol materials ubiquitous in medical devices, due to their mechanics, biocompatibility, and hemocompatibility. Micropatterns inspired by shark skin riblets and tree frogs are demonstrated. The flexibility of this method is demonstrated by transferring patterns to various objects/devices, including 3D printed objects, soft robotic grippers, guidewires, and balloon catheters.
Sequential Photoredox Catalysis for Cascade Aerobic Decarboxylative Povarov and Oxidative Dehydrogenation Reactions of N‐Aryl α‐Amino Acids
Authors: Shao Tianju , Yin Yanli , Lee Richmond , Zhao Xiaowei , Chai Guobi , Jiang Zhiyong
Published: February 2018

A visible‐light‐driven sequential photoredox catalysis to allow N‐aryl α‐amino acids to experience efficient cascade aerobic decarboxylative Povarov and oxidative dehydrogenation (ODH) reactions is described. With a dicyanopyrazine‐derived chromophore (DPZ) as a photoredox catalyst in both transformations, two series of valuable azaarenes, i. e., 4‐amino tetrahydroquinolines (THQs) and quinolines, were obtained in satisfactory yields featuring diverse 2‐ and 2,3‐substituent patterns. To enable the ODH reaction of 4‐amino THQs, a cooperative catalysis with N‐hydroxyphthalimide was developed. Additionally, an unprecedented synthesis of chiral N‐amino‐2‐methyl THQs with high enantioselectivities was realized.

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A hybrid thermo‐kinetic model for high temperature plasma gasification
Authors: Verma Babita K. , Rajeshkannan E. , Renganathan T. , Pushpavanam S.
Published: February 2018

Plasma gasification is a process intensification technique in which the prevailing high temperatures accelerate the reactions resulting in a significant size reduction of the gasifier. Conventionally, a gasifier is modeled using either a thermodynamic or a kinetic approach. Present work proposes a novel method of modeling the plasma gasification process which combines these two approaches. The process is modeled as a combination of two regions: a Plasma Gasifier Zone (PGZ) and a Quenching Zone (QZ). PGZ, where gasification of feedstock takes place at high temperatures is modeled by thermodynamic equilibrium. QZ, where the syngas produced in the PGZ cools down, is modeled by kinetic approach. The hybrid approach captures the behavior more accurately and requires less computational effort. The proposed hybrid model is validated with experimental data from literature. The model is used to analyze the influence of radicals in plasma gasification and the performance for different operating conditions. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2592–2602, 2018
Multiactor multicriteria decision making for life cycle sustainability assessment under uncertainties
Authors: Ren Jingzheng , Ren Xusheng , Dong Lichun , Manzardo Alessandro , He Chang , Pan Ming
Published: February 2018

This article aims at developing a generic multiactor multicriteria decision making (MAMCDM) method for life cycle sustainability assessment (LCSA) of industrial systems under uncertainties, which can help multiple stakeholders/decision‐makers to prioritize the alternative industrial systems in a group decision‐making approach. The interval best–worst method, which can address the ambiguity, vagueness and hesitations existing in human's judgments, was developed for determining the weight of the criteria in LCSA. The consensus convergence model was developed for aggregating the relative importance of each criterion determined by different stakeholders/decision‐makers into an interval weight. Afterward, a novel multicriteria decision‐making method which can address the decision‐making matrix with interval numbers was developed to prioritize industrial systems under data uncertainties. An illustrative case has been studied by the developed model, and it reveals that the developed model allows multiple stakeholders/decision‐makers to participate in the decision‐making processes and prioritize industrial systems accurately by using interval numbers. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2103–2112, 2018
Intermolecular C(sp3)−H Amination of Complex Molecules
Authors: Chiappini Nicholas D. , Mack James B. C. , Du Bois J.
Published: February 2018

A general and operationally convenient method for intermolecular amination of C(sp3)−H bonds is described. This technology allows for efficient functionalization of complex molecules, including numerous pharmaceutical targets. The combination of pivalonitrile as a solvent, Al2O3 as an additive, and phenyl sulfamate as a nitrogen source affords differential reaction performance and substrate scope. Mechanistic data strongly implicate a pathway for catalyst decomposition that initiates with solvent oxidation, thus providing rationale for the marked influence of pivalonitrile on this reaction process.
Der Entwurf einer homogenen Brom‐Redoxkatalyse zur selektiven aliphatischen CH‐Bindungsfunktionalisierung
Authors: Becker Peter , Duhamel Thomas , Martínez Claudio , Muñiz Kilian
Published: February 2018

