bluuebunny/crossref_metadata_2025 huggingface dataset:
A flexibilidade no contexto do desenvolvimento de fábricas inteligentes
Authors: Pereira Fernando Augusto , Dal Forno Ana Julia , Tubino Dalvio Ferrari
Published: April 2014

A globalização e a concorrência entre as empresas estão causando revoluções no desenvolvimento de produtos, reduzindo cada vez mais o seu ciclo de vida. As organizações estão optando por plataformas de produtos mundiais, com estratégias globais. Além da visão mais ampla sobre estratégias corporativas, os mercados mais dinâmicos e a forte concorrência estão impactando nos planejamentos de demanda de médio e curto prazo das empresas. Todas estas características originam turbulências nas organizações, mas também podem trazer oportunidades. Para as empresas introduzirem estas melhorias, é preciso inovar, mudando a forma como planejam e operam suas fábricas. Uma das formas para viabilizar isso é fazendo uso da flexibilidade na manufatura. Neste artigo serão abordados aspectos de flexibilidade, no contexto de faixa, resposta e dimensão, e como as empresas podem aplicar esse benefício para planejar melhor suas fábricas, seus processos produtivos e eliminar desperdícios.

Palavras-chave: Flexibilidade, Sistema Toyota de Produção, Lean Manufacturing, Fábricas Inteligentes, Eliminação de desperdícios.
Revisão de aspectos teóricos e metodológicos do uso de mapas cognitivos na ergonomia
Authors: Poletto Ângela Regina , Schmitz Ana Lúcia Ferraresi , Gontijo Leila Amaral
Published: April 2014

Este estudo tem como objetivo realizar uma revisão dos aspectos teóricos e metodológicos das pesquisas sobre o uso de mapas cognitivos como um recurso de investigação na ergonomia. Com a finalidade de fundamentar a pesquisa exploratória, selecionar e identificar na literatura especializada, o Portal da Capes foi utilizado como ferramenta de busca através do Scopus, Scielo, Medline e Elsevier. Os mapas cognitivos constituem-se em um instrumento importante na observação do comportamento humano em condições específicas, destacando-se, por meio do seu estado da arte, como auxiliar em ergonomia na análise das atividades. Os mapas auxiliam o processamento de informações seletivas e apontam metas para a tomada de decisões nas atividades de trabalho.

Palavras-chaves: mapas cognitivos, instrumento de observação, atividade de trabalho, ergonomia.
Expectativa de sucesso pelo PNQ
Authors: Bilessimo Luciano Dagostin , Cavaler Luiz Carlos de Cerao , Sommer Simone Meister
Published: April 2014

Este trabalho busca desenvolver um instrumento para diagnosticar a expectativa de sucesso da micro e pequena empresa brasileira. Utiliza-se o enfoque PNQ (Prêmio Nacional da Qualidade) como referência. Primeiramente, criou-se um questionário, com linguagem simples e objetiva para os sócios-gerentes, que geram uma pontuação no final da aplicação, facilitando a identificação de pontos fortes e oportunidades de melhoria para a empresa em questão. Desenvolveu-se então um aplicativo para este questionário que fora elaborado anteriormente A partir da aplicação do modelo proposto, o microempresário tem um diagnóstico de sua gestão, servindo de base para seu planejamento estratégico, rumo a melhoria contínua.

Palavras Chave: PNQ, Micro Empresa, Diagnóstico.
SIMULINVE – Um simulador de inventário para um centro de distribuição de peças
Authors: Lopes Jaguaribe Pontes Heráclito , Guenka Palma Jandira , Vieira Porto Arthur José
Published: April 2014

No mercado globalizado atual, as empresas buscam garantir disponibilidade de produto ao cliente final, com o menor nível de inventário possível. As ferramentas de simulação disponibilizam aos gestores melhores visões do negócio e melhores condições para a tomada de decisão. Em um Centro de Distribuição de Peças (CDP), para se alcançar um melhor desempenho no gerenciamento do inventário é importante poder contar com uma ferramenta capacitada para realizações de simulações de possíveis cenários. Este trabalho teve como objetivo desenvolver um processo para gerenciamento de inventario que resultou em um simulador de inventário para CDP. O simulador realiza projeções visando obter como resultados a previsão de demanda, a política de reposição das peças, o percentual de atendimento dos pedidos, os meses de inventário, a quantidade de Scrap e a quantidade de peças. O simulador foi submetido a experimentos com três cenários diferentes e os resultados confirmaram a qualidade do sistema de simulação proposto.
Contratação por desempenho em serviços de manutenção: o caso da CST Arcelor Brasil
Authors: Weber Ambrósio Cristina , Alexandre Leite Maria Silene
Published: April 2014

O objetivo deste artigo é discutir a contratação por desempenho e os benefícios que ela pode proporcionar para as empresas. O trabalho apresenta o processo de contratação por avaliação de desempenho na terceirização de serviços de manutenção. A contribuição do artigo consiste em identificar os fatores motivadores desta modalidade de contrato, bem como as etapas recomendadas para a obtenção de sucesso em um processo de contratação desta natureza. É apresentado o estudo de caso da siderúrgica CST Arcelor Brasil, onde se utiliza o modelo de contratação por desempenho na área de serviços de manutenção. Os contratos são firmados com base em cláusulas de desempenho, que buscam monitorar a performance dos serviços prestados segundo indicadores estabelecidos pela CST  em conjunto com empresas parceiras. A metodologia utilizada consiste  na pesquisa bibliográfica sobre a evolução das relações com fornecedores e em entrevistas com especialistas nas áreas de contratação, logística e vendas.
¿Es posible diseñar estrategias de crecimientos basadas en capital público y capital humano?
Authors: Rebelatto Daisy Aparecida do Nascimento , Delgado Rodríguez Maria Jesús , Ayuso Inmaculada Álvarez
Published: April 2014

