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Search Results: 1 - 10 of 491665 matches for " Luiz H. P. C. Trondoli "
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Testing through Fall of Potential with High Current Injection in Grounding System in Transmission Line of 500 kV of Santo Antonio HPS  [PDF]
Carlos Magno B. Araújo, Luiz H. P. C. Trondoli
Open Access Library Journal (OALib Journal) , 2017, DOI: 10.4236/oalib.1103323
Abstract:
This paper presents the application of grounding resistance measurement by fall of potential with high current injection, applied to the Transmission Line (TL) of 500 kV of Santo Antonio Hydroelectric Power Station (HPS), located in the city of Porto Velho/RO, for the commissioning of the power house grounding system in Generation Group (GG2) and TL during construction of the referred project. Based on measurements obtained in field, computer simulations were performed to assess the effectiveness of the grounding system on future fault scenarios of the TL, as well as the suitability of relevant protection functions. The computer simulations are based on the model developed for TL 500 kV of GG2, and are performed using the PSCAD/EMTDC software, including the grounding values derived from the design of high current injection, according to (IEEE Std 80-2013). In order to attest the efficacy of both GG2 grounding system and TL from the HPS, COMTRADE files, obtained by the software, were used in the simulator Doble 6150 for the design of distinct fault conditions in a SEL-421 relay. Results indicate the correct functioning of relay SEL-421, corroborating the effectiveness of both grounding system and measurement method.
Institutions for collaboration in industrial clusters: proposal of a per-formance and change management model
Luiz C. R. Carpinetti,Rafael H. P. Lima
International Journal of Production Management and Engineering , 2013, DOI: 10.4995/ijpme.2013.1502
Abstract: This paper proposes a performance and change management model for institutions for collaboration (IFCs) in industrial clusters to assist them while planning, conducting and evaluating joint actions. A three-stage implementation scheme and a self-assessment tool that helps an IFC determine its compliance with the proposed model are also introduced. The self-assessment tool was applied in three Brazilian IFCs from different clusters. It was found that the IFCs researched face major difficulties in designing and implementing performance measures to evaluate the results and impacts of joint actions. However, IFCs have been successful in identifying local infrastructure and devising informal strategic plans.
Acesso endoscópico para tratamento de mucoceles fronto-etmoidais
Santos, Rodrigo P.;Barbosa, Luiz H. F.;Belfort, Marco A;Ferri, Ricardo G.;Gregorio, Luiz C.;
Revista Brasileira de Otorrinolaringologia , 2002, DOI: 10.1590/S0034-72992002000300006
Abstract: introduction: the mucocele is an expansive benign tumor due to the filling of a closed cavity with mucus. frequently involving the fronto-ethmoidal sinus, it is a rare otolaryngological condition. the etiology is divided into inflammatory and obstructive causes. aim: to evaluate the endoscopic endonasal surgical approach for fronto-ethmoidal sinus mucoceles. study design: clinical prospective. material and method: thirteen patients were followed during the period of january of 2000 to april of 2001, regarding the clinical findings, evolution and surgical results. results: all patients presented proptosis as the major symptom. seven patients had the inflammatory form and two the obstructive one. two patients presented ophthalmologic complications and underwent orbital decompression associated with the endoscopic endonasal technique. there were no recurrences in our study. conclusions: the endoscopic endonasal approach for fronto-ethmoidal sinus mucoceles is an effective treatment for the disease, avoiding the complications of the early techniques.
Correla??o entre parametros da cinética de intumescimento com características estruturais e hidrofílicas de hidrogéis de poliacrilamida e metilcelulose
Aouada, Fauze A.;Muniz, Edvani C.;Vaz, Carlos M. P.;Mattoso, Luiz H. C.;
Química Nova , 2009, DOI: 10.1590/S0100-40422009000600023
Abstract: in this paper, the effects of acrylamide (aam), methylcellulose (mc) contents, ph and ionic strength on kinetic, network and hydrophilic properties of polyacrylamide and methylcellulose hydrogels were investigated. the hydrogels were characterized by evaluating of network [average molecular weight between crosslinks (mc), crosslink density (q) and the number of elastically effective chains (ve)], and kinetic parameters [diffusional exponent (n), diffusion constant (k) and diffusion coefficient (d)]. such properties were controlled by adjusting of the aam, mc contents, ph and ionic strength factors. due to high hydrophilicity and fast water-uptake, the paam-mc hydrogels can be considered as materials for potential applications in agricultural fields, mainly in controlled release of water or pesticides.
Poly(imide)/Organically-Modified Montmorillonite Nanocomposite as a Potential Membrane for Alkaline Fuel Cells
Liliane C. Battirola,Luiz H. S. Gasparotto,Ubirajara P. Rodrigues-Filho,Germano Tremiliosi-Filho
Membranes , 2012, DOI: 10.3390/membranes2030430
Abstract: In this work we evaluated the potentiality of a poly(imide) (PI)/organically-modified montmorillonite (O-MMT) nanocomposite membrane for the use in alkaline fuel cells. Both X-ray diffraction and scanning electron microscopy revealed a good dispersion of O-MMT into the PI matrix and preservation of the O-MMT layered structure. When compared to the pure PI, the addition of O-MMT improved thermal stability and markedly increased the capability of absorbing electrolyte and ionic conductivity of the composite. The results show that the PI/O-MMT nanocomposite is a promising candidate for alkaline fuel cell applications.