Das Potential der homogenen Oxidationskatalyse unter Verwendung von Brom ist weitgehend unerforscht. Wir zeigen hier, dass die Kombination von Tetraalkylammoniumbromid und 3‐Chlorperbenzoesäure ein einzigartiges Katalysatorsystem für die bequeme und selektive Oxidation gesättigter C(sp3)‐H‐Bindungen unter photochemischer Initiierung mit Tageslicht bietet. Es ermöglicht eine positionsselektive intramolekulare Aminierung, wie anhand von 20 verschiedenen Beispielen gezeigt wurde. Zum ersten Mal konnte ein N‐halogeniertes Intermediat in einer katalytischen Hofmann‐Löffler‐Reaktion isoliert werden. Darüber hinaus wurde eine neuartige schnelle Eintopfsynthese von N‐Sulfonyloxaziridinen aus N‐Sulfonamiden entwickelt und für 15 Transformationen beispielhaft dargestellt. Diese bahnbrechenden Beispiele bieten ein neuartiges Konzept für die molekulare Katalyse mit Brom.
Inversion of Configuration at the Phosphorus Nucleophile in the Diastereoselective and Enantioselective Synthesis of P‐Stereogenic syn‐Phosphiranes from Chiral Epoxides
Authors: Muldoon Jake A. , Varga Balázs R. , Deegan Meaghan M. , Chapp Timothy W. , Eördögh Ádám M. , Hughes Russell P. , Glueck David S. , Moore Curtis E. , Rheingold Arnold L.
Published: February 2018

Nucleophilic substitution results in inversion of configuration at the electrophilic carbon center (SN2) or racemization (SN1). The stereochemistry of the nucleophile is rarely considered, but phosphines, which have a high barrier to pyramidal inversion, attack electrophiles with retention of configuration at P. Surprisingly, cyclization of bifunctional secondary phosphine alkyl tosylates proceeded under mild conditions with inversion of configuration at the nucleophile to yield P‐stereogenic syn‐phosphiranes. DFT studies suggested that the novel stereochemistry results from acid‐promoted tosylate dissociation to yield an intermediate phosphenium‐bridged cation, which undergoes syn‐selective cyclization.
Parahydrogen‐Based Hyperpolarization for Biomedicine
Authors: Hövener Jan‐Bernd , Pravdivtsev Andrey N. , Kidd Bryce , Bowers C. Russell , Glöggler Stefan , Kovtunov Kirill V. , Plaumann Markus , Katz‐Brull Rachel , Buckenmaier Kai , Jerschow Alexej , Reineri Francesca , Theis Thomas , Shchepin Roman V. , Wagner Shawn , Bhattacharya Pratip , Zacharias Niki M. , Chekmenev Eduard Y.
Published: February 2018

Magnetic resonance (MR) is one of the most versatile and useful physical effects used for human imaging, chemical analysis, and the elucidation of molecular structures. However, its full potential is rarely used, because only a small fraction of the nuclear spin ensemble is polarized, that is, aligned with the applied static magnetic field. Hyperpolarization methods seek other means to increase the polarization and thus the MR signal. A unique source of pure spin order is the entangled singlet spin state of dihydrogen, parahydrogen (pH2), which is inherently stable and long‐lived. When brought into contact with another molecule, this “spin order on demand” allows the MR signal to be enhanced by several orders of magnitude. Considerable progress has been made in the past decade in the area of pH2‐based hyperpolarization techniques for biomedical applications. It is the goal of this Review to provide a selective overview of these developments, covering the areas of spin physics, catalysis, instrumentation, preparation of the contrast agents, and applications.
Control of Molar Mass Distribution by Polymerization in the Analytical Ultracentrifuge
Authors: Spinnrock Andreas , Cölfen Helmut
Published: February 2018

Molar mass distributions are of high interest in macromolecular chemistry because they directly determine the physical and chemical properties of polymers. A principal approach to obtain and control the shape of broad molar mass distributions is adjusting the initiator concentration in free radical polymerizations. A controlled gradient of the initiator concentration should potentially lead to tailored molar mass distributions. Here we use analytical ultracentrifugation (AUC) to adjust and measure a macroinitiator's concentration gradient. Subsequent photopolymerization of a uniformly distributed monomer leads to desired chain length distributions. Resulting distributions are described and calculated by a Schulz–Flory approach. The desired concentration profiles are simulated in advance and can be detected anytime by the optical systems in the centrifuge. Therefore, tailored broad molar mass distributions can now be produced using predictions from simulations using the established theory of AUC.
The Pre‐exponential Factor in Electrochemistry
Authors: He Zheng‐Da , Chen Yan‐Xia , Santos Elizabeth , Schmickler Wolfgang
Published: February 2018

Like many branches of science, not to mention culture in general, electrochemistry has a number of recurring topics: Areas of research that are popular for a certain time, then fade away as their possibilities seem to have been exhausted, only to return decades later as progress in experimental or theoretical techniques offer new possibilities for their investigation. A prime example are fuel cells, which have undergone five such cycles, but here we discuss a general concept of kinetics—the pre‐exponential factor of a rate constant—which has undergone two such cycles. The first cycle was in the 1950–1980s, when the methods of electrochemical kinetics were developed, and the interpretation was based on transition‐state theory. The second was triggered by the re‐discovery of Kramers theory for reactions in condensed phases. This Minireview will show that the time has come for a third cycle based on recent progress in electrocatalysis.