En este artículo se emplean técnicas de frontera estocástica para analizar los factores explicativos del crecimiento económico.  Para ello, se implementa una función de producción translogarímica que permite obtener una medida de la eficiencia técnica para los países miembros de la Unión Europea y se incorporan las dotaciones de capital público y capital en educación con objeto de comprobar si han constituido un condicionante de los niveles de eficiencia alcanzados. Para llevar a cabo este trabajo se ha utilizado una valoración del capital privado, capital público y capital en educación para la UE-15 empleando la Metodología del Inventario Permanente.
Planejamento orientado por cenários com o uso de modelos causais lineares e diagramas de estoque e fluxo
Authors: Figueiredo Júlio César Bastos de
Published: April 2014

Para que um determinado projeto de negócios possa ser avaliado, seus resultados devem ser antecipados e considerados de acordo com as possíveis mudanças no ambiente. O uso de modelos mentais e de cenários dinâmicos computacionais, durante o processo de planejamento, visa criar novas fontes de informação que sensibilizem os gestores e planejadores para as implicações de suas decisões sobre a organização. Neste trabalho, será apresentado um novo método de fácil implementação, e que oferece a capacidade de executar simulações contínuas de cenários a partir do levantamento das relações lineares de impacto e retardo entre as variáveis de um sistema. A existência hoje de diversas ferramentas para a modelagem computacional permitirá o uso extensivo desses conceitos em situações práticas de planejamento, tanto no ambiente profissional quanto no de aprendizado.
Avaliação da demanda por biodiesel em função de um modelo de previsão de demanda por diesel
Authors: Carmo Breno Barros Telles do , Pontes Heráclito Lopes Jaguaribe , Albertin Marcos Ronaldo , Neto Júlio Francisco Barros , Dutra Nadja Glheuca da Silva
Published: April 2014

Observa-se uma crescente preocupação mundial com a produção de energias mais limpas. Uma destas é o biodiesel, que está sendo adicionado ao diesel para comercialização no Brasil. O presente artigo busca fazer uma análise da demanda por biodiesel em função do consumo de diesel, identificando qual a capacidade de produção para qual o país está se preparando. Para tanto, foi adotado um modelo de previsão de demanda não-paramétrico para a produção de diesel, que serviu de base para fazer a previsão para o biodiesel. Observa-se que o país está preparado para suprir uma demanda superior a exigida e possui estimativas de crescimento que atinge ao B10 (mistura de 10% de biodiesel ao diesel comercializado no Brasil). Observou-se também que a maior parte da capacidade produtiva está presente na região centro-oeste. Constatou-se também que o grande gargalo para a produção dos biocombustíveis é a falta disponibilidade de matéria-prima.
O papel do setor têxtil e de confecção brasileiro na liderança de um modelo sustentável de desenvolvimento
Authors: Bruno Flavio da Silveira , Bruno Ana Cristina Martins
Published: April 2014

Este trabalho sintetiza e discute resultados do Estudo Prospectivo Setorial Têxtil e de Confecção Brasileiro, promovido pela ABDI,  confrontando-os com iniciativas de enfoque socioambiental e com tendências de consumo consciente no setor. Relacionando os resultados do estudo prospectivo de cunho participativo, elaborado em oficinas com atores empresariais, acadêmicos e de instituições governamentais, com a revisão de literatura técnico-científica são extraídas ênfases para uma política de desenvolvimento sustentável do setor que possa servir  de referência para outras cadeias e atividades econômicas.
Formation of aramid-silica-grafted-multi-walled carbon nanotube-based nanofiber via the sol-gel route: thermal and mechanical profile of hybrids with poly(methyl methacrylate)
Authors: Kausar Ayesha
Published: April 2014

In this study, thermally and mechanically stable poly(methyl methacrylate) (PMMA)-based nanocomposites were produced through the reinforcement of electrospun aramid-silica-grafted multi-walled carbon nanotube-based nanofibers (MWCNT-Ar-Si). The multi-walled carbon nanotube was initially modified to prepare an isocyanatopropyltriethoxysilane-grafted MWCNT via the sol-gel route using 3-isocyanatopropyl-triethoxysilane and tetraethoxysilane (TEOS). The silica network was developed and linked to MWCNT by hydrolysis and condensation of TEOS. The said isocyanatopropyltriethoxysilane-grafted MWCNT was electrospun with the aramid solution. The electrospun MWCNT-Ar-Si nanofibers (0.1–1 wt.%) were then reinforced in a PMMA matrix. For comparative analysis, PMMA was also reinforced with 0.1–1 wt.% of aramid nanofibers. The tensile modulus of PMMA/MWCNT-Ar-Si 0.1 was 5.11 GPa, which was increased to 13.1 GPa in PMMA/MWCNT-Ar-Si 1. The 10% decomposition temperature of PMMA/MWCNT-Ar-Si 0.1–1 hybrids was in the range of 479–531°C. The glass transition temperature, determined from the maxima of tan δ data using dynamic mechanical thermal analysis, showed an increase with the filler loading and was maximum (301°C) for PMMA/MWCNT-Ar-Si 1 with 1 wt.% of MWCNT-Ar-Si nanofibers. In contrast, PMMA/Ar 0.1–1 hybrids showed lower values in the thermal and the mechanical profile depicting the combined effect of nanotube and aramid in electrospun nanofibers.
Characterization and Oxidation Behaviour of Al2O3 Coating Deposited on Ti-Al-Nb Alloy in Air and in 9%O2 + 0.2%HCl + 0.08%SO2 + N2 Atmosphere
Authors: Małecka Joanna
Published: April 2014

