bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon and Nitrogen Isotopic Signatures of Zooplankton Taxa in Five Small Subalpine Lakes along a Trophic Gradient
Authors: Piscia Roberta , Boggio Emanuela , Bettinetti Roberta , Mazzoni Michela , Manca Marina
Published: January 2018

Interest in Stable Isotopes Analyses (SIA) is increasing in freshwater ecology to better clarify ecosystems’ functioning. By measuring carbon and nitrogen isotopic signatures, food sources and organism trophic levels can be tracked, providing quantitative estimates of bi-dimensional niches. In order to describe some general patterns of carbon and nitrogen stable isotope signatures in lakes, we applied SIA to zooplankton community in five subalpine lakes sampled in spring and summer along a trophic gradient (from oligotrophy to hypereutrophy). Within zooplankton taxa, temporal variation in food sources and trophic levels were compared to find out taxon-specific patterns. Carbon and nitrogen isotopic signatures differed among the five lakes, reflecting depth, topography, and trophic status of the lakes. Carbon isotopic signatures varied more considerably in deeper and larger lakes (Mergozzo and Pusiano) than in a shallower and smaller lake (Lake Endine). Nitrogen isotopic signatures were generally more enriched in lakes Pusiano and Moro than in Lake Mergozzo, whereas in summer, they were depleted in all lakes. These observations indicate that zooplankton taxa specific trophic roles differed among lakes and in time.
Recherches nouvelles sur les karsts des gypses et des évaporites associées (première partie : processus et cavernement)
Authors: Nicod Jean
Published: January 2018

Drawing on the results of a great number of studies , this paper aims to make apparent a rationale of the various processes and their interactions in gypsum karst and associated evaporites. They include the effect of diapirism, dissolution and chain reactions, cave collapse and external geomorphic processes. In the case of cave formation, the paper underlines the role of aquifers in wall and roof layers.
Revestimento comestível incorporado com cisteína para inibição do escurecimento enzimático de maçã minimamente processada
Authors: Brandão Camila Cheker , Rodrigues Mara Lina , Torres Maria Célia Lopes , Geraldine Robson Maia , Silveira Miriam Fontes Araújo
Published: January 2018

A maça minimamente processada sofre escurecimento devido à ação da polifenoloxidade. Este trabalho objetivou um revestimento comestível para inibir esse escurecimento. O revestimento foi preparado com incorporação de cisteína a 0.1; 0.3 e 0.5%. Os cubos de maçã revestidos foram armazenadas sob refrigeração. Perda de massa, atividade de água, pH e cor foram avaliados em 0, 2, 4 e 6 dias. Análises de psicrotróficos, coliformes e Salmonella foram feitas nos tempos 0 e 6 dias. O teste sensorial discriminativo diferença do controle avaliou a influência dos revestimentos no sabor das maças. Os resultados mostraram que o uso de revestimento com cisteína inibiu o escurecimento enzimático das maçãs minimamente processadas. O revestimento não afetou o sabor dos cubos de maça. As analises microbiológicas mostraram que as maçãs revestidas continuaram aptas para o consumo. O uso deste revestimento mostrou-se uma alternativa potencial para que a maçã seja comercializada minimamente processada.
Elaboração de produtos alimentícios com farinha de alfarroba (Ceratonia siliqua L)
Authors: Freitas Junior Edson Mendes de , Lemos Rayanne Évelyn Sampaio de , Carvalho Cayko Mayko da Silva , Silva Michele Mendes dos Santos , Alves Vanessa Ramos , Costa Zanelli Russeley Tenório , Nascimento Andrea Dacal Peçanha do , Moura Neto Luís Gomes de , Soares Denise Josino
Published: January 2018

A alfarroba é uma espécie de vagem que pertence à família Leguminosae e possui sabor semelhante ao chocolate. Diante do exposto, o presente trabalho teve como objetivo elaborar produtos alimentícios substituindo o chocolate pela farinha de alfarroba e estudar a aceitação sensorial desses produtos. Optou-se por elaborar cookies, doces tipo brigadeiro, iogurte e leite não fermentado com a alfarroba em pó. Os produtos foram avaliados através da escala hedônica e escala de atitude. A análise sensorial dos produtos elaborados nesta pesquisa permitiu comprovar a boa aceitação sensorial dos mesmos pelos provadores. A utilização da farinha da alfarroba em substituição ao chocolate pode ser realizada, possibilitando a elaboração de produtos mais saudáveis e com alegação funcional.
Elaboração e implantação do manual de boas práticas de fabricação (BPF) no serviço de alimentação escolar, do municipio de Roncador - PR
Authors: De Freitas Graciele Gehring , Oliveira Mariana Dâmaris , Baldi Jackeline Souza , Giopato Viell Franciele Leila , Gozzo Angela Maria
Published: January 2018

