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Search Results: 1 - 10 of 584 matches for " Adriane Salum "
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Development of a New Bio-Based Insulating Fluid from Jatropha curcas Oil for Power Transformers  [PDF]
José M. G. Evangelista Jr., Fabrício E. Bortot Coelho, Juliana A. O. Carvalho, Estêv?o M. R. Araújo, Tania L. S. Miranda, Adriane Salum
Advances in Chemical Engineering and Science (ACES) , 2017, DOI: 10.4236/aces.2017.72018
Abstract: The present work aims to develop a new vegetable insulating fluid for power transformers based on Jatropha curcas oil. Besides its technical benefits, Jatropha curcas oil has a socio-economic role by promoting income to rural families, contributing to the countryside development and avoiding rural exodus. Thus, the entire transformer oil production (extraction, processing, characterization and accelerated aging) was covered and a new process was developed. For oil extraction, the most suitable process was the solvent extraction (5 mL of hexane per gram of crushed non-peeled seeds during 30 minutes) with an oil yield of 32%. In raw oil processing stage, the degumming, with 0.4 g of phosphoric acid per 100 g of oil, at 70°C, was used to remove phosphatides. Then, free fatty acids were 96% neutralized with a sodium hydroxide solution (0.5% w/w) at room temperature. For the oil clarification, the combination of 5% w/woil of activated carbon and 1% w/woil of MgO resulted in a bright, odorless and clear oil with an acid number of 0.04 mgKOH·g1. The oil drying in a vacuum rotary evaporator, at 70°C, for 2 hours reduced the water content to 177 ppm. The processed oil was characterized following ASTM D6871 methods. This oil presented higher dielectric breakdown voltage (55 kV) than commercial transformer fluids (BIOTEMP?, EnvirotempFR3?, and Bivolt?), which increases transformer safety, capacity and lifetime. In addition, the processed oil has a lower viscosity than BIOTEMP? fluid, which can enhance the heat dissipation efficiency in the transformer. Moreover, the processed oil flash and fire points of 310°C and >340°C, respectively, confirm the great security of vegetable insulating fluids. The analyzed properties of the processed oil fulfill all the ASTM D6871, ABNT NBR 15422 and IEC 62770 specifications. Therefore, Jatropha curcas oil is a potential substitute formineral insulating fluids.
Solvent Extraction of Citric Acid with Different Organic Phases  [PDF]
Estêv?o Magno Rodrigues Araújo, Fabrício Eduardo Bortot Coelho, Julio Cézar Balarini, Tania Lúcia Santos Miranda, Adriane Salum
Advances in Chemical Engineering and Science (ACES) , 2017, DOI: 10.4236/aces.2017.73023
Abstract: The present work aimed at the study of citric acid solvent extraction in order to establish the composition of the organic phase and to obtain thermodynamic and kinetic data for the chosen system. Discontinuous extraction experiments in a single stage were performed from a synthetic solution of citric acid, with the typical concentration (10% w/v) observed in industrial fermented musts. Exploratory experiments were carried out using different organic phases in order to select the most suitable solvent phase to further continuous extraction tests in a mechanically agitated column. The selected organic phase composition was: Alamine 336, ExxalTM 13 tridecyl alcohol, and the aliphatic diluent EscaidTM 110. Next, the effects of the contact time and of the concentrations of extractant and modifier on the citric acid extraction were studied. Among the investigated conditions, the best one was 10 minutes of contact time, 30% w/v of Alamine 336, and 10% w/v of ExxalTM 13 tridecyl alcohol. For this condition, the equilibrium isotherm (28°C ± 2°C) was determined, and the equilibrium constant was calculated (36.8 (mol·L-1)-1.5). It was considered that trioctylamine and citric acid complexation reaction occurs mainly with non-dissociated citric acid form, because the aqueous feed solutions’ pH is lower than the citric acid pKa1. It was found that 1.5 molecules of the extractant, on average, are required to react with one citric acid molecule, which can indicate that reactions with different extractant/citric acid ratios occur simultaneously. Next, the rate constants for the direct and inverse reactions, 2.10 (mol·L-1)-1.5·s-1 and 5.69 × 10-2 s-1, respectively, were calculated. Coefficients of determination (R2) values higher than 0.93 were found in these calculations, suggesting that the results obtained using a computer modeling would be very close to those results obtained experimentally. Therefore, the present work provides data required to future modelling, design, and simulation of citric acid solvent extraction processes.
Individual and Combined Effects of the Extractant, Surfactant and Modifier Concentrations on the Droplet Coalescence Time of the Primary Emulsion in the Liquid Surfactant Membrane Extraction Process  [PDF]
Adriane Salum, Lorena da Costa Nascimento, Tania Lúcia Santos Miranda, Leandro Dornellas Sampaio Andrade, Cibele Konzen, Julio Cézar Balarini, Estêv?o Magno Rodrigues Araújo, Fabrício Eduardo Bortot Coelho
Advances in Chemical Engineering and Science (ACES) , 2018, DOI: 10.4236/aces.2018.84014
Abstract: In this work, the individual and combined effects of the extractant, surfactant and modifier concentrations on the droplet coalescence time of the primary emulsion in the liquid surfactant membrane extraction process were evaluated, through emulsification experiments. Adogen 464 was used as extractant (carrier), and Escaid 110, as diluent. Two systems were studied. The first one composed by the extractant, the surfactant and the diluent, and the second one composed by the same reagents, but with the addition of 1-decanol as modifier. It was observed that, when the modifier is not present in the membrane phase, the surfactant not only stabilizes the primary emulsion, but, apparently, it also plays a role similar to that of the alcohol, promoting the solvation of the amine in a low polarity diluent. Furthermore, the extractant, a quaternary amine, helps to stabilize the primary emulsion in systems without a modifier. For membrane phases consisting of 1 or 5% w/w of Adogen 464 and 2% or 5% w/w of ECA 4360, a concentration of 3% w/w of 1-decanol was sufficient to promote the solvation of Adogen 464 in Escaid 110 and to obtain a low droplet coalescence time.