The paper presents research results of isothermal oxidation of Ti-46Al-7Nb-0.7Cr-0.1Si-0.1Ni intermetallic alloy with Al
An Insightful Steady-State Performance of a Squirrel Cage Induction Generator Enhanced with STATCOM
Authors: Ojo Olorunfemi , Khayamy Mehdy , Bule Mehari
Published: April 2014

This paper presents the regulation of the terminal voltage and reactive power of a grid-connected squirrel cage induction generator. A shunt connected voltage source inverter (VSI) with a capacitor in the DC side operating as a Static Compensator (STATCOM) and a shunt capacitor are used for regulating the generator terminal voltage and limit the reactive power demand from the grid. Simulation results for steady-state operation for a wide variation of speed in the super-synchronous region are presented as well as the dynamic stability of the system. Closed-form steady-state characteristics equations for the system are used to determine key variables and to demonstrate how the operation of the system depends on various parameters. This characteristics curve which contains all of the equations of the system provides the all in one insightful view to the inherent characteristics of the system and the effect of the parameter variation on the terminal voltage plane.
Characterization of C2H2O4 doped PVA solid polymer electrolyte
Authors: Alakanandana Karur , Subrahmanyam Annadanam Rama , Sayanna R. , Kumar J. Siva
Published: April 2014

A novel solid polymer electrolyte based on poly vinyl alcohol (PVA) with oxalic acid was prepared by the solution caste technique. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements carried out on the samples clearly revealed the modification of the PVA structure; the PVA crystallinity was reduced with increasing oxalic acid content and became more amorphous. The surface morphology of these complexed polymer electrolytes was analyzed by scanning electron microscopy (SEM). Fourier transform infrared spectroscopy (FTIR) spectral studies of the samples suggested that the interaction between H+ ions of oxalic acid and oxygen of the hydroxyl group (OH) of PVA plays a major role in proton conductivity. The optical absorption studies were performed on these samples in a range of wave numbers from 200 nm to 600 nm and the optical band gap values were evaluated. Direct current (DC) conductivity was measured and temperature dependence in the range 27–273°C was studied. It was observed that the conductivity at temperatures beyond the glass transition temperature (Tg) showed a Vogel-Tamman-Fulcher (VTF) type behavior. The electrical conductivity studies on PVA with oxalic acid, in a 70:30 proportion by wt%, demonstrated that the polymer composite is a promising electrolyte for applications in electrochemical cells.
Thermal behaviour of hafnium diethylenetriaminepentaacetate studied using the Perturbed Angular Correlation Technique
Authors: Chain Cecilia Y. , Rivas Patricia , Pasquevich Alberto F.
Published: April 2014

Polyaminecarboxilic ligands like diethylenetriaminepentaacetic acid form stable complexes with many heavy metal ions,
excelling as cation chelants especially in the field of radiopharmacy. The aim of this work is to characterize, by using the
Time Differential Perturbed Angular Correlations (TDPAC) technique, the hyperfine interactions at hafnium sites in hafnium
diethylenetriaminepentaacetate and to investigate their evolution as temperature increases.

TDPAC results for KHfDTPA · 3H2O obtained by chemical synthesis yield a well defined and highly asymmetric interaction
of quadrupole frequency ω

Q
 = 141 Mrad/s, which is consistent with the existence of a unique site for the
metal in the crystal lattice.

The thermal behaviour of the chelate is investigated by means of differential scanning calorimetry and thermogravimetrical
analyses revealing that an endothermic dehydration of KHfDTPA · 3H2O takes place in one step between
80 ℃ and 180 ℃. The anhydrous KHfDTPA thus arising is characterized by a fully asymmetric
and well defined interaction of quadrupole frequency ω

Q
 = 168 Mrad/s.
Clinical scale preparation and evaluation of 131I-Rituximab for Non-Hodgkin's Lymphoma
Authors: Kameswaran Mythili , Vimalnath K. Viswanathan , Rajeswari Ardhi , Joshi Prahlad Vasudeo , Sarma H. D. , Samuel Grace
Published: April 2014

Radioimmunotherapy (RIT) with anti CD20 MoAb conjugated to a β
− emitting radioisotope like 131I or
90Y has the added advantage of delivering radiation not only to tumor cells that bind the antibody but also due to
a crossfire effect, to neighboring tumor cells inaccessible to the antibody. In order to make available an indigenous
radioimmunotherapeutic agent for Non Hodgkin's Lymphoma (NHL), radioiodinated Rituximab has been prepared and evaluated at a clinical
scale. Radioiodination of Rituximab was performed by the conventional Chloramine T method using 7.4 GBq Na131I
in a lead shielded plant. Six batches of radioiodination were prepared and characterized by electrophoresis and HPLC to evaluate the
reproducibility of the product. The product remained stable retaining the radiochemical purity > 95% upto 5 days after
radioiodination. In vitro cell binding studies and biodistribution studies in normal Swiss mice have indicated the potential
of this molecule as a radioimmunotherapeutic agent for NHL.
Differential Effects of Synaptic and Extrasynaptic NMDA Receptors on Aβ-Induced Nitric Oxide Production in Cerebrocortical Neurons
Authors: Molokanova Elena , Akhtar Mohd Waseem , Sanz-Blasco Sara , Tu Shichun , Piña-Crespo Juan C. , McKercher Scott R. , Lipton Stuart A.
Published: April 2014