A qualidade da merenda escolar é de grande importância, pois muitas escolas oferecem refeições sem o preparo adequado, favorecendo a multiplicação de microrganismos que podem causar doenças. O Programa Nacional de Alimentação Escolar (PNAE) pertence ao governo federal, e beneficia diversos alunos, proporcionando hábitos alimentares mais saudáveis, objetivando suprir 15% das necessidades nutricionais diárias de crianças, num período de 4 a 12 horas por dia. Este programa utiliza o manual de Boas Práticas de Fabricação (BPF) para assegurar a qualidade dos alimentos. Assim, este projeto teve como objetivo elaborar o Manual de Boas Práticas de Fabricação (MBPF) para estabelecer normas adequadas de preparação dos alimentos e treinar os funcionários do serviço de alimentação escolar. Para avaliar as BPF foi aplicado um “check list”. Os resultados obtidos foram apresentados à direção do estabelecimento para a tomada de ações corretivas. O manual foi elaborado com base na Resolução 216/04, que regulamenta as boas práticas para serviços de alimentação. A escola avaliada obteve resultado regular de classificação e aceitou que fossem coletadas amostras das superfícies de equipamentos e utensílios utilizados no preparo da merenda escolar para análise microbiológica. Com a capacitação das merendeiras envolvidas com o preparo da alimentação escolar, pôde-se constatar diminuição da contaminação de bactérias aeróbias mesófilas nas superfícies de contato analisadas. Estes resultados comprovaram que a correta aplicação da BPF aliada à capacitação de merendeiras e a melhoria do “lay-out” da área de produção e estoque torna possível atingir uma classificação melhor quanto às boas práticas higiênico-sanitárias
Una perspectiva prosopogràfica dels oficis musicals de la Catedral de València en temps de Guillem de Podio, 1480-1505
Authors: Villanueva Serrano Francesc
Published: January 2018

La actividad musical anterior al siglo XVI en la catedral de Valencia es muy poco conocida. El presente estudio trata de avanzar en el conocimiento de la cuestión dirigiendo el foco de atención hacia los colectivos de personas que desempeñaron los diferentes oficios catedralicios con responsabilidad en la organización y la práctica de la música en este templo en el período 1480-1505, que enmarca el magisterio del tratadista Guillem de Podio en las escuelas de canto. La perspectiva que se ofrece es la aportada por la prosopografía, a partir de datos procedentes tanto de la misma institución como de otras similares, así como de fuentes de características diferentes tales como las notariales, las diocesanas y las conservadas en archivos civiles y reales. Por otra parte, el trabajo también ha permitido presentar suficientes evidencias para poder descartar la hipótesis de identificación, hasta ahora considerada, entre el compositor Juan Rodríguez de Sanabria y el cantor de Isabel la Católica Juan Rodríguez de la Torre. En apéndice se incluye un catálogo prosopográfico de todos los personajes estudiados.

[ca] L’activitat musical anterior al segle XVI a la catedral de València és molt poc coneguda. El present estudi tracta d’avançar en el coneixement de la qüesti. dirigint el focus d’atenció cap als col·lectius de persones que exerciren els diferents oficis catedralicis amb responsabilitat en l’organització i la pràctica de la música en aquest temple en el període 1480-1505, que emmarca el magisteri del tractadista Guillem de Podio en les escoles de cant. La perspectiva que s’ofereix és aportada per la prosopografi a, a partir de dades procedents tant de la mateixa institució com d’altres semblants, així com de fonts de característiques diferents com ara les notarials, les diocesanes i les conservades en arxius civils i reials. D’altra banda, el treball també ha permés presentar sufi cients evidències per poder descartar la hipòtesi d’identificació, fins ara considerada, entre el compositor Juan Rodríguez de Sanabria i el cantor d’Isabel la Catòlica Juan Rodríguez de la Torre. En apèndix s’inclou un catàleg prosopogràfic de tots els personatges estudiats.
Aportaciones al estudio de la música en la santa capilla de San Andrés de Jaén durante el siglo XVI: dos juegos de versos para ministriles de Gil de Ávila (fl. 1574-1597)
Authors: Marín-López Javier , Sánchez-López Virginia , Gutiérrez-Álvarez José A. , Jiménez-Cavallé Pedro
Published: January 2018

En el año 2015 se conmemora el quinto centenario de la fundación en Jaén de una importante cofradía adscrita a la iglesia parroquial de San Andrés y conocida con el nombre de Santa Capilla. Lo que diferencia a esta hermandad de otras creadas en la España de la época es la presencia, estatutariamente establecida, de una capilla de música con el propósito de enaltecer sus celebraciones religiosas. El presente artículo ofrece un estudio panorámico sobre la Santa Capilla como institución musical durante el siglo XVI, basándose en nuevos hallazgos archivísticos. El trabajo incluye un análisis de los modelos de mecenazgo que pudo tener en mente su fundador, el protonotario apostólico Gutierre González Doncel; una revisión crítica de las actividades musicales de cantores, instrumentistas y maestros de capilla al servicio de la cofradía; algunas hipótesis sobre el repertorio musical empleado; y un estudio específico, acompañado de la edición crítica, de dos singulares juegos de versos para ministriles de Gil de Ávila, únicas piezas del único maestro de la Santa Capilla del siglo XVI del que conocemos música.
Fuentes para el estudio del órgano histórico de la parroquia de Santa Inés Zacatelco (Tlaxcala, México)
Authors: Mauleón Rodríguez Gustavo , Charles Pepe Edward
Published: January 2018