Maxillofacial sarcomas: a ugandan epidemiological survey  [PDF]
Kamulegeya Adriane
Open Journal of Stomatology (OJST) , 2011, DOI: 10.4236/ojst.2011.12009
Abstract: We reviewed the case notes of 203 patients who were treated for sarcomas of the oral and maxillofacial region over a period of 5 years. There were 98 male cases (mean age 31.4 ± 12.8 years) and 105 female cases (mean age 29.3 ± 10.4). Kaposi’s sarcoma accounted for 82.8% cases, and rhabdomyosarcoma 6.9% followed by osteosarcoma and chondrosarcoma at 2.5% each. Except for Kaposi’s sarcoma, surgery in combination with radiotherapy and/or chemothe- rapy was the main stay of treatment. Survival data was not available for most of our patients.
Childhood Trauma Questionnaire (CTQ) in Brazilian Samples of Different Age Groups: Findings from Confirmatory Factor Analysis
Rodrigo Grassi-Oliveira, Hugo Cogo-Moreira, Giovanni Abrah?o Salum, Elisa Brietzke, Thiago Wendt Viola, Gisele Gus Manfro, Christian Haag Kristensen, Adriane Xavier Arteche
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0087118
Abstract: The Childhood Trauma Questionnaire (CTQ) is internationally accepted as a key tool for the assessment of childhood abuse and neglect experiences. However, there are relative few psychometric studies available and some authors have proposed two different factor solutions. We examined the dimensional structure and internal consistency of the Brazilian version of the CTQ. A total of 1,925 participants from eight different clinical and non-clinical samples including adolescents, adults and elders were considered in this study. First, we performed Confirmatory Factor Analysis to investigate the goodness of fit of the two proposed competitive factor structure models for the CTQ. We also investigated the internal consistency of all factors. Second, multi-group analyses were used to investigate measurement invariance and population heterogeneity across age groups and sex. Our findings revealed that the alternative factor structure as opposed to the original factor structure was the most appropriate model within adolescents and adults Brazilian samples. We provide further evidence for the validity and reliability of the CTQ within the Brazilian samples and report that the alternative model showed an improvement in fit indexes and may be a better alternative over the original model.
On the Tractability of Un/Satisfiability
Latif Salum
Computer Science , 2014,
Abstract: The Petri net approach proves to be effective to tackle the $P$ vs $NP$ problem. A safe acyclic Petri net (PN) is associated with some Exactly-1 3SAT formula, in which a clause is an exactly-1 disjunction $\dot{\vee}$ of literals. A clause also corresponds to a set of conflicting transitions in the PN. Some 2SAT/XOR-SAT formula arisen in the inversed PN checks if the truth assignment of a literal (a transition firing) $z_v$ is "incompatible" for the satisfiability of the 3SAT formula (the reachability of the target state in the inversed PN). If $z_v$ is incompatible, then $z_v$ is discarded and $\overline{z}_v$ becomes true. Therefore, a clause $(\overline{z}_v \dot{\vee} z_i \dot{\vee} z_j)$ reduces to the conjunction $(\overline{z}_v \wedge \overline{z}_i \wedge \overline{z}_j)$, and a 3-literal clause $(z_v \dot{\vee} z_u \dot{\vee} z_x)$ reduces to the 2-literal clause $(z_u \oplus z_x)$. This reduction facilitates checking un/satisfiability; the 3SAT formula is un/satisfiable iff the target state of the inversed PN is un/reachable. The solution complexity is $O(n^5)$. Therefore, $P = NP = \text{co}NP$.
Psicanálise e exce o
Maria José Gontijo Salum
ágora: Estudos em Teoria Psicanalítica , 2005, DOI: 10.1590/s1516-14982005000200009
Abstract:
A semana hebdomadária: origens, expans o e designa es
Isaac Nicolau Salum
Alfa : Revista de Linguística , 2001,
Abstract:
Filologia romanica e pós-gradua o
Isaac Nicolau Salum
Alfa : Revista de Linguística , 2001,
Abstract:
Cuckoo Search for Solving Economic Dispatch Load Problem  [PDF]
Adriane B. S. Serapi?o
Intelligent Control and Automation (ICA) , 2013, DOI: 10.4236/ica.2013.44046
Abstract:

Economic Load Dispatch (ELD) is a process of scheduling the required load demand among available generation units such that the fuel cost of operation is minimized. The ELD problem is formulated as a nonlinear constrained optimization problem with both equality and inequality constraints. In this paper, two test systems of the ELD problems are solved by adopting the Cuckoo Search (CS) Algorithm. A comparison of obtained simulation results by using the CS is carried out against six other swarm intelligence algorithms: Particle Swarm Optimization, Shuffled Frog Leaping Algorithm, Bacterial Foraging Optimization, Artificial Bee Colony, Harmony Search and Firefly Algorithm. The effectiveness of each swarm intelligence algorithm is demonstrated on a test system comprising three-generators and other containing six-generators. Results denote superiority of the Cuckoo Search Algorithm and confirm its potential to solve the ELD problem.

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