Oligomerized amyloid-β (Aβ) peptide is thought to contribute to synaptic damage, resulting in dysfunctional neuronal networks in patients with Alzheimer's disease. It has been previously suggested that Aβ may be detrimental to neuronal health, at least in part, by triggering oxidative/nitrosative stress. However, the mechanisms underlying this process remain to be elucidated. Here, using rat primary cerebrocortical cultures, we demonstrate that Aβ1–42oligomers trigger a dramatic increase in intracellular nitric oxide (NO) concentration via a process mediated by activation of NMDA-type glutamate receptors (NMDARs). Considering that synaptic NMDARs and extrasynaptic NMDARs (eNMDARs) can have opposite effects on neuronal viability, we explored their respective roles in Aβ-induced increases in NO levels. Surprisingly, after pharmacological isolation of eNMDARs, we discovered that eNMDARs are primarily responsible for the increase in neuronal NO triggered by Aβ oligomers. Moreover, we found that the eNMDAR-mediated increase in NO can produce S-nitrosylation of Drp1 (dynamin-related protein 1) and Cdk5 (cyclin-dependent kinase 5), targets known to contribute to Aβ-induced synaptic damage. These results suggest that pharmacological intervention specifically aimed at eNMDARs may decrease Aβ-induced nitrosative stress and thus ameliorate neurotoxic damage to synapses.
SDF1 Reduces Interneuron Leading Process Branching through Dual Regulation of Actin and Microtubules
Authors: Lysko Daniel E. , Putt Mary , Golden Jeffrey A.
Published: April 2014

Normal cerebral cortical function requires a highly ordered balance between projection neurons and interneurons. During development these two neuronal populations migrate from distinct progenitor zones to form the cerebral cortex, with interneurons originating in the more distant ganglionic eminences. Moreover, deficits in interneurons have been linked to a variety of neurodevelopmental disorders underscoring the importance of understanding interneuron development and function. We, and others, have identified SDF1 signaling as one important modulator of interneuron migration speed and leading process branching behavior in mice, although how SDF1 signaling impacts these behaviors remains unknown. We previously found SDF1 inhibited leading process branching while increasing the rate of migration. We have now mechanistically linked SDF1 modulation of leading process branching behavior to a dual regulation of both actin and microtubule organization. We find SDF1 consolidates actin at the leading process tip by de-repressing calpain protease and increasing proteolysis of branched-actin-supporting cortactin. Additionally, SDF1 stabilizes the microtubule array in the leading process through activation of the microtubule-associated protein doublecortin (DCX). DCX stabilizes the microtubule array by bundling microtubules within the leading process, reducing branching. These data provide mechanistic insight into the regulation of interneuron leading process dynamics during neuronal migration in mice and provides insight into how cortactin andDCX, a known human neuronal migration disorder gene, participate in this process.
Behavioral Oscillations in Attention: Rhythmic α Pulses Mediated through θ Band
Authors: Song Kun , Meng Ming , Chen Lin , Zhou Ke , Luo Huan
Published: April 2014

Neuronal oscillations are ubiquitous in the brain and contribute to perception and attention. However, most associated evidence derives frompost hoccorrelations between brain dynamics and behavior. Although a few recent studies demonstrate rhythms in behavior, it remains largely unknown whether behavioral performances manifest spectrotemporal dynamics in a neurophysiologically relevant manner (e.g., the temporal modulation of ongoing oscillations, the cross-frequency coupling). To investigate the issue, we examined fine spectrotemporal dynamics of behavioral time courses in a large sample of human participants (n= 49), by taking a high time-resolved psychophysical measurement in a precuing attentional task. We observed compelling dynamic oscillatory patterns directly in behavior. First, typical attentional effects are demonstrated in low-pass (0–2 Hz) filtered time courses of behavioral responses. Second, an uninformative peripheral cue elicits recurring α-band (8–20 Hz) pulses in behavioral performances, and the elicited α pulses for cued and uncued conditions are in a temporally alternating relationship. Finally, ongoing α-band power is phase locked to ongoing θ-bands (3–5 Hz) in behavioral time courses. Our findings constitute manifestation of oscillations at physiologically relevant rhythms and power-phase locking, as widely observed in neurophysiological recordings, in behavior. The findings suggest that behavioral performance actually consists of rich dynamic information and may reflect underlying neuronal oscillatory substrates. Our data also speak to a neural mechanism for item attention based on successive cycles (θ) of a sequential attentional sampling (α) process.
In active acromegaly, IGF1 bioactivity is related to soluble Klotho levels and quality of life
Authors: Varewijck A J , van der Lely A J , Neggers S J C M M , Lamberts S W J , Hofland L J , Janssen J A M J L
Published: April 2014