En esta colaboración presentamos los resultados de un trabajo de investigación y documentación acerca de uno de los órganos mexicanos más importantes en varios sentidos, que fueron construidos durante la primera mitad del siglo XIX, siendo destinado a una parroquia del obispado de Puebla-Tlaxcala. Su constructor fue uno de los miembros más tempranos y notables de la familia de organeros Castro de la ciudad de Puebla de los Ángeles, se trata de Seferino Agustín Castro, a quien le tocó vivir la transición de la Nueva España hacia el México Independiente, siendo heredero una larga tradición local en la fabricación de órganos mecánicos de tipo español o ibérico, ahora diseñados bajo nuevas circunstancias históricas, musicales y tecnológicas, de las que son claros ejemplos sus instrumentos, mismos que, en lo particular, muestran también aspectos de la evolución del órgano poblano, con interesantes características propias.
La tonadilla escénica en Venezuela o el proceso de criollización de un género hispano
Authors: Capelán Fernández Montserrat
Published: January 2018

En el presente trabajo se estudia la interpretación de la tonadilla escénica tanto en la época colonial, en el que se representaban obras de origen peninsular, como en la republicana, cuando ya autores locales empiezan a dedicarse a este género. Se establecerán las características estructurales de lo que la prensa denominaba tonadilla y lo que llamaba opereta y, contraviniendo a José Subirá, se pondrá de manifiesto que la tonadilla no sufre un proceso de italianización sino, muy por el contrario, de hispanización. Una vez llegada la República y con ella el cultivo de la tonadilla escénica por autores venezolanos, este proceso dará lugar a una criollización introduciéndose en la tonadilla escénica bailes autóctonos como el merengue. En el presente texto haremos un estudio detallado de él, y estableceremos la posibilidad de que el origen del merengue, esté en las tiranas de las tonadillas peninsulares del siglo anterior.
La capilla musical de la colegiata de Talavera de la Reina en la primera mitad del siglo XIX
Authors: Capdepón Verdú Paulino
Published: January 2018

Tras la etapa de esplendor que vivió la capilla musical de la Colegiata de Santa María la Mayor de Talavera de la Reina durante el siglo XVIII, asistimos por el contrario a una fase de decadencia, que se enmarca en la crisis que experimenta la música religiosa española durante el siglo XIX. Los efectos de la Guerra de la Independencia, las sucesivas desamortizaciones y la aplicación del Concordato (1851) significaron una disminución del papel de las capillas musicales eclesiásticas en la España de aquella época e incluso algunas de ellas acabaron siendo suprimidas, como es el caso de la capilla talaverana.
El recorrido de las metodologías de principios del siglo XX en la enseñanza de la música en España: aproximación bibliográfica e interpretativa
Authors: Montoya Rubio Juan Carlos
Published: January 2018

En las etapas obligatorias, las metodologías de enseñanza musical en España poseen unas características muy definidas, basadas en la observación y adaptación de algunos métodos considerados ya clásicos (especialmente las propuestas de Orff, Kodály o Jaques–Dalcroze). Ello ha generado unas praxis concretas y una dotación material encaminada a cubrir unas expectativas y necesidades concretas. El modelo educativo musical español ha evolucionado de acuerdo con estos parámetros. Por ello, es esencial rastrear los primeros textos que adoptaron estos métodos y analizar el modo en que la bibliografía posterior los ha abordado, desarrollado y plasmado. Todo ello, unido a las inflexiones legislativas, servirá para encontrar claves interpretativas a los modelos pedagógicos que han llegado hasta nuestros días.
Hacia la codificación digital de la notación mensural blanca hispánica
Authors: Rizo Valero David , Pascual Sánchez Beatriz , Iñesta Quereda José Manuel , Ezquerro Esteban Antonio , González Marín Luis Antonio
Published: January 2018

En este trabajo se presentan los elementos necesarios para codificar digitalmente música preservada en manuscritos de los siglos XVI y XVII. Se presentan soluciones, propuestas para superar las dificultades que generan algunos aspectos que hacen esta notación diferente de la notación occidental moderna. Los problemas abordados son, por ejemplo, la ausencia de líneas divisorias o la duración de las figuras, que se basan en el contexto. También se presenta la nueva fuente tipográfica “Capitán”, específicamente creada para representar este tipo de notación antigua.
Developing Critical Understanding of Computing With the Raspberry Pi
Authors: Gatenby Amanda Banks
Published: January 2018

This article describes a research project for exploring learning activities with Raspberry Pis in four school contexts in the UK. The aim of the project was to compare different learning designs, which had the shared objective of developing computational competencies, to investigate how these designs might simultaneously develop critical understanding of both the practices of Computing and students' own learning with respect to those practices. The study used a novel ‘before/after' implementation of Q methodology in combination with participant observations and reflective interviews with twenty-eight pupils. Findings suggested that where pupils were already predisposed to future involvement in Computing practices, working with Raspberry Pis did develop critical understanding, in ways that were less dependent on learning design. For those who had a more naïve or indifferent view of Computing, the pedagogy was most influential on how student perspectives developed, a pedagogy of expressibility being the key to supporting greater criticality.
Local Area Network (LAN)-Based Digital Signage Solution Using Raspberry Pi
Authors: Zhao MengMeng
Published: January 2018

This article outlines a case study in which the author employs a Raspberry Pi 3 miniature computer as a Digital Signage System, which can be managed from either laptop, smartphone or desktop computers. The author presents it as a case study that high school students (and their teachers) can follow, as a collaborative project that delivers a cost effective and flexible, digital signage system for their school. While it does not require any coding on their part, it presents an excellent use of ICT, by configuring multiple interrelated hardware and open software, in a school community setting, that would fit in with many contemporary digital technology curriculums.
 Análise do nursing activities score na perspectiva do processo de trabalho / Analysis of nursing activities score in the perspective of the work process
Authors: Vargas Elisa De , Cezar-Vaz Marta Regina
Published: January 2018

