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Search Results: 1 - 10 of 489917 matches for " F. M. M.;Pimentel "
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Localization of Voltage Regulators in Distribution Systems by a Mixed Genetic–Tabu Search Algorithm  [PDF]
M. C. Pimentel Filho, M. F. Medeiros
Energy and Power Engineering (EPE) , 2013, DOI: 10.4236/epe.2013.54B145
Abstract:

The optimal allocation of regulators banks in distribution systems is a merely combinatorial problem in which the best points of installation correspond to the best benefit, considering the admitted objective function, without violating and operating limits. The objective function must be chosen so that its value represents the operation state of the system. As the problem possesses combinatorial nature, its complexity will increase exponentially with the number of possibilities. Systems with large numbers of nodes and / or with the possibility of installing more than one bank require a large number of calculations to find the solution. An additional issue is the fact that the problem does not have a continuous nature, presenting discontinuity points in the objective function, limiting the application of optimization methods based on gradients. Based on the nature of the problem two optimization methods were used to solve the problem: Genetic Algorithm (GA) and modified Tabu Search (TS). The GA function will scour the search space and find regions with local minima that are candidates to be the solution. On the other hand the TS provides local search in the regions defined by GA so that the overall optimum is achieved.

Sr and Nd isotopic characteristics of 1.77-1.58 Ga rift-related granites and volcanics of the Goiás tin province, central Brazil
PIMENTEL, MáRCIO M.;BOTELHO, NILSON F.;
Anais da Academia Brasileira de Ciências , 2001, DOI: 10.1590/S0001-37652001000200010
Abstract: supracrustal rocks of the araí group, together with coeval a-type granites represent a ca. 1.77-1.58 ga old continental rift in brazil. two granite families are identified: the older (1.77 ga) group forms small undeformed plutons, and the younger granites (ca. 1.58 ga) constitute larger, deformed plutons. sr-nd isotopic data for these rocks indicate that the magmatism is mostly product of re-melting of paleoproterozoic sialic crust. initial sr ratios for both granite families are ca 0.726 and 0.720. most tdm model ages are between 2.58 and 1.80 ga. end(t) values are between +3.6 and -11.9. araí volcanics are bimodal, with basalts and dacites/rhyolites interlayered with continental sediments. the felsic volcanics show nd isotopic characteristics which are very similar to the granites, and are also interpreted as reworking of paleoproterozoic crust. detrital sediments of the araí group revealed tdm model ages between 2.4 and 2.16 ga, indicating that they are the product of erosion of paleoproterozoic crust. the data indicate that the araí rift system was established on crust that had just become stable after the paleoproterozoic orogeny.
Sm-Nd isotopic characteristics of 1.77-1.6 Ga rift magmatism in central Brazil
M. M. Pimentel,N. F. Botelho
Chinese Science Bulletin , 1998, DOI: 10.1007/BF02891540
Abstract:
Sr and Nd isotopic characteristics of 1.77-1.58 Ga rift-related granites and volcanics of the Goiás tin province, central Brazil
PIMENTEL MáRCIO M.,BOTELHO NILSON F.
Anais da Academia Brasileira de Ciências , 2001,
Abstract: Supracrustal rocks of the Araí Group, together with coeval A-type granites represent a ca. 1.77-1.58 Ga old continental rift in Brazil. Two granite families are identified: the older (1.77 Ga) group forms small undeformed plutons, and the younger granites (ca. 1.58 Ga) constitute larger, deformed plutons. Sr-Nd isotopic data for these rocks indicate that the magmatism is mostly product of re-melting of Paleoproterozoic sialic crust. Initial Sr ratios for both granite families are ca 0.726 and 0.720. Most TDM model ages are between 2.58 and 1.80 Ga. epsilonND(T) values are between +3.6 and -11.9. Araí volcanics are bimodal, with basalts and dacites/rhyolites interlayered with continental sediments. The felsic volcanics show Nd isotopic characteristics which are very similar to the granites, and are also interpreted as reworking of Paleoproterozoic crust. Detrital sediments of the Araí Group revealed T DM model ages between 2.4 and 2.16 Ga, indicating that they are the product of erosion of Paleoproterozoic crust. The data indicate that the Araí rift system was established on crust that had just become stable after the Paleoproterozoic orogeny.