The value of measuring IGF1 bioactivity in active acromegaly is unknown. Soluble Klotho (S-Klotho) level is elevated in active acromegaly and it has been suggested that S-Klotho can inhibit activation of the IGF1 receptor (IGF1R). A cross-sectional study was carried out in 15 patients with active acromegaly based on clinical presentation, unsuppressed GH during an oral glucose tolerance test, and elevated total IGF1 levels (>+2 s.d.). Total IGF1 was measured by immunoassay, IGF1 bioactivity by the IGF1R kinase receptor activation assay and S-Klotho by an ELISA. Quality of Life (QoL) was assessed by Acromegaly QoL (AcroQoL) Questionnaire and Short-Form-36 Health Survey Questionnaire (SF-36). Out of 15 patients, nine had IGF1 bioactivity values within the reference range. S-Klotho was higher in active acromegaly compared with controls. Age-adjusted S-Klotho was significantly related to IGF1 bioactivity (r=0.75, P=0.002) and to total IGF1 (r=0.62, P=0.02). IGF1 bioactivity and total IGF1 were inversely related to the physical component summary of the SF-36 (r=−0.78, P=0.002 vs r=−0.60, P=0.03). Moreover, IGF1 bioactivity, but not total IGF1, was significantly inversely related to the physical dimension of the AcroQoL Questionnaire (r=−0.60, P=0.02 vs r=−0.37, P=0.19). In contrast to total IGF1, IGF1 bioactivity was within the reference range in a considerable number of subjects with active acromegaly. Elevated S-Klotho levels may have reduced IGF1 bioactivity. Moreover, IGF1 bioactivity was more strongly related to physical measures of QoL than total IGF1, suggesting that IGF1 bioactivity may better reflect physical limitations perceived in active acromegaly.
Administration of 3,5‐diiodothyronine (3,5‐T2) causes central hypothyroidism and stimulates thyroid‐sensitive tissues
Authors: Padron Alvaro Souto , Neto Ruy Andrade Louzada , Pantaleão Thiago Urgal , de Souza dos Santos Maria Carolina , Araujo Renata Lopes , de Andrade Bruno Moulin , da Silva Leandro Monique , de Castro João Pedro Saar Werneck , Ferreira Andrea Claudia Freitas , de Carvalho Denise Pires
Published: April 2014

In general, 3,5-diiodothyronine (3,5-T2) increases the resting metabolic rate and oxygen consumption, exerting short-term beneficial metabolic effects on rats subjected to a high-fat diet. Our aim was to evaluate the effects of chronic 3,5-T2 administration on the hypothalamus–pituitary–thyroid axis, body mass gain, adipose tissue mass, and body oxygen consumption in Wistar rats from 3 to 6 months of age. The rats were treated daily with 3,5-T2 (25, 50, or 75 μg/100 g body weight, s.c.) for 90 days between the ages of 3 and 6 months. The administration of 3,5-T2 suppressed thyroid function, reducing not only thyroid iodide uptake but also thyroperoxidase, NADPH oxidase 4 (NOX4), and thyroid type 1 iodothyronine deiodinase (D1 (DIO1)) activities and expression levels, whereas the expression of the TSH receptor and dual oxidase (DUOX) were increased. Serum TSH, 3,3′,5-triiodothyronine, and thyroxine were reduced in a 3,5-T2 dose-dependent manner, whereas oxygen consumption increased in these animals, indicating the direct action of 3,5-T2 on this physiological variable. Type 2 deiodinase activity increased in both the hypothalamus and the pituitary, and D1 activities in the liver and kidney were also increased in groups treated with 3,5-T2. Moreover, after 3 months of 3,5-T2 administration, body mass and retroperitoneal fat pad mass were significantly reduced, whereas the heart rate and mass were unchanged. Thus, 3,5-T2 acts as a direct stimulator of energy expenditure and reduces body mass gain; however, TSH suppression may develop secondary to 3,5-T2 administration.
Aluminum Oxide Passivation Layer for Crystalline Silicon Solar Cells Deposited by Mist CVD in Open-Air Atmosphere
Authors: Kawaharamura Toshiyuki , Uchida Takayuki , Shibayama Kenji , Fujita Shizuo , Hiramatsu Takahiro , Orita Hiroyuki
Published: April 2014

The surface passivation of Si wafer by AlOxthin films grown by mist CVD in an open-air atmosphere was studied with a view to improving the effect of high-performance c-Si solar cells. In AlOxthin film grown at a temperature above 400°C by mist CVD, the OH bonding did not remain in the film and the breakdown field (EBD) was over 6 MV/cm. In Si wafers passivated by AlOxthin films grown by mist CVD at growth temperature above 400°C, the negative fixed charge density (Qf) at the interface was higher than 1012cm-2and the surface recombination velocity (Seff) was 44.4 cm/s. These results show that mist CVD, which is fundamentally an environmentally friendly technique, may be suitable for the fabrication of a passivation film on Si surfaces designed to improve the effect of high-performance c-Si solar cells.
Tryblionella persuadens comb. nov. (Bacillariaceae, Diatomeae): new observations on frustule morphology of a seldom recorded diatom
Authors: CAVALCANTE KAOLI P. , TREMARIN PRISCILA I. , FREIRE EDUARDO G. , LUDWIG THELMA A.V.
Published: April 2014

ABSTRACT The species originally described from brackish waters of the Venetian Lagoon as Nitzschia persuadens is a diatom rarely cited in the literature since its proposition and it is here recorded for the first time in a freshwater environment in South America. Morphological features of this species, such valve slightly panduriform, with a longitudinal straight fold of the valve face, poroidal areolae, and strongly eccentric raphe system clearly assign this species to Tryblionella, and the transfer was made. Here we present new observations on the frustule morphology and comparisons with related species. Light and scanning electron microscopy data of Tryblionella persuadens comb. nov. from Cachoeira River, Northeastern Brazil are documented.
Is the secondary thickening in palms always diffuse?
Authors: BOTaNICO MARLI P. , ANGYALOSSY VERONICA
Published: April 2014

Unlike other arboreal monocotyledons, the secondary growth of palms has for the past 100 years been described as diffuse. Solely cell enlargement and random parenchyma divisions, without the activity of a meristem, characterize such growth. Some previous works of the early 20th century have, however, mentioned the presence of a secondary meristem in the stems of palms, but this information was forgotten since then. Addressing to this question, we analysed palm stems of four species, with the aim to understand the possible presence of such secondary growth. We found that a meristematic band occurs between the cortex and the central cylinder and gives rise to new vascular bundles and parenchyma internally, producing parenchyma and fibres externally. It appears secondarily, i.e., it undergoes meristematic activity in the median and basal stem regions, far away from the apical region. In fact, a meristematic band is present and may be more common than currently believed, but uneasy to detect in certain palms for being restricted to specific regions of their stems. In conclusion, the diffuse secondary thickening is here shown not to be the only mechanism of secondary growth in palms. The presence of a meristem band in the stems of palms merits careful reconsideration.
Horse spleen segmentation technique as large animal model of preclinical trials
Authors: Foz Filho Roberto P.P. , Martin Benedito W. de , Lima Ana Rita de , Miglino Maria Angelica
Published: April 2014