NNa enfermagem, a utilização de instrumentos de avaliação do processo de trabalho é de extrema relevância, especialmente aqueles que se propõem a mensurar suas cargas. O objetivo deste estudo foi refletir sobre a utilização de um instrumento deste tipo. Trata-se de um ensaio teórico-reflexivo construído a partir da estrutura do Nursing Activities Score (NAS), utilizando referenciais teóricos e o diálogo com outros estudos da literatura sobre o processo de trabalho da enfermagem. A aplicação destes instrumentos ao objeto de trabalho, que é o paciente internado na unidade de terapia intensiva, tange ao produto do trabalho da enfermagem, ou seja, o cuidado prestado. Este, por sua vez, não se limita apenas ao completo restabelecimento da saúde do paciente, mas abrange o resultado de cada uma das intervenções empregadas e contempladas no NAS por 24 horas. O NAS, portanto, é importante para a análise da qualidade do trabalho prestado, pois expõe o valor do trabalho da enfermagem, e a representação individual e social do produto deste trabalho − o cuidado.
Efficiency Enhancement in a Medium Scale Gearbox Manufacturing Company through Different Lean Tools - A Case Study
Authors: Saravanan V. , Nallusamy S. , George Abraham
Published: January 2018

Productivity is an important parameter for all small and medium scale manufacturing industries. Lean manufacturing emerged as production strategy capable of increasing productivity by identifying and eliminating non value added activities. This article deals with productivity improvement in a pre-assembly line of gearbox manufacturing company with a case study using lean concepts like process flow chart, process Gantt chart and time study. This paper illustrates using a case study on how a value stream mapping has to be carried out in a planet carrier pre-assembly line. Value stream mapping and work standardization are the key tools used in lean manufacturing and lean transformation. It makes the process smoother, helps in reduction of lead time and ultimately increasing the productivity. From the observed results it was found that, the productivity has been increased from 7 pieces to 10 pieces in the first step assembly when the proposed VSM was implemented. The second step processing time was reduced by the execution of proposed value stream mapping with TAKT time of 126 minutes and 165 minutes of processing time for demand of 10 pieces were achieved and the overall processing time has been reduced by about 24%.
The Behavior of Portland Limestone-Calcined Clays Cement at 5°C
Authors: Ghorab Hanaa Y. , Ahmed Hossam E.H. , Shanour Ali S. , Wahdan Hamdy M.A.
Published: January 2018

The effect of calcined clays of the swelling type, on the strength and expansion behavior of Portland limestone cement is studied at 5°C. Local clays were thermally activated by burning one hour at 900 °C and were ground to a Blaine of 2842 (cm2/g). The pozzolanic reactivity of the activated clays was defined chemically and according to ASTM C311/C311M-13. Portland limestone cement was prepared by replacing 30% CEM I 42.5 N by limestone powder. Pozzolanic cements were prepared by replacing 10 and 20% of the limestone powder by calcined clays, the mixes were used to replace 30% of CEM I. Mortars specimens pre-cured for 28-day long as well as for a short period of one day, were immersed in sulfate solutions at 5°C for time up to 90 days. The compressive strength and length change were measured for the samples.The results show that replacement of limestone with calcined clays improves the compressive strength and the expansion of Portland limestone cement mortars in water and sulfate solutions. Ettringite was detected in the expanded mortars and no thaumasite formed. The results are interpreted in terms of the mechanism of thaumasite formation.
Immobilization of Sr2+, Bi3+ and Zn2+ in Alkali-Activated Materials Based on Blast Furnace Slag and Fly Ash
Authors: Koplík Jan , Solný Tomáš , Kalina Lukáš , Másilko Jiří
Published: January 2018

It is well known, that alkali-activated materials (AAMs) are suitable for immobilization of heavy metals and other hazardous materials. This study is focused on the characterization of inhibition of three metals – Sr2+, Bi3+ and Zn2+ in alkali-activated matrices. Two type of matrices were prepared – alkali-activated blast furnace slag (BFS) and alkali-activated fly ash (FA). Sodium water glass was used as alkaline activator. The ability of these matrices to fix the metals were proved by leaching tests. Compressive strength was measured to characterize mechanical properties of the matrices. Scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) was used to examine distribution and chemical state of metals within the matrices. The observed metals mainly formed the insoluble compounds after alkali activation.
Multiple Phase Identification in Alkali Activated Slag by SEM-EDS
Authors: Alharbi Najat , Hailstone Richard , Varela Benjamin
Published: January 2018

Alkali-activated slag is studied using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and x-ray microanalysis. Attention is focused on delineating the phases induced by the alkali activation, as these phases are important in determining the mechanical properties of the material. The starting material, slag, is found to be a heterogeneous material with at least two phases. Upon alkali activation the material becomes more heterogeneous, now exhibiting at least four phases with significant different chemical composition. Furthermore, the alkali activation is found to modify the phase rich in Ca in the unactivated slag more than the other. Alkali activation of the slag produced mostly an amorphous material with some crystalline phases such as hydrotalcite and calcite, also some nanocrystalline structures were detected by TEM.
Hysteresis Modeling of Bonded Anisotropic Ferrite Magnets
Authors: de Campos Marcos Flavio , Rodrigues Daniel , do Carmo Paresque Mara Carolina , de Castro Jose Adilson
Published: January 2018