Gastric Neoplasia during Anti-TNF Therapy for Crohn’s Disease: Casual Event?  [PDF]
F. M. L. Fortes, B. C. Silva, B. C. Silva, M. C. Lyra, A. M. Pimentel, G. O. Santana
Journal of Cancer Therapy (JCT) , 2015, DOI: 10.4236/jct.2015.68081
Abstract: The increase risk of cancer development in patients with inflammatory intestinal disease (IBD) has already studied for decades. The anti-TNF therapy has changed the treatment strategy of IBD. By using on a larger scale and for a longer time, the anti-TNF raised concern over its potential adverse events. A male Crohn’s disease (CD) patient, 55 years old, diagnosed for nine years, treated with infliximab for 6 years. In 2011, he underwent a nupper endoscopy (UE) which showed flat erosive gastritis with moderate intensity in antrum, gastric polyps and gastric erosion. Pathological examination revealed a chronic gastritis in erosive activity and search for Helicobacter pylori resulted positive. In May 2014, the patient was asymptomatic, when it held UE, which showed suggestive lesion of early gastric cancer, measuring 1.5 cm and search for Helicobacter pylori negative. Histopathological exams confirmed the adenocarcinoma. The patient underwent to a laparoscopic surgery (total gastrectomy with lymphadenectomy and reconstruction Roux-en-Y). Risk factors for the development of gastric cancer in general population are already well defined. However studying a possible association among CD and the different therapeutic modalities used in the treatment of this disease with gastric cancer appearance is important to set specific assessment strategies, prevention and follow-up. While there is no consensus on a proper monitoring for gastric cancer prevention in these patients, individualized conduct, taking into account individual characteristics, family record and other risk factors, should be adopted to avoid unfavorable outcomes in CD patients.
Persistent current and Drude weight in mesoscopic rings
F. Carvalho Dias,I. R. Pimentel,M. Henkel
Physics , 2005, DOI: 10.1103/PhysRevB.73.075109
Abstract: We study the persistent current and the Drude weight of a system of spinless fermions, with repulsive interactions and a hopping impurity, on a mesoscopic ring pierced by a magnetic flux, using a Density Matrix Renormalization Group algorithm for complex fields. Both the Luttinger Liquid (LL) and the Charge Density Wave (CDW) phases of the system are considered. Under a Jordan-Wigner transformation, the system is equivalent to a spin-1/2 XXZ chain with a weakened exchange coupling. We find that the persistent current changes from an algebraic to an exponential decay with the system size, as the system crosses from the LL to the CDW phase with increasing interaction $U$. We also find that in the interacting system the persistent current is invariant under the impurity transformation $\rho\to 1/\rho $, for large system sizes, where $\rho $ is the defect strength. The persistent current exhibits a decay that is in agreement with the behavior obtained for the Drude weight. We find that in the LL phase the Drude weight decreases algebraically with the number of lattice sites $N$, due to the interplay of the electron interaction with the impurity, while in the CDW phase it decreases exponentially, defining a localization length which decreases with increasing interaction and impurity strength. Our results show that the impurity and the interactions always decrease the persistent current, and imply that the Drude weight vanishes in the limit $N\to \infty $, in both phases.
Síntese e caracteriza??o de espinélios à base de ferritas com gelatina como agente direcionador
Costa, A. F.;Pimentel, P. M.;Melo, D. M. A.;Melo, M. A. F.;Aquino, F. M.;
Ceramica , 2011, DOI: 10.1590/S0366-69132011000300015
Abstract: the ferrites with spinel type structure comprise a group of magnetic materials very well established. however, improvements and innovations are still happening seeking new applications and optimization of preparation techniques. among the materials with spinel structure, the ferrite stand out because they have a broad technological importance in the area of materials, with applications in humidity and oxygen sensors, microwave materials, pigments, magnetic materials and electrical, catalytic hydrogenation, thin films ceramic tiles, among others. in this work spinel-type cufe2o4 and cufecr2o4 were synthesized using gelatin as directing agent with the purpose of producing nanosized homogeneous particles through a simple, fast and affordable method. the ferrites were characterized by thermal analysis, x-ray diffraction, infrared spectroscopy and scanning electron microscopy. the results confirmed the feasibility of the used synthesis route.
Sagital abdominal diameter, but not waist circumference is strongly associated with glycemia, triacilglycerols and HDL-C levels in overweight adults
Pimentel,G. D.; Moreto,F.; Takahashi,M. M.; Portero-Mclellan,K. C.; Burini,R. C.;
Nutrición Hospitalaria , 2011,
Abstract: aim: to correlate the sagittal abdominal diameter (sad) and waist circumference (wc) with metabolic syndrome-associated abnormalities in adults. methods: this cross-sectional study included onehundred twelve adults (m = 27, f = 85) aging 54.0 ± 11.2 yrs and average body mass index (bmi) of 30.5 ± 9.0 kg/m2. the assessment included blood pressure, plasma and anthropometric measurements. results: in both men and female, sad and wc were associated positively with body fat% (r = 0.53 vs r = 0.55), uric acid (r = 0.45 vs r = 0.45), us-pcr (r = 0.50 vs r = 0.44), insulin (r = 0.89 vs r = 0.75), insulin resistance homa-ir (r = 0.86 vs r = 0.65), ldl-ox (r = 0.51 vs r = 0.28), ggt (r = 0.70 vs r = 0.61), and diastolic blood pressure (r = 0.35 vs r = 0.33), and negatively with insulin sensibility quicki (r = -0.89 vs r = -0.82) and total cholesterol/tg ratio (r = -0.40 vs r = -0.22). glycemia, tg, and hdl-c were associated significantly only with sad (r = 0.31; r = 39, r = -0.43, respectively). conclusion: though the sad and wc were associated with numerous metabolic abnormalities, only sad correlated with dyslipidemia (tg and hdl-c) and hyperglycemia (glycemia).