The parenchymal distribution of the splenic artery was studied in order to obtain anatomical basis for partial splenectomy. Thirty two spleens were studied, 26 spleens of healthy horses weighing 320 to 450kg, aged 3 to 12 years and 6 spleens of fetus removed from slaughterhouse. The spleens were submitted to arteriography and scintigraphy in order to have their vascular pattern examined and compared to the external aspect of the organ aiming establish anatomo-surgical segments. All radiographs were photographed with a digital camera and the digital images were submitted to a measuring system for comparative analysis of areas of dorsal and ventral anatomo-surgical segments. Anatomical investigations into the angioarchitecture of the equine spleen showed a paucivascular area, which coincides with a thinner external area, allowing the organ to be divided in two anatomo-surgical segments of approximately 50% of the organ each.
The Gauss Map of Complete Minimal Surfaces with Finite Total Curvature
Authors: HINOJOSA PEDRO A. , SILVA GILVANEIDE N.
Published: April 2014

In this paper we are concerned with the image of the normal Gauss map of a minimal surface immersed in ℝ3 with finite total curvature. We give a different proof of the following theorem of R. Osserman: The normal Gauss map of a minimal surface immersed in ℝ3 with finite total curvature, which is not a plane, omits at most three points of��2 Moreover, under an additional hypothesis on the type of ends, we prove that this number is exactly 2.
Standardization of a method to study angiogenesis in a mouse model
Authors: FEDER DAVID , PERRAZO FABIO F. , PEREIRA EDIMAR C. , FORSAIT SILVANA , FEDER CECILIA K.R. , JUNQUEIRA PAULO E.B. , JUNQUEIRA VIRGINIA B.C. , AZZALIS LIGIA A. , FONSECA FERNANDO L.A.
Published: April 2014

In the adult organism, angiogenesis is restricted to a few physiological conditions. On the other hand, uncontrolled angiogenesis have often been associated to angiogenesis-dependent pathologies. A variety of animal models have been described to provide more quantitative analysis of in vivo angiogenesis and to characterize pro- and antiangiogenic molecules. However, it is still necessary to establish a quantitative, reproducible and specific method for studies of angiogenesis factors and inhibitors. This work aimed to standardize a method for the study of angiogenesis and to investigate the effects of thalidomide on angiogenesis. Sponges of 0.5 x 0.5 x 0.5 cm were implanted in the back of mice groups, control and experimental (thalidomide 200 mg/K/day by gavage). After seven days, the sponges were removed. The dosage of hemoglobin in sponge and in circulation was performed and the ratio between the values was tested using nonparametric Mann-Whitney test. Results have shown that sponge-induced angiogenesis quantitated by ratio between hemoglobin content in serum and in sponge is a helpful model for in vivo studies on angiogenesis. Moreover, it was observed that sponge-induced angiogenesis can be suppressed by thalidomide, corroborating to the validity of the standardized method.
Assessing rainfall erosivity indices through synthetic precipitation series and artificial neural networks
Authors: CECILIO ROBERTO A. , MOREIRA MICHEL C. , PEZZOPANE JOSE EDUARDO M. , PRUSKI FERNANDO F. , FUKUNAGA DANILO C.
Published: April 2014

The rainfall parameter that expresses the capacity to promote soil erosion is called rainfall erosivity (R), and is commonly represented by the indexes EI30 and KE>25. The calculations of these indexes requires pluviographical records, that are difficult to obtain in Brazil. This paper describes the use of synthetic rainfall series to compute EI30 and KE>25 in Espírito Santo State (Brazil). Artificial neural networks (ANNs) were also developed to spatially interpolate R values in Espírito Santo. EI30 and KE>25 indexes values were close to those calculated on a homogeneous area according to the similarity of rainfall distribution; indicating the applicability of the use of synthetic rainfall series to estimate the R factor. ANNs had a better performance than Inverse Distance Weighted and Kriging to spatially interpolate rainfall erosivity values in the State of Espírito Santo.
Influence of mineral fertilization on edaphic fauna in Acacia auriculiformis (A. Cunn) plantations
Authors: Ribeiro Liliana Parente , Gama-Rodrigues Emanuela Forestieri , Moço Maria Kellen da Silva , Gama-Rodrigues Antonio Carlos
Published: April 2014

Fertilization and/or the accumulation of organic matter from plant residues can influence the composition of soil and litter community. The goal of this study was to evaluate the effects of P and K fertilization on total faunal and nematode faunal composition and richness in plant litter and soil for 360 days in an area reforested with Acacia auriculiformis (A. Cunn), located in the municipality of Conceição de Macabu in the State of Rio de Janeiro. For each treatment (fertilized and unfertilized plots), samples of litter and soil (to a depth of 5 cm) were collected and transferred into a Berlese-Tüllgren funnels for the extraction of fauna. Mesofauna and macrofauna were quantified, and the major taxa identified. Nematodes were extracted by centrifugal flotation in sucrose solution and identified according to feeding habits. Density (number of individuals m-2) of total fauna, microphages, social insects and saprophages varied significantly per treatment and sampling time in both litter and soil. The total number of individuals collected was 5,127, and the total number of nematodes 894. Phosphorus and potassium fertilization resulted in an increase in total fauna density and richness in the litter due to an increased abundance of social insects, saprophages and herbivores. In the soil, fertilization increased the saprophage and predator densities. Saprophages were the predominant taxa in the litter, while social insects (Formicidae) prevailed in the soil. Litter nematode populations were favored by mineral fertilization. Bacteriophages were the predominant nematode group in both litter and soil.
Análise espaço-temporal de componentes do balanço hídrico em um Latossolo
Authors: Moreira Neilo Bergamin , Libardi Paulo Leonel , Salvador Monica Martins Silva , Sousa Helon Hébano de Freitas
Published: April 2014