The modeling of hysteresis curves of bonded ferrite magnets is discussed. Hysteresis of anisotropic magnets were calculated according to the Stoner-Wohlfarth Model, for the cosn (theta) distribution. The crystallographic texture has significant effect on the hysteresis curve. Two different samples were examined, one isotropic and another anisotropic. The anisotropy field of strontium ferrite magnets was determined to be 19.5 kOe. The Mr/Ms ratio of the anisotropic bonded magnet was estimated as 0.8.
Hydrophilicity, Solubility and Optical Properties in Composite Films of Gelatin and Bentonite Clay in its Natural Form or Modified
Authors: Monteiro Mayra Keroly Sales , dos Santos Francisco Klebson Gomes , Leite Ricardo Henrique de Lima , Aroucha Edna Maria Mendes , Vitoriano Jussier Oliveira , Oliveira Victor Rafael Leal
Published: January 2018

Bentonite clay was initially treated with a quaternary ammonium salt to increase its hydrophobicity, and then was dispersed in a gelatin matrix to serve as barrier to water vapor. The clays were characterized by IR spectroscopy in the infrared (FTIR), and X-ray diffraction (XRD), before and after ion exchange. The ion exchange held in the clay provokes on gelatin film a reduction of 65% in the water vapor permeability (WVP); a decrease in solubility of 55%; an increase of 35º in drop contact angle of water on the surface of the film; and 30% of raise in opacity.
Preparation and Structural Characterization of Hybrid Composites of Semiconductor Oxides with Amorphous Carbon
Authors: Zocolaro Gabriela Delli Colli , Silveira Gisele S. , Nobre Marcos A.L. , Lanfredi Silvania
Published: January 2018

Organic/inorganic hybrids composites type have been reported as an alternative for the preparation of multifunctional materials with superior properties to those of individual constituents. In this work, hybrid composites of semiconductor oxides with amorphous carbon (C/ZnO and C/TiO2) were synthesized by partial pyrolysis method and characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The XRD patterns showed the presence of crystalline diffraction lines overlaid by diffraction halos. Infrared spectra showed bands associated to the stretching of Zn-O and Ti-O bonds, as well as bands assigned to the stretching vibrations of C-O, C=O and C-H. Micrographs showed the formation of organized structures in the shape of plates and agglomerates of particles. Structural characterizations showed that the composites present the characteristics of the pristine semiconductors as well of the amorphous carbon matrix, showing a great synergism between C/semiconductor.
Properties of Pre-Sintered ZrO2(Y2O3) Blocks Consolidated by Cold Isostatic Pressing
Authors: da Silva Jr. Rafael Bernardino , dos Santos Claudinei , de Campos Leonardo Queiroz Bueno , Campos Sabrina Vieira , de Souza Yan Carlos Ambrosio
Published: January 2018

In this work, dental ceramics based on ZrO2-Y2O3, made by cold isostatic pressing, were characterized and the properties were compared to conventional uniaxially pressed blocks. Pre-sintered ZrO2-3%mol Y2O3 blocks were sintered at 1530oC-120min. The crystalline phases were identified by X-ray diffraction (XRD) and microstructural analysis was performed using Scanning Electron Microscopy (SEM). The materials were mechanically evaluated for their hardness, fracture toughness and its bending strength. The results of mechanical tests indicate that the ceramics studied showed hardness greater than 1220HV, fracture toughness of about 8.2 MPam1/2 and bending strength higher than 1000 MPa. The results indicate excellent mechanical behaviour and negligible differences between uniaxial and isostatic products, but it is possible to see an increase of homogeneity in the final shrinkage after sintering.
Concrete Made with Alternative Fine Aggregates: The Reuse of Porcelain Electrical Insulators
Authors: Campos Marco Antonio , Paulon Vladimir Antonio , de Argollo Ferrão André Munhoz
Published: January 2018

The use of alternative materials as substitutes for ordinary aggregates, mainly in concrete and mortar, has been common in recent decades in Brazil. Due to its physical and chemical similarities to common aggregates, ceramic waste, when coupled with a granulometric control, is suitable for use as an aggregate in concrete. Brazil has been estimated to dispose of approximately 25,000 tons of porcelain insulators annually, which are insulators that are often discarded along with other debris and harm the environment. This study examined the grinding methodology for and subsequent use of porcelain to replace fine aggregates in concrete and verified the improvement this substitution provided by evaluating the mechanical properties and durability of the concrete under study and examining scanning electron microscope images.
Alpha-Alumina Synthesis
Authors: Munhoz Jr. Antônio Hortencio , da Silva Heber Silvestre , Yamamoto Marcos V. , Masson Terezinha Jocelen , de Oliveira Mariana Oliva , de Miranda Leila Figueiredo , Andrades Raphael Cons , Peres Renato M.
Published: January 2018