Sagital abdominal diameter, but not waist circumference is strongly associated with glycemia, triacilglycerols and HDL-C levels in overweight adults Diámetro abdominal sagital, pero no la circunferencia de la cintura se asocia fuertemente con la glucemia, triacilglycerols y HDL-C en adultos con sobrepeso
G. D. Pimentel,F. Moreto,M. M. Takahashi,K. C. Portero-Mclellan
Nutrición Hospitalaria , 2011,
Abstract: Aim: To correlate the sagittal abdominal diameter (SAD) and waist circumference (WC) with metabolic syndrome-associated abnormalities in adults. Methods: This cross-sectional study included onehundred twelve adults (M = 27, F = 85) aging 54.0 ± 11.2 yrs and average body mass index (BMI) of 30.5 ± 9.0 kg/m2. The assessment included blood pressure, plasma and anthropometric measurements. Results: In both men and female, SAD and WC were associated positively with body fat% (r = 0.53 vs r = 0.55), uric acid (r = 0.45 vs r = 0.45), us-PCR (r = 0.50 vs r = 0.44), insulin (r = 0.89 vs r = 0.75), insulin resistance HOMA-IR (r = 0.86 vs r = 0.65), LDL-ox (r = 0.51 vs r = 0.28), GGT (r = 0.70 vs r = 0.61), and diastolic blood pressure (r = 0.35 vs r = 0.33), and negatively with insulin sensibility QUICKI (r = -0.89 vs r = -0.82) and total cholesterol/TG ratio (r = -0.40 vs r = -0.22). Glycemia, TG, and HDL-c were associated significantly only with SAD (r = 0.31; r = 39, r = -0.43, respectively). Conclusion: Though the SAD and WC were associated with numerous metabolic abnormalities, only SAD correlated with dyslipidemia (TG and HDL-c) and hyperglycemia (glycemia). Objetivo: Correlacionar el diámetro abdominal sagital (DAS) y la circunferencia de la cintura (CC) con las anomalías asociadas al síndrome metabólico en adultos. Métodos: Este estudio transversal incluyó a 112 adultos (H = 27, M = 85) con edad de 54,0 ± 11,2 a os y un promedio de índice de masa corporal (IMC) de 30,5 ± 9,0 kg/m2. La evaluación incluía la presión sanguínea y medidas plasmáticas y antropométricas. Resultados: Tanto en hombres como mujeres, DAS y CC se asociaban positivamente con el % grasa corporal (r = 0,53 vs r = 0,55), el ácido úrico (r = 0,45 vs r = 0,45), la us-PCR (r = 0,50 vs r = 0,44), la insulina (r = 0,89 vs r = 0,75), la resistencia a la insulina HOMA-IR (r = 0,86 vs r = 0,65), la LDL-ox (r = 0,51 vs r = 0,28), GGT (r = 0,70 vs r = 0,61), y la presión sanguínea diastólica (r = 0,35 vs r = 0,33), y negativamente con la sensibilidad a la insulina QUICKI (r = -0,89 vs r = -0,82) y el cociente colesterol total/TG (r = -0,40 vs r = -0,22). La glucemia, los TG, y la HDL-c se asociaban significativamente sólo con DAS (r = 0,31; r = 0,39, r = -0,43, respectivamente). Conclusión: Aunque DAS y CC se asociaban con numerosas anomalías metabólicas, sólo DAS se correlacionaba con la dislipemia (TG y HDL-c) y la hiperglucemia (glucemia).
Aspectos da determina??o da área basal em fun??o da média aritmética dos diametros: II - vícios na determina??o da área basal retirada
Veiga, Ricardo A. A.;Gomes, F. Pimentel;Godoy, Cássio R. M.;Cruz, Vivaldo F. da;
Anais da Escola Superior de Agricultura Luiz de Queiroz , 1971, DOI: 10.1590/S0071-12761971000100005
Abstract: as shown by pimentel gomes (1965), the theory proves that the use of the arithmetic mean of diameters to estimate basal areas in forestry leads to a bias. this paper evaluates this bias in the computation of cut out basal area in forestry thinnings, by means of theoretical study, samples generated in a computer, and also through the study of actual populations of trees in groves of araucaria angustifolia (bert.) o. ktze, pinus elliottii eng., p. taeda l. and p. caribaea var. hondurensis mor. the study thus carried out showed that the bias indicated can be rather serious.
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