O monitoramento das variáveis que constituem a equação do balanço hídrico do solo em campo cultivado é necessário para avaliar com confiabilidade os períodos de déficits hídricos durante o ciclo das culturas, manejar a irrigação e quantificar perdas de nutrientes por lixiviação. Os componentes da equação do balanço hídrico podem variar no espaço e no tempo, e o estudo da estabilidade temporal da variabilidade espacial desses componentes é essencial para determinar quais são os pontos de observação no campo (locais) para monitorar a água do solo com precisão e esforço amostral reduzido. Assim, os objetivos deste trabalho foram avaliar os componentes do balanço da água (especificamente a variação de armazenamento de água do solo, drenagem interna e evapotranspiração real) de plantas de milho em um Latossolo Vermelho-Amarelo e analisar a variabilidade espacial e temporal, por meio da técnica de estabilidade temporal. O estudo foi realizado em uma área do Campus da ESALQ/USP, município de Piracicaba, Estado de São Paulo, Brasil. O relevo da área experimental, que tem 1.500 m², é plano. Nessa área foram instalados 60 tubos de alumínio para acesso de uma sonda de nêutrons e 120 tensiômetros com manômetro de mercúrio (60 na profundidade de 0,75 m e 60 na profundidade de 0,85 m). Isso permitiu estimar a densidade de fluxo de água do solo na profundidade de 0,80 m por meio da equação de Darcy-Buckingham e o armazenamento de água na camada de 0,0-0,80 m, ao longo do ciclo da cultura. A precipitação pluvial foi medida por meio de um pluviômetro instalado no centro da área experimental, e a evaporação real foi considerada como desconhecida da equação do balanço hídrico. A pesquisa foi realizada dividindo o ciclo de cultivo em 13 períodos (P1 a P13). O uso da estatística descritiva foi feito para evidenciar a variação do comportamento dos dados após a remoção dos pontos discrepantes, que representaram entre 0,0 e 3,9 % dos pontos amostrais por período. O uso da estatística descritiva foi útil por ter apresentado a mudança no comportamento dos dados, após a retirada de valores discrepantes e extremos em alguns períodos. A técnica da estabilidade temporal é viável para avaliação do balanço hídrico no espaço e no tempo. Os coeficientes de correlação de Spearman entre os períodos indicaram estabilidade temporal para a armazenagem da água independentemente do teor de umidade do solo, mas não expressaram confiabilidade para a avaliação da drenagem interna e a evapotranspiração real da cultura. A evapotranspiração oscilou ao longo do ciclo da cultura mantendo-se praticamente constante nos períodos P5 a P9, em que houve maior desenvolvimento vegetativo das plantas.
Estimation of water percolation by different methods using TDR
Authors: Silva Alisson Jadavi Pereira da , Coelho Eugênio Ferreira
Published: April 2014

Detailed knowledge on water percolation into the soil in irrigated areas is fundamental for solving problems of drainage, pollution and the recharge of underground aquifers. The aim of this study was to evaluate the percolation estimated by time-domain-reflectometry (TDR) in a drainage lysimeter. We used Darcy's law with K(θ) functions determined by field and laboratory methods and by the change in water storage in the soil profile at 16 points of moisture measurement at different time intervals. A sandy clay soil was saturated and covered with plastic sheet to prevent evaporation and an internal drainage trial in a drainage lysimeter was installed. The relationship between the observed and estimated percolation values was evaluated by linear regression analysis. The results suggest that percolation in the field or laboratory can be estimated based on continuous monitoring with TDR, and at short time intervals, of the variations in soil water storage. The precision and accuracy of this approach are similar to those of the lysimeter and it has advantages over the other evaluated methods, of which the most relevant are the possibility of estimating percolation in short time intervals and exemption from the predetermination of soil hydraulic properties such as water retention and hydraulic conductivity. The estimates obtained by the Darcy-Buckingham equation for percolation levels using function K(θ) predicted by the method of Hillel et al. (1972) provided compatible water percolation estimates with those obtained in the lysimeter at time intervals greater than 1 h. The methods of Libardi et al. (1980), Sisson et al. (1980) and van Genuchten (1980) underestimated water percolation.
Water storage variability in a vineyard soil in the southern highlands of Santa Catarina state
Authors: Luciano Rodrigo Vieira , Albuquerque Jackson Adriano , Mafra Álvaro Luiz , Costa André da , Grah Josué
Published: April 2014