The development of ceramic matrix composites (CMCs) is currently of great importance in the field of ballistic protection. For that purpose, alumina, silicon carbide and boron carbide are usually used in civil and military armor. Combination of different materials results in increasingly lighter and tougher composite materials, which replace conventional materials in many applications, including aviation, aerospace, military, naval, and sports industry. The production of nanoparticle powders and nanostructured bodies may find many uses in CMCs. In this study, pseudoboehmite powders was synthesized through the sol-gel method. The main goal of this work was to obtain alpha-alumina from nanosized pseudoboehmite particles, aiming to improve the densification and reduction of sintering temperature of alumina. Both pseudoboehmite and alpha-alumina obtained might be used also as raw material for CMCs. The gel of pseudoboehmite, which was derived from aluminum nitrate and ammonium hydroxide, was calcined, thus originating the alpha-alumina used in this study. The powders were characterized by: X-ray diffraction (XRD), nitrogen adsorption isotherm, with specific surface area measured by BET method, thermogravimetric analysis (TG) and differential thermal analysis (DTA). The data show that the alpha-alumina obtained by burning the pseudoboehmite was highly pure.
Sol-Gel Synthesis of Amorphous Silica Nanoparticles: Study of the Process Parameters Influence on Structure and Particle Size Distribution
Authors: Aspasio Renata Deliberato , da Silva Jr. Jairo Freitas , Borges Roger , Marchi Juliana
Published: January 2018

The synthesis of silica particles at the nanoscale through the sol-gel method is of great interest due to their potential use in industrial applications. The Stöber method is the most used method for the silica nanoparticles production using ammonia as a catalyst. This work studied the sol-gel synthesis of amorphous silica nanoparticles described by Stöber, in order to evaluate the influence of the variation of the process parameters (molar ratio water/TEOS = 25 and 55, reagent feed rate = 0.6 mL/min and 18 mL/min, pH = 12 and 9 and reaction time of 0, 5, 30, 60 and 120 minutes) on the particle size distribution and structural functional groups. The particle size distribution was analyzed by dynamic light scattering (DLS) and the structural functional groups was analyzed by infrared spectroscopy through Fourier transform (FTIR). The molar ratio water/TEOS influenced the functional groups presents and the time influenced the particle diameter distribution. It was not possible to identify the influence of the feed rate and pH in the results. The particle diameters found were between 200-500nm. This result may be occurred due to mass diffusion and/or nanoparticles aggregation.
Evaluation of Hardness and the Fracture Toughness of Composite Biphasic Alumina-YAG
Authors: Cabral R.F. , Prado da Silva M.H. , Lima E.S. , de Campos J.B. , Magnago Roberto de Oliveira
Published: January 2018

Currently the composite two-phase Al2O3-YAG laser has been widely exploited by having good properties such as high abrasion resistance and deformation in harsh environments. Thus, one can predict that this material has very attractive applications such as fins of jet engines and gas turbines. In this study, five mixtures were processed Y2O3-Al2O3-Nb2O5, in proportions of 0, 1, 5, 15 and 35 wt% Y2O3 and 4% by weight of Nb2O5. These samples were sintered at 1550 to 1650 °C in air where it was detected by X-Ray Diffraction (XRD) with Rietveld refinement training YAG and also two intermediate stages, and AlNbO4 YNbO4. Finally they were characterized by hardness by Vickers microindentation and fracture toughness. The highest hardness and fracture toughness were 15 GPa and 5.5 MPa.m1/2, respectively.
22q11 Deletion Syndrome with Vascular Anomalies
Authors: Maldjian Pierre , Sanders Alison Esteva
Published: January 2018

DiGeorge syndrome, also termed 22q11.2 deletion syndrome, represents a spectrum of disorders that include thymic aplasia/hypoplasia, parathyroid aplasia/hypoplasia, conotruncal vascular anomalies, and velocardiofacial (Shprintzen) syndrome. This case report describes a novel constellation of cardiovascular anomalies in a 31-year-old patient with 22q11.2 deletion confirmed by fluorescence in situ hybridization at the age of 24. CT angiogram of the thorax revealed a right aortic arch with mirror image branching and unilateral absence of the left pulmonary artery with collateral flow through left intercostal arteries and hypertrophied left bronchial artery. This particular cluster of vascular findings has not been previously described in the imaging literature in a patient with known 22q11.2 deletion.
Top-down constraints on global N2O emissions at optimal resolution: application of a new dimension reduction technique
Authors: Wells Kelley C. , Millet Dylan B. , Bousserez Nicolas , Henze Daven K. , Griffis Timothy J. , Chaliyakunnel Sreelekha , Dlugokencky Edward J. , Saikawa Eri , Xiang Gao , Prinn Ronald G. , O'Doherty Simon , Young Dickon , Weiss Ray F. , Dutton Geoff S. , Elkins James W. , Krummel Paul B. , Langenfelds Ray , Steele L. Paul
Published: January 2018