Caracteriza??o de cálculos renais por análise térmica
Branco, C. H. D.;Silva, A. L.;Luiz, J. M.;Mercuri, L. P.;Matos, J. R.;
Eclética Química , 2009, DOI: 10.1590/S0100-46702009000100008
Abstract: ten samples of kidney stone had been studied through elemental analysis of chn (ea), infrared absorption spectroscopy and x-ray powder diffraction (xrd). the thermal behavior of the samples is studied by thermogravimetry/derivative thermogravimetry (tg/dtg) and differential scanning calorimetry (dsc). the results of ae, iv absorption spectroscopy and xrd showed the presence of struvite (nh4mg [po4].6h2o), apatite, monohydrated calcium oxalate and dihydrated calcium oxalate. the tg and dsc curves allowed to classify the samples in two different groups: group i show typical thermal behavior of struvite and group ii present a profile thermal analytical characteristic of a mixture of calcium oxalate.
Variabilidade espacial e temporal da precipita??o pluvial na bacia hidrográfica do Ribeir?o Jo?o Leite-GO
Santos, Eduardo H. M. dos;Griebeler, Nori P;Oliveira, Luiz F. C. de;
Engenharia Agrícola , 2011, DOI: 10.1590/S0100-69162011000100008
Abstract: the pluvial precipitation is the main hydrology variable input in the hydrological cycle and the knowledge of their spatial and temporal behavior is basic material for hydrological studies, watershed and water resource management, among others. the surface water produced in this basin is essential to the development of the axis anápolis-goiania-brasília and recently, with the increasing of water demand, it has been reported conflicts by the water use. thus, it appears that the development of hydrological studies aimed for better understanding and utilization of water resources are strategic for the development of the region. in this way, this work purpose to map the average monthly and annual precipitation in the jo?o leite watershed, using geostatistical techniques. it was evaluated the spherical, exponential and gaussian semivariogram models, adjusted by the weighted least squares method, being the model used for mapping by kriging the one that produced the lowest average error indicated by cross validation. it was found a good performance of geostatistical techniques in mapping the average monthly and annual precipitation, indicated by small errors, which can be highlighted the exponential model, with the best results in the most of the studied events.
Rela??o entre uso do solo e comportamento hidrológico na Bacia Hidrográfica do Ribeir?o Jo?o Leite
Santos, Eduardo H. M. dos;Griebeler, Nori P.;Oliveira, Luiz F. C. de;
Revista Brasileira de Engenharia Agrícola e Ambiental , 2010, DOI: 10.1590/S1415-43662010000800006
Abstract: the hydrological behavior of watersheds derives mainly from climate variability and land use. the 'ribeir?o jo?o leite' watershed is the main sourse of water supply in goiania city, and recently intense modifications were observed in the land use and availability of water. in this context, this work proposes to classify the land use between 1979 and 2005 and establish the association of the runoff with the land use and climate variability. for this, landsat images from the years 1979, 1989, 1997 and 2005 were used as well as flow and rainfall data provided by the agência nacional de água (ana). the land use was marked by 17.8% of deforestation, expansion of the urbanization and agriculture corresponded to 6.6 and 15.2%, respectively, and by significant areas of pasture. a trend of reduction in flow was observed that could be explained, in part, by a reduction in the rainfall regime. however, due to the significant increase of water withdrawal and the lack of historical records, there was difficulty in qualitative association between the runoff and the land use in spite of generating linear regression models with coefficients of determination (r2) above 0.75.
Stimulated Optical Luminescence Applied to Dating Coastal Sediments in Northeastern Brazil [A Utiliza o do Método de Luminescência Opticamente Estimulada para a Data o de Sedimentos de Dunas Costeiras do Nordeste Setentrional do Brasil]
Luis P. Maia,Francisco Gleidson da C. Gast?o,S?nia H. Tatumi,Luiz D. Lacerda
Revista Virtual de Química , 2011,
Abstract: Stimulated optical luminescence (SOL) was applied in dating coastal sediments in northeastern Brasil and revealed that the evolution of aeolic deposits in the region can be divided in 4 stages related to climate changes occurred during the quaternary leading to sea level changes, which modeled the coastline since the end of the Higher Pleistocene to present. The first stage dated back from 108,000 ± 11,000 years to 103,000 ± 9.000 anos B.P. (Before Present), but related mas que está relacionado ao máximo da Penúltima Transgress o, que aconteceu no Pleistoceno Médio, por volta de 123.000 anos, evento marcado por eros o dos depósitos mais antigos. O segundo estágio revelado pelas idades de 25.000 a 18.100 anos A.P, está relacionado à forma o do vasto campo de dunas, que alcan aram cerca de 160 km da linha de costa e que fixaram no terceiro estágio (14.000 a 12.000 anos A.P). O quarto estágio é representado pelas dunas móveis dos Len óis Maranhenses, que podem ter se formado há pelo menos 3.000 anos A.P.
Microscopia de varredura por for?a: uma ferramenta poderosa no estudo de polímeros
Herrmann, Paulo S. P;Silva, Marcelo A. P. da;Bernardes Fo, Rubens;Job, Aldo E;Colnago, Luiz A;Frommer, Jane E;Mattoso, Luiz H.C;
Polímeros , 1997, DOI: 10.1590/S0104-14281997000400009
Abstract: the scanning force microscopy techniques are promoting a great impact on materials science due to the possibility to obtain images down to the atomic scale. this work reports on the basic principles of the scanning force microscopes, their operation modes and the forces involved and measured. the potential application of these techniques on the study of materials, particularly on polymers, is discussed. a comparison of atomic force microscopy - afm - with other techniques is presented, as well as some examples of the use of afm on the study of polymers.
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