In the subtropical regions of southern Brazil, rainfall distribution is uneven, which results in temporal variability of soil water storage. For grapes, water is generally available in excess and water deficiency occurs only occasionally. Furthermore, on the Southern Plateau of Santa Catarina, there are differences in soil properties, which results in high spatial variability. These two factors affect the composition of wine grapes. Spatio-temporal analyses are therefore useful in the selection of cultural practices as well as of adequate soils for vineyards. In this way, well-suited areas can produce grapes with a more appropriate composition for the production of quality wines. The aim of this study was to evaluate the spatio-temporal variability of water storage in a Cambisol during the growth cycle of a Cabernet Sauvignon vineyard and its relation to selected soil properties. The experimental area consisted of a commercial 8-year-old vineyard in São Joaquim, Santa Catarina, Brazil. A sampling grid with five rows and seven points per row, spaced 12 m apart, was outlined on an area of 3,456 m². Soil samples were collected with an auger at these points, 0.30 m away from the grapevines, in the 0.00-0.30 m layer, to determine gravimetric soil moisture. Measurements were taken once a week from December 2008 to April 2009, and every two weeks from December 2009 to March 2010. In December 2008, undisturbed soil samples were collected to determine bulk density, macro- and microporosity, and disturbed samples were used to quantify particle size distribution and organic carbon content. Results were subjected to descriptive analysis and semivariogram analysis, calculating the mean relative difference and the Pearson correlation. The average water storage in a Cambisol under grapevine on ridges had variable spatial dependence, i.e., the lower the average water storage, the higher the range of spatial dependence. Water storage had a stable spatial pattern during the trial period, indicating that the points with lower water storage or points with higher water storage during a certain period maintain these conditions throughout the experimental period. The relative difference is a simple method to identify positions that represent the average soil water storage more adequately at any time for a given area.
Estrutura e armazenamento de água em um Argissolo sob pastagem cultivada, floresta nativa e povoamento de eucalipto no Rio Grande do Sul
Authors: Suzuki Luis Eduardo Akiyoshi Sanches , Lima Cláudia Liane Rodrigues de , Reinert Dalvan José , Reichert José Miguel , Pillon Clênio Nailto
Published: April 2014

Práticas pouco adequadas de manejo têm ocasionado a compactação e a degradação da estrutura do solo. Identificar atributos que melhor representem essas alterações são relevantes na recuperação e na indicação de práticas para evitar danos na estrutura do solo. Objetivou-se avaliar o impacto de diferentes usos em atributos estruturais e hídricos de um Argissolo Vermelho. O estudo foi realizado no município de Butiá, na região fisiográfica da Serra do Sudeste do Estado do Rio Grande do Sul, em um Argissolo Vermelho distrófico. As áreas analisadas corresponderam a: floresta antropizada constituída por espécies arbóreas e arbustivas (Floresta); pastagem com cinco anos de idade, com braquiária brizanta (Brachiaria brizantha) consorciada com pensacola (Paspalum lourai) e trevo (Trifolium sp.) (Pastagem); povoamento de Eucalyptus saligna com 20 anos de idade (Eucalipto 20); e plantio clonal de Eucalyptus saligna conduzido em segunda rotação, com 4,5 anos de idade (Eucalipto 4,5). Avaliaram-se nessas áreas a textura, a condutividade hidráulica, a porosidade, a densidade, o diâmetro médio ponderado de agregados (DMP), a curva de retenção de água, a distribuição do tamanho de poros e o parâmetro S, obtendo-se as seguintes conclusões: até a camada de 0,10 m na Pastagem, e 0,40 m no Eucalipto 4,5, os agregados foram formados pela ação da textura e matéria orgânica e pelo efeito compressivo, decorrente do pisoteio dos bovinos e da colheita do eucalipto. Conforme a profundidade aumentou, ocorreu redução do DMP de agregados, em razão da diminuição da matéria orgânica, e aumento do cascalho, especialmente para as áreas de Pastagem e Eucalipto 4,5, e ao menor efeito da compressão do solo. A textura e a matéria orgânica evidenciaram influência na agregação do solo e, mesmo em pequena proporção, o cascalho reduziu o DMP de agregados, pois sua baixa reatividade e seu maior diâmetro dificultaram a formação de agregados estáveis. Em relação aos atributos hídricos do solo, as áreas de Floresta e a Pastagem apresentaram maior disponibilidade de água, enquanto o maior parâmetro S está relacionado ao maior armazenamento de água.
Iron oxidation on the surface of adventitious roots and its relation to aerenchyma formation in rice genotypes
Authors: Holzschuh Marquel Jonas , Carlos Filipe Selau , Carmona Felipe de Campos , Bohnen Humberto , Anghinoni Ibanor
Published: April 2014

Establishment of the water layer in an irrigated rice crop leads to consumption of free oxygen in the soil which enters in a chemical reduction process mediated by anaerobic microorganisms, changing the crop environment. To maintain optimal growth in an environment without O2, rice plants develop pore spaces (aerenchyma) that allow O2 transport from air to the roots. Carrying capacity is determined by the rice genome and it may vary among cultivars. Plants that have higher capacity for formation of aerenchyma should theoretically carry more O2 to the roots. However, part of the O2 that reaches the roots is lost due to permeability of the roots and the O2 gradient created between the soil and roots. The O2 that is lost to the outside medium can react with chemically reduced elements present in the soil; one of them is iron, which reacts with oxygen and forms an iron plaque on the outer root surface. Therefore, evaluation of the iron plaque and of the formation of pore spaces on the root can serve as a parameter to differentiate rice cultivars in regard to the volume of O2 transported via aerenchyma. An experiment was thus carried out in a greenhouse with the aim of comparing aerenchyma and iron plaque formation in 13 rice cultivars grown in flooded soils to their formation under growing conditions similar to a normal field, without free oxygen. The results indicated significant differences in the volume of pore spaces in the roots among cultivars and along the root segment in each cultivar, indicating that under flooded conditions the genetic potential of the plant is crucial in induction of cell death and formation of aerenchyma in response to lack of O2. In addition, the amount of Fe accumulated on the root surface was different among genotypes and along the roots. Thus, we concluded that the rice genotypes exhibit different responses for aerenchyma formation, oxygen release by the roots and iron plaque formation, and that there is a direct relationship between porosity and the amount of iron oxidized on the root surface.