Abstract. We present top-down constraints on global monthly N2O emissions for 2011 from a multi-inversion approach and an ensemble of surface observations. The inversions employ the GEOS-Chem adjoint and an array of aggregation strategies to test how well current observations can constrain the spatial distribution of global N2O emissions. The strategies include (1) a standard 4D-Var inversion at native model resolution (4° × 5°), (2) an inversion for six continental and three ocean regions, and (3) a fast 4D-Var inversion based on a novel dimension reduction technique employing randomized singular value decomposition (SVD). The optimized global flux ranges from 15.9 Tg N yr−1 (SVD-based inversion) to 17.5–17.7 Tg N yr−1 (continental-scale, standard 4D-Var inversions), with the former better capturing the extratropical N2O background measured during the HIAPER Pole-to-Pole Observations (HIPPO) airborne campaigns. We find that the tropics provide a greater contribution to the global N2O flux than is predicted by the prior bottom-up inventories, likely due to underestimated agricultural and oceanic emissions. We infer an overestimate of natural soil emissions in the extratropics and find that predicted emissions are seasonally biased in northern midlatitudes. Here, optimized fluxes exhibit a springtime peak consistent with the timing of spring fertilizer and manure application, soil thawing, and elevated soil moisture. Finally, the inversions reveal a major emission underestimate in the US Corn Belt in the bottom-up inventory used here. We extensively test the impact of initial conditions on the analysis and recommend formally optimizing the initial N2O distribution to avoid biasing the inferred fluxes. We find that the SVD-based approach provides a powerful framework for deriving emission information from N2O observations: by defining the optimal resolution of the solution based on the information content of the inversion, it provides spatial information that is lost when aggregating to political or geographic regions, while also providing more temporal information than a standard 4D-Var inversion.
Multiplatform
analysis
of upper air haze visibility in downtown
Beijing
Authors: Ji Hongzhu , Chen Siying , Zhang Yinchao , Chen He , Guo Pan , Zhao Peitao
Published: January 2018

Abstract. The vertical features of upper air visibility in the northwest of downtown Beijing was studied by using a multiplatform analysis during haze episodes near the 2017 New Year's Day. Through the multiplatform data analysis in hourly and daily variation, the upper air visibility follows the opposite trend against the PM2.5 mass concentration. The upper air visibility on non-haze days was about 3–5 times higher than that on haze days. The strong correlation between PM2.5 mass concentration and haze parameters shows the effect of spatial transport of particles on haze parameters. In addition, a higher atmospheric boundary layer improves upper air visibility. The characteristics of multi-parameters have been analysed and concluded for different haze levels.
A Singular Value Decomposition framework for retrievals with
vertical distribution information from greenhouse gas column
absorption spectroscopy measurements
Authors: Ramanathan Anand K. , Nguyen Hai M. , Sun Xiaoli , Mao Jianping , Abshire James B. , Hobbs Jonathan M. , Braverman Amy J.
Published: January 2018

Abstract. We review the singular value decomposition (SVD) framework and use it for quantifying and discerning vertical information in greenhouse gas retrievals from column integrated absorption measurements. While the commonly used traditional Bayesian optimal estimation (OE) assumes a prior distribution in order to regularize the inversion problem, the SVD approach identifies principal components that can be retrieved from the measurement without explicitly specifying a prior mean and prior covariance matrix. We review the SVD method, explicitly recognize the use of an uninformative prior and show it to be bias-free in the absence of forward model error irrespective of the choice of the uninformative prior. We also make the connection between the SVD method and the pseudo-inverse, which makes it more intuitive and easy to understand. We illustrate the use of the SVD method on an integrated path differential absorption CO2 lidar measurement model, and verify our derivations and bias free properties versus optimal estimation using numerical simulations. In contrast, traditional OE retrievals exhibit bias when the prior mean used in the retrieval differs from the true mean. Hence, the SVD method is particularly useful for situations where knowledge of the prior mean and prior covariance of the true state (e.g., greenhouse gas profiles) is inadequate.
How does the terrestrial carbon exchange respond to interannual climatic variations? A quantification based on atmospheric CO2 data
Authors: Rödenbeck Christian , Zaehle Sönke , Keeling Ralph , Heimann Martin
Published: January 2018

Abstract. The response of the terrestrial Net Ecosystem Exchange (NEE) of CO2 to climate variations and trends may crucially determine the future climate trajectory. Here we directly quantify this response on interannual time scales, by building a linear regression of interannual NEE anomalies against observed air temperature anomalies into an atmospheric inverse calculation based on long-term atmospheric CO2 observations. This allows us to estimate the sensitivity of NEE to interannual variations in temperature (seen as climate proxy) resolved in space and with season. As this sensitivity comprises both direct temperature effects and effects of other climate variables co-varying with temperature, we interpret it as interannual climate sensitivity. We find distinct seasonal patterns of this sensitivity in the northern extratropics, that are consistent with the expected seasonal responses of photosynthesis, respiration, and fire. Within uncertainties, these sensitivity patterns are consistent with independent inferrences from eddy covariance data. On large spatial scales, northern extratropical as well as tropical interannual NEE variations inferred from the NEE-T regression are very similar to the estimates of an atmospheric inversion with explicit interannual degrees of freedom. The results of this study can be used to benchmark ecosystem process models, to gap-fill or extrapolate observational records, or to separate interannual variations from longer-term trends.
Diversity II water quality parameters for 300 lakes worldwide from ENVISAT (2002–2012)
Authors: Odermatt Daniel , Danne Olaf , Philipson Petra , Brockmann Carsten
Published: January 2018

Abstract. The use of ground sampled water quality information for global studies is limited due to practical and financial constraints. Remote sensing is a valuable means to overcome such limitations and to provide synoptic views of ambient water quality at appropriate spatio-temporal scales. In past years several large data processing efforts were initiated to provide corresponding data sources. The Diversity II water quality dataset consists of several monthly, yearly and 9-year averaged water quality parameters for 340 lakes worldwide and is based on data from the full ENVISAT MERIS operation period (2002–2012). Existing retrieval methods and datasets were selected after an extensive algorithm intercomparison exercise using in situ reference measurements for more than 40 lakes representing a wide range of bio-optical conditions. Chlorophyll-a, total suspended matter, turbidity, coloured dissolved organic matter, lake surface water temperature, cyanobacteria and floating vegetation maps, as well as several auxiliary data layers, provide a generically specified data basis that can be used for assessing a variety of locally relevant ecosystem properties and environmental problems. We demonstrate the use of the products by illustrating and discussing remotely sensed evidence of lake-specific processes and prominent regime shifts documented in literature. The Diversity II data are available from https://doi.pangaea.de/10.1594/PANGAEA.871462, and Python scripts for their analysis and visualization are provided at https://github.com/odermatt/diversity/.
The CarbonTracker Data Assimilation System for CO2 and δ13C (CTDAS-C13 v1.0): retrieving information on land–atmosphere exchange processes
Authors: van der Velde Ivar R. , Miller John B. , van der Molen Michiel K. , Tans Pieter P. , Vaughn Bruce H. , White James W. C. , Schaefer Kevin , Peters Wouter
Published: January 2018

Abstract. To improve our understanding of the global carbon balance and its representation in terrestrial biosphere models, we present here a first dual-species application of the CarbonTracker Data Assimilation System (CTDAS). The system's modular design allows for assimilating multiple atmospheric trace gases simultaneously to infer exchange fluxes at the Earth surface. In the prototype discussed here, we interpret signals recorded in observed carbon dioxide (CO2) along with observed ratios of its stable isotopologues 13CO2∕12CO2 (δ13C). The latter is in particular a valuable tracer to untangle CO2 exchange from land and oceans. Potentially, it can also be used as a proxy for continent-wide drought stress in plants, largely because the ratio of 13CO2 and 12CO2 molecules removed from the atmosphere by plants is dependent on moisture conditions.The dual-species CTDAS system varies the net exchange fluxes of both 13CO2 and CO2 in ocean and terrestrial biosphere models to create an ensemble of 13CO2 and CO2 fluxes that propagates through an atmospheric transport model. Based on differences between observed and simulated 13CO2 and CO2 mole fractions (and thus δ13C) our Bayesian minimization approach solves for weekly adjustments to both net fluxes and isotopic terrestrial discrimination that minimizes the difference between observed and estimated mole fractions.With this system, we are able to estimate changes in terrestrial δ13C exchange on seasonal and continental scales in the Northern Hemisphere where the observational network is most dense. Our results indicate a decrease in stomatal conductance on a continent-wide scale during a severe drought. These changes could only be detected after applying combined atmospheric CO2 and δ13C constraints as done in this work. The additional constraints on surface CO2 exchange from δ13C observations neither affected the estimated carbon fluxes nor compromised our ability to match observed CO2 variations. The prototype presented here can be of great benefit not only to study the global carbon balance but also to potentially function as a data-driven diagnostic to assess multiple leaf-level exchange parameterizations in carbon-climate models that influence the CO2, water, isotope, and energy balance.
The role of glacier changes and threshold definition in the characterisation of future streamflow droughts in glacierised catchments
Authors: Van Tiel Marit , Teuling Adriaan J. , Wanders Niko , Vis Marc J. P. , Stahl Kerstin , Van Loon Anne F.
Published: January 2018

Abstract. Glaciers are essential hydrological reservoirs, storing and releasing water at various timescales. Short-term variability in glacier melt is one of the causes of streamflow droughts, here defined as deficiencies from the flow regime. Streamflow droughts in glacierised catchments have a wide range of interlinked causing factors related to precipitation and temperature on short and long timescales. Climate change affects glacier storage capacity, with resulting consequences for discharge regimes and streamflow drought. Future projections of streamflow drought in glacierised basins can, however, strongly depend on the modelling strategies and analysis approaches applied. Here, we examine the effect of different approaches, concerning the glacier modelling and the drought threshold, on the characterisation of streamflow droughts in glacierised catchments. Streamflow is simulated with the Hydrologiska Byråns Vattenbalansavdelning (HBV-light) model for two case study catchments, the Nigardsbreen catchment in Norway and the Wolverine catchment in Alaska, and two future climate change scenarios (RCP4.5 and RCP8.5). Two types of glacier modelling are applied, a constant and dynamic glacier area conceptualisation. Streamflow droughts are identified with the variable threshold level method and their characteristics are compared between two periods, a historical (1975–2004) and future (2071–2100) period. Two existing threshold approaches to define future droughts are employed: (1) the threshold from the historical period; (2) a transient threshold approach, whereby the threshold adapts every year in the future to the changing regimes. Results show that drought characteristics differ among the combinations of glacier area modelling and thresholds. The historical threshold combined with a dynamic glacier area projects extreme increases in drought severity in the future, caused by the regime shift due to a reduction in glacier area. The historical threshold combined with a constant glacier area results in a drastic decrease of the number of droughts. The drought characteristics between future and historical periods are more similar when the transient threshold is used, for both glacier area conceptualisations. With the transient threshold, factors causing future droughts can be analysed. This study revealed the different effects of methodological choices on future streamflow drought projections and it highlights how the options can be used to analyse different aspects of future droughts: the transient threshold for analysing future drought processes, the historical threshold to assess changes between periods, the constant glacier area to analyse the effect of short-term climate variability on droughts and the dynamic glacier area to model more realistic future discharges under climate change.